/*

 * Copyright (C) 2014 Nikos Mavrogiannopoulos

 *

 * 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)

int main()

{

	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 <errno.h>

#include <gnutls/gnutls.h>

#include <gnutls/dtls.h>

#include "utils.h"

#define TXT1 "hello there"

#define TXT1_SIZE (sizeof(TXT1)-1)

#define TXT2 "2hello there"

#define TXT2_SIZE (sizeof(TXT2)-1)

static void terminate(void);

/* This program tests the client hello verify 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);

}

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

 */

#define MAX_BUF 1024

static ssize_t

push(gnutls_transport_ptr_t tr, const void *data, size_t len)

{

	int fd = (long int) tr;

	static int counter = 0;

	if (counter % 2 == 0) {

		errno = EAGAIN;

		counter++;

		return -1;

	}

	return send(fd, data, len, 0);

}

static void client(int fd)

{

	int ret;

	gnutls_anon_client_credentials_t anoncred;

	gnutls_session_t session;

	/* Need to enable anonymous KX specifically. */

	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_dtls_set_mtu(session, 1500);

	gnutls_handshake_set_timeout(session, 20 * 1000);

	/* Use default priorities */

	gnutls_priority_set_direct(session,

				   "NONE:+VERS-DTLS-ALL:+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_int(session, 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: TLS version is: %s\n",

			gnutls_protocol_get_name

			(gnutls_protocol_get_version(session)));

	gnutls_transport_set_push_function(session, push);

	do {

		ret = gnutls_record_send(session, TXT1, TXT1_SIZE);

		if (ret == GNUTLS_E_AGAIN) {

			if (debug) success("discarding\n");

			gnutls_record_discard_queued(session);

		}

	} while (ret == GNUTLS_E_INTERRUPTED);

	do {

		ret = gnutls_record_send(session, TXT2, TXT2_SIZE);

	} while (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN);

	gnutls_bye(session, GNUTLS_SHUT_WR);

	close(fd);

	gnutls_deinit(session);

	gnutls_anon_free_client_credentials(anoncred);

	gnutls_global_deinit();

}

/* These are global */

pid_t child;

static void terminate(void)

{

	int status;

	kill(child, SIGTERM);

	wait(&status);

	exit(1);

}

static void server(int fd)

{

	int ret;

	gnutls_anon_server_credentials_t anoncred;

	char buffer[MAX_BUF + 1];

	gnutls_session_t session;

	/* this must be called once in the program

	 */

	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_handshake_set_timeout(session, 20 * 1000);

	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);

	gnutls_credentials_set(session, GNUTLS_CRD_ANON, anoncred);

	gnutls_transport_set_int(session, 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); */

	do {

		ret = gnutls_record_recv(session, buffer, sizeof(buffer));

	} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);

	if (ret != TXT2_SIZE || memcmp(buffer, TXT2, TXT2_SIZE) != 0) {

		fail("didn't receive the expected data!\n");

		terminate();

	}

	if (ret < 0) {

		close(fd);

		gnutls_deinit(session);

		fail("server: data sending has failed (%s)\n\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");

}

void doit(void)

{

	int fd[2];

	int ret;

	ret = socketpair(AF_UNIX, SOCK_STREAM, 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]);

		wait(&status);

		check_wait_status(status);

	} else {

		close(fd[0]);

		client(fd[1]);

		exit(0);

	}

}

#endif				/* _WIN32 */