1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
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. 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.
To use a helper, you must first select one to use. Git does not yet
include any credential helpers, but you may 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
-------------------------------------------
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
password, no more helpers will be tried.
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.
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.
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. See the documentation for git's
link:technical/api-credentials.html[credentials API] for details.
GIT
---
Part of the linkgit:git[1] suite
|
