int check_command(gnutls_session_t session, const char *str)
{
size_t len = strnlen(str, 128);
int ret;
fprintf(stderr, "*** Processing %u bytes command: %s\n", (unsigned)len,
str);
if (len > 2 && str[0] == str[1] && str[0] == '*') {
if (strncmp
(str, "**REHANDSHAKE**",
sizeof("**REHANDSHAKE**") - 1) == 0) {
fprintf(stderr,
"*** Sending rehandshake request\n");
gnutls_rehandshake(session);
return 1;
} else
if (strncmp
(str, "**HEARTBEAT**",
sizeof("**HEARTBEAT**") - 1) == 0) {
ret =
gnutls_heartbeat_ping(session, 300, 5,
GNUTLS_HEARTBEAT_WAIT);
if (ret < 0) {
if (ret == GNUTLS_E_INVALID_REQUEST) {
fprintf(stderr,
"No heartbeat in this session\n");
} else {
fprintf(stderr, "ping: %s\n",
gnutls_strerror(ret));
exit(1);
}
}
return 2;
}
}
return 0;
}
static void
client (int fd, int server_init)
{
gnutls_session_t session;
int ret, ret2;
char buffer[MAX_BUF + 1];
gnutls_anon_client_credentials_t anoncred;
/* Need to enable anonymous KX specifically. */
gnutls_global_init ();
if (debug)
{
gnutls_global_set_log_function (client_log_func);
gnutls_global_set_log_level (4711);
}
gnutls_anon_allocate_client_credentials (&anoncred);
/* Initialize TLS session
*/
gnutls_init (&session, GNUTLS_CLIENT | GNUTLS_DATAGRAM);
gnutls_heartbeat_enable (session, GNUTLS_HB_PEER_ALLOWED_TO_SEND);
gnutls_dtls_set_mtu (session, 1500);
/* Use default priorities */
gnutls_priority_set_direct (session,
"NONE:+VERS-DTLS1.0:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-ECDH:+CURVE-ALL",
NULL);
/* put the anonymous credentials to the current session
*/
gnutls_credentials_set (session, GNUTLS_CRD_ANON, anoncred);
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) fd);
/* Perform the TLS handshake
*/
do
{
ret = gnutls_handshake (session);
}
while (ret < 0 && gnutls_error_is_fatal (ret) == 0);
if (ret < 0)
{
fail ("client: Handshake failed\n");
gnutls_perror (ret);
exit (1);
}
else
{
if (debug)
success ("client: Handshake was completed\n");
}
if (debug)
success ("client: DTLS version is: %s\n",
gnutls_protocol_get_name (gnutls_protocol_get_version
(session)));
if (!server_init)
{
do
{
ret =
gnutls_record_recv (session, buffer, sizeof (buffer));
if (ret == GNUTLS_E_HEARTBEAT_PING_RECEIVED)
{
if (debug)
success ("Ping received. Replying with pong.\n");
ret2 = gnutls_heartbeat_pong (session, 0);
if (ret2 < 0)
{
fail ("pong: %s\n", gnutls_strerror (ret));
terminate ();
}
}
}
while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED
|| ret == GNUTLS_E_HEARTBEAT_PING_RECEIVED);
}
else
{
do
{
ret =
gnutls_heartbeat_ping (session, 256, 5,
GNUTLS_HEARTBEAT_WAIT);
if (debug)
success ("Ping sent.\n");
}
while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
if (ret < 0)
{
fail ("ping: %s\n", gnutls_strerror (ret));
terminate ();
}
}
gnutls_bye (session, GNUTLS_SHUT_WR);
close (fd);
gnutls_deinit (session);
gnutls_anon_free_client_credentials (anoncred);
gnutls_global_deinit ();
}
static void
server (int fd, int server_init)
{
int ret, ret2;
char buffer[MAX_BUF + 1];
gnutls_session_t session;
gnutls_anon_server_credentials_t anoncred;
/* this must be called once in the program
*/
gnutls_global_init ();
if (debug)
{
gnutls_global_set_log_function (server_log_func);
gnutls_global_set_log_level (4711);
}
gnutls_anon_allocate_server_credentials (&anoncred);
session = initialize_tls_session ();
gnutls_credentials_set (session, GNUTLS_CRD_ANON, anoncred);
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) fd);
do
{
ret = gnutls_handshake (session);
}
while (ret < 0 && gnutls_error_is_fatal (ret) == 0);
if (ret < 0)
{
close (fd);
gnutls_deinit (session);
fail ("server: Handshake has failed (%s)\n\n",
gnutls_strerror (ret));
terminate ();
}
if (debug)
success ("server: Handshake was completed\n");
if (debug)
success ("server: TLS version is: %s\n",
gnutls_protocol_get_name (gnutls_protocol_get_version
(session)));
/* see the Getting peer's information example */
/* print_info(session); */
if (server_init)
{
do
{
ret =
gnutls_record_recv (session, buffer, sizeof (buffer));
if (ret == GNUTLS_E_HEARTBEAT_PING_RECEIVED)
{
if (debug)
success ("Ping received. Replying with pong.\n");
ret2 = gnutls_heartbeat_pong (session, 0);
if (ret2 < 0)
{
fail ("pong: %s\n", gnutls_strerror (ret));
terminate ();
}
}
}
while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED
|| ret == GNUTLS_E_HEARTBEAT_PING_RECEIVED);
}
else
{
do
{
ret =
gnutls_heartbeat_ping (session, 256, 5,
GNUTLS_HEARTBEAT_WAIT);
if (debug)
success ("Ping sent.\n");
}
while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);
if (ret < 0)
{
fail ("ping: %s\n", gnutls_strerror (ret));
terminate ();
}
}
/* do not wait for the peer to close the connection.
*/
gnutls_bye (session, GNUTLS_SHUT_WR);
close (fd);
gnutls_deinit (session);
gnutls_anon_free_server_credentials (anoncred);
gnutls_global_deinit ();
if (debug)
success ("server: finished\n");
}
