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)
116 /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
117 * is way too long for http, the cache would over fill */
121 int dtls1_new(SSL *s)
125 if (!ssl3_new(s)) return(0);
126 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
127 memset(d1,0, sizeof *d1);
129 /* d1->handshake_epoch=0; */
131 d1->unprocessed_rcds.q=pqueue_new();
132 d1->processed_rcds.q=pqueue_new();
133 d1->buffered_messages = pqueue_new();
134 d1->sent_messages=pqueue_new();
135 d1->buffered_app_data.q=pqueue_new();
139 d1->cookie_len = sizeof(s->d1->cookie);
145 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
146 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
148 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
149 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
150 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
151 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
152 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
158 s->method->ssl_clear(s);
162 static void dtls1_clear_queues(SSL *s)
165 hm_fragment *frag = NULL;
166 DTLS1_RECORD_DATA *rdata;
168 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
170 rdata = (DTLS1_RECORD_DATA *) item->data;
173 OPENSSL_free(rdata->rbuf.buf);
175 OPENSSL_free(item->data);
179 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
181 rdata = (DTLS1_RECORD_DATA *) item->data;
184 OPENSSL_free(rdata->rbuf.buf);
186 OPENSSL_free(item->data);
190 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
192 frag = (hm_fragment *)item->data;
193 dtls1_hm_fragment_free(frag);
197 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
199 frag = (hm_fragment *)item->data;
200 dtls1_hm_fragment_free(frag);
204 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
206 rdata = (DTLS1_RECORD_DATA *) item->data;
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;
244 unprocessed_rcds = s->d1->unprocessed_rcds.q;
245 processed_rcds = s->d1->processed_rcds.q;
246 buffered_messages = s->d1->buffered_messages;
247 sent_messages = s->d1->sent_messages;
248 buffered_app_data = s->d1->buffered_app_data.q;
250 link_mtu = s->d1->link_mtu;
252 dtls1_clear_queues(s);
254 memset(s->d1, 0, sizeof(*(s->d1)));
258 s->d1->cookie_len = sizeof(s->d1->cookie);
261 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
264 s->d1->link_mtu = link_mtu;
267 s->d1->unprocessed_rcds.q = unprocessed_rcds;
268 s->d1->processed_rcds.q = processed_rcds;
269 s->d1->buffered_messages = buffered_messages;
270 s->d1->sent_messages = sent_messages;
271 s->d1->buffered_app_data.q = buffered_app_data;
275 if (s->options & SSL_OP_CISCO_ANYCONNECT)
276 s->version=DTLS1_BAD_VER;
277 else if (s->method->version == DTLS_ANY_VERSION)
278 s->version=DTLS1_2_VERSION;
280 s->version=s->method->version;
283 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
289 case DTLS_CTRL_GET_TIMEOUT:
290 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
295 case DTLS_CTRL_HANDLE_TIMEOUT:
296 ret = dtls1_handle_timeout(s);
298 case DTLS_CTRL_LISTEN:
299 ret = dtls1_listen(s, parg);
301 case SSL_CTRL_CHECK_PROTO_VERSION:
302 /* For library-internal use; checks that the current protocol
303 * is the highest enabled version (according to s->ctx->method,
304 * as version negotiation may have changed s->method). */
305 if (s->version == s->ctx->method->version)
307 /* Apparently we're using a version-flexible SSL_METHOD
308 * (not at its highest protocol version). */
309 if (s->ctx->method->version == DTLS_method()->version)
311 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
312 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
314 if (!(s->options & SSL_OP_NO_DTLSv1_2))
315 return s->version == DTLS1_2_VERSION;
316 if (!(s->options & SSL_OP_NO_DTLSv1))
317 return s->version == DTLS1_VERSION;
319 return 0; /* Unexpected state; fail closed. */
321 /* Just one protocol version is supported so far;
322 * fail closed if the version is not as expected. */
323 return s->version == DTLS_MAX_VERSION;
324 case DTLS_CTRL_SET_LINK_MTU:
325 if (larg < (long)dtls1_link_min_mtu())
327 s->d1->link_mtu = larg;
329 case DTLS_CTRL_GET_LINK_MIN_MTU:
330 return (long)dtls1_link_min_mtu();
331 case SSL_CTRL_SET_MTU:
333 * We may not have a BIO set yet so can't call dtls1_min_mtu()
334 * We'll have to make do with dtls1_link_min_mtu() and max overhead
336 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
341 ret = ssl3_ctrl(s, cmd, larg, parg);
348 * As it's impossible to use stream ciphers in "datagram" mode, this
349 * simple filter is designed to disengage them in DTLS. Unfortunately
350 * there is no universal way to identify stream SSL_CIPHER, so we have
351 * to explicitly list their SSL_* codes. Currently RC4 is the only one
352 * available, but if new ones emerge, they will have to be added...
354 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
356 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
360 if (ciph->algorithm_enc == SSL_RC4)
367 void dtls1_start_timer(SSL *s)
369 #ifndef OPENSSL_NO_SCTP
370 /* Disable timer for SCTP */
371 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
373 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
378 /* If timer is not set, initialize duration with 1 second */
379 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
381 s->d1->timeout_duration = 1;
384 /* Set timeout to current time */
385 get_current_time(&(s->d1->next_timeout));
387 /* Add duration to current time */
388 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
389 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
392 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
394 struct timeval timenow;
396 /* If no timeout is set, just return NULL */
397 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
402 /* Get current time */
403 get_current_time(&timenow);
405 /* If timer already expired, set remaining time to 0 */
406 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
407 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
408 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
410 memset(timeleft, 0, sizeof(struct timeval));
414 /* Calculate time left until timer expires */
415 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
416 timeleft->tv_sec -= timenow.tv_sec;
417 timeleft->tv_usec -= timenow.tv_usec;
418 if (timeleft->tv_usec < 0)
421 timeleft->tv_usec += 1000000;
424 /* If remaining time is less than 15 ms, set it to 0
425 * to prevent issues because of small devergences with
428 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
430 memset(timeleft, 0, sizeof(struct timeval));
437 int dtls1_is_timer_expired(SSL *s)
439 struct timeval timeleft;
441 /* Get time left until timeout, return false if no timer running */
442 if (dtls1_get_timeout(s, &timeleft) == NULL)
447 /* Return false if timer is not expired yet */
448 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, &(s->d1->next_timeout));
472 /* Clear retransmission buffer */
473 dtls1_clear_record_buffer(s);
476 int dtls1_check_timeout_num(SSL *s)
480 s->d1->timeout.num_alerts++;
482 /* Reduce MTU after 2 unsuccessful retransmissions */
483 if (s->d1->timeout.num_alerts > 2
484 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
486 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
491 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
493 /* fail the connection, enough alerts have been sent */
494 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
501 int dtls1_handle_timeout(SSL *s)
503 /* if no timer is expired, don't do anything */
504 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)
517 s->d1->timeout.read_timeouts = 1;
520 #ifndef OPENSSL_NO_HEARTBEATS
521 if (s->tlsext_hb_pending)
523 s->tlsext_hb_pending = 0;
524 return dtls1_heartbeat(s);
528 dtls1_start_timer(s);
529 return dtls1_retransmit_buffered_messages(s);
532 static void get_current_time(struct timeval *t)
536 union { unsigned __int64 ul; FILETIME ft; } now;
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 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
565 if (ret <= 0) return ret;
567 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
571 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
573 unsigned char *p = (unsigned char *)s->init_buf->data;
574 dtls1_set_message_header(s, p, htype, len, 0, len);
575 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
577 /* Buffer the message to handle re-xmits */
578 dtls1_buffer_message(s, 0);
581 static int dtls1_handshake_write(SSL *s)
583 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);