This is the The GNU Privacy Guard Manual (version 2.4.5, March 2024).
© 2002, 2004, 2005, 2006, 2007, 2010 Free Software Foundation, Inc.
© 2013, 2014, 2015 Werner Koch.
© 2015, 2016, 2017 g10 Code GmbH.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. The text of the license can be found in the section entitled “Copying”.
This manual documents how to use the GNU Privacy Guard system as well as the administration and the architecture.
Unfortunately the installation guide has not been finished in time. Instead of delaying the release of GnuPG 2.0 even further, I decided to release without that guide. The chapter on gpg-agent and gpgsm do include brief information on how to set up the whole thing. Please watch the GnuPG website for updates of the documentation. In the meantime you may search the GnuPG mailing list archives or ask on the gnupg-users mailing list for advise on how to solve problems or how to get that whole thing up and running.
** Building the software
Building the software is described in the file INSTALL. Given that you are already reading this documentation we can only give some extra hints.
To comply with the rules on GNU systems you should have build time
configured gnupg
using:
./configure --sysconfdir=/etc --localstatedir=/var
This is to make sure that system wide configuration files are searched in the directory /etc and variable data below /var; the default would be to also install them below /usr/local where the binaries get installed. If you selected to use the --prefix=/ you obviously don’t need those option as they are the default then.
** Notes on setting a root CA key to trusted
X.509 is based on a hierarchical key infrastructure. At the root of the tree a trusted anchor (root certificate) is required. There are usually no other means of verifying whether this root certificate is trustworthy than looking it up in a list. GnuPG uses a file (trustlist.txt) to keep track of all root certificates it knows about. There are 3 ways to get certificates into this list:
gpgsm
ask you whether you want to insert a new root
certificate. This feature is enabled by default; you may disable it
using the option no-allow-mark-trusted into
gpg-agent.conf.
gpg-agent
is a daemon to manage secret (private) keys
independently from any protocol. It is used as a backend for
gpg
and gpgsm
as well as for a couple of other
utilities.
The agent is automatically started on demand by gpg
,
gpgsm
, gpgconf
, or gpg-connect-agent
.
Thus there is no reason to start it manually. In case you want to use
the included Secure Shell Agent you may start the agent using:
gpg-connect-agent /bye
If you want to manually terminate the currently-running agent, you can safely do so with:
gpgconf --kill gpg-agent
You should always add the following lines to your .bashrc
or
whatever initialization file is used for all shell invocations:
GPG_TTY=$(tty) export GPG_TTY
It is important that this environment variable always reflects the
output of the tty
command. For W32 systems this option is not
required.
Please make sure that a proper pinentry program has been installed under the default filename (which is system dependent) or use the option pinentry-program to specify the full name of that program. It is often useful to install a symbolic link from the actual used pinentry (e.g. /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/bin/pinentry-gtk) to the expected one (e.g. /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/bin/pinentry).
See Option Index, for an index to GPG-AGENT
’s commands and options.
Commands are not distinguished from options except for the fact that only one command is allowed.
--version
¶Print the program version and licensing information. Note that you cannot abbreviate this command.
--help
¶-h
Print a usage message summarizing the most useful command-line options. Note that you cannot abbreviate this command.
--dump-options
¶Print a list of all available options and commands. Note that you cannot abbreviate this command.
--server
¶Run in server mode and wait for commands on the stdin
. The
default mode is to create a socket and listen for commands there.
--daemon [command line]
¶Start the gpg-agent as a daemon; that is, detach it from the console and run it in the background.
As an alternative you may create a new process as a child of
gpg-agent: gpg-agent --daemon /bin/sh
. This way you get a new
shell with the environment setup properly; after you exit from this
shell, gpg-agent terminates within a few seconds.
--supervised
¶Run in the foreground, sending logs by default to stderr, and listening on provided file descriptors, which must already be bound to listening sockets. This option is deprecated and not supported on Windows.
If in common.conf the option no-autostart is set, any start attempts will be ignored.
In –supervised mode, different file descriptors can be provided for
use as different socket types (e.g. ssh, extra) as long as they are
identified in the environment variable LISTEN_FDNAMES
(see
sd_listen_fds(3) on some Linux distributions for more information on
this convention).
Options may either be used on the command line or, after stripping off the two leading dashes, in the configuration file.
--options file
¶Reads configuration from file instead of from the default per-user configuration file. The default configuration file is named gpg-agent.conf and expected in the .gnupg directory directly below the home directory of the user. This option is ignored if used in an options file.
--homedir dir
¶Set the name of the home directory to dir. If this option is not
used, the home directory defaults to ~/.gnupg. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable GNUPGHOME
or
(on Windows systems) by means of the Registry entry
HKCU\Software\GNU\GnuPG:HomeDir.
On Windows systems it is possible to install GnuPG as a portable application. In this case only this command line option is considered, all other ways to set a home directory are ignored.
-v
¶--verbose
Outputs additional information while running.
You can increase the verbosity by giving several
verbose commands to gpg-agent
, such as ‘-vv’.
-q
¶--quiet
Try to be as quiet as possible.
--batch
¶Don’t invoke a pinentry or do any other thing requiring human interaction.
--faked-system-time epoch
¶This option is only useful for testing; it sets the system time back or forth to epoch which is the number of seconds elapsed since the year 1970.
--debug-level level
¶Select the debug level for investigating problems. level may be a numeric value or a keyword:
none
No debugging at all. A value of less than 1 may be used instead of the keyword.
basic
Some basic debug messages. A value between 1 and 2 may be used instead of the keyword.
advanced
More verbose debug messages. A value between 3 and 5 may be used instead of the keyword.
expert
Even more detailed messages. A value between 6 and 8 may be used instead of the keyword.
guru
All of the debug messages you can get. A value greater than 8 may be used instead of the keyword. The creation of hash tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not specified and may change with newer releases of this program. They are however carefully selected to best aid in debugging.
--debug flags
¶Set debug flags. All flags are or-ed and flags may be given in C syntax (e.g. 0x0042) or as a comma separated list of flag names. To get a list of all supported flags the single word "help" can be used. This option is only useful for debugging and the behavior may change at any time without notice.
--debug-all
¶Same as --debug=0xffffffff
--debug-wait n
¶When running in server mode, wait n seconds before entering the actual processing loop and print the pid. This gives time to attach a debugger.
--debug-quick-random
¶This option inhibits the use of the very secure random quality level
(Libgcrypt’s GCRY_VERY_STRONG_RANDOM
) and degrades all request
down to standard random quality. It is only used for testing and
should not be used for any production quality keys. This option is
only effective when given on the command line.
On GNU/Linux, another way to quickly generate insecure keys is to use
rngd
to fill the kernel’s entropy pool with lower quality
random data. rngd
is typically provided by the
rng-tools
package. It can be run as follows: ‘sudo
rngd -f -r /dev/urandom’.
--debug-pinentry
¶This option enables extra debug information pertaining to the
Pinentry. As of now it is only useful when used along with
--debug 1024
.
--no-detach
¶Don’t detach the process from the console. This is mainly useful for debugging.
--steal-socket
¶In --daemon mode, gpg-agent detects an already running gpg-agent and does not allow one to start a new instance. This option can be used to override this check: the new gpg-agent process will try to take over the communication sockets from the already running process and start anyway. This option should in general not be used.
-s
¶--sh
-c
--csh
Format the info output in daemon mode for use with the standard Bourne
shell or the C-shell respectively. The default is to guess it based on
the environment variable SHELL
which is correct in almost all
cases.
--grab
¶--no-grab
Tell the pinentry to grab the keyboard and mouse. This option should be used on X-Servers to avoid X-sniffing attacks. Any use of the option --grab overrides an used option --no-grab. The default is --no-grab.
--log-file file
¶Append all logging output to file. This is very helpful in
seeing what the agent actually does. Use socket:// to log to
socket. If neither a log file nor a log file descriptor has been set
on a Windows platform, the Registry entry
HKCU\Software\GNU\GnuPG:DefaultLogFile
, if set, is used to
specify the logging output.
--no-allow-mark-trusted
¶Do not allow clients to mark keys as trusted, i.e. put them into the trustlist.txt file. This makes it harder for users to inadvertently accept Root-CA keys.
--no-user-trustlist
¶Entirely ignore the user trust list and consider only the global trustlist (/etc/gnupg/trustlist.txt). This implies the option --no-allow-mark-trusted.
--sys-trustlist-name file
¶Changes the default name for the global trustlist from "trustlist.txt" to file. If file does not contain any slashes and does not start with "~/" it is searched in the system configuration directory (/etc/gnupg).
--allow-preset-passphrase
¶This option allows the use of gpg-preset-passphrase
to seed the
internal cache of gpg-agent
with passphrases.
--no-allow-loopback-pinentry
--allow-loopback-pinentry
¶Disallow or allow clients to use the loopback pinentry features; see the option pinentry-mode for details. Allow is the default.
The --force option of the Assuan command DELETE_KEY
is also controlled by this option: The option is ignored if a loopback
pinentry is disallowed.
--no-allow-external-cache
¶Tell Pinentry not to enable features which use an external cache for passphrases.
Some desktop environments prefer to unlock all credentials with one master password and may have installed a Pinentry which employs an additional external cache to implement such a policy. By using this option the Pinentry is advised not to make use of such a cache and instead always ask the user for the requested passphrase.
--allow-emacs-pinentry
¶Tell Pinentry to allow features to divert the passphrase entry to a running Emacs instance. How this is exactly handled depends on the version of the used Pinentry.
--ignore-cache-for-signing
¶This option will let gpg-agent
bypass the passphrase cache for all
signing operation. Note that there is also a per-session option to
control this behavior but this command line option takes precedence.
--default-cache-ttl n
¶Set the time a cache entry is valid to n seconds. The default
is 600 seconds. Each time a cache entry is accessed, the entry’s
timer is reset. To set an entry’s maximum lifetime, use
max-cache-ttl
. Note that a cached passphrase may not be
evicted immediately from memory if no client requests a cache
operation. This is due to an internal housekeeping function which is
only run every few seconds.
--default-cache-ttl-ssh n
¶Set the time a cache entry used for SSH keys is valid to n
seconds. The default is 1800 seconds. Each time a cache entry is
accessed, the entry’s timer is reset. To set an entry’s maximum
lifetime, use max-cache-ttl-ssh
.
--max-cache-ttl n
¶Set the maximum time a cache entry is valid to n seconds. After
this time a cache entry will be expired even if it has been accessed
recently or has been set using gpg-preset-passphrase
. The
default is 2 hours (7200 seconds).
--max-cache-ttl-ssh n
¶Set the maximum time a cache entry used for SSH keys is valid to
n seconds. After this time a cache entry will be expired even
if it has been accessed recently or has been set using
gpg-preset-passphrase
. The default is 2 hours (7200
seconds).
--enforce-passphrase-constraints
¶Enforce the passphrase constraints by not allowing the user to bypass them using the “Take it anyway” button.
--min-passphrase-len n
¶Set the minimal length of a passphrase. When entering a new passphrase shorter than this value a warning will be displayed. Defaults to 8.
--min-passphrase-nonalpha n
¶Set the minimal number of digits or special characters required in a passphrase. When entering a new passphrase with less than this number of digits or special characters a warning will be displayed. Defaults to 1.
--check-passphrase-pattern file
¶--check-sym-passphrase-pattern file
Check the passphrase against the pattern given in file. When entering a new passphrase matching one of these pattern a warning will be displayed. If file does not contain any slashes and does not start with "~/" it is searched in the system configuration directory (/etc/gnupg). The default is not to use any pattern file. The second version of this option is only used when creating a new symmetric key to allow the use of different patterns for such passphrases.
Security note: It is known that checking a passphrase against a list of pattern or even against a complete dictionary is not very effective to enforce good passphrases. Users will soon figure up ways to bypass such a policy. A better policy is to educate users on good security behavior and optionally to run a passphrase cracker regularly on all users passphrases to catch the very simple ones.
--max-passphrase-days n
¶Ask the user to change the passphrase if n days have passed since the last change. With --enforce-passphrase-constraints set the user may not bypass this check.
--enable-passphrase-history
¶This option does nothing yet.
--pinentry-invisible-char char
¶This option asks the Pinentry to use char for displaying hidden characters. char must be one character UTF-8 string. A Pinentry may or may not honor this request.
--pinentry-timeout n
¶This option asks the Pinentry to timeout after n seconds with no user input. The default value of 0 does not ask the pinentry to timeout, however a Pinentry may use its own default timeout value in this case. A Pinentry may or may not honor this request.
--pinentry-formatted-passphrase
¶This option asks the Pinentry to enable passphrase formatting when asking the user for a new passphrase and masking of the passphrase is turned off.
If passphrase formatting is enabled, then all non-breaking space characters are stripped from the entered passphrase. Passphrase formatting is mostly useful in combination with passphrases generated with the GENPIN feature of some Pinentries. Note that such a generated passphrase, if not modified by the user, skips all passphrase constraints checking because such constraints would actually weaken the generated passphrase.
--pinentry-program filename
¶Use program filename as the PIN entry. The default is installation dependent. With the default configuration the name of the default pinentry is pinentry; if that file does not exist but a pinentry-basic exist the latter is used.
On a Windows platform the default is to use the first existing program from this list: bin\pinentry.exe, ..\Gpg4win\bin\pinentry.exe, ..\Gpg4win\pinentry.exe, ..\GNU\GnuPG\pinentry.exe, ..\GNU\bin\pinentry.exe, bin\pinentry-basic.exe where the file names are relative to the GnuPG installation directory.
--pinentry-touch-file filename
¶By default the filename of the socket gpg-agent is listening for
requests is passed to Pinentry, so that it can touch that file before
exiting (it does this only in curses mode). This option changes the
file passed to Pinentry to filename. The special name
/dev/null
may be used to completely disable this feature. Note
that Pinentry will not create that file, it will only change the
modification and access time.
--scdaemon-program filename
¶Use program filename as the Smartcard daemon. The default is
installation dependent and can be shown with the gpgconf
command.
--disable-scdaemon
¶Do not make use of the scdaemon tool. This option has the effect of disabling the ability to do smartcard operations. Note, that enabling this option at runtime does not kill an already forked scdaemon.
--disable-check-own-socket
¶gpg-agent
employs a periodic self-test to detect a stolen
socket. This usually means a second instance of gpg-agent
has taken over the socket and gpg-agent
will then terminate
itself. This option may be used to disable this self-test for
debugging purposes.
--use-standard-socket
¶--no-use-standard-socket
--use-standard-socket-p
Since GnuPG 2.1 the standard socket is always used. These options
have no more effect. The command gpg-agent
--use-standard-socket-p
will thus always return success.
--display string
¶--ttyname string
--ttytype string
--lc-ctype string
--lc-messages string
--xauthority string
These options are used with the server mode to pass localization information.
--keep-tty
¶--keep-display
Ignore requests to change the current tty
or X window system’s
DISPLAY
variable respectively. This is useful to lock the
pinentry to pop up at the tty
or display you started the agent.
--listen-backlog n
¶Set the size of the queue for pending connections. The default is 64.
--extra-socket name
¶The extra socket is created by default, you may use this option to change the name of the socket. To disable the creation of the socket use “none” or “/dev/null” for name.
Also listen on native gpg-agent connections on the given socket. The
intended use for this extra socket is to setup a Unix domain socket
forwarding from a remote machine to this socket on the local machine.
A gpg
running on the remote machine may then connect to the
local gpg-agent and use its private keys. This enables decrypting or
signing data on a remote machine without exposing the private keys to the
remote machine.
--enable-extended-key-format
¶--disable-extended-key-format
These options are obsolete and have no effect. The extended key format is used for years now and has been supported since 2.1.12. Existing keys in the old format are migrated to the new format as soon as they are touched.
--enable-ssh-support
¶--enable-win32-openssh-support
--enable-putty-support
On Unix platforms the OpenSSH Agent protocol is always enabled, but
gpg-agent
will only set the SSH_AUTH_SOCK
variable if
the option enable-ssh-support is given. Some Linux
distributions use the presence of this option to decide whether the
old ssh-agent shall be started.
On Windows support for the native ssh implementation must be enabled using the the option enable-win32-openssh-support. For using gpg-agent as a replacement for PuTTY’s Pageant, the option enable-putty-support must be enabled.
In this mode of operation, the agent does not only implement the gpg-agent protocol, but also the agent protocol used by OpenSSH (through a separate socket or via Named Pipes) or the protocol used by PuTTY. Consequently, this allows one to use the gpg-agent as a drop-in replacement for the ssh-agent.
SSH keys, which are to be used through the agent, need to be added to the gpg-agent initially through the ssh-add utility. When a key is added, ssh-add will ask for the password of the provided key file and send the unprotected key material to the agent; this causes the gpg-agent to ask for a passphrase, which is to be used for encrypting the newly received key and storing it in a gpg-agent specific directory.
Once a key has been added to the gpg-agent this way, the gpg-agent will be ready to use the key.
Note: in case the gpg-agent receives a signature request, the user might need to be prompted for a passphrase, which is necessary for decrypting the stored key. Since the ssh-agent protocol does not contain a mechanism for telling the agent on which display/terminal it is running, gpg-agent’s ssh-support will use the TTY or X display where gpg-agent has been started. To switch this display to the current one, the following command may be used:
gpg-connect-agent updatestartuptty /bye
Although all GnuPG components try to start the gpg-agent as needed, this is not possible for the ssh support because ssh does not know about it. Thus if no GnuPG tool which accesses the agent has been run, there is no guarantee that ssh is able to use gpg-agent for authentication. To fix this you may start gpg-agent if needed using this simple command:
gpg-connect-agent /bye
Adding the --verbose shows the progress of starting the agent.
The --enable-putty-support is only available under Windows
and allows the use of gpg-agent with the ssh implementation
putty
. This is similar to the regular ssh-agent support but
makes use of Windows message queue as required by putty
.
The order in which keys are presented to ssh are:
Negative Use-for-ssh values
If a key file has the attribute "Use-for-ssh" and its value is negative, these keys are presented first to ssh. The negative values are capped at -999 with -999 being lower ranked than -1. These values can be used to prefer on-disk keys over keys taken from active cards.
Active cards
Active cards (inserted into a card reader or plugged in tokens) are always tried; they are ordered by their serial numbers.
Keys listed in the sshcontrol file
Non-disabled keys from the sshcontrol file are presented in the order they appear in this file. Note that the sshcontrol file is deprecated.
Positive Use-for-ssh values
If a key file has the attribute "Use-for-ssh" and its value is "yes", "true", or any positive number the key is presented in the order of their values. "yes" and "true" have a value of 1; other values are capped at 99999.
Editing the "Use-for-ssh" values can be done with an editor or using
gpg-connect-agent
and "KEYATTR" (Remember to append a colon
to the key; i.e. use "Use-for-ssh:").
--ssh-fingerprint-digest
¶Select the digest algorithm used to compute ssh fingerprints that are communicated to the user, e.g. in pinentry dialogs. OpenSSH has transitioned from using MD5 to the more secure SHA256.
--auto-expand-secmem n
¶Allow Libgcrypt to expand its secure memory area as required. The optional value n is a non-negative integer with a suggested size in bytes of each additionally allocated secure memory area. The value is rounded up to the next 32 KiB; usual C style prefixes are allowed. For an heavy loaded gpg-agent with many concurrent connection this option avoids sign or decrypt errors due to out of secure memory error returns.
--s2k-calibration milliseconds
¶Change the default calibration time to milliseconds. The given
value is capped at 60 seconds; a value of 0 resets to the compiled-in
default. This option is re-read on a SIGHUP (or gpgconf
--reload gpg-agent
) and the S2K count is then re-calibrated.
--s2k-count n
¶Specify the iteration count used to protect the passphrase. This option can be used to override the auto-calibration done by default. The auto-calibration computes a count which requires by default 100ms to mangle a given passphrase. See also --s2k-calibration.
To view the actually used iteration count and the milliseconds required for an S2K operation use:
gpg-connect-agent 'GETINFO s2k_count' /bye gpg-connect-agent 'GETINFO s2k_time' /bye
To view the auto-calibrated count use:
gpg-connect-agent 'GETINFO s2k_count_cal' /bye
There are a few configuration files needed for the operation of the agent. By default they may all be found in the current home directory (see option --homedir).
This is the standard configuration file read by gpg-agent
on
startup. It may contain any valid long option; the leading
two dashes may not be entered and the option may not be abbreviated.
This file is also read after a SIGHUP
however only a few
options will actually have an effect. This default name may be
changed on the command line (see option --options).
You should backup this file.
This is the list of trusted keys. You should backup this file.
Comment lines, indicated by a leading hash mark, as well as empty
lines are ignored. To mark a key as trusted you need to enter its
fingerprint followed by a space and a capital letter S
. Colons
may optionally be used to separate the bytes of a fingerprint; this
enables cutting and pasting the fingerprint from a key listing output. If
the line is prefixed with a !
the key is explicitly marked as
not trusted.
Here is an example where two keys are marked as ultimately trusted and one as not trusted:
# CN=Wurzel ZS 3,O=Intevation GmbH,C=DE A6935DD34EF3087973C706FC311AA2CCF733765B S # CN=PCA-1-Verwaltung-02/O=PKI-1-Verwaltung/C=DE DC:BD:69:25:48:BD:BB:7E:31:6E:BB:80:D3:00:80:35:D4:F8:A6:CD S # CN=Root-CA/O=Schlapphuete/L=Pullach/C=DE !14:56:98:D3:FE:9C:CA:5A:31:6E:BC:81:D3:11:4E:00:90:A3:44:C2 S |
Before entering a key into this file, you need to ensure its authenticity. How to do this depends on your organisation; your administrator might have already entered those keys which are deemed trustworthy enough into this file. Places where to look for the fingerprint of a root certificate are letters received from the CA or the website of the CA (after making 100% sure that this is indeed the website of that CA). You may want to consider disallowing interactive updates of this file by using the option --no-allow-mark-trusted. It might even be advisable to change the permissions to read-only so that this file can’t be changed inadvertently.
As a special feature a line include-default
will include a global
list of trusted certificates (e.g. /etc/gnupg/trustlist.txt).
This global list is also used if the local list is not available;
the option --no-user-trustlist enforces the use of only
this global list.
It is possible to add further flags after the S
for use by the
caller:
relax
¶Relax checking of some root certificate requirements. As of now this flag allows the use of root certificates with a missing basicConstraints attribute (despite that it is a MUST for CA certificates) and disables CRL checking for the root certificate.
cm
If validation of a certificate finally issued by a CA with this flag set fails, try again using the chain validation model.
qual
The CA is allowed to issue certificates for qualified signatures. This flag has an effect only if used in the global list. This is now the preferred way to mark such CA; the old way of having a separate file qualified.txt is still supported.
de-vs
The CA is part of an approved PKI for the German classification level VS-NfD. It is only valid in the global trustlist. As of now this is used only for documentation purpose.
This file is used when support for the secure shell agent protocol has been enabled (see option --enable-ssh-support). Only keys present in this file are used in the SSH protocol. You should backup this file.
This file is deprecated in favor of the "Use-for-ssh" attribute in the key files.
The ssh-add
tool may be used to add new entries to this file;
you may also add them manually. Comment lines, indicated by a leading
hash mark, as well as empty lines are ignored. An entry starts with
optional whitespace, followed by the keygrip of the key given as 40 hex
digits, optionally followed by the caching TTL in seconds and another
optional field for arbitrary flags. A non-zero TTL overrides the global
default as set by --default-cache-ttl-ssh.
The only flag support is confirm
. If this flag is found for a
key, each use of the key will pop up a pinentry to confirm the use of
that key. The flag is automatically set if a new key was loaded into
gpg-agent
using the option -c of the ssh-add
command.
The keygrip may be prefixed with a !
to disable an entry.
The following example lists exactly one key. Note that keys available through a OpenPGP smartcard in the active smartcard reader are implicitly added to this list; i.e. there is no need to list them.
# Key added on: 2011-07-20 20:38:46 # Fingerprint: 5e:8d:c4:ad:e7:af:6e:27:8a:d6:13:e4:79:ad:0b:81 34B62F25E277CF13D3C6BCEBFD3F85D08F0A864B 0 confirm |
This is the directory where gpg-agent stores the private keys. Each key is stored in a file with the name made up of the keygrip and the suffix key. You should backup all files in this directory and take great care to keep this backup closed away.
Note that on larger installations, it is useful to put predefined files into the directory /etc/skel/.gnupg so that newly created users start up with a working configuration. For existing users the a small helper script is provided to create these files (see Create .gnupg home directories).
A running gpg-agent
may be controlled by signals, i.e. using
the kill
command to send a signal to the process.
Here is a list of supported signals:
SIGHUP
¶This signal flushes all cached passphrases and if the program has been
started with a configuration file, the configuration file is read
again. Only certain options are honored: quiet
,
verbose
, debug
, debug-all
, debug-level
,
debug-pinentry
,
no-grab
,
pinentry-program
,
pinentry-invisible-char
,
default-cache-ttl
,
max-cache-ttl
, ignore-cache-for-signing
,
s2k-count
,
no-allow-external-cache
, allow-emacs-pinentry
,
no-allow-mark-trusted
, disable-scdaemon
, and
disable-check-own-socket
. scdaemon-program
is also
supported but due to the current implementation, which calls the
scdaemon only once, it is not of much use unless you manually kill the
scdaemon.
SIGTERM
¶Shuts down the process but waits until all current requests are fulfilled. If the process has received 3 of these signals and requests are still pending, a shutdown is forced.
SIGINT
¶Shuts down the process immediately.
SIGUSR1
¶Dump internal information to the log file.
SIGUSR2
¶This signal is used for internal purposes.
It is important to set the environment variable GPG_TTY
in
your login shell, for example in the ~/.bashrc init script:
export GPG_TTY=$(tty) |
If you enabled the Ssh Agent Support, you also need to tell ssh about it by adding this to your init script:
unset SSH_AGENT_PID if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]; then export SSH_AUTH_SOCK="$(gpgconf --list-dirs agent-ssh-socket)" fi |
Note: this section does only document the protocol, which is used by GnuPG components; it does not deal with the ssh-agent protocol. To see the full specification of each command, use
gpg-connect-agent 'help COMMAND' /bye
or just ’help’ to list all available commands.
The gpg-agent
daemon is started on demand by the GnuPG
components.
To identify a key we use a thing called keygrip which is the SHA-1 hash of an canonical encoded S-Expression of the public key as used in Libgcrypt. For the purpose of this interface the keygrip is given as a hex string. The advantage of using this and not the hash of a certificate is that it will be possible to use the same keypair for different protocols, thereby saving space on the token used to keep the secret keys.
The gpg-agent
may send status messages during a command or when
returning from a command to inform a client about the progress or result of an
operation. For example, the INQUIRE_MAXLEN status message may be sent
during a server inquire to inform the client of the maximum usable length of
the inquired data (which should not be exceeded).
The client asks the server to decrypt a session key. The encrypted session key should have all information needed to select the appropriate secret key or to delegate it to a smartcard.
SETKEY <keyGrip>
Tell the server about the key to be used for decryption. If this is
not used, gpg-agent
may try to figure out the key by trying to
decrypt the message with each key available.
PKDECRYPT
The agent checks whether this command is allowed and then does an INQUIRY to get the ciphertext the client should then send the cipher text.
S: INQUIRE CIPHERTEXT C: D (xxxxxx C: D xxxx) C: END
Please note that the server may send status info lines while reading the data lines from the client. The data send is a SPKI like S-Exp with this structure:
(enc-val (<algo> (<param_name1> <mpi>) ... (<param_namen> <mpi>)))
Where algo is a string with the name of the algorithm; see the libgcrypt documentation for a list of valid algorithms. The number and names of the parameters depend on the algorithm. The agent does return an error if there is an inconsistency.
If the decryption was successful the decrypted data is returned by means of "D" lines.
Here is an example session:
C: PKDECRYPT S: INQUIRE CIPHERTEXT C: D (enc-val elg (a 349324324) C: D (b 3F444677CA))) C: END S: # session key follows S: S PADDING 0 S: D (value 1234567890ABCDEF0) S: OK decryption successful |
The “PADDING” status line is only send if gpg-agent can tell what kind of padding is used. As of now only the value 0 is used to indicate that the padding has been removed.
The client asks the agent to sign a given hash value. A default key will be chosen if no key has been set. To set a key a client first uses:
SIGKEY <keyGrip>
This can be used multiple times to create multiple signature, the list of keys is reset with the next PKSIGN command or a RESET. The server tests whether the key is a valid key to sign something and responds with okay.
SETHASH --hash=<name>|<algo> <hexstring>
The client can use this command to tell the server about the data <hexstring> (which usually is a hash) to be signed. <algo> is the decimal encoded hash algorithm number as used by Libgcrypt. Either <algo> or –hash=<name> must be given. Valid names for <name> are:
sha1
The SHA-1 hash algorithm
sha256
The SHA-256 hash algorithm
rmd160
The RIPE-MD160 hash algorithm
md5
The old and broken MD5 hash algorithm
tls-md5sha1
A combined hash algorithm as used by the TLS protocol.
The actual signing is done using
PKSIGN <options>
Options are not yet defined, but may later be used to choose among different algorithms. The agent does then some checks, asks for the passphrase and as a result the server returns the signature as an SPKI like S-expression in "D" lines:
(sig-val (<algo> (<param_name1> <mpi>) ... (<param_namen> <mpi>)))
The operation is affected by the option
OPTION use-cache-for-signing=0|1
The default of 1
uses the cache. Setting this option to 0
will lead gpg-agent
to ignore the passphrase cache. Note, that there is
also a global command line option for gpg-agent
to globally disable the
caching.
Here is an example session:
C: SIGKEY <keyGrip> S: OK key available C: SIGKEY <keyGrip> S: OK key available C: PKSIGN S: # I did ask the user whether he really wants to sign S: # I did ask the user for the passphrase S: INQUIRE HASHVAL C: D ABCDEF012345678901234 C: END S: # signature follows S: D (sig-val rsa (s 45435453654612121212)) S: OK |
This is used to create a new keypair and store the secret key inside the active PSE — which is in most cases a Soft-PSE. A not-yet-defined option allows choosing the storage location. To get the secret key out of the PSE, a special export tool has to be used.
GENKEY [--no-protection] [--preset] [<cache_nonce>]
Invokes the key generation process and the server will then inquire on the generation parameters, like:
S: INQUIRE KEYPARM C: D (genkey (rsa (nbits 1024))) C: END
The format of the key parameters which depends on the algorithm is of the form:
(genkey (algo (parameter_name_1 ....) .... (parameter_name_n ....)))
If everything succeeds, the server returns the *public key* in a SPKI like S-Expression like this:
(public-key (rsa (n <mpi>) (e <mpi>)))
Here is an example session:
C: GENKEY S: INQUIRE KEYPARM C: D (genkey (rsa (nbits 1024))) C: END S: D (public-key S: D (rsa (n 326487324683264) (e 10001))) S OK key created |
The --no-protection option may be used to prevent prompting for a passphrase to protect the secret key while leaving the secret key unprotected. The --preset option may be used to add the passphrase to the cache using the default cache parameters.
The --inq-passwd option may be used to create the key with a
supplied passphrase. When used the agent does an inquiry with the
keyword NEWPASSWD
to retrieve that passphrase. This option
takes precedence over --no-protection; however if the client
sends a empty (zero-length) passphrase, this is identical to
--no-protection.
This operation is not yet supported by GpgAgent. Specialized tools are to be used for this.
There is no actual need because we can expect that secret keys created by a 3rd party are stored on a smartcard. If we have generated the key ourselves, we do not need to import it.
Actually we do not import a Root Cert but provide a way to validate any piece of data by storing its Hash along with a description and an identifier in the PSE. Here is the interface description:
ISTRUSTED <fingerprint>
Check whether the OpenPGP primary key or the X.509 certificate with the given fingerprint is an ultimately trusted key or a trusted Root CA certificate. The fingerprint should be given as a hexstring (without any blanks or colons or whatever in between) and may be left padded with 00 in case of an MD5 fingerprint. GPGAgent will answer with:
OK
The key is in the table of trusted keys.
ERR 304 (Not Trusted)
The key is not in this table.
Gpg needs the entire list of trusted keys to maintain the web of trust; the following command is therefore quite helpful:
LISTTRUSTED
GpgAgent returns a list of trusted keys line by line:
S: D 000000001234454556565656677878AF2F1ECCFF P S: D 340387563485634856435645634856438576457A P S: D FEDC6532453745367FD83474357495743757435D S S: OK
The first item on a line is the hexified fingerprint where MD5
fingerprints are 00
padded to the left and the second item is a
flag to indicate the type of key (so that gpg is able to only take care
of PGP keys). P = OpenPGP, S = S/MIME. A client should ignore the rest
of the line, so that we can extend the format in the future.
Finally a client should be able to mark a key as trusted:
MARKTRUSTED fingerprint "P"|"S"
The server will then pop up a window to ask the user whether she really trusts this key. For this it will probably ask for a text to be displayed like this:
S: INQUIRE TRUSTDESC C: D Do you trust the key with the fingerprint @FPR@ C: D bla fasel blurb. C: END S: OK
Known sequences with the pattern @foo@ are replaced according to this table:
@FPR16@
Format the fingerprint according to gpg rules for a v3 keys.
@FPR20@
Format the fingerprint according to gpg rules for a v4 keys.
@FPR@
Choose an appropriate format to format the fingerprint.
@@
Replaced by a single @
.
This function is usually used to ask for a passphrase to be used for symmetric encryption, but may also be used by programs which need special handling of passphrases. This command uses a syntax which helps clients to use the agent with minimum effort.
GET_PASSPHRASE [--data] [--check] [--no-ask] [--repeat[=N]] \ [--qualitybar] cache_id \ [error_message prompt description]
cache_id is expected to be a string used to identify a cached
passphrase. Use a X
to bypass the cache. With no other
arguments the agent returns a cached passphrase or an error. By
convention either the hexified fingerprint of the key shall be used for
cache_id or an arbitrary string prefixed with the name of the
calling application and a colon: Like gpg:somestring
.
error_message is either a single X
for no error message or
a string to be shown as an error message like (e.g. "invalid
passphrase"). Blanks must be percent escaped or replaced by +
’.
prompt is either a single X
for a default prompt or the
text to be shown as the prompt. Blanks must be percent escaped or
replaced by +
.
description is a text shown above the entry field. Blanks must be
percent escaped or replaced by +
.
The agent either returns with an error or with a OK followed by the hex encoded passphrase. Note that the length of the strings is implicitly limited by the maximum length of a command. If the option --data is used, the passphrase is not returned on the OK line but by regular data lines; this is the preferred method.
If the option --check is used, the standard passphrase constraints checks are applied. A check is not done if the passphrase has been found in the cache.
If the option --no-ask is used and the passphrase is not in the
cache the user will not be asked to enter a passphrase but the error
code GPG_ERR_NO_DATA
is returned.
If the option --qualitybar is used and a minimum passphrase length has been configured, a visual indication of the entered passphrase quality is shown.
CLEAR_PASSPHRASE cache_id
may be used to invalidate the cache entry for a passphrase. The function returns with OK even when there is no cached passphrase.
Use this command to remove a cached passphrase.
CLEAR_PASSPHRASE [--mode=normal] <cache_id>
The --mode=normal option can be used to clear a cache_id that was set by gpg-agent.
This command adds a passphrase to the cache for the specified keygrip.
PRESET_PASSPHRASE [--inquire] <string_or_keygrip> <timeout> [<hexstring>]
The passphrase is a hexadecimal string when specified. When not specified, the passphrase will be retrieved from the pinentry module unless the --inquire option was specified in which case the passphrase will be retrieved from the client.
The timeout parameter keeps the passphrase cached for the specified
number of seconds. A value of -1
means infinite while 0
means
the default (currently only a timeout of -1 is allowed, which means to never
expire it).
This command may be used to ask for a simple confirmation by presenting a text and 2 buttons: Okay and Cancel.
GET_CONFIRMATION description
descriptionis displayed along with a Okay and Cancel
button. Blanks must be percent escaped or replaced by +
. A
X
may be used to display confirmation dialog with a default
text.
The agent either returns with an error or with a OK. Note, that the length of description is implicitly limited by the maximum length of a command.
This can be used to see whether a secret key is available. It does not return any information on whether the key is somehow protected.
HAVEKEY keygrips
The agent answers either with OK or No_Secret_Key
(208). The
caller may want to check for other error codes as well. More than one
keygrip may be given. In this case the command returns success if at
least one of the keygrips corresponds to an available secret key.
LEARN [--send]
This command is used to register a smartcard. With the --send option given the certificates are sent back.
PASSWD [--cache-nonce=<c>] [--passwd-nonce=<s>] [--preset] keygrip
This command is used to interactively change the passphrase of the key identified by the hex string keygrip. The --preset option may be used to add the new passphrase to the cache using the default cache parameters.
UPDATESTARTUPTTY
Set the startup TTY and X-DISPLAY variables to the values of this session. This command is useful to direct future pinentry invocations to another screen. It is only required because there is no way in the ssh-agent protocol to convey this information.
GETEVENTCOUNTER
This function return one status line with the current values of the
event counters. The event counters are useful to avoid polling by
delaying a poll until something has changed. The values are decimal
numbers in the range 0
to UINT_MAX
and wrapping around to
0. The actual values should not be relied upon; they shall only be used
to detect a change.
The currently defined counters are:
ANY
Incremented with any change of any of the other counters.
KEY
Incremented for added or removed private keys.
CARD
Incremented for each change of the card reader’s status.
This is a multipurpose function to return a variety of information.
GETINFO what
The value of what specifies the kind of information returned:
version
Return the version of the program.
pid
Return the process id of the process.
socket_name
Return the name of the socket used to connect the agent.
ssh_socket_name
Return the name of the socket used for SSH connections. If SSH support
has not been enabled the error GPG_ERR_NO_DATA
will be returned.
Here is a list of session options which are not yet described with other commands. The general syntax for an Assuan option is:
OPTION key=value
Supported keys are:
agent-awareness
This may be used to tell gpg-agent of which gpg-agent version the client is aware of. gpg-agent uses this information to enable features which might break older clients.
putenv
Change the session’s environment to be used for the Pinentry. Valid values are:
name
Delete envvar name
name=
Set envvar name to the empty string
name=value
Set envvar name to the string value.
use-cache-for-signing
See Assuan command PKSIGN
.
allow-pinentry-notify
This does not need any value. It is used to enable the PINENTRY_LAUNCHED inquiry.
pinentry-mode
This option is used to change the operation mode of the pinentry. The following values are defined:
ask
This is the default mode which pops up a pinentry as needed.
cancel
Instead of popping up a pinentry, return the error code
GPG_ERR_CANCELED
.
error
Instead of popping up a pinentry, return the error code
GPG_ERR_NO_PIN_ENTRY
.
loopback
Use a loopback pinentry. This fakes a pinentry by using inquiries back to the caller to ask for a passphrase. This option may only be set if the agent has been configured for that. To disable this feature use option --no-allow-loopback-pinentry.
cache-ttl-opt-preset
This option sets the cache TTL for new entries created by GENKEY and PASSWD commands when using the --preset option. It is not used a default value is used.
s2k-count
Instead of using the standard S2K count (which is computed on the fly), the given S2K count is used for new keys or when changing the passphrase of a key. Values below 65536 are considered to be 0. This option is valid for the entire session or until reset to 0. This option is useful if the key is later used on boxes which are either much slower or faster than the actual box.
pretend-request-origin
This option switches the connection into a restricted mode which handles all further commands in the same way as they would be handled when originating from the extra or browser socket. Note that this option is not available in the restricted mode. Valid values for this option are:
none
local
This is a NOP and leaves the connection in the standard way.
remote
Pretend to come from a remote origin in the same way as connections from the --extra-socket.
browser
Pretend to come from a local web browser in the same way as connections from the --browser-socket.
Since version 2.1 of GnuPG, dirmngr
takes care of accessing
the OpenPGP keyservers. As with previous versions it is also used as
a server for managing and downloading certificate revocation lists
(CRLs) for X.509 certificates, downloading X.509 certificates, and
providing access to OCSP providers. Dirmngr is invoked internally by
gpg
, gpgsm
, or via the gpg-connect-agent
tool.
See Option Index,for an index to DIRMNGR
’s commands and
options.
Commands are not distinguished from options except for the fact that only one command is allowed.
--version
¶Print the program version and licensing information. Note that you cannot abbreviate this command.
--help, -h
¶Print a usage message summarizing the most useful command-line options. Note that you cannot abbreviate this command.
--dump-options
¶Print a list of all available options and commands. Note that you cannot abbreviate this command.
--server
¶Run in server mode and wait for commands on the stdin
. The
default mode is to create a socket and listen for commands there.
This is only used for testing.
--daemon
¶Run in background daemon mode and listen for commands on a socket.
This is the way dirmngr
is started on demand by the other
GnuPG components. To force starting dirmngr
it is in
general best to use gpgconf --launch dirmngr
.
--supervised
¶Run in the foreground, sending logs to stderr, and listening on file descriptor 3, which must already be bound to a listening socket. This option is deprecated and not supported on Windows.
--list-crls
¶List the contents of the CRL cache on stdout
. This is probably
only useful for debugging purposes.
--load-crl file
¶This command requires a filename as additional argument, and it will
make Dirmngr try to import the CRL in file into it’s cache.
Note, that this is only possible if Dirmngr is able to retrieve the
CA’s certificate directly by its own means. In general it is better
to use gpgsm
’s --call-dirmngr loadcrl filename
command
so that gpgsm
can help dirmngr.
--fetch-crl url
¶This command requires an URL as additional argument, and it will make
dirmngr try to retrieve and import the CRL from that url into
it’s cache. This is mainly useful for debugging purposes. The
dirmngr-client
provides the same feature for a running dirmngr.
--shutdown
¶This commands shuts down an running instance of Dirmngr. This command has currently no effect.
--flush
¶This command removes all CRLs from Dirmngr’s cache. Client requests will thus trigger reading of fresh CRLs.
Note that all long options with the exception of --options and --homedir may also be given in the configuration file after stripping off the two leading dashes.
--options file
¶Reads configuration from file instead of from the default per-user configuration file. The default configuration file is named dirmngr.conf and expected in the home directory.
--homedir dir
¶Set the name of the home directory to dir. This option is only
effective when used on the command line. The default is
the directory named .gnupg directly below the home directory
of the user unless the environment variable GNUPGHOME
has been set
in which case its value will be used. Many kinds of data are stored within
this directory.
-v
--verbose
¶Outputs additional information while running. You can increase the verbosity by giving several verbose commands to DIRMNGR, such as -vv.
--log-file file
¶Append all logging output to file. This is very helpful in seeing what the agent actually does. Use socket:// to log to socket.
--compatibility-flags flags
¶Set compatibility flags to work around certain problems or to emulate bugs. The flags are given as a comma separated list of flag names and are OR-ed together. The special flag "none" clears the list and allows one to start over with an empty list. To get a list of available flags the sole word "help" can be used.
--faked-system-time epoch
¶This option is only useful for testing; it sets the system time back or forth to epoch which is the number of seconds elapsed since the year 1970. Alternatively epoch may be given as a full ISO time string (e.g. "20070924T154812").
--debug-level level
¶Select the debug level for investigating problems. level may be a numeric value or by a keyword:
none
No debugging at all. A value of less than 1 may be used instead of the keyword.
basic
Some basic debug messages. A value between 1 and 2 may be used instead of the keyword.
advanced
More verbose debug messages. A value between 3 and 5 may be used instead of the keyword.
expert
Even more detailed messages. A value between 6 and 8 may be used instead of the keyword.
guru
All of the debug messages you can get. A value greater than 8 may be used instead of the keyword. The creation of hash tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not specified and may change with newer releases of this program. They are however carefully selected to best aid in debugging.
--debug flags
¶Set debug flags. All flags are or-ed and flags may be given in C syntax (e.g. 0x0042) or as a comma separated list of flag names. To get a list of all supported flags the single word "help" can be used. This option is only useful for debugging and the behavior may change at any time without notice.
--debug-all
¶Same as --debug=0xffffffff
--tls-debug level
¶Enable debugging of the TLS layer at level. The details of the debug level depend on the used TLS library and are not set in stone.
--debug-wait n
¶When running in server mode, wait n seconds before entering the actual processing loop and print the pid. This gives time to attach a debugger.
--disable-check-own-socket
¶On some platforms dirmngr
is able to detect the removal of
its socket file and shutdown itself. This option disable this
self-test for debugging purposes.
-s
¶--sh
-c
--csh
Format the info output in daemon mode for use with the standard Bourne
shell respective the C-shell. The default is to guess it based on the
environment variable SHELL
which is in almost all cases
sufficient.
--force
¶Enabling this option forces loading of expired CRLs; this is only useful for debugging.
--use-tor
¶--no-use-tor
The option --use-tor switches Dirmngr and thus GnuPG into “Tor mode” to route all network access via Tor (an anonymity network). Certain other features are disabled in this mode. The effect of --use-tor cannot be overridden by any other command or even by reloading dirmngr. The use of --no-use-tor disables the use of Tor. The default is to use Tor if it is available on startup or after reloading dirmngr. The test on the availability of Tor is done by trying to connect to a SOCKS proxy at either port 9050 or 9150; if another type of proxy is listening on one of these ports, you should use --no-use-tor.
--standard-resolver
¶This option forces the use of the system’s standard DNS resolver code. This is mainly used for debugging. Note that on Windows a standard resolver is not used and all DNS access will return the error “Not Implemented” if this option is used. Using this together with enabled Tor mode returns the error “Not Enabled”.
--recursive-resolver
¶When possible use a recursive resolver instead of a stub resolver.
--resolver-timeout n
¶Set the timeout for the DNS resolver to N seconds. The default are 30 seconds.
--connect-timeout n
--connect-quick-timeout n
¶Set the timeout for HTTP and generic TCP connection attempts to N seconds. The value set with the quick variant is used when the –quick option has been given to certain Assuan commands. The quick value is capped at the value of the regular connect timeout. The default values are 15 and 2 seconds. Note that the timeout values are for each connection attempt; the connection code will attempt to connect all addresses listed for a server.
--listen-backlog n
¶Set the size of the queue for pending connections. The default is 64.
--allow-version-check
¶Allow Dirmngr to connect to https://versions.gnupg.org
to get
the list of current software versions. If this option is enabled
the list is retrieved in case the local
copy does not exist or is older than 5 to 7 days. See the option
--query-swdb of the command gpgconf
for more
details. Note, that regardless of this option a version check can
always be triggered using this command:
gpg-connect-agent --dirmngr 'loadswdb --force' /bye
--keyserver name
¶Use name as your keyserver. This is the server that gpg
communicates with to receive keys, send keys, and search for
keys. The format of the name is a URI:
‘scheme:[//]keyservername[:port]’ The scheme is the type of keyserver:
"hkp" for the HTTP (or compatible) keyservers or "ldap" for the LDAP
keyservers. Note that your particular installation of GnuPG may have
other keyserver types available as well. Keyserver schemes are
case-insensitive. After the keyserver name, optional keyserver
configuration options may be provided. These are the same as the
--keyserver-options of gpg
, but apply only to this
particular keyserver.
Some keyservers synchronize with each other, so there is not always a need to send keys to more than one server. Some keyservers use round robin DNS to give a different keyserver each time you use it.
If exactly two keyservers are configured and only one is a Tor hidden service (.onion), Dirmngr selects the keyserver to use depending on whether Tor is locally running or not. The check for a running Tor is done for each new connection.
If no keyserver is explicitly configured, dirmngr will use the
built-in default of hkps://keys.openpgp.org
. To avoid the
use of a default keyserver the value none
can be used.
Windows users with a keyserver running on their Active Directory
may use the short form ldap:///
for name to access this directory.
For accessing anonymous LDAP keyservers name is in general just
a ldaps://ldap.example.com
. A BaseDN parameter should never be
specified. If authentication is required things are more complicated
and two methods are available:
The modern method (since version 2.2.28) is to use the very same syntax as used with the option --ldapserver. Please see over there for details; here is an example:
keyserver ldap:ldap.example.com::uid=USERNAME,ou=GnuPG Users, dc=example,dc=com:PASSWORD::starttls
The other method is to use a full URL for name; for example:
keyserver ldaps://ldap.example.com/????bindname=uid=USERNAME %2Cou=GnuPG%20Users%2Cdc=example%2Cdc=com,password=PASSWORD
Put this all on one line without any spaces and keep the ’%2C’
as given. Replace USERNAME, PASSWORD, and the ’dc’ parts
according to the instructions received from your LDAP
administrator. Note that only simple authentication
(i.e. cleartext passwords) is supported and thus using ldaps is
strongly suggested (since 2.2.28 "ldaps" defaults to port 389
and uses STARTTLS). On Windows authentication via AD can be
requested by adding gpgNtds=1
after the fourth question
mark instead of the bindname and password parameter.
--nameserver ipaddr
¶In “Tor mode” Dirmngr uses a public resolver via Tor to resolve DNS
names. If the default public resolver, which is 8.8.8.8
, shall
not be used a different one can be given using this option. Note that
a numerical IP address must be given (IPv6 or IPv4) and that no error
checking is done for ipaddr.
--disable-ipv4
--disable-ipv6
¶Disable the use of all IPv4 or IPv6 addresses.
--disable-ldap
¶Entirely disables the use of LDAP.
--disable-http
¶Entirely disables the use of HTTP.
--ignore-http-dp
¶When looking for the location of a CRL, the to be tested certificate usually contains so called CRL Distribution Point (DP) entries which are URLs describing the way to access the CRL. The first found DP entry is used. With this option all entries using the HTTP scheme are ignored when looking for a suitable DP.
--ignore-ldap-dp
¶This is similar to --ignore-http-dp but ignores entries using the LDAP scheme. Both options may be combined resulting in ignoring DPs entirely.
--ignore-ocsp-service-url
¶Ignore all OCSP URLs contained in the certificate. The effect is to force the use of the default responder.
--honor-http-proxy
¶If the environment variable http_proxy
has been set, use its
value to access HTTP servers. If on Windows the option is used but
the environment variable is not set, the proxy settings are taken
from the system.
--http-proxy host[:port]
¶Use host and port to access HTTP servers. The use of this
option overrides the environment variable http_proxy
regardless
whether --honor-http-proxy has been set.
--ldap-proxy host[:port]
¶Use host and port to connect to LDAP servers. If port is omitted, port 389 (standard LDAP port) is used. This overrides any specified host and port part in a LDAP URL and will also be used if host and port have been omitted from the URL.
--only-ldap-proxy
¶Never use anything else but the LDAP "proxy" as configured with
--ldap-proxy. Usually dirmngr
tries to use other
configured LDAP server if the connection using the "proxy" failed.
--ldapserverlist-file file
¶Read the list of LDAP servers to consult for CRLs and X.509 certificates from file instead of the default per-user ldap server list file. The default value for file is dirmngr_ldapservers.conf.
This server list file contains one LDAP server per line in the format
HOSTNAME:PORT:USERNAME:PASSWORD:BASE_DN:FLAGS
Lines starting with a ‘#’ are comments.
Note that as usual all strings entered are expected to be UTF-8 encoded. Obviously this will lead to problems if the password has originally been encoded as Latin-1. There is no other solution here than to put such a password in the binary encoding into the file (i.e. non-ascii characters won’t show up readable).1
--ldapserver spec
¶This is an alternative way to specify LDAP servers for CRL and X.509 certificate retrieval. If this option is used the servers configured in dirmngr_ldapservers.conf (or the file given by --ldapserverlist-file) are cleared. Note that dirmngr_ldapservers.conf is not read again by a reload signal. However, --ldapserver options are read again.
spec is either a proper LDAP URL or a colon delimited list of the form
HOSTNAME:PORT:USERNAME:PASSWORD:BASE_DN:FLAGS:
with an optional prefix of ldap:
(but without the two slashes
which would turn this into a proper LDAP URL). FLAGS is a list
of one or more comma delimited keywords:
plain
The default: Do not use a TLS secured connection at all; the default port is 389.
starttls
Use STARTTLS to secure the connection; the default port is 389.
ldaptls
Tunnel LDAP through a TLS connection; the default port is 636.
ntds
On Windows authenticate the LDAP connection using the Active Directory with the current user.
areconly
On Windows use only the A or AAAA record when resolving the LDAP server name.
Note that in an URL style specification the scheme ldaps://
refers to STARTTLS and _not_ to LDAP-over-TLS.
--ldaptimeout secs
¶Specify the number of seconds to wait for an LDAP query before timing out. The default are 15 seconds. 0 will never timeout.
--add-servers
¶This option makes dirmngr add any servers it discovers when validating certificates against CRLs to the internal list of servers to consult for certificates and CRLs. This option should in general not be used.
This option might be useful when trying to validate a certificate that
has a CRL distribution point that points to a server that is not
already listed in the ldapserverlist. Dirmngr will always go to this
server and try to download the CRL, but chances are high that the
certificate used to sign the CRL is located on the same server. So if
dirmngr doesn’t add that new server to list, it will often not be able
to verify the signature of the CRL unless the --add-servers
option is used.
Caveat emptor: Using this option may enable denial-of-service attacks and leak search requests to unknown third parties. This is because arbitrary servers are added to the internal list of LDAP servers which in turn is used for all unspecific LDAP queries as well as a fallback for queries which did not return a result.
--allow-ocsp
¶This option enables OCSP support if requested by the client.
OCSP requests are rejected by default because they may violate the privacy of the user; for example it is possible to track the time when a user is reading a mail.
--ocsp-responder url
¶Use url as the default OCSP Responder if the certificate does
not contain information about an assigned responder. Note, that
--ocsp-signer
must also be set to a valid certificate.
--ocsp-signer fpr|file
¶Use the certificate with the fingerprint fpr to check the
responses of the default OCSP Responder. Alternatively a filename can be
given in which case the response is expected to be signed by one of the
certificates described in that file. Any argument which contains a
slash, dot or tilde is considered a filename. Usual filename expansion
takes place: A tilde at the start followed by a slash is replaced by the
content of HOME
, no slash at start describes a relative filename
which will be searched at the home directory. To make sure that the
file is searched in the home directory, either prepend the name
with "./" or use a name which contains a dot.
If a response has been signed by a certificate described by these fingerprints no further check upon the validity of this certificate is done.
The format of the FILE is a list of SHA-1 fingerprint, one per line with optional colons between the bytes. Empty lines and lines prefix with a hash mark are ignored.
--ocsp-max-clock-skew n
¶The number of seconds a skew between the OCSP responder and them local clock is accepted. Default is 600 (10 minutes).
--ocsp-max-period n
¶Seconds a response is at maximum considered valid after the time given in the thisUpdate field. Default is 7776000 (90 days).
--ocsp-current-period n
¶The number of seconds an OCSP response is considered valid after the time given in the NEXT_UPDATE datum. Default is 10800 (3 hours).
--max-replies n
¶Do not return more that n items in one query. The default is 10.
--ignore-cert-extension oid
¶Add oid to the list of ignored certificate extensions. The
oid is expected to be in dotted decimal form, like
2.5.29.3
. This option may be used more than once. Critical
flagged certificate extensions matching one of the OIDs in the list
are treated as if they are actually handled and thus the certificate
won’t be rejected due to an unknown critical extension. Use this
option with care because extensions are usually flagged as critical
for a reason.
--ignore-crl-extension oid
¶Add oid to the list of ignored CRL extensions. The oid is expected to be in dotted decimal form. Critical flagged CRL extensions matching one of the OIDs in the list are treated as if they are actually handled and thus the certificate won’t be rejected due to an unknown critical extension. Use this option with care because extensions are usually flagged as critical for a reason.
--ignore-cert fpr|file
¶Entirely ignore certificates with the fingerprint fpr. As an
alternative to the fingerprint a filename can be given in which case
all certificates described in that file are ignored. Any argument
which contains a slash, dot or tilde is considered a filename. Usual
filename expansion takes place: A tilde at the start followed by a
slash is replaced by the content of HOME
, no slash at start
describes a relative filename which will be searched at the home
directory. To make sure that the file is searched in the home
directory, either prepend the name with "./" or use a name which
contains a dot. The format of such a file is a list of SHA-1
fingerprint, one per line with optional colons between the bytes.
Empty lines and lines prefixed with a hash mark are ignored.
This option is useful as a quick workaround to exclude certain certificates from the system store.
--hkp-cacert file
Use the root certificates in file for verification of the TLS
certificates used with hkps
(keyserver access over TLS). If
the file is in PEM format a suffix of .pem
is expected for
file. This option may be given multiple times to add more
root certificates. Tilde expansion is supported.
If no hkp-cacert
directive is present, dirmngr will use the
system CAs.
Dirmngr makes use of several directories when running in daemon mode: There are a few configuration files to control the operation of dirmngr. By default they may all be found in the current home directory (see option --homedir).
This is the standard configuration file read by dirmngr
on
startup. It may contain any valid long option; the leading two dashes
may not be entered and the option may not be abbreviated. This file
is also read after a SIGHUP
however not all options will
actually have an effect. This default name may be changed on the
command line (see option --options). You should backup this file.
This directory should be filled with certificates of Root CAs you are trusting in checking the CRLs and signing OCSP Responses.
Usually these are the same certificates you use with the applications
making use of dirmngr. It is expected that each of these certificate
files contain exactly one DER encoded certificate in a file
with the suffix .crt or .der. dirmngr
reads
those certificates on startup and when given a SIGHUP. Certificates
which are not readable or do not make up a proper X.509 certificate
are ignored; see the log file for details.
Applications using dirmngr (e.g. gpgsm) can request these certificates to complete a trust chain in the same way as with the extra-certs directory (see below).
Note that for OCSP responses the certificate specified using the option --ocsp-signer is always considered valid to sign OCSP requests.
This directory may contain extra certificates which are preloaded into the internal cache on startup. Applications using dirmngr (e.g. gpgsm) can request cached certificates to complete a trust chain. This is convenient in cases you have a couple intermediate CA certificates or certificates usually used to sign OCSP responses. These certificates are first tried before going out to the net to look for them. These certificates must also be DER encoded and suffixed with .crt or .der.
This directory is used to store cached CRLs. The crls.d part will be created by dirmngr if it does not exists but you need to make sure that the upper directory exists.
Several options control the use of trusted certificates for TLS and CRLs. Here is an Overview on the use and origin of those Root CA certificates:
These System root certificates are used by: FIXME
The origin of the system provided certificates depends on the
platform. On Windows all certificates from the Windows System Stores
ROOT
and CA
are used.
On other platforms the certificates are read from the first file found form this list: /etc/ssl/ca-bundle.pem, /etc/ssl/certs/ca-certificates.crt, /etc/pki/tls/cert.pem, /usr/local/share/certs/ca-root-nss.crt, /etc/ssl/cert.pem.
The GnuPG specific certificates stored in the directory /etc/gnupg/trusted-certs are only used to validate CRLs.
For accessing the OpenPGP keyservers the only certificates used are those set with the configuration option hkp-cacert.
This is usually only one certificate read from the file
/nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/share/gnupg/gnupg/sks-keyservers.netCA.pem. If this
certificate exists it is used to access the special keyservers
hkps.pool.sks-keyservers.net
(or hkps://keys.gnupg.net).
Please note that gpgsm
accepts Root CA certificates for its
own purposes only if they are listed in its file trustlist.txt.
dirmngr
does not make use of this list - except FIXME.
To be able to see diagnostics it is often useful to put at least the following lines into the configuration file ~/gnupg/dirmngr.conf:
log-file ~/dirmngr.log verbose
You may want to check the log file to see whether all desired root CA certificates are correctly loaded.
To be able to perform OCSP requests you probably want to add the line:
allow-ocsp
To make sure that new options are read or that after the installation of a new GnuPG versions the right dirmngr version is running, you should kill an existing dirmngr so that a new instance is started as needed by the other components:
gpgconf --kill dirmngr
Direct interfaction with the dirmngr is possible by using the command
gpg-connect-agent --dirmngr
Enter HELP
at the prompt to see a list of commands and enter
HELP
followed by a command name to get help on that command.
A running dirmngr
may be controlled by signals, i.e. using
the kill
command to send a signal to the process.
Here is a list of supported signals:
SIGHUP
¶This signal flushes all internally cached CRLs as well as any cached certificates. Then the certificate cache is reinitialized as on startup. Options are re-read from the configuration file. Instead of sending this signal it is better to use
gpgconf --reload dirmngr
SIGTERM
¶Shuts down the process but waits until all current requests are fulfilled. If the process has received 3 of these signals and requests are still pending, a shutdown is forced. You may also use
gpgconf --kill dirmngr
instead of this signal
SIGINT
¶Shuts down the process immediately.
SIGUSR1
¶This prints some caching statistics to the log file.
Here is an example on how to show dirmngr’s internal table of OpenPGP keyserver addresses. The output is intended for debugging purposes and not part of a defined API.
gpg-connect-agent --dirmngr 'keyserver --hosttable' /bye
To inhibit the use of a particular host you have noticed in one of the keyserver pools, you may use
gpg-connect-agent --dirmngr 'keyserver --dead pgpkeys.bnd.de' /bye
The description of the keyserver
command can be printed using
gpg-connect-agent --dirmngr 'help keyserver' /bye
Assuan is the IPC protocol used to access dirmngr. This is a description of the commands implemented by dirmngr.
Lookup certificate. To allow multiple patterns (which are ORed) quoting is required: Spaces are to be translated into "+" or into "%20"; obviously this requires that the usual escape quoting rules are applied. The server responds with:
S: D <DER encoded certificate> S: END S: D <second DER encoded certificate> S: END S: OK
In this example 2 certificates are returned. The server may return any number of certificates; OK will also be returned when no certificates were found. The dirmngr might return a status line
S: S TRUNCATED <n>
To indicate that the output was truncated to N items due to a limitation of the server or by an arbitrary set limit.
The option --url may be used if instead of a search pattern a complete URL to the certificate is known:
C: LOOKUP --url CN%3DWerner%20Koch,o%3DIntevation%20GmbH,c%3DDE?userCertificate
If the option --cache-only is given, no external lookup is done so that only certificates from the cache are returned.
With the option --single, the first and only the first match will be returned. Unless option --cache-only is also used, no local lookup will be done in this case.
ISVALID [--only-ocsp] [--force-default-responder] certid|certfpr
Check whether the certificate described by the certid has been revoked. Due to caching, the Dirmngr is able to answer immediately in most cases.
The certid is a hex encoded string consisting of two parts, delimited by a single dot. The first part is the SHA-1 hash of the issuer name and the second part the serial number.
Alternatively the certificate’s SHA-1 fingerprint certfpr may be given in which case an OCSP request is done before consulting the CRL. If the option --only-ocsp is given, no fallback to a CRL check will be used. If the option --force-default-responder is given, only the default OCSP responder will be used and any other methods of obtaining an OCSP responder URL won’t be used.
Common return values are:
GPG_ERR_NO_ERROR (0)
This is the positive answer: The certificate is not revoked and we have an up-to-date revocation list for that certificate. If OCSP was used the responder confirmed that the certificate has not been revoked.
GPG_ERR_CERT_REVOKED
This is the negative answer: The certificate has been revoked. Either it is in a CRL and that list is up to date or an OCSP responder informed us that it has been revoked.
GPG_ERR_NO_CRL_KNOWN
No CRL is known for this certificate or the CRL is not valid or out of date.
GPG_ERR_NO_DATA
The OCSP responder returned an “unknown” status. This means that it is not aware of the certificate’s status.
GPG_ERR_NOT_SUPPORTED
This is commonly seen if OCSP support has not been enabled in the configuration.
If DirMngr has not enough information about the given certificate (which is the case for not yet cached certificates), it will inquire the missing data:
S: INQUIRE SENDCERT <CertID> C: D <DER encoded certificate> C: END
A client should be aware that DirMngr may ask for more than one certificate.
If Dirmngr has a certificate but the signature of the certificate could not been validated because the root certificate is not known to dirmngr as trusted, it may ask back to see whether the client trusts this the root certificate:
S: INQUIRE ISTRUSTED <CertHexfpr> C: D 1 C: END
Only this answer will let Dirmngr consider the certificate as valid.
Check whether the certificate with FINGERPRINT (SHA-1 hash of the entire X.509 certificate blob) is valid or not by consulting the CRL responsible for this certificate. If the fingerprint has not been given or the certificate is not known, the function inquires the certificate using:
S: INQUIRE TARGETCERT C: D <DER encoded certificate> C: END
Thus the caller is expected to return the certificate for the request (which should match FINGERPRINT) as a binary blob. Processing then takes place without further interaction; in particular dirmngr tries to locate other required certificate by its own mechanism which includes a local certificate store as well as a list of trusted root certificates.
The return code is 0 for success; i.e. the certificate has not been revoked or one of the usual error codes from libgpg-error.
CHECKOCSP [--force-default-responder] [fingerprint]
Check whether the certificate with fingerprint (the SHA-1 hash of the entire X.509 certificate blob) is valid by consulting the appropriate OCSP responder. If the fingerprint has not been given or the certificate is not known by Dirmngr, the function inquires the certificate using:
S: INQUIRE TARGETCERT C: D <DER encoded certificate> C: END
Thus the caller is expected to return the certificate for the request (which should match fingerprint) as a binary blob. Processing then takes place without further interaction; in particular dirmngr tries to locate other required certificates by its own mechanism which includes a local certificate store as well as a list of trusted root certificates.
If the option --force-default-responder is given, only the default OCSP responder is used. This option is the per-command variant of the global option --ignore-ocsp-service-url.
The return code is 0 for success; i.e. the certificate has not been revoked or one of the usual error codes from libgpg-error.
Put a certificate into the internal cache. This command might be useful if a client knows in advance certificates required for a test and wants to make sure they get added to the internal cache. It is also helpful for debugging. To get the actual certificate, this command immediately inquires it using
S: INQUIRE TARGETCERT C: D <DER encoded certificate> C: END
Thus the caller is expected to return the certificate for the request as a binary blob.
The return code is 0 for success; i.e. the certificate has not been successfully cached or one of the usual error codes from libgpg-error.
Validate a certificate using the certificate validation function used internally by dirmngr. This command is only useful for debugging. To get the actual certificate, this command immediately inquires it using
S: INQUIRE TARGETCERT C: D <DER encoded certificate> C: END
Thus the caller is expected to return the certificate for the request as a binary blob.
gpg
is the OpenPGP part of the GNU Privacy Guard (GnuPG). It
is a tool to provide digital encryption and signing services using the
OpenPGP standard. gpg
features complete key management and
all the bells and whistles you would expect from a full OpenPGP
implementation.
There are two main versions of GnuPG: GnuPG 1.x and GnuPG 2.x. GnuPG 2.x supports modern encryption algorithms and thus should be preferred over GnuPG 1.x. You only need to use GnuPG 1.x if your platform doesn’t support GnuPG 2.x, or you need support for some features that GnuPG 2.x has deprecated, e.g., decrypting data created with PGP-2 keys.
If you are looking for version 1 of GnuPG, you may find that version
installed under the name gpg1
.
See Option Index, for an index to gpg
’s commands and options.
Commands are not distinguished from options except for the fact that only one command is allowed. Generally speaking, irrelevant options are silently ignored, and may not be checked for correctness.
gpg
may be run with no commands. In this case it will
print a warning perform a reasonable action depending on the type of
file it is given as input (an encrypted message is decrypted, a
signature is verified, a file containing keys is listed, etc.).
If you run into any problems, please add the option --verbose to the invocation to see more diagnostics.
--version
¶Print the program version and licensing information. Note that you cannot abbreviate this command.
--help
¶-h
Print a usage message summarizing the most useful command-line options. Note that you cannot arbitrarily abbreviate this command (though you can use its short form -h).
--warranty
¶Print warranty information.
--dump-options
¶Print a list of all available options and commands. Note that you cannot abbreviate this command.
--sign
¶-s
Sign a message. This command may be combined with --encrypt (to sign and encrypt a message), --symmetric (to sign and symmetrically encrypt a message), or both --encrypt and --symmetric (to sign and encrypt a message that can be decrypted using a secret key or a passphrase). The signing key is chosen by default or can be set explicitly using the --local-user and --default-key options.
--clear-sign
¶--clearsign
Make a cleartext signature. The content in a cleartext signature is readable without any special software. OpenPGP software is only needed to verify the signature. cleartext signatures may modify end-of-line whitespace for platform independence and are not intended to be reversible. The signing key is chosen by default or can be set explicitly using the --local-user and --default-key options.
--detach-sign
¶-b
Make a detached signature.
--encrypt
¶-e
Encrypt data to one or more public keys. This command may be combined with --sign (to sign and encrypt a message), --symmetric (to encrypt a message that can be decrypted using a secret key or a passphrase), or --sign and --symmetric together (for a signed message that can be decrypted using a secret key or a passphrase). --recipient and related options specify which public keys to use for encryption.
--symmetric
¶-c
Encrypt with a symmetric cipher using a passphrase. The default
symmetric cipher used is AES-128, but may be chosen with the
--cipher-algo option. This command may be combined with
--sign (for a signed and symmetrically encrypted message),
--encrypt (for a message that may be decrypted via a secret key
or a passphrase), or --sign and --encrypt together
(for a signed message that may be decrypted via a secret key or a
passphrase). gpg
caches the passphrase used for
symmetric encryption so that a decrypt operation may not require that
the user needs to enter the passphrase. The option
--no-symkey-cache can be used to disable this feature.
--store
¶Store only (make a simple literal data packet).
--decrypt
¶-d
Decrypt the file given on the command line (or STDIN if no file is specified) and write it to STDOUT (or the file specified with --output). If the decrypted file is signed, the signature is also verified. This command differs from the default operation, as it never writes to the filename which is included in the file and it rejects files that don’t begin with an encrypted message.
--verify
¶Assume that the first argument is a signed file and verify it without generating any output. With no arguments, the signature packet is read from STDIN. If only one argument is given, the specified file is expected to include a complete signature.
With more than one argument, the first argument should specify a file with a detached signature and the remaining files should contain the signed data. To read the signed data from STDIN, use ‘-’ as the second filename. For security reasons, a detached signature will not read the signed material from STDIN if not explicitly specified.
Note: If the option --batch is not used, gpg
may assume that a single argument is a file with a detached signature,
and it will try to find a matching data file by stripping certain
suffixes. Using this historical feature to verify a detached
signature is strongly discouraged; you should always specify the data file
explicitly.
Note: When verifying a cleartext signature, gpg
verifies
only what makes up the cleartext signed data and not any extra data
outside of the cleartext signature or the header lines directly following
the dash marker line. The option --output
may be used to write
out the actual signed data, but there are other pitfalls with this
format as well. It is suggested to avoid cleartext signatures in
favor of detached signatures.
Note: To check whether a file was signed by a certain key the option
--assert-signer can be used. As an alternative the
gpgv
tool can be used. gpgv
is designed to
compare signed data against a list of trusted keys and returns with
success only for a good signature. It has its own manual page.
--multifile
¶This modifies certain other commands to accept multiple files for processing on the command line or read from STDIN with each filename on a separate line. This allows for many files to be processed at once. --multifile may currently be used along with --verify, --encrypt, and --decrypt. Note that --multifile --verify may not be used with detached signatures.
--verify-files
¶Identical to --multifile --verify.
--encrypt-files
¶Identical to --multifile --encrypt.
--decrypt-files
¶Identical to --multifile --decrypt.
--list-keys
¶-k
--list-public-keys
List the specified keys. If no keys are specified, then all keys from the configured public keyrings are listed.
Never use the output of this command in scripts or other programs. The output is intended only for humans and its format is likely to change. The --with-colons option emits the output in a stable, machine-parseable format, which is intended for use by scripts and other programs.
--list-secret-keys
¶-K
List the specified secret keys. If no keys are specified, then all
known secret keys are listed. A #
after the initial tags
sec
or ssb
means that the secret key or subkey is
currently not usable. We also say that this key has been taken
offline (for example, a primary key can be taken offline by exporting
the key using the command --export-secret-subkeys). A
>
after these tags indicate that the key is stored on a
smartcard. See also --list-keys.
--check-signatures
¶--check-sigs
Same as --list-keys, but the key signatures are verified and listed too. Note that for performance reasons the revocation status of a signing key is not shown. This command has the same effect as using --list-keys with --with-sig-check.
The status of the verification is indicated by a flag directly following the "sig" tag (and thus before the flags described below. A "!" indicates that the signature has been successfully verified, a "-" denotes a bad signature and a "%" is used if an error occurred while checking the signature (e.g. a non supported algorithm). Signatures where the public key is not available are not listed; to see their keyids the command --list-sigs can be used.
For each signature listed, there are several flags in between the signature status flag and keyid. These flags give additional information about each key signature. From left to right, they are the numbers 1-3 for certificate check level (see --ask-cert-level), "L" for a local or non-exportable signature (see --lsign-key), "R" for a nonRevocable signature (see the --edit-key command "nrsign"), "P" for a signature that contains a policy URL (see --cert-policy-url), "N" for a signature that contains a notation (see --cert-notation), "X" for an eXpired signature (see --ask-cert-expire), and the numbers 1-9 or "T" for 10 and above to indicate trust signature levels (see the --edit-key command "tsign").
--locate-keys
¶--locate-external-keys
Locate the keys given as arguments. This command basically uses the
same algorithm as used when locating keys for encryption and may thus
be used to see what keys gpg
might use. In particular
external methods as defined by --auto-key-locate are used to
locate a key if the arguments comain valid mail addresses. Only
public keys are listed.
The variant --locate-external-keys does not consider a locally existing key and can thus be used to force the refresh of a key via the defined external methods. If a fingerprint is given and and the methods defined by –auto-key-locate define LDAP servers, the key is fetched from these resources; defined non-LDAP keyservers are skipped.
--show-keys
¶This commands takes OpenPGP keys as input and prints information about
them in the same way the command --list-keys does for locally
stored key. In addition the list options show-unusable-uids
,
show-unusable-subkeys
, show-notations
and
show-policy-urls
are also enabled. As usual for automated
processing, this command should be combined with the option
--with-colons.
--fingerprint
¶List all keys (or the specified ones) along with their fingerprints. This is the same output as --list-keys but with the additional output of a line with the fingerprint. May also be combined with --check-signatures. If this command is given twice, the fingerprints of all secondary keys are listed too. This command also forces pretty printing of fingerprints if the keyid format has been set to "none".
--list-packets
¶List only the sequence of packets. This command is only useful for debugging. When used with option --verbose the actual MPI values are dumped and not only their lengths. Note that the output of this command may change with new releases.
--edit-card
¶--card-edit
Present a menu to work with a smartcard. The subcommand "help" provides an overview on available commands. For a detailed description, please see the Card HOWTO at https://gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO . Please note that the command "openpgp" can be used to switch to the OpenPGP application of cards which by default are presenting another application (e.g. PIV).
--card-status
¶Show the content of the smart card.
--change-pin
¶Present a menu to allow changing the PIN of a smartcard. This functionality is also available as the subcommand "passwd" with the --edit-card command.
--delete-keys name
¶Remove key from the public keyring. In batch mode either --yes is required or the key must be specified by fingerprint. This is a safeguard against accidental deletion of multiple keys. If the exclamation mark syntax is used with the fingerprint of a subkey only that subkey is deleted; if the exclamation mark is used with the fingerprint of the primary key the entire public key is deleted.
--delete-secret-keys name
¶Remove key from the secret keyring. In batch mode the key must be
specified by fingerprint. The option --yes can be used to
advise gpg-agent not to request a confirmation. This extra
pre-caution is done because gpg
can’t be sure that the
secret key (as controlled by gpg-agent) is only used for the given
OpenPGP public key. If the exclamation mark syntax is used with the
fingerprint of a subkey only the secret part of that subkey is
deleted; if the exclamation mark is used with the fingerprint of the
primary key only the secret part of the primary key is deleted.
--delete-secret-and-public-key name
¶Same as --delete-key, but if a secret key exists, it will be removed first. In batch mode the key must be specified by fingerprint. The option --yes can be used to advise gpg-agent not to request a confirmation.
--export
¶Either export all keys from all keyrings (default keyring and those registered via option --keyring), or if at least one name is given, those of the given name. The exported keys are written to STDOUT or to the file given with option --output. Use together with --armor to mail those keys.
--send-keys keyIDs
¶Similar to --export but sends the keys to a keyserver.
Fingerprints may be used instead of key IDs.
Don’t send your complete keyring to a keyserver — select
only those keys which are new or changed by you. If no keyIDs
are given, gpg
does nothing.
Take care: Keyservers are by design write only systems and thus it is not possible to ever delete keys once they have been send to a keyserver.
--export-secret-keys
¶--export-secret-subkeys
Same as --export, but exports the secret keys instead. The
exported keys are written to STDOUT or to the file given with option
--output. This command is often used along with the option
--armor to allow for easy printing of the key for paper backup;
however the external tool paperkey
does a better job of
creating backups on paper. Note that exporting a secret key can be a
security risk if the exported keys are sent over an insecure channel.
The second form of the command has the special property to render the secret part of the primary key useless; this is a GNU extension to OpenPGP and other implementations can not be expected to successfully import such a key. Its intended use is in generating a full key with an additional signing subkey on a dedicated machine. This command then exports the key without the primary key to the main machine.
GnuPG may ask you to enter the passphrase for the key. This is required, because the internal protection method of the secret key is different from the one specified by the OpenPGP protocol.
--export-ssh-key
¶This command is used to export a key in the OpenSSH public key format. It requires the specification of one key by the usual means and exports the latest valid subkey which has an authentication capability to STDOUT or to the file given with option --output. That output can directly be added to ssh’s authorized_key file.
By specifying the key to export using a key ID or a fingerprint suffixed with an exclamation mark (!), a specific subkey or the primary key can be exported. This does not even require that the key has the authentication capability flag set.
--import
¶--fast-import
Import/merge keys. This adds the given keys to the keyring. The fast version is currently just a synonym.
There are a few other options which control how this command works. Most notable here is the --import-options merge-only option which does not insert new keys but does only the merging of new signatures, user-IDs and subkeys.
--receive-keys keyIDs
¶--recv-keys keyIDs
Import the keys with the given keyIDs from a keyserver.
--refresh-keys
¶Request updates from a keyserver for keys that already exist on the local keyring. This is useful for updating a key with the latest signatures, user IDs, etc. Calling this with no arguments will refresh the entire keyring.
--search-keys names
¶Search the keyserver for the given names. Multiple names given here will be joined together to create the search string for the keyserver. Note that keyservers search for names in a different and simpler way than gpg does. The best choice is to use a mail address. Due to data privacy reasons keyservers may even not even allow searching by user id or mail address and thus may only return results when being used with the --recv-key command to search by key fingerprint or keyid.
--fetch-keys URIs
¶Retrieve keys located at the specified URIs. Note that different installations of GnuPG may support different protocols (HTTP, FTP, LDAP, etc.). When using HTTPS the system provided root certificates are used by this command.
--update-trustdb
¶Do trust database maintenance. This command iterates over all keys and builds the Web of Trust. This is an interactive command because it may have to ask for the "ownertrust" values for keys. The user has to give an estimation of how far she trusts the owner of the displayed key to correctly certify (sign) other keys. GnuPG only asks for the ownertrust value if it has not yet been assigned to a key. Using the --edit-key menu, the assigned value can be changed at any time.
--check-trustdb
¶Do trust database maintenance without user interaction. From time to time the trust database must be updated so that expired keys or signatures and the resulting changes in the Web of Trust can be tracked. Normally, GnuPG will calculate when this is required and do it automatically unless --no-auto-check-trustdb is set. This command can be used to force a trust database check at any time. The processing is identical to that of --update-trustdb but it skips keys with a not yet defined "ownertrust".
For use with cron jobs, this command can be used together with --batch in which case the trust database check is done only if a check is needed. To force a run even in batch mode add the option --yes.
--export-ownertrust
¶Send the ownertrust values to STDOUT. This is useful for backup purposes as these values are the only ones which can’t be re-created from a corrupted trustdb. Example:
gpg --export-ownertrust > otrust.txt
--import-ownertrust
¶Update the trustdb with the ownertrust values stored in files
(or
STDIN if not given); existing values will be overwritten. In case of a
severely damaged trustdb and if you have a recent backup of the
ownertrust values (e.g. in the file otrust.txt), you may re-create
the trustdb using these commands:
cd ~/.gnupg rm trustdb.gpg gpg --import-ownertrust < otrust.txt
--rebuild-keydb-caches
¶When updating from version 1.0.6 to 1.0.7 this command should be used to create signature caches in the keyring. It might be handy in other situations too.
--print-md algo
¶--print-mds
Print message digest of algorithm algo for all given files or STDIN. With the second form (or a deprecated "*" for algo) digests for all available algorithms are printed.
--gen-random 0|1|2|16|30 count
¶Emit count random bytes of the given quality level 0, 1 or 2. If count is not given or zero, an endless sequence of random bytes will be emitted. If used with --armor the output will be base64 encoded. The special level 16 uses a quality level of 1 and outputs an endless stream of hex-encoded octets. The special level 30 outputs random as 30 zBase-32 characters.
--gen-prime mode bits
¶Use the source, Luke :-). The output format is subject to change with any release.
--enarmor
¶--dearmor
Pack or unpack an arbitrary input into/from an OpenPGP ASCII armor. This is a GnuPG extension to OpenPGP and in general not very useful. The --dearmor command can also be used to dearmor PEM armors.
--unwrap
¶This option modifies the command --decrypt to output the original message with the encryption layer removed. Thus the output will be an OpenPGP data structure which often means a signed OpenPGP message. Note that this option may or may not remove a compression layer which is often found beneath the encryption layer.
--tofu-policy {auto|good|unknown|bad|ask} keys
¶Set the TOFU policy for all the bindings associated with the specified keys. For more information about the meaning of the policies, see trust-model-tofu. The keys may be specified either by their fingerprint (preferred) or their keyid.
This section explains the main commands for key management.
--quick-generate-key user-id [algo [usage [expire]]]
¶--quick-gen-key
This is a simple command to generate a standard key with one user id. In contrast to --generate-key the key is generated directly without the need to answer a bunch of prompts. Unless the option --yes is given, the key creation will be canceled if the given user id already exists in the keyring.
If invoked directly on the console without any special options an answer to a “Continue?” style confirmation prompt is required. In case the user id already exists in the keyring a second prompt to force the creation of the key will show up.
If algo or usage are given, only the primary key is
created and no prompts are shown. To specify an expiration date but
still create a primary and subkey use “default” or
“future-default” for algo and “default” for usage.
For a description of these optional arguments see the command
--quick-add-key
. The usage accepts also the value
“cert” which can be used to create a certification only primary key;
the default is to a create certification and signing key.
The expire argument can be used to specify an expiration date for the key. Several formats are supported; commonly the ISO formats “YYYY-MM-DD” or “YYYYMMDDThhmmss” are used. To make the key expire in N seconds, N days, N weeks, N months, or N years use “seconds=N”, “Nd”, “Nw”, “Nm”, or “Ny” respectively. Not specifying a value, or using “-” results in a key expiring in a reasonable default interval. The values “never”, “none” can be used for no expiration date.
If this command is used with --batch,
--pinentry-mode has been set to loopback
, and one of
the passphrase options (--passphrase,
--passphrase-fd, or --passphrase-file) is used, the
supplied passphrase is used for the new key and the agent does not ask
for it. To create a key without any protection --passphrase ''
may be used.
To create an OpenPGP key from the keys available on the currently inserted smartcard, the special string “card” can be used for algo. If the card features an encryption and a signing key, gpg will figure them out and creates an OpenPGP key consisting of the usual primary key and one subkey. This works only with certain smartcards. Note that the interactive --full-gen-key command allows one to do the same but with greater flexibility in the selection of the smartcard keys.
Note that it is possible to create a primary key and a subkey using non-default algorithms by using “default” and changing the default parameters using the option --default-new-key-algo.
--quick-set-expire fpr expire [*|subfprs]
¶With two arguments given, directly set the expiration time of the
primary key identified by fpr to expire. To remove the
expiration time 0
can be used. With three arguments and the
third given as an asterisk, the expiration time of all non-revoked and
not yet expired subkeys are set to expire. With more than two
arguments and a list of fingerprints given for subfprs, all
non-revoked subkeys matching these fingerprints are set to
expire.
--quick-add-key fpr [algo [usage [expire]]]
¶Directly add a subkey to the key identified by the fingerprint fpr. Without the optional arguments an encryption subkey is added. If any of the arguments are given a more specific subkey is added.
algo may be any of the supported algorithms or curve names
given in the format as used by key listings. To use the default
algorithm the string “default” or “-” can be used. Supported
algorithms are “rsa”, “dsa”, “elg”, “ed25519”, “cv25519”,
and other ECC curves. For example the string “rsa” adds an RSA key
with the default key length; a string “rsa4096” requests that the
key length is 4096 bits. The string “future-default” is an alias
for the algorithm which will likely be used as default algorithm in
future versions of gpg. To list the supported ECC curves the command
gpg --with-colons --list-config curve
can be used.
Depending on the given algo the subkey may either be an encryption subkey or a signing subkey. If an algorithm is capable of signing and encryption and such a subkey is desired, a usage string must be given. This string is either “default” or “-” to keep the default or a comma delimited list (or space delimited list) of keywords: “sign” for a signing subkey, “auth” for an authentication subkey, and “encr” for an encryption subkey (“encrypt” can be used as alias for “encr”). The valid combinations depend on the algorithm.
The expire argument can be used to specify an expiration date for the key. Several formats are supported; commonly the ISO formats “YYYY-MM-DD” or “YYYYMMDDThhmmss” are used. To make the key expire in N seconds, N days, N weeks, N months, or N years use “seconds=N”, “Nd”, “Nw”, “Nm”, or “Ny” respectively. Not specifying a value, or using “-” results in a key expiring in a reasonable default interval. The values “never”, “none” can be used for no expiration date.
--quick-add-adsk fpr adskfpr
¶Directly add an Additional Decryption Subkey to the key identified by the fingerprint fpr. adskfpr is the fingerprint of another key’s encryption subkey. A subkey is commonly used here because by default a primary key has no encryption capability. Use the option --with-subkey-fingerprint with a list command to display the subkey fingerprints.
--generate-key
¶--gen-key
Generate a new key pair using the current default parameters. This is the standard command to create a new key. In addition to the key a revocation certificate is created and stored in the openpgp-revocs.d directory below the GnuPG home directory.
--full-generate-key
¶--full-gen-key
Generate a new key pair with dialogs for all options. This is an extended version of --generate-key.
There is also a feature which allows you to create keys in batch mode. See the manual section “Unattended key generation” on how to use this.
--generate-revocation name
¶--gen-revoke name
Generate a revocation certificate for the complete key. To only revoke a subkey or a key signature, use the --edit command.
This command merely creates the revocation certificate so that it can be used to revoke the key if that is ever needed. To actually revoke a key the created revocation certificate needs to be merged with the key to revoke. This is done by importing the revocation certificate using the --import command. Then the revoked key needs to be published, which is best done by sending the key to a keyserver (command --send-key) and by exporting (--export) it to a file which is then send to frequent communication partners.
--generate-designated-revocation name
¶--desig-revoke name
Generate a designated revocation certificate for a key. This allows a user (with the permission of the keyholder) to revoke someone else’s key.
--edit-key
¶Present a menu which enables you to do most of the key management related tasks. It expects the specification of a key on the command line.
Toggle selection of user ID or photographic user ID with index n.
Use *
to select all and 0
to deselect all.
Toggle selection of subkey with index n or key ID n.
Use *
to select all and 0
to deselect all.
Make a signature on key of user name
. If the key is not yet
signed by the default user (or the users given with -u), the program
displays the information of the key again, together with its
fingerprint and asks whether it should be signed. This question is
repeated for all users specified with
-u.
Same as "sign" but the signature is marked as non-exportable and will therefore never be used by others. This may be used to make keys valid only in the local environment.
Same as "sign" but the signature is marked as non-revocable and can therefore never be revoked.
Make a trust signature. This is a signature that combines the notions of certification (like a regular signature), and trust (like the "trust" command). It is generally useful in distinct communities or groups to implement the concept of a Trusted Introducer. For more information please read the sections “Trust Signature” and “Regular Expression” in RFC-4880.
Note that "l" (for local / non-exportable), "nr" (for non-revocable, and "t" (for trust) may be freely mixed and prefixed to "sign" to create a signature of any type desired.
If the option --only-sign-text-ids is specified, then any non-text based user ids (e.g., photo IDs) will not be selected for signing.
Delete a signature. Note that it is not possible to retract a signature,
once it has been send to the public (i.e. to a keyserver). In that case
you better use revsig
.
Revoke a signature. For every signature which has been generated by one of the secret keys, GnuPG asks whether a revocation certificate should be generated.
Check the signatures on all selected user IDs. With the extra
option selfsig
only self-signatures are shown.
Create an additional user ID.
Create a photographic user ID. This will prompt for a JPEG file that will be embedded into the user ID. Note that a very large JPEG will make for a very large key. Also note that some programs will display your JPEG unchanged (GnuPG), and some programs will scale it to fit in a dialog box (PGP).
Display the selected photographic user ID.
Delete a user ID or photographic user ID. Note that it is not
possible to retract a user id, once it has been send to the public
(i.e. to a keyserver). In that case you better use revuid
.
Revoke a user ID or photographic user ID.
Flag the current user id as the primary one, removes the primary user id flag from all other user ids and sets the timestamp of all affected self-signatures one second ahead. Note that setting a photo user ID as primary makes it primary over other photo user IDs, and setting a regular user ID as primary makes it primary over other regular user IDs.
Set a preferred keyserver for the specified user ID(s). This allows other users to know where you prefer they get your key from. See --keyserver-options honor-keyserver-url for more on how this works. Setting a value of "none" removes an existing preferred keyserver.
Set a name=value notation for the specified user ID(s). See --cert-notation for more on how this works. Setting a value of "none" removes all notations, setting a notation prefixed with a minus sign (-) removes that notation, and setting a notation name (without the =value) prefixed with a minus sign removes all notations with that name.
List preferences from the selected user ID. This shows the actual preferences, without including any implied preferences.
More verbose preferences listing for the selected user ID. This shows the preferences in effect by including the implied preferences of 3DES (cipher), SHA-1 (digest), and Uncompressed (compression) if they are not already included in the preference list. In addition, the preferred keyserver and signature notations (if any) are shown.
Set the list of user ID preferences to string for all (or just
the selected) user IDs. Calling setpref with no arguments sets the
preference list to the default (either built-in or set via
--default-preference-list), and calling setpref with "none"
as the argument sets an empty preference list. Use gpg
--version
to get a list of available algorithms. Note that while you
can change the preferences on an attribute user ID (aka "photo ID"),
GnuPG does not select keys via attribute user IDs so these preferences
will not be used by GnuPG. Note that an unattended version of this
command is available as --quick-update-pref.
When setting preferences, you should list the algorithms in the order which you’d like to see them used by someone else when encrypting a message to your key. If you don’t include 3DES, it will be automatically added at the end. Note that there are many factors that go into choosing an algorithm (for example, your key may not be the only recipient), and so the remote OpenPGP application being used to send to you may or may not follow your exact chosen order for a given message. It will, however, only choose an algorithm that is present on the preference list of every recipient key. See also the INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS section below.
Add a subkey to this key.
Generate a subkey on a card and add it to this key.
Transfer the selected secret subkey (or the primary key if no subkey has been selected) to a smartcard. The secret key in the keyring will be replaced by a stub if the key could be stored successfully on the card and you use the save command later. Only certain key types may be transferred to the card. A sub menu allows you to select on what card to store the key. Note that it is not possible to get that key back from the card - if the card gets broken your secret key will be lost unless you have a backup somewhere.
Restore the given file to a card. This command may be used to restore a backup key (as generated during card initialization) to a new card. In almost all cases this will be the encryption key. You should use this command only with the corresponding public key and make sure that the file given as argument is indeed the backup to restore. You should then select 2 to restore as encryption key. You will first be asked to enter the passphrase of the backup key and then for the Admin PIN of the card.
Transfer the selected secret subkey (or the primary key if no subkey has been selected) to TPM form. The secret key in the keyring will be replaced by the TPM representation of that key, which can only be read by the particular TPM that created it (so the keyfile now becomes locked to the laptop containing the TPM). Only certain key types may be transferred to the TPM (all TPM 2.0 systems are mandated to have the rsa2048 and nistp256 algorithms but newer TPMs may have more). Note that the key itself is not transferred into the TPM, merely encrypted by the TPM in-place, so if the keyfile is deleted, the key will be lost. Once transferred to TPM representation, the key file can never be converted back to non-TPM form and the key will die when the TPM does, so you should first have a backup on secure offline storage of the actual secret key file before conversion. It is essential to use the physical system TPM that you have rw permission on the TPM resource manager device (/dev/tpmrm0). Usually this means you must be a member of the tss group.
Remove a subkey (secondary key). Note that it is not possible to retract
a subkey, once it has been send to the public (i.e. to a keyserver). In
that case you better use revkey
. Also note that this only
deletes the public part of a key.
Revoke a subkey.
Change the key or subkey expiration time. If a subkey is selected, the expiration time of this subkey will be changed. With no selection, the key expiration of the primary key is changed.
Change the owner trust value for the key. This updates the trust-db immediately and no save is required.
Disable or enable an entire key. A disabled key can not normally be used for encryption.
Add a designated revoker to the key. This takes one optional argument: "sensitive". If a designated revoker is marked as sensitive, it will not be exported by default (see export-options).
Add an Additional Decryption Subkey. The user is asked to enter the fingerprint of another encryption subkey. Note that the exact fingerprint of another key’s encryption subkey needs to be entered. This is because commonly the primary key has no encryption capability. Use the option --with-subkey-fingerprint with a list command to display the subkey fingerprints.
Change the passphrase of the secret key.
This is dummy command which exists only for backward compatibility.
Compact (by removing all signatures except the selfsig) any user ID that is no longer usable (e.g. revoked, or expired). Then, remove any signatures that are not usable by the trust calculations. Specifically, this removes any signature that does not validate, any signature that is superseded by a later signature, revoked signatures, and signatures issued by keys that are not present on the keyring.
Make the key as small as possible. This removes all signatures from each user ID except for the most recent self-signature.
Change the usage flags (capabilities) of the primary key or of subkeys. These usage flags (e.g. Certify, Sign, Authenticate, Encrypt) are set during key creation. Sometimes it is useful to have the opportunity to change them (for example to add Authenticate) after they have been created. Please take care when doing this; the allowed usage flags depend on the key algorithm.
Add cross-certification signatures to signing subkeys that may not currently have them. Cross-certification signatures protect against a subtle attack against signing subkeys. See --require-cross-certification. All new keys generated have this signature by default, so this command is only useful to bring older keys up to date.
Save all changes to the keyring and quit.
Quit the program without updating the keyring.
The listing shows you the key with its secondary keys and all user IDs. The primary user ID is indicated by a dot, and selected keys or user IDs are indicated by an asterisk. The trust value is displayed with the primary key: "trust" is the assigned owner trust and "validity" is the calculated validity of the key. Validity values are also displayed for all user IDs. For possible values of trust, see trust-values.
--sign-key name
¶Signs a public key with your secret key. This is a shortcut version of the subcommand "sign" from --edit-key.
--lsign-key name
¶Signs a public key with your secret key but marks it as non-exportable. This is a shortcut version of the subcommand "lsign" from --edit-key.
--quick-sign-key fpr [names]
¶--quick-lsign-key fpr [names]
Directly sign a key from the passphrase without any further user interaction. The fpr must be the verified primary fingerprint of a key in the local keyring. If no names are given, all useful user ids are signed; with given [names] only useful user ids matching one of these names are signed. By default, or if a name is prefixed with a ’*’, a case insensitive substring match is used. If a name is prefixed with a ’=’ a case sensitive exact match is done.
The command --quick-lsign-key marks the signatures as non-exportable. If such a non-exportable signature already exists the --quick-sign-key turns it into a exportable signature. If you need to update an existing signature, for example to add or change notation data, you need to use the option --force-sign-key.
This command uses reasonable defaults and thus does not provide the full flexibility of the "sign" subcommand from --edit-key. Its intended use is to help unattended key signing by utilizing a list of verified fingerprints.
--quick-add-uid user-id new-user-id
¶This command adds a new user id to an existing key. In contrast to
the interactive sub-command adduid
of --edit-key the
new-user-id is added verbatim with only leading and trailing
white space removed, it is expected to be UTF-8 encoded, and no checks
on its form are applied.
--quick-revoke-uid user-id user-id-to-revoke
¶This command revokes a user ID on an existing key. It cannot be used
to revoke the last user ID on key (some non-revoked user ID must
remain), with revocation reason “User ID is no longer valid”. If
you want to specify a different revocation reason, or to supply
supplementary revocation text, you should use the interactive
sub-command revuid
of --edit-key.
--quick-revoke-sig fpr signing-fpr [names]
¶This command revokes the key signatures made by signing-fpr from the key specified by the fingerprint fpr. With names given only the signatures on user ids of the key matching any of the given names are affected (see --quick-sign-key). If a revocation already exists a notice is printed instead of creating a new revocation; no error is returned in this case. Note that key signature revocations may be superseded by a newer key signature and in turn again revoked.
--quick-set-primary-uid user-id primary-user-id
¶This command sets or updates the primary user ID flag on an existing key. user-id specifies the key and primary-user-id the user ID which shall be flagged as the primary user ID. The primary user ID flag is removed from all other user ids and the timestamp of all affected self-signatures is set one second ahead.
--quick-update-pref user-id
¶This command updates the preference list of the key to the current default value (either built-in or set via --default-preference-list). This is the unattended version of of using "setpref" in the --key-edit menu without giving a list. Note that you can show the preferences in a key listing by using --list-options show-pref or --list-options show-pref-verbose. You should also re-distribute updated keys to your peers.
--change-passphrase user-id
¶--passwd user-id
Change the passphrase of the secret key belonging to the certificate
specified as user-id. This is a shortcut for the sub-command
passwd
of the --edit-key menu. When using together with the
option --dry-run this will not actually change the passphrase
but check that the current passphrase is correct.
gpg
features a bunch of options to control the exact
behaviour and to change the default configuration.
Long options can be put in an options file (default "~/.gnupg/gpg.conf"). Short option names will not work - for example, "armor" is a valid option for the options file, while "a" is not. Do not write the 2 dashes, but simply the name of the option and any required arguments. Lines with a hash (’#’) as the first non-white-space character are ignored. Commands may be put in this file too, but that is not generally useful as the command will execute automatically with every execution of gpg.
Please remember that option parsing stops as soon as a non-option is encountered, you can explicitly stop parsing by using the special option --.
These options are used to change the configuration and most of them are usually found in the option file.
--default-key name
¶Use name as the default key to sign with. It is suggested to use a fingerprint or at least a long keyID for name. If this option is not used, the default key is the first key found in the secret keyring. Note that -u or --local-user overrides this option. This option may be given multiple times. In this case, the last key for which a secret key is available is used. If there is no secret key available for any of the specified values, GnuPG will not emit an error message but continue as if this option wasn’t given.
--default-recipient name
¶Use name as default recipient if option --recipient is not used and don’t ask if this is a valid one. name must be non-empty and it is suggested to use a fingerprint for name.
--default-recipient-self
¶Use the default key as default recipient if option --recipient is not used and don’t ask if this is a valid one. The default key is the first one from the secret keyring or the one set with --default-key.
--no-default-recipient
¶Reset --default-recipient and --default-recipient-self. Should not be used in an option file.
-v, --verbose
¶Give more information during processing. If used twice, the input data is listed in detail.
--no-verbose
¶Reset verbose level to 0. Should not be used in an option file.
-q, --quiet
¶Try to be as quiet as possible. Should not be used in an option file.
--batch
¶--no-batch
Use batch mode. Never ask, do not allow interactive commands. --no-batch disables this option. Note that even with a filename given on the command line, gpg might still need to read from STDIN (in particular if gpg figures that the input is a detached signature and no data file has been specified). Thus if you do not want to feed data via STDIN, you should connect STDIN to /dev/null.
It is highly recommended to use this option along with the options
--status-fd and --with-colons for any unattended use of
gpg
. Should not be used in an option file.
--no-tty
¶Make sure that the TTY (terminal) is never used for any output. This option is needed in some cases because GnuPG sometimes prints warnings to the TTY even if --batch is used.
--yes
¶Assume "yes" on most questions. Should not be used in an option file.
--no
¶Assume "no" on most questions. Should not be used in an option file.
--list-filter {select=expr}
¶A list filter can be used to output only certain keys during key listing commands. For the available property names, see the description of --import-filter.
--list-options parameters
¶This is a space or comma delimited string that gives options used when listing keys and signatures (that is, --list-keys, --check-signatures, --list-public-keys, --list-secret-keys, and the --edit-key functions). Options can be prepended with a no- (after the two dashes) to give the opposite meaning. The options are:
Causes --list-keys, --check-signatures, --list-public-keys, and --list-secret-keys to display any photo IDs attached to the key. Defaults to no. See also --photo-viewer. Does not work with --with-colons: see --attribute-fd for the appropriate way to get photo data for scripts and other frontends.
Show usage information for keys and subkeys in the standard key
listing. This is a list of letters indicating the allowed usage for a
key (E
=encryption, S
=signing, C
=certification,
A
=authentication). Defaults to yes.
Show policy URLs in the --check-signatures listings. Defaults to no.
Show all, IETF standard, or user-defined signature notations in the --check-signatures listings. Defaults to no.
Show any preferred keyserver URL in the --check-signatures listings. Defaults to no.
Display the calculated validity of user IDs during key listings. Defaults to yes.
Show revoked and expired user IDs in key listings. Defaults to no.
Show revoked and expired subkeys in key listings. Defaults to no.
Show key signature made using weak or unsupported algorithms.
Display the keyring name at the head of key listings to show which keyring a given key resides on. Defaults to no.
Show signature expiration dates (if any) during --check-signatures listings. Defaults to no.
Include signature subpackets in the key listing. This option can take an optional argument list of the subpackets to list. If no argument is passed, list all subpackets. Defaults to no. This option is only meaningful when using --with-colons along with --check-signatures.
For each user-id which has a valid mail address print only the fingerprint followed by the mail address.
With –list-sigs and –check-sigs sort the signatures by keyID and creation time to make it easier to view the history of these signatures. The self-signature is also listed before other signatures. Defaults to yes.
--verify-options parameters
¶This is a space or comma delimited string that gives options used when verifying signatures. Options can be prepended with a ‘no-’ to give the opposite meaning. The options are:
Display any photo IDs present on the key that issued the signature. Defaults to no. See also --photo-viewer.
Show policy URLs in the signature being verified. Defaults to yes.
Show all, IETF standard, or user-defined signature notations in the signature being verified. Defaults to IETF standard.
Show any preferred keyserver URL in the signature being verified. Defaults to yes.
Display the calculated validity of the user IDs on the key that issued the signature. Defaults to yes.
Show revoked and expired user IDs during signature verification. Defaults to no.
Show only the primary user ID during signature verification. That is all the AKA lines as well as photo Ids are not shown with the signature verification status.
--enable-large-rsa
¶--disable-large-rsa
With –generate-key and –batch, enable the creation of RSA secret keys as large as 8192 bit. Note: 8192 bit is more than is generally recommended. These large keys don’t significantly improve security, but they are more expensive to use, and their signatures and certifications are larger. This option is only available if the binary was build with large-secmem support.
--enable-dsa2
¶--disable-dsa2
Enable hash truncation for all DSA keys even for old DSA Keys up to 1024 bit. This is also the default with --openpgp. Note that older versions of GnuPG also required this flag to allow the generation of DSA larger than 1024 bit.
--photo-viewer string
¶This is the command line that should be run to view a photo ID. "%i" will be expanded to a filename containing the photo. "%I" does the same, except the file will not be deleted once the viewer exits. Other flags are "%k" for the key ID, "%K" for the long key ID, "%f" for the key fingerprint, "%t" for the extension of the image type (e.g. "jpg"), "%T" for the MIME type of the image (e.g. "image/jpeg"), "%v" for the single-character calculated validity of the image being viewed (e.g. "f"), "%V" for the calculated validity as a string (e.g. "full"), "%U" for a base32 encoded hash of the user ID, and "%%" for an actual percent sign. If neither %i or %I are present, then the photo will be supplied to the viewer on standard input.
On Unix the default viewer is
xloadimage -fork -quiet -title 'KeyID 0x%k' STDIN
with a fallback to
display -title 'KeyID 0x%k' %i
and finally to
xdg-open %i
.
On Windows
!ShellExecute 400 %i
is used; here the command is a meta
command to use that API call followed by a wait time in milliseconds
which is used to give the viewer time to read the temporary image file
before gpg deletes it again. Note that if your image viewer program
is not secure, then executing it from gpg does not make it secure.
--exec-path string
¶Sets a list of directories to search for photo viewers If not provided
photo viewers use the PATH
environment variable.
--keyring file
¶Add file to the current list of keyrings. If file begins with a tilde and a slash, these are replaced by the $HOME directory. If the filename does not contain a slash, it is assumed to be in the GnuPG home directory ("~/.gnupg" unless --homedir or $GNUPGHOME is used).
Note that this adds a keyring to the current list. If the intent is to use the specified keyring alone, use --keyring along with --no-default-keyring.
If the option --no-keyring has been used no keyrings will be used at all.
Note that if the option use-keyboxd is enabled in common.conf, no keyrings are used at all and keys are all maintained by the keyboxd process in its own database.
--primary-keyring file
¶This is a varian of --keyring and designates file as the primary public keyring. This means that newly imported keys (via --import or keyserver --recv-from) will go to this keyring.
--secret-keyring file
¶This is an obsolete option and ignored. All secret keys are stored in the private-keys-v1.d directory below the GnuPG home directory.
--trustdb-name file
¶Use file instead of the default trustdb. If file begins with a tilde and a slash, these are replaced by the $HOME directory. If the filename does not contain a slash, it is assumed to be in the GnuPG home directory (~/.gnupg if --homedir or $GNUPGHOME is not used).
--homedir dir
¶Set the name of the home directory to dir. If this option is not
used, the home directory defaults to ~/.gnupg. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable GNUPGHOME
or
(on Windows systems) by means of the Registry entry
HKCU\Software\GNU\GnuPG:HomeDir.
On Windows systems it is possible to install GnuPG as a portable application. In this case only this command line option is considered, all other ways to set a home directory are ignored.
--display-charset name
¶Set the name of the native character set. This is used to convert some informational strings like user IDs to the proper UTF-8 encoding. Note that this has nothing to do with the character set of data to be encrypted or signed; GnuPG does not recode user-supplied data. If this option is not used, the default character set is determined from the current locale. A verbosity level of 3 shows the chosen set. This option should not be used on Windows. Valid values for name are:
--utf8-strings
¶--no-utf8-strings
Assume that command line arguments are given as UTF-8 strings. The default (--no-utf8-strings) is to assume that arguments are encoded in the character set as specified by --display-charset. These options affect all following arguments. Both options may be used multiple times. This option should not be used in an option file.
This option has no effect on Windows. There the internal used UTF-8 encoding is translated for console input and output. The command line arguments are expected as Unicode and translated to UTF-8. Thus when calling this program from another, make sure to use the Unicode version of CreateProcess.
--options file
¶Read options from file and do not try to read them from the default options file in the homedir (see --homedir). This option is ignored if used in an options file.
--no-options
¶Shortcut for --options /dev/null. This option is detected before an attempt to open an option file. Using this option will also prevent the creation of a ~/.gnupg homedir.
-z n
¶--compress-level n
--bzip2-compress-level n
--no-compress
Set compression level to n for the ZIP and ZLIB compression algorithms. The default is to use the default compression level of zlib (normally 6). --bzip2-compress-level sets the compression level for the BZIP2 compression algorithm (defaulting to 6 as well). This is a different option from --compress-level since BZIP2 uses a significant amount of memory for each additional compression level.
Option -z sets both. A value of 0 for n disables compression. A value of -1 forces compression using the default level. Option --no-compress is identical to -z0.
Except for the --store command compression is always used
unless gpg
detects that the input is already compressed. To
inhibit the use of compression use -z0 or
--no-compress; to force compression use -z-1 or
option z with another compression level than the default as
indicated by -1. Note that this overriding of the default deection
works only with z and not with the long variant of this
option.
--bzip2-decompress-lowmem
¶Use a different decompression method for BZIP2 compressed files. This alternate method uses a bit more than half the memory, but also runs at half the speed. This is useful under extreme low memory circumstances when the file was originally compressed at a high --bzip2-compress-level.
--mangle-dos-filenames
¶--no-mangle-dos-filenames
Older version of Windows cannot handle filenames with more than one dot. --mangle-dos-filenames causes GnuPG to replace (rather than add to) the extension of an output filename to avoid this problem. This option is off by default and has no effect on non-Windows platforms.
--ask-cert-level
¶--no-ask-cert-level
When making a key signature, prompt for a certification level. If this option is not specified, the certification level used is set via --default-cert-level. See --default-cert-level for information on the specific levels and how they are used. --no-ask-cert-level disables this option. This option defaults to no.
--default-cert-level n
¶The default to use for the check level when signing a key.
0 means you make no particular claim as to how carefully you verified the key.
1 means you believe the key is owned by the person who claims to own it but you could not, or did not verify the key at all. This is useful for a "persona" verification, where you sign the key of a pseudonymous user.
2 means you did casual verification of the key. For example, this could mean that you verified the key fingerprint and checked the user ID on the key against a photo ID.
3 means you did extensive verification of the key. For example, this could mean that you verified the key fingerprint with the owner of the key in person, and that you checked, by means of a hard to forge document with a photo ID (such as a passport) that the name of the key owner matches the name in the user ID on the key, and finally that you verified (by exchange of email) that the email address on the key belongs to the key owner.
Note that the examples given above for levels 2 and 3 are just that: examples. In the end, it is up to you to decide just what "casual" and "extensive" mean to you.
This option defaults to 0 (no particular claim).
--min-cert-level
¶When building the trust database, treat any signatures with a certification level below this as invalid. Defaults to 2, which disregards level 1 signatures. Note that level 0 "no particular claim" signatures are always accepted.
--trusted-key long key ID or fingerprint
¶Assume that the specified key (which should be given as fingerprint) is as trustworthy as one of your own secret keys. This option is useful if you don’t want to keep your secret keys (or one of them) online but still want to be able to check the validity of a given recipient’s or signator’s key. If the given key is not locally available but an LDAP keyserver is configured the missing key is imported from that server. The value "none" is explicitly allowed to distinguish between the use of any trusted-key option and no use of this option at all (e.g. due to the --no-options option).
--add-desig-revoker [sensitive:]fingerprint
¶Add the key specified by fingerprint as a designated revoker to newly created keys. If the fingerprint is prefixed with the keyword “sensitive:” that info is normally not exported wit the key. This option may be given several time to add more than one designated revoker. If the keyword “clear” is used instead of a fingerprint, all designated options previously encountered are discarded. Designated revokers are marked on the key as non-revocable. Note that a designated revoker specified using a parameter file will also be added to the key.
--trust-model {pgp|classic|tofu|tofu+pgp|direct|always|auto}
¶Set what trust model GnuPG should follow. The models are:
This is the Web of Trust combined with trust signatures as used in PGP 5.x and later. This is the default trust model when creating a new trust database.
This is the standard Web of Trust as introduced by PGP 2.
TOFU stands for Trust On First Use. In this experimental trust model, the first time a key is seen, it is memorized. If later another key with a user id with the same email address is seen, both keys are marked as suspect. In that case, the next time either is used, a warning is displayed describing the conflict, why it might have occurred (either the user generated a new key and failed to cross sign the old and new keys, the key is forgery, or a man-in-the-middle attack is being attempted), and the user is prompted to manually confirm the validity of the key in question.
Because a potential attacker is able to control the email address and thereby circumvent the conflict detection algorithm by using an email address that is similar in appearance to a trusted email address, whenever a message is verified, statistics about the number of messages signed with the key are shown. In this way, a user can easily identify attacks using fake keys for regular correspondents.
When compared with the Web of Trust, TOFU offers significantly weaker security guarantees. In particular, TOFU only helps ensure consistency (that is, that the binding between a key and email address doesn’t change). A major advantage of TOFU is that it requires little maintenance to use correctly. To use the web of trust properly, you need to actively sign keys and mark users as trusted introducers. This is a time-consuming process and anecdotal evidence suggests that even security-conscious users rarely take the time to do this thoroughly and instead rely on an ad-hoc TOFU process.
In the TOFU model, policies are associated with bindings between keys and email addresses (which are extracted from user ids and normalized). There are five policies, which can be set manually using the --tofu-policy option. The default policy can be set using the --tofu-default-policy option.
The TOFU policies are: auto
, good
, unknown
,
bad
and ask
. The auto
policy is used by
default (unless overridden by --tofu-default-policy) and
marks a binding as marginally trusted. The good
,
unknown
and bad
policies mark a binding as fully
trusted, as having unknown trust or as having trust never,
respectively. The unknown
policy is useful for just using
TOFU to detect conflicts, but to never assign positive trust to a
binding. The final policy, ask
prompts the user to indicate
the binding’s trust. If batch mode is enabled (or input is
inappropriate in the context), then the user is not prompted and the
undefined
trust level is returned.
This experimental trust model combines TOFU with the Web of Trust.
This is done
by computing the trust level for each model and then taking the
maximum trust level where the trust levels are ordered as follows:
unknown < undefined < marginal < fully < ultimate < expired <
never
.
By setting --tofu-default-policy=unknown, this model can be used to implement the web of trust with TOFU’s conflict detection algorithm, but without its assignment of positive trust values, which some security-conscious users don’t like.
Key validity is set directly by the user and not calculated via the Web of Trust. This model is solely based on the key and does not distinguish user IDs. Note that when changing to another trust model the trust values assigned to a key are transformed into ownertrust values, which also indicate how you trust the owner of the key to sign other keys.
Skip key validation and assume that used keys are always fully valid. You generally won’t use this unless you are using some external validation scheme. This option also suppresses the "[uncertain]" tag printed with signature checks when there is no evidence that the user ID is bound to the key. Note that this trust model still does not allow the use of expired, revoked, or disabled keys.
Select the trust model depending on whatever the internal trust database says. This is the default model if such a database already exists. Note that a tofu trust model is not considered here and must be enabled explicitly.
--always-trust
¶Identical to --trust-model always.
--assert-signer fpr_or_file
¶This option checks whether at least one valid signature on a file has been made with the specified key. The key is either specified as a fingerprint or a file listing fingerprints. The fingerprint must be given or listed in compact format (no colons or spaces in between). This option can be given multiple times and each fingerprint is checked against the signing key as well as the corresponding primary key. If fpr_or_file specifies a file, empty lines are ignored as well as all lines starting with a hash sign. With this option gpg is guaranteed to return with an exit code of 0 if and only if a signature has been encountered, is valid, and the key matches one of the fingerprints given by this option.
--assert-pubkey-algo algolist
¶During data signature verification this options checks whether the used public key algorithm matches the algorithms given by algolist. This option can be given multiple times to concatenate more algorithms to the list; the delimiter of the list are either commas or spaces.
The algorithm names given in the list may either be verbatim names like "ed25519" with an optional leading single equal sign, or being prefixed with ">", ">=", "<=", or "<". That prefix operator is applied to the number part of the algorithm name; for example 2048 in "rsa2048" or 384 in "brainpoolP384r1". If the the leading non-digits in the name matches, the prefix operator is used to compare the number part, a trailing suffix is ignored in this case. For example an algorithm list ">rsa3000, >=brainpool384r1, =ed25519" allows RSA signatures with more that 3000 bits, Brainpool curves 384 and 512, and the ed25519 algorithm.
With this option gpg (and also gpgv) is guaranteed to return with an exit code of 0 if and only if all valid signatures on data are made using a matching algorithm from the given list.
--auto-key-locate mechanisms
¶--no-auto-key-locate
GnuPG can automatically locate and retrieve keys as needed using this option. This happens when encrypting to an email address (in the "user@example.com" form), and there are no "user@example.com" keys on the local keyring. This option takes any number of the mechanisms listed below, in the order they are to be tried. Instead of listing the mechanisms as comma delimited arguments, the option may also be given several times to add more mechanism. The option --no-auto-key-locate or the mechanism "clear" resets the list. The default is "local,wkd".
Locate a key using DNS CERT, as specified in RFC-4398.
Locate a key using DANE, as specified in draft-ietf-dane-openpgpkey-05.txt.
Locate a key using the Web Key Directory protocol.
Using DNS Service Discovery, check the domain in question for any LDAP keyservers to use. If this fails, attempt to locate the key using the PGP Universal method of checking ‘ldap://keys.(thedomain)’.
Locate the key using the Active Directory (Windows only). This method also allows one to search by fingerprint using the command --locate-external-key. Note that this mechanism is actually a shortcut for the mechanism ‘keyserver’ but using "ldap:///" as the keyserver.
Locate a key using a keyserver. This method also allows one to search by fingerprint using the command --locate-external-key if any of the configured keyservers is an LDAP server.
In addition, a keyserver URL as used in the dirmngr
configuration may be used here to query that particular keyserver.
This method also allows one to search by fingerprint using the command
--locate-external-key if the URL specifies an LDAP server.
Locate the key using the local keyrings. This mechanism allows the user to select the order a local key lookup is done. Thus using ‘--auto-key-locate local’ is identical to --no-auto-key-locate.
This flag disables the standard local key lookup, done before any of the
mechanisms defined by the --auto-key-locate are tried. The
position of this mechanism in the list does not matter. It is not
required if local
is also used.
Clear all defined mechanisms. This is useful to override
mechanisms given in a config file. Note that a nodefault
in
mechanisms will also be cleared unless it is given after the
clear
.
--auto-key-import
¶--no-auto-key-import
This is an offline mechanism to get a missing key for signature verification and for later encryption to this key. If this option is enabled and a signature includes an embedded key, that key is used to verify the signature and on verification success the key is imported. The default is --no-auto-key-import.
On the sender (signing) site the option --include-key-block needs to be used to put the public part of the signing key as “Key Block subpacket” into the signature.
--auto-key-retrieve
¶--no-auto-key-retrieve
These options enable or disable the automatic retrieving of keys from a keyserver when verifying signatures made by keys that are not on the local keyring. The default is --no-auto-key-retrieve.
The order of methods tried to lookup the key is:
1. If the option --auto-key-import is set and the signatures includes an embedded key, that key is used to verify the signature and on verification success that key is imported.
2. If a preferred keyserver is specified in the signature and the option honor-keyserver-url is active (which is not the default), that keyserver is tried. Note that the creator of the signature uses the option --sig-keyserver-url to specify the preferred keyserver for data signatures.
3. If the signature has the Signer’s UID set (e.g. using --sender while creating the signature) a Web Key Directory (WKD) lookup is done. This is the default configuration but can be disabled by removing WKD from the auto-key-locate list or by using the option --disable-signer-uid.
4. If any keyserver is configured and the Issuer Fingerprint is part of the signature (since GnuPG 2.1.16), the configured keyservers are tried.
Note that this option makes a "web bug" like behavior possible. Keyserver or Web Key Directory operators can see which keys you request, so by sending you a message signed by a brand new key (which you naturally will not have on your local keyring), the operator can tell both your IP address and the time when you verified the signature.
--keyid-format {none|short|0xshort|long|0xlong}
¶Select how to display key IDs. "none" does not show the key ID at all but shows the fingerprint in a separate line. "short" is the traditional 8-character key ID. "long" is the more accurate (but less convenient) 16-character key ID. Add an "0x" to either to include an "0x" at the beginning of the key ID, as in 0x99242560. Note that this option is ignored if the option --with-colons is used.
--keyserver name
¶This option is deprecated - please use the --keyserver in dirmngr.conf instead.
Use name as your keyserver. This is the server that --receive-keys, --send-keys, and --search-keys will communicate with to receive keys from, send keys to, and search for keys on. The format of the name is a URI: ‘scheme:[//]keyservername[:port]’ The scheme is the type of keyserver: "hkp"/"hkps" for the HTTP (or compatible) keyservers or "ldap"/"ldaps" for the LDAP keyservers. Note that your particular installation of GnuPG may have other keyserver types available as well. Keyserver schemes are case-insensitive.
Most keyservers synchronize with each other, so there is generally no
need to send keys to more than one server. The keyserver
hkp://keys.gnupg.net
uses round robin DNS to give a different
keyserver each time you use it.
--keyserver-options {name=value}
¶This is a space or comma delimited string that gives options for the keyserver. Options can be prefixed with a ‘no-’ to give the opposite meaning. Valid import-options or export-options may be used here as well to apply to importing (--recv-key) or exporting (--send-key) a key from a keyserver. While not all options are available for all keyserver types, some common options are:
When searching for a key with --search-keys, include keys that are marked on the keyserver as revoked. Note that not all keyservers differentiate between revoked and unrevoked keys, and for such keyservers this option is meaningless. Note also that most keyservers do not have cryptographic verification of key revocations, and so turning this option off may result in skipping keys that are incorrectly marked as revoked.
When searching for a key with --search-keys, include keys that are marked on the keyserver as disabled. Note that this option is not used with HKP keyservers.
This is an obsolete alias for the option auto-key-retrieve. Please do not use it; it will be removed in future versions..
When using --refresh-keys, if the key in question has a preferred keyserver URL, then use that preferred keyserver to refresh the key from. In addition, if auto-key-retrieve is set, and the signature being verified has a preferred keyserver URL, then use that preferred keyserver to fetch the key from. Note that this option introduces a "web bug": The creator of the key can see when the keys is refreshed. Thus this option is not enabled by default.
When receiving a key, include subkeys as potential targets. Note that this option is not used with HKP keyservers, as they do not support retrieving keys by subkey id.
These options have no more function since GnuPG 2.1. Use the
dirmngr
configuration options instead.
The default list of options is: "self-sigs-only, import-clean, repair-keys, repair-pks-subkey-bug, export-attributes". However, if the actual used source is an LDAP server "no-self-sigs-only" is assumed unless "self-sigs-only" has been explicitly configured.
--completes-needed n
¶Number of completely trusted users to introduce a new key signer (defaults to 1).
--marginals-needed n
¶Number of marginally trusted users to introduce a new key signer (defaults to 3)
--tofu-default-policy {auto|good|unknown|bad|ask}
¶The default TOFU policy (defaults to auto
). For more
information about the meaning of this option, see trust-model-tofu.
--max-cert-depth n
¶Maximum depth of a certification chain (default is 5).
--no-sig-cache
¶Do not cache the verification status of key signatures. Caching gives a much better performance in key listings. However, if you suspect that your public keyring is not safe against write modifications, you can use this option to disable the caching. It probably does not make sense to disable it because all kind of damage can be done if someone else has write access to your public keyring.
--auto-check-trustdb
¶--no-auto-check-trustdb
If GnuPG feels that its information about the Web of Trust has to be updated, it automatically runs the --check-trustdb command internally. This may be a time consuming process. --no-auto-check-trustdb disables this option.
--use-agent
¶--no-use-agent
This is dummy option. gpg
always requires the agent.
--gpg-agent-info
¶This is dummy option. It has no effect when used with gpg
.
--agent-program file
¶Specify an agent program to be used for secret key operations. The
default value is determined by running gpgconf
with the
option --list-dirs. Note that the pipe symbol (|
) is
used for a regression test suite hack and may thus not be used in the
file name.
--dirmngr-program file
¶Specify a dirmngr program to be used for keyserver access. The default value is /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/bin/dirmngr.
--disable-dirmngr
Entirely disable the use of the Dirmngr.
--no-autostart
¶Do not start the gpg-agent or the dirmngr if it has not yet been
started and its service is required. This option is mostly useful on
machines where the connection to gpg-agent has been redirected to
another machines. If dirmngr is required on the remote machine, it
may be started manually using gpgconf --launch dirmngr
.
--lock-once
¶Lock the databases the first time a lock is requested and do not release the lock until the process terminates.
--lock-multiple
¶Release the locks every time a lock is no longer needed. Use this to override a previous --lock-once from a config file.
--lock-never
¶Disable locking entirely. This option should be used only in very special environments, where it can be assured that only one process is accessing those files. A bootable floppy with a stand-alone encryption system will probably use this. Improper usage of this option may lead to data and key corruption.
--exit-on-status-write-error
¶This option will cause write errors on the status FD to immediately terminate the process. That should in fact be the default but it never worked this way and thus we need an option to enable this, so that the change won’t break applications which close their end of a status fd connected pipe too early. Using this option along with --enable-progress-filter may be used to cleanly cancel long running gpg operations.
--limit-card-insert-tries n
¶With n greater than 0 the number of prompts asking to insert a smartcard gets limited to N-1. Thus with a value of 1 gpg won’t at all ask to insert a card if none has been inserted at startup. This option is useful in the configuration file in case an application does not know about the smartcard support and waits ad infinitum for an inserted card.
--no-random-seed-file
¶GnuPG uses a file to store its internal random pool over invocations. This makes random generation faster; however sometimes write operations are not desired. This option can be used to achieve that with the cost of slower random generation.
--no-greeting
¶Suppress the initial copyright message.
--no-secmem-warning
¶Suppress the warning about "using insecure memory".
--no-permission-warning
¶Suppress the warning about unsafe file and home directory (--homedir) permissions. Note that the permission checks that GnuPG performs are not intended to be authoritative, but rather they simply warn about certain common permission problems. Do not assume that the lack of a warning means that your system is secure.
Note that the warning for unsafe --homedir permissions cannot be suppressed in the gpg.conf file, as this would allow an attacker to place an unsafe gpg.conf file in place, and use this file to suppress warnings about itself. The --homedir permissions warning may only be suppressed on the command line.
--require-secmem
¶--no-require-secmem
Refuse to run if GnuPG cannot get secure memory. Defaults to no (i.e. run, but give a warning).
--require-cross-certification
¶--no-require-cross-certification
When verifying a signature made from a subkey, ensure that the cross
certification "back signature" on the subkey is present and valid. This
protects against a subtle attack against subkeys that can sign.
Defaults to --require-cross-certification for
gpg
.
--expert
¶--no-expert
Allow the user to do certain nonsensical or "silly" things like signing an expired or revoked key, or certain potentially incompatible things like generating unusual key types. This also disables certain warning messages about potentially incompatible actions. As the name implies, this option is for experts only. If you don’t fully understand the implications of what it allows you to do, leave this off. --no-expert disables this option.
--armor
¶-a
Create ASCII armored output. The default is to create the binary OpenPGP format.
--no-armor
¶Assume the input data is not in ASCII armored format.
--output file
¶-o file
Write output to file. To write to stdout use -
as the
filename.
--max-output n
¶This option sets a limit on the number of bytes that will be generated when processing a file. Since OpenPGP supports various levels of compression, it is possible that the plaintext of a given message may be significantly larger than the original OpenPGP message. While GnuPG works properly with such messages, there is often a desire to set a maximum file size that will be generated before processing is forced to stop by the OS limits. Defaults to 0, which means "no limit".
--chunk-size n
¶The AEAD encryption mode encrypts the data in chunks so that a receiving side can check for transmission errors or tampering at the end of each chunk and does not need to delay this until all data has been received. The used chunk size is 2^n byte. The lowest allowed value for n is 6 (64 byte) and the largest is the default of 22 which creates chunks not larger than 4 MiB.
--input-size-hint n
¶This option can be used to tell GPG the size of the input data in bytes. n must be a positive base-10 number. This option is only useful if the input is not taken from a file. GPG may use this hint to optimize its buffer allocation strategy. It is also used by the --status-fd line “PROGRESS” to provide a value for “total” if that is not available by other means.
--key-origin string[,url]
¶gpg can track the origin of a key. Certain origins are implicitly known (e.g. keyserver, web key directory) and set. For a standard import the origin of the keys imported can be set with this option. To list the possible values use "help" for string. Some origins can store an optional url argument. That URL can appended to string after a comma.
--import-options parameters
¶This is a space or comma delimited string that gives options for importing keys. Options can be prepended with a ‘no-’ to give the opposite meaning. The options are:
Allow importing key signatures marked as "local". This is not generally useful unless a shared keyring scheme is being used. Defaults to no.
Normally possible still existing ownertrust values of a key are cleared if a key is imported. This is in general desirable so that a formerly deleted key does not automatically gain an ownertrust values merely due to import. On the other hand it is sometimes necessary to re-import a trusted set of keys again but keeping already assigned ownertrust values. This can be achieved by using this option.
During import, attempt to repair the damage caused by the PKS keyserver bug (pre version 0.9.6) that mangles keys with multiple subkeys. Note that this cannot completely repair the damaged key as some crucial data is removed by the keyserver, but it does at least give you back one subkey. Defaults to no for regular --import and to yes for keyserver --receive-keys.
Show a listing of the key as imported right before it is stored. This can be combined with the option --dry-run to only look at keys; the option show-only is a shortcut for this combination. The command --show-keys is another shortcut for this. Note that suffixes like ’#’ for "sec" and "sbb" lines may or may not be printed.
Run the entire import code but instead of storing the key to the local keyring write it to the output. The export option export-dane affect the output. This option can for example be used to remove all invalid parts from a key without the need to store it.
During import, allow key updates to existing keys, but do not allow any new keys to be imported. Defaults to no.
After import, compact (remove all signatures except the self-signature) any user IDs from the new key that are not usable. Then, remove any signatures from the new key that are not usable. This includes signatures that were issued by keys that are not present on the keyring. This option is the same as running the --edit-key command "clean" after import. Defaults to no.
Accept only self-signatures while importing a key. All other key
signatures are skipped at an early import stage. This option can be
used with keyserver-options
to mitigate attempts to flood a
key with bogus signatures from a keyserver. The drawback is that
all other valid key signatures, as required by the Web of Trust are
also not imported. Note that when using this option along with
import-clean it suppresses the final clean step after merging the
imported key into the existing key.
Ignore all attribute user IDs (photo IDs) and their signatures while importing a key.
After import, fix various problems with the keys. For example, this reorders signatures, and strips duplicate signatures. Defaults to yes.
When used the keyboxd (option use-keyboxd in common.conf) does the import within a single transaction.
Import the smallest key possible. This removes all signatures except the most recent self-signature on each user ID. This option is the same as running the --edit-key command "minimize" after import. Defaults to no.
Import in key restore mode. This imports all data which is usually skipped during import; including all GnuPG specific data. All other contradicting options are overridden.
--import-filter {name=expr}
¶--export-filter {name=expr}
These options define an import/export filter which are applied to the imported/exported keyblock right before it will be stored/written. name defines the type of filter to use, expr the expression to evaluate. The option can be used several times which then appends more expression to the same name.
The available filter types are:
This filter will keep a user id packet and its dependent packets in the keyblock if the expression evaluates to true.
This filter drops the selected subkeys. Currently only implemented for –export-filter.
This filter drops the selected key signatures on user ids. Self-signatures are not considered. Currently only implemented for –import-filter.
This filter is only implemented by --list-filter. All property names may be used.
For the syntax of the expression see the chapter "FILTER EXPRESSIONS". The property names for the expressions depend on the actual filter type and are indicated in the following table. Note that all property names may also be used by --list-filter.
Property names may be prefix with a scope delimited by a slash. Valid scopes are "pub" for public and secret primary keys, "sub" for public and secret subkeys, "uid" for for user-ID packets, and "sig" for signature packets. Invalid scopes are currently ignored.
The available properties are:
A string with the user id. (keep-uid)
The addr-spec part of a user id with mailbox or the empty string. (keep-uid)
A string with the key algorithm description. For example "rsa3072" or "ed25519".
A number with the public key algorithm of a key or subkey packet. (drop-subkey)
A number with the effective key size of a key or subkey packet. (drop-subkey)
The first is the timestamp a public key or subkey packet was created. The second is the same but given as an ISO string, e.g. "2016-08-17". (drop-subkey)
The expiration time of a public key or subkey or 0 if it does not expire. The second is the same but given as an ISO date string or an empty string e.g. "2038-01-19".
The hexified fingerprint of the current subkey or primary key. (drop-subkey)
Boolean indicating whether the user id is the primary one. (keep-uid)
Boolean indicating whether a user id (keep-uid), a key (drop-subkey), or a signature (drop-sig) expired.
Boolean indicating whether a user id (keep-uid) or a key (drop-subkey) has been revoked.
Boolean indicating whether a primary key is disabled.
Boolean indicating whether a key or subkey is a secret one. (drop-subkey)
A string indicating the usage flags for the subkey, from the sequence “ecsa?”. For example, a subkey capable of just signing and authentication would be an exact match for “sa”. (drop-subkey)
The first is the timestamp a signature packet was created. The second is the same but given as an ISO date string, e.g. "2016-08-17". (drop-sig)
The expiration time of a signature packet or 0 if it does not expire. The second is the same but given as an ISO date string or an empty string e.g. "2038-01-19".
A number with the public key algorithm of a signature packet. (drop-sig)
A number with the digest algorithm of a signature packet. (drop-sig)
A string with the key origin or a question mark. For example the string “wkd” is used if a key originated from a Web Key Directory lookup.
The timestamp the key was last updated from a keyserver or the Web Key Directory.
A string with the the URL associated wit the last key lookup.
--export-options parameters
¶This is a space or comma delimited string that gives options for exporting keys. Options can be prepended with a ‘no-’ to give the opposite meaning. The options are:
Allow exporting key signatures marked as "local". This is not generally useful unless a shared keyring scheme is being used. Defaults to no.
Include attribute user IDs (photo IDs) while exporting. Not including attribute user IDs is useful to export keys that are going to be used by an OpenPGP program that does not accept attribute user IDs. Defaults to yes.
Include designated revoker information that was marked as "sensitive". Defaults to no.
Export for use as a backup. The exported data includes all data which is needed to restore the key or keys later with GnuPG. The format is basically the OpenPGP format but enhanced with GnuPG specific data. All other contradicting options are overridden.
Compact (remove all signatures from) user IDs on the key being exported if the user IDs are not usable. Also, do not export any signatures that are not usable. This includes signatures that were issued by keys that are not present on the keyring. This option is the same as running the --edit-key command "clean" before export except that the local copy of the key is not modified. Defaults to no.
Export the smallest key possible. This removes all signatures except the most recent self-signature on each user ID. This option is the same as running the --edit-key command "minimize" before export except that the local copy of the key is not modified. Defaults to no.
Export only standalone revocation certificates of the key. This option does not export revocations of 3rd party certificate revocations.
Instead of outputting the key material output OpenPGP DANE records suitable to put into DNS zone files. An ORIGIN line is printed before each record to allow diverting the records to the corresponding zone file.
Enable the use of a new secret key export format. This format avoids the re-encryption as required with the current OpenPGP format and also improves the security of the secret key if it has been protected with a passphrase. Note that an unprotected key is exported as-is and thus not secure; the general rule to convey secret keys in an OpenPGP encrypted file still applies with this mode. Versions of GnuPG before 2.4.0 are not able to import such a secret file.
--with-colons
¶Print key listings delimited by colons. Note that the output will be encoded in UTF-8 regardless of any --display-charset setting. This format is useful when GnuPG is called from scripts and other programs as it is easily machine parsed. The details of this format are documented in the file doc/DETAILS, which is included in the GnuPG source distribution.
--fixed-list-mode
¶Do not merge primary user ID and primary key in --with-colon listing mode and print all timestamps as seconds since 1970-01-01. Since GnuPG 2.0.10, this mode is always used and thus this option is obsolete; it does not harm to use it though.
--legacy-list-mode
¶Revert to the pre-2.1 public key list mode. This only affects the
human readable output and not the machine interface
(i.e. --with-colons
). Note that the legacy format does not
convey suitable information for elliptic curves.
--with-fingerprint
¶Same as the command --fingerprint but changes only the format of the output and may be used together with another command.
--with-subkey-fingerprint
¶If a fingerprint is printed for the primary key, this option forces printing of the fingerprint for all subkeys. This could also be achieved by using the --with-fingerprint twice but by using this option along with keyid-format "none" a compact fingerprint is printed.
--with-v5-fingerprint
¶In a colon mode listing emit "fp2" lines for version 4 OpenPGP keys having a v5 style fingerprint of the key.
--with-icao-spelling
¶Print the ICAO spelling of the fingerprint in addition to the hex digits.
--with-keygrip
¶Include the keygrip in the key listings. In --with-colons
mode
this is implicitly enable for secret keys.
--with-key-origin
¶Include the locally held information on the origin and last update of
a key in a key listing. In --with-colons
mode this is always
printed. This data is currently experimental and shall not be
considered part of the stable API.
--with-wkd-hash
¶Print a Web Key Directory identifier along with each user ID in key listings. This is an experimental feature and semantics may change.
--with-secret
¶Include info about the presence of a secret key in public key listings
done with --with-colons
.
--force-ocb
¶--force-aead
Force the use of AEAD encryption over MDC encryption. AEAD is a modern and faster way to do authenticated encryption than the old MDC method. --force-aead is an alias and deprecated. See also option --chunk-size.
--force-mdc
¶--disable-mdc
These options are obsolete and have no effect since GnuPG 2.2.8. The MDC is always used unless the keys indicate that an AEAD algorithm can be used in which case AEAD is used. But note: If the creation of a legacy non-MDC message is exceptionally required, the option --rfc2440 allows for this.
--disable-signer-uid
¶By default the user ID of the signing key is embedded in the data signature. As of now this is only done if the signing key has been specified with local-user using a mail address, or with sender. This information can be helpful for verifier to locate the key; see option --auto-key-retrieve.
--include-key-block
¶--no-include-key-block
This option is used to embed the actual signing key into a data
signature. The embedded key is stripped down to a single user id and
includes only the signing subkey used to create the signature as well
as as valid encryption subkeys. All other info is removed from the
key to keep it and thus the signature small. This option is the
OpenPGP counterpart to the gpgsm
option
--include-certs and allows the recipient of a signed message
to reply encrypted to the sender without using any online directories
to lookup the key. The default is --no-include-key-block.
See also the option --auto-key-import.
--personal-cipher-preferences string
¶Set the list of personal cipher preferences to string. Use
gpg --version
to get a list of available algorithms,
and use none
to set no preference at all. This allows the user
to safely override the algorithm chosen by the recipient key
preferences, as GPG will only select an algorithm that is usable by
all recipients. The most highly ranked cipher in this list is also
used for the --symmetric encryption command.
--personal-digest-preferences string
¶Set the list of personal digest preferences to string. Use
gpg --version
to get a list of available algorithms,
and use none
to set no preference at all. This allows the user
to safely override the algorithm chosen by the recipient key
preferences, as GPG will only select an algorithm that is usable by
all recipients. The most highly ranked digest algorithm in this list
is also used when signing without encryption
(e.g. --clear-sign or --sign).
--personal-compress-preferences string
¶Set the list of personal compression preferences to string.
Use gpg --version
to get a list of available
algorithms, and use none
to set no preference at all. This
allows the user to safely override the algorithm chosen by the
recipient key preferences, as GPG will only select an algorithm that
is usable by all recipients. The most highly ranked compression
algorithm in this list is also used when there are no recipient keys
to consider (e.g. --symmetric).
--s2k-cipher-algo name
¶Use name as the cipher algorithm for symmetric encryption with a passphrase if --personal-cipher-preferences and --cipher-algo are not given. The default is AES-128.
--s2k-digest-algo name
¶Use name as the digest algorithm used to mangle the passphrases for symmetric encryption. The default is SHA-1.
--s2k-mode n
¶Selects how passphrases for symmetric encryption are mangled. If n is 0 a plain passphrase (which is in general not recommended) will be used, a 1 adds a salt (which should not be used) to the passphrase and a 3 (the default) iterates the whole process a number of times (see --s2k-count).
--s2k-count n
¶Specify how many times the passphrases mangling for symmetric encryption is repeated. This value may range between 1024 and 65011712 inclusive. The default is inquired from gpg-agent. Note that not all values in the 1024-65011712 range are legal and if an illegal value is selected, GnuPG will round up to the nearest legal value. This option is only meaningful if --s2k-mode is set to the default of 3.
These options control what GnuPG is compliant to. Only one of these options may be active at a time. Note that the default setting of this is nearly always the correct one. See the INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS section below before using one of these options.
--gnupg
¶Use standard GnuPG behavior. This is essentially OpenPGP behavior (see --openpgp), but with extension from the proposed update to OpenPGP and with some additional workarounds for common compatibility problems in different versions of PGP. This is the default option, so it is not generally needed, but it may be useful to override a different compliance option in the gpg.conf file.
--openpgp
¶Reset all packet, cipher and digest options to strict OpenPGP behavior. This option implies --allow-old-cipher-algos. Use this option to reset all previous options like --s2k-*, --cipher-algo, --digest-algo and --compress-algo to OpenPGP compliant values. All PGP workarounds are disabled.
--rfc4880
¶Reset all packet, cipher and digest options to strict RFC-4880 behavior. This option implies --allow-old-cipher-algos. Note that this is currently the same thing as --openpgp.
--rfc4880bis
¶Reset all packet, cipher and digest options to strict according to the proposed updates of RFC-4880.
--rfc2440
¶Reset all packet, cipher and digest options to strict RFC-2440 behavior. Note that by using this option encryption packets are created in a legacy mode without MDC protection. This is dangerous and should thus only be used for experiments. This option implies --allow-old-cipher-algos. See also option --ignore-mdc-error.
--pgp6
¶This option is obsolete; it is handled as an alias for --pgp7
--pgp7
¶Set up all options to be as PGP 7 compliant as possible. This allowed the ciphers IDEA, 3DES, CAST5,AES128, AES192, AES256, and TWOFISH., the hashes MD5, SHA1 and RIPEMD160, and the compression algorithms none and ZIP. This option implies --escape-from-lines and disables --throw-keyids,
--pgp8
¶Set up all options to be as PGP 8 compliant as possible. PGP 8 is a lot closer to the OpenPGP standard than previous versions of PGP, so all this does is disable --throw-keyids and set --escape-from-lines. All algorithms are allowed except for the SHA224, SHA384, and SHA512 digests.
--compliance string
¶This option can be used instead of one of the options above. Valid values for string are the above option names (without the double dash) and possibly others as shown when using "help" for string.
--min-rsa-length n
¶This option adjusts the compliance mode "de-vs" for stricter key size requirements. For example, a value of 3000 turns rsa2048 and dsa2048 keys into non-VS-NfD compliant keys.
--require-compliance
¶To check that data has been encrypted according to the rules of the current compliance mode, a gpg user needs to evaluate the status lines. This is allows frontends to handle compliance check in a more flexible way. However, for scripted use the required evaluation of the status-line requires quite some effort; this option can be used instead to make sure that the gpg process exits with a failure if the compliance rules are not fulfilled. Note that this option has currently an effect only in "de-vs" mode.
-n
¶--dry-run
Don’t make any changes (this is not completely implemented).
--list-only
¶Changes the behaviour of some commands. This is like --dry-run but different in some cases. The semantic of this option may be extended in the future. Currently it only skips the actual decryption pass and therefore enables a fast listing of the encryption keys.
-i
¶--interactive
Prompt before overwriting any files.
--compatibility-flags flags
¶Set compatibility flags to work around problems due to non-compliant keys or data. The flags are given as a comma separated list of flag names and are OR-ed together. The special flag "none" clears the list and allows one to start over with an empty list. To get a list of available flags the sole word "help" can be used.
--debug-level level
¶Select the debug level for investigating problems. level may be a numeric value or by a keyword:
none
No debugging at all. A value of less than 1 may be used instead of the keyword.
basic
Some basic debug messages. A value between 1 and 2 may be used instead of the keyword.
advanced
More verbose debug messages. A value between 3 and 5 may be used instead of the keyword.
expert
Even more detailed messages. A value between 6 and 8 may be used instead of the keyword.
guru
All of the debug messages you can get. A value greater than 8 may be used instead of the keyword. The creation of hash tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not specified and may change with newer releases of this program. They are however carefully selected to best aid in debugging.
--debug flags
¶Set debug flags. All flags are or-ed and flags may be given in C syntax (e.g. 0x0042) or as a comma separated list of flag names. To get a list of all supported flags the single word "help" can be used. This option is only useful for debugging and the behavior may change at any time without notice.
--debug-all
¶Set all useful debugging flags.
--debug-iolbf
¶Set stdout into line buffered mode. This option is only honored when given on the command line.
--debug-set-iobuf-size n
¶Change the buffer size of the IOBUFs to n kilobyte. Using 0 prints the current size. Note well: This is a maintainer only option and may thus be changed or removed at any time without notice.
--debug-allow-large-chunks
¶To facilitate software tests and experiments this option allows one to
specify a limit of up to 4 EiB (--chunk-size 62
).
--debug-ignore-expiration
¶This option tries to override certain key expiration dates. It is only useful for certain regression tests.
--faked-system-time epoch
¶This option is only useful for testing; it sets the system time back or forth to epoch which is the number of seconds elapsed since the year 1970. Alternatively epoch may be given as a full ISO time string (e.g. "20070924T154812").
If you suffix epoch with an exclamation mark (!), the system time will appear to be frozen at the specified time.
--full-timestrings
¶Change the format of printed creation and expiration times from just the date to the date and time. This is in general not useful and the same information is anyway available in --with-colons mode. These longer strings are also not well aligned with other printed data.
--enable-progress-filter
¶Enable certain PROGRESS status outputs. This option allows frontends to display a progress indicator while gpg is processing larger files. There is a slight performance overhead using it.
--status-fd n
¶Write special status strings to the file descriptor n. See the file DETAILS in the documentation for a listing of them.
--status-file file
¶Same as --status-fd, except the status data is written to file file.
--logger-fd n
¶Write log output to file descriptor n and not to STDERR.
--log-file file
¶--logger-file file
Same as --logger-fd, except the logger data is written to file file. Use socket:// to log to s socket.
--log-time
¶Prefix all log output with a timestamp even if no log file is used.
--attribute-fd n
¶Write attribute subpackets to the file descriptor n. This is most useful for use with --status-fd, since the status messages are needed to separate out the various subpackets from the stream delivered to the file descriptor.
--attribute-file file
¶Same as --attribute-fd, except the attribute data is written to file file.
--comment string
¶--no-comments
Use string as a comment string in cleartext signatures and ASCII armored messages or keys (see --armor). The default behavior is not to use a comment string. --comment may be repeated multiple times to get multiple comment strings. --no-comments removes all comments. It is a good idea to keep the length of a single comment below 60 characters to avoid problems with mail programs wrapping such lines. Note that comment lines, like all other header lines, are not protected by the signature.
--emit-version
¶--no-emit-version
Force inclusion of the version string in ASCII armored output. If given once only the name of the program and the major number is emitted, given twice the minor is also emitted, given thrice the micro is added, and given four times an operating system identification is also emitted. --no-emit-version (default) disables the version line.
--sig-notation {name=value}
¶--cert-notation {name=value}
-N, --set-notation {name=value}
Put the name value pair into the signature as notation data. name must consist only of printable characters or spaces, and must contain a ’@’ character in the form keyname@domain.example.com (substituting the appropriate keyname and domain name, of course). This is to help prevent pollution of the IETF reserved notation namespace. The --expert flag overrides the ’@’ check. value may be any printable string; it will be encoded in UTF-8, so you should check that your --display-charset is set correctly. If you prefix name with an exclamation mark (!), the notation data will be flagged as critical (rfc4880:5.2.3.16). --sig-notation sets a notation for data signatures. --cert-notation sets a notation for key signatures (certifications). --set-notation sets both.
There are special codes that may be used in notation names. "%k" will be expanded into the key ID of the key being signed, "%K" into the long key ID of the key being signed, "%f" into the fingerprint of the key being signed, "%s" into the key ID of the key making the signature, "%S" into the long key ID of the key making the signature, "%g" into the fingerprint of the key making the signature (which might be a subkey), "%p" into the fingerprint of the primary key of the key making the signature, "%c" into the signature count from the OpenPGP smartcard, and "%%" results in a single "%". %k, %K, and %f are only meaningful when making a key signature (certification), and %c is only meaningful when using the OpenPGP smartcard.
--known-notation name
¶Adds name to a list of known critical signature notations. The effect of this is that gpg will not mark a signature with a critical signature notation of that name as bad. Note that gpg already knows by default about a few critical signatures notation names.
--sig-policy-url string
¶--cert-policy-url string
--set-policy-url string
Use string as a Policy URL for signatures (rfc4880:5.2.3.20). If you prefix it with an exclamation mark (!), the policy URL packet will be flagged as critical. --sig-policy-url sets a policy url for data signatures. --cert-policy-url sets a policy url for key signatures (certifications). --set-policy-url sets both.
The same %-expandos used for notation data are available here as well.
--sig-keyserver-url string
¶Use string as a preferred keyserver URL for data signatures. If you prefix it with an exclamation mark (!), the keyserver URL packet will be flagged as critical.
The same %-expandos used for notation data are available here as well.
--set-filename string
¶Use string as the filename which is stored inside messages. This overrides the default, which is to use the actual filename of the file being encrypted. Using the empty string for string effectively removes the filename from the output.
--for-your-eyes-only
¶--no-for-your-eyes-only
Set the ‘for your eyes only’ flag in the message. This causes GnuPG to refuse to save the file unless the --output option is given, and PGP to use a "secure viewer" with a claimed Tempest-resistant font to display the message. This option overrides --set-filename. --no-for-your-eyes-only disables this option.
--use-embedded-filename
¶--no-use-embedded-filename
Try to create a file with a name as embedded in the data. This can be a dangerous option as it enables overwriting files by giving the sender control on how to store files. Defaults to no. Note that the option --output overrides this option.
A better approach than using this option is to decrypt to a temporary
filename and then rename that file to the embedded file name after
checking that the embedded filename is harmless. When using the
--status-fd option gpg tells the filename as part of the
PLAINTEXT status message. If the filename is important, the use of
gpgtar
is another option because gpgtar will never overwrite
a file but decrypt the files to a new directory.
Note also that unless a modern version 5 signature is used the embedded filename is not part of the signed data.
--cipher-algo name
¶Use name as cipher algorithm. Running the program with the command --version yields a list of supported algorithms. If this is not used the cipher algorithm is selected from the preferences stored with the key. In general, you do not want to use this option as it allows you to violate the OpenPGP standard. The option --personal-cipher-preferences is the safe way to accomplish the same thing.
--digest-algo name
¶Use name as the message digest algorithm. Running the program with the command --version yields a list of supported algorithms. In general, you do not want to use this option as it allows you to violate the OpenPGP standard. The option --personal-digest-preferences is the safe way to accomplish the same thing.
--compress-algo name
¶Use compression algorithm name. "zlib" is RFC-1950 ZLIB compression. "zip" is RFC-1951 ZIP compression which is used by PGP. "bzip2" is a more modern compression scheme that can compress some things better than zip or zlib, but at the cost of more memory used during compression and decompression. "uncompressed" or "none" disables compression. If this option is not used, the default behavior is to examine the recipient key preferences to see which algorithms the recipient supports. If all else fails, ZIP is used for maximum compatibility.
ZLIB may give better compression results than ZIP, as the compression window size is not limited to 8k. BZIP2 may give even better compression results than that, but will use a significantly larger amount of memory while compressing and decompressing. This may be significant in low memory situations. Note, however, that PGP (all versions) only supports ZIP compression. Using any algorithm other than ZIP or "none" will make the message unreadable with PGP. In general, you do not want to use this option as it allows you to violate the OpenPGP standard. The option --personal-compress-preferences is the safe way to accomplish the same thing.
--cert-digest-algo name
¶Use name as the message digest algorithm used when signing a key. Running the program with the command --version yields a list of supported algorithms. Be aware that if you choose an algorithm that GnuPG supports but other OpenPGP implementations do not, then some users will not be able to use the key signatures you make, or quite possibly your entire key. Note also that a public key algorithm must be compatible with the specified digest algorithm; thus selecting an arbitrary digest algorithm may result in error messages from lower crypto layers or lead to security flaws.
--disable-cipher-algo name
¶Never allow the use of name as cipher algorithm. The given name will not be checked so that a later loaded algorithm will still get disabled.
--disable-pubkey-algo name
¶Never allow the use of name as public key algorithm. The given name will not be checked so that a later loaded algorithm will still get disabled.
--throw-keyids
¶--no-throw-keyids
Do not put the recipient key IDs into encrypted messages. This helps to hide the receivers of the message and is a limited countermeasure against traffic analysis.2 On the receiving side, it may slow down the decryption process because all available secret keys must be tried. --no-throw-keyids disables this option. This option is essentially the same as using --hidden-recipient for all recipients.
--not-dash-escaped
¶This option changes the behavior of cleartext signatures so that they can be used for patch files. You should not send such an armored file via email because all spaces and line endings are hashed too. You can not use this option for data which has 5 dashes at the beginning of a line, patch files don’t have this. A special armor header line tells GnuPG about this cleartext signature option.
--escape-from-lines
¶--no-escape-from-lines
Because some mailers change lines starting with "From " to ">From " it is good to handle such lines in a special way when creating cleartext signatures to prevent the mail system from breaking the signature. Note that all other PGP versions do it this way too. Enabled by default. --no-escape-from-lines disables this option.
--passphrase-repeat n
¶Specify how many times gpg
will request a new
passphrase be repeated. This is useful for helping memorize a
passphrase. Defaults to 1 repetition; can be set to 0 to disable any
passphrase repetition. Note that a n greater than 1 will pop up
the pinentry window n+1 times even if a modern pinentry with
two entry fields is used.
--passphrase-fd n
¶Read the passphrase from file descriptor n. Only the first line will be read from file descriptor n. If you use 0 for n, the passphrase will be read from STDIN. This can only be used if only one passphrase is supplied.
Note that since Version 2.0 this passphrase is only used if the
option --batch has also been given. Since Version 2.1
the --pinentry-mode also needs to be set to loopback
.
--passphrase-file file
¶Read the passphrase from file file. Only the first line will be read from file file. This can only be used if only one passphrase is supplied. Obviously, a passphrase stored in a file is of questionable security if other users can read this file. Don’t use this option if you can avoid it.
Note that since Version 2.0 this passphrase is only used if the
option --batch has also been given. Since Version 2.1
the --pinentry-mode also needs to be set to loopback
.
--passphrase string
¶Use string as the passphrase. This can only be used if only one passphrase is supplied. Obviously, this is of very questionable security on a multi-user system. Don’t use this option if you can avoid it.
Note that since Version 2.0 this passphrase is only used if the
option --batch has also been given. Since Version 2.1
the --pinentry-mode also needs to be set to loopback
.
--pinentry-mode mode
¶Set the pinentry mode to mode. Allowed values for mode are:
Use the default of the agent, which is ask
.
Force the use of the Pinentry.
Emulate use of Pinentry’s cancel button.
Return a Pinentry error (“No Pinentry”).
Redirect Pinentry queries to the caller. Note that in contrast to Pinentry the user is not prompted again if he enters a bad password.
--no-symkey-cache
¶Disable the passphrase cache used for symmetrical en- and decryption. This cache is based on the message specific salt value (cf. --s2k-mode).
--request-origin origin
¶Tell gpg to assume that the operation ultimately originated at
origin. Depending on the origin certain restrictions are applied
and the Pinentry may include an extra note on the origin. Supported
values for origin are: local
which is the default,
remote
to indicate a remote origin or browser
for an
operation requested by a web browser.
--command-fd n
¶This is a replacement for the deprecated shared-memory IPC mode. If this option is enabled, user input on questions is not expected from the TTY but from the given file descriptor. It should be used together with --status-fd. See the file doc/DETAILS in the source distribution for details on how to use it.
--command-file file
¶Same as --command-fd, except the commands are read out of file file
--allow-non-selfsigned-uid
¶--no-allow-non-selfsigned-uid
Allow the import and use of keys with user IDs which are not self-signed. This is not recommended, as a non self-signed user ID is trivial to forge. --no-allow-non-selfsigned-uid disables.
--allow-freeform-uid
¶Disable all checks on the form of the user ID while generating a new one. This option should only be used in very special environments as it does not ensure the de-facto standard format of user IDs.
--ignore-time-conflict
¶GnuPG normally checks that the timestamps associated with keys and signatures have plausible values. However, sometimes a signature seems to be older than the key due to clock problems. This option makes these checks just a warning. See also --ignore-valid-from for timestamp issues on subkeys.
--ignore-valid-from
¶GnuPG normally does not select and use subkeys created in the future. This option allows the use of such keys and thus exhibits the pre-1.0.7 behaviour. You should not use this option unless there is some clock problem. See also --ignore-time-conflict for timestamp issues with signatures.
--ignore-crc-error
¶The ASCII armor used by OpenPGP is protected by a CRC checksum against transmission errors. Occasionally the CRC gets mangled somewhere on the transmission channel but the actual content (which is protected by the OpenPGP protocol anyway) is still okay. This option allows GnuPG to ignore CRC errors.
--ignore-mdc-error
¶This option changes a MDC integrity protection failure into a warning. It is required to decrypt old messages which did not use an MDC. It may also be useful if a message is partially garbled, but it is necessary to get as much data as possible out of that garbled message. Be aware that a missing or failed MDC can be an indication of an attack. Use with great caution; see also option --rfc2440.
--allow-old-cipher-algos
¶Old cipher algorithms like 3DES, IDEA, or CAST5 encrypt data using blocks of 64 bits; modern algorithms use blocks of 128 bit instead. To avoid certain attack on these old algorithms it is suggested not to encrypt more than 150 MiByte using the same key. For this reason gpg does not allow the use of 64 bit block size algorithms for encryption unless this option is specified.
--allow-weak-digest-algos
¶Signatures made with known-weak digest algorithms are normally rejected with an “invalid digest algorithm” message. This option allows the verification of signatures made with such weak algorithms. MD5 is the only digest algorithm considered weak by default. See also --weak-digest to reject other digest algorithms.
--weak-digest name
¶Treat the specified digest algorithm as weak. Signatures made over weak digests algorithms are normally rejected. This option can be supplied multiple times if multiple algorithms should be considered weak. See also --allow-weak-digest-algos to disable rejection of weak digests. MD5 is always considered weak, and does not need to be listed explicitly.
--allow-weak-key-signatures
¶To avoid a minor risk of collision attacks on third-party key signatures made using SHA-1, those key signatures are considered invalid. This options allows one to override this restriction.
--override-compliance-check
This was a temporary introduced option and has no more effect.
--no-default-keyring
¶Do not add the default keyring to the list of keyrings. Note that GnuPG needs for almost all operations a keyring. Thus if you use this option and do not provide alternate keyrings via --keyring, then GnuPG will still use the default keyring.
Note that if the option use-keyboxd is enabled in common.conf, no keyrings are used at all and keys are all maintained by the keyboxd process in its own database.
--no-keyring
¶Do not use any keyring at all. This overrides the default and all options which specify keyrings.
--skip-verify
¶Skip the signature verification step. This may be used to make the decryption faster if the signature verification is not needed.
--with-key-data
¶Print key listings delimited by colons (like --with-colons) and print the public key data.
--list-signatures
¶--list-sigs
Same as --list-keys, but the signatures are listed too. This command has the same effect as using --list-keys with --with-sig-list. Note that in contrast to --check-signatures the key signatures are not verified. This command can be used to create a list of signing keys missing in the local keyring; for example:
gpg --list-sigs --with-colons USERID | \ awk -F: '$1=="sig" && $2=="?" {if($13){print $13}else{print $5}}'
--fast-list-mode
¶Changes the output of the list commands to work faster; this is achieved by leaving some parts empty. Some applications don’t need the user ID and the trust information given in the listings. By using this options they can get a faster listing. The exact behaviour of this option may change in future versions. If you are missing some information, don’t use this option.
--no-literal
¶This is not for normal use. Use the source to see for what it might be useful.
--set-filesize
¶This is not for normal use. Use the source to see for what it might be useful.
--show-session-key
¶Display the session key used for one message. See --override-session-key for the counterpart of this option.
We think that Key Escrow is a Bad Thing; however the user should have the freedom to decide whether to go to prison or to reveal the content of one specific message without compromising all messages ever encrypted for one secret key.
You can also use this option if you receive an encrypted message which is abusive or offensive, to prove to the administrators of the messaging system that the ciphertext transmitted corresponds to an inappropriate plaintext so they can take action against the offending user.
--override-session-key string
¶--override-session-key-fd fd
Don’t use the public key but the session key string respective the session key taken from the first line read from file descriptor fd. The format of this string is the same as the one printed by --show-session-key. This option is normally not used but comes handy in case someone forces you to reveal the content of an encrypted message; using this option you can do this without handing out the secret key. Note that using --override-session-key may reveal the session key to all local users via the global process table. Often it is useful to combine this option with --no-keyring.
--ask-sig-expire
¶--no-ask-sig-expire
When making a data signature, prompt for an expiration time. If this option is not specified, the expiration time set via --default-sig-expire is used. --no-ask-sig-expire disables this option.
--default-sig-expire
¶The default expiration time to use for signature expiration. Valid values are "0" for no expiration, a number followed by the letter d (for days), w (for weeks), m (for months), or y (for years) (for example "2m" for two months, or "5y" for five years), or an absolute date in the form YYYY-MM-DD. Defaults to "0".
--ask-cert-expire
¶--no-ask-cert-expire
When making a key signature, prompt for an expiration time. If this option is not specified, the expiration time set via --default-cert-expire is used. --no-ask-cert-expire disables this option.
--default-cert-expire
¶The default expiration time to use for key signature expiration. Valid values are "0" for no expiration, a number followed by the letter d (for days), w (for weeks), m (for months), or y (for years) (for example "2m" for two months, or "5y" for five years), or an absolute date in the form YYYY-MM-DD. Defaults to "0".
--default-new-key-algo string
¶This option can be used to change the default algorithms for key
generation. The string is similar to the arguments required for
the command --quick-add-key but slightly different. For
example the current default of "rsa2048/cert,sign+rsa2048/encr"
(or "rsa3072"
) can be changed to the value of what we currently
call future default, which is "ed25519/cert,sign+cv25519/encr"
.
You need to consult the source code to learn the details. Note that
the advanced key generation commands can always be used to specify a
key algorithm directly.
--no-auto-trust-new-key
¶When creating a new key the ownertrust of the new key is set to ultimate. This option disables this and the user needs to manually assign an ownertrust value.
--force-sign-key
¶This option modifies the behaviour of the commands --quick-sign-key, --quick-lsign-key, and the "sign" sub-commands of --edit-key by forcing the creation of a key signature, even if one already exists.
--forbid-gen-key
¶This option is intended for use in the global config file to disallow the use of generate key commands. Those commands will then fail with the error code for Not Enabled.
--allow-secret-key-import
¶This is an obsolete option and is not used anywhere.
--allow-multiple-messages
--no-allow-multiple-messages
These are obsolete options; they have no more effect since GnuPG 2.2.8.
--enable-special-filenames
¶This option enables a mode in which filenames of the form -&n, where n is a non-negative decimal number, refer to the file descriptor n and not to a file with that name.
--no-expensive-trust-checks
¶Experimental use only.
--preserve-permissions
¶Don’t change the permissions of a secret keyring back to user read/write only. Use this option only if you really know what you are doing.
--default-preference-list string
¶Set the list of default preferences to string. This preference list is used for new keys and becomes the default for "setpref" in the --edit-key menu.
--default-keyserver-url name
¶Set the default keyserver URL to name. This keyserver will be used as the keyserver URL when writing a new self-signature on a key, which includes key generation and changing preferences.
--list-config
¶Display various internal configuration parameters of GnuPG. This option is intended for external programs that call GnuPG to perform tasks, and is thus not generally useful. See the file doc/DETAILS in the source distribution for the details of which configuration items may be listed. --list-config is only usable with --with-colons set.
--list-gcrypt-config
¶Display various internal configuration parameters of Libgcrypt.
--gpgconf-list
¶This command is similar to --list-config but in general only
internally used by the gpgconf
tool.
--gpgconf-test
¶This is more or less dummy action. However it parses the configuration
file and returns with failure if the configuration file would prevent
gpg
from startup. Thus it may be used to run a syntax check
on the configuration file.
--chuid uid
¶Change the current user to uid which may either be a number or a name. This can be used from the root account to run gpg for another user. If uid is not the current UID a standard PATH is set and the envvar GNUPGHOME is unset. To override the latter the option --homedir can be used. This option has only an effect when used on the command line. This option has currently no effect at all on Windows.
-t, --textmode
¶--no-textmode
Treat input files as text and store them in the OpenPGP canonical text form with standard "CRLF" line endings. This also sets the necessary flags to inform the recipient that the encrypted or signed data is text and may need its line endings converted back to whatever the local system uses. This option was useful when communicating between two platforms with different line ending conventions (UNIX-like to Mac, Mac to Windows, etc). --no-textmode disables this option, and is the default. Note that this is a legacy option which should not anymore be used by any modern software.
--force-v3-sigs
--no-force-v3-sigs
--force-v4-certs
--no-force-v4-certs
These options are obsolete and have no effect since GnuPG 2.1.
--show-photos
¶--no-show-photos
Causes --list-keys, --list-signatures, --list-public-keys, --list-secret-keys, and verifying a signature to also display the photo ID attached to the key, if any. See also --photo-viewer. These options are deprecated. Use --list-options [no-]show-photos and/or --verify-options [no-]show-photos instead.
--show-keyring
¶Display the keyring name at the head of key listings to show which keyring a given key resides on. This option is deprecated: use --list-options [no-]show-keyring instead.
--show-notation
¶--no-show-notation
Show signature notations in the --list-signatures or --check-signatures listings as well as when verifying a signature with a notation in it. These options are deprecated. Use --list-options [no-]show-notation and/or --verify-options [no-]show-notation instead.
--show-policy-url
¶--no-show-policy-url
Show policy URLs in the --list-signatures or --check-signatures listings as well as when verifying a signature with a policy URL in it. These options are deprecated. Use --list-options [no-]show-policy-url and/or --verify-options [no-]show-policy-url instead.
--personal-aead-preferences string
¶This option is deprecated and has no more effect since version 2.3.9.
--aead-algo name
This option is deprecated and has no more effect since version 2.3.9.
There are a few configuration files to control certain aspects of
gpg
’s operation. Unless noted, they are expected in the
current home directory (see option --homedir).
This is the standard configuration file read by gpg
on
startup. It may contain any valid long option; the leading two dashes
may not be entered and the option may not be abbreviated. This default
name may be changed on the command line (see gpg-option --options).
You should backup this file.
This is an optional configuration file read by gpg
on
startup. It may contain options pertaining to all components of
GnuPG. Its current main use is for the "use-keyboxd" option. If
the default home directory ~/.gnupg does not exist, GnuPG creates
this directory and a common.conf file with "use_keyboxd".
Note that on larger installations, it is useful to put predefined files into the directory /etc/skel/.gnupg so that newly created users start up with a working configuration. For existing users a small helper script is provided to create these files (see Create .gnupg home directories).
For internal purposes gpg
creates and maintains a few other
files; They all live in the current home directory (see option --homedir). Only the gpg
program may modify these files.
This is the default home directory which is used if neither the
environment variable GNUPGHOME
nor the option
--homedir is given.
The public keyring using a legacy format. You should backup this file.
If this file is not available, gpg
defaults to the new
keybox format and creates a file pubring.kbx unless that file
already exists in which case that file will also be used for OpenPGP
keys.
Note that in the case that both files, pubring.gpg and pubring.kbx exists but the latter has no OpenPGP keys, the legacy file pubring.gpg will be used. Take care: GnuPG versions before 2.1 will always use the file pubring.gpg because they do not know about the new keybox format. In the case that you have to use GnuPG 1.4 to decrypt archived data you should keep this file.
The lock file for the public keyring.
The public keyring using the new keybox format. This file is shared
with gpgsm
. You should backup this file. See above for
the relation between this file and it predecessor.
To convert an existing pubring.gpg file to the keybox format, you first backup the ownertrust values, then rename pubring.gpg to publickeys.backup, so it won’t be recognized by any GnuPG version, run import, and finally restore the ownertrust values:
$ cd ~/.gnupg $ gpg --export-ownertrust >otrust.lst $ mv pubring.gpg publickeys.backup $ gpg --import-options restore --import publickeys.backup $ gpg --import-ownertrust otrust.lst
The lock file for pubring.kbx.
The legacy secret keyring as used by GnuPG versions before 2.1. It is not used by GnuPG 2.1 and later. You may want to keep it in case you have to use GnuPG 1.4 to decrypt archived data.
The lock file for the legacy secret keyring.
File indicating that a migration to GnuPG 2.1 has been done.
The trust database. There is no need to backup this file; it is better to backup the ownertrust values (see option --export-ownertrust).
The lock file for the trust database.
A file used to preserve the state of the internal random pool.
This is the directory where gpg stores pre-generated revocation certificates. The file name corresponds to the OpenPGP fingerprint of the respective key. It is suggested to backup those certificates and if the primary private key is not stored on the disk to move them to an external storage device. Anyone who can access these files is able to revoke the corresponding key. You may want to print them out. You should backup all files in this directory and take care to keep this backup closed away.
Operation is further controlled by a few environment variables:
Used to locate the default home directory.
If set directory used instead of "~/.gnupg".
This variable is obsolete; it was used by GnuPG versions before 2.1.
This value is passed via gpg-agent to pinentry. It is useful to convey extra information to a custom pinentry.
Used to size some displays to the full size of the screen.
Apart from its use by GNU, it is used in the W32 version to override the
language selection done through the Registry. If used and set to a
valid and available language name (langid), the file with the
translation is loaded from
gpgdir/gnupg.nls/langid.mo
. Here gpgdir is the
directory out of which the gpg binary has been loaded. If it can’t be
loaded the Registry is tried and as last resort the native Windows
locale system is used.
This variable is only used by the regression test suite as a helper under operating systems without proper support to figure out the name of a process’ text file.
This variable allows one to enable diagnostics for process management. A numeric decimal value is expected. Bit 0 enables general diagnostics, bit 1 enables certain warnings on Windows.
When calling the gpg-agent component gpg
sends a set of
environment variables to gpg-agent. The names of these variables can
be listed using the command:
gpg-connect-agent 'getinfo std_env_names' /bye | awk '$1=="D" {print $2}'
Bob
file
sign and encrypt for user Bob
file
make a cleartext signature
file
make a detached signature
file
make a detached signature with the key 0x12345678
user_ID
show keys
user_ID
show fingerprint
pgpfile
sigfile
[datafile
]Verify the signature of the file but do not output the data unless
requested. The second form is used for detached signatures, where
sigfile
is the detached signature (either ASCII armored or
binary) and datafile
are the signed data; if this is not given, the name of the
file holding the signed data is constructed by cutting off the
extension (".asc" or ".sig") of sigfile
or by asking the user
for the filename. If the option --output is also used the
signed data is written to the file specified by that option; use
-
to write the signed data to stdout.
The options --import-filter and --export-filter use expressions with this syntax (square brackets indicate an optional part and curly braces a repetition, white space between the elements are allowed):
[lc] {[{flag}] PROPNAME op VALUE [lc]}
The name of a property (PROPNAME) may only consist of letters,
digits and underscores. The description for the filter type
describes which properties are defined. If an undefined property is
used it evaluates to the empty string. Unless otherwise noted, the
VALUE must always be given and may not be the empty string. No
quoting is defined for the value, thus the value may not contain the
strings &&
or ||
, which are used as logical connection
operators. The flag --
can be used to remove this restriction.
Numerical values are computed as long int; standard C notation
applies. lc is the logical connection operator; either
&&
for a conjunction or ||
for a disjunction. A
conjunction is assumed at the begin of an expression. Conjunctions
have higher precedence than disjunctions. If VALUE starts with
one of the characters used in any op a space after the
op is required.
The supported operators (op) are:
Substring must match.
Substring must not match.
The full string must match.
The full string must not match.
The numerical value must match.
The numerical value must not match.
The numerical value of the field must be LE than the value.
The numerical value of the field must be LT than the value.
The numerical value of the field must be GT than the value.
The numerical value of the field must be GE than the value.
The string value of the field must be less or equal than the value.
The string value of the field must be less than the value.
The string value of the field must be greater than the value.
The string value of the field must be greater or equal than the value.
True if value is not empty (no value allowed).
True if value is empty (no value allowed).
Alias for "PROPNAME != 0" (no value allowed).
Alias for "PROPNAME == 0" (no value allowed).
Values for flag must be space separated. The supported flags are:
VALUE spans to the end of the expression.
The string match in this part is done case-sensitive.
Leading and trailing spaces are not removed from VALUE. The optional single space after op is here required.
The filter options concatenate several specifications for a filter of the same type. For example the four options in this example:
--import-filter keep-uid="uid =~ Alfa" --import-filter keep-uid="&& uid !~ Test" --import-filter keep-uid="|| uid =~ Alpha" --import-filter keep-uid="uid !~ Test"
which is equivalent to
--import-filter \ keep-uid="uid =~ Alfa" && uid !~ Test" || uid =~ Alpha" && "uid !~ Test"
imports only the user ids of a key containing the strings "Alfa" or "Alpha" but not the string "test".
The program returns 0 if there are no severe errors, 1 if at least a signature was bad, and other error codes for fatal errors.
Note that signature verification requires exact knowledge of what has
been signed and by whom it has been signed. Using only the return code
is thus not an appropriate way to verify a signature by a script.
Either make proper use or the status codes or use the gpgv
tool which has been designed to make signature verification easy for
scripts.
Use a good password for your user account and make sure that all security issues are always fixed on your machine. Also employ diligent physical protection to your machine. Consider to use a good passphrase as a last resort protection to your secret key in the case your machine gets stolen. It is important that your secret key is never leaked. Using an easy to carry around token or smartcard with the secret key is often a advisable.
If you are going to verify detached signatures, make sure that the program knows about it; either give both filenames on the command line or use ‘-’ to specify STDIN.
For scripted or other unattended use of gpg
make sure to use
the machine-parseable interface and not the default interface which is
intended for direct use by humans. The machine-parseable interface
provides a stable and well documented API independent of the locale or
future changes of gpg
. To enable this interface use the
options --with-colons and --status-fd. For certain
operations the option --command-fd may come handy too. See
this man page and the file DETAILS for the specification of the
interface. Note that the GnuPG “info” pages as well as the PDF
version of the GnuPG manual features a chapter on unattended use of
GnuPG. As an alternative the library GPGME
can be used as a
high-level abstraction on top of that interface.
GnuPG tries to be a very flexible implementation of the OpenPGP standard. In particular, GnuPG implements many of the optional parts of the standard, such as the SHA-512 hash, and the ZLIB and BZIP2 compression algorithms. It is important to be aware that not all OpenPGP programs implement these optional algorithms and that by forcing their use via the --cipher-algo, --digest-algo, --cert-digest-algo, or --compress-algo options in GnuPG, it is possible to create a perfectly valid OpenPGP message, but one that cannot be read by the intended recipient.
There are dozens of variations of OpenPGP programs available, and each supports a slightly different subset of these optional algorithms. For example, until recently, no (unhacked) version of PGP supported the BLOWFISH cipher algorithm. A message using BLOWFISH simply could not be read by a PGP user. By default, GnuPG uses the standard OpenPGP preferences system that will always do the right thing and create messages that are usable by all recipients, regardless of which OpenPGP program they use. Only override this safe default if you really know what you are doing.
If you absolutely must override the safe default, or if the preferences on a given key are invalid for some reason, you are far better off using the --pgp6, --pgp7, or --pgp8 options. These options are safe as they do not force any particular algorithms in violation of OpenPGP, but rather reduce the available algorithms to a "PGP-safe" list.
On older systems this program should be installed as setuid(root). This is necessary to lock memory pages. Locking memory pages prevents the operating system from writing memory pages (which may contain passphrases or other sensitive material) to disk. If you get no warning message about insecure memory your operating system supports locking without being root. The program drops root privileges as soon as locked memory is allocated.
Note also that some systems (especially laptops) have the ability to “suspend to disk” (also known as “safe sleep” or “hibernate”). This writes all memory to disk before going into a low power or even powered off mode. Unless measures are taken in the operating system to protect the saved memory, passphrases or other sensitive material may be recoverable from it later.
Before you report a bug you should first search the mailing list archives for similar problems and second check whether such a bug has already been reported to our bug tracker at https://bugs.gnupg.org.
gpg
is often used as a backend engine by other software. To help
with this a machine interface has been defined to have an unambiguous
way to do this. The options --status-fd and --batch
are almost always required for this.
Please consider using GPGME instead of calling gpg
directly. GPGME offers a stable, backend-independent interface for
many cryptographic operations. It supports OpenPGP and S/MIME, and
also allows interaction with various GnuPG components.
GPGME provides a C-API, and comes with bindings for C++, Qt, and Python. Bindings for other languages are available.
Sometimes you want to contain effects of some operation, for example you want to import a key to inspect it, but you do not want this key to be added to your keyring. In earlier versions of GnuPG, it was possible to specify alternate keyring files for both public and secret keys. In modern GnuPG versions, however, we changed how secret keys are stored in order to better protect secret key material, and it was not possible to preserve this interface.
The preferred way to do this is to use ephemeral home directories. This technique works across all versions of GnuPG.
Create a temporary directory, create (or copy) a configuration that
meets your needs, make gpg
use this directory either
using the environment variable GNUPGHOME, or the option
--homedir. GPGME supports this too on a per-context basis,
by modifying the engine info of contexts. Now execute whatever
operation you like, import and export key material as necessary. Once
finished, you can delete the directory. All GnuPG backend services
that were started will detect this and shut down.
Recent versions of GnuPG have an interface to manipulate keys without using the interactive command --edit-key. This interface was added mainly for the benefit of GPGME (please consider using GPGME, see the manual subsection “Programmatic use of GnuPG”). This interface is described in the subsection “How to manage your keys”.
The command --generate-key may be used along with the option --batch for unattended key generation. This is the most flexible way of generating keys, but it is also the most complex one. Consider using the quick key manipulation interface described in the previous subsection “The quick key manipulation interface”.
The parameters for the key are either read from stdin or given as a file on the command line. The format of the parameter file is as follows: Text only, line length is limited to about 1000 characters. UTF-8 encoding must be used to specify non-ASCII characters. Empty lines are ignored. Leading and trailing white space is ignored. A hash sign as the first non white space character indicates a comment line. Control statements are indicated by a leading percent sign, their arguments are separated by white space from the keyword. Parameters are specified by a keyword, followed by a colon; arguments are separated by white space. The first parameter must be ‘Key-Type’ but control statements may be placed anywhere. The order of the parameters does not matter except for ‘Key-Type’. The parameters are only used for the generated keyblock (primary and subkeys); parameters from previous sets are not used. Some syntax checks may be performed. Key commences when either the end of the parameter file is reached, the next ‘Key-Type’ parameter is encountered, or the control statement ‘%commit’ is encountered.
Control statements:
Print text as diagnostic.
Suppress actual key generation (useful for syntax checking).
Perform the key generation. Note that an implicit commit is done at the next Key-Type parameter.
Do not write the key to the default or commandline given keyring but to filename. This must be given before the first commit to take place, duplicate specification of the same filename is ignored, the last filename before a commit is used. The filename is used until a new filename is used (at commit points) and all keys are written to that file. If a new filename is given, this file is created (and overwrites an existing one).
See the previous subsection “Ephemeral home directories” for a more robust way to contain side-effects.
This option is a no-op for GnuPG 2.1 and later.
See the previous subsection “Ephemeral home directories”.
This option is a no-op since GnuPG version 2.1.
Using this option allows the creation of keys without any passphrase protection. This option is mainly intended for regression tests.
If given the keys are created using a faster and a somewhat less secure random number generator. This option may be used for keys which are only used for a short time and do not require full cryptographic strength. It takes only effect if used together with the control statement ‘%no-protection’.
General Parameters:
Starts a new parameter block by giving the type of the primary key. The algorithm must be capable of signing. This is a required parameter. algo may either be an OpenPGP algorithm number or a string with the algorithm name. The special value ‘default’ may be used for algo to create the default key type; in this case a ‘Key-Usage’ shall not be given and ‘default’ also be used for ‘Subkey-Type’.
The requested length of the generated key in bits. The default is returned by running the command ‘gpg --gpgconf-list’. For ECC keys this parameter is ignored.
The requested elliptic curve of the generated key. This is a required parameter for ECC keys. It is ignored for non-ECC keys.
This is optional and used to generate a CSR or certificate for an already existing key. Key-Length will be ignored when given.
Space or comma delimited list of key usages. Allowed values are ‘encrypt’, ‘sign’, and ‘auth’. This is used to generate the key flags. Please make sure that the algorithm is capable of this usage. Note that OpenPGP requires that all primary keys are capable of certification, so no matter what usage is given here, the ‘cert’ flag will be on. If no ‘Key-Usage’ is specified and the ‘Key-Type’ is not ‘default’, all allowed usages for that particular algorithm are used; if it is not given but ‘default’ is used the usage will be ‘sign’.
This generates a secondary key (subkey). Currently only one subkey can be handled. See also ‘Key-Type’ above.
Length of the secondary key (subkey) in bits. The default is returned by running the command ‘gpg --gpgconf-list’.
Key curve for a subkey; similar to ‘Key-Curve’.
Key usage lists for a subkey; similar to ‘Key-Usage’.
If you want to specify a passphrase for the secret key, enter it here. Default is to use the Pinentry dialog to ask for a passphrase.
The three parts of a user name. Remember to use UTF-8 encoding here. If you don’t give any of them, no user ID is created.
Set the expiration date for the key (and the subkey). It may either be entered in ISO date format (e.g. "20000815T145012") or as number of days, weeks, month or years after the creation date. The special notation "seconds=N" is also allowed to specify a number of seconds since creation. Without a letter days are assumed. Note that there is no check done on the overflow of the type used by OpenPGP for timestamps. Thus you better make sure that the given value make sense. Although OpenPGP works with time intervals, GnuPG uses an absolute value internally and thus the last year we can represent is 2105.
Set the creation date of the key as stored in the key information and which is also part of the fingerprint calculation. Either a date like "1986-04-26" or a full timestamp like "19860426T042640" may be used. The time is considered to be UTC. The special notation "seconds=N" may be used to directly specify a the number of seconds since Epoch (Unix time). If it is not given the current time is used.
Set the cipher, hash, and compression preference values for this key. This expects the same type of string as the sub-command ‘setpref’ in the --edit-key menu.
Add a designated revoker to the generated key. Algo is the public key algorithm of the designated revoker (i.e. RSA=1, DSA=17, etc.) fpr is the fingerprint of the designated revoker. fpr may not contain spaces or colons. The optional ‘sensitive’ flag marks the designated revoker as sensitive information. Only v4 and v5 keys may be designated revokers.
This is an optional parameter that specifies the preferred keyserver URL for the key.
This is an optional parameter only used with the status lines KEY_CREATED and KEY_NOT_CREATED. string may be up to 100 characters and should not contain spaces. It is useful for batch key generation to associate a key parameter block with a status line.
Here is an example on how to create a key in an ephemeral home directory:
$ export GNUPGHOME="$(mktemp -d)" $ cat >foo <<EOF %echo Generating a basic OpenPGP key Key-Type: DSA Key-Length: 1024 Subkey-Type: ELG-E Subkey-Length: 1024 Name-Real: Joe Tester Name-Comment: with stupid passphrase Name-Email: joe@foo.bar Expire-Date: 0 Passphrase: abc # Do a commit here, so that we can later print "done" :-) %commit %echo done EOF $ gpg --batch --generate-key foo [...] $ gpg --list-secret-keys /tmp/tmp.0NQxB74PEf/pubring.kbx ------------------------------- sec dsa1024 2016-12-16 [SCA] 768E895903FC1C44045C8CB95EEBDB71E9E849D0 uid [ultimate] Joe Tester (with stupid passphrase) <joe@foo.bar> ssb elg1024 2016-12-16 [E]
If you want to create a key with the default algorithms you would use these parameters:
%echo Generating a default key Key-Type: default Subkey-Type: default Name-Real: Joe Tester Name-Comment: with stupid passphrase Name-Email: joe@foo.bar Expire-Date: 0 Passphrase: abc # Do a commit here, so that we can later print "done" :-) %commit %echo done
gpgsm
is a tool similar to gpg
to provide digital
encryption and signing services on X.509 certificates and the CMS
protocol. It is mainly used as a backend for S/MIME mail processing.
gpgsm
includes a full featured certificate management and
complies with all rules defined for the German Sphinx project.
See Option Index, for an index to GPGSM
’s commands and options.
Commands are not distinguished from options except for the fact that only one command is allowed.
--version
¶Print the program version and licensing information. Note that you cannot abbreviate this command.
--help, -h
¶Print a usage message summarizing the most useful command-line options. Note that you cannot abbreviate this command.
--warranty
¶Print warranty information. Note that you cannot abbreviate this command.
--dump-options
¶Print a list of all available options and commands. Note that you cannot abbreviate this command.
--encrypt
¶Perform an encryption. The keys the data is encrypted to must be set using the option --recipient.
--decrypt
¶Perform a decryption; the type of input is automatically determined. It may either be in binary form or PEM encoded; automatic determination of base-64 encoding is not done.
--sign
¶Create a digital signature. The key used is either the fist one found in the keybox or those set with the --local-user option.
--verify
¶Check a signature file for validity. Depending on the arguments a detached signature may also be checked.
--server
¶Run in server mode and wait for commands on the stdin
.
--call-dirmngr command [args]
¶Behave as a Dirmngr client issuing the request command with the
optional list of args. The output of the Dirmngr is printed
stdout. Please note that file names given as arguments should have an
absolute file name (i.e. commencing with /
) because they are
passed verbatim to the Dirmngr and the working directory of the
Dirmngr might not be the same as the one of this client. Currently it
is not possible to pass data via stdin to the Dirmngr. command
should not contain spaces.
This is command is required for certain maintaining tasks of the dirmngr
where a dirmngr must be able to call back to gpgsm
. See the Dirmngr
manual for details.
--call-protect-tool arguments
¶Certain maintenance operations are done by an external program call
gpg-protect-tool
; this is usually not installed in a directory
listed in the PATH variable. This command provides a simple wrapper to
access this tool. arguments are passed verbatim to this command;
use ‘--help’ to get a list of supported operations.
--generate-key
¶--gen-key
This command allows the creation of a certificate signing request or a self-signed certificate. It is commonly used along with the --output option to save the created CSR or certificate into a file. If used with the --batch a parameter file is used to create the CSR or certificate and it is further possible to create non-self-signed certificates.
--list-keys
¶-k
List all available certificates stored in the local key database. Note that the displayed data might be reformatted for better human readability and illegal characters are replaced by safe substitutes.
--list-secret-keys
¶-K
List all available certificates for which a corresponding a secret key is available.
--list-external-keys pattern
¶List certificates matching pattern using an external server. This
utilizes the dirmngr
service.
--list-chain
¶Same as --list-keys but also prints all keys making up the chain.
--dump-cert
¶--dump-keys
List all available certificates stored in the local key database using a format useful mainly for debugging.
--dump-chain
¶Same as --dump-keys but also prints all keys making up the chain.
--dump-secret-keys
¶List all available certificates for which a corresponding a secret key is available using a format useful mainly for debugging.
--dump-external-keys pattern
¶List certificates matching pattern using an external server.
This utilizes the dirmngr
service. It uses a format useful
mainly for debugging.
--show-certs [files]
¶This command takes certificate files as input and prints information about them in the same format as --dump-cert does. Each file may either contain a single binary certificate or several PEM encoded certificates. If no files are given, the input is taken from stdin.
Please note that the listing format may be changed in future releases and that the option --with-colons has currently no effect.
--keydb-clear-some-cert-flags
¶This is a debugging aid to reset certain flags in the key database
which are used to cache certain certificate statuses. It is especially
useful if a bad CRL or a weird running OCSP responder did accidentally
revoke certificate. There is no security issue with this command
because gpgsm
always make sure that the validity of a certificate is
checked right before it is used.
--delete-keys pattern
¶Delete the keys matching pattern. Note that there is no command
to delete the secret part of the key directly. In case you need to do
this, you should run the command gpgsm --dump-secret-keys KEYID
before you delete the key, copy the string of hex-digits in the
“keygrip” line and delete the file consisting of these hex-digits
and the suffix .key
from the private-keys-v1.d directory
below our GnuPG home directory (usually ~/.gnupg).
--export [pattern]
¶Export all certificates stored in the Keybox or those specified by the optional pattern. Those pattern consist of a list of user ids (see how-to-specify-a-user-id). When used along with the --armor option a few informational lines are prepended before each block. There is one limitation: As there is no commonly agreed upon way to pack more than one certificate into an ASN.1 structure, the binary export (i.e. without using armor) works only for the export of one certificate. Thus it is required to specify a pattern which yields exactly one certificate. Ephemeral certificate are only exported if all pattern are given as fingerprints or keygrips.
--export-secret-key-p12 key-id
¶Export the private key and the certificate identified by key-id
using the PKCS#12 format. When used with the --armor
option a few
informational lines are prepended to the output. Note, that the PKCS#12
format is not very secure and proper transport security should be used
to convey the exported key. (See option --p12-charset.)
--export-secret-key-p8 key-id
¶--export-secret-key-raw key-id
Export the private key of the certificate identified by key-id
with any encryption stripped. The ...-raw
command exports in
PKCS#1 format; the ...-p8
command exports in PKCS#8 format.
When used with the --armor
option a few informational lines are
prepended to the output. These commands are useful to prepare a key
for use on a TLS server.
--import [files]
¶Import the certificates from the PEM or binary encoded files as well as from signed-only messages. This command may also be used to import a secret key from a PKCS#12 file.
--learn-card
¶Read information about the private keys from the smartcard and import
the certificates from there. This command utilizes the gpg-agent
and in turn the scdaemon
.
--change-passphrase user_id
¶--passwd user_id
Change the passphrase of the private key belonging to the certificate specified as user_id. Note, that changing the passphrase/PIN of a smartcard is not yet supported.
GPGSM
features a bunch of options to control the exact behaviour
and to change the default configuration.
These options are used to change the configuration and are usually found in the option file.
--options file
¶Reads configuration from file instead of from the default per-user configuration file. The default configuration file is named gpgsm.conf and expected in the .gnupg directory directly below the home directory of the user.
--homedir dir
¶Set the name of the home directory to dir. If this option is not
used, the home directory defaults to ~/.gnupg. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable GNUPGHOME
or
(on Windows systems) by means of the Registry entry
HKCU\Software\GNU\GnuPG:HomeDir.
On Windows systems it is possible to install GnuPG as a portable application. In this case only this command line option is considered, all other ways to set a home directory are ignored.
-v
--verbose
¶Outputs additional information while running.
You can increase the verbosity by giving several
verbose commands to gpgsm
, such as ‘-vv’.
--keyserver string
¶This is a deprecated option. It was used to add an LDAP server to use for X.509 certificate and CRL lookup. The alias --ldapserver existed from version 2.2.28 to 2.2.33 and 2.3.2 to 2.3.4 but is now entirely ignored.
LDAP servers must be given in the configuration for dirmngr
.
--policy-file filename
¶Change the default name of the policy file to filename. The default name is policies.txt.
--agent-program file
¶Specify an agent program to be used for secret key operations. The
default value is determined by running the command gpgconf
.
Note that the pipe symbol (|
) is used for a regression test
suite hack and may thus not be used in the file name.
--dirmngr-program file
¶Specify a dirmngr program to be used for CRL checks. The default value is /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/bin/dirmngr.
--prefer-system-dirmngr
¶This option is obsolete and ignored.
--disable-dirmngr
Entirely disable the use of the Dirmngr.
--no-autostart
¶Do not start the gpg-agent or the dirmngr if it has not yet been
started and its service is required. This option is mostly useful on
machines where the connection to gpg-agent has been redirected to
another machines. If dirmngr is required on the remote machine, it
may be started manually using gpgconf --launch dirmngr
.
--no-secmem-warning
¶Do not print a warning when the so called "secure memory" cannot be used.
--log-file file
¶When running in server mode, append all logging output to file. Use socket:// to log to socket.
--log-time
¶Prefix all log output with a timestamp even if no log file is used.
--enable-policy-checks
¶--disable-policy-checks
By default policy checks are enabled. These options may be used to change it.
--enable-crl-checks
¶--disable-crl-checks
By default the CRL checks are enabled and the DirMngr is used to check for revoked certificates. The disable option is most useful with an off-line network connection to suppress this check and also to avoid that new certificates introduce a web bug by including a certificate specific CRL DP. The disable option also disables an issuer certificate lookup via the authorityInfoAccess property of the certificate; the --enable-issuer-key-retrieve can be used to make use of that property anyway.
--enable-trusted-cert-crl-check
¶--disable-trusted-cert-crl-check
By default the CRL for trusted root certificates are checked like for any other certificates. This allows a CA to revoke its own certificates voluntary without the need of putting all ever issued certificates into a CRL. The disable option may be used to switch this extra check off. Due to the caching done by the Dirmngr, there will not be any noticeable performance gain. Note, that this also disables possible OCSP checks for trusted root certificates. A more specific way of disabling this check is by adding the “relax” keyword to the root CA line of the trustlist.txt
--force-crl-refresh
¶Tell the dirmngr to reload the CRL for each request. For better performance, the dirmngr will actually optimize this by suppressing the loading for short time intervals (e.g. 30 minutes). This option is useful to make sure that a fresh CRL is available for certificates hold in the keybox. The suggested way of doing this is by using it along with the option --with-validation for a key listing command. This option should not be used in a configuration file.
--enable-issuer-based-crl-check
¶Run a CRL check even for certificates which do not have any CRL distribution point. This requires that a suitable LDAP server has been configured in Dirmngr and that the CRL can be found using the issuer. This option reverts to what GnuPG did up to version 2.2.20. This option is in general not useful.
--enable-ocsp
¶--disable-ocsp
By default OCSP checks are disabled. The enable option may be used to enable OCSP checks via Dirmngr. If CRL checks are also enabled, CRLs will be used as a fallback if for some reason an OCSP request will not succeed. Note, that you have to allow OCSP requests in Dirmngr’s configuration too (option --allow-ocsp) and configure Dirmngr properly. If you do not do so you will get the error code ‘Not supported’.
--auto-issuer-key-retrieve
¶If a required certificate is missing while validating the chain of certificates, try to load that certificate from an external location. This usually means that Dirmngr is employed to search for the certificate. Note that this option makes a "web bug" like behavior possible. LDAP server operators can see which keys you request, so by sending you a message signed by a brand new key (which you naturally will not have on your local keybox), the operator can tell both your IP address and the time when you verified the signature. Note that if CRL checking is not disabled issuer certificates are retrieved in any case using the caIssuers authorityInfoAccess method.
--validation-model name
¶This option changes the default validation model. The only possible values are "shell" (which is the default), "chain" which forces the use of the chain model and "steed" for a new simplified model. The chain model is also used if an option in the trustlist.txt or an attribute of the certificate requests it. However the standard model (shell) is in that case always tried first.
--ignore-cert-extension oid
¶Add oid to the list of ignored certificate extensions. The
oid is expected to be in dotted decimal form, like
2.5.29.3
. This option may be used more than once. Critical
flagged certificate extensions matching one of the OIDs in the list
are treated as if they are actually handled and thus the certificate
will not be rejected due to an unknown critical extension. Use this
option with care because extensions are usually flagged as critical
for a reason.
--armor
¶-a
Create PEM encoded output. Default is binary output.
--base64
¶Create Base-64 encoded output; i.e. PEM without the header lines.
--assume-armor
¶Assume the input data is PEM encoded. Default is to autodetect the encoding but this is may fail.
--assume-base64
¶Assume the input data is plain base-64 encoded.
--assume-binary
¶Assume the input data is binary encoded.
--input-size-hint n
¶This option can be used to tell GPGSM the size of the input data in bytes. n must be a positive base-10 number. It is used by the --status-fd line “PROGRESS” to provide a value for “total” if that is not available by other means.
--p12-charset name
¶gpgsm
uses the UTF-8 encoding when encoding passphrases for
PKCS#12 files. This option may be used to force the passphrase to be
encoded in the specified encoding name. This is useful if the
application used to import the key uses a different encoding and thus
will not be able to import a file generated by gpgsm
. Commonly
used values for name are Latin1
and CP850
. Note
that gpgsm
itself automagically imports any file with a
passphrase encoded to the most commonly used encodings.
--default-key user_id
¶Use user_id as the standard key for signing. This key is used if no other key has been defined as a signing key. Note, that the first --local-users option also sets this key if it has not yet been set; however --default-key always overrides this.
--local-user user_id
-u user_id
¶Set the user(s) to be used for signing. The default is the first secret key found in the database.
--recipient name
¶-r
Encrypt to the user id name. There are several ways a user id may be given (see how-to-specify-a-user-id).
--output file
¶-o file
Write output to file. The default is to write it to stdout.
--with-key-data
¶Displays extra information with the --list-keys
commands. Especially
a line tagged grp
is printed which tells you the keygrip of a
key. This string is for example used as the file name of the
secret key. Implies --with-colons
.
--with-validation
¶When doing a key listing, do a full validation check for each key and print the result. This is usually a slow operation because it requires a CRL lookup and other operations.
When used along with --import, a validation of the certificate to import is done and only imported if it succeeds the test. Note that this does not affect an already available certificate in the DB. This option is therefore useful to simply verify a certificate.
--with-md5-fingerprint
For standard key listings, also print the MD5 fingerprint of the certificate.
--with-keygrip
Include the keygrip in standard key listings. Note that the keygrip is always listed in --with-colons mode.
--with-secret
¶Include info about the presence of a secret key in public key listings
done with --with-colons
.
--no-pretty-dn
¶By default gpgsm prints distinguished names (DNs) like the Issuer or Subject in a more readable format (e.g. using a well defined order of the parts). However, this format can’t be used as input strings. This option reverts printing to standard RFC-2253 format and thus avoids the need to use –dump-cert or –with-colons to get the “real” name.
--include-certs n
¶Using n of -2 includes all certificate except for the root cert, -1 includes all certs, 0 does not include any certs, 1 includes only the signers cert and all other positive values include up to n certificates starting with the signer cert. The default is -2.
--cipher-algo oid
¶Use the cipher algorithm with the ASN.1 object identifier oid for
encryption. For convenience the strings 3DES
, AES
and
AES256
may be used instead of their OIDs. The default is
AES
(2.16.840.1.101.3.4.1.2).
--digest-algo name
Use name
as the message digest algorithm. Usually this
algorithm is deduced from the respective signing certificate. This
option forces the use of the given algorithm and may lead to severe
interoperability problems.
--chuid uid
¶Change the current user to uid which may either be a number or a name. This can be used from the root account to run gpgsm for another user. If uid is not the current UID a standard PATH is set and the envvar GNUPGHOME is unset. To override the latter the option --homedir can be used. This option has only an effect when used on the command line. This option has currently no effect at all on Windows.
--extra-digest-algo name
¶Sometimes signatures are broken in that they announce a different digest
algorithm than actually used. gpgsm
uses a one-pass data
processing model and thus needs to rely on the announced digest
algorithms to properly hash the data. As a workaround this option may
be used to tell gpgsm
to also hash the data using the algorithm
name; this slows processing down a little bit but allows verification of
such broken signatures. If gpgsm
prints an error like
“digest algo 8 has not been enabled” you may want to try this option,
with ‘SHA256’ for name.
--compliance string
¶Set the compliance mode. Valid values are shown when using "help" for string.
--min-rsa-length n
¶This option adjusts the compliance mode "de-vs" for stricter key size requirements. For example, a value of 3000 turns rsa2048 and dsa2048 keys into non-VS-NfD compliant keys.
--require-compliance
¶To check that data has been encrypted according to the rules of the current compliance mode, a gpgsm user needs to evaluate the status lines. This is allows frontends to handle compliance check in a more flexible way. However, for scripted use the required evaluation of the status-line requires quite some effort; this option can be used instead to make sure that the gpgsm process exits with a failure if the compliance rules are not fulfilled. Note that this option has currently an effect only in "de-vs" mode.
--always-trust
¶Force encryption to the specified certificates without any validation of the certificate chain. The only requirement is that the certificate is capable of encryption. Note that this option is ineffective if --require-compliance is used.
--ignore-cert-with-oid oid
¶Add oid to the list of OIDs to be checked while reading
certificates from smartcards. The oid is expected to be in
dotted decimal form, like 2.5.29.3
. This option may be used
more than once. As of now certificates with an extended key usage
matching one of those OIDs are ignored during a --learn-card
operation and not imported. This option can help to keep the local
key database clear of unneeded certificates stored on smartcards.
--faked-system-time epoch
¶This option is only useful for testing; it sets the system time back or forth to epoch which is the number of seconds elapsed since the year 1970. Alternatively epoch may be given as a full ISO time string (e.g. "20070924T154812").
--with-ephemeral-keys
¶Include ephemeral flagged keys in the output of key listings. Note that they are included anyway if the key specification for a listing is given as fingerprint or keygrip.
--compatibility-flags flags
¶Set compatibility flags to work around problems due to non-compliant certificates or data. The flags are given as a comma separated list of flag names and are OR-ed together. The special flag "none" clears the list and allows one to start over with an empty list. To get a list of available flags the sole word "help" can be used.
--debug-level level
¶Select the debug level for investigating problems. level may be a numeric value or by a keyword:
none
No debugging at all. A value of less than 1 may be used instead of the keyword.
basic
Some basic debug messages. A value between 1 and 2 may be used instead of the keyword.
advanced
More verbose debug messages. A value between 3 and 5 may be used instead of the keyword.
expert
Even more detailed messages. A value between 6 and 8 may be used instead of the keyword.
guru
All of the debug messages you can get. A value greater than 8 may be used instead of the keyword. The creation of hash tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not specified and may change with newer releases of this program. They are however carefully selected to best aid in debugging.
--debug flags
¶Set debug flags. All flags are or-ed and flags may be given in C syntax (e.g. 0x0042) or as a comma separated list of flag names. To get a list of all supported flags the single word "help" can be used. This option is only useful for debugging and the behavior may change at any time without notice.
Note, that all flags set using this option may get overridden by
--debug-level
.
--debug-all
¶Same as --debug=0xffffffff
--debug-allow-core-dump
¶Usually gpgsm
tries to avoid dumping core by well written code and by
disabling core dumps for security reasons. However, bugs are pretty
durable beasts and to squash them it is sometimes useful to have a core
dump. This option enables core dumps unless the Bad Thing happened
before the option parsing.
--debug-no-chain-validation
¶This is actually not a debugging option but only useful as such. It
lets gpgsm
bypass all certificate chain validation checks.
--debug-ignore-expiration
¶This is actually not a debugging option but only useful as such. It
lets gpgsm
ignore all notAfter dates, this is used by the regression
tests.
--passphrase-fd n
¶Read the passphrase from file descriptor n
. Only the first line
will be read from file descriptor n
. If you use 0 for n
,
the passphrase will be read from STDIN. This can only be used if only
one passphrase is supplied.
Note that this passphrase is only used if the option --batch has also been given.
--pinentry-mode mode
¶Set the pinentry mode to mode
. Allowed values for mode
are:
Use the default of the agent, which is ask
.
Force the use of the Pinentry.
Emulate use of Pinentry’s cancel button.
Return a Pinentry error (“No Pinentry”).
Redirect Pinentry queries to the caller. Note that in contrast to Pinentry the user is not prompted again if he enters a bad password.
--request-origin origin
¶Tell gpgsm to assume that the operation ultimately originated at
origin. Depending on the origin certain restrictions are applied
and the Pinentry may include an extra note on the origin. Supported
values for origin are: local
which is the default,
remote
to indicate a remote origin or browser
for an
operation requested by a web browser.
--no-common-certs-import
¶Suppress the import of common certificates on keybox creation.
All the long options may also be given in the configuration file after stripping off the two leading dashes.
There are a few configuration files to control certain aspects of
gpgsm
’s operation. Unless noted, they are expected in the
current home directory (see option --homedir).
This is the standard configuration file read by gpgsm
on
startup. It may contain any valid long option; the leading two dashes
may not be entered and the option may not be abbreviated. This default
name may be changed on the command line (see gpgsm-option --options).
You should backup this file.
This is an optional configuration file read by gpgsm
on
startup. It may contain options pertaining to all components of
GnuPG. Its current main use is for the "use-keyboxd" option.
This is a list of allowed CA policies. This file should list the object identifiers of the policies line by line. Empty lines and lines starting with a hash mark are ignored. Policies missing in this file and not marked as critical in the certificate will print only a warning; certificates with policies marked as critical and not listed in this file will fail the signature verification. You should backup this file.
For example, to allow only the policy 2.289.9.9, the file should look like this:
# Allowed policies 2.289.9.9
This is the list of root certificates used for qualified certificates.
They are defined as certificates capable of creating legally binding
signatures in the same way as handwritten signatures are. Comments
start with a hash mark and empty lines are ignored. Lines do have a
length limit but this is not a serious limitation as the format of the
entries is fixed and checked by gpgsm
: A non-comment line starts with
optional whitespace, followed by exactly 40 hex characters, white space
and a lowercased 2 letter country code. Additional data delimited with
by a white space is current ignored but might late be used for other
purposes.
Note that even if a certificate is listed in this file, this does not mean that the certificate is trusted; in general the certificates listed in this file need to be listed also in trustlist.txt. This is a global file an installed in the sysconf directory (e.g. /etc/gnupg/qualified.txt).
Every time gpgsm
uses a certificate for signing or verification
this file will be consulted to check whether the certificate under
question has ultimately been issued by one of these CAs. If this is the
case the user will be informed that the verified signature represents a
legally binding (“qualified”) signature. When creating a signature
using such a certificate an extra prompt will be issued to let the user
confirm that such a legally binding signature shall really be created.
Because this software has not yet been approved for use with such certificates, appropriate notices will be shown to indicate this fact.
This is plain text file with a few help entries used with
pinentry
as well as a large list of help items for
gpg
and gpgsm
. The standard file has English help
texts; to install localized versions use filenames like help.LL.txt
with LL denoting the locale. GnuPG comes with a set of predefined help
files in the data directory (e.g. /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/share/gnupg/gnupg/help.de.txt)
and allows overriding of any help item by help files stored in the
system configuration directory (e.g. /etc/gnupg/help.de.txt).
For a reference of the help file’s syntax, please see the installed
help.txt file.
This file is a collection of common certificates used to populated a newly created pubring.kbx. An administrator may replace this file with a custom one. The format is a concatenation of PEM encoded X.509 certificates. This global file is installed in the data directory (e.g. /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/share/gnupg/com-certs.pem).
Note that on larger installations, it is useful to put predefined files into the directory /etc/skel/.gnupg/ so that newly created users start up with a working configuration. For existing users a small helper script is provided to create these files (see Create .gnupg home directories).
For internal purposes gpgsm
creates and maintains a few other files;
they all live in the current home directory (see option --homedir). Only gpgsm
may modify these files.
This a database file storing the certificates as well as meta
information. For debugging purposes the tool kbxutil
may be
used to show the internal structure of this file. You should backup
this file.
This content of this file is used to maintain the internal state of the random number generator across invocations. The same file is used by other programs of this software too.
If this file exists
gpgsm
will first try to connect to this socket for
accessing gpg-agent
before starting a new gpg-agent
instance. Under Windows this socket (which in reality be a plain file
describing a regular TCP listening port) is the standard way of
connecting the gpg-agent
.
gpgsm
is often used as a backend engine by other software. To help
with this a machine interface has been defined to have an unambiguous
way to do this. This is most likely used with the --server
command
but may also be used in the standard operation mode by using the
--status-fd
option.
It is very important to understand the semantics used with signature verification. Checking a signature is not as simple as it may sound and so the operation is a bit complicated. In most cases it is required to look at several status lines. Here is a table of all cases a signed message may have:
This does mean that the signature has been successfully verified, the
certificates are all sane. However there are two subcases with
important information: One of the certificates may have expired or a
signature of a message itself as expired. It is a sound practise to
consider such a signature still as valid but additional information
should be displayed. Depending on the subcase gpgsm
will issue
these status codes:
GOODSIG
, VALIDSIG
, TRUST_FULLY
EXPKEYSIG
, VALIDSIG
, TRUST_FULLY
EXPSIG
, VALIDSIG
, TRUST_FULLY
Note, that this case is currently not implemented.
This means that the signature verification failed (this is an indication
of a transfer error, a program error or tampering with the message).
gpgsm
issues one of these status codes sequences:
BADSIG
GOODSIG
, VALIDSIG
TRUST_NEVER
For some reason the signature could not be verified, i.e. it cannot be decided whether the signature is valid or invalid. A common reason for this is a missing certificate.
The command --generate-key may be used along with the option --batch to either create a certificate signing request (CSR) or an X.509 certificate. This is controlled by a parameter file; the format of this file is as follows:
Control statements:
Print text as diagnostic.
Suppress actual key generation (useful for syntax checking).
Perform the key generation. Note that an implicit commit is done at the next Key-Type parameter.
General Parameters:
Starts a new parameter block by giving the type of the primary key. The algorithm must be capable of signing. This is a required parameter. The supported values for algo are ‘rsa’, ‘ecdsa’, and ‘eddsa’.
The requested length of a generated key in bits. Defaults to 3072. The value is ignored for ECC algorithms.
This is optional and used to generate a CSR or certificate for an already existing key. Key-Length will be ignored when given.
Space or comma delimited list of key usage, allowed values are ‘encrypt’, ‘sign’ and ‘cert’. This is used to generate the keyUsage extension. Please make sure that the algorithm is capable of this usage. Default is to allow encrypt and sign.
This is the Distinguished Name (DN) of the subject in RFC-2253 format.
This is an email address for the altSubjectName. This parameter is optional but may occur several times to add several email addresses to a certificate.
The is an DNS name for the altSubjectName. This parameter is optional but may occur several times to add several DNS names to a certificate.
This is an URI for the altSubjectName. This parameter is optional but may occur several times to add several URIs to a certificate.
Additional parameters used to create a certificate (in contrast to a certificate signing request):
If this parameter is given an X.509 certificate will be generated. sn is expected to be a hex string representing an unsigned integer of arbitrary length. The special value ‘random’ can be used to create a 64 bit random serial number.
This is the DN name of the issuer in RFC-2253 format. If it is not set it will default to the subject DN and a special GnuPG extension will be included in the certificate to mark it as a standalone certificate.
Set the notBefore date of the certificate. Either a date like ‘1986-04-26’ or ‘1986-04-26 12:00’ or a standard ISO timestamp like ‘19860426T042640’ may be used. The time is considered to be UTC. If it is not given the current date is used.
Set the notAfter date of the certificate. Either a date like ‘2063-04-05’ or ‘2063-04-05 17:00’ or a standard ISO timestamp like ‘20630405T170000’ may be used. The time is considered to be UTC. If it is not given a default value in the not too far future is used.
This gives the keygrip of the key used to sign the certificate. If it is not given a self-signed certificate will be created. For compatibility with future versions, it is suggested to prefix the keygrip with a ‘&’.
Use hash-algo for this CSR or certificate. The supported hash algorithms are: ‘sha1’, ‘sha256’, ‘sha384’ and ‘sha512’; they may also be specified with uppercase letters. The default is ‘sha256’.
Insert the decoded value of hexstring as authorityKeyIdentifier.
If this is not given and an ECC algorithm is used the public part of
the certified public key is used as authorityKeyIdentifier. To
inhibit any authorityKeyIdentifier use the special value none
for hexstring.
Insert the decoded value of hexstring as subjectKeyIdentifier.
If this is not given and an ECC algorithm is used the public part of
the signing key is used as authorityKeyIdentifier. To inhibit any
subjectKeyIdentifier use the special value none
for
hexstring.
Description of the protocol used to access GPGSM
.
GPGSM
does implement the Assuan protocol and in addition
provides a regular command line interface which exhibits a full client
to this protocol (but uses internal linking). To start
gpgsm
as a server the command line the option
--server
must be used. Additional options are provided to
select the communication method (i.e. the name of the socket).
We assume that the connection has already been established; see the Assuan manual for details.
Before encryption can be done the recipient must be set using the command:
RECIPIENT userID
Set the recipient for the encryption. userID should be the
internal representation of the key; the server may accept any other way
of specification. If this is a valid and trusted recipient the server
does respond with OK, otherwise the return is an ERR with the reason why
the recipient cannot be used, the encryption will then not be done for
this recipient. If the policy is not to encrypt at all if not all
recipients are valid, the client has to take care of this. All
RECIPIENT
commands are cumulative until a RESET
or an
successful ENCRYPT
command.
INPUT FD[=n] [--armor|--base64|--binary]
Set the file descriptor for the message to be encrypted to n. Obviously the pipe must be open at that point, the server establishes its own end. If the server returns an error the client should consider this session failed. If n is not given, this commands uses the last file descriptor passed to the application. See the assuan_sendfd function in the Libassuan manual, on how to do descriptor passing.
The --armor
option may be used to advise the server that the
input data is in PEM format, --base64
advises that a
raw base-64 encoding is used, --binary
advises of raw binary
input (BER). If none of these options is used, the server
tries to figure out the used encoding, but this may not always be
correct.
OUTPUT FD[=n] [--armor|--base64]
Set the file descriptor to be used for the output (i.e. the encrypted message). Obviously the pipe must be open at that point, the server establishes its own end. If the server returns an error the client should consider this session failed.
The option --armor encodes the output in PEM format, the --base64 option applies just a base-64 encoding. No option creates binary output (BER).
The actual encryption is done using the command
ENCRYPT
It takes the plaintext from the INPUT
command, writes to the
ciphertext to the file descriptor set with the OUTPUT
command,
take the recipients from all the recipients set so far. If this command
fails the clients should try to delete all output currently done or
otherwise mark it as invalid. GPGSM
does ensure that there
will not be any
security problem with leftover data on the output in this case.
This command should in general not fail, as all necessary checks have been done while setting the recipients. The input and output pipes are closed.
Input and output FDs are set the same way as in encryption, but
INPUT
refers to the ciphertext and OUTPUT
to the plaintext. There
is no need to set recipients. GPGSM
automatically strips any
S/MIME headers from the input, so it is valid to pass an
entire MIME part to the INPUT pipe.
The decryption is done by using the command
DECRYPT
It performs the decrypt operation after doing some check on the internal state (e.g. that all needed data has been set). Because it utilizes the GPG-Agent for the session key decryption, there is no need to ask the client for a protecting passphrase - GpgAgent takes care of this by requesting this from the user.
Signing is usually done with these commands:
INPUT FD[=n] [--armor|--base64|--binary]
This tells GPGSM
to read the data to sign from file descriptor n.
OUTPUT FD[=m] [--armor|--base64]
Write the output to file descriptor m. If a detached signature is requested, only the signature is written.
SIGN [--detached]
Sign the data set with the INPUT
command and write it to the sink set by
OUTPUT
. With --detached
, a detached signature is created
(surprise).
The key used for signing is the default one or the one specified in the configuration file. To get finer control over the keys, it is possible to use the command
SIGNER userID
to set the signer’s key. userID should be the
internal representation of the key; the server may accept any other way
of specification. If this is a valid and trusted recipient the server
does respond with OK, otherwise the return is an ERR with the reason why
the key cannot be used, the signature will then not be created using
this key. If the policy is not to sign at all if not all
keys are valid, the client has to take care of this. All
SIGNER
commands are cumulative until a RESET
is done.
Note that a SIGN
does not reset this list of signers which is in
contrast to the RECIPIENT
command.
To verify a message the command:
VERIFY
is used. It does a verify operation on the message send to the input FD. The result is written out using status lines. If an output FD was given, the signed text will be written to that. If the signature is a detached one, the server will inquire about the signed material and the client must provide it.
This is used to generate a new keypair, store the secret part in the
PSE and the public key in the key database. We will probably
add optional commands to allow the client to select whether a hardware
token is used to store the key. Configuration options to
GPGSM
can be used to restrict the use of this command.
GENKEY
GPGSM
checks whether this command is allowed and then does an
INQUIRY to get the key parameters, the client should then send the
key parameters in the native format:
S: INQUIRE KEY_PARAM native C: D foo:fgfgfg C: D bar C: END
Please note that the server may send Status info lines while reading the data lines from the client. After this the key generation takes place and the server eventually does send an ERR or OK response. Status lines may be issued as a progress indicator.
To list the keys in the internal database or using an external key provider, the command:
LISTKEYS pattern
is used. To allow multiple patterns (which are ORed during the search) quoting is required: Spaces are to be translated into "+" or into "%20"; in turn this requires that the usual escape quoting rules are done.
LISTSECRETKEYS pattern
Lists only the keys where a secret key is available.
The list commands are affected by the option
OPTION list-mode=mode
where mode may be:
0
Use default (which is usually the same as 1).
1
List only the internal keys.
2
List only the external keys.
3
List internal and external keys.
Note that options are valid for the entire session.
To export certificate from the internal key database the command:
EXPORT [--data [--armor] [--base64]] [--] pattern
is used. To allow multiple patterns (which are ORed) quoting is required: Spaces are to be translated into "+" or into "%20"; in turn this requires that the usual escape quoting rules are done.
If the --data option has not been given, the format of the
output depends on what was set with the OUTPUT
command. When using
PEM encoding a few informational lines are prepended.
If the --data has been given, a target set via OUTPUT
is
ignored and the data is returned inline using standard
D
-lines. This avoids the need for an extra file descriptor. In
this case the options --armor and --base64 may be used
in the same way as with the OUTPUT
command.
To import certificates into the internal key database, the command
IMPORT [--re-import]
is used. The data is expected on the file descriptor set with the
INPUT
command. Certain checks are performed on the
certificate. Note that the code will also handle PKCS#12 files and
import private keys; a helper program is used for that.
With the option --re-import the input data is expected to a be a linefeed separated list of fingerprints. The command will re-import the corresponding certificates; that is they are made permanent by removing their ephemeral flag.
To delete a certificate the command
DELKEYS pattern
is used. To allow multiple patterns (which are ORed) quoting is required: Spaces are to be translated into "+" or into "%20"; in turn this requires that the usual escape quoting rules are done.
The certificates must be specified unambiguously otherwise an error is returned.
This command is used to retrieve an audit log.
GETAUDITLOG [--data] [--html]
If --data is used, the audit log is send using D-lines
instead of being sent to the file descriptor given by an OUTPUT
command. If --html is used, the output is formatted as an
XHTML block. This is designed to be incorporated into a HTML
document.
This is a multipurpose function to return a variety of information.
GETINFO what
The value of what specifies the kind of information returned:
version
Return the version of the program.
pid
Return the process id of the process.
agent-check
Return OK if the agent is running.
cmd_has_option cmd opt
Return OK if the command cmd implements the option opt. The leading two dashes usually used with opt shall not be given.
offline
Return OK if the connection is in offline mode. This may be either
due to a OPTION offline=1
or due to gpgsm
being
started with option --disable-dirmngr.
always-trust
Returns OK of the connection is in always-trust mode. That is either --always-trust or GPGSM OPTION always-trust are active.
The standard Assuan option handler supports these options.
OPTION name[=value]
These names are recognized:
putenv
Change the session’s environment to be passed via gpg-agent to
Pinentry. value is a string of the form
<KEY>[=[<STRING>]]
. If only <KEY>
is given the
environment variable <KEY>
is removed from the session
environment, if <KEY>=
is given that environment variable is
set to the empty string, and if <STRING>
is given it is set to
that string.
display
¶Set the session environment variable DISPLAY
is set to value.
ttyname
¶Set the session environment variable GPG_TTY
is set to value.
ttytype
¶Set the session environment variable TERM
is set to value.
lc-ctype
¶Set the session environment variable LC_CTYPE
is set to value.
lc-messages
¶Set the session environment variable LC_MESSAGES
is set to value.
xauthority
¶Set the session environment variable XAUTHORITY
is set to value.
pinentry-user-data
¶Set the session environment variable PINENTRY_USER_DATA
is set
to value.
include-certs
This option overrides the command line option --include-certs. A value of -2 includes all certificates except for the root certificate, -1 includes all certificates, 0 does not include any certificates, 1 includes only the signers certificate and all other positive values include up to value certificates starting with the signer cert.
list-mode
See gpgsm-cmd listkeys.
list-to-output
If value is true the output of the list commands
(see gpgsm-cmd listkeys) is written to the file descriptor set
with the last OUTPUT
command. If value is false the output is
written via data lines; this is the default.
with-validation
If value is true for each listed certificate the validation status is printed. This may result in the download of a CRL or the user being asked about the trustworthiness of a root certificate. The default is given by a command line option (see gpgsm-option --with-validation).
with-secret
If value is true certificates with a corresponding private key are marked by the list commands.
validation-model
This option overrides the command line option validation-model for the session. (See gpgsm-option --validation-model.)
with-key-data
This option globally enables the command line option --with-key-data. (See gpgsm-option --with-key-data.)
enable-audit-log
If value is true data to write an audit log is gathered. (See gpgsm-cmd getauditlog.)
allow-pinentry-notify
If this option is used notifications about the launch of a Pinentry are passed back to the client.
with-ephemeral-keys
If value is true ephemeral certificates are included in the output of the list commands.
no-encrypt-to
If this option is used all keys set by the command line option --encrypt-to are ignored.
offline
If value is true or value is not given all network access is disabled for this session. This is the same as the command line option --disable-dirmngr.
always-trust
If value is true or value is not given encryption to the specified certificates is forced without any validation of the certificate chain. The only requirement is that the certificates are capable of encryption. If set to false the standard behaviour is re-established. This option is cleared by a RESET and after each encrypt operation. Note that this option is ignored if --always-trust or --require-compliance are used.
input-size-hint
This is the same as the --input-size-hint command line option.
The scdaemon
is a daemon to manage smartcards. It is usually
invoked by gpg-agent
and in general not used directly.
See Option Index, for an index to scdaemon
’s commands and
options.
Commands are not distinguished from options except for the fact that only one command is allowed.
--version
¶Print the program version and licensing information. Note that you cannot abbreviate this command.
--help, -h
¶Print a usage message summarizing the most useful command-line options. Note that you cannot abbreviate this command.
--dump-options
¶Print a list of all available options and commands. Note that you cannot abbreviate this command.
--server
¶Run in server mode and wait for commands on the stdin
. The
default mode is to create a socket and listen for commands there.
--multi-server
¶Run in server mode and wait for commands on the stdin
as well as
on an additional Unix Domain socket. The server command GETINFO
may be used to get the name of that extra socket.
--daemon
¶Run the program in the background. This option is required to prevent it from being accidentally running in the background.
--options file
¶Reads configuration from file instead of from the default per-user configuration file. The default configuration file is named scdaemon.conf and expected in the .gnupg directory directly below the home directory of the user.
--homedir dir
¶Set the name of the home directory to dir. If this option is not
used, the home directory defaults to ~/.gnupg. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable GNUPGHOME
or
(on Windows systems) by means of the Registry entry
HKCU\Software\GNU\GnuPG:HomeDir.
On Windows systems it is possible to install GnuPG as a portable application. In this case only this command line option is considered, all other ways to set a home directory are ignored.
-v
--verbose
¶Outputs additional information while running.
You can increase the verbosity by giving several
verbose commands to gpgsm
, such as ‘-vv’.
--debug-level level
¶Select the debug level for investigating problems. level may be a numeric value or a keyword:
none
No debugging at all. A value of less than 1 may be used instead of the keyword.
basic
Some basic debug messages. A value between 1 and 2 may be used instead of the keyword.
advanced
More verbose debug messages. A value between 3 and 5 may be used instead of the keyword.
expert
Even more detailed messages. A value between 6 and 8 may be used instead of the keyword.
guru
All of the debug messages you can get. A value greater than 8 may be used instead of the keyword. The creation of hash tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not specified and may change with newer releases of this program. They are however carefully selected to best aid in debugging.
Note: All debugging options are subject to change and thus should not be used by any application program. As the name says, they are only used as helpers to debug problems.
--debug flags
¶Set debug flags. All flags are or-ed and flags may be given in C syntax (e.g. 0x0042) or as a comma separated list of flag names. To get a list of all supported flags the single word "help" can be used. This option is only useful for debugging and the behavior may change at any time without notice.
--debug-all
¶Same as --debug=0xffffffff
--debug-wait n
¶When running in server mode, wait n seconds before entering the actual processing loop and print the pid. This gives time to attach a debugger.
--debug-ccid-driver
¶Enable debug output from the included CCID driver for smartcards. Using this option twice will also enable some tracing of the T=1 protocol. Note that this option may reveal sensitive data.
--debug-disable-ticker
¶This option disables all ticker functions like checking for card insertions.
--debug-allow-core-dump
¶For security reasons we won’t create a core dump when the process aborts. For debugging purposes it is sometimes better to allow core dump. This option enables it and also changes the working directory to /tmp when running in --server mode.
--debug-log-tid
¶This option appends a thread ID to the PID in the log output.
--debug-assuan-log-cats cats
¶Changes the active Libassuan logging categories to cats. The
value for cats is an unsigned integer given in usual C-Syntax.
A value of 0 switches to a default category. If this option is not
used the categories are taken from the environment variable
ASSUAN_DEBUG
. Note that this option has only an effect if the
Assuan debug flag has also been with the option --debug. For
a list of categories see the Libassuan manual.
--no-detach
¶Don’t detach the process from the console. This is mainly useful for debugging.
--listen-backlog n
¶Set the size of the queue for pending connections. The default is 64. This option has an effect only if --multi-server is also used.
--log-file file
¶Append all logging output to file. This is very helpful in seeing what the agent actually does. Use socket:// to log to socket.
--pcsc-shared
¶Use shared mode to access the card via PC/SC. This is a somewhat dangerous option because Scdaemon assumes exclusive access to the card and for example caches certain information from the card. Use this option only if you know what you are doing.
--pcsc-driver library
¶Use library to access the smartcard reader. The current default on Unix is libpcsclite.so and on Windows winscard.dll. Instead of using this option you might also want to install a symbolic link to the default file name (e.g. from libpcsclite.so.1). A Unicode file name may not be used on Windows.
--disable-ccid
¶The integrated CCID driver for CCID compliant devices can be available when libusb was detected at build time, and it is used to access the smartcard reader. If access via PC/SC driver is needed, please configure this option to disable CCID driver support (if any). In GnuPG 2.2, there was a fallback mechanism from CCID driver to PC/SC driver. The fallback mechanism worked, because scdaemon in GnuPG 2.2 only supported a single token/reader. To support of multiple tokens/readers at the same time, fallback mechanism was removed.
--reader-port number_or_string
¶This option may be used to specify the port of the card terminal. A value of 0 refers to the first serial device; add 32768 to access USB devices. The default is 32768 (first USB device). PC/SC or CCID readers might need a string here; run the program in verbose mode to get a list of available readers. The default is then the first reader found.
To get a list of available CCID readers you may use this command:
echo scd getinfo reader_list \ | gpg-connect-agent --decode | awk '/^D/ {print $2}' |
--card-timeout n
¶This option is deprecated. In GnuPG 2.0, it used to be used for DISCONNECT command to control timing issue. Since DISCONNECT command works synchronously, it has no effect.
--enable-pinpad-varlen
¶Please specify this option when the card reader supports variable length input for pinpad (default is no). For known readers (listed in ccid-driver.c and apdu.c), this option is not needed. Note that if your card reader doesn’t supports variable length input but you want to use it, you need to specify your pinpad request on your card.
--disable-pinpad
¶Even if a card reader features a pinpad, do not try to use it.
--deny-admin
¶This option disables the use of admin class commands for card applications where this is supported. Currently we support it for the OpenPGP card. This option is useful to inhibit accidental access to admin class command which could ultimately lock the card through wrong PIN numbers. Note that GnuPG versions older than 2.0.11 featured an --allow-admin option which was required to use such admin commands. This option has no more effect today because the default is now to allow admin commands.
--disable-application name
¶This option disables the use of the card application named name. This is mainly useful for debugging or if a application with lower priority should be used by default.
--application-priority namelist
¶This option allows one to change the order in which applications of a card a tried if no specific application was requested. namelist is a space or comma delimited list of application names. Unknown names are simply skipped. Applications not mentioned in the list are put in the former order at the end of the new priority list.
To get the list of current active applications, use
gpg-connect-agent 'scd getinfo app_list' /bye |
All the long options may also be given in the configuration file after stripping off the two leading dashes.
scdaemon
supports the card applications as described below.
This application is currently only used by gpg
but may in
future also be useful with gpgsm
. Version 1 and version 2 of
the card is supported.
The specifications for these cards are available at
http://g10code.com/docs/openpgp-card-1.0.pdf and
http://g10code.com/docs/openpgp-card-2.0.pdf.
This is the main application of the Telesec cards as available in
Germany. It is a superset of the German DINSIG card. The card is
used by gpgsm
.
This is an application as described in the German draft standard DIN V 66291-1. It is intended to be used by cards supporting the German signature law and its bylaws (SigG and SigV).
This is common framework for smart card applications. It is used by
gpgsm
.
This is a simple application to display information of a German Geldkarte. The Geldkarte is a small amount debit card application which comes with almost all German banking cards.
This application adds read-only support for keys and certificates stored on a SmartCard-HSM.
To generate keys and store certificates you may use OpenSC or the tools from OpenSCDP.
The SmartCard-HSM cards requires a card reader that supports Extended Length APDUs.
This is a stub application to allow the use of the APDU command even if no supported application is found on the card. This application is not used automatically but must be explicitly requested using the SERIALNO command.
There are a few configuration files to control certain aspects of
scdaemons
’s operation. Unless noted, they are expected in the
current home directory (see option --homedir).
This is the standard configuration file read by scdaemon
on
startup. It may contain any valid long option; the leading two dashes
may not be entered and the option may not be abbreviated. This default
name may be changed on the command line (see option --options).
If this file is present and executable, it will be called on every card
reader’s status change. An example of this script is provided with the
source code distribution. This option is deprecated in favor of the
DEVINFO --watch
.
This file is created by scdaemon
to let other applications now
about reader status changes. Its use is now deprecated in favor of
scd-event.
The SC-Daemon should be started by the system to provide access to external tokens. Using Smartcards on a multi-user system does not make much sense except for system services, but in this case no regular user accounts are hosted on the machine.
A client connects to the SC-Daemon by connecting to the socket named /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/var/run/gnupg/scdaemon/socket, configuration information is read from /etc/gnupg/scdaemon.conf
Each connection acts as one session, SC-Daemon takes care of synchronizing access to a token between sessions.
This command should be used to check for the presence of a card. It is special in that it can be used to reset the card. Most other commands will return an error when a card change has been detected and the use of this function is therefore required.
Background: We want to keep the client clear of handling card changes between operations; i.e. the client can assume that all operations are done on the same card unless he call this function.
SERIALNO
Return the serial number of the card using a status response like:
S SERIALNO D27600000000000000000000
The serial number is the hex encoded value identified by
the 0x5A
tag in the GDO file (FIX=0x2F02).
LEARN [--force]
Learn all useful information of the currently inserted card. When used without the --force option, the command might do an INQUIRE like this:
INQUIRE KNOWNCARDP <hexstring_with_serialNumber>
The client should just send an END
if the processing should go on
or a CANCEL
to force the function to terminate with a cancel
error message. The response of this command is a list of status lines
formatted as this:
S KEYPAIRINFO hexstring_with_keygrip hexstring_with_id
If there is no certificate yet stored on the card a single "X" is returned in hexstring_with_keygrip.
READCERT hexified_certid|keyid
This function is used to read a certificate identified by
hexified_certid from the card. With OpenPGP cards the keyid
OpenPGP.3
may be used to read the certificate of version 2 cards.
READKEY hexified_certid
Return the public key for the given cert or key ID as an standard S-Expression.
To sign some data the caller should use the command
SETDATA hexstring
to tell scdaemon
about the data to be signed. The data must be given in
hex notation. The actual signing is done using the command
PKSIGN keyid
where keyid is the hexified ID of the key to be used. The key id
may have been retrieved using the command LEARN
. If another
hash algorithm than SHA-1 is used, that algorithm may be given like:
PKSIGN --hash=algoname keyid
With algoname are one of sha1
, rmd160
or md5
.
To decrypt some data the caller should use the command
SETDATA hexstring
to tell scdaemon
about the data to be decrypted. The data
must be given in hex notation. The actual decryption is then done
using the command
PKDECRYPT keyid
where keyid is the hexified ID of the key to be used.
If the card is aware of the apdding format a status line with padding
information is send before the plaintext data. The key for this
status line is PADDING
with the only defined value being 0 and
meaning padding has been removed.
WRITEKEY [--force] keyid
This command is used to store a secret key on a smartcard. The
allowed keyids depend on the currently selected smartcard
application. The actual keydata is requested using the inquiry
KEYDATA
and need to be provided without any protection. With
--force set an existing key under this keyid will get
overwritten. The key data is expected to be the usual canonical encoded
S-expression.
A PIN will be requested in most cases. This however depends on the actual card application.
PASSWD [--reset] [--nullpin] chvno
Change the PIN or reset the retry counter of the card holder verification vector number chvno. The option --nullpin is used to initialize the PIN of TCOS cards (6 byte NullPIN only).
CHECKPIN idstr
Perform a VERIFY operation without doing anything else. This may be used to initialize a the PIN cache earlier to long lasting operations. Its use is highly application dependent:
Perform a simple verify operation for CHV1 and CHV2, so that further operations won’t ask for CHV2 and it is possible to do a cheap check on the PIN: If there is something wrong with the PIN entry system, only the regular CHV will get blocked and not the dangerous CHV3. idstr is the usual card’s serial number in hex notation; an optional fingerprint part will get ignored.
There is however a special mode if idstr is suffixed with the
literal string [CHV3]
: In this case the Admin PIN is checked if
and only if the retry counter is still at 3.
RESTART
Restart the current connection; this is a kind of warm reset. It deletes the context used by this connection but does not actually reset the card.
This is used by gpg-agent to reuse a primary pipe connection and may be used by clients to backup from a conflict in the serial command; i.e. to select another application.
APDU [--atr] [--more] [--exlen[=n]] [hexstring]
Send an APDU to the current reader. This command bypasses the high level functions and sends the data directly to the card. hexstring is expected to be a proper APDU. If hexstring is not given no commands are send to the card; However the command will implicitly check whether the card is ready for use.
Using the option --atr
returns the ATR of the card as a status
message before any data like this:
S CARD-ATR 3BFA1300FF813180450031C173C00100009000B1
Using the option --more
handles the card status word MORE_DATA
(61xx) and concatenate all responses to one block.
Using the option --exlen
the returned APDU may use extended
length up to N bytes. If N is not given a default value is used
(currently 4096).
There are different ways to specify a user ID to GnuPG. Some of them
are only valid for gpg
others are only good for
gpgsm
. Here is the entire list of ways to specify a key:
0x
prefix. The key Id of an X.509 certificate are the low 64 bits
of its SHA-1 fingerprint. The use of key Ids is just a shortcut, for
all automated processing the fingerprint should be used.
When using gpg
an exclamation mark (!) may be appended to
force using the specified primary or secondary key and not to try and
calculate which primary or secondary key to use.
The last four lines of the example give the key ID in their long form as internally used by the OpenPGP protocol. You can see the long key ID using the option --with-colons.
234567C4 0F34E556E 01347A56A 0xAB123456 234AABBCC34567C4 0F323456784E56EAB 01AB3FED1347A5612 0x234AABBCC34567C4 |
0x
prefix. Note, that only the 20 byte version fingerprint
is available with gpgsm
(i.e. the SHA-1 hash of the
certificate).
When using gpg
an exclamation mark (!) may be appended to
force using the specified primary or secondary key and not to try and
calculate which primary or secondary key to use.
The best way to specify a key Id is by using the fingerprint. This avoids any ambiguities in case that there are duplicated key IDs.
1234343434343434C434343434343434 123434343434343C3434343434343734349A3434 0E12343434343434343434EAB3484343434343434 0xE12343434343434343434EAB3484343434343434 |
gpgsm
also accepts colons between each pair of hexadecimal
digits because this is the de-facto standard on how to present X.509
fingerprints. gpg
also allows the use of the space
separated SHA-1 fingerprint as printed by the key listing commands.
=Heinrich Heine <heinrichh@uni-duesseldorf.de> |
<heinrichh@uni-duesseldorf.de> |
@
.
This uses a substring search but considers only the mail address
(i.e. inside the angle brackets).
@heinrichh |
gpgsm --list-keys
because that one has been reordered and modified
for better readability; use --with-colons to print the raw
(but standard escaped) RFC-2253 string.
/CN=Heinrich Heine,O=Poets,L=Paris,C=FR |
#/CN=Root Cert,O=Poets,L=Paris,C=FR |
#4F03/CN=Root Cert,O=Poets,L=Paris,C=FR |
gpgsm
prints the keygrip when using the command
--dump-cert.
&D75F22C3F86E355877348498CDC92BD21010A480 |
Heine *Heine |
Please note that we have reused the hash mark identifier which was used in old GnuPG versions to indicate the so called local-id. It is not anymore used and there should be no conflict when used with X.509 stuff.
Using the RFC-2253 format of DNs has the drawback that it is not possible to map them back to the original encoding, however we don’t have to do this because our key database stores this encoding as meta data.
Trust values are used to indicate ownertrust and validity of keys and user IDs. They are displayed with letters or strings:
No ownertrust assigned / not yet calculated.
Trust calculation has failed; probably due to an expired key.
Not enough information for calculation.
Never trust this key.
Marginally trusted.
Fully trusted.
Ultimately trusted.
For validity only: the key or the user ID has been revoked.
The program encountered an unknown trust value.
GnuPG comes with a tool to administrate smart cards and USB tokens.
This tool is an enhanced version of the --edit-key command
available with gpg
.
The gpg-card
is used to administrate smart cards and USB
tokens. It provides a superset of features from gpg
--card-edit
an can be considered a frontend to scdaemon
which is a daemon started by gpg-agent
to handle smart
cards.
If gpg-card
is invoked without commands an interactive
mode is used.
If gpg-card
is invoked with one or more commands the
same commands as available in the interactive mode are run from the
command line. These commands need to be delimited with a double-dash.
If a double-dash or a shell specific character is required as part of
a command the entire command needs to be put in quotes. If one of
those commands returns an error the remaining commands are not anymore
run unless the command was prefixed with a single dash.
A list of commands is available by using the command help
and a
brief description of each command is printed by using help CMD
.
See the section COMMANDS for a full description.
See the NOTES sections for instructions pertaining to specific cards or card applications.
gpg-card
understands these options:
--with-colons
¶This option has currently no effect.
--status-fd n
¶Write special status strings to the file descriptor n. This program returns only the status messages SUCCESS or FAILURE which are helpful when the caller uses a double fork approach and can’t easily get the return code of the process.
--verbose
¶Enable extra informational output.
--quiet
¶Disable almost all informational output.
--version
¶Print version of the program and exit.
--help
¶Display a brief help page and exit.
--no-autostart
¶Do not start the gpg-agent if it has not yet been started and its service is required. This option is mostly useful on machines where the connection to gpg-agent has been redirected to another machines.
--no-history
¶In interactive mode the command line history is usually saved and restored to and from a file below the GnuPG home directory. This option inhibits the use of that file.
--agent-program file
¶Specify the agent program to be started if none is running. The
default value is determined by running gpgconf
with the
option --list-dirs.
--gpg-program file
¶Specify a non-default gpg binary to be used by certain commands.
--gpgsm-program file
¶Specify a non-default gpgsm binary to be used by certain commands.
--chuid uid
¶Change the current user to uid which may either be a number or a name. This can be used from the root account to run gpg-card for another user. If uid is not the current UID a standard PATH is set and the envvar GNUPGHOME is unset. To override the latter the option --homedir can be used. This option has only an effect when used on the command line. This option has currently no effect at all on Windows.
gpg-card
understands the following commands, which have
options of their own. The pseudo-option ‘--’ can be used to
separate command options from arguments; if this pseudo option is used
on the command line the entire command with options and arguments must
be quoted, so that it is not mixed up with the ‘--’ as used on
the command line to separate commands. Note that a short online help
is available for all commands by prefixing them with “help”.
Command completion in the interactive mode is also supported.
AUTHENTICATE [--setkey] [--raw] [< file]|key]
¶AUTH
Authenticate to the card. Perform a mutual authentication either by reading the key from file or by taking it from the command line as key. Without the option --raw the key is expected to be hex encoded. To install a new administration key --setkey is used; this requires a prior authentication with the old key. This is used with PIV cards.
CAFPR [--clear] N
¶Change the CA fingerprint number N of an OpenPGP card. N must be in the range 1 to 3. The option --clear clears the specified CA fingerprint N or all of them if N is 0 or not given.
FACTORY-RESET
¶Do a complete reset of some OpenPGP and PIV cards. This command deletes all data and keys and resets the PINs to their default. Don’t worry, you need to confirm before the command proceeds.
FETCH
¶Retrieve a key using the URL data object of an OpenPGP card or if that is missing using the stored fingerprint.
FORCESIG
¶Toggle the forcesig flag of an OpenPGP card.
GENERATE [--force] [--algo=algo{+algo2}] keyref
¶Create a new key on a card. Use --force to overwrite an existing key. Use "help" for algo to get a list of known algorithms. For OpenPGP cards several algos may be given. Note that the OpenPGP key generation is done interactively unless --algo or keyref are given.
KDF-SETUP
¶Prepare the OpenPGP card KDF feature for this card.
LANG [--clear]
¶Change the language info for the card. This info can be used by applications for a personalized greeting. Up to 4 two-digit language identifiers can be entered as a preference. The option --clear removes all identifiers. GnuPG does not use this info.
LIST [--cards] [--apps] [--info] [--no-key-lookup] [n] [app]
¶L
This command reads all information from the current card and display them in a human readable format. The first section shows generic information vaialable for all cards. The next section shows information pertaining to keys which depend on the actual card and application.
With n given select and list the n-th card; with app also given select that application. To select an app on the current card use "-" for n. The serial number of the card may be used instead of n.
The option --cards lists the serial numbers of available cards. The option --apps lists all card applications. The option --info selects a card and prints its serial number. The option --no-key-lookup suppresses the listing of matching OpenPGP or X.509 keys.
LOGIN [--clear] [< file]
¶Set the login data object of OpenPGP cards. If file is given the data is is read from that file. This allows one to store binary data in the login field. The option --clear deletes the login data object.
NAME [--clear]
¶Set the name field of an OpenPGP card. With option --clear the stored name is cleared off the card.
PASSWD [--reset|--nullpin] [pinref]
¶Change or unblock the PINs. Note that in interactive mode and without a pinref a menu is presented for certain cards." In non-interactive mode and without a pinref a default value i used for these cards. The option --reset is used with TCOS cards to reset the PIN using the PUK or vice versa; the option –nullpin is used for these cards to set the initial PIN.
PRIVATEDO [--clear] n [< file]
¶Change the private data object n of an OpenPGP card. n must be in the range 1 to 4. If file is given the data is is read from that file. The option --clear clears the data.
QUIT
¶Q
Stop processing and terminate gpg-card
.
READCERT [--openpgp] certref > file
¶Read the certificate for key certref and store it in file. With option --openpgp an OpenPGP keyblock wrapped in a dedicated CMS content type (OID=1.3.6.1.4.1.11591.2.3.1) is expected and extracted to file. Note that for current OpenPGP cards a certificate may only be available at the certref "OPENPGP.3".
RESET
¶Send a reset to the card daemon.
SALUTATION [--clear]
¶SALUT
Change the salutation info for the card. This info can be used by applications for a personalized greeting. The option --clear removes this data object. GnuPG does not use this info.
UIF N [on|off|permanent]
¶Change the User Interaction Flag. That flags tells whether the confirmation button of a token shall be used. n must in the range 1 to 3. "permanent" is the same as "on" but the flag can’t be changed anmore.
UNBLOCK
¶Unblock a PIN using a PUK or Reset Code. Note that OpenPGP cards
prior to version 2 can’t use this; instead the PASSWD
can be
used to set a new PIN.
URL [--clear]
¶Set the URL data object of an OpenPGP card. That data object can be
used by by gpg
’s --fetch command to retrieve the
full public key. The option --clear deletes the content of
that data object.
VERIFY [chvid]
¶Verify the PIN identified by chvid or the default PIN.
WRITECERT certref < file
¶WRITECERT --openpgp certref [< file|fpr]
WRITECERT --clear certref
Write a certificate to the card under the id certref. The option --clear removes the certificate from the card. The option --openpgp expects an OpenPGP keyblock and stores it encapsulated in a CMS container; the keyblock is taken from file or directly from the OpenPGP key identified by fingerprint fpr.
WRITEKEY [--force] keyref keygrip
¶Write a private key object identified by keygrip to the card under the id keyref. Option --force allows overwriting an existing key.
CHECKKEYS [--ondisk] [--delete-clear-copy] [--delete-protected-copy]
¶Print a list of keys noticed on all inserted cards. With --ondisk only smartcard keys with a copy on disk are listed. With --delete-clear-copy copies of smartcard keys stored on disk without any protection will be deleted. With --delete-protected-copy password protected copies of smartcard keys stored on disk will be deleted.
This command creates missing shadow keys. The delete options print the status of the keys before they are deleted.
The format of the output is:
A hex-string with the serial number of the card.
This gives the type of the card’s application. For example "OpenPGP" or "PIV".
A hex-string identifying a key.
The application slot where the key is stored on the card. For example "OpenPGP.1"
The status of the key. The most common value is "shadowed" for a key where only the public key along with the card’s serial number is stored on the disk. The value "clear" indicates that a copy of the card’s key is stored unprotected on disk. The value "protected" indicated that a copy of the car’s key is stored on disk but is protected by a password. The value "error" may also be shown if there was a problem reading information from the card.
YUBIKEY cmd args
¶Various commands pertaining to Yubikey tokens with cmd being:
List supported and enabled Yubikey applications.
Enable or disable the specified or all applications on the given interface.
The support for OpenPGP cards in gpg-card
is not yet
complete. For missing features, please continue to use gpg
--card-edit
.
GnuPG has support for PIV cards (“Personal Identity Verification” as specified by NIST Special Publication 800-73-4). This section describes how to initialize (personalize) a fresh Yubikey token featuring the PIV application (requires Yubikey-5). We assume that the credentials have not yet been changed and thus are:
This is a 24 byte key described by the hex string
010203040506070801020304050607080102030405060708
.
This is the string 123456
.
This is the string 12345678
.
See the example section on how to change these defaults. For production use it is important to use secure values for them. Note that the Authentication Key is not queried via the usual Pinentry dialog but needs to be entered manually or read from a file. The use of a dedicated machine to personalize tokens is strongly suggested.
To see what is on the card, the command list
can be given. We
will use the interactive mode in the following (the string
gpg/card> is the prompt). An example output for a fresh card
is:
gpg/card> list Reader ...........: 1050:0407:X:0 Card type ........: yubikey Card firmware ....: 5.1.2 Serial number ....: D2760001240102010006090746250000 Application type .: OpenPGP Version ..........: 2.1 [...]
It can be seen by the “Application type” line that GnuPG selected the OpenPGP application of the Yubikey. This is because GnuPG assigns the highest priority to the OpenPGP application. To use the PIV application of the Yubikey several methods can be used:
With a Yubikey 5 or later the OpenPGP application on the Yubikey can be disabled:
gpg/card> yubikey disable all opgp gpg/card> yubikey list Application USB NFC ----------------------- OTP yes yes U2F yes yes OPGP no no PIV yes no OATH yes yes FIDO2 yes yes gpg/card> reset
The reset
is required so that the GnuPG system rereads the
card. Note that disabled applications keep all their data and can at
any time be re-enabled (use help yubikey).
Another option, which works for all Yubikey versions, is to disable the support for OpenPGP cards in scdaemon. This is done by adding the line
disable-application openpgp
to ~/.gnupg/scdaemon.conf and by restarting scdaemon, either by killing the process or by using gpgconf --kill scdaemon. Finally the default order in which card applications are tried by scdaemon can be changed. For example to prefer PIV over OpenPGP it is sufficient to add
application-priority piv
to ~/.gnupg/scdaemon.conf and to restart scdaemon
.
This has an effect only on tokens which support both, PIV and OpenPGP,
but does not hamper the use of OpenPGP only tokens.
With one of these methods employed the list
command of
gpg-card
shows this:
gpg/card> list Reader ...........: 1050:0407:X:0 Card type ........: yubikey Card firmware ....: 5.1.2 Serial number ....: FF020001008A77C1 Application type .: PIV Version ..........: 1.0 Displayed s/n ....: yk-9074625 PIN usage policy .: app-pin PIN retry counter : - 3 - PIV authentication: [none] keyref .....: PIV.9A Card authenticat. : [none] keyref .....: PIV.9E Digital signature : [none] keyref .....: PIV.9C Key management ...: [none] keyref .....: PIV.9D
In case several tokens are plugged into the computer, gpg-card will
show only one. To show another token the number of the token (0, 1,
2, ...) can be given as an argument to the list
command. The
command list --cards prints a list of all inserted tokens.
Note that the “Displayed s/n” is printed on the token and also shown in Pinentry prompts asking for the PIN. The four standard key slots are always shown, if other key slots are initialized they are shown as well. The PIV authentication key (internal reference PIV.9A) is used to authenticate the card and the card holder. The use of the associated private key is protected by the Application PIN which needs to be provided once and the key can the be used until the card is reset or removed from the reader or USB port. GnuPG uses this key with its Secure Shell support. The Card authentication key (PIV.9E) is also known as the CAK and used to support physical access applications. The private key is not protected by a PIN and can thus immediately be used. The Digital signature key (PIV.9C) is used to digitally sign documents. The use of the associated private key is protected by the Application PIN which needs to be provided for each signing operation. The Key management key (PIV.9D) is used for encryption. The use of the associated private key is protected by the Application PIN which needs to be provided only once so that decryption operations can then be done until the card is reset or removed from the reader or USB port.
We now generate three of the four keys. Note that GnuPG does currently not use the the Card authentication key; however, that key is mandatory by the PIV standard and thus we create it too. Key generation requires that we authenticate to the card. This can be done either on the command line (which would reveal the key):
gpg/card> auth 010203040506070801020304050607080102030405060708
or by reading the key from a file. That file needs to consist of one LF terminated line with the hex encoded key (as above):
gpg/card> auth < myauth.key
As usual ‘help auth’ gives help for this command. An error message is printed if a non-matching key is used. The authentication is valid until a reset of the card or until the card is removed from the reader or the USB port. Note that that in non-interactive mode the ‘<’ needs to be quoted so that the shell does not interpret it as a its own redirection symbol.
Here are the actual commands to generate the keys:
gpg/card> generate --algo=nistp384 PIV.9A PIV card no. yk-9074625 detected gpg/card> generate --algo=nistp256 PIV.9E PIV card no. yk-9074625 detected gpg/card> generate --algo=rsa2048 PIV.9C PIV card no. yk-9074625 detected
If a key has already been created for one of the slots an error will
be printed; to create a new key anyway the option ‘--force’ can be
used. Note that only the private and public keys have been created
but no certificates are stored in the key slots. In fact, GnuPG uses
its own non-standard method to store just the public key in place of
the the certificate. Other application will not be able to make use
these keys until gpgsm
or another tool has been used to
create and store the respective certificates. Let us see what the
list command now shows:
gpg/card> list Reader ...........: 1050:0407:X:0 Card type ........: yubikey Card firmware ....: 5.1.2 Serial number ....: FF020001008A77C1 Application type .: PIV Version ..........: 1.0 Displayed s/n ....: yk-9074625 PIN usage policy .: app-pin PIN retry counter : - 3 - PIV authentication: 213D1825FDE0F8240CB4E4229F01AF90AC658C2E keyref .....: PIV.9A (auth) algorithm ..: nistp384 Card authenticat. : 7A53E6CFFE7220A0E646B4632EE29E5A7104499C keyref .....: PIV.9E (auth) algorithm ..: nistp256 Digital signature : 32A6C6FAFCB8421878608AAB452D5470DD3223ED keyref .....: PIV.9C (sign,cert) algorithm ..: rsa2048 Key management ...: [none] keyref .....: PIV.9D
The primary information for each key is the keygrip, a 40 byte
hex-string identifying the key. This keygrip is a unique identifier
for the specific parameters of a key. It is used by
gpg-agent
and other parts of GnuPG to associate a private
key to its protocol specific certificate format (X.509, OpenPGP, or
SecureShell). Below the keygrip the key reference along with the key
usage capabilities are show. Finally the algorithm is printed in the
format used by gpg
. At that point no other information is
shown because for these new keys gpg won’t be able to find matching
certificates.
Although we could have created the Key management key also with
the generate command, we will create that key off-card so that a
backup exists. To accomplish this a key needs to be created with
either gpg
or gpgsm
or imported in one of these
tools. In our example we create a self-signed X.509 certificate (exit
the gpg-card tool, first):
$ gpgsm --gen-key -o encr.crt (1) RSA (2) Existing key (3) Existing key from card Your selection? 1 What keysize do you want? (3072) 2048 Requested keysize is 2048 bits Possible actions for a RSA key: (1) sign, encrypt (2) sign (3) encrypt Your selection? 3 Enter the X.509 subject name: CN=Encryption key for yk-9074625,O=example,C=DE Enter email addresses (end with an empty line): > otto@example.net > Enter DNS names (optional; end with an empty line): > Enter URIs (optional; end with an empty line): > Create self-signed certificate? (y/N) y These parameters are used: Key-Type: RSA Key-Length: 2048 Key-Usage: encrypt Serial: random Name-DN: CN=Encryption key for yk-9074625,O=example,C=DE Name-Email: otto@example.net Proceed with creation? (y/N) Now creating self-signed certificate. This may take a while ... gpgsm: about to sign the certificate for key: &34798AAFE0A7565088101CC4AE31C5C8C74461CB gpgsm: certificate created Ready. $ gpgsm --import encr.crt gpgsm: certificate imported gpgsm: total number processed: 1 gpgsm: imported: 1
Note the last step which imported the created certificate. If you
you instead created a certificate signing request (CSR) instead of a
self-signed certificate and sent this off to a CA you would do the
same import step with the certificate received from the CA. Take note
of the keygrip (prefixed with an ampersand) as shown during the
certificate creation or listed it again using ‘gpgsm
--with-keygrip -k otto@example.net’. Now to move the key and
certificate to the card start gpg-card
again and enter:
gpg/card> writekey PIV.9D 34798AAFE0A7565088101CC4AE31C5C8C74461CB gpg/card> writecert PIV.9D < encr.crt
If you entered a passphrase to protect the private key, you will be
asked for it via the Pinentry prompt. On success the key and the
certificate has been written to the card and a list
command
shows:
[...] Key management ...: 34798AAFE0A7565088101CC4AE31C5C8C74461CB keyref .....: PIV.9D (encr) algorithm ..: rsa2048 used for ...: X.509 user id ..: CN=Encryption key for yk-9074625,O=example,C=DE user id ..: <otto@example.net>
In case the same key (identified by the keygrip) has been used for several certificates you will see several “used for” parts. With this the encryption key is now fully functional and can be used to decrypt messages encrypted to this certificate. TAKE CARE: the original key is still stored on-disk and should be moved to a backup medium. This can simply be done by copying the file 34798AAFE0A7565088101CC4AE31C5C8C74461CB.key from the directory ~/.gnupg/private-keys-v1.d/ to the backup medium and deleting the file at its original place.
The final example is to create a self-signed certificate for digital
signatures. Leave gpg-card
using quit
or by pressing
Control-D and use gpgsm:
$ gpgsm --learn $ gpgsm --gen-key -o sign.crt Please select what kind of key you want: (1) RSA (2) Existing key (3) Existing key from card Your selection? 3 Serial number of the card: FF020001008A77C1 Available keys: (1) 213D1825FDE0F8240CB4E4229F01AF90AC658C2E PIV.9A nistp384 (2) 7A53E6CFFE7220A0E646B4632EE29E5A7104499C PIV.9E nistp256 (3) 32A6C6FAFCB8421878608AAB452D5470DD3223ED PIV.9C rsa2048 (4) 34798AAFE0A7565088101CC4AE31C5C8C74461CB PIV.9D rsa2048 Your selection? 3 Possible actions for a RSA key: (1) sign, encrypt (2) sign (3) encrypt Your selection? 2 Enter the X.509 subject name: CN=Signing key for yk-9074625,O=example,C=DE Enter email addresses (end with an empty line): > otto@example.net > Enter DNS names (optional; end with an empty line): > Enter URIs (optional; end with an empty line): > Create self-signed certificate? (y/N) These parameters are used: Key-Type: card:PIV.9C Key-Length: 1024 Key-Usage: sign Serial: random Name-DN: CN=Signing key for yk-9074625,O=example,C=DE Name-Email: otto@example.net Proceed with creation? (y/N) y Now creating self-signed certificate. This may take a while ... gpgsm: about to sign the certificate for key: &32A6C6FAFCB8421878608AAB452D5470DD3223ED gpgsm: certificate created Ready. $ gpgsm --import sign.crt gpgsm: certificate imported gpgsm: total number processed: 1 gpgsm: imported: 1
The use of ‘gpgsm --learn’ is currently necessary so that
gpg-agent knows what keys are available on the card. The need for
this command will eventually be removed. The remaining commands are
similar to the creation of an on-disk key. However, here we select
the ‘Digital signature’ key. During the creation process you
will be asked for the Application PIN of the card. The final step is
to write the certificate to the card using gpg-card
:
gpg/card> writecert PIV.9C < sign.crt
By running list again we will see the fully initialized card:
Reader ...........: 1050:0407:X:0 Card type ........: yubikey Card firmware ....: 5.1.2 Serial number ....: FF020001008A77C1 Application type .: PIV Version ..........: 1.0 Displayed s/n ....: yk-9074625 PIN usage policy .: app-pin PIN retry counter : - [verified] - PIV authentication: 213D1825FDE0F8240CB4E4229F01AF90AC658C2E keyref .....: PIV.9A (auth) algorithm ..: nistp384 Card authenticat. : 7A53E6CFFE7220A0E646B4632EE29E5A7104499C keyref .....: PIV.9E (auth) algorithm ..: nistp256 Digital signature : 32A6C6FAFCB8421878608AAB452D5470DD3223ED keyref .....: PIV.9C (sign,cert) algorithm ..: rsa2048 used for ...: X.509 user id ..: CN=Signing key for yk-9074625,O=example,C=DE user id ..: <otto@example.net> Key management ...: 34798AAFE0A7565088101CC4AE31C5C8C74461CB keyref .....: PIV.9D (encr) algorithm ..: rsa2048 used for ...: X.509 user id ..: CN=Encryption key for yk-9074625,O=example,C=DE user id ..: <otto@example.net>
It is now possible to sign and to encrypt with this card using gpgsm and to use the ‘PIV authentication’ key with ssh:
$ ssh-add -l 384 SHA256:0qnJ0Y0ehWxKcx2frLfEljf6GCdlO55OZed5HqGHsaU cardno:yk-9074625 (ECDSA)
As usual use ssh-add with the uppercase ‘-L’ to list the public ssh key. To use the certificates with Thunderbird or Mozilla, please consult the Scute manual for details.
If you want to use the same PIV keys also for OpenPGP (for example on a Yubikey to avoid switching between OpenPGP and PIV), this is also possible:
$ gpgsm --learn $ gpg --full-gen-key Please select what kind of key you want: (1) RSA and RSA (default) (2) DSA and Elgamal (3) DSA (sign only) (4) RSA (sign only) (14) Existing key from card Your selection? 14 Serial number of the card: FF020001008A77C1 Available keys: (1) 213D1825FDE0F8240CB4E4229F01AF90AC658C2E PIV.9A nistp384 (auth) (2) 7A53E6CFFE7220A0E646B4632EE29E5A7104499C PIV.9E nistp256 (auth) (3) 32A6C6FAFCB8421878608AAB452D5470DD3223ED PIV.9C rsa2048 (cert,sign) (4) 34798AAFE0A7565088101CC4AE31C5C8C74461CB PIV.9D rsa2048 (encr) Your selection? 3 Please specify how long the key should be valid. 0 = key does not expire <n> = key expires in n days <n>w = key expires in n weeks <n>m = key expires in n months <n>y = key expires in n years Key is valid for? (0) Key does not expire at all Is this correct? (y/N) y GnuPG needs to construct a user ID to identify your key. Real name: Email address: otto@example.net Comment: You selected this USER-ID: "otto@example.net" Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o gpg: key C3AFA9ED971BB365 marked as ultimately trusted gpg: revocation certificate stored as '[...]D971BB365.rev' public and secret key created and signed. Note that this key cannot be used for encryption. You may want to use the command "--edit-key" to generate a subkey for this purpose. pub rsa2048 2019-04-04 [SC] 7F899AE2FB73159DD68A1B20C3AFA9ED971BB365 uid otto@example.net
Note that you will be asked two times to enter the PIN of your PIV
card. If you run gpg
in --expert mode you will
also ge given the option to change the usage flags of the key. The next
typescript shows how to add the encryption subkey:
$ gpg --edit-key 7F899AE2FB73159DD68A1B20C3AFA9ED971BB365 Secret key is available. sec rsa2048/C3AFA9ED971BB365 created: 2019-04-04 expires: never usage: SC card-no: FF020001008A77C1 trust: ultimate validity: ultimate [ultimate] (1). otto@example.net gpg> addkey Secret parts of primary key are stored on-card. Please select what kind of key you want: (3) DSA (sign only) (4) RSA (sign only) (5) Elgamal (encrypt only) (6) RSA (encrypt only) (14) Existing key from card Your selection? 14 Serial number of the card: FF020001008A77C1 Available keys: (1) 213D1825FDE0F8240CB4E4229F01AF90AC658C2E PIV.9A nistp384 (auth) (2) 7A53E6CFFE7220A0E646B4632EE29E5A7104499C PIV.9E nistp256 (auth) (3) 32A6C6FAFCB8421878608AAB452D5470DD3223ED PIV.9C rsa2048 (cert,sign) (4) 34798AAFE0A7565088101CC4AE31C5C8C74461CB PIV.9D rsa2048 (encr) Your selection? 4 Please specify how long the key should be valid. 0 = key does not expire <n> = key expires in n days <n>w = key expires in n weeks <n>m = key expires in n months <n>y = key expires in n years Key is valid for? (0) Key does not expire at all Is this correct? (y/N) y Really create? (y/N) y sec rsa2048/C3AFA9ED971BB365 created: 2019-04-04 expires: never usage: SC card-no: FF020001008A77C1 trust: ultimate validity: ultimate ssb rsa2048/7067860A98FCE6E1 created: 2019-04-04 expires: never usage: E card-no: FF020001008A77C1 [ultimate] (1). otto@example.net gpg> save
Now you can use your PIV card also with gpg
.
GnuPG comes with a couple of smaller tools:
Most of the main utilities are able to write their log files to a Unix
Domain socket if configured that way. watchgnupg
is a simple
listener for such a socket. It ameliorates the output with a time stamp
and makes sure that long lines are not interspersed with log output from
other utilities. This tool is not available for Windows.
watchgnupg
is commonly invoked as
watchgnupg
which is a shorthand for
watchgnupg --force $(gpgconf --list-dirs socketdir)/S.log
To watch GnuPG running with a different home directory, use
watchgnupg --homedir DIR
This starts it on the current terminal for listening on the standard logging socket (this is commonly /var/run/user/UID/gnupg/S.log or if no such user directory hierarchy exists ~/.gnupg/S.log).
watchgnupg
understands these options:
--force
¶Delete an already existing socket file. This option is implicitly used if no socket name has been given on the command line.
--homedir DIR
If no socket name is given on the command line, pass DIR to gpgconf so that the socket for a GnuPG running with DIR has its home directory is used. Note that the environment variable GNUPGHOME is ignored by watchgnupg.
--tcp n
Instead of reading from a local socket, listen for connects on TCP port n. A Unix domain socket can optionally also be given as a second source. This option does not use a default socket name.
--time-only
¶Do not print the date part of the timestamp.
--verbose
¶Enable extra informational output.
--version
¶Print version of the program and exit.
--help
¶Display a brief help page and exit.
$ watchgnupg --time-only
This waits for connections on the local socket (e.g. /var/run/user/1234/gnupg/S.log) and shows all log entries. To make this work the option log-file needs to be used with all modules which logs are to be shown. The suggested entry for the configuration files is:
log-file socket://
If the default socket as given above and returned by "echo $(gpgconf –list-dirs socketdir)/S.log" is not desired an arbitrary socket name can be specified, for example socket:///home/foo/bar/mysocket. For debugging purposes it is also possible to do remote logging. Take care if you use this feature because the information is send in the clear over the network. Use this syntax in the conf files:
log-file tcp://192.168.1.1:4711
You may use any port and not just 4711 as shown above; only IP
addresses are supported (v4 and v6) and no host names. You need to
start watchgnupg
with the tcp option. Note that
under Windows the registry entry
HKCU\Software\GNU\GnuPG:DefaultLogFile can be used to change the
default log output from stderr
to whatever is given by that
entry. However the only useful entry is a TCP name for remote
debugging.
gpgv
is an OpenPGP signature verification tool.
This program is actually a stripped-down version of gpg
which is
only able to check signatures. It is somewhat smaller than the fully-blown
gpg
and uses a different (and simpler) way to check that
the public keys used to make the signature are valid. There are
no configuration files and only a few options are implemented.
gpgv
assumes that all keys in the keyring are trustworthy.
That does also mean that it does not check for expired or revoked
keys.
If no --keyring
option is given, gpgv
looks for a
“default” keyring named trustedkeys.kbx (preferred) or
trustedkeys.gpg in the home directory of GnuPG, either the
default home directory or the one set by the --homedir
option
or the GNUPGHOME
environment variable. If any --keyring
option is used, gpgv
will not look for the default keyring. The
--keyring
option may be used multiple times and all specified
keyrings will be used together.
gpgv
recognizes these options:
--verbose
¶-v
Gives more information during processing. If used twice, the input data is listed in detail.
--quiet
¶-q
Try to be as quiet as possible.
--keyring file
¶Add file to the list of keyrings. If file begins with a tilde and a slash, these are replaced by the HOME directory. If the filename does not contain a slash, it is assumed to be in the home-directory ("~/.gnupg" if –homedir is not used).
--output file
¶-o file
Write output to file; to write to stdout use -
. This
option can be used to get the signed text from a cleartext or binary
signature; it also works for detached signatures, but in that case
this option is in general not useful. Note that an existing file will
be overwritten.
--status-fd n
¶Write special status strings to the file descriptor n. See the file DETAILS in the documentation for a listing of them.
--logger-fd n
¶Write log output to file descriptor n
and not to stderr.
--log-file file
¶Same as --logger-fd, except the logger data is written to
file file
. Use socket:// to log to socket.
--ignore-time-conflict
¶GnuPG normally checks that the timestamps associated with keys and signatures have plausible values. However, sometimes a signature seems to be older than the key due to clock problems. This option turns these checks into warnings.
--homedir dir
¶Set the name of the home directory to dir. If this option is not
used, the home directory defaults to ~/.gnupg. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable GNUPGHOME
or
(on Windows systems) by means of the Registry entry
HKCU\Software\GNU\GnuPG:HomeDir.
On Windows systems it is possible to install GnuPG as a portable application. In this case only this command line option is considered, all other ways to set a home directory are ignored.
--weak-digest name
¶Treat the specified digest algorithm as weak. Signatures made over weak digests algorithms are normally rejected. This option can be supplied multiple times if multiple algorithms should be considered weak. MD5 is always considered weak, and does not need to be listed explicitly.
--enable-special-filenames
¶This option enables a mode in which filenames of the form -&n, where n is a non-negative decimal number, refer to the file descriptor n and not to a file with that name.
--assert-pubkey-algo algolist
¶This option works in the same way as described for gpg
.
The program returns 0 if everything is fine, 1 if at least one signature was bad, and other error codes for fatal errors.
pgpfile
sigfile
[datafile
]Verify the signature of the file. The second form is used for detached
signatures, where sigfile
is the detached signature (either
ASCII-armored or binary) and datafile
contains the signed data;
if datafile
is "-" the signed data is expected on
stdin
; if datafile
is not given the name of the file
holding the signed data is constructed by cutting off the extension
(".asc", ".sig" or ".sign") from sigfile
.
Used to locate the default home directory.
If set directory used instead of "~/.gnupg".
If GnuPG is installed on a system with existing user accounts, it is sometimes required to populate the GnuPG home directory with existing files. Especially a trustlist.txt and a keybox with some initial certificates are often desired. This script helps to do this by copying all files from /etc/skel/.gnupg to the home directories of the accounts given on the command line. It takes care not to overwrite existing GnuPG home directories.
addgnupghome
is invoked by root as:
addgnupghome account1 account2 ... accountn
The gpgconf
is a utility to automatically and reasonable
safely query and modify configuration files in the .gnupg home
directory. It is designed not to be invoked manually by the user, but
automatically by graphical user interfaces (GUI).3
gpgconf
provides access to the configuration of one or more
components of the GnuPG system. These components correspond more or
less to the programs that exist in the GnuPG framework, like GPG,
GPGSM, DirMngr, etc. But this is not a strict one-to-one
relationship. Not all configuration options are available through
gpgconf
. gpgconf
provides a generic and abstract
method to access the most important configuration options that can
feasibly be controlled via such a mechanism.
gpgconf
can be used to gather and change the options
available in each component, and can also provide their default
values. gpgconf
will give detailed type information that
can be used to restrict the user’s input without making an attempt to
commit the changes.
gpgconf
provides the backend of a configuration editor. The
configuration editor would usually be a graphical user interface
program that displays the current options, their default
values, and allows the user to make changes to the options. These
changes can then be made active with gpgconf
again. Such a
program that uses gpgconf
in this way will be called GUI
throughout this section.
One of the following commands must be given:
--list-components
List all components. This is the default command used if none is specified.
--check-programs
List all available backend programs and test whether they are runnable.
--list-options component
List all options of the component component.
--change-options component
Change the options of the component component.
--check-options component
Check the options for the component component.
--apply-profile file
Apply the configuration settings listed in file to the
configuration files. If file has no suffix and no slashes the
command first tries to read a file with the suffix .prf
from
the data directory (gpgconf --list-dirs datadir
) before it
reads the file verbatim. A profile is divided into sections using the
bracketed component name. Each section then lists the option which
shall go into the respective configuration file.
--apply-defaults
Update all configuration files with values taken from the global configuration file (usually /etc/gnupg/gpgconf.conf). Note: This is a legacy mechanism. Please use global configuration files instead.
--list-dirs [names]
-L
Lists the directories used by gpgconf
. One directory is
listed per line, and each line consists of a colon-separated list where
the first field names the directory type (for example sysconfdir
)
and the second field contains the percent-escaped directory. Although
they are not directories, the socket file names used by
gpg-agent
and dirmngr
are printed as well. Note
that the socket file names and the homedir
lines are the default
names and they may be overridden by command line switches. If
names are given only the directories or file names specified by
the list names are printed without any escaping.
--list-config [filename]
List the global configuration file in a colon separated format. If filename is given, check that file instead.
--check-config [filename]
Run a syntax check on the global configuration file. If filename is given, check that file instead.
--query-swdb package_name [version_string]
Returns the current version for package_name and if
version_string is given also an indicator on whether an update
is available. The actual file with the software version is
automatically downloaded and checked by dirmngr
.
dirmngr
uses a thresholds to avoid download the file too
often and it does this by default only if it can be done via Tor. To
force an update of that file this command can be used:
gpg-connect-agent --dirmngr 'loadswdb --force' /bye
--reload [component]
¶-R
Reload all or the given component. This is basically the same as sending a SIGHUP to the component. Components which don’t support reloading are ignored. Without component or by using "all" for component all components which are daemons are reloaded.
--launch [component]
¶If the component is not already running, start it.
component
must be a daemon. This is in general not required
because the system starts these daemons as needed. However, external
software making direct use of gpg-agent
or dirmngr
may use this command to ensure that they are started. Using "all" for
component launches all components which are daemons.
--kill [component]
¶-K
Kill the given component that runs as a daemon, including
gpg-agent
, dirmngr
, and scdaemon
. A
component
which does not run as a daemon will be ignored.
Using "all" for component kills all components running as
daemons. Note that as of now reload and kill have the same effect for
scdaemon
.
--create-socketdir
¶Create a directory for sockets below /run/user or /var/run/user. This is command is only required if a non default home directory is used and the /run based sockets shall be used. For the default home directory GnuPG creates a directory on the fly.
--remove-socketdir
¶Remove a directory created with command --create-socketdir.
--unlock name
--lock name
Remove a stale lock file hold for file. The file is expected in the current GnuPG home directory. This command is usually not required because GnuPG is able to detect and remove stale lock files. Before using the command make sure that the file protected by the lock file is actually not in use. The lock command may be used to lock an accidentally removed lock file. Note that the commands have no effect on Windows because the mere existence of a lock file does not mean that the lock is active.
The following options may be used:
-o file
--output file
Write output to file. Default is to write to stdout.
-v
--verbose
Outputs additional information while running. Specifically, this extends numerical field values by human-readable descriptions.
-q
¶--quiet
Try to be as quiet as possible.
--homedir dir
¶Set the name of the home directory to dir. If this option is not
used, the home directory defaults to ~/.gnupg. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable GNUPGHOME
or
(on Windows systems) by means of the Registry entry
HKCU\Software\GNU\GnuPG:HomeDir.
On Windows systems it is possible to install GnuPG as a portable application. In this case only this command line option is considered, all other ways to set a home directory are ignored.
--chuid uid
¶Change the current user to uid which may either be a number or a name. This can be used from the root account to get information on the GnuPG environment of the specified user or to start or kill daemons. If uid is not the current UID a standard PATH is set and the envvar GNUPGHOME is unset. To override the latter the option --homedir can be used. This option has currently no effect on Windows.
-n
--dry-run
Do not actually change anything. This is currently only implemented
for --change-options
and can be used for testing purposes.
-r
--runtime
Only used together with --change-options
. If one of the
modified options can be changed in a running daemon process, signal
the running daemon to ask it to reparse its configuration file after
changing.
This means that the changes will take effect at run-time, as far as this is possible. Otherwise, they will take effect at the next start of the respective backend programs.
--status-fd n
¶Write special status strings to the file descriptor n. This program returns the status messages SUCCESS or FAILURE which are helpful when the caller uses a double fork approach and can’t easily get the return code of the process.
Some lines in the output of gpgconf
contain a list of
colon-separated fields. The following conventions apply:
gpgconf
will never leave out fields. If a certain version
provides a certain field, this field will always be present in all
gpgconf
versions from that time on.
gpgconf
might append fields to the list.
New fields will always be separated from the previously last field by
a colon separator. The GUI should be prepared to parse the last field
it knows about up until a colon or end of line.
There are several standard types for the content of a field:
Some fields contain strings that are not escaped in any way. Such fields are described to be used verbatim. These fields will never contain a colon character (for obvious reasons). No de-escaping or other formatting is required to use the field content. This is for easy parsing of the output, when it is known that the content can never contain any special characters.
Some fields contain strings that are described to be
percent-escaped. Such strings need to be de-escaped before
their content can be presented to the user. A percent-escaped string
is de-escaped by replacing all occurrences of %XY
by the byte
that has the hexadecimal value XY
. X
and Y
are
from the set 0-9a-f
.
Some fields contain strings that are described to be localized. Such strings are translated to the active language and formatted in the active character set.
Some fields contain an unsigned number. This number will always fit into a 32-bit unsigned integer variable. The number may be followed by a space, followed by a human readable description of that value (if the verbose option is used). You should ignore everything in the field that follows the number.
Some fields contain a signed number. This number will always fit into a 32-bit signed integer variable. The number may be followed by a space, followed by a human readable description of that value (if the verbose option is used). You should ignore everything in the field that follows the number.
Some fields contain a boolean value. This is a number with either the value 0 or 1. The number may be followed by a space, followed by a human readable description of that value (if the verbose option is used). You should ignore everything in the field that follows the number; checking just the first character is sufficient in this case.
Some fields contain an option argument. The format of an option argument depends on the type of the option and on some flags:
The simplest case is that the option does not take an argument at all
(type 0
). Then the option argument is an unsigned number
that specifies how often the option occurs. If the list
flag
is not set, then the only valid number is 1
. Options that do
not take an argument never have the default
or optional
arg
flag set.
If the option takes a number argument (alt-type is 2
or
3
), and it can only occur once (list
flag is not set),
then the option argument is either empty (only allowed if the argument
is optional), or it is a number. A number is a string that begins
with an optional minus character, followed by one or more digits. The
number must fit into an integer variable (unsigned or signed,
depending on alt-type).
If the option takes a number argument and it can occur more than once, then the option argument is either empty, or it is a comma-separated list of numbers as described above.
If the option takes a string argument (alt-type is 1), and it
can only occur once (list
flag is not set) then the option
argument is either empty (only allowed if the argument is optional),
or it starts with a double quote character ("
) followed by a
percent-escaped string that is the argument value. Note that there is
only a leading double quote character, no trailing one. The double
quote character is only needed to be able to differentiate between no
value and the empty string as value.
If the option takes a string argument and it can occur more than once, then the option argument is either empty, or it is a comma-separated list of string arguments as described above.
The active language and character set are currently determined from
the locale environment of the gpgconf
program.
The command --list-components
will list all components that can
be configured with gpgconf
. Usually, one component will
correspond to one GnuPG-related program and contain the options of
that program’s configuration file that can be modified using
gpgconf
. However, this is not necessarily the case. A
component might also be a group of selected options from several
programs, or contain entirely virtual options that have a special
effect rather than changing exactly one option in one configuration
file.
A component is a set of configuration options that semantically belong together. Furthermore, several changes to a component can be made in an atomic way with a single operation. The GUI could for example provide a menu with one entry for each component, or a window with one tabulator sheet per component.
The command --list-components
lists all available
components, one per line. The format of each line is:
name:description:pgmname:
This field contains a name tag of the component. The name tag is used
to specify the component in all communication with gpgconf
.
The name tag is to be used verbatim. It is thus not in any
escaped format.
The string in this field contains a human-readable description of the component. It can be displayed to the user of the GUI for informational purposes. It is percent-escaped and localized.
The string in this field contains the absolute name of the program’s file. It can be used to unambiguously invoke that program. It is percent-escaped.
Example:
$ gpgconf --list-components gpg:GPG for OpenPGP:/usr/local/bin/gpg2: gpg-agent:GPG Agent:/usr/local/bin/gpg-agent: scdaemon:Smartcard Daemon:/usr/local/bin/scdaemon: gpgsm:GPG for S/MIME:/usr/local/bin/gpgsm: dirmngr:Directory Manager:/usr/local/bin/dirmngr:
The command --check-programs
is similar to
--list-components
but works on backend programs and not on
components. It runs each program to test whether it is installed and
runnable. This also includes a syntax check of all config file options
of the program.
The command --check-programs
lists all available
programs, one per line. The format of each line is:
name:description:pgmname:avail:okay:cfgfile:line:error:
This field contains a name tag of the program which is identical to the name of the component. The name tag is to be used verbatim. It is thus not in any escaped format. This field may be empty to indicate a continuation of error descriptions for the last name. The description and pgmname fields are then also empty.
The string in this field contains a human-readable description of the component. It can be displayed to the user of the GUI for informational purposes. It is percent-escaped and localized.
The string in this field contains the absolute name of the program’s file. It can be used to unambiguously invoke that program. It is percent-escaped.
The boolean value in this field indicates whether the program is installed and runnable.
The boolean value in this field indicates whether the program’s config file is syntactically okay.
If an error occurred in the configuration file (as indicated by a false
value in the field okay
), this field has the name of the failing
configuration file. It is percent-escaped.
If an error occurred in the configuration file, this field has the line number of the failing statement in the configuration file. It is an unsigned number.
If an error occurred in the configuration file, this field has the error text of the failing statement in the configuration file. It is percent-escaped and localized.
In the following example the dirmngr
is not runnable and the
configuration file of scdaemon
is not okay.
$ gpgconf --check-programs gpg:GPG for OpenPGP:/usr/local/bin/gpg2:1:1: gpg-agent:GPG Agent:/usr/local/bin/gpg-agent:1:1: scdaemon:Smartcard Daemon:/usr/local/bin/scdaemon:1:0: gpgsm:GPG for S/MIME:/usr/local/bin/gpgsm:1:1: dirmngr:Directory Manager:/usr/local/bin/dirmngr:0:0:
The command --check-options component
will verify the
configuration file in the same manner as --check-programs
, but
only for the component component.
Every component contains one or more options. Options may be gathered into option groups to allow the GUI to give visual hints to the user about which options are related.
The command --list-options component
lists
all options (and the groups they belong to) in the component
component, one per line. component must be the string in
the field name in the output of the --list-components
command.
There is one line for each option and each group. First come all options that are not in any group. Then comes a line describing a group. Then come all options that belong into each group. Then comes the next group and so on. There does not need to be any group (and in this case the output will stop after the last non-grouped option).
The format of each line is:
name:flags:level:description:type:alt-type:argname:default:argdef:value
This field contains a name tag for the group or option. The name tag
is used to specify the group or option in all communication with
gpgconf
. The name tag is to be used verbatim. It is
thus not in any escaped format.
The flags field contains an unsigned number. Its value is the OR-wise combination of the following flag values:
group (1)
If this flag is set, this is a line describing a group and not an option.
The following flag values are only defined for options (that is, if
the group
flag is not used).
optional arg (2)
If this flag is set, the argument is optional. This is never set for
type 0
(none) options.
list (4)
If this flag is set, the option can be given multiple times.
runtime (8)
If this flag is set, the option can be changed at runtime.
default (16)
If this flag is set, a default value is available.
default desc (32)
If this flag is set, a (runtime) default is available. This and the
default
flag are mutually exclusive.
no arg desc (64)
If this flag is set, and the optional arg
flag is set, then the
option has a special meaning if no argument is given.
no change (128)
If this flag is set, gpgconf
ignores requests to change the
value. GUI frontends should grey out this option. Note, that manual
changes of the configuration files are still possible.
This field is defined for options and for groups. It contains an unsigned number that specifies the expert level under which this group or option should be displayed. The following expert levels are defined for options (they have analogous meaning for groups):
basic (0)
This option should always be offered to the user.
advanced (1)
This option may be offered to advanced users.
expert (2)
This option should only be offered to expert users.
invisible (3)
This option should normally never be displayed, not even to expert users.
internal (4)
This option is for internal use only. Ignore it.
The level of a group will always be the lowest level of all options it contains.
This field is defined for options and groups. The string in this field contains a human-readable description of the option or group. It can be displayed to the user of the GUI for informational purposes. It is percent-escaped and localized.
This field is only defined for options. It contains an unsigned number that specifies the type of the option’s argument, if any. The following types are defined:
Basic types:
none (0)
No argument allowed.
string (1)
An unformatted string.
int32 (2)
A signed number.
uint32 (3)
An unsigned number.
Complex types:
pathname (32)
A string that describes the pathname of a file. The file does not necessarily need to exist.
ldap server (33)
A string that describes an LDAP server in the format:
hostname:port:username:password:base_dn
key fingerprint (34)
A string with a 40 digit fingerprint specifying a certificate.
pub key (35)
A string that describes a certificate by user ID, key ID or fingerprint.
sec key (36)
A string that describes a certificate with a key by user ID, key ID or fingerprint.
alias list (37)
A string that describes an alias list, like the one used with gpg’s group option. The list consists of a key, an equal sign and space separated values.
More types will be added in the future. Please see the alt-type field for information on how to cope with unknown types.
This field is identical to type, except that only the types
0
to 31
are allowed. The GUI is expected to present the
user the option in the format specified by type. But if the
argument type type is not supported by the GUI, it can still
display the option in the more generic basic type alt-type. The
GUI must support all the defined basic types to be able to display all
options. More basic types may be added in future versions. If the
GUI encounters a basic type it doesn’t support, it should report an
error and abort the operation.
This field is only defined for options with an argument type
type that is not 0
. In this case it may contain a
percent-escaped and localized string that gives a short
name for the argument. The field may also be empty, though, in which
case a short name is not known.
This field is defined only for options for which the default
or
default desc
flag is set. If the default
flag is set,
its format is that of an option argument (see Format conventions, for details). If the default value is empty, then no
default is known. Otherwise, the value specifies the default value
for this option. If the default desc
flag is set, the field is
either empty or contains a description of the effect if the option is
not given.
This field is defined only for options for which the optional
arg
flag is set. If the no arg desc
flag is not set, its
format is that of an option argument (see Format conventions, for details). If the default value is empty, then no
default is known. Otherwise, the value specifies the default argument
for this option. If the no arg desc
flag is set, the field is
either empty or contains a description of the effect of this option if
no argument is given.
This field is defined only for options. Its format is that of an option argument. If it is empty, then the option is not explicitly set in the current configuration, and the default applies (if any). Otherwise, it contains the current value of the option. Note that this field is also meaningful if the option itself does not take a real argument (in this case, it contains the number of times the option appears).
The command --change-options component
will attempt
to change the options of the component component to the
specified values. component must be the string in the field
name in the output of the --list-components
command. You
have to provide the options that shall be changed in the following
format on standard input:
name:flags:new-value
This is the name of the option to change. name must be the
string in the field name in the output of the
--list-options
command.
The flags field contains an unsigned number. Its value is the OR-wise combination of the following flag values:
default (16)
If this flag is set, the option is deleted and the default value is used instead (if applicable).
The new value for the option. This field is only defined if the
default
flag is not set. The format is that of an option
argument. If it is empty (or the field is omitted), the default
argument is used (only allowed if the argument is optional for this
option). Otherwise, the option will be set to the specified value.
The output of the command is the same as that of
--check-options
for the modified configuration file.
Examples:
To set the force option, which is of basic type none (0)
:
$ echo 'force:0:1' | gpgconf --change-options dirmngr
To delete the force option:
$ echo 'force:16:' | gpgconf --change-options dirmngr
The --runtime
option can influence when the changes take
effect.
Some legacy applications look at the global configuration file for the gpgconf tool itself; this is the file gpgconf.conf. Modern applications should not use it but use per component global configuration files which are more flexible than the gpgconf.conf. Using both files is not suggested.
The colon separated listing format is record oriented and uses the first field to identify the record type:
k
This describes a key record to start the definition of a new ruleset for a user/group. The format of a key record is:
k:user:group:
This is the user field of the key. It is percent escaped. See the definition of the gpgconf.conf format for details.
This is the group field of the key. It is percent escaped.
r
This describes a rule record. All rule records up to the next key record make up a rule set for that key. The format of a rule record is:
r:::component:option:flag:value:
This is the component part of a rule. It is a plain string.
This is the option part of a rule. It is a plain string.
This is the flags part of a rule. There may be only one flag per rule but by using the same component and option, several flags may be assigned to an option. It is a plain string.
This is the optional value for the option. It is a percent escaped string with a single quotation mark to indicate a string. The quotation mark is only required to distinguish between no value specified and an empty string.
Unknown record types should be ignored. Note that there is intentionally
no feature to change the global option file through gpgconf
.
The GnuPG Project operates a server to query the current versions of
software packages related to GnuPG. gpgconf
can be used to
access this online database. To allow for offline operations, this
feature works by having dirmngr
download a file from
https://versions.gnupg.org
, checking the signature of that file
and storing the file in the GnuPG home directory. If
gpgconf
is used and dirmngr
is running, it may ask
dirmngr
to refresh that file before itself uses the file.
The command --query-swdb returns information for the given package in a colon delimited format:
This is the name of the package as requested. Note that "gnupg" is a
special name which is replaced by the actual package implementing this
version of GnuPG. For this name it is also not required to specify a
version because gpgconf
takes its own version in this case.
The currently installed version or an empty string. The value is taken from the command line argument but may be provided by gpg if not given.
The status of the software package according to this table:
-
No information available. This is either because no current version has been specified or due to an error.
?
The given name is not known in the online database.
u
An update of the software is available.
c
The installed version of the software is current.
n
The installed version is already newer than the released version.
If the value (the empty string should be considered as zero) is greater than zero an important update is available.
This returns an gpg-error
error code to distinguish between
various failure modes.
This gives the date of the file with the version numbers in standard
ISO format (yyyymmddThhmmss
). The date has been extracted by
dirmngr
from the signature of the file.
This gives the date in ISO format the file was downloaded. This value can be used to evaluate the freshness of the information.
This returns the version string for the requested software from the file.
This returns the release date in ISO format.
This returns the size of the package as decimal number of bytes.
This returns a hexified SHA-2 hash of the package.
More fields may be added in future to the output.
Under Unix gpgconf.ctl may be used to change some of the
compiled in directories where the GnuPG components are expected. This
file is expected in the same directory as gpgconf. The
physical installation directories are evaluated and no symlinks.
Blank lines and lines starting with pound sign are ignored in the
file. The keywords must be followed by optional white space, an equal
sign, optional white space, and the value. Environment variables are
substituted in standard shell manner, the final value must start with
a slash, trailing slashes are stripped. Valid keywords are
rootdir
, sysconfdir
, socketdir
, and
.enable
. No errors are printed for unknown keywords. The
.enable
keyword is special: if the keyword is used and its
value evaluates to true the entire file is ignored.
Under Windows this file is used to install GnuPG as a portable application. An empty file named gpgconf.ctl is expected in the same directory as the tool gpgconf.exe. The root of the installation is then that directory; or, if gpgconf.exe has been installed directly below a directory named bin, its parent directory. You also need to make sure that the following directories exist and are writable: ROOT/home for the GnuPG home and ROOT/nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/var/cache/gnupg for internal cache files.
If this file exists, it is processed as a global configuration file. This is a legacy mechanism which should not be used together with the modern global per component configuration files. A commented example can be found in the examples directory of the distribution.
A file with current software versions. dirmngr
creates
this file on demand from an online resource.
This is a legacy script. Modern application should use the per component global configuration files under /etc/gnupg/.
This script is a wrapper around gpgconf
to run it with the
command --apply-defaults
for all real users with an existing
GnuPG home directory. Admins might want to use this script to update he
GnuPG configuration files for all users after
/etc/gnupg/gpgconf.conf has been changed. This allows enforcing
certain policies for all users. Note, that this is not a bulletproof way to
force a user to use certain options. A user may always directly edit
the configuration files and bypass gpgconf.
applygnupgdefaults
is invoked by root as:
applygnupgdefaults
The gpg-preset-passphrase
is a utility to seed the internal
cache of a running gpg-agent
with passphrases. It is mainly
useful for unattended machines, where the usual pinentry
tool
may not be used and the passphrases for the to be used keys are given at
machine startup.
This program works with GnuPG 2 and later. GnuPG 1.x is not supported.
Passphrases set with this utility don’t expire unless the
--forget option is used to explicitly clear them from the
cache — or gpg-agent
is either restarted or reloaded (by
sending a SIGHUP to it). Note that the maximum cache time as set with
--max-cache-ttl is still honored. It is necessary to allow
this passphrase presetting by starting gpg-agent
with the
--allow-preset-passphrase.
gpg-preset-passphrase
is invoked this way:
gpg-preset-passphrase [options] [command] cacheid
cacheid is either a 40 character keygrip of hexadecimal
characters identifying the key for which the passphrase should be set
or cleared. The keygrip is listed along with the key when running the
command: gpgsm --with-keygrip --list-secret-keys
.
Alternatively an arbitrary string may be used to identify a
passphrase; it is suggested that such a string is prefixed with the
name of the application (e.g foo:12346
). Scripts should always
use the option --with-colons, which provides the keygrip in a
"grp" line (cf. doc/DETAILS)/
One of the following command options must be given:
--preset
¶Preset a passphrase. This is what you usually will
use. gpg-preset-passphrase
will then read the passphrase from
stdin
.
--forget
¶Flush the passphrase for the given cache ID from the cache.
The following additional options may be used:
-v
¶--verbose
Output additional information while running.
-P string
¶--passphrase string
Instead of reading the passphrase from stdin
, use the supplied
string as passphrase. Note that this makes the passphrase visible
for other users.
The gpg-connect-agent
is a utility to communicate with a
running gpg-agent
. It is useful to check out the commands
gpg-agent
provides using the Assuan interface. It might
also be useful for scripting simple applications. Input is expected
at stdin and output gets printed to stdout.
It is very similar to running gpg-agent
in server mode; but
here we connect to a running instance.
gpg-connect-agent
is invoked this way:
gpg-connect-agent [options] [commands]
The following options may be used:
--dirmngr
¶Connect to a running directory manager (keyserver client) instead of to the gpg-agent. If a dirmngr is not running, start it.
--keyboxd
¶Connect to a running keybox daemon instead of to the gpg-agent. If a keyboxd is not running, start it.
-S
¶--raw-socket name
Connect to socket name assuming this is an Assuan style server. Do not run any special initializations or environment checks. This may be used to directly connect to any Assuan style socket server.
-E
¶--exec
Take the rest of the command line as a program and it’s arguments and
execute it as an Assuan server. Here is how you would run gpgsm
:
gpg-connect-agent --exec gpgsm --server
Note that you may not use options on the command line in this case.
-v
¶--verbose
Output additional information while running.
-q
--quiet
¶Try to be as quiet as possible.
--homedir dir
¶Set the name of the home directory to dir. If this option is not
used, the home directory defaults to ~/.gnupg. It is only
recognized when given on the command line. It also overrides any home
directory stated through the environment variable GNUPGHOME
or
(on Windows systems) by means of the Registry entry
HKCU\Software\GNU\GnuPG:HomeDir.
On Windows systems it is possible to install GnuPG as a portable application. In this case only this command line option is considered, all other ways to set a home directory are ignored.
--chuid uid
¶Change the current user to uid which may either be a number or a name. This can be used from the root account to run gpg-connect-agent for another user. If uid is not the current UID a standard PATH is set and the envvar GNUPGHOME is unset. To override the latter the option --homedir can be used. This option has only an effect when used on the command line. This option has currently no effect at all on Windows.
--no-ext-connect
¶When using -S or --exec, gpg-connect-agent
connects to the Assuan server in extended mode to allow descriptor
passing. This option makes it use the old mode.
--no-autostart
¶Do not start the gpg-agent or the dirmngr if it has not yet been started.
--no-history
¶In interactive mode the command line history is usually saved and restored to and from a file below the GnuPG home directory. This option inhibits the use of that file.
--agent-program file
¶Specify the agent program to be started if none is running. The
default value is determined by running gpgconf
with the
option --list-dirs. Note that the pipe symbol (|
) is
used for a regression test suite hack and may thus not be used in the
file name.
--dirmngr-program file
¶Specify the directory manager (keyserver client) program to be started if none is running. This has only an effect if used together with the option --dirmngr.
--keyboxd-program file
¶Specify the keybox daemon program to be started if none is running. This has only an effect if used together with the option --keyboxd.
-r file
¶--run file
Run the commands from file at startup and then continue with the regular input method. Note, that commands given on the command line are executed after this file.
-s
¶--subst
Run the command /subst
at startup.
--hex
¶Print data lines in a hex format and the ASCII representation of non-control characters.
--decode
¶Decode data lines. That is to remove percent escapes but make sure that a new line always starts with a D and a space.
-u
¶--unbuffered
Set stdin and stdout into unbuffered I/O mode. This this sometimes useful for scripting.
While reading Assuan commands, gpg-agent also allows a few special
commands to control its operation. These control commands all start
with a slash (/
).
/echo args
Just print args.
/let name value
Set the variable name to value. Variables are only
substituted on the input if the /subst
has been used.
Variables are referenced by prefixing the name with a dollar sign and
optionally include the name in curly braces. The rules for a valid name
are identically to those of the standard bourne shell. This is not yet
enforced but may be in the future. When used with curly braces no
leading or trailing white space is allowed.
If a variable is not found, it is searched in the environment and if found copied to the table of variables.
Variable functions are available: The name of the function must be followed by at least one space and the at least one argument. The following functions are available:
get
Return a value described by the argument. Available arguments are:
cwd
The current working directory.
homedir
The gnupg homedir.
sysconfdir
GnuPG’s system configuration directory.
bindir
GnuPG’s binary directory.
libdir
GnuPG’s library directory.
libexecdir
GnuPG’s library directory for executable files.
datadir
GnuPG’s data directory.
serverpid
The PID of the current server. Command /serverpid
must
have been given to return a useful value.
unescape args
Remove C-style escapes from args. Note that \0
and
\x00
terminate the returned string implicitly. The string to be
converted are the entire arguments right behind the delimiting space of
the function name.
unpercent args
unpercent+ args
Remove percent style escaping from args. Note that %00
terminates the string implicitly. The string to be converted are the
entire arguments right behind the delimiting space of the function
name. unpercent+
also maps plus signs to a spaces.
percent args
percent+ args
Escape the args using percent style escaping. Tabs, formfeeds,
linefeeds, carriage returns and colons are escaped. percent+
also
maps spaces to plus signs.
errcode arg
errsource arg
errstring arg
Assume arg is an integer and evaluate it using strtol
. Return
the gpg-error error code, error source or a formatted string with the
error code and error source.
+
-
*
/
%
Evaluate all arguments as long integers using strtol
and apply
this operator. A division by zero yields an empty string.
!
|
&
Evaluate all arguments as long integers using strtol
and apply
the logical operators NOT, OR or AND. The NOT operator works on the
last argument only.
/definq name var
Use content of the variable var for inquiries with name.
name may be an asterisk (*
) to match any inquiry.
/definqfile name file
Use content of file for inquiries with name.
name may be an asterisk (*
) to match any inquiry.
/definqprog name prog
Run prog for inquiries matching name and pass the entire line to it as command line arguments.
/datafile name
Write all data lines from the server to the file name. The file is opened for writing and created if it does not exists. An existing file is first truncated to 0. The data written to the file fully decoded. Using a single dash for name writes to stdout. The file is kept open until a new file is set using this command or this command is used without an argument.
/showdef
Print all definitions
/cleardef
Delete all definitions
/sendfd file mode
Open file in mode (which needs to be a valid fopen
mode string) and send the file descriptor to the server. This is
usually followed by a command like INPUT FD
to set the
input source for other commands.
/recvfd
Not yet implemented.
/open var file [mode]
Open file and assign the file descriptor to var. Warning: This command is experimental and might change in future versions.
/close fd
Close the file descriptor fd. Warning: This command is experimental and might change in future versions.
/showopen
Show a list of open files.
/serverpid
Send the Assuan command GETINFO pid
to the server and store
the returned PID for internal purposes.
/sleep
Sleep for a second.
/hex
/nohex
Same as the command line option --hex.
/decode
/nodecode
Same as the command line option --decode.
/subst
/nosubst
Enable and disable variable substitution. It defaults to disabled unless the command line option --subst has been used. If /subst as been enabled once, leading whitespace is removed from input lines which makes scripts easier to read.
/while condition
/end
These commands provide a way for executing loops. All lines between
the while
and the corresponding end
are executed as long
as the evaluation of condition yields a non-zero value or is the
string true
or yes
. The evaluation is done by passing
condition to the strtol
function. Example:
/subst /let i 3 /while $i /echo loop counter is $i /let i ${- $i 1} /end
/if condition
/end
These commands provide a way for conditional execution. All lines between
the if
and the corresponding end
are executed only if
the evaluation of condition yields a non-zero value or is the
string true
or yes
. The evaluation is done by passing
condition to the strtol
function.
/run file
Run commands from file.
/history --clear
Clear the command history.
/bye
Terminate the connection and the program.
/help
Print a list of available control commands.
The dirmngr-client
is a simple tool to contact a running
dirmngr and test whether a certificate has been revoked — either by
being listed in the corresponding CRL or by running the OCSP protocol.
If no dirmngr is running, a new instances will be started but this is
in general not a good idea due to the huge performance overhead.
The usual way to run this tool is either:
dirmngr-client acert
or
dirmngr-client <acert
Where acert is one DER encoded (binary) X.509 certificates to be tested. The return value of this command is
0
The certificate under question is valid; i.e. there is a valid CRL available and it is not listed there or the OCSP request returned that that certificate is valid.
1
The certificate has been revoked
2 (and other values)
There was a problem checking the revocation state of the certificate. A message to stderr has given more detailed information. Most likely this is due to a missing or expired CRL or due to a network problem.
dirmngr-client
may be called with the following options:
--version
¶Print the program version and licensing information. Note that you cannot abbreviate this command.
--help, -h
¶Print a usage message summarizing the most useful command-line options. Note that you cannot abbreviate this command.
--quiet, -q
¶Make the output extra brief by suppressing any informational messages.
-v
--verbose
¶Outputs additional information while running. You can increase the verbosity by giving several verbose commands to DIRMNGR, such as ‘-vv’.
--pem
¶Assume that the given certificate is in PEM (armored) format.
--ocsp
¶Do the check using the OCSP protocol and ignore any CRLs.
--force-default-responder
¶When checking using the OCSP protocol, force the use of the default OCSP responder. That is not to use the Reponder as given by the certificate.
--ping
¶Check whether the dirmngr daemon is up and running.
--cache-cert
¶Put the given certificate into the cache of a running dirmngr. This is mainly useful for debugging.
--validate
¶Validate the given certificate using dirmngr’s internal validation code. This is mainly useful for debugging.
--load-crl
¶This command expects a list of filenames with DER encoded CRL files. With the option --url URLs are expected in place of filenames and they are loaded directly from the given location. All CRLs will be validated and then loaded into dirmngr’s cache.
--lookup
¶Take the remaining arguments and run a lookup command on each of them. The results are Base-64 encoded outputs (without header lines). This may be used to retrieve certificates from a server. However the output format is not very well suited if more than one certificate is returned.
--url
¶-u
Modify the lookup
and load-crl
commands to take an URL.
--local
¶-l
Let the lookup
command only search the local cache.
--squid-mode
¶Run DIRMNGR-CLIENT in a mode suitable as a helper program for Squid’s external_acl_type option.
The gpgparsemail
is a utility currently only useful for
debugging. Run it with --help
for usage information.
gpgtar
encrypts or signs files into an archive. It is an
gpg-ized tar using the same format as used by PGP’s PGP Zip.
gpgtar
is invoked this way:
gpgtar [options] filename1 [filename2, ...] directory [directory2, ...]
gpgtar
understands these options:
--create
¶Put given files and directories into a vanilla “ustar” archive.
--extract
¶Extract all files from a vanilla “ustar” archive. If no file name is given (or it is "-") the archive is taken from stdin.
--encrypt
¶-e
Encrypt given files and directories into an archive. This option may be combined with option --symmetric for an archive that may be decrypted via a secret key or a passphrase.
--decrypt
¶-d
Extract all files from an encrypted archive. If no file name is given (or it is "-") the archive is taken from stdin.
--sign
-s
Make a signed archive from the given files and directories. This can be combined with option --encrypt to create a signed and then encrypted archive.
--list-archive
¶-t
List the contents of the specified archive. If no file name is given (or it is "-") the archive is taken from stdin.
--symmetric
-c
Encrypt with a symmetric cipher using a passphrase. The default
symmetric cipher used is AES-128, but may be chosen with the
--cipher-algo option to gpg
.
--recipient user
¶-r user
Encrypt for user id user. For details see gpg
.
--local-user user
¶-u user
Use user as the key to sign with. For details see gpg
.
--output file
¶-o file
Write the archive to the specified file file.
--verbose
¶-v
Enable extra informational output.
--quiet
¶-q
Try to be as quiet as possible.
--skip-crypto
¶Skip all crypto operations and create or extract vanilla “ustar” archives.
--dry-run
¶Do not actually output the extracted files.
--directory dir
¶-C dir
Extract the files into the directory dir. The default is to take the directory name from the input filename. If no input filename is known a directory named GPGARCH is used. For tarball creation, switch to directory dir before performing any operations.
--files-from file
-T file
Take the file names to work from the file file; one file per line.
--null
¶Modify option --files-from to use a binary nul instead of a linefeed to separate file names.
--utf8-strings
¶Assume that the file names read by --files-from are UTF-8 encoded. This option has an effect only on Windows where the active code page is otherwise assumed.
--openpgp
¶This option has no effect because OpenPGP encryption and signing is the default.
--cms
¶This option is reserved and shall not be used. It will eventually be used to encrypt or sign using the CMS protocol; but that is not yet implemented.
--batch
¶Use batch mode. Never ask but use the default action. This option is
passed directly to gpg
.
--yes
¶Assume "yes" on most questions. Often used together with
--batch to overwrite existing files. This option is passed
directly to gpg
.
--no
¶Assume "no" on most questions. This option is passed directly to
gpg
.
--require-compliance
¶This option is passed directly to gpg
.
--status-fd n
¶Write special status strings to the file descriptor n. See the file DETAILS in the documentation for a listing of them.
--with-log
¶When extracting an encrypted tarball also write a log file with the gpg output to a file named after the extraction directory with the suffix ".log".
--set-filename file
¶Use the last component of file as the output directory. The default is to take the directory name from the input filename. If no input filename is known a directory named GPGARCH is used. This option is deprecated in favor of option --directory.
--no-compress
¶This option tells gpg to disable compression (i.e. using option -z0). It is useful for archiving only large files which are are already compressed (e.g. a set of videos).
--gpg gpgcmd
¶Use the specified command gpgcmd instead of gpg
.
--gpg-args args
¶Pass the specified extra options to gpg
.
--tar-args args
¶Assume args are standard options of the command tar
and parse them. The only supported tar options are "–directory",
"–files-from", and "–null" This is an obsolete options because those
supported tar options can also be given directly.
--tar command
¶This is a dummy option for backward compatibility.
--version
¶Print version of the program and exit.
--help
¶Display a brief help page and exit.
The program returns 0 if everything was fine, 1 otherwise.
Some examples:
Encrypt the contents of directory mydocs for user Bob to file test1:
gpgtar --encrypt --output test1 -r Bob mydocs
List the contents of archive test1:
gpgtar --list-archive test1
gpg-check-pattern
checks a passphrase given on stdin against
a specified pattern file.
The pattern file is line based with comment lines beginning on the
first position with a #
. Empty lines and lines with
only white spaces are ignored. The actual pattern lines may either be
verbatim string pattern and match as they are (trailing spaces are
ignored) or extended regular expressions indicated by a /
or
!/
in the first column and terminated by another /
or
end of line. If a regular expression starts with !/
the match
result is reversed. By default all comparisons are case insensitive.
Tag lines may be used to further control the operation of this tool. The currently defined tags are:
[icase]
Switch to case insensitive comparison for all further patterns. This is the default.
[case]
Switch to case sensitive comparison for all further patterns.
[reject]
Switch to reject mode. This is the default mode.
[accept]
Switch to accept mode.
In the future more tags may be introduced and thus it is advisable not to start a plain pattern string with an open bracket. The tags must be given verbatim on the line with no spaces to the left or any non white space characters to the right.
In reject mode the program exits on the first match with an exit code of 1 (failure). If at the end of the pattern list the reject mode is still active the program exits with code 0 (success).
In accept mode blocks of patterns are used. A block starts at the next pattern after an "accept" tag and ends with the last pattern before the next "accept" or "reject" tag or at the end of the pattern list. If all patterns in a block match the program exits with an exit code of 0 (success). If any pattern in a block do not match the next pattern block is evaluated. If at the end of the pattern list the accept mode is still active the program exits with code 1 (failure).
--verbose
¶Enable extra informational output.
--check
¶Run only a syntax check on the patternfile.
--null
¶Input is expected to be null delimited.
GnuPG comes with tools used to maintain and access a Web Key Directory.
The gpg-wks-client
is used to send requests to a Web Key
Service provider. This is usually done to upload a key into a Web
Key Directory.
With the --supported command the caller can test whether a site supports the Web Key Service. The argument is an arbitrary address in the to be tested domain. For example foo@example.net. The command returns success if the Web Key Service is supported. The operation is silent; to get diagnostic output use the option --verbose. See option --with-colons for a variant of this command.
With the --check command the caller can test whether a key exists for a supplied mail address. The command returns success if a key is available.
The --create command is used to send a request for
publication in the Web Key Directory. The arguments are the
fingerprint of the key and the user id to publish. The output from
the command is a properly formatted mail with all standard headers.
This mail can be fed to sendmail(8)
or any other tool to
actually send that mail. If sendmail(8)
is installed the
option --send can be used to directly send the created
request. If the provider request a ’mailbox-only’ user id and no such
user id is found, gpg-wks-client
will try an additional user
id.
The --receive and --read commands are used to process confirmation mails as send from the service provider. The former expects an encrypted MIME messages, the latter an already decrypted MIME message. The result of these commands are another mail which can be send in the same way as the mail created with --create.
The command --install-key manually installs a key into a local directory (see option -C) reflecting the structure of a WKD. The arguments are a file with the keyblock and the user-id to install. If the first argument resembles a fingerprint the key is taken from the current keyring; to force the use of a file, prefix the first argument with "./". If no arguments are given the parameters are read from stdin; the expected format are lines with the fingerprint and the mailbox separated by a space. The command --remove-key removes a key from that directory, its only argument is a user-id.
The command --mirror is similar to --install-key but takes the keys from the the LDAP server configured for Dirmngr. If no arguments are given all keys and user ids are installed. If arguments are given they are taken as domain names to limit the to be installed keys. The option --blacklist may be used to further limit the to be installed keys.
The command --print-wkd-hash prints the WKD user-id identifiers and the corresponding mailboxes from the user-ids given on the command line or via stdin (one user-id per line).
The command --print-wkd-url prints the URLs used to fetch the key for the given user-ids from WKD. The meanwhile preferred format with sub-domains is used here.
All commands may also be given without the two leading dashes.
gpg-wks-client
understands these options:
--send
¶Directly send created mails using the sendmail
command.
Requires installation of that command.
--with-colons
¶This option has currently only an effect on the --supported command. If it is used all arguments on the command line are taken as domain names and tested for WKD support. The output format is one line per domain with colon delimited fields. The currently specified fields are (future versions may specify additional fields):
This is the domain name. Although quoting is not required for valid domain names this field is specified to be quoted in standard C manner.
If the value is true the domain supports the Web Key Directory.
If the value is true the domain supports the Web Key Service protocol to upload keys to the directory.
This may contain an gpg-error code to describe certain failures. Use ‘gpg-error CODE’ to explain the code.
The minimum protocol version supported by the server.
The auth-submit flag from the policy file of the server.
The mailbox-only flag from the policy file of the server.
--output file
¶-o
Write the created mail to file instead of stdout. Note that the
value -
for file is the same as writing to stdout. If
this option is used with the --check command and a key was
found it is written to the given file.
--status-fd n
¶Write special status strings to the file descriptor n. This program returns only the status messages SUCCESS or FAILURE which are helpful when the caller uses a double fork approach and can’t easily get the return code of the process.
-C dir
¶--directory dir
Use dir as top level directory for the commands --mirror, --install-key and --remove-key. The default is openpgpkey.
--blacklist file
¶This option is used to exclude certain mail addresses from a mirror operation. The format of file is one mail address (just the addrspec, e.g. "postel@isi.edu") per line. Empty lines and lines starting with a ’#’ are ignored.
--add-revocs
¶--no-add-revocs
If enabled append revocation certificates for the same addrspec as used in the WKD to the key. Modern gpg version are able to import and apply them for existing keys. Note that when used with the --mirror command the revocation are searched in the local keyring and not in an LDAP directory. The default is --add-revocs.
--verbose
¶Enable extra informational output.
--quiet
¶Disable almost all informational output.
--version
¶Print version of the program and exit.
--help
¶Display a brief help page and exit.
To use the services with clients lacking integrated support, the mailcap mechanism can be used. Simply put:
application/vnd.gnupg.wks; \ /nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/bin/gpg-wks-client -v --read --send; \ needsterminal; \ description=WKS message
into the /etc/mailcap. This assumes that a /usr/lib/sendmail is installed. With this configuration any real mail programs will run gpg-wks-client for messages received from a Web Key Service.
The gpg-wks-server
is a server side implementation of the
Web Key Service. It receives requests for publication, sends
confirmation requests, receives confirmations, and published the key.
It also has features to ease the setup and maintenance of a Web Key
Directory.
When used with the command --receive a single Web Key Service mail is processed. Commonly this command is used with the option --send to directly send the created mails back. See below for an installation example.
The command --cron is used for regular cleanup tasks. For example non-confirmed requested should be removed after their expire time. It is best to run this command once a day from a cronjob.
The command --list-domains prints all configured domains. Further it creates missing directories for the configuration and prints warnings pertaining to problems in the configuration.
The command --check-key (or just --check) checks whether a key with the given user-id is installed. The process returns success in this case; to also print a diagnostic use the option -v. If the key is not installed a diagnostic is printed and the process returns failure; to suppress the diagnostic, use option -q. More than one user-id can be given; see also option with-file.
The command --install-key manually installs a key into the WKD. The arguments are a file with the keyblock and the user-id to install. If the first argument resembles a fingerprint the key is taken from the current keyring; to force the use of a file, prefix the first argument with "./". If no arguments are given the parameters are read from stdin; the expected format are lines with the fingerprint and the mailbox separated by a space.
The command --remove-key uninstalls a key from the WKD. The process returns success in this case; to also print a diagnostic, use option -v. If the key is not installed a diagnostic is printed and the process returns failure; to suppress the diagnostic, use option -q.
The command --revoke-key is not yet functional.
gpg-wks-server
understands these options:
-C dir
¶--directory dir
Use dir as top level directory for domains. The default is /var/lib/gnupg/wks.
--from mailaddr
¶Use mailaddr as the default sender address.
--header name=value
¶Add the mail header "name: value" to all outgoing mails.
--send
¶Directly send created mails using the sendmail
command.
Requires installation of that command.
-o file
¶--output file
Write the created mail also to file. Note that the value
-
for file would write it to stdout.
--with-dir
¶When used with the command --list-domains print for each installed domain the domain name and its directory name.
--with-file
¶When used with the command --check-key print for each user-id, the address, ’i’ for installed key or ’n’ for not installed key, and the filename.
--verbose
¶Enable extra informational output.
--quiet
¶Disable almost all informational output.
--version
¶Print version of the program and exit.
--help
¶Display a brief help page and exit.
The Web Key Service requires a working directory to store keys pending for publication. As root create a working directory:
# mkdir /var/lib/gnupg/wks # chown webkey:webkey /var/lib/gnupg/wks # chmod 2750 /var/lib/gnupg/wks
Then under your webkey account create directories for all your domains. Here we do it for "example.net":
$ mkdir /var/lib/gnupg/wks/example.net
Finally run
$ gpg-wks-server --list-domains
to create the required sub-directories with the permissions set correctly. For each domain a submission address needs to be configured. All service mails are directed to that address. It can be the same address for all configured domains, for example:
$ cd /var/lib/gnupg/wks/example.net $ echo key-submission@example.net >submission-address
The protocol requires that the key to be published is sent with an encrypted mail to the service. Thus you need to create a key for the submission address:
$ gpg --batch --passphrase '' --quick-gen-key key-submission@example.net $ gpg -K key-submission@example.net
The output of the last command looks similar to this:
sec rsa3072 2016-08-30 [SC] C0FCF8642D830C53246211400346653590B3795B uid [ultimate] key-submission@example.net bxzcxpxk8h87z1k7bzk86xn5aj47intu@example.net ssb rsa3072 2016-08-30 [E]
Take the fingerprint from that output and manually publish the key:
$ gpg-wks-server --install-key C0FCF8642D830C53246211400346653590B3795B \ > key-submission@example.net
Finally that submission address needs to be redirected to a script
running gpg-wks-server
. The procmail
command can
be used for this: Redirect the submission address to the user "webkey"
and put this into webkey’s .procmailrc:
:0 * !^From: webkey@example.net * !^X-WKS-Loop: webkey.example.net |gpg-wks-server -v --receive \ --header X-WKS-Loop=webkey.example.net \ --from webkey@example.net --send
This is a collection of small howto documents.
Here is a brief run up on how to create a server certificate. It has actually been done this way to get a certificate from CAcert to be used on a real server. It has only been tested with this CA, but there shouldn’t be any problem to run this against any other CA.
We start by generating an X.509 certificate signing request. As there is no need for a configuration file, you may simply enter:
$ gpgsm --generate-key >example.com.cert-req.pem Please select what kind of key you want: (1) RSA (2) Existing key (3) Existing key from card Your selection? 1 |
I opted for creating a new RSA key. The other option is to use an already existing key, by selecting 2 and entering the so-called keygrip. Running the command ‘gpgsm --dump-secret-key USERID’ shows you this keygrip. Using 3 offers another menu to create a certificate directly from a smart card based key.
Let’s continue:
What keysize do you want? (3072) Requested keysize is 3072 bits |
Hitting enter chooses the default RSA key size of 3072 bits. Keys smaller than 2048 bits are too weak on the modern Internet. If you choose a larger (stronger) key, your server will need to do more work.
Possible actions for a RSA key: (1) sign, encrypt (2) sign (3) encrypt Your selection? 1 |
Selecting “sign” enables use of the key for Diffie-Hellman key exchange mechanisms (DHE and ECDHE) in TLS, which are preferred because they offer forward secrecy. Selecting “encrypt” enables RSA key exchange mechanisms, which are still common in some places. Selecting both enables both key exchange mechanisms.
Now for some real data:
Enter the X.509 subject name: CN=example.com |
This is the most important value for a server certificate. Enter here the canonical name of your server machine. You may add other virtual server names later.
E-Mail addresses (end with an empty line): > |
We don’t need email addresses in a TLS server certificate and CAcert would anyway ignore such a request. Thus just hit enter.
If you want to create a client certificate for email encryption, this would be the place to enter your mail address (e.g. joe@example.org). You may enter as many addresses as you like, however the CA may not accept them all or reject the entire request.
Enter DNS names (optional; end with an empty line): > example.com > www.example.com > |
Here I entered the names of the services which the machine actually provides. You almost always want to include the canonical name here too. The browser will accept a certificate for any of these names. As usual the CA must approve all of these names.
URIs (optional; end with an empty line): > |
It is possible to insert arbitrary URIs into a certificate; for a server certificate this does not make sense.
Create self-signed certificate? (y/N) |
Since we are creating a certificate signing request, and not a full certificate, we answer no here, or just hit enter for the default.
We have now entered all required information and gpgsm
will
display what it has gathered and ask whether to create the certificate
request:
These parameters are used: Key-Type: RSA Key-Length: 3072 Key-Usage: sign, encrypt Name-DN: CN=example.com Name-DNS: example.com Name-DNS: www.example.com Proceed with creation? (y/N) y |
gpgsm
will now start working on creating the request. As this
includes the creation of an RSA key it may take a while. During this
time you will be asked 3 times for a passphrase to protect the created
private key on your system. A pop up window will appear to ask for
it. The first two prompts are for the new passphrase and for re-entering it;
the third one is required to actually create the certificate signing request.
When it is ready, you should see the final notice:
Ready. You should now send this request to your CA. |
Now, you may look at the created request:
$ cat example.com.cert-req.pem -----BEGIN CERTIFICATE REQUEST----- MIIClTCCAX0CAQAwFjEUMBIGA1UEAxMLZXhhbXBsZS5jb20wggEiMA0GCSqGSIb3 DQEBAQUAA4IBDwAwggEKAoIBAQDP1QEcbTvOLLCX4gAoOzH9AW7jNOMj7OSOL0uW h2bCdkK5YVpnX212Z6COTC3ZG0pJiCeGt1TbbDJUlTa4syQ6JXavjK66N8ASZsyC Rwcl0m6hbXp541t1dbgt2VgeGk25okWw3j+brw6zxLD2TnthJxOatID0lDIG47HW GqzZmA6WHbIBIONmGnReIHTpPAPCDm92vUkpKG1xLPszuRmsQbwEl870W/FHrsvm DPvVUUSdIvTV9NuRt7/WY6G4nPp9QlIuTf1ESPzIuIE91gKPdrRCAx0yuT708S1n xCv3ETQ/bKPoAQ67eE3mPBqkcVwv9SE/2/36Lz06kAizRgs5AgMBAAGgOjA4Bgkq hkiG9w0BCQ4xKzApMCcGA1UdEQQgMB6CC2V4YW1wbGUuY29tgg93d3cuZXhhbXBs ZS5jb20wDQYJKoZIhvcNAQELBQADggEBAEWD0Qqz4OENLYp6yyO/KqF0ig9FDsLN b5/R+qhms5qlhdB5+Dh+j693Sj0UgbcNKc6JT86IuBqEBZmRCJuXRoKoo5aMS1cJ hXga7N9IA3qb4VBUzBWvlL92U2Iptr/cEbikFlYZF2Zv3PBv8RfopVlI3OLbKV9D bJJTt/6kuoydXKo/Vx4G0DFzIKNdFdJk86o/Ziz8NOs9JjZxw9H9VY5sHKFM5LKk VcLwnnLRlNjBGB+9VK/Tze575eG0cJomTp7UGIB+1xzIQVAhUZOizRDv9tHDeaK3 k+tUhV0kuJcYHucpJycDSrP/uAY5zuVJ0rs2QSjdnav62YrRgEsxJrU= -----END CERTIFICATE REQUEST----- $ |
You may now proceed by logging into your account at the CAcert website,
choose Server Certificates - New
, check sign by class 3 root
certificate
, paste the above request block into the text field and
click on Submit
.
If everything works out fine, a certificate will be shown. Now run
$ gpgsm --import |
and paste the certificate from the CAcert page into your terminal followed by a Ctrl-D
-----BEGIN CERTIFICATE----- MIIEIjCCAgqgAwIBAgIBTDANBgkqhkiG9w0BAQQFADBUMRQwEgYDVQQKEwtDQWNl [...] rUTFlNElRXCwIl0YcJkIaYYqWf7+A/aqYJCi8+51usZwMy3Jsq3hJ6MA3h1BgwZs Rtct3tIX -----END CERTIFICATE----- gpgsm: issuer certificate (#/CN=CAcert Class 3 Ro[...]) not found gpgsm: certificate imported gpgsm: total number processed: 1 gpgsm: imported: 1 |
gpgsm
tells you that it has imported the certificate. It is now
associated with the key you used when creating the request. The root
certificate has not been found, so you may want to import it from the
CACert website.
To see the content of your certificate, you may now enter:
$ gpgsm -K example.com /home/foo/.gnupg/pubring.kbx --------------------------- Serial number: 4C Issuer: /CN=CAcert Class 3 Root/OU=http:\x2f\x2fwww.[...] Subject: /CN=example.com aka: (dns-name example.com) aka: (dns-name www.example.com) validity: 2015-07-01 16:20:51 through 2016-07-01 16:20:51 key type: 3072 bit RSA key usage: digitalSignature keyEncipherment ext key usage: clientAuth (suggested), serverAuth (suggested), [...] fingerprint: 0F:9C:27:B2:DA:05:5F:CB:33:D8:19:E9:65:B9:4F:BD:B1:98:CC:57 |
I used -K above because this will only list certificates for which a private key is available. To see more details, you may use --dump-secret-keys instead of -K.
To make actual use of the certificate you need to install it on your server. Server software usually expects a PKCS\#12 file with key and certificate. To create such a file, run:
$ gpgsm --export-secret-key-p12 -a >example.com-cert.pem |
You will be asked for the passphrase as well as for a new passphrase to be used to protect the PKCS\#12 file. The file now contains the certificate as well as the private key:
$ cat example-cert.pem Issuer ...: /CN=CAcert Class 3 Root/OU=http:\x2f\x2fwww.CA[...] Serial ...: 4C Subject ..: /CN=example.com aka ..: (dns-name example.com) aka ..: (dns-name www.example.com) -----BEGIN PKCS12----- MIIHlwIBAzCCB5AGCSqGSIb37QdHAaCCB4EEggd9MIIHeTk1BJ8GCSqGSIb3DQEu [...many more lines...] -----END PKCS12----- $ |
Copy this file in a secure way to the server, install it there and delete the file then. You may export the file again at any time as long as it is available in GnuPG’s private key database.
GnuPG has been developed on GNU/Linux systems and is know to work on almost all Free OSes. All modern POSIX systems should be supported right now, however there are probably a lot of smaller glitches we need to fix first. The major problem areas are:
There is one exception of this rule: Systems based the Microsoft Windows API (called here W32) will be supported to some extend.
Current limitations are:
gpgconf
does not create backup files, so in case of trouble
your configuration file might get lost.
watchgnupg
is not available. Logging to sockets is not
possible.
scdaemon
is
not yet supported.
Everyone knows that software often does not do what it should do and thus there is a need to track down problems. We call this debugging in a reminiscent to the moth jamming a relay in a Mark II box back in 1947.
Most of the problems a merely configuration and user problems but nevertheless they are the most annoying ones and responsible for many gray hairs. We try to give some guidelines here on how to identify and solve the problem at hand.
The GnuPG distribution comes with a couple of tools, useful to help find and solving problems.
A keybox is a file format used to store public keys along with meta information and indices. The commonly used one is the file pubring.kbx in the .gnupg directory. It contains all X.509 certificates as well as OpenPGP keys.
When called the standard way, e.g.:
‘kbxutil ~/.gnupg/pubring.kbx’
it lists all records (called blobs) with there meta-information in a human readable format.
To see statistics on the keybox in question, run it using
‘kbxutil --stats ~/.gnupg/pubring.kbx’
and you get an output like:
Total number of blobs: 99 header: 1 empty: 0 openpgp: 0 x509: 98 non flagged: 81 secret flagged: 0 ephemeral flagged: 17
In this example you see that the keybox does not have any OpenPGP keys
but contains 98 X.509 certificates and a total of 17 keys or certificates
are flagged as ephemeral, meaning that they are only temporary stored
(cached) in the keybox and won’t get listed using the usual commands
provided by gpgsm
or gpg
. 81 certificates are stored
in a standard way and directly available from gpgsm
.
To find duplicated certificates and keyblocks in a keybox file (this should not occur but sometimes things go wrong), run it using
‘kbxutil --find-dups ~/.gnupg/pubring.kbx’
If a round robin URL of is used for a keyserver (e.g. subkeys.gnupg.org); it is not easy to see what server is actually used. Using the keyserver debug option as in
gpg --keyserver-options debug=1 -v --refresh-key 1E42B367
is thus often helpful. Note that the actual output depends on the backend and may change from release to release.
For development, the best logging method on WindowsCE is the use of
remote debugging using a log file name of tcp://<ip-addr>:<port>.
The command watchgnupg
may be used on the remote host to listen
on the given port (see option watchgnupg --tcp). For in the field
tests it is better to make use of the logging facility provided by the
gpgcedev
driver (part of libassuan); this is enabled by using
a log file name of GPG2: (see option --log-file).
Most likely the option enable-ocsp is active for gpgsm but Dirmngr’s OCSP feature has not been enabled using allow-ocsp in dirmngr.conf.
The far most common reason for this is that the environment variable
GPG_TTY
has not been set correctly. Make sure that it has been
set to a real tty device and not just to ‘/dev/tty’;
i.e. ‘GPG_TTY=tty’ is plainly wrong; what you want is
‘GPG_TTY=`tty`’ — note the back ticks. Also make sure that
this environment variable gets exported, that is you should follow up
the setting with an ‘export GPG_TTY’ (assuming a Bourne style
shell). Even for GUI based Pinentries; you should have set
GPG_TTY
. See the section on installing the gpg-agent
on how to do it.
SSH has no way to tell the gpg-agent what terminal or X display it is running on. So when remotely logging into a box where a gpg-agent with SSH support is running, the pinentry will get popped up on whatever display the gpg-agent has been started. To solve this problem you may issue the command
echo UPDATESTARTUPTTY | gpg-connect-agent
and the next pinentry will pop up on your display or screen. However, you need to kill the running pinentry first because only one pinentry may be running at once. If you plan to use ssh on a new display you should issue the above command before invoking ssh or any other service making use of ssh.
It may happen that you have created a certificate request using
gpgsm
but not yet received and imported the certificate from
the CA. However, you want to export the secret key to another machine
right now to import the certificate over there then. You can do this
with a little trick but it requires that you know the approximate time
you created the signing request. By running the command
ls -ltr ~/.gnupg/private-keys-v1.d
you get a listing of all private keys under control of gpg-agent
.
Pick the key which best matches the creation time and run the command
/nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/libexec/gpg-protect-tool --p12-export \ ~/.gnupg/private-keys-v1.d/foo >foo.p12 |
(Please adjust the path to gpg-protect-tool
to the appropriate
location). foo is the name of the key file you picked (it should
have the suffix .key). A Pinentry box will pop up and ask you
for the current passphrase of the key and a new passphrase to protect it
in the pkcs#12 file.
To import the created file on the machine you use this command:
/nix/store/chpkba53g5gfap7xjy7dwf269f162dyh-gnupg-2.4.5/libexec/gpg-protect-tool --p12-import --store foo.p12 |
You will be asked for the pkcs#12 passphrase and a new passphrase to protect the imported private key at its new location.
Note that there is no easy way to match existing certificates with stored private keys because some private keys are used for Secure Shell or other purposes and don’t have a corresponding certificate.
A common problem is that the root certificate misses the required
basicConstraints attribute and thus gpgsm
rejects this
certificate. An error message indicating “no value” is a sign for
such a certificate. You may use the relax
flag in
trustlist.txt to accept the certificate anyway. Note that the
fingerprint and this flag may only be added manually to
trustlist.txt.
The signature is broken. You may try the option --extra-digest-algo SHA256 to workaround the problem. The number N is the internal algorithm identifier; for example 8 refers to SHA-256.
When running the W32 version of gpg
under Wine you may get
an error messages like:
gpg: fatal: WriteConsole failed: Access denied
The solution is to use the command wineconsole
.
Some operations like --generate-key really want to talk to
the console directly
for increased security (for example to prevent the passphrase from
appearing on the screen). So, you should use wineconsole
instead of wine
, which will launch a windows console that
implements those additional features.
For performance reasons the keyservers do not check the keys the same
way gpg
does. It may happen that the listing of keys
available on the keyservers shows keys with wrong user IDs or with user
Ids from other keys. If you try to import this key, the bad keys or bad
user ids won’t get imported, though. This is a bit unfortunate but we
can’t do anything about it without actually downloading the keys.
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The GnuPG project would like to thank its many contributors. Without them the project would not have been nearly as successful as it has been. Any omissions in this list are accidental. Feel free to contact the maintainer if you have been left out or some of your contributions are not listed.
David Shaw, Matthew Skala, Michael Roth, Niklas Hernaeus, Nils Ellmenreich, Rémi Guyomarch, Stefan Bellon, Timo Schulz and Werner Koch wrote the code. Birger Langkjer, Daniel Resare, Dokianakis Theofanis, Edmund GRIMLEY EVANS, Gaël Quéri, Gregory Steuck, Nagy Ferenc László, Ivo Timmermans, Jacobo Tarri’o Barreiro, Janusz Aleksander Urbanowicz, Jedi Lin, Jouni Hiltunen, Laurentiu Buzdugan, Magda Procha’zkova’, Michael Anckaert, Michal Majer, Marco d’Itri, Nilgun Belma Buguner, Pedro Morais, Tedi Heriyanto, Thiago Jung Bauermann, Rafael Caetano dos Santos, Toomas Soome, Urko Lusa, Walter Koch, Yosiaki IIDA did the official translations. Mike Ashley wrote and maintains the GNU Privacy Handbook. David Scribner is the current FAQ editor. Lorenzo Cappelletti maintains the web site.
The new modularized architecture of gnupg 1.9 as well as the X.509/CMS part has been developed as part of the Ägypten project. Direct contributors to this project are: Bernhard Herzog, who did extensive testing and tracked down a lot of bugs. Bernhard Reiter, who made sure that we met the specifications and the deadlines. He did extensive testing and came up with a lot of suggestions. Jan-Oliver Wagner made sure that we met the specifications and the deadlines. He also did extensive testing and came up with a lot of suggestions. Karl-Heinz Zimmer and Marc Mutz had to struggle with all the bugs and misconceptions while working on KDE integration. Marcus Brinkman extended GPGME, cleaned up the Assuan code and fixed bugs all over the place. Moritz Schulte took over Libgcrypt maintenance and developed it into a stable an useful library. Steffen Hansen had a hard time to write the dirmngr due to underspecified interfaces. Thomas Koester did extensive testing and tracked down a lot of bugs. Werner Koch designed the system and wrote most of the code.
The following people helped greatly by suggesting improvements, testing, fixing bugs, providing resources and doing other important tasks: Adam Mitchell, Albert Chin, Alec Habig, Allan Clark, Anand Kumria, Andreas Haumer, Anthony Mulcahy, Ariel T Glenn, Bob Mathews, Bodo Moeller, Brendan O’Dea, Brenno de Winter, Brian M. Carlson, Brian Moore, Brian Warner, Bryan Fullerton, Caskey L. Dickson, Cees van de Griend, Charles Levert, Chip Salzenberg, Chris Adams, Christian Biere, Christian Kurz, Christian von Roques, Christopher Oliver, Christian Recktenwald, Dan Winship, Daniel Eisenbud, Daniel Koening, Dave Dykstra, David C Niemi, David Champion, David Ellement, David Hallinan, David Hollenberg, David Mathog, David R. Bergstein, Detlef Lannert, Dimitri, Dirk Lattermann, Dirk Meyer, Disastry, Douglas Calvert, Ed Boraas, Edmund GRIMLEY EVANS, Edwin Woudt, Enzo Michelangeli, Ernst Molitor, Fabio Coatti, Felix von Leitner, fish stiqz, Florian Weimer, Francesco Potorti, Frank Donahoe, Frank Heckenbach, Frank Stajano, Frank Tobin, Gabriel Rosenkoetter, Gaël Quéri, Gene Carter, Geoff Keating, Georg Schwarz, Giampaolo Tomassoni, Gilbert Fernandes, Greg Louis, Greg Troxel, Gregory Steuck, Gregery Barton, Harald Denker, Holger Baust, Hendrik Buschkamp, Holger Schurig, Holger Smolinski, Holger Trapp, Hugh Daniel, Huy Le, Ian McKellar, Ivo Timmermans, Jan Krueger, Jan Niehusmann, Janusz A. Urbanowicz, James Troup, Jean-loup Gailly, Jeff Long, Jeffery Von Ronne, Jens Bachem, Jeroen C. van Gelderen, J Horacio MG, J. Michael Ashley, Jim Bauer, Jim Small, Joachim Backes, Joe Rhett, John A. Martin, Johnny Teveßen, Jörg Schilling, Jos Backus, Joseph Walton, Juan F. Codagnone, Jun Kuriyama, Kahil D. Jallad, Karl Fogel, Karsten Thygesen, Katsuhiro Kondou, Kazu Yamamoto, Keith Clayton, Kevin Ryde, Klaus Singvogel, Kurt Garloff, Lars Kellogg-Stedman, L. Sassaman, M Taylor, Marcel Waldvogel, Marco d’Itri, Marco Parrone, Marcus Brinkmann, Mark Adler, Mark Elbrecht, Mark Pettit, Markus Friedl, Martin Kahlert, Martin Hamilton, Martin Schulte, Matt Kraai, Matthew Skala, Matthew Wilcox, Matthias Urlichs, Max Valianskiy, Michael Engels, Michael Fischer v. Mollard, Michael Roth, Michael Sobolev, Michael Tokarev, Nicolas Graner, Mike McEwan, Neal H Walfield, Nelson H. F. Beebe, NIIBE Yutaka, Niklas Hernaeus, Nimrod Zimerman, N J Doye, Oliver Haakert, Oskari Jääskeläinen, Pascal Scheffers, Paul D. Smith, Per Cederqvist, Phil Blundell, Philippe Laliberte, Peter Fales, Peter Gutmann, Peter Marschall, Peter Valchev, Piotr Krukowiecki, QingLong, Ralph Gillen, Rat, Reinhard Wobst, Rémi Guyomarch, Reuben Sumner, Richard Outerbridge, Robert Joop, Roddy Strachan, Roger Sondermann, Roland Rosenfeld, Roman Pavlik, Ross Golder, Ryan Malayter, Sam Roberts, Sami Tolvanen, Sean MacLennan, Sebastian Klemke, Serge Munhoven, SL Baur, Stefan Bellon, Dr.Stefan.Dalibor, Stefan Karrmann, Stefan Keller, Steffen Ullrich, Steffen Zahn, Steven Bakker, Steven Murdoch, Susanne Schultz, Ted Cabeen, Thiago Jung Bauermann, Thijmen Klok, Thomas Roessler, Tim Mooney, Timo Schulz, Todd Vierling, TOGAWA Satoshi, Tom Spindler, Tom Zerucha, Tomas Fasth, Tommi Komulainen, Thomas Klausner, Tomasz Kozlowski, Thomas Mikkelsen, Ulf Möller, Urko Lusa, Vincent P. Broman, Volker Quetschke, W Lewis, Walter Hofmann, Walter Koch, Wayne Chapeskie, Wim Vandeputte, Winona Brown, Yosiaki IIDA, Yoshihiro Kajiki and Gerlinde Klaes.
This software has been made possible by the previous work of Chris Wedgwood, Jean-loup Gailly, Jon Callas, Mark Adler, Martin Hellman, Paul Kendall, Philip R. Zimmermann, Peter Gutmann, Philip A. Nelson, Taher Elgamal, Torbjorn Granlund, Whitfield Diffie, some unknown NSA mathematicians and all the folks who have worked hard to create complete and free operating systems.
And finally we’d like to thank everyone who uses these tools, submits bug reports and generally reminds us why we’re doing this work in the first place.
The Authority Revocation List is technical identical to a CRL but used for CAs and not for end user certificates.
Verification model for X.509 which uses the creation date of a signature as the date the validation starts and in turn checks that each certificate has been issued within the time frame, the issuing certificate was valid. This allows the verification of signatures after the CA’s certificate expired. The validation test also required an online check of the certificate status. The chain model is required by the German signature law. See also Shell model.
The Cryptographic Message Standard describes a message
format for encryption and digital signing. It is closely related to the
X.509 certificate format. CMS was formerly known under the
name PKCS#7
and is described by RFC3369
.
The Certificate Revocation List is a list containing certificates revoked by the issuer.
The Certificate Signing Request is a message send to a CA to ask them to issue a new certificate. The data format of such a signing request is called PCKS#10.
A data format used to build a PKI and to exchange encrypted or signed messages. In contrast to X.509, OpenPGP also includes the message format but does not explicitly demand a specific PKI. However any kind of PKI may be build upon the OpenPGP protocol.
This term is used by GnuPG to describe a 20 byte hash value used to identify a certain key without referencing to a concrete protocol. It is used internally to access a private key. Usually it is shown and entered as a 40 character hexadecimal formatted string.
The Online Certificate Status Protocol is used as an
alternative to a CRL. It is described in RFC 2560
.
The Personal Security Environment describes a database to store private keys. This is either a smartcard or a collection of files on a disk; the latter is often called a Soft-PSE.
The standard model for validation of certificates under X.509. At the time of the verification all certificates must be valid and not expired. See also Chain model.
Description of a PKI used with CMS. It is for example
defined by RFC3280
.