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         dtls1_hm_fragment_free(frag);
 165         pitem_free(item);
 166         }
 167
 168     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 169         {
 170         frag = (hm_fragment *)item->data;
 171         dtls1_hm_fragment_free(frag);
 172         pitem_free(item);
 173         }
 174
 175         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 176                 {
 177                 rdata = (DTLS1_RECORD_DATA *) item->data;
 178                 if (rdata->rbuf.buf)
 179                         {
 180                         OPENSSL_free(rdata->rbuf.buf);
 181                         }
 182                 OPENSSL_free(item->data);
 183                 pitem_free(item);
 184                 }
 185         }
 186
 187 void dtls1_free(SSL *s)
 188         {
 189         ssl3_free(s);
 190
 191         dtls1_clear_queues(s);
 192
 193     pqueue_free(s->d1->unprocessed_rcds.q);
 194     pqueue_free(s->d1->processed_rcds.q);
 195     pqueue_free(s->d1->buffered_messages);
 196         pqueue_free(s->d1->sent_messages);
 197         pqueue_free(s->d1->buffered_app_data.q);
 198
 199         OPENSSL_free(s->d1);
 200         s->d1 = NULL;
 201         }
 202
 203 void dtls1_clear(SSL *s)
 204         {
 205     pqueue unprocessed_rcds;
 206     pqueue processed_rcds;
 207     pqueue buffered_messages;
 208         pqueue sent_messages;
 209         pqueue buffered_app_data;
 210         unsigned int mtu;
 211
 212         if (s->d1)
 213                 {
 214                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 215                 processed_rcds = s->d1->processed_rcds.q;
 216                 buffered_messages = s->d1->buffered_messages;
 217                 sent_messages = s->d1->sent_messages;
 218                 buffered_app_data = s->d1->buffered_app_data.q;
 219                 mtu = s->d1->mtu;
 220
 221                 dtls1_clear_queues(s);
 222
 223                 memset(s->d1, 0, sizeof(*(s->d1)));
 224
 225                 if (s->server)
 226                         {
 227                         s->d1->cookie_len = sizeof(s->d1->cookie);
 228                         }
 229
 230                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 231                         {
 232                         s->d1->mtu = mtu;
 233                         }
 234
 235                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 236                 s->d1->processed_rcds.q = processed_rcds;
 237                 s->d1->buffered_messages = buffered_messages;
 238                 s->d1->sent_messages = sent_messages;
 239                 s->d1->buffered_app_data.q = buffered_app_data;
 240                 }
 241
 242         ssl3_clear(s);
 243         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 244                 s->version=DTLS1_BAD_VER;
 245         else
 246                 s->version=DTLS1_VERSION;
 247         }
 248
 249 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 250         {
 251         int ret=0;
 252
 253         switch (cmd)
 254                 {
 255         case DTLS_CTRL_GET_TIMEOUT:
 256                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 257                         {
 258                         ret = 1;
 259                         }
 260                 break;
 261         case DTLS_CTRL_HANDLE_TIMEOUT:
 262                 ret = dtls1_handle_timeout(s);
 263                 break;
 264         case DTLS_CTRL_LISTEN:
 265                 ret = dtls1_listen(s, parg);
 266                 break;
 267         case SSL_CTRL_CHECK_PROTO_VERSION:
 268                 /* For library-internal use; checks that the current protocol
 269                  * is the highest enabled version (according to s->ctx->method,
 270                  * as version negotiation may have changed s->method). */
 271 #if DTLS_MAX_VERSION != DTLS1_VERSION
 272 #  error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
 273 #endif
 274                 /* Just one protocol version is supported so far;
 275                  * fail closed if the version is not as expected. */
 276                 return s->version == DTLS_MAX_VERSION;
 277
 278         default:
 279                 ret = ssl3_ctrl(s, cmd, larg, parg);
 280                 break;
 281                 }
 282         return(ret);
 283         }
 284
 285 /*
 286  * As it's impossible to use stream ciphers in "datagram" mode, this
 287  * simple filter is designed to disengage them in DTLS. Unfortunately
 288  * there is no universal way to identify stream SSL_CIPHER, so we have
 289  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 290  * available, but if new ones emerge, they will have to be added...
 291  */
 292 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 293         {
 294         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 295
 296         if (ciph != NULL)
 297                 {
 298                 if (ciph->algorithm_enc == SSL_RC4)
 299                         return NULL;
 300                 }
 301
 302         return ciph;
 303         }
 304
 305 void dtls1_start_timer(SSL *s)
 306         {
 307 #ifndef OPENSSL_NO_SCTP
 308         /* Disable timer for SCTP */
 309         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 310                 {
 311                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 312                 return;
 313                 }
 314 #endif
 315
 316         /* If timer is not set, initialize duration with 1 second */
 317         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 318                 {
 319                 s->d1->timeout_duration = 1;
 320                 }
 321
 322         /* Set timeout to current time */
 323         get_current_time(&(s->d1->next_timeout));
 324
 325         /* Add duration to current time */
 326         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 327         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 328         }
 329
 330 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 331         {
 332         struct timeval timenow;
 333
 334         /* If no timeout is set, just return NULL */
 335         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 336                 {
 337                 return NULL;
 338                 }
 339
 340         /* Get current time */
 341         get_current_time(&timenow);
 342
 343         /* If timer already expired, set remaining time to 0 */
 344         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 345                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 346                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 347                 {
 348                 memset(timeleft, 0, sizeof(struct timeval));
 349                 return timeleft;
 350                 }
 351
 352         /* Calculate time left until timer expires */
 353         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 354         timeleft->tv_sec -= timenow.tv_sec;
 355         timeleft->tv_usec -= timenow.tv_usec;
 356         if (timeleft->tv_usec < 0)
 357                 {
 358                 timeleft->tv_sec--;
 359                 timeleft->tv_usec += 1000000;
 360                 }
 361
 362         /* If remaining time is less than 15 ms, set it to 0
 363          * to prevent issues because of small devergences with
 364          * socket timeouts.
 365          */
 366         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 367                 {
 368                 memset(timeleft, 0, sizeof(struct timeval));
 369                 }
 370
 371
 372         return timeleft;
 373         }
 374
 375 int dtls1_is_timer_expired(SSL *s)
 376         {
 377         struct timeval timeleft;
 378
 379         /* Get time left until timeout, return false if no timer running */
 380         if (dtls1_get_timeout(s, &timeleft) == NULL)
 381                 {
 382                 return 0;
 383                 }
 384
 385         /* Return false if timer is not expired yet */
 386         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 387                 {
 388                 return 0;
 389                 }
 390
 391         /* Timer expired, so return true */
 392         return 1;
 393         }
 394
 395 void dtls1_double_timeout(SSL *s)
 396         {
 397         s->d1->timeout_duration *= 2;
 398         if (s->d1->timeout_duration > 60)
 399                 s->d1->timeout_duration = 60;
 400         dtls1_start_timer(s);
 401         }
 402
 403 void dtls1_stop_timer(SSL *s)
 404         {
 405         /* Reset everything */
 406         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 407         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 408         s->d1->timeout_duration = 1;
 409         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 410         /* Clear retransmission buffer */
 411         dtls1_clear_record_buffer(s);
 412         }
 413
 414 int dtls1_check_timeout_num(SSL *s)
 415         {
 416         s->d1->timeout.num_alerts++;
 417
 418         /* Reduce MTU after 2 unsuccessful retransmissions */
 419         if (s->d1->timeout.num_alerts > 2)
 420                 {
 421                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 422                 }
 423
 424         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 425                 {
 426                 /* fail the connection, enough alerts have been sent */
 427                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 428                 return -1;
 429                 }
 430
 431         return 0;
 432         }
 433
 434 int dtls1_handle_timeout(SSL *s)
 435         {
 436         /* if no timer is expired, don't do anything */
 437         if (!dtls1_is_timer_expired(s))
 438                 {
 439                 return 0;
 440                 }
 441
 442         dtls1_double_timeout(s);
 443
 444         if (dtls1_check_timeout_num(s) < 0)
 445                 return -1;
 446
 447         s->d1->timeout.read_timeouts++;
 448         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 449                 {
 450                 s->d1->timeout.read_timeouts = 1;
 451                 }
 452
 453 #ifndef OPENSSL_NO_HEARTBEATS
 454         if (s->tlsext_hb_pending)
 455                 {
 456                 s->tlsext_hb_pending = 0;
 457                 return dtls1_heartbeat(s);
 458                 }
 459 #endif
 460
 461         dtls1_start_timer(s);
 462         return dtls1_retransmit_buffered_messages(s);
 463         }
 464
 465 static void get_current_time(struct timeval *t)
 466 {
 467 #ifdef OPENSSL_SYS_WIN32
 468         struct _timeb tb;
 469         _ftime(&tb);
 470         t->tv_sec = (long)tb.time;
 471         t->tv_usec = (long)tb.millitm * 1000;
 472 #elif defined(OPENSSL_SYS_VMS)
 473         struct timeb tb;
 474         ftime(&tb);
 475         t->tv_sec = (long)tb.time;
 476         t->tv_usec = (long)tb.millitm * 1000;
 477 #else
 478         gettimeofday(t, NULL);
 479 #endif
 480 }
 481
 482 int dtls1_listen(SSL *s, struct sockaddr *client)
 483         {
 484         int ret;
 485
 486         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 487         s->d1->listen = 1;
 488
 489         ret = SSL_accept(s);
 490         if (ret <= 0) return ret;
 491
 492         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 493         return 1;
 494         }