/*

 * Copyright (C) 2017 Red Hat, 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 Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>

 */

#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 <gnutls/gnutls.h>

#include <gnutls/dtls.h>

#include <signal.h>

#include <assert.h>

#include "cert-common.h"

#include "utils.h"

/* This program checks whether a TLS 1.3 client will detect

 * a TLS 1.2 rollback attempt via the server random value.

 */

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);

}

#ifdef TLS12

# define name "TLS1.2"

# define RND tls12_rnd

# define PRIO "NORMAL:-VERS-TLS-ALL:+VERS-TLS1.2"

#elif TLS11

# define name "TLS1.1"

# define RND tls11_rnd

# define PRIO "NORMAL:-VERS-TLS-ALL:+VERS-TLS1.1:+VERS-TLS1.0"

#else

# error unknown version to test

#endif

gnutls_datum_t tls12_rnd = {(void*)"\x44\x4F\x57\x4E\x47\x52\x44\x01",

			      8};

gnutls_datum_t tls11_rnd = {(void*)"\x44\x4F\x57\x4E\x47\x52\x44\x00",

			      8};

static void client(int fd)

{

	int ret;

	gnutls_certificate_credentials_t x509_cred;

	gnutls_session_t session;

	gnutls_datum_t srandom;

	unsigned try = 0;

	gnutls_datum_t session_data = { NULL, 0 };

	global_init();

	if (debug) {

		gnutls_global_set_log_function(client_log_func);

		gnutls_global_set_log_level(7);

	}

	gnutls_certificate_allocate_credentials(&x509_cred);

	gnutls_certificate_set_x509_key_mem(x509_cred, &cli_ca3_cert,

					    &cli_ca3_key,

					    GNUTLS_X509_FMT_PEM);

 retry:

	/* Initialize TLS session

	 */

	gnutls_init(&session, GNUTLS_CLIENT);

	gnutls_handshake_set_timeout(session, 20 * 1000);

	ret = gnutls_priority_set_direct(session, PRIO, NULL);

	if (ret < 0)

		fail("cannot set TLS priorities\n");

	if (try > 0)

		gnutls_session_set_data(session, session_data.data, session_data.size);

	/* put the anonymous credentials to the current session

	 */

	gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);

	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("error in handshake: %s\n", gnutls_strerror(ret));

	}

	if (try > 0)

		assert(gnutls_session_is_resumed(session));

	gnutls_session_get_random(session, NULL, &srandom);

	if (srandom.size != 32)

		fail("unexpected random size\n");

	if (memcmp(&srandom.data[32-8], RND.data, 8) != 0) {

		unsigned i;

		printf("expected: ");

		for (i=0;i<8;i++)

			printf("%.2x", (unsigned)RND.data[i]);

		printf("\n");

		printf("got:      ");

		for (i=0;i<8;i++)

			printf("%.2x", (unsigned)srandom.data[32-8+i]);

		printf("\n");

		fail("unexpected random data for %s\n", name);

	}

	do {

		ret = gnutls_record_send(session, "\x00", 1);

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

	if (try == 0) {

		ret = gnutls_session_get_data2(session, &session_data);

		if (ret < 0)

			fail("couldn't retrieve session data: %s\n",

			     gnutls_strerror(ret));

	}

	gnutls_deinit(session);

	if (try == 0) {

		try++;

		goto retry;

	}

	close(fd);

	gnutls_free(session_data.data);

	gnutls_certificate_free_credentials(x509_cred);

	gnutls_global_deinit();

}

static void server(int fd)

{

	int ret;

	gnutls_session_t session;

	gnutls_certificate_credentials_t x509_cred;

	gnutls_datum_t skey;

	unsigned try = 0;

	unsigned char buf[16];

	/* 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_certificate_allocate_credentials(&x509_cred);

	gnutls_certificate_set_x509_key_mem(x509_cred, &server_cert,

					    &server_key,

					    GNUTLS_X509_FMT_PEM);

	assert(gnutls_session_ticket_key_generate(&skey) >= 0);

 retry:

	gnutls_init(&session, GNUTLS_SERVER);

	gnutls_handshake_set_timeout(session, 20 * 1000);

	assert(gnutls_priority_set_direct(session, "NORMAL:-VERS-TLS-ALL:+VERS-TLS1.3:+VERS-TLS1.2:+VERS-TLS1.1:+VERS-TLS1.0", NULL)>=0);

	gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);

	assert(gnutls_session_ticket_enable_server(session, &skey) >= 0);

	gnutls_transport_set_int(session, fd);

	do {

		ret = gnutls_handshake(session);

		if (ret == GNUTLS_E_INTERRUPTED) { /* expected */

			break;

		}

	} while (ret < 0 && gnutls_error_is_fatal(ret) == 0);

	if (ret < 0)

		fail("error in handshake: %s\n", gnutls_strerror(ret));

	if (try > 0)

		assert(gnutls_session_is_resumed(session));

	do {

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

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

	if (ret < 0)

		fail("server: recv did not succeed as expected: %s\n", gnutls_strerror(ret));

	gnutls_deinit(session);

	if (try == 0) {

		try++;

		goto retry;

	}

	close(fd);

	gnutls_free(skey.data);

	gnutls_certificate_free_credentials(x509_cred);

	gnutls_global_deinit();

	if (debug)

		success("server: client/server hello were verified\n");

}

static void ch_handler(int sig)

{

	int status = 0;

	wait(&status);

	check_wait_status(status);

	return;

}

void doit(void)

{

	int fd[2];

	int ret;

	pid_t child;

	signal(SIGCHLD, ch_handler);

	signal(SIGPIPE, SIG_IGN);

	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) {

		/* parent */

		close(fd[1]);

		client(fd[0]);

		kill(child, SIGTERM);

	} else {

		close(fd[0]);

		server(fd[1]);

		exit(0);

	}

}

#endif				/* _WIN32 */