PR: 2555
[openssl.git] / ssl / d1_lib.c
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
69 static void get_current_time(struct timeval *t);
70 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
71 int dtls1_listen(SSL *s, struct sockaddr *client);
72
73 SSL3_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
87 long 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
94 int 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
132 static void dtls1_clear_queues(SSL *s)
133         {
134     pitem *item = NULL;
135     hm_fragment *frag = NULL;
136         DTLS1_RECORD_DATA *rdata;
137
138     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
139         {
140                 rdata = (DTLS1_RECORD_DATA *) item->data;
141                 if (rdata->rbuf.buf)
142                         {
143                         OPENSSL_free(rdata->rbuf.buf);
144                         }
145         OPENSSL_free(item->data);
146         pitem_free(item);
147         }
148
149     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
150         {
151                 rdata = (DTLS1_RECORD_DATA *) item->data;
152                 if (rdata->rbuf.buf)
153                         {
154                         OPENSSL_free(rdata->rbuf.buf);
155                         }
156         OPENSSL_free(item->data);
157         pitem_free(item);
158         }
159
160     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
161         {
162         frag = (hm_fragment *)item->data;
163         OPENSSL_free(frag->fragment);
164         OPENSSL_free(frag);
165         pitem_free(item);
166         }
167
168     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
169         {
170         frag = (hm_fragment *)item->data;
171         OPENSSL_free(frag->fragment);
172         OPENSSL_free(frag);
173         pitem_free(item);
174         }
175
176         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
177                 {
178                 frag = (hm_fragment *)item->data;
179                 OPENSSL_free(frag->fragment);
180                 OPENSSL_free(frag);
181                 pitem_free(item);
182                 }
183         }
184
185 void dtls1_free(SSL *s)
186         {
187         ssl3_free(s);
188
189         dtls1_clear_queues(s);
190
191     pqueue_free(s->d1->unprocessed_rcds.q);
192     pqueue_free(s->d1->processed_rcds.q);
193     pqueue_free(s->d1->buffered_messages);
194         pqueue_free(s->d1->sent_messages);
195         pqueue_free(s->d1->buffered_app_data.q);
196
197         OPENSSL_free(s->d1);
198         }
199
200 void dtls1_clear(SSL *s)
201         {
202     pqueue unprocessed_rcds;
203     pqueue processed_rcds;
204     pqueue buffered_messages;
205         pqueue sent_messages;
206         pqueue buffered_app_data;
207         
208         if (s->d1)
209                 {
210                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
211                 processed_rcds = s->d1->processed_rcds.q;
212                 buffered_messages = s->d1->buffered_messages;
213                 sent_messages = s->d1->sent_messages;
214                 buffered_app_data = s->d1->buffered_app_data.q;
215
216                 dtls1_clear_queues(s);
217
218                 memset(s->d1, 0, sizeof(*(s->d1)));
219
220                 if (s->server)
221                         {
222                         s->d1->cookie_len = sizeof(s->d1->cookie);
223                         }
224
225                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
226                 s->d1->processed_rcds.q = processed_rcds;
227                 s->d1->buffered_messages = buffered_messages;
228                 s->d1->sent_messages = sent_messages;
229                 s->d1->buffered_app_data.q = buffered_app_data;
230                 }
231
232         ssl3_clear(s);
233         if (s->options & SSL_OP_CISCO_ANYCONNECT)
234                 s->version=DTLS1_BAD_VER;
235         else
236                 s->version=DTLS1_VERSION;
237         }
238
239 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
240         {
241         int ret=0;
242
243         switch (cmd)
244                 {
245         case DTLS_CTRL_GET_TIMEOUT:
246                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
247                         {
248                         ret = 1;
249                         }
250                 break;
251         case DTLS_CTRL_HANDLE_TIMEOUT:
252                 ret = dtls1_handle_timeout(s);
253                 break;
254         case DTLS_CTRL_LISTEN:
255                 ret = dtls1_listen(s, parg);
256                 break;
257
258         default:
259                 ret = ssl3_ctrl(s, cmd, larg, parg);
260                 break;
261                 }
262         return(ret);
263         }
264
265 /*
266  * As it's impossible to use stream ciphers in "datagram" mode, this
267  * simple filter is designed to disengage them in DTLS. Unfortunately
268  * there is no universal way to identify stream SSL_CIPHER, so we have
269  * to explicitly list their SSL_* codes. Currently RC4 is the only one
270  * available, but if new ones emerge, they will have to be added...
271  */
272 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
273         {
274         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
275
276         if (ciph != NULL)
277                 {
278                 if (ciph->algorithm_enc == SSL_RC4)
279                         return NULL;
280                 }
281
282         return ciph;
283         }
284
285 void dtls1_start_timer(SSL *s)
286         {
287         /* If timer is not set, initialize duration with 1 second */
288         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
289                 {
290                 s->d1->timeout_duration = 1;
291                 }
292         
293         /* Set timeout to current time */
294         get_current_time(&(s->d1->next_timeout));
295
296         /* Add duration to current time */
297         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
298         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
299         }
300
301 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
302         {
303         struct timeval timenow;
304
305         /* If no timeout is set, just return NULL */
306         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
307                 {
308                 return NULL;
309                 }
310
311         /* Get current time */
312         get_current_time(&timenow);
313
314         /* If timer already expired, set remaining time to 0 */
315         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
316                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
317                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
318                 {
319                 memset(timeleft, 0, sizeof(struct timeval));
320                 return timeleft;
321                 }
322
323         /* Calculate time left until timer expires */
324         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
325         timeleft->tv_sec -= timenow.tv_sec;
326         timeleft->tv_usec -= timenow.tv_usec;
327         if (timeleft->tv_usec < 0)
328                 {
329                 timeleft->tv_sec--;
330                 timeleft->tv_usec += 1000000;
331                 }
332
333         /* If remaining time is less than 15 ms, set it to 0
334          * to prevent issues because of small devergences with
335          * socket timeouts.
336          */
337         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
338                 {
339                 memset(timeleft, 0, sizeof(struct timeval));
340                 }
341         
342
343         return timeleft;
344         }
345
346 int dtls1_is_timer_expired(SSL *s)
347         {
348         struct timeval timeleft;
349
350         /* Get time left until timeout, return false if no timer running */
351         if (dtls1_get_timeout(s, &timeleft) == NULL)
352                 {
353                 return 0;
354                 }
355
356         /* Return false if timer is not expired yet */
357         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
358                 {
359                 return 0;
360                 }
361
362         /* Timer expired, so return true */     
363         return 1;
364         }
365
366 void dtls1_double_timeout(SSL *s)
367         {
368         s->d1->timeout_duration *= 2;
369         if (s->d1->timeout_duration > 60)
370                 s->d1->timeout_duration = 60;
371         dtls1_start_timer(s);
372         }
373
374 void dtls1_stop_timer(SSL *s)
375         {
376         /* Reset everything */
377         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
378         s->d1->timeout_duration = 1;
379         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
380         /* Clear retransmission buffer */
381         dtls1_clear_record_buffer(s);
382         }
383
384 int dtls1_handle_timeout(SSL *s)
385         {
386         DTLS1_STATE *state;
387
388         /* if no timer is expired, don't do anything */
389         if (!dtls1_is_timer_expired(s))
390                 {
391                 return 0;
392                 }
393
394         dtls1_double_timeout(s);
395         state = s->d1;
396         state->timeout.num_alerts++;
397         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
398                 {
399                 /* fail the connection, enough alerts have been sent */
400                 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
401                 return -1;
402                 }
403
404         state->timeout.read_timeouts++;
405         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
406                 {
407                 state->timeout.read_timeouts = 1;
408                 }
409
410         dtls1_start_timer(s);
411         return dtls1_retransmit_buffered_messages(s);
412         }
413
414 static void get_current_time(struct timeval *t)
415 {
416 #ifdef OPENSSL_SYS_WIN32
417         struct _timeb tb;
418         _ftime(&tb);
419         t->tv_sec = (long)tb.time;
420         t->tv_usec = (long)tb.millitm * 1000;
421 #elif defined(OPENSSL_SYS_VMS)
422         struct timeb tb;
423         ftime(&tb);
424         t->tv_sec = (long)tb.time;
425         t->tv_usec = (long)tb.millitm * 1000;
426 #else
427         gettimeofday(t, NULL);
428 #endif
429 }
430
431 int dtls1_listen(SSL *s, struct sockaddr *client)
432         {
433         int ret;
434
435         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
436         s->d1->listen = 1;
437
438         ret = SSL_accept(s);
439         if (ret <= 0) return ret;
440         
441         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
442         return 1;
443         }