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 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         s->d1 = NULL;
 225         }
 226
 227 void dtls1_clear(SSL *s)
 228         {
 229     pqueue unprocessed_rcds;
 230     pqueue processed_rcds;
 231     pqueue buffered_messages;
 232         pqueue sent_messages;
 233         pqueue buffered_app_data;
 234         unsigned int mtu;
 235
 236         if (s->d1)
 237                 {
 238                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 239                 processed_rcds = s->d1->processed_rcds.q;
 240                 buffered_messages = s->d1->buffered_messages;
 241                 sent_messages = s->d1->sent_messages;
 242                 buffered_app_data = s->d1->buffered_app_data.q;
 243                 mtu = s->d1->mtu;
 244
 245                 dtls1_clear_queues(s);
 246
 247                 memset(s->d1, 0, sizeof(*(s->d1)));
 248
 249                 if (s->server)
 250                         {
 251                         s->d1->cookie_len = sizeof(s->d1->cookie);
 252                         }
 253
 254                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 255                         {
 256                         s->d1->mtu = mtu;
 257                         }
 258
 259                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 260                 s->d1->processed_rcds.q = processed_rcds;
 261                 s->d1->buffered_messages = buffered_messages;
 262                 s->d1->sent_messages = sent_messages;
 263                 s->d1->buffered_app_data.q = buffered_app_data;
 264                 }
 265
 266         ssl3_clear(s);
 267         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 268                 s->version=DTLS1_BAD_VER;
 269         else
 270                 s->version=s->method->version;
 271         }
 272
 273 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 274         {
 275         int ret=0;
 276
 277         switch (cmd)
 278                 {
 279         case DTLS_CTRL_GET_TIMEOUT:
 280                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 281                         {
 282                         ret = 1;
 283                         }
 284                 break;
 285         case DTLS_CTRL_HANDLE_TIMEOUT:
 286                 ret = dtls1_handle_timeout(s);
 287                 break;
 288         case DTLS_CTRL_LISTEN:
 289                 ret = dtls1_listen(s, parg);
 290                 break;
 291
 292         default:
 293                 ret = ssl3_ctrl(s, cmd, larg, parg);
 294                 break;
 295                 }
 296         return(ret);
 297         }
 298
 299 /*
 300  * As it's impossible to use stream ciphers in "datagram" mode, this
 301  * simple filter is designed to disengage them in DTLS. Unfortunately
 302  * there is no universal way to identify stream SSL_CIPHER, so we have
 303  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 304  * available, but if new ones emerge, they will have to be added...
 305  */
 306 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 307         {
 308         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 309
 310         if (ciph != NULL)
 311                 {
 312                 if (ciph->algorithm_enc == SSL_RC4)
 313                         return NULL;
 314                 }
 315
 316         return ciph;
 317         }
 318
 319 void dtls1_start_timer(SSL *s)
 320         {
 321 #ifndef OPENSSL_NO_SCTP
 322         /* Disable timer for SCTP */
 323         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 324                 {
 325                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 326                 return;
 327                 }
 328 #endif
 329
 330         /* If timer is not set, initialize duration with 1 second */
 331         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 332                 {
 333                 s->d1->timeout_duration = 1;
 334                 }
 335
 336         /* Set timeout to current time */
 337         get_current_time(&(s->d1->next_timeout));
 338
 339         /* Add duration to current time */
 340         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 341         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 342         }
 343
 344 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 345         {
 346         struct timeval timenow;
 347
 348         /* If no timeout is set, just return NULL */
 349         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 350                 {
 351                 return NULL;
 352                 }
 353
 354         /* Get current time */
 355         get_current_time(&timenow);
 356
 357         /* If timer already expired, set remaining time to 0 */
 358         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 359                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 360                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 361                 {
 362                 memset(timeleft, 0, sizeof(struct timeval));
 363                 return timeleft;
 364                 }
 365
 366         /* Calculate time left until timer expires */
 367         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 368         timeleft->tv_sec -= timenow.tv_sec;
 369         timeleft->tv_usec -= timenow.tv_usec;
 370         if (timeleft->tv_usec < 0)
 371                 {
 372                 timeleft->tv_sec--;
 373                 timeleft->tv_usec += 1000000;
 374                 }
 375
 376         /* If remaining time is less than 15 ms, set it to 0
 377          * to prevent issues because of small devergences with
 378          * socket timeouts.
 379          */
 380         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 381                 {
 382                 memset(timeleft, 0, sizeof(struct timeval));
 383                 }
 384
 385
 386         return timeleft;
 387         }
 388
 389 int dtls1_is_timer_expired(SSL *s)
 390         {
 391         struct timeval timeleft;
 392
 393         /* Get time left until timeout, return false if no timer running */
 394         if (dtls1_get_timeout(s, &timeleft) == NULL)
 395                 {
 396                 return 0;
 397                 }
 398
 399         /* Return false if timer is not expired yet */
 400         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 401                 {
 402                 return 0;
 403                 }
 404
 405         /* Timer expired, so return true */
 406         return 1;
 407         }
 408
 409 void dtls1_double_timeout(SSL *s)
 410         {
 411         s->d1->timeout_duration *= 2;
 412         if (s->d1->timeout_duration > 60)
 413                 s->d1->timeout_duration = 60;
 414         dtls1_start_timer(s);
 415         }
 416
 417 void dtls1_stop_timer(SSL *s)
 418         {
 419         /* Reset everything */
 420         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 421         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 422         s->d1->timeout_duration = 1;
 423         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 424         /* Clear retransmission buffer */
 425         dtls1_clear_record_buffer(s);
 426         }
 427
 428 int dtls1_check_timeout_num(SSL *s)
 429         {
 430         s->d1->timeout.num_alerts++;
 431
 432         /* Reduce MTU after 2 unsuccessful retransmissions */
 433         if (s->d1->timeout.num_alerts > 2)
 434                 {
 435                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 436                 }
 437
 438         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 439                 {
 440                 /* fail the connection, enough alerts have been sent */
 441                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 442                 return -1;
 443                 }
 444
 445         return 0;
 446         }
 447
 448 int dtls1_handle_timeout(SSL *s)
 449         {
 450         /* if no timer is expired, don't do anything */
 451         if (!dtls1_is_timer_expired(s))
 452                 {
 453                 return 0;
 454                 }
 455
 456         dtls1_double_timeout(s);
 457
 458         if (dtls1_check_timeout_num(s) < 0)
 459                 return -1;
 460
 461         s->d1->timeout.read_timeouts++;
 462         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 463                 {
 464                 s->d1->timeout.read_timeouts = 1;
 465                 }
 466
 467 #ifndef OPENSSL_NO_HEARTBEATS
 468         if (s->tlsext_hb_pending)
 469                 {
 470                 s->tlsext_hb_pending = 0;
 471                 return dtls1_heartbeat(s);
 472                 }
 473 #endif
 474
 475         dtls1_start_timer(s);
 476         return dtls1_retransmit_buffered_messages(s);
 477         }
 478
 479 static void get_current_time(struct timeval *t)
 480 {
 481 #ifdef OPENSSL_SYS_WIN32
 482         struct _timeb tb;
 483         _ftime(&tb);
 484         t->tv_sec = (long)tb.time;
 485         t->tv_usec = (long)tb.millitm * 1000;
 486 #elif defined(OPENSSL_SYS_VMS)
 487         struct timeb tb;
 488         ftime(&tb);
 489         t->tv_sec = (long)tb.time;
 490         t->tv_usec = (long)tb.millitm * 1000;
 491 #else
 492         gettimeofday(t, NULL);
 493 #endif
 494 }
 495
 496 int dtls1_listen(SSL *s, struct sockaddr *client)
 497         {
 498         int ret;
 499
 500         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 501         s->d1->listen = 1;
 502
 503         ret = SSL_accept(s);
 504         if (ret <= 0) return ret;
 505
 506         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 507         return 1;
 508         }
 509
 510 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 511         {
 512         unsigned char *p = (unsigned char *)s->init_buf->data;
 513         dtls1_set_message_header(s, p, htype, len, 0, len);
 514         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 515         s->init_off = 0;
 516         /* Buffer the message to handle re-xmits */
 517         dtls1_buffer_message(s, 0);
 518         }
 519
 520 static int dtls1_handshake_write(SSL *s)
 521         {
 522         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 523         }
 524
 525