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 IMPLEMENT_dtls1_meth_func(dtlsv1_base_method,
  95                         ssl_undefined_function,
  96                         ssl_undefined_function,
  97                         ssl_bad_method)
  98
  99 int 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
 148 static void dtls1_clear_queues(SSL *s)
 149         {
 150     pitem *item = NULL;
 151     hm_fragment *frag = NULL;
 152         DTLS1_RECORD_DATA *rdata;
 153
 154     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 155         {
 156                 rdata = (DTLS1_RECORD_DATA *) item->data;
 157                 if (rdata->rbuf.buf)
 158                         {
 159                         OPENSSL_free(rdata->rbuf.buf);
 160                         }
 161         OPENSSL_free(item->data);
 162         pitem_free(item);
 163         }
 164
 165     while( (item = pqueue_pop(s->d1->processed_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->buffered_messages)) != NULL)
 177         {
 178         frag = (hm_fragment *)item->data;
 179         OPENSSL_free(frag->fragment);
 180         OPENSSL_free(frag);
 181         pitem_free(item);
 182         }
 183
 184     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 185         {
 186         frag = (hm_fragment *)item->data;
 187         OPENSSL_free(frag->fragment);
 188         OPENSSL_free(frag);
 189         pitem_free(item);
 190         }
 191
 192         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 193                 {
 194                 frag = (hm_fragment *)item->data;
 195                 OPENSSL_free(frag->fragment);
 196                 OPENSSL_free(frag);
 197                 pitem_free(item);
 198                 }
 199         }
 200
 201 void dtls1_free(SSL *s)
 202         {
 203         ssl3_free(s);
 204
 205         dtls1_clear_queues(s);
 206
 207     pqueue_free(s->d1->unprocessed_rcds.q);
 208     pqueue_free(s->d1->processed_rcds.q);
 209     pqueue_free(s->d1->buffered_messages);
 210         pqueue_free(s->d1->sent_messages);
 211         pqueue_free(s->d1->buffered_app_data.q);
 212
 213         pq_64bit_free(&(s->d1->bitmap.map));
 214         pq_64bit_free(&(s->d1->bitmap.max_seq_num));
 215
 216         pq_64bit_free(&(s->d1->next_bitmap.map));
 217         pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
 218
 219         OPENSSL_free(s->d1);
 220         }
 221
 222 void dtls1_clear(SSL *s)
 223         {
 224     pqueue unprocessed_rcds;
 225     pqueue processed_rcds;
 226     pqueue buffered_messages;
 227         pqueue sent_messages;
 228         pqueue buffered_app_data;
 229
 230         if (s->d1)
 231                 {
 232                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 233                 processed_rcds = s->d1->processed_rcds.q;
 234                 buffered_messages = s->d1->buffered_messages;
 235                 sent_messages = s->d1->sent_messages;
 236                 buffered_app_data = s->d1->buffered_app_data.q;
 237
 238                 dtls1_clear_queues(s);
 239
 240                 pq_64bit_free(&(s->d1->bitmap.map));
 241                 pq_64bit_free(&(s->d1->bitmap.max_seq_num));
 242
 243                 pq_64bit_free(&(s->d1->next_bitmap.map));
 244                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
 245
 246                 memset(s->d1, 0, sizeof(*(s->d1)));
 247
 248                 if (s->server)
 249                         {
 250                         s->d1->cookie_len = sizeof(s->d1->cookie);
 251                         }
 252
 253                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 254                 s->d1->processed_rcds.q = processed_rcds;
 255                 s->d1->buffered_messages = buffered_messages;
 256                 s->d1->sent_messages = sent_messages;
 257                 s->d1->buffered_app_data.q = buffered_app_data;
 258
 259 #if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
 260                 s->d1->bitmap.length=64;
 261 #else
 262                 s->d1->bitmap.length=sizeof(s->d1->bitmap.map) * 8;
 263 #endif
 264                 pq_64bit_init(&(s->d1->bitmap.map));
 265                 pq_64bit_init(&(s->d1->bitmap.max_seq_num));
 266
 267                 s->d1->next_bitmap.length = s->d1->bitmap.length;
 268                 pq_64bit_init(&(s->d1->next_bitmap.map));
 269                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
 270                 }
 271
 272         ssl3_clear(s);
 273         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 274                 s->version=DTLS1_BAD_VER;
 275         else
 276                 s->version=DTLS1_VERSION;
 277         }
 278
 279 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 280         {
 281         int ret=0;
 282
 283         switch (cmd)
 284                 {
 285         case DTLS_CTRL_GET_TIMEOUT:
 286                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 287                         {
 288                         ret = 1;
 289                         }
 290                 break;
 291         case DTLS_CTRL_HANDLE_TIMEOUT:
 292                 ret = dtls1_handle_timeout(s);
 293                 break;
 294         case DTLS_CTRL_LISTEN:
 295                 ret = dtls1_listen(s, parg);
 296                 break;
 297
 298         default:
 299                 ret = ssl3_ctrl(s, cmd, larg, parg);
 300                 break;
 301                 }
 302         return(ret);
 303         }
 304
 305 /*
 306  * As it's impossible to use stream ciphers in "datagram" mode, this
 307  * simple filter is designed to disengage them in DTLS. Unfortunately
 308  * there is no universal way to identify stream SSL_CIPHER, so we have
 309  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 310  * available, but if new ones emerge, they will have to be added...
 311  */
 312 SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 313         {
 314         SSL_CIPHER *ciph = ssl3_get_cipher(u);
 315
 316         if (ciph != NULL)
 317                 {
 318                 if ((ciph->algorithms&SSL_ENC_MASK) == SSL_RC4)
 319                         return NULL;
 320                 }
 321
 322         return ciph;
 323         }
 324
 325 void dtls1_start_timer(SSL *s)
 326         {
 327         /* If timer is not set, initialize duration with 1 second */
 328         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 329                 {
 330                 s->d1->timeout_duration = 1;
 331                 }
 332
 333         /* Set timeout to current time */
 334         get_current_time(&(s->d1->next_timeout));
 335
 336         /* Add duration to current time */
 337         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 338         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 339         }
 340
 341 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 342         {
 343         struct timeval timenow;
 344
 345         /* If no timeout is set, just return NULL */
 346         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 347                 {
 348                 return NULL;
 349                 }
 350
 351         /* Get current time */
 352         get_current_time(&timenow);
 353
 354         /* If timer already expired, set remaining time to 0 */
 355         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 356                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 357                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 358                 {
 359                 memset(timeleft, 0, sizeof(struct timeval));
 360                 return timeleft;
 361                 }
 362
 363         /* Calculate time left until timer expires */
 364         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 365         timeleft->tv_sec -= timenow.tv_sec;
 366         timeleft->tv_usec -= timenow.tv_usec;
 367         if (timeleft->tv_usec < 0)
 368                 {
 369                 timeleft->tv_sec--;
 370                 timeleft->tv_usec += 1000000;
 371                 }
 372
 373         /* If remaining time is less than 15 ms, set it to 0
 374          * to prevent issues because of small devergences with
 375          * socket timeouts.
 376          */
 377         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 378                 {
 379                 memset(timeleft, 0, sizeof(struct timeval));
 380                 }
 381
 382
 383         return timeleft;
 384         }
 385
 386 int dtls1_is_timer_expired(SSL *s)
 387         {
 388         struct timeval timeleft;
 389
 390         /* Get time left until timeout, return false if no timer running */
 391         if (dtls1_get_timeout(s, &timeleft) == NULL)
 392                 {
 393                 return 0;
 394                 }
 395
 396         /* Return false if timer is not expired yet */
 397         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 398                 {
 399                 return 0;
 400                 }
 401
 402         /* Timer expired, so return true */
 403         return 1;
 404         }
 405
 406 void dtls1_double_timeout(SSL *s)
 407         {
 408         s->d1->timeout_duration *= 2;
 409         if (s->d1->timeout_duration > 60)
 410                 s->d1->timeout_duration = 60;
 411         dtls1_start_timer(s);
 412         }
 413
 414 void dtls1_stop_timer(SSL *s)
 415         {
 416         /* Reset everything */
 417         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 418         s->d1->timeout_duration = 1;
 419         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 420         /* Clear retransmission buffer */
 421         dtls1_clear_record_buffer(s);
 422         }
 423
 424 int dtls1_handle_timeout(SSL *s)
 425         {
 426         DTLS1_STATE *state;
 427
 428         /* if no timer is expired, don't do anything */
 429         if (!dtls1_is_timer_expired(s))
 430                 {
 431                 return 0;
 432                 }
 433
 434         dtls1_double_timeout(s);
 435         state = s->d1;
 436         state->timeout.num_alerts++;
 437         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 438                 {
 439                 /* fail the connection, enough alerts have been sent */
 440                 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
 441                 return -1;
 442                 }
 443
 444         state->timeout.read_timeouts++;
 445         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 446                 {
 447                 state->timeout.read_timeouts = 1;
 448                 }
 449
 450         dtls1_start_timer(s);
 451         return dtls1_retransmit_buffered_messages(s);
 452         }
 453
 454 static void get_current_time(struct timeval *t)
 455 {
 456 #ifdef OPENSSL_SYS_WIN32
 457         struct _timeb tb;
 458         _ftime(&tb);
 459         t->tv_sec = (long)tb.time;
 460         t->tv_usec = (long)tb.millitm * 1000;
 461 #elif defined(OPENSSL_SYS_VMS)
 462         struct timeb tb;
 463         ftime(&tb);
 464         t->tv_sec = (long)tb.time;
 465         t->tv_usec = (long)tb.millitm * 1000;
 466 #else
 467         gettimeofday(t, NULL);
 468 #endif
 469 }
 470
 471 int dtls1_listen(SSL *s, struct sockaddr *client)
 472         {
 473         int ret;
 474
 475         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 476         s->d1->listen = 1;
 477
 478         ret = SSL_accept(s);
 479         if (ret <= 0) return ret;
 480
 481         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 482         return 1;
 483         }