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_WIN32) || defined(OPENSSL_SYS_VMS)
66 #include <sys/timeb.h>
69 static void get_current_time(struct timeval *t);
70 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
71 int dtls1_listen(SSL *s, struct sockaddr *client);
73 SSL3_ENC_METHOD DTLSv1_enc_data={
77 tls1_generate_master_secret,
78 tls1_change_cipher_state,
79 tls1_final_finish_mac,
80 TLS1_FINISH_MAC_LENGTH,
82 TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
83 TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
87 long dtls1_default_timeout(void)
89 /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
90 * is way too long for http, the cache would over fill */
94 IMPLEMENT_dtls1_meth_func(dtlsv1_base_method,
95 ssl_undefined_function,
96 ssl_undefined_function,
103 if (!ssl3_new(s)) return(0);
104 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
105 memset(d1,0, sizeof *d1);
107 /* d1->handshake_epoch=0; */
108 #if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
109 d1->bitmap.length=64;
111 d1->bitmap.length=sizeof(d1->bitmap.map) * 8;
113 pq_64bit_init(&(d1->bitmap.map));
114 pq_64bit_init(&(d1->bitmap.max_seq_num));
116 d1->next_bitmap.length = d1->bitmap.length;
117 pq_64bit_init(&(d1->next_bitmap.map));
118 pq_64bit_init(&(d1->next_bitmap.max_seq_num));
120 d1->unprocessed_rcds.q=pqueue_new();
121 d1->processed_rcds.q=pqueue_new();
122 d1->buffered_messages = pqueue_new();
123 d1->sent_messages=pqueue_new();
124 d1->buffered_app_data.q=pqueue_new();
128 d1->cookie_len = sizeof(s->d1->cookie);
131 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
132 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
134 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
135 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
136 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
137 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
138 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
144 s->method->ssl_clear(s);
148 static void dtls1_clear_queues(SSL *s)
151 hm_fragment *frag = NULL;
152 DTLS1_RECORD_DATA *rdata;
154 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
156 rdata = (DTLS1_RECORD_DATA *) item->data;
159 OPENSSL_free(rdata->rbuf.buf);
161 OPENSSL_free(item->data);
165 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
167 rdata = (DTLS1_RECORD_DATA *) item->data;
170 OPENSSL_free(rdata->rbuf.buf);
172 OPENSSL_free(item->data);
176 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
178 frag = (hm_fragment *)item->data;
179 OPENSSL_free(frag->fragment);
184 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
186 frag = (hm_fragment *)item->data;
187 OPENSSL_free(frag->fragment);
192 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
194 rdata = (DTLS1_RECORD_DATA *) item->data;
197 OPENSSL_free(rdata->rbuf.buf);
199 OPENSSL_free(item->data);
204 void dtls1_free(SSL *s)
208 dtls1_clear_queues(s);
210 pqueue_free(s->d1->unprocessed_rcds.q);
211 pqueue_free(s->d1->processed_rcds.q);
212 pqueue_free(s->d1->buffered_messages);
213 pqueue_free(s->d1->sent_messages);
214 pqueue_free(s->d1->buffered_app_data.q);
216 pq_64bit_free(&(s->d1->bitmap.map));
217 pq_64bit_free(&(s->d1->bitmap.max_seq_num));
219 pq_64bit_free(&(s->d1->next_bitmap.map));
220 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
226 void dtls1_clear(SSL *s)
228 pqueue unprocessed_rcds;
229 pqueue processed_rcds;
230 pqueue buffered_messages;
231 pqueue sent_messages;
232 pqueue buffered_app_data;
237 unprocessed_rcds = s->d1->unprocessed_rcds.q;
238 processed_rcds = s->d1->processed_rcds.q;
239 buffered_messages = s->d1->buffered_messages;
240 sent_messages = s->d1->sent_messages;
241 buffered_app_data = s->d1->buffered_app_data.q;
244 dtls1_clear_queues(s);
246 pq_64bit_free(&(s->d1->bitmap.map));
247 pq_64bit_free(&(s->d1->bitmap.max_seq_num));
249 pq_64bit_free(&(s->d1->next_bitmap.map));
250 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
252 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)
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;
270 #if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
271 s->d1->bitmap.length=64;
273 s->d1->bitmap.length=sizeof(s->d1->bitmap.map) * 8;
275 pq_64bit_init(&(s->d1->bitmap.map));
276 pq_64bit_init(&(s->d1->bitmap.max_seq_num));
278 s->d1->next_bitmap.length = s->d1->bitmap.length;
279 pq_64bit_init(&(s->d1->next_bitmap.map));
280 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
284 if (s->options & SSL_OP_CISCO_ANYCONNECT)
285 s->version=DTLS1_BAD_VER;
287 s->version=DTLS1_VERSION;
290 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
296 case DTLS_CTRL_GET_TIMEOUT:
297 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
302 case DTLS_CTRL_HANDLE_TIMEOUT:
303 ret = dtls1_handle_timeout(s);
305 case DTLS_CTRL_LISTEN:
306 ret = dtls1_listen(s, parg);
308 case SSL_CTRL_CHECK_PROTO_VERSION:
309 /* For library-internal use; checks that the current protocol
310 * is the highest enabled version (according to s->ctx->method,
311 * as version negotiation may have changed s->method). */
312 #if DTLS_MAX_VERSION != DTLS1_VERSION
313 # error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
315 /* Just one protocol version is supported so far;
316 * fail closed if the version is not as expected. */
317 return s->version == DTLS_MAX_VERSION;
320 ret = ssl3_ctrl(s, cmd, larg, parg);
327 * As it's impossible to use stream ciphers in "datagram" mode, this
328 * simple filter is designed to disengage them in DTLS. Unfortunately
329 * there is no universal way to identify stream SSL_CIPHER, so we have
330 * to explicitly list their SSL_* codes. Currently RC4 is the only one
331 * available, but if new ones emerge, they will have to be added...
333 SSL_CIPHER *dtls1_get_cipher(unsigned int u)
335 SSL_CIPHER *ciph = ssl3_get_cipher(u);
339 if ((ciph->algorithms&SSL_ENC_MASK) == SSL_RC4)
346 void dtls1_start_timer(SSL *s)
348 /* If timer is not set, initialize duration with 1 second */
349 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
351 s->d1->timeout_duration = 1;
354 /* Set timeout to current time */
355 get_current_time(&(s->d1->next_timeout));
357 /* Add duration to current time */
358 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
359 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
362 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
364 struct timeval timenow;
366 /* If no timeout is set, just return NULL */
367 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
372 /* Get current time */
373 get_current_time(&timenow);
375 /* If timer already expired, set remaining time to 0 */
376 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
377 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
378 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
380 memset(timeleft, 0, sizeof(struct timeval));
384 /* Calculate time left until timer expires */
385 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
386 timeleft->tv_sec -= timenow.tv_sec;
387 timeleft->tv_usec -= timenow.tv_usec;
388 if (timeleft->tv_usec < 0)
391 timeleft->tv_usec += 1000000;
394 /* If remaining time is less than 15 ms, set it to 0
395 * to prevent issues because of small devergences with
398 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
400 memset(timeleft, 0, sizeof(struct timeval));
407 int dtls1_is_timer_expired(SSL *s)
409 struct timeval timeleft;
411 /* Get time left until timeout, return false if no timer running */
412 if (dtls1_get_timeout(s, &timeleft) == NULL)
417 /* Return false if timer is not expired yet */
418 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
423 /* Timer expired, so return true */
427 void dtls1_double_timeout(SSL *s)
429 s->d1->timeout_duration *= 2;
430 if (s->d1->timeout_duration > 60)
431 s->d1->timeout_duration = 60;
432 dtls1_start_timer(s);
435 void dtls1_stop_timer(SSL *s)
437 /* Reset everything */
438 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
439 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
440 s->d1->timeout_duration = 1;
441 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
442 /* Clear retransmission buffer */
443 dtls1_clear_record_buffer(s);
446 int dtls1_check_timeout_num(SSL *s)
448 s->d1->timeout.num_alerts++;
450 /* Reduce MTU after 2 unsuccessful retransmissions */
451 if (s->d1->timeout.num_alerts > 2)
453 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
456 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
458 /* fail the connection, enough alerts have been sent */
459 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
466 int dtls1_handle_timeout(SSL *s)
468 /* if no timer is expired, don't do anything */
469 if (!dtls1_is_timer_expired(s))
474 dtls1_double_timeout(s);
476 if (dtls1_check_timeout_num(s) < 0)
479 s->d1->timeout.read_timeouts++;
480 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
482 s->d1->timeout.read_timeouts = 1;
485 dtls1_start_timer(s);
486 return dtls1_retransmit_buffered_messages(s);
489 static void get_current_time(struct timeval *t)
491 #ifdef OPENSSL_SYS_WIN32
494 t->tv_sec = (long)tb.time;
495 t->tv_usec = (long)tb.millitm * 1000;
496 #elif defined(OPENSSL_SYS_VMS)
499 t->tv_sec = (long)tb.time;
500 t->tv_usec = (long)tb.millitm * 1000;
502 gettimeofday(t, NULL);
506 int dtls1_listen(SSL *s, struct sockaddr *client)
510 /* Ensure there is no state left over from a previous invocation */
513 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
517 if (ret <= 0) return ret;
519 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);