d1_lib.c revision 284295
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 94IMPLEMENT_dtls1_meth_func(dtlsv1_base_method, 95 ssl_undefined_function, 96 ssl_undefined_function, 97 ssl_bad_method) 98 99int dtls1_new(SSL *s) 100 { 101 DTLS1_STATE *d1; 102 103 if (!ssl3_new(s)) return(0); 104 if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0); 105 memset(d1,0, sizeof *d1); 106 107 /* d1->handshake_epoch=0; */ 108#if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST) 109 d1->bitmap.length=64; 110#else 111 d1->bitmap.length=sizeof(d1->bitmap.map) * 8; 112#endif 113 pq_64bit_init(&(d1->bitmap.map)); 114 pq_64bit_init(&(d1->bitmap.max_seq_num)); 115 116 d1->next_bitmap.length = d1->bitmap.length; 117 pq_64bit_init(&(d1->next_bitmap.map)); 118 pq_64bit_init(&(d1->next_bitmap.max_seq_num)); 119 120 d1->unprocessed_rcds.q=pqueue_new(); 121 d1->processed_rcds.q=pqueue_new(); 122 d1->buffered_messages = pqueue_new(); 123 d1->sent_messages=pqueue_new(); 124 d1->buffered_app_data.q=pqueue_new(); 125 126 if ( s->server) 127 { 128 d1->cookie_len = sizeof(s->d1->cookie); 129 } 130 131 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 132 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q) 133 { 134 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q); 135 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q); 136 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages); 137 if ( d1->sent_messages) pqueue_free(d1->sent_messages); 138 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q); 139 OPENSSL_free(d1); 140 return (0); 141 } 142 143 s->d1=d1; 144 s->method->ssl_clear(s); 145 return(1); 146 } 147 148static void dtls1_clear_queues(SSL *s) 149 { 150 pitem *item = NULL; 151 hm_fragment *frag = NULL; 152 DTLS1_RECORD_DATA *rdata; 153 154 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) 155 { 156 rdata = (DTLS1_RECORD_DATA *) item->data; 157 if (rdata->rbuf.buf) 158 { 159 OPENSSL_free(rdata->rbuf.buf); 160 } 161 OPENSSL_free(item->data); 162 pitem_free(item); 163 } 164 165 while( (item = pqueue_pop(s->d1->processed_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->buffered_messages)) != NULL) 177 { 178 frag = (hm_fragment *)item->data; 179 OPENSSL_free(frag->fragment); 180 OPENSSL_free(frag); 181 pitem_free(item); 182 } 183 184 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL) 185 { 186 frag = (hm_fragment *)item->data; 187 OPENSSL_free(frag->fragment); 188 OPENSSL_free(frag); 189 pitem_free(item); 190 } 191 192 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) 193 { 194 rdata = (DTLS1_RECORD_DATA *) item->data; 195 if (rdata->rbuf.buf) 196 { 197 OPENSSL_free(rdata->rbuf.buf); 198 } 199 OPENSSL_free(item->data); 200 pitem_free(item); 201 } 202 } 203 204void dtls1_free(SSL *s) 205 { 206 ssl3_free(s); 207 208 dtls1_clear_queues(s); 209 210 pqueue_free(s->d1->unprocessed_rcds.q); 211 pqueue_free(s->d1->processed_rcds.q); 212 pqueue_free(s->d1->buffered_messages); 213 pqueue_free(s->d1->sent_messages); 214 pqueue_free(s->d1->buffered_app_data.q); 215 216 pq_64bit_free(&(s->d1->bitmap.map)); 217 pq_64bit_free(&(s->d1->bitmap.max_seq_num)); 218 219 pq_64bit_free(&(s->d1->next_bitmap.map)); 220 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num)); 221 222 OPENSSL_free(s->d1); 223 s->d1 = NULL; 224 } 225 226void dtls1_clear(SSL *s) 227 { 228 pqueue unprocessed_rcds; 229 pqueue processed_rcds; 230 pqueue buffered_messages; 231 pqueue sent_messages; 232 pqueue buffered_app_data; 233 unsigned int mtu; 234 235 if (s->d1) 236 { 237 unprocessed_rcds = s->d1->unprocessed_rcds.q; 238 processed_rcds = s->d1->processed_rcds.q; 239 buffered_messages = s->d1->buffered_messages; 240 sent_messages = s->d1->sent_messages; 241 buffered_app_data = s->d1->buffered_app_data.q; 242 mtu = s->d1->mtu; 243 244 dtls1_clear_queues(s); 245 246 pq_64bit_free(&(s->d1->bitmap.map)); 247 pq_64bit_free(&(s->d1->bitmap.max_seq_num)); 248 249 pq_64bit_free(&(s->d1->next_bitmap.map)); 250 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num)); 251 252 memset(s->d1, 0, sizeof(*(s->d1))); 253 254 if (s->server) 255 { 256 s->d1->cookie_len = sizeof(s->d1->cookie); 257 } 258 259 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) 260 { 261 s->d1->mtu = mtu; 262 } 263 264 s->d1->unprocessed_rcds.q = unprocessed_rcds; 265 s->d1->processed_rcds.q = processed_rcds; 266 s->d1->buffered_messages = buffered_messages; 267 s->d1->sent_messages = sent_messages; 268 s->d1->buffered_app_data.q = buffered_app_data; 269 270#if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST) 271 s->d1->bitmap.length=64; 272#else 273 s->d1->bitmap.length=sizeof(s->d1->bitmap.map) * 8; 274#endif 275 pq_64bit_init(&(s->d1->bitmap.map)); 276 pq_64bit_init(&(s->d1->bitmap.max_seq_num)); 277 278 s->d1->next_bitmap.length = s->d1->bitmap.length; 279 pq_64bit_init(&(s->d1->next_bitmap.map)); 280 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num)); 281 } 282 283 ssl3_clear(s); 284 if (s->options & SSL_OP_CISCO_ANYCONNECT) 285 s->version=DTLS1_BAD_VER; 286 else 287 s->version=DTLS1_VERSION; 288 } 289 290long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 291 { 292 int ret=0; 293 294 switch (cmd) 295 { 296 case DTLS_CTRL_GET_TIMEOUT: 297 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL) 298 { 299 ret = 1; 300 } 301 break; 302 case DTLS_CTRL_HANDLE_TIMEOUT: 303 ret = dtls1_handle_timeout(s); 304 break; 305 case DTLS_CTRL_LISTEN: 306 ret = dtls1_listen(s, parg); 307 break; 308 case SSL_CTRL_CHECK_PROTO_VERSION: 309 /* For library-internal use; checks that the current protocol 310 * is the highest enabled version (according to s->ctx->method, 311 * as version negotiation may have changed s->method). */ 312#if DTLS_MAX_VERSION != DTLS1_VERSION 313# error Code needs update for DTLS_method() support beyond DTLS1_VERSION. 314#endif 315 /* Just one protocol version is supported so far; 316 * fail closed if the version is not as expected. */ 317 return s->version == DTLS_MAX_VERSION; 318 319 default: 320 ret = ssl3_ctrl(s, cmd, larg, parg); 321 break; 322 } 323 return(ret); 324 } 325 326/* 327 * As it's impossible to use stream ciphers in "datagram" mode, this 328 * simple filter is designed to disengage them in DTLS. Unfortunately 329 * there is no universal way to identify stream SSL_CIPHER, so we have 330 * to explicitly list their SSL_* codes. Currently RC4 is the only one 331 * available, but if new ones emerge, they will have to be added... 332 */ 333SSL_CIPHER *dtls1_get_cipher(unsigned int u) 334 { 335 SSL_CIPHER *ciph = ssl3_get_cipher(u); 336 337 if (ciph != NULL) 338 { 339 if ((ciph->algorithms&SSL_ENC_MASK) == SSL_RC4) 340 return NULL; 341 } 342 343 return ciph; 344 } 345 346void dtls1_start_timer(SSL *s) 347 { 348 /* If timer is not set, initialize duration with 1 second */ 349 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 350 { 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, &(s->d1->next_timeout)); 360 } 361 362struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft) 363 { 364 struct timeval timenow; 365 366 /* If no timeout is set, just return NULL */ 367 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 368 { 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 { 380 memset(timeleft, 0, sizeof(struct timeval)); 381 return timeleft; 382 } 383 384 /* Calculate time left until timer expires */ 385 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval)); 386 timeleft->tv_sec -= timenow.tv_sec; 387 timeleft->tv_usec -= timenow.tv_usec; 388 if (timeleft->tv_usec < 0) 389 { 390 timeleft->tv_sec--; 391 timeleft->tv_usec += 1000000; 392 } 393 394 /* If remaining time is less than 15 ms, set it to 0 395 * to prevent issues because of small devergences with 396 * socket timeouts. 397 */ 398 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) 399 { 400 memset(timeleft, 0, sizeof(struct timeval)); 401 } 402 403 404 return timeleft; 405 } 406 407int dtls1_is_timer_expired(SSL *s) 408 { 409 struct timeval timeleft; 410 411 /* Get time left until timeout, return false if no timer running */ 412 if (dtls1_get_timeout(s, &timeleft) == NULL) 413 { 414 return 0; 415 } 416 417 /* Return false if timer is not expired yet */ 418 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) 419 { 420 return 0; 421 } 422 423 /* Timer expired, so return true */ 424 return 1; 425 } 426 427void dtls1_double_timeout(SSL *s) 428 { 429 s->d1->timeout_duration *= 2; 430 if (s->d1->timeout_duration > 60) 431 s->d1->timeout_duration = 60; 432 dtls1_start_timer(s); 433 } 434 435void dtls1_stop_timer(SSL *s) 436 { 437 /* Reset everything */ 438 memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st)); 439 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 440 s->d1->timeout_duration = 1; 441 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 442 /* Clear retransmission buffer */ 443 dtls1_clear_record_buffer(s); 444 } 445 446int dtls1_check_timeout_num(SSL *s) 447 { 448 s->d1->timeout.num_alerts++; 449 450 /* Reduce MTU after 2 unsuccessful retransmissions */ 451 if (s->d1->timeout.num_alerts > 2) 452 { 453 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL); 454 } 455 456 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 457 { 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 { 471 return 0; 472 } 473 474 dtls1_double_timeout(s); 475 476 if (dtls1_check_timeout_num(s) < 0) 477 return -1; 478 479 s->d1->timeout.read_timeouts++; 480 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 481 { 482 s->d1->timeout.read_timeouts = 1; 483 } 484 485 dtls1_start_timer(s); 486 return dtls1_retransmit_buffered_messages(s); 487 } 488 489static void get_current_time(struct timeval *t) 490{ 491#ifdef OPENSSL_SYS_WIN32 492 struct _timeb tb; 493 _ftime(&tb); 494 t->tv_sec = (long)tb.time; 495 t->tv_usec = (long)tb.millitm * 1000; 496#elif defined(OPENSSL_SYS_VMS) 497 struct timeb tb; 498 ftime(&tb); 499 t->tv_sec = (long)tb.time; 500 t->tv_usec = (long)tb.millitm * 1000; 501#else 502 gettimeofday(t, NULL); 503#endif 504} 505 506int dtls1_listen(SSL *s, struct sockaddr *client) 507 { 508 int ret; 509 510 /* Ensure there is no state left over from a previous invocation */ 511 SSL_clear(s); 512 513 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); 514 s->d1->listen = 1; 515 516 ret = SSL_accept(s); 517 if (ret <= 0) return ret; 518 519 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client); 520 return 1; 521 } 522