xref: /freebsd/crypto/openssl/ssl/d1_lib.c (revision e982e5c5610e41b669d89ce488d65e68f311159d) 
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 	d1->link_mtu = 0;
117 	d1->mtu = 0;
118 
119 	if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
120         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
121 		{
122         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
123         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
124         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
125 		if ( d1->sent_messages) pqueue_free(d1->sent_messages);
126 		if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
127 		OPENSSL_free(d1);
128 		return (0);
129 		}
130 
131 	s->d1=d1;
132 	s->method->ssl_clear(s);
133 	return(1);
134 	}
135 
136 static void dtls1_clear_queues(SSL *s)
137 	{
138     pitem *item = NULL;
139     hm_fragment *frag = NULL;
140 	DTLS1_RECORD_DATA *rdata;
141 
142     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
143         {
144 		rdata = (DTLS1_RECORD_DATA *) item->data;
145 		if (rdata->rbuf.buf)
146 			{
147 			OPENSSL_free(rdata->rbuf.buf);
148 			}
149         OPENSSL_free(item->data);
150         pitem_free(item);
151         }
152 
153     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
154         {
155 		rdata = (DTLS1_RECORD_DATA *) item->data;
156 		if (rdata->rbuf.buf)
157 			{
158 			OPENSSL_free(rdata->rbuf.buf);
159 			}
160         OPENSSL_free(item->data);
161         pitem_free(item);
162         }
163 
164     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
165         {
166         frag = (hm_fragment *)item->data;
167         dtls1_hm_fragment_free(frag);
168         pitem_free(item);
169         }
170 
171     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
172         {
173         frag = (hm_fragment *)item->data;
174         dtls1_hm_fragment_free(frag);
175         pitem_free(item);
176         }
177 
178 	while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
179 		{
180 		rdata = (DTLS1_RECORD_DATA *) item->data;
181 		if (rdata->rbuf.buf)
182 			{
183 			OPENSSL_free(rdata->rbuf.buf);
184 			}
185 		OPENSSL_free(item->data);
186 		pitem_free(item);
187 		}
188 	}
189 
190 void dtls1_free(SSL *s)
191 	{
192 	ssl3_free(s);
193 
194 	dtls1_clear_queues(s);
195 
196     pqueue_free(s->d1->unprocessed_rcds.q);
197     pqueue_free(s->d1->processed_rcds.q);
198     pqueue_free(s->d1->buffered_messages);
199 	pqueue_free(s->d1->sent_messages);
200 	pqueue_free(s->d1->buffered_app_data.q);
201 
202 	OPENSSL_free(s->d1);
203 	s->d1 = NULL;
204 	}
205 
206 void dtls1_clear(SSL *s)
207 	{
208     pqueue unprocessed_rcds;
209     pqueue processed_rcds;
210     pqueue buffered_messages;
211 	pqueue sent_messages;
212 	pqueue buffered_app_data;
213 	unsigned int mtu;
214 	unsigned int link_mtu;
215 
216 	if (s->d1)
217 		{
218 		unprocessed_rcds = s->d1->unprocessed_rcds.q;
219 		processed_rcds = s->d1->processed_rcds.q;
220 		buffered_messages = s->d1->buffered_messages;
221 		sent_messages = s->d1->sent_messages;
222 		buffered_app_data = s->d1->buffered_app_data.q;
223 		mtu = s->d1->mtu;
224 		link_mtu = s->d1->link_mtu;
225 
226 		dtls1_clear_queues(s);
227 
228 		memset(s->d1, 0, sizeof(*(s->d1)));
229 
230 		if (s->server)
231 			{
232 			s->d1->cookie_len = sizeof(s->d1->cookie);
233 			}
234 
235 		if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
236 			{
237 			s->d1->mtu = mtu;
238 			s->d1->link_mtu = link_mtu;
239 			}
240 
241 		s->d1->unprocessed_rcds.q = unprocessed_rcds;
242 		s->d1->processed_rcds.q = processed_rcds;
243 		s->d1->buffered_messages = buffered_messages;
244 		s->d1->sent_messages = sent_messages;
245 		s->d1->buffered_app_data.q = buffered_app_data;
246 		}
247 
248 	ssl3_clear(s);
249 	if (s->options & SSL_OP_CISCO_ANYCONNECT)
250 		s->version=DTLS1_BAD_VER;
251 	else
252 		s->version=DTLS1_VERSION;
253 	}
254 
255 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
256 	{
257 	int ret=0;
258 
259 	switch (cmd)
260 		{
261 	case DTLS_CTRL_GET_TIMEOUT:
262 		if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
263 			{
264 			ret = 1;
265 			}
266 		break;
267 	case DTLS_CTRL_HANDLE_TIMEOUT:
268 		ret = dtls1_handle_timeout(s);
269 		break;
270 	case DTLS_CTRL_LISTEN:
271 		ret = dtls1_listen(s, parg);
272 		break;
273 	case SSL_CTRL_CHECK_PROTO_VERSION:
274 		/* For library-internal use; checks that the current protocol
275 		 * is the highest enabled version (according to s->ctx->method,
276 		 * as version negotiation may have changed s->method). */
277 #if DTLS_MAX_VERSION != DTLS1_VERSION
278 #  error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
279 #endif
280 		/* Just one protocol version is supported so far;
281 		 * fail closed if the version is not as expected. */
282 		return s->version == DTLS_MAX_VERSION;
283 	case DTLS_CTRL_SET_LINK_MTU:
284 		if (larg < (long)dtls1_link_min_mtu())
285 			return 0;
286 		s->d1->link_mtu = larg;
287 		return 1;
288 	case DTLS_CTRL_GET_LINK_MIN_MTU:
289 		return (long)dtls1_link_min_mtu();
290 	case SSL_CTRL_SET_MTU:
291 		/*
292 		 *  We may not have a BIO set yet so can't call dtls1_min_mtu()
293 		 *  We'll have to make do with dtls1_link_min_mtu() and max overhead
294 		 */
295 		if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
296 			return 0;
297 		s->d1->mtu = larg;
298 		return larg;
299 	default:
300 		ret = ssl3_ctrl(s, cmd, larg, parg);
301 		break;
302 		}
303 	return(ret);
304 	}
305 
306 /*
307  * As it's impossible to use stream ciphers in "datagram" mode, this
308  * simple filter is designed to disengage them in DTLS. Unfortunately
309  * there is no universal way to identify stream SSL_CIPHER, so we have
310  * to explicitly list their SSL_* codes. Currently RC4 is the only one
311  * available, but if new ones emerge, they will have to be added...
312  */
313 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
314 	{
315 	const SSL_CIPHER *ciph = ssl3_get_cipher(u);
316 
317 	if (ciph != NULL)
318 		{
319 		if (ciph->algorithm_enc == SSL_RC4)
320 			return NULL;
321 		}
322 
323 	return ciph;
324 	}
325 
326 void dtls1_start_timer(SSL *s)
327 	{
328 #ifndef OPENSSL_NO_SCTP
329 	/* Disable timer for SCTP */
330 	if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
331 		{
332 		memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
333 		return;
334 		}
335 #endif
336 
337 	/* If timer is not set, initialize duration with 1 second */
338 	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
339 		{
340 		s->d1->timeout_duration = 1;
341 		}
342 
343 	/* Set timeout to current time */
344 	get_current_time(&(s->d1->next_timeout));
345 
346 	/* Add duration to current time */
347 	s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
348 	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
349 	}
350 
351 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
352 	{
353 	struct timeval timenow;
354 
355 	/* If no timeout is set, just return NULL */
356 	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
357 		{
358 		return NULL;
359 		}
360 
361 	/* Get current time */
362 	get_current_time(&timenow);
363 
364 	/* If timer already expired, set remaining time to 0 */
365 	if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
366 		(s->d1->next_timeout.tv_sec == timenow.tv_sec &&
367 		 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
368 		{
369 		memset(timeleft, 0, sizeof(struct timeval));
370 		return timeleft;
371 		}
372 
373 	/* Calculate time left until timer expires */
374 	memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
375 	timeleft->tv_sec -= timenow.tv_sec;
376 	timeleft->tv_usec -= timenow.tv_usec;
377 	if (timeleft->tv_usec < 0)
378 		{
379 		timeleft->tv_sec--;
380 		timeleft->tv_usec += 1000000;
381 		}
382 
383 	/* If remaining time is less than 15 ms, set it to 0
384 	 * to prevent issues because of small devergences with
385 	 * socket timeouts.
386 	 */
387 	if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
388 		{
389 		memset(timeleft, 0, sizeof(struct timeval));
390 		}
391 
392 
393 	return timeleft;
394 	}
395 
396 int dtls1_is_timer_expired(SSL *s)
397 	{
398 	struct timeval timeleft;
399 
400 	/* Get time left until timeout, return false if no timer running */
401 	if (dtls1_get_timeout(s, &timeleft) == NULL)
402 		{
403 		return 0;
404 		}
405 
406 	/* Return false if timer is not expired yet */
407 	if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
408 		{
409 		return 0;
410 		}
411 
412 	/* Timer expired, so return true */
413 	return 1;
414 	}
415 
416 void dtls1_double_timeout(SSL *s)
417 	{
418 	s->d1->timeout_duration *= 2;
419 	if (s->d1->timeout_duration > 60)
420 		s->d1->timeout_duration = 60;
421 	dtls1_start_timer(s);
422 	}
423 
424 void dtls1_stop_timer(SSL *s)
425 	{
426 	/* Reset everything */
427 	memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
428 	memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
429 	s->d1->timeout_duration = 1;
430 	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
431 	/* Clear retransmission buffer */
432 	dtls1_clear_record_buffer(s);
433 	}
434 
435 int dtls1_check_timeout_num(SSL *s)
436 	{
437 	unsigned int mtu;
438 
439 	s->d1->timeout.num_alerts++;
440 
441 	/* Reduce MTU after 2 unsuccessful retransmissions */
442 	if (s->d1->timeout.num_alerts > 2
443 			&& !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
444 		{
445 		mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
446 		if(mtu < s->d1->mtu)
447 			s->d1->mtu = mtu;
448 		}
449 
450 	if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
451 		{
452 		/* fail the connection, enough alerts have been sent */
453 		SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
454 		return -1;
455 		}
456 
457 	return 0;
458 	}
459 
460 int dtls1_handle_timeout(SSL *s)
461 	{
462 	/* if no timer is expired, don't do anything */
463 	if (!dtls1_is_timer_expired(s))
464 		{
465 		return 0;
466 		}
467 
468 	dtls1_double_timeout(s);
469 
470 	if (dtls1_check_timeout_num(s) < 0)
471 		return -1;
472 
473 	s->d1->timeout.read_timeouts++;
474 	if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
475 		{
476 		s->d1->timeout.read_timeouts = 1;
477 		}
478 
479 #ifndef OPENSSL_NO_HEARTBEATS
480 	if (s->tlsext_hb_pending)
481 		{
482 		s->tlsext_hb_pending = 0;
483 		return dtls1_heartbeat(s);
484 		}
485 #endif
486 
487 	dtls1_start_timer(s);
488 	return dtls1_retransmit_buffered_messages(s);
489 	}
490 
491 static void get_current_time(struct timeval *t)
492 {
493 #ifdef OPENSSL_SYS_WIN32
494 	struct _timeb tb;
495 	_ftime(&tb);
496 	t->tv_sec = (long)tb.time;
497 	t->tv_usec = (long)tb.millitm * 1000;
498 #elif defined(OPENSSL_SYS_VMS)
499 	struct timeb tb;
500 	ftime(&tb);
501 	t->tv_sec = (long)tb.time;
502 	t->tv_usec = (long)tb.millitm * 1000;
503 #else
504 	gettimeofday(t, NULL);
505 #endif
506 }
507 
508 int dtls1_listen(SSL *s, struct sockaddr *client)
509 	{
510 	int ret;
511 
512 	SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
513 	s->d1->listen = 1;
514 
515 	ret = SSL_accept(s);
516 	if (ret <= 0) return ret;
517 
518 	(void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
519 	return 1;
520 	}
521