5b3de08d51c94f73863b30b11d6fd0489ac8182b
[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_VMS)
66 #include <sys/timeb.h>
67 #endif
68
69 static void get_current_time(struct timeval *t);
70 static void dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
71 static int dtls1_handshake_write(SSL *s);
72 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
73 int dtls1_listen(SSL *s, struct sockaddr *client);
74
75 const SSL3_ENC_METHOD DTLSv1_enc_data={
76         tls1_enc,
77         tls1_mac,
78         tls1_setup_key_block,
79         tls1_generate_master_secret,
80         tls1_change_cipher_state,
81         tls1_final_finish_mac,
82         TLS1_FINISH_MAC_LENGTH,
83         tls1_cert_verify_mac,
84         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
85         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
86         tls1_alert_code,
87         tls1_export_keying_material,
88         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV,
89         DTLS1_HM_HEADER_LENGTH,
90         dtls1_set_handshake_header,
91         dtls1_handshake_write   
92         };
93
94 const SSL3_ENC_METHOD DTLSv1_2_enc_data={
95         tls1_enc,
96         tls1_mac,
97         tls1_setup_key_block,
98         tls1_generate_master_secret,
99         tls1_change_cipher_state,
100         tls1_final_finish_mac,
101         TLS1_FINISH_MAC_LENGTH,
102         tls1_cert_verify_mac,
103         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
104         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
105         tls1_alert_code,
106         tls1_export_keying_material,
107         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS
108                 |SSL_ENC_FLAG_SHA256_PRF|SSL_ENC_FLAG_TLS1_2_CIPHERS,
109         DTLS1_HM_HEADER_LENGTH,
110         dtls1_set_handshake_header,
111         dtls1_handshake_write   
112         };
113
114 long dtls1_default_timeout(void)
115         {
116         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
117          * is way too long for http, the cache would over fill */
118         return(60*60*2);
119         }
120
121 int dtls1_new(SSL *s)
122         {
123         DTLS1_STATE *d1;
124
125         if (!ssl3_new(s)) return(0);
126         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
127         memset(d1,0, sizeof *d1);
128
129         /* d1->handshake_epoch=0; */
130
131         d1->unprocessed_rcds.q=pqueue_new();
132         d1->processed_rcds.q=pqueue_new();
133         d1->buffered_messages = pqueue_new();
134         d1->sent_messages=pqueue_new();
135         d1->buffered_app_data.q=pqueue_new();
136
137         if ( s->server)
138                 {
139                 d1->cookie_len = sizeof(s->d1->cookie);
140                 }
141
142         d1->link_mtu = 0;
143         d1->mtu = 0;
144
145         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 
146         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
147                 {
148         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
149         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
150         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
151                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
152                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
153                 OPENSSL_free(d1);
154                 return (0);
155                 }
156
157         s->d1=d1;
158         s->method->ssl_clear(s);
159         return(1);
160         }
161
162 static void dtls1_clear_queues(SSL *s)
163         {
164     pitem *item = NULL;
165     hm_fragment *frag = NULL;
166         DTLS1_RECORD_DATA *rdata;
167
168     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
169         {
170                 rdata = (DTLS1_RECORD_DATA *) item->data;
171                 if (rdata->rbuf.buf)
172                         {
173                         OPENSSL_free(rdata->rbuf.buf);
174                         }
175         OPENSSL_free(item->data);
176         pitem_free(item);
177         }
178
179     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
180         {
181                 rdata = (DTLS1_RECORD_DATA *) item->data;
182                 if (rdata->rbuf.buf)
183                         {
184                         OPENSSL_free(rdata->rbuf.buf);
185                         }
186         OPENSSL_free(item->data);
187         pitem_free(item);
188         }
189
190     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
191         {
192         frag = (hm_fragment *)item->data;
193         dtls1_hm_fragment_free(frag);
194         pitem_free(item);
195         }
196
197     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
198         {
199         frag = (hm_fragment *)item->data;
200         dtls1_hm_fragment_free(frag);
201         pitem_free(item);
202         }
203
204         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
205                 {
206                 rdata = (DTLS1_RECORD_DATA *) item->data;
207                 if (rdata->rbuf.buf)
208                         {
209                         OPENSSL_free(rdata->rbuf.buf);
210                         }
211                 OPENSSL_free(item->data);
212                 pitem_free(item);
213                 }
214         }
215
216 void dtls1_free(SSL *s)
217         {
218         ssl3_free(s);
219
220         dtls1_clear_queues(s);
221
222     pqueue_free(s->d1->unprocessed_rcds.q);
223     pqueue_free(s->d1->processed_rcds.q);
224     pqueue_free(s->d1->buffered_messages);
225         pqueue_free(s->d1->sent_messages);
226         pqueue_free(s->d1->buffered_app_data.q);
227
228         OPENSSL_free(s->d1);
229         s->d1 = NULL;
230         }
231
232 void dtls1_clear(SSL *s)
233         {
234     pqueue unprocessed_rcds;
235     pqueue processed_rcds;
236     pqueue buffered_messages;
237         pqueue sent_messages;
238         pqueue buffered_app_data;
239         unsigned int mtu;
240         unsigned int link_mtu;
241
242         if (s->d1)
243                 {
244                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
245                 processed_rcds = s->d1->processed_rcds.q;
246                 buffered_messages = s->d1->buffered_messages;
247                 sent_messages = s->d1->sent_messages;
248                 buffered_app_data = s->d1->buffered_app_data.q;
249                 mtu = s->d1->mtu;
250                 link_mtu = s->d1->link_mtu;
251
252                 dtls1_clear_queues(s);
253
254                 memset(s->d1, 0, sizeof(*(s->d1)));
255
256                 if (s->server)
257                         {
258                         s->d1->cookie_len = sizeof(s->d1->cookie);
259                         }
260
261                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
262                         {
263                         s->d1->mtu = mtu;
264                         s->d1->link_mtu = link_mtu;
265                         }
266
267                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
268                 s->d1->processed_rcds.q = processed_rcds;
269                 s->d1->buffered_messages = buffered_messages;
270                 s->d1->sent_messages = sent_messages;
271                 s->d1->buffered_app_data.q = buffered_app_data;
272                 }
273
274         ssl3_clear(s);
275         if (s->options & SSL_OP_CISCO_ANYCONNECT)
276                 s->version=DTLS1_BAD_VER;
277         else if (s->method->version == DTLS_ANY_VERSION)
278                 s->version=DTLS1_2_VERSION;
279         else
280                 s->version=s->method->version;
281         }
282
283 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
284         {
285         int ret=0;
286
287         switch (cmd)
288                 {
289         case DTLS_CTRL_GET_TIMEOUT:
290                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
291                         {
292                         ret = 1;
293                         }
294                 break;
295         case DTLS_CTRL_HANDLE_TIMEOUT:
296                 ret = dtls1_handle_timeout(s);
297                 break;
298         case DTLS_CTRL_LISTEN:
299                 ret = dtls1_listen(s, parg);
300                 break;
301         case SSL_CTRL_CHECK_PROTO_VERSION:
302                 /* For library-internal use; checks that the current protocol
303                  * is the highest enabled version (according to s->ctx->method,
304                  * as version negotiation may have changed s->method). */
305                 if (s->version == s->ctx->method->version)
306                         return 1;
307                 /* Apparently we're using a version-flexible SSL_METHOD
308                  * (not at its highest protocol version). */
309                 if (s->ctx->method->version == DTLS_method()->version)
310                         {
311 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
312 #  error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
313 #endif
314                         if (!(s->options & SSL_OP_NO_DTLSv1_2))
315                                 return s->version == DTLS1_2_VERSION;
316                         if (!(s->options & SSL_OP_NO_DTLSv1))
317                                 return s->version == DTLS1_VERSION;
318                         }
319                 return 0; /* Unexpected state; fail closed. */
320
321                 /* Just one protocol version is supported so far;
322                  * fail closed if the version is not as expected. */
323                 return s->version == DTLS_MAX_VERSION;
324         case DTLS_CTRL_SET_LINK_MTU:
325                 if (larg < (long)dtls1_link_min_mtu())
326                         return 0;
327                 s->d1->link_mtu = larg;
328                 return 1;
329         case DTLS_CTRL_GET_LINK_MIN_MTU:
330                 return (long)dtls1_link_min_mtu();
331         case SSL_CTRL_SET_MTU:
332                 /*
333                  *  We may not have a BIO set yet so can't call dtls1_min_mtu()
334                  *  We'll have to make do with dtls1_link_min_mtu() and max overhead
335                  */
336                 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
337                         return 0;
338                 s->d1->mtu = larg;
339                 return larg;
340         default:
341                 ret = ssl3_ctrl(s, cmd, larg, parg);
342                 break;
343                 }
344         return(ret);
345         }
346
347 /*
348  * As it's impossible to use stream ciphers in "datagram" mode, this
349  * simple filter is designed to disengage them in DTLS. Unfortunately
350  * there is no universal way to identify stream SSL_CIPHER, so we have
351  * to explicitly list their SSL_* codes. Currently RC4 is the only one
352  * available, but if new ones emerge, they will have to be added...
353  */
354 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
355         {
356         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
357
358         if (ciph != NULL)
359                 {
360                 if (ciph->algorithm_enc == SSL_RC4)
361                         return NULL;
362                 }
363
364         return ciph;
365         }
366
367 void dtls1_start_timer(SSL *s)
368         {
369 #ifndef OPENSSL_NO_SCTP
370         /* Disable timer for SCTP */
371         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
372                 {
373                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
374                 return;
375                 }
376 #endif
377
378         /* If timer is not set, initialize duration with 1 second */
379         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
380                 {
381                 s->d1->timeout_duration = 1;
382                 }
383         
384         /* Set timeout to current time */
385         get_current_time(&(s->d1->next_timeout));
386
387         /* Add duration to current time */
388         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
389         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
390         }
391
392 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
393         {
394         struct timeval timenow;
395
396         /* If no timeout is set, just return NULL */
397         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
398                 {
399                 return NULL;
400                 }
401
402         /* Get current time */
403         get_current_time(&timenow);
404
405         /* If timer already expired, set remaining time to 0 */
406         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
407                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
408                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
409                 {
410                 memset(timeleft, 0, sizeof(struct timeval));
411                 return timeleft;
412                 }
413
414         /* Calculate time left until timer expires */
415         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
416         timeleft->tv_sec -= timenow.tv_sec;
417         timeleft->tv_usec -= timenow.tv_usec;
418         if (timeleft->tv_usec < 0)
419                 {
420                 timeleft->tv_sec--;
421                 timeleft->tv_usec += 1000000;
422                 }
423
424         /* If remaining time is less than 15 ms, set it to 0
425          * to prevent issues because of small devergences with
426          * socket timeouts.
427          */
428         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
429                 {
430                 memset(timeleft, 0, sizeof(struct timeval));
431                 }
432         
433
434         return timeleft;
435         }
436
437 int dtls1_is_timer_expired(SSL *s)
438         {
439         struct timeval timeleft;
440
441         /* Get time left until timeout, return false if no timer running */
442         if (dtls1_get_timeout(s, &timeleft) == NULL)
443                 {
444                 return 0;
445                 }
446
447         /* Return false if timer is not expired yet */
448         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
449                 {
450                 return 0;
451                 }
452
453         /* Timer expired, so return true */     
454         return 1;
455         }
456
457 void dtls1_double_timeout(SSL *s)
458         {
459         s->d1->timeout_duration *= 2;
460         if (s->d1->timeout_duration > 60)
461                 s->d1->timeout_duration = 60;
462         dtls1_start_timer(s);
463         }
464
465 void dtls1_stop_timer(SSL *s)
466         {
467         /* Reset everything */
468         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
469         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
470         s->d1->timeout_duration = 1;
471         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
472         /* Clear retransmission buffer */
473         dtls1_clear_record_buffer(s);
474         }
475
476 int dtls1_check_timeout_num(SSL *s)
477         {
478         s->d1->timeout.num_alerts++;
479
480         /* Reduce MTU after 2 unsuccessful retransmissions */
481         if (s->d1->timeout.num_alerts > 2
482                         && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
483                 {
484                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);               
485                 }
486
487         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
488                 {
489                 /* fail the connection, enough alerts have been sent */
490                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
491                 return -1;
492                 }
493
494         return 0;
495         }
496
497 int dtls1_handle_timeout(SSL *s)
498         {
499         /* if no timer is expired, don't do anything */
500         if (!dtls1_is_timer_expired(s))
501                 {
502                 return 0;
503                 }
504
505         dtls1_double_timeout(s);
506
507         if (dtls1_check_timeout_num(s) < 0)
508                 return -1;
509
510         s->d1->timeout.read_timeouts++;
511         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
512                 {
513                 s->d1->timeout.read_timeouts = 1;
514                 }
515
516 #ifndef OPENSSL_NO_HEARTBEATS
517         if (s->tlsext_hb_pending)
518                 {
519                 s->tlsext_hb_pending = 0;
520                 return dtls1_heartbeat(s);
521                 }
522 #endif
523
524         dtls1_start_timer(s);
525         return dtls1_retransmit_buffered_messages(s);
526         }
527
528 static void get_current_time(struct timeval *t)
529 {
530 #if defined(_WIN32)
531         SYSTEMTIME st;
532         union { unsigned __int64 ul; FILETIME ft; } now;
533
534         GetSystemTime(&st);
535         SystemTimeToFileTime(&st,&now.ft);
536 #ifdef  __MINGW32__
537         now.ul -= 116444736000000000ULL;
538 #else
539         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
540 #endif
541         t->tv_sec  = (long)(now.ul/10000000);
542         t->tv_usec = ((int)(now.ul%10000000))/10;
543 #elif defined(OPENSSL_SYS_VMS)
544         struct timeb tb;
545         ftime(&tb);
546         t->tv_sec = (long)tb.time;
547         t->tv_usec = (long)tb.millitm * 1000;
548 #else
549         gettimeofday(t, NULL);
550 #endif
551 }
552
553 int dtls1_listen(SSL *s, struct sockaddr *client)
554         {
555         int ret;
556
557         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
558         s->d1->listen = 1;
559
560         ret = SSL_accept(s);
561         if (ret <= 0) return ret;
562         
563         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
564         return 1;
565         }
566
567 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
568         {
569         unsigned char *p = (unsigned char *)s->init_buf->data;
570         dtls1_set_message_header(s, p, htype, len, 0, len);
571         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
572         s->init_off = 0;
573         /* Buffer the message to handle re-xmits */
574         dtls1_buffer_message(s, 0);
575         }
576
577 static int dtls1_handshake_write(SSL *s)
578         {
579         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
580         }