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 SSL3_ENC_METHOD DTLSv1_enc_data={
  76     dtls1_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 SSL3_ENC_METHOD DTLSv1_2_enc_data={
  95     dtls1_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|SSL_ENC_FLAG_SHA256_PRF,
 108         DTLS1_HM_HEADER_LENGTH,
 109         dtls1_set_handshake_header,
 110         dtls1_handshake_write
 111         };
 112
 113 long dtls1_default_timeout(void)
 114         {
 115         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
 116          * is way too long for http, the cache would over fill */
 117         return(60*60*2);
 118         }
 119
 120 int dtls1_new(SSL *s)
 121         {
 122         DTLS1_STATE *d1;
 123
 124         if (!ssl3_new(s)) return(0);
 125         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
 126         memset(d1,0, sizeof *d1);
 127
 128         /* d1->handshake_epoch=0; */
 129
 130         d1->unprocessed_rcds.q=pqueue_new();
 131         d1->processed_rcds.q=pqueue_new();
 132         d1->buffered_messages = pqueue_new();
 133         d1->sent_messages=pqueue_new();
 134         d1->buffered_app_data.q=pqueue_new();
 135
 136         if ( s->server)
 137                 {
 138                 d1->cookie_len = sizeof(s->d1->cookie);
 139                 }
 140
 141         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 142         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 143                 {
 144         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 145         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 146         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 147                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 148                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 149                 OPENSSL_free(d1);
 150                 return (0);
 151                 }
 152
 153         s->d1=d1;
 154         s->method->ssl_clear(s);
 155         return(1);
 156         }
 157
 158 static void dtls1_clear_queues(SSL *s)
 159         {
 160     pitem *item = NULL;
 161     hm_fragment *frag = NULL;
 162         DTLS1_RECORD_DATA *rdata;
 163
 164     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 165         {
 166                 rdata = (DTLS1_RECORD_DATA *) item->data;
 167                 if (rdata->rbuf.buf)
 168                         {
 169                         OPENSSL_free(rdata->rbuf.buf);
 170                         }
 171         OPENSSL_free(item->data);
 172         pitem_free(item);
 173         }
 174
 175     while( (item = pqueue_pop(s->d1->processed_rcds.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     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 187         {
 188         frag = (hm_fragment *)item->data;
 189         OPENSSL_free(frag->fragment);
 190         OPENSSL_free(frag);
 191         pitem_free(item);
 192         }
 193
 194     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 195         {
 196         frag = (hm_fragment *)item->data;
 197         OPENSSL_free(frag->fragment);
 198         OPENSSL_free(frag);
 199         pitem_free(item);
 200         }
 201
 202         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 203                 {
 204                 frag = (hm_fragment *)item->data;
 205                 OPENSSL_free(frag->fragment);
 206                 OPENSSL_free(frag);
 207                 pitem_free(item);
 208                 }
 209         }
 210
 211 void dtls1_free(SSL *s)
 212         {
 213         ssl3_free(s);
 214
 215         dtls1_clear_queues(s);
 216
 217     pqueue_free(s->d1->unprocessed_rcds.q);
 218     pqueue_free(s->d1->processed_rcds.q);
 219     pqueue_free(s->d1->buffered_messages);
 220         pqueue_free(s->d1->sent_messages);
 221         pqueue_free(s->d1->buffered_app_data.q);
 222
 223         OPENSSL_free(s->d1);
 224         }
 225
 226 void dtls1_clear(SSL *s)
 227         {
 228     pqueue unprocessed_rcds;
 229     pqueue processed_rcds;
 230     pqueue buffered_messages;
 231         pqueue sent_messages;
 232         pqueue buffered_app_data;
 233         unsigned int mtu;
 234
 235         if (s->d1)
 236                 {
 237                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 238                 processed_rcds = s->d1->processed_rcds.q;
 239                 buffered_messages = s->d1->buffered_messages;
 240                 sent_messages = s->d1->sent_messages;
 241                 buffered_app_data = s->d1->buffered_app_data.q;
 242                 mtu = s->d1->mtu;
 243
 244                 dtls1_clear_queues(s);
 245
 246                 memset(s->d1, 0, sizeof(*(s->d1)));
 247
 248                 if (s->server)
 249                         {
 250                         s->d1->cookie_len = sizeof(s->d1->cookie);
 251                         }
 252
 253                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 254                         {
 255                         s->d1->mtu = mtu;
 256                         }
 257
 258                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 259                 s->d1->processed_rcds.q = processed_rcds;
 260                 s->d1->buffered_messages = buffered_messages;
 261                 s->d1->sent_messages = sent_messages;
 262                 s->d1->buffered_app_data.q = buffered_app_data;
 263                 }
 264
 265         ssl3_clear(s);
 266         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 267                 s->version=DTLS1_BAD_VER;
 268         else
 269                 s->version=s->method->version;
 270         }
 271
 272 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 273         {
 274         int ret=0;
 275
 276         switch (cmd)
 277                 {
 278         case DTLS_CTRL_GET_TIMEOUT:
 279                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 280                         {
 281                         ret = 1;
 282                         }
 283                 break;
 284         case DTLS_CTRL_HANDLE_TIMEOUT:
 285                 ret = dtls1_handle_timeout(s);
 286                 break;
 287         case DTLS_CTRL_LISTEN:
 288                 ret = dtls1_listen(s, parg);
 289                 break;
 290
 291         default:
 292                 ret = ssl3_ctrl(s, cmd, larg, parg);
 293                 break;
 294                 }
 295         return(ret);
 296         }
 297
 298 /*
 299  * As it's impossible to use stream ciphers in "datagram" mode, this
 300  * simple filter is designed to disengage them in DTLS. Unfortunately
 301  * there is no universal way to identify stream SSL_CIPHER, so we have
 302  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 303  * available, but if new ones emerge, they will have to be added...
 304  */
 305 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 306         {
 307         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 308
 309         if (ciph != NULL)
 310                 {
 311                 if (ciph->algorithm_enc == SSL_RC4)
 312                         return NULL;
 313                 }
 314
 315         return ciph;
 316         }
 317
 318 void dtls1_start_timer(SSL *s)
 319         {
 320 #ifndef OPENSSL_NO_SCTP
 321         /* Disable timer for SCTP */
 322         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 323                 {
 324                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 325                 return;
 326                 }
 327 #endif
 328
 329         /* If timer is not set, initialize duration with 1 second */
 330         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 331                 {
 332                 s->d1->timeout_duration = 1;
 333                 }
 334
 335         /* Set timeout to current time */
 336         get_current_time(&(s->d1->next_timeout));
 337
 338         /* Add duration to current time */
 339         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 340         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 341         }
 342
 343 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 344         {
 345         struct timeval timenow;
 346
 347         /* If no timeout is set, just return NULL */
 348         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 349                 {
 350                 return NULL;
 351                 }
 352
 353         /* Get current time */
 354         get_current_time(&timenow);
 355
 356         /* If timer already expired, set remaining time to 0 */
 357         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 358                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 359                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 360                 {
 361                 memset(timeleft, 0, sizeof(struct timeval));
 362                 return timeleft;
 363                 }
 364
 365         /* Calculate time left until timer expires */
 366         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 367         timeleft->tv_sec -= timenow.tv_sec;
 368         timeleft->tv_usec -= timenow.tv_usec;
 369         if (timeleft->tv_usec < 0)
 370                 {
 371                 timeleft->tv_sec--;
 372                 timeleft->tv_usec += 1000000;
 373                 }
 374
 375         /* If remaining time is less than 15 ms, set it to 0
 376          * to prevent issues because of small devergences with
 377          * socket timeouts.
 378          */
 379         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 380                 {
 381                 memset(timeleft, 0, sizeof(struct timeval));
 382                 }
 383
 384
 385         return timeleft;
 386         }
 387
 388 int dtls1_is_timer_expired(SSL *s)
 389         {
 390         struct timeval timeleft;
 391
 392         /* Get time left until timeout, return false if no timer running */
 393         if (dtls1_get_timeout(s, &timeleft) == NULL)
 394                 {
 395                 return 0;
 396                 }
 397
 398         /* Return false if timer is not expired yet */
 399         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 400                 {
 401                 return 0;
 402                 }
 403
 404         /* Timer expired, so return true */
 405         return 1;
 406         }
 407
 408 void dtls1_double_timeout(SSL *s)
 409         {
 410         s->d1->timeout_duration *= 2;
 411         if (s->d1->timeout_duration > 60)
 412                 s->d1->timeout_duration = 60;
 413         dtls1_start_timer(s);
 414         }
 415
 416 void dtls1_stop_timer(SSL *s)
 417         {
 418         /* Reset everything */
 419         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 420         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 421         s->d1->timeout_duration = 1;
 422         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 423         /* Clear retransmission buffer */
 424         dtls1_clear_record_buffer(s);
 425         }
 426
 427 int dtls1_check_timeout_num(SSL *s)
 428         {
 429         s->d1->timeout.num_alerts++;
 430
 431         /* Reduce MTU after 2 unsuccessful retransmissions */
 432         if (s->d1->timeout.num_alerts > 2)
 433                 {
 434                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 435                 }
 436
 437         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 438                 {
 439                 /* fail the connection, enough alerts have been sent */
 440                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 441                 return -1;
 442                 }
 443
 444         return 0;
 445         }
 446
 447 int dtls1_handle_timeout(SSL *s)
 448         {
 449         /* if no timer is expired, don't do anything */
 450         if (!dtls1_is_timer_expired(s))
 451                 {
 452                 return 0;
 453                 }
 454
 455         dtls1_double_timeout(s);
 456
 457         if (dtls1_check_timeout_num(s) < 0)
 458                 return -1;
 459
 460         s->d1->timeout.read_timeouts++;
 461         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 462                 {
 463                 s->d1->timeout.read_timeouts = 1;
 464                 }
 465
 466 #ifndef OPENSSL_NO_HEARTBEATS
 467         if (s->tlsext_hb_pending)
 468                 {
 469                 s->tlsext_hb_pending = 0;
 470                 return dtls1_heartbeat(s);
 471                 }
 472 #endif
 473
 474         dtls1_start_timer(s);
 475         return dtls1_retransmit_buffered_messages(s);
 476         }
 477
 478 static void get_current_time(struct timeval *t)
 479 {
 480 #if defined(_WIN32)
 481         SYSTEMTIME st;
 482         union { unsigned __int64 ul; FILETIME ft; } now;
 483
 484         GetSystemTime(&st);
 485         SystemTimeToFileTime(&st,&now.ft);
 486         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
 487         t->tv_sec  = (long)(now.ul/10000000);
 488         t->tv_usec = ((int)(now.ul%10000000))/10;
 489 #elif defined(OPENSSL_SYS_VMS)
 490         struct timeb tb;
 491         ftime(&tb);
 492         t->tv_sec = (long)tb.time;
 493         t->tv_usec = (long)tb.millitm * 1000;
 494 #else
 495         gettimeofday(t, NULL);
 496 #endif
 497 }
 498
 499 int dtls1_listen(SSL *s, struct sockaddr *client)
 500         {
 501         int ret;
 502
 503         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 504         s->d1->listen = 1;
 505
 506         ret = SSL_accept(s);
 507         if (ret <= 0) return ret;
 508
 509         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 510         return 1;
 511         }
 512
 513 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 514         {
 515         unsigned char *p = (unsigned char *)s->init_buf->data;
 516         dtls1_set_message_header(s, p, htype, len, 0, len);
 517         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 518         s->init_off = 0;
 519         /* Buffer the message to handle re-xmits */
 520         dtls1_buffer_message(s, 0);
 521         }
 522
 523 static int dtls1_handshake_write(SSL *s)
 524         {
 525         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 526         }
 527
 528