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 }; 86 87long dtls1_default_timeout(void) 88 { 89 /* 2 hours, the 24 hours mentioned in the DTLSv1 spec 90 * is way too long for http, the cache would over fill */ 91 return(60*60*2); 92 } 93 94int dtls1_new(SSL *s) 95 { 96 DTLS1_STATE *d1; 97 98 if (!ssl3_new(s)) return(0); 99 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0); 100 memset(d1,0, sizeof *d1); 101 102 /* d1->handshake_epoch=0; */ 103 104 d1->unprocessed_rcds.q=pqueue_new(); 105 d1->processed_rcds.q=pqueue_new(); 106 d1->buffered_messages = pqueue_new(); 107 d1->sent_messages=pqueue_new(); 108 d1->buffered_app_data.q=pqueue_new(); 109 110 if ( s->server) 111 { 112 d1->cookie_len = sizeof(s->d1->cookie); 113 } 114 115 d1->link_mtu = 0; 116 d1->mtu = 0; 117 118 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 119 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q) 120 { 121 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q); 122 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q); 123 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages); 124 if ( d1->sent_messages) pqueue_free(d1->sent_messages); 125 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q); 126 OPENSSL_free(d1); 127 return (0); 128 } 129 130 s->d1=d1; 131 s->method->ssl_clear(s); 132 return(1); 133 } 134 135static void dtls1_clear_queues(SSL *s) 136 { 137 pitem *item = NULL; 138 hm_fragment *frag = NULL; 139 DTLS1_RECORD_DATA *rdata; 140 141 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) 142 { 143 rdata = (DTLS1_RECORD_DATA *) item->data; 144 if (rdata->rbuf.buf) 145 { 146 OPENSSL_free(rdata->rbuf.buf); 147 } 148 OPENSSL_free(item->data); 149 pitem_free(item); 150 } 151 152 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) 153 { 154 rdata = (DTLS1_RECORD_DATA *) item->data; 155 if (rdata->rbuf.buf) 156 { 157 OPENSSL_free(rdata->rbuf.buf); 158 } 159 OPENSSL_free(item->data); 160 pitem_free(item); 161 } 162 163 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL) 164 { 165 frag = (hm_fragment *)item->data; 166 dtls1_hm_fragment_free(frag); 167 pitem_free(item); 168 } 169 170 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL) 171 { 172 frag = (hm_fragment *)item->data; 173 dtls1_hm_fragment_free(frag); 174 pitem_free(item); 175 } 176 177 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) 178 { 179 rdata = (DTLS1_RECORD_DATA *) item->data; 180 if (rdata->rbuf.buf) 181 { 182 OPENSSL_free(rdata->rbuf.buf); 183 } 184 OPENSSL_free(item->data); 185 pitem_free(item); 186 } 187 } 188 189void dtls1_free(SSL *s) 190 { 191 ssl3_free(s); 192 193 dtls1_clear_queues(s); 194 195 pqueue_free(s->d1->unprocessed_rcds.q); 196 pqueue_free(s->d1->processed_rcds.q); 197 pqueue_free(s->d1->buffered_messages); 198 pqueue_free(s->d1->sent_messages); 199 pqueue_free(s->d1->buffered_app_data.q); 200 201 OPENSSL_free(s->d1); 202 s->d1 = NULL; 203 } 204 205void dtls1_clear(SSL *s) 206 { 207 pqueue unprocessed_rcds; 208 pqueue processed_rcds; 209 pqueue buffered_messages; 210 pqueue sent_messages; 211 pqueue buffered_app_data; 212 unsigned int mtu; 213 unsigned int link_mtu; 214 215 if (s->d1) 216 { 217 unprocessed_rcds = s->d1->unprocessed_rcds.q; 218 processed_rcds = s->d1->processed_rcds.q; 219 buffered_messages = s->d1->buffered_messages; 220 sent_messages = s->d1->sent_messages; 221 buffered_app_data = s->d1->buffered_app_data.q; 222 mtu = s->d1->mtu; 223 link_mtu = s->d1->link_mtu; 224 225 dtls1_clear_queues(s); 226 227 memset(s->d1, 0, sizeof(*(s->d1))); 228 229 if (s->server) 230 { 231 s->d1->cookie_len = sizeof(s->d1->cookie); 232 } 233 234 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) 235 { 236 s->d1->mtu = mtu; 237 s->d1->link_mtu = link_mtu; 238 } 239 240 s->d1->unprocessed_rcds.q = unprocessed_rcds; 241 s->d1->processed_rcds.q = processed_rcds; 242 s->d1->buffered_messages = buffered_messages; 243 s->d1->sent_messages = sent_messages; 244 s->d1->buffered_app_data.q = buffered_app_data; 245 } 246 247 ssl3_clear(s); 248 if (s->options & SSL_OP_CISCO_ANYCONNECT) 249 s->version=DTLS1_BAD_VER; 250 else 251 s->version=DTLS1_VERSION; 252 } 253 254long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 255 { 256 int ret=0; 257 258 switch (cmd) 259 { 260 case DTLS_CTRL_GET_TIMEOUT: 261 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL) 262 { 263 ret = 1; 264 } 265 break; 266 case DTLS_CTRL_HANDLE_TIMEOUT: 267 ret = dtls1_handle_timeout(s); 268 break; 269 case DTLS_CTRL_LISTEN: 270 ret = dtls1_listen(s, parg); 271 break; 272 case SSL_CTRL_CHECK_PROTO_VERSION: 273 /* For library-internal use; checks that the current protocol 274 * is the highest enabled version (according to s->ctx->method, 275 * as version negotiation may have changed s->method). */ 276#if DTLS_MAX_VERSION != DTLS1_VERSION 277# error Code needs update for DTLS_method() support beyond DTLS1_VERSION. 278#endif 279 /* Just one protocol version is supported so far; 280 * fail closed if the version is not as expected. */ 281 return s->version == DTLS_MAX_VERSION; 282 case DTLS_CTRL_SET_LINK_MTU: 283 if (larg < (long)dtls1_link_min_mtu()) 284 return 0; 285 s->d1->link_mtu = larg; 286 return 1; 287 case DTLS_CTRL_GET_LINK_MIN_MTU: 288 return (long)dtls1_link_min_mtu(); 289 case SSL_CTRL_SET_MTU: 290 /* 291 * We may not have a BIO set yet so can't call dtls1_min_mtu() 292 * We'll have to make do with dtls1_link_min_mtu() and max overhead 293 */ 294 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD) 295 return 0; 296 s->d1->mtu = larg; 297 return larg; 298 default: 299 ret = ssl3_ctrl(s, cmd, larg, parg); 300 break; 301 } 302 return(ret); 303 } 304 305/* 306 * As it's impossible to use stream ciphers in "datagram" mode, this 307 * simple filter is designed to disengage them in DTLS. Unfortunately 308 * there is no universal way to identify stream SSL_CIPHER, so we have 309 * to explicitly list their SSL_* codes. Currently RC4 is the only one 310 * available, but if new ones emerge, they will have to be added... 311 */ 312const SSL_CIPHER *dtls1_get_cipher(unsigned int u) 313 { 314 const SSL_CIPHER *ciph = ssl3_get_cipher(u); 315 316 if (ciph != NULL) 317 { 318 if (ciph->algorithm_enc == SSL_RC4) 319 return NULL; 320 } 321 322 return ciph; 323 } 324 325void dtls1_start_timer(SSL *s) 326 { 327 /* If timer is not set, initialize duration with 1 second */ 328 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 329 { 330 s->d1->timeout_duration = 1; 331 } 332 333 /* Set timeout to current time */ 334 get_current_time(&(s->d1->next_timeout)); 335 336 /* Add duration to current time */ 337 s->d1->next_timeout.tv_sec += s->d1->timeout_duration; 338 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 339 } 340 341struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft) 342 { 343 struct timeval timenow; 344 345 /* If no timeout is set, just return NULL */ 346 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 347 { 348 return NULL; 349 } 350 351 /* Get current time */ 352 get_current_time(&timenow); 353 354 /* If timer already expired, set remaining time to 0 */ 355 if (s->d1->next_timeout.tv_sec < timenow.tv_sec || 356 (s->d1->next_timeout.tv_sec == timenow.tv_sec && 357 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) 358 { 359 memset(timeleft, 0, sizeof(struct timeval)); 360 return timeleft; 361 } 362 363 /* Calculate time left until timer expires */ 364 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval)); 365 timeleft->tv_sec -= timenow.tv_sec; 366 timeleft->tv_usec -= timenow.tv_usec; 367 if (timeleft->tv_usec < 0) 368 { 369 timeleft->tv_sec--; 370 timeleft->tv_usec += 1000000; 371 } 372 373 /* If remaining time is less than 15 ms, set it to 0 374 * to prevent issues because of small devergences with 375 * socket timeouts. 376 */ 377 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) 378 { 379 memset(timeleft, 0, sizeof(struct timeval)); 380 } 381 382 383 return timeleft; 384 } 385 386int dtls1_is_timer_expired(SSL *s) 387 { 388 struct timeval timeleft; 389 390 /* Get time left until timeout, return false if no timer running */ 391 if (dtls1_get_timeout(s, &timeleft) == NULL) 392 { 393 return 0; 394 } 395 396 /* Return false if timer is not expired yet */ 397 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) 398 { 399 return 0; 400 } 401 402 /* Timer expired, so return true */ 403 return 1; 404 } 405 406void dtls1_double_timeout(SSL *s) 407 { 408 s->d1->timeout_duration *= 2; 409 if (s->d1->timeout_duration > 60) 410 s->d1->timeout_duration = 60; 411 dtls1_start_timer(s); 412 } 413 414void dtls1_stop_timer(SSL *s) 415 { 416 /* Reset everything */ 417 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st)); 418 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 419 s->d1->timeout_duration = 1; 420 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 421 /* Clear retransmission buffer */ 422 dtls1_clear_record_buffer(s); 423 } 424 425int dtls1_check_timeout_num(SSL *s) 426 { 427 unsigned int mtu; 428 429 s->d1->timeout.num_alerts++; 430 431 /* Reduce MTU after 2 unsuccessful retransmissions */ 432 if (s->d1->timeout.num_alerts > 2 433 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 434 { 435 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL); 436 if(mtu < s->d1->mtu) 437 s->d1->mtu = mtu; 438 } 439 440 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 441 { 442 /* fail the connection, enough alerts have been sent */ 443 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED); 444 return -1; 445 } 446 447 return 0; 448 } 449 450int dtls1_handle_timeout(SSL *s) 451 { 452 /* if no timer is expired, don't do anything */ 453 if (!dtls1_is_timer_expired(s)) 454 { 455 return 0; 456 } 457 458 dtls1_double_timeout(s); 459 460 if (dtls1_check_timeout_num(s) < 0) 461 return -1; 462 463 s->d1->timeout.read_timeouts++; 464 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 465 { 466 s->d1->timeout.read_timeouts = 1; 467 } 468 469 dtls1_start_timer(s); 470 return dtls1_retransmit_buffered_messages(s); 471 } 472 473static void get_current_time(struct timeval *t) 474{ 475#ifdef OPENSSL_SYS_WIN32 476 struct _timeb tb; 477 _ftime(&tb); 478 t->tv_sec = (long)tb.time; 479 t->tv_usec = (long)tb.millitm * 1000; 480#elif defined(OPENSSL_SYS_VMS) 481 struct timeb tb; 482 ftime(&tb); 483 t->tv_sec = (long)tb.time; 484 t->tv_usec = (long)tb.millitm * 1000; 485#else 486 gettimeofday(t, NULL); 487#endif 488} 489 490int dtls1_listen(SSL *s, struct sockaddr *client) 491 { 492 int ret; 493 494 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); 495 s->d1->listen = 1; 496 497 ret = SSL_accept(s); 498 if (ret <= 0) return ret; 499 500 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client); 501 return 1; 502 } 503