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 IMPLEMENT_dtls1_meth_func(dtlsv1_base_method, 95 ssl_undefined_function, 96 ssl_undefined_function, 97 ssl_bad_method) 98 99 int 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 } 147 148 void dtls1_free(SSL *s) 149 { 150 pitem *item = NULL; 151 hm_fragment *frag = NULL; 152 153 ssl3_free(s); 154 155 while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) 156 { 157 OPENSSL_free(item->data); 158 pitem_free(item); 159 } 160 pqueue_free(s->d1->unprocessed_rcds.q); 161 162 while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) 163 { 164 OPENSSL_free(item->data); 165 pitem_free(item); 166 } 167 pqueue_free(s->d1->processed_rcds.q); 168 169 while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL) 170 { 171 frag = (hm_fragment *)item->data; 172 OPENSSL_free(frag->fragment); 173 OPENSSL_free(frag); 174 pitem_free(item); 175 } 176 pqueue_free(s->d1->buffered_messages); 177 178 while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL) 179 { 180 frag = (hm_fragment *)item->data; 181 OPENSSL_free(frag->fragment); 182 OPENSSL_free(frag); 183 pitem_free(item); 184 } 185 pqueue_free(s->d1->sent_messages); 186 187 while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) 188 { 189 frag = (hm_fragment *)item->data; 190 OPENSSL_free(frag->fragment); 191 OPENSSL_free(frag); 192 pitem_free(item); 193 } 194 pqueue_free(s->d1->buffered_app_data.q); 195 196 pq_64bit_free(&(s->d1->bitmap.map)); 197 pq_64bit_free(&(s->d1->bitmap.max_seq_num)); 198 199 pq_64bit_free(&(s->d1->next_bitmap.map)); 200 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num)); 201 202 OPENSSL_free(s->d1); 203 } 204 205 void dtls1_clear(SSL *s) 206 { 207 ssl3_clear(s); 208 if (s->options & SSL_OP_CISCO_ANYCONNECT) 209 s->version=DTLS1_BAD_VER; 210 else 211 s->version=DTLS1_VERSION; 212 } 213 214 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 215 { 216 int ret=0; 217 218 switch (cmd) 219 { 220 case DTLS_CTRL_GET_TIMEOUT: 221 if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL) 222 { 223 ret = 1; 224 } 225 break; 226 case DTLS_CTRL_HANDLE_TIMEOUT: 227 ret = dtls1_handle_timeout(s); 228 break; 229 case DTLS_CTRL_LISTEN: 230 ret = dtls1_listen(s, parg); 231 break; 232 233 default: 234 ret = ssl3_ctrl(s, cmd, larg, parg); 235 break; 236 } 237 return(ret); 238 } 239 240 /* 241 * As it's impossible to use stream ciphers in "datagram" mode, this 242 * simple filter is designed to disengage them in DTLS. Unfortunately 243 * there is no universal way to identify stream SSL_CIPHER, so we have 244 * to explicitly list their SSL_* codes. Currently RC4 is the only one 245 * available, but if new ones emerge, they will have to be added... 246 */ 247 SSL_CIPHER *dtls1_get_cipher(unsigned int u) 248 { 249 SSL_CIPHER *ciph = ssl3_get_cipher(u); 250 251 if (ciph != NULL) 252 { 253 if ((ciph->algorithms&SSL_ENC_MASK) == SSL_RC4) 254 return NULL; 255 } 256 257 return ciph; 258 } 259 260 void dtls1_start_timer(SSL *s) 261 { 262 /* If timer is not set, initialize duration with 1 second */ 263 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 264 { 265 s->d1->timeout_duration = 1; 266 } 267 268 /* Set timeout to current time */ 269 get_current_time(&(s->d1->next_timeout)); 270 271 /* Add duration to current time */ 272 s->d1->next_timeout.tv_sec += s->d1->timeout_duration; 273 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 274 } 275 276 struct timeval* dtls1_get_timeout(SSL *s, struct timeval* timeleft) 277 { 278 struct timeval timenow; 279 280 /* If no timeout is set, just return NULL */ 281 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) 282 { 283 return NULL; 284 } 285 286 /* Get current time */ 287 get_current_time(&timenow); 288 289 /* If timer already expired, set remaining time to 0 */ 290 if (s->d1->next_timeout.tv_sec < timenow.tv_sec || 291 (s->d1->next_timeout.tv_sec == timenow.tv_sec && 292 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) 293 { 294 memset(timeleft, 0, sizeof(struct timeval)); 295 return timeleft; 296 } 297 298 /* Calculate time left until timer expires */ 299 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval)); 300 timeleft->tv_sec -= timenow.tv_sec; 301 timeleft->tv_usec -= timenow.tv_usec; 302 if (timeleft->tv_usec < 0) 303 { 304 timeleft->tv_sec--; 305 timeleft->tv_usec += 1000000; 306 } 307 308 return timeleft; 309 } 310 311 int dtls1_is_timer_expired(SSL *s) 312 { 313 struct timeval timeleft; 314 315 /* Get time left until timeout, return false if no timer running */ 316 if (dtls1_get_timeout(s, &timeleft) == NULL) 317 { 318 return 0; 319 } 320 321 /* Return false if timer is not expired yet */ 322 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) 323 { 324 return 0; 325 } 326 327 /* Timer expired, so return true */ 328 return 1; 329 } 330 331 void dtls1_double_timeout(SSL *s) 332 { 333 s->d1->timeout_duration *= 2; 334 if (s->d1->timeout_duration > 60) 335 s->d1->timeout_duration = 60; 336 dtls1_start_timer(s); 337 } 338 339 void dtls1_stop_timer(SSL *s) 340 { 341 /* Reset everything */ 342 memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); 343 s->d1->timeout_duration = 1; 344 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &(s->d1->next_timeout)); 345 } 346 347 int dtls1_handle_timeout(SSL *s) 348 { 349 DTLS1_STATE *state; 350 351 /* if no timer is expired, don't do anything */ 352 if (!dtls1_is_timer_expired(s)) 353 { 354 return 0; 355 } 356 357 dtls1_double_timeout(s); 358 state = s->d1; 359 state->timeout.num_alerts++; 360 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 361 { 362 /* fail the connection, enough alerts have been sent */ 363 SSLerr(SSL_F_DTLS1_HANDLE_TIMEOUT,SSL_R_READ_TIMEOUT_EXPIRED); 364 return 0; 365 } 366 367 state->timeout.read_timeouts++; 368 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 369 { 370 state->timeout.read_timeouts = 1; 371 } 372 373 dtls1_start_timer(s); 374 return dtls1_retransmit_buffered_messages(s); 375 } 376 377 static void get_current_time(struct timeval *t) 378 { 379 #ifdef OPENSSL_SYS_WIN32 380 struct _timeb tb; 381 _ftime(&tb); 382 t->tv_sec = (long)tb.time; 383 t->tv_usec = (long)tb.millitm * 1000; 384 #elif defined(OPENSSL_SYS_VMS) 385 struct timeb tb; 386 ftime(&tb); 387 t->tv_sec = (long)tb.time; 388 t->tv_usec = (long)tb.millitm * 1000; 389 #else 390 gettimeofday(t, NULL); 391 #endif 392 } 393 394 int dtls1_listen(SSL *s, struct sockaddr *client) 395 { 396 int ret; 397 398 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); 399 s->d1->listen = 1; 400 401 ret = SSL_accept(s); 402 if (ret <= 0) return ret; 403 404 (void) BIO_dgram_get_peer(SSL_get_rbio(s), client); 405 return 1; 406 } 407
