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 frag = (hm_fragment *)item->data; 180 OPENSSL_free(frag->fragment); 181 OPENSSL_free(frag); 182 pitem_free(item); 183 } 184 } 185 186 void dtls1_free(SSL *s) 187 { 188 ssl3_free(s); 189 190 dtls1_clear_queues(s); 191 192 pqueue_free(s->d1->unprocessed_rcds.q); 193 pqueue_free(s->d1->processed_rcds.q); 194 pqueue_free(s->d1->buffered_messages); 195 pqueue_free(s->d1->sent_messages); 196 pqueue_free(s->d1->buffered_app_data.q); 197 198 OPENSSL_free(s->d1); 199 } 200 201 void dtls1_clear(SSL *s) 202 { 203 pqueue unprocessed_rcds; 204 pqueue processed_rcds; 205 pqueue buffered_messages; 206 pqueue sent_messages; 207 pqueue buffered_app_data; 208 unsigned int mtu; 209 210 if (s->d1) 211 { 212 unprocessed_rcds = s->d1->unprocessed_rcds.q; 213 processed_rcds = s->d1->processed_rcds.q; 214 buffered_messages = s->d1->buffered_messages; 215 sent_messages = s->d1->sent_messages; 216 buffered_app_data = s->d1->buffered_app_data.q; 217 mtu = s->d1->mtu; 218 219 dtls1_clear_queues(s); 220 221 memset(s->d1, 0, sizeof(*(s->d1))); 222 223 if (s->server) 224 { 225 s->d1->cookie_len = sizeof(s->d1->cookie); 226 } 227 228 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) 229 { 230 s->d1->mtu = mtu; 231 } 232 233 s->d1->unprocessed_rcds.q = unprocessed_rcds; 234 s->d1->processed_rcds.q = processed_rcds; 235 s->d1->buffered_messages = buffered_messages; 236 s->d1->sent_messages = sent_messages; 237 s->d1->buffered_app_data.q = buffered_app_data; 238 } 239 240 ssl3_clear(s); 241 if (s->options & SSL_OP_CISCO_ANYCONNECT) 242 s->version=DTLS1_BAD_VER; 243 else 244 s->version=DTLS1_VERSION; 245 } 246 247 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 248 { 249 int ret=0; 250 251 switch (cmd) 252 { 253 case DTLS_CTRL_GET_TIMEOUT: 254 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL) 255 { 256 ret = 1; 257 } 258 break; 259 case DTLS_CTRL_HANDLE_TIMEOUT: 260 ret = dtls1_handle_timeout(s); 261 break; 262 case DTLS_CTRL_LISTEN: 263 ret = dtls1_listen(s, parg); 264 break; 265 266 default: 267 ret = ssl3_ctrl(s, cmd, larg, parg); 268 break; 269 } 270 return(ret); 271 } 272 273 /* 274 * As it's impossible to use stream ciphers in "datagram" mode, this 275 * simple filter is designed to disengage them in DTLS. Unfortunately 276 * there is no universal way to identify stream SSL_CIPHER, so we have 277 * to explicitly list their SSL_* codes. Currently RC4 is the only one 278 * available, but if new ones emerge, they will have to be added... 279 */ 280 const SSL_CIPHER *dtls1_get_cipher(unsigned int u) 281 { 282 const SSL_CIPHER *ciph = ssl3_get_cipher(u); 283 284 if (ciph != NULL) 285 { 286 if (ciph->algorithm_enc == SSL_RC4) 287 return NULL; 288 } 289 290 return ciph; 291 } 292 293 void dtls1_start_timer(SSL *s) 294 { 295 #ifndef OPENSSL_NO_SCTP 296 /* Disable timer for SCTP */ 297 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) 298 { 299 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 300 return; 301 } 302 #endif 303 304 /* If timer is not set, initialize duration with 1 second */ 305 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 306 { 307 s->d1->timeout_duration = 1; 308 } 309 310 /* Set timeout to current time */ 311 get_current_time(&(s->d1->next_timeout)); 312 313 /* Add duration to current time */ 314 s->d1->next_timeout.tv_sec += s->d1->timeout_duration; 315 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 316 } 317 318 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft) 319 { 320 struct timeval timenow; 321 322 /* If no timeout is set, just return NULL */ 323 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 324 { 325 return NULL; 326 } 327 328 /* Get current time */ 329 get_current_time(&timenow); 330 331 /* If timer already expired, set remaining time to 0 */ 332 if (s->d1->next_timeout.tv_sec < timenow.tv_sec || 333 (s->d1->next_timeout.tv_sec == timenow.tv_sec && 334 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) 335 { 336 memset(timeleft, 0, sizeof(struct timeval)); 337 return timeleft; 338 } 339 340 /* Calculate time left until timer expires */ 341 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval)); 342 timeleft->tv_sec -= timenow.tv_sec; 343 timeleft->tv_usec -= timenow.tv_usec; 344 if (timeleft->tv_usec < 0) 345 { 346 timeleft->tv_sec--; 347 timeleft->tv_usec += 1000000; 348 } 349 350 /* If remaining time is less than 15 ms, set it to 0 351 * to prevent issues because of small devergences with 352 * socket timeouts. 353 */ 354 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) 355 { 356 memset(timeleft, 0, sizeof(struct timeval)); 357 } 358 359 360 return timeleft; 361 } 362 363 int dtls1_is_timer_expired(SSL *s) 364 { 365 struct timeval timeleft; 366 367 /* Get time left until timeout, return false if no timer running */ 368 if (dtls1_get_timeout(s, &timeleft) == NULL) 369 { 370 return 0; 371 } 372 373 /* Return false if timer is not expired yet */ 374 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) 375 { 376 return 0; 377 } 378 379 /* Timer expired, so return true */ 380 return 1; 381 } 382 383 void dtls1_double_timeout(SSL *s) 384 { 385 s->d1->timeout_duration *= 2; 386 if (s->d1->timeout_duration > 60) 387 s->d1->timeout_duration = 60; 388 dtls1_start_timer(s); 389 } 390 391 void dtls1_stop_timer(SSL *s) 392 { 393 /* Reset everything */ 394 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st)); 395 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 396 s->d1->timeout_duration = 1; 397 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 398 /* Clear retransmission buffer */ 399 dtls1_clear_record_buffer(s); 400 } 401 402 int dtls1_check_timeout_num(SSL *s) 403 { 404 s->d1->timeout.num_alerts++; 405 406 /* Reduce MTU after 2 unsuccessful retransmissions */ 407 if (s->d1->timeout.num_alerts > 2) 408 { 409 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL); 410 } 411 412 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 413 { 414 /* fail the connection, enough alerts have been sent */ 415 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,SSL_R_READ_TIMEOUT_EXPIRED); 416 return -1; 417 } 418 419 return 0; 420 } 421 422 int dtls1_handle_timeout(SSL *s) 423 { 424 /* if no timer is expired, don't do anything */ 425 if (!dtls1_is_timer_expired(s)) 426 { 427 return 0; 428 } 429 430 dtls1_double_timeout(s); 431 432 if (dtls1_check_timeout_num(s) < 0) 433 return -1; 434 435 s->d1->timeout.read_timeouts++; 436 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 437 { 438 s->d1->timeout.read_timeouts = 1; 439 } 440 441 #ifndef OPENSSL_NO_HEARTBEATS 442 if (s->tlsext_hb_pending) 443 { 444 s->tlsext_hb_pending = 0; 445 return dtls1_heartbeat(s); 446 } 447 #endif 448 449 dtls1_start_timer(s); 450 return dtls1_retransmit_buffered_messages(s); 451 } 452 453 static void get_current_time(struct timeval *t) 454 { 455 #ifdef OPENSSL_SYS_WIN32 456 struct _timeb tb; 457 _ftime(&tb); 458 t->tv_sec = (long)tb.time; 459 t->tv_usec = (long)tb.millitm * 1000; 460 #elif defined(OPENSSL_SYS_VMS) 461 struct timeb tb; 462 ftime(&tb); 463 t->tv_sec = (long)tb.time; 464 t->tv_usec = (long)tb.millitm * 1000; 465 #else 466 gettimeofday(t, NULL); 467 #endif 468 } 469 470 int dtls1_listen(SSL *s, struct sockaddr *client) 471 { 472 int ret; 473 474 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); 475 s->d1->listen = 1; 476 477 ret = SSL_accept(s); 478 if (ret <= 0) return ret; 479 480 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client); 481 return 1; 482 } 483
