/* $OpenBSD: s23_clnt.c,v 1.33 2014/10/18 16:13:16 jsing Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>

#include "ssl_locl.h"

#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/objects.h>

static const SSL_METHOD *ssl23_get_client_method(int ver);
static int ssl23_client_hello(SSL *s);
static int ssl23_get_server_hello(SSL *s);

const SSL_METHOD SSLv23_client_method_data = {
	.version = TLS1_2_VERSION,
	.ssl_new = tls1_new,
	.ssl_clear = tls1_clear,
	.ssl_free = tls1_free,
	.ssl_accept = ssl_undefined_function,
	.ssl_connect = ssl23_connect,
	.ssl_read = ssl23_read,
	.ssl_peek = ssl23_peek,
	.ssl_write = ssl23_write,
	.ssl_shutdown = ssl_undefined_function,
	.ssl_renegotiate = ssl_undefined_function,
	.ssl_renegotiate_check = ssl_ok,
	.ssl_get_message = ssl3_get_message,
	.ssl_read_bytes = ssl3_read_bytes,
	.ssl_write_bytes = ssl3_write_bytes,
	.ssl_dispatch_alert = ssl3_dispatch_alert,
	.ssl_ctrl = ssl3_ctrl,
	.ssl_ctx_ctrl = ssl3_ctx_ctrl,
	.ssl_pending = ssl_undefined_const_function,
	.num_ciphers = ssl3_num_ciphers,
	.get_cipher = ssl3_get_cipher,
	.get_ssl_method = ssl23_get_client_method,
	.get_timeout = ssl23_default_timeout,
	.ssl3_enc = &ssl3_undef_enc_method,
	.ssl_version = ssl_undefined_void_function,
	.ssl_callback_ctrl = ssl3_callback_ctrl,
	.ssl_ctx_callback_ctrl = ssl3_ctx_callback_ctrl,
};

const SSL_METHOD *
SSLv23_client_method(void)
{
	return &SSLv23_client_method_data;
}

static const SSL_METHOD *
ssl23_get_client_method(int ver)
{
	if (ver == SSL3_VERSION)
		return (SSLv3_client_method());
	if (ver == TLS1_VERSION)
		return (TLSv1_client_method());
	if (ver == TLS1_1_VERSION)
		return (TLSv1_1_client_method());
	if (ver == TLS1_2_VERSION)
		return (TLSv1_2_client_method());
	return (NULL);
}

int
ssl23_connect(SSL *s)
{
	BUF_MEM *buf = NULL;
	void (*cb)(const SSL *ssl, int type, int val) = NULL;
	int ret = -1;
	int new_state, state;

	ERR_clear_error();
	errno = 0;

	if (s->info_callback != NULL)
		cb = s->info_callback;
	else if (s->ctx->info_callback != NULL)
		cb = s->ctx->info_callback;

	s->in_handshake++;
	if (!SSL_in_init(s) || SSL_in_before(s))
		SSL_clear(s);

	for (;;) {
		state = s->state;

		switch (s->state) {
		case SSL_ST_BEFORE:
		case SSL_ST_CONNECT:
		case SSL_ST_BEFORE|SSL_ST_CONNECT:
		case SSL_ST_OK|SSL_ST_CONNECT:

			if (s->session != NULL) {
				SSLerr(SSL_F_SSL23_CONNECT, SSL_R_SSL23_DOING_SESSION_ID_REUSE);
				ret = -1;
				goto end;
			}
			s->server = 0;
			if (cb != NULL)
				cb(s, SSL_CB_HANDSHAKE_START, 1);

			/* s->version=TLS1_VERSION; */
			s->type = SSL_ST_CONNECT;

			if (s->init_buf == NULL) {
				if ((buf = BUF_MEM_new()) == NULL) {
					ret = -1;
					goto end;
				}
				if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
					ret = -1;
					goto end;
				}
				s->init_buf = buf;
				buf = NULL;
			}

			if (!ssl3_setup_buffers(s)) {
				ret = -1;
				goto end;
			}

			ssl3_init_finished_mac(s);

			s->state = SSL23_ST_CW_CLNT_HELLO_A;
			s->ctx->stats.sess_connect++;
			s->init_num = 0;
			break;

		case SSL23_ST_CW_CLNT_HELLO_A:
		case SSL23_ST_CW_CLNT_HELLO_B:

			s->shutdown = 0;
			ret = ssl23_client_hello(s);
			if (ret <= 0)
				goto end;
			s->state = SSL23_ST_CR_SRVR_HELLO_A;
			s->init_num = 0;

			break;

		case SSL23_ST_CR_SRVR_HELLO_A:
		case SSL23_ST_CR_SRVR_HELLO_B:
			ret = ssl23_get_server_hello(s);
			if (ret >= 0)
				cb = NULL;
			goto end;
			/* break; */

		default:
			SSLerr(SSL_F_SSL23_CONNECT, SSL_R_UNKNOWN_STATE);
			ret = -1;
			goto end;
			/* break; */
		}

		if (s->debug) {
			(void)BIO_flush(s->wbio);
		}

		if ((cb != NULL) && (s->state != state)) {
			new_state = s->state;
			s->state = state;
			cb(s, SSL_CB_CONNECT_LOOP, 1);
			s->state = new_state;
		}
	}
end:
	s->in_handshake--;
	if (buf != NULL)
		BUF_MEM_free(buf);
	if (cb != NULL)
		cb(s, SSL_CB_CONNECT_EXIT, ret);
	return (ret);
}

static int
ssl23_client_hello(SSL *s)
{
	unsigned char *buf;
	unsigned char *p, *d;
	int i;
	unsigned long l;
	int version = 0, version_major, version_minor;
	int ret;
	unsigned long mask, options = s->options;

	/*
	 * SSL_OP_NO_X disables all protocols above X *if* there are
	 * some protocols below X enabled. This is required in order
	 * to maintain "version capability" vector contiguous. So
	 * that if application wants to disable TLS1.0 in favour of
	 * TLS1>=1, it would be insufficient to pass SSL_NO_TLSv1, the
	 * answer is SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2.
	 */
	mask = SSL_OP_NO_TLSv1_1|SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3;
	version = TLS1_2_VERSION;

	if ((options & SSL_OP_NO_TLSv1_2) && (options & mask) != mask)
		version = TLS1_1_VERSION;
	mask &= ~SSL_OP_NO_TLSv1_1;
	if ((options & SSL_OP_NO_TLSv1_1) && (options & mask) != mask)
		version = TLS1_VERSION;
	mask &= ~SSL_OP_NO_TLSv1;
	if ((options & SSL_OP_NO_TLSv1) && (options & mask) != mask)
		version = SSL3_VERSION;
	mask &= ~SSL_OP_NO_SSLv3;

	buf = (unsigned char *)s->init_buf->data;
	if (s->state == SSL23_ST_CW_CLNT_HELLO_A) {
		arc4random_buf(s->s3->client_random, SSL3_RANDOM_SIZE);

		if (version == TLS1_2_VERSION) {
			version_major = TLS1_2_VERSION_MAJOR;
			version_minor = TLS1_2_VERSION_MINOR;
		} else if (version == TLS1_1_VERSION) {
			version_major = TLS1_1_VERSION_MAJOR;
			version_minor = TLS1_1_VERSION_MINOR;
		} else if (version == TLS1_VERSION) {
			version_major = TLS1_VERSION_MAJOR;
			version_minor = TLS1_VERSION_MINOR;
		} else if (version == SSL3_VERSION) {
			version_major = SSL3_VERSION_MAJOR;
			version_minor = SSL3_VERSION_MINOR;
		} else {
			SSLerr(SSL_F_SSL23_CLIENT_HELLO, SSL_R_NO_PROTOCOLS_AVAILABLE);
			return (-1);
		}

		s->client_version = version;

		/* create Client Hello in SSL 3.0/TLS 1.0 format */

		/*
		 * Do the record header (5 bytes) and handshake
		 * message header (4 bytes) last
		 */
		d = p = &(buf[9]);

		*(p++) = version_major;
		*(p++) = version_minor;

		/* Random stuff */
		memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
		p += SSL3_RANDOM_SIZE;

		/* Session ID (zero since there is no reuse) */
		*(p++) = 0;

		/* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
		i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &p[2]);
		if (i == 0) {
			SSLerr(SSL_F_SSL23_CLIENT_HELLO,
			    SSL_R_NO_CIPHERS_AVAILABLE);
			return -1;
		}
#ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
		/*
		 * Some servers hang if client hello > 256 bytes
		 * as hack workaround chop number of supported ciphers
		 * to keep it well below this if we use TLS v1.2
		 */
		if (TLS1_get_version(s) >= TLS1_2_VERSION &&
		    i > OPENSSL_MAX_TLS1_2_CIPHER_LENGTH)
			i = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
#endif
		s2n(i, p);
		p += i;

		/* add in (no) COMPRESSION */
		*(p++) = 1;
		/* Add the NULL method */
		*(p++) = 0;

		/* TLS extensions*/
		if (ssl_prepare_clienthello_tlsext(s) <= 0) {
			SSLerr(SSL_F_SSL23_CLIENT_HELLO,
			    SSL_R_CLIENTHELLO_TLSEXT);
			return -1;
		}
		if ((p = ssl_add_clienthello_tlsext(s, p,
		    buf + SSL3_RT_MAX_PLAIN_LENGTH)) == NULL) {
			SSLerr(SSL_F_SSL23_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
			return -1;
		}

		l = p - d;

		/* fill in 4-byte handshake header */
		d = &(buf[5]);
		*(d++) = SSL3_MT_CLIENT_HELLO;
		l2n3(l, d);

		l += 4;

		if (l > SSL3_RT_MAX_PLAIN_LENGTH) {
			SSLerr(SSL_F_SSL23_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
			return -1;
		}

		/* fill in 5-byte record header */
		d = buf;
		*(d++) = SSL3_RT_HANDSHAKE;
		*(d++) = version_major;

		/*
		 * Some servers hang if we use long client hellos
		 * and a record number > TLS 1.0.
		 */
		if (TLS1_get_client_version(s) > TLS1_VERSION)
			*(d++) = 1;
		else
			*(d++) = version_minor;
		s2n((int)l, d);

		/* number of bytes to write */
		s->init_num = p - buf;
		s->init_off = 0;

		ssl3_finish_mac(s, &(buf[5]), s->init_num - 5);

		s->state = SSL23_ST_CW_CLNT_HELLO_B;
		s->init_off = 0;
	}

	/* SSL3_ST_CW_CLNT_HELLO_B */
	ret = ssl23_write_bytes(s);

	if ((ret >= 2) && s->msg_callback) {
		/* Client Hello has been sent; tell msg_callback */

		s->msg_callback(1, version, SSL3_RT_HANDSHAKE,
		    s->init_buf->data + 5, ret - 5, s, s->msg_callback_arg);
	}

	return ret;
}

static int
ssl23_get_server_hello(SSL *s)
{
	char buf[8];
	unsigned char *p;
	int i;
	int n;

	n = ssl23_read_bytes(s, 7);

	if (n != 7)
		return (n);
	p = s->packet;

	memcpy(buf, p, n);

	/* Old unsupported sslv2 handshake */
	if ((p[0] & 0x80) && (p[2] == SSL2_MT_SERVER_HELLO) &&
	    (p[5] == 0x00) && (p[6] == 0x02)) {
		SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,
		    SSL_R_UNSUPPORTED_PROTOCOL);
		goto err;
	}

	if (p[1] == SSL3_VERSION_MAJOR &&
	    p[2] <= TLS1_2_VERSION_MINOR &&
	    ((p[0] == SSL3_RT_HANDSHAKE && p[5] == SSL3_MT_SERVER_HELLO) ||
	    (p[0] == SSL3_RT_ALERT && p[3] == 0 && p[4] == 2))) {
		/* we have sslv3 or tls1 (server hello or alert) */

		if ((p[2] == SSL3_VERSION_MINOR) &&
		    !(s->options & SSL_OP_NO_SSLv3)) {
			s->version = SSL3_VERSION;
			s->method = SSLv3_client_method();
		} else if ((p[2] == TLS1_VERSION_MINOR) &&
		    !(s->options & SSL_OP_NO_TLSv1)) {
			s->version = TLS1_VERSION;
			s->method = TLSv1_client_method();
		} else if ((p[2] == TLS1_1_VERSION_MINOR) &&
		    !(s->options & SSL_OP_NO_TLSv1_1)) {
			s->version = TLS1_1_VERSION;
			s->method = TLSv1_1_client_method();
		} else if ((p[2] == TLS1_2_VERSION_MINOR) &&
		    !(s->options & SSL_OP_NO_TLSv1_2)) {
			s->version = TLS1_2_VERSION;
			s->method = TLSv1_2_client_method();
		} else {
			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,
			    SSL_R_UNSUPPORTED_PROTOCOL);
			goto err;
		}

		if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING) {
			/* fatal alert */
			void (*cb)(const SSL *ssl, int type, int val) = NULL;
			int j;

			if (s->info_callback != NULL)
				cb = s->info_callback;
			else if (s->ctx->info_callback != NULL)
				cb = s->ctx->info_callback;

			i = p[5];
			if (cb != NULL) {
				j = (i << 8) | p[6];
				cb(s, SSL_CB_READ_ALERT, j);
			}

			if (s->msg_callback)
				s->msg_callback(0, s->version, SSL3_RT_ALERT,
				    p + 5, 2, s, s->msg_callback_arg);

			s->rwstate = SSL_NOTHING;
			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,
			    SSL_AD_REASON_OFFSET + p[6]);
			goto err;
		}

		if (!ssl_init_wbio_buffer(s, 1))
			goto err;

		/* we are in this state */
		s->state = SSL3_ST_CR_SRVR_HELLO_A;

		/* put the 7 bytes we have read into the input buffer
		 * for SSLv3 */
		s->rstate = SSL_ST_READ_HEADER;
		s->packet_length = n;
		if (s->s3->rbuf.buf == NULL)
			if (!ssl3_setup_read_buffer(s))
				goto err;
		s->packet = &(s->s3->rbuf.buf[0]);
		memcpy(s->packet, buf, n);
		s->s3->rbuf.left = n;
		s->s3->rbuf.offset = 0;

		s->handshake_func = s->method->ssl_connect;
	} else {
		SSLerr(SSL_F_SSL23_GET_SERVER_HELLO, SSL_R_UNKNOWN_PROTOCOL);
		goto err;
	}
	s->init_num = 0;

	/*
	 * Since, if we are sending a ssl23 client hello, we are not
	 * reusing a session-id
	 */
	if (!ssl_get_new_session(s, 0))
		goto err;

	return (SSL_connect(s));
err:
	return (-1);
}
