@item @var{int} @ref{gnutls_x509_trust_list_get_issuer_by_subject_key_id} (gnutls_x509_trust_list_t @var{list}, const gnutls_datum_t * @var{dn}, const gnutls_datum_t * @var{spki}, gnutls_x509_crt_t * @var{issuer}, unsigned int @var{flags})