@deftypefun {int} {gnutls_psk_set_server_known_dh_params} (gnutls_psk_server_credentials_t @var{res}, gnutls_sec_param_t @var{sec_param}) @var{res}: is a gnutls_psk_server_credentials_t type @var{sec_param}: is an option of the @code{gnutls_sec_param_t} enumeration This function will set the Diffie-Hellman parameters for a PSK server to use. These parameters will be used in Ephemeral Diffie-Hellman cipher suites and will be selected from the FFDHE set of RFC7919 according to the security level provided. @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. @strong{Returns:} On success, @code{GNUTLS_E_SUCCESS} (0) is returned, otherwise a negative error value. @strong{Since:} 3.5.6 @end deftypefun