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
dtls1_default_timeout(void)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
dtls1_new(SSL * s)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
dtls1_clear_queues(SSL * s)132 static void dtls1_clear_queues(SSL *s)
133 {
134 pitem *item = NULL;
135 hm_fragment *frag = NULL;
136 DTLS1_RECORD_DATA *rdata;
137
138 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
139 {
140 rdata = (DTLS1_RECORD_DATA *) item->data;
141 if (rdata->rbuf.buf)
142 {
143 OPENSSL_free(rdata->rbuf.buf);
144 }
145 OPENSSL_free(item->data);
146 pitem_free(item);
147 }
148
149 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
150 {
151 rdata = (DTLS1_RECORD_DATA *) item->data;
152 if (rdata->rbuf.buf)
153 {
154 OPENSSL_free(rdata->rbuf.buf);
155 }
156 OPENSSL_free(item->data);
157 pitem_free(item);
158 }
159
160 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
161 {
162 frag = (hm_fragment *)item->data;
163 OPENSSL_free(frag->fragment);
164 OPENSSL_free(frag);
165 pitem_free(item);
166 }
167
168 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
169 {
170 frag = (hm_fragment *)item->data;
171 OPENSSL_free(frag->fragment);
172 OPENSSL_free(frag);
173 pitem_free(item);
174 }
175
176 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
177 {
178 frag = (hm_fragment *)item->data;
179 OPENSSL_free(frag->fragment);
180 OPENSSL_free(frag);
181 pitem_free(item);
182 }
183 }
184
dtls1_free(SSL * s)185 void dtls1_free(SSL *s)
186 {
187 ssl3_free(s);
188
189 dtls1_clear_queues(s);
190
191 pqueue_free(s->d1->unprocessed_rcds.q);
192 pqueue_free(s->d1->processed_rcds.q);
193 pqueue_free(s->d1->buffered_messages);
194 pqueue_free(s->d1->sent_messages);
195 pqueue_free(s->d1->buffered_app_data.q);
196
197 OPENSSL_free(s->d1);
198 }
199
dtls1_clear(SSL * s)200 void dtls1_clear(SSL *s)
201 {
202 pqueue unprocessed_rcds;
203 pqueue processed_rcds;
204 pqueue buffered_messages;
205 pqueue sent_messages;
206 pqueue buffered_app_data;
207
208 if (s->d1)
209 {
210 unprocessed_rcds = s->d1->unprocessed_rcds.q;
211 processed_rcds = s->d1->processed_rcds.q;
212 buffered_messages = s->d1->buffered_messages;
213 sent_messages = s->d1->sent_messages;
214 buffered_app_data = s->d1->buffered_app_data.q;
215
216 dtls1_clear_queues(s);
217
218 memset(s->d1, 0, sizeof(*(s->d1)));
219
220 if (s->server)
221 {
222 s->d1->cookie_len = sizeof(s->d1->cookie);
223 }
224
225 s->d1->unprocessed_rcds.q = unprocessed_rcds;
226 s->d1->processed_rcds.q = processed_rcds;
227 s->d1->buffered_messages = buffered_messages;
228 s->d1->sent_messages = sent_messages;
229 s->d1->buffered_app_data.q = buffered_app_data;
230 }
231
232 ssl3_clear(s);
233 if (s->options & SSL_OP_CISCO_ANYCONNECT)
234 s->version=DTLS1_BAD_VER;
235 else
236 s->version=DTLS1_VERSION;
237 }
238
dtls1_ctrl(SSL * s,int cmd,long larg,void * parg)239 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
240 {
241 int ret=0;
242
243 switch (cmd)
244 {
245 case DTLS_CTRL_GET_TIMEOUT:
246 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
247 {
248 ret = 1;
249 }
250 break;
251 case DTLS_CTRL_HANDLE_TIMEOUT:
252 ret = dtls1_handle_timeout(s);
253 break;
254 case DTLS_CTRL_LISTEN:
255 ret = dtls1_listen(s, parg);
256 break;
257
258 default:
259 ret = ssl3_ctrl(s, cmd, larg, parg);
260 break;
261 }
262 return(ret);
263 }
264
265 /*
266 * As it's impossible to use stream ciphers in "datagram" mode, this
267 * simple filter is designed to disengage them in DTLS. Unfortunately
268 * there is no universal way to identify stream SSL_CIPHER, so we have
269 * to explicitly list their SSL_* codes. Currently RC4 is the only one
270 * available, but if new ones emerge, they will have to be added...
271 */
dtls1_get_cipher(unsigned int u)272 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
273 {
274 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
275
276 if (ciph != NULL)
277 {
278 if (ciph->algorithm_enc == SSL_RC4)
279 return NULL;
280 }
281
282 return ciph;
283 }
284
dtls1_start_timer(SSL * s)285 void dtls1_start_timer(SSL *s)
286 {
287 /* If timer is not set, initialize duration with 1 second */
288 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
289 {
290 s->d1->timeout_duration = 1;
291 }
292
293 /* Set timeout to current time */
294 get_current_time(&(s->d1->next_timeout));
295
296 /* Add duration to current time */
297 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
298 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
299 }
300
dtls1_get_timeout(SSL * s,struct timeval * timeleft)301 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
302 {
303 struct timeval timenow;
304
305 /* If no timeout is set, just return NULL */
306 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
307 {
308 return NULL;
309 }
310
311 /* Get current time */
312 get_current_time(&timenow);
313
314 /* If timer already expired, set remaining time to 0 */
315 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
316 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
317 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
318 {
319 memset(timeleft, 0, sizeof(struct timeval));
320 return timeleft;
321 }
322
323 /* Calculate time left until timer expires */
324 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
325 timeleft->tv_sec -= timenow.tv_sec;
326 timeleft->tv_usec -= timenow.tv_usec;
327 if (timeleft->tv_usec < 0)
328 {
329 timeleft->tv_sec--;
330 timeleft->tv_usec += 1000000;
331 }
332
333 /* If remaining time is less than 15 ms, set it to 0
334 * to prevent issues because of small devergences with
335 * socket timeouts.
336 */
337 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
338 {
339 memset(timeleft, 0, sizeof(struct timeval));
340 }
341
342
343 return timeleft;
344 }
345
dtls1_is_timer_expired(SSL * s)346 int dtls1_is_timer_expired(SSL *s)
347 {
348 struct timeval timeleft;
349
350 /* Get time left until timeout, return false if no timer running */
351 if (dtls1_get_timeout(s, &timeleft) == NULL)
352 {
353 return 0;
354 }
355
356 /* Return false if timer is not expired yet */
357 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
358 {
359 return 0;
360 }
361
362 /* Timer expired, so return true */
363 return 1;
364 }
365
dtls1_double_timeout(SSL * s)366 void dtls1_double_timeout(SSL *s)
367 {
368 s->d1->timeout_duration *= 2;
369 if (s->d1->timeout_duration > 60)
370 s->d1->timeout_duration = 60;
371 dtls1_start_timer(s);
372 }
373
dtls1_stop_timer(SSL * s)374 void dtls1_stop_timer(SSL *s)
375 {
376 /* Reset everything */
377 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
378 s->d1->timeout_duration = 1;
379 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
380 /* Clear retransmission buffer */
381 dtls1_clear_record_buffer(s);
382 }
383
dtls1_handle_timeout(SSL * s)384 int dtls1_handle_timeout(SSL *s)
385 {
386 DTLS1_STATE *state;
387
388 /* if no timer is expired, don't do anything */
389 if (!dtls1_is_timer_expired(s))
390 {
391 return 0;
392 }
393
394 dtls1_double_timeout(s);
395 state = s->d1;
396 state->timeout.num_alerts++;
397 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
398 {
399 /* fail the connection, enough alerts have been sent */
400 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
401 return -1;
402 }
403
404 state->timeout.read_timeouts++;
405 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
406 {
407 state->timeout.read_timeouts = 1;
408 }
409
410 dtls1_start_timer(s);
411 return dtls1_retransmit_buffered_messages(s);
412 }
413
get_current_time(struct timeval * t)414 static void get_current_time(struct timeval *t)
415 {
416 #ifdef OPENSSL_SYS_WIN32
417 struct _timeb tb;
418 _ftime(&tb);
419 t->tv_sec = (long)tb.time;
420 t->tv_usec = (long)tb.millitm * 1000;
421 #elif defined(OPENSSL_SYS_VMS)
422 struct timeb tb;
423 ftime(&tb);
424 t->tv_sec = (long)tb.time;
425 t->tv_usec = (long)tb.millitm * 1000;
426 #else
427 gettimeofday(t, NULL);
428 #endif
429 }
430
dtls1_listen(SSL * s,struct sockaddr * client)431 int dtls1_listen(SSL *s, struct sockaddr *client)
432 {
433 int ret;
434
435 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
436 s->d1->listen = 1;
437
438 ret = SSL_accept(s);
439 if (ret <= 0) return ret;
440
441 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
442 return 1;
443 }
444