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_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         }
 206
 207 void dtls1_clear(SSL *s)
 208         {
 209     pqueue unprocessed_rcds;
 210     pqueue processed_rcds;
 211     pqueue buffered_messages;
 212         pqueue sent_messages;
 213         pqueue buffered_app_data;
 214         unsigned int mtu;
 215
 216         if (s->d1)
 217                 {
 218                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 219                 processed_rcds = s->d1->processed_rcds.q;
 220                 buffered_messages = s->d1->buffered_messages;
 221                 sent_messages = s->d1->sent_messages;
 222                 buffered_app_data = s->d1->buffered_app_data.q;
 223                 mtu = s->d1->mtu;
 224
 225                 dtls1_clear_queues(s);
 226
 227                 memset(s->d1, 0, sizeof(*(s->d1)));
 228
 229                 if (s->server)
 230                         {
 231                         s->d1->cookie_len = sizeof(s->d1->cookie);
 232                         }
 233
 234                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 235                         {
 236                         s->d1->mtu = mtu;
 237                         }
 238
 239                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 240                 s->d1->processed_rcds.q = processed_rcds;
 241                 s->d1->buffered_messages = buffered_messages;
 242                 s->d1->sent_messages = sent_messages;
 243                 s->d1->buffered_app_data.q = buffered_app_data;
 244                 }
 245
 246         ssl3_clear(s);
 247         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 248                 s->version=DTLS1_BAD_VER;
 249         else
 250                 s->version=DTLS1_VERSION;
 251         }
 252
 253 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 254         {
 255         int ret=0;
 256
 257         switch (cmd)
 258                 {
 259         case DTLS_CTRL_GET_TIMEOUT:
 260                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 261                         {
 262                         ret = 1;
 263                         }
 264                 break;
 265         case DTLS_CTRL_HANDLE_TIMEOUT:
 266                 ret = dtls1_handle_timeout(s);
 267                 break;
 268         case DTLS_CTRL_LISTEN:
 269                 ret = dtls1_listen(s, parg);
 270                 break;
 271
 272         default:
 273                 ret = ssl3_ctrl(s, cmd, larg, parg);
 274                 break;
 275                 }
 276         return(ret);
 277         }
 278
 279 /*
 280  * As it's impossible to use stream ciphers in "datagram" mode, this
 281  * simple filter is designed to disengage them in DTLS. Unfortunately
 282  * there is no universal way to identify stream SSL_CIPHER, so we have
 283  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 284  * available, but if new ones emerge, they will have to be added...
 285  */
 286 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 287         {
 288         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 289
 290         if (ciph != NULL)
 291                 {
 292                 if (ciph->algorithm_enc == SSL_RC4)
 293                         return NULL;
 294                 }
 295
 296         return ciph;
 297         }
 298
 299 void dtls1_start_timer(SSL *s)
 300         {
 301 #ifndef OPENSSL_NO_SCTP
 302         /* Disable timer for SCTP */
 303         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 304                 {
 305                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 306                 return;
 307                 }
 308 #endif
 309
 310         /* If timer is not set, initialize duration with 1 second */
 311         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 312                 {
 313                 s->d1->timeout_duration = 1;
 314                 }
 315
 316         /* Set timeout to current time */
 317         get_current_time(&(s->d1->next_timeout));
 318
 319         /* Add duration to current time */
 320         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 321         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 322         }
 323
 324 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 325         {
 326         struct timeval timenow;
 327
 328         /* If no timeout is set, just return NULL */
 329         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 330                 {
 331                 return NULL;
 332                 }
 333
 334         /* Get current time */
 335         get_current_time(&timenow);
 336
 337         /* If timer already expired, set remaining time to 0 */
 338         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 339                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 340                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 341                 {
 342                 memset(timeleft, 0, sizeof(struct timeval));
 343                 return timeleft;
 344                 }
 345
 346         /* Calculate time left until timer expires */
 347         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 348         timeleft->tv_sec -= timenow.tv_sec;
 349         timeleft->tv_usec -= timenow.tv_usec;
 350         if (timeleft->tv_usec < 0)
 351                 {
 352                 timeleft->tv_sec--;
 353                 timeleft->tv_usec += 1000000;
 354                 }
 355
 356         /* If remaining time is less than 15 ms, set it to 0
 357          * to prevent issues because of small devergences with
 358          * socket timeouts.
 359          */
 360         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 361                 {
 362                 memset(timeleft, 0, sizeof(struct timeval));
 363                 }
 364
 365
 366         return timeleft;
 367         }
 368
 369 int dtls1_is_timer_expired(SSL *s)
 370         {
 371         struct timeval timeleft;
 372
 373         /* Get time left until timeout, return false if no timer running */
 374         if (dtls1_get_timeout(s, &timeleft) == NULL)
 375                 {
 376                 return 0;
 377                 }
 378
 379         /* Return false if timer is not expired yet */
 380         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 381                 {
 382                 return 0;
 383                 }
 384
 385         /* Timer expired, so return true */
 386         return 1;
 387         }
 388
 389 void dtls1_double_timeout(SSL *s)
 390         {
 391         s->d1->timeout_duration *= 2;
 392         if (s->d1->timeout_duration > 60)
 393                 s->d1->timeout_duration = 60;
 394         dtls1_start_timer(s);
 395         }
 396
 397 void dtls1_stop_timer(SSL *s)
 398         {
 399         /* Reset everything */
 400         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 401         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 402         s->d1->timeout_duration = 1;
 403         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 404         /* Clear retransmission buffer */
 405         dtls1_clear_record_buffer(s);
 406         }
 407
 408 int dtls1_check_timeout_num(SSL *s)
 409         {
 410         s->d1->timeout.num_alerts++;
 411
 412         /* Reduce MTU after 2 unsuccessful retransmissions */
 413         if (s->d1->timeout.num_alerts > 2)
 414                 {
 415                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 416                 }
 417
 418         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 419                 {
 420                 /* fail the connection, enough alerts have been sent */
 421                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 422                 return -1;
 423                 }
 424
 425         return 0;
 426         }
 427
 428 int dtls1_handle_timeout(SSL *s)
 429         {
 430         /* if no timer is expired, don't do anything */
 431         if (!dtls1_is_timer_expired(s))
 432                 {
 433                 return 0;
 434                 }
 435
 436         dtls1_double_timeout(s);
 437
 438         if (dtls1_check_timeout_num(s) < 0)
 439                 return -1;
 440
 441         s->d1->timeout.read_timeouts++;
 442         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 443                 {
 444                 s->d1->timeout.read_timeouts = 1;
 445                 }
 446
 447 #ifndef OPENSSL_NO_HEARTBEATS
 448         if (s->tlsext_hb_pending)
 449                 {
 450                 s->tlsext_hb_pending = 0;
 451                 return dtls1_heartbeat(s);
 452                 }
 453 #endif
 454
 455         dtls1_start_timer(s);
 456         return dtls1_retransmit_buffered_messages(s);
 457         }
 458
 459 static void get_current_time(struct timeval *t)
 460 {
 461 #if defined(_WIN32)
 462         SYSTEMTIME st;
 463         union { unsigned __int64 ul; FILETIME ft; } now;
 464
 465         GetSystemTime(&st);
 466         SystemTimeToFileTime(&st,&now.ft);
 467         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
 468         t->tv_sec  = (long)(now.ul/10000000);
 469         t->tv_usec = ((int)(now.ul%10000000))/10;
 470 #elif defined(OPENSSL_SYS_VMS)
 471         struct timeb tb;
 472         ftime(&tb);
 473         t->tv_sec = (long)tb.time;
 474         t->tv_usec = (long)tb.millitm * 1000;
 475 #else
 476         gettimeofday(t, NULL);
 477 #endif
 478 }
 479
 480 int dtls1_listen(SSL *s, struct sockaddr *client)
 481         {
 482         int ret;
 483
 484         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 485         s->d1->listen = 1;
 486
 487         ret = SSL_accept(s);
 488         if (ret <= 0) return ret;
 489
 490         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 491         return 1;
 492         }
 493
 494 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 495         {
 496         unsigned char *p = (unsigned char *)s->init_buf->data;
 497         dtls1_set_message_header(s, p, htype, len, 0, len);
 498         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 499         s->init_off = 0;
 500         /* Buffer the message to handle re-xmits */
 501         dtls1_buffer_message(s, 0);
 502         }
 503
 504 static int dtls1_handshake_write(SSL *s)
 505         {
 506         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 507         }
 508
 509