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         };
  86
  87 long dtls1_default_timeout(void)
  88         {
  89         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
  90          * is way too long for http, the cache would over fill */
  91         return(60*60*2);
  92         }
  93
  94 int dtls1_new(SSL *s)
  95         {
  96         DTLS1_STATE *d1;
  97
  98         if (!ssl3_new(s)) return(0);
  99         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
 100         memset(d1,0, sizeof *d1);
 101
 102         /* d1->handshake_epoch=0; */
 103
 104         d1->unprocessed_rcds.q=pqueue_new();
 105         d1->processed_rcds.q=pqueue_new();
 106         d1->buffered_messages = pqueue_new();
 107         d1->sent_messages=pqueue_new();
 108         d1->buffered_app_data.q=pqueue_new();
 109
 110         if ( s->server)
 111                 {
 112                 d1->cookie_len = sizeof(s->d1->cookie);
 113                 }
 114
 115         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 116         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 117                 {
 118         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 119         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 120         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 121                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 122                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 123                 OPENSSL_free(d1);
 124                 return (0);
 125                 }
 126
 127         s->d1=d1;
 128         s->method->ssl_clear(s);
 129         return(1);
 130         }
 131
 132 static void dtls1_clear_queues(SSL *s)
 133         {
 134     pitem *item = NULL;
 135     hm_fragment *frag = NULL;
 136         DTLS1_RECORD_DATA *rdata;
 137
 138     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 139         {
 140                 rdata = (DTLS1_RECORD_DATA *) item->data;
 141                 if (rdata->rbuf.buf)
 142                         {
 143                         OPENSSL_free(rdata->rbuf.buf);
 144                         }
 145         OPENSSL_free(item->data);
 146         pitem_free(item);
 147         }
 148
 149     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 150         {
 151                 rdata = (DTLS1_RECORD_DATA *) item->data;
 152                 if (rdata->rbuf.buf)
 153                         {
 154                         OPENSSL_free(rdata->rbuf.buf);
 155                         }
 156         OPENSSL_free(item->data);
 157         pitem_free(item);
 158         }
 159
 160     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 161         {
 162         frag = (hm_fragment *)item->data;
 163         dtls1_hm_fragment_free(frag);
 164         pitem_free(item);
 165         }
 166
 167     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 168         {
 169         frag = (hm_fragment *)item->data;
 170         dtls1_hm_fragment_free(frag);
 171         pitem_free(item);
 172         }
 173
 174         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 175                 {
 176                 rdata = (DTLS1_RECORD_DATA *) item->data;
 177                 if (rdata->rbuf.buf)
 178                         {
 179                         OPENSSL_free(rdata->rbuf.buf);
 180                         }
 181                 OPENSSL_free(item->data);
 182                 pitem_free(item);
 183                 }
 184         }
 185
 186 void dtls1_free(SSL *s)
 187         {
 188         ssl3_free(s);
 189
 190         dtls1_clear_queues(s);
 191
 192     pqueue_free(s->d1->unprocessed_rcds.q);
 193     pqueue_free(s->d1->processed_rcds.q);
 194     pqueue_free(s->d1->buffered_messages);
 195         pqueue_free(s->d1->sent_messages);
 196         pqueue_free(s->d1->buffered_app_data.q);
 197
 198         OPENSSL_free(s->d1);
 199         s->d1 = NULL;
 200         }
 201
 202 void dtls1_clear(SSL *s)
 203         {
 204     pqueue unprocessed_rcds;
 205     pqueue processed_rcds;
 206     pqueue buffered_messages;
 207         pqueue sent_messages;
 208         pqueue buffered_app_data;
 209         unsigned int mtu;
 210
 211         if (s->d1)
 212                 {
 213                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 214                 processed_rcds = s->d1->processed_rcds.q;
 215                 buffered_messages = s->d1->buffered_messages;
 216                 sent_messages = s->d1->sent_messages;
 217                 buffered_app_data = s->d1->buffered_app_data.q;
 218                 mtu = s->d1->mtu;
 219
 220                 dtls1_clear_queues(s);
 221
 222                 memset(s->d1, 0, sizeof(*(s->d1)));
 223
 224                 if (s->server)
 225                         {
 226                         s->d1->cookie_len = sizeof(s->d1->cookie);
 227                         }
 228
 229                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 230                         {
 231                         s->d1->mtu = mtu;
 232                         }
 233
 234                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 235                 s->d1->processed_rcds.q = processed_rcds;
 236                 s->d1->buffered_messages = buffered_messages;
 237                 s->d1->sent_messages = sent_messages;
 238                 s->d1->buffered_app_data.q = buffered_app_data;
 239                 }
 240
 241         ssl3_clear(s);
 242         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 243                 s->version=DTLS1_BAD_VER;
 244         else
 245                 s->version=DTLS1_VERSION;
 246         }
 247
 248 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 249         {
 250         int ret=0;
 251
 252         switch (cmd)
 253                 {
 254         case DTLS_CTRL_GET_TIMEOUT:
 255                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 256                         {
 257                         ret = 1;
 258                         }
 259                 break;
 260         case DTLS_CTRL_HANDLE_TIMEOUT:
 261                 ret = dtls1_handle_timeout(s);
 262                 break;
 263         case DTLS_CTRL_LISTEN:
 264                 ret = dtls1_listen(s, parg);
 265                 break;
 266         case SSL_CTRL_CHECK_PROTO_VERSION:
 267                 /* For library-internal use; checks that the current protocol
 268                  * is the highest enabled version (according to s->ctx->method,
 269                  * as version negotiation may have changed s->method). */
 270 #if DTLS_MAX_VERSION != DTLS1_VERSION
 271 #  error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
 272 #endif
 273                 /* Just one protocol version is supported so far;
 274                  * fail closed if the version is not as expected. */
 275                 return s->version == DTLS_MAX_VERSION;
 276
 277         default:
 278                 ret = ssl3_ctrl(s, cmd, larg, parg);
 279                 break;
 280                 }
 281         return(ret);
 282         }
 283
 284 /*
 285  * As it's impossible to use stream ciphers in "datagram" mode, this
 286  * simple filter is designed to disengage them in DTLS. Unfortunately
 287  * there is no universal way to identify stream SSL_CIPHER, so we have
 288  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 289  * available, but if new ones emerge, they will have to be added...
 290  */
 291 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 292         {
 293         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 294
 295         if (ciph != NULL)
 296                 {
 297                 if (ciph->algorithm_enc == SSL_RC4)
 298                         return NULL;
 299                 }
 300
 301         return ciph;
 302         }
 303
 304 void dtls1_start_timer(SSL *s)
 305         {
 306         /* If timer is not set, initialize duration with 1 second */
 307         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 308                 {
 309                 s->d1->timeout_duration = 1;
 310                 }
 311
 312         /* Set timeout to current time */
 313         get_current_time(&(s->d1->next_timeout));
 314
 315         /* Add duration to current time */
 316         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 317         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 318         }
 319
 320 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 321         {
 322         struct timeval timenow;
 323
 324         /* If no timeout is set, just return NULL */
 325         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 326                 {
 327                 return NULL;
 328                 }
 329
 330         /* Get current time */
 331         get_current_time(&timenow);
 332
 333         /* If timer already expired, set remaining time to 0 */
 334         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 335                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 336                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 337                 {
 338                 memset(timeleft, 0, sizeof(struct timeval));
 339                 return timeleft;
 340                 }
 341
 342         /* Calculate time left until timer expires */
 343         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 344         timeleft->tv_sec -= timenow.tv_sec;
 345         timeleft->tv_usec -= timenow.tv_usec;
 346         if (timeleft->tv_usec < 0)
 347                 {
 348                 timeleft->tv_sec--;
 349                 timeleft->tv_usec += 1000000;
 350                 }
 351
 352         /* If remaining time is less than 15 ms, set it to 0
 353          * to prevent issues because of small devergences with
 354          * socket timeouts.
 355          */
 356         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 357                 {
 358                 memset(timeleft, 0, sizeof(struct timeval));
 359                 }
 360
 361
 362         return timeleft;
 363         }
 364
 365 int dtls1_is_timer_expired(SSL *s)
 366         {
 367         struct timeval timeleft;
 368
 369         /* Get time left until timeout, return false if no timer running */
 370         if (dtls1_get_timeout(s, &timeleft) == NULL)
 371                 {
 372                 return 0;
 373                 }
 374
 375         /* Return false if timer is not expired yet */
 376         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 377                 {
 378                 return 0;
 379                 }
 380
 381         /* Timer expired, so return true */
 382         return 1;
 383         }
 384
 385 void dtls1_double_timeout(SSL *s)
 386         {
 387         s->d1->timeout_duration *= 2;
 388         if (s->d1->timeout_duration > 60)
 389                 s->d1->timeout_duration = 60;
 390         dtls1_start_timer(s);
 391         }
 392
 393 void dtls1_stop_timer(SSL *s)
 394         {
 395         /* Reset everything */
 396         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 397         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 398         s->d1->timeout_duration = 1;
 399         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 400         /* Clear retransmission buffer */
 401         dtls1_clear_record_buffer(s);
 402         }
 403
 404 int dtls1_check_timeout_num(SSL *s)
 405         {
 406         s->d1->timeout.num_alerts++;
 407
 408         /* Reduce MTU after 2 unsuccessful retransmissions */
 409         if (s->d1->timeout.num_alerts > 2)
 410                 {
 411                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 412                 }
 413
 414         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 415                 {
 416                 /* fail the connection, enough alerts have been sent */
 417                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 418                 return -1;
 419                 }
 420
 421         return 0;
 422         }
 423
 424 int dtls1_handle_timeout(SSL *s)
 425         {
 426         /* if no timer is expired, don't do anything */
 427         if (!dtls1_is_timer_expired(s))
 428                 {
 429                 return 0;
 430                 }
 431
 432         dtls1_double_timeout(s);
 433
 434         if (dtls1_check_timeout_num(s) < 0)
 435                 return -1;
 436
 437         s->d1->timeout.read_timeouts++;
 438         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 439                 {
 440                 s->d1->timeout.read_timeouts = 1;
 441                 }
 442
 443         dtls1_start_timer(s);
 444         return dtls1_retransmit_buffered_messages(s);
 445         }
 446
 447 static void get_current_time(struct timeval *t)
 448 {
 449 #ifdef OPENSSL_SYS_WIN32
 450         struct _timeb tb;
 451         _ftime(&tb);
 452         t->tv_sec = (long)tb.time;
 453         t->tv_usec = (long)tb.millitm * 1000;
 454 #elif defined(OPENSSL_SYS_VMS)
 455         struct timeb tb;
 456         ftime(&tb);
 457         t->tv_sec = (long)tb.time;
 458         t->tv_usec = (long)tb.millitm * 1000;
 459 #else
 460         gettimeofday(t, NULL);
 461 #endif
 462 }
 463
 464 int dtls1_listen(SSL *s, struct sockaddr *client)
 465         {
 466         int ret;
 467
 468         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 469         s->d1->listen = 1;
 470
 471         ret = SSL_accept(s);
 472         if (ret <= 0) return ret;
 473
 474         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 475         return 1;
 476         }