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 const 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 const 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                 rdata = (DTLS1_RECORD_DATA *) item->data;
 206                 if (rdata->rbuf.buf)
 207                         {
 208                         OPENSSL_free(rdata->rbuf.buf);
 209                         }
 210                 OPENSSL_free(item->data);
 211                 pitem_free(item);
 212                 }
 213         }
 214
 215 void dtls1_free(SSL *s)
 216         {
 217         ssl3_free(s);
 218
 219         dtls1_clear_queues(s);
 220
 221     pqueue_free(s->d1->unprocessed_rcds.q);
 222     pqueue_free(s->d1->processed_rcds.q);
 223     pqueue_free(s->d1->buffered_messages);
 224         pqueue_free(s->d1->sent_messages);
 225         pqueue_free(s->d1->buffered_app_data.q);
 226
 227         OPENSSL_free(s->d1);
 228         s->d1 = NULL;
 229         }
 230
 231 void dtls1_clear(SSL *s)
 232         {
 233     pqueue unprocessed_rcds;
 234     pqueue processed_rcds;
 235     pqueue buffered_messages;
 236         pqueue sent_messages;
 237         pqueue buffered_app_data;
 238         unsigned int mtu;
 239
 240         if (s->d1)
 241                 {
 242                 unprocessed_rcds = s->d1->unprocessed_rcds.q;
 243                 processed_rcds = s->d1->processed_rcds.q;
 244                 buffered_messages = s->d1->buffered_messages;
 245                 sent_messages = s->d1->sent_messages;
 246                 buffered_app_data = s->d1->buffered_app_data.q;
 247                 mtu = s->d1->mtu;
 248
 249                 dtls1_clear_queues(s);
 250
 251                 memset(s->d1, 0, sizeof(*(s->d1)));
 252
 253                 if (s->server)
 254                         {
 255                         s->d1->cookie_len = sizeof(s->d1->cookie);
 256                         }
 257
 258                 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)
 259                         {
 260                         s->d1->mtu = mtu;
 261                         }
 262
 263                 s->d1->unprocessed_rcds.q = unprocessed_rcds;
 264                 s->d1->processed_rcds.q = processed_rcds;
 265                 s->d1->buffered_messages = buffered_messages;
 266                 s->d1->sent_messages = sent_messages;
 267                 s->d1->buffered_app_data.q = buffered_app_data;
 268                 }
 269
 270         ssl3_clear(s);
 271         if (s->options & SSL_OP_CISCO_ANYCONNECT)
 272                 s->version=DTLS1_BAD_VER;
 273         else if (s->method->version == DTLS_ANY_VERSION)
 274                 s->version=DTLS1_2_VERSION;
 275         else
 276                 s->version=s->method->version;
 277         }
 278
 279 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 280         {
 281         int ret=0;
 282
 283         switch (cmd)
 284                 {
 285         case DTLS_CTRL_GET_TIMEOUT:
 286                 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL)
 287                         {
 288                         ret = 1;
 289                         }
 290                 break;
 291         case DTLS_CTRL_HANDLE_TIMEOUT:
 292                 ret = dtls1_handle_timeout(s);
 293                 break;
 294         case DTLS_CTRL_LISTEN:
 295                 ret = dtls1_listen(s, parg);
 296                 break;
 297         case SSL_CTRL_CHECK_PROTO_VERSION:
 298                 /* For library-internal use; checks that the current protocol
 299                  * is the highest enabled version (according to s->ctx->method,
 300                  * as version negotiation may have changed s->method). */
 301                 if (s->version == s->ctx->method->version)
 302                         return 1;
 303                 /* Apparently we're using a version-flexible SSL_METHOD
 304                  * (not at its highest protocol version). */
 305                 if (s->ctx->method->version == DTLS_method()->version)
 306                         {
 307 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
 308 #  error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
 309 #endif
 310                         if (!(s->options & SSL_OP_NO_DTLSv1_2))
 311                                 return s->version == DTLS1_2_VERSION;
 312                         if (!(s->options & SSL_OP_NO_DTLSv1))
 313                                 return s->version == DTLS1_VERSION;
 314                         }
 315                 return 0; /* Unexpected state; fail closed. */
 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 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 332         {
 333         const SSL_CIPHER *ciph = ssl3_get_cipher(u);
 334
 335         if (ciph != NULL)
 336                 {
 337                 if (ciph->algorithm_enc == SSL_RC4)
 338                         return NULL;
 339                 }
 340
 341         return ciph;
 342         }
 343
 344 void dtls1_start_timer(SSL *s)
 345         {
 346 #ifndef OPENSSL_NO_SCTP
 347         /* Disable timer for SCTP */
 348         if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 349                 {
 350                 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 351                 return;
 352                 }
 353 #endif
 354
 355         /* If timer is not set, initialize duration with 1 second */
 356         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 357                 {
 358                 s->d1->timeout_duration = 1;
 359                 }
 360
 361         /* Set timeout to current time */
 362         get_current_time(&(s->d1->next_timeout));
 363
 364         /* Add duration to current time */
 365         s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
 366         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 367         }
 368
 369 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft)
 370         {
 371         struct timeval timenow;
 372
 373         /* If no timeout is set, just return NULL */
 374         if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0)
 375                 {
 376                 return NULL;
 377                 }
 378
 379         /* Get current time */
 380         get_current_time(&timenow);
 381
 382         /* If timer already expired, set remaining time to 0 */
 383         if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 384                 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 385                  s->d1->next_timeout.tv_usec <= timenow.tv_usec))
 386                 {
 387                 memset(timeleft, 0, sizeof(struct timeval));
 388                 return timeleft;
 389                 }
 390
 391         /* Calculate time left until timer expires */
 392         memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 393         timeleft->tv_sec -= timenow.tv_sec;
 394         timeleft->tv_usec -= timenow.tv_usec;
 395         if (timeleft->tv_usec < 0)
 396                 {
 397                 timeleft->tv_sec--;
 398                 timeleft->tv_usec += 1000000;
 399                 }
 400
 401         /* If remaining time is less than 15 ms, set it to 0
 402          * to prevent issues because of small devergences with
 403          * socket timeouts.
 404          */
 405         if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000)
 406                 {
 407                 memset(timeleft, 0, sizeof(struct timeval));
 408                 }
 409
 410
 411         return timeleft;
 412         }
 413
 414 int dtls1_is_timer_expired(SSL *s)
 415         {
 416         struct timeval timeleft;
 417
 418         /* Get time left until timeout, return false if no timer running */
 419         if (dtls1_get_timeout(s, &timeleft) == NULL)
 420                 {
 421                 return 0;
 422                 }
 423
 424         /* Return false if timer is not expired yet */
 425         if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0)
 426                 {
 427                 return 0;
 428                 }
 429
 430         /* Timer expired, so return true */
 431         return 1;
 432         }
 433
 434 void dtls1_double_timeout(SSL *s)
 435         {
 436         s->d1->timeout_duration *= 2;
 437         if (s->d1->timeout_duration > 60)
 438                 s->d1->timeout_duration = 60;
 439         dtls1_start_timer(s);
 440         }
 441
 442 void dtls1_stop_timer(SSL *s)
 443         {
 444         /* Reset everything */
 445         memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
 446         memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
 447         s->d1->timeout_duration = 1;
 448         BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout));
 449         /* Clear retransmission buffer */
 450         dtls1_clear_record_buffer(s);
 451         }
 452
 453 int dtls1_check_timeout_num(SSL *s)
 454         {
 455         s->d1->timeout.num_alerts++;
 456
 457         /* Reduce MTU after 2 unsuccessful retransmissions */
 458         if (s->d1->timeout.num_alerts > 2)
 459                 {
 460                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 461                 }
 462
 463         if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 464                 {
 465                 /* fail the connection, enough alerts have been sent */
 466                 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED);
 467                 return -1;
 468                 }
 469
 470         return 0;
 471         }
 472
 473 int dtls1_handle_timeout(SSL *s)
 474         {
 475         /* if no timer is expired, don't do anything */
 476         if (!dtls1_is_timer_expired(s))
 477                 {
 478                 return 0;
 479                 }
 480
 481         dtls1_double_timeout(s);
 482
 483         if (dtls1_check_timeout_num(s) < 0)
 484                 return -1;
 485
 486         s->d1->timeout.read_timeouts++;
 487         if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 488                 {
 489                 s->d1->timeout.read_timeouts = 1;
 490                 }
 491
 492 #ifndef OPENSSL_NO_HEARTBEATS
 493         if (s->tlsext_hb_pending)
 494                 {
 495                 s->tlsext_hb_pending = 0;
 496                 return dtls1_heartbeat(s);
 497                 }
 498 #endif
 499
 500         dtls1_start_timer(s);
 501         return dtls1_retransmit_buffered_messages(s);
 502         }
 503
 504 static void get_current_time(struct timeval *t)
 505 {
 506 #if defined(_WIN32)
 507         SYSTEMTIME st;
 508         union { unsigned __int64 ul; FILETIME ft; } now;
 509
 510         GetSystemTime(&st);
 511         SystemTimeToFileTime(&st,&now.ft);
 512 #ifdef  __MINGW32__
 513         now.ul -= 116444736000000000ULL;
 514 #else
 515         now.ul -= 116444736000000000UI64;       /* re-bias to 1/1/1970 */
 516 #endif
 517         t->tv_sec  = (long)(now.ul/10000000);
 518         t->tv_usec = ((int)(now.ul%10000000))/10;
 519 #elif defined(OPENSSL_SYS_VMS)
 520         struct timeb tb;
 521         ftime(&tb);
 522         t->tv_sec = (long)tb.time;
 523         t->tv_usec = (long)tb.millitm * 1000;
 524 #else
 525         gettimeofday(t, NULL);
 526 #endif
 527 }
 528
 529 int dtls1_listen(SSL *s, struct sockaddr *client)
 530         {
 531         int ret;
 532
 533         SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 534         s->d1->listen = 1;
 535
 536         ret = SSL_accept(s);
 537         if (ret <= 0) return ret;
 538
 539         (void) BIO_dgram_get_peer(SSL_get_rbio(s), client);
 540         return 1;
 541         }
 542
 543 static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 544         {
 545         unsigned char *p = (unsigned char *)s->init_buf->data;
 546         dtls1_set_message_header(s, p, htype, len, 0, len);
 547         s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
 548         s->init_off = 0;
 549         /* Buffer the message to handle re-xmits */
 550         dtls1_buffer_message(s, 0);
 551         }
 552
 553 static int dtls1_handshake_write(SSL *s)
 554         {
 555         return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 556         }