1 /* ssl/d1_lib.c */ 2 /* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra (at) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh (at) 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 69 static void get_current_time(struct timeval *t); 70 const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT; 71 int dtls1_listen(SSL *s, struct sockaddr *client); 72 73 SSL3_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 88 long dtls1_default_timeout(void) 89 { 90 /* 2 hours, the 24 hours mentioned in the DTLSv1 spec 91 * is way too long for http, the cache would over fill */ 92 return(60*60*2); 93 } 94 95 int dtls1_new(SSL *s) 96 { 97 DTLS1_STATE *d1; 98 99 if (!ssl3_new(s)) return(0); 100 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0); 101 memset(d1,0, sizeof *d1); 102 103 /* d1->handshake_epoch=0; */ 104 105 d1->unprocessed_rcds.q=pqueue_new(); 106 d1->processed_rcds.q=pqueue_new(); 107 d1->buffered_messages = pqueue_new(); 108 d1->sent_messages=pqueue_new(); 109 d1->buffered_app_data.q=pqueue_new(); 110 111 if ( s->server) 112 { 113 d1->cookie_len = sizeof(s->d1->cookie); 114 } 115 116 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 117 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q) 118 { 119 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q); 120 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q); 121 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages); 122 if ( d1->sent_messages) pqueue_free(d1->sent_messages); 123 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q); 124 OPENSSL_free(d1); 125 return (0); 126 } 127 128 s->d1=d1; 129 s->method->ssl_clear(s); 130 return(1); 131 } 132 133 static void dtls1_clear_queues(SSL *s) 134 { 135 pitem *item = NULL; 136 hm_fragment *frag = NULL; 137 DTLS1_RECORD_DATA *rdata; 138 139 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) 140 { 141 rdata = (DTLS1_RECORD_DATA *) item->data; 142 if (rdata->rbuf.buf) 143 { 144 OPENSSL_free(rdata->rbuf.buf); 145 } 146 OPENSSL_free(item->data); 147 pitem_free(item); 148 } 149 150 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) 151 { 152 rdata = (DTLS1_RECORD_DATA *) item->data; 153 if (rdata->rbuf.buf) 154 { 155 OPENSSL_free(rdata->rbuf.buf); 156 } 157 OPENSSL_free(item->data); 158 pitem_free(item); 159 } 160 161 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL) 162 { 163 frag = (hm_fragment *)item->data; 164 OPENSSL_free(frag->fragment); 165 OPENSSL_free(frag); 166 pitem_free(item); 167 } 168 169 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL) 170 { 171 frag = (hm_fragment *)item->data; 172 OPENSSL_free(frag->fragment); 173 OPENSSL_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 } 188 189 void 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 } 204 205 void 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; 213 214 if (s->d1) 215 { 216 unprocessed_rcds = s->d1->unprocessed_rcds.q; 217 processed_rcds = s->d1->processed_rcds.q; 218 buffered_messages = s->d1->buffered_messages; 219 sent_messages = s->d1->sent_messages; 220 buffered_app_data = s->d1->buffered_app_data.q; 221 mtu = s->d1->mtu; 222 223 dtls1_clear_queues(s); 224 225 memset(s->d1, 0, sizeof(*(s->d1))); 226 227 if (s->server) 228 { 229 s->d1->cookie_len = sizeof(s->d1->cookie); 230 } 231 232 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) 233 { 234 s->d1->mtu = mtu; 235 } 236 237 s->d1->unprocessed_rcds.q = unprocessed_rcds; 238 s->d1->processed_rcds.q = processed_rcds; 239 s->d1->buffered_messages = buffered_messages; 240 s->d1->sent_messages = sent_messages; 241 s->d1->buffered_app_data.q = buffered_app_data; 242 } 243 244 ssl3_clear(s); 245 if (s->options & SSL_OP_CISCO_ANYCONNECT) 246 s->version=DTLS1_BAD_VER; 247 else 248 s->version=DTLS1_VERSION; 249 } 250 251 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 252 { 253 int ret=0; 254 255 switch (cmd) 256 { 257 case DTLS_CTRL_GET_TIMEOUT: 258 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL) 259 { 260 ret = 1; 261 } 262 break; 263 case DTLS_CTRL_HANDLE_TIMEOUT: 264 ret = dtls1_handle_timeout(s); 265 break; 266 case DTLS_CTRL_LISTEN: 267 ret = dtls1_listen(s, parg); 268 break; 269 case SSL_CTRL_CHECK_PROTO_VERSION: 270 /* For library-internal use; checks that the current protocol 271 * is the highest enabled version (according to s->ctx->method, 272 * as version negotiation may have changed s->method). */ 273 #if DTLS_MAX_VERSION != DTLS1_VERSION 274 # error Code needs update for DTLS_method() support beyond DTLS1_VERSION. 275 #endif 276 /* Just one protocol version is supported so far; 277 * fail closed if the version is not as expected. */ 278 return s->version == DTLS_MAX_VERSION; 279 280 default: 281 ret = ssl3_ctrl(s, cmd, larg, parg); 282 break; 283 } 284 return(ret); 285 } 286 287 /* 288 * As it's impossible to use stream ciphers in "datagram" mode, this 289 * simple filter is designed to disengage them in DTLS. Unfortunately 290 * there is no universal way to identify stream SSL_CIPHER, so we have 291 * to explicitly list their SSL_* codes. Currently RC4 is the only one 292 * available, but if new ones emerge, they will have to be added... 293 */ 294 const SSL_CIPHER *dtls1_get_cipher(unsigned int u) 295 { 296 const SSL_CIPHER *ciph = ssl3_get_cipher(u); 297 298 if (ciph != NULL) 299 { 300 if (ciph->algorithm_enc == SSL_RC4) 301 return NULL; 302 } 303 304 return ciph; 305 } 306 307 void dtls1_start_timer(SSL *s) 308 { 309 #ifndef OPENSSL_NO_SCTP 310 /* Disable timer for SCTP */ 311 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) 312 { 313 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 314 return; 315 } 316 #endif 317 318 /* If timer is not set, initialize duration with 1 second */ 319 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 320 { 321 s->d1->timeout_duration = 1; 322 } 323 324 /* Set timeout to current time */ 325 get_current_time(&(s->d1->next_timeout)); 326 327 /* Add duration to current time */ 328 s->d1->next_timeout.tv_sec += s->d1->timeout_duration; 329 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 330 } 331 332 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft) 333 { 334 struct timeval timenow; 335 336 /* If no timeout is set, just return NULL */ 337 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 338 { 339 return NULL; 340 } 341 342 /* Get current time */ 343 get_current_time(&timenow); 344 345 /* If timer already expired, set remaining time to 0 */ 346 if (s->d1->next_timeout.tv_sec < timenow.tv_sec || 347 (s->d1->next_timeout.tv_sec == timenow.tv_sec && 348 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) 349 { 350 memset(timeleft, 0, sizeof(struct timeval)); 351 return timeleft; 352 } 353 354 /* Calculate time left until timer expires */ 355 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval)); 356 timeleft->tv_sec -= timenow.tv_sec; 357 timeleft->tv_usec -= timenow.tv_usec; 358 if (timeleft->tv_usec < 0) 359 { 360 timeleft->tv_sec--; 361 timeleft->tv_usec += 1000000; 362 } 363 364 /* If remaining time is less than 15 ms, set it to 0 365 * to prevent issues because of small devergences with 366 * socket timeouts. 367 */ 368 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) 369 { 370 memset(timeleft, 0, sizeof(struct timeval)); 371 } 372 373 374 return timeleft; 375 } 376 377 int dtls1_is_timer_expired(SSL *s) 378 { 379 struct timeval timeleft; 380 381 /* Get time left until timeout, return false if no timer running */ 382 if (dtls1_get_timeout(s, &timeleft) == NULL) 383 { 384 return 0; 385 } 386 387 /* Return false if timer is not expired yet */ 388 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) 389 { 390 return 0; 391 } 392 393 /* Timer expired, so return true */ 394 return 1; 395 } 396 397 void dtls1_double_timeout(SSL *s) 398 { 399 s->d1->timeout_duration *= 2; 400 if (s->d1->timeout_duration > 60) 401 s->d1->timeout_duration = 60; 402 dtls1_start_timer(s); 403 } 404 405 void dtls1_stop_timer(SSL *s) 406 { 407 /* Reset everything */ 408 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st)); 409 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 410 s->d1->timeout_duration = 1; 411 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 412 /* Clear retransmission buffer */ 413 dtls1_clear_record_buffer(s); 414 } 415 416 int dtls1_check_timeout_num(SSL *s) 417 { 418 s->d1->timeout.num_alerts++; 419 420 /* Reduce MTU after 2 unsuccessful retransmissions */ 421 if (s->d1->timeout.num_alerts > 2) 422 { 423 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL); 424 } 425 426 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 427 { 428 /* fail the connection, enough alerts have been sent */ 429 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED); 430 return -1; 431 } 432 433 return 0; 434 } 435 436 int dtls1_handle_timeout(SSL *s) 437 { 438 /* if no timer is expired, don't do anything */ 439 if (!dtls1_is_timer_expired(s)) 440 { 441 return 0; 442 } 443 444 dtls1_double_timeout(s); 445 446 if (dtls1_check_timeout_num(s) < 0) 447 return -1; 448 449 s->d1->timeout.read_timeouts++; 450 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 451 { 452 s->d1->timeout.read_timeouts = 1; 453 } 454 455 #ifndef OPENSSL_NO_HEARTBEATS 456 if (s->tlsext_hb_pending) 457 { 458 s->tlsext_hb_pending = 0; 459 return dtls1_heartbeat(s); 460 } 461 #endif 462 463 dtls1_start_timer(s); 464 return dtls1_retransmit_buffered_messages(s); 465 } 466 467 static void get_current_time(struct timeval *t) 468 { 469 #ifdef OPENSSL_SYS_WIN32 470 struct _timeb tb; 471 _ftime(&tb); 472 t->tv_sec = (long)tb.time; 473 t->tv_usec = (long)tb.millitm * 1000; 474 #elif defined(OPENSSL_SYS_VMS) 475 struct timeb tb; 476 ftime(&tb); 477 t->tv_sec = (long)tb.time; 478 t->tv_usec = (long)tb.millitm * 1000; 479 #else 480 gettimeofday(t, NULL); 481 #endif 482 } 483 484 int dtls1_listen(SSL *s, struct sockaddr *client) 485 { 486 int ret; 487 488 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); 489 s->d1->listen = 1; 490 491 ret = SSL_accept(s); 492 if (ret <= 0) return ret; 493 494 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client); 495 return 1; 496 } 497
