s23_clnt.c revision 273399
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
274/* Fill a ClientRandom or ServerRandom field of length len. Returns <= 0
275 * on failure, 1 on success. */
276int ssl_fill_hello_random(SSL *s, int server, unsigned char *result, int len)
277	{
278	int send_time = 0;
279
280	if (len < 4)
281		return 0;
282	if (server)
283		send_time = (s->mode & SSL_MODE_SEND_SERVERHELLO_TIME) != 0;
284	else
285		send_time = (s->mode & SSL_MODE_SEND_CLIENTHELLO_TIME) != 0;
286	if (send_time)
287		{
288		unsigned long Time = (unsigned long)time(NULL);
289		unsigned char *p = result;
290		l2n(Time, p);
291		return RAND_pseudo_bytes(p, len-4);
292		}
293	else
294		return RAND_pseudo_bytes(result, len);
295	}
296
297static int ssl23_client_hello(SSL *s)
298	{
299	unsigned char *buf;
300	unsigned char *p,*d;
301	int i,ch_len;
302	unsigned long l;
303	int ssl2_compat;
304	int version = 0, version_major, version_minor;
305#ifndef OPENSSL_NO_COMP
306	int j;
307	SSL_COMP *comp;
308#endif
309	int ret;
310	unsigned long mask, options = s->options;
311
312	ssl2_compat = (options & SSL_OP_NO_SSLv2) ? 0 : 1;
313
314	if (ssl2_compat && ssl23_no_ssl2_ciphers(s))
315		ssl2_compat = 0;
316
317	/*
318	 * SSL_OP_NO_X disables all protocols above X *if* there are
319	 * some protocols below X enabled. This is required in order
320	 * to maintain "version capability" vector contiguous. So
321	 * that if application wants to disable TLS1.0 in favour of
322	 * TLS1>=1, it would be insufficient to pass SSL_NO_TLSv1, the
323	 * answer is SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2.
324	 */
325	mask =	SSL_OP_NO_TLSv1_1|SSL_OP_NO_TLSv1
326#if !defined(OPENSSL_NO_SSL3)
327		|SSL_OP_NO_SSLv3
328#endif
329#if !defined(OPENSSL_NO_SSL2)
330		|(ssl2_compat?SSL_OP_NO_SSLv2:0)
331#endif
332		;
333#if !defined(OPENSSL_NO_TLS1_2_CLIENT)
334	version = TLS1_2_VERSION;
335
336	if ((options & SSL_OP_NO_TLSv1_2) && (options & mask) != mask)
337		version = TLS1_1_VERSION;
338#else
339	version = TLS1_1_VERSION;
340#endif
341	mask &= ~SSL_OP_NO_TLSv1_1;
342	if ((options & SSL_OP_NO_TLSv1_1) && (options & mask) != mask)
343		version = TLS1_VERSION;
344	mask &= ~SSL_OP_NO_TLSv1;
345#if !defined(OPENSSL_NO_SSL3)
346	if ((options & SSL_OP_NO_TLSv1) && (options & mask) != mask)
347		version = SSL3_VERSION;
348	mask &= ~SSL_OP_NO_SSLv3;
349#endif
350#if !defined(OPENSSL_NO_SSL2)
351	if ((options & SSL_OP_NO_SSLv3) && (options & mask) != mask)
352		version = SSL2_VERSION;
353#endif
354
355#ifndef OPENSSL_NO_TLSEXT
356	if (version != SSL2_VERSION)
357		{
358		/* have to disable SSL 2.0 compatibility if we need TLS extensions */
359
360		if (s->tlsext_hostname != NULL)
361			ssl2_compat = 0;
362		if (s->tlsext_status_type != -1)
363			ssl2_compat = 0;
364#ifdef TLSEXT_TYPE_opaque_prf_input
365		if (s->ctx->tlsext_opaque_prf_input_callback != 0 || s->tlsext_opaque_prf_input != NULL)
366			ssl2_compat = 0;
367#endif
368		}
369#endif
370
371	buf=(unsigned char *)s->init_buf->data;
372	if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
373		{
374#if 0
375		/* don't reuse session-id's */
376		if (!ssl_get_new_session(s,0))
377			{
378			return(-1);
379			}
380#endif
381
382		p=s->s3->client_random;
383		if (ssl_fill_hello_random(s, 0, p, SSL3_RANDOM_SIZE) <= 0)
384			return -1;
385
386		if (version == TLS1_2_VERSION)
387			{
388			version_major = TLS1_2_VERSION_MAJOR;
389			version_minor = TLS1_2_VERSION_MINOR;
390			}
391		else if (version == TLS1_1_VERSION)
392			{
393			version_major = TLS1_1_VERSION_MAJOR;
394			version_minor = TLS1_1_VERSION_MINOR;
395			}
396		else if (version == TLS1_VERSION)
397			{
398			version_major = TLS1_VERSION_MAJOR;
399			version_minor = TLS1_VERSION_MINOR;
400			}
401#ifdef OPENSSL_FIPS
402		else if(FIPS_mode())
403			{
404			SSLerr(SSL_F_SSL23_CLIENT_HELLO,
405					SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
406			return -1;
407			}
408#endif
409		else if (version == SSL3_VERSION)
410			{
411			version_major = SSL3_VERSION_MAJOR;
412			version_minor = SSL3_VERSION_MINOR;
413			}
414		else if (version == SSL2_VERSION)
415			{
416			version_major = SSL2_VERSION_MAJOR;
417			version_minor = SSL2_VERSION_MINOR;
418			}
419		else
420			{
421			SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_PROTOCOLS_AVAILABLE);
422			return(-1);
423			}
424
425		s->client_version = version;
426
427		if (ssl2_compat)
428			{
429			/* create SSL 2.0 compatible Client Hello */
430
431			/* two byte record header will be written last */
432			d = &(buf[2]);
433			p = d + 9; /* leave space for message type, version, individual length fields */
434
435			*(d++) = SSL2_MT_CLIENT_HELLO;
436			*(d++) = version_major;
437			*(d++) = version_minor;
438
439			/* Ciphers supported */
440			i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),p,0);
441			if (i == 0)
442				{
443				/* no ciphers */
444				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
445				return -1;
446				}
447			s2n(i,d);
448			p+=i;
449
450			/* put in the session-id length (zero since there is no reuse) */
451#if 0
452			s->session->session_id_length=0;
453#endif
454			s2n(0,d);
455
456			if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
457				ch_len=SSL2_CHALLENGE_LENGTH;
458			else
459				ch_len=SSL2_MAX_CHALLENGE_LENGTH;
460
461			/* write out sslv2 challenge */
462			/* Note that ch_len must be <= SSL3_RANDOM_SIZE (32),
463			   because it is one of SSL2_MAX_CHALLENGE_LENGTH (32)
464			   or SSL2_MAX_CHALLENGE_LENGTH (16), but leave the
465			   check in for futurproofing */
466			if (SSL3_RANDOM_SIZE < ch_len)
467				i=SSL3_RANDOM_SIZE;
468			else
469				i=ch_len;
470			s2n(i,d);
471			memset(&(s->s3->client_random[0]),0,SSL3_RANDOM_SIZE);
472			if (RAND_pseudo_bytes(&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i) <= 0)
473				return -1;
474
475			memcpy(p,&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
476			p+=i;
477
478			i= p- &(buf[2]);
479			buf[0]=((i>>8)&0xff)|0x80;
480			buf[1]=(i&0xff);
481
482			/* number of bytes to write */
483			s->init_num=i+2;
484			s->init_off=0;
485
486			ssl3_finish_mac(s,&(buf[2]),i);
487			}
488		else
489			{
490			/* create Client Hello in SSL 3.0/TLS 1.0 format */
491
492			/* do the record header (5 bytes) and handshake message header (4 bytes) last */
493			d = p = &(buf[9]);
494
495			*(p++) = version_major;
496			*(p++) = version_minor;
497
498			/* Random stuff */
499			memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
500			p += SSL3_RANDOM_SIZE;
501
502			/* Session ID (zero since there is no reuse) */
503			*(p++) = 0;
504
505			/* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
506			i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),&(p[2]),ssl3_put_cipher_by_char);
507			if (i == 0)
508				{
509				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
510				return -1;
511				}
512#ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
513			/* Some servers hang if client hello > 256 bytes
514			 * as hack workaround chop number of supported ciphers
515			 * to keep it well below this if we use TLS v1.2
516			 */
517			if (TLS1_get_version(s) >= TLS1_2_VERSION
518				&& i > OPENSSL_MAX_TLS1_2_CIPHER_LENGTH)
519				i = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
520#endif
521			s2n(i,p);
522			p+=i;
523
524			/* COMPRESSION */
525#ifdef OPENSSL_NO_COMP
526			*(p++)=1;
527#else
528			if ((s->options & SSL_OP_NO_COMPRESSION)
529						|| !s->ctx->comp_methods)
530				j=0;
531			else
532				j=sk_SSL_COMP_num(s->ctx->comp_methods);
533			*(p++)=1+j;
534			for (i=0; i<j; i++)
535				{
536				comp=sk_SSL_COMP_value(s->ctx->comp_methods,i);
537				*(p++)=comp->id;
538				}
539#endif
540			*(p++)=0; /* Add the NULL method */
541
542#ifndef OPENSSL_NO_TLSEXT
543			/* TLS extensions*/
544			if (ssl_prepare_clienthello_tlsext(s) <= 0)
545				{
546				SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
547				return -1;
548				}
549			if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
550				{
551				SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
552				return -1;
553				}
554#endif
555
556			l = p-d;
557
558			/* fill in 4-byte handshake header */
559			d=&(buf[5]);
560			*(d++)=SSL3_MT_CLIENT_HELLO;
561			l2n3(l,d);
562
563			l += 4;
564
565			if (l > SSL3_RT_MAX_PLAIN_LENGTH)
566				{
567				SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
568				return -1;
569				}
570
571			/* fill in 5-byte record header */
572			d=buf;
573			*(d++) = SSL3_RT_HANDSHAKE;
574			*(d++) = version_major;
575			/* Some servers hang if we use long client hellos
576			 * and a record number > TLS 1.0.
577			 */
578			if (TLS1_get_client_version(s) > TLS1_VERSION)
579				*(d++) = 1;
580			else
581				*(d++) = version_minor;
582			s2n((int)l,d);
583
584			/* number of bytes to write */
585			s->init_num=p-buf;
586			s->init_off=0;
587
588			ssl3_finish_mac(s,&(buf[5]), s->init_num - 5);
589			}
590
591		s->state=SSL23_ST_CW_CLNT_HELLO_B;
592		s->init_off=0;
593		}
594
595	/* SSL3_ST_CW_CLNT_HELLO_B */
596	ret = ssl23_write_bytes(s);
597
598	if ((ret >= 2) && s->msg_callback)
599		{
600		/* Client Hello has been sent; tell msg_callback */
601
602		if (ssl2_compat)
603			s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data+2, ret-2, s, s->msg_callback_arg);
604		else
605			s->msg_callback(1, version, SSL3_RT_HANDSHAKE, s->init_buf->data+5, ret-5, s, s->msg_callback_arg);
606		}
607
608	return ret;
609	}
610
611static int ssl23_get_server_hello(SSL *s)
612	{
613	char buf[8];
614	unsigned char *p;
615	int i;
616	int n;
617
618	n=ssl23_read_bytes(s,7);
619
620	if (n != 7) return(n);
621	p=s->packet;
622
623	memcpy(buf,p,n);
624
625	if ((p[0] & 0x80) && (p[2] == SSL2_MT_SERVER_HELLO) &&
626		(p[5] == 0x00) && (p[6] == 0x02))
627		{
628#ifdef OPENSSL_NO_SSL2
629		SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
630		goto err;
631#else
632		/* we are talking sslv2 */
633		/* we need to clean up the SSLv3 setup and put in the
634		 * sslv2 stuff. */
635		int ch_len;
636
637		if (s->options & SSL_OP_NO_SSLv2)
638			{
639			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
640			goto err;
641			}
642		if (s->s2 == NULL)
643			{
644			if (!ssl2_new(s))
645				goto err;
646			}
647		else
648			ssl2_clear(s);
649
650		if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
651			ch_len=SSL2_CHALLENGE_LENGTH;
652		else
653			ch_len=SSL2_MAX_CHALLENGE_LENGTH;
654
655		/* write out sslv2 challenge */
656		/* Note that ch_len must be <= SSL3_RANDOM_SIZE (32), because
657		   it is one of SSL2_MAX_CHALLENGE_LENGTH (32) or
658		   SSL2_MAX_CHALLENGE_LENGTH (16), but leave the check in for
659		   futurproofing */
660		i=(SSL3_RANDOM_SIZE < ch_len)
661			?SSL3_RANDOM_SIZE:ch_len;
662		s->s2->challenge_length=i;
663		memcpy(s->s2->challenge,
664			&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
665
666		if (s->s3 != NULL) ssl3_free(s);
667
668		if (!BUF_MEM_grow_clean(s->init_buf,
669			SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
670			{
671			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,ERR_R_BUF_LIB);
672			goto err;
673			}
674
675		s->state=SSL2_ST_GET_SERVER_HELLO_A;
676		if (!(s->client_version == SSL2_VERSION))
677			/* use special padding (SSL 3.0 draft/RFC 2246, App. E.2) */
678			s->s2->ssl2_rollback=1;
679
680		/* setup the 7 bytes we have read so we get them from
681		 * the sslv2 buffer */
682		s->rstate=SSL_ST_READ_HEADER;
683		s->packet_length=n;
684		s->packet= &(s->s2->rbuf[0]);
685		memcpy(s->packet,buf,n);
686		s->s2->rbuf_left=n;
687		s->s2->rbuf_offs=0;
688
689		/* we have already written one */
690		s->s2->write_sequence=1;
691
692		s->method=SSLv2_client_method();
693		s->handshake_func=s->method->ssl_connect;
694#endif
695		}
696	else if (p[1] == SSL3_VERSION_MAJOR &&
697	         p[2] <= TLS1_2_VERSION_MINOR &&
698	         ((p[0] == SSL3_RT_HANDSHAKE && p[5] == SSL3_MT_SERVER_HELLO) ||
699	          (p[0] == SSL3_RT_ALERT && p[3] == 0 && p[4] == 2)))
700		{
701		/* we have sslv3 or tls1 (server hello or alert) */
702
703#ifndef OPENSSL_NO_SSL3
704		if ((p[2] == SSL3_VERSION_MINOR) &&
705			!(s->options & SSL_OP_NO_SSLv3))
706			{
707#ifdef OPENSSL_FIPS
708			if(FIPS_mode())
709				{
710				SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,
711					SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
712				goto err;
713				}
714#endif
715			s->version=SSL3_VERSION;
716			s->method=SSLv3_client_method();
717			}
718		else
719#endif
720		if ((p[2] == TLS1_VERSION_MINOR) &&
721			!(s->options & SSL_OP_NO_TLSv1))
722			{
723			s->version=TLS1_VERSION;
724			s->method=TLSv1_client_method();
725			}
726		else if ((p[2] == TLS1_1_VERSION_MINOR) &&
727			!(s->options & SSL_OP_NO_TLSv1_1))
728			{
729			s->version=TLS1_1_VERSION;
730			s->method=TLSv1_1_client_method();
731			}
732		else if ((p[2] == TLS1_2_VERSION_MINOR) &&
733			!(s->options & SSL_OP_NO_TLSv1_2))
734			{
735			s->version=TLS1_2_VERSION;
736			s->method=TLSv1_2_client_method();
737			}
738		else
739			{
740			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
741			goto err;
742			}
743
744		/* ensure that TLS_MAX_VERSION is up-to-date */
745		OPENSSL_assert(s->version <= TLS_MAX_VERSION);
746
747		if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING)
748			{
749			/* fatal alert */
750
751			void (*cb)(const SSL *ssl,int type,int val)=NULL;
752			int j;
753
754			if (s->info_callback != NULL)
755				cb=s->info_callback;
756			else if (s->ctx->info_callback != NULL)
757				cb=s->ctx->info_callback;
758
759			i=p[5];
760			if (cb != NULL)
761				{
762				j=(i<<8)|p[6];
763				cb(s,SSL_CB_READ_ALERT,j);
764				}
765
766			if (s->msg_callback)
767				s->msg_callback(0, s->version, SSL3_RT_ALERT, p+5, 2, s, s->msg_callback_arg);
768
769			s->rwstate=SSL_NOTHING;
770			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_AD_REASON_OFFSET+p[6]);
771			goto err;
772			}
773
774		if (!ssl_init_wbio_buffer(s,1)) goto err;
775
776		/* we are in this state */
777		s->state=SSL3_ST_CR_SRVR_HELLO_A;
778
779		/* put the 7 bytes we have read into the input buffer
780		 * for SSLv3 */
781		s->rstate=SSL_ST_READ_HEADER;
782		s->packet_length=n;
783		if (s->s3->rbuf.buf == NULL)
784			if (!ssl3_setup_read_buffer(s))
785				goto err;
786		s->packet= &(s->s3->rbuf.buf[0]);
787		memcpy(s->packet,buf,n);
788		s->s3->rbuf.left=n;
789		s->s3->rbuf.offset=0;
790
791		s->handshake_func=s->method->ssl_connect;
792		}
793	else
794		{
795		SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNKNOWN_PROTOCOL);
796		goto err;
797		}
798	s->init_num=0;
799
800	/* Since, if we are sending a ssl23 client hello, we are not
801	 * reusing a session-id */
802	if (!ssl_get_new_session(s,0))
803		goto err;
804
805	return(SSL_connect(s));
806err:
807	return(-1);
808	}
809