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 #ifdef OPENSSL_SYS_WIN32
  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 void dtls1_free(SSL *s)
 133         {
 134     pitem *item = NULL;
 135     hm_fragment *frag = NULL;
 136
 137         ssl3_free(s);
 138
 139     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 140         {
 141         OPENSSL_free(item->data);
 142         pitem_free(item);
 143         }
 144     pqueue_free(s->d1->unprocessed_rcds.q);
 145
 146     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 147         {
 148         OPENSSL_free(item->data);
 149         pitem_free(item);
 150         }
 151     pqueue_free(s->d1->processed_rcds.q);
 152
 153     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 154         {
 155         frag = (hm_fragment *)item->data;
 156         OPENSSL_free(frag->fragment);
 157         OPENSSL_free(frag);
 158         pitem_free(item);
 159         }
 160     pqueue_free(s->d1->buffered_messages);
 161
 162     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 163         {
 164         frag = (hm_fragment *)item->data;
 165         OPENSSL_free(frag->fragment);
 166         OPENSSL_free(frag);
 167         pitem_free(item);
 168         }
 169         pqueue_free(s->d1->sent_messages);
 170
 171         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 172                 {
 173                 frag = (hm_fragment *)item->data;
 174                 OPENSSL_free(frag->fragment);
 175                 OPENSSL_free(frag);
 176                 pitem_free(item);
 177                 }
 178         pqueue_free(s->d1->buffered_app_data.q);
 179
 180         OPENSSL_free(s->d1);
 181         }
 182
 183 void dtls1_clear(SSL *s)
 184         {
 185         ssl3_clear(s);
 186         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 187                 s->version=DTLS1_BAD_VER;
 188         else
 189                 s->version=DTLS1_VERSION;
 190         }
 191
 192 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 193         {
 194         int ret=0;
 195
 196         switch (cmd)
 197                 {
 198         case DTLS_CTRL_GET_TIMEOUT:
 199                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 200                         {
 201                         ret = 1;
 202                         }
 203                 break;
 204         case DTLS_CTRL_HANDLE_TIMEOUT:
 205                 ret = dtls1_handle_timeout(s);
 206                 break;
 207         case DTLS_CTRL_LISTEN:
 208                 ret = dtls1_listen(s, parg);
 209                 break;
 210
 211         default:
 212                 ret = ssl3_ctrl(s, cmd, larg, parg);
 213                 break;
 214                 }
 215         return(ret);
 216         }
 217
 218 /*
 219  * As it's impossible to use stream ciphers in "datagram" mode, this
 220  * simple filter is designed to disengage them in DTLS. Unfortunately
 221  * there is no universal way to identify stream SSL_CIPHER, so we have
 222  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 223  * available, but if new ones emerge, they will have to be added...
 224  */
 225 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 226         {
 227         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 228
 229         if (ciph != NULL)
 230                 {
 231                 if (ciph->algorithm_enc == SSL_RC4)
 232                         return NULL;
 233                 }
 234
 235         return ciph;
 236         }
 237
 238 void dtls1_start_timer(SSL *s)
 239         {
 240         /* If timer is not set, initialize duration with 1 second */
 241         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 242                 {
 243                 s->d1->timeout_duration = 1;
 244                 }
 245
 246         /* Set timeout to current time */
 247         get_current_time(&(s->d1->next_timeout));
 248
 249         /* Add duration to current time */
 250         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 251         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 252         }
 253
 254 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 255         {
 256         struct timeval timenow;
 257
 258         /* If no timeout is set, just return NULL */
 259         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 260                 {
 261                 return NULL;
 262                 }
 263
 264         /* Get current time */
 265         get_current_time(&timenow);
 266
 267         /* If timer already expired, set remaining time to 0 */
 268         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 269                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 270                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 271                 {
 272                 memset(timeleft, 0, sizeof(struct timeval));
 273                 return timeleft;
 274                 }
 275
 276         /* Calculate time left until timer expires */
 277         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 278         timeleft->tv_sec -= timenow.tv_sec;
 279         timeleft->tv_usec -= timenow.tv_usec;
 280         if (timeleft->tv_usec < 0)
 281                 {
 282                 timeleft->tv_sec--;
 283                 timeleft->tv_usec += 1000000;
 284                 }
 285
 286         return timeleft;
 287         }
 288
 289 int dtls1_is_timer_expired(SSL *s)
 290         {
 291         struct timeval timeleft;
 292
 293         /* Get time left until timeout, return false if no timer running */
 294         if (dtls1_get_timeout(s, &timeleft) == NULL)
 295                 {
 296                 return 0;
 297                 }
 298
 299         /* Return false if timer is not expired yet */
 300         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 301                 {
 302                 return 0;
 303                 }
 304
 305         /* Timer expired, so return true */
 306         return 1;
 307         }
 308
 309 void dtls1_double_timeout(SSL *s)
 310         {
 311         s->d1->timeout_duration *= 2;
 312         if (s->d1->timeout_duration > 60)
 313                 s->d1->timeout_duration = 60;
 314         dtls1_start_timer(s);
 315         }
 316
 317 void dtls1_stop_timer(SSL *s)
 318         {
 319         /* Reset everything */
 320         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 321         s->d1->timeout_duration = 1;
 322         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 323         }
 324
 325 int dtls1_handle_timeout(SSL *s)
 326         {
 327         DTLS1_STATE *state;
 328
 329         /* if no timer is expired, don't do anything */
 330         if (!dtls1_is_timer_expired(s))
 331                 {
 332                 return 0;
 333                 }
 334
 335         dtls1_double_timeout(s);
 336         state = s->d1;
 337         state->timeout.num_alerts++;
 338         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 339                 {
 340                 /* fail the connection, enough alerts have been sent */
 341                 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
 342                 return 0;
 343                 }
 344
 345         state->timeout.read_timeouts++;
 346         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 347                 {
 348                 state->timeout.read_timeouts = 1;
 349                 }
 350
 351         dtls1_start_timer(s);
 352         return dtls1_retransmit_buffered_messages(s);
 353         }
 354
 355 static void get_current_time(struct timeval *t)
 356 {
 357 #ifdef OPENSSL_SYS_WIN32
 358         struct _timeb tb;
 359         _ftime(&tb);
 360         t->tv_sec = (long)tb.time;
 361         t->tv_usec = (long)tb.millitm * 1000;
 362 #elif defined(OPENSSL_SYS_VMS)
 363         struct timeb tb;
 364         ftime(&tb);
 365         t->tv_sec = (long)tb.time;
 366         t->tv_usec = (long)tb.millitm * 1000;
 367 #else
 368         gettimeofday(t, NULL);
 369 #endif
 370 }
 371
 372 int dtls1_listen(SSL *s, struct sockaddr *client)
 373         {
 374         int ret;
 375
 376         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 377         s->d1->listen = 1;
 378
 379         ret = SSL_accept(s);
 380         if (ret <= 0) return ret;
 381
 382         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 383         return 1;
 384         }