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 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|SSL_ENC_FLAG_SHA256_PRF,
108 DTLS1_HM_HEADER_LENGTH,
109 dtls1_set_handshake_header,
110 dtls1_handshake_write
113 long dtls1_default_timeout(void)
115 /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
116 * is way too long for http, the cache would over fill */
120 int dtls1_new(SSL *s)
124 if (!ssl3_new(s)) return(0);
125 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
126 memset(d1,0, sizeof *d1);
128 /* d1->handshake_epoch=0; */
130 d1->unprocessed_rcds.q=pqueue_new();
131 d1->processed_rcds.q=pqueue_new();
132 d1->buffered_messages = pqueue_new();
133 d1->sent_messages=pqueue_new();
134 d1->buffered_app_data.q=pqueue_new();
138 d1->cookie_len = sizeof(s->d1->cookie);
141 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
142 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
144 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
145 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
146 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
147 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
148 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
154 s->method->ssl_clear(s);
158 static void dtls1_clear_queues(SSL *s)
161 hm_fragment *frag = NULL;
162 DTLS1_RECORD_DATA *rdata;
164 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
166 rdata = (DTLS1_RECORD_DATA *) item->data;
169 OPENSSL_free(rdata->rbuf.buf);
171 OPENSSL_free(item->data);
175 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
177 rdata = (DTLS1_RECORD_DATA *) item->data;
180 OPENSSL_free(rdata->rbuf.buf);
182 OPENSSL_free(item->data);
186 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
188 frag = (hm_fragment *)item->data;
189 OPENSSL_free(frag->fragment);
194 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
196 frag = (hm_fragment *)item->data;
197 OPENSSL_free(frag->fragment);
202 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
204 frag = (hm_fragment *)item->data;
205 OPENSSL_free(frag->fragment);
211 void dtls1_free(SSL *s)
215 dtls1_clear_queues(s);
217 pqueue_free(s->d1->unprocessed_rcds.q);
218 pqueue_free(s->d1->processed_rcds.q);
219 pqueue_free(s->d1->buffered_messages);
220 pqueue_free(s->d1->sent_messages);
221 pqueue_free(s->d1->buffered_app_data.q);
227 void dtls1_clear(SSL *s)
229 pqueue unprocessed_rcds;
230 pqueue processed_rcds;
231 pqueue buffered_messages;
232 pqueue sent_messages;
233 pqueue buffered_app_data;
238 unprocessed_rcds = s->d1->unprocessed_rcds.q;
239 processed_rcds = s->d1->processed_rcds.q;
240 buffered_messages = s->d1->buffered_messages;
241 sent_messages = s->d1->sent_messages;
242 buffered_app_data = s->d1->buffered_app_data.q;
245 dtls1_clear_queues(s);
247 memset(s->d1, 0, sizeof(*(s->d1)));
251 s->d1->cookie_len = sizeof(s->d1->cookie);
254 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
259 s->d1->unprocessed_rcds.q = unprocessed_rcds;
260 s->d1->processed_rcds.q = processed_rcds;
261 s->d1->buffered_messages = buffered_messages;
262 s->d1->sent_messages = sent_messages;
263 s->d1->buffered_app_data.q = buffered_app_data;
267 if (s->options & SSL_OP_CISCO_ANYCONNECT)
268 s->version=DTLS1_BAD_VER;
270 s->version=s->method->version;
273 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
279 case DTLS_CTRL_GET_TIMEOUT:
280 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
285 case DTLS_CTRL_HANDLE_TIMEOUT:
286 ret = dtls1_handle_timeout(s);
288 case DTLS_CTRL_LISTEN:
289 ret = dtls1_listen(s, parg);
293 ret = ssl3_ctrl(s, cmd, larg, parg);
300 * As it's impossible to use stream ciphers in "datagram" mode, this
301 * simple filter is designed to disengage them in DTLS. Unfortunately
302 * there is no universal way to identify stream SSL_CIPHER, so we have
303 * to explicitly list their SSL_* codes. Currently RC4 is the only one
304 * available, but if new ones emerge, they will have to be added...
306 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
308 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
312 if (ciph->algorithm_enc == SSL_RC4)
319 void dtls1_start_timer(SSL *s)
321 #ifndef OPENSSL_NO_SCTP
322 /* Disable timer for SCTP */
323 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
325 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
330 /* If timer is not set, initialize duration with 1 second */
331 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, &(s->d1->next_timeout));
344 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
346 struct timeval timenow;
348 /* If no timeout is set, just return NULL */
349 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))
362 memset(timeleft, 0, sizeof(struct timeval));
366 /* Calculate time left until timer expires */
367 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
368 timeleft->tv_sec -= timenow.tv_sec;
369 timeleft->tv_usec -= timenow.tv_usec;
370 if (timeleft->tv_usec < 0)
373 timeleft->tv_usec += 1000000;
376 /* If remaining time is less than 15 ms, set it to 0
377 * to prevent issues because of small devergences with
380 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
382 memset(timeleft, 0, sizeof(struct timeval));
389 int dtls1_is_timer_expired(SSL *s)
391 struct timeval timeleft;
393 /* Get time left until timeout, return false if no timer running */
394 if (dtls1_get_timeout(s, &timeleft) == NULL)
399 /* Return false if timer is not expired yet */
400 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
405 /* Timer expired, so return true */
409 void dtls1_double_timeout(SSL *s)
411 s->d1->timeout_duration *= 2;
412 if (s->d1->timeout_duration > 60)
413 s->d1->timeout_duration = 60;
414 dtls1_start_timer(s);
417 void dtls1_stop_timer(SSL *s)
419 /* Reset everything */
420 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
421 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
422 s->d1->timeout_duration = 1;
423 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
424 /* Clear retransmission buffer */
425 dtls1_clear_record_buffer(s);
428 int dtls1_check_timeout_num(SSL *s)
430 s->d1->timeout.num_alerts++;
432 /* Reduce MTU after 2 unsuccessful retransmissions */
433 if (s->d1->timeout.num_alerts > 2)
435 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
438 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))
456 dtls1_double_timeout(s);
458 if (dtls1_check_timeout_num(s) < 0)
461 s->d1->timeout.read_timeouts++;
462 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
464 s->d1->timeout.read_timeouts = 1;
467 #ifndef OPENSSL_NO_HEARTBEATS
468 if (s->tlsext_hb_pending)
470 s->tlsext_hb_pending = 0;
471 return dtls1_heartbeat(s);
475 dtls1_start_timer(s);
476 return dtls1_retransmit_buffered_messages(s);
479 static void get_current_time(struct timeval *t)
481 #ifdef OPENSSL_SYS_WIN32
484 t->tv_sec = (long)tb.time;
485 t->tv_usec = (long)tb.millitm * 1000;
486 #elif defined(OPENSSL_SYS_VMS)
489 t->tv_sec = (long)tb.time;
490 t->tv_usec = (long)tb.millitm * 1000;
492 gettimeofday(t, NULL);
496 int dtls1_listen(SSL *s, struct sockaddr *client)
500 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
504 if (ret <= 0) return ret;
506 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
510 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
512 unsigned char *p = (unsigned char *)s->init_buf->data;
513 dtls1_set_message_header(s, p, htype, len, 0, len);
514 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
516 /* Buffer the message to handle re-xmits */
517 dtls1_buffer_message(s, 0);
520 static int dtls1_handshake_write(SSL *s)
522 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);