[prev in list] [next in list] [prev in thread] [next in thread] 

List:       pgp-keyserver-folk
Subject:    [Pgp-keyserver-folk] Fingerprint calculation bug
From:       David Shaw <dshaw () jabberwocky ! com>
Date:       2003-05-21 22:34:59
[Download RAW message or body]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi folks,

Minor bug in pksd (all versions, including CVS).  V4 fingerprints are
calculated incorrectly for very small keys.  Basically, a v4
fingerprint is calculated over a canonicalized public key packet, and
pksd isn't canonicalizing.  This isn't a problem for the majority of
keys, but if a key is really small, the fingerprint is wrong.

I'm really busy right now and don't have the time to do the fix and
properly test it.  If someone else could pick it up, that would be a
good thing.

The trick is that when the packet tag is something other than 0x99,
you need to hash a literal 0x99, followed by the two-byte packet
length (network byte order), followed by the packet contents.  The
problem is that small keys are hashing a packet tag of 0x98, followed
by a one-byte packet length.

David
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3-cvs (GNU/Linux)
Comment: http://www.jabberwocky.com/david/keys.asc

iD8DBQE+y/8T4mZch0nhy8kRAsDaAJ0e6lV2AU3eaGIdzkbnAFZqkSb1xwCgky4R
FescxP8IvWLmtlawnon7VFw=
=SW47
-----END PGP SIGNATURE-----
[prev in list] [next in list] [prev in thread] [next in thread]