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)
127 if(!DTLS_RECORD_LAYER_new(&s->rlayer)) {
133 if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL) {
137 memset(d1, 0, sizeof *d1);
139 d1->buffered_messages = pqueue_new();
140 d1->sent_messages = pqueue_new();
143 d1->cookie_len = sizeof(s->d1->cookie);
149 if (!d1->buffered_messages || !d1->sent_messages) {
150 if (d1->buffered_messages)
151 pqueue_free(d1->buffered_messages);
152 if (d1->sent_messages)
153 pqueue_free(d1->sent_messages);
160 s->method->ssl_clear(s);
164 static void dtls1_clear_queues(SSL *s)
167 hm_fragment *frag = NULL;
169 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
170 frag = (hm_fragment *)item->data;
171 dtls1_hm_fragment_free(frag);
175 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
176 frag = (hm_fragment *)item->data;
177 dtls1_hm_fragment_free(frag);
182 void dtls1_free(SSL *s)
184 DTLS_RECORD_LAYER_free(&s->rlayer);
188 dtls1_clear_queues(s);
190 pqueue_free(s->d1->buffered_messages);
191 pqueue_free(s->d1->sent_messages);
197 void dtls1_clear(SSL *s)
199 pqueue buffered_messages;
200 pqueue sent_messages;
202 unsigned int link_mtu;
204 DTLS_RECORD_LAYER_clear(&s->rlayer);
207 buffered_messages = s->d1->buffered_messages;
208 sent_messages = s->d1->sent_messages;
210 link_mtu = s->d1->link_mtu;
212 dtls1_clear_queues(s);
214 memset(s->d1, 0, sizeof(*(s->d1)));
217 s->d1->cookie_len = sizeof(s->d1->cookie);
220 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
222 s->d1->link_mtu = link_mtu;
225 s->d1->buffered_messages = buffered_messages;
226 s->d1->sent_messages = sent_messages;
230 if (s->options & SSL_OP_CISCO_ANYCONNECT)
231 s->client_version = s->version = DTLS1_BAD_VER;
232 else if (s->method->version == DTLS_ANY_VERSION)
233 s->version = DTLS1_2_VERSION;
235 s->version = s->method->version;
238 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
243 case DTLS_CTRL_GET_TIMEOUT:
244 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
248 case DTLS_CTRL_HANDLE_TIMEOUT:
249 ret = dtls1_handle_timeout(s);
251 case DTLS_CTRL_LISTEN:
252 ret = dtls1_listen(s, parg);
254 case SSL_CTRL_CHECK_PROTO_VERSION:
256 * For library-internal use; checks that the current protocol is the
257 * highest enabled version (according to s->ctx->method, as version
258 * negotiation may have changed s->method).
260 if (s->version == s->ctx->method->version)
263 * Apparently we're using a version-flexible SSL_METHOD (not at its
264 * highest protocol version).
266 if (s->ctx->method->version == DTLS_method()->version) {
267 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
268 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
270 if (!(s->options & SSL_OP_NO_DTLSv1_2))
271 return s->version == DTLS1_2_VERSION;
272 if (!(s->options & SSL_OP_NO_DTLSv1))
273 return s->version == DTLS1_VERSION;
275 return 0; /* Unexpected state; fail closed. */
276 case DTLS_CTRL_SET_LINK_MTU:
277 if (larg < (long)dtls1_link_min_mtu())
279 s->d1->link_mtu = larg;
281 case DTLS_CTRL_GET_LINK_MIN_MTU:
282 return (long)dtls1_link_min_mtu();
283 case SSL_CTRL_SET_MTU:
285 * We may not have a BIO set yet so can't call dtls1_min_mtu()
286 * We'll have to make do with dtls1_link_min_mtu() and max overhead
288 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
293 ret = ssl3_ctrl(s, cmd, larg, parg);
300 * As it's impossible to use stream ciphers in "datagram" mode, this
301 * simple filter is designed to disengage them in DTLS. Unfortunately
302 * there is no universal way to identify stream SSL_CIPHER, so we have
303 * to explicitly list their SSL_* codes. Currently RC4 is the only one
304 * available, but if new ones emerge, they will have to be added...
306 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
308 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
311 if (ciph->algorithm_enc == SSL_RC4)
318 void dtls1_start_timer(SSL *s)
320 #ifndef OPENSSL_NO_SCTP
321 /* Disable timer for SCTP */
322 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
323 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
328 /* If timer is not set, initialize duration with 1 second */
329 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
330 s->d1->timeout_duration = 1;
333 /* Set timeout to current time */
334 get_current_time(&(s->d1->next_timeout));
336 /* Add duration to current time */
337 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
338 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
339 &(s->d1->next_timeout));
342 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
344 struct timeval timenow;
346 /* If no timeout is set, just return NULL */
347 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
351 /* Get current time */
352 get_current_time(&timenow);
354 /* If timer already expired, set remaining time to 0 */
355 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
356 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
357 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
358 memset(timeleft, 0, sizeof(struct timeval));
362 /* Calculate time left until timer expires */
363 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
364 timeleft->tv_sec -= timenow.tv_sec;
365 timeleft->tv_usec -= timenow.tv_usec;
366 if (timeleft->tv_usec < 0) {
368 timeleft->tv_usec += 1000000;
372 * If remaining time is less than 15 ms, set it to 0 to prevent issues
373 * because of small devergences with socket timeouts.
375 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
376 memset(timeleft, 0, sizeof(struct timeval));
382 int dtls1_is_timer_expired(SSL *s)
384 struct timeval timeleft;
386 /* Get time left until timeout, return false if no timer running */
387 if (dtls1_get_timeout(s, &timeleft) == NULL) {
391 /* Return false if timer is not expired yet */
392 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
396 /* Timer expired, so return true */
400 void dtls1_double_timeout(SSL *s)
402 s->d1->timeout_duration *= 2;
403 if (s->d1->timeout_duration > 60)
404 s->d1->timeout_duration = 60;
405 dtls1_start_timer(s);
408 void dtls1_stop_timer(SSL *s)
410 /* Reset everything */
411 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
412 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
413 s->d1->timeout_duration = 1;
414 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
415 &(s->d1->next_timeout));
416 /* Clear retransmission buffer */
417 dtls1_clear_record_buffer(s);
420 int dtls1_check_timeout_num(SSL *s)
424 s->d1->timeout.num_alerts++;
426 /* Reduce MTU after 2 unsuccessful retransmissions */
427 if (s->d1->timeout.num_alerts > 2
428 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
430 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
432 if (mtu < s->d1->mtu)
436 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
437 /* fail the connection, enough alerts have been sent */
438 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
445 int dtls1_handle_timeout(SSL *s)
447 /* if no timer is expired, don't do anything */
448 if (!dtls1_is_timer_expired(s)) {
452 dtls1_double_timeout(s);
454 if (dtls1_check_timeout_num(s) < 0)
457 s->d1->timeout.read_timeouts++;
458 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
459 s->d1->timeout.read_timeouts = 1;
461 #ifndef OPENSSL_NO_HEARTBEATS
462 if (s->tlsext_hb_pending) {
463 s->tlsext_hb_pending = 0;
464 return dtls1_heartbeat(s);
468 dtls1_start_timer(s);
469 return dtls1_retransmit_buffered_messages(s);
472 static void get_current_time(struct timeval *t)
482 SystemTimeToFileTime(&st, &now.ft);
484 now.ul -= 116444736000000000ULL;
486 now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
488 t->tv_sec = (long)(now.ul / 10000000);
489 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
490 #elif defined(OPENSSL_SYS_VMS)
493 t->tv_sec = (long)tb.time;
494 t->tv_usec = (long)tb.millitm * 1000;
496 gettimeofday(t, NULL);
500 int dtls1_listen(SSL *s, struct sockaddr *client)
504 /* Ensure there is no state left over from a previous invocation */
508 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
515 (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
519 static int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
521 unsigned char *p = (unsigned char *)s->init_buf->data;
522 dtls1_set_message_header(s, p, htype, len, 0, len);
523 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
525 /* Buffer the message to handle re-xmits */
527 if(!dtls1_buffer_message(s, 0))
533 static int dtls1_handshake_write(SSL *s)
535 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);