sad: introduce gnupg mac library Four Message Authentication Code (MAC) libraries will be added: 1. nettle 2. gnutls 3. gnupg (this patch) 4. openssl This patch introduces the gnupg mac library along with all functions required including initialization/deinitialization of mac handle using key data and generating the digest/mac/icv Signed-off-by: Clay Kaiser <Clay.Kaiser@ibm.com> Acked-by: Miroslav Lichvar <mlichvar@redhat.com> Reviewed-by: Erez Geva <ErezGeva2@gmail.com>