1 /* 2 * Copyright 2005-2019 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <stdio.h> 11 #include <errno.h> 12 #include "../ssl_local.h" 13 #include <openssl/evp.h> 14 #include <openssl/buffer.h> 15 #include "record_local.h" 16 #include "../packet_local.h" 17 #include "internal/cryptlib.h" 18 19 int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl) 20 { 21 DTLS_RECORD_LAYER *d; 22 23 if ((d = OPENSSL_malloc(sizeof(*d))) == NULL) { 24 SSLerr(SSL_F_DTLS_RECORD_LAYER_NEW, ERR_R_MALLOC_FAILURE); 25 return 0; 26 } 27 28 rl->d = d; 29 30 d->unprocessed_rcds.q = pqueue_new(); 31 d->processed_rcds.q = pqueue_new(); 32 d->buffered_app_data.q = pqueue_new(); 33 34 if (d->unprocessed_rcds.q == NULL || d->processed_rcds.q == NULL 35 || d->buffered_app_data.q == NULL) { 36 pqueue_free(d->unprocessed_rcds.q); 37 pqueue_free(d->processed_rcds.q); 38 pqueue_free(d->buffered_app_data.q); 39 OPENSSL_free(d); 40 rl->d = NULL; 41 return 0; 42 } 43 44 return 1; 45 } 46 47 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl) 48 { 49 DTLS_RECORD_LAYER_clear(rl); 50 pqueue_free(rl->d->unprocessed_rcds.q); 51 pqueue_free(rl->d->processed_rcds.q); 52 pqueue_free(rl->d->buffered_app_data.q); 53 OPENSSL_free(rl->d); 54 rl->d = NULL; 55 } 56 57 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl) 58 { 59 DTLS_RECORD_LAYER *d; 60 pitem *item = NULL; 61 DTLS1_RECORD_DATA *rdata; 62 pqueue *unprocessed_rcds; 63 pqueue *processed_rcds; 64 pqueue *buffered_app_data; 65 66 d = rl->d; 67 68 while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) { 69 rdata = (DTLS1_RECORD_DATA *)item->data; 70 OPENSSL_free(rdata->rbuf.buf); 71 OPENSSL_free(item->data); 72 pitem_free(item); 73 } 74 75 while ((item = pqueue_pop(d->processed_rcds.q)) != NULL) { 76 rdata = (DTLS1_RECORD_DATA *)item->data; 77 OPENSSL_free(rdata->rbuf.buf); 78 OPENSSL_free(item->data); 79 pitem_free(item); 80 } 81 82 while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) { 83 rdata = (DTLS1_RECORD_DATA *)item->data; 84 OPENSSL_free(rdata->rbuf.buf); 85 OPENSSL_free(item->data); 86 pitem_free(item); 87 } 88 89 unprocessed_rcds = d->unprocessed_rcds.q; 90 processed_rcds = d->processed_rcds.q; 91 buffered_app_data = d->buffered_app_data.q; 92 memset(d, 0, sizeof(*d)); 93 d->unprocessed_rcds.q = unprocessed_rcds; 94 d->processed_rcds.q = processed_rcds; 95 d->buffered_app_data.q = buffered_app_data; 96 } 97 98 void DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER *rl, unsigned short e) 99 { 100 if (e == rl->d->w_epoch - 1) { 101 memcpy(rl->d->curr_write_sequence, 102 rl->write_sequence, sizeof(rl->write_sequence)); 103 memcpy(rl->write_sequence, 104 rl->d->last_write_sequence, sizeof(rl->write_sequence)); 105 } else if (e == rl->d->w_epoch + 1) { 106 memcpy(rl->d->last_write_sequence, 107 rl->write_sequence, sizeof(unsigned char[8])); 108 memcpy(rl->write_sequence, 109 rl->d->curr_write_sequence, sizeof(rl->write_sequence)); 110 } 111 rl->d->w_epoch = e; 112 } 113 114 void DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER *rl, unsigned char *seq) 115 { 116 memcpy(rl->write_sequence, seq, SEQ_NUM_SIZE); 117 } 118 119 /* copy buffered record into SSL structure */ 120 static int dtls1_copy_record(SSL *s, pitem *item) 121 { 122 DTLS1_RECORD_DATA *rdata; 123 124 rdata = (DTLS1_RECORD_DATA *)item->data; 125 126 SSL3_BUFFER_release(&s->rlayer.rbuf); 127 128 s->rlayer.packet = rdata->packet; 129 s->rlayer.packet_length = rdata->packet_length; 130 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER)); 131 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD)); 132 133 /* Set proper sequence number for mac calculation */ 134 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6); 135 136 return 1; 137 } 138 139 int dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 140 { 141 DTLS1_RECORD_DATA *rdata; 142 pitem *item; 143 144 /* Limit the size of the queue to prevent DOS attacks */ 145 if (pqueue_size(queue->q) >= 100) 146 return 0; 147 148 rdata = OPENSSL_malloc(sizeof(*rdata)); 149 item = pitem_new(priority, rdata); 150 if (rdata == NULL || item == NULL) { 151 OPENSSL_free(rdata); 152 pitem_free(item); 153 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_BUFFER_RECORD, 154 ERR_R_INTERNAL_ERROR); 155 return -1; 156 } 157 158 rdata->packet = s->rlayer.packet; 159 rdata->packet_length = s->rlayer.packet_length; 160 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER)); 161 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD)); 162 163 item->data = rdata; 164 165 #ifndef OPENSSL_NO_SCTP 166 /* Store bio_dgram_sctp_rcvinfo struct */ 167 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 168 (SSL_get_state(s) == TLS_ST_SR_FINISHED 169 || SSL_get_state(s) == TLS_ST_CR_FINISHED)) { 170 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, 171 sizeof(rdata->recordinfo), &rdata->recordinfo); 172 } 173 #endif 174 175 s->rlayer.packet = NULL; 176 s->rlayer.packet_length = 0; 177 memset(&s->rlayer.rbuf, 0, sizeof(s->rlayer.rbuf)); 178 memset(&s->rlayer.rrec, 0, sizeof(s->rlayer.rrec)); 179 180 if (!ssl3_setup_buffers(s)) { 181 /* SSLfatal() already called */ 182 OPENSSL_free(rdata->rbuf.buf); 183 OPENSSL_free(rdata); 184 pitem_free(item); 185 return -1; 186 } 187 188 if (pqueue_insert(queue->q, item) == NULL) { 189 /* Must be a duplicate so ignore it */ 190 OPENSSL_free(rdata->rbuf.buf); 191 OPENSSL_free(rdata); 192 pitem_free(item); 193 } 194 195 return 1; 196 } 197 198 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 199 { 200 pitem *item; 201 202 item = pqueue_pop(queue->q); 203 if (item) { 204 dtls1_copy_record(s, item); 205 206 OPENSSL_free(item->data); 207 pitem_free(item); 208 209 return 1; 210 } 211 212 return 0; 213 } 214 215 /* 216 * retrieve a buffered record that belongs to the new epoch, i.e., not 217 * processed yet 218 */ 219 #define dtls1_get_unprocessed_record(s) \ 220 dtls1_retrieve_buffered_record((s), \ 221 &((s)->rlayer.d->unprocessed_rcds)) 222 223 int dtls1_process_buffered_records(SSL *s) 224 { 225 pitem *item; 226 SSL3_BUFFER *rb; 227 SSL3_RECORD *rr; 228 DTLS1_BITMAP *bitmap; 229 unsigned int is_next_epoch; 230 int replayok = 1; 231 232 item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q); 233 if (item) { 234 /* Check if epoch is current. */ 235 if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch) 236 return 1; /* Nothing to do. */ 237 238 rr = RECORD_LAYER_get_rrec(&s->rlayer); 239 240 rb = RECORD_LAYER_get_rbuf(&s->rlayer); 241 242 if (SSL3_BUFFER_get_left(rb) > 0) { 243 /* 244 * We've still got data from the current packet to read. There could 245 * be a record from the new epoch in it - so don't overwrite it 246 * with the unprocessed records yet (we'll do it when we've 247 * finished reading the current packet). 248 */ 249 return 1; 250 } 251 252 /* Process all the records. */ 253 while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) { 254 dtls1_get_unprocessed_record(s); 255 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 256 if (bitmap == NULL) { 257 /* 258 * Should not happen. This will only ever be NULL when the 259 * current record is from a different epoch. But that cannot 260 * be the case because we already checked the epoch above 261 */ 262 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 263 SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS, 264 ERR_R_INTERNAL_ERROR); 265 return 0; 266 } 267 #ifndef OPENSSL_NO_SCTP 268 /* Only do replay check if no SCTP bio */ 269 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) 270 #endif 271 { 272 /* 273 * Check whether this is a repeat, or aged record. We did this 274 * check once already when we first received the record - but 275 * we might have updated the window since then due to 276 * records we subsequently processed. 277 */ 278 replayok = dtls1_record_replay_check(s, bitmap); 279 } 280 281 if (!replayok || !dtls1_process_record(s, bitmap)) { 282 if (ossl_statem_in_error(s)) { 283 /* dtls1_process_record called SSLfatal() */ 284 return -1; 285 } 286 /* dump this record */ 287 rr->length = 0; 288 RECORD_LAYER_reset_packet_length(&s->rlayer); 289 continue; 290 } 291 292 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds), 293 SSL3_RECORD_get_seq_num(s->rlayer.rrec)) < 0) { 294 /* SSLfatal() already called */ 295 return 0; 296 } 297 } 298 } 299 300 /* 301 * sync epoch numbers once all the unprocessed records have been 302 * processed 303 */ 304 s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch; 305 s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1; 306 307 return 1; 308 } 309 310 /*- 311 * Return up to 'len' payload bytes received in 'type' records. 312 * 'type' is one of the following: 313 * 314 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 315 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 316 * - 0 (during a shutdown, no data has to be returned) 317 * 318 * If we don't have stored data to work from, read a SSL/TLS record first 319 * (possibly multiple records if we still don't have anything to return). 320 * 321 * This function must handle any surprises the peer may have for us, such as 322 * Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec 323 * messages are treated as if they were handshake messages *if* the |recd_type| 324 * argument is non NULL. 325 * Also if record payloads contain fragments too small to process, we store 326 * them until there is enough for the respective protocol (the record protocol 327 * may use arbitrary fragmentation and even interleaving): 328 * Change cipher spec protocol 329 * just 1 byte needed, no need for keeping anything stored 330 * Alert protocol 331 * 2 bytes needed (AlertLevel, AlertDescription) 332 * Handshake protocol 333 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 334 * to detect unexpected Client Hello and Hello Request messages 335 * here, anything else is handled by higher layers 336 * Application data protocol 337 * none of our business 338 */ 339 int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf, 340 size_t len, int peek, size_t *readbytes) 341 { 342 int i, j, iret; 343 size_t n; 344 SSL3_RECORD *rr; 345 void (*cb) (const SSL *ssl, int type2, int val) = NULL; 346 347 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) { 348 /* Not initialized yet */ 349 if (!ssl3_setup_buffers(s)) { 350 /* SSLfatal() already called */ 351 return -1; 352 } 353 } 354 355 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 356 (type != SSL3_RT_HANDSHAKE)) || 357 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 358 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES, 359 ERR_R_INTERNAL_ERROR); 360 return -1; 361 } 362 363 if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s)) { 364 /* type == SSL3_RT_APPLICATION_DATA */ 365 i = s->handshake_func(s); 366 /* SSLfatal() already called if appropriate */ 367 if (i < 0) 368 return i; 369 if (i == 0) 370 return -1; 371 } 372 373 start: 374 s->rwstate = SSL_NOTHING; 375 376 /*- 377 * s->s3->rrec.type - is the type of record 378 * s->s3->rrec.data, - data 379 * s->s3->rrec.off, - offset into 'data' for next read 380 * s->s3->rrec.length, - number of bytes. 381 */ 382 rr = s->rlayer.rrec; 383 384 /* 385 * We are not handshaking and have no data yet, so process data buffered 386 * during the last handshake in advance, if any. 387 */ 388 if (SSL_is_init_finished(s) && SSL3_RECORD_get_length(rr) == 0) { 389 pitem *item; 390 item = pqueue_pop(s->rlayer.d->buffered_app_data.q); 391 if (item) { 392 #ifndef OPENSSL_NO_SCTP 393 /* Restore bio_dgram_sctp_rcvinfo struct */ 394 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) { 395 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data; 396 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, 397 sizeof(rdata->recordinfo), &rdata->recordinfo); 398 } 399 #endif 400 401 dtls1_copy_record(s, item); 402 403 OPENSSL_free(item->data); 404 pitem_free(item); 405 } 406 } 407 408 /* Check for timeout */ 409 if (dtls1_handle_timeout(s) > 0) { 410 goto start; 411 } else if (ossl_statem_in_error(s)) { 412 /* dtls1_handle_timeout() has failed with a fatal error */ 413 return -1; 414 } 415 416 /* get new packet if necessary */ 417 if ((SSL3_RECORD_get_length(rr) == 0) 418 || (s->rlayer.rstate == SSL_ST_READ_BODY)) { 419 RECORD_LAYER_set_numrpipes(&s->rlayer, 0); 420 iret = dtls1_get_record(s); 421 if (iret <= 0) { 422 iret = dtls1_read_failed(s, iret); 423 /* 424 * Anything other than a timeout is an error. SSLfatal() already 425 * called if appropriate. 426 */ 427 if (iret <= 0) 428 return iret; 429 else 430 goto start; 431 } 432 RECORD_LAYER_set_numrpipes(&s->rlayer, 1); 433 } 434 435 /* 436 * Reset the count of consecutive warning alerts if we've got a non-empty 437 * record that isn't an alert. 438 */ 439 if (SSL3_RECORD_get_type(rr) != SSL3_RT_ALERT 440 && SSL3_RECORD_get_length(rr) != 0) 441 s->rlayer.alert_count = 0; 442 443 /* we now have a packet which can be read and processed */ 444 445 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 446 * reset by ssl3_get_finished */ 447 && (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) { 448 /* 449 * We now have application data between CCS and Finished. Most likely 450 * the packets were reordered on their way, so buffer the application 451 * data for later processing rather than dropping the connection. 452 */ 453 if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data), 454 SSL3_RECORD_get_seq_num(rr)) < 0) { 455 /* SSLfatal() already called */ 456 return -1; 457 } 458 SSL3_RECORD_set_length(rr, 0); 459 SSL3_RECORD_set_read(rr); 460 goto start; 461 } 462 463 /* 464 * If the other end has shut down, throw anything we read away (even in 465 * 'peek' mode) 466 */ 467 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 468 SSL3_RECORD_set_length(rr, 0); 469 SSL3_RECORD_set_read(rr); 470 s->rwstate = SSL_NOTHING; 471 return 0; 472 } 473 474 if (type == SSL3_RECORD_get_type(rr) 475 || (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC 476 && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) { 477 /* 478 * SSL3_RT_APPLICATION_DATA or 479 * SSL3_RT_HANDSHAKE or 480 * SSL3_RT_CHANGE_CIPHER_SPEC 481 */ 482 /* 483 * make sure that we are not getting application data when we are 484 * doing a handshake for the first time 485 */ 486 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 487 (s->enc_read_ctx == NULL)) { 488 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES, 489 SSL_R_APP_DATA_IN_HANDSHAKE); 490 return -1; 491 } 492 493 if (recvd_type != NULL) 494 *recvd_type = SSL3_RECORD_get_type(rr); 495 496 if (len == 0) { 497 /* 498 * Mark a zero length record as read. This ensures multiple calls to 499 * SSL_read() with a zero length buffer will eventually cause 500 * SSL_pending() to report data as being available. 501 */ 502 if (SSL3_RECORD_get_length(rr) == 0) 503 SSL3_RECORD_set_read(rr); 504 return 0; 505 } 506 507 if (len > SSL3_RECORD_get_length(rr)) 508 n = SSL3_RECORD_get_length(rr); 509 else 510 n = len; 511 512 memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n); 513 if (peek) { 514 if (SSL3_RECORD_get_length(rr) == 0) 515 SSL3_RECORD_set_read(rr); 516 } else { 517 SSL3_RECORD_sub_length(rr, n); 518 SSL3_RECORD_add_off(rr, n); 519 if (SSL3_RECORD_get_length(rr) == 0) { 520 s->rlayer.rstate = SSL_ST_READ_HEADER; 521 SSL3_RECORD_set_off(rr, 0); 522 SSL3_RECORD_set_read(rr); 523 } 524 } 525 #ifndef OPENSSL_NO_SCTP 526 /* 527 * We might had to delay a close_notify alert because of reordered 528 * app data. If there was an alert and there is no message to read 529 * anymore, finally set shutdown. 530 */ 531 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 532 s->d1->shutdown_received 533 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 534 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 535 return 0; 536 } 537 #endif 538 *readbytes = n; 539 return 1; 540 } 541 542 /* 543 * If we get here, then type != rr->type; if we have a handshake message, 544 * then it was unexpected (Hello Request or Client Hello). 545 */ 546 547 if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) { 548 unsigned int alert_level, alert_descr; 549 unsigned char *alert_bytes = SSL3_RECORD_get_data(rr) 550 + SSL3_RECORD_get_off(rr); 551 PACKET alert; 552 553 if (!PACKET_buf_init(&alert, alert_bytes, SSL3_RECORD_get_length(rr)) 554 || !PACKET_get_1(&alert, &alert_level) 555 || !PACKET_get_1(&alert, &alert_descr) 556 || PACKET_remaining(&alert) != 0) { 557 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES, 558 SSL_R_INVALID_ALERT); 559 return -1; 560 } 561 562 if (s->msg_callback) 563 s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_bytes, 2, s, 564 s->msg_callback_arg); 565 566 if (s->info_callback != NULL) 567 cb = s->info_callback; 568 else if (s->ctx->info_callback != NULL) 569 cb = s->ctx->info_callback; 570 571 if (cb != NULL) { 572 j = (alert_level << 8) | alert_descr; 573 cb(s, SSL_CB_READ_ALERT, j); 574 } 575 576 if (alert_level == SSL3_AL_WARNING) { 577 s->s3->warn_alert = alert_descr; 578 SSL3_RECORD_set_read(rr); 579 580 s->rlayer.alert_count++; 581 if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) { 582 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES, 583 SSL_R_TOO_MANY_WARN_ALERTS); 584 return -1; 585 } 586 587 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 588 #ifndef OPENSSL_NO_SCTP 589 /* 590 * With SCTP and streams the socket may deliver app data 591 * after a close_notify alert. We have to check this first so 592 * that nothing gets discarded. 593 */ 594 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 595 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 596 s->d1->shutdown_received = 1; 597 s->rwstate = SSL_READING; 598 BIO_clear_retry_flags(SSL_get_rbio(s)); 599 BIO_set_retry_read(SSL_get_rbio(s)); 600 return -1; 601 } 602 #endif 603 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 604 return 0; 605 } 606 } else if (alert_level == SSL3_AL_FATAL) { 607 char tmp[16]; 608 609 s->rwstate = SSL_NOTHING; 610 s->s3->fatal_alert = alert_descr; 611 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_DTLS1_READ_BYTES, 612 SSL_AD_REASON_OFFSET + alert_descr); 613 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); 614 ERR_add_error_data(2, "SSL alert number ", tmp); 615 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 616 SSL3_RECORD_set_read(rr); 617 SSL_CTX_remove_session(s->session_ctx, s->session); 618 return 0; 619 } else { 620 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS1_READ_BYTES, 621 SSL_R_UNKNOWN_ALERT_TYPE); 622 return -1; 623 } 624 625 goto start; 626 } 627 628 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a 629 * shutdown */ 630 s->rwstate = SSL_NOTHING; 631 SSL3_RECORD_set_length(rr, 0); 632 SSL3_RECORD_set_read(rr); 633 return 0; 634 } 635 636 if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) { 637 /* 638 * We can't process a CCS now, because previous handshake messages 639 * are still missing, so just drop it. 640 */ 641 SSL3_RECORD_set_length(rr, 0); 642 SSL3_RECORD_set_read(rr); 643 goto start; 644 } 645 646 /* 647 * Unexpected handshake message (Client Hello, or protocol violation) 648 */ 649 if ((SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) && 650 !ossl_statem_get_in_handshake(s)) { 651 struct hm_header_st msg_hdr; 652 653 /* 654 * This may just be a stale retransmit. Also sanity check that we have 655 * at least enough record bytes for a message header 656 */ 657 if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch 658 || SSL3_RECORD_get_length(rr) < DTLS1_HM_HEADER_LENGTH) { 659 SSL3_RECORD_set_length(rr, 0); 660 SSL3_RECORD_set_read(rr); 661 goto start; 662 } 663 664 dtls1_get_message_header(rr->data, &msg_hdr); 665 666 /* 667 * If we are server, we may have a repeated FINISHED of the client 668 * here, then retransmit our CCS and FINISHED. 669 */ 670 if (msg_hdr.type == SSL3_MT_FINISHED) { 671 if (dtls1_check_timeout_num(s) < 0) { 672 /* SSLfatal) already called */ 673 return -1; 674 } 675 676 if (dtls1_retransmit_buffered_messages(s) <= 0) { 677 /* Fail if we encountered a fatal error */ 678 if (ossl_statem_in_error(s)) 679 return -1; 680 } 681 SSL3_RECORD_set_length(rr, 0); 682 SSL3_RECORD_set_read(rr); 683 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 684 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) { 685 /* no read-ahead left? */ 686 BIO *bio; 687 688 s->rwstate = SSL_READING; 689 bio = SSL_get_rbio(s); 690 BIO_clear_retry_flags(bio); 691 BIO_set_retry_read(bio); 692 return -1; 693 } 694 } 695 goto start; 696 } 697 698 /* 699 * To get here we must be trying to read app data but found handshake 700 * data. But if we're trying to read app data, and we're not in init 701 * (which is tested for at the top of this function) then init must be 702 * finished 703 */ 704 if (!ossl_assert(SSL_is_init_finished(s))) { 705 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES, 706 ERR_R_INTERNAL_ERROR); 707 return -1; 708 } 709 710 /* We found handshake data, so we're going back into init */ 711 ossl_statem_set_in_init(s, 1); 712 713 i = s->handshake_func(s); 714 /* SSLfatal() called if appropriate */ 715 if (i < 0) 716 return i; 717 if (i == 0) 718 return -1; 719 720 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 721 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) { 722 /* no read-ahead left? */ 723 BIO *bio; 724 /* 725 * In the case where we try to read application data, but we 726 * trigger an SSL handshake, we return -1 with the retry 727 * option set. Otherwise renegotiation may cause nasty 728 * problems in the blocking world 729 */ 730 s->rwstate = SSL_READING; 731 bio = SSL_get_rbio(s); 732 BIO_clear_retry_flags(bio); 733 BIO_set_retry_read(bio); 734 return -1; 735 } 736 } 737 goto start; 738 } 739 740 switch (SSL3_RECORD_get_type(rr)) { 741 default: 742 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES, 743 SSL_R_UNEXPECTED_RECORD); 744 return -1; 745 case SSL3_RT_CHANGE_CIPHER_SPEC: 746 case SSL3_RT_ALERT: 747 case SSL3_RT_HANDSHAKE: 748 /* 749 * we already handled all of these, with the possible exception of 750 * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but 751 * that should not happen when type != rr->type 752 */ 753 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES, 754 ERR_R_INTERNAL_ERROR); 755 return -1; 756 case SSL3_RT_APPLICATION_DATA: 757 /* 758 * At this point, we were expecting handshake data, but have 759 * application data. If the library was running inside ssl3_read() 760 * (i.e. in_read_app_data is set) and it makes sense to read 761 * application data at this point (session renegotiation not yet 762 * started), we will indulge it. 763 */ 764 if (s->s3->in_read_app_data && 765 (s->s3->total_renegotiations != 0) && 766 ossl_statem_app_data_allowed(s)) { 767 s->s3->in_read_app_data = 2; 768 return -1; 769 } else { 770 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES, 771 SSL_R_UNEXPECTED_RECORD); 772 return -1; 773 } 774 } 775 /* not reached */ 776 } 777 778 /* 779 * Call this to write data in records of type 'type' It will return <= 0 if 780 * not all data has been sent or non-blocking IO. 781 */ 782 int dtls1_write_bytes(SSL *s, int type, const void *buf, size_t len, 783 size_t *written) 784 { 785 int i; 786 787 if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) { 788 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_WRITE_BYTES, 789 ERR_R_INTERNAL_ERROR); 790 return -1; 791 } 792 s->rwstate = SSL_NOTHING; 793 i = do_dtls1_write(s, type, buf, len, 0, written); 794 return i; 795 } 796 797 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 798 size_t len, int create_empty_fragment, size_t *written) 799 { 800 unsigned char *p, *pseq; 801 int i, mac_size, clear = 0; 802 size_t prefix_len = 0; 803 int eivlen; 804 SSL3_RECORD wr; 805 SSL3_BUFFER *wb; 806 SSL_SESSION *sess; 807 808 wb = &s->rlayer.wbuf[0]; 809 810 /* 811 * first check if there is a SSL3_BUFFER still being written out. This 812 * will happen with non blocking IO 813 */ 814 if (!ossl_assert(SSL3_BUFFER_get_left(wb) == 0)) { 815 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE, 816 ERR_R_INTERNAL_ERROR); 817 return 0; 818 } 819 820 /* If we have an alert to send, lets send it */ 821 if (s->s3->alert_dispatch) { 822 i = s->method->ssl_dispatch_alert(s); 823 if (i <= 0) 824 return i; 825 /* if it went, fall through and send more stuff */ 826 } 827 828 if (len == 0 && !create_empty_fragment) 829 return 0; 830 831 if (len > ssl_get_max_send_fragment(s)) { 832 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE, 833 SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE); 834 return 0; 835 } 836 837 sess = s->session; 838 839 if ((sess == NULL) || 840 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL)) 841 clear = 1; 842 843 if (clear) 844 mac_size = 0; 845 else { 846 mac_size = EVP_MD_CTX_size(s->write_hash); 847 if (mac_size < 0) { 848 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE, 849 SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE); 850 return -1; 851 } 852 } 853 854 p = SSL3_BUFFER_get_buf(wb) + prefix_len; 855 856 /* write the header */ 857 858 *(p++) = type & 0xff; 859 SSL3_RECORD_set_type(&wr, type); 860 /* 861 * Special case: for hello verify request, client version 1.0 and we 862 * haven't decided which version to use yet send back using version 1.0 863 * header: otherwise some clients will ignore it. 864 */ 865 if (s->method->version == DTLS_ANY_VERSION && 866 s->max_proto_version != DTLS1_BAD_VER) { 867 *(p++) = DTLS1_VERSION >> 8; 868 *(p++) = DTLS1_VERSION & 0xff; 869 } else { 870 *(p++) = s->version >> 8; 871 *(p++) = s->version & 0xff; 872 } 873 874 /* field where we are to write out packet epoch, seq num and len */ 875 pseq = p; 876 p += 10; 877 878 /* Explicit IV length, block ciphers appropriate version flag */ 879 if (s->enc_write_ctx) { 880 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx); 881 if (mode == EVP_CIPH_CBC_MODE) { 882 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx); 883 if (eivlen <= 1) 884 eivlen = 0; 885 } 886 /* Need explicit part of IV for GCM mode */ 887 else if (mode == EVP_CIPH_GCM_MODE) 888 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN; 889 else if (mode == EVP_CIPH_CCM_MODE) 890 eivlen = EVP_CCM_TLS_EXPLICIT_IV_LEN; 891 else 892 eivlen = 0; 893 } else 894 eivlen = 0; 895 896 /* lets setup the record stuff. */ 897 SSL3_RECORD_set_data(&wr, p + eivlen); /* make room for IV in case of CBC */ 898 SSL3_RECORD_set_length(&wr, len); 899 SSL3_RECORD_set_input(&wr, (unsigned char *)buf); 900 901 /* 902 * we now 'read' from wr.input, wr.length bytes into wr.data 903 */ 904 905 /* first we compress */ 906 if (s->compress != NULL) { 907 if (!ssl3_do_compress(s, &wr)) { 908 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE, 909 SSL_R_COMPRESSION_FAILURE); 910 return -1; 911 } 912 } else { 913 memcpy(SSL3_RECORD_get_data(&wr), SSL3_RECORD_get_input(&wr), 914 SSL3_RECORD_get_length(&wr)); 915 SSL3_RECORD_reset_input(&wr); 916 } 917 918 /* 919 * we should still have the output to wr.data and the input from 920 * wr.input. Length should be wr.length. wr.data still points in the 921 * wb->buf 922 */ 923 924 if (!SSL_WRITE_ETM(s) && mac_size != 0) { 925 if (!s->method->ssl3_enc->mac(s, &wr, 926 &(p[SSL3_RECORD_get_length(&wr) + eivlen]), 927 1)) { 928 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE, 929 ERR_R_INTERNAL_ERROR); 930 return -1; 931 } 932 SSL3_RECORD_add_length(&wr, mac_size); 933 } 934 935 /* this is true regardless of mac size */ 936 SSL3_RECORD_set_data(&wr, p); 937 SSL3_RECORD_reset_input(&wr); 938 939 if (eivlen) 940 SSL3_RECORD_add_length(&wr, eivlen); 941 942 if (s->method->ssl3_enc->enc(s, &wr, 1, 1) < 1) { 943 if (!ossl_statem_in_error(s)) { 944 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE, 945 ERR_R_INTERNAL_ERROR); 946 } 947 return -1; 948 } 949 950 if (SSL_WRITE_ETM(s) && mac_size != 0) { 951 if (!s->method->ssl3_enc->mac(s, &wr, 952 &(p[SSL3_RECORD_get_length(&wr)]), 1)) { 953 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE, 954 ERR_R_INTERNAL_ERROR); 955 return -1; 956 } 957 SSL3_RECORD_add_length(&wr, mac_size); 958 } 959 960 /* record length after mac and block padding */ 961 962 /* there's only one epoch between handshake and app data */ 963 964 s2n(s->rlayer.d->w_epoch, pseq); 965 966 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6); 967 pseq += 6; 968 s2n(SSL3_RECORD_get_length(&wr), pseq); 969 970 if (s->msg_callback) 971 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, 972 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg); 973 974 /* 975 * we should now have wr.data pointing to the encrypted data, which is 976 * wr->length long 977 */ 978 SSL3_RECORD_set_type(&wr, type); /* not needed but helps for debugging */ 979 SSL3_RECORD_add_length(&wr, DTLS1_RT_HEADER_LENGTH); 980 981 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0])); 982 983 if (create_empty_fragment) { 984 /* 985 * we are in a recursive call; just return the length, don't write 986 * out anything here 987 */ 988 *written = wr.length; 989 return 1; 990 } 991 992 /* now let's set up wb */ 993 SSL3_BUFFER_set_left(wb, prefix_len + SSL3_RECORD_get_length(&wr)); 994 SSL3_BUFFER_set_offset(wb, 0); 995 996 /* 997 * memorize arguments so that ssl3_write_pending can detect bad write 998 * retries later 999 */ 1000 s->rlayer.wpend_tot = len; 1001 s->rlayer.wpend_buf = buf; 1002 s->rlayer.wpend_type = type; 1003 s->rlayer.wpend_ret = len; 1004 1005 /* we now just need to write the buffer. Calls SSLfatal() as required. */ 1006 return ssl3_write_pending(s, type, buf, len, written); 1007 } 1008 1009 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 1010 unsigned int *is_next_epoch) 1011 { 1012 1013 *is_next_epoch = 0; 1014 1015 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1016 if (rr->epoch == s->rlayer.d->r_epoch) 1017 return &s->rlayer.d->bitmap; 1018 1019 /* 1020 * Only HM and ALERT messages can be from the next epoch and only if we 1021 * have already processed all of the unprocessed records from the last 1022 * epoch 1023 */ 1024 else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) && 1025 s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch && 1026 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1027 *is_next_epoch = 1; 1028 return &s->rlayer.d->next_bitmap; 1029 } 1030 1031 return NULL; 1032 } 1033 1034 void dtls1_reset_seq_numbers(SSL *s, int rw) 1035 { 1036 unsigned char *seq; 1037 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence); 1038 1039 if (rw & SSL3_CC_READ) { 1040 seq = s->rlayer.read_sequence; 1041 s->rlayer.d->r_epoch++; 1042 memcpy(&s->rlayer.d->bitmap, &s->rlayer.d->next_bitmap, 1043 sizeof(s->rlayer.d->bitmap)); 1044 memset(&s->rlayer.d->next_bitmap, 0, sizeof(s->rlayer.d->next_bitmap)); 1045 1046 /* 1047 * We must not use any buffered messages received from the previous 1048 * epoch 1049 */ 1050 dtls1_clear_received_buffer(s); 1051 } else { 1052 seq = s->rlayer.write_sequence; 1053 memcpy(s->rlayer.d->last_write_sequence, seq, 1054 sizeof(s->rlayer.write_sequence)); 1055 s->rlayer.d->w_epoch++; 1056 } 1057 1058 memset(seq, 0, seq_bytes); 1059 } 1060