@deftypefun {int} {gnutls_x509_crl_set_authority_key_id} (gnutls_x509_crl_t @var{crl}, const void * @var{id}, size_t @var{id_size}) @var{crl}: a CRL of type @code{gnutls_x509_crl_t} @var{id}: The key ID @var{id_size}: Holds the size of the serial field. This function will set the CRL's authority key ID extension. Only the keyIdentifier field can be set with this function. This may be used by an authority that holds multiple private keys, to distinguish the used key. @strong{Returns:} On success, @code{GNUTLS_E_SUCCESS} (0) is returned, otherwise a negative error value. @strong{Since:} 2.8.0 @end deftypefun