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 };
  86
  87 long dtls1_default_timeout(void)
  88 {
  89     /*
  90      * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
  91      * http, the cache would over fill
  92      */
  93     return (60 * 60 * 2);
  94 }
  95
  96 IMPLEMENT_dtls1_meth_func(dtlsv1_base_method,
  97                           ssl_undefined_function,
  98                           ssl_undefined_function, ssl_bad_method)
  99
 100 int dtls1_new(SSL *s)
 101 {
 102     DTLS1_STATE *d1;
 103
 104     if (!ssl3_new(s))
 105         return (0);
 106     if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL)
 107         return (0);
 108     memset(d1, 0, sizeof *d1);
 109
 110     /* d1->handshake_epoch=0; */
 111 #if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
 112     d1->bitmap.length = 64;
 113 #else
 114     d1->bitmap.length = sizeof(d1->bitmap.map) * 8;
 115 #endif
 116     pq_64bit_init(&(d1->bitmap.map));
 117     pq_64bit_init(&(d1->bitmap.max_seq_num));
 118
 119     d1->next_bitmap.length = d1->bitmap.length;
 120     pq_64bit_init(&(d1->next_bitmap.map));
 121     pq_64bit_init(&(d1->next_bitmap.max_seq_num));
 122
 123     d1->unprocessed_rcds.q = pqueue_new();
 124     d1->processed_rcds.q = pqueue_new();
 125     d1->buffered_messages = pqueue_new();
 126     d1->sent_messages = pqueue_new();
 127     d1->buffered_app_data.q = pqueue_new();
 128
 129     if (s->server) {
 130         d1->cookie_len = sizeof(s->d1->cookie);
 131     }
 132
 133     if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q
 134         || !d1->buffered_messages || !d1->sent_messages
 135         || !d1->buffered_app_data.q) {
 136         if (d1->unprocessed_rcds.q)
 137             pqueue_free(d1->unprocessed_rcds.q);
 138         if (d1->processed_rcds.q)
 139             pqueue_free(d1->processed_rcds.q);
 140         if (d1->buffered_messages)
 141             pqueue_free(d1->buffered_messages);
 142         if (d1->sent_messages)
 143             pqueue_free(d1->sent_messages);
 144         if (d1->buffered_app_data.q)
 145             pqueue_free(d1->buffered_app_data.q);
 146         OPENSSL_free(d1);
 147         return (0);
 148     }
 149
 150     s->d1 = d1;
 151     s->method->ssl_clear(s);
 152     return (1);
 153 }
 154
 155 static void dtls1_clear_queues(SSL *s)
 156 {
 157     pitem *item = NULL;
 158     hm_fragment *frag = NULL;
 159     DTLS1_RECORD_DATA *rdata;
 160
 161     while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) {
 162         rdata = (DTLS1_RECORD_DATA *)item->data;
 163         if (rdata->rbuf.buf) {
 164             OPENSSL_free(rdata->rbuf.buf);
 165         }
 166         OPENSSL_free(item->data);
 167         pitem_free(item);
 168     }
 169
 170     while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {
 171         rdata = (DTLS1_RECORD_DATA *)item->data;
 172         if (rdata->rbuf.buf) {
 173             OPENSSL_free(rdata->rbuf.buf);
 174         }
 175         OPENSSL_free(item->data);
 176         pitem_free(item);
 177     }
 178
 179     while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
 180         frag = (hm_fragment *)item->data;
 181         OPENSSL_free(frag->fragment);
 182         OPENSSL_free(frag);
 183         pitem_free(item);
 184     }
 185
 186     while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
 187         frag = (hm_fragment *)item->data;
 188         OPENSSL_free(frag->fragment);
 189         OPENSSL_free(frag);
 190         pitem_free(item);
 191     }
 192
 193     while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
 194         rdata = (DTLS1_RECORD_DATA *)item->data;
 195         if (rdata->rbuf.buf) {
 196             OPENSSL_free(rdata->rbuf.buf);
 197         }
 198         OPENSSL_free(item->data);
 199         pitem_free(item);
 200     }
 201 }
 202
 203 void dtls1_free(SSL *s)
 204 {
 205     ssl3_free(s);
 206
 207     dtls1_clear_queues(s);
 208
 209     pqueue_free(s->d1->unprocessed_rcds.q);
 210     pqueue_free(s->d1->processed_rcds.q);
 211     pqueue_free(s->d1->buffered_messages);
 212     pqueue_free(s->d1->sent_messages);
 213     pqueue_free(s->d1->buffered_app_data.q);
 214
 215     pq_64bit_free(&(s->d1->bitmap.map));
 216     pq_64bit_free(&(s->d1->bitmap.max_seq_num));
 217
 218     pq_64bit_free(&(s->d1->next_bitmap.map));
 219     pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
 220
 221     OPENSSL_free(s->d1);
 222     s->d1 = NULL;
 223 }
 224
 225 void dtls1_clear(SSL *s)
 226 {
 227     pqueue unprocessed_rcds;
 228     pqueue processed_rcds;
 229     pqueue buffered_messages;
 230     pqueue sent_messages;
 231     pqueue buffered_app_data;
 232     unsigned int mtu;
 233
 234     if (s->d1) {
 235         unprocessed_rcds = s->d1->unprocessed_rcds.q;
 236         processed_rcds = s->d1->processed_rcds.q;
 237         buffered_messages = s->d1->buffered_messages;
 238         sent_messages = s->d1->sent_messages;
 239         buffered_app_data = s->d1->buffered_app_data.q;
 240         mtu = s->d1->mtu;
 241
 242         dtls1_clear_queues(s);
 243
 244         pq_64bit_free(&(s->d1->bitmap.map));
 245         pq_64bit_free(&(s->d1->bitmap.max_seq_num));
 246
 247         pq_64bit_free(&(s->d1->next_bitmap.map));
 248         pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
 249
 250         memset(s->d1, 0, sizeof(*(s->d1)));
 251
 252         if (s->server) {
 253             s->d1->cookie_len = sizeof(s->d1->cookie);
 254         }
 255
 256         if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
 257             s->d1->mtu = mtu;
 258         }
 259
 260         s->d1->unprocessed_rcds.q = unprocessed_rcds;
 261         s->d1->processed_rcds.q = processed_rcds;
 262         s->d1->buffered_messages = buffered_messages;
 263         s->d1->sent_messages = sent_messages;
 264         s->d1->buffered_app_data.q = buffered_app_data;
 265
 266 #if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
 267         s->d1->bitmap.length = 64;
 268 #else
 269         s->d1->bitmap.length = sizeof(s->d1->bitmap.map) * 8;
 270 #endif
 271         pq_64bit_init(&(s->d1->bitmap.map));
 272         pq_64bit_init(&(s->d1->bitmap.max_seq_num));
 273
 274         s->d1->next_bitmap.length = s->d1->bitmap.length;
 275         pq_64bit_init(&(s->d1->next_bitmap.map));
 276         pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
 277     }
 278
 279     ssl3_clear(s);
 280     if (s->options & SSL_OP_CISCO_ANYCONNECT)
 281         s->version = DTLS1_BAD_VER;
 282     else
 283         s->version = DTLS1_VERSION;
 284 }
 285
 286 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 287 {
 288     int ret = 0;
 289
 290     switch (cmd) {
 291     case DTLS_CTRL_GET_TIMEOUT:
 292         if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
 293             ret = 1;
 294         }
 295         break;
 296     case DTLS_CTRL_HANDLE_TIMEOUT:
 297         ret = dtls1_handle_timeout(s);
 298         break;
 299     case DTLS_CTRL_LISTEN:
 300         ret = dtls1_listen(s, parg);
 301         break;
 302     case SSL_CTRL_CHECK_PROTO_VERSION:
 303         /*
 304          * For library-internal use; checks that the current protocol is the
 305          * highest enabled version (according to s->ctx->method, as version
 306          * negotiation may have changed s->method).
 307          */
 308 #if DTLS_MAX_VERSION != DTLS1_VERSION
 309 # error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
 310 #endif
 311         /*
 312          * Just one protocol version is supported so far; fail closed if the
 313          * version is not as expected.
 314          */
 315         return s->version == DTLS_MAX_VERSION;
 316
 317     default:
 318         ret = ssl3_ctrl(s, cmd, larg, parg);
 319         break;
 320     }
 321     return (ret);
 322 }
 323
 324 /*
 325  * As it's impossible to use stream ciphers in "datagram" mode, this
 326  * simple filter is designed to disengage them in DTLS. Unfortunately
 327  * there is no universal way to identify stream SSL_CIPHER, so we have
 328  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 329  * available, but if new ones emerge, they will have to be added...
 330  */
 331 SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 332 {
 333     SSL_CIPHER *ciph = ssl3_get_cipher(u);
 334
 335     if (ciph != NULL) {
 336         if ((ciph->algorithms & SSL_ENC_MASK) == SSL_RC4)
 337             return NULL;
 338     }
 339
 340     return ciph;
 341 }
 342
 343 void dtls1_start_timer(SSL *s)
 344 {
 345     /* If timer is not set, initialize duration with 1 second */
 346     if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
 347         s->d1->timeout_duration = 1;
 348     }
 349
 350     /* Set timeout to current time */
 351     get_current_time(&(s->d1->next_timeout));
 352
 353     /* Add duration to current time */
 354     s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 355     BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
 356              &(s->d1->next_timeout));
 357 }
 358
 359 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
 360 {
 361     struct timeval timenow;
 362
 363     /* If no timeout is set, just return NULL */
 364     if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
 365         return NULL;
 366     }
 367
 368     /* Get current time */
 369     get_current_time(&timenow);
 370
 371     /* If timer already expired, set remaining time to 0 */
 372     if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 373         (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 374          s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
 375         memset(timeleft, 0, sizeof(struct timeval));
 376         return timeleft;
 377     }
 378
 379     /* Calculate time left until timer expires */
 380     memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 381     timeleft->tv_sec -= timenow.tv_sec;
 382     timeleft->tv_usec -= timenow.tv_usec;
 383     if (timeleft->tv_usec < 0) {
 384         timeleft->tv_sec--;
 385         timeleft->tv_usec += 1000000;
 386     }
 387
 388     /*
 389      * If remaining time is less than 15 ms, set it to 0 to prevent issues
 390      * because of small devergences with socket timeouts.
 391      */
 392     if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
 393         memset(timeleft, 0, sizeof(struct timeval));
 394     }
 395
 396     return timeleft;
 397 }
 398
 399 int dtls1_is_timer_expired(SSL *s)
 400 {
 401     struct timeval timeleft;
 402
 403     /* Get time left until timeout, return false if no timer running */
 404     if (dtls1_get_timeout(s, &timeleft) == NULL) {
 405         return 0;
 406     }
 407
 408     /* Return false if timer is not expired yet */
 409     if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
 410         return 0;
 411     }
 412
 413     /* Timer expired, so return true */
 414     return 1;
 415 }
 416
 417 void dtls1_double_timeout(SSL *s)
 418 {
 419     s->d1->timeout_duration *= 2;
 420     if (s->d1->timeout_duration > 60)
 421         s->d1->timeout_duration = 60;
 422     dtls1_start_timer(s);
 423 }
 424
 425 void dtls1_stop_timer(SSL *s)
 426 {
 427     /* Reset everything */
 428     memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 429     memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 430     s->d1->timeout_duration = 1;
 431     BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
 432              &(s->d1->next_timeout));
 433     /* Clear retransmission buffer */
 434     dtls1_clear_record_buffer(s);
 435 }
 436
 437 int dtls1_check_timeout_num(SSL *s)
 438 {
 439     s->d1->timeout.num_alerts++;
 440
 441     /* Reduce MTU after 2 unsuccessful retransmissions */
 442     if (s->d1->timeout.num_alerts > 2) {
 443         s->d1->mtu =
 444             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
 445                      NULL);
 446     }
 447
 448     if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
 449         /* fail the connection, enough alerts have been sent */
 450         SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
 451         return -1;
 452     }
 453
 454     return 0;
 455 }
 456
 457 int dtls1_handle_timeout(SSL *s)
 458 {
 459     /* if no timer is expired, don't do anything */
 460     if (!dtls1_is_timer_expired(s)) {
 461         return 0;
 462     }
 463
 464     dtls1_double_timeout(s);
 465
 466     if (dtls1_check_timeout_num(s) < 0)
 467         return -1;
 468
 469     s->d1->timeout.read_timeouts++;
 470     if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
 471         s->d1->timeout.read_timeouts = 1;
 472     }
 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 }