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)
91 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
92 * http, the cache would over fill
103 if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL)
105 memset(d1, 0, sizeof *d1);
107 /* d1->handshake_epoch=0; */
109 d1->unprocessed_rcds.q = pqueue_new();
110 d1->processed_rcds.q = pqueue_new();
111 d1->buffered_messages = pqueue_new();
112 d1->sent_messages = pqueue_new();
113 d1->buffered_app_data.q = pqueue_new();
116 d1->cookie_len = sizeof(s->d1->cookie);
122 if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q
123 || !d1->buffered_messages || !d1->sent_messages
124 || !d1->buffered_app_data.q) {
125 if (d1->unprocessed_rcds.q)
126 pqueue_free(d1->unprocessed_rcds.q);
127 if (d1->processed_rcds.q)
128 pqueue_free(d1->processed_rcds.q);
129 if (d1->buffered_messages)
130 pqueue_free(d1->buffered_messages);
131 if (d1->sent_messages)
132 pqueue_free(d1->sent_messages);
133 if (d1->buffered_app_data.q)
134 pqueue_free(d1->buffered_app_data.q);
140 s->method->ssl_clear(s);
144 static void dtls1_clear_queues(SSL *s)
147 DTLS1_RECORD_DATA *rdata;
149 while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) {
150 rdata = (DTLS1_RECORD_DATA *)item->data;
151 if (rdata->rbuf.buf) {
152 OPENSSL_free(rdata->rbuf.buf);
154 OPENSSL_free(item->data);
158 while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {
159 rdata = (DTLS1_RECORD_DATA *)item->data;
160 if (rdata->rbuf.buf) {
161 OPENSSL_free(rdata->rbuf.buf);
163 OPENSSL_free(item->data);
167 while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
168 rdata = (DTLS1_RECORD_DATA *)item->data;
169 if (rdata->rbuf.buf) {
170 OPENSSL_free(rdata->rbuf.buf);
172 OPENSSL_free(item->data);
176 dtls1_clear_received_buffer(s);
177 dtls1_clear_sent_buffer(s);
180 void dtls1_clear_received_buffer(SSL *s)
183 hm_fragment *frag = NULL;
185 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
186 frag = (hm_fragment *)item->data;
187 dtls1_hm_fragment_free(frag);
192 void dtls1_clear_sent_buffer(SSL *s)
195 hm_fragment *frag = NULL;
197 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
198 frag = (hm_fragment *)item->data;
199 dtls1_hm_fragment_free(frag);
205 void dtls1_free(SSL *s)
209 dtls1_clear_queues(s);
211 pqueue_free(s->d1->unprocessed_rcds.q);
212 pqueue_free(s->d1->processed_rcds.q);
213 pqueue_free(s->d1->buffered_messages);
214 pqueue_free(s->d1->sent_messages);
215 pqueue_free(s->d1->buffered_app_data.q);
221 void dtls1_clear(SSL *s)
223 pqueue unprocessed_rcds;
224 pqueue processed_rcds;
225 pqueue buffered_messages;
226 pqueue sent_messages;
227 pqueue buffered_app_data;
229 unsigned int link_mtu;
232 unprocessed_rcds = s->d1->unprocessed_rcds.q;
233 processed_rcds = s->d1->processed_rcds.q;
234 buffered_messages = s->d1->buffered_messages;
235 sent_messages = s->d1->sent_messages;
236 buffered_app_data = s->d1->buffered_app_data.q;
238 link_mtu = s->d1->link_mtu;
240 dtls1_clear_queues(s);
242 memset(s->d1, 0, sizeof(*(s->d1)));
245 s->d1->cookie_len = sizeof(s->d1->cookie);
248 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
250 s->d1->link_mtu = link_mtu;
253 s->d1->unprocessed_rcds.q = unprocessed_rcds;
254 s->d1->processed_rcds.q = processed_rcds;
255 s->d1->buffered_messages = buffered_messages;
256 s->d1->sent_messages = sent_messages;
257 s->d1->buffered_app_data.q = buffered_app_data;
261 if (s->options & SSL_OP_CISCO_ANYCONNECT)
262 s->version = DTLS1_BAD_VER;
264 s->version = DTLS1_VERSION;
267 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
272 case DTLS_CTRL_GET_TIMEOUT:
273 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
277 case DTLS_CTRL_HANDLE_TIMEOUT:
278 ret = dtls1_handle_timeout(s);
280 case DTLS_CTRL_LISTEN:
281 ret = dtls1_listen(s, parg);
283 case SSL_CTRL_CHECK_PROTO_VERSION:
285 * For library-internal use; checks that the current protocol is the
286 * highest enabled version (according to s->ctx->method, as version
287 * negotiation may have changed s->method).
289 #if DTLS_MAX_VERSION != DTLS1_VERSION
290 # error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
293 * Just one protocol version is supported so far; fail closed if the
294 * version is not as expected.
296 return s->version == DTLS_MAX_VERSION;
297 case DTLS_CTRL_SET_LINK_MTU:
298 if (larg < (long)dtls1_link_min_mtu())
300 s->d1->link_mtu = larg;
302 case DTLS_CTRL_GET_LINK_MIN_MTU:
303 return (long)dtls1_link_min_mtu();
304 case SSL_CTRL_SET_MTU:
306 * We may not have a BIO set yet so can't call dtls1_min_mtu()
307 * We'll have to make do with dtls1_link_min_mtu() and max overhead
309 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
314 ret = ssl3_ctrl(s, cmd, larg, parg);
321 * As it's impossible to use stream ciphers in "datagram" mode, this
322 * simple filter is designed to disengage them in DTLS. Unfortunately
323 * there is no universal way to identify stream SSL_CIPHER, so we have
324 * to explicitly list their SSL_* codes. Currently RC4 is the only one
325 * available, but if new ones emerge, they will have to be added...
327 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
329 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
332 if (ciph->algorithm_enc == SSL_RC4)
339 void dtls1_start_timer(SSL *s)
341 #ifndef OPENSSL_NO_SCTP
342 /* Disable timer for SCTP */
343 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
344 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
349 /* If timer is not set, initialize duration with 1 second */
350 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
351 s->d1->timeout_duration = 1;
354 /* Set timeout to current time */
355 get_current_time(&(s->d1->next_timeout));
357 /* Add duration to current time */
358 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
359 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
360 &(s->d1->next_timeout));
363 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
365 struct timeval timenow;
367 /* If no timeout is set, just return NULL */
368 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
372 /* Get current time */
373 get_current_time(&timenow);
375 /* If timer already expired, set remaining time to 0 */
376 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
377 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
378 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
379 memset(timeleft, 0, sizeof(struct timeval));
383 /* Calculate time left until timer expires */
384 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
385 timeleft->tv_sec -= timenow.tv_sec;
386 timeleft->tv_usec -= timenow.tv_usec;
387 if (timeleft->tv_usec < 0) {
389 timeleft->tv_usec += 1000000;
393 * If remaining time is less than 15 ms, set it to 0 to prevent issues
394 * because of small devergences with socket timeouts.
396 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
397 memset(timeleft, 0, sizeof(struct timeval));
403 int dtls1_is_timer_expired(SSL *s)
405 struct timeval timeleft;
407 /* Get time left until timeout, return false if no timer running */
408 if (dtls1_get_timeout(s, &timeleft) == NULL) {
412 /* Return false if timer is not expired yet */
413 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
417 /* Timer expired, so return true */
421 void dtls1_double_timeout(SSL *s)
423 s->d1->timeout_duration *= 2;
424 if (s->d1->timeout_duration > 60)
425 s->d1->timeout_duration = 60;
426 dtls1_start_timer(s);
429 void dtls1_stop_timer(SSL *s)
431 /* Reset everything */
432 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
433 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
434 s->d1->timeout_duration = 1;
435 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
436 &(s->d1->next_timeout));
437 /* Clear retransmission buffer */
438 dtls1_clear_sent_buffer(s);
441 int dtls1_check_timeout_num(SSL *s)
445 s->d1->timeout.num_alerts++;
447 /* Reduce MTU after 2 unsuccessful retransmissions */
448 if (s->d1->timeout.num_alerts > 2
449 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
451 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
453 if (mtu < s->d1->mtu)
457 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
458 /* fail the connection, enough alerts have been sent */
459 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
466 int dtls1_handle_timeout(SSL *s)
468 /* if no timer is expired, don't do anything */
469 if (!dtls1_is_timer_expired(s)) {
473 dtls1_double_timeout(s);
475 if (dtls1_check_timeout_num(s) < 0)
478 s->d1->timeout.read_timeouts++;
479 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
480 s->d1->timeout.read_timeouts = 1;
482 #ifndef OPENSSL_NO_HEARTBEATS
483 if (s->tlsext_hb_pending) {
484 s->tlsext_hb_pending = 0;
485 return dtls1_heartbeat(s);
489 dtls1_start_timer(s);
490 return dtls1_retransmit_buffered_messages(s);
493 static void get_current_time(struct timeval *t)
495 #ifdef OPENSSL_SYS_WIN32
498 t->tv_sec = (long)tb.time;
499 t->tv_usec = (long)tb.millitm * 1000;
500 #elif defined(OPENSSL_SYS_VMS)
503 t->tv_sec = (long)tb.time;
504 t->tv_usec = (long)tb.millitm * 1000;
506 gettimeofday(t, NULL);
510 int dtls1_listen(SSL *s, struct sockaddr *client)
514 /* Ensure there is no state left over from a previous invocation */
517 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
524 (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);