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