5c7e9fa97fcd6a9d45819a1340393a6d34bfd58f
[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) 1998-2001 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 SSL_METHOD *ssl23_get_server_method(int ver);
120 int ssl23_get_client_hello(SSL *s);
121 static SSL_METHOD *ssl23_get_server_method(int ver)
122         {
123 #ifndef OPENSSL_NO_SSL2
124         if (ver == SSL2_VERSION)
125                 return(SSLv2_server_method());
126 #endif
127         if (ver == SSL3_VERSION)
128                 return(SSLv3_server_method());
129         else if (ver == TLS1_VERSION)
130                 return(TLSv1_server_method());
131         else
132                 return(NULL);
133         }
134
135 SSL_METHOD *SSLv23_server_method(void)
136         {
137         static int init=1;
138         static SSL_METHOD SSLv23_server_data;
139
140         if (init)
141                 {
142                 CRYPTO_w_lock(CRYPTO_LOCK_SSL_METHOD);
143
144                 memcpy((char *)&SSLv23_server_data,
145                         (char *)sslv23_base_method(),sizeof(SSL_METHOD));
146                 SSLv23_server_data.ssl_accept=ssl23_accept;
147                 SSLv23_server_data.get_ssl_method=ssl23_get_server_method;
148                 init=0;
149
150                 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_METHOD);
151                 }
152         return(&SSLv23_server_data);
153         }
154
155 int ssl23_accept(SSL *s)
156         {
157         BUF_MEM *buf;
158         unsigned long Time=time(NULL);
159         void (*cb)(const SSL *ssl,int type,int val)=NULL;
160         int ret= -1;
161         int new_state,state;
162
163         RAND_add(&Time,sizeof(Time),0);
164         ERR_clear_error();
165         clear_sys_error();
166
167         if (s->info_callback != NULL)
168                 cb=s->info_callback;
169         else if (s->ctx->info_callback != NULL)
170                 cb=s->ctx->info_callback;
171         
172         s->in_handshake++;
173         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); 
174
175         for (;;)
176                 {
177                 state=s->state;
178
179                 switch(s->state)
180                         {
181                 case SSL_ST_BEFORE:
182                 case SSL_ST_ACCEPT:
183                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
184                 case SSL_ST_OK|SSL_ST_ACCEPT:
185
186                         s->server=1;
187                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
188
189                         /* s->version=SSL3_VERSION; */
190                         s->type=SSL_ST_ACCEPT;
191
192                         if (s->init_buf == NULL)
193                                 {
194                                 if ((buf=BUF_MEM_new()) == NULL)
195                                         {
196                                         ret= -1;
197                                         goto end;
198                                         }
199                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
200                                         {
201                                         ret= -1;
202                                         goto end;
203                                         }
204                                 s->init_buf=buf;
205                                 }
206
207                         ssl3_init_finished_mac(s);
208
209                         s->state=SSL23_ST_SR_CLNT_HELLO_A;
210                         s->ctx->stats.sess_accept++;
211                         s->init_num=0;
212                         break;
213
214                 case SSL23_ST_SR_CLNT_HELLO_A:
215                 case SSL23_ST_SR_CLNT_HELLO_B:
216
217                         s->shutdown=0;
218                         ret=ssl23_get_client_hello(s);
219                         if (ret >= 0) cb=NULL;
220                         goto end;
221                         /* break; */
222
223                 default:
224                         SSLerr(SSL_F_SSL23_ACCEPT,SSL_R_UNKNOWN_STATE);
225                         ret= -1;
226                         goto end;
227                         /* break; */
228                         }
229
230                 if ((cb != NULL) && (s->state != state))
231                         {
232                         new_state=s->state;
233                         s->state=state;
234                         cb(s,SSL_CB_ACCEPT_LOOP,1);
235                         s->state=new_state;
236                         }
237                 }
238 end:
239         s->in_handshake--;
240         if (cb != NULL)
241                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
242         return(ret);
243         }
244
245
246 int ssl23_get_client_hello(SSL *s)
247         {
248         char buf_space[11]; /* Request this many bytes in initial read.
249                              * We can detect SSL 3.0/TLS 1.0 Client Hellos
250                              * ('type == 3') correctly only when the following
251                              * is in a single record, which is not guaranteed by
252                              * the protocol specification:
253                              * Byte  Content
254                              *  0     type            \
255                              *  1/2   version          > record header
256                              *  3/4   length          /
257                              *  5     msg_type        \
258                              *  6-8   length           > Client Hello message
259                              *  9/10  client_version  /
260                              */
261         char *buf= &(buf_space[0]);
262         unsigned char *p,*d,*d_len,*dd;
263         unsigned int i;
264         unsigned int csl,sil,cl;
265         int n=0,j;
266         int type=0;
267         int v[2];
268 #ifndef OPENSSL_NO_RSA
269         int use_sslv2_strong=0;
270 #endif
271
272         if (s->state == SSL23_ST_SR_CLNT_HELLO_A)
273                 {
274                 /* read the initial header */
275                 v[0]=v[1]=0;
276
277                 if (!ssl3_setup_buffers(s)) goto err;
278
279                 n=ssl23_read_bytes(s, sizeof buf_space);
280                 if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */
281
282                 p=s->packet;
283
284                 memcpy(buf,p,n);
285
286                 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO))
287                         {
288                         /*
289                          * SSLv2 header
290                          */
291                         if ((p[3] == 0x00) && (p[4] == 0x02))
292                                 {
293                                 v[0]=p[3]; v[1]=p[4];
294                                 /* SSLv2 */
295                                 if (!(s->options & SSL_OP_NO_SSLv2))
296                                         type=1;
297                                 }
298                         else if (p[3] == SSL3_VERSION_MAJOR)
299                                 {
300                                 v[0]=p[3]; v[1]=p[4];
301                                 /* SSLv3/TLSv1 */
302                                 if (p[4] >= TLS1_VERSION_MINOR)
303                                         {
304                                         if (!(s->options & SSL_OP_NO_TLSv1))
305                                                 {
306                                                 s->version=TLS1_VERSION;
307                                                 /* type=2; */ /* done later to survive restarts */
308                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
309                                                 }
310                                         else if (!(s->options & SSL_OP_NO_SSLv3))
311                                                 {
312                                                 s->version=SSL3_VERSION;
313                                                 /* type=2; */
314                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
315                                                 }
316                                         else if (!(s->options & SSL_OP_NO_SSLv2))
317                                                 {
318                                                 type=1;
319                                                 }
320                                         }
321                                 else if (!(s->options & SSL_OP_NO_SSLv3))
322                                         {
323                                         s->version=SSL3_VERSION;
324                                         /* type=2; */
325                                         s->state=SSL23_ST_SR_CLNT_HELLO_B;
326                                         }
327                                 else if (!(s->options & SSL_OP_NO_SSLv2))
328                                         type=1;
329
330                                 }
331                         }
332                 else if ((p[0] == SSL3_RT_HANDSHAKE) &&
333                          (p[1] == SSL3_VERSION_MAJOR) &&
334                          (p[5] == SSL3_MT_CLIENT_HELLO) &&
335                          ((p[3] == 0 && p[4] < 5 /* silly record length? */)
336                                 || (p[9] == p[1])))
337                         {
338                         /*
339                          * SSLv3 or tls1 header
340                          */
341                         
342                         v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */
343                         /* We must look at client_version inside the Client Hello message
344                          * to get the correct minor version.
345                          * However if we have only a pathologically small fragment of the
346                          * Client Hello message, this would be difficult, and we'd have
347                          * to read more records to find out.
348                          * No known SSL 3.0 client fragments ClientHello like this,
349                          * so we simply assume TLS 1.0 to avoid protocol version downgrade
350                          * attacks. */
351                         if (p[3] == 0 && p[4] < 6)
352                                 {
353 #if 0
354                                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL);
355                                 goto err;
356 #else
357                                 v[1] = TLS1_VERSION_MINOR;
358 #endif
359                                 }
360                         else
361                                 v[1]=p[10]; /* minor version according to client_version */
362                         if (v[1] >= TLS1_VERSION_MINOR)
363                                 {
364                                 if (!(s->options & SSL_OP_NO_TLSv1))
365                                         {
366                                         s->version=TLS1_VERSION;
367                                         type=3;
368                                         }
369                                 else if (!(s->options & SSL_OP_NO_SSLv3))
370                                         {
371                                         s->version=SSL3_VERSION;
372                                         type=3;
373                                         }
374                                 }
375                         else
376                                 {
377                                 /* client requests SSL 3.0 */
378                                 if (!(s->options & SSL_OP_NO_SSLv3))
379                                         {
380                                         s->version=SSL3_VERSION;
381                                         type=3;
382                                         }
383                                 else if (!(s->options & SSL_OP_NO_TLSv1))
384                                         {
385                                         /* we won't be able to use TLS of course,
386                                          * but this will send an appropriate alert */
387                                         s->version=TLS1_VERSION;
388                                         type=3;
389                                         }
390                                 }
391                         }
392                 else if ((strncmp("GET ", (char *)p,4) == 0) ||
393                          (strncmp("POST ",(char *)p,5) == 0) ||
394                          (strncmp("HEAD ",(char *)p,5) == 0) ||
395                          (strncmp("PUT ", (char *)p,4) == 0))
396                         {
397                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTP_REQUEST);
398                         goto err;
399                         }
400                 else if (strncmp("CONNECT",(char *)p,7) == 0)
401                         {
402                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTPS_PROXY_REQUEST);
403                         goto err;
404                         }
405                 }
406
407         if (s->state == SSL23_ST_SR_CLNT_HELLO_B)
408                 {
409                 /* we have SSLv3/TLSv1 in an SSLv2 header
410                  * (other cases skip this state) */
411
412                 type=2;
413                 p=s->packet;
414                 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
415                 v[1] = p[4];
416
417                 n=((p[0]&0x7f)<<8)|p[1];
418                 if (n > (1024*4))
419                         {
420                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
421                         goto err;
422                         }
423
424                 j=ssl23_read_bytes(s,n+2);
425                 if (j <= 0) return(j);
426
427                 ssl3_finish_mac(s, s->packet+2, s->packet_length-2);
428                 if (s->msg_callback)
429                         s->msg_callback(0, SSL2_VERSION, 0, s->packet+2, s->packet_length-2, s, s->msg_callback_arg); /* CLIENT-HELLO */
430
431                 p=s->packet;
432                 p+=5;
433                 n2s(p,csl);
434                 n2s(p,sil);
435                 n2s(p,cl);
436                 d=(unsigned char *)s->init_buf->data;
437                 if ((csl+sil+cl+11) != s->packet_length)
438                         {
439                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
440                         goto err;
441                         }
442
443                 /* record header: msg_type ... */
444                 *(d++) = SSL3_MT_CLIENT_HELLO;
445                 /* ... and length (actual value will be written later) */
446                 d_len = d;
447                 d += 3;
448
449                 /* client_version */
450                 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
451                 *(d++) = v[1];
452
453                 /* lets populate the random area */
454                 /* get the challenge_length */
455                 i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl;
456                 memset(d,0,SSL3_RANDOM_SIZE);
457                 memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i);
458                 d+=SSL3_RANDOM_SIZE;
459
460                 /* no session-id reuse */
461                 *(d++)=0;
462
463                 /* ciphers */
464                 j=0;
465                 dd=d;
466                 d+=2;
467                 for (i=0; i<csl; i+=3)
468                         {
469                         if (p[i] != 0) continue;
470                         *(d++)=p[i+1];
471                         *(d++)=p[i+2];
472                         j+=2;
473                         }
474                 s2n(j,dd);
475
476                 /* COMPRESSION */
477                 *(d++)=1;
478                 *(d++)=0;
479                 
480                 i = (d-(unsigned char *)s->init_buf->data) - 4;
481                 l2n3((long)i, d_len);
482
483                 /* get the data reused from the init_buf */
484                 s->s3->tmp.reuse_message=1;
485                 s->s3->tmp.message_type=SSL3_MT_CLIENT_HELLO;
486                 s->s3->tmp.message_size=i;
487                 }
488
489         /* imaginary new state (for program structure): */
490         /* s->state = SSL23_SR_CLNT_HELLO_C */
491
492         if (type == 1)
493                 {
494 #ifdef OPENSSL_NO_SSL2
495                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
496                 goto err;
497 #else
498                 /* we are talking sslv2 */
499                 /* we need to clean up the SSLv3/TLSv1 setup and put in the
500                  * sslv2 stuff. */
501
502                 if (s->s2 == NULL)
503                         {
504                         if (!ssl2_new(s))
505                                 goto err;
506                         }
507                 else
508                         ssl2_clear(s);
509
510                 if (s->s3 != NULL) ssl3_free(s);
511
512                 if (!BUF_MEM_grow(s->init_buf,
513                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
514                         {
515                         goto err;
516                         }
517
518                 s->state=SSL2_ST_GET_CLIENT_HELLO_A;
519                 if ((s->options & SSL_OP_MSIE_SSLV2_RSA_PADDING) ||
520                         use_sslv2_strong ||
521                         (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3))
522                         s->s2->ssl2_rollback=0;
523                 else
524                         /* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
525                          * (SSL 3.0 draft/RFC 2246, App. E.2) */
526                         s->s2->ssl2_rollback=1;
527
528                 /* setup the n bytes we have read so we get them from
529                  * the sslv2 buffer */
530                 s->rstate=SSL_ST_READ_HEADER;
531                 s->packet_length=n;
532                 s->packet= &(s->s2->rbuf[0]);
533                 memcpy(s->packet,buf,n);
534                 s->s2->rbuf_left=n;
535                 s->s2->rbuf_offs=0;
536
537                 s->method=SSLv2_server_method();
538                 s->handshake_func=s->method->ssl_accept;
539 #endif
540                 }
541
542         if ((type == 2) || (type == 3))
543                 {
544                 /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
545
546                 if (!ssl_init_wbio_buffer(s,1)) goto err;
547
548                 /* we are in this state */
549                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
550
551                 if (type == 3)
552                         {
553                         /* put the 'n' bytes we have read into the input buffer
554                          * for SSLv3 */
555                         s->rstate=SSL_ST_READ_HEADER;
556                         s->packet_length=n;
557                         s->packet= &(s->s3->rbuf.buf[0]);
558                         memcpy(s->packet,buf,n);
559                         s->s3->rbuf.left=n;
560                         s->s3->rbuf.offset=0;
561                         }
562                 else
563                         {
564                         s->packet_length=0;
565                         s->s3->rbuf.left=0;
566                         s->s3->rbuf.offset=0;
567                         }
568
569                 if (s->version == TLS1_VERSION)
570                         s->method = TLSv1_server_method();
571                 else
572                         s->method = SSLv3_server_method();
573 #if 0 /* ssl3_get_client_hello does this */
574                 s->client_version=(v[0]<<8)|v[1];
575 #endif
576                 s->handshake_func=s->method->ssl_accept;
577                 }
578         
579         if ((type < 1) || (type > 3))
580                 {
581                 /* bad, very bad */
582                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNKNOWN_PROTOCOL);
583                 goto err;
584                 }
585         s->init_num=0;
586
587         if (buf != buf_space) OPENSSL_free(buf);
588         s->first_packet=1;
589         return(SSL_accept(s));
590 err:
591         if (buf != buf_space) OPENSSL_free(buf);
592         return(-1);
593         }