/*
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software
 * Foundation, Inc.
 *
 * Author: Simon Josefsson
 *
 * 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
 */

/* Parts copied from GnuTLS example programs. */

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

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

#include "ex-session-info.c"
#include "ex-x509-info.c"
#include "tcp.c"

pid_t child;

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

/* A very basic TLS client, with anonymous authentication.
 */


#define MAX_BUF 1024
#define MSG "Hello TLS"

static unsigned char ca_pem[] =
  "-----BEGIN CERTIFICATE-----\n"
  "MIIB5zCCAVKgAwIBAgIERiYdJzALBgkqhkiG9w0BAQUwGTEXMBUGA1UEAxMOR251\n"
  "VExTIHRlc3QgQ0EwHhcNMDcwNDE4MTMyOTExWhcNMDgwNDE3MTMyOTExWjAZMRcw\n"
  "FQYDVQQDEw5HbnVUTFMgdGVzdCBDQTCBnDALBgkqhkiG9w0BAQEDgYwAMIGIAoGA\n"
  "vuyYeh1vfmslnuggeEKgZAVmQ5ltSdUY7H25WGSygKMUYZ0KT74v8C780qtcNt9T\n"
  "7EPH/N6RvB4BprdssgcQLsthR3XKA84jbjjxNCcaGs33lvOz8A1nf8p3hD+cKfRi\n"
  "kfYSW2JazLrtCC4yRCas/SPOUxu78of+3HiTfFm/oXUCAwEAAaNDMEEwDwYDVR0T\n"
  "AQH/BAUwAwEB/zAPBgNVHQ8BAf8EBQMDBwQAMB0GA1UdDgQWBBTpPBz7rZJu5gak\n"
  "Viyi4cBTJ8jylTALBgkqhkiG9w0BAQUDgYEAiaIRqGfp1jPpNeVhABK60SU0KIAy\n"
  "njuu7kHq5peUgYn8Jd9zNzExBOEp1VOipGsf6G66oQAhDFp2o8zkz7ZH71zR4HEW\n"
  "KoX6n5Emn6DvcEH/9pAhnGxNHJAoS7czTKv/JDZJhkqHxyrE1fuLsg5Qv25DTw7+\n"
  "PfqUpIhz5Bbm7J4=\n" "-----END CERTIFICATE-----\n";
const gnutls_datum_t ca = { ca_pem, sizeof (ca_pem) };

static unsigned char cert_pem[] =
  "-----BEGIN CERTIFICATE-----\n"
  "MIICHjCCAYmgAwIBAgIERiYdNzALBgkqhkiG9w0BAQUwGTEXMBUGA1UEAxMOR251\n"
  "VExTIHRlc3QgQ0EwHhcNMDcwNDE4MTMyOTI3WhcNMDgwNDE3MTMyOTI3WjAdMRsw\n"
  "GQYDVQQDExJHbnVUTFMgdGVzdCBjbGllbnQwgZwwCwYJKoZIhvcNAQEBA4GMADCB\n"
  "iAKBgLtmQ/Xyxde2jMzF3/WIO7HJS2oOoa0gUEAIgKFPXKPQ+GzP5jz37AR2ExeL\n"
  "ZIkiW8DdU3w77XwEu4C5KL6Om8aOoKUSy/VXHqLnu7czSZ/ju0quak1o/8kR4jKN\n"
  "zj2AC41179gAgY8oBAOgIo1hBAf6tjd9IQdJ0glhaZiQo1ipAgMBAAGjdjB0MAwG\n"
  "A1UdEwEB/wQCMAAwEwYDVR0lBAwwCgYIKwYBBQUHAwIwDwYDVR0PAQH/BAUDAweg\n"
  "ADAdBgNVHQ4EFgQUTLkKm/odNON+3svSBxX+odrLaJEwHwYDVR0jBBgwFoAU6Twc\n"
  "+62SbuYGpFYsouHAUyfI8pUwCwYJKoZIhvcNAQEFA4GBALujmBJVZnvaTXr9cFRJ\n"
  "jpfc/3X7sLUsMvumcDE01ls/cG5mIatmiyEU9qI3jbgUf82z23ON/acwJf875D3/\n"
  "U7jyOsBJ44SEQITbin2yUeJMIm1tievvdNXBDfW95AM507ShzP12sfiJkJfjjdhy\n"
  "dc8Siq5JojruiMizAf0pA7in\n" "-----END CERTIFICATE-----\n";
const gnutls_datum_t cert = { cert_pem, sizeof (cert_pem) };

static unsigned char key_pem[] =
  "-----BEGIN RSA PRIVATE KEY-----\n"
  "MIICXAIBAAKBgQC7ZkP18sXXtozMxd/1iDuxyUtqDqGtIFBACIChT1yj0Phsz+Y8\n"
  "9+wEdhMXi2SJIlvA3VN8O+18BLuAuSi+jpvGjqClEsv1Vx6i57u3M0mf47tKrmpN\n"
  "aP/JEeIyjc49gAuNde/YAIGPKAQDoCKNYQQH+rY3fSEHSdIJYWmYkKNYqQIDAQAB\n"
  "AoGADpmARG5CQxS+AesNkGmpauepiCz1JBF/JwnyiX6vEzUh0Ypd39SZztwrDxvF\n"
  "PJjQaKVljml1zkJpIDVsqvHdyVdse8M+Qn6hw4x2p5rogdvhhIL1mdWo7jWeVJTF\n"
  "RKB7zLdMPs3ySdtcIQaF9nUAQ2KJEvldkO3m/bRJFEp54k0CQQDYy+RlTmwRD6hy\n"
  "7UtMjR0H3CSZJeQ8svMCxHLmOluG9H1UKk55ZBYfRTsXniqUkJBZ5wuV1L+pR9EK\n"
  "ca89a+1VAkEA3UmBelwEv2u9cAU1QjKjmwju1JgXbrjEohK+3B5y0ESEXPAwNQT9\n"
  "TrDM1m9AyxYTWLxX93dI5QwNFJtmbtjeBQJARSCWXhsoaDRG8QZrCSjBxfzTCqZD\n"
  "ZXtl807ymCipgJm60LiAt0JLr4LiucAsMZz6+j+quQbSakbFCACB8SLV1QJBAKZQ\n"
  "YKf+EPNtnmta/rRKKvySsi3GQZZN+Dt3q0r094XgeTsAqrqujVNfPhTMeP4qEVBX\n"
  "/iVX2cmMTSh3w3z8MaECQEp0XJWDVKOwcTW6Ajp9SowtmiZ3YDYo1LF9igb4iaLv\n"
  "sWZGfbnU3ryjvkb6YuFjgtzbZDZHWQCo8/cOtOBmPdk=\n"
  "-----END RSA PRIVATE KEY-----\n";
const gnutls_datum_t key = { key_pem, sizeof (key_pem) };

static void
client (void)
{
  int ret, sd, ii;
  gnutls_session_t session;
  char buffer[MAX_BUF + 1];
  gnutls_certificate_credentials_t xcred;

  gnutls_global_init ();

  gnutls_global_set_log_function (tls_log_func);
  if (debug)
    gnutls_global_set_log_level (6);

  gnutls_certificate_allocate_credentials (&xcred);

  /* sets the trusted cas file
   */
  gnutls_certificate_set_x509_trust_mem (xcred, &ca, GNUTLS_X509_FMT_PEM);
  gnutls_certificate_set_x509_key_mem (xcred, &cert, &key,
				       GNUTLS_X509_FMT_PEM);

  /* Initialize TLS session
   */
  gnutls_init (&session, GNUTLS_CLIENT);

  /* Use default priorities */
  gnutls_set_default_priority (session);

  /* put the x509 credentials to the current session
   */
  gnutls_credentials_set (session, GNUTLS_CRD_CERTIFICATE, xcred);

  /* connect to the peer
   */
  sd = tcp_connect ();

  gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) sd);

  /* Perform the TLS handshake
   */
  ret = gnutls_handshake (session);

  if (ret < 0)
    {
      fail ("client: Handshake failed\n");
      gnutls_perror (ret);
      goto end;
    }
  else if (debug)
    {
      success ("client: Handshake was completed\n");
    }

  if (debug)
    success ("client: TLS version is: %s\n",
	     gnutls_protocol_get_name (gnutls_protocol_get_version
				       (session)));

  /* see the Getting peer's information example */
  if (debug)
    print_info (session);

  ret = gnutls_record_send (session, MSG, strlen (MSG));

  if (ret == strlen (MSG))
    {
      if (debug)
	success ("client: sent record.\n");
    }
  else
    {
      fail ("client: failed to send record.\n");
      gnutls_perror (ret);
      goto end;
    }

  ret = gnutls_record_recv (session, buffer, MAX_BUF);

  if (debug)
    success ("client: recv returned %d.\n", ret);

  if (ret == GNUTLS_E_REHANDSHAKE)
    {
      if (debug)
	success ("client: doing handshake!\n");
      ret = gnutls_handshake (session);
      if (ret == 0)
	{
	  if (debug)
	    success ("client: handshake complete, reading again.\n");
	  ret = gnutls_record_recv (session, buffer, MAX_BUF);
	}
      else
	{
	  fail ("client: handshake failed.\n");
	}
    }

  if (ret == 0)
    {
      if (debug)
	success ("client: Peer has closed the TLS connection\n");
      goto end;
    }
  else if (ret < 0)
    {
      fail ("client: Error: %s\n", gnutls_strerror (ret));
      goto end;
    }

  if (debug)
    {
      printf ("- Received %d bytes: ", ret);
      for (ii = 0; ii < ret; ii++)
	{
	  fputc (buffer[ii], stdout);
	}
      fputs ("\n", stdout);
    }

  gnutls_bye (session, GNUTLS_SHUT_RDWR);

end:

  tcp_close (sd);

  gnutls_deinit (session);

  gnutls_certificate_free_credentials (xcred);

  gnutls_global_deinit ();
}

/* This is a sample TLS 1.0 echo server, using X.509 authentication.
 */

#define SA struct sockaddr
#define MAX_BUF 1024
#define PORT 5556		/* listen to 5556 port */
#define DH_BITS 1024

/* These are global */
gnutls_certificate_credentials_t x509_cred;

static gnutls_session_t
initialize_tls_session (void)
{
  gnutls_session_t session;

  gnutls_init (&session, GNUTLS_SERVER);

  /* avoid calling all the priority functions, since the defaults
   * are adequate.
   */
  gnutls_set_default_priority (session);

  gnutls_credentials_set (session, GNUTLS_CRD_CERTIFICATE, x509_cred);

  /* request client certificate if any.
     Moved to later on to be able to test re-handshakes.
     gnutls_certificate_server_set_request (session, GNUTLS_CERT_REQUEST);
   */

  gnutls_dh_set_prime_bits (session, DH_BITS);

  return session;
}

static gnutls_dh_params_t dh_params;

static int
generate_dh_params (void)
{
  const gnutls_datum_t p3 = { (char *) pkcs3, strlen (pkcs3) };
  /* Generate Diffie-Hellman parameters - for use with DHE
   * kx algorithms. These should be discarded and regenerated
   * once a day, once a week or once a month. Depending on the
   * security requirements.
   */
  gnutls_dh_params_init (&dh_params);
  return gnutls_dh_params_import_pkcs3 (dh_params, &p3, GNUTLS_X509_FMT_PEM);
}

int err, listen_sd, i;
int sd, ret;
struct sockaddr_in sa_serv;
struct sockaddr_in sa_cli;
int client_len;
char topbuf[512];
gnutls_session_t session;
char buffer[MAX_BUF + 1];
int optval = 1;


static unsigned char server_cert_pem[] =
  "-----BEGIN CERTIFICATE-----\n"
  "MIICVjCCAcGgAwIBAgIERiYdMTALBgkqhkiG9w0BAQUwGTEXMBUGA1UEAxMOR251\n"
  "VExTIHRlc3QgQ0EwHhcNMDcwNDE4MTMyOTIxWhcNMDgwNDE3MTMyOTIxWjA3MRsw\n"
  "GQYDVQQKExJHbnVUTFMgdGVzdCBzZXJ2ZXIxGDAWBgNVBAMTD3Rlc3QuZ251dGxz\n"
  "Lm9yZzCBnDALBgkqhkiG9w0BAQEDgYwAMIGIAoGA17pcr6MM8C6pJ1aqU46o63+B\n"
  "dUxrmL5K6rce+EvDasTaDQC46kwTHzYWk95y78akXrJutsoKiFV1kJbtple8DDt2\n"
  "DZcevensf9Op7PuFZKBroEjOd35znDET/z3IrqVgbtm2jFqab7a+n2q9p/CgMyf1\n"
  "tx2S5Zacc1LWn9bIjrECAwEAAaOBkzCBkDAMBgNVHRMBAf8EAjAAMBoGA1UdEQQT\n"
  "MBGCD3Rlc3QuZ251dGxzLm9yZzATBgNVHSUEDDAKBggrBgEFBQcDATAPBgNVHQ8B\n"
  "Af8EBQMDB6AAMB0GA1UdDgQWBBTrx0Vu5fglyoyNgw106YbU3VW0dTAfBgNVHSME\n"
  "GDAWgBTpPBz7rZJu5gakViyi4cBTJ8jylTALBgkqhkiG9w0BAQUDgYEAaFEPTt+7\n"
  "bzvBuOf7+QmeQcn29kT6Bsyh1RHJXf8KTk5QRfwp6ogbp94JQWcNQ/S7YDFHglD1\n"
  "AwUNBRXwd3riUsMnsxgeSDxYBfJYbDLeohNBsqaPDJb7XailWbMQKfAbFQ8cnOxg\n"
  "rOKLUQRWJ0K3HyXRMhbqjdLIaQiCvQLuizo=\n" "-----END CERTIFICATE-----\n";

const gnutls_datum_t server_cert = { server_cert_pem,
  sizeof (server_cert_pem)
};

static unsigned char server_key_pem[] =
  "-----BEGIN RSA PRIVATE KEY-----\n"
  "MIICXAIBAAKBgQDXulyvowzwLqknVqpTjqjrf4F1TGuYvkrqtx74S8NqxNoNALjq\n"
  "TBMfNhaT3nLvxqResm62ygqIVXWQlu2mV7wMO3YNlx696ex/06ns+4VkoGugSM53\n"
  "fnOcMRP/PciupWBu2baMWppvtr6far2n8KAzJ/W3HZLllpxzUtaf1siOsQIDAQAB\n"
  "AoGAYAFyKkAYC/PYF8e7+X+tsVCHXppp8AoP8TEZuUqOZz/AArVlle/ROrypg5kl\n"
  "8YunrvUdzH9R/KZ7saNZlAPLjZyFG9beL/am6Ai7q7Ma5HMqjGU8kTEGwD7K+lbG\n"
  "iomokKMOl+kkbY/2sI5Czmbm+/PqLXOjtVc5RAsdbgvtmvkCQQDdV5QuU8jap8Hs\n"
  "Eodv/tLJ2z4+SKCV2k/7FXSKWe0vlrq0cl2qZfoTUYRnKRBcWxc9o92DxK44wgPi\n"
  "oMQS+O7fAkEA+YG+K9e60sj1K4NYbMPAbYILbZxORDecvP8lcphvwkOVUqbmxOGh\n"
  "XRmTZUuhBrJhJKKf6u7gf3KWlPl6ShKEbwJASC118cF6nurTjuLf7YKARDjNTEws\n"
  "qZEeQbdWYINAmCMj0RH2P0mvybrsXSOD5UoDAyO7aWuqkHGcCLv6FGG+qwJAOVqq\n"
  "tXdUucl6GjOKKw5geIvRRrQMhb/m5scb+5iw8A4LEEHPgGiBaF5NtJZLALgWfo5n\n"
  "hmC8+G8F0F78znQtPwJBANexu+Tg5KfOnzSILJMo3oXiXhf5PqXIDmbN0BKyCKAQ\n"
  "LfkcEcUbVfmDaHpvzwY9VEaoMOKVLitETXdNSxVpvWM=\n"
  "-----END RSA PRIVATE KEY-----\n";

const gnutls_datum_t server_key = { server_key_pem,
  sizeof (server_key_pem)
};

static void
server_start (void)
{
  /* Socket operations
   */
  listen_sd = socket (AF_INET, SOCK_STREAM, 0);
  if (err == -1)
    {
      perror ("socket");
      fail ("server: socket failed\n");
      return;
    }

  memset (&sa_serv, '\0', sizeof (sa_serv));
  sa_serv.sin_family = AF_INET;
  sa_serv.sin_addr.s_addr = INADDR_ANY;
  sa_serv.sin_port = htons (PORT);	/* Server Port number */

  setsockopt (listen_sd, SOL_SOCKET, SO_REUSEADDR, (void *) &optval,
	      sizeof (int));

  err = bind (listen_sd, (SA *) & sa_serv, sizeof (sa_serv));
  if (err == -1)
    {
      perror ("bind");
      fail ("server: bind failed\n");
      return;
    }

  err = listen (listen_sd, 1024);
  if (err == -1)
    {
      perror ("listen");
      fail ("server: listen failed\n");
      return;
    }

  if (debug)
    success ("server: ready. Listening to port '%d'.\n", PORT);
}

static void
server (void)
{
  /* this must be called once in the program
   */
  gnutls_global_init ();

  gnutls_global_set_log_function (tls_log_func);
  if (debug)
    gnutls_global_set_log_level (6);

  gnutls_certificate_allocate_credentials (&x509_cred);
  gnutls_certificate_set_x509_trust_mem (x509_cred, &ca, GNUTLS_X509_FMT_PEM);

  gnutls_certificate_set_x509_key_mem (x509_cred, &server_cert, &server_key,
				       GNUTLS_X509_FMT_PEM);

  if (debug)
    success ("Launched, generating DH parameters...\n");

  generate_dh_params ();

  gnutls_certificate_set_dh_params (x509_cred, dh_params);

  client_len = sizeof (sa_cli);

  session = initialize_tls_session ();

  sd = accept (listen_sd, (SA *) & sa_cli, &client_len);

  if (debug)
    success ("server: connection from %s, port %d\n",
	     inet_ntop (AF_INET, &sa_cli.sin_addr, topbuf,
			sizeof (topbuf)), ntohs (sa_cli.sin_port));

  gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) sd);
  ret = gnutls_handshake (session);
  if (ret < 0)
    {
      close (sd);
      gnutls_deinit (session);
      fail ("server: Handshake has failed (%s)\n\n", gnutls_strerror (ret));
      return;
    }
  if (debug)
    {
      success ("server: Handshake was completed\n");
      success ("server: TLS version is: %s\n",
	       gnutls_protocol_get_name (gnutls_protocol_get_version
					 (session)));
    }

  /* see the Getting peer's information example */
  if (debug)
    print_info (session);

  i = 0;
  for (;;)
    {
      memset (buffer, 0, MAX_BUF + 1);
      ret = gnutls_record_recv (session, buffer, MAX_BUF);

      if (ret == 0)
	{
	  if (debug)
	    success ("server: Peer has closed the GnuTLS connection\n");
	  break;
	}
      else if (ret < 0)
	{
	  fail ("server: Received corrupted data(%d). Closing...\n", ret);
	  break;
	}
      else if (ret > 0)
	{
	  gnutls_certificate_server_set_request (session,
						 GNUTLS_CERT_REQUEST);

	  if (debug)
	    success ("server: got data, forcing rehandshake.\n");

	  ret = gnutls_rehandshake (session);
	  if (ret < 0)
	    {
	      fail ("server: rehandshake failed\n");
	      gnutls_perror (ret);
	      break;
	    }

	  ret = gnutls_handshake (session);
	  if (ret < 0)
	    {
	      fail ("server: (re)handshake failed\n");
	      gnutls_perror (ret);
	      break;
	    }

	  if (debug)
	    success ("server: rehandshake complete.\n");

	  /* echo data back to the client
	   */
	  gnutls_record_send (session, buffer, strlen (buffer));
	}
    }
  /* do not wait for the peer to close the connection.
   */
  gnutls_bye (session, GNUTLS_SHUT_WR);

  close (sd);
  gnutls_deinit (session);

  close (listen_sd);

  gnutls_certificate_free_credentials (x509_cred);

  gnutls_dh_params_deinit (dh_params);

  gnutls_global_deinit ();

  if (debug)
    success ("server: finished\n");
}


void
doit (void)
{
  /* parent */
  server_start ();
  if (error_count)
    return;

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

  if (child)
    {
      int status;

      server ();
      wait (&status);
    }
  else
    client ();
}