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 tls1_export_keying_material,
86 };
87
88 long dtls1_default_timeout(void)
89 {
90 /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
91 * is way too long for http, the cache would over fill */
92 return(60*60*2);
93 }
94
95 int dtls1_new(SSL *s)
96 {
97 DTLS1_STATE *d1;
98
99 if (!ssl3_new(s)) return(0);
100 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
101 memset(d1,0, sizeof *d1);
102
103 /* d1->handshake_epoch=0; */
104
105 d1->unprocessed_rcds.q=pqueue_new();
106 d1->processed_rcds.q=pqueue_new();
107 d1->buffered_messages = pqueue_new();
108 d1->sent_messages=pqueue_new();
109 d1->buffered_app_data.q=pqueue_new();
110
111 if ( s->server)
112 {
113 d1->cookie_len = sizeof(s->d1->cookie);
114 }
115
116 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
117 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
118 {
119 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
120 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
121 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
122 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
123 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
124 OPENSSL_free(d1);
125 return (0);
126 }
127
128 s->d1=d1;
129 s->method->ssl_clear(s);
130 return(1);
131 }
132
133 static void dtls1_clear_queues(SSL *s)
134 {
135 pitem *item = NULL;
136 hm_fragment *frag = NULL;
137 DTLS1_RECORD_DATA *rdata;
138
139 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
140 {
141 rdata = (DTLS1_RECORD_DATA *) item->data;
142 if (rdata->rbuf.buf)
143 {
144 OPENSSL_free(rdata->rbuf.buf);
145 }
146 OPENSSL_free(item->data);
147 pitem_free(item);
148 }
149
150 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
151 {
152 rdata = (DTLS1_RECORD_DATA *) item->data;
153 if (rdata->rbuf.buf)
154 {
155 OPENSSL_free(rdata->rbuf.buf);
156 }
157 OPENSSL_free(item->data);
158 pitem_free(item);
159 }
160
161 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
162 {
163 frag = (hm_fragment *)item->data;
164 OPENSSL_free(frag->fragment);
165 OPENSSL_free(frag);
166 pitem_free(item);
167 }
168
169 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
170 {
171 frag = (hm_fragment *)item->data;
172 OPENSSL_free(frag->fragment);
173 OPENSSL_free(frag);
174 pitem_free(item);
175 }
176
177 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
178 {
179 rdata = (DTLS1_RECORD_DATA *) item->data;
180 if (rdata->rbuf.buf)
181 {
182 OPENSSL_free(rdata->rbuf.buf);
183 }
184 OPENSSL_free(item->data);
185 pitem_free(item);
186 }
187 }
188
189 void dtls1_free(SSL *s)
190 {
191 ssl3_free(s);
192
193 dtls1_clear_queues(s);
194
195 pqueue_free(s->d1->unprocessed_rcds.q);
196 pqueue_free(s->d1->processed_rcds.q);
197 pqueue_free(s->d1->buffered_messages);
198 pqueue_free(s->d1->sent_messages);
199 pqueue_free(s->d1->buffered_app_data.q);
200
201 OPENSSL_free(s->d1);
202 s->d1 = NULL;
203 }
204
205 void dtls1_clear(SSL *s)
206 {
207 pqueue unprocessed_rcds;
208 pqueue processed_rcds;
209 pqueue buffered_messages;
210 pqueue sent_messages;
211 pqueue buffered_app_data;
212 unsigned int mtu;
213
214 if (s->d1)
215 {
216 unprocessed_rcds = s->d1->unprocessed_rcds.q;
217 processed_rcds = s->d1->processed_rcds.q;
218 buffered_messages = s->d1->buffered_messages;
219 sent_messages = s->d1->sent_messages;
220 buffered_app_data = s->d1->buffered_app_data.q;
221 mtu = s->d1->mtu;
222
223 dtls1_clear_queues(s);
224
225 memset(s->d1, 0, sizeof(*(s->d1)));
226
227 if (s->server)
228 {
229 s->d1->cookie_len = sizeof(s->d1->cookie);
230 }
231
232 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
233 {
234 s->d1->mtu = mtu;
235 }
236
237 s->d1->unprocessed_rcds.q = unprocessed_rcds;
238 s->d1->processed_rcds.q = processed_rcds;
239 s->d1->buffered_messages = buffered_messages;
240 s->d1->sent_messages = sent_messages;
241 s->d1->buffered_app_data.q = buffered_app_data;
242 }
243
244 ssl3_clear(s);
245 if (s->options & SSL_OP_CISCO_ANYCONNECT)
246 s->version=DTLS1_BAD_VER;
247 else
248 s->version=DTLS1_VERSION;
249 }
250
251 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
252 {
253 int ret=0;
254
255 switch (cmd)
256 {
257 case DTLS_CTRL_GET_TIMEOUT:
258 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
259 {
260 ret = 1;
261 }
262 break;
263 case DTLS_CTRL_HANDLE_TIMEOUT:
264 ret = dtls1_handle_timeout(s);
265 break;
266 case DTLS_CTRL_LISTEN:
267 ret = dtls1_listen(s, parg);
268 break;
269
270 default:
271 ret = ssl3_ctrl(s, cmd, larg, parg);
272 break;
273 }
274 return(ret);
275 }
276
277 /*
278 * As it's impossible to use stream ciphers in "datagram" mode, this
279 * simple filter is designed to disengage them in DTLS. Unfortunately
280 * there is no universal way to identify stream SSL_CIPHER, so we have
281 * to explicitly list their SSL_* codes. Currently RC4 is the only one
282 * available, but if new ones emerge, they will have to be added...
283 */
284 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
285 {
286 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
287
288 if (ciph != NULL)
289 {
290 if (ciph->algorithm_enc == SSL_RC4)
291 return NULL;
292 }
293
294 return ciph;
295 }
296
297 void dtls1_start_timer(SSL *s)
298 {
299 #ifndef OPENSSL_NO_SCTP
300 /* Disable timer for SCTP */
301 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
302 {
303 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
304 return;
305 }
306 #endif
307
308 /* If timer is not set, initialize duration with 1 second */
309 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
310 {
311 s->d1->timeout_duration = 1;
312 }
313
314 /* Set timeout to current time */
315 get_current_time(&(s->d1->next_timeout));
316
317 /* Add duration to current time */
318 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
319 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
320 }
321
322 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
323 {
324 struct timeval timenow;
325
326 /* If no timeout is set, just return NULL */
327 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
328 {
329 return NULL;
330 }
331
332 /* Get current time */
333 get_current_time(&timenow);
334
335 /* If timer already expired, set remaining time to 0 */
336 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
337 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
338 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
339 {
340 memset(timeleft, 0, sizeof(struct timeval));
341 return timeleft;
342 }
343
344 /* Calculate time left until timer expires */
345 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
346 timeleft->tv_sec -= timenow.tv_sec;
347 timeleft->tv_usec -= timenow.tv_usec;
348 if (timeleft->tv_usec < 0)
349 {
350 timeleft->tv_sec--;
351 timeleft->tv_usec += 1000000;
352 }
353
354 /* If remaining time is less than 15 ms, set it to 0
355 * to prevent issues because of small devergences with
356 * socket timeouts.
357 */
358 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
359 {
360 memset(timeleft, 0, sizeof(struct timeval));
361 }
362
363
364 return timeleft;
365 }
366
367 int dtls1_is_timer_expired(SSL *s)
368 {
369 struct timeval timeleft;
370
371 /* Get time left until timeout, return false if no timer running */
372 if (dtls1_get_timeout(s, &timeleft) == NULL)
373 {
374 return 0;
375 }
376
377 /* Return false if timer is not expired yet */
378 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
379 {
380 return 0;
381 }
382
383 /* Timer expired, so return true */
384 return 1;
385 }
386
387 void dtls1_double_timeout(SSL *s)
388 {
389 s->d1->timeout_duration *= 2;
390 if (s->d1->timeout_duration > 60)
391 s->d1->timeout_duration = 60;
392 dtls1_start_timer(s);
393 }
394
395 void dtls1_stop_timer(SSL *s)
396 {
397 /* Reset everything */
398 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
399 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
400 s->d1->timeout_duration = 1;
401 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
402 /* Clear retransmission buffer */
403 dtls1_clear_record_buffer(s);
404 }
405
406 int dtls1_check_timeout_num(SSL *s)
407 {
408 s->d1->timeout.num_alerts++;
409
410 /* Reduce MTU after 2 unsuccessful retransmissions */
411 if (s->d1->timeout.num_alerts > 2)
412 {
413 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
414 }
415
416 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
417 {
418 /* fail the connection, enough alerts have been sent */
419 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
420 return -1;
421 }
422
423 return 0;
424 }
425
426 int dtls1_handle_timeout(SSL *s)
427 {
428 /* if no timer is expired, don't do anything */
429 if (!dtls1_is_timer_expired(s))
430 {
431 return 0;
432 }
433
434 dtls1_double_timeout(s);
435
436 if (dtls1_check_timeout_num(s) < 0)
437 return -1;
438
439 s->d1->timeout.read_timeouts++;
440 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
441 {
442 s->d1->timeout.read_timeouts = 1;
443 }
444
445 #ifndef OPENSSL_NO_HEARTBEATS
446 if (s->tlsext_hb_pending)
447 {
448 s->tlsext_hb_pending = 0;
449 return dtls1_heartbeat(s);
450 }
451 #endif
452
453 dtls1_start_timer(s);
454 return dtls1_retransmit_buffered_messages(s);
455 }
456
457 static void get_current_time(struct timeval *t)
458 {
459 #ifdef OPENSSL_SYS_WIN32
460 struct _timeb tb;
461 _ftime(&tb);
462 t->tv_sec = (long)tb.time;
463 t->tv_usec = (long)tb.millitm * 1000;
464 #elif defined(OPENSSL_SYS_VMS)
465 struct timeb tb;
466 ftime(&tb);
467 t->tv_sec = (long)tb.time;
468 t->tv_usec = (long)tb.millitm * 1000;
469 #else
470 gettimeofday(t, NULL);
471 #endif
472 }
473
474 int dtls1_listen(SSL *s, struct sockaddr *client)
475 {
476 int ret;
477
478 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
479 s->d1->listen = 1;
480
481 ret = SSL_accept(s);
482 if (ret <= 0) return ret;
483
484 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
485 return 1;
486 }