8b5311277015b747f000f76de6a757209be9e418
[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                                         if (dsize < 0)
515                                                 {
516                                                 *al = SSL_AD_DECODE_ERROR;
517                                                 return 0;
518                                                 }
519                                         sdata = data;
520                                         data += idsize;
521                                         id = d2i_OCSP_RESPID(NULL,
522                                                                 &sdata, idsize);
523                                         if (!id)
524                                                 {
525                                                 *al = SSL_AD_DECODE_ERROR;
526                                                 return 0;
527                                                 }
528                                         if (data != sdata)
529                                                 {
530                                                 OCSP_RESPID_free(id);
531                                                 *al = SSL_AD_DECODE_ERROR;
532                                                 return 0;
533                                                 }
534                                         if (!s->tlsext_ocsp_ids
535                                                 && !(s->tlsext_ocsp_ids =
536                                                 sk_OCSP_RESPID_new_null()))
537                                                 {
538                                                 OCSP_RESPID_free(id);
539                                                 *al = SSL_AD_INTERNAL_ERROR;
540                                                 return 0;
541                                                 }
542                                         if (!sk_OCSP_RESPID_push(
543                                                         s->tlsext_ocsp_ids, id))
544                                                 {
545                                                 OCSP_RESPID_free(id);
546                                                 *al = SSL_AD_INTERNAL_ERROR;
547                                                 return 0;
548                                                 }
549                                         }
550
551                                 /* Read in request_extensions */
552                                 n2s(data,dsize);
553                                 size -= 2;
554                                 if (dsize > size) 
555                                         {
556                                         *al = SSL_AD_DECODE_ERROR;
557                                         return 0;
558                                         }
559                                 sdata = data;
560                                 if (dsize > 0)
561                                         {
562                                         s->tlsext_ocsp_exts =
563                                                 d2i_X509_EXTENSIONS(NULL,
564                                                         &sdata, dsize);
565                                         if (!s->tlsext_ocsp_exts
566                                                 || (data + dsize != sdata))
567                                                 {
568                                                 *al = SSL_AD_DECODE_ERROR;
569                                                 return 0;
570                                                 }
571                                         }
572                                 }
573                                 /* We don't know what to do with any other type
574                                 * so ignore it.
575                                 */
576                                 else
577                                         s->tlsext_status_type = -1;
578                         }
579
580                 /* session ticket processed earlier */
581
582                 data+=size;             
583                 }
584         *p = data;
585
586         ri_check:
587
588         /* Need RI if renegotiating */
589
590         if (!renegotiate_seen && s->new_session &&
591                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
592                 {
593                 *al = SSL_AD_HANDSHAKE_FAILURE;
594                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,
595                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
596                 return 0;
597                 }
598
599         return 1;
600         }
601
602 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
603         {
604         unsigned short type;
605         unsigned short size;
606         unsigned short len;  
607         unsigned char *data = *p;
608         int tlsext_servername = 0;
609         int renegotiate_seen = 0;
610
611         if (data >= (d+n-2))
612                 goto ri_check;
613
614         n2s(data,len);
615
616         while(data <= (d+n-4))
617                 {
618                 n2s(data,type);
619                 n2s(data,size);
620
621                 if (data+size > (d+n))
622                         goto ri_check;
623
624                 if (s->tlsext_debug_cb)
625                         s->tlsext_debug_cb(s, 1, type, data, size,
626                                                 s->tlsext_debug_arg);
627
628                 if (type == TLSEXT_TYPE_server_name)
629                         {
630                         if (s->tlsext_hostname == NULL || size > 0)
631                                 {
632                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
633                                 return 0;
634                                 }
635                         tlsext_servername = 1;   
636                         }
637                 else if (type == TLSEXT_TYPE_session_ticket)
638                         {
639                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
640                                 || (size > 0))
641                                 {
642                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
643                                 return 0;
644                                 }
645                         s->tlsext_ticket_expected = 1;
646                         }
647                 else if (type == TLSEXT_TYPE_status_request &&
648                          s->version != DTLS1_VERSION)
649                         {
650                         /* MUST be empty and only sent if we've requested
651                          * a status request message.
652                          */ 
653                         if ((s->tlsext_status_type == -1) || (size > 0))
654                                 {
655                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
656                                 return 0;
657                                 }
658                         /* Set flag to expect CertificateStatus message */
659                         s->tlsext_status_expected = 1;
660                         }
661                 else if (type == TLSEXT_TYPE_renegotiate)
662                         {
663                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
664                                 return 0;
665                         renegotiate_seen = 1;
666                         }
667                 data+=size;             
668                 }
669
670         if (data != d+n)
671                 {
672                 *al = SSL_AD_DECODE_ERROR;
673                 return 0;
674                 }
675
676         if (!s->hit && tlsext_servername == 1)
677                 {
678                 if (s->tlsext_hostname)
679                         {
680                         if (s->session->tlsext_hostname == NULL)
681                                 {
682                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);   
683                                 if (!s->session->tlsext_hostname)
684                                         {
685                                         *al = SSL_AD_UNRECOGNIZED_NAME;
686                                         return 0;
687                                         }
688                                 }
689                         else 
690                                 {
691                                 *al = SSL_AD_DECODE_ERROR;
692                                 return 0;
693                                 }
694                         }
695                 }
696
697         *p = data;
698
699         ri_check:
700
701         /* Determine if we need to see RI. Strictly speaking if we want to
702          * avoid an attack we should *always* see RI even on initial server
703          * hello because the client doesn't see any renegotiation during an
704          * attack. However this would mean we could not connect to any server
705          * which doesn't support RI so for the immediate future tolerate RI
706          * absence on initial connect only.
707          */
708         if (!renegotiate_seen
709                 && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
710                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
711                 {
712                 *al = SSL_AD_HANDSHAKE_FAILURE;
713                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
714                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
715                 return 0;
716                 }
717
718         return 1;
719         }
720
721 int ssl_check_clienthello_tlsext(SSL *s)
722         {
723         int ret=SSL_TLSEXT_ERR_NOACK;
724         int al = SSL_AD_UNRECOGNIZED_NAME;
725
726         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
727                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
728         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
729                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
730
731         /* If status request then ask callback what to do.
732          * Note: this must be called after servername callbacks in case 
733          * the certificate has changed.
734          */
735         if ((s->tlsext_status_type != -1) && s->ctx->tlsext_status_cb)
736                 {
737                 int r;
738                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
739                 switch (r)
740                         {
741                         /* We don't want to send a status request response */
742                         case SSL_TLSEXT_ERR_NOACK:
743                                 s->tlsext_status_expected = 0;
744                                 break;
745                         /* status request response should be sent */
746                         case SSL_TLSEXT_ERR_OK:
747                                 if (s->tlsext_ocsp_resp)
748                                         s->tlsext_status_expected = 1;
749                                 else
750                                         s->tlsext_status_expected = 0;
751                                 break;
752                         /* something bad happened */
753                         case SSL_TLSEXT_ERR_ALERT_FATAL:
754                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
755                                 al = SSL_AD_INTERNAL_ERROR;
756                                 goto err;
757                         }
758                 }
759         else
760                 s->tlsext_status_expected = 0;
761         err:
762         switch (ret)
763                 {
764                 case SSL_TLSEXT_ERR_ALERT_FATAL:
765                         ssl3_send_alert(s,SSL3_AL_FATAL,al); 
766                         return -1;
767
768                 case SSL_TLSEXT_ERR_ALERT_WARNING:
769                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
770                         return 1; 
771                                         
772                 case SSL_TLSEXT_ERR_NOACK:
773                         s->servername_done=0;
774                         default:
775                 return 1;
776                 }
777         }
778
779 int ssl_check_serverhello_tlsext(SSL *s)
780         {
781         int ret=SSL_TLSEXT_ERR_NOACK;
782         int al = SSL_AD_UNRECOGNIZED_NAME;
783
784         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
785                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
786         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
787                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
788
789         /* If we've requested certificate status and we wont get one
790          * tell the callback
791          */
792         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
793                         && s->ctx->tlsext_status_cb)
794                 {
795                 int r;
796                 /* Set resp to NULL, resplen to -1 so callback knows
797                  * there is no response.
798                  */
799                 if (s->tlsext_ocsp_resp)
800                         {
801                         OPENSSL_free(s->tlsext_ocsp_resp);
802                         s->tlsext_ocsp_resp = NULL;
803                         }
804                 s->tlsext_ocsp_resplen = -1;
805                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
806                 if (r == 0)
807                         {
808                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
809                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
810                         }
811                 if (r < 0)
812                         {
813                         al = SSL_AD_INTERNAL_ERROR;
814                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
815                         }
816                 }
817
818         switch (ret)
819                 {
820                 case SSL_TLSEXT_ERR_ALERT_FATAL:
821                         ssl3_send_alert(s,SSL3_AL_FATAL,al); 
822                         return -1;
823
824                 case SSL_TLSEXT_ERR_ALERT_WARNING:
825                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
826                         return 1; 
827                                         
828                 case SSL_TLSEXT_ERR_NOACK:
829                         s->servername_done=0;
830                         default:
831                 return 1;
832                 }
833         }
834
835 /* Since the server cache lookup is done early on in the processing of client
836  * hello and other operations depend on the result we need to handle any TLS
837  * session ticket extension at the same time.
838  */
839
840 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
841                                 const unsigned char *limit, SSL_SESSION **ret)
842         {
843         /* Point after session ID in client hello */
844         const unsigned char *p = session_id + len;
845         unsigned short i;
846
847         /* If tickets disabled behave as if no ticket present
848          * to permit stateful resumption.
849          */
850         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
851                 return 1;
852
853         if ((s->version <= SSL3_VERSION) || !limit)
854                 return 1;
855         if (p >= limit)
856                 return -1;
857         /* Skip past DTLS cookie */
858         if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
859                 {
860                 i = *(p++);
861                 p+= i;
862                 if (p >= limit)
863                         return -1;
864                 }
865         /* Skip past cipher list */
866         n2s(p, i);
867         p+= i;
868         if (p >= limit)
869                 return -1;
870         /* Skip past compression algorithm list */
871         i = *(p++);
872         p += i;
873         if (p > limit)
874                 return -1;
875         /* Now at start of extensions */
876         if ((p + 2) >= limit)
877                 return 1;
878         n2s(p, i);
879         while ((p + 4) <= limit)
880                 {
881                 unsigned short type, size;
882                 n2s(p, type);
883                 n2s(p, size);
884                 if (p + size > limit)
885                         return 1;
886                 if (type == TLSEXT_TYPE_session_ticket)
887                         {
888                         /* If zero length note client will accept a ticket
889                          * and indicate cache miss to trigger full handshake
890                          */
891                         if (size == 0)
892                                 {
893                                 s->tlsext_ticket_expected = 1;
894                                 return 0;       /* Cache miss */
895                                 }
896                         return tls_decrypt_ticket(s, p, size, session_id, len,
897                                                                         ret);
898                         }
899                 p += size;
900                 }
901         return 1;
902         }
903
904 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
905                                 const unsigned char *sess_id, int sesslen,
906                                 SSL_SESSION **psess)
907         {
908         SSL_SESSION *sess;
909         unsigned char *sdec;
910         const unsigned char *p;
911         int slen, mlen, renew_ticket = 0;
912         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
913         HMAC_CTX hctx;
914         EVP_CIPHER_CTX ctx;
915         SSL_CTX *tctx = s->initial_ctx;
916         /* Need at least keyname + iv + some encrypted data */
917         if (eticklen < 48)
918                 goto tickerr;
919         /* Initialize session ticket encryption and HMAC contexts */
920         HMAC_CTX_init(&hctx);
921         EVP_CIPHER_CTX_init(&ctx);
922         if (tctx->tlsext_ticket_key_cb)
923                 {
924                 unsigned char *nctick = (unsigned char *)etick;
925                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
926                                                         &ctx, &hctx, 0);
927                 if (rv < 0)
928                         return -1;
929                 if (rv == 0)
930                         goto tickerr;
931                 if (rv == 2)
932                         renew_ticket = 1;
933                 }
934         else
935                 {
936                 /* Check key name matches */
937                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
938                         goto tickerr;
939                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
940                                         tlsext_tick_md(), NULL);
941                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
942                                 tctx->tlsext_tick_aes_key, etick + 16);
943                 }
944         /* Attempt to process session ticket, first conduct sanity and
945          * integrity checks on ticket.
946          */
947         mlen = HMAC_size(&hctx);
948         eticklen -= mlen;
949         /* Check HMAC of encrypted ticket */
950         HMAC_Update(&hctx, etick, eticklen);
951         HMAC_Final(&hctx, tick_hmac, NULL);
952         HMAC_CTX_cleanup(&hctx);
953         if (memcmp(tick_hmac, etick + eticklen, mlen))
954                 goto tickerr;
955         /* Attempt to decrypt session data */
956         /* Move p after IV to start of encrypted ticket, update length */
957         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
958         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
959         sdec = OPENSSL_malloc(eticklen);
960         if (!sdec)
961                 {
962                 EVP_CIPHER_CTX_cleanup(&ctx);
963                 return -1;
964                 }
965         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
966         if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
967                 goto tickerr;
968         slen += mlen;
969         EVP_CIPHER_CTX_cleanup(&ctx);
970         p = sdec;
971                 
972         sess = d2i_SSL_SESSION(NULL, &p, slen);
973         OPENSSL_free(sdec);
974         if (sess)
975                 {
976                 /* The session ID if non-empty is used by some clients to
977                  * detect that the ticket has been accepted. So we copy it to
978                  * the session structure. If it is empty set length to zero
979                  * as required by standard.
980                  */
981                 if (sesslen)
982                         memcpy(sess->session_id, sess_id, sesslen);
983                 sess->session_id_length = sesslen;
984                 *psess = sess;
985                 s->tlsext_ticket_expected = renew_ticket;
986                 return 1;
987                 }
988         /* If session decrypt failure indicate a cache miss and set state to
989          * send a new ticket
990          */
991         tickerr:        
992         s->tlsext_ticket_expected = 1;
993         return 0;
994         }
995
996 #endif