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                 rdata = (DTLS1_RECORD_DATA *) item->data;
 195                 if (rdata->rbuf.buf)
 196                         {
 197                         OPENSSL_free(rdata->rbuf.buf);
 198                         }
 199                 OPENSSL_free(item->data);
 200                 pitem_free(item);
 201                 }
 202         }
 203
 204 void dtls1_free(SSL *s)
 205         {
 206         ssl3_free(s);
 207
 208         dtls1_clear_queues(s);
 209
 210     pqueue_free(s->d1->unprocessed_rcds.q);
 211     pqueue_free(s->d1->processed_rcds.q);
 212     pqueue_free(s->d1->buffered_messages);
 213         pqueue_free(s->d1->sent_messages);
 214         pqueue_free(s->d1->buffered_app_data.q);
 215
 216         pq_64bit_free(&(s->d1->bitmap.map));
 217         pq_64bit_free(&(s->d1->bitmap.max_seq_num));
 218
 219         pq_64bit_free(&(s->d1->next_bitmap.map));
 220         pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
 221
 222         OPENSSL_free(s->d1);
 223         s->d1 = NULL;
 224         }
 225
 226 void dtls1_clear(SSL *s)
 227         {
 228     pqueue unprocessed_rcds;
 229     pqueue processed_rcds;
 230     pqueue buffered_messages;
 231         pqueue sent_messages;
 232         pqueue buffered_app_data;
 233         unsigned int mtu;
 234
 235         if (s->d1)
 236                 {
 237                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 238                 processed_rcds = s->d1->processed_rcds.q;
 239                 buffered_messages = s->d1->buffered_messages;
 240                 sent_messages = s->d1->sent_messages;
 241                 buffered_app_data = s->d1->buffered_app_data.q;
 242                 mtu = s->d1->mtu;
 243
 244                 dtls1_clear_queues(s);
 245
 246                 pq_64bit_free(&(s->d1->bitmap.map));
 247                 pq_64bit_free(&(s->d1->bitmap.max_seq_num));
 248
 249                 pq_64bit_free(&(s->d1->next_bitmap.map));
 250                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
 251
 252                 memset(s->d1, 0, sizeof(*(s->d1)));
 253
 254                 if (s->server)
 255                         {
 256                         s->d1->cookie_len = sizeof(s->d1->cookie);
 257                         }
 258
 259                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 260                         {
 261                         s->d1->mtu = mtu;
 262                         }
 263
 264                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 265                 s->d1->processed_rcds.q = processed_rcds;
 266                 s->d1->buffered_messages = buffered_messages;
 267                 s->d1->sent_messages = sent_messages;
 268                 s->d1->buffered_app_data.q = buffered_app_data;
 269
 270 #if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
 271                 s->d1->bitmap.length=64;
 272 #else
 273                 s->d1->bitmap.length=sizeof(s->d1->bitmap.map) * 8;
 274 #endif
 275                 pq_64bit_init(&(s->d1->bitmap.map));
 276                 pq_64bit_init(&(s->d1->bitmap.max_seq_num));
 277
 278                 s->d1->next_bitmap.length = s->d1->bitmap.length;
 279                 pq_64bit_init(&(s->d1->next_bitmap.map));
 280                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
 281                 }
 282
 283         ssl3_clear(s);
 284         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 285                 s->version=DTLS1_BAD_VER;
 286         else
 287                 s->version=DTLS1_VERSION;
 288         }
 289
 290 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 291         {
 292         int ret=0;
 293
 294         switch (cmd)
 295                 {
 296         case DTLS_CTRL_GET_TIMEOUT:
 297                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 298                         {
 299                         ret = 1;
 300                         }
 301                 break;
 302         case DTLS_CTRL_HANDLE_TIMEOUT:
 303                 ret = dtls1_handle_timeout(s);
 304                 break;
 305         case DTLS_CTRL_LISTEN:
 306                 ret = dtls1_listen(s, parg);
 307                 break;
 308
 309         default:
 310                 ret = ssl3_ctrl(s, cmd, larg, parg);
 311                 break;
 312                 }
 313         return(ret);
 314         }
 315
 316 /*
 317  * As it's impossible to use stream ciphers in "datagram" mode, this
 318  * simple filter is designed to disengage them in DTLS. Unfortunately
 319  * there is no universal way to identify stream SSL_CIPHER, so we have
 320  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 321  * available, but if new ones emerge, they will have to be added...
 322  */
 323 SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 324         {
 325         SSL_CIPHER *ciph = ssl3_get_cipher(u);
 326
 327         if (ciph != NULL)
 328                 {
 329                 if ((ciph->algorithms&SSL_ENC_MASK) == SSL_RC4)
 330                         return NULL;
 331                 }
 332
 333         return ciph;
 334         }
 335
 336 void dtls1_start_timer(SSL *s)
 337         {
 338         /* If timer is not set, initialize duration with 1 second */
 339         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 340                 {
 341                 s->d1->timeout_duration = 1;
 342                 }
 343
 344         /* Set timeout to current time */
 345         get_current_time(&(s->d1->next_timeout));
 346
 347         /* Add duration to current time */
 348         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 349         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 350         }
 351
 352 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 353         {
 354         struct timeval timenow;
 355
 356         /* If no timeout is set, just return NULL */
 357         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 358                 {
 359                 return NULL;
 360                 }
 361
 362         /* Get current time */
 363         get_current_time(&timenow);
 364
 365         /* If timer already expired, set remaining time to 0 */
 366         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 367                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 368                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 369                 {
 370                 memset(timeleft, 0, sizeof(struct timeval));
 371                 return timeleft;
 372                 }
 373
 374         /* Calculate time left until timer expires */
 375         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 376         timeleft->tv_sec -= timenow.tv_sec;
 377         timeleft->tv_usec -= timenow.tv_usec;
 378         if (timeleft->tv_usec < 0)
 379                 {
 380                 timeleft->tv_sec--;
 381                 timeleft->tv_usec += 1000000;
 382                 }
 383
 384         /* If remaining time is less than 15 ms, set it to 0
 385          * to prevent issues because of small devergences with
 386          * socket timeouts.
 387          */
 388         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 389                 {
 390                 memset(timeleft, 0, sizeof(struct timeval));
 391                 }
 392
 393
 394         return timeleft;
 395         }
 396
 397 int dtls1_is_timer_expired(SSL *s)
 398         {
 399         struct timeval timeleft;
 400
 401         /* Get time left until timeout, return false if no timer running */
 402         if (dtls1_get_timeout(s, &timeleft) == NULL)
 403                 {
 404                 return 0;
 405                 }
 406
 407         /* Return false if timer is not expired yet */
 408         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 409                 {
 410                 return 0;
 411                 }
 412
 413         /* Timer expired, so return true */
 414         return 1;
 415         }
 416
 417 void dtls1_double_timeout(SSL *s)
 418         {
 419         s->d1->timeout_duration *= 2;
 420         if (s->d1->timeout_duration > 60)
 421                 s->d1->timeout_duration = 60;
 422         dtls1_start_timer(s);
 423         }
 424
 425 void dtls1_stop_timer(SSL *s)
 426         {
 427         /* Reset everything */
 428         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 429         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 430         s->d1->timeout_duration = 1;
 431         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 432         /* Clear retransmission buffer */
 433         dtls1_clear_record_buffer(s);
 434         }
 435
 436 int dtls1_check_timeout_num(SSL *s)
 437         {
 438         s->d1->timeout.num_alerts++;
 439
 440         /* Reduce MTU after 2 unsuccessful retransmissions */
 441         if (s->d1->timeout.num_alerts > 2)
 442                 {
 443                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 444                 }
 445
 446         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 447                 {
 448                 /* fail the connection, enough alerts have been sent */
 449                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 450                 return -1;
 451                 }
 452
 453         return 0;
 454         }
 455
 456 int dtls1_handle_timeout(SSL *s)
 457         {
 458         /* if no timer is expired, don't do anything */
 459         if (!dtls1_is_timer_expired(s))
 460                 {
 461                 return 0;
 462                 }
 463
 464         dtls1_double_timeout(s);
 465
 466         if (dtls1_check_timeout_num(s) < 0)
 467                 return -1;
 468
 469         s->d1->timeout.read_timeouts++;
 470         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 471                 {
 472                 s->d1->timeout.read_timeouts = 1;
 473                 }
 474
 475         dtls1_start_timer(s);
 476         return dtls1_retransmit_buffered_messages(s);
 477         }
 478
 479 static void get_current_time(struct timeval *t)
 480 {
 481 #ifdef OPENSSL_SYS_WIN32
 482         struct _timeb tb;
 483         _ftime(&tb);
 484         t->tv_sec = (long)tb.time;
 485         t->tv_usec = (long)tb.millitm * 1000;
 486 #elif defined(OPENSSL_SYS_VMS)
 487         struct timeb tb;
 488         ftime(&tb);
 489         t->tv_sec = (long)tb.time;
 490         t->tv_usec = (long)tb.millitm * 1000;
 491 #else
 492         gettimeofday(t, NULL);
 493 #endif
 494 }
 495
 496 int dtls1_listen(SSL *s, struct sockaddr *client)
 497         {
 498         int ret;
 499
 500         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 501         s->d1->listen = 1;
 502
 503         ret = SSL_accept(s);
 504         if (ret <= 0) return ret;
 505
 506         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 507         return 1;
 508         }