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[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         tls1_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 SSL3_ENC_METHOD DTLSv1_2_enc_data={
95         tls1_enc,
96         tls1_mac,
97         tls1_setup_key_block,
98         tls1_generate_master_secret,
99         tls1_change_cipher_state,
100         tls1_final_finish_mac,
101         TLS1_FINISH_MAC_LENGTH,
102         tls1_cert_verify_mac,
103         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
104         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
105         tls1_alert_code,
106         tls1_export_keying_material,
107         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS
108                 |SSL_ENC_FLAG_SHA256_PRF|SSL_ENC_FLAG_TLS1_2_CIPHERS,
109         DTLS1_HM_HEADER_LENGTH,
110         dtls1_set_handshake_header,
111         dtls1_handshake_write   
112         };
113
114 long dtls1_default_timeout(void)
115         {
116         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
117          * is way too long for http, the cache would over fill */
118         return(60*60*2);
119         }
120
121 int dtls1_new(SSL *s)
122         {
123         DTLS1_STATE *d1;
124
125         if (!ssl3_new(s)) return(0);
126         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
127         memset(d1,0, sizeof *d1);
128
129         /* d1->handshake_epoch=0; */
130
131         d1->unprocessed_rcds.q=pqueue_new();
132         d1->processed_rcds.q=pqueue_new();
133         d1->buffered_messages = pqueue_new();
134         d1->sent_messages=pqueue_new();
135         d1->buffered_app_data.q=pqueue_new();
136
137         if ( s->server)
138                 {
139                 d1->cookie_len = sizeof(s->d1->cookie);
140                 }
141
142         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 
143         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
144                 {
145         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
146         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
147         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
148                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
149                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
150                 OPENSSL_free(d1);
151                 return (0);
152                 }
153
154         s->d1=d1;
155         s->method->ssl_clear(s);
156         return(1);
157         }
158
159 static void dtls1_clear_queues(SSL *s)
160         {
161     pitem *item = NULL;
162     hm_fragment *frag = NULL;
163         DTLS1_RECORD_DATA *rdata;
164
165     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
166         {
167                 rdata = (DTLS1_RECORD_DATA *) item->data;
168                 if (rdata->rbuf.buf)
169                         {
170                         OPENSSL_free(rdata->rbuf.buf);
171                         }
172         OPENSSL_free(item->data);
173         pitem_free(item);
174         }
175
176     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
177         {
178                 rdata = (DTLS1_RECORD_DATA *) item->data;
179                 if (rdata->rbuf.buf)
180                         {
181                         OPENSSL_free(rdata->rbuf.buf);
182                         }
183         OPENSSL_free(item->data);
184         pitem_free(item);
185         }
186
187     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
188         {
189         frag = (hm_fragment *)item->data;
190         OPENSSL_free(frag->fragment);
191         OPENSSL_free(frag);
192         pitem_free(item);
193         }
194
195     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
196         {
197         frag = (hm_fragment *)item->data;
198         OPENSSL_free(frag->fragment);
199         OPENSSL_free(frag);
200         pitem_free(item);
201         }
202
203         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
204                 {
205                 frag = (hm_fragment *)item->data;
206                 OPENSSL_free(frag->fragment);
207                 OPENSSL_free(frag);
208                 pitem_free(item);
209                 }
210         }
211
212 void dtls1_free(SSL *s)
213         {
214         ssl3_free(s);
215
216         dtls1_clear_queues(s);
217
218     pqueue_free(s->d1->unprocessed_rcds.q);
219     pqueue_free(s->d1->processed_rcds.q);
220     pqueue_free(s->d1->buffered_messages);
221         pqueue_free(s->d1->sent_messages);
222         pqueue_free(s->d1->buffered_app_data.q);
223
224         OPENSSL_free(s->d1);
225         s->d1 = NULL;
226         }
227
228 void dtls1_clear(SSL *s)
229         {
230     pqueue unprocessed_rcds;
231     pqueue processed_rcds;
232     pqueue buffered_messages;
233         pqueue sent_messages;
234         pqueue buffered_app_data;
235         unsigned int mtu;
236
237         if (s->d1)
238                 {
239                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
240                 processed_rcds = s->d1->processed_rcds.q;
241                 buffered_messages = s->d1->buffered_messages;
242                 sent_messages = s->d1->sent_messages;
243                 buffered_app_data = s->d1->buffered_app_data.q;
244                 mtu = s->d1->mtu;
245
246                 dtls1_clear_queues(s);
247
248                 memset(s->d1, 0, sizeof(*(s->d1)));
249
250                 if (s->server)
251                         {
252                         s->d1->cookie_len = sizeof(s->d1->cookie);
253                         }
254
255                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
256                         {
257                         s->d1->mtu = mtu;
258                         }
259
260                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
261                 s->d1->processed_rcds.q = processed_rcds;
262                 s->d1->buffered_messages = buffered_messages;
263                 s->d1->sent_messages = sent_messages;
264                 s->d1->buffered_app_data.q = buffered_app_data;
265                 }
266
267         ssl3_clear(s);
268         if (s->options & SSL_OP_CISCO_ANYCONNECT)
269                 s->version=DTLS1_BAD_VER;
270         else if (s->method->version == DTLS_ANY_VERSION)
271                 s->version=DTLS1_2_VERSION;
272         else
273                 s->version=s->method->version;
274         }
275
276 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
277         {
278         int ret=0;
279
280         switch (cmd)
281                 {
282         case DTLS_CTRL_GET_TIMEOUT:
283                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
284                         {
285                         ret = 1;
286                         }
287                 break;
288         case DTLS_CTRL_HANDLE_TIMEOUT:
289                 ret = dtls1_handle_timeout(s);
290                 break;
291         case DTLS_CTRL_LISTEN:
292                 ret = dtls1_listen(s, parg);
293                 break;
294
295         default:
296                 ret = ssl3_ctrl(s, cmd, larg, parg);
297                 break;
298                 }
299         return(ret);
300         }
301
302 /*
303  * As it's impossible to use stream ciphers in "datagram" mode, this
304  * simple filter is designed to disengage them in DTLS. Unfortunately
305  * there is no universal way to identify stream SSL_CIPHER, so we have
306  * to explicitly list their SSL_* codes. Currently RC4 is the only one
307  * available, but if new ones emerge, they will have to be added...
308  */
309 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
310         {
311         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
312
313         if (ciph != NULL)
314                 {
315                 if (ciph->algorithm_enc == SSL_RC4)
316                         return NULL;
317                 }
318
319         return ciph;
320         }
321
322 void dtls1_start_timer(SSL *s)
323         {
324 #ifndef OPENSSL_NO_SCTP
325         /* Disable timer for SCTP */
326         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
327                 {
328                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
329                 return;
330                 }
331 #endif
332
333         /* If timer is not set, initialize duration with 1 second */
334         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
335                 {
336                 s->d1->timeout_duration = 1;
337                 }
338         
339         /* Set timeout to current time */
340         get_current_time(&(s->d1->next_timeout));
341
342         /* Add duration to current time */
343         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
344         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
345         }
346
347 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
348         {
349         struct timeval timenow;
350
351         /* If no timeout is set, just return NULL */
352         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
353                 {
354                 return NULL;
355                 }
356
357         /* Get current time */
358         get_current_time(&timenow);
359
360         /* If timer already expired, set remaining time to 0 */
361         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
362                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
363                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
364                 {
365                 memset(timeleft, 0, sizeof(struct timeval));
366                 return timeleft;
367                 }
368
369         /* Calculate time left until timer expires */
370         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
371         timeleft->tv_sec -= timenow.tv_sec;
372         timeleft->tv_usec -= timenow.tv_usec;
373         if (timeleft->tv_usec < 0)
374                 {
375                 timeleft->tv_sec--;
376                 timeleft->tv_usec += 1000000;
377                 }
378
379         /* If remaining time is less than 15 ms, set it to 0
380          * to prevent issues because of small devergences with
381          * socket timeouts.
382          */
383         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
384                 {
385                 memset(timeleft, 0, sizeof(struct timeval));
386                 }
387         
388
389         return timeleft;
390         }
391
392 int dtls1_is_timer_expired(SSL *s)
393         {
394         struct timeval timeleft;
395
396         /* Get time left until timeout, return false if no timer running */
397         if (dtls1_get_timeout(s, &timeleft) == NULL)
398                 {
399                 return 0;
400                 }
401
402         /* Return false if timer is not expired yet */
403         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
404                 {
405                 return 0;
406                 }
407
408         /* Timer expired, so return true */     
409         return 1;
410         }
411
412 void dtls1_double_timeout(SSL *s)
413         {
414         s->d1->timeout_duration *= 2;
415         if (s->d1->timeout_duration > 60)
416                 s->d1->timeout_duration = 60;
417         dtls1_start_timer(s);
418         }
419
420 void dtls1_stop_timer(SSL *s)
421         {
422         /* Reset everything */
423         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
424         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
425         s->d1->timeout_duration = 1;
426         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
427         /* Clear retransmission buffer */
428         dtls1_clear_record_buffer(s);
429         }
430
431 int dtls1_check_timeout_num(SSL *s)
432         {
433         s->d1->timeout.num_alerts++;
434
435         /* Reduce MTU after 2 unsuccessful retransmissions */
436         if (s->d1->timeout.num_alerts > 2)
437                 {
438                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);               
439                 }
440
441         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
442                 {
443                 /* fail the connection, enough alerts have been sent */
444                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
445                 return -1;
446                 }
447
448         return 0;
449         }
450
451 int dtls1_handle_timeout(SSL *s)
452         {
453         /* if no timer is expired, don't do anything */
454         if (!dtls1_is_timer_expired(s))
455                 {
456                 return 0;
457                 }
458
459         dtls1_double_timeout(s);
460
461         if (dtls1_check_timeout_num(s) < 0)
462                 return -1;
463
464         s->d1->timeout.read_timeouts++;
465         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
466                 {
467                 s->d1->timeout.read_timeouts = 1;
468                 }
469
470 #ifndef OPENSSL_NO_HEARTBEATS
471         if (s->tlsext_hb_pending)
472                 {
473                 s->tlsext_hb_pending = 0;
474                 return dtls1_heartbeat(s);
475                 }
476 #endif
477
478         dtls1_start_timer(s);
479         return dtls1_retransmit_buffered_messages(s);
480         }
481
482 static void get_current_time(struct timeval *t)
483 {
484 #if defined(_WIN32)
485         SYSTEMTIME st;
486         union { unsigned __int64 ul; FILETIME ft; } now;
487
488         GetSystemTime(&st);
489         SystemTimeToFileTime(&st,&now.ft);
490         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
491         t->tv_sec  = (long)(now.ul/10000000);
492         t->tv_usec = ((int)(now.ul%10000000))/10;
493 #elif defined(OPENSSL_SYS_VMS)
494         struct timeb tb;
495         ftime(&tb);
496         t->tv_sec = (long)tb.time;
497         t->tv_usec = (long)tb.millitm * 1000;
498 #else
499         gettimeofday(t, NULL);
500 #endif
501 }
502
503 int dtls1_listen(SSL *s, struct sockaddr *client)
504         {
505         int ret;
506
507         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
508         s->d1->listen = 1;
509
510         ret = SSL_accept(s);
511         if (ret <= 0) return ret;
512         
513         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
514         return 1;
515         }
516
517 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
518         {
519         unsigned char *p = (unsigned char *)s->init_buf->data;
520         dtls1_set_message_header(s, p, htype, len, 0, len);
521         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
522         s->init_off = 0;
523         /* Buffer the message to handle re-xmits */
524         dtls1_buffer_message(s, 0);
525         }
526
527 static int dtls1_handshake_write(SSL *s)
528         {
529         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
530         }