k5_asn1_decode_bitstring
krb5_error_code k5_asn1_decode_bitstring(const uint8_t *asn1, size_t len,
k5_asn1_encode_bitstring, k5_asn1_decode_bitstring,
ret = k5_asn1_decode_bitstring(asn1, len, &bits, &blen);