gnutls: gnutls_x509_crt_get_serial incorrect serial decoding from ASN1 (BE64) [GNUTLS-SA-2010-1]

The gnutlsx509crtgetserial function in the GnuTLS library before 1.2.1, when running on big-endian, 64-bit platforms, calls the asn1readvalue with a pointer to the wrong data type and the wrong length value, which allows remote attackers to bypass the certificate revocation list CRL check and cau...