gitcredentials.adoc - pub/scm/git/git-htmldocs - Git at Google

 gitcredentials(7)
 =================

 NAME
 ----
 gitcredentials - Providing usernames and passwords to Git

 SYNOPSIS
 --------
 ------------------
 git config credential.https://example.com.username myusername
 git config credential.helper "$helper $options"
 ------------------

 DESCRIPTION
 -----------

 Git will sometimes need credentials from the user in order to perform
 operations; for example, it may need to ask for a username and password
 in order to access a remote repository over HTTP. Some remotes accept
 a personal access token or OAuth access token as a password. This
 manual describes the mechanisms Git uses to request these credentials,
 as well as some features to avoid inputting these credentials repeatedly.

 REQUESTING CREDENTIALS
 ----------------------

 Without any credential helpers defined, Git will try the following
 strategies to ask the user for usernames and passwords:

 1. If the `GIT_ASKPASS` environment variable is set, the program
    specified by the variable is invoked. A suitable prompt is provided
    to the program on the command line, and the user's input is read
    from its standard output.

 2. Otherwise, if the `core.askPass` configuration variable is set, its
    value is used as above.

 3. Otherwise, if the `SSH_ASKPASS` environment variable is set, its
    value is used as above.

 4. Otherwise, the user is prompted on the terminal.

 AVOIDING REPETITION
 -------------------

 It can be cumbersome to input the same credentials over and over.  Git
 provides two methods to reduce this annoyance:

 1. Static configuration of usernames for a given authentication context.

 2. Credential helpers to cache or store passwords, or to interact with
    a system password wallet or keychain.

 The first is simple and appropriate if you do not have secure storage available
 for a password. It is generally configured by adding this to your config:

 ---------------------------------------
 [credential "https://example.com"]
 	username = me
 ---------------------------------------

 Credential helpers, on the other hand, are external programs from which Git can
 request both usernames and passwords; they typically interface with secure
 storage provided by the OS or other programs. Alternatively, a
 credential-generating helper might generate credentials for certain servers via
 some API.

 To use a helper, you must first select one to use (see below for a list).

 You may also have third-party helpers installed; search for
 `credential-*` in the output of `git help -a`, and consult the
 documentation of individual helpers.  Once you have selected a helper,
 you can tell Git to use it by putting its name into the
 credential.helper variable.

 1. Find a helper.
 +
 -------------------------------------------
 $ git help -a | grep credential-
 credential-foo
 -------------------------------------------

 2. Read its description.
 +
 -------------------------------------------
 $ git help credential-foo
 -------------------------------------------

 3. Tell Git to use it.
 +
 -------------------------------------------
 $ git config --global credential.helper foo
 -------------------------------------------

 === Available helpers

 Git currently includes the following helpers:

 cache::

     Cache credentials in memory for a short period of time. See
     linkgit:git-credential-cache[1] for details.

 store::

     Store credentials indefinitely on disk. See
     linkgit:git-credential-store[1] for details.

 Popular helpers with secure persistent storage include:

     - git-credential-libsecret (Linux)

     - git-credential-osxkeychain (macOS)

     - git-credential-wincred (Windows)

     - https://github.com/git-ecosystem/git-credential-manager[Git Credential Manager] (cross platform, included in Git for Windows)

 The community maintains a comprehensive list of Git credential helpers at
 https://git-scm.com/doc/credential-helpers.

 === OAuth

 An alternative to inputting passwords or personal access tokens is to use an
 OAuth credential helper. Initial authentication opens a browser window to the
 host. Subsequent authentication happens in the background. Many popular Git
 hosts support OAuth.

 Popular helpers with OAuth support include:

     - https://github.com/git-ecosystem/git-credential-manager[Git Credential Manager] (cross platform, included in Git for Windows)

     - https://github.com/hickford/git-credential-oauth[git-credential-oauth] (cross platform, included in many Linux distributions)

 CREDENTIAL CONTEXTS
 -------------------

 Git considers each credential to have a context defined by a URL. This context
 is used to look up context-specific configuration, and is passed to any
 helpers, which may use it as an index into secure storage.

 For instance, imagine we are accessing `https://example.com/foo.git`. When Git
 looks into a config file to see if a section matches this context, it will
 consider the two a match if the context is a more-specific subset of the
 pattern in the config file. For example, if you have this in your config file:

 --------------------------------------
 [credential "https://example.com"]
 	username = foo
 --------------------------------------

 then we will match: both protocols are the same, both hosts are the same, and
 the "pattern" URL does not care about the path component at all. However, this
 context would not match:

 --------------------------------------
 [credential "https://kernel.org"]
 	username = foo
 --------------------------------------

 because the hostnames differ. Nor would it match `foo.example.com`; Git
 compares hostnames exactly, without considering whether two hosts are part of
 the same domain. Likewise, a config entry for `http://example.com` would not
 match: Git compares the protocols exactly.  However, you may use wildcards in
 the domain name and other pattern matching techniques as with the `http.<URL>.*`
 options.

 If the "pattern" URL does include a path component, then this too must match
 exactly: the context `https://example.com/bar/baz.git` will match a config
 entry for `https://example.com/bar/baz.git` (in addition to matching the config
 entry for `https://example.com`) but will not match a config entry for
 `https://example.com/bar`.


 CONFIGURATION OPTIONS
 ---------------------

 Options for a credential context can be configured either in
 `credential.*` (which applies to all credentials), or
 `credential.<URL>.*`, where <URL> matches the context as described
 above.

 The following options are available in either location:

 helper::

 	The name of an external credential helper, and any associated options.
 	If the helper name is not an absolute path, then the string `git
 	credential-` is prepended. The resulting string is executed by the
 	shell (so, for example, setting this to `foo --option=bar` will execute
 	`git credential-foo --option=bar` via the shell. See the manual of
 	specific helpers for examples of their use.
 +
 If there are multiple instances of the `credential.helper` configuration
 variable, each helper will be tried in turn, and may provide a username,
 password, or nothing. Once Git has acquired both a username and a
 non-expired password, no more helpers will be tried.
 +
 If `credential.helper` is configured to the empty string, this resets
 the helper list to empty (so you may override a helper set by a
 lower-priority config file by configuring the empty-string helper,
 followed by whatever set of helpers you would like).

 username::

 	A default username, if one is not provided in the URL.

 useHttpPath::

 	By default, Git does not consider the "path" component of an http URL
 	to be worth matching via external helpers. This means that a credential
 	stored for `https://example.com/foo.git` will also be used for
 	`https://example.com/bar.git`. If you do want to distinguish these
 	cases, set this option to `true`.


 CUSTOM HELPERS
 --------------

 You can write your own custom helpers to interface with any system in
 which you keep credentials.

 Credential helpers are programs executed by Git to fetch or save
 credentials from and to long-term storage (where "long-term" is simply
 longer than a single Git process; e.g., credentials may be stored
 in-memory for a few minutes, or indefinitely on disk).

 Each helper is specified by a single string in the configuration
 variable `credential.helper` (and others, see linkgit:git-config[1]).
 The string is transformed by Git into a command to be executed using
 these rules:

   1. If the helper string begins with "!", it is considered a shell
      snippet, and everything after the "!" becomes the command.

   2. Otherwise, if the helper string begins with an absolute path, the
      verbatim helper string becomes the command.

   3. Otherwise, the string "git credential-" is prepended to the helper
      string, and the result becomes the command.

 The resulting command then has an "operation" argument appended to it
 (see below for details), and the result is executed by the shell.

 Here are some example specifications:

 ----------------------------------------------------
 # run "git credential-foo"
 [credential]
 	helper = foo

 # same as above, but pass an argument to the helper
 [credential]
 	helper = "foo --bar=baz"

 # the arguments are parsed by the shell, so use shell
 # quoting if necessary
 [credential]
 	helper = "foo --bar='whitespace arg'"

 # store helper (discouraged) with custom location for the db file;
 # use `--file ~/.git-secret.txt`, rather than `--file=~/.git-secret.txt`,
 # to allow the shell to expand tilde to the home directory.
 [credential]
 	helper = "store --file ~/.git-secret.txt"

 # you can also use an absolute path, which will not use the git wrapper
 [credential]
 	helper = "/path/to/my/helper --with-arguments"

 # or you can specify your own shell snippet
 [credential "https://example.com"]
 	username = your_user
 	helper = "!f() { test \"$1\" = get && echo \"password=$(cat $HOME/.secret)\"; }; f"
 ----------------------------------------------------

 Generally speaking, rule (3) above is the simplest for users to specify.
 Authors of credential helpers should make an effort to assist their
 users by naming their program "git-credential-$NAME", and putting it in
 the `$PATH` or `$GIT_EXEC_PATH` during installation, which will allow a
 user to enable it with `git config credential.helper $NAME`.

 When a helper is executed, it will have one "operation" argument
 appended to its command line, which is one of:

 `get`::

 	Return a matching credential, if any exists.

 `store`::

 	Store the credential, if applicable to the helper.

 `erase`::

 	Remove matching credentials, if any, from the helper's storage.

 The details of the credential will be provided on the helper's stdin
 stream. The exact format is the same as the input/output format of the
 `git credential` plumbing command (see the section `INPUT/OUTPUT
 FORMAT` in linkgit:git-credential[1] for a detailed specification).

 For a `get` operation, the helper should produce a list of attributes on
 stdout in the same format (see linkgit:git-credential[1] for common
 attributes). A helper is free to produce a subset, or even no values at
 all if it has nothing useful to provide. Any provided attributes will
 overwrite those already known about by Git's credential subsystem.
 Unrecognised attributes are silently discarded.

 While it is possible to override all attributes, well behaving helpers
 should refrain from doing so for any attribute other than username and
 password.

 If a helper outputs a `quit` attribute with a value of `true` or `1`,
 no further helpers will be consulted, nor will the user be prompted
 (if no credential has been provided, the operation will then fail).

 Similarly, no more helpers will be consulted once both username and
 password had been provided.

 For a `store` or `erase` operation, the helper's output is ignored.

 If a helper fails to perform the requested operation or needs to notify
 the user of a potential issue, it may write to stderr.

 If it does not support the requested operation (e.g., a read-only store
 or generator), it should silently ignore the request.

 If a helper receives any other operation, it should silently ignore the
 request. This leaves room for future operations to be added (older
 helpers will just ignore the new requests).

 GIT
 ---
 Part of the linkgit:git[1] suite
	gitcredentials(7)
	=================

	NAME
	----
	gitcredentials - Providing usernames and passwords to Git

	SYNOPSIS
	--------
	------------------
	git config credential.https://example.com.username myusername
	git config credential.helper "$helper $options"
	------------------

	DESCRIPTION
	-----------

	Git will sometimes need credentials from the user in order to perform
	operations; for example, it may need to ask for a username and password
	in order to access a remote repository over HTTP. Some remotes accept
	a personal access token or OAuth access token as a password. This
	manual describes the mechanisms Git uses to request these credentials,
	as well as some features to avoid inputting these credentials repeatedly.

	REQUESTING CREDENTIALS
	----------------------

	Without any credential helpers defined, Git will try the following
	strategies to ask the user for usernames and passwords:

	1. If the `GIT_ASKPASS` environment variable is set, the program
	specified by the variable is invoked. A suitable prompt is provided
	to the program on the command line, and the user's input is read
	from its standard output.

	2. Otherwise, if the `core.askPass` configuration variable is set, its
	value is used as above.

	3. Otherwise, if the `SSH_ASKPASS` environment variable is set, its
	value is used as above.

	4. Otherwise, the user is prompted on the terminal.

	AVOIDING REPETITION
	-------------------

	It can be cumbersome to input the same credentials over and over. Git
	provides two methods to reduce this annoyance:

	1. Static configuration of usernames for a given authentication context.

	2. Credential helpers to cache or store passwords, or to interact with
	a system password wallet or keychain.

	The first is simple and appropriate if you do not have secure storage available
	for a password. It is generally configured by adding this to your config:

	---------------------------------------
	[credential "https://example.com"]
	username = me
	---------------------------------------

	Credential helpers, on the other hand, are external programs from which Git can
	request both usernames and passwords; they typically interface with secure
	storage provided by the OS or other programs. Alternatively, a
	credential-generating helper might generate credentials for certain servers via
	some API.

	To use a helper, you must first select one to use (see below for a list).

	You may also have third-party helpers installed; search for
	`credential-*` in the output of `git help -a`, and consult the
	documentation of individual helpers. Once you have selected a helper,
	you can tell Git to use it by putting its name into the
	credential.helper variable.

	1. Find a helper.
	+
	-------------------------------------------
	$ git help -a \| grep credential-
	credential-foo
	-------------------------------------------

	2. Read its description.
	+
	-------------------------------------------
	$ git help credential-foo
	-------------------------------------------

	3. Tell Git to use it.
	+
	-------------------------------------------
	$ git config --global credential.helper foo
	-------------------------------------------

	=== Available helpers

	Git currently includes the following helpers:

	cache::

	Cache credentials in memory for a short period of time. See
	linkgit:git-credential-cache[1] for details.

	store::

	Store credentials indefinitely on disk. See
	linkgit:git-credential-store[1] for details.

	Popular helpers with secure persistent storage include:

	- git-credential-libsecret (Linux)

	- git-credential-osxkeychain (macOS)

	- git-credential-wincred (Windows)

	- https://github.com/git-ecosystem/git-credential-manager[Git Credential Manager] (cross platform, included in Git for Windows)

	The community maintains a comprehensive list of Git credential helpers at
	https://git-scm.com/doc/credential-helpers.

	=== OAuth

	An alternative to inputting passwords or personal access tokens is to use an
	OAuth credential helper. Initial authentication opens a browser window to the
	host. Subsequent authentication happens in the background. Many popular Git
	hosts support OAuth.

	Popular helpers with OAuth support include:

	- https://github.com/git-ecosystem/git-credential-manager[Git Credential Manager] (cross platform, included in Git for Windows)

	- https://github.com/hickford/git-credential-oauth[git-credential-oauth] (cross platform, included in many Linux distributions)

	CREDENTIAL CONTEXTS
	-------------------

	Git considers each credential to have a context defined by a URL. This context
	is used to look up context-specific configuration, and is passed to any
	helpers, which may use it as an index into secure storage.

	For instance, imagine we are accessing `https://example.com/foo.git`. When Git
	looks into a config file to see if a section matches this context, it will
	consider the two a match if the context is a more-specific subset of the
	pattern in the config file. For example, if you have this in your config file:

	--------------------------------------
	[credential "https://example.com"]
	username = foo
	--------------------------------------

	then we will match: both protocols are the same, both hosts are the same, and
	the "pattern" URL does not care about the path component at all. However, this
	context would not match:

	--------------------------------------
	[credential "https://kernel.org"]
	username = foo
	--------------------------------------

	because the hostnames differ. Nor would it match `foo.example.com`; Git
	compares hostnames exactly, without considering whether two hosts are part of
	the same domain. Likewise, a config entry for `http://example.com` would not
	match: Git compares the protocols exactly. However, you may use wildcards in
	the domain name and other pattern matching techniques as with the `http.<URL>.*`
	options.

	If the "pattern" URL does include a path component, then this too must match
	exactly: the context `https://example.com/bar/baz.git` will match a config
	entry for `https://example.com/bar/baz.git` (in addition to matching the config
	entry for `https://example.com`) but will not match a config entry for
	`https://example.com/bar`.


	CONFIGURATION OPTIONS
	---------------------

	Options for a credential context can be configured either in
	`credential.*` (which applies to all credentials), or
	`credential.<URL>.*`, where <URL> matches the context as described
	above.

	The following options are available in either location:

	helper::

	The name of an external credential helper, and any associated options.
	If the helper name is not an absolute path, then the string `git
	credential-` is prepended. The resulting string is executed by the
	shell (so, for example, setting this to `foo --option=bar` will execute
	`git credential-foo --option=bar` via the shell. See the manual of
	specific helpers for examples of their use.
	+
	If there are multiple instances of the `credential.helper` configuration
	variable, each helper will be tried in turn, and may provide a username,
	password, or nothing. Once Git has acquired both a username and a
	non-expired password, no more helpers will be tried.
	+
	If `credential.helper` is configured to the empty string, this resets
	the helper list to empty (so you may override a helper set by a
	lower-priority config file by configuring the empty-string helper,
	followed by whatever set of helpers you would like).

	username::

	A default username, if one is not provided in the URL.

	useHttpPath::

	By default, Git does not consider the "path" component of an http URL
	to be worth matching via external helpers. This means that a credential
	stored for `https://example.com/foo.git` will also be used for
	`https://example.com/bar.git`. If you do want to distinguish these
	cases, set this option to `true`.


	CUSTOM HELPERS
	--------------

	You can write your own custom helpers to interface with any system in
	which you keep credentials.

	Credential helpers are programs executed by Git to fetch or save
	credentials from and to long-term storage (where "long-term" is simply
	longer than a single Git process; e.g., credentials may be stored
	in-memory for a few minutes, or indefinitely on disk).

	Each helper is specified by a single string in the configuration
	variable `credential.helper` (and others, see linkgit:git-config[1]).
	The string is transformed by Git into a command to be executed using
	these rules:

	1. If the helper string begins with "!", it is considered a shell
	snippet, and everything after the "!" becomes the command.

	2. Otherwise, if the helper string begins with an absolute path, the
	verbatim helper string becomes the command.

	3. Otherwise, the string "git credential-" is prepended to the helper
	string, and the result becomes the command.

	The resulting command then has an "operation" argument appended to it
	(see below for details), and the result is executed by the shell.

	Here are some example specifications:

	----------------------------------------------------
	# run "git credential-foo"
	[credential]
	helper = foo

	# same as above, but pass an argument to the helper
	[credential]
	helper = "foo --bar=baz"

	# the arguments are parsed by the shell, so use shell
	# quoting if necessary
	[credential]
	helper = "foo --bar='whitespace arg'"

	# store helper (discouraged) with custom location for the db file;
	# use `--file ~/.git-secret.txt`, rather than `--file=~/.git-secret.txt`,
	# to allow the shell to expand tilde to the home directory.
	[credential]
	helper = "store --file ~/.git-secret.txt"

	# you can also use an absolute path, which will not use the git wrapper
	[credential]
	helper = "/path/to/my/helper --with-arguments"

	# or you can specify your own shell snippet
	[credential "https://example.com"]
	username = your_user
	helper = "!f() { test \"$1\" = get && echo \"password=$(cat $HOME/.secret)\"; }; f"
	----------------------------------------------------

	Generally speaking, rule (3) above is the simplest for users to specify.
	Authors of credential helpers should make an effort to assist their
	users by naming their program "git-credential-$NAME", and putting it in
	the `$PATH` or `$GIT_EXEC_PATH` during installation, which will allow a
	user to enable it with `git config credential.helper $NAME`.

	When a helper is executed, it will have one "operation" argument
	appended to its command line, which is one of:

	`get`::

	Return a matching credential, if any exists.

	`store`::

	Store the credential, if applicable to the helper.

	`erase`::

	Remove matching credentials, if any, from the helper's storage.

	The details of the credential will be provided on the helper's stdin
	stream. The exact format is the same as the input/output format of the
	`git credential` plumbing command (see the section `INPUT/OUTPUT
	FORMAT` in linkgit:git-credential[1] for a detailed specification).

	For a `get` operation, the helper should produce a list of attributes on
	stdout in the same format (see linkgit:git-credential[1] for common
	attributes). A helper is free to produce a subset, or even no values at
	all if it has nothing useful to provide. Any provided attributes will
	overwrite those already known about by Git's credential subsystem.
	Unrecognised attributes are silently discarded.

	While it is possible to override all attributes, well behaving helpers
	should refrain from doing so for any attribute other than username and
	password.

	If a helper outputs a `quit` attribute with a value of `true` or `1`,
	no further helpers will be consulted, nor will the user be prompted
	(if no credential has been provided, the operation will then fail).

	Similarly, no more helpers will be consulted once both username and
	password had been provided.

	For a `store` or `erase` operation, the helper's output is ignored.

	If a helper fails to perform the requested operation or needs to notify
	the user of a potential issue, it may write to stderr.

	If it does not support the requested operation (e.g., a read-only store
	or generator), it should silently ignore the request.

	If a helper receives any other operation, it should silently ignore the
	request. This leaves room for future operations to be added (older
	helpers will just ignore the new requests).

	GIT
	---
	Part of the linkgit:git[1] suite