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
     contains the fields provided in step (1)).

[[IOFMT]]
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 information (e.g. host, protocol, path), or to the actual
credential data to be obtained (username/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.  A line, including the trailing
newline, may not exceed 65535 bytes in order to allow implementations to
parse efficiently.

Attributes with keys that end with C-style array brackets `[]` can have
multiple values. Each instance of a multi-valued attribute forms an
ordered list of values - the order of the repeated attributes defines
the order of the values. An empty multi-valued attribute (`key[]=\n`)
acts to clear any previous entries and reset the list.

In all 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.  This includes
	the port number if one was specified (e.g., "example.com:8088").

`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, the configuration, the user, or from a previously run helper).

`password`::

	The credential's password, if we are asking it to be stored.

`password_expiry_utc`::

	Generated passwords such as an OAuth access token may have an expiry date.
	When reading credentials from helpers, `git credential fill` ignores expired
	passwords. Represented as Unix time UTC, seconds since 1970.

`oauth_refresh_token`::

	An OAuth refresh token may accompany a password that is an OAuth access
	token. Helpers must treat this attribute as confidential like the password
	attribute. Git itself has no special behaviour for this attribute.

`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 specifying a protocol is mandatory and if the URL
doesn't specify a hostname (e.g., "cert:///path/to/file") the
credential will contain a hostname attribute whose value is an
empty string.
+
Components which are missing from the URL (e.g., there is no
username in the