/*
 * Copyright (C) 2008-2012 Free Software Foundation, 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
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <gnutls/gnutls.h>
#include <gnutls/dtls.h>
#include <gnutls/crypto.h>
#include "utils.h"
#define RANDOMIZE
#define IGNORE_PUSH
#include "eagain-common.h"

const char *side = "";

static void tls_log_func(int level, const char *str)
{
	fprintf(stderr, "%s|<%d>| %s", side, level, str);
}

static int handshake = 0;

#define MAX_BUF 1024
#define MSG "Hello TLS, and hi and how are you and more data here... and more... and even more and even more more data..."

static ssize_t
client_push_300(gnutls_transport_ptr_t tr, const void *data, size_t len)
{
	size_t newlen;

	if (len > 300) {
		gnutls_transport_set_errno((gnutls_session_t) tr,
					   EMSGSIZE);
		return -1;
	}

	len = min(len, sizeof(to_server) - to_server_len);

	newlen = to_server_len + len;
	memcpy(to_server + to_server_len, data, len);
	to_server_len = newlen;
#ifdef EAGAIN_DEBUG
	fprintf(stderr, "eagain: pushed %d bytes to server (avail: %d)\n",
		(int) len, (int) to_server_len);
#endif
	return len;
}

static ssize_t
server_push_300(gnutls_transport_ptr_t tr, const void *data, size_t len)
{
	size_t newlen;

	if (len > 300) {
		gnutls_transport_set_errno((gnutls_session_t) tr,
					   EMSGSIZE);
		return -1;
	}

	len = min(len, sizeof(to_client) - to_client_len);

	newlen = to_client_len + len;
	memcpy(to_client + to_client_len, data, len);
	to_client_len = newlen;
#ifdef EAGAIN_DEBUG
	fprintf(stderr, "eagain: pushed %d bytes to client (avail: %d)\n",
		(int) len, (int) to_client_len);
#endif

	return len;
}

void doit(void)
{
	/* Server stuff. */
	gnutls_anon_server_credentials_t s_anoncred;
	const gnutls_datum_t p3 = { (void *) pkcs3, strlen(pkcs3) };
	static gnutls_dh_params_t dh_params;
	gnutls_session_t server;
	int sret, cret;
	/* Client stuff. */
	gnutls_anon_client_credentials_t c_anoncred;
	gnutls_session_t client;
	/* Need to enable anonymous KX specifically. */
	char buffer[MAX_BUF + 1];
	int ret, transferred = 0, msglen;

	/* General init. */
	global_init();
	gnutls_global_set_log_function(tls_log_func);
	if (debug)
		gnutls_global_set_log_level(99);

	/* Init server */
	gnutls_anon_allocate_server_credentials(&s_anoncred);
	gnutls_dh_params_init(&dh_params);
	gnutls_dh_params_import_pkcs3(dh_params, &p3, GNUTLS_X509_FMT_PEM);
	gnutls_anon_set_server_dh_params(s_anoncred, dh_params);
	gnutls_init(&server,
		    GNUTLS_SERVER | GNUTLS_DATAGRAM | GNUTLS_NONBLOCK);
	ret =
	    gnutls_priority_set_direct(server,
					"NONE:+VERS-DTLS1.2:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-DH",
					NULL);
	if (ret < 0)
		exit(1);
	gnutls_credentials_set(server, GNUTLS_CRD_ANON, s_anoncred);
	gnutls_transport_set_push_function(server, server_push_300);
	gnutls_transport_set_pull_function(server, server_pull);
	gnutls_transport_set_pull_timeout_function(server,
						   server_pull_timeout_func);
	gnutls_transport_set_ptr(server, server);

	/* Init client */
	gnutls_anon_allocate_client_credentials(&c_anoncred);
	gnutls_init(&client,
		    GNUTLS_CLIENT | GNUTLS_DATAGRAM | GNUTLS_NONBLOCK);
	cret =
	    gnutls_priority_set_direct(client,
					"NONE:+VERS-DTLS1.2:+CIPHER-ALL:+MAC-ALL:+SIGN-ALL:+COMP-ALL:+ANON-DH",
					NULL);
	if (cret < 0)
		exit(1);
	gnutls_credentials_set(client, GNUTLS_CRD_ANON, c_anoncred);
	gnutls_transport_set_push_function(client, client_push_300);
	gnutls_transport_set_pull_function(client, client_pull);
	gnutls_transport_set_pull_timeout_function(client,
						   client_pull_timeout_func);
	gnutls_transport_set_ptr(client, client);

	handshake = 1;
	HANDSHAKE_DTLS(client, server);

	if (gnutls_protocol_get_version(client) != GNUTLS_DTLS1_2) {
		fail("Error in negotiated version\n");
		exit(1);
	}

	handshake = 0;
	if (debug)
		success("Handshake established\n");

	do {
		ret = gnutls_record_send(client, MSG, strlen(MSG));
	}
	while (ret == GNUTLS_E_AGAIN);

	msglen = strlen(MSG);
	TRANSFER(client, server, MSG, msglen, buffer, MAX_BUF);

	if (debug)
		fputs("\n", stdout);

	gnutls_bye(client, GNUTLS_SHUT_WR);
	gnutls_bye(server, GNUTLS_SHUT_WR);

	gnutls_deinit(client);
	gnutls_deinit(server);

	gnutls_anon_free_client_credentials(c_anoncred);
	gnutls_anon_free_server_credentials(s_anoncred);

	gnutls_dh_params_deinit(dh_params);

	gnutls_global_deinit();
}