/*

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

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

 *

 * 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

 */

/* Parts copied from GnuTLS example programs. */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdio.h>

#include <stdlib.h>

#if defined(_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 <gnutls/dtls.h>

#include <sys/wait.h>

#include <signal.h>

#include "utils.h"

static void wrap_db_init(void);

static void wrap_db_deinit(void);

static int wrap_db_store(void *dbf, gnutls_datum_t key,

			 gnutls_datum_t data);

static gnutls_datum_t wrap_db_fetch(void *dbf, gnutls_datum_t key);

static int wrap_db_delete(void *dbf, gnutls_datum_t key);

#define TLS_SESSION_CACHE 50

struct params_res {

	const char *desc;

	int enable_db;

	int enable_session_ticket_server;

	int enable_session_ticket_client;

	int expect_resume;

};

pid_t child;

struct params_res resume_tests[] = {

	{"try to resume from db", 50, 0, 0, 1},

	{"try to resume from session ticket", 0, 1, 1, 1},

	{"try to resume from session ticket (server only)", 0, 1, 0, 0},

	{"try to resume from session ticket (client only)", 0, 0, 1, 0},

	{NULL, -1}

};

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

 */

#define SESSIONS 2

#define MAX_BUF 5*1024

#define MSG "Hello TLS"

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

{

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

		str);

}

static void client(int sds[], struct params_res *params)

{

	int ret, ii;

	gnutls_session_t session;

	char buffer[MAX_BUF + 1];

	gnutls_anon_client_credentials_t anoncred;

	/* Need to enable anonymous KX specifically. */

	/* variables used in session resuming

	 */

	int t;

	gnutls_datum_t session_data;

	if (debug) {

		gnutls_global_set_log_function(tls_log_func);

		gnutls_global_set_log_level(3);

	}

	global_init();

	gnutls_anon_allocate_client_credentials(&anoncred);

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

		int sd = sds[t];

		/* Initialize TLS session

		 */

		gnutls_init(&session,

			    GNUTLS_CLIENT | GNUTLS_DATAGRAM);

		/* Use default priorities */

		if (params->enable_session_ticket_client)

			gnutls_priority_set_direct(session,

					   "NONE:+VERS-DTLS1.0:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-DH",

					   NULL);

		else

			gnutls_priority_set_direct(session,

					   "NONE:+VERS-DTLS1.0:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-DH:%NO_TICKETS",

					   NULL);

		/* put the anonymous credentials to the current session

		 */

		gnutls_credentials_set(session, GNUTLS_CRD_ANON, anoncred);

		if (t > 0) {

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

			gnutls_session_set_data(session, session_data.data,

						session_data.size);

			gnutls_free(session_data.data);

		}

		gnutls_transport_set_int(session, sd);

		/* Perform the TLS handshake

		 */

		gnutls_dtls_set_timeouts(session, 3*1000, 240 * 1000);

		do {

			ret = gnutls_handshake(session);

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

		if (ret < 0) {

			gnutls_perror(ret);

			fail("client: Handshake failed\n");

			goto end;

		} else {

			if (debug)

				success

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

		}

		if (t == 0) {	/* the first time we connect */

			/* 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) {

				if (params->expect_resume) {

					if (debug)

						success

						    ("- Previous session was resumed\n");

				} else

					fail("- Previous session was resumed\n");

			} else {

				if (params->expect_resume) {

					fail("*** Previous session was NOT resumed\n");

				} else {

					if (debug)

						success

						    ("*** Previous session was NOT resumed (expected)\n");

				}

			}

		}

		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);

		close(sd);

		gnutls_deinit(session);

	}

      end:

	gnutls_anon_free_client_credentials(anoncred);

}

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

 */

#define DH_BITS 1024

/* These are global */

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 char buffer[MAX_BUF + 1];

static void global_stop(void)

{

	if (debug)

		success("global stop\n");

	gnutls_dh_params_deinit(dh_params);

	gnutls_global_deinit();

}

static void server(int sds[], struct params_res *params)

{

	gnutls_anon_server_credentials_t anoncred;

	static gnutls_datum_t session_ticket_key = { NULL, 0 };

	int ret;

	size_t t;

	gnutls_session_t session;

	/* 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(3);

	}

	global_init();

	gnutls_anon_allocate_server_credentials(&anoncred);

	if (debug)

		success("Launched, generating DH parameters...\n");

	gnutls_anon_set_server_dh_params(anoncred, dh_params);

	if (params->enable_db) {

		wrap_db_init();

	}

	if (params->enable_session_ticket_server)

		gnutls_session_ticket_key_generate(&session_ticket_key);

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

		int sd = sds[t];

		gnutls_init(&session, GNUTLS_SERVER | GNUTLS_DATAGRAM);

		gnutls_priority_set_direct(session,

				   "NONE:+VERS-DTLS1.0:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-DH",

				   NULL);

		gnutls_credentials_set(session, GNUTLS_CRD_ANON, anoncred);

		gnutls_dh_set_prime_bits(session, DH_BITS);

		if (params->enable_db) {

			gnutls_db_set_retrieve_function(session, wrap_db_fetch);

			gnutls_db_set_remove_function(session, wrap_db_delete);

			gnutls_db_set_store_function(session, wrap_db_store);

			gnutls_db_set_ptr(session, NULL);

		}

		if (params->enable_session_ticket_server)

			gnutls_session_ticket_enable_server(session,

						    &session_ticket_key);

		gnutls_transport_set_int(session, sd);

		gnutls_dtls_set_timeouts(session, 3*1000, 240 * 1000);

		do {

			ret = gnutls_handshake(session);

		} while (ret < 0 && (ret == GNUTLS_E_INTERRUPTED||ret == GNUTLS_E_AGAIN));

		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");

		/* 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);

	}

	if (params->enable_db) {

		wrap_db_deinit();

	}

	gnutls_free(session_ticket_key.data);

	gnutls_anon_free_server_credentials(anoncred);

	if (debug)

		success("server: finished\n");

}

void doit(void)

{

	int i, err;

	signal(SIGCHLD, SIG_IGN);

	signal(SIGPIPE, SIG_IGN);

	generate_dh_params();

	for (i = 0; resume_tests[i].desc; i++) {

		int client_sds[SESSIONS], server_sds[SESSIONS];

		int j;

		printf("%s\n", resume_tests[i].desc);

		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");

			return;

		}

		if (child) {

			int status = 0;

			/* parent */

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

				close(client_sds[j]);

			server(server_sds, &resume_tests[i]);

			wait(&status);

			check_wait_status(status);

		} else {

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

				close(server_sds[j]);

			client(client_sds, &resume_tests[i]);

			gnutls_global_deinit();

			exit(0);

		}

	}

	global_stop();

}

/* Functions and other stuff needed for session resuming.

 * This is done using a very simple list which holds session ids

 * and session data.

 */

#define MAX_SESSION_ID_SIZE 32

#define MAX_SESSION_DATA_SIZE 1024

typedef struct {

	unsigned char session_id[MAX_SESSION_ID_SIZE];

	unsigned int session_id_size;

	char session_data[MAX_SESSION_DATA_SIZE];

	int session_data_size;

} CACHE;

static CACHE *cache_db;

static int cache_db_ptr = 0;

static void wrap_db_init(void)

{

	/* allocate cache_db */

	cache_db = calloc(1, TLS_SESSION_CACHE * sizeof(CACHE));

}

static void wrap_db_deinit(void)

{

	free(cache_db);

	cache_db = NULL;

	return;

}

static int

wrap_db_store(void *dbf, gnutls_datum_t key, gnutls_datum_t data)

{

	if (debug)

		success("resume db storing... (%d-%d)\n", key.size,

			data.size);

	if (debug) {

		unsigned int i;

		printf("key:\n");

		for (i = 0; i < key.size; i++) {

			printf("%02x ", key.data[i] & 0xFF);

			if ((i + 1) % 16 == 0)

				printf("\n");

		}

		printf("\n");

		printf("data:\n");

		for (i = 0; i < data.size; i++) {

			printf("%02x ", data.data[i] & 0xFF);

			if ((i + 1) % 16 == 0)

				printf("\n");

		}

		printf("\n");

	}

	if (cache_db == NULL)

		return -1;

	if (key.size > MAX_SESSION_ID_SIZE)

		return -1;

	if (data.size > MAX_SESSION_DATA_SIZE)

		return -1;

	memcpy(cache_db[cache_db_ptr].session_id, key.data, key.size);

	cache_db[cache_db_ptr].session_id_size = key.size;

	memcpy(cache_db[cache_db_ptr].session_data, data.data, data.size);

	cache_db[cache_db_ptr].session_data_size = data.size;

	cache_db_ptr++;

	cache_db_ptr %= TLS_SESSION_CACHE;

	return 0;

}

static gnutls_datum_t wrap_db_fetch(void *dbf, gnutls_datum_t key)

{

	gnutls_datum_t res = { NULL, 0 };

	unsigned i;

	if (debug)

		success("resume db fetch... (%d)\n", key.size);

	if (debug) {

		printf("key:\n");

		for (i = 0; i < key.size; i++) {

			printf("%02x ", key.data[i] & 0xFF);

			if ((i + 1) % 16 == 0)

				printf("\n");

		}

		printf("\n");

	}

	if (cache_db == NULL)

		return res;

	for (i = 0; i < TLS_SESSION_CACHE; i++) {

		if (key.size == cache_db[i].session_id_size &&

		    memcmp(key.data, cache_db[i].session_id,

			   key.size) == 0) {

			if (debug)

				success

				    ("resume db fetch... return info\n");

			res.size = cache_db[i].session_data_size;

			res.data = gnutls_malloc(res.size);

			if (res.data == NULL)

				return res;

			memcpy(res.data, cache_db[i].session_data,

				res.size);

			if (debug) {

				unsigned j;

				printf("data:\n");

				for (j = 0; j < res.size; j++) {

					printf("%02x ",

						res.data[j] & 0xFF);

					if ((j + 1) % 16 == 0)

						printf("\n");

				}

				printf("\n");

			}

			return res;

		}

	}

	if (debug)

		success("resume db fetch... NOT FOUND\n");

	return res;

}

static int wrap_db_delete(void *dbf, gnutls_datum_t key)

{

	int i;

	if (cache_db == NULL)

		return -1;

	for (i = 0; i < TLS_SESSION_CACHE; i++) {

		if (key.size == cache_db[i].session_id_size &&

		    memcmp(key.data, cache_db[i].session_id,

			   key.size) == 0) {

			cache_db[i].session_id_size = 0;

			cache_db[i].session_data_size = 0;

			return 0;

		}

	}

	return -1;

}

#endif				/* _WIN32 */