Keep old method in case of an unsupported protocol
[openssl.git] / ssl / s23_srvr.c
1 /* ssl/s23_srvr.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 #ifdef OPENSSL_FIPS
119 #include <openssl/fips.h>
120 #endif
121
122 static const SSL_METHOD *ssl23_get_server_method(int ver);
123 int ssl23_get_client_hello(SSL *s);
124 static const SSL_METHOD *ssl23_get_server_method(int ver)
125         {
126 #ifndef OPENSSL_NO_SSL2
127         if (ver == SSL2_VERSION)
128                 return(SSLv2_server_method());
129 #endif
130 #ifndef OPENSSL_NO_SSL3
131         if (ver == SSL3_VERSION)
132                 return(SSLv3_server_method());
133 #endif
134         if (ver == TLS1_VERSION)
135                 return(TLSv1_server_method());
136         else if (ver == TLS1_1_VERSION)
137                 return(TLSv1_1_server_method());
138         else if (ver == TLS1_2_VERSION)
139                 return(TLSv1_2_server_method());
140         else
141                 return(NULL);
142         }
143
144 IMPLEMENT_ssl23_meth_func(SSLv23_server_method,
145                         ssl23_accept,
146                         ssl_undefined_function,
147                         ssl23_get_server_method)
148
149 int ssl23_accept(SSL *s)
150         {
151         BUF_MEM *buf;
152         unsigned long Time=(unsigned long)time(NULL);
153         void (*cb)(const SSL *ssl,int type,int val)=NULL;
154         int ret= -1;
155         int new_state,state;
156
157         RAND_add(&Time,sizeof(Time),0);
158         ERR_clear_error();
159         clear_sys_error();
160
161         if (s->info_callback != NULL)
162                 cb=s->info_callback;
163         else if (s->ctx->info_callback != NULL)
164                 cb=s->ctx->info_callback;
165         
166         s->in_handshake++;
167         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); 
168
169         for (;;)
170                 {
171                 state=s->state;
172
173                 switch(s->state)
174                         {
175                 case SSL_ST_BEFORE:
176                 case SSL_ST_ACCEPT:
177                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
178                 case SSL_ST_OK|SSL_ST_ACCEPT:
179
180                         s->server=1;
181                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
182
183                         /* s->version=SSL3_VERSION; */
184                         s->type=SSL_ST_ACCEPT;
185
186                         if (s->init_buf == NULL)
187                                 {
188                                 if ((buf=BUF_MEM_new()) == NULL)
189                                         {
190                                         ret= -1;
191                                         goto end;
192                                         }
193                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
194                                         {
195                                         ret= -1;
196                                         goto end;
197                                         }
198                                 s->init_buf=buf;
199                                 }
200
201                         ssl3_init_finished_mac(s);
202
203                         s->state=SSL23_ST_SR_CLNT_HELLO_A;
204                         s->ctx->stats.sess_accept++;
205                         s->init_num=0;
206                         break;
207
208                 case SSL23_ST_SR_CLNT_HELLO_A:
209                 case SSL23_ST_SR_CLNT_HELLO_B:
210
211                         s->shutdown=0;
212                         ret=ssl23_get_client_hello(s);
213                         if (ret >= 0) cb=NULL;
214                         goto end;
215                         /* break; */
216
217                 default:
218                         SSLerr(SSL_F_SSL23_ACCEPT,SSL_R_UNKNOWN_STATE);
219                         ret= -1;
220                         goto end;
221                         /* break; */
222                         }
223
224                 if ((cb != NULL) && (s->state != state))
225                         {
226                         new_state=s->state;
227                         s->state=state;
228                         cb(s,SSL_CB_ACCEPT_LOOP,1);
229                         s->state=new_state;
230                         }
231                 }
232 end:
233         s->in_handshake--;
234         if (cb != NULL)
235                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
236         return(ret);
237         }
238
239
240 int ssl23_get_client_hello(SSL *s)
241         {
242         char buf_space[11]; /* Request this many bytes in initial read.
243                              * We can detect SSL 3.0/TLS 1.0 Client Hellos
244                              * ('type == 3') correctly only when the following
245                              * is in a single record, which is not guaranteed by
246                              * the protocol specification:
247                              * Byte  Content
248                              *  0     type            \
249                              *  1/2   version          > record header
250                              *  3/4   length          /
251                              *  5     msg_type        \
252                              *  6-8   length           > Client Hello message
253                              *  9/10  client_version  /
254                              */
255         char *buf= &(buf_space[0]);
256         unsigned char *p,*d,*d_len,*dd;
257         unsigned int i;
258         unsigned int csl,sil,cl;
259         int n=0,j;
260         int type=0;
261         int v[2];
262
263         if (s->state == SSL23_ST_SR_CLNT_HELLO_A)
264                 {
265                 /* read the initial header */
266                 v[0]=v[1]=0;
267
268                 if (!ssl3_setup_buffers(s)) goto err;
269
270                 n=ssl23_read_bytes(s, sizeof buf_space);
271                 if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */
272
273                 p=s->packet;
274
275                 memcpy(buf,p,n);
276
277                 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO))
278                         {
279                         /*
280                          * SSLv2 header
281                          */
282                         if ((p[3] == 0x00) && (p[4] == 0x02))
283                                 {
284                                 v[0]=p[3]; v[1]=p[4];
285                                 /* SSLv2 */
286                                 if (!(s->options & SSL_OP_NO_SSLv2))
287                                         type=1;
288                                 }
289                         else if (p[3] == SSL3_VERSION_MAJOR)
290                                 {
291                                 v[0]=p[3]; v[1]=p[4];
292                                 /* SSLv3/TLSv1 */
293                                 if (p[4] >= TLS1_VERSION_MINOR)
294                                         {
295                                         if (p[4] >= TLS1_2_VERSION_MINOR &&
296                                            !(s->options & SSL_OP_NO_TLSv1_2))
297                                                 {
298                                                 s->version=TLS1_2_VERSION;
299                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
300                                                 }
301                                         else if (p[4] >= TLS1_1_VERSION_MINOR &&
302                                            !(s->options & SSL_OP_NO_TLSv1_1))
303                                                 {
304                                                 s->version=TLS1_1_VERSION;
305                                                 /* type=2; */ /* done later to survive restarts */
306                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
307                                                 }
308                                         else if (!(s->options & SSL_OP_NO_TLSv1))
309                                                 {
310                                                 s->version=TLS1_VERSION;
311                                                 /* type=2; */ /* done later to survive restarts */
312                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
313                                                 }
314                                         else if (!(s->options & SSL_OP_NO_SSLv3))
315                                                 {
316                                                 s->version=SSL3_VERSION;
317                                                 /* type=2; */
318                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
319                                                 }
320                                         else if (!(s->options & SSL_OP_NO_SSLv2))
321                                                 {
322                                                 type=1;
323                                                 }
324                                         }
325                                 else if (!(s->options & SSL_OP_NO_SSLv3))
326                                         {
327                                         s->version=SSL3_VERSION;
328                                         /* type=2; */
329                                         s->state=SSL23_ST_SR_CLNT_HELLO_B;
330                                         }
331                                 else if (!(s->options & SSL_OP_NO_SSLv2))
332                                         type=1;
333
334                                 }
335                         }
336                 else if ((p[0] == SSL3_RT_HANDSHAKE) &&
337                          (p[1] == SSL3_VERSION_MAJOR) &&
338                          (p[5] == SSL3_MT_CLIENT_HELLO) &&
339                          ((p[3] == 0 && p[4] < 5 /* silly record length? */)
340                                 || (p[9] >= p[1])))
341                         {
342                         /*
343                          * SSLv3 or tls1 header
344                          */
345                         
346                         v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */
347                         /* We must look at client_version inside the Client Hello message
348                          * to get the correct minor version.
349                          * However if we have only a pathologically small fragment of the
350                          * Client Hello message, this would be difficult, and we'd have
351                          * to read more records to find out.
352                          * No known SSL 3.0 client fragments ClientHello like this,
353                          * so we simply reject such connections to avoid
354                          * protocol version downgrade attacks. */
355                         if (p[3] == 0 && p[4] < 6)
356                                 {
357                                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL);
358                                 goto err;
359                                 }
360                         /* if major version number > 3 set minor to a value
361                          * which will use the highest version 3 we support.
362                          * If TLS 2.0 ever appears we will need to revise
363                          * this....
364                          */
365                         if (p[9] > SSL3_VERSION_MAJOR)
366                                 v[1]=0xff;
367                         else
368                                 v[1]=p[10]; /* minor version according to client_version */
369                         if (v[1] >= TLS1_VERSION_MINOR)
370                                 {
371                                 if (v[1] >= TLS1_2_VERSION_MINOR &&
372                                         !(s->options & SSL_OP_NO_TLSv1_2))
373                                         {
374                                         s->version=TLS1_2_VERSION;
375                                         type=3;
376                                         }
377                                 else if (v[1] >= TLS1_1_VERSION_MINOR &&
378                                         !(s->options & SSL_OP_NO_TLSv1_1))
379                                         {
380                                         s->version=TLS1_1_VERSION;
381                                         type=3;
382                                         }
383                                 else if (!(s->options & SSL_OP_NO_TLSv1))
384                                         {
385                                         s->version=TLS1_VERSION;
386                                         type=3;
387                                         }
388                                 else if (!(s->options & SSL_OP_NO_SSLv3))
389                                         {
390                                         s->version=SSL3_VERSION;
391                                         type=3;
392                                         }
393                                 }
394                         else
395                                 {
396                                 /* client requests SSL 3.0 */
397                                 if (!(s->options & SSL_OP_NO_SSLv3))
398                                         {
399                                         s->version=SSL3_VERSION;
400                                         type=3;
401                                         }
402                                 else if (!(s->options & SSL_OP_NO_TLSv1))
403                                         {
404                                         /* we won't be able to use TLS of course,
405                                          * but this will send an appropriate alert */
406                                         s->version=TLS1_VERSION;
407                                         type=3;
408                                         }
409                                 }
410                         }
411                 else if ((strncmp("GET ", (char *)p,4) == 0) ||
412                          (strncmp("POST ",(char *)p,5) == 0) ||
413                          (strncmp("HEAD ",(char *)p,5) == 0) ||
414                          (strncmp("PUT ", (char *)p,4) == 0))
415                         {
416                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTP_REQUEST);
417                         goto err;
418                         }
419                 else if (strncmp("CONNECT",(char *)p,7) == 0)
420                         {
421                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTPS_PROXY_REQUEST);
422                         goto err;
423                         }
424                 }
425
426         /* ensure that TLS_MAX_VERSION is up-to-date */
427         OPENSSL_assert(s->version <= TLS_MAX_VERSION);
428
429         if (s->version < TLS1_2_VERSION && tls1_suiteb(s))
430                 {
431                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
432                                 SSL_R_ONLY_TLS_1_2_ALLOWED_IN_SUITEB_MODE);
433                 goto err;
434                 }
435
436 #ifdef OPENSSL_FIPS
437         if (FIPS_mode() && (s->version < TLS1_VERSION))
438                 {
439                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
440                                         SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
441                 goto err;
442                 }
443 #endif
444
445         if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL))
446                 {
447                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_VERSION_TOO_LOW);
448                 goto err;
449                 }
450
451         if (s->state == SSL23_ST_SR_CLNT_HELLO_B)
452                 {
453                 /* we have SSLv3/TLSv1 in an SSLv2 header
454                  * (other cases skip this state) */
455
456                 type=2;
457                 p=s->packet;
458                 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
459                 v[1] = p[4];
460
461                 /* An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2
462                  * header is sent directly on the wire, not wrapped as a TLS
463                  * record. It's format is:
464                  * Byte  Content
465                  * 0-1   msg_length
466                  * 2     msg_type
467                  * 3-4   version
468                  * 5-6   cipher_spec_length
469                  * 7-8   session_id_length
470                  * 9-10  challenge_length
471                  * ...   ...
472                  */
473                 n=((p[0]&0x7f)<<8)|p[1];
474                 if (n > (1024*4))
475                         {
476                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
477                         goto err;
478                         }
479                 if (n < 9)
480                         {
481                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
482                         goto err;
483                         }
484
485                 j=ssl23_read_bytes(s,n+2);
486                 /* We previously read 11 bytes, so if j > 0, we must have
487                  * j == n+2 == s->packet_length. We have at least 11 valid
488                  * packet bytes. */
489                 if (j <= 0) return(j);
490
491                 ssl3_finish_mac(s, s->packet+2, s->packet_length-2);
492                 if (s->msg_callback)
493                         s->msg_callback(0, SSL2_VERSION, 0, s->packet+2, s->packet_length-2, s, s->msg_callback_arg); /* CLIENT-HELLO */
494
495                 p=s->packet;
496                 p+=5;
497                 n2s(p,csl);
498                 n2s(p,sil);
499                 n2s(p,cl);
500                 d=(unsigned char *)s->init_buf->data;
501                 if ((csl+sil+cl+11) != s->packet_length) /* We can't have TLS extensions in SSL 2.0 format
502                                                           * Client Hello, can we? Error condition should be
503                                                           * '>' otherweise */
504                         {
505                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
506                         goto err;
507                         }
508
509                 /* record header: msg_type ... */
510                 *(d++) = SSL3_MT_CLIENT_HELLO;
511                 /* ... and length (actual value will be written later) */
512                 d_len = d;
513                 d += 3;
514
515                 /* client_version */
516                 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
517                 *(d++) = v[1];
518
519                 /* lets populate the random area */
520                 /* get the challenge_length */
521                 i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl;
522                 memset(d,0,SSL3_RANDOM_SIZE);
523                 memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i);
524                 d+=SSL3_RANDOM_SIZE;
525
526                 /* no session-id reuse */
527                 *(d++)=0;
528
529                 /* ciphers */
530                 j=0;
531                 dd=d;
532                 d+=2;
533                 for (i=0; i<csl; i+=3)
534                         {
535                         if (p[i] != 0) continue;
536                         *(d++)=p[i+1];
537                         *(d++)=p[i+2];
538                         j+=2;
539                         }
540                 s2n(j,dd);
541
542                 /* COMPRESSION */
543                 *(d++)=1;
544                 *(d++)=0;
545                 
546 #if 0
547                 /* copy any remaining data with may be extensions */
548                 p = p+csl+sil+cl;
549                 while (p <  s->packet+s->packet_length)
550                         {
551                         *(d++)=*(p++);
552                         }
553 #endif
554
555                 i = (d-(unsigned char *)s->init_buf->data) - 4;
556                 l2n3((long)i, d_len);
557
558                 /* get the data reused from the init_buf */
559                 s->s3->tmp.reuse_message=1;
560                 s->s3->tmp.message_type=SSL3_MT_CLIENT_HELLO;
561                 s->s3->tmp.message_size=i;
562                 }
563
564         /* imaginary new state (for program structure): */
565         /* s->state = SSL23_SR_CLNT_HELLO_C */
566
567         if (type == 1)
568                 {
569 #ifdef OPENSSL_NO_SSL2
570                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
571                 goto err;
572 #else
573                 /* we are talking sslv2 */
574                 /* we need to clean up the SSLv3/TLSv1 setup and put in the
575                  * sslv2 stuff. */
576
577                 if (s->s2 == NULL)
578                         {
579                         if (!ssl2_new(s))
580                                 goto err;
581                         }
582                 else
583                         ssl2_clear(s);
584
585                 if (s->s3 != NULL) ssl3_free(s);
586
587                 if (!BUF_MEM_grow_clean(s->init_buf,
588                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
589                         {
590                         goto err;
591                         }
592
593                 s->state=SSL2_ST_GET_CLIENT_HELLO_A;
594                 if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3)
595                         s->s2->ssl2_rollback=0;
596                 else
597                         /* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
598                          * (SSL 3.0 draft/RFC 2246, App. E.2) */
599                         s->s2->ssl2_rollback=1;
600
601                 /* setup the n bytes we have read so we get them from
602                  * the sslv2 buffer */
603                 s->rstate=SSL_ST_READ_HEADER;
604                 s->packet_length=n;
605                 s->packet= &(s->s2->rbuf[0]);
606                 memcpy(s->packet,buf,n);
607                 s->s2->rbuf_left=n;
608                 s->s2->rbuf_offs=0;
609
610                 s->method=SSLv2_server_method();
611                 s->handshake_func=s->method->ssl_accept;
612 #endif
613                 }
614
615         if ((type == 2) || (type == 3))
616                 {
617                 /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
618                 const SSL_METHOD *new_method;
619                 new_method = ssl23_get_server_method(s->version);
620                 if (new_method == NULL)
621                         {
622                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
623                         goto err;
624                         }
625                 s->method = new_method;
626
627                 if (!ssl_init_wbio_buffer(s,1)) goto err;
628
629                 /* we are in this state */
630                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
631
632                 if (type == 3)
633                         {
634                         /* put the 'n' bytes we have read into the input buffer
635                          * for SSLv3 */
636                         s->rstate=SSL_ST_READ_HEADER;
637                         s->packet_length=n;
638                         if (s->s3->rbuf.buf == NULL)
639                                 if (!ssl3_setup_read_buffer(s))
640                                         goto err;
641
642                         s->packet= &(s->s3->rbuf.buf[0]);
643                         memcpy(s->packet,buf,n);
644                         s->s3->rbuf.left=n;
645                         s->s3->rbuf.offset=0;
646                         }
647                 else
648                         {
649                         s->packet_length=0;
650                         s->s3->rbuf.left=0;
651                         s->s3->rbuf.offset=0;
652                         }
653 #if 0 /* ssl3_get_client_hello does this */
654                 s->client_version=(v[0]<<8)|v[1];
655 #endif
656                 s->handshake_func=s->method->ssl_accept;
657                 }
658         
659         if ((type < 1) || (type > 3))
660                 {
661                 /* bad, very bad */
662                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNKNOWN_PROTOCOL);
663                 goto err;
664                 }
665         s->init_num=0;
666
667         if (buf != buf_space) OPENSSL_free(buf);
668         return(SSL_accept(s));
669 err:
670         if (buf != buf_space) OPENSSL_free(buf);
671         return(-1);
672         }