d1_lib.c revision 306196
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 69static void get_current_time(struct timeval *t); 70const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT; 71int dtls1_listen(SSL *s, struct sockaddr *client); 72 73SSL3_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 88long 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 97int 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 144static void dtls1_clear_queues(SSL *s) 145{ 146 pitem *item = NULL; 147 DTLS1_RECORD_DATA *rdata; 148 149 while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) { 150 rdata = (DTLS1_RECORD_DATA *)item->data; 151 if (rdata->rbuf.buf) { 152 OPENSSL_free(rdata->rbuf.buf); 153 } 154 OPENSSL_free(item->data); 155 pitem_free(item); 156 } 157 158 while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) { 159 rdata = (DTLS1_RECORD_DATA *)item->data; 160 if (rdata->rbuf.buf) { 161 OPENSSL_free(rdata->rbuf.buf); 162 } 163 OPENSSL_free(item->data); 164 pitem_free(item); 165 } 166 167 while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) { 168 rdata = (DTLS1_RECORD_DATA *)item->data; 169 if (rdata->rbuf.buf) { 170 OPENSSL_free(rdata->rbuf.buf); 171 } 172 OPENSSL_free(item->data); 173 pitem_free(item); 174 } 175 176 dtls1_clear_received_buffer(s); 177 dtls1_clear_sent_buffer(s); 178} 179 180void dtls1_clear_received_buffer(SSL *s) 181{ 182 pitem *item = NULL; 183 hm_fragment *frag = NULL; 184 185 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) { 186 frag = (hm_fragment *)item->data; 187 dtls1_hm_fragment_free(frag); 188 pitem_free(item); 189 } 190} 191 192void dtls1_clear_sent_buffer(SSL *s) 193{ 194 pitem *item = NULL; 195 hm_fragment *frag = NULL; 196 197 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) { 198 frag = (hm_fragment *)item->data; 199 dtls1_hm_fragment_free(frag); 200 pitem_free(item); 201 } 202} 203 204 205void dtls1_free(SSL *s) 206{ 207 ssl3_free(s); 208 209 dtls1_clear_queues(s); 210 211 pqueue_free(s->d1->unprocessed_rcds.q); 212 pqueue_free(s->d1->processed_rcds.q); 213 pqueue_free(s->d1->buffered_messages); 214 pqueue_free(s->d1->sent_messages); 215 pqueue_free(s->d1->buffered_app_data.q); 216 217 OPENSSL_free(s->d1); 218 s->d1 = NULL; 219} 220 221void dtls1_clear(SSL *s) 222{ 223 pqueue unprocessed_rcds; 224 pqueue processed_rcds; 225 pqueue buffered_messages; 226 pqueue sent_messages; 227 pqueue buffered_app_data; 228 unsigned int mtu; 229 unsigned int link_mtu; 230 231 if (s->d1) { 232 unprocessed_rcds = s->d1->unprocessed_rcds.q; 233 processed_rcds = s->d1->processed_rcds.q; 234 buffered_messages = s->d1->buffered_messages; 235 sent_messages = s->d1->sent_messages; 236 buffered_app_data = s->d1->buffered_app_data.q; 237 mtu = s->d1->mtu; 238 link_mtu = s->d1->link_mtu; 239 240 dtls1_clear_queues(s); 241 242 memset(s->d1, 0, sizeof(*(s->d1))); 243 244 if (s->server) { 245 s->d1->cookie_len = sizeof(s->d1->cookie); 246 } 247 248 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) { 249 s->d1->mtu = mtu; 250 s->d1->link_mtu = link_mtu; 251 } 252 253 s->d1->unprocessed_rcds.q = unprocessed_rcds; 254 s->d1->processed_rcds.q = processed_rcds; 255 s->d1->buffered_messages = buffered_messages; 256 s->d1->sent_messages = sent_messages; 257 s->d1->buffered_app_data.q = buffered_app_data; 258 } 259 260 ssl3_clear(s); 261 if (s->options & SSL_OP_CISCO_ANYCONNECT) 262 s->version = DTLS1_BAD_VER; 263 else 264 s->version = DTLS1_VERSION; 265} 266 267long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 268{ 269 int ret = 0; 270 271 switch (cmd) { 272 case DTLS_CTRL_GET_TIMEOUT: 273 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) { 274 ret = 1; 275 } 276 break; 277 case DTLS_CTRL_HANDLE_TIMEOUT: 278 ret = dtls1_handle_timeout(s); 279 break; 280 case DTLS_CTRL_LISTEN: 281 ret = dtls1_listen(s, parg); 282 break; 283 case SSL_CTRL_CHECK_PROTO_VERSION: 284 /* 285 * For library-internal use; checks that the current protocol is the 286 * highest enabled version (according to s->ctx->method, as version 287 * negotiation may have changed s->method). 288 */ 289#if DTLS_MAX_VERSION != DTLS1_VERSION 290# error Code needs update for DTLS_method() support beyond DTLS1_VERSION. 291#endif 292 /* 293 * Just one protocol version is supported so far; fail closed if the 294 * version is not as expected. 295 */ 296 return s->version == DTLS_MAX_VERSION; 297 case DTLS_CTRL_SET_LINK_MTU: 298 if (larg < (long)dtls1_link_min_mtu()) 299 return 0; 300 s->d1->link_mtu = larg; 301 return 1; 302 case DTLS_CTRL_GET_LINK_MIN_MTU: 303 return (long)dtls1_link_min_mtu(); 304 case SSL_CTRL_SET_MTU: 305 /* 306 * We may not have a BIO set yet so can't call dtls1_min_mtu() 307 * We'll have to make do with dtls1_link_min_mtu() and max overhead 308 */ 309 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD) 310 return 0; 311 s->d1->mtu = larg; 312 return larg; 313 default: 314 ret = ssl3_ctrl(s, cmd, larg, parg); 315 break; 316 } 317 return (ret); 318} 319 320/* 321 * As it's impossible to use stream ciphers in "datagram" mode, this 322 * simple filter is designed to disengage them in DTLS. Unfortunately 323 * there is no universal way to identify stream SSL_CIPHER, so we have 324 * to explicitly list their SSL_* codes. Currently RC4 is the only one 325 * available, but if new ones emerge, they will have to be added... 326 */ 327const SSL_CIPHER *dtls1_get_cipher(unsigned int u) 328{ 329 const SSL_CIPHER *ciph = ssl3_get_cipher(u); 330 331 if (ciph != NULL) { 332 if (ciph->algorithm_enc == SSL_RC4) 333 return NULL; 334 } 335 336 return ciph; 337} 338 339void dtls1_start_timer(SSL *s) 340{ 341#ifndef OPENSSL_NO_SCTP 342 /* Disable timer for SCTP */ 343 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) { 344 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 345 return; 346 } 347#endif 348 349 /* If timer is not set, initialize duration with 1 second */ 350 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) { 351 s->d1->timeout_duration = 1; 352 } 353 354 /* Set timeout to current time */ 355 get_current_time(&(s->d1->next_timeout)); 356 357 /* Add duration to current time */ 358 s->d1->next_timeout.tv_sec += s->d1->timeout_duration; 359 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, 360 &(s->d1->next_timeout)); 361} 362 363struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft) 364{ 365 struct timeval timenow; 366 367 /* If no timeout is set, just return NULL */ 368 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) { 369 return NULL; 370 } 371 372 /* Get current time */ 373 get_current_time(&timenow); 374 375 /* If timer already expired, set remaining time to 0 */ 376 if (s->d1->next_timeout.tv_sec < timenow.tv_sec || 377 (s->d1->next_timeout.tv_sec == timenow.tv_sec && 378 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) { 379 memset(timeleft, 0, sizeof(struct timeval)); 380 return timeleft; 381 } 382 383 /* Calculate time left until timer expires */ 384 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval)); 385 timeleft->tv_sec -= timenow.tv_sec; 386 timeleft->tv_usec -= timenow.tv_usec; 387 if (timeleft->tv_usec < 0) { 388 timeleft->tv_sec--; 389 timeleft->tv_usec += 1000000; 390 } 391 392 /* 393 * If remaining time is less than 15 ms, set it to 0 to prevent issues 394 * because of small devergences with socket timeouts. 395 */ 396 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) { 397 memset(timeleft, 0, sizeof(struct timeval)); 398 } 399 400 return timeleft; 401} 402 403int dtls1_is_timer_expired(SSL *s) 404{ 405 struct timeval timeleft; 406 407 /* Get time left until timeout, return false if no timer running */ 408 if (dtls1_get_timeout(s, &timeleft) == NULL) { 409 return 0; 410 } 411 412 /* Return false if timer is not expired yet */ 413 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) { 414 return 0; 415 } 416 417 /* Timer expired, so return true */ 418 return 1; 419} 420 421void dtls1_double_timeout(SSL *s) 422{ 423 s->d1->timeout_duration *= 2; 424 if (s->d1->timeout_duration > 60) 425 s->d1->timeout_duration = 60; 426 dtls1_start_timer(s); 427} 428 429void dtls1_stop_timer(SSL *s) 430{ 431 /* Reset everything */ 432 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st)); 433 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 434 s->d1->timeout_duration = 1; 435 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, 436 &(s->d1->next_timeout)); 437 /* Clear retransmission buffer */ 438 dtls1_clear_sent_buffer(s); 439} 440 441int dtls1_check_timeout_num(SSL *s) 442{ 443 unsigned int mtu; 444 445 s->d1->timeout.num_alerts++; 446 447 /* Reduce MTU after 2 unsuccessful retransmissions */ 448 if (s->d1->timeout.num_alerts > 2 449 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 450 mtu = 451 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, 452 NULL); 453 if (mtu < s->d1->mtu) 454 s->d1->mtu = mtu; 455 } 456 457 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) { 458 /* fail the connection, enough alerts have been sent */ 459 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED); 460 return -1; 461 } 462 463 return 0; 464} 465 466int dtls1_handle_timeout(SSL *s) 467{ 468 /* if no timer is expired, don't do anything */ 469 if (!dtls1_is_timer_expired(s)) { 470 return 0; 471 } 472 473 dtls1_double_timeout(s); 474 475 if (dtls1_check_timeout_num(s) < 0) 476 return -1; 477 478 s->d1->timeout.read_timeouts++; 479 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) { 480 s->d1->timeout.read_timeouts = 1; 481 } 482#ifndef OPENSSL_NO_HEARTBEATS 483 if (s->tlsext_hb_pending) { 484 s->tlsext_hb_pending = 0; 485 return dtls1_heartbeat(s); 486 } 487#endif 488 489 dtls1_start_timer(s); 490 return dtls1_retransmit_buffered_messages(s); 491} 492 493static void get_current_time(struct timeval *t) 494{ 495#ifdef OPENSSL_SYS_WIN32 496 struct _timeb tb; 497 _ftime(&tb); 498 t->tv_sec = (long)tb.time; 499 t->tv_usec = (long)tb.millitm * 1000; 500#elif defined(OPENSSL_SYS_VMS) 501 struct timeb tb; 502 ftime(&tb); 503 t->tv_sec = (long)tb.time; 504 t->tv_usec = (long)tb.millitm * 1000; 505#else 506 gettimeofday(t, NULL); 507#endif 508} 509 510int dtls1_listen(SSL *s, struct sockaddr *client) 511{ 512 int ret; 513 514 /* Ensure there is no state left over from a previous invocation */ 515 SSL_clear(s); 516 517 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); 518 s->d1->listen = 1; 519 520 ret = SSL_accept(s); 521 if (ret <= 0) 522 return ret; 523 524 (void)BIO_dgram_get_peer(SSL_get_rbio(s), client); 525 return 1; 526} 527