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NAME | SYNOPSIS | DESCRIPTION | REQUESTING CREDENTIALS | AVOIDING REPETITION | CREDENTIAL CONTEXTS | CONFIGURATION OPTIONS | CUSTOM HELPERS | GIT | COLOPHON |
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GITCREDENTIALS(7) Git Manual GITCREDENTIALS(7)
gitcredentials - Providing usernames and passwords to Git
git config credential.https://example.com.username myusername
git config credential.helper "$helper $options"
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.
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.
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. Git currently
includes the following helpers:
cache
Cache credentials in memory for a short period of time. See
git-credential-cache(1) for details.
store
Store credentials indefinitely on disk. See
git-credential-store(1) for details.
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
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.
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 .
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.
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 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'"
# 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 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 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).
Part of the git(1) suite
This page is part of the git (Git distributed version control
system) project. Information about the project can be found at
⟨http://git-scm.com/⟩. If you have a bug report for this manual
page, see ⟨http://git-scm.com/community⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/git/git.git⟩ on 2024-06-14. (At that time,
the date of the most recent commit that was found in the
repository was 2024-06-12.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Git 2.45.2.492.gd63586 2024-06-12 GITCREDENTIALS(7)
Pages that refer to this page: git(1), git-config(1), git-credential-cache(1), git-credential-store(1)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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