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         tls1_export_keying_material,
  86         };
  87
  88 long dtls1_default_timeout(void)
  89         {
  90         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
  91          * is way too long for http, the cache would over fill */
  92         return(60*60*2);
  93         }
  94
  95 int dtls1_new(SSL *s)
  96         {
  97         DTLS1_STATE *d1;
  98
  99         if (!ssl3_new(s)) return(0);
 100         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
 101         memset(d1,0, sizeof *d1);
 102
 103         /* d1->handshake_epoch=0; */
 104
 105         d1->unprocessed_rcds.q=pqueue_new();
 106         d1->processed_rcds.q=pqueue_new();
 107         d1->buffered_messages = pqueue_new();
 108         d1->sent_messages=pqueue_new();
 109         d1->buffered_app_data.q=pqueue_new();
 110
 111         if ( s->server)
 112                 {
 113                 d1->cookie_len = sizeof(s->d1->cookie);
 114                 }
 115
 116         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 117         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 118                 {
 119         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 120         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 121         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 122                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 123                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 124                 OPENSSL_free(d1);
 125                 return (0);
 126                 }
 127
 128         s->d1=d1;
 129         s->method->ssl_clear(s);
 130         return(1);
 131         }
 132
 133 static void dtls1_clear_queues(SSL *s)
 134         {
 135     pitem *item = NULL;
 136     hm_fragment *frag = NULL;
 137         DTLS1_RECORD_DATA *rdata;
 138
 139     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 140         {
 141                 rdata = (DTLS1_RECORD_DATA *) item->data;
 142                 if (rdata->rbuf.buf)
 143                         {
 144                         OPENSSL_free(rdata->rbuf.buf);
 145                         }
 146         OPENSSL_free(item->data);
 147         pitem_free(item);
 148         }
 149
 150     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 151         {
 152                 rdata = (DTLS1_RECORD_DATA *) item->data;
 153                 if (rdata->rbuf.buf)
 154                         {
 155                         OPENSSL_free(rdata->rbuf.buf);
 156                         }
 157         OPENSSL_free(item->data);
 158         pitem_free(item);
 159         }
 160
 161     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 162         {
 163         frag = (hm_fragment *)item->data;
 164         OPENSSL_free(frag->fragment);
 165         OPENSSL_free(frag);
 166         pitem_free(item);
 167         }
 168
 169     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 170         {
 171         frag = (hm_fragment *)item->data;
 172         OPENSSL_free(frag->fragment);
 173         OPENSSL_free(frag);
 174         pitem_free(item);
 175         }
 176
 177         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 178                 {
 179                 rdata = (DTLS1_RECORD_DATA *) item->data;
 180                 if (rdata->rbuf.buf)
 181                         {
 182                         OPENSSL_free(rdata->rbuf.buf);
 183                         }
 184                 OPENSSL_free(item->data);
 185                 pitem_free(item);
 186                 }
 187         }
 188
 189 void dtls1_free(SSL *s)
 190         {
 191         ssl3_free(s);
 192
 193         dtls1_clear_queues(s);
 194
 195     pqueue_free(s->d1->unprocessed_rcds.q);
 196     pqueue_free(s->d1->processed_rcds.q);
 197     pqueue_free(s->d1->buffered_messages);
 198         pqueue_free(s->d1->sent_messages);
 199         pqueue_free(s->d1->buffered_app_data.q);
 200
 201         OPENSSL_free(s->d1);
 202         s->d1 = NULL;
 203         }
 204
 205 void dtls1_clear(SSL *s)
 206         {
 207     pqueue unprocessed_rcds;
 208     pqueue processed_rcds;
 209     pqueue buffered_messages;
 210         pqueue sent_messages;
 211         pqueue buffered_app_data;
 212         unsigned int mtu;
 213
 214         if (s->d1)
 215                 {
 216                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 217                 processed_rcds = s->d1->processed_rcds.q;
 218                 buffered_messages = s->d1->buffered_messages;
 219                 sent_messages = s->d1->sent_messages;
 220                 buffered_app_data = s->d1->buffered_app_data.q;
 221                 mtu = s->d1->mtu;
 222
 223                 dtls1_clear_queues(s);
 224
 225                 memset(s->d1, 0, sizeof(*(s->d1)));
 226
 227                 if (s->server)
 228                         {
 229                         s->d1->cookie_len = sizeof(s->d1->cookie);
 230                         }
 231
 232                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 233                         {
 234                         s->d1->mtu = mtu;
 235                         }
 236
 237                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 238                 s->d1->processed_rcds.q = processed_rcds;
 239                 s->d1->buffered_messages = buffered_messages;
 240                 s->d1->sent_messages = sent_messages;
 241                 s->d1->buffered_app_data.q = buffered_app_data;
 242                 }
 243
 244         ssl3_clear(s);
 245         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 246                 s->version=DTLS1_BAD_VER;
 247         else
 248                 s->version=DTLS1_VERSION;
 249         }
 250
 251 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 252         {
 253         int ret=0;
 254
 255         switch (cmd)
 256                 {
 257         case DTLS_CTRL_GET_TIMEOUT:
 258                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 259                         {
 260                         ret = 1;
 261                         }
 262                 break;
 263         case DTLS_CTRL_HANDLE_TIMEOUT:
 264                 ret = dtls1_handle_timeout(s);
 265                 break;
 266         case DTLS_CTRL_LISTEN:
 267                 ret = dtls1_listen(s, parg);
 268                 break;
 269         case SSL_CTRL_CHECK_PROTO_VERSION:
 270                 /* For library-internal use; checks that the current protocol
 271                  * is the highest enabled version (according to s->ctx->method,
 272                  * as version negotiation may have changed s->method). */
 273 #if DTLS_MAX_VERSION != DTLS1_VERSION
 274 #  error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
 275 #endif
 276                 /* Just one protocol version is supported so far;
 277                  * fail closed if the version is not as expected. */
 278                 return s->version == DTLS_MAX_VERSION;
 279
 280         default:
 281                 ret = ssl3_ctrl(s, cmd, larg, parg);
 282                 break;
 283                 }
 284         return(ret);
 285         }
 286
 287 /*
 288  * As it's impossible to use stream ciphers in "datagram" mode, this
 289  * simple filter is designed to disengage them in DTLS. Unfortunately
 290  * there is no universal way to identify stream SSL_CIPHER, so we have
 291  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 292  * available, but if new ones emerge, they will have to be added...
 293  */
 294 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 295         {
 296         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 297
 298         if (ciph != NULL)
 299                 {
 300                 if (ciph->algorithm_enc == SSL_RC4)
 301                         return NULL;
 302                 }
 303
 304         return ciph;
 305         }
 306
 307 void dtls1_start_timer(SSL *s)
 308         {
 309 #ifndef OPENSSL_NO_SCTP
 310         /* Disable timer for SCTP */
 311         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 312                 {
 313                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 314                 return;
 315                 }
 316 #endif
 317
 318         /* If timer is not set, initialize duration with 1 second */
 319         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 320                 {
 321                 s->d1->timeout_duration = 1;
 322                 }
 323
 324         /* Set timeout to current time */
 325         get_current_time(&(s->d1->next_timeout));
 326
 327         /* Add duration to current time */
 328         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 329         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 330         }
 331
 332 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 333         {
 334         struct timeval timenow;
 335
 336         /* If no timeout is set, just return NULL */
 337         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 338                 {
 339                 return NULL;
 340                 }
 341
 342         /* Get current time */
 343         get_current_time(&timenow);
 344
 345         /* If timer already expired, set remaining time to 0 */
 346         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 347                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 348                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 349                 {
 350                 memset(timeleft, 0, sizeof(struct timeval));
 351                 return timeleft;
 352                 }
 353
 354         /* Calculate time left until timer expires */
 355         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 356         timeleft->tv_sec -= timenow.tv_sec;
 357         timeleft->tv_usec -= timenow.tv_usec;
 358         if (timeleft->tv_usec < 0)
 359                 {
 360                 timeleft->tv_sec--;
 361                 timeleft->tv_usec += 1000000;
 362                 }
 363
 364         /* If remaining time is less than 15 ms, set it to 0
 365          * to prevent issues because of small devergences with
 366          * socket timeouts.
 367          */
 368         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 369                 {
 370                 memset(timeleft, 0, sizeof(struct timeval));
 371                 }
 372
 373
 374         return timeleft;
 375         }
 376
 377 int dtls1_is_timer_expired(SSL *s)
 378         {
 379         struct timeval timeleft;
 380
 381         /* Get time left until timeout, return false if no timer running */
 382         if (dtls1_get_timeout(s, &timeleft) == NULL)
 383                 {
 384                 return 0;
 385                 }
 386
 387         /* Return false if timer is not expired yet */
 388         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 389                 {
 390                 return 0;
 391                 }
 392
 393         /* Timer expired, so return true */
 394         return 1;
 395         }
 396
 397 void dtls1_double_timeout(SSL *s)
 398         {
 399         s->d1->timeout_duration *= 2;
 400         if (s->d1->timeout_duration > 60)
 401                 s->d1->timeout_duration = 60;
 402         dtls1_start_timer(s);
 403         }
 404
 405 void dtls1_stop_timer(SSL *s)
 406         {
 407         /* Reset everything */
 408         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 409         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 410         s->d1->timeout_duration = 1;
 411         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 412         /* Clear retransmission buffer */
 413         dtls1_clear_record_buffer(s);
 414         }
 415
 416 int dtls1_check_timeout_num(SSL *s)
 417         {
 418         s->d1->timeout.num_alerts++;
 419
 420         /* Reduce MTU after 2 unsuccessful retransmissions */
 421         if (s->d1->timeout.num_alerts > 2)
 422                 {
 423                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 424                 }
 425
 426         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 427                 {
 428                 /* fail the connection, enough alerts have been sent */
 429                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 430                 return -1;
 431                 }
 432
 433         return 0;
 434         }
 435
 436 int dtls1_handle_timeout(SSL *s)
 437         {
 438         /* if no timer is expired, don't do anything */
 439         if (!dtls1_is_timer_expired(s))
 440                 {
 441                 return 0;
 442                 }
 443
 444         dtls1_double_timeout(s);
 445
 446         if (dtls1_check_timeout_num(s) < 0)
 447                 return -1;
 448
 449         s->d1->timeout.read_timeouts++;
 450         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 451                 {
 452                 s->d1->timeout.read_timeouts = 1;
 453                 }
 454
 455 #ifndef OPENSSL_NO_HEARTBEATS
 456         if (s->tlsext_hb_pending)
 457                 {
 458                 s->tlsext_hb_pending = 0;
 459                 return dtls1_heartbeat(s);
 460                 }
 461 #endif
 462
 463         dtls1_start_timer(s);
 464         return dtls1_retransmit_buffered_messages(s);
 465         }
 466
 467 static void get_current_time(struct timeval *t)
 468 {
 469 #ifdef OPENSSL_SYS_WIN32
 470         struct _timeb tb;
 471         _ftime(&tb);
 472         t->tv_sec = (long)tb.time;
 473         t->tv_usec = (long)tb.millitm * 1000;
 474 #elif defined(OPENSSL_SYS_VMS)
 475         struct timeb tb;
 476         ftime(&tb);
 477         t->tv_sec = (long)tb.time;
 478         t->tv_usec = (long)tb.millitm * 1000;
 479 #else
 480         gettimeofday(t, NULL);
 481 #endif
 482 }
 483
 484 int dtls1_listen(SSL *s, struct sockaddr *client)
 485         {
 486         int ret;
 487
 488         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 489         s->d1->listen = 1;
 490
 491         ret = SSL_accept(s);
 492         if (ret <= 0) return ret;
 493
 494         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 495         return 1;
 496         }