d1_lib.c revision 264331 
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		frag = (hm_fragment *)item->data;
180		OPENSSL_free(frag->fragment);
181		OPENSSL_free(frag);
182		pitem_free(item);
183		}
184	}
185
186void dtls1_free(SSL *s)
187	{
188	ssl3_free(s);
189
190	dtls1_clear_queues(s);
191
192    pqueue_free(s->d1->unprocessed_rcds.q);
193    pqueue_free(s->d1->processed_rcds.q);
194    pqueue_free(s->d1->buffered_messages);
195	pqueue_free(s->d1->sent_messages);
196	pqueue_free(s->d1->buffered_app_data.q);
197
198	OPENSSL_free(s->d1);
199	s->d1 = NULL;
200	}
201
202void dtls1_clear(SSL *s)
203	{
204    pqueue unprocessed_rcds;
205    pqueue processed_rcds;
206    pqueue buffered_messages;
207	pqueue sent_messages;
208	pqueue buffered_app_data;
209	unsigned int mtu;
210
211	if (s->d1)
212		{
213		unprocessed_rcds = s->d1->unprocessed_rcds.q;
214		processed_rcds = s->d1->processed_rcds.q;
215		buffered_messages = s->d1->buffered_messages;
216		sent_messages = s->d1->sent_messages;
217		buffered_app_data = s->d1->buffered_app_data.q;
218		mtu = s->d1->mtu;
219
220		dtls1_clear_queues(s);
221
222		memset(s->d1, 0, sizeof(*(s->d1)));
223
224		if (s->server)
225			{
226			s->d1->cookie_len = sizeof(s->d1->cookie);
227			}
228
229		if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
230			{
231			s->d1->mtu = mtu;
232			}
233
234		s->d1->unprocessed_rcds.q = unprocessed_rcds;
235		s->d1->processed_rcds.q = processed_rcds;
236		s->d1->buffered_messages = buffered_messages;
237		s->d1->sent_messages = sent_messages;
238		s->d1->buffered_app_data.q = buffered_app_data;
239		}
240
241	ssl3_clear(s);
242	if (s->options & SSL_OP_CISCO_ANYCONNECT)
243		s->version=DTLS1_BAD_VER;
244	else
245		s->version=DTLS1_VERSION;
246	}
247
248long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
249	{
250	int ret=0;
251
252	switch (cmd)
253		{
254	case DTLS_CTRL_GET_TIMEOUT:
255		if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
256			{
257			ret = 1;
258			}
259		break;
260	case DTLS_CTRL_HANDLE_TIMEOUT:
261		ret = dtls1_handle_timeout(s);
262		break;
263	case DTLS_CTRL_LISTEN:
264		ret = dtls1_listen(s, parg);
265		break;
266
267	default:
268		ret = ssl3_ctrl(s, cmd, larg, parg);
269		break;
270		}
271	return(ret);
272	}
273
274/*
275 * As it's impossible to use stream ciphers in "datagram" mode, this
276 * simple filter is designed to disengage them in DTLS. Unfortunately
277 * there is no universal way to identify stream SSL_CIPHER, so we have
278 * to explicitly list their SSL_* codes. Currently RC4 is the only one
279 * available, but if new ones emerge, they will have to be added...
280 */
281const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
282	{
283	const SSL_CIPHER *ciph = ssl3_get_cipher(u);
284
285	if (ciph != NULL)
286		{
287		if (ciph->algorithm_enc == SSL_RC4)
288			return NULL;
289		}
290
291	return ciph;
292	}
293
294void dtls1_start_timer(SSL *s)
295	{
296#ifndef OPENSSL_NO_SCTP
297	/* Disable timer for SCTP */
298	if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
299		{
300		memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
301		return;
302		}
303#endif
304
305	/* If timer is not set, initialize duration with 1 second */
306	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
307		{
308		s->d1->timeout_duration = 1;
309		}
310
311	/* Set timeout to current time */
312	get_current_time(&(s->d1->next_timeout));
313
314	/* Add duration to current time */
315	s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
316	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
317	}
318
319struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
320	{
321	struct timeval timenow;
322
323	/* If no timeout is set, just return NULL */
324	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
325		{
326		return NULL;
327		}
328
329	/* Get current time */
330	get_current_time(&timenow);
331
332	/* If timer already expired, set remaining time to 0 */
333	if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
334		(s->d1->next_timeout.tv_sec == timenow.tv_sec &&
335		 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
336		{
337		memset(timeleft, 0, sizeof(struct timeval));
338		return timeleft;
339		}
340
341	/* Calculate time left until timer expires */
342	memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
343	timeleft->tv_sec -= timenow.tv_sec;
344	timeleft->tv_usec -= timenow.tv_usec;
345	if (timeleft->tv_usec < 0)
346		{
347		timeleft->tv_sec--;
348		timeleft->tv_usec += 1000000;
349		}
350
351	/* If remaining time is less than 15 ms, set it to 0
352	 * to prevent issues because of small devergences with
353	 * socket timeouts.
354	 */
355	if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
356		{
357		memset(timeleft, 0, sizeof(struct timeval));
358		}
359
360
361	return timeleft;
362	}
363
364int dtls1_is_timer_expired(SSL *s)
365	{
366	struct timeval timeleft;
367
368	/* Get time left until timeout, return false if no timer running */
369	if (dtls1_get_timeout(s, &timeleft) == NULL)
370		{
371		return 0;
372		}
373
374	/* Return false if timer is not expired yet */
375	if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
376		{
377		return 0;
378		}
379
380	/* Timer expired, so return true */
381	return 1;
382	}
383
384void dtls1_double_timeout(SSL *s)
385	{
386	s->d1->timeout_duration *= 2;
387	if (s->d1->timeout_duration > 60)
388		s->d1->timeout_duration = 60;
389	dtls1_start_timer(s);
390	}
391
392void dtls1_stop_timer(SSL *s)
393	{
394	/* Reset everything */
395	memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
396	memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
397	s->d1->timeout_duration = 1;
398	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
399	/* Clear retransmission buffer */
400	dtls1_clear_record_buffer(s);
401	}
402
403int dtls1_check_timeout_num(SSL *s)
404	{
405	s->d1->timeout.num_alerts++;
406
407	/* Reduce MTU after 2 unsuccessful retransmissions */
408	if (s->d1->timeout.num_alerts > 2)
409		{
410		s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
411		}
412
413	if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
414		{
415		/* fail the connection, enough alerts have been sent */
416		SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
417		return -1;
418		}
419
420	return 0;
421	}
422
423int dtls1_handle_timeout(SSL *s)
424	{
425	/* if no timer is expired, don't do anything */
426	if (!dtls1_is_timer_expired(s))
427		{
428		return 0;
429		}
430
431	dtls1_double_timeout(s);
432
433	if (dtls1_check_timeout_num(s) < 0)
434		return -1;
435
436	s->d1->timeout.read_timeouts++;
437	if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
438		{
439		s->d1->timeout.read_timeouts = 1;
440		}
441
442#ifndef OPENSSL_NO_HEARTBEATS
443	if (s->tlsext_hb_pending)
444		{
445		s->tlsext_hb_pending = 0;
446		return dtls1_heartbeat(s);
447		}
448#endif
449
450	dtls1_start_timer(s);
451	return dtls1_retransmit_buffered_messages(s);
452	}
453
454static void get_current_time(struct timeval *t)
455{
456#ifdef OPENSSL_SYS_WIN32
457	struct _timeb tb;
458	_ftime(&tb);
459	t->tv_sec = (long)tb.time;
460	t->tv_usec = (long)tb.millitm * 1000;
461#elif defined(OPENSSL_SYS_VMS)
462	struct timeb tb;
463	ftime(&tb);
464	t->tv_sec = (long)tb.time;
465	t->tv_usec = (long)tb.millitm * 1000;
466#else
467	gettimeofday(t, NULL);
468#endif
469}
470
471int dtls1_listen(SSL *s, struct sockaddr *client)
472	{
473	int ret;
474
475	SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
476	s->d1->listen = 1;
477
478	ret = SSL_accept(s);
479	if (ret <= 0) return ret;
480
481	(void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
482	return 1;
483	}
484