This manual describes the Emacs auth-source library.
It is a way for multiple applications to share a single configuration (in Emacs and in files) for user convenience.
This file describes the Emacs auth-source library.
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The auth-source library is simply a way for Emacs and Gnus, among others, to answer the old burning question “What are my user name and password?”
(This is different from the old question about burning “Where is the fire extinguisher, please?”.)
The auth-source library supports more than just the user name or the password (known as the secret).
Similarly, the auth-source library supports multiple storage backend, currently either the classic “netrc” backend, examples of which you can see later in this document, JSON files, the Secret Service API, and pass, the standard unix password manager. This is done with EIEIO-based backends and you can write your own if you want.
“Netrc” files are a de facto standard. They look like this:
machine mymachine login myloginname password mypassword port myport
The machine is the server (either a DNS name or an IP address).
It’s known as :host in auth-source-search queries.
The port is the connection port or protocol. It’s known as
:port in auth-source-search queries.
The user is the user name. It’s known as :user in
auth-source-search queries. You can also use login and
account.
Matching entries are usually used in the order they appear, so placing the most specific entries first in the file is a good idea. For instance:
machine example.com login foobar password geheimnis port smtp machine example.com login foobar password hemmelig
Here we’re using one password for the smtp service, and a
different one for all the other services.
You can also use this file to specify client certificates to use when setting up TLS connections. The format is:
machine mymachine port myport key key cert cert
key and cert are filenames containing the key and
certificate to use respectively. In order to make network connections
use them automatically, either pass :client-certificate t to
open-network-stream, or customize
network-stream-use-client-certificates to t.
You can use spaces inside a password or other token by surrounding the token with either single or double quotes.
You can use apostrophes inside a password or other token by
surrounding it with double quotes, e.g., "he'llo". Similarly you
can use double quotes inside a password or other token by surrounding
it with apostrophes, e.g., 'he"llo'. You can’t mix both (so a
password or other token can’t have both apostrophes and double quotes).
All this is optional. You could just say (but we don’t recommend it, we’re just showing that it’s possible)
password mypassword
to use the same password everywhere. Again, DO NOT DO THIS or you will be pwned as the kids say.
“Netrc” files are usually called .authinfo or .netrc; nowadays .authinfo seems to be more popular and the auth-source library encourages this confusion by accepting both, as you’ll see later.
If you have problems with the search, set auth-source-debug to
'trivia and see what host, port, and user the library is
checking in the *Messages* buffer. Ditto for any other
problems, your first step is always to see what’s being checked. The
second step, of course, is to write a blog entry about it and wait for
the answer in the comments.
You can customize the variable auth-sources. The following may
be needed if you are using an older version of Emacs or if the
auth-source library is not loaded for some other reason.
(require 'auth-source) ;; probably not necessary (customize-variable 'auth-sources) ;; optional, do it once
The auth-sources variable tells the auth-source library where
your netrc files, Secret Service API collection items, or your
password store live for a particular host and protocol. While you can
get fancy, the default and simplest configuration is:
;;; old default: required :host and :port, not needed anymore
(setq auth-sources '((:source "~/.authinfo.gpg" :host t :port t)))
;;; mostly equivalent (see below about fallbacks) but shorter:
(setq auth-sources '((:source "~/.authinfo.gpg")))
;;; even shorter and the default:
(setq auth-sources '("~/.authinfo.gpg" "~/.authinfo" "~/.netrc"))
;;; use the Secrets API Login collection
;;; (see Secret Service API)
(setq auth-sources '("secrets:Login"))
;;; use pass (~/.password-store)
;;; (see The Unix password store)
(auth-source-pass-enable)
;;; JSON data in format [{ "machine": "SERVER",
;;; "login": "USER", "password": "PASSWORD" }...]
(setq auth-sources '("~/.authinfo.json.gpg"))
By adding multiple entries to auth-sources with a particular
host or protocol, you can have specific netrc files for that host or
protocol. Usually this is unnecessary but may make sense if you have
shared netrc files or some other unusual setup (90% of Emacs users
have unusual setups and the remaining 10% are really unusual).
Here’s a mixed example using two sources:
(setq auth-sources '((:source (:secrets default)
:host "myserver" :user "joe")
"~/.authinfo.gpg"))
If you don’t customize auth-sources, you’ll have to live with
the defaults: the unencrypted netrc file ~/.authinfo will be
used for any host and any port.
If that fails, any host and any port are looked up in the netrc file ~/.authinfo.gpg, which is a GnuPG encrypted file (see GnuPG and EasyPG Assistant Configuration).
Finally, the unencrypted netrc file ~/.netrc will be used for any host and any port.
The typical netrc line example is without a port.
machine YOURMACHINE login YOU password YOURPASSWORD
This will match any authentication port. Simple, right? But what if there’s a SMTP server on port 433 of that machine that needs a different password from the IMAP server?
machine YOURMACHINE login YOU password SMTPPASSWORD port 433 machine YOURMACHINE login YOU password GENERALPASSWORD
If you wish to specify a particular SMTP authentication method to use
with a machine, you can use the smtp-auth keyword.
See Authentication in Emacs SMTP Library,
for available methods.
For url-auth authentication (HTTP/HTTPS), you need to put this in your netrc file:
machine yourmachine.com:80 port http login testuser password testpass
This will match any realm and authentication method (basic or digest) over HTTP. HTTPS is set up similarly. If you want finer controls, explore the url-auth source code and variables.
For Tramp authentication, use:
machine yourmachine.com port scp login testuser password testpass
Note that the port denotes the Tramp connection method. When you don’t use a port entry, you match any Tramp method, as explained earlier. Since Tramp has about 88 connection methods, this may be necessary if you have an unusual (see earlier comment on those) setup.
The netrc format is directly translated into JSON, if you are into that sort of thing. Just point to a JSON file with entries like this:
[
{ "machine": "yourmachine.com", "port": "http",
"login": "testuser", "password": "testpass" }
]
For multiple GMail accounts with Gnus, you have to make two nnimap
entries in your gnus-secondary-select-methods with distinct
names:
(setq gnus-secondary-select-methods '((nnimap "gmail"
(nnimap-address "imap.gmail.com"))
(nnimap "gmail2"
(nnimap-address "imap.gmail.com"))))
Your netrc entries will then be:
machine gmail login account@gmail.com password "account password" port imap machine gmail2 login account2@gmail.com password "account2 password" port imap
The Secret Service API is a standard from freedesktop.org to securely store passwords and other confidential information. This API is implemented by system daemons such as the GNOME Keyring and the KDE Wallet (these are GNOME and KDE packages respectively and should be available on most modern GNU/Linux systems). It has been tested also with KeePassXC.
The auth-source library uses the secrets.el library to connect through the Secret Service API. You can also use that library in other packages, it’s not exclusive to auth-source.
After loading secrets.el, a non-nil value of this
variable indicates the existence of a daemon providing the Secret
Service API.
This command shows all collections, items, and their attributes.
The atomic objects managed by the Secret Service API are secret items, which contain things an application wishes to store securely, like a password. Secret items have a label (a name), the secret (which is the string we want, like a password), and a set of lookup attributes. The attributes can be used to search and retrieve a secret item at a later date.
Secret items are grouped in collections. A collection is sometimes called a ‘keyring’ or ‘wallet’ in GNOME Keyring and KDE Wallet but it’s the same thing, a group of secrets. Collections are personal and protected so only the owner can open them.
The most common collection is called "login".
A collection can have an alias. The alias "default" is
commonly used so the clients don’t have to know the specific name of
the collection they open. Other aliases are not supported yet.
Since aliases are globally accessible, set the "default" alias
only when you’re sure it’s appropriate.
This function returns all the collection names as a list.
Set alias as alias of collection labeled collection.
Currently only the alias "default" is supported.
Return the collection name alias is referencing to.
Currently only the alias "default" is supported.
Collections can be created and deleted by the functions
secrets-create-collection and secrets-delete-collection.
Usually, this is not done from within Emacs. Do not delete standard
collections such as "login".
With GNOME Keyring, there exists a special collection called
"session", which has the lifetime of the user being logged in.
Its data are not stored on disk and go away when the user logs out.
Therefore, it can be used to store and retrieve secret items
temporarily. The "session" collection is better than a
persistent collection when the secret items should not live
permanently. The "session" collection can be addressed either
by the string "session", or by nil, whenever a
collection parameter is needed.
However, other Secret Service provider don’t create this temporary
"session" collection. You shall check first that this
collection exists, before you use it.
Returns all the item labels of collection as a list.
This function creates a new item in collection with label item and password password. The label item does not have to be unique in collection. attributes are key-value pairs set for the created item. The keys are keyword symbols, starting with a colon; values are strings. Example:
;;; The collection is "session", the label is "my item" ;;; and the secret (password) is "geheim". (secrets-create-item "session" "my item" "geheim" :method "sudo" :user "joe" :host "remote-host")
The key :xdg:schema determines the scope of the item to be
generated, i.e. for which applications the item is intended for.
This is just a string like "org.freedesktop.NetworkManager.Mobile" or
"org.gnome.OnlineAccounts", the other required keys are determined by
this. If no :xdg:schema is given,
"org.freedesktop.Secret.Generic" is used by default.
Return the secret of item labeled item in collection. If
there are several items labeled item, it is undefined which one
is returned. If there is no such item, return nil.
This function deletes item item in collection. If there are several items labeled item, it is undefined which one is deleted.
The lookup attributes, which are specified during creation of a secret item, must be a key-value pair. Keys are keyword symbols, starting with a colon; values are strings. They can be retrieved from a given secret item and they can be used for searching of items.
Returns the value of key attribute of item labeled item in
collection. If there are several items labeled item, it
is undefined which one is returned. If there is no such item, or the
item doesn’t own this key, the function returns nil.
Return the lookup attributes of item labeled item in
collection. If there are several items labeled item, it
is undefined which one is returned. If there is no such item, or the
item has no attributes, it returns nil. Example:
(secrets-get-attributes "session" "my item")
⇒ ((:user . "joe") (:host . "remote-host"))
Search for the items in collection with matching
attributes. The attributes are key-value pairs, as used
in secrets-create-item. Example:
(secrets-search-items "session" :user "joe")
⇒ ("my item" "another item")
The auth-source library uses the secrets.el library and thus
the Secret Service API when you specify a source matching
"secrets:COLLECTION". For instance, you could use
"secrets:session" to use the "session" collection, open only
for the lifetime of Emacs. Or you could use "secrets:Login" to
open the "Login" collection. As a special case, you can use the
symbol default in auth-sources (not a string, but a
symbol) to specify the "default" alias. Here is a contrived
example that sets auth-sources to search three collections and
then fall back to ~/.authinfo.gpg.
(setq auth-sources '(default
"secrets:session"
"secrets:Login"
"~/.authinfo.gpg"))
Attribute values in the auth-source spec, which are not strings (like port numbers), are stringified prior calling the secrets.el functions.
The standard unix password
manager (or just pass) stores your passwords in
gpg-protected files following the Unix philosophy. The store
location (any directory) must be specified in the
auth-source-pass-filename variable which defaults to
~/.password-store.
Emacs integration of pass follows the approach suggested by the
pass project itself for data organization to find data. In
particular, to store a password for the user rms on the host
gnu.org and port 22, you should use one of the following
filenames.
No username or port in the filename means that any username and port will match.
The username to match can be expressed as filename inside a directory whose name matches the host. This is useful if the store has passwords for several users on the same host.
The username can also be expressed as a prefix, separated from the
host with an at-sign (@).
The port (aka. service) to match can only be expressed after the host and separated with a colon (:). The separator can be changed through the auth-source-pass-port-separator variable.
Entries can be stored in arbitrary directories.
If several entries match, the one matching the most items (where an
“item” is one of username, port or host) is preferred. For example,
while searching for an entry matching the rms user on host
gnu.org and port 22, then the entry
gnu.org:22/rms.gpg is preferred over gnu.org.gpg.
However, such processing is not applied when the option
auth-source-pass-extra-query-keywords is set to t.
Users of pass may also be interested in functionality provided
by other Emacs packages:
pass;
Set this variable to a string locating the password store on the disk. Defaults to ~/.password-store.
Set this variable to a string that should separate an host name from a port in an entry. Defaults to ‘:’.
This expands the selection of available keywords to include
:max and :require and tells more of them to accept a
list of query parameters as an argument. When searching, it also
favors the ‘rms@gnu.org.gpg’ form for usernames over the
‘gnu.org/rms.gpg’ form, regardless of whether a :user
param was provided.
In general, if you prefer idiosyncrasies traditionally exhibited by
this backend, such as prioritizing field count in a filename or
matching against subdomain labels, keep this option set to nil
(the default). But, if you experience problems predicting the outcome
of searches relative to other auth-source backends or encounter code
expecting to query multiple backends uniformly, try flipping it to
t.
The auth-source library lets you control logging output easily.
Set this variable to 'trivia to see lots of output in
*Messages*, or set it to a function that behaves like
message to do your own logging.
The auth-source library only has a few functions for external use.
This function searches (or modifies) authentication backends according to spec. See the function’s doc-string for details.
Let’s take a look at an example of using auth-source-search
from Gnus’s nnimap.el.
(defun nnimap-credentials (address ports)
(let* ((auth-source-creation-prompts
'((user . "IMAP user at %h: ")
(secret . "IMAP password for %u@%h: ")))
(found (nth 0 (auth-source-search :max 1
:host address
:port ports
:require '(:user :secret)
:create t))))
(if found
(list (plist-get found :user)
(auth-info-password found)
(plist-get found :save-function))
nil)))
This call requires the user and password (secret) to be in the
results. It also requests that an entry be created if it doesn’t
exist already. While the created entry is being assembled, the shown
prompts will be used to interact with the user. The caller can also
pass data in auth-source-creation-defaults to supply defaults
for any of the prompts.
Note that the password needs to be evaluated if it’s a function. It’s wrapped in a function to provide some security.
Later, after a successful login, nnimap.el calls the
:save-function like so:
(when (functionp (nth 2 credentials)) (funcall (nth 2 credentials)))
This will work whether the :save-function was provided or not.
:save-function will be provided only when a new entry was
created, so this effectively says “after a successful login, save the
authentication information we just used, if it was newly created.”
After the first time it’s called, the :save-function will not
run again (but it will log something if you have set
auth-source-debug to 'trivia). This is so it won’t ask
the same question again, which is annoying. This is so it won’t ask
the same question again, which is annoying. This is so it won’t ask
the same question again, which is annoying.
So the responsibility of the API user that specified :create t
is to call the :save-function if it’s provided.
This function deletes entries matching spec from the authentication backends. It returns the entries that were deleted. The backend may not actually delete the entries.
This function forgets any cached data that exactly matches spec.
It returns t if it forget some data, and nil if no
matching data was found.
This function forgets any cached data matching spec. It returns the number of items forgotten.
This function returns the password of the first record found by
applying auth-source-search to spec.
This function extracts the password string from the auth-info record.
If the auth-sources variable contains ~/.authinfo.gpg
before ~/.authinfo, the auth-source library will try to
read the GnuPG encrypted .gpg file first, before
the unencrypted file.
The EasyPG Assistant, which comes bundled with Emacs, handles decryption of encrypted files automatically, see Top in EasyPG Assistant User’s Manual. It is an Emacs user interface to GnuPG (GNU Privacy Guard), see Top in Using the GNU Privacy Guard. To get started with these quickly, see Quick Start in EasyPG Assistant User’s Manual.
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However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.
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An MMC is “eligible for relicensing” if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008.
The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing.
To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:
Copyright (C) year your name. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''.
If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with…Texts.” line with this:
with the Invariant Sections being list their titles, with
the Front-Cover Texts being list, and with the Back-Cover Texts
being list.
If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.
If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.