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