d1_lib.c revision 221304ee937bc0910948a8be1320cb8cc4eb6d36 
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	};
86
87long dtls1_default_timeout(void)
88	{
89	/* 2 hours, the 24 hours mentioned in the DTLSv1 spec
90	 * is way too long for http, the cache would over fill */
91	return(60*60*2);
92	}
93
94int dtls1_new(SSL *s)
95	{
96	DTLS1_STATE *d1;
97
98	if (!ssl3_new(s)) return(0);
99	if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
100	memset(d1,0, sizeof *d1);
101
102	/* d1->handshake_epoch=0; */
103
104	d1->unprocessed_rcds.q=pqueue_new();
105	d1->processed_rcds.q=pqueue_new();
106	d1->buffered_messages = pqueue_new();
107	d1->sent_messages=pqueue_new();
108	d1->buffered_app_data.q=pqueue_new();
109
110	if ( s->server)
111		{
112		d1->cookie_len = sizeof(s->d1->cookie);
113		}
114
115	if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
116        || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
117		{
118        if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
119        if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
120        if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
121		if ( d1->sent_messages) pqueue_free(d1->sent_messages);
122		if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
123		OPENSSL_free(d1);
124		return (0);
125		}
126
127	s->d1=d1;
128	s->method->ssl_clear(s);
129	return(1);
130	}
131
132void dtls1_free(SSL *s)
133	{
134    pitem *item = NULL;
135    hm_fragment *frag = NULL;
136
137	ssl3_free(s);
138
139    while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
140        {
141        OPENSSL_free(item->data);
142        pitem_free(item);
143        }
144    pqueue_free(s->d1->unprocessed_rcds.q);
145
146    while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
147        {
148        OPENSSL_free(item->data);
149        pitem_free(item);
150        }
151    pqueue_free(s->d1->processed_rcds.q);
152
153    while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
154        {
155        frag = (hm_fragment *)item->data;
156        OPENSSL_free(frag->fragment);
157        OPENSSL_free(frag);
158        pitem_free(item);
159        }
160    pqueue_free(s->d1->buffered_messages);
161
162    while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
163        {
164        frag = (hm_fragment *)item->data;
165        OPENSSL_free(frag->fragment);
166        OPENSSL_free(frag);
167        pitem_free(item);
168        }
169	pqueue_free(s->d1->sent_messages);
170
171	while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
172		{
173		frag = (hm_fragment *)item->data;
174		OPENSSL_free(frag->fragment);
175		OPENSSL_free(frag);
176		pitem_free(item);
177		}
178	pqueue_free(s->d1->buffered_app_data.q);
179
180	OPENSSL_free(s->d1);
181	}
182
183void dtls1_clear(SSL *s)
184	{
185	ssl3_clear(s);
186	if (s->options & SSL_OP_CISCO_ANYCONNECT)
187		s->version=DTLS1_BAD_VER;
188	else
189		s->version=DTLS1_VERSION;
190	}
191
192long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
193	{
194	int ret=0;
195
196	switch (cmd)
197		{
198	case DTLS_CTRL_GET_TIMEOUT:
199		if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
200			{
201			ret = 1;
202			}
203		break;
204	case DTLS_CTRL_HANDLE_TIMEOUT:
205		ret = dtls1_handle_timeout(s);
206		break;
207	case DTLS_CTRL_LISTEN:
208		ret = dtls1_listen(s, parg);
209		break;
210
211	default:
212		ret = ssl3_ctrl(s, cmd, larg, parg);
213		break;
214		}
215	return(ret);
216	}
217
218/*
219 * As it's impossible to use stream ciphers in "datagram" mode, this
220 * simple filter is designed to disengage them in DTLS. Unfortunately
221 * there is no universal way to identify stream SSL_CIPHER, so we have
222 * to explicitly list their SSL_* codes. Currently RC4 is the only one
223 * available, but if new ones emerge, they will have to be added...
224 */
225const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
226	{
227	const SSL_CIPHER *ciph = ssl3_get_cipher(u);
228
229	if (ciph != NULL)
230		{
231		if (ciph->algorithm_enc == SSL_RC4)
232			return NULL;
233		}
234
235	return ciph;
236	}
237
238void dtls1_start_timer(SSL *s)
239	{
240	/* If timer is not set, initialize duration with 1 second */
241	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
242		{
243		s->d1->timeout_duration = 1;
244		}
245
246	/* Set timeout to current time */
247	get_current_time(&(s->d1->next_timeout));
248
249	/* Add duration to current time */
250	s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
251	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
252	}
253
254struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
255	{
256	struct timeval timenow;
257
258	/* If no timeout is set, just return NULL */
259	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
260		{
261		return NULL;
262		}
263
264	/* Get current time */
265	get_current_time(&timenow);
266
267	/* If timer already expired, set remaining time to 0 */
268	if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
269		(s->d1->next_timeout.tv_sec == timenow.tv_sec &&
270		 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
271		{
272		memset(timeleft, 0, sizeof(struct timeval));
273		return timeleft;
274		}
275
276	/* Calculate time left until timer expires */
277	memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
278	timeleft->tv_sec -= timenow.tv_sec;
279	timeleft->tv_usec -= timenow.tv_usec;
280	if (timeleft->tv_usec < 0)
281		{
282		timeleft->tv_sec--;
283		timeleft->tv_usec += 1000000;
284		}
285
286	return timeleft;
287	}
288
289int dtls1_is_timer_expired(SSL *s)
290	{
291	struct timeval timeleft;
292
293	/* Get time left until timeout, return false if no timer running */
294	if (dtls1_get_timeout(s, &timeleft) == NULL)
295		{
296		return 0;
297		}
298
299	/* Return false if timer is not expired yet */
300	if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
301		{
302		return 0;
303		}
304
305	/* Timer expired, so return true */
306	return 1;
307	}
308
309void dtls1_double_timeout(SSL *s)
310	{
311	s->d1->timeout_duration *= 2;
312	if (s->d1->timeout_duration > 60)
313		s->d1->timeout_duration = 60;
314	dtls1_start_timer(s);
315	}
316
317void dtls1_stop_timer(SSL *s)
318	{
319	/* Reset everything */
320	memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
321	s->d1->timeout_duration = 1;
322	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
323	}
324
325int dtls1_handle_timeout(SSL *s)
326	{
327	DTLS1_STATE *state;
328
329	/* if no timer is expired, don't do anything */
330	if (!dtls1_is_timer_expired(s))
331		{
332		return 0;
333		}
334
335	dtls1_double_timeout(s);
336	state = s->d1;
337	state->timeout.num_alerts++;
338	if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
339		{
340		/* fail the connection, enough alerts have been sent */
341		SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
342		return 0;
343		}
344
345	state->timeout.read_timeouts++;
346	if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
347		{
348		state->timeout.read_timeouts = 1;
349		}
350
351	dtls1_start_timer(s);
352	return dtls1_retransmit_buffered_messages(s);
353	}
354
355static void get_current_time(struct timeval *t)
356{
357#ifdef OPENSSL_SYS_WIN32
358	struct _timeb tb;
359	_ftime(&tb);
360	t->tv_sec = (long)tb.time;
361	t->tv_usec = (long)tb.millitm * 1000;
362#elif defined(OPENSSL_SYS_VMS)
363	struct timeb tb;
364	ftime(&tb);
365	t->tv_sec = (long)tb.time;
366	t->tv_usec = (long)tb.millitm * 1000;
367#else
368	gettimeofday(t, NULL);
369#endif
370}
371
372int dtls1_listen(SSL *s, struct sockaddr *client)
373	{
374	int ret;
375
376	SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
377	s->d1->listen = 1;
378
379	ret = SSL_accept(s);
380	if (ret <= 0) return ret;
381
382	(void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
383	return 1;
384	}
385