/*

 * Copyright (C) 2004-2016 Free Software Foundation, Inc.

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

 * Copyright (C) 2016-2019 Red Hat, Inc.

 *

 * Author: Simon Josefsson, Nikos Mavrogiannopoulos, Daiki Ueno

 *

 * 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/>

 */

/* 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

#ifndef _GNU_SOURCE

# define _GNU_SOURCE

#endif

#include <string.h>

#include <stdint.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 <sys/wait.h>

#include <signal.h>

#include <assert.h>

#include "utils.h"

#include "cert-common.h"

#include "virt-time.h"

#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; \

	}

pid_t child;

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

 */

#define SESSIONS 2

#define MAX_BUF 5*1024

#define MSG "Hello TLS"

/* 2^13, which is not supported by max_fragment_length */

#define MAX_DATA_SIZE 8192

#define HANDSHAKE_SESSION_ID_POS (2+32)

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

{

	fprintf(stderr, "%s |<%d>| %s", child ? "server" : "client", level,

		str);

}

static int ext_callback(void *ctx, unsigned tls_id, const unsigned char *data, unsigned size)

{

	if (tls_id == 28) { /* record size limit */

		uint16_t max_data_size;

		assert(size == 2);

		max_data_size = (data[0] << 8) | data[1];

		if (max_data_size == MAX_DATA_SIZE)

			fail("record_size_limit is not reset: %u == %u\n",

			     max_data_size, MAX_DATA_SIZE);

	}

	return 0;

}

static int handshake_callback(gnutls_session_t session, unsigned int htype,

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

{

	int ret;

	unsigned pos;

	gnutls_datum_t mmsg;

	if (!post)

		return 0;

	switch (htype) {

	case GNUTLS_HANDSHAKE_ENCRYPTED_EXTENSIONS:

		ret = gnutls_ext_raw_parse(NULL, ext_callback, msg, 0);

		assert(ret >= 0);

		break;

	case GNUTLS_HANDSHAKE_SERVER_HELLO:

		assert(msg->size >= HANDSHAKE_SESSION_ID_POS);

		pos = HANDSHAKE_SESSION_ID_POS;

		SKIP8(pos, msg->size);

		pos += 3;

		mmsg.data = &msg->data[pos];

		mmsg.size = msg->size - pos;

		ret = gnutls_ext_raw_parse(NULL, ext_callback, &mmsg, 0);

		assert(ret >= 0);

		break;

	default:

		break;

	}

	return 0;

}

static void client(int sds[], const char *prio)

{

	int ret, ii;

	gnutls_session_t session;

	char buffer[MAX_BUF + 1];

	gnutls_certificate_credentials_t clientx509cred;

	/* variables used in session resuming

	 */

	int t;

	gnutls_datum_t session_data = {NULL, 0};

	if (debug) {

		gnutls_global_set_log_function(tls_log_func);

		gnutls_global_set_log_level(4);

	}

	gnutls_certificate_allocate_credentials(&clientx509cred);

	assert(gnutls_certificate_set_x509_key_mem(clientx509cred,

						   &cli_cert, &cli_key,

						   GNUTLS_X509_FMT_PEM) >= 0);

	for (t = 0; t < SESSIONS; t++) {

		int sd = sds[t];

		assert(gnutls_init(&session, GNUTLS_CLIENT)>=0);

		ret = gnutls_priority_set_direct(session, prio, NULL);

		if (ret < 0) {

			fail("prio: %s\n", gnutls_strerror(ret));

		}

		gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, clientx509cred);

		if (t == 0) {

			ret = gnutls_record_set_max_size(session, MAX_DATA_SIZE);

			if (ret < 0)

				fail("gnutls_set_max_size: %s\n", gnutls_strerror(ret));

		}

		if (t > 0) {

			/* if this is not the first time we connect */

			gnutls_session_set_data(session, session_data.data,

						session_data.size);

			gnutls_handshake_set_hook_function(session,

							   GNUTLS_HANDSHAKE_ANY,

							   GNUTLS_HOOK_POST,

							   handshake_callback);

		}

		gnutls_transport_set_int(session, sd);

		/* Perform the TLS handshake

		 */

		gnutls_handshake_set_timeout(session, 20 * 1000);

		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);

			break;

		} else {

			if (debug)

				success

				    ("client: Handshake was completed\n");

		}

		if (t == 0) {

			/* get the session data size */

			ret =

			    gnutls_session_get_data2(session,

						     &session_data);

			if (ret < 0)

				fail("Getting resume data failed\n");

		} else {	/* the second time we connect */

			/* check if we actually resumed the previous session */

			if (gnutls_session_is_resumed(session) == 0) {

				fail("- Previous session was resumed but NOT expected\n");

			}

		}

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

		do {

			ret = gnutls_record_recv(session, buffer, MAX_BUF);

		} while (ret == GNUTLS_E_AGAIN);

		if (ret == 0) {

			if (debug)

				success

				    ("client: Peer has closed the TLS connection\n");

			break;

		} else if (ret < 0) {

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

		}

		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);

		close(sd);

		gnutls_deinit(session);

	}

	gnutls_free(session_data.data);

	gnutls_certificate_free_credentials(clientx509cred);

}

/* These are global */

static gnutls_datum_t session_ticket_key = { NULL, 0 };

gnutls_certificate_credentials_t serverx509cred;

static void global_stop(void)

{

	if (debug)

		success("global stop\n");

	gnutls_certificate_free_credentials(serverx509cred);

}

static void server(int sds[], const char *prio)

{

	int t;

	int ret;

	gnutls_session_t session;

	char buffer[MAX_BUF + 1];

	unsigned iflags = GNUTLS_SERVER;

	virt_time_init();

	/* this must be called once in the program, it is mostly for the server.

	 */

	if (debug) {

		gnutls_global_set_log_function(tls_log_func);

		gnutls_global_set_log_level(4);

	}

	gnutls_certificate_allocate_credentials(&serverx509cred);

	assert(gnutls_certificate_set_x509_key_mem(serverx509cred,

		&server_cert, &server_key, GNUTLS_X509_FMT_PEM) >= 0);

	gnutls_session_ticket_key_generate(&session_ticket_key);

	for (t = 0; t < SESSIONS; t++) {

		int sd = sds[t];

		assert(gnutls_init(&session, iflags) >= 0);

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

		 * are adequate.

		 */

		assert(gnutls_priority_set_direct(session, prio, NULL) >= 0);

		gnutls_session_ticket_enable_server(session,

						    &session_ticket_key);

		gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, serverx509cred);

		gnutls_transport_set_int(session, sd);

		gnutls_handshake_set_timeout(session, 20 * 1000);

		do {

			ret = gnutls_handshake(session);

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

		if (ret < 0) {

			close(sd);

			gnutls_deinit(session);

			kill(child, SIGTERM);

			fail("server: Handshake has failed (%s)\n\n",

			     gnutls_strerror(ret));

			return;

		}

		if (debug)

			success("server: Handshake was completed\n");

		if (t > 0) {

			ret = gnutls_session_is_resumed(session);

			if (ret == 0) {

				fail("server: session_is_resumed error (%d)\n", t);

			}

		}

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

		/* print_info(session); */

		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) {

				kill(child, SIGTERM);

				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_free(session_ticket_key.data);

	session_ticket_key.data = NULL;

	if (debug)

		success("server: finished\n");

}

static void run(const char *prio)

{

	int client_sds[SESSIONS], server_sds[SESSIONS];

	int j;

	int err;

	signal(SIGCHLD, SIG_IGN);

	signal(SIGPIPE, SIG_IGN);

	for (j = 0; j < SESSIONS; j++) {

		int sockets[2];

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

		if (err == -1) {

			perror("socketpair");

			fail("socketpair failed\n");

			return;

		}

		server_sds[j] = sockets[0];

		client_sds[j] = sockets[1];

	}

	child = fork();

	if (child < 0) {

		perror("fork");

		fail("fork\n");

		return;

	}

	if (child) {

		int status = 0;

		/* parent */

		for (j = 0; j < SESSIONS; j++)

			close(client_sds[j]);

		server(server_sds, prio);

		waitpid(child, &status, 0);

		check_wait_status(status);

		global_stop();

	} else {

		for (j = 0; j < SESSIONS; j++)

			close(server_sds[j]);

		client(client_sds, prio);

		exit(0);

	}

}

void doit(void)

{

	run("NORMAL:-VERS-ALL:+VERS-TLS1.2");

	run("NORMAL:-VERS-ALL:+VERS-TLS1.3");

}

#endif				/* _WIN32 */