git-credential - Retrieve and store user credentials
git credential <fill|approve|reject>
GIT-CREDENTIAL(1) Git Manual GIT-CREDENTIAL(1)
NAME
git-credential - Retrieve and store user credentials
SYNOPSIS
git credential <fill|approve|reject>
DESCRIPTION
Git has an internal interface for storing and retrieving credentials
from system-specific helpers, as well as prompting the user for
usernames and passwords. The git-credential command exposes this
interface to scripts which may want to retrieve, store, or prompt for
credentials in the same manner as Git. The design of this scriptable
interface models the internal C API; see the Git credential API[1] for
more background on the concepts.
git-credential takes an "action" option on the command-line (one of
fill, approve, or reject) and reads a credential description on stdin
(see INPUT/OUTPUT FORMAT).
If the action is fill, git-credential will attempt to add "username"
and "password" attributes to the description by reading config files,
by contacting any configured credential helpers, or by prompting the
user. The username and password attributes of the credential
description are then printed to stdout together with the attributes
already provided.
If the action is approve, git-credential will send the description to
any configured credential helpers, which may store the credential for
later use.
If the action is reject, git-credential will send the description to
any configured credential helpers, which may erase any stored
credential matching the description.
If the action is approve or reject, no output should be emitted.
TYPICAL USE OF GIT CREDENTIAL
An application using git-credential will typically use git credential
following these steps:
1. Generate a credential description based on the context.
For example, if we want a password for https://example.com/foo.git,
we might generate the following credential description (don't
forget the blank line at the end; it tells git credential that the
application finished feeding all the information it has):
protocol=https
host=example.com
path=foo.git
2. Ask git-credential to give us a username and password for this
description. This is done by running git credential fill, feeding
the description from step (1) to its standard input. The complete
credential description (including the credential per se, i.e. the
login and password) will be produced on standard output, like:
protocol=https
host=example.com
username=bob
password=secr3t
In most cases, this means the attributes given in the input will be
repeated in the output, but Git may also modify the credential
description, for example by removing the path attribute when the
protocol is HTTP(s) and credential.useHttpPath is false.
If the git credential knew about the password, this step may not
have involved the user actually typing this password (the user may
have typed a password to unlock the keychain instead, or no user
interaction was done if the keychain was already unlocked) before
it returned password=secr3t.
3. Use the credential (e.g., access the URL with the username and
password from step (2)), and see if it's accepted.
4. Report on the success or failure of the password. If the credential
allowed the operation to complete successfully, then it can be
marked with an "approve" action to tell git credential to reuse it
in its next invocation. If the credential was rejected during the
operation, use the "reject" action so that git credential will ask
for a new password in its next invocation. In either case, git
credential should be fed with the credential description obtained
from step (2) (which also contain the ones provided in step (1)).
INPUT/OUTPUT FORMAT
git credential reads and/or writes (depending on the action used)
credential information in its standard input/output. This information
can correspond either to keys for which git credential will obtain the
login/password information (e.g. host, protocol, path), or to the
actual credential data to be obtained (login/password).
The credential is split into a set of named attributes, with one
attribute per line. Each attribute is specified by a key-value pair,
separated by an = (equals) sign, followed by a newline. The key may
contain any bytes except =, newline, or NUL. The value may contain any
bytes except newline or NUL. In both cases, all bytes are treated as-is
(i.e., there is no quoting, and one cannot transmit a value with
newline or NUL in it). The list of attributes is terminated by a blank
line or end-of-file. Git understands the following attributes:
protocol
The protocol over which the credential will be used (e.g., https).
host
The remote hostname for a network credential.
path
The path with which the credential will be used. E.g., for
accessing a remote https repository, this will be the repository's
path on the server.
username
The credential's username, if we already have one (e.g., from a
URL, from the user, or from a previously run helper).
password
The credential's password, if we are asking it to be stored.
url
When this special attribute is read by git credential, the value is
parsed as a URL and treated as if its constituent parts were read
(e.g., url=https://example.com would behave as if protocol=https
and host=example.com had been provided). This can help callers
avoid parsing URLs themselves. Note that any components which are
missing from the URL (e.g., there is no username in the example
above) will be set to empty; if you want to provide a URL and
override some attributes, provide the URL attribute first, followed
by any overrides.
NOTES
1. the Git credential API
git-htmldocs/technical/api-credentials.html
Git 2.15.2 05/29/2018 GIT-CREDENTIAL(1)