/*
 * Copyright (C) 2008-2012 Free Software Foundation, Inc.
 *
 * Author: Simon Josefsson, 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>
#include <string.h>
#include <errno.h>
#include <gnutls/gnutls.h>
#include <gnutls/dtls.h>
#include <gnutls/crypto.h>
#include "utils.h"
#define RANDOMIZE
#define IGNORE_PUSH
#include "eagain-common.h"

const char* side = "";

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

static int handshake = 0;

#define MAX_BUF 1024
#define MSG "Hello TLS, and hi and how are you and more data here... and more... and even more and even more more data..."

static ssize_t
client_push_300 (gnutls_transport_ptr_t tr, const void *data, size_t len)
{
  size_t newlen;
  
  if (len > 300)
    {
      gnutls_transport_set_errno ((gnutls_session_t)tr, EMSGSIZE);
      return -1;
    }

  len = min(len, sizeof(to_server)-to_server_len);

  newlen = to_server_len + len;
  memcpy (to_server + to_server_len, data, len);
  to_server_len = newlen;
#ifdef EAGAIN_DEBUG
  fprintf(stderr, "eagain: pushed %d bytes to server (avail: %d)\n", (int)len, (int)to_server_len);
#endif
  return len;
}

static ssize_t
server_push_300 (gnutls_transport_ptr_t tr, const void *data, size_t len)
{
  size_t newlen;

  if (len > 300)
    {
      gnutls_transport_set_errno ((gnutls_session_t)tr, EMSGSIZE);
      return -1;
    }

  len = min(len, sizeof(to_client)-to_client_len);

  newlen = to_client_len + len;
  memcpy (to_client + to_client_len, data, len);
  to_client_len = newlen;
#ifdef EAGAIN_DEBUG
  fprintf(stderr, "eagain: pushed %d bytes to client (avail: %d)\n", (int)len, (int)to_client_len);
#endif

  return len;
}

void
doit (void)
{
  /* Server stuff. */
  gnutls_anon_server_credentials_t s_anoncred;
  const gnutls_datum_t p3 = { (void *) pkcs3, strlen (pkcs3) };
  static gnutls_dh_params_t dh_params;
  gnutls_session_t server;
  int sret, cret;
  /* Client stuff. */
  gnutls_anon_client_credentials_t c_anoncred;
  gnutls_session_t client;
  /* Need to enable anonymous KX specifically. */
  char buffer[MAX_BUF + 1];
  ssize_t ns;
  int ret, transferred = 0, msglen;

  /* General init. */
  global_init ();
  gnutls_global_set_log_function (tls_log_func);
  if (debug)
    gnutls_global_set_log_level (99);

  /* Init server */
  gnutls_anon_allocate_server_credentials (&s_anoncred);
  gnutls_dh_params_init (&dh_params);
  gnutls_dh_params_import_pkcs3 (dh_params, &p3, GNUTLS_X509_FMT_PEM);
  gnutls_anon_set_server_dh_params (s_anoncred, dh_params);
  gnutls_init (&server, GNUTLS_SERVER|GNUTLS_DATAGRAM|GNUTLS_NONBLOCK);
  ret = gnutls_priority_set_direct (server, "NONE:+VERS-DTLS1.2:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-DH", NULL);
  if (ret < 0)
    exit(1);
  gnutls_credentials_set (server, GNUTLS_CRD_ANON, s_anoncred);
  gnutls_dh_set_prime_bits (server, 1024);
  gnutls_transport_set_push_function (server, server_push_300);
  gnutls_transport_set_pull_function (server, server_pull);
  gnutls_transport_set_pull_timeout_function (server, server_pull_timeout_func);
  gnutls_transport_set_ptr (server, server);

  /* Init client */
  gnutls_anon_allocate_client_credentials (&c_anoncred);
  gnutls_init (&client, GNUTLS_CLIENT|GNUTLS_DATAGRAM|GNUTLS_NONBLOCK);
  cret = gnutls_priority_set_direct (client, "NONE:+VERS-DTLS1.2:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-DH", NULL);
  if (cret < 0)
    exit(1);
  gnutls_credentials_set (client, GNUTLS_CRD_ANON, c_anoncred);
  gnutls_transport_set_push_function (client, client_push_300);
  gnutls_transport_set_pull_function (client, client_pull);
  gnutls_transport_set_pull_timeout_function (client, client_pull_timeout_func);
  gnutls_transport_set_ptr (client, client);

  handshake = 1;
  HANDSHAKE_DTLS(client, server);
  
  if (gnutls_protocol_get_version(client) != GNUTLS_DTLS1_2)
    {
      fail("Error in negotiated version\n");
      exit(1);
    }

  handshake = 0;
  if (debug)
    success ("Handshake established\n");

  do
    {
      ret = gnutls_record_send (client, MSG, strlen (MSG));
    }
  while(ret == GNUTLS_E_AGAIN);
  //success ("client: sent %d\n", ns);

  msglen = strlen(MSG);
  TRANSFER(client, server, MSG, msglen, buffer, MAX_BUF);

  if (debug)
    fputs ("\n", stdout);

  gnutls_bye (client, GNUTLS_SHUT_WR);
  gnutls_bye (server, GNUTLS_SHUT_WR);

  gnutls_deinit (client);
  gnutls_deinit (server);

  gnutls_anon_free_client_credentials (c_anoncred);
  gnutls_anon_free_server_credentials (s_anoncred);

  gnutls_dh_params_deinit (dh_params);

  gnutls_global_deinit ();
}