V4 Key ID Mismatch - Check Me?

V Alex Brennen vab@cryptnet.net
Tue Jul 24 17:36:01 2001


On Tue, 24 Jul 2001, Justin Wienckowski wrote:


> For the life of me, I can't figure out why the key ID I compute
> (0A9A90AC3971FE26) doesn't match gpg's computed value. To compute the
> key id, I'm doing the following:
>
> 1) Hash the public key packet (tag 0x99, 2-octet length, 6-octet
> public key header, and the MPIs [mpi headers and data]) through SHA-1
> (using cryptlib's SHA1 stuff) 2) Use low-order 64 bits of the hash
> value as the key id.
IIRC, you shouldn't hash the 0x99 and 2-octet length in with the pubkey. (offset+3). You may find an easier time looking at the keyserver code I wrote which is simpler and more linear than the GnuPG code. You can download the code here: http://www.cryptnet.net/fsp/cks/ Make sure you get the snapshot and not the release. There's been allot of changes and improvements since the release. - VAB