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 if (s->method->version == DTLS_ANY_VERSION)
 271                 s->version=DTLS1_2_VERSION;
 272         else
 273                 s->version=s->method->version;
 274         }
 275
 276 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 277         {
 278         int ret=0;
 279
 280         switch (cmd)
 281                 {
 282         case DTLS_CTRL_GET_TIMEOUT:
 283                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 284                         {
 285                         ret = 1;
 286                         }
 287                 break;
 288         case DTLS_CTRL_HANDLE_TIMEOUT:
 289                 ret = dtls1_handle_timeout(s);
 290                 break;
 291         case DTLS_CTRL_LISTEN:
 292                 ret = dtls1_listen(s, parg);
 293                 break;
 294
 295         default:
 296                 ret = ssl3_ctrl(s, cmd, larg, parg);
 297                 break;
 298                 }
 299         return(ret);
 300         }
 301
 302 /*
 303  * As it's impossible to use stream ciphers in "datagram" mode, this
 304  * simple filter is designed to disengage them in DTLS. Unfortunately
 305  * there is no universal way to identify stream SSL_CIPHER, so we have
 306  * to explicitly list their SSL_* codes. Currently RC4 is the only one
 307  * available, but if new ones emerge, they will have to be added...
 308  */
 309 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 310         {
 311         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 312
 313         if (ciph != NULL)
 314                 {
 315                 if (ciph->algorithm_enc == SSL_RC4)
 316                         return NULL;
 317                 }
 318
 319         return ciph;
 320         }
 321
 322 void dtls1_start_timer(SSL *s)
 323         {
 324 #ifndef OPENSSL_NO_SCTP
 325         /* Disable timer for SCTP */
 326         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 327                 {
 328                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 329                 return;
 330                 }
 331 #endif
 332
 333         /* If timer is not set, initialize duration with 1 second */
 334         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 335                 {
 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, &(s->d1->next_timeout));
 345         }
 346
 347 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 348         {
 349         struct timeval timenow;
 350
 351         /* If no timeout is set, just return NULL */
 352         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 353                 {
 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                 {
 365                 memset(timeleft, 0, sizeof(struct timeval));
 366                 return timeleft;
 367                 }
 368
 369         /* Calculate time left until timer expires */
 370         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 371         timeleft->tv_sec -= timenow.tv_sec;
 372         timeleft->tv_usec -= timenow.tv_usec;
 373         if (timeleft->tv_usec < 0)
 374                 {
 375                 timeleft->tv_sec--;
 376                 timeleft->tv_usec += 1000000;
 377                 }
 378
 379         /* If remaining time is less than 15 ms, set it to 0
 380          * to prevent issues because of small devergences with
 381          * socket timeouts.
 382          */
 383         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 384                 {
 385                 memset(timeleft, 0, sizeof(struct timeval));
 386                 }
 387
 388
 389         return timeleft;
 390         }
 391
 392 int dtls1_is_timer_expired(SSL *s)
 393         {
 394         struct timeval timeleft;
 395
 396         /* Get time left until timeout, return false if no timer running */
 397         if (dtls1_get_timeout(s, &timeleft) == NULL)
 398                 {
 399                 return 0;
 400                 }
 401
 402         /* Return false if timer is not expired yet */
 403         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 404                 {
 405                 return 0;
 406                 }
 407
 408         /* Timer expired, so return true */
 409         return 1;
 410         }
 411
 412 void dtls1_double_timeout(SSL *s)
 413         {
 414         s->d1->timeout_duration *= 2;
 415         if (s->d1->timeout_duration > 60)
 416                 s->d1->timeout_duration = 60;
 417         dtls1_start_timer(s);
 418         }
 419
 420 void dtls1_stop_timer(SSL *s)
 421         {
 422         /* Reset everything */
 423         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 424         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 425         s->d1->timeout_duration = 1;
 426         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 427         /* Clear retransmission buffer */
 428         dtls1_clear_record_buffer(s);
 429         }
 430
 431 int dtls1_check_timeout_num(SSL *s)
 432         {
 433         s->d1->timeout.num_alerts++;
 434
 435         /* Reduce MTU after 2 unsuccessful retransmissions */
 436         if (s->d1->timeout.num_alerts > 2)
 437                 {
 438                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 439                 }
 440
 441         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 442                 {
 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                 {
 456                 return 0;
 457                 }
 458
 459         dtls1_double_timeout(s);
 460
 461         if (dtls1_check_timeout_num(s) < 0)
 462                 return -1;
 463
 464         s->d1->timeout.read_timeouts++;
 465         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 466                 {
 467                 s->d1->timeout.read_timeouts = 1;
 468                 }
 469
 470 #ifndef OPENSSL_NO_HEARTBEATS
 471         if (s->tlsext_hb_pending)
 472                 {
 473                 s->tlsext_hb_pending = 0;
 474                 return dtls1_heartbeat(s);
 475                 }
 476 #endif
 477
 478         dtls1_start_timer(s);
 479         return dtls1_retransmit_buffered_messages(s);
 480         }
 481
 482 static void get_current_time(struct timeval *t)
 483 {
 484 #if defined(_WIN32)
 485         SYSTEMTIME st;
 486         union { unsigned __int64 ul; FILETIME ft; } now;
 487
 488         GetSystemTime(&st);
 489         SystemTimeToFileTime(&st,&now.ft);
 490         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
 491         t->tv_sec  = (long)(now.ul/10000000);
 492         t->tv_usec = ((int)(now.ul%10000000))/10;
 493 #elif defined(OPENSSL_SYS_VMS)
 494         struct timeb tb;
 495         ftime(&tb);
 496         t->tv_sec = (long)tb.time;
 497         t->tv_usec = (long)tb.millitm * 1000;
 498 #else
 499         gettimeofday(t, NULL);
 500 #endif
 501 }
 502
 503 int dtls1_listen(SSL *s, struct sockaddr *client)
 504         {
 505         int ret;
 506
 507         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 508         s->d1->listen = 1;
 509
 510         ret = SSL_accept(s);
 511         if (ret <= 0) return ret;
 512
 513         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 514         return 1;
 515         }
 516
 517 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 518         {
 519         unsigned char *p = (unsigned char *)s->init_buf->data;
 520         dtls1_set_message_header(s, p, htype, len, 0, len);
 521         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 522         s->init_off = 0;
 523         /* Buffer the message to handle re-xmits */
 524         dtls1_buffer_message(s, 0);
 525         }
 526
 527 static int dtls1_handshake_write(SSL *s)
 528         {
 529         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 530         }