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
 137     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 138         {
 139         OPENSSL_free(item->data);
 140         pitem_free(item);
 141         }
 142
 143     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 144         {
 145         OPENSSL_free(item->data);
 146         pitem_free(item);
 147         }
 148
 149     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 150         {
 151         frag = (hm_fragment *)item->data;
 152         OPENSSL_free(frag->fragment);
 153         OPENSSL_free(frag);
 154         pitem_free(item);
 155         }
 156
 157     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 158         {
 159         frag = (hm_fragment *)item->data;
 160         OPENSSL_free(frag->fragment);
 161         OPENSSL_free(frag);
 162         pitem_free(item);
 163         }
 164
 165         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 166                 {
 167                 frag = (hm_fragment *)item->data;
 168                 OPENSSL_free(frag->fragment);
 169                 OPENSSL_free(frag);
 170                 pitem_free(item);
 171                 }
 172         }
 173
 174 void dtls1_free(SSL *s)
 175         {
 176         ssl3_free(s);
 177
 178         dtls1_clear_queues(s);
 179
 180     pqueue_free(s->d1->unprocessed_rcds.q);
 181     pqueue_free(s->d1->processed_rcds.q);
 182     pqueue_free(s->d1->buffered_messages);
 183         pqueue_free(s->d1->sent_messages);
 184         pqueue_free(s->d1->buffered_app_data.q);
 185
 186         OPENSSL_free(s->d1);
 187         }
 188
 189 void dtls1_clear(SSL *s)
 190         {
 191     pqueue unprocessed_rcds;
 192     pqueue processed_rcds;
 193     pqueue buffered_messages;
 194         pqueue sent_messages;
 195         pqueue buffered_app_data;
 196
 197         if (s->d1)
 198                 {
 199                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 200                 processed_rcds = s->d1->processed_rcds.q;
 201                 buffered_messages = s->d1->buffered_messages;
 202                 sent_messages = s->d1->sent_messages;
 203                 buffered_app_data = s->d1->buffered_app_data.q;
 204
 205                 dtls1_clear_queues(s);
 206
 207                 memset(s->d1, 0, sizeof(*(s->d1)));
 208
 209                 if (s->server)
 210                         {
 211                         s->d1->cookie_len = sizeof(s->d1->cookie);
 212                         }
 213
 214                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 215                 s->d1->processed_rcds.q = processed_rcds;
 216                 s->d1->buffered_messages = buffered_messages;
 217                 s->d1->sent_messages = sent_messages;
 218                 s->d1->buffered_app_data.q = buffered_app_data;
 219                 }
 220
 221         ssl3_clear(s);
 222         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 223                 s->version=DTLS1_BAD_VER;
 224         else
 225                 s->version=DTLS1_VERSION;
 226         }
 227
 228 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 229         {
 230         int ret=0;
 231
 232         switch (cmd)
 233                 {
 234         case DTLS_CTRL_GET_TIMEOUT:
 235                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 236                         {
 237                         ret = 1;
 238                         }
 239                 break;
 240         case DTLS_CTRL_HANDLE_TIMEOUT:
 241                 ret = dtls1_handle_timeout(s);
 242                 break;
 243         case DTLS_CTRL_LISTEN:
 244                 ret = dtls1_listen(s, parg);
 245                 break;
 246
 247         default:
 248                 ret = ssl3_ctrl(s, cmd, larg, parg);
 249                 break;
 250                 }
 251         return(ret);
 252         }
 253
 254 /*
 255  * As it's impossible to use stream ciphers in "datagram" mode, this
 256  * simple filter is designed to disengage them in DTLS. Unfortunately
 257  * there is no universal way to identify stream SSL_CIPHER, so we have
 258  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 259  * available, but if new ones emerge, they will have to be added...
 260  */
 261 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 262         {
 263         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 264
 265         if (ciph != NULL)
 266                 {
 267                 if (ciph->algorithm_enc == SSL_RC4)
 268                         return NULL;
 269                 }
 270
 271         return ciph;
 272         }
 273
 274 void dtls1_start_timer(SSL *s)
 275         {
 276         /* If timer is not set, initialize duration with 1 second */
 277         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 278                 {
 279                 s->d1->timeout_duration = 1;
 280                 }
 281
 282         /* Set timeout to current time */
 283         get_current_time(&(s->d1->next_timeout));
 284
 285         /* Add duration to current time */
 286         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 287         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 288         }
 289
 290 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 291         {
 292         struct timeval timenow;
 293
 294         /* If no timeout is set, just return NULL */
 295         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 296                 {
 297                 return NULL;
 298                 }
 299
 300         /* Get current time */
 301         get_current_time(&timenow);
 302
 303         /* If timer already expired, set remaining time to 0 */
 304         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 305                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 306                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 307                 {
 308                 memset(timeleft, 0, sizeof(struct timeval));
 309                 return timeleft;
 310                 }
 311
 312         /* Calculate time left until timer expires */
 313         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 314         timeleft->tv_sec -= timenow.tv_sec;
 315         timeleft->tv_usec -= timenow.tv_usec;
 316         if (timeleft->tv_usec < 0)
 317                 {
 318                 timeleft->tv_sec--;
 319                 timeleft->tv_usec += 1000000;
 320                 }
 321
 322         /* If remaining time is less than 15 ms, set it to 0
 323          * to prevent issues because of small devergences with
 324          * socket timeouts.
 325          */
 326         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 327                 {
 328                 memset(timeleft, 0, sizeof(struct timeval));
 329                 }
 330
 331
 332         return timeleft;
 333         }
 334
 335 int dtls1_is_timer_expired(SSL *s)
 336         {
 337         struct timeval timeleft;
 338
 339         /* Get time left until timeout, return false if no timer running */
 340         if (dtls1_get_timeout(s, &timeleft) == NULL)
 341                 {
 342                 return 0;
 343                 }
 344
 345         /* Return false if timer is not expired yet */
 346         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 347                 {
 348                 return 0;
 349                 }
 350
 351         /* Timer expired, so return true */
 352         return 1;
 353         }
 354
 355 void dtls1_double_timeout(SSL *s)
 356         {
 357         s->d1->timeout_duration *= 2;
 358         if (s->d1->timeout_duration > 60)
 359                 s->d1->timeout_duration = 60;
 360         dtls1_start_timer(s);
 361         }
 362
 363 void dtls1_stop_timer(SSL *s)
 364         {
 365         /* Reset everything */
 366         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 367         s->d1->timeout_duration = 1;
 368         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 369         /* Clear retransmission buffer */
 370         dtls1_clear_record_buffer(s);
 371         }
 372
 373 int dtls1_handle_timeout(SSL *s)
 374         {
 375         DTLS1_STATE *state;
 376
 377         /* if no timer is expired, don't do anything */
 378         if (!dtls1_is_timer_expired(s))
 379                 {
 380                 return 0;
 381                 }
 382
 383         dtls1_double_timeout(s);
 384         state = s->d1;
 385         state->timeout.num_alerts++;
 386         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 387                 {
 388                 /* fail the connection, enough alerts have been sent */
 389                 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
 390                 return 0;
 391                 }
 392
 393         state->timeout.read_timeouts++;
 394         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 395                 {
 396                 state->timeout.read_timeouts = 1;
 397                 }
 398
 399         dtls1_start_timer(s);
 400         return dtls1_retransmit_buffered_messages(s);
 401         }
 402
 403 static void get_current_time(struct timeval *t)
 404 {
 405 #ifdef OPENSSL_SYS_WIN32
 406         struct _timeb tb;
 407         _ftime(&tb);
 408         t->tv_sec = (long)tb.time;
 409         t->tv_usec = (long)tb.millitm * 1000;
 410 #elif defined(OPENSSL_SYS_VMS)
 411         struct timeb tb;
 412         ftime(&tb);
 413         t->tv_sec = (long)tb.time;
 414         t->tv_usec = (long)tb.millitm * 1000;
 415 #else
 416         gettimeofday(t, NULL);
 417 #endif
 418 }
 419
 420 int dtls1_listen(SSL *s, struct sockaddr *client)
 421         {
 422         int ret;
 423
 424         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 425         s->d1->listen = 1;
 426
 427         ret = SSL_accept(s);
 428         if (ret <= 0) return ret;
 429
 430         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 431         return 1;
 432         }