CVE-2022-2031 s4:kpasswd: Do not accept TGTs as kpasswd tickets

CVE-2022-2031 s4:kpasswd: Do not accept TGTs as kpasswd tickets

If TGTs can be used as kpasswd tickets, the two-minute lifetime of a
authentic kpasswd ticket may be bypassed. Furthermore, kpasswd tickets
are not supposed to be cached, but using this flaw, a stolen credentials
cache containing a TGT may be used to change that account's password,
and thus is made more valuable to an attacker.

Since all TGTs should be issued with a REQUESTER_SID PAC buffer, and
service tickets without it, we assert the absence of this buffer to
ensure we're not accepting a TGT.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15047
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15049

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andreas Schneider <asn@samba.org>