s3_srvr.c

/* ssl/s3_srvr.c -*- mode:C; c-file-style: "eay" -*- */
/* 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) 1998-2007 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).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 *
 * Portions of the attached software ("Contribution") are developed by 
 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
 *
 * The Contribution is licensed pursuant to the OpenSSL open source
 * license provided above.
 *
 * ECC cipher suite support in OpenSSL originally written by
 * Vipul Gupta and Sumit Gupta of Sun Microsystems Laboratories.
 *
 */
/* ====================================================================
 * Copyright 2005 Nokia. All rights reserved.
 *
 * The portions of the attached software ("Contribution") is developed by
 * Nokia Corporation and is licensed pursuant to the OpenSSL open source
 * license.
 *
 * The Contribution, originally written by Mika Kousa and Pasi Eronen of
 * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
 * support (see RFC 4279) to OpenSSL.
 *
 * No patent licenses or other rights except those expressly stated in
 * the OpenSSL open source license shall be deemed granted or received
 * expressly, by implication, estoppel, or otherwise.
 *
 * No assurances are provided by Nokia that the Contribution does not
 * infringe the patent or other intellectual property rights of any third
 * party or that the license provides you with all the necessary rights
 * to make use of the Contribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
 * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
 * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
 * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
 * OTHERWISE.
 */

#define REUSE_CIPHER_BUG
#define NETSCAPE_HANG_BUG

#include <stdio.h>
#include "ssl_locl.h"
#include "kssl_lcl.h"
#include <openssl/buffer.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/x509.h>
#ifndef OPENSSL_NO_DH
#include <openssl/dh.h>
#endif
#include <openssl/bn.h>
#ifndef OPENSSL_NO_KRB5
#include <openssl/krb5_asn.h>
#endif
#include <openssl/md5.h>

static const SSL_METHOD *ssl3_get_server_method(int ver);

static const SSL_METHOD *ssl3_get_server_method(int ver)
	{
	if (ver == SSL3_VERSION)
		return(SSLv3_server_method());
	else
		return(NULL);
	}

IMPLEMENT_ssl3_meth_func(SSLv3_server_method,
			ssl3_accept,
			ssl_undefined_function,
			ssl3_get_server_method)

int ssl3_accept(SSL *s)
	{
	BUF_MEM *buf;
	unsigned long alg_k,Time=(unsigned long)time(NULL);
	void (*cb)(const SSL *ssl,int type,int val)=NULL;
	long num1;
	int ret= -1;
	int new_state,state,skip=0;

	RAND_add(&Time,sizeof(Time),0);
	ERR_clear_error();
	clear_sys_error();

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

	/* init things to blank */
	s->in_handshake++;
	if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);

	if (s->cert == NULL)
		{
		SSLerr(SSL_F_SSL3_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
		return(-1);
		}

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

		switch (s->state)
			{
		case SSL_ST_RENEGOTIATE:
			s->new_session=1;
			/* s->state=SSL_ST_ACCEPT; */

		case SSL_ST_BEFORE:
		case SSL_ST_ACCEPT:
		case SSL_ST_BEFORE|SSL_ST_ACCEPT:
		case SSL_ST_OK|SSL_ST_ACCEPT:

			s->server=1;
			if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);

			if ((s->version>>8) != 3)
				{
				SSLerr(SSL_F_SSL3_ACCEPT, ERR_R_INTERNAL_ERROR);
				return -1;
				}
			s->type=SSL_ST_ACCEPT;

			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;
				}

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

			s->init_num=0;

			if (s->state != SSL_ST_RENEGOTIATE)
				{
				/* Ok, we now need to push on a buffering BIO so that
				 * the output is sent in a way that TCP likes :-)
				 */
				if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
				
				ssl3_init_finished_mac(s);
				s->state=SSL3_ST_SR_CLNT_HELLO_A;
				s->ctx->stats.sess_accept++;
				}
			else
				{
				/* s->state == SSL_ST_RENEGOTIATE,
				 * we will just send a HelloRequest */
				s->ctx->stats.sess_accept_renegotiate++;
				s->state=SSL3_ST_SW_HELLO_REQ_A;
				}
			break;

		case SSL3_ST_SW_HELLO_REQ_A:
		case SSL3_ST_SW_HELLO_REQ_B:

			s->shutdown=0;
			ret=ssl3_send_hello_request(s);
			if (ret <= 0) goto end;
			s->s3->tmp.next_state=SSL3_ST_SW_HELLO_REQ_C;
			s->state=SSL3_ST_SW_FLUSH;
			s->init_num=0;

			ssl3_init_finished_mac(s);
			break;

		case SSL3_ST_SW_HELLO_REQ_C:
			s->state=SSL_ST_OK;
			break;

		case SSL3_ST_SR_CLNT_HELLO_A:
		case SSL3_ST_SR_CLNT_HELLO_B:
		case SSL3_ST_SR_CLNT_HELLO_C:

			s->shutdown=0;
			ret=ssl3_get_client_hello(s);
			if (ret <= 0) goto end;
			
			s->new_session = 2;
			s->state=SSL3_ST_SW_SRVR_HELLO_A;
			s->init_num=0;
			break;

		case SSL3_ST_SW_SRVR_HELLO_A:
		case SSL3_ST_SW_SRVR_HELLO_B:
			ret=ssl3_send_server_hello(s);
			if (ret <= 0) goto end;

			if (s->hit)
				s->state=SSL3_ST_SW_CHANGE_A;
			else
				s->state=SSL3_ST_SW_CERT_A;
			s->init_num=0;
			break;

		case SSL3_ST_SW_CERT_A:
		case SSL3_ST_SW_CERT_B:
			/* Check if it is anon DH or anon ECDH, */
			/* normal PSK or KRB5 */
			if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
				&& !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)
				&& !(s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5))
				{
				ret=ssl3_send_server_certificate(s);
				if (ret <= 0) goto end;
#ifndef OPENSSL_NO_TLSEXT
				if (s->tlsext_status_expected)
					s->state=SSL3_ST_SW_CERT_STATUS_A;
				else
					s->state=SSL3_ST_SW_KEY_EXCH_A;
				}
			else
				{
				skip = 1;
				s->state=SSL3_ST_SW_KEY_EXCH_A;
				}
#else
			else
				skip=1;

			s->state=SSL3_ST_SW_KEY_EXCH_A;
#endif
			s->init_num=0;
			break;

		case SSL3_ST_SW_KEY_EXCH_A:
		case SSL3_ST_SW_KEY_EXCH_B:
			alg_k = s->s3->tmp.new_cipher->algorithm_mkey;

			/* clear this, it may get reset by
			 * send_server_key_exchange */
			if ((s->options & SSL_OP_EPHEMERAL_RSA)
#ifndef OPENSSL_NO_KRB5
				&& !(alg_k & SSL_kKRB5)
#endif /* OPENSSL_NO_KRB5 */
				)
				/* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key
				 * even when forbidden by protocol specs
				 * (handshake may fail as clients are not required to
				 * be able to handle this) */
				s->s3->tmp.use_rsa_tmp=1;
			else
				s->s3->tmp.use_rsa_tmp=0;


			/* only send if a DH key exchange, fortezza or
			 * RSA but we have a sign only certificate
			 *
			 * PSK: may send PSK identity hints
			 *
			 * For ECC ciphersuites, we send a serverKeyExchange
			 * message only if the cipher suite is either
			 * ECDH-anon or ECDHE. In other cases, the
			 * server certificate contains the server's
			 * public key for key exchange.
			 */
			if (s->s3->tmp.use_rsa_tmp
			/* PSK: send ServerKeyExchange if PSK identity
			 * hint if provided */
#ifndef OPENSSL_NO_PSK
			    || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
#endif
			    || (alg_k & (SSL_kDHr|SSL_kDHd|SSL_kEDH))
			    || (alg_k & SSL_kEECDH)
			    || ((alg_k & SSL_kRSA)
				&& (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
				    || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
					&& EVP_PKEY_size(s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey)*8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
					)
				    )
				)
			    )
				{
				ret=ssl3_send_server_key_exchange(s);
				if (ret <= 0) goto end;
				}
			else
				skip=1;

			s->state=SSL3_ST_SW_CERT_REQ_A;
			s->init_num=0;
			break;

		case SSL3_ST_SW_CERT_REQ_A:
		case SSL3_ST_SW_CERT_REQ_B:
			if (/* don't request cert unless asked for it: */
				!(s->verify_mode & SSL_VERIFY_PEER) ||
				/* if SSL_VERIFY_CLIENT_ONCE is set,
				 * don't request cert during re-negotiation: */
				((s->session->peer != NULL) &&
				 (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
				/* never request cert in anonymous ciphersuites
				 * (see section "Certificate request" in SSL 3 drafts
				 * and in RFC 2246): */
				((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
				 /* ... except when the application insists on verification
				  * (against the specs, but s3_clnt.c accepts this for SSL 3) */
				 !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
				 /* never request cert in Kerberos ciphersuites */
				(s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
				/* With normal PSK Certificates and
				 * Certificate Requests are omitted */
				|| (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK))
				{
				/* no cert request */
				skip=1;
				s->s3->tmp.cert_request=0;
				s->state=SSL3_ST_SW_SRVR_DONE_A;
				}
			else
				{
				s->s3->tmp.cert_request=1;
				ret=ssl3_send_certificate_request(s);
				if (ret <= 0) goto end;
#ifndef NETSCAPE_HANG_BUG
				s->state=SSL3_ST_SW_SRVR_DONE_A;
#else
				s->state=SSL3_ST_SW_FLUSH;
				s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
#endif
				s->init_num=0;
				}
			break;

		case SSL3_ST_SW_SRVR_DONE_A:
		case SSL3_ST_SW_SRVR_DONE_B:
			ret=ssl3_send_server_done(s);
			if (ret <= 0) goto end;
			s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
			s->state=SSL3_ST_SW_FLUSH;
			s->init_num=0;
			break;
		
		case SSL3_ST_SW_FLUSH:
			/* number of bytes to be flushed */
			num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
			if (num1 > 0)
				{
				s->rwstate=SSL_WRITING;
				num1=BIO_flush(s->wbio);
				if (num1 <= 0) { ret= -1; goto end; }
				s->rwstate=SSL_NOTHING;
				}

			s->state=s->s3->tmp.next_state;
			break;

		case SSL3_ST_SR_CERT_A:
		case SSL3_ST_SR_CERT_B:
			/* Check for second client hello (MS SGC) */
			ret = ssl3_check_client_hello(s);
			if (ret <= 0)
				goto end;
			if (ret == 2)
				s->state = SSL3_ST_SR_CLNT_HELLO_C;
			else {
				if (s->s3->tmp.cert_request)
					{
					ret=ssl3_get_client_certificate(s);
					if (ret <= 0) goto end;
					}
				s->init_num=0;
				s->state=SSL3_ST_SR_KEY_EXCH_A;
			}
			break;

		case SSL3_ST_SR_KEY_EXCH_A:
		case SSL3_ST_SR_KEY_EXCH_B:
			ret=ssl3_get_client_key_exchange(s);
			if (ret <= 0)
				goto end;
			if (ret == 2)
				{
				/* For the ECDH ciphersuites when
				 * the client sends its ECDH pub key in
				 * a certificate, the CertificateVerify
				 * message is not sent.
				 */
				s->state=SSL3_ST_SR_FINISHED_A;
				s->init_num = 0;
				}
			else
				{
				s->state=SSL3_ST_SR_CERT_VRFY_A;
				s->init_num=0;

				/* We need to get hashes here so if there is
				 * a client cert, it can be verified
				 * FIXME - digest processing for CertificateVerify
				 * should be generalized. But it is next step
				 */
								
				s->method->ssl3_enc->cert_verify_mac(s,
					NID_md5,
				    &(s->s3->tmp.cert_verify_md[0]));
				s->method->ssl3_enc->cert_verify_mac(s,
					NID_sha1,
				    &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]));
				}
			break;

		case SSL3_ST_SR_CERT_VRFY_A:
		case SSL3_ST_SR_CERT_VRFY_B:

			/* we should decide if we expected this one */
			ret=ssl3_get_cert_verify(s);
			if (ret <= 0) goto end;

			s->state=SSL3_ST_SR_FINISHED_A;
			s->init_num=0;
			break;

		case SSL3_ST_SR_FINISHED_A:
		case SSL3_ST_SR_FINISHED_B:
			ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
				SSL3_ST_SR_FINISHED_B);
			if (ret <= 0) goto end;
			if (s->hit)
				s->state=SSL_ST_OK;
#ifndef OPENSSL_NO_TLSEXT
			else if (s->tlsext_ticket_expected)
				s->state=SSL3_ST_SW_SESSION_TICKET_A;
#endif
			else
				s->state=SSL3_ST_SW_CHANGE_A;
			s->init_num=0;
			break;

#ifndef OPENSSL_NO_TLSEXT
		case SSL3_ST_SW_SESSION_TICKET_A:
		case SSL3_ST_SW_SESSION_TICKET_B:
			ret=ssl3_send_newsession_ticket(s);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_SW_CHANGE_A;
			s->init_num=0;
			break;

		case SSL3_ST_SW_CERT_STATUS_A:
		case SSL3_ST_SW_CERT_STATUS_B:
			ret=ssl3_send_cert_status(s);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_SW_KEY_EXCH_A;
			s->init_num=0;
			break;

#endif

		case SSL3_ST_SW_CHANGE_A:
		case SSL3_ST_SW_CHANGE_B:

			s->session->cipher=s->s3->tmp.new_cipher;
			if (!s->method->ssl3_enc->setup_key_block(s))
				{ ret= -1; goto end; }

			ret=ssl3_send_change_cipher_spec(s,
				SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);

			if (ret <= 0) goto end;
			s->state=SSL3_ST_SW_FINISHED_A;
			s->init_num=0;

			if (!s->method->ssl3_enc->change_cipher_state(s,
				SSL3_CHANGE_CIPHER_SERVER_WRITE))
				{
				ret= -1;
				goto end;
				}

			break;

		case SSL3_ST_SW_FINISHED_A:
		case SSL3_ST_SW_FINISHED_B:
			ret=ssl3_send_finished(s,
				SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
				s->method->ssl3_enc->server_finished_label,
				s->method->ssl3_enc->server_finished_label_len);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_SW_FLUSH;
			if (s->hit)
				s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
			else
				s->s3->tmp.next_state=SSL_ST_OK;
			s->init_num=0;
			break;

		case SSL_ST_OK:
			/* clean a few things up */
			ssl3_cleanup_key_block(s);

			BUF_MEM_free(s->init_buf);
			s->init_buf=NULL;

			/* remove buffering on output */
			ssl_free_wbio_buffer(s);

			s->init_num=0;

			if (s->new_session == 2) /* skipped if we just sent a HelloRequest */
				{
				/* actually not necessarily a 'new' session unless
				 * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION is set */
				
				s->new_session=0;
				
				ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
				
				s->ctx->stats.sess_accept_good++;
				/* s->server=1; */
				s->handshake_func=ssl3_accept;

				if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
				}
			
			ret = 1;
			goto end;
			/* break; */

		default:
			SSLerr(SSL_F_SSL3_ACCEPT,SSL_R_UNKNOWN_STATE);
			ret= -1;
			goto end;
			/* break; */
			}
		
		if (!s->s3->tmp.reuse_message && !skip)
			{
			if (s->debug)
				{
				if ((ret=BIO_flush(s->wbio)) <= 0)
					goto end;
				}


			if ((cb != NULL) && (s->state != state))
				{
				new_state=s->state;
				s->state=state;
				cb(s,SSL_CB_ACCEPT_LOOP,1);
				s->state=new_state;
				}
			}
		skip=0;
		}
end:
	/* BIO_flush(s->wbio); */

	s->in_handshake--;
	if (cb != NULL)
		cb(s,SSL_CB_ACCEPT_EXIT,ret);
	return(ret);
	}

int ssl3_send_hello_request(SSL *s)
	{
	unsigned char *p;

	if (s->state == SSL3_ST_SW_HELLO_REQ_A)
		{
		p=(unsigned char *)s->init_buf->data;
		*(p++)=SSL3_MT_HELLO_REQUEST;
		*(p++)=0;
		*(p++)=0;
		*(p++)=0;

		s->state=SSL3_ST_SW_HELLO_REQ_B;
		/* number of bytes to write */
		s->init_num=4;
		s->init_off=0;
		}

	/* SSL3_ST_SW_HELLO_REQ_B */
	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
	}

int ssl3_check_client_hello(SSL *s)
	{
	int ok;
	long n;

	/* this function is called when we really expect a Certificate message,
	 * so permit appropriate message length */
	n=s->method->ssl_get_message(s,
		SSL3_ST_SR_CERT_A,
		SSL3_ST_SR_CERT_B,
		-1,
		s->max_cert_list,
		&ok);
	if (!ok) return((int)n);
	s->s3->tmp.reuse_message = 1;
	if (s->s3->tmp.message_type == SSL3_MT_CLIENT_HELLO)
		{
		/* Throw away what we have done so far in the current handshake,
		 * which will now be aborted. (A full SSL_clear would be too much.)
		 * I hope that tmp.dh is the only thing that may need to be cleared
		 * when a handshake is not completed ... */
#ifndef OPENSSL_NO_DH
		if (s->s3->tmp.dh != NULL)
			{
			DH_free(s->s3->tmp.dh);
			s->s3->tmp.dh = NULL;
			}
#endif
		return 2;
		}
	return 1;
}

int ssl3_get_client_hello(SSL *s)
	{
	int i,j,ok,al,ret= -1;
	unsigned int cookie_len;
	long n;
	unsigned long id;
	unsigned char *p,*d,*q;
	SSL_CIPHER *c;
#ifndef OPENSSL_NO_COMP
	SSL_COMP *comp=NULL;
#endif
	STACK_OF(SSL_CIPHER) *ciphers=NULL;

	/* We do this so that we will respond with our native type.
	 * If we are TLSv1 and we get SSLv3, we will respond with TLSv1,
	 * This down switching should be handled by a different method.
	 * If we are SSLv3, we will respond with SSLv3, even if prompted with
	 * TLSv1.
	 */
	if (s->state == SSL3_ST_SR_CLNT_HELLO_A)
		{
		s->state=SSL3_ST_SR_CLNT_HELLO_B;
		}
	s->first_packet=1;
	n=s->method->ssl_get_message(s,
		SSL3_ST_SR_CLNT_HELLO_B,
		SSL3_ST_SR_CLNT_HELLO_C,
		SSL3_MT_CLIENT_HELLO,
		SSL3_RT_MAX_PLAIN_LENGTH,
		&ok);

	if (!ok) return((int)n);
	s->first_packet=0;
	d=p=(unsigned char *)s->init_msg;

	/* use version from inside client hello, not from record header
	 * (may differ: see RFC 2246, Appendix E, second paragraph) */
	s->client_version=(((int)p[0])<<8)|(int)p[1];
	p+=2;

	if ((s->version == DTLS1_VERSION && s->client_version > s->version) ||
	    (s->version != DTLS1_VERSION && s->client_version < s->version))
		{
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_WRONG_VERSION_NUMBER);
		if ((s->client_version>>8) == SSL3_VERSION_MAJOR)
			{
			/* similar to ssl3_get_record, send alert using remote version number */
			s->version = s->client_version;
			}
		al = SSL_AD_PROTOCOL_VERSION;
		goto f_err;
		}

	/* load the client random */
	memcpy(s->s3->client_random,p,SSL3_RANDOM_SIZE);
	p+=SSL3_RANDOM_SIZE;

	/* get the session-id */
	j= *(p++);

	s->hit=0;
	/* Versions before 0.9.7 always allow session reuse during renegotiation
	 * (i.e. when s->new_session is true), option
	 * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION is new with 0.9.7.
	 * Maybe this optional behaviour should always have been the default,
	 * but we cannot safely change the default behaviour (or new applications
	 * might be written that become totally unsecure when compiled with
	 * an earlier library version)
	 */
	if ((s->new_session && (s->options & SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION)))
		{
		if (!ssl_get_new_session(s,1))
			goto err;
		}
	else
		{
		i=ssl_get_prev_session(s, p, j, d + n);
		if (i == 1)
			{ /* previous session */
			s->hit=1;
			}
		else if (i == -1)
			goto err;
		else /* i == 0 */
			{
			if (!ssl_get_new_session(s,1))
				goto err;
			}
		}

	p+=j;

	if (s->version == DTLS1_VERSION)
		{
		/* cookie stuff */
		cookie_len = *(p++);

		if ( (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) &&
			s->d1->send_cookie == 0)
			{
			/* HelloVerifyMessage has already been sent */
			if ( cookie_len != s->d1->cookie_len)
				{
				al = SSL_AD_HANDSHAKE_FAILURE;
				SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_COOKIE_MISMATCH);
				goto f_err;
				}
			}

		/* 
		 * The ClientHello may contain a cookie even if the
		 * HelloVerify message has not been sent--make sure that it
		 * does not cause an overflow.
		 */
		if ( cookie_len > sizeof(s->d1->rcvd_cookie))
			{
			/* too much data */
			al = SSL_AD_DECODE_ERROR;
			SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_COOKIE_MISMATCH);
			goto f_err;
			}

		/* verify the cookie if appropriate option is set. */
		if ( (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) &&
			cookie_len > 0)
			{
			memcpy(s->d1->rcvd_cookie, p, cookie_len);

			if ( s->ctx->app_verify_cookie_cb != NULL)
				{
				if ( s->ctx->app_verify_cookie_cb(s, s->d1->rcvd_cookie,
					cookie_len) == 0)
					{
					al=SSL_AD_HANDSHAKE_FAILURE;
					SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, 
						SSL_R_COOKIE_MISMATCH);
					goto f_err;
					}
				/* else cookie verification succeeded */
				}
			else if ( memcmp(s->d1->rcvd_cookie, s->d1->cookie, 
						  s->d1->cookie_len) != 0) /* default verification */
				{
					al=SSL_AD_HANDSHAKE_FAILURE;
					SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, 
						SSL_R_COOKIE_MISMATCH);
					goto f_err;
				}
			}

		p += cookie_len;
		}

	n2s(p,i);
	if ((i == 0) && (j != 0))
		{
		/* we need a cipher if we are not resuming a session */
		al=SSL_AD_ILLEGAL_PARAMETER;
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_CIPHERS_SPECIFIED);
		goto f_err;
		}
	if ((p+i) >= (d+n))
		{
		/* not enough data */
		al=SSL_AD_DECODE_ERROR;
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_LENGTH_MISMATCH);
		goto f_err;
		}
	if ((i > 0) && (ssl_bytes_to_cipher_list(s,p,i,&(ciphers))
		== NULL))
		{
		goto err;
		}
	p+=i;

	/* If it is a hit, check that the cipher is in the list */
	if ((s->hit) && (i > 0))
		{
		j=0;
		id=s->session->cipher->id;

#ifdef CIPHER_DEBUG
		printf("client sent %d ciphers\n",sk_num(ciphers));
#endif
		for (i=0; i<sk_SSL_CIPHER_num(ciphers); i++)
			{
			c=sk_SSL_CIPHER_value(ciphers,i);
#ifdef CIPHER_DEBUG
			printf("client [%2d of %2d]:%s\n",
				i,sk_num(ciphers),SSL_CIPHER_get_name(c));
#endif
			if (c->id == id)
				{
				j=1;
				break;
				}
			}
		if (j == 0)
			{
			if ((s->options & SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG) && (sk_SSL_CIPHER_num(ciphers) == 1))
				{
				/* Very bad for multi-threading.... */
				s->session->cipher=sk_SSL_CIPHER_value(ciphers, 0);
				}
			else
				{
				/* we need to have the cipher in the cipher
				 * list if we are asked to reuse it */
				al=SSL_AD_ILLEGAL_PARAMETER;
				SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_REQUIRED_CIPHER_MISSING);
				goto f_err;
				}
			}
		}

	/* compression */
	i= *(p++);
	if ((p+i) > (d+n))
		{
		/* not enough data */
		al=SSL_AD_DECODE_ERROR;
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_LENGTH_MISMATCH);
		goto f_err;
		}
	q=p;
	for (j=0; j<i; j++)
		{
		if (p[j] == 0) break;
		}

	p+=i;
	if (j >= i)
		{
		/* no compress */
		al=SSL_AD_DECODE_ERROR;
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_COMPRESSION_SPECIFIED);
		goto f_err;
		}

#ifndef OPENSSL_NO_TLSEXT
	/* TLS extensions*/
	if (s->version > SSL3_VERSION)
		{
		if (!ssl_parse_clienthello_tlsext(s,&p,d,n, &al))
			{
			/* 'al' set by ssl_parse_clienthello_tlsext */
			SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_PARSE_TLSEXT);
			goto f_err;
			}
		}
		if (ssl_check_clienthello_tlsext(s) <= 0) {
			SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
			goto err;
		}
#endif

	/* Worst case, we will use the NULL compression, but if we have other
	 * options, we will now look for them.  We have i-1 compression
	 * algorithms from the client, starting at q. */
	s->s3->tmp.new_compression=NULL;
#ifndef OPENSSL_NO_COMP
	if (!(s->options & SSL_OP_NO_COMPRESSION) && s->ctx->comp_methods)
		{ /* See if we have a match */
		int m,nn,o,v,done=0;