<feed xmlns='http://www.w3.org/2005/Atom'>
<title>git/credential.c, branch v2.45.2</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/git/git.git/
</subtitle>
<id>https://git.shady.money/git/atom?h=v2.45.2</id>
<link rel='self' href='https://git.shady.money/git/atom?h=v2.45.2'/>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/'/>
<updated>2023-08-30T00:56:26Z</updated>
<entry>
<title>credential: mark unused parameter in urlmatch callback</title>
<updated>2023-08-30T00:56:26Z</updated>
<author>
<name>Jeff King</name>
<email>peff@peff.net</email>
</author>
<published>2023-08-29T23:45:36Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=8ca199511bf7867c87f0f542102c26f0fb9558b4'/>
<id>urn:sha1:8ca199511bf7867c87f0f542102c26f0fb9558b4</id>
<content type='text'>
Our select_all() callback does not need to actually look at its
parameters, since the point is to match everything. But we need to mark
its parameters to satisfy -Wunused-parameter.

Signed-off-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>config: add ctx arg to config_fn_t</title>
<updated>2023-06-28T21:06:39Z</updated>
<author>
<name>Glen Choo</name>
<email>chooglen@google.com</email>
</author>
<published>2023-06-28T19:26:22Z</published>
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<id>urn:sha1:a4e7e317f8f27f861321e6eb08b9c8c0f3ab570c</id>
<content type='text'>
Add a new "const struct config_context *ctx" arg to config_fn_t to hold
additional information about the config iteration operation.
config_context has a "struct key_value_info kvi" member that holds
metadata about the config source being read (e.g. what kind of config
source it is, the filename, etc). In this series, we're only interested
in .kvi, so we could have just used "struct key_value_info" as an arg,
but config_context makes it possible to add/adjust members in the future
without changing the config_fn_t signature. We could also consider other
ways of organizing the args (e.g. moving the config name and value into
config_context or key_value_info), but in my experiments, the
incremental benefit doesn't justify the added complexity (e.g. a
config_fn_t will sometimes invoke another config_fn_t but with a
different config value).

In subsequent commits, the .kvi member will replace the global "struct
config_reader" in config.c, making config iteration a global-free
operation. It requires much more work for the machinery to provide
meaningful values of .kvi, so for now, merely change the signature and
call sites, pass NULL as a placeholder value, and don't rely on the arg
in any meaningful way.

Most of the changes are performed by
contrib/coccinelle/config_fn_ctx.pending.cocci, which, for every
config_fn_t:

- Modifies the signature to accept "const struct config_context *ctx"
- Passes "ctx" to any inner config_fn_t, if needed
- Adds UNUSED attributes to "ctx", if needed

Most config_fn_t instances are easily identified by seeing if they are
called by the various config functions. Most of the remaining ones are
manually named in the .cocci patch. Manual cleanups are still needed,
but the majority of it is trivial; it's either adjusting config_fn_t
that the .cocci patch didn't catch, or adding forward declarations of
"struct config_context ctx" to make the signatures make sense.

The non-trivial changes are in cases where we are invoking a config_fn_t
outside of config machinery, and we now need to decide what value of
"ctx" to pass. These cases are:

- trace2/tr2_cfg.c:tr2_cfg_set_fl()

  This is indirectly called by git_config_set() so that the trace2
  machinery can notice the new config values and update its settings
  using the tr2 config parsing function, i.e. tr2_cfg_cb().

- builtin/checkout.c:checkout_main()

  This calls git_xmerge_config() as a shorthand for parsing a CLI arg.
  This might be worth refactoring away in the future, since
  git_xmerge_config() can call git_default_config(), which can do much
  more than just parsing.

Handle them by creating a KVI_INIT macro that initializes "struct
key_value_info" to a reasonable default, and use that to construct the
"ctx" arg.

Signed-off-by: Glen Choo &lt;chooglen@google.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>credential: avoid erasing distinct password</title>
<updated>2023-06-15T20:26:39Z</updated>
<author>
<name>M Hickford</name>
<email>mirth.hickford@gmail.com</email>
</author>
<published>2023-06-15T19:19:32Z</published>
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<id>urn:sha1:aeb21ce22eec112b37975443a160cb5418c6ec22</id>
<content type='text'>
Test that credential helpers do not erase a password distinct from the
input. Such calls can happen when multiple credential helpers are
configured.

Fixes for credential-cache and credential-store.

Signed-off-by: M Hickford &lt;mirth.hickford@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'mh/credential-oauth-refresh-token'</title>
<updated>2023-05-10T17:23:29Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2023-05-10T17:23:28Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=2ca91d1ee07f934fa7f57ba34c397b150eef023f'/>
<id>urn:sha1:2ca91d1ee07f934fa7f57ba34c397b150eef023f</id>
<content type='text'>
The credential subsystem learns to help OAuth framework.

* mh/credential-oauth-refresh-token:
  credential: new attribute oauth_refresh_token
</content>
</entry>
<entry>
<title>Merge branch 'tb/credential-long-lines'</title>
<updated>2023-05-10T17:23:27Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2023-05-10T17:23:27Z</published>
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<id>urn:sha1:fbbf60a9bc4d7139efa70a0246cec2b3f2cc63fb</id>
<content type='text'>
The implementation of credential helpers used fgets() over fixed
size buffers to read protocol messages, causing the remainder of
the folded long line to trigger unexpected behaviour, which has
been corrected.

* tb/credential-long-lines:
  contrib/credential: embiggen fixed-size buffer in wincred
  contrib/credential: avoid fixed-size buffer in libsecret
  contrib/credential: .gitignore libsecret build artifacts
  contrib/credential: remove 'gnome-keyring' credential helper
  contrib/credential: avoid fixed-size buffer in osxkeychain
  t/lib-credential.sh: ensure credential helpers handle long headers
  credential.c: store "wwwauth[]" values in `credential_read()`
</content>
</entry>
<entry>
<title>credential.c: store "wwwauth[]" values in `credential_read()`</title>
<updated>2023-05-01T16:27:00Z</updated>
<author>
<name>Taylor Blau</name>
<email>me@ttaylorr.com</email>
</author>
<published>2023-05-01T15:53:48Z</published>
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<id>urn:sha1:16b305cd2ba1747bcc6d160665eccdbbf7f2ea10</id>
<content type='text'>
Teach git-credential to read "wwwauth[]" value(s) when parsing the
output of a credential helper.

These extra headers are not needed for Git's own HTTP support to use the
feature internally, but the feature would not be available for a
scripted caller (say, git-remote-mediawiki providing the header in the
same way).

As a bonus, this also makes it easier to use wwwauth[] in synthetic
credential inputs in our test suite.

Co-authored-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Taylor Blau &lt;me@ttaylorr.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>treewide: remove cache.h inclusion due to previous changes</title>
<updated>2023-04-24T19:47:33Z</updated>
<author>
<name>Elijah Newren</name>
<email>newren@gmail.com</email>
</author>
<published>2023-04-22T20:17:23Z</published>
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<id>urn:sha1:5e3f94dfe3c69bc2a711a9dc3b1635e7ff91ab54</id>
<content type='text'>
Signed-off-by: Elijah Newren &lt;newren@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>treewide: be explicit about dependence on strbuf.h</title>
<updated>2023-04-24T19:47:31Z</updated>
<author>
<name>Elijah Newren</name>
<email>newren@gmail.com</email>
</author>
<published>2023-04-22T20:17:08Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=69a63fe663874716d2b5bf49b90c550f8279358e'/>
<id>urn:sha1:69a63fe663874716d2b5bf49b90c550f8279358e</id>
<content type='text'>
Signed-off-by: Elijah Newren &lt;newren@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>credential: new attribute oauth_refresh_token</title>
<updated>2023-04-21T16:38:30Z</updated>
<author>
<name>M Hickford</name>
<email>mirth.hickford@gmail.com</email>
</author>
<published>2023-04-21T09:47:59Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=a5c76569e798ad3656afe6b67f37cbbb2e47f28c'/>
<id>urn:sha1:a5c76569e798ad3656afe6b67f37cbbb2e47f28c</id>
<content type='text'>
Git authentication with OAuth access token is supported by every popular
Git host including GitHub, GitLab and BitBucket [1][2][3]. Credential
helpers Git Credential Manager (GCM) and git-credential-oauth generate
OAuth credentials [4][5]. Following RFC 6749, the application prints a
link for the user to authorize access in browser. A loopback redirect
communicates the response including access token to the application.

For security, RFC 6749 recommends that OAuth response also includes
expiry date and refresh token [6]. After expiry, applications can use
the refresh token to generate a new access token without user
reauthorization in browser. GitLab and BitBucket set the expiry at two
hours [2][3]. (GitHub doesn't populate expiry or refresh token.)

However the Git credential protocol has no attribute to store the OAuth
refresh token (unrecognised attributes are silently discarded). This
means that the user has to regularly reauthorize the helper in browser.
On a browserless system, this is particularly intrusive, requiring a
second device.

Introduce a new attribute oauth_refresh_token. This is especially
useful when a storage helper and a read-only OAuth helper are configured
together. Recall that `credential fill` calls each helper until it has a
non-expired password.

```
[credential]
	helper = storage  # eg. cache or osxkeychain
	helper = oauth
```

The OAuth helper can use the stored refresh token forwarded by
`credential fill` to generate a fresh access token without opening the
browser. See
https://github.com/hickford/git-credential-oauth/pull/3/files
for an implementation tested with this patch.

Add support for the new attribute to credential-cache. Eventually, I
hope to see support in other popular storage helpers.

Alternatives considered: ask helpers to store all unrecognised
attributes. This seems excessively complex for no obvious gain.
Helpers would also need extra information to distinguish between
confidential and non-confidential attributes.

Workarounds: GCM abuses the helper get/store/erase contract to store the
refresh token during credential *get* as the password for a fictitious
host [7] (I wrote this hack). This workaround is only feasible for a
monolithic helper with its own storage.

[1] https://github.blog/2012-09-21-easier-builds-and-deployments-using-git-over-https-and-oauth/
[2] https://docs.gitlab.com/ee/api/oauth2.html#access-git-over-https-with-access-token
[3] https://support.atlassian.com/bitbucket-cloud/docs/use-oauth-on-bitbucket-cloud/#Cloning-a-repository-with-an-access-token
[4] https://github.com/GitCredentialManager/git-credential-manager
[5] https://github.com/hickford/git-credential-oauth
[6] https://datatracker.ietf.org/doc/html/rfc6749#section-5.1
[7] https://github.com/GitCredentialManager/git-credential-manager/blob/66b94e489ad8cc1982836355493e369770b30211/src/shared/GitLab/GitLabHostProvider.cs#L207

Signed-off-by: M Hickford &lt;mirth.hickford@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>abspath.h: move absolute path functions from cache.h</title>
<updated>2023-03-21T17:56:52Z</updated>
<author>
<name>Elijah Newren</name>
<email>newren@gmail.com</email>
</author>
<published>2023-03-21T06:25:58Z</published>
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<id>urn:sha1:0b027f6ca79cafbc14f36ff1741fc7378282f295</id>
<content type='text'>
This is another step towards letting us remove the include of cache.h in
strbuf.c.  It does mean that we also need to add includes of abspath.h
in a number of C files.

Signed-off-by: Elijah Newren &lt;newren@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
</feed>
