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         tls1_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 SSL3_ENC_METHOD DTLSv1_2_enc_data={
  95         tls1_enc,
  96         tls1_mac,
  97         tls1_setup_key_block,
  98         tls1_generate_master_secret,
  99         tls1_change_cipher_state,
 100         tls1_final_finish_mac,
 101         TLS1_FINISH_MAC_LENGTH,
 102         tls1_cert_verify_mac,
 103         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
 104         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
 105         tls1_alert_code,
 106         tls1_export_keying_material,
 107         SSL_ENC_FLAG_DTLS|SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS
 108                 |SSL_ENC_FLAG_SHA256_PRF|SSL_ENC_FLAG_TLS1_2_CIPHERS,
 109         DTLS1_HM_HEADER_LENGTH,
 110         dtls1_set_handshake_header,
 111         dtls1_handshake_write
 112         };
 113
 114 long dtls1_default_timeout(void)
 115         {
 116         /* 2 hours, the 24 hours mentioned in the DTLSv1 spec
 117          * is way too long for http, the cache would over fill */
 118         return(60*60*2);
 119         }
 120
 121 int dtls1_new(SSL *s)
 122         {
 123         DTLS1_STATE *d1;
 124
 125         if (!ssl3_new(s)) return(0);
 126         if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
 127         memset(d1,0, sizeof *d1);
 128
 129         /* d1->handshake_epoch=0; */
 130
 131         d1->unprocessed_rcds.q=pqueue_new();
 132         d1->processed_rcds.q=pqueue_new();
 133         d1->buffered_messages = pqueue_new();
 134         d1->sent_messages=pqueue_new();
 135         d1->buffered_app_data.q=pqueue_new();
 136
 137         if ( s->server)
 138                 {
 139                 d1->cookie_len = sizeof(s->d1->cookie);
 140                 }
 141
 142         if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
 143         || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
 144                 {
 145         if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
 146         if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
 147         if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
 148                 if ( d1->sent_messages) pqueue_free(d1->sent_messages);
 149                 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
 150                 OPENSSL_free(d1);
 151                 return (0);
 152                 }
 153
 154         s->d1=d1;
 155         s->method->ssl_clear(s);
 156         return(1);
 157         }
 158
 159 static void dtls1_clear_queues(SSL *s)
 160         {
 161     pitem *item = NULL;
 162     hm_fragment *frag = NULL;
 163         DTLS1_RECORD_DATA *rdata;
 164
 165     while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
 166         {
 167                 rdata = (DTLS1_RECORD_DATA *) item->data;
 168                 if (rdata->rbuf.buf)
 169                         {
 170                         OPENSSL_free(rdata->rbuf.buf);
 171                         }
 172         OPENSSL_free(item->data);
 173         pitem_free(item);
 174         }
 175
 176     while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
 177         {
 178                 rdata = (DTLS1_RECORD_DATA *) item->data;
 179                 if (rdata->rbuf.buf)
 180                         {
 181                         OPENSSL_free(rdata->rbuf.buf);
 182                         }
 183         OPENSSL_free(item->data);
 184         pitem_free(item);
 185         }
 186
 187     while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
 188         {
 189         frag = (hm_fragment *)item->data;
 190         OPENSSL_free(frag->fragment);
 191         OPENSSL_free(frag);
 192         pitem_free(item);
 193         }
 194
 195     while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
 196         {
 197         frag = (hm_fragment *)item->data;
 198         OPENSSL_free(frag->fragment);
 199         OPENSSL_free(frag);
 200         pitem_free(item);
 201         }
 202
 203         while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
 204                 {
 205                 frag = (hm_fragment *)item->data;
 206                 OPENSSL_free(frag->fragment);
 207                 OPENSSL_free(frag);
 208                 pitem_free(item);
 209                 }
 210         }
 211
 212 void dtls1_free(SSL *s)
 213         {
 214         ssl3_free(s);
 215
 216         dtls1_clear_queues(s);
 217
 218     pqueue_free(s->d1->unprocessed_rcds.q);
 219     pqueue_free(s->d1->processed_rcds.q);
 220     pqueue_free(s->d1->buffered_messages);
 221         pqueue_free(s->d1->sent_messages);
 222         pqueue_free(s->d1->buffered_app_data.q);
 223
 224         OPENSSL_free(s->d1);
 225         s->d1 = NULL;
 226         }
 227
 228 void dtls1_clear(SSL *s)
 229         {
 230     pqueue unprocessed_rcds;
 231     pqueue processed_rcds;
 232     pqueue buffered_messages;
 233         pqueue sent_messages;
 234         pqueue buffered_app_data;
 235         unsigned int mtu;
 236
 237         if (s->d1)
 238                 {
 239                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 240                 processed_rcds = s->d1->processed_rcds.q;
 241                 buffered_messages = s->d1->buffered_messages;
 242                 sent_messages = s->d1->sent_messages;
 243                 buffered_app_data = s->d1->buffered_app_data.q;
 244                 mtu = s->d1->mtu;
 245
 246                 dtls1_clear_queues(s);
 247
 248                 memset(s->d1, 0, sizeof(*(s->d1)));
 249
 250                 if (s->server)
 251                         {
 252                         s->d1->cookie_len = sizeof(s->d1->cookie);
 253                         }
 254
 255                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 256                         {
 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
 267         ssl3_clear(s);
 268         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 269                 s->version=DTLS1_BAD_VER;
 270         else
 271                 s->version=s->method->version;
 272         }
 273
 274 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 275         {
 276         int ret=0;
 277
 278         switch (cmd)
 279                 {
 280         case DTLS_CTRL_GET_TIMEOUT:
 281                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 282                         {
 283                         ret = 1;
 284                         }
 285                 break;
 286         case DTLS_CTRL_HANDLE_TIMEOUT:
 287                 ret = dtls1_handle_timeout(s);
 288                 break;
 289         case DTLS_CTRL_LISTEN:
 290                 ret = dtls1_listen(s, parg);
 291                 break;
 292
 293         default:
 294                 ret = ssl3_ctrl(s, cmd, larg, parg);
 295                 break;
 296                 }
 297         return(ret);
 298         }
 299
 300 /*
 301  * As it's impossible to use stream ciphers in "datagram" mode, this
 302  * simple filter is designed to disengage them in DTLS. Unfortunately
 303  * there is no universal way to identify stream SSL_CIPHER, so we have
 304  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 305  * available, but if new ones emerge, they will have to be added...
 306  */
 307 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 308         {
 309         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 310
 311         if (ciph != NULL)
 312                 {
 313                 if (ciph->algorithm_enc == SSL_RC4)
 314                         return NULL;
 315                 }
 316
 317         return ciph;
 318         }
 319
 320 void dtls1_start_timer(SSL *s)
 321         {
 322 #ifndef OPENSSL_NO_SCTP
 323         /* Disable timer for SCTP */
 324         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 325                 {
 326                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 327                 return;
 328                 }
 329 #endif
 330
 331         /* If timer is not set, initialize duration with 1 second */
 332         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 333                 {
 334                 s->d1->timeout_duration = 1;
 335                 }
 336
 337         /* Set timeout to current time */
 338         get_current_time(&(s->d1->next_timeout));
 339
 340         /* Add duration to current time */
 341         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 342         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 343         }
 344
 345 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 346         {
 347         struct timeval timenow;
 348
 349         /* If no timeout is set, just return NULL */
 350         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 351                 {
 352                 return NULL;
 353                 }
 354
 355         /* Get current time */
 356         get_current_time(&timenow);
 357
 358         /* If timer already expired, set remaining time to 0 */
 359         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 360                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 361                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 362                 {
 363                 memset(timeleft, 0, sizeof(struct timeval));
 364                 return timeleft;
 365                 }
 366
 367         /* Calculate time left until timer expires */
 368         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 369         timeleft->tv_sec -= timenow.tv_sec;
 370         timeleft->tv_usec -= timenow.tv_usec;
 371         if (timeleft->tv_usec < 0)
 372                 {
 373                 timeleft->tv_sec--;
 374                 timeleft->tv_usec += 1000000;
 375                 }
 376
 377         /* If remaining time is less than 15 ms, set it to 0
 378          * to prevent issues because of small devergences with
 379          * socket timeouts.
 380          */
 381         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 382                 {
 383                 memset(timeleft, 0, sizeof(struct timeval));
 384                 }
 385
 386
 387         return timeleft;
 388         }
 389
 390 int dtls1_is_timer_expired(SSL *s)
 391         {
 392         struct timeval timeleft;
 393
 394         /* Get time left until timeout, return false if no timer running */
 395         if (dtls1_get_timeout(s, &timeleft) == NULL)
 396                 {
 397                 return 0;
 398                 }
 399
 400         /* Return false if timer is not expired yet */
 401         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 402                 {
 403                 return 0;
 404                 }
 405
 406         /* Timer expired, so return true */
 407         return 1;
 408         }
 409
 410 void dtls1_double_timeout(SSL *s)
 411         {
 412         s->d1->timeout_duration *= 2;
 413         if (s->d1->timeout_duration > 60)
 414                 s->d1->timeout_duration = 60;
 415         dtls1_start_timer(s);
 416         }
 417
 418 void dtls1_stop_timer(SSL *s)
 419         {
 420         /* Reset everything */
 421         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 422         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 423         s->d1->timeout_duration = 1;
 424         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 425         /* Clear retransmission buffer */
 426         dtls1_clear_record_buffer(s);
 427         }
 428
 429 int dtls1_check_timeout_num(SSL *s)
 430         {
 431         s->d1->timeout.num_alerts++;
 432
 433         /* Reduce MTU after 2 unsuccessful retransmissions */
 434         if (s->d1->timeout.num_alerts > 2)
 435                 {
 436                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 437                 }
 438
 439         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 440                 {
 441                 /* fail the connection, enough alerts have been sent */
 442                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 443                 return -1;
 444                 }
 445
 446         return 0;
 447         }
 448
 449 int dtls1_handle_timeout(SSL *s)
 450         {
 451         /* if no timer is expired, don't do anything */
 452         if (!dtls1_is_timer_expired(s))
 453                 {
 454                 return 0;
 455                 }
 456
 457         dtls1_double_timeout(s);
 458
 459         if (dtls1_check_timeout_num(s) < 0)
 460                 return -1;
 461
 462         s->d1->timeout.read_timeouts++;
 463         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 464                 {
 465                 s->d1->timeout.read_timeouts = 1;
 466                 }
 467
 468 #ifndef OPENSSL_NO_HEARTBEATS
 469         if (s->tlsext_hb_pending)
 470                 {
 471                 s->tlsext_hb_pending = 0;
 472                 return dtls1_heartbeat(s);
 473                 }
 474 #endif
 475
 476         dtls1_start_timer(s);
 477         return dtls1_retransmit_buffered_messages(s);
 478         }
 479
 480 static void get_current_time(struct timeval *t)
 481 {
 482 #if defined(_WIN32)
 483         SYSTEMTIME st;
 484         union { unsigned __int64 ul; FILETIME ft; } now;
 485
 486         GetSystemTime(&st);
 487         SystemTimeToFileTime(&st,&now.ft);
 488         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
 489         t->tv_sec  = (long)(now.ul/10000000);
 490         t->tv_usec = ((int)(now.ul%10000000))/10;
 491 #elif defined(OPENSSL_SYS_VMS)
 492         struct timeb tb;
 493         ftime(&tb);
 494         t->tv_sec = (long)tb.time;
 495         t->tv_usec = (long)tb.millitm * 1000;
 496 #else
 497         gettimeofday(t, NULL);
 498 #endif
 499 }
 500
 501 int dtls1_listen(SSL *s, struct sockaddr *client)
 502         {
 503         int ret;
 504
 505         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 506         s->d1->listen = 1;
 507
 508         ret = SSL_accept(s);
 509         if (ret <= 0) return ret;
 510
 511         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 512         return 1;
 513         }
 514
 515 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 516         {
 517         unsigned char *p = (unsigned char *)s->init_buf->data;
 518         dtls1_set_message_header(s, p, htype, len, 0, len);
 519         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 520         s->init_off = 0;
 521         /* Buffer the message to handle re-xmits */
 522         dtls1_buffer_message(s, 0);
 523         }
 524
 525 static int dtls1_handshake_write(SSL *s)
 526         {
 527         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 528         }
 529
 530