@deftypefun {int} {gnutls_certificate_set_x509_trust_mem} (gnutls_certificate_credentials_t @var{res}, const gnutls_datum_t * @var{ca}, gnutls_x509_crt_fmt_t @var{type})
@var{res}: is a @code{gnutls_certificate_credentials_t}  type.

@var{ca}: is a list of trusted CAs or a DER certificate

@var{type}: is DER or PEM

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.
@end deftypefun