crypto/openssl/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         d1->link_mtu = 0;
 117         d1->mtu = 0;
 118
 119         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 120         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 121                 {
 122         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 123         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 124         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 125                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 126                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 127                 OPENSSL_free(d1);
 128                 return (0);
 129                 }
 130
 131         s->d1=d1;
 132         s->method->ssl_clear(s);
 133         return(1);
 134         }
 135
 136 static void dtls1_clear_queues(SSL *s)
 137         {
 138     pitem *item = NULL;
 139     hm_fragment *frag = NULL;
 140         DTLS1_RECORD_DATA *rdata;
 141
 142     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 143         {
 144                 rdata = (DTLS1_RECORD_DATA *) item->data;
 145                 if (rdata->rbuf.buf)
 146                         {
 147                         OPENSSL_free(rdata->rbuf.buf);
 148                         }
 149         OPENSSL_free(item->data);
 150         pitem_free(item);
 151         }
 152
 153     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 154         {
 155                 rdata = (DTLS1_RECORD_DATA *) item->data;
 156                 if (rdata->rbuf.buf)
 157                         {
 158                         OPENSSL_free(rdata->rbuf.buf);
 159                         }
 160         OPENSSL_free(item->data);
 161         pitem_free(item);
 162         }
 163
 164     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 165         {
 166         frag = (hm_fragment *)item->data;
 167         dtls1_hm_fragment_free(frag);
 168         pitem_free(item);
 169         }
 170
 171     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 172         {
 173         frag = (hm_fragment *)item->data;
 174         dtls1_hm_fragment_free(frag);
 175         pitem_free(item);
 176         }
 177
 178         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 179                 {
 180                 rdata = (DTLS1_RECORD_DATA *) item->data;
 181                 if (rdata->rbuf.buf)
 182                         {
 183                         OPENSSL_free(rdata->rbuf.buf);
 184                         }
 185                 OPENSSL_free(item->data);
 186                 pitem_free(item);
 187                 }
 188         }
 189
 190 void dtls1_free(SSL *s)
 191         {
 192         ssl3_free(s);
 193
 194         dtls1_clear_queues(s);
 195
 196     pqueue_free(s->d1->unprocessed_rcds.q);
 197     pqueue_free(s->d1->processed_rcds.q);
 198     pqueue_free(s->d1->buffered_messages);
 199         pqueue_free(s->d1->sent_messages);
 200         pqueue_free(s->d1->buffered_app_data.q);
 201
 202         OPENSSL_free(s->d1);
 203         s->d1 = NULL;
 204         }
 205
 206 void dtls1_clear(SSL *s)
 207         {
 208     pqueue unprocessed_rcds;
 209     pqueue processed_rcds;
 210     pqueue buffered_messages;
 211         pqueue sent_messages;
 212         pqueue buffered_app_data;
 213         unsigned int mtu;
 214         unsigned int link_mtu;
 215
 216         if (s->d1)
 217                 {
 218                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 219                 processed_rcds = s->d1->processed_rcds.q;
 220                 buffered_messages = s->d1->buffered_messages;
 221                 sent_messages = s->d1->sent_messages;
 222                 buffered_app_data = s->d1->buffered_app_data.q;
 223                 mtu = s->d1->mtu;
 224                 link_mtu = s->d1->link_mtu;
 225
 226                 dtls1_clear_queues(s);
 227
 228                 memset(s->d1, 0, sizeof(*(s->d1)));
 229
 230                 if (s->server)
 231                         {
 232                         s->d1->cookie_len = sizeof(s->d1->cookie);
 233                         }
 234
 235                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 236                         {
 237                         s->d1->mtu = mtu;
 238                         s->d1->link_mtu = link_mtu;
 239                         }
 240
 241                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 242                 s->d1->processed_rcds.q = processed_rcds;
 243                 s->d1->buffered_messages = buffered_messages;
 244                 s->d1->sent_messages = sent_messages;
 245                 s->d1->buffered_app_data.q = buffered_app_data;
 246                 }
 247
 248         ssl3_clear(s);
 249         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 250                 s->version=DTLS1_BAD_VER;
 251         else
 252                 s->version=DTLS1_VERSION;
 253         }
 254
 255 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 256         {
 257         int ret=0;
 258
 259         switch (cmd)
 260                 {
 261         case DTLS_CTRL_GET_TIMEOUT:
 262                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 263                         {
 264                         ret = 1;
 265                         }
 266                 break;
 267         case DTLS_CTRL_HANDLE_TIMEOUT:
 268                 ret = dtls1_handle_timeout(s);
 269                 break;
 270         case DTLS_CTRL_LISTEN:
 271                 ret = dtls1_listen(s, parg);
 272                 break;
 273         case SSL_CTRL_CHECK_PROTO_VERSION:
 274                 /* For library-internal use; checks that the current protocol
 275                  * is the highest enabled version (according to s->ctx->method,
 276                  * as version negotiation may have changed s->method). */
 277 #if DTLS_MAX_VERSION != DTLS1_VERSION
 278 #  error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
 279 #endif
 280                 /* Just one protocol version is supported so far;
 281                  * fail closed if the version is not as expected. */
 282                 return s->version == DTLS_MAX_VERSION;
 283         case DTLS_CTRL_SET_LINK_MTU:
 284                 if (larg < (long)dtls1_link_min_mtu())
 285                         return 0;
 286                 s->d1->link_mtu = larg;
 287                 return 1;
 288         case DTLS_CTRL_GET_LINK_MIN_MTU:
 289                 return (long)dtls1_link_min_mtu();
 290         case SSL_CTRL_SET_MTU:
 291                 /*
 292                  *  We may not have a BIO set yet so can't call dtls1_min_mtu()
 293                  *  We'll have to make do with dtls1_link_min_mtu() and max overhead
 294                  */
 295                 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
 296                         return 0;
 297                 s->d1->mtu = larg;
 298                 return larg;
 299         default:
 300                 ret = ssl3_ctrl(s, cmd, larg, parg);
 301                 break;
 302                 }
 303         return(ret);
 304         }
 305
 306 /*
 307  * As it's impossible to use stream ciphers in "datagram" mode, this
 308  * simple filter is designed to disengage them in DTLS. Unfortunately
 309  * there is no universal way to identify stream SSL_CIPHER, so we have
 310  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 311  * available, but if new ones emerge, they will have to be added...
 312  */
 313 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 314         {
 315         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 316
 317         if (ciph != NULL)
 318                 {
 319                 if (ciph->algorithm_enc == SSL_RC4)
 320                         return NULL;
 321                 }
 322
 323         return ciph;
 324         }
 325
 326 void dtls1_start_timer(SSL *s)
 327         {
 328 #ifndef OPENSSL_NO_SCTP
 329         /* Disable timer for SCTP */
 330         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 331                 {
 332                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 333                 return;
 334                 }
 335 #endif
 336
 337         /* If timer is not set, initialize duration with 1 second */
 338         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 339                 {
 340                 s->d1->timeout_duration = 1;
 341                 }
 342
 343         /* Set timeout to current time */
 344         get_current_time(&(s->d1->next_timeout));
 345
 346         /* Add duration to current time */
 347         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 348         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 349         }
 350
 351 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 352         {
 353         struct timeval timenow;
 354
 355         /* If no timeout is set, just return NULL */
 356         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 357                 {
 358                 return NULL;
 359                 }
 360
 361         /* Get current time */
 362         get_current_time(&timenow);
 363
 364         /* If timer already expired, set remaining time to 0 */
 365         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 366                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 367                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 368                 {
 369                 memset(timeleft, 0, sizeof(struct timeval));
 370                 return timeleft;
 371                 }
 372
 373         /* Calculate time left until timer expires */
 374         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 375         timeleft->tv_sec -= timenow.tv_sec;
 376         timeleft->tv_usec -= timenow.tv_usec;
 377         if (timeleft->tv_usec < 0)
 378                 {
 379                 timeleft->tv_sec--;
 380                 timeleft->tv_usec += 1000000;
 381                 }
 382
 383         /* If remaining time is less than 15 ms, set it to 0
 384          * to prevent issues because of small devergences with
 385          * socket timeouts.
 386          */
 387         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 388                 {
 389                 memset(timeleft, 0, sizeof(struct timeval));
 390                 }
 391
 392
 393         return timeleft;
 394         }
 395
 396 int dtls1_is_timer_expired(SSL *s)
 397         {
 398         struct timeval timeleft;
 399
 400         /* Get time left until timeout, return false if no timer running */
 401         if (dtls1_get_timeout(s, &timeleft) == NULL)
 402                 {
 403                 return 0;
 404                 }
 405
 406         /* Return false if timer is not expired yet */
 407         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 408                 {
 409                 return 0;
 410                 }
 411
 412         /* Timer expired, so return true */
 413         return 1;
 414         }
 415
 416 void dtls1_double_timeout(SSL *s)
 417         {
 418         s->d1->timeout_duration *= 2;
 419         if (s->d1->timeout_duration > 60)
 420                 s->d1->timeout_duration = 60;
 421         dtls1_start_timer(s);
 422         }
 423
 424 void dtls1_stop_timer(SSL *s)
 425         {
 426         /* Reset everything */
 427         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 428         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 429         s->d1->timeout_duration = 1;
 430         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 431         /* Clear retransmission buffer */
 432         dtls1_clear_record_buffer(s);
 433         }
 434
 435 int dtls1_check_timeout_num(SSL *s)
 436         {
 437         unsigned int mtu;
 438
 439         s->d1->timeout.num_alerts++;
 440
 441         /* Reduce MTU after 2 unsuccessful retransmissions */
 442         if (s->d1->timeout.num_alerts > 2
 443                         && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 444                 {
 445                 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 446                 if(mtu < s->d1->mtu)
 447                         s->d1->mtu = mtu;
 448                 }
 449
 450         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 451                 {
 452                 /* fail the connection, enough alerts have been sent */
 453                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 454                 return -1;
 455                 }
 456
 457         return 0;
 458         }
 459
 460 int dtls1_handle_timeout(SSL *s)
 461         {
 462         /* if no timer is expired, don't do anything */
 463         if (!dtls1_is_timer_expired(s))
 464                 {
 465                 return 0;
 466                 }
 467
 468         dtls1_double_timeout(s);
 469
 470         if (dtls1_check_timeout_num(s) < 0)
 471                 return -1;
 472
 473         s->d1->timeout.read_timeouts++;
 474         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 475                 {
 476                 s->d1->timeout.read_timeouts = 1;
 477                 }
 478
 479 #ifndef OPENSSL_NO_HEARTBEATS
 480         if (s->tlsext_hb_pending)
 481                 {
 482                 s->tlsext_hb_pending = 0;
 483                 return dtls1_heartbeat(s);
 484                 }
 485 #endif
 486
 487         dtls1_start_timer(s);
 488         return dtls1_retransmit_buffered_messages(s);
 489         }
 490
 491 static void get_current_time(struct timeval *t)
 492 {
 493 #ifdef OPENSSL_SYS_WIN32
 494         struct _timeb tb;
 495         _ftime(&tb);
 496         t->tv_sec = (long)tb.time;
 497         t->tv_usec = (long)tb.millitm * 1000;
 498 #elif defined(OPENSSL_SYS_VMS)
 499         struct timeb tb;
 500         ftime(&tb);
 501         t->tv_sec = (long)tb.time;
 502         t->tv_usec = (long)tb.millitm * 1000;
 503 #else
 504         gettimeofday(t, NULL);
 505 #endif
 506 }
 507
 508 int dtls1_listen(SSL *s, struct sockaddr *client)
 509         {
 510         int ret;
 511
 512         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 513         s->d1->listen = 1;
 514
 515         ret = SSL_accept(s);
 516         if (ret <= 0) return ret;
 517
 518         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 519         return 1;
 520         }