/*

 * Copyright (C) 2016 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 <gnutls/gnutls.h>

#include <gnutls/dtls.h>

#include <signal.h>

#include "cert-common.h"

#include "utils.h"

static void terminate(void);

/* This program tests that the server does not send the

 * status request extension if no status response exists. That

 * is to provide compatibility with gnutls 3.3.x which requires

 * that behavior.

 */

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);

}

#define SKIP16(pos, total) { \

	uint16_t _s; \

	if (pos+2 > total) fail("error\n"); \

	_s = (msg->data[pos] << 8) | msg->data[pos+1]; \

	if ((size_t)(pos+2+_s) > total) fail("error\n"); \

	pos += 2+_s; \

	}

#define SKIP8(pos, total) { \

	uint8_t _s; \

	if (pos+1 > total) fail("error\n"); \

	_s = msg->data[pos]; \

	if ((size_t)(pos+1+_s) > total) fail("error\n"); \

	pos += 1+_s; \

	}

#define TLS_EXT_STATUS_REQUEST 5

#define HANDSHAKE_SESSION_ID_POS 34

/* This returns either the application-specific ID extension contents,

 * or the session ID contents. The former is used on the new protocol,

 * while the latter on the legacy protocol.

 *

 * Extension ID: 48018

 * opaque ApplicationID<1..2^8-1>;

 *

 * struct {

 *          ExtensionType extension_type;

 *          opaque extension_data<0..2^16-1>;

 *      } Extension;

 *

 *      struct {

 *          ProtocolVersion server_version;

 *          Random random;

 *          SessionID session_id;

 *          CipherSuite cipher_suite;

 *          CompressionMethod compression_method;

 *          Extension server_hello_extension_list<0..2^16-1>;

 *      } ServerHello;

 */

static int handshake_callback(gnutls_session_t session, unsigned int htype,

	unsigned post, unsigned int incoming, const gnutls_datum_t *msg)

{

	size_t pos = 0;

	/* A client hello packet. We can get the session ID and figure

	 * the associated connection. */

	if (msg->size < HANDSHAKE_SESSION_ID_POS+GNUTLS_MAX_SESSION_ID+2) {

		fail("invalid client hello\n");

	}

	/* try to read the extension data */

	pos = HANDSHAKE_SESSION_ID_POS;

	/* session id */

	SKIP8(pos, msg->size);

	/* CipherSuite */

	pos+=2;

	/* CompressionMethod */

	SKIP8(pos, msg->size);

	if (pos+2 > msg->size)

		fail("invalid client hello\n");

	pos+=2;

	/* Extension(s) */

	while (pos < msg->size) {

		uint16_t type;

		if (pos+4 > msg->size)

			fail("invalid client hello\n");

		type = (msg->data[pos] << 8) | msg->data[pos+1];

		pos+=2;

		if (type != TLS_EXT_STATUS_REQUEST) {

			SKIP16(pos, msg->size);

		} else { /* found */

			fail("found extension, although no status response\n");

			break;

		}

	}

	return 0;

}

#define MAX_BUF 1024

static void client(int fd)

{

	int ret;

	gnutls_certificate_credentials_t x509_cred;

	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(7);

	}

	gnutls_certificate_allocate_credentials(&x509_cred);

	/* Initialize TLS session

	 */

	gnutls_init(&session, GNUTLS_CLIENT);

	/* Use default priorities */

	gnutls_priority_set_direct(session, "NORMAL:-KX-ALL:+ECDHE-RSA", NULL);

	/* 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 == GNUTLS_E_UNSUPPORTED_SIGNATURE_ALGORITHM) {

		/* success */

		goto end;

	}

	if (ret < 0) {

		fail("client: Handshake failed: %s\n", gnutls_strerror(ret));

		terminate();

	} 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_bye(session, GNUTLS_SHUT_WR);

      end:

	close(fd);

	gnutls_deinit(session);

	gnutls_certificate_free_credentials(x509_cred);

	gnutls_global_deinit();

}

/* These are global */

pid_t child;

static void terminate(void)

{

	kill(child, SIGTERM);

	exit(1);

}

static void server(int fd)

{

	int ret;

	char buffer[MAX_BUF + 1];

	gnutls_session_t session;

	gnutls_certificate_credentials_t x509_cred;

	/* this must be called once in the program

	 */

	global_init();

	memset(buffer, 0, sizeof(buffer));

	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);

	gnutls_init(&session, GNUTLS_SERVER);

	gnutls_handshake_set_hook_function(session, GNUTLS_HANDSHAKE_SERVER_HELLO,

					   GNUTLS_HOOK_POST,

					   handshake_callback);

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

	 * are adequate.

	 */

	gnutls_priority_set_direct(session, "NORMAL", NULL);

	gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);

	gnutls_transport_set_int(session, fd);

	do {

		ret = gnutls_handshake(session);

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

	if (ret < 0) {

		/* failure is expected here */

		goto end;

	}

	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)));

	/* do not wait for the peer to close the connection.

	 */

	gnutls_bye(session, GNUTLS_SHUT_WR);

 end:

	close(fd);

	gnutls_deinit(session);

	gnutls_certificate_free_credentials(x509_cred);

	gnutls_global_deinit();

	if (debug)

		success("server: finished\n");

}

static void ch_handler(int sig)

{

	return;

}

void doit(void)

{

	int fd[2];

	int ret, status = 0;

	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]);

		server(fd[0]);

		waitpid(child, &status, 0);

		check_wait_status(status);

	} else {

		close(fd[0]);

		client(fd[1]);

		exit(0);

	}

}

#endif				/* _WIN32 */