/*

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

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

 * Copyright (C) 2016 Red Hat, Inc.

 *

 * Author: Simon Josefsson, 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)

/* 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 <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 "utils.h"

#include "cert-common.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;

	int first_no_ext_master;

	int second_no_ext_master;

	int try_alpn;

	int try_resumed_data;

	int try_diff_sni;

	int try_sni;

};

pid_t child;

struct params_res resume_tests[] = {

	{.desc = "try to resume from db",

	 .enable_db = 1,

	 .enable_session_ticket_server = 0,

	 .enable_session_ticket_client = 0,

	 .expect_resume = 1},

	{.desc = "try to resume from db using resumed session's data",

	 .enable_db = 1,

	 .enable_session_ticket_server = 0,

	 .enable_session_ticket_client = 0,

	 .try_resumed_data = 1,

	 .expect_resume = 1},

	{.desc = "try to resume from db and check ALPN",

	 .enable_db = 1,

	 .enable_session_ticket_server = 0,

	 .enable_session_ticket_client = 0,

	 .try_alpn = 1,

	 .expect_resume = 1},

	{.desc = "try to resume from db (ext master secret -> none)",

	 .enable_db = 1,

	 .enable_session_ticket_server = 0,

	 .enable_session_ticket_client = 0,

	 .expect_resume = 0,

	 .first_no_ext_master = 0,

	 .second_no_ext_master = 1},

	{.desc = "try to resume from db (none -> ext master secret)",

	 .enable_db = 1,

	 .enable_session_ticket_server = 0,

	 .enable_session_ticket_client = 0,

	 .expect_resume = 0,

	 .first_no_ext_master = 1,

	 .second_no_ext_master = 0},

	{.desc = "try to resume from session ticket", 

	 .enable_db = 0, 

	 .enable_session_ticket_server = 1,

	 .enable_session_ticket_client = 1,

	 .expect_resume = 1},

	{.desc = "try to resume from session ticket using resumed session's data", 

	 .enable_db = 0, 

	 .enable_session_ticket_server = 1,

	 .enable_session_ticket_client = 1,

	 .try_resumed_data = 1,

	 .expect_resume = 1},

	{.desc = "try to resume from session ticket (ext master secret -> none)", 

	 .enable_db = 0, 

	 .enable_session_ticket_server = 1,

	 .enable_session_ticket_client = 1,

	 .expect_resume = 0,

	 .first_no_ext_master = 0,

	 .second_no_ext_master = 1},

	{.desc = "try to resume from session ticket (none -> ext master secret)", 

	 .enable_db = 0, 

	 .enable_session_ticket_server = 1,

	 .enable_session_ticket_client = 1,

	 .expect_resume = 0,

	 .first_no_ext_master = 1,

	 .second_no_ext_master = 0},

	{.desc = "try to resume from session ticket (server only)",

	  .enable_db = 0,

	  .enable_session_ticket_server = 1,

	  .enable_session_ticket_client = 0,

	  .expect_resume = 0},

	{.desc = "try to resume from session ticket (client only)",

	 .enable_db = 0,

	 .enable_session_ticket_server = 0,

	 .enable_session_ticket_client = 1,

	 .expect_resume = 0},

	{.desc = "try to resume from db and ticket",

	 .enable_db = 1,

	 .enable_session_ticket_server = 1,

	 .enable_session_ticket_client = 1,

	 .expect_resume = 1},

	{.desc = "try to resume from db and different SNI",

	 .enable_db = 1,

	 .try_sni = 1,

	 .try_diff_sni = 1,

	 .expect_resume = 0},

	{.desc = "try to resume with ticket and different SNI",

	 .enable_session_ticket_server = 1,

	 .enable_session_ticket_client = 1,

	 .try_sni = 1,

	 .try_diff_sni = 1,

	 .expect_resume = 0},

	{.desc = "try to resume from db and same SNI",

	 .enable_db = 1,

	 .try_sni = 1,

	 .expect_resume = 1},

	{.desc = "try to resume with ticket and same SNI",

	 .enable_session_ticket_server = 1,

	 .enable_session_ticket_client = 1,

	 .try_sni = 1,

	 .expect_resume = 1},

	{NULL, -1}

};

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

 */

#define SESSIONS 3

#define MAX_BUF 5*1024

#define MSG "Hello TLS"

#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 hsk_hook_cb(gnutls_session_t session, unsigned int htype, unsigned post,

			unsigned int incoming, const gnutls_datum_t *_msg)

{

	unsigned size;

	gnutls_datum_t msg = {_msg->data, _msg->size};

	/* skip up to session ID */

	if (msg.size <= HANDSHAKE_SESSION_ID_POS+6) {

		fail("Cannot parse server hello\n");

		return -1;

	}

	msg.data += HANDSHAKE_SESSION_ID_POS;

	msg.size -= HANDSHAKE_SESSION_ID_POS;

	size = msg.data[0];

	if (msg.size <= size) {

		fail("Cannot parse server hello 2\n");

		return -1;

	}

	msg.data += size;

	msg.size -= size;

	if (memmem(msg.data, msg.size, "\x00\x17\x00\x00", 4) == 0) {

		fail("Extended master secret extension was not found in resumed session hello\n");

		exit(1);

	}

	return 0;

}

static void append_alpn(gnutls_session_t session, struct params_res *params, unsigned alpn_counter)

{

	gnutls_datum_t protocol;

	int ret;

	char str[64];

	if (!params->try_alpn)

		return;

	snprintf(str, sizeof(str), "myproto-%d", alpn_counter);

	protocol.data = (void*)str;

	protocol.size = strlen(str);

	ret = gnutls_alpn_set_protocols(session, &protocol, 1, 0);

	if (ret < 0) {

		gnutls_perror(ret);

		exit(1);

	}

}

static void verify_alpn(gnutls_session_t session, struct params_res *params, unsigned alpn_counter)

{

	int ret;

	gnutls_datum_t selected;

	char str[64];

	if (!params->try_alpn)

		return;

	snprintf(str, sizeof(str), "myproto-%d", alpn_counter);

	ret = gnutls_alpn_get_selected_protocol(session, &selected);

	if (ret < 0) {

		gnutls_perror(ret);

		exit(1);

	}

	if (strlen(str) != selected.size || memcmp(str, selected.data, selected.size) != 0) {

		fail("expected protocol %s, got %.*s\n", str, selected.size, selected.data);

		exit(1);

	}

	if (debug)

		success("ALPN got: %s\n", str);

}

static void verify_group(gnutls_session_t session, gnutls_group_t *group, unsigned counter)

{

	int ret;

	if (counter == 0) {

		*group = gnutls_group_get(session);

		return;

	}

	if (gnutls_group_get(session) != *group) {

		fail("expected group %s, got group %s\n", gnutls_group_get_name(*group),

		     gnutls_group_get_name(gnutls_group_get(session)));

	}

}

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

{

	int ret, ii;

	gnutls_session_t session;

	char buffer[MAX_BUF + 1];

	unsigned int ext_master_secret_check = 0;

	gnutls_group_t pgroup;

	char prio_str[256];

	const char *dns_name1 = "example.com";

	const char *dns_name2 = "www.example.com";

#ifdef USE_PSK

# define PRIO_STR "NONE:+VERS-TLS-ALL:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+PSK:+CURVE-ALL"

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

	gnutls_psk_client_credentials_t pskcred;

#elif defined(USE_ANON)

# define PRIO_STR "NONE:+VERS-TLS-ALL:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-ECDH:+ANON-DH:+CURVE-ALL"

	gnutls_anon_client_credentials_t anoncred;

#elif defined(USE_X509)

# define PRIO_STR "NONE:+VERS-TLS-ALL:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ECDHE-RSA:+RSA:+CURVE-ALL"

	gnutls_certificate_credentials_t clientx509cred;

#endif

	/* Need to enable anonymous KX specifically. */

	/* 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(2);

	}

	global_init();

#ifdef USE_PSK

	gnutls_psk_allocate_client_credentials(&pskcred);

	gnutls_psk_set_client_credentials(pskcred, "test", &pskkey, GNUTLS_PSK_KEY_HEX);

#elif defined(USE_ANON)

	gnutls_anon_allocate_client_credentials(&anoncred);

#elif defined(USE_X509)

	gnutls_certificate_allocate_credentials(&clientx509cred);

#endif

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

		int sd = sds[t];

		/* Initialize TLS session

		 */

		gnutls_init(&session, GNUTLS_CLIENT);

		snprintf(prio_str, sizeof(prio_str), "%s", PRIO_STR);

		/* Use default priorities */

		if (params->enable_session_ticket_client == 0) {

			strcat(prio_str, ":%NO_TICKETS");

		}

		if (params->first_no_ext_master && t == 0) {

			strcat(prio_str, ":%NO_SESSION_HASH");

			ext_master_secret_check = 0;

		}

		if (params->second_no_ext_master && t > 0) {

			strcat(prio_str, ":%NO_SESSION_HASH");

			ext_master_secret_check = 0;

		}

		append_alpn(session, params, t);

		ret = gnutls_priority_set_direct(session, prio_str, NULL);

		if (ret < 0) {

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

		}

		/* put the anonymous credentials to the current session

		 */

#ifdef USE_PSK

		gnutls_credentials_set(session, GNUTLS_CRD_PSK, pskcred);

#elif defined(USE_ANON)

		gnutls_credentials_set(session, GNUTLS_CRD_ANON, anoncred);

#elif defined(USE_X509)

		gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, clientx509cred);

#endif

		if (t > 0) {

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

			gnutls_session_set_data(session, session_data.data,

						session_data.size);

			if (params->try_diff_sni)

				gnutls_server_name_set(session, GNUTLS_NAME_DNS, dns_name1, strlen(dns_name1));

			else if (params->try_sni)

				gnutls_server_name_set(session, GNUTLS_NAME_DNS, dns_name2, strlen(dns_name2));

		} else {

			if (params->try_sni)

				gnutls_server_name_set(session, GNUTLS_NAME_DNS, dns_name2, strlen(dns_name2));

		}

		if (ext_master_secret_check)

			gnutls_handshake_set_hook_function(session, GNUTLS_HANDSHAKE_SERVER_HELLO, GNUTLS_HOOK_PRE, hsk_hook_cb);

		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);

			goto end;

		} else {

			if (debug)

				success

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

		}

		ext_master_secret_check = 0;

		if (t == 0) {

			ext_master_secret_check =  gnutls_session_ext_master_secret_status(session);

			/* 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 */

			if (params->try_resumed_data) {

				gnutls_free(session_data.data);

				ret =

				    gnutls_session_get_data2(session,

							     &session_data);

				if (ret < 0)

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

			}

			/* 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 but NOT expected\n");

			} else {

				if (params->expect_resume) {

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

				} else {

					if (debug)

						success

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

				}

			}

		}

		verify_alpn(session, params, t);

		verify_group(session, &pgroup, t);

		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);

	}

	gnutls_free(session_data.data);

      end:

#ifdef USE_PSK

	gnutls_psk_free_client_credentials(pskcred);

#elif defined(USE_ANON)

	gnutls_anon_free_client_credentials(anoncred);

#elif defined(USE_X509)

	gnutls_certificate_free_credentials(clientx509cred);

#endif

}

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

 */

#define DH_BITS 1024

/* These are global */

static gnutls_datum_t session_ticket_key = { NULL, 0 };

static gnutls_session_t initialize_tls_session(struct params_res *params)

{

	gnutls_session_t session;

	gnutls_init(&session, GNUTLS_SERVER);

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

	 * are adequate.

	 */

	gnutls_priority_set_direct(session,

				   PRIO_STR,

				   NULL);

	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);

	return session;

}

static gnutls_dh_params_t dh_params;

#ifdef USE_PSK

gnutls_psk_server_credentials_t pskcred;

#elif defined(USE_ANON)

gnutls_anon_server_credentials_t anoncred;

#elif defined(USE_X509)

gnutls_certificate_credentials_t serverx509cred;

#endif

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 global_stop(void)

{

	if (debug)

		success("global stop\n");

#ifdef USE_PSK

	gnutls_psk_free_server_credentials(pskcred);

#elif defined(USE_ANON)

	gnutls_anon_free_server_credentials(anoncred);

#elif defined(USE_X509)

	gnutls_certificate_free_credentials(serverx509cred);

#endif

	gnutls_dh_params_deinit(dh_params);

	gnutls_global_deinit();

}

#ifdef USE_PSK

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;

}

#endif

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

{

	size_t t;

	int ret;

	gnutls_session_t session;

	char buffer[MAX_BUF + 1];

	gnutls_group_t pgroup;

	/* 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(2);

	}

	global_init();

#ifdef USE_PSK

	gnutls_psk_allocate_server_credentials(&pskcred);

	gnutls_psk_set_server_credentials_function(pskcred, pskfunc);

#elif defined(USE_ANON)

	gnutls_anon_allocate_server_credentials(&anoncred);

#elif defined(USE_X509)

	gnutls_certificate_allocate_credentials(&serverx509cred);

	gnutls_certificate_set_x509_key_mem(serverx509cred,

		&server_cert, &server_key, GNUTLS_X509_FMT_PEM);

#endif

	if (debug)

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

	generate_dh_params();

#if USE_ANON

	gnutls_anon_set_server_dh_params(anoncred, dh_params);

#endif

	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];

		session = initialize_tls_session(params);

		append_alpn(session, params, t);

#ifdef USE_PSK

		gnutls_credentials_set(session, GNUTLS_CRD_PSK, pskcred);

#elif defined(USE_ANON)

		gnutls_credentials_set(session, GNUTLS_CRD_ANON, anoncred);

#elif defined(USE_X509)

		gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, serverx509cred);

#endif

		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");

		verify_alpn(session, params, t);

		verify_group(session, &pgroup, 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);

	}

	if (params->enable_db) {

		wrap_db_deinit();

	}

	gnutls_free(session_ticket_key.data);

	session_ticket_key.data = NULL;

	if (debug)

		success("server: finished\n");

}

void doit(void)

{

	int i, err;

	signal(SIGCHLD, SIG_IGN);

	signal(SIGPIPE, SIG_IGN);

	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]);

			waitpid(child, &status, 0);

			check_wait_status(status);

			global_stop();

		} else {

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

				close(server_sds[j]);

			client(client_sds, &resume_tests[i]);

			gnutls_global_deinit();

			exit(0);

		}

	}

}

/* 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)

{

	time_t t, now = time(0);

#ifdef DEBUG_CACHE

	if (debug) {

		unsigned int i;

		fprintf(stderr, "resume db storing (%d-%d): ", key.size,

			data.size);

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

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

		}

		fprintf(stderr, "\n");

		fprintf(stderr, "data: ");

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

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

		}

		fprintf(stderr, "\n");

	}

#endif

	/* check the correctness of gnutls_db_check_entry_time() */

	t = gnutls_db_check_entry_time(&data);

	if (t < now - 10 || t > now + 10) {

		fail("Time returned by gnutls_db_check_entry_time is bogus\n");

		exit(1);

	}

	if (cache_db == NULL)

		return -1;

	if (key.size > MAX_SESSION_ID_SIZE) {

		fail("Key size is too large\n");

		return -1;

	}

	if (data.size > MAX_SESSION_DATA_SIZE) {

		fail("Data size is too large\n");

		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) {

		fprintf(stderr, "resume db looking for (%d): ", key.size);

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

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

		}

		fprintf(stderr, "\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);