/*
 * Copyright (C) 2012 Free Software Foundation, Inc.
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * GnuTLS is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GnuTLS is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GnuTLS; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>

#if defined(_WIN32) || !defined(ENABLE_DTLS_SRTP)

int
main (int argc, char** argv)
{
    exit (77);
}

#else

#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <gnutls/gnutls.h>
#include <gnutls/dtls.h>

#include "utils.h"

static void terminate (void);

/* This program tests the rehandshake in DTLS
 */

static void
server_log_func (int level, const char *str)
{
    fprintf (stderr, "server|<%d>| %s", level, str);
}

static void
client_log_func (int level, const char *str)
{
    fprintf (stderr, "client|<%d>| %s", level, str);
}

/* These are global */
static pid_t child;

#define MAX_KEY_MATERIAL 64*4
/* A very basic DTLS client, with anonymous authentication, that negotiates SRTP
 */

static void
client (int fd, int profile)
{
    gnutls_session_t session;
    int ret;
    gnutls_anon_client_credentials_t anoncred;
    uint8_t km[MAX_KEY_MATERIAL];
    char buf[2*MAX_KEY_MATERIAL];
    gnutls_datum_t cli_key, cli_salt, server_key, server_salt;
    /* 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);
    if (profile)
      ret = gnutls_srtp_set_profile_direct(session, "SRTP_AES128_CM_HMAC_SHA1_80",
                                           NULL);
    else
      ret = gnutls_srtp_set_profile_direct(session, "SRTP_NULL_HMAC_SHA1_80",
                                           NULL);
    if (ret < 0)
      {
        gnutls_perror(ret);
        exit(1);
      }
    

    /* 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)));

    ret = gnutls_srtp_get_keys (session, km, sizeof(km), &cli_key, &cli_salt, &server_key, &server_salt);
    if (ret < 0)
      {
        gnutls_perror(ret);
        exit(1);
      }

    if (debug)
      {
        size_t size = sizeof(buf);
        gnutls_hex_encode(&cli_key, buf, &size);
        success ("Client key: %s\n", buf);

        size = sizeof(buf);
        gnutls_hex_encode(&cli_salt, buf, &size);
        success ("Client salt: %s\n", buf);

        size = sizeof(buf);
        gnutls_hex_encode(&server_key, buf, &size);
        success ("Server key: %s\n", buf);

        size = sizeof(buf);
        gnutls_hex_encode(&server_salt, buf, &size);
        success ("Server salt: %s\n", buf);
      }


    gnutls_bye (session, GNUTLS_SHUT_WR);

    close (fd);

    gnutls_deinit (session);

    gnutls_anon_free_client_credentials (anoncred);

    gnutls_global_deinit ();
}

static void
terminate (void)
{
    int status;

    kill (child, SIGTERM);
    wait (&status);
    exit (1);
}

static void
server (int fd, int profile)
{
    int ret;
    gnutls_session_t session;
    gnutls_anon_server_credentials_t anoncred;
    uint8_t km[MAX_KEY_MATERIAL];
    char buf[2*MAX_KEY_MATERIAL];
    gnutls_datum_t cli_key, cli_salt, server_key, server_salt;

    /* 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);

    gnutls_init (&session, GNUTLS_SERVER | GNUTLS_DATAGRAM);
    gnutls_heartbeat_enable (session, GNUTLS_HB_PEER_ALLOWED_TO_SEND);
    gnutls_dtls_set_mtu (session, 1500);

    /* avoid calling all the priority functions, since the defaults
     * are adequate.
     */
    gnutls_priority_set_direct (session,
                                "NONE:+VERS-DTLS1.0:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-ECDH:+CURVE-ALL",
                                NULL);

    if (profile)
      ret = gnutls_srtp_set_profile_direct(session, "SRTP_AES128_CM_HMAC_SHA1_80",
                                           NULL);
    else
      ret = gnutls_srtp_set_profile_direct(session, "SRTP_NULL_HMAC_SHA1_80",
                                           NULL);
    if (ret < 0)
      {
        gnutls_perror(ret);
        exit(1);
      }

    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)));

    ret = gnutls_srtp_get_keys (session, km, sizeof(km), &cli_key, &cli_salt, &server_key, &server_salt);
    if (ret < 0)
      {
        gnutls_perror(ret);
        exit(1);
      }
    
    if (debug)
      {
        size_t size = sizeof(buf);
        gnutls_hex_encode(&cli_key, buf, &size);
        success ("Client key: %s\n", buf);

        size = sizeof(buf);
        gnutls_hex_encode(&cli_salt, buf, &size);
        success ("Client salt: %s\n", buf);

        size = sizeof(buf);
        gnutls_hex_encode(&server_key, buf, &size);
        success ("Server key: %s\n", buf);

        size = sizeof(buf);
        gnutls_hex_encode(&server_salt, buf, &size);
        success ("Server salt: %s\n", buf);
      }

    /* 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");
}

static void
start (int profile)
{
    int fd[2];
    int ret;

    ret = socketpair (AF_UNIX, SOCK_DGRAM, 0, fd);
    if (ret < 0)
      {
          perror ("socketpair");
          exit (1);
      }

    child = fork ();
    if (child < 0)
      {
          perror ("fork");
          fail ("fork");
          exit (1);
      }

    if (child)
      {
          int status;
          /* parent */

          server (fd[0], profile);
          wait (&status);
          if (WEXITSTATUS (status) != 0)
              fail ("Child died with status %d\n", WEXITSTATUS (status));
      }
    else
      {
          close (fd[0]);
          client (fd[1], profile);
          exit (0);
      }
}

void
doit (void)
{
    start (0);
    start (1);
}

#endif /* _WIN32 */