- Add support to set `gpg.format` in the Git config, via the new `[repository.signing].FORMAT` option. This is to tell Git that the instance would like to use SSH instead of OpenPGP to sign its commits. This is guarded behind a Git version check for v2.34.0 and a check that a `ssh-keygen` binary is present.
- Add support to recognize the public SSH key that is given to `[repository.signing].SIGNING_KEY` as the signing key by the instance.
- Thus this allows the instance to use SSH commit signing for commits that the instance creates (e.g. initial and squash commits) instead of using PGP.
- Technically (although I have no clue how as this is not documented) you can have a different PGP signing key for different repositories; this is not implemented for SSH signing.
- Add unit and integration testing.
- `TestInstanceSigning` was reworked from `TestGPGGit`, now also includes testing for SHA256 repositories. Is the main integration test that actually signs commits and checks that they are marked as verified by Forgejo.
- `TestParseCommitWithSSHSignature` is a unit test that makes sure that if a SSH instnace signing key is set, that it is used to possibly verify instance SSH signed commits.
- `TestSyncConfigGPGFormat` is a unit test that makes sure the correct git config is set according to the signing format setting. Also checks that the guarded git version check and ssh-keygen binary presence check is done correctly.
- `TestSSHInstanceKey` is a unit test that makes sure the parsing of a SSH signing key is done correctly.
- `TestAPISSHSigningKey` is a integration test that makes sure the newly added API route `/api/v1/signing-key.ssh` responds correctly.
Documentation PR: forgejo/docs#1122
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6897
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>