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 IMPLEMENT_dtls1_meth_func(dtlsv1_base_method,
  94                         ssl_undefined_function,
  95                         ssl_undefined_function,
  96                         ssl_bad_method)
  97
  98 int dtls1_new(SSL *s)
  99         {
 100         DTLS1_STATE *d1;
 101
 102         if (!ssl3_new(s)) return(0);
 103         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
 104         memset(d1,0, sizeof *d1);
 105
 106         /* d1->handshake_epoch=0; */
 107 #if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
 108         d1->bitmap.length=64;
 109 #else
 110         d1->bitmap.length=sizeof(d1->bitmap.map) * 8;
 111 #endif
 112         pq_64bit_init(&(d1->bitmap.map));
 113         pq_64bit_init(&(d1->bitmap.max_seq_num));
 114
 115         d1->next_bitmap.length = d1->bitmap.length;
 116         pq_64bit_init(&(d1->next_bitmap.map));
 117         pq_64bit_init(&(d1->next_bitmap.max_seq_num));
 118
 119         d1->unprocessed_rcds.q=pqueue_new();
 120         d1->processed_rcds.q=pqueue_new();
 121         d1->buffered_messages = pqueue_new();
 122         d1->sent_messages=pqueue_new();
 123         d1->buffered_app_data.q=pqueue_new();
 124
 125         if ( s->server)
 126                 {
 127                 d1->cookie_len = sizeof(s->d1->cookie);
 128                 }
 129
 130         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 131         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 132                 {
 133         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 134         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 135         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 136                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 137                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 138                 OPENSSL_free(d1);
 139                 return (0);
 140                 }
 141
 142         s->d1=d1;
 143         s->method->ssl_clear(s);
 144         return(1);
 145         }
 146
 147 void dtls1_free(SSL *s)
 148         {
 149     pitem *item = NULL;
 150     hm_fragment *frag = NULL;
 151
 152         ssl3_free(s);
 153
 154     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 155         {
 156         OPENSSL_free(item->data);
 157         pitem_free(item);
 158         }
 159     pqueue_free(s->d1->unprocessed_rcds.q);
 160
 161     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 162         {
 163         OPENSSL_free(item->data);
 164         pitem_free(item);
 165         }
 166     pqueue_free(s->d1->processed_rcds.q);
 167
 168     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 169         {
 170         frag = (hm_fragment *)item->data;
 171         OPENSSL_free(frag->fragment);
 172         OPENSSL_free(frag);
 173         pitem_free(item);
 174         }
 175     pqueue_free(s->d1->buffered_messages);
 176
 177     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 178         {
 179         frag = (hm_fragment *)item->data;
 180         OPENSSL_free(frag->fragment);
 181         OPENSSL_free(frag);
 182         pitem_free(item);
 183         }
 184         pqueue_free(s->d1->sent_messages);
 185
 186         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 187         {
 188                 frag = (hm_fragment *)item->data;
 189                 OPENSSL_free(frag->fragment);
 190                 OPENSSL_free(frag);
 191                 pitem_free(item);
 192         }
 193         pqueue_free(s->d1->buffered_app_data.q);
 194
 195         pq_64bit_free(&(s->d1->bitmap.map));
 196         pq_64bit_free(&(s->d1->bitmap.max_seq_num));
 197
 198         pq_64bit_free(&(s->d1->next_bitmap.map));
 199         pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
 200
 201         OPENSSL_free(s->d1);
 202         }
 203
 204 void dtls1_clear(SSL *s)
 205         {
 206         ssl3_clear(s);
 207         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 208                 s->version=DTLS1_BAD_VER;
 209         else
 210                 s->version=DTLS1_VERSION;
 211         }
 212
 213 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 214         {
 215         int ret=0;
 216
 217         switch (cmd)
 218                 {
 219         case DTLS_CTRL_GET_TIMEOUT:
 220                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 221                         {
 222                         ret = 1;
 223                         }
 224                 break;
 225         case DTLS_CTRL_HANDLE_TIMEOUT:
 226                 ret = dtls1_handle_timeout(s);
 227                 break;
 228
 229         default:
 230                 ret = ssl3_ctrl(s, cmd, larg, parg);
 231                 break;
 232                 }
 233         return(ret);
 234         }
 235
 236 /*
 237  * As it's impossible to use stream ciphers in "datagram" mode, this
 238  * simple filter is designed to disengage them in DTLS. Unfortunately
 239  * there is no universal way to identify stream SSL_CIPHER, so we have
 240  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 241  * available, but if new ones emerge, they will have to be added...
 242  */
 243 SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 244         {
 245         SSL_CIPHER *ciph = ssl3_get_cipher(u);
 246
 247         if (ciph != NULL)
 248                 {
 249                 if ((ciph->algorithms&SSL_ENC_MASK) == SSL_RC4)
 250                         return NULL;
 251                 }
 252
 253         return ciph;
 254         }
 255
 256 void dtls1_start_timer(SSL *s)
 257         {
 258         /* If timer is not set, initialize duration with 1 second */
 259         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 260                 {
 261                 s->d1->timeout_duration = 1;
 262                 }
 263
 264         /* Set timeout to current time */
 265         get_current_time(&(s->d1->next_timeout));
 266
 267         /* Add duration to current time */
 268         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 269         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 270         }
 271
 272 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 273         {
 274         struct timeval timenow;
 275
 276         /* If no timeout is set, just return NULL */
 277         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 278                 {
 279                 return NULL;
 280                 }
 281
 282         /* Get current time */
 283         get_current_time(&timenow);
 284
 285         /* If timer already expired, set remaining time to 0 */
 286         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 287                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 288                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 289                 {
 290                 memset(timeleft, 0, sizeof(struct timeval));
 291                 return timeleft;
 292                 }
 293
 294         /* Calculate time left until timer expires */
 295         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 296         timeleft->tv_sec -= timenow.tv_sec;
 297         timeleft->tv_usec -= timenow.tv_usec;
 298         if (timeleft->tv_usec < 0)
 299                 {
 300                 timeleft->tv_sec--;
 301                 timeleft->tv_usec += 1000000;
 302                 }
 303
 304         return timeleft;
 305         }
 306
 307 int dtls1_is_timer_expired(SSL *s)
 308         {
 309         struct timeval timeleft;
 310
 311         /* Get time left until timeout, return false if no timer running */
 312         if (dtls1_get_timeout(s, &timeleft) == NULL)
 313                 {
 314                 return 0;
 315                 }
 316
 317         /* Return false if timer is not expired yet */
 318         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 319                 {
 320                 return 0;
 321                 }
 322
 323         /* Timer expired, so return true */
 324         return 1;
 325         }
 326
 327 void dtls1_double_timeout(SSL *s)
 328         {
 329         s->d1->timeout_duration *= 2;
 330         if (s->d1->timeout_duration > 60)
 331                 s->d1->timeout_duration = 60;
 332         dtls1_start_timer(s);
 333         }
 334
 335 void dtls1_stop_timer(SSL *s)
 336         {
 337         /* Reset everything */
 338         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 339         s->d1->timeout_duration = 1;
 340         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 341         }
 342
 343 int dtls1_handle_timeout(SSL *s)
 344         {
 345         DTLS1_STATE *state;
 346
 347         /* if no timer is expired, don't do anything */
 348         if (!dtls1_is_timer_expired(s))
 349                 {
 350                 return 0;
 351                 }
 352
 353         dtls1_double_timeout(s);
 354         state = s->d1;
 355         state->timeout.num_alerts++;
 356         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 357                 {
 358                 /* fail the connection, enough alerts have been sent */
 359                 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED);
 360                 return 0;
 361                 }
 362
 363         state->timeout.read_timeouts++;
 364         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 365                 {
 366                 state->timeout.read_timeouts = 1;
 367                 }
 368
 369         dtls1_start_timer(s);
 370         return dtls1_retransmit_buffered_messages(s);
 371         }
 372
 373 static void get_current_time(struct timeval *t)
 374 {
 375 #ifdef OPENSSL_SYS_WIN32
 376         struct _timeb tb;
 377         _ftime(&tb);
 378         t->tv_sec = (long)tb.time;
 379         t->tv_usec = (long)tb.millitm * 1000;
 380 #elif defined(OPENSSL_SYS_VMS)
 381         struct timeb tb;
 382         ftime(&tb);
 383         t->tv_sec = (long)tb.time;
 384         t->tv_usec = (long)tb.millitm * 1000;
 385 #else
 386         gettimeofday(t, NULL);
 387 #endif
 388 }