s23_clnt.c revision 273415
1/* ssl/s23_clnt.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58/* ====================================================================
59 * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
60 *
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
63 * are met:
64 *
65 * 1. Redistributions of source code must retain the above copyright
66 *    notice, this list of conditions and the following disclaimer.
67 *
68 * 2. Redistributions in binary form must reproduce the above copyright
69 *    notice, this list of conditions and the following disclaimer in
70 *    the documentation and/or other materials provided with the
71 *    distribution.
72 *
73 * 3. All advertising materials mentioning features or use of this
74 *    software must display the following acknowledgment:
75 *    "This product includes software developed by the OpenSSL Project
76 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77 *
78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79 *    endorse or promote products derived from this software without
80 *    prior written permission. For written permission, please contact
81 *    openssl-core@openssl.org.
82 *
83 * 5. Products derived from this software may not be called "OpenSSL"
84 *    nor may "OpenSSL" appear in their names without prior written
85 *    permission of the OpenSSL Project.
86 *
87 * 6. Redistributions of any form whatsoever must retain the following
88 *    acknowledgment:
89 *    "This product includes software developed by the OpenSSL Project
90 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 *
92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103 * OF THE POSSIBILITY OF SUCH DAMAGE.
104 * ====================================================================
105 *
106 * This product includes cryptographic software written by Eric Young
107 * (eay@cryptsoft.com).  This product includes software written by Tim
108 * Hudson (tjh@cryptsoft.com).
109 *
110 */
111
112#include <stdio.h>
113#include "ssl_locl.h"
114#include <openssl/buffer.h>
115#include <openssl/rand.h>
116#include <openssl/objects.h>
117#include <openssl/evp.h>
118
119static const SSL_METHOD *ssl23_get_client_method(int ver);
120static int ssl23_client_hello(SSL *s);
121static int ssl23_get_server_hello(SSL *s);
122static const SSL_METHOD *ssl23_get_client_method(int ver)
123	{
124#ifndef OPENSSL_NO_SSL2
125	if (ver == SSL2_VERSION)
126		return(SSLv2_client_method());
127#endif
128#ifndef OPENSSL_NO_SSL3
129	if (ver == SSL3_VERSION)
130		return(SSLv3_client_method());
131#endif
132	if (ver == TLS1_VERSION)
133		return(TLSv1_client_method());
134	else if (ver == TLS1_1_VERSION)
135		return(TLSv1_1_client_method());
136	else if (ver == TLS1_2_VERSION)
137		return(TLSv1_2_client_method());
138	else
139		return(NULL);
140	}
141
142IMPLEMENT_ssl23_meth_func(SSLv23_client_method,
143			ssl_undefined_function,
144			ssl23_connect,
145			ssl23_get_client_method)
146
147int ssl23_connect(SSL *s)
148	{
149	BUF_MEM *buf=NULL;
150	unsigned long Time=(unsigned long)time(NULL);
151	void (*cb)(const SSL *ssl,int type,int val)=NULL;
152	int ret= -1;
153	int new_state,state;
154
155	RAND_add(&Time,sizeof(Time),0);
156	ERR_clear_error();
157	clear_sys_error();
158
159	if (s->info_callback != NULL)
160		cb=s->info_callback;
161	else if (s->ctx->info_callback != NULL)
162		cb=s->ctx->info_callback;
163
164	s->in_handshake++;
165	if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
166
167	for (;;)
168		{
169		state=s->state;
170
171		switch(s->state)
172			{
173		case SSL_ST_BEFORE:
174		case SSL_ST_CONNECT:
175		case SSL_ST_BEFORE|SSL_ST_CONNECT:
176		case SSL_ST_OK|SSL_ST_CONNECT:
177
178			if (s->session != NULL)
179				{
180				SSLerr(SSL_F_SSL23_CONNECT,SSL_R_SSL23_DOING_SESSION_ID_REUSE);
181				ret= -1;
182				goto end;
183				}
184			s->server=0;
185			if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
186
187			/* s->version=TLS1_VERSION; */
188			s->type=SSL_ST_CONNECT;
189
190			if (s->init_buf == NULL)
191				{
192				if ((buf=BUF_MEM_new()) == NULL)
193					{
194					ret= -1;
195					goto end;
196					}
197				if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
198					{
199					ret= -1;
200					goto end;
201					}
202				s->init_buf=buf;
203				buf=NULL;
204				}
205
206			if (!ssl3_setup_buffers(s)) { ret= -1; goto end; }
207
208			ssl3_init_finished_mac(s);
209
210			s->state=SSL23_ST_CW_CLNT_HELLO_A;
211			s->ctx->stats.sess_connect++;
212			s->init_num=0;
213			break;
214
215		case SSL23_ST_CW_CLNT_HELLO_A:
216		case SSL23_ST_CW_CLNT_HELLO_B:
217
218			s->shutdown=0;
219			ret=ssl23_client_hello(s);
220			if (ret <= 0) goto end;
221			s->state=SSL23_ST_CR_SRVR_HELLO_A;
222			s->init_num=0;
223
224			break;
225
226		case SSL23_ST_CR_SRVR_HELLO_A:
227		case SSL23_ST_CR_SRVR_HELLO_B:
228			ret=ssl23_get_server_hello(s);
229			if (ret >= 0) cb=NULL;
230			goto end;
231			/* break; */
232
233		default:
234			SSLerr(SSL_F_SSL23_CONNECT,SSL_R_UNKNOWN_STATE);
235			ret= -1;
236			goto end;
237			/* break; */
238			}
239
240		if (s->debug) { (void)BIO_flush(s->wbio); }
241
242		if ((cb != NULL) && (s->state != state))
243			{
244			new_state=s->state;
245			s->state=state;
246			cb(s,SSL_CB_CONNECT_LOOP,1);
247			s->state=new_state;
248			}
249		}
250end:
251	s->in_handshake--;
252	if (buf != NULL)
253		BUF_MEM_free(buf);
254	if (cb != NULL)
255		cb(s,SSL_CB_CONNECT_EXIT,ret);
256	return(ret);
257	}
258
259static int ssl23_no_ssl2_ciphers(SSL *s)
260	{
261	SSL_CIPHER *cipher;
262	STACK_OF(SSL_CIPHER) *ciphers;
263	int i;
264	ciphers = SSL_get_ciphers(s);
265	for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++)
266		{
267		cipher = sk_SSL_CIPHER_value(ciphers, i);
268		if (cipher->algorithm_ssl == SSL_SSLV2)
269			return 0;
270		}
271	return 1;
272	}
273
274static int ssl23_client_hello(SSL *s)
275	{
276	unsigned char *buf;
277	unsigned char *p,*d;
278	int i,ch_len;
279	unsigned long Time,l;
280	int ssl2_compat;
281	int version = 0, version_major, version_minor;
282#ifndef OPENSSL_NO_COMP
283	int j;
284	SSL_COMP *comp;
285#endif
286	int ret;
287	unsigned long mask, options = s->options;
288
289	ssl2_compat = (options & SSL_OP_NO_SSLv2) ? 0 : 1;
290
291	if (ssl2_compat && ssl23_no_ssl2_ciphers(s))
292		ssl2_compat = 0;
293
294	/*
295	 * SSL_OP_NO_X disables all protocols above X *if* there are
296	 * some protocols below X enabled. This is required in order
297	 * to maintain "version capability" vector contiguous. So
298	 * that if application wants to disable TLS1.0 in favour of
299	 * TLS1>=1, it would be insufficient to pass SSL_NO_TLSv1, the
300	 * answer is SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2.
301	 */
302	mask =	SSL_OP_NO_TLSv1_1|SSL_OP_NO_TLSv1
303#if !defined(OPENSSL_NO_SSL3)
304		|SSL_OP_NO_SSLv3
305#endif
306#if !defined(OPENSSL_NO_SSL2)
307		|(ssl2_compat?SSL_OP_NO_SSLv2:0)
308#endif
309		;
310#if !defined(OPENSSL_NO_TLS1_2_CLIENT)
311	version = TLS1_2_VERSION;
312
313	if ((options & SSL_OP_NO_TLSv1_2) && (options & mask) != mask)
314		version = TLS1_1_VERSION;
315#else
316	version = TLS1_1_VERSION;
317#endif
318	mask &= ~SSL_OP_NO_TLSv1_1;
319	if ((options & SSL_OP_NO_TLSv1_1) && (options & mask) != mask)
320		version = TLS1_VERSION;
321	mask &= ~SSL_OP_NO_TLSv1;
322#if !defined(OPENSSL_NO_SSL3)
323	if ((options & SSL_OP_NO_TLSv1) && (options & mask) != mask)
324		version = SSL3_VERSION;
325	mask &= ~SSL_OP_NO_SSLv3;
326#endif
327#if !defined(OPENSSL_NO_SSL2)
328	if ((options & SSL_OP_NO_SSLv3) && (options & mask) != mask)
329		version = SSL2_VERSION;
330#endif
331
332#ifndef OPENSSL_NO_TLSEXT
333	if (version != SSL2_VERSION)
334		{
335		/* have to disable SSL 2.0 compatibility if we need TLS extensions */
336
337		if (s->tlsext_hostname != NULL)
338			ssl2_compat = 0;
339		if (s->tlsext_status_type != -1)
340			ssl2_compat = 0;
341#ifdef TLSEXT_TYPE_opaque_prf_input
342		if (s->ctx->tlsext_opaque_prf_input_callback != 0 || s->tlsext_opaque_prf_input != NULL)
343			ssl2_compat = 0;
344#endif
345		}
346#endif
347
348	buf=(unsigned char *)s->init_buf->data;
349	if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
350		{
351#if 0
352		/* don't reuse session-id's */
353		if (!ssl_get_new_session(s,0))
354			{
355			return(-1);
356			}
357#endif
358
359		p=s->s3->client_random;
360		Time=(unsigned long)time(NULL);		/* Time */
361		l2n(Time,p);
362		if (RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-4) <= 0)
363			return -1;
364
365		if (version == TLS1_2_VERSION)
366			{
367			version_major = TLS1_2_VERSION_MAJOR;
368			version_minor = TLS1_2_VERSION_MINOR;
369			}
370		else if (version == TLS1_1_VERSION)
371			{
372			version_major = TLS1_1_VERSION_MAJOR;
373			version_minor = TLS1_1_VERSION_MINOR;
374			}
375		else if (version == TLS1_VERSION)
376			{
377			version_major = TLS1_VERSION_MAJOR;
378			version_minor = TLS1_VERSION_MINOR;
379			}
380#ifdef OPENSSL_FIPS
381		else if(FIPS_mode())
382			{
383			SSLerr(SSL_F_SSL23_CLIENT_HELLO,
384					SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
385			return -1;
386			}
387#endif
388		else if (version == SSL3_VERSION)
389			{
390			version_major = SSL3_VERSION_MAJOR;
391			version_minor = SSL3_VERSION_MINOR;
392			}
393		else if (version == SSL2_VERSION)
394			{
395			version_major = SSL2_VERSION_MAJOR;
396			version_minor = SSL2_VERSION_MINOR;
397			}
398		else
399			{
400			SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_PROTOCOLS_AVAILABLE);
401			return(-1);
402			}
403
404		s->client_version = version;
405
406		if (ssl2_compat)
407			{
408			/* create SSL 2.0 compatible Client Hello */
409
410			/* two byte record header will be written last */
411			d = &(buf[2]);
412			p = d + 9; /* leave space for message type, version, individual length fields */
413
414			*(d++) = SSL2_MT_CLIENT_HELLO;
415			*(d++) = version_major;
416			*(d++) = version_minor;
417
418			/* Ciphers supported */
419			i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),p,0);
420			if (i == 0)
421				{
422				/* no ciphers */
423				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
424				return -1;
425				}
426			s2n(i,d);
427			p+=i;
428
429			/* put in the session-id length (zero since there is no reuse) */
430#if 0
431			s->session->session_id_length=0;
432#endif
433			s2n(0,d);
434
435			if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
436				ch_len=SSL2_CHALLENGE_LENGTH;
437			else
438				ch_len=SSL2_MAX_CHALLENGE_LENGTH;
439
440			/* write out sslv2 challenge */
441			/* Note that ch_len must be <= SSL3_RANDOM_SIZE (32),
442			   because it is one of SSL2_MAX_CHALLENGE_LENGTH (32)
443			   or SSL2_MAX_CHALLENGE_LENGTH (16), but leave the
444			   check in for futurproofing */
445			if (SSL3_RANDOM_SIZE < ch_len)
446				i=SSL3_RANDOM_SIZE;
447			else
448				i=ch_len;
449			s2n(i,d);
450			memset(&(s->s3->client_random[0]),0,SSL3_RANDOM_SIZE);
451			if (RAND_pseudo_bytes(&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i) <= 0)
452				return -1;
453
454			memcpy(p,&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
455			p+=i;
456
457			i= p- &(buf[2]);
458			buf[0]=((i>>8)&0xff)|0x80;
459			buf[1]=(i&0xff);
460
461			/* number of bytes to write */
462			s->init_num=i+2;
463			s->init_off=0;
464
465			ssl3_finish_mac(s,&(buf[2]),i);
466			}
467		else
468			{
469			/* create Client Hello in SSL 3.0/TLS 1.0 format */
470
471			/* do the record header (5 bytes) and handshake message header (4 bytes) last */
472			d = p = &(buf[9]);
473
474			*(p++) = version_major;
475			*(p++) = version_minor;
476
477			/* Random stuff */
478			memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
479			p += SSL3_RANDOM_SIZE;
480
481			/* Session ID (zero since there is no reuse) */
482			*(p++) = 0;
483
484			/* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
485			i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),&(p[2]),ssl3_put_cipher_by_char);
486			if (i == 0)
487				{
488				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
489				return -1;
490				}
491#ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
492			/* Some servers hang if client hello > 256 bytes
493			 * as hack workaround chop number of supported ciphers
494			 * to keep it well below this if we use TLS v1.2
495			 */
496			if (TLS1_get_version(s) >= TLS1_2_VERSION
497				&& i > OPENSSL_MAX_TLS1_2_CIPHER_LENGTH)
498				i = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
499#endif
500			s2n(i,p);
501			p+=i;
502
503			/* COMPRESSION */
504#ifdef OPENSSL_NO_COMP
505			*(p++)=1;
506#else
507			if ((s->options & SSL_OP_NO_COMPRESSION)
508						|| !s->ctx->comp_methods)
509				j=0;
510			else
511				j=sk_SSL_COMP_num(s->ctx->comp_methods);
512			*(p++)=1+j;
513			for (i=0; i<j; i++)
514				{
515				comp=sk_SSL_COMP_value(s->ctx->comp_methods,i);
516				*(p++)=comp->id;
517				}
518#endif
519			*(p++)=0; /* Add the NULL method */
520
521#ifndef OPENSSL_NO_TLSEXT
522			/* TLS extensions*/
523			if (ssl_prepare_clienthello_tlsext(s) <= 0)
524				{
525				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
526				return -1;
527				}
528			if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
529				{
530				SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
531				return -1;
532				}
533#endif
534
535			l = p-d;
536
537			/* fill in 4-byte handshake header */
538			d=&(buf[5]);
539			*(d++)=SSL3_MT_CLIENT_HELLO;
540			l2n3(l,d);
541
542			l += 4;
543
544			if (l > SSL3_RT_MAX_PLAIN_LENGTH)
545				{
546				SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
547				return -1;
548				}
549
550			/* fill in 5-byte record header */
551			d=buf;
552			*(d++) = SSL3_RT_HANDSHAKE;
553			*(d++) = version_major;
554			/* Some servers hang if we use long client hellos
555			 * and a record number > TLS 1.0.
556			 */
557			if (TLS1_get_client_version(s) > TLS1_VERSION)
558				*(d++) = 1;
559			else
560				*(d++) = version_minor;
561			s2n((int)l,d);
562
563			/* number of bytes to write */
564			s->init_num=p-buf;
565			s->init_off=0;
566
567			ssl3_finish_mac(s,&(buf[5]), s->init_num - 5);
568			}
569
570		s->state=SSL23_ST_CW_CLNT_HELLO_B;
571		s->init_off=0;
572		}
573
574	/* SSL3_ST_CW_CLNT_HELLO_B */
575	ret = ssl23_write_bytes(s);
576
577	if ((ret >= 2) && s->msg_callback)
578		{
579		/* Client Hello has been sent; tell msg_callback */
580
581		if (ssl2_compat)
582			s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data+2, ret-2, s, s->msg_callback_arg);
583		else
584			s->msg_callback(1, version, SSL3_RT_HANDSHAKE, s->init_buf->data+5, ret-5, s, s->msg_callback_arg);
585		}
586
587	return ret;
588	}
589
590static int ssl23_get_server_hello(SSL *s)
591	{
592	char buf[8];
593	unsigned char *p;
594	int i;
595	int n;
596
597	n=ssl23_read_bytes(s,7);
598
599	if (n != 7) return(n);
600	p=s->packet;
601
602	memcpy(buf,p,n);
603
604	if ((p[0] & 0x80) && (p[2] == SSL2_MT_SERVER_HELLO) &&
605		(p[5] == 0x00) && (p[6] == 0x02))
606		{
607#ifdef OPENSSL_NO_SSL2
608		SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
609		goto err;
610#else
611		/* we are talking sslv2 */
612		/* we need to clean up the SSLv3 setup and put in the
613		 * sslv2 stuff. */
614		int ch_len;
615
616		if (s->options & SSL_OP_NO_SSLv2)
617			{
618			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
619			goto err;
620			}
621		if (s->s2 == NULL)
622			{
623			if (!ssl2_new(s))
624				goto err;
625			}
626		else
627			ssl2_clear(s);
628
629		if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
630			ch_len=SSL2_CHALLENGE_LENGTH;
631		else
632			ch_len=SSL2_MAX_CHALLENGE_LENGTH;
633
634		/* write out sslv2 challenge */
635		/* Note that ch_len must be <= SSL3_RANDOM_SIZE (32), because
636		   it is one of SSL2_MAX_CHALLENGE_LENGTH (32) or
637		   SSL2_MAX_CHALLENGE_LENGTH (16), but leave the check in for
638		   futurproofing */
639		i=(SSL3_RANDOM_SIZE < ch_len)
640			?SSL3_RANDOM_SIZE:ch_len;
641		s->s2->challenge_length=i;
642		memcpy(s->s2->challenge,
643			&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
644
645		if (s->s3 != NULL) ssl3_free(s);
646
647		if (!BUF_MEM_grow_clean(s->init_buf,
648			SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
649			{
650			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,ERR_R_BUF_LIB);
651			goto err;
652			}
653
654		s->state=SSL2_ST_GET_SERVER_HELLO_A;
655		if (!(s->client_version == SSL2_VERSION))
656			/* use special padding (SSL 3.0 draft/RFC 2246, App. E.2) */
657			s->s2->ssl2_rollback=1;
658
659		/* setup the 7 bytes we have read so we get them from
660		 * the sslv2 buffer */
661		s->rstate=SSL_ST_READ_HEADER;
662		s->packet_length=n;
663		s->packet= &(s->s2->rbuf[0]);
664		memcpy(s->packet,buf,n);
665		s->s2->rbuf_left=n;
666		s->s2->rbuf_offs=0;
667
668		/* we have already written one */
669		s->s2->write_sequence=1;
670
671		s->method=SSLv2_client_method();
672		s->handshake_func=s->method->ssl_connect;
673#endif
674		}
675	else if (p[1] == SSL3_VERSION_MAJOR &&
676	         p[2] <= TLS1_2_VERSION_MINOR &&
677	         ((p[0] == SSL3_RT_HANDSHAKE && p[5] == SSL3_MT_SERVER_HELLO) ||
678	          (p[0] == SSL3_RT_ALERT && p[3] == 0 && p[4] == 2)))
679		{
680		/* we have sslv3 or tls1 (server hello or alert) */
681
682#ifndef OPENSSL_NO_SSL3
683		if ((p[2] == SSL3_VERSION_MINOR) &&
684			!(s->options & SSL_OP_NO_SSLv3))
685			{
686#ifdef OPENSSL_FIPS
687			if(FIPS_mode())
688				{
689				SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,
690					SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
691				goto err;
692				}
693#endif
694			s->version=SSL3_VERSION;
695			s->method=SSLv3_client_method();
696			}
697		else
698#endif
699		if ((p[2] == TLS1_VERSION_MINOR) &&
700			!(s->options & SSL_OP_NO_TLSv1))
701			{
702			s->version=TLS1_VERSION;
703			s->method=TLSv1_client_method();
704			}
705		else if ((p[2] == TLS1_1_VERSION_MINOR) &&
706			!(s->options & SSL_OP_NO_TLSv1_1))
707			{
708			s->version=TLS1_1_VERSION;
709			s->method=TLSv1_1_client_method();
710			}
711		else if ((p[2] == TLS1_2_VERSION_MINOR) &&
712			!(s->options & SSL_OP_NO_TLSv1_2))
713			{
714			s->version=TLS1_2_VERSION;
715			s->method=TLSv1_2_client_method();
716			}
717		else
718			{
719			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
720			goto err;
721			}
722
723		/* ensure that TLS_MAX_VERSION is up-to-date */
724		OPENSSL_assert(s->version <= TLS_MAX_VERSION);
725
726		if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING)
727			{
728			/* fatal alert */
729
730			void (*cb)(const SSL *ssl,int type,int val)=NULL;
731			int j;
732
733			if (s->info_callback != NULL)
734				cb=s->info_callback;
735			else if (s->ctx->info_callback != NULL)
736				cb=s->ctx->info_callback;
737
738			i=p[5];
739			if (cb != NULL)
740				{
741				j=(i<<8)|p[6];
742				cb(s,SSL_CB_READ_ALERT,j);
743				}
744
745			if (s->msg_callback)
746				s->msg_callback(0, s->version, SSL3_RT_ALERT, p+5, 2, s, s->msg_callback_arg);
747
748			s->rwstate=SSL_NOTHING;
749			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_AD_REASON_OFFSET+p[6]);
750			goto err;
751			}
752
753		if (!ssl_init_wbio_buffer(s,1)) goto err;
754
755		/* we are in this state */
756		s->state=SSL3_ST_CR_SRVR_HELLO_A;
757
758		/* put the 7 bytes we have read into the input buffer
759		 * for SSLv3 */
760		s->rstate=SSL_ST_READ_HEADER;
761		s->packet_length=n;
762		if (s->s3->rbuf.buf == NULL)
763			if (!ssl3_setup_read_buffer(s))
764				goto err;
765		s->packet= &(s->s3->rbuf.buf[0]);
766		memcpy(s->packet,buf,n);
767		s->s3->rbuf.left=n;
768		s->s3->rbuf.offset=0;
769
770		s->handshake_func=s->method->ssl_connect;
771		}
772	else
773		{
774		SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNKNOWN_PROTOCOL);
775		goto err;
776		}
777	s->init_num=0;
778
779	/* Since, if we are sending a ssl23 client hello, we are not
780	 * reusing a session-id */
781	if (!ssl_get_new_session(s,0))
782		goto err;
783
784	return(SSL_connect(s));
785err:
786	return(-1);
787	}
788