release/src/router/openssl/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 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     tls1_export_keying_material,
  86 };
  87
  88 long dtls1_default_timeout(void)
  89 {
  90     /*
  91      * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
  92      * http, the cache would over fill
  93      */
  94     return (60 * 60 * 2);
  95 }
  96
  97 int dtls1_new(SSL *s)
  98 {
  99     DTLS1_STATE *d1;
 100
 101     if (!ssl3_new(s))
 102         return (0);
 103     if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL)
 104         return (0);
 105     memset(d1, 0, sizeof *d1);
 106
 107     /* d1->handshake_epoch=0; */
 108
 109     d1->unprocessed_rcds.q = pqueue_new();
 110     d1->processed_rcds.q = pqueue_new();
 111     d1->buffered_messages = pqueue_new();
 112     d1->sent_messages = pqueue_new();
 113     d1->buffered_app_data.q = pqueue_new();
 114
 115     if (s->server) {
 116         d1->cookie_len = sizeof(s->d1->cookie);
 117     }
 118
 119     d1->link_mtu = 0;
 120     d1->mtu = 0;
 121
 122     if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q
 123         || !d1->buffered_messages || !d1->sent_messages
 124         || !d1->buffered_app_data.q) {
 125         if (d1->unprocessed_rcds.q)
 126             pqueue_free(d1->unprocessed_rcds.q);
 127         if (d1->processed_rcds.q)
 128             pqueue_free(d1->processed_rcds.q);
 129         if (d1->buffered_messages)
 130             pqueue_free(d1->buffered_messages);
 131         if (d1->sent_messages)
 132             pqueue_free(d1->sent_messages);
 133         if (d1->buffered_app_data.q)
 134             pqueue_free(d1->buffered_app_data.q);
 135         OPENSSL_free(d1);
 136         return (0);
 137     }
 138
 139     s->d1 = d1;
 140     s->method->ssl_clear(s);
 141     return (1);
 142 }
 143
 144 static void dtls1_clear_queues(SSL *s)
 145 {
 146     pitem *item = NULL;
 147     hm_fragment *frag = NULL;
 148     DTLS1_RECORD_DATA *rdata;
 149
 150     while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) {
 151         rdata = (DTLS1_RECORD_DATA *)item->data;
 152         if (rdata->rbuf.buf) {
 153             OPENSSL_free(rdata->rbuf.buf);
 154         }
 155         OPENSSL_free(item->data);
 156         pitem_free(item);
 157     }
 158
 159     while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {
 160         rdata = (DTLS1_RECORD_DATA *)item->data;
 161         if (rdata->rbuf.buf) {
 162             OPENSSL_free(rdata->rbuf.buf);
 163         }
 164         OPENSSL_free(item->data);
 165         pitem_free(item);
 166     }
 167
 168     while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
 169         frag = (hm_fragment *)item->data;
 170         dtls1_hm_fragment_free(frag);
 171         pitem_free(item);
 172     }
 173
 174     while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
 175         frag = (hm_fragment *)item->data;
 176         dtls1_hm_fragment_free(frag);
 177         pitem_free(item);
 178     }
 179
 180     while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
 181         rdata = (DTLS1_RECORD_DATA *)item->data;
 182         if (rdata->rbuf.buf) {
 183             OPENSSL_free(rdata->rbuf.buf);
 184         }
 185         OPENSSL_free(item->data);
 186         pitem_free(item);
 187     }
 188 }
 189
 190 void dtls1_free(SSL *s)
 191 {
 192     ssl3_free(s);
 193
 194     dtls1_clear_queues(s);
 195
 196     pqueue_free(s->d1->unprocessed_rcds.q);
 197     pqueue_free(s->d1->processed_rcds.q);
 198     pqueue_free(s->d1->buffered_messages);
 199     pqueue_free(s->d1->sent_messages);
 200     pqueue_free(s->d1->buffered_app_data.q);
 201
 202     OPENSSL_free(s->d1);
 203     s->d1 = NULL;
 204 }
 205
 206 void dtls1_clear(SSL *s)
 207 {
 208     pqueue unprocessed_rcds;
 209     pqueue processed_rcds;
 210     pqueue buffered_messages;
 211     pqueue sent_messages;
 212     pqueue buffered_app_data;
 213     unsigned int mtu;
 214     unsigned int link_mtu;
 215
 216     if (s->d1) {
 217         unprocessed_rcds = s->d1->unprocessed_rcds.q;
 218         processed_rcds = s->d1->processed_rcds.q;
 219         buffered_messages = s->d1->buffered_messages;
 220         sent_messages = s->d1->sent_messages;
 221         buffered_app_data = s->d1->buffered_app_data.q;
 222         mtu = s->d1->mtu;
 223         link_mtu = s->d1->link_mtu;
 224
 225         dtls1_clear_queues(s);
 226
 227         memset(s->d1, 0, sizeof(*(s->d1)));
 228
 229         if (s->server) {
 230             s->d1->cookie_len = sizeof(s->d1->cookie);
 231         }
 232
 233         if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
 234             s->d1->mtu = mtu;
 235             s->d1->link_mtu = link_mtu;
 236         }
 237
 238         s->d1->unprocessed_rcds.q = unprocessed_rcds;
 239         s->d1->processed_rcds.q = processed_rcds;
 240         s->d1->buffered_messages = buffered_messages;
 241         s->d1->sent_messages = sent_messages;
 242         s->d1->buffered_app_data.q = buffered_app_data;
 243     }
 244
 245     ssl3_clear(s);
 246     if (s->options & SSL_OP_CISCO_ANYCONNECT)
 247         s->version = DTLS1_BAD_VER;
 248     else
 249         s->version = DTLS1_VERSION;
 250 }
 251
 252 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 253 {
 254     int ret = 0;
 255
 256     switch (cmd) {
 257     case DTLS_CTRL_GET_TIMEOUT:
 258         if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
 259             ret = 1;
 260         }
 261         break;
 262     case DTLS_CTRL_HANDLE_TIMEOUT:
 263         ret = dtls1_handle_timeout(s);
 264         break;
 265     case DTLS_CTRL_LISTEN:
 266         ret = dtls1_listen(s, parg);
 267         break;
 268     case SSL_CTRL_CHECK_PROTO_VERSION:
 269         /*
 270          * For library-internal use; checks that the current protocol is the
 271          * highest enabled version (according to s->ctx->method, as version
 272          * negotiation may have changed s->method).
 273          */
 274 #if DTLS_MAX_VERSION != DTLS1_VERSION
 275 # error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
 276 #endif
 277         /*
 278          * Just one protocol version is supported so far; fail closed if the
 279          * version is not as expected.
 280          */
 281         return s->version == DTLS_MAX_VERSION;
 282     case DTLS_CTRL_SET_LINK_MTU:
 283         if (larg < (long)dtls1_link_min_mtu())
 284             return 0;
 285         s->d1->link_mtu = larg;
 286         return 1;
 287     case DTLS_CTRL_GET_LINK_MIN_MTU:
 288         return (long)dtls1_link_min_mtu();
 289     case SSL_CTRL_SET_MTU:
 290         /*
 291          *  We may not have a BIO set yet so can't call dtls1_min_mtu()
 292          *  We'll have to make do with dtls1_link_min_mtu() and max overhead
 293          */
 294         if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
 295             return 0;
 296         s->d1->mtu = larg;
 297         return larg;
 298     default:
 299         ret = ssl3_ctrl(s, cmd, larg, parg);
 300         break;
 301     }
 302     return (ret);
 303 }
 304
 305 /*
 306  * As it's impossible to use stream ciphers in "datagram" mode, this
 307  * simple filter is designed to disengage them in DTLS. Unfortunately
 308  * there is no universal way to identify stream SSL_CIPHER, so we have
 309  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 310  * available, but if new ones emerge, they will have to be added...
 311  */
 312 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 313 {
 314     const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 315
 316     if (ciph != NULL) {
 317         if (ciph->algorithm_enc == SSL_RC4)
 318             return NULL;
 319     }
 320
 321     return ciph;
 322 }
 323
 324 void dtls1_start_timer(SSL *s)
 325 {
 326 #ifndef OPENSSL_NO_SCTP
 327     /* Disable timer for SCTP */
 328     if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 329         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 330         return;
 331     }
 332 #endif
 333
 334     /* If timer is not set, initialize duration with 1 second */
 335     if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
 336         s->d1->timeout_duration = 1;
 337     }
 338
 339     /* Set timeout to current time */
 340     get_current_time(&(s->d1->next_timeout));
 341
 342     /* Add duration to current time */
 343     s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 344     BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
 345              &(s->d1->next_timeout));
 346 }
 347
 348 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
 349 {
 350     struct timeval timenow;
 351
 352     /* If no timeout is set, just return NULL */
 353     if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
 354         return NULL;
 355     }
 356
 357     /* Get current time */
 358     get_current_time(&timenow);
 359
 360     /* If timer already expired, set remaining time to 0 */
 361     if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 362         (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 363          s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
 364         memset(timeleft, 0, sizeof(struct timeval));
 365         return timeleft;
 366     }
 367
 368     /* Calculate time left until timer expires */
 369     memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 370     timeleft->tv_sec -= timenow.tv_sec;
 371     timeleft->tv_usec -= timenow.tv_usec;
 372     if (timeleft->tv_usec < 0) {
 373         timeleft->tv_sec--;
 374         timeleft->tv_usec += 1000000;
 375     }
 376
 377     /*
 378      * If remaining time is less than 15 ms, set it to 0 to prevent issues
 379      * because of small devergences with socket timeouts.
 380      */
 381     if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
 382         memset(timeleft, 0, sizeof(struct timeval));
 383     }
 384
 385     return timeleft;
 386 }
 387
 388 int dtls1_is_timer_expired(SSL *s)
 389 {
 390     struct timeval timeleft;
 391
 392     /* Get time left until timeout, return false if no timer running */
 393     if (dtls1_get_timeout(s, &timeleft) == NULL) {
 394         return 0;
 395     }
 396
 397     /* Return false if timer is not expired yet */
 398     if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
 399         return 0;
 400     }
 401
 402     /* Timer expired, so return true */
 403     return 1;
 404 }
 405
 406 void dtls1_double_timeout(SSL *s)
 407 {
 408     s->d1->timeout_duration *= 2;
 409     if (s->d1->timeout_duration > 60)
 410         s->d1->timeout_duration = 60;
 411     dtls1_start_timer(s);
 412 }
 413
 414 void dtls1_stop_timer(SSL *s)
 415 {
 416     /* Reset everything */
 417     memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 418     memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 419     s->d1->timeout_duration = 1;
 420     BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
 421              &(s->d1->next_timeout));
 422     /* Clear retransmission buffer */
 423     dtls1_clear_record_buffer(s);
 424 }
 425
 426 int dtls1_check_timeout_num(SSL *s)
 427 {
 428     unsigned int mtu;
 429
 430     s->d1->timeout.num_alerts++;
 431
 432     /* Reduce MTU after 2 unsuccessful retransmissions */
 433     if (s->d1->timeout.num_alerts > 2
 434         && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
 435         mtu =
 436             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
 437                      NULL);
 438         if (mtu < s->d1->mtu)
 439             s->d1->mtu = mtu;
 440     }
 441
 442     if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
 443         /* fail the connection, enough alerts have been sent */
 444         SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
 445         return -1;
 446     }
 447
 448     return 0;
 449 }
 450
 451 int dtls1_handle_timeout(SSL *s)
 452 {
 453     /* if no timer is expired, don't do anything */
 454     if (!dtls1_is_timer_expired(s)) {
 455         return 0;
 456     }
 457
 458     dtls1_double_timeout(s);
 459
 460     if (dtls1_check_timeout_num(s) < 0)
 461         return -1;
 462
 463     s->d1->timeout.read_timeouts++;
 464     if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
 465         s->d1->timeout.read_timeouts = 1;
 466     }
 467 #ifndef OPENSSL_NO_HEARTBEATS
 468     if (s->tlsext_hb_pending) {
 469         s->tlsext_hb_pending = 0;
 470         return dtls1_heartbeat(s);
 471     }
 472 #endif
 473
 474     dtls1_start_timer(s);
 475     return dtls1_retransmit_buffered_messages(s);
 476 }
 477
 478 static void get_current_time(struct timeval *t)
 479 {
 480 #ifdef OPENSSL_SYS_WIN32
 481     struct _timeb tb;
 482     _ftime(&tb);
 483     t->tv_sec = (long)tb.time;
 484     t->tv_usec = (long)tb.millitm * 1000;
 485 #elif defined(OPENSSL_SYS_VMS)
 486     struct timeb tb;
 487     ftime(&tb);
 488     t->tv_sec = (long)tb.time;
 489     t->tv_usec = (long)tb.millitm * 1000;
 490 #else
 491     gettimeofday(t, NULL);
 492 #endif
 493 }
 494
 495 int dtls1_listen(SSL *s, struct sockaddr *client)
 496 {
 497     int ret;
 498
 499     SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 500     s->d1->listen = 1;
 501
 502     ret = SSL_accept(s);
 503     if (ret <= 0)
 504         return ret;
 505
 506     (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
 507     return 1;
 508 }