b739153309f0fe9b8cb69ea18a9f07dac9e002f1
[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_VMS)
66 #include <sys/timeb.h>
67 #endif
68
69 static void get_current_time(struct timeval *t);
70 static void dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
71 static int dtls1_handshake_write(SSL *s);
72 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
73 int dtls1_listen(SSL *s, struct sockaddr *client);
74
75 SSL3_ENC_METHOD DTLSv1_enc_data={
76     dtls1_enc,
77         tls1_mac,
78         tls1_setup_key_block,
79         tls1_generate_master_secret,
80         tls1_change_cipher_state,
81         tls1_final_finish_mac,
82         TLS1_FINISH_MAC_LENGTH,
83         tls1_cert_verify_mac,
84         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
85         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
86         tls1_alert_code,
87         tls1_export_keying_material,
88         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV,
89         DTLS1_HM_HEADER_LENGTH,
90         dtls1_set_handshake_header,
91         dtls1_handshake_write   
92         };
93
94 long dtls1_default_timeout(void)
95         {
96         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
97          * is way too long for http, the cache would over fill */
98         return(60*60*2);
99         }
100
101 int dtls1_new(SSL *s)
102         {
103         DTLS1_STATE *d1;
104
105         if (!ssl3_new(s)) return(0);
106         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
107         memset(d1,0, sizeof *d1);
108
109         /* d1->handshake_epoch=0; */
110
111         d1->unprocessed_rcds.q=pqueue_new();
112         d1->processed_rcds.q=pqueue_new();
113         d1->buffered_messages = pqueue_new();
114         d1->sent_messages=pqueue_new();
115         d1->buffered_app_data.q=pqueue_new();
116
117         if ( s->server)
118                 {
119                 d1->cookie_len = sizeof(s->d1->cookie);
120                 }
121
122         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 
123         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
124                 {
125         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
126         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
127         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
128                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
129                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
130                 OPENSSL_free(d1);
131                 return (0);
132                 }
133
134         s->d1=d1;
135         s->method->ssl_clear(s);
136         return(1);
137         }
138
139 static void dtls1_clear_queues(SSL *s)
140         {
141     pitem *item = NULL;
142     hm_fragment *frag = NULL;
143         DTLS1_RECORD_DATA *rdata;
144
145     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
146         {
147                 rdata = (DTLS1_RECORD_DATA *) item->data;
148                 if (rdata->rbuf.buf)
149                         {
150                         OPENSSL_free(rdata->rbuf.buf);
151                         }
152         OPENSSL_free(item->data);
153         pitem_free(item);
154         }
155
156     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
157         {
158                 rdata = (DTLS1_RECORD_DATA *) item->data;
159                 if (rdata->rbuf.buf)
160                         {
161                         OPENSSL_free(rdata->rbuf.buf);
162                         }
163         OPENSSL_free(item->data);
164         pitem_free(item);
165         }
166
167     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
168         {
169         frag = (hm_fragment *)item->data;
170         OPENSSL_free(frag->fragment);
171         OPENSSL_free(frag);
172         pitem_free(item);
173         }
174
175     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
176         {
177         frag = (hm_fragment *)item->data;
178         OPENSSL_free(frag->fragment);
179         OPENSSL_free(frag);
180         pitem_free(item);
181         }
182
183         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
184                 {
185                 frag = (hm_fragment *)item->data;
186                 OPENSSL_free(frag->fragment);
187                 OPENSSL_free(frag);
188                 pitem_free(item);
189                 }
190         }
191
192 void dtls1_free(SSL *s)
193         {
194         ssl3_free(s);
195
196         dtls1_clear_queues(s);
197
198     pqueue_free(s->d1->unprocessed_rcds.q);
199     pqueue_free(s->d1->processed_rcds.q);
200     pqueue_free(s->d1->buffered_messages);
201         pqueue_free(s->d1->sent_messages);
202         pqueue_free(s->d1->buffered_app_data.q);
203
204         OPENSSL_free(s->d1);
205         }
206
207 void dtls1_clear(SSL *s)
208         {
209     pqueue unprocessed_rcds;
210     pqueue processed_rcds;
211     pqueue buffered_messages;
212         pqueue sent_messages;
213         pqueue buffered_app_data;
214         unsigned int mtu;
215
216         if (s->d1)
217                 {
218                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
219                 processed_rcds = s->d1->processed_rcds.q;
220                 buffered_messages = s->d1->buffered_messages;
221                 sent_messages = s->d1->sent_messages;
222                 buffered_app_data = s->d1->buffered_app_data.q;
223                 mtu = s->d1->mtu;
224
225                 dtls1_clear_queues(s);
226
227                 memset(s->d1, 0, sizeof(*(s->d1)));
228
229                 if (s->server)
230                         {
231                         s->d1->cookie_len = sizeof(s->d1->cookie);
232                         }
233
234                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
235                         {
236                         s->d1->mtu = mtu;
237                         }
238
239                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
240                 s->d1->processed_rcds.q = processed_rcds;
241                 s->d1->buffered_messages = buffered_messages;
242                 s->d1->sent_messages = sent_messages;
243                 s->d1->buffered_app_data.q = buffered_app_data;
244                 }
245
246         ssl3_clear(s);
247         if (s->options & SSL_OP_CISCO_ANYCONNECT)
248                 s->version=DTLS1_BAD_VER;
249         else
250                 s->version=DTLS1_VERSION;
251         }
252
253 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
254         {
255         int ret=0;
256
257         switch (cmd)
258                 {
259         case DTLS_CTRL_GET_TIMEOUT:
260                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
261                         {
262                         ret = 1;
263                         }
264                 break;
265         case DTLS_CTRL_HANDLE_TIMEOUT:
266                 ret = dtls1_handle_timeout(s);
267                 break;
268         case DTLS_CTRL_LISTEN:
269                 ret = dtls1_listen(s, parg);
270                 break;
271
272         default:
273                 ret = ssl3_ctrl(s, cmd, larg, parg);
274                 break;
275                 }
276         return(ret);
277         }
278
279 /*
280  * As it's impossible to use stream ciphers in "datagram" mode, this
281  * simple filter is designed to disengage them in DTLS. Unfortunately
282  * there is no universal way to identify stream SSL_CIPHER, so we have
283  * to explicitly list their SSL_* codes. Currently RC4 is the only one
284  * available, but if new ones emerge, they will have to be added...
285  */
286 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
287         {
288         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
289
290         if (ciph != NULL)
291                 {
292                 if (ciph->algorithm_enc == SSL_RC4)
293                         return NULL;
294                 }
295
296         return ciph;
297         }
298
299 void dtls1_start_timer(SSL *s)
300         {
301 #ifndef OPENSSL_NO_SCTP
302         /* Disable timer for SCTP */
303         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
304                 {
305                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
306                 return;
307                 }
308 #endif
309
310         /* If timer is not set, initialize duration with 1 second */
311         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
312                 {
313                 s->d1->timeout_duration = 1;
314                 }
315         
316         /* Set timeout to current time */
317         get_current_time(&(s->d1->next_timeout));
318
319         /* Add duration to current time */
320         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
321         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
322         }
323
324 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
325         {
326         struct timeval timenow;
327
328         /* If no timeout is set, just return NULL */
329         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
330                 {
331                 return NULL;
332                 }
333
334         /* Get current time */
335         get_current_time(&timenow);
336
337         /* If timer already expired, set remaining time to 0 */
338         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
339                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
340                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
341                 {
342                 memset(timeleft, 0, sizeof(struct timeval));
343                 return timeleft;
344                 }
345
346         /* Calculate time left until timer expires */
347         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
348         timeleft->tv_sec -= timenow.tv_sec;
349         timeleft->tv_usec -= timenow.tv_usec;
350         if (timeleft->tv_usec < 0)
351                 {
352                 timeleft->tv_sec--;
353                 timeleft->tv_usec += 1000000;
354                 }
355
356         /* If remaining time is less than 15 ms, set it to 0
357          * to prevent issues because of small devergences with
358          * socket timeouts.
359          */
360         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
361                 {
362                 memset(timeleft, 0, sizeof(struct timeval));
363                 }
364         
365
366         return timeleft;
367         }
368
369 int dtls1_is_timer_expired(SSL *s)
370         {
371         struct timeval timeleft;
372
373         /* Get time left until timeout, return false if no timer running */
374         if (dtls1_get_timeout(s, &timeleft) == NULL)
375                 {
376                 return 0;
377                 }
378
379         /* Return false if timer is not expired yet */
380         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
381                 {
382                 return 0;
383                 }
384
385         /* Timer expired, so return true */     
386         return 1;
387         }
388
389 void dtls1_double_timeout(SSL *s)
390         {
391         s->d1->timeout_duration *= 2;
392         if (s->d1->timeout_duration > 60)
393                 s->d1->timeout_duration = 60;
394         dtls1_start_timer(s);
395         }
396
397 void dtls1_stop_timer(SSL *s)
398         {
399         /* Reset everything */
400         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
401         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
402         s->d1->timeout_duration = 1;
403         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
404         /* Clear retransmission buffer */
405         dtls1_clear_record_buffer(s);
406         }
407
408 int dtls1_check_timeout_num(SSL *s)
409         {
410         s->d1->timeout.num_alerts++;
411
412         /* Reduce MTU after 2 unsuccessful retransmissions */
413         if (s->d1->timeout.num_alerts > 2)
414                 {
415                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);               
416                 }
417
418         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
419                 {
420                 /* fail the connection, enough alerts have been sent */
421                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
422                 return -1;
423                 }
424
425         return 0;
426         }
427
428 int dtls1_handle_timeout(SSL *s)
429         {
430         /* if no timer is expired, don't do anything */
431         if (!dtls1_is_timer_expired(s))
432                 {
433                 return 0;
434                 }
435
436         dtls1_double_timeout(s);
437
438         if (dtls1_check_timeout_num(s) < 0)
439                 return -1;
440
441         s->d1->timeout.read_timeouts++;
442         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
443                 {
444                 s->d1->timeout.read_timeouts = 1;
445                 }
446
447 #ifndef OPENSSL_NO_HEARTBEATS
448         if (s->tlsext_hb_pending)
449                 {
450                 s->tlsext_hb_pending = 0;
451                 return dtls1_heartbeat(s);
452                 }
453 #endif
454
455         dtls1_start_timer(s);
456         return dtls1_retransmit_buffered_messages(s);
457         }
458
459 static void get_current_time(struct timeval *t)
460 {
461 #if defined(_WIN32)
462         SYSTEMTIME st;
463         union { unsigned __int64 ul; FILETIME ft; } now;
464
465         GetSystemTime(&st);
466         SystemTimeToFileTime(&st,&now.ft);
467         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
468         t->tv_sec  = (long)(now.ul/10000000);
469         t->tv_usec = ((int)(now.ul%10000000))/10;
470 #elif defined(OPENSSL_SYS_VMS)
471         struct timeb tb;
472         ftime(&tb);
473         t->tv_sec = (long)tb.time;
474         t->tv_usec = (long)tb.millitm * 1000;
475 #else
476         gettimeofday(t, NULL);
477 #endif
478 }
479
480 int dtls1_listen(SSL *s, struct sockaddr *client)
481         {
482         int ret;
483
484         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
485         s->d1->listen = 1;
486
487         ret = SSL_accept(s);
488         if (ret <= 0) return ret;
489         
490         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
491         return 1;
492         }
493
494 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
495         {
496         unsigned char *p = (unsigned char *)s->init_buf->data;
497         dtls1_set_message_header(s, p, htype, len, 0, len);
498         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
499         s->init_off = 0;
500         /* Buffer the message to handle re-xmits */
501         dtls1_buffer_message(s, 0);
502         }
503
504 static int dtls1_handshake_write(SSL *s)
505         {
506         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
507         }
508         
509