cast to unsigned int, not to int to avoid the warning -- all these
[openssl.git] / ssl / s2_srvr.c
1 /* ssl/s2_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 "ssl_locl.h"
113 #ifndef OPENSSL_NO_SSL2
114 #include <stdio.h>
115 #include <openssl/bio.h>
116 #include <openssl/rand.h>
117 #include <openssl/objects.h>
118 #include <openssl/evp.h>
119
120 static SSL_METHOD *ssl2_get_server_method(int ver);
121 static int get_client_master_key(SSL *s);
122 static int get_client_hello(SSL *s);
123 static int server_hello(SSL *s); 
124 static int get_client_finished(SSL *s);
125 static int server_verify(SSL *s);
126 static int server_finish(SSL *s);
127 static int request_certificate(SSL *s);
128 static int ssl_rsa_private_decrypt(CERT *c, int len, unsigned char *from,
129         unsigned char *to,int padding);
130 #define BREAK   break
131
132 static SSL_METHOD *ssl2_get_server_method(int ver)
133         {
134         if (ver == SSL2_VERSION)
135                 return(SSLv2_server_method());
136         else
137                 return(NULL);
138         }
139
140 SSL_METHOD *SSLv2_server_method(void)
141         {
142         static int init=1;
143         static SSL_METHOD SSLv2_server_data;
144
145         if (init)
146                 {
147                 memcpy((char *)&SSLv2_server_data,(char *)sslv2_base_method(),
148                         sizeof(SSL_METHOD));
149                 SSLv2_server_data.ssl_accept=ssl2_accept;
150                 SSLv2_server_data.get_ssl_method=ssl2_get_server_method;
151                 init=0;
152                 }
153         return(&SSLv2_server_data);
154         }
155
156 int ssl2_accept(SSL *s)
157         {
158         unsigned long l=time(NULL);
159         BUF_MEM *buf=NULL;
160         int ret= -1;
161         long num1;
162         void (*cb)()=NULL;
163         int new_state,state;
164
165         RAND_add(&l,sizeof(l),0);
166         ERR_clear_error();
167         clear_sys_error();
168
169         if (s->info_callback != NULL)
170                 cb=s->info_callback;
171         else if (s->ctx->info_callback != NULL)
172                 cb=s->ctx->info_callback;
173
174         /* init things to blank */
175         s->in_handshake++;
176         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
177
178         if (s->cert == NULL)
179                 {
180                 SSLerr(SSL_F_SSL2_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
181                 return(-1);
182                 }
183
184         clear_sys_error();
185         for (;;)
186                 {
187                 state=s->state;
188
189                 switch (s->state)
190                         {
191                 case SSL_ST_BEFORE:
192                 case SSL_ST_ACCEPT:
193                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
194                 case SSL_ST_OK|SSL_ST_ACCEPT:
195
196                         s->server=1;
197                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
198
199                         s->version=SSL2_VERSION;
200                         s->type=SSL_ST_ACCEPT;
201
202                         buf=s->init_buf;
203                         if ((buf == NULL) && ((buf=BUF_MEM_new()) == NULL))
204                                 { ret= -1; goto end; }
205                         if (!BUF_MEM_grow(buf,(int)
206                                 SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
207                                 { ret= -1; goto end; }
208                         s->init_buf=buf;
209                         s->init_num=0;
210                         s->ctx->stats.sess_accept++;
211                         s->handshake_func=ssl2_accept;
212                         s->state=SSL2_ST_GET_CLIENT_HELLO_A;
213                         BREAK;
214
215                 case SSL2_ST_GET_CLIENT_HELLO_A:
216                 case SSL2_ST_GET_CLIENT_HELLO_B:
217                 case SSL2_ST_GET_CLIENT_HELLO_C:
218                         s->shutdown=0;
219                         ret=get_client_hello(s);
220                         if (ret <= 0) goto end;
221                         s->init_num=0;
222                         s->state=SSL2_ST_SEND_SERVER_HELLO_A;
223                         BREAK;
224
225                 case SSL2_ST_SEND_SERVER_HELLO_A:
226                 case SSL2_ST_SEND_SERVER_HELLO_B:
227                         ret=server_hello(s);
228                         if (ret <= 0) goto end;
229                         s->init_num=0;
230                         if (!s->hit)
231                                 {
232                                 s->state=SSL2_ST_GET_CLIENT_MASTER_KEY_A;
233                                 BREAK;
234                                 }
235                         else
236                                 {
237                                 s->state=SSL2_ST_SERVER_START_ENCRYPTION;
238                                 BREAK;
239                                 }
240                 case SSL2_ST_GET_CLIENT_MASTER_KEY_A:
241                 case SSL2_ST_GET_CLIENT_MASTER_KEY_B:
242                         ret=get_client_master_key(s);
243                         if (ret <= 0) goto end;
244                         s->init_num=0;
245                         s->state=SSL2_ST_SERVER_START_ENCRYPTION;
246                         BREAK;
247
248                 case SSL2_ST_SERVER_START_ENCRYPTION:
249                         /* Ok we how have sent all the stuff needed to
250                          * start encrypting, the next packet back will
251                          * be encrypted. */
252                         if (!ssl2_enc_init(s,0))
253                                 { ret= -1; goto end; }
254                         s->s2->clear_text=0;
255                         s->state=SSL2_ST_SEND_SERVER_VERIFY_A;
256                         BREAK;
257
258                 case SSL2_ST_SEND_SERVER_VERIFY_A:
259                 case SSL2_ST_SEND_SERVER_VERIFY_B:
260                         ret=server_verify(s);
261                         if (ret <= 0) goto end;
262                         s->init_num=0;
263                         if (s->hit)
264                                 {
265                                 /* If we are in here, we have been
266                                  * buffering the output, so we need to
267                                  * flush it and remove buffering from
268                                  * future traffic */
269                                 s->state=SSL2_ST_SEND_SERVER_VERIFY_C;
270                                 BREAK;
271                                 }
272                         else
273                                 {
274                                 s->state=SSL2_ST_GET_CLIENT_FINISHED_A;
275                                 break;
276                                 }
277
278                 case SSL2_ST_SEND_SERVER_VERIFY_C:
279                         /* get the number of bytes to write */
280                         num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
281                         if (num1 != 0)
282                                 {
283                                 s->rwstate=SSL_WRITING;
284                                 num1=BIO_flush(s->wbio);
285                                 if (num1 <= 0) { ret= -1; goto end; }
286                                 s->rwstate=SSL_NOTHING;
287                                 }
288
289                         /* flushed and now remove buffering */
290                         s->wbio=BIO_pop(s->wbio);
291
292                         s->state=SSL2_ST_GET_CLIENT_FINISHED_A;
293                         BREAK;
294
295                 case SSL2_ST_GET_CLIENT_FINISHED_A:
296                 case SSL2_ST_GET_CLIENT_FINISHED_B:
297                         ret=get_client_finished(s);
298                         if (ret <= 0)
299                                 goto end;
300                         s->init_num=0;
301                         s->state=SSL2_ST_SEND_REQUEST_CERTIFICATE_A;
302                         BREAK;
303
304                 case SSL2_ST_SEND_REQUEST_CERTIFICATE_A:
305                 case SSL2_ST_SEND_REQUEST_CERTIFICATE_B:
306                 case SSL2_ST_SEND_REQUEST_CERTIFICATE_C:
307                 case SSL2_ST_SEND_REQUEST_CERTIFICATE_D:
308                         /* don't do a 'request certificate' if we
309                          * don't want to, or we already have one, and
310                          * we only want to do it once. */
311                         if (!(s->verify_mode & SSL_VERIFY_PEER) ||
312                                 ((s->session->peer != NULL) &&
313                                 (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)))
314                                 {
315                                 s->state=SSL2_ST_SEND_SERVER_FINISHED_A;
316                                 break;
317                                 }
318                         else
319                                 {
320                                 ret=request_certificate(s);
321                                 if (ret <= 0) goto end;
322                                 s->init_num=0;
323                                 s->state=SSL2_ST_SEND_SERVER_FINISHED_A;
324                                 }
325                         BREAK;
326
327                 case SSL2_ST_SEND_SERVER_FINISHED_A:
328                 case SSL2_ST_SEND_SERVER_FINISHED_B:
329                         ret=server_finish(s);
330                         if (ret <= 0) goto end;
331                         s->init_num=0;
332                         s->state=SSL_ST_OK;
333                         break;
334
335                 case SSL_ST_OK:
336                         BUF_MEM_free(s->init_buf);
337                         ssl_free_wbio_buffer(s);
338                         s->init_buf=NULL;
339                         s->init_num=0;
340                 /*      ERR_clear_error();*/
341
342                         ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
343
344                         s->ctx->stats.sess_accept_good++;
345                         /* s->server=1; */
346                         ret=1;
347
348                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
349
350                         goto end;
351                         /* BREAK; */
352
353                 default:
354                         SSLerr(SSL_F_SSL2_ACCEPT,SSL_R_UNKNOWN_STATE);
355                         ret= -1;
356                         goto end;
357                         /* BREAK; */
358                         }
359                 
360                 if ((cb != NULL) && (s->state != state))
361                         {
362                         new_state=s->state;
363                         s->state=state;
364                         cb(s,SSL_CB_ACCEPT_LOOP,1);
365                         s->state=new_state;
366                         }
367                 }
368 end:
369         s->in_handshake--;
370         if (cb != NULL)
371                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
372         return(ret);
373         }
374
375 static int get_client_master_key(SSL *s)
376         {
377         int is_export,i,n,keya,ek;
378         unsigned long len;
379         unsigned char *p;
380         SSL_CIPHER *cp;
381         const EVP_CIPHER *c;
382         const EVP_MD *md;
383
384         p=(unsigned char *)s->init_buf->data;
385         if (s->state == SSL2_ST_GET_CLIENT_MASTER_KEY_A)
386                 {
387                 i=ssl2_read(s,(char *)&(p[s->init_num]),10-s->init_num);
388
389                 if (i < (10-s->init_num))
390                         return(ssl2_part_read(s,SSL_F_GET_CLIENT_MASTER_KEY,i));
391                 s->init_num = 10;
392
393                 if (*(p++) != SSL2_MT_CLIENT_MASTER_KEY)
394                         {
395                         if (p[-1] != SSL2_MT_ERROR)
396                                 {
397                                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
398                                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_READ_WRONG_PACKET_TYPE);
399                                 }
400                         else
401                                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,
402                                         SSL_R_PEER_ERROR);
403                         return(-1);
404                         }
405
406                 cp=ssl2_get_cipher_by_char(p);
407                 if (cp == NULL)
408                         {
409                         ssl2_return_error(s,SSL2_PE_NO_CIPHER);
410                         SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,
411                                 SSL_R_NO_CIPHER_MATCH);
412                         return(-1);
413                         }
414                 s->session->cipher= cp;
415
416                 p+=3;
417                 n2s(p,i); s->s2->tmp.clear=i;
418                 n2s(p,i); s->s2->tmp.enc=i;
419                 n2s(p,i); s->session->key_arg_length=i;
420                 s->state=SSL2_ST_GET_CLIENT_MASTER_KEY_B;
421                 }
422
423         /* SSL2_ST_GET_CLIENT_MASTER_KEY_B */
424         p=(unsigned char *)s->init_buf->data;
425         keya=s->session->key_arg_length;
426         len = 10 + (unsigned long)s->s2->tmp.clear + (unsigned long)s->s2->tmp.enc + (unsigned long)keya;
427         if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
428                 {
429                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_MESSAGE_TOO_LONG);
430                 return -1;
431                 }
432         n = (int)len - s->init_num;
433         i = ssl2_read(s,(char *)&(p[s->init_num]),n);
434         if (i != n) return(ssl2_part_read(s,SSL_F_GET_CLIENT_MASTER_KEY,i));
435         if (s->msg_callback)
436                 s->msg_callback(0, s->version, 0, p, (size_t)len, s, s->msg_callback_arg); /* CLIENT-MASTER-KEY */
437         p += 10;
438
439         memcpy(s->session->key_arg,&(p[s->s2->tmp.clear+s->s2->tmp.enc]),
440                 (unsigned int)keya);
441
442         if (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL)
443                 {
444                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
445                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_NO_PRIVATEKEY);
446                 return(-1);
447                 }
448         i=ssl_rsa_private_decrypt(s->cert,s->s2->tmp.enc,
449                 &(p[s->s2->tmp.clear]),&(p[s->s2->tmp.clear]),
450                 (s->s2->ssl2_rollback)?RSA_SSLV23_PADDING:RSA_PKCS1_PADDING);
451
452         is_export=SSL_C_IS_EXPORT(s->session->cipher);
453         
454         if (!ssl_cipher_get_evp(s->session,&c,&md,NULL))
455                 {
456                 ssl2_return_error(s,SSL2_PE_NO_CIPHER);
457                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
458                 return(0);
459                 }
460
461         if (s->session->cipher->algorithm2 & SSL2_CF_8_BYTE_ENC)
462                 {
463                 is_export=1;
464                 ek=8;
465                 }
466         else
467                 ek=5;
468
469         /* bad decrypt */
470 #if 1
471         /* If a bad decrypt, continue with protocol but with a
472          * random master secret (Bleichenbacher attack) */
473         if ((i < 0) ||
474                 ((!is_export && (i != EVP_CIPHER_key_length(c)))
475                 || (is_export && ((i != ek) || (s->s2->tmp.clear+(unsigned int)i !=
476                         (unsigned int)EVP_CIPHER_key_length(c))))))
477                 {
478                 ERR_clear_error();
479                 if (is_export)
480                         i=ek;
481                 else
482                         i=EVP_CIPHER_key_length(c);
483                 RAND_pseudo_bytes(p,i);
484                 }
485 #else
486         if (i < 0)
487                 {
488                 error=1;
489                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_BAD_RSA_DECRYPT);
490                 }
491         /* incorrect number of key bytes for non export cipher */
492         else if ((!is_export && (i != EVP_CIPHER_key_length(c)))
493                 || (is_export && ((i != ek) || (s->s2->tmp.clear+i !=
494                         EVP_CIPHER_key_length(c)))))
495                 {
496                 error=1;
497                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_WRONG_NUMBER_OF_KEY_BITS);
498                 }
499         if (error)
500                 {
501                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
502                 return(-1);
503                 }
504 #endif
505
506         if (is_export) i+=s->s2->tmp.clear;
507         s->session->master_key_length=i;
508         memcpy(s->session->master_key,p,(unsigned int)i);
509         return(1);
510         }
511
512 static int get_client_hello(SSL *s)
513         {
514         int i,n;
515         unsigned long len;
516         unsigned char *p;
517         STACK_OF(SSL_CIPHER) *cs; /* a stack of SSL_CIPHERS */
518         STACK_OF(SSL_CIPHER) *cl; /* the ones we want to use */
519         STACK_OF(SSL_CIPHER) *prio, *allow;
520         int z;
521
522         /* This is a bit of a hack to check for the correct packet
523          * type the first time round. */
524         if (s->state == SSL2_ST_GET_CLIENT_HELLO_A)
525                 {
526                 s->first_packet=1;
527                 s->state=SSL2_ST_GET_CLIENT_HELLO_B;
528                 }
529
530         p=(unsigned char *)s->init_buf->data;
531         if (s->state == SSL2_ST_GET_CLIENT_HELLO_B)
532                 {
533                 i=ssl2_read(s,(char *)&(p[s->init_num]),9-s->init_num);
534                 if (i < (9-s->init_num)) 
535                         return(ssl2_part_read(s,SSL_F_GET_CLIENT_HELLO,i));
536                 s->init_num = 9;
537         
538                 if (*(p++) != SSL2_MT_CLIENT_HELLO)
539                         {
540                         if (p[-1] != SSL2_MT_ERROR)
541                                 {
542                                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
543                                 SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_READ_WRONG_PACKET_TYPE);
544                                 }
545                         else
546                                 SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_PEER_ERROR);
547                         return(-1);
548                         }
549                 n2s(p,i);
550                 if (i < s->version) s->version=i;
551                 n2s(p,i); s->s2->tmp.cipher_spec_length=i;
552                 n2s(p,i); s->s2->tmp.session_id_length=i;
553                 n2s(p,i); s->s2->challenge_length=i;
554                 if (    (i < SSL2_MIN_CHALLENGE_LENGTH) ||
555                         (i > SSL2_MAX_CHALLENGE_LENGTH))
556                         {
557                         SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_INVALID_CHALLENGE_LENGTH);
558                         return(-1);
559                         }
560                 s->state=SSL2_ST_GET_CLIENT_HELLO_C;
561                 }
562
563         /* SSL2_ST_GET_CLIENT_HELLO_C */
564         p=(unsigned char *)s->init_buf->data;
565         len = 9 + (unsigned long)s->s2->tmp.cipher_spec_length + (unsigned long)s->s2->challenge_length + (unsigned long)s->s2->tmp.session_id_length;
566         if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
567                 {
568                 SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_MESSAGE_TOO_LONG);
569                 return -1;
570                 }
571         n = (int)len - s->init_num;
572         i = ssl2_read(s,(char *)&(p[s->init_num]),n);
573         if (i != n) return(ssl2_part_read(s,SSL_F_GET_CLIENT_HELLO,i));
574         if (s->msg_callback)
575                 s->msg_callback(0, s->version, 0, p, (size_t)len, s, s->msg_callback_arg); /* CLIENT-HELLO */
576         p += 9;
577
578         /* get session-id before cipher stuff so we can get out session
579          * structure if it is cached */
580         /* session-id */
581         if ((s->s2->tmp.session_id_length != 0) && 
582                 (s->s2->tmp.session_id_length != SSL2_SSL_SESSION_ID_LENGTH))
583                 {
584                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
585                 SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_BAD_SSL_SESSION_ID_LENGTH);
586                 return(-1);
587                 }
588
589         if (s->s2->tmp.session_id_length == 0)
590                 {
591                 if (!ssl_get_new_session(s,1))
592                         {
593                         ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
594                         return(-1);
595                         }
596                 }
597         else
598                 {
599                 i=ssl_get_prev_session(s,&(p[s->s2->tmp.cipher_spec_length]),
600                         s->s2->tmp.session_id_length);
601                 if (i == 1)
602                         { /* previous session */
603                         s->hit=1;
604                         }
605                 else if (i == -1)
606                         {
607                         ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
608                         return(-1);
609                         }
610                 else
611                         {
612                         if (s->cert == NULL)
613                                 {
614                                 ssl2_return_error(s,SSL2_PE_NO_CERTIFICATE);
615                                 SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_NO_CERTIFICATE_SET);
616                                 return(-1);
617                                 }
618
619                         if (!ssl_get_new_session(s,1))
620                                 {
621                                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
622                                 return(-1);
623                                 }
624                         }
625                 }
626
627         if (!s->hit)
628                 {
629                 cs=ssl_bytes_to_cipher_list(s,p,s->s2->tmp.cipher_spec_length,
630                         &s->session->ciphers);
631                 if (cs == NULL) goto mem_err;
632
633                 cl=SSL_get_ciphers(s);
634
635                 if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE)
636                     {
637                     prio=sk_SSL_CIPHER_dup(cl);
638                     if (prio == NULL) goto mem_err;
639                     allow = cs;
640                     }
641                 else
642                     {
643                     prio = cs;
644                     allow = cl;
645                     }
646                 for (z=0; z<sk_SSL_CIPHER_num(prio); z++)
647                         {
648                         if (sk_SSL_CIPHER_find(allow,sk_SSL_CIPHER_value(prio,z)) < 0)
649                                 {
650                                 sk_SSL_CIPHER_delete(prio,z);
651                                 z--;
652                                 }
653                         }
654                 if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE)
655                     {
656                     sk_SSL_CIPHER_free(s->session->ciphers);
657                     s->session->ciphers = prio;
658                     }
659                 /* s->session->ciphers should now have a list of
660                  * ciphers that are on both the client and server.
661                  * This list is ordered by the order the client sent
662                  * the ciphers or in the order of the server's preference
663                  * if SSL_OP_CIPHER_SERVER_PREFERENCE was set.
664                  */
665                 }
666         p+=s->s2->tmp.cipher_spec_length;
667         /* done cipher selection */
668
669         /* session id extracted already */
670         p+=s->s2->tmp.session_id_length;
671
672         /* challenge */
673         memcpy(s->s2->challenge,p,(unsigned int)s->s2->challenge_length);
674         return(1);
675 mem_err:
676         SSLerr(SSL_F_GET_CLIENT_HELLO,ERR_R_MALLOC_FAILURE);
677         return(0);
678         }
679
680 static int server_hello(SSL *s)
681         {
682         unsigned char *p,*d;
683         int n,hit;
684         STACK_OF(SSL_CIPHER) *sk;
685
686         p=(unsigned char *)s->init_buf->data;
687         if (s->state == SSL2_ST_SEND_SERVER_HELLO_A)
688                 {
689                 d=p+11;
690                 *(p++)=SSL2_MT_SERVER_HELLO;            /* type */
691                 hit=s->hit;
692                 *(p++)=(unsigned char)hit;
693 #if 1
694                 if (!hit)
695                         {
696                         if (s->session->sess_cert != NULL)
697                                 /* This can't really happen because get_client_hello
698                                  * has called ssl_get_new_session, which does not set
699                                  * sess_cert. */
700                                 ssl_sess_cert_free(s->session->sess_cert);
701                         s->session->sess_cert = ssl_sess_cert_new();
702                         if (s->session->sess_cert == NULL)
703                                 {
704                                 SSLerr(SSL_F_SERVER_HELLO, ERR_R_MALLOC_FAILURE);
705                                 return(-1);
706                                 }
707                         }
708                 /* If 'hit' is set, then s->sess_cert may be non-NULL or NULL,
709                  * depending on whether it survived in the internal cache
710                  * or was retrieved from an external cache.
711                  * If it is NULL, we cannot put any useful data in it anyway,
712                  * so we don't touch it.
713                  */
714
715 #else /* That's what used to be done when cert_st and sess_cert_st were
716            * the same. */
717                 if (!hit)
718                         {                       /* else add cert to session */
719                         CRYPTO_add(&s->cert->references,1,CRYPTO_LOCK_SSL_CERT);
720                         if (s->session->sess_cert != NULL)
721                                 ssl_cert_free(s->session->sess_cert);
722                         s->session->sess_cert=s->cert;          
723                         }
724                 else    /* We have a session id-cache hit, if the
725                          * session-id has no certificate listed against
726                          * the 'cert' structure, grab the 'old' one
727                          * listed against the SSL connection */
728                         {
729                         if (s->session->sess_cert == NULL)
730                                 {
731                                 CRYPTO_add(&s->cert->references,1,
732                                         CRYPTO_LOCK_SSL_CERT);
733                                 s->session->sess_cert=s->cert;
734                                 }
735                         }
736 #endif
737
738                 if (s->cert == NULL)
739                         {
740                         ssl2_return_error(s,SSL2_PE_NO_CERTIFICATE);
741                         SSLerr(SSL_F_SERVER_HELLO,SSL_R_NO_CERTIFICATE_SPECIFIED);
742                         return(-1);
743                         }
744
745                 if (hit)
746                         {
747                         *(p++)=0;               /* no certificate type */
748                         s2n(s->version,p);      /* version */
749                         s2n(0,p);               /* cert len */
750                         s2n(0,p);               /* ciphers len */
751                         }
752                 else
753                         {
754                         /* EAY EAY */
755                         /* put certificate type */
756                         *(p++)=SSL2_CT_X509_CERTIFICATE;
757                         s2n(s->version,p);      /* version */
758                         n=i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509,NULL);
759                         s2n(n,p);               /* certificate length */
760                         i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509,&d);
761                         n=0;
762                         
763                         /* lets send out the ciphers we like in the
764                          * prefered order */
765                         sk= s->session->ciphers;
766                         n=ssl_cipher_list_to_bytes(s,s->session->ciphers,d);
767                         d+=n;
768                         s2n(n,p);               /* add cipher length */
769                         }
770
771                 /* make and send conn_id */
772                 s2n(SSL2_CONNECTION_ID_LENGTH,p);       /* add conn_id length */
773                 s->s2->conn_id_length=SSL2_CONNECTION_ID_LENGTH;
774                 RAND_pseudo_bytes(s->s2->conn_id,(int)s->s2->conn_id_length);
775                 memcpy(d,s->s2->conn_id,SSL2_CONNECTION_ID_LENGTH);
776                 d+=SSL2_CONNECTION_ID_LENGTH;
777
778                 s->state=SSL2_ST_SEND_SERVER_HELLO_B;
779                 s->init_num=d-(unsigned char *)s->init_buf->data;
780                 s->init_off=0;
781                 }
782         /* SSL2_ST_SEND_SERVER_HELLO_B */
783         /* If we are using TCP/IP, the performance is bad if we do 2
784          * writes without a read between them.  This occurs when
785          * Session-id reuse is used, so I will put in a buffering module
786          */
787         if (s->hit)
788                 {
789                 if (!ssl_init_wbio_buffer(s,1)) return(-1);
790                 }
791  
792         return(ssl2_do_write(s));
793         }
794
795 static int get_client_finished(SSL *s)
796         {
797         unsigned char *p;
798         int i, n;
799         unsigned long len;
800
801         p=(unsigned char *)s->init_buf->data;
802         if (s->state == SSL2_ST_GET_CLIENT_FINISHED_A)
803                 {
804                 i=ssl2_read(s,(char *)&(p[s->init_num]),1-s->init_num);
805                 if (i < 1-s->init_num)
806                         return(ssl2_part_read(s,SSL_F_GET_CLIENT_FINISHED,i));
807                 s->init_num += i;
808
809                 if (*p != SSL2_MT_CLIENT_FINISHED)
810                         {
811                         if (*p != SSL2_MT_ERROR)
812                                 {
813                                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
814                                 SSLerr(SSL_F_GET_CLIENT_FINISHED,SSL_R_READ_WRONG_PACKET_TYPE);
815                                 }
816                         else
817                                 {
818                                 SSLerr(SSL_F_GET_CLIENT_FINISHED,SSL_R_PEER_ERROR);
819                                 /* try to read the error message */
820                                 i=ssl2_read(s,(char *)&(p[s->init_num]),3-s->init_num);
821                                 return ssl2_part_read(s,SSL_F_GET_SERVER_VERIFY,i);
822                                 }
823                         return(-1);
824                         }
825                 s->state=SSL2_ST_GET_CLIENT_FINISHED_B;
826                 }
827
828         /* SSL2_ST_GET_CLIENT_FINISHED_B */
829         len = 1 + (unsigned long)s->s2->conn_id_length;
830         n = (int)len - s->init_num;
831         i = ssl2_read(s,(char *)&(p[s->init_num]),n);
832         if (i < n)
833                 {
834                 return(ssl2_part_read(s,SSL_F_GET_CLIENT_FINISHED,i));
835                 }
836         if (s->msg_callback)
837                 s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg); /* CLIENT-FINISHED */
838         p += 1;
839         if (memcmp(p,s->s2->conn_id,(unsigned int)s->s2->conn_id_length) != 0)
840                 {
841                 ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
842                 SSLerr(SSL_F_GET_CLIENT_FINISHED,SSL_R_CONNECTION_ID_IS_DIFFERENT);
843                 return(-1);
844                 }
845         return(1);
846         }
847
848 static int server_verify(SSL *s)
849         {
850         unsigned char *p;
851
852         if (s->state == SSL2_ST_SEND_SERVER_VERIFY_A)
853                 {
854                 p=(unsigned char *)s->init_buf->data;
855                 *(p++)=SSL2_MT_SERVER_VERIFY;
856                 memcpy(p,s->s2->challenge,(unsigned int)s->s2->challenge_length);
857                 /* p+=s->s2->challenge_length; */
858
859                 s->state=SSL2_ST_SEND_SERVER_VERIFY_B;
860                 s->init_num=s->s2->challenge_length+1;
861                 s->init_off=0;
862                 }
863         return(ssl2_do_write(s));
864         }
865
866 static int server_finish(SSL *s)
867         {
868         unsigned char *p;
869
870         if (s->state == SSL2_ST_SEND_SERVER_FINISHED_A)
871                 {
872                 p=(unsigned char *)s->init_buf->data;
873                 *(p++)=SSL2_MT_SERVER_FINISHED;
874
875                 memcpy(p,s->session->session_id,
876                         (unsigned int)s->session->session_id_length);
877                 /* p+=s->session->session_id_length; */
878
879                 s->state=SSL2_ST_SEND_SERVER_FINISHED_B;
880                 s->init_num=s->session->session_id_length+1;
881                 s->init_off=0;
882                 }
883
884         /* SSL2_ST_SEND_SERVER_FINISHED_B */
885         return(ssl2_do_write(s));
886         }
887
888 /* send the request and check the response */
889 static int request_certificate(SSL *s)
890         {
891         unsigned char *p,*p2,*buf2;
892         unsigned char *ccd;
893         int i,j,ctype,ret= -1;
894         unsigned long len;
895         X509 *x509=NULL;
896         STACK_OF(X509) *sk=NULL;
897
898         ccd=s->s2->tmp.ccl;
899         if (s->state == SSL2_ST_SEND_REQUEST_CERTIFICATE_A)
900                 {
901                 p=(unsigned char *)s->init_buf->data;
902                 *(p++)=SSL2_MT_REQUEST_CERTIFICATE;
903                 *(p++)=SSL2_AT_MD5_WITH_RSA_ENCRYPTION;
904                 RAND_pseudo_bytes(ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH);
905                 memcpy(p,ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH);
906
907                 s->state=SSL2_ST_SEND_REQUEST_CERTIFICATE_B;
908                 s->init_num=SSL2_MIN_CERT_CHALLENGE_LENGTH+2;
909                 s->init_off=0;
910                 }
911
912         if (s->state == SSL2_ST_SEND_REQUEST_CERTIFICATE_B)
913                 {
914                 i=ssl2_do_write(s);
915                 if (i <= 0)
916                         {
917                         ret=i;
918                         goto end;
919                         }
920
921                 s->init_num=0;
922                 s->state=SSL2_ST_SEND_REQUEST_CERTIFICATE_C;
923                 }
924
925         if (s->state == SSL2_ST_SEND_REQUEST_CERTIFICATE_C)
926                 {
927                 p=(unsigned char *)s->init_buf->data;
928                 i=ssl2_read(s,(char *)&(p[s->init_num]),6-s->init_num); /* try to read 6 octets ... */
929                 if (i < 3-s->init_num) /* ... but don't call ssl2_part_read now if we got at least 3
930                                         * (probably NO-CERTIFICATE-ERROR) */
931                         {
932                         ret=ssl2_part_read(s,SSL_F_REQUEST_CERTIFICATE,i);
933                         goto end;
934                         }
935                 s->init_num += i;
936
937                 if ((s->init_num >= 3) && (p[0] == SSL2_MT_ERROR))
938                         {
939                         n2s(p,i);
940                         if (i != SSL2_PE_NO_CERTIFICATE)
941                                 {
942                                 /* not the error message we expected -- let ssl2_part_read handle it */
943                                 s->init_num -= 3;
944                                 ret = ssl2_part_read(s,SSL_F_REQUEST_CERTIFICATE, 3);
945                                 goto end;
946                                 }
947
948                         if (s->msg_callback)
949                                 s->msg_callback(0, s->version, 0, p, 3, s, s->msg_callback_arg); /* ERROR */
950
951                         /* this is the one place where we can recover from an SSL 2.0 error */
952
953                         if (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)
954                                 {
955                                 ssl2_return_error(s,SSL2_PE_BAD_CERTIFICATE);
956                                 SSLerr(SSL_F_REQUEST_CERTIFICATE,SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
957                                 goto end;
958                                 }
959                         ret=1;
960                         goto end;
961                         }
962                 if ((*(p++) != SSL2_MT_CLIENT_CERTIFICATE) || (s->init_num < 6))
963                         {
964                         ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
965                         SSLerr(SSL_F_REQUEST_CERTIFICATE,SSL_R_SHORT_READ);
966                         goto end;
967                         }
968                 if (s->init_num != 6)
969                         {
970                         SSLerr(SSL_F_REQUEST_CERTIFICATE, ERR_R_INTERNAL_ERROR);
971                         goto end;
972                         }
973                 
974                 /* ok we have a response */
975                 /* certificate type, there is only one right now. */
976                 ctype= *(p++);
977                 if (ctype != SSL2_AT_MD5_WITH_RSA_ENCRYPTION)
978                         {
979                         ssl2_return_error(s,SSL2_PE_UNSUPPORTED_CERTIFICATE_TYPE);
980                         SSLerr(SSL_F_REQUEST_CERTIFICATE,SSL_R_BAD_RESPONSE_ARGUMENT);
981                         goto end;
982                         }
983                 n2s(p,i); s->s2->tmp.clen=i;
984                 n2s(p,i); s->s2->tmp.rlen=i;
985                 s->state=SSL2_ST_SEND_REQUEST_CERTIFICATE_D;
986                 }
987
988         /* SSL2_ST_SEND_REQUEST_CERTIFICATE_D */
989         p=(unsigned char *)s->init_buf->data;
990         len = 6 + (unsigned long)s->s2->tmp.clen + (unsigned long)s->s2->tmp.rlen;
991         if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
992                 {
993                 SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_MESSAGE_TOO_LONG);
994                 goto end;
995                 }
996         j = (int)len - s->init_num;
997         i = ssl2_read(s,(char *)&(p[s->init_num]),j);
998         if (i < j) 
999                 {
1000                 ret=ssl2_part_read(s,SSL_F_REQUEST_CERTIFICATE,i);
1001                 goto end;
1002                 }
1003         if (s->msg_callback)
1004                 s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg); /* CLIENT-CERTIFICATE */
1005         p += 6;
1006
1007         x509=(X509 *)d2i_X509(NULL,&p,(long)s->s2->tmp.clen);
1008         if (x509 == NULL)
1009                 {
1010                 SSLerr(SSL_F_REQUEST_CERTIFICATE,ERR_R_X509_LIB);
1011                 goto msg_end;
1012                 }
1013
1014         if (((sk=sk_X509_new_null()) == NULL) || (!sk_X509_push(sk,x509)))
1015                 {
1016                 SSLerr(SSL_F_REQUEST_CERTIFICATE,ERR_R_MALLOC_FAILURE);
1017                 goto msg_end;
1018                 }
1019
1020         i=ssl_verify_cert_chain(s,sk);
1021
1022         if (i)  /* we like the packet, now check the chksum */
1023                 {
1024                 EVP_MD_CTX ctx;
1025                 EVP_PKEY *pkey=NULL;
1026
1027                 EVP_MD_CTX_init(&ctx);
1028                 EVP_VerifyInit_ex(&ctx,s->ctx->rsa_md5, NULL);
1029                 EVP_VerifyUpdate(&ctx,s->s2->key_material,
1030                         (unsigned int)s->s2->key_material_length);
1031                 EVP_VerifyUpdate(&ctx,ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH);
1032
1033                 i=i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509,NULL);
1034                 buf2=OPENSSL_malloc((unsigned int)i);
1035                 if (buf2 == NULL)
1036                         {
1037                         SSLerr(SSL_F_REQUEST_CERTIFICATE,ERR_R_MALLOC_FAILURE);
1038                         goto msg_end;
1039                         }
1040                 p2=buf2;
1041                 i=i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509,&p2);
1042                 EVP_VerifyUpdate(&ctx,buf2,(unsigned int)i);
1043                 OPENSSL_free(buf2);
1044
1045                 pkey=X509_get_pubkey(x509);
1046                 if (pkey == NULL) goto end;
1047                 i=EVP_VerifyFinal(&ctx,p,s->s2->tmp.rlen,pkey);
1048                 EVP_PKEY_free(pkey);
1049                 EVP_MD_CTX_cleanup(&ctx);
1050
1051                 if (i) 
1052                         {
1053                         if (s->session->peer != NULL)
1054                                 X509_free(s->session->peer);
1055                         s->session->peer=x509;
1056                         CRYPTO_add(&x509->references,1,CRYPTO_LOCK_X509);
1057                         s->session->verify_result = s->verify_result;
1058                         ret=1;
1059                         goto end;
1060                         }
1061                 else
1062                         {
1063                         SSLerr(SSL_F_REQUEST_CERTIFICATE,SSL_R_BAD_CHECKSUM);
1064                         goto msg_end;
1065                         }
1066                 }
1067         else
1068                 {
1069 msg_end:
1070                 ssl2_return_error(s,SSL2_PE_BAD_CERTIFICATE);
1071                 }
1072 end:
1073         sk_X509_free(sk);
1074         X509_free(x509);
1075         return(ret);
1076         }
1077
1078 static int ssl_rsa_private_decrypt(CERT *c, int len, unsigned char *from,
1079              unsigned char *to, int padding)
1080         {
1081         RSA *rsa;
1082         int i;
1083
1084         if ((c == NULL) || (c->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL))
1085                 {
1086                 SSLerr(SSL_F_SSL_RSA_PRIVATE_DECRYPT,SSL_R_NO_PRIVATEKEY);
1087                 return(-1);
1088                 }
1089         if (c->pkeys[SSL_PKEY_RSA_ENC].privatekey->type != EVP_PKEY_RSA)
1090                 {
1091                 SSLerr(SSL_F_SSL_RSA_PRIVATE_DECRYPT,SSL_R_PUBLIC_KEY_IS_NOT_RSA);
1092                 return(-1);
1093                 }
1094         rsa=c->pkeys[SSL_PKEY_RSA_ENC].privatekey->pkey.rsa;
1095
1096         /* we have the public key */
1097         i=RSA_private_decrypt(len,from,to,rsa,padding);
1098         if (i < 0)
1099                 SSLerr(SSL_F_SSL_RSA_PRIVATE_DECRYPT,ERR_R_RSA_LIB);
1100         return(i);
1101         }
1102 #else /* !OPENSSL_NO_SSL2 */
1103
1104 # if PEDANTIC
1105 static void *dummy=&dummy;
1106 # endif
1107
1108 #endif