[PR3597] Advance to the next state variant when reusing messages.
[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 const 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 const 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         dtls1_hm_fragment_free(frag);
191         pitem_free(item);
192         }
193
194     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
195         {
196         frag = (hm_fragment *)item->data;
197         dtls1_hm_fragment_free(frag);
198         pitem_free(item);
199         }
200
201         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
202                 {
203                 rdata = (DTLS1_RECORD_DATA *) item->data;
204                 if (rdata->rbuf.buf)
205                         {
206                         OPENSSL_free(rdata->rbuf.buf);
207                         }
208                 OPENSSL_free(item->data);
209                 pitem_free(item);
210                 }
211         }
212
213 void dtls1_free(SSL *s)
214         {
215         ssl3_free(s);
216
217         dtls1_clear_queues(s);
218
219     pqueue_free(s->d1->unprocessed_rcds.q);
220     pqueue_free(s->d1->processed_rcds.q);
221     pqueue_free(s->d1->buffered_messages);
222         pqueue_free(s->d1->sent_messages);
223         pqueue_free(s->d1->buffered_app_data.q);
224
225         OPENSSL_free(s->d1);
226         s->d1 = NULL;
227         }
228
229 void dtls1_clear(SSL *s)
230         {
231     pqueue unprocessed_rcds;
232     pqueue processed_rcds;
233     pqueue buffered_messages;
234         pqueue sent_messages;
235         pqueue buffered_app_data;
236         unsigned int mtu;
237
238         if (s->d1)
239                 {
240                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
241                 processed_rcds = s->d1->processed_rcds.q;
242                 buffered_messages = s->d1->buffered_messages;
243                 sent_messages = s->d1->sent_messages;
244                 buffered_app_data = s->d1->buffered_app_data.q;
245                 mtu = s->d1->mtu;
246
247                 dtls1_clear_queues(s);
248
249                 memset(s->d1, 0, sizeof(*(s->d1)));
250
251                 if (s->server)
252                         {
253                         s->d1->cookie_len = sizeof(s->d1->cookie);
254                         }
255
256                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
257                         {
258                         s->d1->mtu = mtu;
259                         }
260
261                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
262                 s->d1->processed_rcds.q = processed_rcds;
263                 s->d1->buffered_messages = buffered_messages;
264                 s->d1->sent_messages = sent_messages;
265                 s->d1->buffered_app_data.q = buffered_app_data;
266                 }
267
268         ssl3_clear(s);
269         if (s->options & SSL_OP_CISCO_ANYCONNECT)
270                 s->version=DTLS1_BAD_VER;
271         else if (s->method->version == DTLS_ANY_VERSION)
272                 s->version=DTLS1_2_VERSION;
273         else
274                 s->version=s->method->version;
275         }
276
277 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
278         {
279         int ret=0;
280
281         switch (cmd)
282                 {
283         case DTLS_CTRL_GET_TIMEOUT:
284                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
285                         {
286                         ret = 1;
287                         }
288                 break;
289         case DTLS_CTRL_HANDLE_TIMEOUT:
290                 ret = dtls1_handle_timeout(s);
291                 break;
292         case DTLS_CTRL_LISTEN:
293                 ret = dtls1_listen(s, parg);
294                 break;
295         case SSL_CTRL_CHECK_PROTO_VERSION:
296                 /* For library-internal use; checks that the current protocol
297                  * is the highest enabled version (according to s->ctx->method,
298                  * as version negotiation may have changed s->method). */
299                 if (s->version == s->ctx->method->version)
300                         return 1;
301                 /* Apparently we're using a version-flexible SSL_METHOD
302                  * (not at its highest protocol version). */
303                 if (s->ctx->method->version == DTLS_method()->version)
304                         {
305 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
306 #  error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
307 #endif
308                         if (!(s->options & SSL_OP_NO_DTLSv1_2))
309                                 return s->version == DTLS1_2_VERSION;
310                         if (!(s->options & SSL_OP_NO_DTLSv1))
311                                 return s->version == DTLS1_VERSION;
312                         }
313                 return 0; /* Unexpected state; fail closed. */
314
315         default:
316                 ret = ssl3_ctrl(s, cmd, larg, parg);
317                 break;
318                 }
319         return(ret);
320         }
321
322 /*
323  * As it's impossible to use stream ciphers in "datagram" mode, this
324  * simple filter is designed to disengage them in DTLS. Unfortunately
325  * there is no universal way to identify stream SSL_CIPHER, so we have
326  * to explicitly list their SSL_* codes. Currently RC4 is the only one
327  * available, but if new ones emerge, they will have to be added...
328  */
329 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
330         {
331         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
332
333         if (ciph != NULL)
334                 {
335                 if (ciph->algorithm_enc == SSL_RC4)
336                         return NULL;
337                 }
338
339         return ciph;
340         }
341
342 void dtls1_start_timer(SSL *s)
343         {
344 #ifndef OPENSSL_NO_SCTP
345         /* Disable timer for SCTP */
346         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
347                 {
348                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
349                 return;
350                 }
351 #endif
352
353         /* If timer is not set, initialize duration with 1 second */
354         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
355                 {
356                 s->d1->timeout_duration = 1;
357                 }
358         
359         /* Set timeout to current time */
360         get_current_time(&(s->d1->next_timeout));
361
362         /* Add duration to current time */
363         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
364         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
365         }
366
367 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
368         {
369         struct timeval timenow;
370
371         /* If no timeout is set, just return NULL */
372         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
373                 {
374                 return NULL;
375                 }
376
377         /* Get current time */
378         get_current_time(&timenow);
379
380         /* If timer already expired, set remaining time to 0 */
381         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
382                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
383                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
384                 {
385                 memset(timeleft, 0, sizeof(struct timeval));
386                 return timeleft;
387                 }
388
389         /* Calculate time left until timer expires */
390         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
391         timeleft->tv_sec -= timenow.tv_sec;
392         timeleft->tv_usec -= timenow.tv_usec;
393         if (timeleft->tv_usec < 0)
394                 {
395                 timeleft->tv_sec--;
396                 timeleft->tv_usec += 1000000;
397                 }
398
399         /* If remaining time is less than 15 ms, set it to 0
400          * to prevent issues because of small devergences with
401          * socket timeouts.
402          */
403         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
404                 {
405                 memset(timeleft, 0, sizeof(struct timeval));
406                 }
407         
408
409         return timeleft;
410         }
411
412 int dtls1_is_timer_expired(SSL *s)
413         {
414         struct timeval timeleft;
415
416         /* Get time left until timeout, return false if no timer running */
417         if (dtls1_get_timeout(s, &timeleft) == NULL)
418                 {
419                 return 0;
420                 }
421
422         /* Return false if timer is not expired yet */
423         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
424                 {
425                 return 0;
426                 }
427
428         /* Timer expired, so return true */     
429         return 1;
430         }
431
432 void dtls1_double_timeout(SSL *s)
433         {
434         s->d1->timeout_duration *= 2;
435         if (s->d1->timeout_duration > 60)
436                 s->d1->timeout_duration = 60;
437         dtls1_start_timer(s);
438         }
439
440 void dtls1_stop_timer(SSL *s)
441         {
442         /* Reset everything */
443         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
444         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
445         s->d1->timeout_duration = 1;
446         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
447         /* Clear retransmission buffer */
448         dtls1_clear_record_buffer(s);
449         }
450
451 int dtls1_check_timeout_num(SSL *s)
452         {
453         s->d1->timeout.num_alerts++;
454
455         /* Reduce MTU after 2 unsuccessful retransmissions */
456         if (s->d1->timeout.num_alerts > 2)
457                 {
458                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);               
459                 }
460
461         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
462                 {
463                 /* fail the connection, enough alerts have been sent */
464                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
465                 return -1;
466                 }
467
468         return 0;
469         }
470
471 int dtls1_handle_timeout(SSL *s)
472         {
473         /* if no timer is expired, don't do anything */
474         if (!dtls1_is_timer_expired(s))
475                 {
476                 return 0;
477                 }
478
479         dtls1_double_timeout(s);
480
481         if (dtls1_check_timeout_num(s) < 0)
482                 return -1;
483
484         s->d1->timeout.read_timeouts++;
485         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
486                 {
487                 s->d1->timeout.read_timeouts = 1;
488                 }
489
490 #ifndef OPENSSL_NO_HEARTBEATS
491         if (s->tlsext_hb_pending)
492                 {
493                 s->tlsext_hb_pending = 0;
494                 return dtls1_heartbeat(s);
495                 }
496 #endif
497
498         dtls1_start_timer(s);
499         return dtls1_retransmit_buffered_messages(s);
500         }
501
502 static void get_current_time(struct timeval *t)
503 {
504 #if defined(_WIN32)
505         SYSTEMTIME st;
506         union { unsigned __int64 ul; FILETIME ft; } now;
507
508         GetSystemTime(&st);
509         SystemTimeToFileTime(&st,&now.ft);
510 #ifdef  __MINGW32__
511         now.ul -= 116444736000000000ULL;
512 #else
513         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
514 #endif
515         t->tv_sec  = (long)(now.ul/10000000);
516         t->tv_usec = ((int)(now.ul%10000000))/10;
517 #elif defined(OPENSSL_SYS_VMS)
518         struct timeb tb;
519         ftime(&tb);
520         t->tv_sec = (long)tb.time;
521         t->tv_usec = (long)tb.millitm * 1000;
522 #else
523         gettimeofday(t, NULL);
524 #endif
525 }
526
527 int dtls1_listen(SSL *s, struct sockaddr *client)
528         {
529         int ret;
530
531         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
532         s->d1->listen = 1;
533
534         ret = SSL_accept(s);
535         if (ret <= 0) return ret;
536         
537         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
538         return 1;
539         }
540
541 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
542         {
543         unsigned char *p = (unsigned char *)s->init_buf->data;
544         dtls1_set_message_header(s, p, htype, len, 0, len);
545         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
546         s->init_off = 0;
547         /* Buffer the message to handle re-xmits */
548         dtls1_buffer_message(s, 0);
549         }
550
551 static int dtls1_handshake_write(SSL *s)
552         {
553         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
554         }