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