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 DTLS1_RECORD_DATA *rdata;
175 while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) {
176 rdata = (DTLS1_RECORD_DATA *)item->data;
177 if (rdata->rbuf.buf) {
178 OPENSSL_free(rdata->rbuf.buf);
180 OPENSSL_free(item->data);
184 while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {
185 rdata = (DTLS1_RECORD_DATA *)item->data;
186 if (rdata->rbuf.buf) {
187 OPENSSL_free(rdata->rbuf.buf);
189 OPENSSL_free(item->data);
193 while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
194 rdata = (DTLS1_RECORD_DATA *)item->data;
195 if (rdata->rbuf.buf) {
196 OPENSSL_free(rdata->rbuf.buf);
198 OPENSSL_free(item->data);
202 dtls1_clear_received_buffer(s);
203 dtls1_clear_sent_buffer(s);
206 void dtls1_clear_received_buffer(SSL *s)
209 hm_fragment *frag = NULL;
211 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
212 frag = (hm_fragment *)item->data;
213 dtls1_hm_fragment_free(frag);
218 void dtls1_clear_sent_buffer(SSL *s)
221 hm_fragment *frag = NULL;
223 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
224 frag = (hm_fragment *)item->data;
225 dtls1_hm_fragment_free(frag);
231 void dtls1_free(SSL *s)
235 dtls1_clear_queues(s);
237 pqueue_free(s->d1->unprocessed_rcds.q);
238 pqueue_free(s->d1->processed_rcds.q);
239 pqueue_free(s->d1->buffered_messages);
240 pqueue_free(s->d1->sent_messages);
241 pqueue_free(s->d1->buffered_app_data.q);
247 void dtls1_clear(SSL *s)
249 pqueue unprocessed_rcds;
250 pqueue processed_rcds;
251 pqueue buffered_messages;
252 pqueue sent_messages;
253 pqueue buffered_app_data;
255 unsigned int link_mtu;
258 unprocessed_rcds = s->d1->unprocessed_rcds.q;
259 processed_rcds = s->d1->processed_rcds.q;
260 buffered_messages = s->d1->buffered_messages;
261 sent_messages = s->d1->sent_messages;
262 buffered_app_data = s->d1->buffered_app_data.q;
264 link_mtu = s->d1->link_mtu;
266 dtls1_clear_queues(s);
268 memset(s->d1, 0, sizeof(*(s->d1)));
271 s->d1->cookie_len = sizeof(s->d1->cookie);
274 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
276 s->d1->link_mtu = link_mtu;
279 s->d1->unprocessed_rcds.q = unprocessed_rcds;
280 s->d1->processed_rcds.q = processed_rcds;
281 s->d1->buffered_messages = buffered_messages;
282 s->d1->sent_messages = sent_messages;
283 s->d1->buffered_app_data.q = buffered_app_data;
287 if (s->options & SSL_OP_CISCO_ANYCONNECT)
288 s->client_version = s->version = DTLS1_BAD_VER;
289 else if (s->method->version == DTLS_ANY_VERSION)
290 s->version = DTLS1_2_VERSION;
292 s->version = s->method->version;
295 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
300 case DTLS_CTRL_GET_TIMEOUT:
301 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
305 case DTLS_CTRL_HANDLE_TIMEOUT:
306 ret = dtls1_handle_timeout(s);
308 case DTLS_CTRL_LISTEN:
309 ret = dtls1_listen(s, parg);
311 case SSL_CTRL_CHECK_PROTO_VERSION:
313 * For library-internal use; checks that the current protocol is the
314 * highest enabled version (according to s->ctx->method, as version
315 * negotiation may have changed s->method).
317 if (s->version == s->ctx->method->version)
320 * Apparently we're using a version-flexible SSL_METHOD (not at its
321 * highest protocol version).
323 if (s->ctx->method->version == DTLS_method()->version) {
324 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
325 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
327 if (!(s->options & SSL_OP_NO_DTLSv1_2))
328 return s->version == DTLS1_2_VERSION;
329 if (!(s->options & SSL_OP_NO_DTLSv1))
330 return s->version == DTLS1_VERSION;
332 return 0; /* Unexpected state; fail closed. */
333 case DTLS_CTRL_SET_LINK_MTU:
334 if (larg < (long)dtls1_link_min_mtu())
336 s->d1->link_mtu = larg;
338 case DTLS_CTRL_GET_LINK_MIN_MTU:
339 return (long)dtls1_link_min_mtu();
340 case SSL_CTRL_SET_MTU:
342 * We may not have a BIO set yet so can't call dtls1_min_mtu()
343 * We'll have to make do with dtls1_link_min_mtu() and max overhead
345 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
350 ret = ssl3_ctrl(s, cmd, larg, parg);
357 * As it's impossible to use stream ciphers in "datagram" mode, this
358 * simple filter is designed to disengage them in DTLS. Unfortunately
359 * there is no universal way to identify stream SSL_CIPHER, so we have
360 * to explicitly list their SSL_* codes. Currently RC4 is the only one
361 * available, but if new ones emerge, they will have to be added...
363 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
365 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
368 if (ciph->algorithm_enc == SSL_RC4)
375 void dtls1_start_timer(SSL *s)
377 #ifndef OPENSSL_NO_SCTP
378 /* Disable timer for SCTP */
379 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
380 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
385 /* If timer is not set, initialize duration with 1 second */
386 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
387 s->d1->timeout_duration = 1;
390 /* Set timeout to current time */
391 get_current_time(&(s->d1->next_timeout));
393 /* Add duration to current time */
394 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
395 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
396 &(s->d1->next_timeout));
399 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
401 struct timeval timenow;
403 /* If no timeout is set, just return NULL */
404 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
408 /* Get current time */
409 get_current_time(&timenow);
411 /* If timer already expired, set remaining time to 0 */
412 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
413 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
414 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
415 memset(timeleft, 0, sizeof(struct timeval));
419 /* Calculate time left until timer expires */
420 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
421 timeleft->tv_sec -= timenow.tv_sec;
422 timeleft->tv_usec -= timenow.tv_usec;
423 if (timeleft->tv_usec < 0) {
425 timeleft->tv_usec += 1000000;
429 * If remaining time is less than 15 ms, set it to 0 to prevent issues
430 * because of small devergences with socket timeouts.
432 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
433 memset(timeleft, 0, sizeof(struct timeval));
439 int dtls1_is_timer_expired(SSL *s)
441 struct timeval timeleft;
443 /* Get time left until timeout, return false if no timer running */
444 if (dtls1_get_timeout(s, &timeleft) == NULL) {
448 /* Return false if timer is not expired yet */
449 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
453 /* Timer expired, so return true */
457 void dtls1_double_timeout(SSL *s)
459 s->d1->timeout_duration *= 2;
460 if (s->d1->timeout_duration > 60)
461 s->d1->timeout_duration = 60;
462 dtls1_start_timer(s);
465 void dtls1_stop_timer(SSL *s)
467 /* Reset everything */
468 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
469 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
470 s->d1->timeout_duration = 1;
471 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
472 &(s->d1->next_timeout));
473 /* Clear retransmission buffer */
474 dtls1_clear_sent_buffer(s);
477 int dtls1_check_timeout_num(SSL *s)
481 s->d1->timeout.num_alerts++;
483 /* Reduce MTU after 2 unsuccessful retransmissions */
484 if (s->d1->timeout.num_alerts > 2
485 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
487 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
489 if (mtu < s->d1->mtu)
493 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
494 /* fail the connection, enough alerts have been sent */
495 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
502 int dtls1_handle_timeout(SSL *s)
504 /* if no timer is expired, don't do anything */
505 if (!dtls1_is_timer_expired(s)) {
509 dtls1_double_timeout(s);
511 if (dtls1_check_timeout_num(s) < 0)
514 s->d1->timeout.read_timeouts++;
515 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
516 s->d1->timeout.read_timeouts = 1;
518 #ifndef OPENSSL_NO_HEARTBEATS
519 if (s->tlsext_hb_pending) {
520 s->tlsext_hb_pending = 0;
521 return dtls1_heartbeat(s);
525 dtls1_start_timer(s);
526 return dtls1_retransmit_buffered_messages(s);
529 static void get_current_time(struct timeval *t)
539 SystemTimeToFileTime(&st, &now.ft);
541 now.ul -= 116444736000000000ULL;
543 now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
545 t->tv_sec = (long)(now.ul / 10000000);
546 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
547 #elif defined(OPENSSL_SYS_VMS)
550 t->tv_sec = (long)tb.time;
551 t->tv_usec = (long)tb.millitm * 1000;
553 gettimeofday(t, NULL);
557 int dtls1_listen(SSL *s, struct sockaddr *client)
561 /* Ensure there is no state left over from a previous invocation */
564 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
571 (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
575 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
577 unsigned char *p = (unsigned char *)s->init_buf->data;
578 dtls1_set_message_header(s, p, htype, len, 0, len);
579 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
581 /* Buffer the message to handle re-xmits */
582 dtls1_buffer_message(s, 0);
585 static int dtls1_handshake_write(SSL *s)
587 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);