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)
 127                 {
 128                 ssl3_free(s);
 129                 return (0);
 130                 }
 131         memset(d1,0, sizeof *d1);
 132
 133         /* d1->handshake_epoch=0; */
 134
 135         d1->unprocessed_rcds.q=pqueue_new();
 136         d1->processed_rcds.q=pqueue_new();
 137         d1->buffered_messages = pqueue_new();
 138         d1->sent_messages=pqueue_new();
 139         d1->buffered_app_data.q=pqueue_new();
 140
 141         if ( s->server)
 142                 {
 143                 d1->cookie_len = sizeof(s->d1->cookie);
 144                 }
 145
 146         d1->link_mtu = 0;
 147         d1->mtu = 0;
 148
 149         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 150         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 151                 {
 152                 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 153                 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 154                 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 155                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 156                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 157                 OPENSSL_free(d1);
 158                 ssl3_free(s);
 159                 return (0);
 160                 }
 161
 162         s->d1=d1;
 163         s->method->ssl_clear(s);
 164         return(1);
 165         }
 166
 167 static void dtls1_clear_queues(SSL *s)
 168         {
 169     pitem *item = NULL;
 170     hm_fragment *frag = NULL;
 171         DTLS1_RECORD_DATA *rdata;
 172
 173     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 174         {
 175                 rdata = (DTLS1_RECORD_DATA *) item->data;
 176                 if (rdata->rbuf.buf)
 177                         {
 178                         OPENSSL_free(rdata->rbuf.buf);
 179                         }
 180         OPENSSL_free(item->data);
 181         pitem_free(item);
 182         }
 183
 184     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 185         {
 186                 rdata = (DTLS1_RECORD_DATA *) item->data;
 187                 if (rdata->rbuf.buf)
 188                         {
 189                         OPENSSL_free(rdata->rbuf.buf);
 190                         }
 191         OPENSSL_free(item->data);
 192         pitem_free(item);
 193         }
 194
 195     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 196         {
 197         frag = (hm_fragment *)item->data;
 198         dtls1_hm_fragment_free(frag);
 199         pitem_free(item);
 200         }
 201
 202     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 203         {
 204         frag = (hm_fragment *)item->data;
 205         dtls1_hm_fragment_free(frag);
 206         pitem_free(item);
 207         }
 208
 209         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 210                 {
 211                 rdata = (DTLS1_RECORD_DATA *) item->data;
 212                 if (rdata->rbuf.buf)
 213                         {
 214                         OPENSSL_free(rdata->rbuf.buf);
 215                         }
 216                 OPENSSL_free(item->data);
 217                 pitem_free(item);
 218                 }
 219         }
 220
 221 void dtls1_free(SSL *s)
 222         {
 223         ssl3_free(s);
 224
 225         dtls1_clear_queues(s);
 226
 227     pqueue_free(s->d1->unprocessed_rcds.q);
 228     pqueue_free(s->d1->processed_rcds.q);
 229     pqueue_free(s->d1->buffered_messages);
 230         pqueue_free(s->d1->sent_messages);
 231         pqueue_free(s->d1->buffered_app_data.q);
 232
 233         OPENSSL_free(s->d1);
 234         s->d1 = NULL;
 235         }
 236
 237 void dtls1_clear(SSL *s)
 238         {
 239     pqueue unprocessed_rcds;
 240     pqueue processed_rcds;
 241     pqueue buffered_messages;
 242         pqueue sent_messages;
 243         pqueue buffered_app_data;
 244         unsigned int mtu;
 245         unsigned int link_mtu;
 246
 247         if (s->d1)
 248                 {
 249                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 250                 processed_rcds = s->d1->processed_rcds.q;
 251                 buffered_messages = s->d1->buffered_messages;
 252                 sent_messages = s->d1->sent_messages;
 253                 buffered_app_data = s->d1->buffered_app_data.q;
 254                 mtu = s->d1->mtu;
 255                 link_mtu = s->d1->link_mtu;
 256
 257                 dtls1_clear_queues(s);
 258
 259                 memset(s->d1, 0, sizeof(*(s->d1)));
 260
 261                 if (s->server)
 262                         {
 263                         s->d1->cookie_len = sizeof(s->d1->cookie);
 264                         }
 265
 266                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 267                         {
 268                         s->d1->mtu = mtu;
 269                         s->d1->link_mtu = link_mtu;
 270                         }
 271
 272                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 273                 s->d1->processed_rcds.q = processed_rcds;
 274                 s->d1->buffered_messages = buffered_messages;
 275                 s->d1->sent_messages = sent_messages;
 276                 s->d1->buffered_app_data.q = buffered_app_data;
 277                 }
 278
 279         ssl3_clear(s);
 280         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 281                 s->version=DTLS1_BAD_VER;
 282         else if (s->method->version == DTLS_ANY_VERSION)
 283                 s->version=DTLS1_2_VERSION;
 284         else
 285                 s->version=s->method->version;
 286         }
 287
 288 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 289         {
 290         int ret=0;
 291
 292         switch (cmd)
 293                 {
 294         case DTLS_CTRL_GET_TIMEOUT:
 295                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 296                         {
 297                         ret = 1;
 298                         }
 299                 break;
 300         case DTLS_CTRL_HANDLE_TIMEOUT:
 301                 ret = dtls1_handle_timeout(s);
 302                 break;
 303         case DTLS_CTRL_LISTEN:
 304                 ret = dtls1_listen(s, parg);
 305                 break;
 306         case SSL_CTRL_CHECK_PROTO_VERSION:
 307                 /* For library-internal use; checks that the current protocol
 308                  * is the highest enabled version (according to s->ctx->method,
 309                  * as version negotiation may have changed s->method). */
 310                 if (s->version == s->ctx->method->version)
 311                         return 1;
 312                 /* Apparently we're using a version-flexible SSL_METHOD
 313                  * (not at its highest protocol version). */
 314                 if (s->ctx->method->version == DTLS_method()->version)
 315                         {
 316 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
 317 #  error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
 318 #endif
 319                         if (!(s->options & SSL_OP_NO_DTLSv1_2))
 320                                 return s->version == DTLS1_2_VERSION;
 321                         if (!(s->options & SSL_OP_NO_DTLSv1))
 322                                 return s->version == DTLS1_VERSION;
 323                         }
 324                 return 0; /* Unexpected state; fail closed. */
 325         case DTLS_CTRL_SET_LINK_MTU:
 326                 if (larg < (long)dtls1_link_min_mtu())
 327                         return 0;
 328                 s->d1->link_mtu = larg;
 329                 return 1;
 330         case DTLS_CTRL_GET_LINK_MIN_MTU:
 331                 return (long)dtls1_link_min_mtu();
 332         case SSL_CTRL_SET_MTU:
 333                 /*
 334                  *  We may not have a BIO set yet so can't call dtls1_min_mtu()
 335                  *  We'll have to make do with dtls1_link_min_mtu() and max overhead
 336                  */
 337                 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
 338                         return 0;
 339                 s->d1->mtu = larg;
 340                 return larg;
 341         default:
 342                 ret = ssl3_ctrl(s, cmd, larg, parg);
 343                 break;
 344                 }
 345         return(ret);
 346         }
 347
 348 /*
 349  * As it's impossible to use stream ciphers in "datagram" mode, this
 350  * simple filter is designed to disengage them in DTLS. Unfortunately
 351  * there is no universal way to identify stream SSL_CIPHER, so we have
 352  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 353  * available, but if new ones emerge, they will have to be added...
 354  */
 355 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 356         {
 357         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 358
 359         if (ciph != NULL)
 360                 {
 361                 if (ciph->algorithm_enc == SSL_RC4)
 362                         return NULL;
 363                 }
 364
 365         return ciph;
 366         }
 367
 368 void dtls1_start_timer(SSL *s)
 369         {
 370 #ifndef OPENSSL_NO_SCTP
 371         /* Disable timer for SCTP */
 372         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 373                 {
 374                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 375                 return;
 376                 }
 377 #endif
 378
 379         /* If timer is not set, initialize duration with 1 second */
 380         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 381                 {
 382                 s->d1->timeout_duration = 1;
 383                 }
 384
 385         /* Set timeout to current time */
 386         get_current_time(&(s->d1->next_timeout));
 387
 388         /* Add duration to current time */
 389         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 390         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 391         }
 392
 393 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 394         {
 395         struct timeval timenow;
 396
 397         /* If no timeout is set, just return NULL */
 398         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 399                 {
 400                 return NULL;
 401                 }
 402
 403         /* Get current time */
 404         get_current_time(&timenow);
 405
 406         /* If timer already expired, set remaining time to 0 */
 407         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 408                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 409                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 410                 {
 411                 memset(timeleft, 0, sizeof(struct timeval));
 412                 return timeleft;
 413                 }
 414
 415         /* Calculate time left until timer expires */
 416         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 417         timeleft->tv_sec -= timenow.tv_sec;
 418         timeleft->tv_usec -= timenow.tv_usec;
 419         if (timeleft->tv_usec < 0)
 420                 {
 421                 timeleft->tv_sec--;
 422                 timeleft->tv_usec += 1000000;
 423                 }
 424
 425         /* If remaining time is less than 15 ms, set it to 0
 426          * to prevent issues because of small devergences with
 427          * socket timeouts.
 428          */
 429         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 430                 {
 431                 memset(timeleft, 0, sizeof(struct timeval));
 432                 }
 433
 434
 435         return timeleft;
 436         }
 437
 438 int dtls1_is_timer_expired(SSL *s)
 439         {
 440         struct timeval timeleft;
 441
 442         /* Get time left until timeout, return false if no timer running */
 443         if (dtls1_get_timeout(s, &timeleft) == NULL)
 444                 {
 445                 return 0;
 446                 }
 447
 448         /* Return false if timer is not expired yet */
 449         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 450                 {
 451                 return 0;
 452                 }
 453
 454         /* Timer expired, so return true */
 455         return 1;
 456         }
 457
 458 void dtls1_double_timeout(SSL *s)
 459         {
 460         s->d1->timeout_duration *= 2;
 461         if (s->d1->timeout_duration > 60)
 462                 s->d1->timeout_duration = 60;
 463         dtls1_start_timer(s);
 464         }
 465
 466 void dtls1_stop_timer(SSL *s)
 467         {
 468         /* Reset everything */
 469         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 470         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 471         s->d1->timeout_duration = 1;
 472         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 473         /* Clear retransmission buffer */
 474         dtls1_clear_record_buffer(s);
 475         }
 476
 477 int dtls1_check_timeout_num(SSL *s)
 478         {
 479         unsigned int mtu;
 480
 481         s->d1->timeout.num_alerts++;
 482
 483         /* Reduce MTU after 2 unsuccessful retransmissions */
 484         if (s->d1->timeout.num_alerts > 2
 485                         && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 486                 {
 487                 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 488                 if(mtu < s->d1->mtu)
 489                         s->d1->mtu = mtu;
 490                 }
 491
 492         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 493                 {
 494                 /* fail the connection, enough alerts have been sent */
 495                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 496                 return -1;
 497                 }
 498
 499         return 0;
 500         }
 501
 502 int dtls1_handle_timeout(SSL *s)
 503         {
 504         /* if no timer is expired, don't do anything */
 505         if (!dtls1_is_timer_expired(s))
 506                 {
 507                 return 0;
 508                 }
 509
 510         dtls1_double_timeout(s);
 511
 512         if (dtls1_check_timeout_num(s) < 0)
 513                 return -1;
 514
 515         s->d1->timeout.read_timeouts++;
 516         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 517                 {
 518                 s->d1->timeout.read_timeouts = 1;
 519                 }
 520
 521 #ifndef OPENSSL_NO_HEARTBEATS
 522         if (s->tlsext_hb_pending)
 523                 {
 524                 s->tlsext_hb_pending = 0;
 525                 return dtls1_heartbeat(s);
 526                 }
 527 #endif
 528
 529         dtls1_start_timer(s);
 530         return dtls1_retransmit_buffered_messages(s);
 531         }
 532
 533 static void get_current_time(struct timeval *t)
 534 {
 535 #if defined(_WIN32)
 536         SYSTEMTIME st;
 537         union { unsigned __int64 ul; FILETIME ft; } now;
 538
 539         GetSystemTime(&st);
 540         SystemTimeToFileTime(&st,&now.ft);
 541 #ifdef  __MINGW32__
 542         now.ul -= 116444736000000000ULL;
 543 #else
 544         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
 545 #endif
 546         t->tv_sec  = (long)(now.ul/10000000);
 547         t->tv_usec = ((int)(now.ul%10000000))/10;
 548 #elif defined(OPENSSL_SYS_VMS)
 549         struct timeb tb;
 550         ftime(&tb);
 551         t->tv_sec = (long)tb.time;
 552         t->tv_usec = (long)tb.millitm * 1000;
 553 #else
 554         gettimeofday(t, NULL);
 555 #endif
 556 }
 557
 558 int dtls1_listen(SSL *s, struct sockaddr *client)
 559         {
 560         int ret;
 561
 562         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 563         s->d1->listen = 1;
 564
 565         ret = SSL_accept(s);
 566         if (ret <= 0) return ret;
 567
 568         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 569         return 1;
 570         }
 571
 572 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 573         {
 574         unsigned char *p = (unsigned char *)s->init_buf->data;
 575         dtls1_set_message_header(s, p, htype, len, 0, len);
 576         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 577         s->init_off = 0;
 578         /* Buffer the message to handle re-xmits */
 579         dtls1_buffer_message(s, 0);
 580         }
 581
 582 static int dtls1_handshake_write(SSL *s)
 583         {
 584         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 585         }