Re: [PATCHv2] Documentation/technical: push certificate format

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 17, 2016, 19:14 UTC
Message-ID: <xmqq1t3v1vbm.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <358c097f88671847e5003696a65d3a107aa2f59b.1466153557.git.git@drmicha.warpmail.net>

Michael J Gruber <git@drmicha.warpmail.net> writes:

Show 45 quoted lines

> Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
> ---
> This is the version describing the current state, not assuming any new
> verify command for blobs.
>
>  Documentation/technical/signature-format.txt | 51 ++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
>
> diff --git a/Documentation/technical/signature-format.txt b/Documentation/technical/signature-format.txt
> index 7afd403..1c21379 100644
> --- a/Documentation/technical/signature-format.txt
> +++ b/Documentation/technical/signature-format.txt
> @@ -184,3 +184,54 @@ Date:   Wed Jun 15 09:13:29 2016 +0000
>      # gpg:          There is no indication that the signature belongs to the owner.
>      # Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA  29A4 6109 2E85 B722 7189
>  ----
> +
> +== Push certificates
> +
> +- created by: `git push --signed`
> +- payload: a push certificate header followed by the push transcript
> +  (see pack-protocol.txt and below)
> +- embedding: append the signature to the push transcript and pass it to receive hooks
> +  via the environment (see below)
> +- example: push of commit `dd1416f` updating `master` on `.` from `d36de3d`,
> +  resulting in push certificate object `d4169b9`:
> +
> +----
> +certificate version 0.1
> +pusher C O Mitter <committer@example.com> 1465983405 +0000
> +pushee .
> +nonce 1465983405-07421dc1515c6f4d76d4
> +
> +d36de3db9b6a83076477254a3186b721a7bfaab7 dd1416f2cd1ec85957a9520a33e9053a133a775d refs/heads/master
> +-----BEGIN PGP SIGNATURE-----
> +Version: GnuPG v1
> +
> +iEYEABECAAYFAldhIa0ACgkQE7b1Hs3eQw2pGwCgmJs98xETSDZb6rooh/X7af3V
> +zWgAn08ctVNga27jRkIdhFNetJy3x8De
> +=WH0m
> +-----END PGP SIGNATURE-----
> +----
> +
> +- verify with: `gpg --verify <(git cat-file -p pushcert | sed -n '/-----BEGIN PGP/,$p') <(git cat-file -p pushcert | sed  '/-----BEGIN PGP/Q')`
> +  (assuming the push certificate is stored in the blob tagged `pushcert`)

And assuming your sed is GNU, assuming your shell is bash.

Let's have a version of this without "verify with", finish that "generalized way to verify the 'payload followed by detached signature'" patch, and add a description to use that command here when it is done.

Show 22 quoted lines

> +
> +----
> +gpg: Signature made Wed Jun 15 11:36:45 2016 CEST using DSA key ID CDDE430D
> +gpg: Good signature from "C O Mitter <committer@example.com>"
> +----
> +
> +- pre- and post-receive hook input:
> +
> +----
> +d36de3db9b6a83076477254a3186b721a7bfaab7 dd1416f2cd1ec85957a9520a33e9053a133a775d refs/heads/master
> +----
> +
> +- pre- and post-receive hook environment:
> +
> +----
> +GIT_PUSH_CERT_NONCE_STATUS=OK
> +GIT_PUSH_CERT_KEY=13B6F51ECDDE430D
> +GIT_PUSH_CERT=d4169b9a3c2674458f9656796132c145bbc5ba74
> +GIT_PUSH_CERT_STATUS=G
> +GIT_PUSH_CERT_SIGNER=C O Mitter <committer@example.com>
> +GIT_PUSH_CERT_NONCE=1465983405-07421dc1515c6f4d76d4
> +----