SSL according to RFC 2712.  His comment is:

This is a patch to openssl-SNAP-20010702 to support Kerberized SSL
authentication.  I'm expecting to have the full kssl-0.5 kit up on
sourceforge by the end of the week.  The full kit includes patches
for mod-ssl, apache, and a few text clients.  The sourceforge URL
is http://sourceforge.net/projects/kssl/ .

Thanks to a note from Simon Wilkinson I've replaced my KRB5 AP_REQ
message with a real KerberosWrapper struct.  I think this is fully
RFC 2712 compliant now, including support for the optional
authenticator field.  I also added openssl-style ASN.1 macros for
a few Kerberos structs; see crypto/krb5/ if you're interested.