@deftypefun {int} {gnutls_certificate_set_x509_trust_file} (gnutls_certificate_credentials_t            @var{cred}, const char * @var{cafile}, gnutls_x509_crt_fmt_t @var{type})
@var{cred}: is a @code{gnutls_certificate_credentials_t}  type.

@var{cafile}: is a file containing the list of trusted CAs (DER or PEM list)

@var{type}: is PEM or DER

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 names of 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()} .

This function can also accept URLs. In that case it
will import all certificates that are marked as trusted. Note
that the supported URLs are the ones indicated by @code{gnutls_url_is_supported()} .

@strong{Returns:} the number of certificates processed
@end deftypefun