@deftypefun {int} {gnutls_certificate_set_x509_trust} (gnutls_certificate_credentials_t @var{res}, gnutls_x509_crt_t * @var{ca_list}, int @var{ca_list_size}) @var{res}: is a @code{gnutls_certificate_credentials_t} type. @var{ca_list}: is a list of trusted CAs @var{ca_list_size}: holds the size of the CA list This function adds the trusted CAs in order to verify client or server certificates. In case of a client this is not required to be called if the certificates are not verified using @code{gnutls_certificate_verify_peers2()} . This function may be called multiple times. In case of a server the CAs set here will be sent to the client if a certificate request is sent. This can be disabled using @code{gnutls_certificate_send_x509_rdn_sequence()} . @strong{Returns:} the number of certificates processed or a negative error code on error. @strong{Since:} 2.4.0 @end deftypefun