3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1999-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 * ====================================================================
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).
62 #include <openssl/objects.h>
65 #if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS)
66 #include <sys/timeb.h>
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);
73 SSL3_ENC_METHOD DTLSv1_enc_data={
77 tls1_generate_master_secret,
78 tls1_change_cipher_state,
79 tls1_final_finish_mac,
80 TLS1_FINISH_MAC_LENGTH,
82 TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
83 TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
85 tls1_export_keying_material,
88 long dtls1_default_timeout(void)
90 /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
91 * is way too long for http, the cache would over fill */
99 if (!ssl3_new(s)) return(0);
100 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
101 memset(d1,0, sizeof *d1);
103 /* d1->handshake_epoch=0; */
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();
113 d1->cookie_len = sizeof(s->d1->cookie);
119 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
120 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
122 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
123 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
124 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
125 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
126 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
132 s->method->ssl_clear(s);
136 static void dtls1_clear_queues(SSL *s)
139 hm_fragment *frag = NULL;
140 DTLS1_RECORD_DATA *rdata;
142 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
144 rdata = (DTLS1_RECORD_DATA *) item->data;
147 OPENSSL_free(rdata->rbuf.buf);
149 OPENSSL_free(item->data);
153 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
155 rdata = (DTLS1_RECORD_DATA *) item->data;
158 OPENSSL_free(rdata->rbuf.buf);
160 OPENSSL_free(item->data);
164 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
166 frag = (hm_fragment *)item->data;
167 dtls1_hm_fragment_free(frag);
171 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
173 frag = (hm_fragment *)item->data;
174 dtls1_hm_fragment_free(frag);
178 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
180 rdata = (DTLS1_RECORD_DATA *) item->data;
183 OPENSSL_free(rdata->rbuf.buf);
185 OPENSSL_free(item->data);
190 void dtls1_free(SSL *s)
194 dtls1_clear_queues(s);
196 pqueue_free(s->d1->unprocessed_rcds.q);
197 pqueue_free(s->d1->processed_rcds.q);
198 pqueue_free(s->d1->buffered_messages);
199 pqueue_free(s->d1->sent_messages);
200 pqueue_free(s->d1->buffered_app_data.q);
206 void dtls1_clear(SSL *s)
208 pqueue unprocessed_rcds;
209 pqueue processed_rcds;
210 pqueue buffered_messages;
211 pqueue sent_messages;
212 pqueue buffered_app_data;
214 unsigned int link_mtu;
218 unprocessed_rcds = s->d1->unprocessed_rcds.q;
219 processed_rcds = s->d1->processed_rcds.q;
220 buffered_messages = s->d1->buffered_messages;
221 sent_messages = s->d1->sent_messages;
222 buffered_app_data = s->d1->buffered_app_data.q;
224 link_mtu = s->d1->link_mtu;
226 dtls1_clear_queues(s);
228 memset(s->d1, 0, sizeof(*(s->d1)));
232 s->d1->cookie_len = sizeof(s->d1->cookie);
235 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
238 s->d1->link_mtu = link_mtu;
241 s->d1->unprocessed_rcds.q = unprocessed_rcds;
242 s->d1->processed_rcds.q = processed_rcds;
243 s->d1->buffered_messages = buffered_messages;
244 s->d1->sent_messages = sent_messages;
245 s->d1->buffered_app_data.q = buffered_app_data;
249 if (s->options & SSL_OP_CISCO_ANYCONNECT)
250 s->version=DTLS1_BAD_VER;
252 s->version=DTLS1_VERSION;
255 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
261 case DTLS_CTRL_GET_TIMEOUT:
262 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
267 case DTLS_CTRL_HANDLE_TIMEOUT:
268 ret = dtls1_handle_timeout(s);
270 case DTLS_CTRL_LISTEN:
271 ret = dtls1_listen(s, parg);
273 case SSL_CTRL_CHECK_PROTO_VERSION:
274 /* For library-internal use; checks that the current protocol
275 * is the highest enabled version (according to s->ctx->method,
276 * as version negotiation may have changed s->method). */
277 #if DTLS_MAX_VERSION != DTLS1_VERSION
278 # error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
280 /* Just one protocol version is supported so far;
281 * fail closed if the version is not as expected. */
282 return s->version == DTLS_MAX_VERSION;
283 case DTLS_CTRL_SET_LINK_MTU:
284 if (larg < (long)dtls1_link_min_mtu())
286 s->d1->link_mtu = larg;
288 case DTLS_CTRL_GET_LINK_MIN_MTU:
289 return (long)dtls1_link_min_mtu();
290 case SSL_CTRL_SET_MTU:
292 * We may not have a BIO set yet so can't call dtls1_min_mtu()
293 * We'll have to make do with dtls1_link_min_mtu() and max overhead
295 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
300 ret = ssl3_ctrl(s, cmd, larg, parg);
307 * As it's impossible to use stream ciphers in "datagram" mode, this
308 * simple filter is designed to disengage them in DTLS. Unfortunately
309 * there is no universal way to identify stream SSL_CIPHER, so we have
310 * to explicitly list their SSL_* codes. Currently RC4 is the only one
311 * available, but if new ones emerge, they will have to be added...
313 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
315 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
319 if (ciph->algorithm_enc == SSL_RC4)
326 void dtls1_start_timer(SSL *s)
328 #ifndef OPENSSL_NO_SCTP
329 /* Disable timer for SCTP */
330 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
332 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
337 /* If timer is not set, initialize duration with 1 second */
338 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
340 s->d1->timeout_duration = 1;
343 /* Set timeout to current time */
344 get_current_time(&(s->d1->next_timeout));
346 /* Add duration to current time */
347 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
348 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
351 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
353 struct timeval timenow;
355 /* If no timeout is set, just return NULL */
356 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
361 /* Get current time */
362 get_current_time(&timenow);
364 /* If timer already expired, set remaining time to 0 */
365 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
366 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
367 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
369 memset(timeleft, 0, sizeof(struct timeval));
373 /* Calculate time left until timer expires */
374 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
375 timeleft->tv_sec -= timenow.tv_sec;
376 timeleft->tv_usec -= timenow.tv_usec;
377 if (timeleft->tv_usec < 0)
380 timeleft->tv_usec += 1000000;
383 /* If remaining time is less than 15 ms, set it to 0
384 * to prevent issues because of small devergences with
387 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
389 memset(timeleft, 0, sizeof(struct timeval));
396 int dtls1_is_timer_expired(SSL *s)
398 struct timeval timeleft;
400 /* Get time left until timeout, return false if no timer running */
401 if (dtls1_get_timeout(s, &timeleft) == NULL)
406 /* Return false if timer is not expired yet */
407 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
412 /* Timer expired, so return true */
416 void dtls1_double_timeout(SSL *s)
418 s->d1->timeout_duration *= 2;
419 if (s->d1->timeout_duration > 60)
420 s->d1->timeout_duration = 60;
421 dtls1_start_timer(s);
424 void dtls1_stop_timer(SSL *s)
426 /* Reset everything */
427 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
428 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
429 s->d1->timeout_duration = 1;
430 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
431 /* Clear retransmission buffer */
432 dtls1_clear_record_buffer(s);
435 int dtls1_check_timeout_num(SSL *s)
439 s->d1->timeout.num_alerts++;
441 /* Reduce MTU after 2 unsuccessful retransmissions */
442 if (s->d1->timeout.num_alerts > 2
443 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
445 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
450 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
452 /* fail the connection, enough alerts have been sent */
453 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
460 int dtls1_handle_timeout(SSL *s)
462 /* if no timer is expired, don't do anything */
463 if (!dtls1_is_timer_expired(s))
468 dtls1_double_timeout(s);
470 if (dtls1_check_timeout_num(s) < 0)
473 s->d1->timeout.read_timeouts++;
474 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
476 s->d1->timeout.read_timeouts = 1;
479 #ifndef OPENSSL_NO_HEARTBEATS
480 if (s->tlsext_hb_pending)
482 s->tlsext_hb_pending = 0;
483 return dtls1_heartbeat(s);
487 dtls1_start_timer(s);
488 return dtls1_retransmit_buffered_messages(s);
491 static void get_current_time(struct timeval *t)
493 #ifdef OPENSSL_SYS_WIN32
496 t->tv_sec = (long)tb.time;
497 t->tv_usec = (long)tb.millitm * 1000;
498 #elif defined(OPENSSL_SYS_VMS)
501 t->tv_sec = (long)tb.time;
502 t->tv_usec = (long)tb.millitm * 1000;
504 gettimeofday(t, NULL);
508 int dtls1_listen(SSL *s, struct sockaddr *client)
512 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
516 if (ret <= 0) return ret;
518 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);