d1_lib.c revision 205128 
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
94IMPLEMENT_dtls1_meth_func(dtlsv1_base_method,
95			ssl_undefined_function,
96			ssl_undefined_function,
97			ssl_bad_method)
98
99int dtls1_new(SSL *s)
100	{
101	DTLS1_STATE *d1;
102
103	if (!ssl3_new(s)) return(0);
104	if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
105	memset(d1,0, sizeof *d1);
106
107	/* d1->handshake_epoch=0; */
108#if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
109	d1->bitmap.length=64;
110#else
111	d1->bitmap.length=sizeof(d1->bitmap.map) * 8;
112#endif
113	pq_64bit_init(&(d1->bitmap.map));
114	pq_64bit_init(&(d1->bitmap.max_seq_num));
115
116	d1->next_bitmap.length = d1->bitmap.length;
117	pq_64bit_init(&(d1->next_bitmap.map));
118	pq_64bit_init(&(d1->next_bitmap.max_seq_num));
119
120	d1->unprocessed_rcds.q=pqueue_new();
121	d1->processed_rcds.q=pqueue_new();
122	d1->buffered_messages = pqueue_new();
123	d1->sent_messages=pqueue_new();
124	d1->buffered_app_data.q=pqueue_new();
125
126	if ( s->server)
127		{
128		d1->cookie_len = sizeof(s->d1->cookie);
129		}
130
131	if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
132        || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
133		{
134        if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
135        if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
136        if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
137		if ( d1->sent_messages) pqueue_free(d1->sent_messages);
138		if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
139		OPENSSL_free(d1);
140		return (0);
141		}
142
143	s->d1=d1;
144	s->method->ssl_clear(s);
145	return(1);
146	}
147
148void dtls1_free(SSL *s)
149	{
150    pitem *item = NULL;
151    hm_fragment *frag = NULL;
152
153	ssl3_free(s);
154
155    while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
156        {
157        OPENSSL_free(item->data);
158        pitem_free(item);
159        }
160    pqueue_free(s->d1->unprocessed_rcds.q);
161
162    while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
163        {
164        OPENSSL_free(item->data);
165        pitem_free(item);
166        }
167    pqueue_free(s->d1->processed_rcds.q);
168
169    while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
170        {
171        frag = (hm_fragment *)item->data;
172        OPENSSL_free(frag->fragment);
173        OPENSSL_free(frag);
174        pitem_free(item);
175        }
176    pqueue_free(s->d1->buffered_messages);
177
178    while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
179        {
180        frag = (hm_fragment *)item->data;
181        OPENSSL_free(frag->fragment);
182        OPENSSL_free(frag);
183        pitem_free(item);
184        }
185	pqueue_free(s->d1->sent_messages);
186
187	while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
188	{
189		frag = (hm_fragment *)item->data;
190		OPENSSL_free(frag->fragment);
191		OPENSSL_free(frag);
192		pitem_free(item);
193	}
194	pqueue_free(s->d1->buffered_app_data.q);
195
196	pq_64bit_free(&(s->d1->bitmap.map));
197	pq_64bit_free(&(s->d1->bitmap.max_seq_num));
198
199	pq_64bit_free(&(s->d1->next_bitmap.map));
200	pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
201
202	OPENSSL_free(s->d1);
203	}
204
205void dtls1_clear(SSL *s)
206	{
207	ssl3_clear(s);
208	if (s->options & SSL_OP_CISCO_ANYCONNECT)
209		s->version=DTLS1_BAD_VER;
210	else
211		s->version=DTLS1_VERSION;
212	}
213
214long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
215	{
216	int ret=0;
217
218	switch (cmd)
219		{
220	case DTLS_CTRL_GET_TIMEOUT:
221		if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
222			{
223			ret = 1;
224			}
225		break;
226	case DTLS_CTRL_HANDLE_TIMEOUT:
227		ret = dtls1_handle_timeout(s);
228		break;
229	case DTLS_CTRL_LISTEN:
230		ret = dtls1_listen(s, parg);
231		break;
232
233	default:
234		ret = ssl3_ctrl(s, cmd, larg, parg);
235		break;
236		}
237	return(ret);
238	}
239
240/*
241 * As it's impossible to use stream ciphers in "datagram" mode, this
242 * simple filter is designed to disengage them in DTLS. Unfortunately
243 * there is no universal way to identify stream SSL_CIPHER, so we have
244 * to explicitly list their SSL_* codes. Currently RC4 is the only one
245 * available, but if new ones emerge, they will have to be added...
246 */
247SSL_CIPHER *dtls1_get_cipher(unsigned int u)
248	{
249	SSL_CIPHER *ciph = ssl3_get_cipher(u);
250
251	if (ciph != NULL)
252		{
253		if ((ciph->algorithms&SSL_ENC_MASK) == SSL_RC4)
254			return NULL;
255		}
256
257	return ciph;
258	}
259
260void dtls1_start_timer(SSL *s)
261	{
262	/* If timer is not set, initialize duration with 1 second */
263	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
264		{
265		s->d1->timeout_duration = 1;
266		}
267
268	/* Set timeout to current time */
269	get_current_time(&(s->d1->next_timeout));
270
271	/* Add duration to current time */
272	s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
273	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
274	}
275
276struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
277	{
278	struct timeval timenow;
279
280	/* If no timeout is set, just return NULL */
281	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
282		{
283		return NULL;
284		}
285
286	/* Get current time */
287	get_current_time(&timenow);
288
289	/* If timer already expired, set remaining time to 0 */
290	if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
291		(s->d1->next_timeout.tv_sec == timenow.tv_sec &&
292		 s->d1->next_timeout.tv_usec <= timenow.tv_usec))
293		{
294		memset(timeleft, 0, sizeof(struct timeval));
295		return timeleft;
296		}
297
298	/* Calculate time left until timer expires */
299	memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
300	timeleft->tv_sec -= timenow.tv_sec;
301	timeleft->tv_usec -= timenow.tv_usec;
302	if (timeleft->tv_usec < 0)
303		{
304		timeleft->tv_sec--;
305		timeleft->tv_usec += 1000000;
306		}
307
308	return timeleft;
309	}
310
311int dtls1_is_timer_expired(SSL *s)
312	{
313	struct timeval timeleft;
314
315	/* Get time left until timeout, return false if no timer running */
316	if (dtls1_get_timeout(s, &timeleft) == NULL)
317		{
318		return 0;
319		}
320
321	/* Return false if timer is not expired yet */
322	if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
323		{
324		return 0;
325		}
326
327	/* Timer expired, so return true */
328	return 1;
329	}
330
331void dtls1_double_timeout(SSL *s)
332	{
333	s->d1->timeout_duration *= 2;
334	if (s->d1->timeout_duration > 60)
335		s->d1->timeout_duration = 60;
336	dtls1_start_timer(s);
337	}
338
339void dtls1_stop_timer(SSL *s)
340	{
341	/* Reset everything */
342	memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
343	s->d1->timeout_duration = 1;
344	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
345	}
346
347int dtls1_handle_timeout(SSL *s)
348	{
349	DTLS1_STATE *state;
350
351	/* if no timer is expired, don't do anything */
352	if (!dtls1_is_timer_expired(s))
353		{
354		return 0;
355		}
356
357	dtls1_double_timeout(s);
358	state = s->d1;
359	state->timeout.num_alerts++;
360	if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
361		{
362		/* fail the connection, enough alerts have been sent */
363		SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
364		return 0;
365		}
366
367	state->timeout.read_timeouts++;
368	if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
369		{
370		state->timeout.read_timeouts = 1;
371		}
372
373	dtls1_start_timer(s);
374	return dtls1_retransmit_buffered_messages(s);
375	}
376
377static void get_current_time(struct timeval *t)
378{
379#ifdef OPENSSL_SYS_WIN32
380	struct _timeb tb;
381	_ftime(&tb);
382	t->tv_sec = (long)tb.time;
383	t->tv_usec = (long)tb.millitm * 1000;
384#elif defined(OPENSSL_SYS_VMS)
385	struct timeb tb;
386	ftime(&tb);
387	t->tv_sec = (long)tb.time;
388	t->tv_usec = (long)tb.millitm * 1000;
389#else
390	gettimeofday(t, NULL);
391#endif
392}
393
394int dtls1_listen(SSL *s, struct sockaddr *client)
395	{
396	int ret;
397
398	SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
399	s->d1->listen = 1;
400
401	ret = SSL_accept(s);
402	if (ret <= 0) return ret;
403
404	(void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
405	return 1;
406	}
407