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>
67 #elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
68 # include <sys/timeval.h>
69 #elif defined(OPENSSL_SYS_VXWORKS)
70 # include <sys/times.h>
71 #elif !defined(OPENSSL_SYS_WIN32)
72 # include <sys/time.h>
75 static void get_current_time(struct timeval *t);
76 static int dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
77 static int dtls1_handshake_write(SSL *s);
78 int dtls1_listen(SSL *s, struct sockaddr *client);
80 const SSL3_ENC_METHOD DTLSv1_enc_data = {
84 tls1_generate_master_secret,
85 tls1_change_cipher_state,
86 tls1_final_finish_mac,
87 TLS1_FINISH_MAC_LENGTH,
89 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
90 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
92 tls1_export_keying_material,
93 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
94 DTLS1_HM_HEADER_LENGTH,
95 dtls1_set_handshake_header,
99 const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
102 tls1_setup_key_block,
103 tls1_generate_master_secret,
104 tls1_change_cipher_state,
105 tls1_final_finish_mac,
106 TLS1_FINISH_MAC_LENGTH,
107 tls1_cert_verify_mac,
108 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
109 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
111 tls1_export_keying_material,
112 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
113 | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
114 DTLS1_HM_HEADER_LENGTH,
115 dtls1_set_handshake_header,
116 dtls1_handshake_write
119 long dtls1_default_timeout(void)
122 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
123 * http, the cache would over fill
125 return (60 * 60 * 2);
128 int dtls1_new(SSL *s)
132 if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
138 if ((d1 = OPENSSL_malloc(sizeof(*d1))) == NULL) {
142 memset(d1, 0, sizeof(*d1));
144 d1->buffered_messages = pqueue_new();
145 d1->sent_messages = pqueue_new();
148 d1->cookie_len = sizeof(s->d1->cookie);
154 if (!d1->buffered_messages || !d1->sent_messages) {
155 pqueue_free(d1->buffered_messages);
156 pqueue_free(d1->sent_messages);
163 s->method->ssl_clear(s);
167 static void dtls1_clear_queues(SSL *s)
170 hm_fragment *frag = NULL;
172 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
173 frag = (hm_fragment *)item->data;
174 dtls1_hm_fragment_free(frag);
178 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
179 frag = (hm_fragment *)item->data;
180 dtls1_hm_fragment_free(frag);
185 void dtls1_free(SSL *s)
187 DTLS_RECORD_LAYER_free(&s->rlayer);
191 dtls1_clear_queues(s);
193 pqueue_free(s->d1->buffered_messages);
194 pqueue_free(s->d1->sent_messages);
200 void dtls1_clear(SSL *s)
202 pqueue buffered_messages;
203 pqueue sent_messages;
205 unsigned int link_mtu;
207 DTLS_RECORD_LAYER_clear(&s->rlayer);
210 buffered_messages = s->d1->buffered_messages;
211 sent_messages = s->d1->sent_messages;
213 link_mtu = s->d1->link_mtu;
215 dtls1_clear_queues(s);
217 memset(s->d1, 0, sizeof(*s->d1));
220 s->d1->cookie_len = sizeof(s->d1->cookie);
223 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
225 s->d1->link_mtu = link_mtu;
228 s->d1->buffered_messages = buffered_messages;
229 s->d1->sent_messages = sent_messages;
233 if (s->options & SSL_OP_CISCO_ANYCONNECT)
234 s->client_version = s->version = DTLS1_BAD_VER;
235 else if (s->method->version == DTLS_ANY_VERSION)
236 s->version = DTLS1_2_VERSION;
238 s->version = s->method->version;
241 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
246 case DTLS_CTRL_GET_TIMEOUT:
247 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
251 case DTLS_CTRL_HANDLE_TIMEOUT:
252 ret = dtls1_handle_timeout(s);
254 case DTLS_CTRL_LISTEN:
255 ret = dtls1_listen(s, parg);
257 case SSL_CTRL_CHECK_PROTO_VERSION:
259 * For library-internal use; checks that the current protocol is the
260 * highest enabled version (according to s->ctx->method, as version
261 * negotiation may have changed s->method).
263 if (s->version == s->ctx->method->version)
266 * Apparently we're using a version-flexible SSL_METHOD (not at its
267 * highest protocol version).
269 if (s->ctx->method->version == DTLS_method()->version) {
270 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
271 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
273 if (!(s->options & SSL_OP_NO_DTLSv1_2))
274 return s->version == DTLS1_2_VERSION;
275 if (!(s->options & SSL_OP_NO_DTLSv1))
276 return s->version == DTLS1_VERSION;
278 return 0; /* Unexpected state; fail closed. */
279 case DTLS_CTRL_SET_LINK_MTU:
280 if (larg < (long)dtls1_link_min_mtu())
282 s->d1->link_mtu = larg;
284 case DTLS_CTRL_GET_LINK_MIN_MTU:
285 return (long)dtls1_link_min_mtu();
286 case SSL_CTRL_SET_MTU:
288 * We may not have a BIO set yet so can't call dtls1_min_mtu()
289 * We'll have to make do with dtls1_link_min_mtu() and max overhead
291 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
296 ret = ssl3_ctrl(s, cmd, larg, parg);
303 * As it's impossible to use stream ciphers in "datagram" mode, this
304 * simple filter is designed to disengage them in DTLS. Unfortunately
305 * there is no universal way to identify stream SSL_CIPHER, so we have
306 * to explicitly list their SSL_* codes. Currently RC4 is the only one
307 * available, but if new ones emerge, they will have to be added...
309 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
311 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
314 if (ciph->algorithm_enc == SSL_RC4)
321 void dtls1_start_timer(SSL *s)
323 #ifndef OPENSSL_NO_SCTP
324 /* Disable timer for SCTP */
325 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
326 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
331 /* If timer is not set, initialize duration with 1 second */
332 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
333 s->d1->timeout_duration = 1;
336 /* Set timeout to current time */
337 get_current_time(&(s->d1->next_timeout));
339 /* Add duration to current time */
340 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
341 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
342 &(s->d1->next_timeout));
345 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
347 struct timeval timenow;
349 /* If no timeout is set, just return NULL */
350 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
354 /* Get current time */
355 get_current_time(&timenow);
357 /* If timer already expired, set remaining time to 0 */
358 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
359 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
360 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
361 memset(timeleft, 0, sizeof(*timeleft));
365 /* Calculate time left until timer expires */
366 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
367 timeleft->tv_sec -= timenow.tv_sec;
368 timeleft->tv_usec -= timenow.tv_usec;
369 if (timeleft->tv_usec < 0) {
371 timeleft->tv_usec += 1000000;
375 * If remaining time is less than 15 ms, set it to 0 to prevent issues
376 * because of small devergences with socket timeouts.
378 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
379 memset(timeleft, 0, sizeof(*timeleft));
385 int dtls1_is_timer_expired(SSL *s)
387 struct timeval timeleft;
389 /* Get time left until timeout, return false if no timer running */
390 if (dtls1_get_timeout(s, &timeleft) == NULL) {
394 /* Return false if timer is not expired yet */
395 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
399 /* Timer expired, so return true */
403 void dtls1_double_timeout(SSL *s)
405 s->d1->timeout_duration *= 2;
406 if (s->d1->timeout_duration > 60)
407 s->d1->timeout_duration = 60;
408 dtls1_start_timer(s);
411 void dtls1_stop_timer(SSL *s)
413 /* Reset everything */
414 memset(&s->d1->timeout, 0, sizeof(s->d1->timeout));
415 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
416 s->d1->timeout_duration = 1;
417 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
418 &(s->d1->next_timeout));
419 /* Clear retransmission buffer */
420 dtls1_clear_record_buffer(s);
423 int dtls1_check_timeout_num(SSL *s)
427 s->d1->timeout.num_alerts++;
429 /* Reduce MTU after 2 unsuccessful retransmissions */
430 if (s->d1->timeout.num_alerts > 2
431 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
433 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
435 if (mtu < s->d1->mtu)
439 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
440 /* fail the connection, enough alerts have been sent */
441 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
448 int dtls1_handle_timeout(SSL *s)
450 /* if no timer is expired, don't do anything */
451 if (!dtls1_is_timer_expired(s)) {
455 dtls1_double_timeout(s);
457 if (dtls1_check_timeout_num(s) < 0)
460 s->d1->timeout.read_timeouts++;
461 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
462 s->d1->timeout.read_timeouts = 1;
464 #ifndef OPENSSL_NO_HEARTBEATS
465 if (s->tlsext_hb_pending) {
466 s->tlsext_hb_pending = 0;
467 return dtls1_heartbeat(s);
471 dtls1_start_timer(s);
472 return dtls1_retransmit_buffered_messages(s);
475 static void get_current_time(struct timeval *t)
485 SystemTimeToFileTime(&st, &now.ft);
487 now.ul -= 116444736000000000ULL;
489 now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
491 t->tv_sec = (long)(now.ul / 10000000);
492 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
493 #elif defined(OPENSSL_SYS_VMS)
496 t->tv_sec = (long)tb.time;
497 t->tv_usec = (long)tb.millitm * 1000;
499 gettimeofday(t, NULL);
503 int dtls1_listen(SSL *s, struct sockaddr *client)
507 /* Ensure there is no state left over from a previous invocation */
511 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
518 (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
522 static int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
524 unsigned char *p = (unsigned char *)s->init_buf->data;
525 dtls1_set_message_header(s, p, htype, len, 0, len);
526 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
528 /* Buffer the message to handle re-xmits */
530 if (!dtls1_buffer_message(s, 0))
536 static int dtls1_handshake_write(SSL *s)
538 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);