b1bc3f58502b9f6ba3818bd15c32f45d921743d5
[openssl.git] / ssl / d1_lib.c
1 /* ssl/d1_lib.c */
2 /* 
3  * DTLS implementation written by Nagendra Modadugu
4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  
5  */
6 /* ====================================================================
7  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer. 
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in
18  *    the documentation and/or other materials provided with the
19  *    distribution.
20  *
21  * 3. All advertising materials mentioning features or use of this
22  *    software must display the following acknowledgment:
23  *    "This product includes software developed by the OpenSSL Project
24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25  *
26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27  *    endorse or promote products derived from this software without
28  *    prior written permission. For written permission, please contact
29  *    openssl-core@OpenSSL.org.
30  *
31  * 5. Products derived from this software may not be called "OpenSSL"
32  *    nor may "OpenSSL" appear in their names without prior written
33  *    permission of the OpenSSL Project.
34  *
35  * 6. Redistributions of any form whatsoever must retain the following
36  *    acknowledgment:
37  *    "This product includes software developed by the OpenSSL Project
38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51  * OF THE POSSIBILITY OF SUCH DAMAGE.
52  * ====================================================================
53  *
54  * This product includes cryptographic software written by Eric Young
55  * (eay@cryptsoft.com).  This product includes software written by Tim
56  * Hudson (tjh@cryptsoft.com).
57  *
58  */
59
60 #include <stdio.h>
61 #define USE_SOCKETS
62 #include <openssl/objects.h>
63 #include "ssl_locl.h"
64
65 #if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS)
66 #include <sys/timeb.h>
67 #endif
68
69 static void get_current_time(struct timeval *t);
70 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
71 int dtls1_listen(SSL *s, struct sockaddr *client);
72
73 SSL3_ENC_METHOD DTLSv1_enc_data={
74     dtls1_enc,
75         tls1_mac,
76         tls1_setup_key_block,
77         tls1_generate_master_secret,
78         tls1_change_cipher_state,
79         tls1_final_finish_mac,
80         TLS1_FINISH_MAC_LENGTH,
81         tls1_cert_verify_mac,
82         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
83         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
84         tls1_alert_code,
85         };
86
87 long dtls1_default_timeout(void)
88         {
89         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
90          * is way too long for http, the cache would over fill */
91         return(60*60*2);
92         }
93
94 int dtls1_new(SSL *s)
95         {
96         DTLS1_STATE *d1;
97
98         if (!ssl3_new(s)) return(0);
99         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
100         memset(d1,0, sizeof *d1);
101
102         /* d1->handshake_epoch=0; */
103
104         d1->unprocessed_rcds.q=pqueue_new();
105         d1->processed_rcds.q=pqueue_new();
106         d1->buffered_messages = pqueue_new();
107         d1->sent_messages=pqueue_new();
108         d1->buffered_app_data.q=pqueue_new();
109
110         if ( s->server)
111                 {
112                 d1->cookie_len = sizeof(s->d1->cookie);
113                 }
114
115         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 
116         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
117                 {
118         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
119         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
120         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
121                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
122                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
123                 OPENSSL_free(d1);
124                 return (0);
125                 }
126
127         s->d1=d1;
128         s->method->ssl_clear(s);
129         return(1);
130         }
131
132 void dtls1_free(SSL *s)
133         {
134     pitem *item = NULL;
135     hm_fragment *frag = NULL;
136
137         ssl3_free(s);
138
139     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
140         {
141         OPENSSL_free(item->data);
142         pitem_free(item);
143         }
144     pqueue_free(s->d1->unprocessed_rcds.q);
145
146     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
147         {
148         OPENSSL_free(item->data);
149         pitem_free(item);
150         }
151     pqueue_free(s->d1->processed_rcds.q);
152
153     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
154         {
155         frag = (hm_fragment *)item->data;
156         OPENSSL_free(frag->fragment);
157         OPENSSL_free(frag);
158         pitem_free(item);
159         }
160     pqueue_free(s->d1->buffered_messages);
161
162     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
163         {
164         frag = (hm_fragment *)item->data;
165         OPENSSL_free(frag->fragment);
166         OPENSSL_free(frag);
167         pitem_free(item);
168         }
169         pqueue_free(s->d1->sent_messages);
170
171         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
172                 {
173                 frag = (hm_fragment *)item->data;
174                 OPENSSL_free(frag->fragment);
175                 OPENSSL_free(frag);
176                 pitem_free(item);
177                 }
178         pqueue_free(s->d1->buffered_app_data.q);
179
180         OPENSSL_free(s->d1);
181         }
182
183 void dtls1_clear(SSL *s)
184         {
185         ssl3_clear(s);
186         if (s->options & SSL_OP_CISCO_ANYCONNECT)
187                 s->version=DTLS1_BAD_VER;
188         else
189                 s->version=DTLS1_VERSION;
190         }
191
192 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
193         {
194         int ret=0;
195
196         switch (cmd)
197                 {
198         case DTLS_CTRL_GET_TIMEOUT:
199                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
200                         {
201                         ret = 1;
202                         }
203                 break;
204         case DTLS_CTRL_HANDLE_TIMEOUT:
205                 ret = dtls1_handle_timeout(s);
206                 break;
207         case DTLS_CTRL_LISTEN:
208                 ret = dtls1_listen(s, parg);
209                 break;
210
211         default:
212                 ret = ssl3_ctrl(s, cmd, larg, parg);
213                 break;
214                 }
215         return(ret);
216         }
217
218 /*
219  * As it's impossible to use stream ciphers in "datagram" mode, this
220  * simple filter is designed to disengage them in DTLS. Unfortunately
221  * there is no universal way to identify stream SSL_CIPHER, so we have
222  * to explicitly list their SSL_* codes. Currently RC4 is the only one
223  * available, but if new ones emerge, they will have to be added...
224  */
225 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
226         {
227         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
228
229         if (ciph != NULL)
230                 {
231                 if (ciph->algorithm_enc == SSL_RC4)
232                         return NULL;
233                 }
234
235         return ciph;
236         }
237
238 void dtls1_start_timer(SSL *s)
239         {
240         /* If timer is not set, initialize duration with 1 second */
241         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
242                 {
243                 s->d1->timeout_duration = 1;
244                 }
245         
246         /* Set timeout to current time */
247         get_current_time(&(s->d1->next_timeout));
248
249         /* Add duration to current time */
250         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
251         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
252         }
253
254 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
255         {
256         struct timeval timenow;
257
258         /* If no timeout is set, just return NULL */
259         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
260                 {
261                 return NULL;
262                 }
263
264         /* Get current time */
265         get_current_time(&timenow);
266
267         /* If timer already expired, set remaining time to 0 */
268         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
269                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
270                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
271                 {
272                 memset(timeleft, 0, sizeof(struct timeval));
273                 return timeleft;
274                 }
275
276         /* Calculate time left until timer expires */
277         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
278         timeleft->tv_sec -= timenow.tv_sec;
279         timeleft->tv_usec -= timenow.tv_usec;
280         if (timeleft->tv_usec < 0)
281                 {
282                 timeleft->tv_sec--;
283                 timeleft->tv_usec += 1000000;
284                 }
285
286         return timeleft;
287         }
288
289 int dtls1_is_timer_expired(SSL *s)
290         {
291         struct timeval timeleft;
292
293         /* Get time left until timeout, return false if no timer running */
294         if (dtls1_get_timeout(s, &timeleft) == NULL)
295                 {
296                 return 0;
297                 }
298
299         /* Return false if timer is not expired yet */
300         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
301                 {
302                 return 0;
303                 }
304
305         /* Timer expired, so return true */     
306         return 1;
307         }
308
309 void dtls1_double_timeout(SSL *s)
310         {
311         s->d1->timeout_duration *= 2;
312         if (s->d1->timeout_duration > 60)
313                 s->d1->timeout_duration = 60;
314         dtls1_start_timer(s);
315         }
316
317 void dtls1_stop_timer(SSL *s)
318         {
319         /* Reset everything */
320         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
321         s->d1->timeout_duration = 1;
322         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
323         }
324
325 int dtls1_handle_timeout(SSL *s)
326         {
327         DTLS1_STATE *state;
328
329         /* if no timer is expired, don't do anything */
330         if (!dtls1_is_timer_expired(s))
331                 {
332                 return 0;
333                 }
334
335         dtls1_double_timeout(s);
336         state = s->d1;
337         state->timeout.num_alerts++;
338         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
339                 {
340                 /* fail the connection, enough alerts have been sent */
341                 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
342                 return 0;
343                 }
344
345         state->timeout.read_timeouts++;
346         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
347                 {
348                 state->timeout.read_timeouts = 1;
349                 }
350
351         dtls1_start_timer(s);
352         return dtls1_retransmit_buffered_messages(s);
353         }
354
355 static void get_current_time(struct timeval *t)
356 {
357 #ifdef OPENSSL_SYS_WIN32
358         struct _timeb tb;
359         _ftime(&tb);
360         t->tv_sec = (long)tb.time;
361         t->tv_usec = (long)tb.millitm * 1000;
362 #elif defined(OPENSSL_SYS_VMS)
363         struct timeb tb;
364         ftime(&tb);
365         t->tv_sec = (long)tb.time;
366         t->tv_usec = (long)tb.millitm * 1000;
367 #else
368         gettimeofday(t, NULL);
369 #endif
370 }
371
372 int dtls1_listen(SSL *s, struct sockaddr *client)
373         {
374         int ret;
375
376         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
377         s->d1->listen = 1;
378
379         ret = SSL_accept(s);
380         if (ret <= 0) return ret;
381         
382         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
383         return 1;
384         }
385
386 #ifndef OPENSSL_NO_TLSEXT
387 unsigned char *ssl_add_clienthello_dtlsext(SSL *s, unsigned char *p, unsigned char *limit)
388         {
389         int extdatalen = 0;
390         unsigned char *ret = p;
391         int el;
392
393         ret+=2;
394         
395         if (ret>=limit) return NULL; /* this really never occurs, but ... */
396
397         /* Renegotiate extension */
398         if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
399                 {
400                 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
401                 return NULL;
402                 }
403
404         if((limit - p - 4 - el) < 0) return NULL;
405           
406         s2n(TLSEXT_TYPE_renegotiate,ret);
407         s2n(el,ret);
408
409         if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
410                 {
411                 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
412                 return NULL;
413                 }
414
415         ret += el;
416
417         if ((extdatalen = ret-p-2)== 0) 
418                 return p;
419
420         s2n(extdatalen,p);
421
422         return ret;
423         }
424
425 int ssl_parse_clienthello_dtlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
426         {
427         unsigned short type;
428         unsigned short size;
429         unsigned short len;
430         unsigned char *data = *p;
431         int renegotiate_seen = 0;
432
433         if (data >= (d+n-2))
434                 {
435                 if (s->new_session
436                         && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
437                         {
438                         /* We should always see one extension: the renegotiate extension */
439                         SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
440                         *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
441                         return 0;
442                         }
443                 return 1;
444                 }
445         n2s(data,len);
446
447         if (data > (d+n-len)) 
448                 return 1;
449
450         while (data <= (d+n-4))
451                 {
452                 n2s(data,type);
453                 n2s(data,size);
454                 
455                 if (data+size > (d+n))
456                         return 1;
457                 
458                 if (type == TLSEXT_TYPE_renegotiate)
459                         {
460                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
461                                 return 0;
462                         renegotiate_seen = 1;
463                         }
464                 
465                 data+=size;
466                 }
467
468         if (s->new_session && !renegotiate_seen
469                 && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
470                 {
471                 *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
472                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
473                 return 0;
474                 }
475
476         *p = data;
477         return 1;
478         }
479
480 unsigned char *ssl_add_serverhello_dtlsext(SSL *s, unsigned char *p, unsigned char *limit)
481         {
482         int extdatalen = 0;
483         unsigned char *ret = p;
484         
485         ret+=2;
486         
487         if (ret>=limit) return NULL; /* this really never occurs, but ... */
488         
489         if(s->s3->send_connection_binding)
490                 {
491                 int el;
492
493                 if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
494                         {
495                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
496                         return NULL;
497                         }
498
499                 if((limit - p - 4 - el) < 0) return NULL;
500           
501                 s2n(TLSEXT_TYPE_renegotiate,ret);
502                 s2n(el,ret);
503
504                 if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
505                         {
506                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
507                         return NULL;
508                         }
509
510                 ret += el;
511                 }
512
513         if ((extdatalen = ret-p-2)== 0) 
514                 return p;
515
516         s2n(extdatalen,p);
517
518         return ret;
519         }
520
521 int ssl_parse_serverhello_dtlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
522         {
523         unsigned short type;
524         unsigned short size;
525         unsigned short len;
526         unsigned char *data = *p;
527         int renegotiate_seen = 0;
528         
529         if (data >= (d+n-2))
530                 {
531                 if (s->new_session
532                         && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
533                         {
534                         /* We should always see one extension: the renegotiate extension */
535                         SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
536                         *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
537                         return 0;
538                         }
539                 return 1;
540                 }
541         n2s(data,len);
542         
543         if (data > (d+n-len)) 
544                 return 1;
545         
546         while (data <= (d+n-4))
547                 {
548                 n2s(data,type);
549                 n2s(data,size);
550                 
551                 if (data+size > (d+n))
552                         return 1;
553                 
554                 if (type == TLSEXT_TYPE_renegotiate)
555                         {
556                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
557                                 return 0;
558                         renegotiate_seen = 1;
559                         }
560                 
561                 data+=size;
562                 }
563
564         if (s->new_session && !renegotiate_seen
565                 && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
566                 {
567                 *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
568                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
569                 return 0;
570                 }
571
572         *p = data;
573         return 1;
574         }
575 #endif