RE: How to Verify Git GPG Signed Downloads?

From: brian m. carlson
Sent: Sunday, January 24, 2021 4:34 PM

On 2021-01-24 at 17:57:13, Jason Pyeron wrote:

quoted

$ gpg --recv-keys 96AFE6CB
gpg: requesting key 96AFE6CB from hkp server keys.gnupg.net
gpg: key 713660A7: "Junio C Hamano [off-list ref]" 59 new signatures
gpg: key 713660A7: "Junio C Hamano [off-list ref]" 2 new subkeys
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg:            new subkeys: 2
gpg:         new signatures: 59

$ gpg --verify -v git-2.30.0.tar.sign git-2.30.0.tar.gz
gpg: Signature made Mon Dec 28 01:12:30 2020 EST using RSA key ID 96AFE6CB
gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
gpg: NOTE: signature key B3F7CAC9 expired Sun Jul 26 13:41:42 2020 EDT
gpg: using subkey 96AFE6CB instead of primary key 713660A7
gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
gpg: NOTE: signature key B3F7CAC9 expired Sun Jul 26 13:41:42 2020 EDT
gpg: using PGP trust model
gpg: BAD signature from "Junio C Hamano [off-list ref]"
gpg: binary signature, digest algorithm SHA256

The signature is bad because it's over the uncompressed .tar, not the
.tar.gz.  There is also a .tar.xz and the signature is the same.  You
therefore need to uncompress it first with gunzip.

Silly me, but maybe there should be a README in that directory, along with the signatures.asc. If not, then it should easily be found on the git-scm site.

$ gpg --verify  git-2.30.0.tar.sign git-2.30.0.tar
gpg: Signature made Mon Dec 28 01:12:30 2020 EST using RSA key ID 96AFE6CB
gpg: Good signature from "Junio C Hamano [off-list ref]"
gpg:                 aka "Junio C Hamano [off-list ref]"
gpg:                 aka "Junio C Hamano [off-list ref]"
gpg: Note: This key has expired!
Primary key fingerprint: 96E0 7AF2 5771 9559 80DA  D100 20D0 4E5A 7136 60A7
     Subkey fingerprint: E1F0 36B1 FEE7 221F C778  ECEF B0B5 E886 96AF E6CB

quoted

$ gpg --list-keys -v 96AFE6CB
gpg: using PGP trust model
gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
gpg: NOTE: signature key B3F7CAC9 expired Sun Jul 26 13:41:42 2020 EDT
pub   4096R/713660A7 2011-10-01
uid                  Junio C Hamano [off-list ref]
uid                  Junio C Hamano [off-list ref]
uid                  Junio C Hamano [off-list ref]
sub   4096R/96AFE6CB 2011-10-03 [expired: 2020-07-26]
sub   4096R/833262C4 2011-10-01
sub   4096R/B3F7CAC9 2014-09-20 [expired: 2020-07-26]

It is possible that Junio forgot to push his refreshed public key.

Yes, I think that's the case.