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 void 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 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 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)
131 memset(d1, 0, sizeof *d1);
133 /* d1->handshake_epoch=0; */
135 d1->unprocessed_rcds.q = pqueue_new();
136 d1->processed_rcds.q = pqueue_new();
137 d1->buffered_messages = pqueue_new();
138 d1->sent_messages = pqueue_new();
139 d1->buffered_app_data.q = pqueue_new();
142 d1->cookie_len = sizeof(s->d1->cookie);
148 if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q
149 || !d1->buffered_messages || !d1->sent_messages
150 || !d1->buffered_app_data.q) {
151 if (d1->unprocessed_rcds.q)
152 pqueue_free(d1->unprocessed_rcds.q);
153 if (d1->processed_rcds.q)
154 pqueue_free(d1->processed_rcds.q);
155 if (d1->buffered_messages)
156 pqueue_free(d1->buffered_messages);
157 if (d1->sent_messages)
158 pqueue_free(d1->sent_messages);
159 if (d1->buffered_app_data.q)
160 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->unprocessed_rcds.q)) != NULL) {
177 rdata = (DTLS1_RECORD_DATA *)item->data;
178 if (rdata->rbuf.buf) {
179 OPENSSL_free(rdata->rbuf.buf);
181 OPENSSL_free(item->data);
185 while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {
186 rdata = (DTLS1_RECORD_DATA *)item->data;
187 if (rdata->rbuf.buf) {
188 OPENSSL_free(rdata->rbuf.buf);
190 OPENSSL_free(item->data);
194 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
195 frag = (hm_fragment *)item->data;
196 dtls1_hm_fragment_free(frag);
200 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
201 frag = (hm_fragment *)item->data;
202 dtls1_hm_fragment_free(frag);
206 while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
207 rdata = (DTLS1_RECORD_DATA *)item->data;
208 if (rdata->rbuf.buf) {
209 OPENSSL_free(rdata->rbuf.buf);
211 OPENSSL_free(item->data);
216 void dtls1_free(SSL *s)
220 dtls1_clear_queues(s);
222 pqueue_free(s->d1->unprocessed_rcds.q);
223 pqueue_free(s->d1->processed_rcds.q);
224 pqueue_free(s->d1->buffered_messages);
225 pqueue_free(s->d1->sent_messages);
226 pqueue_free(s->d1->buffered_app_data.q);
232 void dtls1_clear(SSL *s)
234 pqueue unprocessed_rcds;
235 pqueue processed_rcds;
236 pqueue buffered_messages;
237 pqueue sent_messages;
238 pqueue buffered_app_data;
240 unsigned int link_mtu;
243 unprocessed_rcds = s->d1->unprocessed_rcds.q;
244 processed_rcds = s->d1->processed_rcds.q;
245 buffered_messages = s->d1->buffered_messages;
246 sent_messages = s->d1->sent_messages;
247 buffered_app_data = s->d1->buffered_app_data.q;
249 link_mtu = s->d1->link_mtu;
251 dtls1_clear_queues(s);
253 memset(s->d1, 0, sizeof(*(s->d1)));
256 s->d1->cookie_len = sizeof(s->d1->cookie);
259 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
261 s->d1->link_mtu = link_mtu;
264 s->d1->unprocessed_rcds.q = unprocessed_rcds;
265 s->d1->processed_rcds.q = processed_rcds;
266 s->d1->buffered_messages = buffered_messages;
267 s->d1->sent_messages = sent_messages;
268 s->d1->buffered_app_data.q = buffered_app_data;
272 if (s->options & SSL_OP_CISCO_ANYCONNECT)
273 s->client_version = s->version = DTLS1_BAD_VER;
274 else if (s->method->version == DTLS_ANY_VERSION)
275 s->version = DTLS1_2_VERSION;
277 s->version = s->method->version;
280 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
285 case DTLS_CTRL_GET_TIMEOUT:
286 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
290 case DTLS_CTRL_HANDLE_TIMEOUT:
291 ret = dtls1_handle_timeout(s);
293 case DTLS_CTRL_LISTEN:
294 ret = dtls1_listen(s, parg);
296 case SSL_CTRL_CHECK_PROTO_VERSION:
298 * For library-internal use; checks that the current protocol is the
299 * highest enabled version (according to s->ctx->method, as version
300 * negotiation may have changed s->method).
302 if (s->version == s->ctx->method->version)
305 * Apparently we're using a version-flexible SSL_METHOD (not at its
306 * highest protocol version).
308 if (s->ctx->method->version == DTLS_method()->version) {
309 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
310 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
312 if (!(s->options & SSL_OP_NO_DTLSv1_2))
313 return s->version == DTLS1_2_VERSION;
314 if (!(s->options & SSL_OP_NO_DTLSv1))
315 return s->version == DTLS1_VERSION;
317 return 0; /* Unexpected state; fail closed. */
318 case DTLS_CTRL_SET_LINK_MTU:
319 if (larg < (long)dtls1_link_min_mtu())
321 s->d1->link_mtu = larg;
323 case DTLS_CTRL_GET_LINK_MIN_MTU:
324 return (long)dtls1_link_min_mtu();
325 case SSL_CTRL_SET_MTU:
327 * We may not have a BIO set yet so can't call dtls1_min_mtu()
328 * We'll have to make do with dtls1_link_min_mtu() and max overhead
330 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
335 ret = ssl3_ctrl(s, cmd, larg, parg);
342 * As it's impossible to use stream ciphers in "datagram" mode, this
343 * simple filter is designed to disengage them in DTLS. Unfortunately
344 * there is no universal way to identify stream SSL_CIPHER, so we have
345 * to explicitly list their SSL_* codes. Currently RC4 is the only one
346 * available, but if new ones emerge, they will have to be added...
348 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
350 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
353 if (ciph->algorithm_enc == SSL_RC4)
360 void dtls1_start_timer(SSL *s)
362 #ifndef OPENSSL_NO_SCTP
363 /* Disable timer for SCTP */
364 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
365 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
370 /* If timer is not set, initialize duration with 1 second */
371 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
372 s->d1->timeout_duration = 1;
375 /* Set timeout to current time */
376 get_current_time(&(s->d1->next_timeout));
378 /* Add duration to current time */
379 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
380 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
381 &(s->d1->next_timeout));
384 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
386 struct timeval timenow;
388 /* If no timeout is set, just return NULL */
389 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
393 /* Get current time */
394 get_current_time(&timenow);
396 /* If timer already expired, set remaining time to 0 */
397 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
398 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
399 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
400 memset(timeleft, 0, sizeof(struct timeval));
404 /* Calculate time left until timer expires */
405 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
406 timeleft->tv_sec -= timenow.tv_sec;
407 timeleft->tv_usec -= timenow.tv_usec;
408 if (timeleft->tv_usec < 0) {
410 timeleft->tv_usec += 1000000;
414 * If remaining time is less than 15 ms, set it to 0 to prevent issues
415 * because of small devergences with socket timeouts.
417 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
418 memset(timeleft, 0, sizeof(struct timeval));
424 int dtls1_is_timer_expired(SSL *s)
426 struct timeval timeleft;
428 /* Get time left until timeout, return false if no timer running */
429 if (dtls1_get_timeout(s, &timeleft) == NULL) {
433 /* Return false if timer is not expired yet */
434 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
438 /* Timer expired, so return true */
442 void dtls1_double_timeout(SSL *s)
444 s->d1->timeout_duration *= 2;
445 if (s->d1->timeout_duration > 60)
446 s->d1->timeout_duration = 60;
447 dtls1_start_timer(s);
450 void dtls1_stop_timer(SSL *s)
452 /* Reset everything */
453 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
454 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
455 s->d1->timeout_duration = 1;
456 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
457 &(s->d1->next_timeout));
458 /* Clear retransmission buffer */
459 dtls1_clear_record_buffer(s);
462 int dtls1_check_timeout_num(SSL *s)
466 s->d1->timeout.num_alerts++;
468 /* Reduce MTU after 2 unsuccessful retransmissions */
469 if (s->d1->timeout.num_alerts > 2
470 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
472 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
474 if (mtu < s->d1->mtu)
478 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
479 /* fail the connection, enough alerts have been sent */
480 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
487 int dtls1_handle_timeout(SSL *s)
489 /* if no timer is expired, don't do anything */
490 if (!dtls1_is_timer_expired(s)) {
494 dtls1_double_timeout(s);
496 if (dtls1_check_timeout_num(s) < 0)
499 s->d1->timeout.read_timeouts++;
500 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
501 s->d1->timeout.read_timeouts = 1;
503 #ifndef OPENSSL_NO_HEARTBEATS
504 if (s->tlsext_hb_pending) {
505 s->tlsext_hb_pending = 0;
506 return dtls1_heartbeat(s);
510 dtls1_start_timer(s);
511 return dtls1_retransmit_buffered_messages(s);
514 static void get_current_time(struct timeval *t)
524 SystemTimeToFileTime(&st, &now.ft);
526 now.ul -= 116444736000000000ULL;
528 now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
530 t->tv_sec = (long)(now.ul / 10000000);
531 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
532 #elif defined(OPENSSL_SYS_VMS)
535 t->tv_sec = (long)tb.time;
536 t->tv_usec = (long)tb.millitm * 1000;
538 gettimeofday(t, NULL);
542 int dtls1_listen(SSL *s, struct sockaddr *client)
546 /* Ensure there is no state left over from a previous invocation */
549 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
556 (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
560 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
562 unsigned char *p = (unsigned char *)s->init_buf->data;
563 dtls1_set_message_header(s, p, htype, len, 0, len);
564 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
566 /* Buffer the message to handle re-xmits */
567 dtls1_buffer_message(s, 0);
570 static int dtls1_handshake_write(SSL *s)
572 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);