Re: Git credential store conflicting configuration leads to unexpected behavior

From: Philip Oakley <philipoakley@iee.email>
Date: Dec 7, 2022, 12:01 UTC
Message-ID: <aa8a0d4b-961f-cdad-6e67-452ac945ed1e@iee.email>
In-Reply-To: <CACH4KQSj64WeqAV3CDkCXc+YW6dr+S2vN_QBj5SwcSP05fM0Eg@mail.gmail.com>

On 06/12/2022 23:53, Gennady Uraltsev wrote:

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> Thank you!
>
> This makes sense and the solution is simple. Is this somewhere in the
> documentation (honest question, I am not being a jerk)? I tried my
> best to figure this out before bugging people on the mailinglist.

I think it's all hidden in the docs, but isn't easy to tease out.

The 'override a multi-value config with a leading empty value" technique, I think, is covered in the general discussions about how config values are entered and parsed.

A useful question would be to ask, where did, or would, you look to hope to find this information? If we put the info in the right place, sufficient folks will read it.

Philip PS in-line posting preferred.

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>
> Best,
>
> Gennady
>
> --
> Gennady Uraltsev
> <gennady.uraltsev@gmail.com>
> (https://guraltsev.github.io)
>
>
> On Tue, Dec 6, 2022 at 5:16 PM brian m. carlson
> <sandals@crustytoothpaste.net> wrote:
>> On 2022-12-06 at 22:05:22, Gennady Uraltsev wrote:
>>> Hello everyone,
>>>
>>> I have an issue with git credential-store. In my global configuration
>>> dir  (.config/git/config) I had the line
>>>
>>> [credential]
>>> helper = store
>>>
>>> while ini a repository's .git/config while I have
>>>
>>> [credential]
>>> helper = "store --file=./.git/git-credentials"
>>>
>>> to store credentials "locally".
>>>
>>> I thought the latter would overrule the former However what happens is
>>> the following:
>>>
>>> 1) On first run the file repo-local file ./.git/git-credentials gets
>>> created and the credentials are saved there after the user is queried
>>> for a password
>>> 2) On subsequent runs the credentials get recovered from
>>> ./.git/git-credentials and the user is NOT asked for credentials
>>> 2b) **Here is the weird behavior** git ALSO creates the
>>> .git-credentials file in the home directory and saves a copy of
>>> credentials there.
>>>
>>> The behavior 2b leads to exfiltration of passwords to a location a
>>> user might not expect.
>>>
>>> Workaround: Remove the line
>>>
>>> [credential]
>>> helper = store
>>>
>>> in the global config.
>>>
>>> It seems that the global config somehow does not get shadowed by the local one!
>> This behaviour is by design.  The reason is that sometimes the user may
>> have two sets of credential helpers, one for one set of domains, and
>> another for another.  For example, I believe AWS has its own custom
>> credential helper.  Git calls credential helpers until it finds a
>> credential, and then it sends store commands to all of them.  A
>> credential helper which has no credentials for a domain will generally
>> respond with no credentials.
>>
>> If you want to override the credential helpers in the `.git/config`
>> file, you can do so by first writing an empty value, like so:
>>
>> [credential]
>> helper =
>> helper = "store --file=./.git/git-credentials"
>> --
>> brian m. carlson (he/him or they/them)
>> Toronto, Ontario, CA