xref: /freebsd/crypto/openssl/ssl/d1_lib.c (revision b1f9167f94059fd55c630891d359bcff987bd7eb) 
1 /* ssl/d1_lib.c */
2 /*
3  * DTLS implementation written by Nagendra Modadugu
4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5  */
6 /* ====================================================================
7  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  *
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
19  *    distribution.
20  *
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/)"
25  *
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.
30  *
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.
34  *
35  * 6. Redistributions of any form whatsoever must retain the following
36  *    acknowledgment:
37  *    "This product includes software developed by the OpenSSL Project
38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39  *
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  * ====================================================================
53  *
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).
57  *
58  */
59 
60 #include <stdio.h>
61 #define USE_SOCKETS
62 #include <openssl/objects.h>
63 #include "ssl_locl.h"
64 
65 #if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS)
66 #include <sys/timeb.h>
67 #endif
68 
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);
72 
73 SSL3_ENC_METHOD DTLSv1_enc_data={
74     dtls1_enc,
75 	tls1_mac,
76 	tls1_setup_key_block,
77 	tls1_generate_master_secret,
78 	tls1_change_cipher_state,
79 	tls1_final_finish_mac,
80 	TLS1_FINISH_MAC_LENGTH,
81 	tls1_cert_verify_mac,
82 	TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
83 	TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
84 	tls1_alert_code,
85 	tls1_export_keying_material,
86 	};
87 
88 long dtls1_default_timeout(void)
89 	{
90 	/* 2 hours, the 24 hours mentioned in the DTLSv1 spec
91 	 * is way too long for http, the cache would over fill */
92 	return(60*60*2);
93 	}
94 
95 int dtls1_new(SSL *s)
96 	{
97 	DTLS1_STATE *d1;
98 
99 	if (!ssl3_new(s)) return(0);
100 	if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
101 	memset(d1,0, sizeof *d1);
102 
103 	/* d1->handshake_epoch=0; */
104 
105 	d1->unprocessed_rcds.q=pqueue_new();
106 	d1->processed_rcds.q=pqueue_new();
107 	d1->buffered_messages = pqueue_new();
108 	d1->sent_messages=pqueue_new();
109 	d1->buffered_app_data.q=pqueue_new();
110 
111 	if ( s->server)
112 		{
113 		d1->cookie_len = sizeof(s->d1->cookie);
114 		}
115 
116 	if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
117         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
118 		{
119         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
120         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
121         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
122 		if ( d1->sent_messages) pqueue_free(d1->sent_messages);
123 		if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
124 		OPENSSL_free(d1);
125 		return (0);
126 		}
127 
128 	s->d1=d1;
129 	s->method->ssl_clear(s);
130 	return(1);
131 	}
132 
133 static void dtls1_clear_queues(SSL *s)
134 	{
135     pitem *item = NULL;
136     hm_fragment *frag = NULL;
137 	DTLS1_RECORD_DATA *rdata;
138 
139     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
140         {
141 		rdata = (DTLS1_RECORD_DATA *) item->data;
142 		if (rdata->rbuf.buf)
143 			{
144 			OPENSSL_free(rdata->rbuf.buf);
145 			}
146         OPENSSL_free(item->data);
147         pitem_free(item);
148         }
149 
150     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
151         {
152 		rdata = (DTLS1_RECORD_DATA *) item->data;
153 		if (rdata->rbuf.buf)
154 			{
155 			OPENSSL_free(rdata->rbuf.buf);
156 			}
157         OPENSSL_free(item->data);
158         pitem_free(item);
159         }
160 
161     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
162         {
163         frag = (hm_fragment *)item->data;
164         OPENSSL_free(frag->fragment);
165         OPENSSL_free(frag);
166         pitem_free(item);
167         }
168 
169     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
170         {
171         frag = (hm_fragment *)item->data;
172         OPENSSL_free(frag->fragment);
173         OPENSSL_free(frag);
174         pitem_free(item);
175         }
176 
177 	while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
178 		{
179 		rdata = (DTLS1_RECORD_DATA *) item->data;
180 		if (rdata->rbuf.buf)
181 			{
182 			OPENSSL_free(rdata->rbuf.buf);
183 			}
184 		OPENSSL_free(item->data);
185 		pitem_free(item);
186 		}
187 	}
188 
189 void dtls1_free(SSL *s)
190 	{
191 	ssl3_free(s);
192 
193 	dtls1_clear_queues(s);
194 
195     pqueue_free(s->d1->unprocessed_rcds.q);
196     pqueue_free(s->d1->processed_rcds.q);
197     pqueue_free(s->d1->buffered_messages);
198 	pqueue_free(s->d1->sent_messages);
199 	pqueue_free(s->d1->buffered_app_data.q);
200 
201 	OPENSSL_free(s->d1);
202 	s->d1 = NULL;
203 	}
204 
205 void dtls1_clear(SSL *s)
206 	{
207     pqueue unprocessed_rcds;
208     pqueue processed_rcds;
209     pqueue buffered_messages;
210 	pqueue sent_messages;
211 	pqueue buffered_app_data;
212 	unsigned int mtu;
213 
214 	if (s->d1)
215 		{
216 		unprocessed_rcds = s->d1->unprocessed_rcds.q;
217 		processed_rcds = s->d1->processed_rcds.q;
218 		buffered_messages = s->d1->buffered_messages;
219 		sent_messages = s->d1->sent_messages;
220 		buffered_app_data = s->d1->buffered_app_data.q;
221 		mtu = s->d1->mtu;
222 
223 		dtls1_clear_queues(s);
224 
225 		memset(s->d1, 0, sizeof(*(s->d1)));
226 
227 		if (s->server)
228 			{
229 			s->d1->cookie_len = sizeof(s->d1->cookie);
230 			}
231 
232 		if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
233 			{
234 			s->d1->mtu = mtu;
235 			}
236 
237 		s->d1->unprocessed_rcds.q = unprocessed_rcds;
238 		s->d1->processed_rcds.q = processed_rcds;
239 		s->d1->buffered_messages = buffered_messages;
240 		s->d1->sent_messages = sent_messages;
241 		s->d1->buffered_app_data.q = buffered_app_data;
242 		}
243 
244 	ssl3_clear(s);
245 	if (s->options & SSL_OP_CISCO_ANYCONNECT)
246 		s->version=DTLS1_BAD_VER;
247 	else
248 		s->version=DTLS1_VERSION;
249 	}
250 
251 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
252 	{
253 	int ret=0;
254 
255 	switch (cmd)
256 		{
257 	case DTLS_CTRL_GET_TIMEOUT:
258 		if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
259 			{
260 			ret = 1;
261 			}
262 		break;
263 	case DTLS_CTRL_HANDLE_TIMEOUT:
264 		ret = dtls1_handle_timeout(s);
265 		break;
266 	case DTLS_CTRL_LISTEN:
267 		ret = dtls1_listen(s, parg);
268 		break;
269 
270 	default:
271 		ret = ssl3_ctrl(s, cmd, larg, parg);
272 		break;
273 		}
274 	return(ret);
275 	}
276 
277 /*
278  * As it's impossible to use stream ciphers in "datagram" mode, this
279  * simple filter is designed to disengage them in DTLS. Unfortunately
280  * there is no universal way to identify stream SSL_CIPHER, so we have
281  * to explicitly list their SSL_* codes. Currently RC4 is the only one
282  * available, but if new ones emerge, they will have to be added...
283  */
284 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
285 	{
286 	const SSL_CIPHER *ciph = ssl3_get_cipher(u);
287 
288 	if (ciph != NULL)
289 		{
290 		if (ciph->algorithm_enc == SSL_RC4)
291 			return NULL;
292 		}
293 
294 	return ciph;
295 	}
296 
297 void dtls1_start_timer(SSL *s)
298 	{
299 #ifndef OPENSSL_NO_SCTP
300 	/* Disable timer for SCTP */
301 	if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
302 		{
303 		memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
304 		return;
305 		}
306 #endif
307 
308 	/* If timer is not set, initialize duration with 1 second */
309 	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
310 		{
311 		s->d1->timeout_duration = 1;
312 		}
313 
314 	/* Set timeout to current time */
315 	get_current_time(&(s->d1->next_timeout));
316 
317 	/* Add duration to current time */
318 	s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
319 	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
320 	}
321 
322 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
323 	{
324 	struct timeval timenow;
325 
326 	/* If no timeout is set, just return NULL */
327 	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
328 		{
329 		return NULL;
330 		}
331 
332 	/* Get current time */
333 	get_current_time(&timenow);
334 
335 	/* If timer already expired, set remaining time to 0 */
336 	if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
337 		(s->d1->next_timeout.tv_sec == timenow.tv_sec &&
338 		 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
339 		{
340 		memset(timeleft, 0, sizeof(struct timeval));
341 		return timeleft;
342 		}
343 
344 	/* Calculate time left until timer expires */
345 	memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
346 	timeleft->tv_sec -= timenow.tv_sec;
347 	timeleft->tv_usec -= timenow.tv_usec;
348 	if (timeleft->tv_usec < 0)
349 		{
350 		timeleft->tv_sec--;
351 		timeleft->tv_usec += 1000000;
352 		}
353 
354 	/* If remaining time is less than 15 ms, set it to 0
355 	 * to prevent issues because of small devergences with
356 	 * socket timeouts.
357 	 */
358 	if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
359 		{
360 		memset(timeleft, 0, sizeof(struct timeval));
361 		}
362 
363 
364 	return timeleft;
365 	}
366 
367 int dtls1_is_timer_expired(SSL *s)
368 	{
369 	struct timeval timeleft;
370 
371 	/* Get time left until timeout, return false if no timer running */
372 	if (dtls1_get_timeout(s, &timeleft) == NULL)
373 		{
374 		return 0;
375 		}
376 
377 	/* Return false if timer is not expired yet */
378 	if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
379 		{
380 		return 0;
381 		}
382 
383 	/* Timer expired, so return true */
384 	return 1;
385 	}
386 
387 void dtls1_double_timeout(SSL *s)
388 	{
389 	s->d1->timeout_duration *= 2;
390 	if (s->d1->timeout_duration > 60)
391 		s->d1->timeout_duration = 60;
392 	dtls1_start_timer(s);
393 	}
394 
395 void dtls1_stop_timer(SSL *s)
396 	{
397 	/* Reset everything */
398 	memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
399 	memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
400 	s->d1->timeout_duration = 1;
401 	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
402 	/* Clear retransmission buffer */
403 	dtls1_clear_record_buffer(s);
404 	}
405 
406 int dtls1_check_timeout_num(SSL *s)
407 	{
408 	s->d1->timeout.num_alerts++;
409 
410 	/* Reduce MTU after 2 unsuccessful retransmissions */
411 	if (s->d1->timeout.num_alerts > 2)
412 		{
413 		s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
414 		}
415 
416 	if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
417 		{
418 		/* fail the connection, enough alerts have been sent */
419 		SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
420 		return -1;
421 		}
422 
423 	return 0;
424 	}
425 
426 int dtls1_handle_timeout(SSL *s)
427 	{
428 	/* if no timer is expired, don't do anything */
429 	if (!dtls1_is_timer_expired(s))
430 		{
431 		return 0;
432 		}
433 
434 	dtls1_double_timeout(s);
435 
436 	if (dtls1_check_timeout_num(s) < 0)
437 		return -1;
438 
439 	s->d1->timeout.read_timeouts++;
440 	if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
441 		{
442 		s->d1->timeout.read_timeouts = 1;
443 		}
444 
445 #ifndef OPENSSL_NO_HEARTBEATS
446 	if (s->tlsext_hb_pending)
447 		{
448 		s->tlsext_hb_pending = 0;
449 		return dtls1_heartbeat(s);
450 		}
451 #endif
452 
453 	dtls1_start_timer(s);
454 	return dtls1_retransmit_buffered_messages(s);
455 	}
456 
457 static void get_current_time(struct timeval *t)
458 {
459 #ifdef OPENSSL_SYS_WIN32
460 	struct _timeb tb;
461 	_ftime(&tb);
462 	t->tv_sec = (long)tb.time;
463 	t->tv_usec = (long)tb.millitm * 1000;
464 #elif defined(OPENSSL_SYS_VMS)
465 	struct timeb tb;
466 	ftime(&tb);
467 	t->tv_sec = (long)tb.time;
468 	t->tv_usec = (long)tb.millitm * 1000;
469 #else
470 	gettimeofday(t, NULL);
471 #endif
472 }
473 
474 int dtls1_listen(SSL *s, struct sockaddr *client)
475 	{
476 	int ret;
477 
478 	SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
479 	s->d1->listen = 1;
480 
481 	ret = SSL_accept(s);
482 	if (ret <= 0) return ret;
483 
484 	(void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
485 	return 1;
486 	}
487