@deftypefun {int} {gnutls_x509_ext_export_subject_alt_names} (gnutls_subject_alt_names_t @var{sans}, gnutls_datum_t * @var{ext}) @var{sans}: The alternative names @var{ext}: The DER-encoded extension data; must be freed using @code{gnutls_free()} . This function will convert the provided alternative names structure to a DER-encoded SubjectAltName PKIX extension. The output data in @code{ext} will be allocated using @code{gnutls_malloc()} . @strong{Returns:} On success, @code{GNUTLS_E_SUCCESS} (0) is returned, otherwise a negative error value. @strong{Since:} 3.3.0 @end deftypefun