On Fri, Apr 25, 2025 at 12:05 AM brian m. carlson <sandals@xxxxxxxxxxxxxxxxxxxx> wrote: > > On 2025-04-24 at 20:39:04, Christian Couder wrote: > > Here <alg> specifies which hashing algorithm is used for this > > -signature, either `sha1` or `sha256`. > > +signature. Current valid values are: > > + > > +* "openpgp" for SHA-1 OpenPGP signatures, > > + > > +* "sha256" for SHA-256 OpenPGP signatures, > > + > > +* "x509" for X.509 (GPGSM) signatures, > > + > > +* "ssh", for SSH signatures, > > + > > +* "unknown" for signatures that can't be identified (a warning is > > + emitted). > > I don't think this is a good set of options. We can have SHA-1 or > SHA-256 options for any of the three. If I create a SHA-256 commit and > sign it with SSH, then it couldn't be exported with this type. > > It is even possible and valid to create a signature over the SHA-1 > content of an object and sign it with one protocol, say, OpenPGP, and > then create a signature over the SHA-256 content of the object and sign > it with a different one, such as SSH. Git does not natively support > this, but it is possible to do by hand. > > These should be separate fields: one for the hash algorithm and one for > the protocol. Yeah, I agree that the set of options is not ideal and it would be better if it was possible to get these two separate fields. > Alternatively, we can just keep the hash algorithm field > and parse the protocol by reading the first line, which will differ for > different protocols. I am not sure it's easy to get all the information without checking the signature. I have tried a different approach based on checking the signature in the v2. Thanks for the review!
