/*

 * Copyright (C) 2004-2012 Free Software Foundation, Inc.

 * Copyright (C) 2013 Adam Sampson <ats@offog.org>

 *

 * 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>

#if defined(_WIN32)

/* socketpair isn't supported on Win32. */

int main(int argc, char **argv)

{

	exit(77);

}

#else

#include <string.h>

#include <sys/types.h>

#include <sys/socket.h>

#if !defined(_WIN32)

#include <sys/wait.h>

#endif

#include <unistd.h>

#include <gnutls/gnutls.h>

#include "utils.h"

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

 */

const char *side = "";

static void tls_log_func(int level, const char *str)

{

	fprintf(stderr, "%s|<%d>| %s", side, level, str);

}

#define MAX_BUF 1024

#define MSG "Hello TLS"

static void client(int sd, const char *prio)

{

	int ret, ii;

	gnutls_session_t session;

	char buffer[MAX_BUF + 1];

	gnutls_psk_client_credentials_t pskcred;

	/* Need to enable anonymous KX specifically. */

	const gnutls_datum_t key = { (void *) "DEADBEEF", 8 };

	const char *hint;

	global_init();

	gnutls_global_set_log_function(tls_log_func);

	if (debug)

		gnutls_global_set_log_level(4711);

	side = "client";

	gnutls_psk_allocate_client_credentials(&pskcred);

	gnutls_psk_set_client_credentials(pskcred, "test", &key,

					  GNUTLS_PSK_KEY_HEX);

	/* Initialize TLS session

	 */

	gnutls_init(&session, GNUTLS_CLIENT);

	/* Use default priorities */

	gnutls_priority_set_direct(session, prio, NULL);

	/* put the anonymous credentials to the current session

	 */

	gnutls_credentials_set(session, GNUTLS_CRD_PSK, pskcred);

	gnutls_transport_set_int(session, 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");

	}

	/* check the hint */

	hint = gnutls_psk_client_get_hint(session);

	if (hint == NULL || strcmp(hint, "hint") != 0) {

		fail("client: hint is not the expected: %s\n", gnutls_psk_client_get_hint(session));

		goto end;

	}

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

	ret = gnutls_record_recv(session, buffer, MAX_BUF);

	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:

	close(sd);

	gnutls_deinit(session);

	gnutls_psk_free_client_credentials(pskcred);

	gnutls_global_deinit();

}

/* This is a sample TLS 1.0 echo server, for PSK authentication.

 */

#define MAX_BUF 1024

/* These are global */

static int

pskfunc(gnutls_session_t session, const char *username,

	gnutls_datum_t * key)

{

	if (debug)

		printf("psk: username %s\n", username);

	key->data = gnutls_malloc(4);

	key->data[0] = 0xDE;

	key->data[1] = 0xAD;

	key->data[2] = 0xBE;

	key->data[3] = 0xEF;

	key->size = 4;

	return 0;

}

static gnutls_dh_params_t dh_params;

static int generate_dh_params(void)

{

	const gnutls_datum_t p3 = { (void *) 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);

}

static void server(int sd, const char *prio)

{

gnutls_psk_server_credentials_t server_pskcred;

int ret;

gnutls_session_t session;

char buffer[MAX_BUF + 1];

	/* this must be called once in the program

	 */

	global_init();

	gnutls_global_set_log_function(tls_log_func);

	if (debug)

		gnutls_global_set_log_level(4711);

	side = "server";

	gnutls_psk_allocate_server_credentials(&server_pskcred);

	gnutls_psk_set_server_credentials_hint(server_pskcred, "hint");

	gnutls_psk_set_server_credentials_function(server_pskcred,

						   pskfunc);

	gnutls_psk_set_server_dh_params(server_pskcred, dh_params);

	gnutls_init(&session, GNUTLS_SERVER);

	/* avoid calling all the priority functions, since the defaults

	 * are adequate.

	 */

	gnutls_priority_set_direct(session, prio, NULL);

	gnutls_credentials_set(session, GNUTLS_CRD_PSK, server_pskcred);

	gnutls_transport_set_int(session, 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");

	/* see the Getting peer's information example */

	/* print_info(session); */

	for (;;) {

		memset(buffer, 0, MAX_BUF + 1);

		gnutls_record_set_timeout(session, 10000);

		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) {

			/* 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);

	gnutls_psk_free_server_credentials(server_pskcred);

	gnutls_global_deinit();

	if (debug)

		success("server: finished\n");

}

static

void run_test(const char *prio)

{

	pid_t child;

	int err;

	int sockets[2];

	err = socketpair(AF_UNIX, SOCK_STREAM, 0, sockets);

	if (err == -1) {

		perror("socketpair");

		fail("socketpair failed\n");

		return;

	}

	child = fork();

	if (child < 0) {

		perror("fork");

		fail("fork");

		return;

	}

	if (child) {

		int status;

		/* parent */

		server(sockets[0], prio);

		wait(&status);

	} else {

		client(sockets[1], prio);

	}

}

void doit(void)

{

	generate_dh_params();

	run_test("NORMAL:-KX-ALL:+PSK");

	run_test("NORMAL:-KX-ALL:+ECDHE-PSK");

	run_test("NORMAL:-KX-ALL:+DHE-PSK");

	gnutls_dh_params_deinit(dh_params);

}

#endif				/* _WIN32 */