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 static void dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
  71 static int dtls1_handshake_write(SSL *s);
  72 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
  73 int dtls1_listen(SSL *s, struct sockaddr *client);
  74
  75 SSL3_ENC_METHOD DTLSv1_enc_data={
  76     dtls1_enc,
  77         tls1_mac,
  78         tls1_setup_key_block,
  79         tls1_generate_master_secret,
  80         tls1_change_cipher_state,
  81         tls1_final_finish_mac,
  82         TLS1_FINISH_MAC_LENGTH,
  83         tls1_cert_verify_mac,
  84         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
  85         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
  86         tls1_alert_code,
  87         tls1_export_keying_material,
  88         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV,
  89         DTLS1_HM_HEADER_LENGTH,
  90         dtls1_set_handshake_header,
  91         dtls1_handshake_write
  92         };
  93
  94 long dtls1_default_timeout(void)
  95         {
  96         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
  97          * is way too long for http, the cache would over fill */
  98         return(60*60*2);
  99         }
 100
 101 int dtls1_new(SSL *s)
 102         {
 103         DTLS1_STATE *d1;
 104
 105         if (!ssl3_new(s)) return(0);
 106         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
 107         memset(d1,0, sizeof *d1);
 108
 109         /* d1->handshake_epoch=0; */
 110
 111         d1->unprocessed_rcds.q=pqueue_new();
 112         d1->processed_rcds.q=pqueue_new();
 113         d1->buffered_messages = pqueue_new();
 114         d1->sent_messages=pqueue_new();
 115         d1->buffered_app_data.q=pqueue_new();
 116
 117         if ( s->server)
 118                 {
 119                 d1->cookie_len = sizeof(s->d1->cookie);
 120                 }
 121
 122         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 123         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 124                 {
 125         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 126         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 127         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 128                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 129                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 130                 OPENSSL_free(d1);
 131                 return (0);
 132                 }
 133
 134         s->d1=d1;
 135         s->method->ssl_clear(s);
 136         return(1);
 137         }
 138
 139 static void dtls1_clear_queues(SSL *s)
 140         {
 141     pitem *item = NULL;
 142     hm_fragment *frag = NULL;
 143         DTLS1_RECORD_DATA *rdata;
 144
 145     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 146         {
 147                 rdata = (DTLS1_RECORD_DATA *) item->data;
 148                 if (rdata->rbuf.buf)
 149                         {
 150                         OPENSSL_free(rdata->rbuf.buf);
 151                         }
 152         OPENSSL_free(item->data);
 153         pitem_free(item);
 154         }
 155
 156     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 157         {
 158                 rdata = (DTLS1_RECORD_DATA *) item->data;
 159                 if (rdata->rbuf.buf)
 160                         {
 161                         OPENSSL_free(rdata->rbuf.buf);
 162                         }
 163         OPENSSL_free(item->data);
 164         pitem_free(item);
 165         }
 166
 167     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 168         {
 169         frag = (hm_fragment *)item->data;
 170         OPENSSL_free(frag->fragment);
 171         OPENSSL_free(frag);
 172         pitem_free(item);
 173         }
 174
 175     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 176         {
 177         frag = (hm_fragment *)item->data;
 178         OPENSSL_free(frag->fragment);
 179         OPENSSL_free(frag);
 180         pitem_free(item);
 181         }
 182
 183         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 184                 {
 185                 frag = (hm_fragment *)item->data;
 186                 OPENSSL_free(frag->fragment);
 187                 OPENSSL_free(frag);
 188                 pitem_free(item);
 189                 }
 190         }
 191
 192 void dtls1_free(SSL *s)
 193         {
 194         ssl3_free(s);
 195
 196         dtls1_clear_queues(s);
 197
 198     pqueue_free(s->d1->unprocessed_rcds.q);
 199     pqueue_free(s->d1->processed_rcds.q);
 200     pqueue_free(s->d1->buffered_messages);
 201         pqueue_free(s->d1->sent_messages);
 202         pqueue_free(s->d1->buffered_app_data.q);
 203
 204         OPENSSL_free(s->d1);
 205         s->d1 = NULL;
 206         }
 207
 208 void dtls1_clear(SSL *s)
 209         {
 210     pqueue unprocessed_rcds;
 211     pqueue processed_rcds;
 212     pqueue buffered_messages;
 213         pqueue sent_messages;
 214         pqueue buffered_app_data;
 215         unsigned int mtu;
 216
 217         if (s->d1)
 218                 {
 219                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 220                 processed_rcds = s->d1->processed_rcds.q;
 221                 buffered_messages = s->d1->buffered_messages;
 222                 sent_messages = s->d1->sent_messages;
 223                 buffered_app_data = s->d1->buffered_app_data.q;
 224                 mtu = s->d1->mtu;
 225
 226                 dtls1_clear_queues(s);
 227
 228                 memset(s->d1, 0, sizeof(*(s->d1)));
 229
 230                 if (s->server)
 231                         {
 232                         s->d1->cookie_len = sizeof(s->d1->cookie);
 233                         }
 234
 235                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 236                         {
 237                         s->d1->mtu = mtu;
 238                         }
 239
 240                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 241                 s->d1->processed_rcds.q = processed_rcds;
 242                 s->d1->buffered_messages = buffered_messages;
 243                 s->d1->sent_messages = sent_messages;
 244                 s->d1->buffered_app_data.q = buffered_app_data;
 245                 }
 246
 247         ssl3_clear(s);
 248         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 249                 s->version=DTLS1_BAD_VER;
 250         else
 251                 s->version=DTLS1_VERSION;
 252         }
 253
 254 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 255         {
 256         int ret=0;
 257
 258         switch (cmd)
 259                 {
 260         case DTLS_CTRL_GET_TIMEOUT:
 261                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 262                         {
 263                         ret = 1;
 264                         }
 265                 break;
 266         case DTLS_CTRL_HANDLE_TIMEOUT:
 267                 ret = dtls1_handle_timeout(s);
 268                 break;
 269         case DTLS_CTRL_LISTEN:
 270                 ret = dtls1_listen(s, parg);
 271                 break;
 272
 273         default:
 274                 ret = ssl3_ctrl(s, cmd, larg, parg);
 275                 break;
 276                 }
 277         return(ret);
 278         }
 279
 280 /*
 281  * As it's impossible to use stream ciphers in "datagram" mode, this
 282  * simple filter is designed to disengage them in DTLS. Unfortunately
 283  * there is no universal way to identify stream SSL_CIPHER, so we have
 284  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 285  * available, but if new ones emerge, they will have to be added...
 286  */
 287 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 288         {
 289         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 290
 291         if (ciph != NULL)
 292                 {
 293                 if (ciph->algorithm_enc == SSL_RC4)
 294                         return NULL;
 295                 }
 296
 297         return ciph;
 298         }
 299
 300 void dtls1_start_timer(SSL *s)
 301         {
 302 #ifndef OPENSSL_NO_SCTP
 303         /* Disable timer for SCTP */
 304         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 305                 {
 306                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 307                 return;
 308                 }
 309 #endif
 310
 311         /* If timer is not set, initialize duration with 1 second */
 312         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 313                 {
 314                 s->d1->timeout_duration = 1;
 315                 }
 316
 317         /* Set timeout to current time */
 318         get_current_time(&(s->d1->next_timeout));
 319
 320         /* Add duration to current time */
 321         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 322         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 323         }
 324
 325 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 326         {
 327         struct timeval timenow;
 328
 329         /* If no timeout is set, just return NULL */
 330         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 331                 {
 332                 return NULL;
 333                 }
 334
 335         /* Get current time */
 336         get_current_time(&timenow);
 337
 338         /* If timer already expired, set remaining time to 0 */
 339         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 340                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 341                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 342                 {
 343                 memset(timeleft, 0, sizeof(struct timeval));
 344                 return timeleft;
 345                 }
 346
 347         /* Calculate time left until timer expires */
 348         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 349         timeleft->tv_sec -= timenow.tv_sec;
 350         timeleft->tv_usec -= timenow.tv_usec;
 351         if (timeleft->tv_usec < 0)
 352                 {
 353                 timeleft->tv_sec--;
 354                 timeleft->tv_usec += 1000000;
 355                 }
 356
 357         /* If remaining time is less than 15 ms, set it to 0
 358          * to prevent issues because of small devergences with
 359          * socket timeouts.
 360          */
 361         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 362                 {
 363                 memset(timeleft, 0, sizeof(struct timeval));
 364                 }
 365
 366
 367         return timeleft;
 368         }
 369
 370 int dtls1_is_timer_expired(SSL *s)
 371         {
 372         struct timeval timeleft;
 373
 374         /* Get time left until timeout, return false if no timer running */
 375         if (dtls1_get_timeout(s, &timeleft) == NULL)
 376                 {
 377                 return 0;
 378                 }
 379
 380         /* Return false if timer is not expired yet */
 381         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 382                 {
 383                 return 0;
 384                 }
 385
 386         /* Timer expired, so return true */
 387         return 1;
 388         }
 389
 390 void dtls1_double_timeout(SSL *s)
 391         {
 392         s->d1->timeout_duration *= 2;
 393         if (s->d1->timeout_duration > 60)
 394                 s->d1->timeout_duration = 60;
 395         dtls1_start_timer(s);
 396         }
 397
 398 void dtls1_stop_timer(SSL *s)
 399         {
 400         /* Reset everything */
 401         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 402         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 403         s->d1->timeout_duration = 1;
 404         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 405         /* Clear retransmission buffer */
 406         dtls1_clear_record_buffer(s);
 407         }
 408
 409 int dtls1_check_timeout_num(SSL *s)
 410         {
 411         s->d1->timeout.num_alerts++;
 412
 413         /* Reduce MTU after 2 unsuccessful retransmissions */
 414         if (s->d1->timeout.num_alerts > 2)
 415                 {
 416                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 417                 }
 418
 419         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 420                 {
 421                 /* fail the connection, enough alerts have been sent */
 422                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 423                 return -1;
 424                 }
 425
 426         return 0;
 427         }
 428
 429 int dtls1_handle_timeout(SSL *s)
 430         {
 431         /* if no timer is expired, don't do anything */
 432         if (!dtls1_is_timer_expired(s))
 433                 {
 434                 return 0;
 435                 }
 436
 437         dtls1_double_timeout(s);
 438
 439         if (dtls1_check_timeout_num(s) < 0)
 440                 return -1;
 441
 442         s->d1->timeout.read_timeouts++;
 443         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 444                 {
 445                 s->d1->timeout.read_timeouts = 1;
 446                 }
 447
 448 #ifndef OPENSSL_NO_HEARTBEATS
 449         if (s->tlsext_hb_pending)
 450                 {
 451                 s->tlsext_hb_pending = 0;
 452                 return dtls1_heartbeat(s);
 453                 }
 454 #endif
 455
 456         dtls1_start_timer(s);
 457         return dtls1_retransmit_buffered_messages(s);
 458         }
 459
 460 static void get_current_time(struct timeval *t)
 461 {
 462 #ifdef OPENSSL_SYS_WIN32
 463         struct _timeb tb;
 464         _ftime(&tb);
 465         t->tv_sec = (long)tb.time;
 466         t->tv_usec = (long)tb.millitm * 1000;
 467 #elif defined(OPENSSL_SYS_VMS)
 468         struct timeb tb;
 469         ftime(&tb);
 470         t->tv_sec = (long)tb.time;
 471         t->tv_usec = (long)tb.millitm * 1000;
 472 #else
 473         gettimeofday(t, NULL);
 474 #endif
 475 }
 476
 477 int dtls1_listen(SSL *s, struct sockaddr *client)
 478         {
 479         int ret;
 480
 481         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 482         s->d1->listen = 1;
 483
 484         ret = SSL_accept(s);
 485         if (ret <= 0) return ret;
 486
 487         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 488         return 1;
 489         }
 490
 491 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 492         {
 493         unsigned char *p = (unsigned char *)s->init_buf->data;
 494         dtls1_set_message_header(s, p, htype, len, 0, len);
 495         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 496         s->init_off = 0;
 497         /* Buffer the message to handle re-xmits */
 498         dtls1_buffer_message(s, 0);
 499         }
 500
 501 static int dtls1_handshake_write(SSL *s)
 502         {
 503         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 504         }
 505
 506