Fix memory leak in sssdpac_verify() Resolves https://fedorahosted.org/sssd/ticket/2803 Reviewed-by: Sumit Bose <sbose@redhat.com>

PAC: Fix memory leak Reported by clang static analyser. Reviewed-by: Sumit Bose <sbose@redhat.com>

PAC: krb5_pac_verify failures should not be fatal As noted in the MIT KRB5 documentation, some servers send PAC with no checksum, therefire the PAC validation should not be fatal, instead, we should treat a failure from krb5_pac_verify as if there was no PAC at all. Reported on sssd-devel by Thomas Sondergaard

Enhance PAC responder for AD users This patch modifies the PAC responder so that it can be used with the AD provider as well. The main difference is that the POSIX UIDs and GIDs are now lookup up with the help of the SID instead of being calculated algorithmically. This was necessary because the AD provider allows either algorithmic mapping or reading the value from attributes stored in AD. Fixes https://fedorahosted.org/sssd/ticket/1558

Remove resource leak in sssdpac_import_authdata Fixes https://fedorahosted.org/sssd/ticket/1409

PAC client: add krb5 authdata plugin