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
  72 SSL3_ENC_METHOD DTLSv1_enc_data={
  73     dtls1_enc,
  74         tls1_mac,
  75         tls1_setup_key_block,
  76         tls1_generate_master_secret,
  77         tls1_change_cipher_state,
  78         tls1_final_finish_mac,
  79         TLS1_FINISH_MAC_LENGTH,
  80         tls1_cert_verify_mac,
  81         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
  82         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
  83         tls1_alert_code,
  84         };
  85
  86 long dtls1_default_timeout(void)
  87         {
  88         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
  89          * is way too long for http, the cache would over fill */
  90         return(60*60*2);
  91         }
  92
  93 int dtls1_new(SSL *s)
  94         {
  95         DTLS1_STATE *d1;
  96
  97         if (!ssl3_new(s)) return(0);
  98         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
  99         memset(d1,0, sizeof *d1);
 100
 101         /* d1->handshake_epoch=0; */
 102
 103         d1->unprocessed_rcds.q=pqueue_new();
 104         d1->processed_rcds.q=pqueue_new();
 105         d1->buffered_messages = pqueue_new();
 106         d1->sent_messages=pqueue_new();
 107         d1->buffered_app_data.q=pqueue_new();
 108
 109         if ( s->server)
 110                 {
 111                 d1->cookie_len = sizeof(s->d1->cookie);
 112                 }
 113
 114         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 115         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 116                 {
 117         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 118         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 119         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 120                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 121                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 122                 OPENSSL_free(d1);
 123                 return (0);
 124                 }
 125
 126         s->d1=d1;
 127         s->method->ssl_clear(s);
 128         return(1);
 129         }
 130
 131 void dtls1_free(SSL *s)
 132         {
 133     pitem *item = NULL;
 134     hm_fragment *frag = NULL;
 135
 136         ssl3_free(s);
 137
 138     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 139         {
 140         OPENSSL_free(item->data);
 141         pitem_free(item);
 142         }
 143     pqueue_free(s->d1->unprocessed_rcds.q);
 144
 145     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 146         {
 147         OPENSSL_free(item->data);
 148         pitem_free(item);
 149         }
 150     pqueue_free(s->d1->processed_rcds.q);
 151
 152     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 153         {
 154         frag = (hm_fragment *)item->data;
 155         OPENSSL_free(frag->fragment);
 156         OPENSSL_free(frag);
 157         pitem_free(item);
 158         }
 159     pqueue_free(s->d1->buffered_messages);
 160
 161     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 162         {
 163         frag = (hm_fragment *)item->data;
 164         OPENSSL_free(frag->fragment);
 165         OPENSSL_free(frag);
 166         pitem_free(item);
 167         }
 168         pqueue_free(s->d1->sent_messages);
 169
 170         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 171                 {
 172                 frag = (hm_fragment *)item->data;
 173                 OPENSSL_free(frag->fragment);
 174                 OPENSSL_free(frag);
 175                 pitem_free(item);
 176                 }
 177         pqueue_free(s->d1->buffered_app_data.q);
 178
 179         OPENSSL_free(s->d1);
 180         }
 181
 182 void dtls1_clear(SSL *s)
 183         {
 184         ssl3_clear(s);
 185         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 186                 s->version=DTLS1_BAD_VER;
 187         else
 188                 s->version=DTLS1_VERSION;
 189         }
 190
 191 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 192         {
 193         int ret=0;
 194
 195         switch (cmd)
 196                 {
 197         case DTLS_CTRL_GET_TIMEOUT:
 198                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 199                         {
 200                         ret = 1;
 201                         }
 202                 break;
 203         case DTLS_CTRL_HANDLE_TIMEOUT:
 204                 ret = dtls1_handle_timeout(s);
 205                 break;
 206
 207         default:
 208                 ret = ssl3_ctrl(s, cmd, larg, parg);
 209                 break;
 210                 }
 211         return(ret);
 212         }
 213
 214 /*
 215  * As it's impossible to use stream ciphers in "datagram" mode, this
 216  * simple filter is designed to disengage them in DTLS. Unfortunately
 217  * there is no universal way to identify stream SSL_CIPHER, so we have
 218  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 219  * available, but if new ones emerge, they will have to be added...
 220  */
 221 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 222         {
 223         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 224
 225         if (ciph != NULL)
 226                 {
 227                 if (ciph->algorithm_enc == SSL_RC4)
 228                         return NULL;
 229                 }
 230
 231         return ciph;
 232         }
 233
 234 void dtls1_start_timer(SSL *s)
 235         {
 236         /* If timer is not set, initialize duration with 1 second */
 237         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 238                 {
 239                 s->d1->timeout_duration = 1;
 240                 }
 241
 242         /* Set timeout to current time */
 243         get_current_time(&(s->d1->next_timeout));
 244
 245         /* Add duration to current time */
 246         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 247         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 248         }
 249
 250 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 251         {
 252         struct timeval timenow;
 253
 254         /* If no timeout is set, just return NULL */
 255         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 256                 {
 257                 return NULL;
 258                 }
 259
 260         /* Get current time */
 261         get_current_time(&timenow);
 262
 263         /* If timer already expired, set remaining time to 0 */
 264         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 265                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 266                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 267                 {
 268                 memset(timeleft, 0, sizeof(struct timeval));
 269                 return timeleft;
 270                 }
 271
 272         /* Calculate time left until timer expires */
 273         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 274         timeleft->tv_sec -= timenow.tv_sec;
 275         timeleft->tv_usec -= timenow.tv_usec;
 276         if (timeleft->tv_usec < 0)
 277                 {
 278                 timeleft->tv_sec--;
 279                 timeleft->tv_usec += 1000000;
 280                 }
 281
 282         return timeleft;
 283         }
 284
 285 int dtls1_is_timer_expired(SSL *s)
 286         {
 287         struct timeval timeleft;
 288
 289         /* Get time left until timeout, return false if no timer running */
 290         if (dtls1_get_timeout(s, &timeleft) == NULL)
 291                 {
 292                 return 0;
 293                 }
 294
 295         /* Return false if timer is not expired yet */
 296         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 297                 {
 298                 return 0;
 299                 }
 300
 301         /* Timer expired, so return true */
 302         return 1;
 303         }
 304
 305 void dtls1_double_timeout(SSL *s)
 306         {
 307         s->d1->timeout_duration *= 2;
 308         if (s->d1->timeout_duration > 60)
 309                 s->d1->timeout_duration = 60;
 310         dtls1_start_timer(s);
 311         }
 312
 313 void dtls1_stop_timer(SSL *s)
 314         {
 315         /* Reset everything */
 316         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 317         s->d1->timeout_duration = 1;
 318         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 319         }
 320
 321 int dtls1_handle_timeout(SSL *s)
 322         {
 323         DTLS1_STATE *state;
 324
 325         /* if no timer is expired, don't do anything */
 326         if (!dtls1_is_timer_expired(s))
 327                 {
 328                 return 0;
 329                 }
 330
 331         dtls1_double_timeout(s);
 332         state = s->d1;
 333         state->timeout.num_alerts++;
 334         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 335                 {
 336                 /* fail the connection, enough alerts have been sent */
 337                 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
 338                 return 0;
 339                 }
 340
 341         state->timeout.read_timeouts++;
 342         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 343                 {
 344                 state->timeout.read_timeouts = 1;
 345                 }
 346
 347         dtls1_start_timer(s);
 348         return dtls1_retransmit_buffered_messages(s);
 349         }
 350
 351 static void get_current_time(struct timeval *t)
 352 {
 353 #ifdef OPENSSL_SYS_WIN32
 354         struct _timeb tb;
 355         _ftime(&tb);
 356         t->tv_sec = (long)tb.time;
 357         t->tv_usec = (long)tb.millitm * 1000;
 358 #elif defined(OPENSSL_SYS_VMS)
 359         struct timeb tb;
 360         ftime(&tb);
 361         t->tv_sec = (long)tb.time;
 362         t->tv_usec = (long)tb.millitm * 1000;
 363 #else
 364         gettimeofday(t, NULL);
 365 #endif
 366 }