anon_server_credentials_st
typedef struct {
gnutls_dh_params_t dh_params;
unsigned deinit_dh_params;
gnutls_sec_param_t dh_sec_param;
/* this callback is used to retrieve the DH or RSA
* parameters.
*/
gnutls_params_function *params_func;
} anon_server_credentials_st;