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