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 }; 86 87 long 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 94 int 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 if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q 116 || ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q) 117 { 118 if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q); 119 if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q); 120 if ( d1->buffered_messages) pqueue_free(d1->buffered_messages); 121 if ( d1->sent_messages) pqueue_free(d1->sent_messages); 122 if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q); 123 OPENSSL_free(d1); 124 return (0); 125 } 126 127 s->d1=d1; 128 s->method->ssl_clear(s); 129 return(1); 130 } 131 132 static void dtls1_clear_queues(SSL *s) 133 { 134 pitem *item = NULL; 135 hm_fragment *frag = NULL; 136 DTLS1_RECORD_DATA *rdata; 137 138 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) 139 { 140 rdata = (DTLS1_RECORD_DATA *) item->data; 141 if (rdata->rbuf.buf) 142 { 143 OPENSSL_free(rdata->rbuf.buf); 144 } 145 OPENSSL_free(item->data); 146 pitem_free(item); 147 } 148 149 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) 150 { 151 rdata = (DTLS1_RECORD_DATA *) item->data; 152 if (rdata->rbuf.buf) 153 { 154 OPENSSL_free(rdata->rbuf.buf); 155 } 156 OPENSSL_free(item->data); 157 pitem_free(item); 158 } 159 160 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL) 161 { 162 frag = (hm_fragment *)item->data; 163 OPENSSL_free(frag->fragment); 164 OPENSSL_free(frag); 165 pitem_free(item); 166 } 167 168 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL) 169 { 170 frag = (hm_fragment *)item->data; 171 OPENSSL_free(frag->fragment); 172 OPENSSL_free(frag); 173 pitem_free(item); 174 } 175 176 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) 177 { 178 frag = (hm_fragment *)item->data; 179 OPENSSL_free(frag->fragment); 180 OPENSSL_free(frag); 181 pitem_free(item); 182 } 183 } 184 185 void dtls1_free(SSL *s) 186 { 187 ssl3_free(s); 188 189 dtls1_clear_queues(s); 190 191 pqueue_free(s->d1->unprocessed_rcds.q); 192 pqueue_free(s->d1->processed_rcds.q); 193 pqueue_free(s->d1->buffered_messages); 194 pqueue_free(s->d1->sent_messages); 195 pqueue_free(s->d1->buffered_app_data.q); 196 197 OPENSSL_free(s->d1); 198 } 199 200 void dtls1_clear(SSL *s) 201 { 202 pqueue unprocessed_rcds; 203 pqueue processed_rcds; 204 pqueue buffered_messages; 205 pqueue sent_messages; 206 pqueue buffered_app_data; 207 208 if (s->d1) 209 { 210 unprocessed_rcds = s->d1->unprocessed_rcds.q; 211 processed_rcds = s->d1->processed_rcds.q; 212 buffered_messages = s->d1->buffered_messages; 213 sent_messages = s->d1->sent_messages; 214 buffered_app_data = s->d1->buffered_app_data.q; 215 216 dtls1_clear_queues(s); 217 218 memset(s->d1, 0, sizeof(*(s->d1))); 219 220 if (s->server) 221 { 222 s->d1->cookie_len = sizeof(s->d1->cookie); 223 } 224 225 s->d1->unprocessed_rcds.q = unprocessed_rcds; 226 s->d1->processed_rcds.q = processed_rcds; 227 s->d1->buffered_messages = buffered_messages; 228 s->d1->sent_messages = sent_messages; 229 s->d1->buffered_app_data.q = buffered_app_data; 230 } 231 232 ssl3_clear(s); 233 if (s->options & SSL_OP_CISCO_ANYCONNECT) 234 s->version=DTLS1_BAD_VER; 235 else 236 s->version=DTLS1_VERSION; 237 } 238 239 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 240 { 241 int ret=0; 242 243 switch (cmd) 244 { 245 case DTLS_CTRL_GET_TIMEOUT: 246 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL) 247 { 248 ret = 1; 249 } 250 break; 251 case DTLS_CTRL_HANDLE_TIMEOUT: 252 ret = dtls1_handle_timeout(s); 253 break; 254 case DTLS_CTRL_LISTEN: 255 ret = dtls1_listen(s, parg); 256 break; 257 258 default: 259 ret = ssl3_ctrl(s, cmd, larg, parg); 260 break; 261 } 262 return(ret); 263 } 264 265 /* 266 * As it's impossible to use stream ciphers in "datagram" mode, this 267 * simple filter is designed to disengage them in DTLS. Unfortunately 268 * there is no universal way to identify stream SSL_CIPHER, so we have 269 * to explicitly list their SSL_* codes. Currently RC4 is the only one 270 * available, but if new ones emerge, they will have to be added... 271 */ 272 const SSL_CIPHER *dtls1_get_cipher(unsigned int u) 273 { 274 const SSL_CIPHER *ciph = ssl3_get_cipher(u); 275 276 if (ciph != NULL) 277 { 278 if (ciph->algorithm_enc == SSL_RC4) 279 return NULL; 280 } 281 282 return ciph; 283 } 284 285 void dtls1_start_timer(SSL *s) 286 { 287 /* If timer is not set, initialize duration with 1 second */ 288 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 289 { 290 s->d1->timeout_duration = 1; 291 } 292 293 /* Set timeout to current time */ 294 get_current_time(&(s->d1->next_timeout)); 295 296 /* Add duration to current time */ 297 s->d1->next_timeout.tv_sec += s->d1->timeout_duration; 298 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 299 } 300 301 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft) 302 { 303 struct timeval timenow; 304 305 /* If no timeout is set, just return NULL */ 306 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 307 { 308 return NULL; 309 } 310 311 /* Get current time */ 312 get_current_time(&timenow); 313 314 /* If timer already expired, set remaining time to 0 */ 315 if (s->d1->next_timeout.tv_sec < timenow.tv_sec || 316 (s->d1->next_timeout.tv_sec == timenow.tv_sec && 317 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) 318 { 319 memset(timeleft, 0, sizeof(struct timeval)); 320 return timeleft; 321 } 322 323 /* Calculate time left until timer expires */ 324 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval)); 325 timeleft->tv_sec -= timenow.tv_sec; 326 timeleft->tv_usec -= timenow.tv_usec; 327 if (timeleft->tv_usec < 0) 328 { 329 timeleft->tv_sec--; 330 timeleft->tv_usec += 1000000; 331 } 332 333 /* If remaining time is less than 15 ms, set it to 0 334 * to prevent issues because of small devergences with 335 * socket timeouts. 336 */ 337 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) 338 { 339 memset(timeleft, 0, sizeof(struct timeval)); 340 } 341 342 343 return timeleft; 344 } 345 346 int dtls1_is_timer_expired(SSL *s) 347 { 348 struct timeval timeleft; 349 350 /* Get time left until timeout, return false if no timer running */ 351 if (dtls1_get_timeout(s, &timeleft) == NULL) 352 { 353 return 0; 354 } 355 356 /* Return false if timer is not expired yet */ 357 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) 358 { 359 return 0; 360 } 361 362 /* Timer expired, so return true */ 363 return 1; 364 } 365 366 void dtls1_double_timeout(SSL *s) 367 { 368 s->d1->timeout_duration *= 2; 369 if (s->d1->timeout_duration > 60) 370 s->d1->timeout_duration = 60; 371 dtls1_start_timer(s); 372 } 373 374 void dtls1_stop_timer(SSL *s) 375 { 376 /* Reset everything */ 377 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 378 s->d1->timeout_duration = 1; 379 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 380 /* Clear retransmission buffer */ 381 dtls1_clear_record_buffer(s); 382 } 383 384 int dtls1_handle_timeout(SSL *s) 385 { 386 DTLS1_STATE *state; 387 388 /* if no timer is expired, don't do anything */ 389 if (!dtls1_is_timer_expired(s)) 390 { 391 return 0; 392 } 393 394 dtls1_double_timeout(s); 395 state = s->d1; 396 state->timeout.num_alerts++; 397 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 398 { 399 /* fail the connection, enough alerts have been sent */ 400 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED); 401 return -1; 402 } 403 404 state->timeout.read_timeouts++; 405 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 406 { 407 state->timeout.read_timeouts = 1; 408 } 409 410 dtls1_start_timer(s); 411 return dtls1_retransmit_buffered_messages(s); 412 } 413 414 static void get_current_time(struct timeval *t) 415 { 416 #ifdef OPENSSL_SYS_WIN32 417 struct _timeb tb; 418 _ftime(&tb); 419 t->tv_sec = (long)tb.time; 420 t->tv_usec = (long)tb.millitm * 1000; 421 #elif defined(OPENSSL_SYS_VMS) 422 struct timeb tb; 423 ftime(&tb); 424 t->tv_sec = (long)tb.time; 425 t->tv_usec = (long)tb.millitm * 1000; 426 #else 427 gettimeofday(t, NULL); 428 #endif 429 } 430 431 int dtls1_listen(SSL *s, struct sockaddr *client) 432 { 433 int ret; 434 435 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); 436 s->d1->listen = 1; 437 438 ret = SSL_accept(s); 439 if (ret <= 0) return ret; 440 441 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client); 442 return 1; 443 } 444
