d1_lib.c revision 267258 
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
69static void get_current_time(struct timeval *t);
70const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
71int dtls1_listen(SSL *s, struct sockaddr *client);
72
73SSL3_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
88long 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
95int 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
133static 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
189void 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
205void 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
251long 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 */
284const 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
297void 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
322struct 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
367int 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
387void 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
395void 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
406int 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
426int 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
457static 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
474int 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