openssl: Fix CVE-2011-0014.
[dragonfly.git] / crypto / openssl / ssl / t1_lib.c
1 /* ssl/t1_lib.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 #include <stdio.h>
60 #include <openssl/objects.h>
61 #include <openssl/evp.h>
62 #include <openssl/hmac.h>
63 #include <openssl/ocsp.h>
64 #include "ssl_locl.h"
65
66 const char tls1_version_str[]="TLSv1" OPENSSL_VERSION_PTEXT;
67
68 #ifndef OPENSSL_NO_TLSEXT
69 static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
70                                 const unsigned char *sess_id, int sesslen,
71                                 SSL_SESSION **psess);
72 #endif
73
74 SSL3_ENC_METHOD TLSv1_enc_data={
75         tls1_enc,
76         tls1_mac,
77         tls1_setup_key_block,
78         tls1_generate_master_secret,
79         tls1_change_cipher_state,
80         tls1_final_finish_mac,
81         TLS1_FINISH_MAC_LENGTH,
82         tls1_cert_verify_mac,
83         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
84         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
85         tls1_alert_code,
86         };
87
88 long tls1_default_timeout(void)
89         {
90         /* 2 hours, the 24 hours mentioned in the TLSv1 spec
91          * is way too long for http, the cache would over fill */
92         return(60*60*2);
93         }
94
95 IMPLEMENT_tls1_meth_func(tlsv1_base_method,
96                         ssl_undefined_function,
97                         ssl_undefined_function,
98                         ssl_bad_method)
99
100 int tls1_new(SSL *s)
101         {
102         if (!ssl3_new(s)) return(0);
103         s->method->ssl_clear(s);
104         return(1);
105         }
106
107 void tls1_free(SSL *s)
108         {
109         ssl3_free(s);
110         }
111
112 void tls1_clear(SSL *s)
113         {
114         ssl3_clear(s);
115         s->version=TLS1_VERSION;
116         }
117
118 #if 0
119 long tls1_ctrl(SSL *s, int cmd, long larg, char *parg)
120         {
121         return(0);
122         }
123
124 long tls1_callback_ctrl(SSL *s, int cmd, void *(*fp)())
125         {
126         return(0);
127         }
128 #endif
129
130 #ifndef OPENSSL_NO_TLSEXT
131 unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
132         {
133         int extdatalen=0;
134         unsigned char *ret = p;
135
136         /* don't add extensions for SSLv3 unless doing secure renegotiation */
137         if (s->client_version == SSL3_VERSION
138                                         && !s->s3->send_connection_binding)
139                 return p;
140
141         ret+=2;
142
143         if (ret>=limit) return NULL; /* this really never occurs, but ... */
144
145         if (s->tlsext_hostname != NULL)
146                 { 
147                 /* Add TLS extension servername to the Client Hello message */
148                 unsigned long size_str;
149                 long lenmax; 
150
151                 /* check for enough space.
152                    4 for the servername type and entension length
153                    2 for servernamelist length
154                    1 for the hostname type
155                    2 for hostname length
156                    + hostname length 
157                 */
158                    
159                 if ((lenmax = limit - ret - 9) < 0 
160                 || (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax) 
161                         return NULL;
162                         
163                 /* extension type and length */
164                 s2n(TLSEXT_TYPE_server_name,ret); 
165                 s2n(size_str+5,ret);
166                 
167                 /* length of servername list */
168                 s2n(size_str+3,ret);
169         
170                 /* hostname type, length and hostname */
171                 *(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
172                 s2n(size_str,ret);
173                 memcpy(ret, s->tlsext_hostname, size_str);
174                 ret+=size_str;
175
176                 }
177  
178         /* Add RI if renegotiating */
179         if (s->new_session)
180           {
181           int el;
182           
183           if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
184               {
185               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
186               return NULL;
187               }
188
189           if((limit - p - 4 - el) < 0) return NULL;
190           
191           s2n(TLSEXT_TYPE_renegotiate,ret);
192           s2n(el,ret);
193
194           if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
195               {
196               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
197               return NULL;
198               }
199
200           ret += el;
201         }
202
203            
204         if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
205                 {
206                 int ticklen;
207                 if (!s->new_session && s->session && s->session->tlsext_tick)
208                         ticklen = s->session->tlsext_ticklen;
209                 else
210                         ticklen = 0;
211                 /* Check for enough room 2 for extension type, 2 for len
212                  * rest for ticket
213                  */
214                 if (limit - ret - 4 - ticklen < 0)
215                         return NULL;
216                 s2n(TLSEXT_TYPE_session_ticket,ret); 
217                 s2n(ticklen,ret);
218                 if (ticklen)
219                         {
220                         memcpy(ret, s->session->tlsext_tick, ticklen);
221                         ret += ticklen;
222                         }
223                 }
224
225         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp &&
226             s->version != DTLS1_VERSION)
227                 {
228                 int i;
229                 long extlen, idlen, itmp;
230                 OCSP_RESPID *id;
231
232                 idlen = 0;
233                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
234                         {
235                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
236                         itmp = i2d_OCSP_RESPID(id, NULL);
237                         if (itmp <= 0)
238                                 return NULL;
239                         idlen += itmp + 2;
240                         }
241
242                 if (s->tlsext_ocsp_exts)
243                         {
244                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
245                         if (extlen < 0)
246                                 return NULL;
247                         }
248                 else
249                         extlen = 0;
250                         
251                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
252                 s2n(TLSEXT_TYPE_status_request, ret);
253                 if (extlen + idlen > 0xFFF0)
254                         return NULL;
255                 s2n(extlen + idlen + 5, ret);
256                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
257                 s2n(idlen, ret);
258                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
259                         {
260                         /* save position of id len */
261                         unsigned char *q = ret;
262                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
263                         /* skip over id len */
264                         ret += 2;
265                         itmp = i2d_OCSP_RESPID(id, &ret);
266                         /* write id len */
267                         s2n(itmp, q);
268                         }
269                 s2n(extlen, ret);
270                 if (extlen > 0)
271                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
272                 }
273
274         if ((extdatalen = ret-p-2)== 0) 
275                 return p;
276
277         s2n(extdatalen,p);
278         return ret;
279         }
280
281 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
282         {
283         int extdatalen=0;
284         unsigned char *ret = p;
285
286         /* don't add extensions for SSLv3, unless doing secure renegotiation */
287         if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
288                 return p;
289         
290         ret+=2;
291         if (ret>=limit) return NULL; /* this really never occurs, but ... */
292
293         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
294                 { 
295                 if (limit - ret - 4 < 0) return NULL; 
296
297                 s2n(TLSEXT_TYPE_server_name,ret);
298                 s2n(0,ret);
299                 }
300
301         if(s->s3->send_connection_binding)
302         {
303           int el;
304           
305           if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
306               {
307               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
308               return NULL;
309               }
310
311           if((limit - p - 4 - el) < 0) return NULL;
312           
313           s2n(TLSEXT_TYPE_renegotiate,ret);
314           s2n(el,ret);
315
316           if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
317               {
318               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
319               return NULL;
320               }
321
322           ret += el;
323         }
324         
325         if (s->tlsext_ticket_expected
326                 && !(SSL_get_options(s) & SSL_OP_NO_TICKET)) 
327                 { 
328                 if (limit - ret - 4 < 0) return NULL; 
329                 s2n(TLSEXT_TYPE_session_ticket,ret);
330                 s2n(0,ret);
331                 }
332
333         if (s->tlsext_status_expected)
334                 { 
335                 if ((long)(limit - ret - 4) < 0) return NULL; 
336                 s2n(TLSEXT_TYPE_status_request,ret);
337                 s2n(0,ret);
338                 }
339
340         if ((extdatalen = ret-p-2)== 0) 
341                 return p;
342
343         s2n(extdatalen,p);
344         return ret;
345         }
346
347 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
348         {
349         unsigned short type;
350         unsigned short size;
351         unsigned short len;
352         unsigned char *data = *p;
353         int renegotiate_seen = 0;
354
355         s->servername_done = 0;
356         s->tlsext_status_type = -1;
357
358         if (data >= (d+n-2))
359                 goto ri_check;
360
361         n2s(data,len);
362
363         if (data > (d+n-len)) 
364                 goto ri_check;
365
366         while (data <= (d+n-4))
367                 {
368                 n2s(data,type);
369                 n2s(data,size);
370
371                 if (data+size > (d+n))
372                         goto ri_check;
373
374                 if (s->tlsext_debug_cb)
375                         s->tlsext_debug_cb(s, 0, type, data, size,
376                                                 s->tlsext_debug_arg);
377 /* The servername extension is treated as follows:
378
379    - Only the hostname type is supported with a maximum length of 255.
380    - The servername is rejected if too long or if it contains zeros,
381      in which case an fatal alert is generated.
382    - The servername field is maintained together with the session cache.
383    - When a session is resumed, the servername call back invoked in order
384      to allow the application to position itself to the right context. 
385    - The servername is acknowledged if it is new for a session or when 
386      it is identical to a previously used for the same session. 
387      Applications can control the behaviour.  They can at any time
388      set a 'desirable' servername for a new SSL object. This can be the
389      case for example with HTTPS when a Host: header field is received and
390      a renegotiation is requested. In this case, a possible servername
391      presented in the new client hello is only acknowledged if it matches
392      the value of the Host: field. 
393    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
394      if they provide for changing an explicit servername context for the session,
395      i.e. when the session has been established with a servername extension. 
396    - On session reconnect, the servername extension may be absent. 
397
398 */      
399
400                 if (type == TLSEXT_TYPE_server_name)
401                         {
402                         unsigned char *sdata;
403                         int servname_type;
404                         int dsize; 
405                 
406                         if (size < 2) 
407                                 {
408                                 *al = SSL_AD_DECODE_ERROR;
409                                 return 0;
410                                 }
411                         n2s(data,dsize);  
412                         size -= 2;
413                         if (dsize > size  ) 
414                                 {
415                                 *al = SSL_AD_DECODE_ERROR;
416                                 return 0;
417                                 } 
418
419                         sdata = data;
420                         while (dsize > 3) 
421                                 {
422                                 servname_type = *(sdata++); 
423                                 n2s(sdata,len);
424                                 dsize -= 3;
425
426                                 if (len > dsize) 
427                                         {
428                                         *al = SSL_AD_DECODE_ERROR;
429                                         return 0;
430                                         }
431                                 if (s->servername_done == 0)
432                                 switch (servname_type)
433                                         {
434                                 case TLSEXT_NAMETYPE_host_name:
435                                         if (s->session->tlsext_hostname == NULL)
436                                                 {
437                                                 if (len > TLSEXT_MAXLEN_host_name || 
438                                                         ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL))
439                                                         {
440                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
441                                                         return 0;
442                                                         }
443                                                 memcpy(s->session->tlsext_hostname, sdata, len);
444                                                 s->session->tlsext_hostname[len]='\0';
445                                                 if (strlen(s->session->tlsext_hostname) != len) {
446                                                         OPENSSL_free(s->session->tlsext_hostname);
447                                                         s->session->tlsext_hostname = NULL;
448                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
449                                                         return 0;
450                                                 }
451                                                 s->servername_done = 1; 
452
453                                                 }
454                                         else 
455                                                 s->servername_done = strlen(s->session->tlsext_hostname) == len 
456                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
457                                         
458                                         break;
459
460                                 default:
461                                         break;
462                                         }
463                                  
464                                 dsize -= len;
465                                 }
466                         if (dsize != 0) 
467                                 {
468                                 *al = SSL_AD_DECODE_ERROR;
469                                 return 0;
470                                 }
471
472                         }
473                 else if (type == TLSEXT_TYPE_renegotiate)
474                         {
475                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
476                                 return 0;
477                         renegotiate_seen = 1;
478                         }
479                 else if (type == TLSEXT_TYPE_status_request &&
480                          s->version != DTLS1_VERSION && s->ctx->tlsext_status_cb)
481                         {
482                 
483                         if (size < 5) 
484                                 {
485                                 *al = SSL_AD_DECODE_ERROR;
486                                 return 0;
487                                 }
488
489                         s->tlsext_status_type = *data++;
490                         size--;
491                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
492                                 {
493                                 const unsigned char *sdata;
494                                 int dsize;
495                                 /* Read in responder_id_list */
496                                 n2s(data,dsize);
497                                 size -= 2;
498                                 if (dsize > size  ) 
499                                         {
500                                         *al = SSL_AD_DECODE_ERROR;
501                                         return 0;
502                                         }
503                                 while (dsize > 0)
504                                         {
505                                         OCSP_RESPID *id;
506                                         int idsize;
507                                         if (dsize < 4)
508                                                 {
509                                                 *al = SSL_AD_DECODE_ERROR;
510                                                 return 0;
511                                                 }
512                                         n2s(data, idsize);
513                                         dsize -= 2 + idsize;
514                                         size -= 2 + idsize;
515                                         if (dsize < 0)
516                                                 {
517                                                 *al = SSL_AD_DECODE_ERROR;
518                                                 return 0;
519                                                 }
520                                         sdata = data;
521                                         data += idsize;
522                                         id = d2i_OCSP_RESPID(NULL,
523                                                                 &sdata, idsize);
524                                         if (!id)
525                                                 {
526                                                 *al = SSL_AD_DECODE_ERROR;
527                                                 return 0;
528                                                 }
529                                         if (data != sdata)
530                                                 {
531                                                 OCSP_RESPID_free(id);
532                                                 *al = SSL_AD_DECODE_ERROR;
533                                                 return 0;
534                                                 }
535                                         if (!s->tlsext_ocsp_ids
536                                                 && !(s->tlsext_ocsp_ids =
537                                                 sk_OCSP_RESPID_new_null()))
538                                                 {
539                                                 OCSP_RESPID_free(id);
540                                                 *al = SSL_AD_INTERNAL_ERROR;
541                                                 return 0;
542                                                 }
543                                         if (!sk_OCSP_RESPID_push(
544                                                         s->tlsext_ocsp_ids, id))
545                                                 {
546                                                 OCSP_RESPID_free(id);
547                                                 *al = SSL_AD_INTERNAL_ERROR;
548                                                 return 0;
549                                                 }
550                                         }
551
552                                 /* Read in request_extensions */
553                                 if (size < 2)
554                                         {
555                                         *al = SSL_AD_DECODE_ERROR;
556                                         return 0;
557                                         }
558                                 n2s(data,dsize);
559                                 size -= 2;
560                                 if (dsize != size)
561                                         {
562                                         *al = SSL_AD_DECODE_ERROR;
563                                         return 0;
564                                         }
565                                 sdata = data;
566                                 if (dsize > 0)
567                                         {
568                                         s->tlsext_ocsp_exts =
569                                                 d2i_X509_EXTENSIONS(NULL,
570                                                         &sdata, dsize);
571                                         if (!s->tlsext_ocsp_exts
572                                                 || (data + dsize != sdata))
573                                                 {
574                                                 *al = SSL_AD_DECODE_ERROR;
575                                                 return 0;
576                                                 }
577                                         }
578                                 }
579                                 /* We don't know what to do with any other type
580                                 * so ignore it.
581                                 */
582                                 else
583                                         s->tlsext_status_type = -1;
584                         }
585
586                 /* session ticket processed earlier */
587
588                 data+=size;             
589                 }
590         *p = data;
591
592         ri_check:
593
594         /* Need RI if renegotiating */
595
596         if (!renegotiate_seen && s->new_session &&
597                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
598                 {
599                 *al = SSL_AD_HANDSHAKE_FAILURE;
600                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,
601                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
602                 return 0;
603                 }
604
605         return 1;
606         }
607
608 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
609         {
610         unsigned short type;
611         unsigned short size;
612         unsigned short len;  
613         unsigned char *data = *p;
614         int tlsext_servername = 0;
615         int renegotiate_seen = 0;
616
617         if (data >= (d+n-2))
618                 goto ri_check;
619
620         n2s(data,len);
621
622         while(data <= (d+n-4))
623                 {
624                 n2s(data,type);
625                 n2s(data,size);
626
627                 if (data+size > (d+n))
628                         goto ri_check;
629
630                 if (s->tlsext_debug_cb)
631                         s->tlsext_debug_cb(s, 1, type, data, size,
632                                                 s->tlsext_debug_arg);
633
634                 if (type == TLSEXT_TYPE_server_name)
635                         {
636                         if (s->tlsext_hostname == NULL || size > 0)
637                                 {
638                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
639                                 return 0;
640                                 }
641                         tlsext_servername = 1;   
642                         }
643                 else if (type == TLSEXT_TYPE_session_ticket)
644                         {
645                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
646                                 || (size > 0))
647                                 {
648                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
649                                 return 0;
650                                 }
651                         s->tlsext_ticket_expected = 1;
652                         }
653                 else if (type == TLSEXT_TYPE_status_request &&
654                          s->version != DTLS1_VERSION)
655                         {
656                         /* MUST be empty and only sent if we've requested
657                          * a status request message.
658                          */ 
659                         if ((s->tlsext_status_type == -1) || (size > 0))
660                                 {
661                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
662                                 return 0;
663                                 }
664                         /* Set flag to expect CertificateStatus message */
665                         s->tlsext_status_expected = 1;
666                         }
667                 else if (type == TLSEXT_TYPE_renegotiate)
668                         {
669                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
670                                 return 0;
671                         renegotiate_seen = 1;
672                         }
673                 data+=size;             
674                 }
675
676         if (data != d+n)
677                 {
678                 *al = SSL_AD_DECODE_ERROR;
679                 return 0;
680                 }
681
682         if (!s->hit && tlsext_servername == 1)
683                 {
684                 if (s->tlsext_hostname)
685                         {
686                         if (s->session->tlsext_hostname == NULL)
687                                 {
688                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);   
689                                 if (!s->session->tlsext_hostname)
690                                         {
691                                         *al = SSL_AD_UNRECOGNIZED_NAME;
692                                         return 0;
693                                         }
694                                 }
695                         else 
696                                 {
697                                 *al = SSL_AD_DECODE_ERROR;
698                                 return 0;
699                                 }
700                         }
701                 }
702
703         *p = data;
704
705         ri_check:
706
707         /* Determine if we need to see RI. Strictly speaking if we want to
708          * avoid an attack we should *always* see RI even on initial server
709          * hello because the client doesn't see any renegotiation during an
710          * attack. However this would mean we could not connect to any server
711          * which doesn't support RI so for the immediate future tolerate RI
712          * absence on initial connect only.
713          */
714         if (!renegotiate_seen
715                 && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
716                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
717                 {
718                 *al = SSL_AD_HANDSHAKE_FAILURE;
719                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
720                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
721                 return 0;
722                 }
723
724         return 1;
725         }
726
727 int ssl_check_clienthello_tlsext(SSL *s)
728         {
729         int ret=SSL_TLSEXT_ERR_NOACK;
730         int al = SSL_AD_UNRECOGNIZED_NAME;
731
732         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
733                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
734         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
735                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
736
737         /* If status request then ask callback what to do.
738          * Note: this must be called after servername callbacks in case 
739          * the certificate has changed.
740          */
741         if ((s->tlsext_status_type != -1) && s->ctx->tlsext_status_cb)
742                 {
743                 int r;
744                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
745                 switch (r)
746                         {
747                         /* We don't want to send a status request response */
748                         case SSL_TLSEXT_ERR_NOACK:
749                                 s->tlsext_status_expected = 0;
750                                 break;
751                         /* status request response should be sent */
752                         case SSL_TLSEXT_ERR_OK:
753                                 if (s->tlsext_ocsp_resp)
754                                         s->tlsext_status_expected = 1;
755                                 else
756                                         s->tlsext_status_expected = 0;
757                                 break;
758                         /* something bad happened */
759                         case SSL_TLSEXT_ERR_ALERT_FATAL:
760                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
761                                 al = SSL_AD_INTERNAL_ERROR;
762                                 goto err;
763                         }
764                 }
765         else
766                 s->tlsext_status_expected = 0;
767         err:
768         switch (ret)
769                 {
770                 case SSL_TLSEXT_ERR_ALERT_FATAL:
771                         ssl3_send_alert(s,SSL3_AL_FATAL,al); 
772                         return -1;
773
774                 case SSL_TLSEXT_ERR_ALERT_WARNING:
775                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
776                         return 1; 
777                                         
778                 case SSL_TLSEXT_ERR_NOACK:
779                         s->servername_done=0;
780                         default:
781                 return 1;
782                 }
783         }
784
785 int ssl_check_serverhello_tlsext(SSL *s)
786         {
787         int ret=SSL_TLSEXT_ERR_NOACK;
788         int al = SSL_AD_UNRECOGNIZED_NAME;
789
790         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
791                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
792         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
793                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
794
795         /* If we've requested certificate status and we wont get one
796          * tell the callback
797          */
798         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
799                         && s->ctx->tlsext_status_cb)
800                 {
801                 int r;
802                 /* Set resp to NULL, resplen to -1 so callback knows
803                  * there is no response.
804                  */
805                 if (s->tlsext_ocsp_resp)
806                         {
807                         OPENSSL_free(s->tlsext_ocsp_resp);
808                         s->tlsext_ocsp_resp = NULL;
809                         }
810                 s->tlsext_ocsp_resplen = -1;
811                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
812                 if (r == 0)
813                         {
814                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
815                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
816                         }
817                 if (r < 0)
818                         {
819                         al = SSL_AD_INTERNAL_ERROR;
820                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
821                         }
822                 }
823
824         switch (ret)
825                 {
826                 case SSL_TLSEXT_ERR_ALERT_FATAL:
827                         ssl3_send_alert(s,SSL3_AL_FATAL,al); 
828                         return -1;
829
830                 case SSL_TLSEXT_ERR_ALERT_WARNING:
831                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
832                         return 1; 
833                                         
834                 case SSL_TLSEXT_ERR_NOACK:
835                         s->servername_done=0;
836                         default:
837                 return 1;
838                 }
839         }
840
841 /* Since the server cache lookup is done early on in the processing of client
842  * hello and other operations depend on the result we need to handle any TLS
843  * session ticket extension at the same time.
844  */
845
846 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
847                                 const unsigned char *limit, SSL_SESSION **ret)
848         {
849         /* Point after session ID in client hello */
850         const unsigned char *p = session_id + len;
851         unsigned short i;
852
853         /* If tickets disabled behave as if no ticket present
854          * to permit stateful resumption.
855          */
856         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
857                 return 1;
858
859         if ((s->version <= SSL3_VERSION) || !limit)
860                 return 1;
861         if (p >= limit)
862                 return -1;
863         /* Skip past DTLS cookie */
864         if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
865                 {
866                 i = *(p++);
867                 p+= i;
868                 if (p >= limit)
869                         return -1;
870                 }
871         /* Skip past cipher list */
872         n2s(p, i);
873         p+= i;
874         if (p >= limit)
875                 return -1;
876         /* Skip past compression algorithm list */
877         i = *(p++);
878         p += i;
879         if (p > limit)
880                 return -1;
881         /* Now at start of extensions */
882         if ((p + 2) >= limit)
883                 return 1;
884         n2s(p, i);
885         while ((p + 4) <= limit)
886                 {
887                 unsigned short type, size;
888                 n2s(p, type);
889                 n2s(p, size);
890                 if (p + size > limit)
891                         return 1;
892                 if (type == TLSEXT_TYPE_session_ticket)
893                         {
894                         /* If zero length note client will accept a ticket
895                          * and indicate cache miss to trigger full handshake
896                          */
897                         if (size == 0)
898                                 {
899                                 s->tlsext_ticket_expected = 1;
900                                 return 0;       /* Cache miss */
901                                 }
902                         return tls_decrypt_ticket(s, p, size, session_id, len,
903                                                                         ret);
904                         }
905                 p += size;
906                 }
907         return 1;
908         }
909
910 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
911                                 const unsigned char *sess_id, int sesslen,
912                                 SSL_SESSION **psess)
913         {
914         SSL_SESSION *sess;
915         unsigned char *sdec;
916         const unsigned char *p;
917         int slen, mlen, renew_ticket = 0;
918         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
919         HMAC_CTX hctx;
920         EVP_CIPHER_CTX ctx;
921         SSL_CTX *tctx = s->initial_ctx;
922         /* Need at least keyname + iv + some encrypted data */
923         if (eticklen < 48)
924                 goto tickerr;
925         /* Initialize session ticket encryption and HMAC contexts */
926         HMAC_CTX_init(&hctx);
927         EVP_CIPHER_CTX_init(&ctx);
928         if (tctx->tlsext_ticket_key_cb)
929                 {
930                 unsigned char *nctick = (unsigned char *)etick;
931                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
932                                                         &ctx, &hctx, 0);
933                 if (rv < 0)
934                         return -1;
935                 if (rv == 0)
936                         goto tickerr;
937                 if (rv == 2)
938                         renew_ticket = 1;
939                 }
940         else
941                 {
942                 /* Check key name matches */
943                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
944                         goto tickerr;
945                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
946                                         tlsext_tick_md(), NULL);
947                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
948                                 tctx->tlsext_tick_aes_key, etick + 16);
949                 }
950         /* Attempt to process session ticket, first conduct sanity and
951          * integrity checks on ticket.
952          */
953         mlen = HMAC_size(&hctx);
954         eticklen -= mlen;
955         /* Check HMAC of encrypted ticket */
956         HMAC_Update(&hctx, etick, eticklen);
957         HMAC_Final(&hctx, tick_hmac, NULL);
958         HMAC_CTX_cleanup(&hctx);
959         if (memcmp(tick_hmac, etick + eticklen, mlen))
960                 goto tickerr;
961         /* Attempt to decrypt session data */
962         /* Move p after IV to start of encrypted ticket, update length */
963         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
964         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
965         sdec = OPENSSL_malloc(eticklen);
966         if (!sdec)
967                 {
968                 EVP_CIPHER_CTX_cleanup(&ctx);
969                 return -1;
970                 }
971         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
972         if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
973                 goto tickerr;
974         slen += mlen;
975         EVP_CIPHER_CTX_cleanup(&ctx);
976         p = sdec;
977                 
978         sess = d2i_SSL_SESSION(NULL, &p, slen);
979         OPENSSL_free(sdec);
980         if (sess)
981                 {
982                 /* The session ID if non-empty is used by some clients to
983                  * detect that the ticket has been accepted. So we copy it to
984                  * the session structure. If it is empty set length to zero
985                  * as required by standard.
986                  */
987                 if (sesslen)
988                         memcpy(sess->session_id, sess_id, sesslen);
989                 sess->session_id_length = sesslen;
990                 *psess = sess;
991                 s->tlsext_ticket_expected = renew_ticket;
992                 return 1;
993                 }
994         /* If session decrypt failure indicate a cache miss and set state to
995          * send a new ticket
996          */
997         tickerr:        
998         s->tlsext_ticket_expected = 1;
999         return 0;
1000         }
1001
1002 #endif