PR: 2778(part)
[openssl.git] / ssl / s23_clnt.c
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
119 static const SSL_METHOD *ssl23_get_client_method(int ver);
120 static int ssl23_client_hello(SSL *s);
121 static int ssl23_get_server_hello(SSL *s);
122 static 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         if (ver == SSL3_VERSION)
129                 return(SSLv3_client_method());
130         else if (ver == TLS1_VERSION)
131                 return(TLSv1_client_method());
132         else if (ver == TLS1_1_VERSION)
133                 return(TLSv1_1_client_method());
134         else if (ver == TLS1_2_VERSION)
135                 return(TLSv1_2_client_method());
136         else
137                 return(NULL);
138         }
139
140 IMPLEMENT_ssl23_meth_func(SSLv23_client_method,
141                         ssl_undefined_function,
142                         ssl23_connect,
143                         ssl23_get_client_method)
144
145 int ssl23_connect(SSL *s)
146         {
147         BUF_MEM *buf=NULL;
148         unsigned long Time=(unsigned long)time(NULL);
149         void (*cb)(const SSL *ssl,int type,int val)=NULL;
150         int ret= -1;
151         int new_state,state;
152
153         RAND_add(&Time,sizeof(Time),0);
154         ERR_clear_error();
155         clear_sys_error();
156
157         if (s->info_callback != NULL)
158                 cb=s->info_callback;
159         else if (s->ctx->info_callback != NULL)
160                 cb=s->ctx->info_callback;
161         
162         s->in_handshake++;
163         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); 
164
165         for (;;)
166                 {
167                 state=s->state;
168
169                 switch(s->state)
170                         {
171                 case SSL_ST_BEFORE:
172                 case SSL_ST_CONNECT:
173                 case SSL_ST_BEFORE|SSL_ST_CONNECT:
174                 case SSL_ST_OK|SSL_ST_CONNECT:
175
176                         if (s->session != NULL)
177                                 {
178                                 SSLerr(SSL_F_SSL23_CONNECT,SSL_R_SSL23_DOING_SESSION_ID_REUSE);
179                                 ret= -1;
180                                 goto end;
181                                 }
182                         s->server=0;
183                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
184
185                         /* s->version=TLS1_VERSION; */
186                         s->type=SSL_ST_CONNECT;
187
188                         if (s->init_buf == NULL)
189                                 {
190                                 if ((buf=BUF_MEM_new()) == NULL)
191                                         {
192                                         ret= -1;
193                                         goto end;
194                                         }
195                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
196                                         {
197                                         ret= -1;
198                                         goto end;
199                                         }
200                                 s->init_buf=buf;
201                                 buf=NULL;
202                                 }
203
204                         if (!ssl3_setup_buffers(s)) { ret= -1; goto end; }
205
206                         ssl3_init_finished_mac(s);
207
208                         s->state=SSL23_ST_CW_CLNT_HELLO_A;
209                         s->ctx->stats.sess_connect++;
210                         s->init_num=0;
211                         break;
212
213                 case SSL23_ST_CW_CLNT_HELLO_A:
214                 case SSL23_ST_CW_CLNT_HELLO_B:
215
216                         s->shutdown=0;
217                         ret=ssl23_client_hello(s);
218                         if (ret <= 0) goto end;
219                         s->state=SSL23_ST_CR_SRVR_HELLO_A;
220                         s->init_num=0;
221
222                         break;
223
224                 case SSL23_ST_CR_SRVR_HELLO_A:
225                 case SSL23_ST_CR_SRVR_HELLO_B:
226                         ret=ssl23_get_server_hello(s);
227                         if (ret >= 0) cb=NULL;
228                         goto end;
229                         /* break; */
230
231                 default:
232                         SSLerr(SSL_F_SSL23_CONNECT,SSL_R_UNKNOWN_STATE);
233                         ret= -1;
234                         goto end;
235                         /* break; */
236                         }
237
238                 if (s->debug) { (void)BIO_flush(s->wbio); }
239
240                 if ((cb != NULL) && (s->state != state))
241                         {
242                         new_state=s->state;
243                         s->state=state;
244                         cb(s,SSL_CB_CONNECT_LOOP,1);
245                         s->state=new_state;
246                         }
247                 }
248 end:
249         s->in_handshake--;
250         if (buf != NULL)
251                 BUF_MEM_free(buf);
252         if (cb != NULL)
253                 cb(s,SSL_CB_CONNECT_EXIT,ret);
254         return(ret);
255         }
256
257 static int ssl23_no_ssl2_ciphers(SSL *s)
258         {
259         SSL_CIPHER *cipher;
260         STACK_OF(SSL_CIPHER) *ciphers;
261         int i;
262         ciphers = SSL_get_ciphers(s);
263         for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++)
264                 {
265                 cipher = sk_SSL_CIPHER_value(ciphers, i);
266                 if (cipher->algorithm_ssl == SSL_SSLV2)
267                         return 0;
268                 }
269         return 1;
270         }
271
272 static int ssl23_client_hello(SSL *s)
273         {
274         unsigned char *buf;
275         unsigned char *p,*d;
276         int i,ch_len;
277         unsigned long Time,l;
278         int ssl2_compat;
279         int version = 0, version_major, version_minor;
280 #ifndef OPENSSL_NO_COMP
281         int j;
282         SSL_COMP *comp;
283 #endif
284         int ret;
285
286         ssl2_compat = (s->options & SSL_OP_NO_SSLv2) ? 0 : 1;
287
288         if (ssl2_compat && ssl23_no_ssl2_ciphers(s))
289                 ssl2_compat = 0;
290 #ifndef OPENSSL_NO_TLS1_2_CLIENT
291         if (!(s->options & SSL_OP_NO_TLSv1_2))
292                 {
293                 version = TLS1_2_VERSION;
294                 }
295         else
296 #endif
297         if (!(s->options & SSL_OP_NO_TLSv1_1))
298                 {
299                 version = TLS1_1_VERSION;
300                 }
301         else if (!(s->options & SSL_OP_NO_TLSv1))
302                 {
303                 version = TLS1_VERSION;
304                 }
305         else if (!(s->options & SSL_OP_NO_SSLv3))
306                 {
307                 version = SSL3_VERSION;
308                 }
309         else if (!(s->options & SSL_OP_NO_SSLv2))
310                 {
311                 version = SSL2_VERSION;
312                 }
313 #ifndef OPENSSL_NO_TLSEXT
314         if (version != SSL2_VERSION)
315                 {
316                 /* have to disable SSL 2.0 compatibility if we need TLS extensions */
317
318                 if (s->tlsext_hostname != NULL)
319                         ssl2_compat = 0;
320                 if (s->tlsext_status_type != -1)
321                         ssl2_compat = 0;
322 #ifdef TLSEXT_TYPE_opaque_prf_input
323                 if (s->ctx->tlsext_opaque_prf_input_callback != 0 || s->tlsext_opaque_prf_input != NULL)
324                         ssl2_compat = 0;
325 #endif
326                 }
327 #endif
328
329         buf=(unsigned char *)s->init_buf->data;
330         if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
331                 {
332 #if 0
333                 /* don't reuse session-id's */
334                 if (!ssl_get_new_session(s,0))
335                         {
336                         return(-1);
337                         }
338 #endif
339
340                 p=s->s3->client_random;
341                 Time=(unsigned long)time(NULL);         /* Time */
342                 l2n(Time,p);
343                 if (RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-4) <= 0)
344                         return -1;
345
346                 if (version == TLS1_2_VERSION)
347                         {
348                         version_major = TLS1_2_VERSION_MAJOR;
349                         version_minor = TLS1_2_VERSION_MINOR;
350                         }
351                 else if (version == TLS1_1_VERSION)
352                         {
353                         version_major = TLS1_1_VERSION_MAJOR;
354                         version_minor = TLS1_1_VERSION_MINOR;
355                         }
356                 else if (version == TLS1_VERSION)
357                         {
358                         version_major = TLS1_VERSION_MAJOR;
359                         version_minor = TLS1_VERSION_MINOR;
360                         }
361 #ifdef OPENSSL_FIPS
362                 else if(FIPS_mode())
363                         {
364                         SSLerr(SSL_F_SSL23_CLIENT_HELLO,
365                                         SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
366                         return -1;
367                         }
368 #endif
369                 else if (version == SSL3_VERSION)
370                         {
371                         version_major = SSL3_VERSION_MAJOR;
372                         version_minor = SSL3_VERSION_MINOR;
373                         }
374                 else if (version == SSL2_VERSION)
375                         {
376                         version_major = SSL2_VERSION_MAJOR;
377                         version_minor = SSL2_VERSION_MINOR;
378                         }
379                 else
380                         {
381                         SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_PROTOCOLS_AVAILABLE);
382                         return(-1);
383                         }
384
385                 s->client_version = version;
386
387                 if (ssl2_compat)
388                         {
389                         /* create SSL 2.0 compatible Client Hello */
390
391                         /* two byte record header will be written last */
392                         d = &(buf[2]);
393                         p = d + 9; /* leave space for message type, version, individual length fields */
394
395                         *(d++) = SSL2_MT_CLIENT_HELLO;
396                         *(d++) = version_major;
397                         *(d++) = version_minor;
398                         
399                         /* Ciphers supported */
400                         i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),p,0);
401                         if (i == 0)
402                                 {
403                                 /* no ciphers */
404                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
405                                 return -1;
406                                 }
407                         s2n(i,d);
408                         p+=i;
409                         
410                         /* put in the session-id length (zero since there is no reuse) */
411 #if 0
412                         s->session->session_id_length=0;
413 #endif
414                         s2n(0,d);
415
416                         if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
417                                 ch_len=SSL2_CHALLENGE_LENGTH;
418                         else
419                                 ch_len=SSL2_MAX_CHALLENGE_LENGTH;
420
421                         /* write out sslv2 challenge */
422                         /* Note that ch_len must be <= SSL3_RANDOM_SIZE (32),
423                            because it is one of SSL2_MAX_CHALLENGE_LENGTH (32)
424                            or SSL2_MAX_CHALLENGE_LENGTH (16), but leave the
425                            check in for futurproofing */
426                         if (SSL3_RANDOM_SIZE < ch_len)
427                                 i=SSL3_RANDOM_SIZE;
428                         else
429                                 i=ch_len;
430                         s2n(i,d);
431                         memset(&(s->s3->client_random[0]),0,SSL3_RANDOM_SIZE);
432                         if (RAND_pseudo_bytes(&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i) <= 0)
433                                 return -1;
434
435                         memcpy(p,&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
436                         p+=i;
437
438                         i= p- &(buf[2]);
439                         buf[0]=((i>>8)&0xff)|0x80;
440                         buf[1]=(i&0xff);
441
442                         /* number of bytes to write */
443                         s->init_num=i+2;
444                         s->init_off=0;
445
446                         ssl3_finish_mac(s,&(buf[2]),i);
447                         }
448                 else
449                         {
450                         /* create Client Hello in SSL 3.0/TLS 1.0 format */
451
452                         /* do the record header (5 bytes) and handshake message header (4 bytes) last */
453                         d = p = &(buf[9]);
454                         
455                         *(p++) = version_major;
456                         *(p++) = version_minor;
457
458                         /* Random stuff */
459                         memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
460                         p += SSL3_RANDOM_SIZE;
461
462                         /* Session ID (zero since there is no reuse) */
463                         *(p++) = 0;
464
465                         /* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
466                         i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),&(p[2]),ssl3_put_cipher_by_char);
467                         if (i == 0)
468                                 {
469                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
470                                 return -1;
471                                 }
472                         s2n(i,p);
473                         p+=i;
474
475                         /* COMPRESSION */
476 #ifdef OPENSSL_NO_COMP
477                         *(p++)=1;
478 #else
479                         if ((s->options & SSL_OP_NO_COMPRESSION)
480                                                 || !s->ctx->comp_methods)
481                                 j=0;
482                         else
483                                 j=sk_SSL_COMP_num(s->ctx->comp_methods);
484                         *(p++)=1+j;
485                         for (i=0; i<j; i++)
486                                 {
487                                 comp=sk_SSL_COMP_value(s->ctx->comp_methods,i);
488                                 *(p++)=comp->id;
489                                 }
490 #endif
491                         *(p++)=0; /* Add the NULL method */
492
493 #ifndef OPENSSL_NO_TLSEXT
494                         /* TLS extensions*/
495                         if (ssl_prepare_clienthello_tlsext(s) <= 0)
496                                 {
497                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
498                                 return -1;
499                                 }
500                         if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
501                                 {
502                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
503                                 return -1;
504                                 }
505 #endif
506                         
507                         l = p-d;
508
509                         /* fill in 4-byte handshake header */
510                         d=&(buf[5]);
511                         *(d++)=SSL3_MT_CLIENT_HELLO;
512                         l2n3(l,d);
513
514                         l += 4;
515
516                         if (l > SSL3_RT_MAX_PLAIN_LENGTH)
517                                 {
518                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
519                                 return -1;
520                                 }
521                         
522                         /* fill in 5-byte record header */
523                         d=buf;
524                         *(d++) = SSL3_RT_HANDSHAKE;
525                         *(d++) = version_major;
526                         *(d++) = version_minor; /* arguably we should send the *lowest* suported version here
527                                                  * (indicating, e.g., TLS 1.0 in "SSL 3.0 format") */
528                         s2n((int)l,d);
529
530                         /* number of bytes to write */
531                         s->init_num=p-buf;
532                         s->init_off=0;
533
534                         ssl3_finish_mac(s,&(buf[5]), s->init_num - 5);
535                         }
536
537                 s->state=SSL23_ST_CW_CLNT_HELLO_B;
538                 s->init_off=0;
539                 }
540
541         /* SSL3_ST_CW_CLNT_HELLO_B */
542         ret = ssl23_write_bytes(s);
543
544         if ((ret >= 2) && s->msg_callback)
545                 {
546                 /* Client Hello has been sent; tell msg_callback */
547
548                 if (ssl2_compat)
549                         s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data+2, ret-2, s, s->msg_callback_arg);
550                 else
551                         s->msg_callback(1, version, SSL3_RT_HANDSHAKE, s->init_buf->data+5, ret-5, s, s->msg_callback_arg);
552                 }
553
554         return ret;
555         }
556
557 static int ssl23_get_server_hello(SSL *s)
558         {
559         char buf[8];
560         unsigned char *p;
561         int i;
562         int n;
563
564         n=ssl23_read_bytes(s,7);
565
566         if (n != 7) return(n);
567         p=s->packet;
568
569         memcpy(buf,p,n);
570
571         if ((p[0] & 0x80) && (p[2] == SSL2_MT_SERVER_HELLO) &&
572                 (p[5] == 0x00) && (p[6] == 0x02))
573                 {
574 #ifdef OPENSSL_NO_SSL2
575                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
576                 goto err;
577 #else
578                 /* we are talking sslv2 */
579                 /* we need to clean up the SSLv3 setup and put in the
580                  * sslv2 stuff. */
581                 int ch_len;
582
583                 if (s->options & SSL_OP_NO_SSLv2)
584                         {
585                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
586                         goto err;
587                         }
588                 if (s->s2 == NULL)
589                         {
590                         if (!ssl2_new(s))
591                                 goto err;
592                         }
593                 else
594                         ssl2_clear(s);
595
596                 if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
597                         ch_len=SSL2_CHALLENGE_LENGTH;
598                 else
599                         ch_len=SSL2_MAX_CHALLENGE_LENGTH;
600
601                 /* write out sslv2 challenge */
602                 /* Note that ch_len must be <= SSL3_RANDOM_SIZE (32), because
603                    it is one of SSL2_MAX_CHALLENGE_LENGTH (32) or
604                    SSL2_MAX_CHALLENGE_LENGTH (16), but leave the check in for
605                    futurproofing */
606                 i=(SSL3_RANDOM_SIZE < ch_len)
607                         ?SSL3_RANDOM_SIZE:ch_len;
608                 s->s2->challenge_length=i;
609                 memcpy(s->s2->challenge,
610                         &(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
611
612                 if (s->s3 != NULL) ssl3_free(s);
613
614                 if (!BUF_MEM_grow_clean(s->init_buf,
615                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
616                         {
617                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,ERR_R_BUF_LIB);
618                         goto err;
619                         }
620
621                 s->state=SSL2_ST_GET_SERVER_HELLO_A;
622                 if (!(s->client_version == SSL2_VERSION))
623                         /* use special padding (SSL 3.0 draft/RFC 2246, App. E.2) */
624                         s->s2->ssl2_rollback=1;
625
626                 /* setup the 7 bytes we have read so we get them from
627                  * the sslv2 buffer */
628                 s->rstate=SSL_ST_READ_HEADER;
629                 s->packet_length=n;
630                 s->packet= &(s->s2->rbuf[0]);
631                 memcpy(s->packet,buf,n);
632                 s->s2->rbuf_left=n;
633                 s->s2->rbuf_offs=0;
634
635                 /* we have already written one */
636                 s->s2->write_sequence=1;
637
638                 s->method=SSLv2_client_method();
639                 s->handshake_func=s->method->ssl_connect;
640 #endif
641                 }
642         else if (p[1] == SSL3_VERSION_MAJOR &&
643                  p[2] <= TLS1_2_VERSION_MINOR &&
644                  ((p[0] == SSL3_RT_HANDSHAKE && p[5] == SSL3_MT_SERVER_HELLO) ||
645                   (p[0] == SSL3_RT_ALERT && p[3] == 0 && p[4] == 2)))
646                 {
647                 /* we have sslv3 or tls1 (server hello or alert) */
648
649                 if ((p[2] == SSL3_VERSION_MINOR) &&
650                         !(s->options & SSL_OP_NO_SSLv3))
651                         {
652 #ifdef OPENSSL_FIPS
653                         if(FIPS_mode())
654                                 {
655                                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,
656                                         SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
657                                 goto err;
658                                 }
659 #endif
660                         s->version=SSL3_VERSION;
661                         s->method=SSLv3_client_method();
662                         }
663                 else if ((p[2] == TLS1_VERSION_MINOR) &&
664                         !(s->options & SSL_OP_NO_TLSv1))
665                         {
666                         s->version=TLS1_VERSION;
667                         s->method=TLSv1_client_method();
668                         }
669                 else if ((p[2] == TLS1_1_VERSION_MINOR) &&
670                         !(s->options & SSL_OP_NO_TLSv1_1))
671                         {
672                         s->version=TLS1_1_VERSION;
673                         s->method=TLSv1_1_client_method();
674                         }
675                 else if ((p[2] == TLS1_2_VERSION_MINOR) &&
676                         !(s->options & SSL_OP_NO_TLSv1_2))
677                         {
678                         s->version=TLS1_2_VERSION;
679                         s->method=TLSv1_2_client_method();
680                         }
681                 else
682                         {
683                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
684                         goto err;
685                         }
686
687                 if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING)
688                         {
689                         /* fatal alert */
690
691                         void (*cb)(const SSL *ssl,int type,int val)=NULL;
692                         int j;
693
694                         if (s->info_callback != NULL)
695                                 cb=s->info_callback;
696                         else if (s->ctx->info_callback != NULL)
697                                 cb=s->ctx->info_callback;
698  
699                         i=p[5];
700                         if (cb != NULL)
701                                 {
702                                 j=(i<<8)|p[6];
703                                 cb(s,SSL_CB_READ_ALERT,j);
704                                 }
705                         
706                         if (s->msg_callback)
707                                 s->msg_callback(0, s->version, SSL3_RT_ALERT, p+5, 2, s, s->msg_callback_arg);
708
709                         s->rwstate=SSL_NOTHING;
710                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_AD_REASON_OFFSET+p[6]);
711                         goto err;
712                         }
713
714                 if (!ssl_init_wbio_buffer(s,1)) goto err;
715
716                 /* we are in this state */
717                 s->state=SSL3_ST_CR_SRVR_HELLO_A;
718
719                 /* put the 7 bytes we have read into the input buffer
720                  * for SSLv3 */
721                 s->rstate=SSL_ST_READ_HEADER;
722                 s->packet_length=n;
723                 if (s->s3->rbuf.buf == NULL)
724                         if (!ssl3_setup_read_buffer(s))
725                                 goto err;
726                 s->packet= &(s->s3->rbuf.buf[0]);
727                 memcpy(s->packet,buf,n);
728                 s->s3->rbuf.left=n;
729                 s->s3->rbuf.offset=0;
730
731                 s->handshake_func=s->method->ssl_connect;
732                 }
733         else
734                 {
735                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNKNOWN_PROTOCOL);
736                 goto err;
737                 }
738         s->init_num=0;
739
740         /* Since, if we are sending a ssl23 client hello, we are not
741          * reusing a session-id */
742         if (!ssl_get_new_session(s,0))
743                 goto err;
744
745         return(SSL_connect(s));
746 err:
747         return(-1);
748         }