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_VMS)
  66 #include <sys/timeb.h>
  67 #endif
  68
  69 static void get_current_time(struct timeval *t);
  70 static void dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
  71 static int dtls1_handshake_write(SSL *s);
  72 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
  73 int dtls1_listen(SSL *s, struct sockaddr *client);
  74
  75 const SSL3_ENC_METHOD DTLSv1_enc_data={
  76         tls1_enc,
  77         tls1_mac,
  78         tls1_setup_key_block,
  79         tls1_generate_master_secret,
  80         tls1_change_cipher_state,
  81         tls1_final_finish_mac,
  82         TLS1_FINISH_MAC_LENGTH,
  83         tls1_cert_verify_mac,
  84         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
  85         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
  86         tls1_alert_code,
  87         tls1_export_keying_material,
  88         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV,
  89         DTLS1_HM_HEADER_LENGTH,
  90         dtls1_set_handshake_header,
  91         dtls1_handshake_write
  92         };
  93
  94 const SSL3_ENC_METHOD DTLSv1_2_enc_data={
  95         tls1_enc,
  96         tls1_mac,
  97         tls1_setup_key_block,
  98         tls1_generate_master_secret,
  99         tls1_change_cipher_state,
 100         tls1_final_finish_mac,
 101         TLS1_FINISH_MAC_LENGTH,
 102         tls1_cert_verify_mac,
 103         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
 104         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
 105         tls1_alert_code,
 106         tls1_export_keying_material,
 107         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS
 108                 |SSL_ENC_FLAG_SHA256_PRF|SSL_ENC_FLAG_TLS1_2_CIPHERS,
 109         DTLS1_HM_HEADER_LENGTH,
 110         dtls1_set_handshake_header,
 111         dtls1_handshake_write
 112         };
 113
 114 long dtls1_default_timeout(void)
 115         {
 116         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
 117          * is way too long for http, the cache would over fill */
 118         return(60*60*2);
 119         }
 120
 121 int dtls1_new(SSL *s)
 122         {
 123         DTLS1_STATE *d1;
 124
 125         if (!ssl3_new(s)) return(0);
 126         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
 127         memset(d1,0, sizeof *d1);
 128
 129         /* d1->handshake_epoch=0; */
 130
 131         d1->unprocessed_rcds.q=pqueue_new();
 132         d1->processed_rcds.q=pqueue_new();
 133         d1->buffered_messages = pqueue_new();
 134         d1->sent_messages=pqueue_new();
 135         d1->buffered_app_data.q=pqueue_new();
 136
 137         if ( s->server)
 138                 {
 139                 d1->cookie_len = sizeof(s->d1->cookie);
 140                 }
 141
 142         d1->link_mtu = 0;
 143         d1->mtu = 0;
 144
 145         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 146         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 147                 {
 148         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 149         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 150         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 151                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 152                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 153                 OPENSSL_free(d1);
 154                 return (0);
 155                 }
 156
 157         s->d1=d1;
 158         s->method->ssl_clear(s);
 159         return(1);
 160         }
 161
 162 static void dtls1_clear_queues(SSL *s)
 163         {
 164     pitem *item = NULL;
 165     hm_fragment *frag = NULL;
 166         DTLS1_RECORD_DATA *rdata;
 167
 168     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 169         {
 170                 rdata = (DTLS1_RECORD_DATA *) item->data;
 171                 if (rdata->rbuf.buf)
 172                         {
 173                         OPENSSL_free(rdata->rbuf.buf);
 174                         }
 175         OPENSSL_free(item->data);
 176         pitem_free(item);
 177         }
 178
 179     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 180         {
 181                 rdata = (DTLS1_RECORD_DATA *) item->data;
 182                 if (rdata->rbuf.buf)
 183                         {
 184                         OPENSSL_free(rdata->rbuf.buf);
 185                         }
 186         OPENSSL_free(item->data);
 187         pitem_free(item);
 188         }
 189
 190     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 191         {
 192         frag = (hm_fragment *)item->data;
 193         dtls1_hm_fragment_free(frag);
 194         pitem_free(item);
 195         }
 196
 197     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 198         {
 199         frag = (hm_fragment *)item->data;
 200         dtls1_hm_fragment_free(frag);
 201         pitem_free(item);
 202         }
 203
 204         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 205                 {
 206                 rdata = (DTLS1_RECORD_DATA *) item->data;
 207                 if (rdata->rbuf.buf)
 208                         {
 209                         OPENSSL_free(rdata->rbuf.buf);
 210                         }
 211                 OPENSSL_free(item->data);
 212                 pitem_free(item);
 213                 }
 214         }
 215
 216 void dtls1_free(SSL *s)
 217         {
 218         ssl3_free(s);
 219
 220         dtls1_clear_queues(s);
 221
 222     pqueue_free(s->d1->unprocessed_rcds.q);
 223     pqueue_free(s->d1->processed_rcds.q);
 224     pqueue_free(s->d1->buffered_messages);
 225         pqueue_free(s->d1->sent_messages);
 226         pqueue_free(s->d1->buffered_app_data.q);
 227
 228         OPENSSL_free(s->d1);
 229         s->d1 = NULL;
 230         }
 231
 232 void dtls1_clear(SSL *s)
 233         {
 234     pqueue unprocessed_rcds;
 235     pqueue processed_rcds;
 236     pqueue buffered_messages;
 237         pqueue sent_messages;
 238         pqueue buffered_app_data;
 239         unsigned int mtu;
 240         unsigned int link_mtu;
 241
 242         if (s->d1)
 243                 {
 244                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 245                 processed_rcds = s->d1->processed_rcds.q;
 246                 buffered_messages = s->d1->buffered_messages;
 247                 sent_messages = s->d1->sent_messages;
 248                 buffered_app_data = s->d1->buffered_app_data.q;
 249                 mtu = s->d1->mtu;
 250                 link_mtu = s->d1->link_mtu;
 251
 252                 dtls1_clear_queues(s);
 253
 254                 memset(s->d1, 0, sizeof(*(s->d1)));
 255
 256                 if (s->server)
 257                         {
 258                         s->d1->cookie_len = sizeof(s->d1->cookie);
 259                         }
 260
 261                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 262                         {
 263                         s->d1->mtu = mtu;
 264                         s->d1->link_mtu = link_mtu;
 265                         }
 266
 267                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 268                 s->d1->processed_rcds.q = processed_rcds;
 269                 s->d1->buffered_messages = buffered_messages;
 270                 s->d1->sent_messages = sent_messages;
 271                 s->d1->buffered_app_data.q = buffered_app_data;
 272                 }
 273
 274         ssl3_clear(s);
 275         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 276                 s->version=DTLS1_BAD_VER;
 277         else if (s->method->version == DTLS_ANY_VERSION)
 278                 s->version=DTLS1_2_VERSION;
 279         else
 280                 s->version=s->method->version;
 281         }
 282
 283 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 284         {
 285         int ret=0;
 286
 287         switch (cmd)
 288                 {
 289         case DTLS_CTRL_GET_TIMEOUT:
 290                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 291                         {
 292                         ret = 1;
 293                         }
 294                 break;
 295         case DTLS_CTRL_HANDLE_TIMEOUT:
 296                 ret = dtls1_handle_timeout(s);
 297                 break;
 298         case DTLS_CTRL_LISTEN:
 299                 ret = dtls1_listen(s, parg);
 300                 break;
 301         case SSL_CTRL_CHECK_PROTO_VERSION:
 302                 /* For library-internal use; checks that the current protocol
 303                  * is the highest enabled version (according to s->ctx->method,
 304                  * as version negotiation may have changed s->method). */
 305                 if (s->version == s->ctx->method->version)
 306                         return 1;
 307                 /* Apparently we're using a version-flexible SSL_METHOD
 308                  * (not at its highest protocol version). */
 309                 if (s->ctx->method->version == DTLS_method()->version)
 310                         {
 311 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
 312 #  error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
 313 #endif
 314                         if (!(s->options & SSL_OP_NO_DTLSv1_2))
 315                                 return s->version == DTLS1_2_VERSION;
 316                         if (!(s->options & SSL_OP_NO_DTLSv1))
 317                                 return s->version == DTLS1_VERSION;
 318                         }
 319                 return 0; /* Unexpected state; fail closed. */
 320
 321                 /* Just one protocol version is supported so far;
 322                  * fail closed if the version is not as expected. */
 323                 return s->version == DTLS_MAX_VERSION;
 324         case DTLS_CTRL_SET_LINK_MTU:
 325                 if (larg < (long)dtls1_link_min_mtu())
 326                         return 0;
 327                 s->d1->link_mtu = larg;
 328                 return 1;
 329         case DTLS_CTRL_GET_LINK_MIN_MTU:
 330                 return (long)dtls1_link_min_mtu();
 331         case SSL_CTRL_SET_MTU:
 332                 /*
 333                  *  We may not have a BIO set yet so can't call dtls1_min_mtu()
 334                  *  We'll have to make do with dtls1_link_min_mtu() and max overhead
 335                  */
 336                 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
 337                         return 0;
 338                 s->d1->mtu = larg;
 339                 return larg;
 340         default:
 341                 ret = ssl3_ctrl(s, cmd, larg, parg);
 342                 break;
 343                 }
 344         return(ret);
 345         }
 346
 347 /*
 348  * As it's impossible to use stream ciphers in "datagram" mode, this
 349  * simple filter is designed to disengage them in DTLS. Unfortunately
 350  * there is no universal way to identify stream SSL_CIPHER, so we have
 351  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 352  * available, but if new ones emerge, they will have to be added...
 353  */
 354 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 355         {
 356         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 357
 358         if (ciph != NULL)
 359                 {
 360                 if (ciph->algorithm_enc == SSL_RC4)
 361                         return NULL;
 362                 }
 363
 364         return ciph;
 365         }
 366
 367 void dtls1_start_timer(SSL *s)
 368         {
 369 #ifndef OPENSSL_NO_SCTP
 370         /* Disable timer for SCTP */
 371         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 372                 {
 373                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 374                 return;
 375                 }
 376 #endif
 377
 378         /* If timer is not set, initialize duration with 1 second */
 379         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 380                 {
 381                 s->d1->timeout_duration = 1;
 382                 }
 383
 384         /* Set timeout to current time */
 385         get_current_time(&(s->d1->next_timeout));
 386
 387         /* Add duration to current time */
 388         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 389         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 390         }
 391
 392 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 393         {
 394         struct timeval timenow;
 395
 396         /* If no timeout is set, just return NULL */
 397         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 398                 {
 399                 return NULL;
 400                 }
 401
 402         /* Get current time */
 403         get_current_time(&timenow);
 404
 405         /* If timer already expired, set remaining time to 0 */
 406         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 407                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 408                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 409                 {
 410                 memset(timeleft, 0, sizeof(struct timeval));
 411                 return timeleft;
 412                 }
 413
 414         /* Calculate time left until timer expires */
 415         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 416         timeleft->tv_sec -= timenow.tv_sec;
 417         timeleft->tv_usec -= timenow.tv_usec;
 418         if (timeleft->tv_usec < 0)
 419                 {
 420                 timeleft->tv_sec--;
 421                 timeleft->tv_usec += 1000000;
 422                 }
 423
 424         /* If remaining time is less than 15 ms, set it to 0
 425          * to prevent issues because of small devergences with
 426          * socket timeouts.
 427          */
 428         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 429                 {
 430                 memset(timeleft, 0, sizeof(struct timeval));
 431                 }
 432
 433
 434         return timeleft;
 435         }
 436
 437 int dtls1_is_timer_expired(SSL *s)
 438         {
 439         struct timeval timeleft;
 440
 441         /* Get time left until timeout, return false if no timer running */
 442         if (dtls1_get_timeout(s, &timeleft) == NULL)
 443                 {
 444                 return 0;
 445                 }
 446
 447         /* Return false if timer is not expired yet */
 448         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 449                 {
 450                 return 0;
 451                 }
 452
 453         /* Timer expired, so return true */
 454         return 1;
 455         }
 456
 457 void dtls1_double_timeout(SSL *s)
 458         {
 459         s->d1->timeout_duration *= 2;
 460         if (s->d1->timeout_duration > 60)
 461                 s->d1->timeout_duration = 60;
 462         dtls1_start_timer(s);
 463         }
 464
 465 void dtls1_stop_timer(SSL *s)
 466         {
 467         /* Reset everything */
 468         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 469         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 470         s->d1->timeout_duration = 1;
 471         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 472         /* Clear retransmission buffer */
 473         dtls1_clear_record_buffer(s);
 474         }
 475
 476 int dtls1_check_timeout_num(SSL *s)
 477         {
 478         s->d1->timeout.num_alerts++;
 479
 480         /* Reduce MTU after 2 unsuccessful retransmissions */
 481         if (s->d1->timeout.num_alerts > 2
 482                         && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 483                 {
 484                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 485                 }
 486
 487         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 488                 {
 489                 /* fail the connection, enough alerts have been sent */
 490                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 491                 return -1;
 492                 }
 493
 494         return 0;
 495         }
 496
 497 int dtls1_handle_timeout(SSL *s)
 498         {
 499         /* if no timer is expired, don't do anything */
 500         if (!dtls1_is_timer_expired(s))
 501                 {
 502                 return 0;
 503                 }
 504
 505         dtls1_double_timeout(s);
 506
 507         if (dtls1_check_timeout_num(s) < 0)
 508                 return -1;
 509
 510         s->d1->timeout.read_timeouts++;
 511         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 512                 {
 513                 s->d1->timeout.read_timeouts = 1;
 514                 }
 515
 516 #ifndef OPENSSL_NO_HEARTBEATS
 517         if (s->tlsext_hb_pending)
 518                 {
 519                 s->tlsext_hb_pending = 0;
 520                 return dtls1_heartbeat(s);
 521                 }
 522 #endif
 523
 524         dtls1_start_timer(s);
 525         return dtls1_retransmit_buffered_messages(s);
 526         }
 527
 528 static void get_current_time(struct timeval *t)
 529 {
 530 #if defined(_WIN32)
 531         SYSTEMTIME st;
 532         union { unsigned __int64 ul; FILETIME ft; } now;
 533
 534         GetSystemTime(&st);
 535         SystemTimeToFileTime(&st,&now.ft);
 536 #ifdef  __MINGW32__
 537         now.ul -= 116444736000000000ULL;
 538 #else
 539         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
 540 #endif
 541         t->tv_sec  = (long)(now.ul/10000000);
 542         t->tv_usec = ((int)(now.ul%10000000))/10;
 543 #elif defined(OPENSSL_SYS_VMS)
 544         struct timeb tb;
 545         ftime(&tb);
 546         t->tv_sec = (long)tb.time;
 547         t->tv_usec = (long)tb.millitm * 1000;
 548 #else
 549         gettimeofday(t, NULL);
 550 #endif
 551 }
 552
 553 int dtls1_listen(SSL *s, struct sockaddr *client)
 554         {
 555         int ret;
 556
 557         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 558         s->d1->listen = 1;
 559
 560         ret = SSL_accept(s);
 561         if (ret <= 0) return ret;
 562
 563         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 564         return 1;
 565         }
 566
 567 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 568         {
 569         unsigned char *p = (unsigned char *)s->init_buf->data;
 570         dtls1_set_message_header(s, p, htype, len, 0, len);
 571         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 572         s->init_off = 0;
 573         /* Buffer the message to handle re-xmits */
 574         dtls1_buffer_message(s, 0);
 575         }
 576
 577 static int dtls1_handshake_write(SSL *s)
 578         {
 579         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 580         }