@deftypefun {void} {gnutls_certificate_set_params_function} (gnutls_certificate_credentials_t            @var{res}, gnutls_params_function * @var{func})

@var{res}: is a gnutls_certificate_credentials_t type

@var{func}: is the function to be called

This function will set a callback in order for the server to get

the Diffie-Hellman or RSA parameters for certificate

authentication.  The callback should return @code{GNUTLS_E_SUCCESS}  (0) on success.

@strong{Deprecated:} This function is unnecessary and discouraged on GnuTLS 3.6.0

or later. Since 3.6.0, DH parameters are negotiated

following RFC7919.

@end deftypefun