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_VMS)
66 # include <sys/timeb.h>
69 static void get_current_time(struct timeval *t);
70 static int dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
71 static int dtls1_handshake_write(SSL *s);
72 const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT;
73 int dtls1_listen(SSL *s, struct sockaddr *client);
75 const SSL3_ENC_METHOD DTLSv1_enc_data = {
79 tls1_generate_master_secret,
80 tls1_change_cipher_state,
81 tls1_final_finish_mac,
82 TLS1_FINISH_MAC_LENGTH,
84 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
85 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
87 tls1_export_keying_material,
88 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
89 DTLS1_HM_HEADER_LENGTH,
90 dtls1_set_handshake_header,
94 const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
98 tls1_generate_master_secret,
99 tls1_change_cipher_state,
100 tls1_final_finish_mac,
101 TLS1_FINISH_MAC_LENGTH,
102 tls1_cert_verify_mac,
103 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
104 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
106 tls1_export_keying_material,
107 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
108 | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
109 DTLS1_HM_HEADER_LENGTH,
110 dtls1_set_handshake_header,
111 dtls1_handshake_write
114 long dtls1_default_timeout(void)
117 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
118 * http, the cache would over fill
120 return (60 * 60 * 2);
123 int dtls1_new(SSL *s)
129 if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL) {
133 memset(d1, 0, sizeof *d1);
135 if(!DTLS_RECORD_LAYER_new(&s->rlayer)) {
141 d1->buffered_messages = pqueue_new();
142 d1->sent_messages = pqueue_new();
143 d1->buffered_app_data.q = pqueue_new();
146 d1->cookie_len = sizeof(s->d1->cookie);
152 if (!d1->buffered_messages || !d1->sent_messages
153 || !d1->buffered_app_data.q) {
154 if (d1->buffered_messages)
155 pqueue_free(d1->buffered_messages);
156 if (d1->sent_messages)
157 pqueue_free(d1->sent_messages);
158 if (d1->buffered_app_data.q)
159 pqueue_free(d1->buffered_app_data.q);
166 s->method->ssl_clear(s);
170 static void dtls1_clear_queues(SSL *s)
173 hm_fragment *frag = NULL;
174 DTLS1_RECORD_DATA *rdata;
176 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
177 frag = (hm_fragment *)item->data;
178 dtls1_hm_fragment_free(frag);
182 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
183 frag = (hm_fragment *)item->data;
184 dtls1_hm_fragment_free(frag);
188 while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
189 rdata = (DTLS1_RECORD_DATA *)item->data;
190 if (rdata->rbuf.buf) {
191 OPENSSL_free(rdata->rbuf.buf);
193 OPENSSL_free(item->data);
198 void dtls1_free(SSL *s)
200 DTLS_RECORD_LAYER_free(&s->rlayer);
204 dtls1_clear_queues(s);
206 pqueue_free(s->d1->buffered_messages);
207 pqueue_free(s->d1->sent_messages);
208 pqueue_free(s->d1->buffered_app_data.q);
214 void dtls1_clear(SSL *s)
216 pqueue buffered_messages;
217 pqueue sent_messages;
218 pqueue buffered_app_data;
220 unsigned int link_mtu;
222 DTLS_RECORD_LAYER_clear(&s->rlayer);
225 buffered_messages = s->d1->buffered_messages;
226 sent_messages = s->d1->sent_messages;
227 buffered_app_data = s->d1->buffered_app_data.q;
229 link_mtu = s->d1->link_mtu;
231 dtls1_clear_queues(s);
233 memset(s->d1, 0, sizeof(*(s->d1)));
236 s->d1->cookie_len = sizeof(s->d1->cookie);
239 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
241 s->d1->link_mtu = link_mtu;
244 s->d1->buffered_messages = buffered_messages;
245 s->d1->sent_messages = sent_messages;
246 s->d1->buffered_app_data.q = buffered_app_data;
250 if (s->options & SSL_OP_CISCO_ANYCONNECT)
251 s->client_version = s->version = DTLS1_BAD_VER;
252 else if (s->method->version == DTLS_ANY_VERSION)
253 s->version = DTLS1_2_VERSION;
255 s->version = s->method->version;
258 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
263 case DTLS_CTRL_GET_TIMEOUT:
264 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
268 case DTLS_CTRL_HANDLE_TIMEOUT:
269 ret = dtls1_handle_timeout(s);
271 case DTLS_CTRL_LISTEN:
272 ret = dtls1_listen(s, parg);
274 case SSL_CTRL_CHECK_PROTO_VERSION:
276 * For library-internal use; checks that the current protocol is the
277 * highest enabled version (according to s->ctx->method, as version
278 * negotiation may have changed s->method).
280 if (s->version == s->ctx->method->version)
283 * Apparently we're using a version-flexible SSL_METHOD (not at its
284 * highest protocol version).
286 if (s->ctx->method->version == DTLS_method()->version) {
287 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
288 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
290 if (!(s->options & SSL_OP_NO_DTLSv1_2))
291 return s->version == DTLS1_2_VERSION;
292 if (!(s->options & SSL_OP_NO_DTLSv1))
293 return s->version == DTLS1_VERSION;
295 return 0; /* Unexpected state; fail closed. */
296 case DTLS_CTRL_SET_LINK_MTU:
297 if (larg < (long)dtls1_link_min_mtu())
299 s->d1->link_mtu = larg;
301 case DTLS_CTRL_GET_LINK_MIN_MTU:
302 return (long)dtls1_link_min_mtu();
303 case SSL_CTRL_SET_MTU:
305 * We may not have a BIO set yet so can't call dtls1_min_mtu()
306 * We'll have to make do with dtls1_link_min_mtu() and max overhead
308 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
313 ret = ssl3_ctrl(s, cmd, larg, parg);
320 * As it's impossible to use stream ciphers in "datagram" mode, this
321 * simple filter is designed to disengage them in DTLS. Unfortunately
322 * there is no universal way to identify stream SSL_CIPHER, so we have
323 * to explicitly list their SSL_* codes. Currently RC4 is the only one
324 * available, but if new ones emerge, they will have to be added...
326 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
328 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
331 if (ciph->algorithm_enc == SSL_RC4)
338 void dtls1_start_timer(SSL *s)
340 #ifndef OPENSSL_NO_SCTP
341 /* Disable timer for SCTP */
342 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
343 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
348 /* If timer is not set, initialize duration with 1 second */
349 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
350 s->d1->timeout_duration = 1;
353 /* Set timeout to current time */
354 get_current_time(&(s->d1->next_timeout));
356 /* Add duration to current time */
357 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
358 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
359 &(s->d1->next_timeout));
362 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
364 struct timeval timenow;
366 /* If no timeout is set, just return NULL */
367 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
371 /* Get current time */
372 get_current_time(&timenow);
374 /* If timer already expired, set remaining time to 0 */
375 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
376 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
377 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
378 memset(timeleft, 0, sizeof(struct timeval));
382 /* Calculate time left until timer expires */
383 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
384 timeleft->tv_sec -= timenow.tv_sec;
385 timeleft->tv_usec -= timenow.tv_usec;
386 if (timeleft->tv_usec < 0) {
388 timeleft->tv_usec += 1000000;
392 * If remaining time is less than 15 ms, set it to 0 to prevent issues
393 * because of small devergences with socket timeouts.
395 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
396 memset(timeleft, 0, sizeof(struct timeval));
402 int dtls1_is_timer_expired(SSL *s)
404 struct timeval timeleft;
406 /* Get time left until timeout, return false if no timer running */
407 if (dtls1_get_timeout(s, &timeleft) == NULL) {
411 /* Return false if timer is not expired yet */
412 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
416 /* Timer expired, so return true */
420 void dtls1_double_timeout(SSL *s)
422 s->d1->timeout_duration *= 2;
423 if (s->d1->timeout_duration > 60)
424 s->d1->timeout_duration = 60;
425 dtls1_start_timer(s);
428 void dtls1_stop_timer(SSL *s)
430 /* Reset everything */
431 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
432 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
433 s->d1->timeout_duration = 1;
434 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
435 &(s->d1->next_timeout));
436 /* Clear retransmission buffer */
437 dtls1_clear_record_buffer(s);
440 int dtls1_check_timeout_num(SSL *s)
444 s->d1->timeout.num_alerts++;
446 /* Reduce MTU after 2 unsuccessful retransmissions */
447 if (s->d1->timeout.num_alerts > 2
448 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
450 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
452 if (mtu < s->d1->mtu)
456 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
457 /* fail the connection, enough alerts have been sent */
458 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
465 int dtls1_handle_timeout(SSL *s)
467 /* if no timer is expired, don't do anything */
468 if (!dtls1_is_timer_expired(s)) {
472 dtls1_double_timeout(s);
474 if (dtls1_check_timeout_num(s) < 0)
477 s->d1->timeout.read_timeouts++;
478 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
479 s->d1->timeout.read_timeouts = 1;
481 #ifndef OPENSSL_NO_HEARTBEATS
482 if (s->tlsext_hb_pending) {
483 s->tlsext_hb_pending = 0;
484 return dtls1_heartbeat(s);
488 dtls1_start_timer(s);
489 return dtls1_retransmit_buffered_messages(s);
492 static void get_current_time(struct timeval *t)
502 SystemTimeToFileTime(&st, &now.ft);
504 now.ul -= 116444736000000000ULL;
506 now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
508 t->tv_sec = (long)(now.ul / 10000000);
509 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
510 #elif defined(OPENSSL_SYS_VMS)
513 t->tv_sec = (long)tb.time;
514 t->tv_usec = (long)tb.millitm * 1000;
516 gettimeofday(t, NULL);
520 int dtls1_listen(SSL *s, struct sockaddr *client)
524 /* Ensure there is no state left over from a previous invocation */
528 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
535 (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
539 static int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
541 unsigned char *p = (unsigned char *)s->init_buf->data;
542 dtls1_set_message_header(s, p, htype, len, 0, len);
543 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
545 /* Buffer the message to handle re-xmits */
547 if(!dtls1_buffer_message(s, 0))
553 static int dtls1_handshake_write(SSL *s)
555 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);