d1_pkt.c revision 306230
1/* ssl/d1_pkt.c */ 2/* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1998-2005 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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116#include <stdio.h> 117#include <errno.h> 118#define USE_SOCKETS 119#include "ssl_locl.h" 120#include <openssl/evp.h> 121#include <openssl/buffer.h> 122#include <openssl/pqueue.h> 123#include <openssl/rand.h> 124 125/* mod 128 saturating subtract of two 64-bit values in big-endian order */ 126static int satsub64be(const unsigned char *v1, const unsigned char *v2) 127{ 128 int ret, sat, brw, i; 129 130 if (sizeof(long) == 8) 131 do { 132 const union { 133 long one; 134 char little; 135 } is_endian = { 136 1 137 }; 138 long l; 139 140 if (is_endian.little) 141 break; 142 /* not reached on little-endians */ 143 /* 144 * following test is redundant, because input is always aligned, 145 * but I take no chances... 146 */ 147 if (((size_t)v1 | (size_t)v2) & 0x7) 148 break; 149 150 l = *((long *)v1); 151 l -= *((long *)v2); 152 if (l > 128) 153 return 128; 154 else if (l < -128) 155 return -128; 156 else 157 return (int)l; 158 } while (0); 159 160 ret = (int)v1[7] - (int)v2[7]; 161 sat = 0; 162 brw = ret >> 8; /* brw is either 0 or -1 */ 163 if (ret & 0x80) { 164 for (i = 6; i >= 0; i--) { 165 brw += (int)v1[i] - (int)v2[i]; 166 sat |= ~brw; 167 brw >>= 8; 168 } 169 } else { 170 for (i = 6; i >= 0; i--) { 171 brw += (int)v1[i] - (int)v2[i]; 172 sat |= brw; 173 brw >>= 8; 174 } 175 } 176 brw <<= 8; /* brw is either 0 or -256 */ 177 178 if (sat & 0xff) 179 return brw | 0x80; 180 else 181 return brw + (ret & 0xFF); 182} 183 184static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 185 int len, int peek); 186static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 187static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 188static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 189 unsigned int *is_next_epoch); 190#if 0 191static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 192 unsigned short *priority, 193 unsigned long *offset); 194#endif 195static int dtls1_buffer_record(SSL *s, record_pqueue *q, 196 unsigned char *priority); 197static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap); 198 199/* copy buffered record into SSL structure */ 200static int dtls1_copy_record(SSL *s, pitem *item) 201{ 202 DTLS1_RECORD_DATA *rdata; 203 204 rdata = (DTLS1_RECORD_DATA *)item->data; 205 206 if (s->s3->rbuf.buf != NULL) 207 OPENSSL_free(s->s3->rbuf.buf); 208 209 s->packet = rdata->packet; 210 s->packet_length = rdata->packet_length; 211 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 212 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 213 214 /* Set proper sequence number for mac calculation */ 215 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 216 217 return (1); 218} 219 220static int 221dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 222{ 223 DTLS1_RECORD_DATA *rdata; 224 pitem *item; 225 226 /* Limit the size of the queue to prevent DOS attacks */ 227 if (pqueue_size(queue->q) >= 100) 228 return 0; 229 230 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 231 item = pitem_new(priority, rdata); 232 if (rdata == NULL || item == NULL) { 233 if (rdata != NULL) 234 OPENSSL_free(rdata); 235 if (item != NULL) 236 pitem_free(item); 237 238 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 239 return -1; 240 } 241 242 rdata->packet = s->packet; 243 rdata->packet_length = s->packet_length; 244 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 245 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 246 247 item->data = rdata; 248 249#ifndef OPENSSL_NO_SCTP 250 /* Store bio_dgram_sctp_rcvinfo struct */ 251 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 252 (s->state == SSL3_ST_SR_FINISHED_A 253 || s->state == SSL3_ST_CR_FINISHED_A)) { 254 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, 255 sizeof(rdata->recordinfo), &rdata->recordinfo); 256 } 257#endif 258 259 s->packet = NULL; 260 s->packet_length = 0; 261 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 262 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 263 264 if (!ssl3_setup_buffers(s)) { 265 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 266 if (rdata->rbuf.buf != NULL) 267 OPENSSL_free(rdata->rbuf.buf); 268 OPENSSL_free(rdata); 269 pitem_free(item); 270 return (-1); 271 } 272 273 /* insert should not fail, since duplicates are dropped */ 274 if (pqueue_insert(queue->q, item) == NULL) { 275 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 276 if (rdata->rbuf.buf != NULL) 277 OPENSSL_free(rdata->rbuf.buf); 278 OPENSSL_free(rdata); 279 pitem_free(item); 280 return (-1); 281 } 282 283 return (1); 284} 285 286static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 287{ 288 pitem *item; 289 290 item = pqueue_pop(queue->q); 291 if (item) { 292 dtls1_copy_record(s, item); 293 294 OPENSSL_free(item->data); 295 pitem_free(item); 296 297 return (1); 298 } 299 300 return (0); 301} 302 303/* 304 * retrieve a buffered record that belongs to the new epoch, i.e., not 305 * processed yet 306 */ 307#define dtls1_get_unprocessed_record(s) \ 308 dtls1_retrieve_buffered_record((s), \ 309 &((s)->d1->unprocessed_rcds)) 310 311/* 312 * retrieve a buffered record that belongs to the current epoch, ie, 313 * processed 314 */ 315#define dtls1_get_processed_record(s) \ 316 dtls1_retrieve_buffered_record((s), \ 317 &((s)->d1->processed_rcds)) 318 319static int dtls1_process_buffered_records(SSL *s) 320{ 321 pitem *item; 322 SSL3_BUFFER *rb; 323 SSL3_RECORD *rr; 324 DTLS1_BITMAP *bitmap; 325 unsigned int is_next_epoch; 326 int replayok = 1; 327 328 item = pqueue_peek(s->d1->unprocessed_rcds.q); 329 if (item) { 330 /* Check if epoch is current. */ 331 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 332 return 1; /* Nothing to do. */ 333 334 rr = &s->s3->rrec; 335 rb = &s->s3->rbuf; 336 337 if (rb->left > 0) { 338 /* 339 * We've still got data from the current packet to read. There could 340 * be a record from the new epoch in it - so don't overwrite it 341 * with the unprocessed records yet (we'll do it when we've 342 * finished reading the current packet). 343 */ 344 return 1; 345 } 346 347 348 /* Process all the records. */ 349 while (pqueue_peek(s->d1->unprocessed_rcds.q)) { 350 dtls1_get_unprocessed_record(s); 351 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 352 if (bitmap == NULL) { 353 /* 354 * Should not happen. This will only ever be NULL when the 355 * current record is from a different epoch. But that cannot 356 * be the case because we already checked the epoch above 357 */ 358 SSLerr(SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS, 359 ERR_R_INTERNAL_ERROR); 360 return 0; 361 } 362#ifndef OPENSSL_NO_SCTP 363 /* Only do replay check if no SCTP bio */ 364 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) 365#endif 366 { 367 /* 368 * Check whether this is a repeat, or aged record. We did this 369 * check once already when we first received the record - but 370 * we might have updated the window since then due to 371 * records we subsequently processed. 372 */ 373 replayok = dtls1_record_replay_check(s, bitmap); 374 } 375 376 if (!replayok || !dtls1_process_record(s, bitmap)) { 377 /* dump this record */ 378 rr->length = 0; 379 s->packet_length = 0; 380 continue; 381 } 382 383 if (dtls1_buffer_record(s, &(s->d1->processed_rcds), 384 s->s3->rrec.seq_num) < 0) 385 return 0; 386 } 387 } 388 389 /* 390 * sync epoch numbers once all the unprocessed records have been 391 * processed 392 */ 393 s->d1->processed_rcds.epoch = s->d1->r_epoch; 394 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 395 396 return 1; 397} 398 399#if 0 400 401static int dtls1_get_buffered_record(SSL *s) 402{ 403 pitem *item; 404 PQ_64BIT priority = 405 (((PQ_64BIT) s->d1->handshake_read_seq) << 32) | 406 ((PQ_64BIT) s->d1->r_msg_hdr.frag_off); 407 408 /* if we're not (re)negotiating, nothing buffered */ 409 if (!SSL_in_init(s)) 410 return 0; 411 412 item = pqueue_peek(s->d1->rcvd_records); 413 if (item && item->priority == priority) { 414 /* 415 * Check if we've received the record of interest. It must be a 416 * handshake record, since data records as passed up without 417 * buffering 418 */ 419 DTLS1_RECORD_DATA *rdata; 420 item = pqueue_pop(s->d1->rcvd_records); 421 rdata = (DTLS1_RECORD_DATA *)item->data; 422 423 if (s->s3->rbuf.buf != NULL) 424 OPENSSL_free(s->s3->rbuf.buf); 425 426 s->packet = rdata->packet; 427 s->packet_length = rdata->packet_length; 428 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 429 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 430 431 OPENSSL_free(item->data); 432 pitem_free(item); 433 434 /* s->d1->next_expected_seq_num++; */ 435 return (1); 436 } 437 438 return 0; 439} 440 441#endif 442 443static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap) 444{ 445 int i, al; 446 int enc_err; 447 SSL_SESSION *sess; 448 SSL3_RECORD *rr; 449 unsigned int mac_size, orig_len; 450 unsigned char md[EVP_MAX_MD_SIZE]; 451 452 rr = &(s->s3->rrec); 453 sess = s->session; 454 455 /* 456 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 457 * and we have that many bytes in s->packet 458 */ 459 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]); 460 461 /* 462 * ok, we can now read from 's->packet' data into 'rr' rr->input points 463 * at rr->length bytes, which need to be copied into rr->data by either 464 * the decryption or by the decompression When the data is 'copied' into 465 * the rr->data buffer, rr->input will be pointed at the new buffer 466 */ 467 468 /* 469 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length 470 * bytes of encrypted compressed stuff. 471 */ 472 473 /* check is not needed I believe */ 474 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 475 al = SSL_AD_RECORD_OVERFLOW; 476 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 477 goto f_err; 478 } 479 480 /* decrypt in place in 'rr->input' */ 481 rr->data = rr->input; 482 483 enc_err = s->method->ssl3_enc->enc(s, 0); 484 /*- 485 * enc_err is: 486 * 0: (in non-constant time) if the record is publically invalid. 487 * 1: if the padding is valid 488 * -1: if the padding is invalid 489 */ 490 if (enc_err == 0) { 491 /* For DTLS we simply ignore bad packets. */ 492 rr->length = 0; 493 s->packet_length = 0; 494 goto err; 495 } 496#ifdef TLS_DEBUG 497 printf("dec %d\n", rr->length); 498 { 499 unsigned int z; 500 for (z = 0; z < rr->length; z++) 501 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); 502 } 503 printf("\n"); 504#endif 505 506 /* r->length is now the compressed data plus mac */ 507 if ((sess != NULL) && 508 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) { 509 /* s->read_hash != NULL => mac_size != -1 */ 510 unsigned char *mac = NULL; 511 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 512 mac_size = EVP_MD_CTX_size(s->read_hash); 513 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 514 515 /* 516 * kludge: *_cbc_remove_padding passes padding length in rr->type 517 */ 518 orig_len = rr->length + ((unsigned int)rr->type >> 8); 519 520 /* 521 * orig_len is the length of the record before any padding was 522 * removed. This is public information, as is the MAC in use, 523 * therefore we can safely process the record in a different amount 524 * of time if it's too short to possibly contain a MAC. 525 */ 526 if (orig_len < mac_size || 527 /* CBC records must have a padding length byte too. */ 528 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 529 orig_len < mac_size + 1)) { 530 al = SSL_AD_DECODE_ERROR; 531 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT); 532 goto f_err; 533 } 534 535 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 536 /* 537 * We update the length so that the TLS header bytes can be 538 * constructed correctly but we need to extract the MAC in 539 * constant time from within the record, without leaking the 540 * contents of the padding bytes. 541 */ 542 mac = mac_tmp; 543 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 544 rr->length -= mac_size; 545 } else { 546 /* 547 * In this case there's no padding, so |orig_len| equals 548 * |rec->length| and we checked that there's enough bytes for 549 * |mac_size| above. 550 */ 551 rr->length -= mac_size; 552 mac = &rr->data[rr->length]; 553 } 554 555 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ ); 556 if (i < 0 || mac == NULL 557 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 558 enc_err = -1; 559 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 560 enc_err = -1; 561 } 562 563 if (enc_err < 0) { 564 /* decryption failed, silently discard message */ 565 rr->length = 0; 566 s->packet_length = 0; 567 goto err; 568 } 569 570 /* r->length is now just compressed */ 571 if (s->expand != NULL) { 572 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) { 573 al = SSL_AD_RECORD_OVERFLOW; 574 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, 575 SSL_R_COMPRESSED_LENGTH_TOO_LONG); 576 goto f_err; 577 } 578 if (!ssl3_do_uncompress(s)) { 579 al = SSL_AD_DECOMPRESSION_FAILURE; 580 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION); 581 goto f_err; 582 } 583 } 584 585 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 586 al = SSL_AD_RECORD_OVERFLOW; 587 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); 588 goto f_err; 589 } 590 591 rr->off = 0; 592 /*- 593 * So at this point the following is true 594 * ssl->s3->rrec.type is the type of record 595 * ssl->s3->rrec.length == number of bytes in record 596 * ssl->s3->rrec.off == offset to first valid byte 597 * ssl->s3->rrec.data == where to take bytes from, increment 598 * after use :-). 599 */ 600 601 /* we have pulled in a full packet so zero things */ 602 s->packet_length = 0; 603 604 /* Mark receipt of record. */ 605 dtls1_record_bitmap_update(s, bitmap); 606 607 return (1); 608 609 f_err: 610 ssl3_send_alert(s, SSL3_AL_FATAL, al); 611 err: 612 return (0); 613} 614 615/*- 616 * Call this to get a new input record. 617 * It will return <= 0 if more data is needed, normally due to an error 618 * or non-blocking IO. 619 * When it finishes, one packet has been decoded and can be found in 620 * ssl->s3->rrec.type - is the type of record 621 * ssl->s3->rrec.data, - data 622 * ssl->s3->rrec.length, - number of bytes 623 */ 624/* used only by dtls1_read_bytes */ 625int dtls1_get_record(SSL *s) 626{ 627 int ssl_major, ssl_minor; 628 int i, n; 629 SSL3_RECORD *rr; 630 unsigned char *p = NULL; 631 unsigned short version; 632 DTLS1_BITMAP *bitmap; 633 unsigned int is_next_epoch; 634 635 rr = &(s->s3->rrec); 636 637 again: 638 /* 639 * The epoch may have changed. If so, process all the pending records. 640 * This is a non-blocking operation. 641 */ 642 if (!dtls1_process_buffered_records(s)) 643 return -1; 644 645 /* if we're renegotiating, then there may be buffered records */ 646 if (dtls1_get_processed_record(s)) 647 return 1; 648 649 /* get something from the wire */ 650 /* check if we have the header */ 651 if ((s->rstate != SSL_ST_READ_BODY) || 652 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { 653 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 654 /* read timeout is handled by dtls1_read_bytes */ 655 if (n <= 0) 656 return (n); /* error or non-blocking */ 657 658 /* this packet contained a partial record, dump it */ 659 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) { 660 s->packet_length = 0; 661 goto again; 662 } 663 664 s->rstate = SSL_ST_READ_BODY; 665 666 p = s->packet; 667 668 /* Pull apart the header into the DTLS1_RECORD */ 669 rr->type = *(p++); 670 ssl_major = *(p++); 671 ssl_minor = *(p++); 672 version = (ssl_major << 8) | ssl_minor; 673 674 /* sequence number is 64 bits, with top 2 bytes = epoch */ 675 n2s(p, rr->epoch); 676 677 memcpy(&(s->s3->read_sequence[2]), p, 6); 678 p += 6; 679 680 n2s(p, rr->length); 681 682 /* Lets check version */ 683 if (!s->first_packet) { 684 if (version != s->version) { 685 /* unexpected version, silently discard */ 686 rr->length = 0; 687 s->packet_length = 0; 688 goto again; 689 } 690 } 691 692 if ((version & 0xff00) != (s->version & 0xff00)) { 693 /* wrong version, silently discard record */ 694 rr->length = 0; 695 s->packet_length = 0; 696 goto again; 697 } 698 699 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 700 /* record too long, silently discard it */ 701 rr->length = 0; 702 s->packet_length = 0; 703 goto again; 704 } 705 706 /* now s->rstate == SSL_ST_READ_BODY */ 707 } 708 709 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 710 711 if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) { 712 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 713 i = rr->length; 714 n = ssl3_read_n(s, i, i, 1); 715 /* this packet contained a partial record, dump it */ 716 if (n != i) { 717 rr->length = 0; 718 s->packet_length = 0; 719 goto again; 720 } 721 722 /* 723 * now n == rr->length, and s->packet_length == 724 * DTLS1_RT_HEADER_LENGTH + rr->length 725 */ 726 } 727 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 728 729 /* match epochs. NULL means the packet is dropped on the floor */ 730 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 731 if (bitmap == NULL) { 732 rr->length = 0; 733 s->packet_length = 0; /* dump this record */ 734 goto again; /* get another record */ 735 } 736#ifndef OPENSSL_NO_SCTP 737 /* Only do replay check if no SCTP bio */ 738 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) { 739#endif 740 /* 741 * Check whether this is a repeat, or aged record. Don't check if 742 * we're listening and this message is a ClientHello. They can look 743 * as if they're replayed, since they arrive from different 744 * connections and would be dropped unnecessarily. 745 */ 746 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 747 s->packet_length > DTLS1_RT_HEADER_LENGTH && 748 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) && 749 !dtls1_record_replay_check(s, bitmap)) { 750 rr->length = 0; 751 s->packet_length = 0; /* dump this record */ 752 goto again; /* get another record */ 753 } 754#ifndef OPENSSL_NO_SCTP 755 } 756#endif 757 758 /* just read a 0 length packet */ 759 if (rr->length == 0) 760 goto again; 761 762 /* 763 * If this record is from the next epoch (either HM or ALERT), and a 764 * handshake is currently in progress, buffer it since it cannot be 765 * processed at this time. However, do not buffer anything while 766 * listening. 767 */ 768 if (is_next_epoch) { 769 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) { 770 if (dtls1_buffer_record 771 (s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0) 772 return -1; 773 } 774 rr->length = 0; 775 s->packet_length = 0; 776 goto again; 777 } 778 779 if (!dtls1_process_record(s, bitmap)) { 780 rr->length = 0; 781 s->packet_length = 0; /* dump this record */ 782 goto again; /* get another record */ 783 } 784 785 return (1); 786 787} 788 789/*- 790 * Return up to 'len' payload bytes received in 'type' records. 791 * 'type' is one of the following: 792 * 793 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 794 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 795 * - 0 (during a shutdown, no data has to be returned) 796 * 797 * If we don't have stored data to work from, read a SSL/TLS record first 798 * (possibly multiple records if we still don't have anything to return). 799 * 800 * This function must handle any surprises the peer may have for us, such as 801 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 802 * a surprise, but handled as if it were), or renegotiation requests. 803 * Also if record payloads contain fragments too small to process, we store 804 * them until there is enough for the respective protocol (the record protocol 805 * may use arbitrary fragmentation and even interleaving): 806 * Change cipher spec protocol 807 * just 1 byte needed, no need for keeping anything stored 808 * Alert protocol 809 * 2 bytes needed (AlertLevel, AlertDescription) 810 * Handshake protocol 811 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 812 * to detect unexpected Client Hello and Hello Request messages 813 * here, anything else is handled by higher layers 814 * Application data protocol 815 * none of our business 816 */ 817int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 818{ 819 int al, i, j, ret; 820 unsigned int n; 821 SSL3_RECORD *rr; 822 void (*cb) (const SSL *ssl, int type2, int val) = NULL; 823 824 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 825 if (!ssl3_setup_buffers(s)) 826 return (-1); 827 828 /* XXX: check what the second '&& type' is about */ 829 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 830 (type != SSL3_RT_HANDSHAKE) && type) || 831 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 832 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 833 return -1; 834 } 835 836 /* 837 * check whether there's a handshake message (client hello?) waiting 838 */ 839 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 840 return ret; 841 842 /* 843 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. 844 */ 845 846#ifndef OPENSSL_NO_SCTP 847 /* 848 * Continue handshake if it had to be interrupted to read app data with 849 * SCTP. 850 */ 851 if ((!s->in_handshake && SSL_in_init(s)) || 852 (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 853 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK 854 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) 855 && s->s3->in_read_app_data != 2)) 856#else 857 if (!s->in_handshake && SSL_in_init(s)) 858#endif 859 { 860 /* type == SSL3_RT_APPLICATION_DATA */ 861 i = s->handshake_func(s); 862 if (i < 0) 863 return (i); 864 if (i == 0) { 865 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 866 return (-1); 867 } 868 } 869 870 start: 871 s->rwstate = SSL_NOTHING; 872 873 /*- 874 * s->s3->rrec.type - is the type of record 875 * s->s3->rrec.data, - data 876 * s->s3->rrec.off, - offset into 'data' for next read 877 * s->s3->rrec.length, - number of bytes. 878 */ 879 rr = &(s->s3->rrec); 880 881 /* 882 * We are not handshaking and have no data yet, so process data buffered 883 * during the last handshake in advance, if any. 884 */ 885 if (s->state == SSL_ST_OK && rr->length == 0) { 886 pitem *item; 887 item = pqueue_pop(s->d1->buffered_app_data.q); 888 if (item) { 889#ifndef OPENSSL_NO_SCTP 890 /* Restore bio_dgram_sctp_rcvinfo struct */ 891 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) { 892 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data; 893 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, 894 sizeof(rdata->recordinfo), &rdata->recordinfo); 895 } 896#endif 897 898 dtls1_copy_record(s, item); 899 900 OPENSSL_free(item->data); 901 pitem_free(item); 902 } 903 } 904 905 /* Check for timeout */ 906 if (dtls1_handle_timeout(s) > 0) 907 goto start; 908 909 /* get new packet if necessary */ 910 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) { 911 ret = dtls1_get_record(s); 912 if (ret <= 0) { 913 ret = dtls1_read_failed(s, ret); 914 /* anything other than a timeout is an error */ 915 if (ret <= 0) 916 return (ret); 917 else 918 goto start; 919 } 920 } 921 922 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) { 923 rr->length = 0; 924 goto start; 925 } 926 927 /* we now have a packet which can be read and processed */ 928 929 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 930 * reset by ssl3_get_finished */ 931 && (rr->type != SSL3_RT_HANDSHAKE)) { 932 /* 933 * We now have application data between CCS and Finished. Most likely 934 * the packets were reordered on their way, so buffer the application 935 * data for later processing rather than dropping the connection. 936 */ 937 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) < 938 0) { 939 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 940 return -1; 941 } 942 rr->length = 0; 943 goto start; 944 } 945 946 /* 947 * If the other end has shut down, throw anything we read away (even in 948 * 'peek' mode) 949 */ 950 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 951 rr->length = 0; 952 s->rwstate = SSL_NOTHING; 953 return (0); 954 } 955 956 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or 957 * SSL3_RT_HANDSHAKE */ 958 /* 959 * make sure that we are not getting application data when we are 960 * doing a handshake for the first time 961 */ 962 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 963 (s->enc_read_ctx == NULL)) { 964 al = SSL_AD_UNEXPECTED_MESSAGE; 965 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE); 966 goto f_err; 967 } 968 969 if (len <= 0) 970 return (len); 971 972 if ((unsigned int)len > rr->length) 973 n = rr->length; 974 else 975 n = (unsigned int)len; 976 977 memcpy(buf, &(rr->data[rr->off]), n); 978 if (!peek) { 979 rr->length -= n; 980 rr->off += n; 981 if (rr->length == 0) { 982 s->rstate = SSL_ST_READ_HEADER; 983 rr->off = 0; 984 } 985 } 986#ifndef OPENSSL_NO_SCTP 987 /* 988 * We were about to renegotiate but had to read belated application 989 * data first, so retry. 990 */ 991 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 992 rr->type == SSL3_RT_APPLICATION_DATA && 993 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK 994 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) { 995 s->rwstate = SSL_READING; 996 BIO_clear_retry_flags(SSL_get_rbio(s)); 997 BIO_set_retry_read(SSL_get_rbio(s)); 998 } 999 1000 /* 1001 * We might had to delay a close_notify alert because of reordered 1002 * app data. If there was an alert and there is no message to read 1003 * anymore, finally set shutdown. 1004 */ 1005 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1006 s->d1->shutdown_received 1007 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 1008 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1009 return (0); 1010 } 1011#endif 1012 return (n); 1013 } 1014 1015 /* 1016 * If we get here, then type != rr->type; if we have a handshake message, 1017 * then it was unexpected (Hello Request or Client Hello). 1018 */ 1019 1020 /* 1021 * In case of record types for which we have 'fragment' storage, fill 1022 * that so that we can process the data at a fixed place. 1023 */ 1024 { 1025 unsigned int k, dest_maxlen = 0; 1026 unsigned char *dest = NULL; 1027 unsigned int *dest_len = NULL; 1028 1029 if (rr->type == SSL3_RT_HANDSHAKE) { 1030 dest_maxlen = sizeof s->d1->handshake_fragment; 1031 dest = s->d1->handshake_fragment; 1032 dest_len = &s->d1->handshake_fragment_len; 1033 } else if (rr->type == SSL3_RT_ALERT) { 1034 dest_maxlen = sizeof(s->d1->alert_fragment); 1035 dest = s->d1->alert_fragment; 1036 dest_len = &s->d1->alert_fragment_len; 1037 } 1038#ifndef OPENSSL_NO_HEARTBEATS 1039 else if (rr->type == TLS1_RT_HEARTBEAT) { 1040 dtls1_process_heartbeat(s); 1041 1042 /* Exit and notify application to read again */ 1043 rr->length = 0; 1044 s->rwstate = SSL_READING; 1045 BIO_clear_retry_flags(SSL_get_rbio(s)); 1046 BIO_set_retry_read(SSL_get_rbio(s)); 1047 return (-1); 1048 } 1049#endif 1050 /* else it's a CCS message, or application data or wrong */ 1051 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 1052 /* 1053 * Application data while renegotiating is allowed. Try again 1054 * reading. 1055 */ 1056 if (rr->type == SSL3_RT_APPLICATION_DATA) { 1057 BIO *bio; 1058 s->s3->in_read_app_data = 2; 1059 bio = SSL_get_rbio(s); 1060 s->rwstate = SSL_READING; 1061 BIO_clear_retry_flags(bio); 1062 BIO_set_retry_read(bio); 1063 return (-1); 1064 } 1065 1066 /* Not certain if this is the right error handling */ 1067 al = SSL_AD_UNEXPECTED_MESSAGE; 1068 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1069 goto f_err; 1070 } 1071 1072 if (dest_maxlen > 0) { 1073 /* 1074 * XDTLS: In a pathalogical case, the Client Hello may be 1075 * fragmented--don't always expect dest_maxlen bytes 1076 */ 1077 if (rr->length < dest_maxlen) { 1078#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1079 /* 1080 * for normal alerts rr->length is 2, while 1081 * dest_maxlen is 7 if we were to handle this 1082 * non-existing alert... 1083 */ 1084 FIX ME 1085#endif 1086 s->rstate = SSL_ST_READ_HEADER; 1087 rr->length = 0; 1088 goto start; 1089 } 1090 1091 /* now move 'n' bytes: */ 1092 for (k = 0; k < dest_maxlen; k++) { 1093 dest[k] = rr->data[rr->off++]; 1094 rr->length--; 1095 } 1096 *dest_len = dest_maxlen; 1097 } 1098 } 1099 1100 /*- 1101 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 1102 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 1103 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) 1104 */ 1105 1106 /* If we are a client, check for an incoming 'Hello Request': */ 1107 if ((!s->server) && 1108 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1109 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1110 (s->session != NULL) && (s->session->cipher != NULL)) { 1111 s->d1->handshake_fragment_len = 0; 1112 1113 if ((s->d1->handshake_fragment[1] != 0) || 1114 (s->d1->handshake_fragment[2] != 0) || 1115 (s->d1->handshake_fragment[3] != 0)) { 1116 al = SSL_AD_DECODE_ERROR; 1117 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST); 1118 goto f_err; 1119 } 1120 1121 /* 1122 * no need to check sequence number on HELLO REQUEST messages 1123 */ 1124 1125 if (s->msg_callback) 1126 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1127 s->d1->handshake_fragment, 4, s, 1128 s->msg_callback_arg); 1129 1130 if (SSL_is_init_finished(s) && 1131 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1132 !s->s3->renegotiate) { 1133 s->d1->handshake_read_seq++; 1134 s->new_session = 1; 1135 ssl3_renegotiate(s); 1136 if (ssl3_renegotiate_check(s)) { 1137 i = s->handshake_func(s); 1138 if (i < 0) 1139 return (i); 1140 if (i == 0) { 1141 SSLerr(SSL_F_DTLS1_READ_BYTES, 1142 SSL_R_SSL_HANDSHAKE_FAILURE); 1143 return (-1); 1144 } 1145 1146 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1147 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1148 BIO *bio; 1149 /* 1150 * In the case where we try to read application data, 1151 * but we trigger an SSL handshake, we return -1 with 1152 * the retry option set. Otherwise renegotiation may 1153 * cause nasty problems in the blocking world 1154 */ 1155 s->rwstate = SSL_READING; 1156 bio = SSL_get_rbio(s); 1157 BIO_clear_retry_flags(bio); 1158 BIO_set_retry_read(bio); 1159 return (-1); 1160 } 1161 } 1162 } 1163 } 1164 /* 1165 * we either finished a handshake or ignored the request, now try 1166 * again to obtain the (application) data we were asked for 1167 */ 1168 goto start; 1169 } 1170 1171 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 1172 int alert_level = s->d1->alert_fragment[0]; 1173 int alert_descr = s->d1->alert_fragment[1]; 1174 1175 s->d1->alert_fragment_len = 0; 1176 1177 if (s->msg_callback) 1178 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1179 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1180 1181 if (s->info_callback != NULL) 1182 cb = s->info_callback; 1183 else if (s->ctx->info_callback != NULL) 1184 cb = s->ctx->info_callback; 1185 1186 if (cb != NULL) { 1187 j = (alert_level << 8) | alert_descr; 1188 cb(s, SSL_CB_READ_ALERT, j); 1189 } 1190 1191 if (alert_level == SSL3_AL_WARNING) { 1192 s->s3->warn_alert = alert_descr; 1193 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 1194#ifndef OPENSSL_NO_SCTP 1195 /* 1196 * With SCTP and streams the socket may deliver app data 1197 * after a close_notify alert. We have to check this first so 1198 * that nothing gets discarded. 1199 */ 1200 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1201 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 1202 s->d1->shutdown_received = 1; 1203 s->rwstate = SSL_READING; 1204 BIO_clear_retry_flags(SSL_get_rbio(s)); 1205 BIO_set_retry_read(SSL_get_rbio(s)); 1206 return -1; 1207 } 1208#endif 1209 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1210 return (0); 1211 } 1212#if 0 1213 /* XXX: this is a possible improvement in the future */ 1214 /* now check if it's a missing record */ 1215 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1216 unsigned short seq; 1217 unsigned int frag_off; 1218 unsigned char *p = &(s->d1->alert_fragment[2]); 1219 1220 n2s(p, seq); 1221 n2l3(p, frag_off); 1222 1223 dtls1_retransmit_message(s, 1224 dtls1_get_queue_priority 1225 (frag->msg_header.seq, 0), frag_off, 1226 &found); 1227 if (!found && SSL_in_init(s)) { 1228 /* 1229 * fprintf( stderr,"in init = %d\n", SSL_in_init(s)); 1230 */ 1231 /* 1232 * requested a message not yet sent, send an alert 1233 * ourselves 1234 */ 1235 ssl3_send_alert(s, SSL3_AL_WARNING, 1236 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1237 } 1238 } 1239#endif 1240 } else if (alert_level == SSL3_AL_FATAL) { 1241 char tmp[16]; 1242 1243 s->rwstate = SSL_NOTHING; 1244 s->s3->fatal_alert = alert_descr; 1245 SSLerr(SSL_F_DTLS1_READ_BYTES, 1246 SSL_AD_REASON_OFFSET + alert_descr); 1247 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); 1248 ERR_add_error_data(2, "SSL alert number ", tmp); 1249 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1250 SSL_CTX_remove_session(s->ctx, s->session); 1251 return (0); 1252 } else { 1253 al = SSL_AD_ILLEGAL_PARAMETER; 1254 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE); 1255 goto f_err; 1256 } 1257 1258 goto start; 1259 } 1260 1261 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a 1262 * shutdown */ 1263 s->rwstate = SSL_NOTHING; 1264 rr->length = 0; 1265 return (0); 1266 } 1267 1268 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1269 struct ccs_header_st ccs_hdr; 1270 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1271 1272 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1273 1274 if (s->version == DTLS1_BAD_VER) 1275 ccs_hdr_len = 3; 1276 1277 /* 1278 * 'Change Cipher Spec' is just a single byte, so we know exactly 1279 * what the record payload has to look like 1280 */ 1281 /* XDTLS: check that epoch is consistent */ 1282 if ((rr->length != ccs_hdr_len) || 1283 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 1284 i = SSL_AD_ILLEGAL_PARAMETER; 1285 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1286 goto err; 1287 } 1288 1289 rr->length = 0; 1290 1291 if (s->msg_callback) 1292 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1293 rr->data, 1, s, s->msg_callback_arg); 1294 1295 /* 1296 * We can't process a CCS now, because previous handshake messages 1297 * are still missing, so just drop it. 1298 */ 1299 if (!s->d1->change_cipher_spec_ok) { 1300 goto start; 1301 } 1302 1303 s->d1->change_cipher_spec_ok = 0; 1304 1305 s->s3->change_cipher_spec = 1; 1306 if (!ssl3_do_change_cipher_spec(s)) 1307 goto err; 1308 1309 /* do this whenever CCS is processed */ 1310 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1311 1312 if (s->version == DTLS1_BAD_VER) 1313 s->d1->handshake_read_seq++; 1314 1315#ifndef OPENSSL_NO_SCTP 1316 /* 1317 * Remember that a CCS has been received, so that an old key of 1318 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no 1319 * SCTP is used 1320 */ 1321 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1322#endif 1323 1324 goto start; 1325 } 1326 1327 /* 1328 * Unexpected handshake message (Client Hello, or protocol violation) 1329 */ 1330 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1331 !s->in_handshake) { 1332 struct hm_header_st msg_hdr; 1333 1334 /* this may just be a stale retransmit */ 1335 dtls1_get_message_header(rr->data, &msg_hdr); 1336 if (rr->epoch != s->d1->r_epoch) { 1337 rr->length = 0; 1338 goto start; 1339 } 1340 1341 /* 1342 * If we are server, we may have a repeated FINISHED of the client 1343 * here, then retransmit our CCS and FINISHED. 1344 */ 1345 if (msg_hdr.type == SSL3_MT_FINISHED) { 1346 if (dtls1_check_timeout_num(s) < 0) 1347 return -1; 1348 1349 dtls1_retransmit_buffered_messages(s); 1350 rr->length = 0; 1351 goto start; 1352 } 1353 1354 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) && 1355 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1356#if 0 /* worked only because C operator preferences 1357 * are not as expected (and because this is 1358 * not really needed for clients except for 1359 * detecting protocol violations): */ 1360 s->state = SSL_ST_BEFORE | (s->server) 1361 ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1362#else 1363 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1364#endif 1365 s->renegotiate = 1; 1366 s->new_session = 1; 1367 } 1368 i = s->handshake_func(s); 1369 if (i < 0) 1370 return (i); 1371 if (i == 0) { 1372 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1373 return (-1); 1374 } 1375 1376 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1377 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1378 BIO *bio; 1379 /* 1380 * In the case where we try to read application data, but we 1381 * trigger an SSL handshake, we return -1 with the retry 1382 * option set. Otherwise renegotiation may cause nasty 1383 * problems in the blocking world 1384 */ 1385 s->rwstate = SSL_READING; 1386 bio = SSL_get_rbio(s); 1387 BIO_clear_retry_flags(bio); 1388 BIO_set_retry_read(bio); 1389 return (-1); 1390 } 1391 } 1392 goto start; 1393 } 1394 1395 switch (rr->type) { 1396 default: 1397#ifndef OPENSSL_NO_TLS 1398 /* TLS just ignores unknown message types */ 1399 if (s->version == TLS1_VERSION) { 1400 rr->length = 0; 1401 goto start; 1402 } 1403#endif 1404 al = SSL_AD_UNEXPECTED_MESSAGE; 1405 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1406 goto f_err; 1407 case SSL3_RT_CHANGE_CIPHER_SPEC: 1408 case SSL3_RT_ALERT: 1409 case SSL3_RT_HANDSHAKE: 1410 /* 1411 * we already handled all of these, with the possible exception of 1412 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not 1413 * happen when type != rr->type 1414 */ 1415 al = SSL_AD_UNEXPECTED_MESSAGE; 1416 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 1417 goto f_err; 1418 case SSL3_RT_APPLICATION_DATA: 1419 /* 1420 * At this point, we were expecting handshake data, but have 1421 * application data. If the library was running inside ssl3_read() 1422 * (i.e. in_read_app_data is set) and it makes sense to read 1423 * application data at this point (session renegotiation not yet 1424 * started), we will indulge it. 1425 */ 1426 if (s->s3->in_read_app_data && 1427 (s->s3->total_renegotiations != 0) && 1428 (((s->state & SSL_ST_CONNECT) && 1429 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1430 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1431 ) || ((s->state & SSL_ST_ACCEPT) && 1432 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1433 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1434 ) 1435 )) { 1436 s->s3->in_read_app_data = 2; 1437 return (-1); 1438 } else { 1439 al = SSL_AD_UNEXPECTED_MESSAGE; 1440 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1441 goto f_err; 1442 } 1443 } 1444 /* not reached */ 1445 1446 f_err: 1447 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1448 err: 1449 return (-1); 1450} 1451 1452int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1453{ 1454 int i; 1455 1456#ifndef OPENSSL_NO_SCTP 1457 /* 1458 * Check if we have to continue an interrupted handshake for reading 1459 * belated app data with SCTP. 1460 */ 1461 if ((SSL_in_init(s) && !s->in_handshake) || 1462 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1463 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK 1464 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1465#else 1466 if (SSL_in_init(s) && !s->in_handshake) 1467#endif 1468 { 1469 i = s->handshake_func(s); 1470 if (i < 0) 1471 return (i); 1472 if (i == 0) { 1473 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, 1474 SSL_R_SSL_HANDSHAKE_FAILURE); 1475 return -1; 1476 } 1477 } 1478 1479 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 1480 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG); 1481 return -1; 1482 } 1483 1484 i = dtls1_write_bytes(s, type, buf_, len); 1485 return i; 1486} 1487 1488 /* 1489 * this only happens when a client hello is received and a handshake 1490 * is started. 1491 */ 1492static int 1493have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1494 int len, int peek) 1495{ 1496 1497 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1498 /* (partially) satisfy request from storage */ 1499 { 1500 unsigned char *src = s->d1->handshake_fragment; 1501 unsigned char *dst = buf; 1502 unsigned int k, n; 1503 1504 /* peek == 0 */ 1505 n = 0; 1506 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) { 1507 *dst++ = *src++; 1508 len--; 1509 s->d1->handshake_fragment_len--; 1510 n++; 1511 } 1512 /* move any remaining fragment bytes: */ 1513 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1514 s->d1->handshake_fragment[k] = *src++; 1515 return n; 1516 } 1517 1518 return 0; 1519} 1520 1521/* 1522 * Call this to write data in records of type 'type' It will return <= 0 if 1523 * not all data has been sent or non-blocking IO. 1524 */ 1525int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1526{ 1527 int i; 1528 1529 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1530 s->rwstate = SSL_NOTHING; 1531 i = do_dtls1_write(s, type, buf, len, 0); 1532 return i; 1533} 1534 1535int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 1536 unsigned int len, int create_empty_fragment) 1537{ 1538 unsigned char *p, *pseq; 1539 int i, mac_size, clear = 0; 1540 int prefix_len = 0; 1541 SSL3_RECORD *wr; 1542 SSL3_BUFFER *wb; 1543 SSL_SESSION *sess; 1544 int bs; 1545 1546 /* 1547 * first check if there is a SSL3_BUFFER still being written out. This 1548 * will happen with non blocking IO 1549 */ 1550 if (s->s3->wbuf.left != 0) { 1551 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1552 return (ssl3_write_pending(s, type, buf, len)); 1553 } 1554 1555 /* If we have an alert to send, lets send it */ 1556 if (s->s3->alert_dispatch) { 1557 i = s->method->ssl_dispatch_alert(s); 1558 if (i <= 0) 1559 return (i); 1560 /* if it went, fall through and send more stuff */ 1561 } 1562 1563 if (len == 0 && !create_empty_fragment) 1564 return 0; 1565 1566 wr = &(s->s3->wrec); 1567 wb = &(s->s3->wbuf); 1568 sess = s->session; 1569 1570 if ((sess == NULL) || 1571 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL)) 1572 clear = 1; 1573 1574 if (clear) 1575 mac_size = 0; 1576 else { 1577 mac_size = EVP_MD_CTX_size(s->write_hash); 1578 if (mac_size < 0) 1579 goto err; 1580 } 1581 1582 /* DTLS implements explicit IV, so no need for empty fragments */ 1583#if 0 1584 /* 1585 * 'create_empty_fragment' is true only when this function calls itself 1586 */ 1587 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1588 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1589 { 1590 /* 1591 * countermeasure against known-IV weakness in CBC ciphersuites (see 1592 * http://www.openssl.org/~bodo/tls-cbc.txt) 1593 */ 1594 1595 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) { 1596 /* 1597 * recursive function call with 'create_empty_fragment' set; this 1598 * prepares and buffers the data for an empty fragment (these 1599 * 'prefix_len' bytes are sent out later together with the actual 1600 * payload) 1601 */ 1602 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1603 if (prefix_len <= 0) 1604 goto err; 1605 1606 if (s->s3->wbuf.len < 1607 (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) { 1608 /* insufficient space */ 1609 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1610 goto err; 1611 } 1612 } 1613 1614 s->s3->empty_fragment_done = 1; 1615 } 1616#endif 1617 p = wb->buf + prefix_len; 1618 1619 /* write the header */ 1620 1621 *(p++) = type & 0xff; 1622 wr->type = type; 1623 1624 *(p++) = (s->version >> 8); 1625 *(p++) = s->version & 0xff; 1626 1627 /* field where we are to write out packet epoch, seq num and len */ 1628 pseq = p; 1629 p += 10; 1630 1631 /* lets setup the record stuff. */ 1632 1633 /* 1634 * Make space for the explicit IV in case of CBC. (this is a bit of a 1635 * boundary violation, but what the heck). 1636 */ 1637 if (s->enc_write_ctx && 1638 (EVP_CIPHER_mode(s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 1639 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1640 else 1641 bs = 0; 1642 1643 wr->data = p + bs; /* make room for IV in case of CBC */ 1644 wr->length = (int)len; 1645 wr->input = (unsigned char *)buf; 1646 1647 /* 1648 * we now 'read' from wr->input, wr->length bytes into wr->data 1649 */ 1650 1651 /* first we compress */ 1652 if (s->compress != NULL) { 1653 if (!ssl3_do_compress(s)) { 1654 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE); 1655 goto err; 1656 } 1657 } else { 1658 memcpy(wr->data, wr->input, wr->length); 1659 wr->input = wr->data; 1660 } 1661 1662 /* 1663 * we should still have the output to wr->data and the input from 1664 * wr->input. Length should be wr->length. wr->data still points in the 1665 * wb->buf 1666 */ 1667 1668 if (mac_size != 0) { 1669 if (s->method->ssl3_enc->mac(s, &(p[wr->length + bs]), 1) < 0) 1670 goto err; 1671 wr->length += mac_size; 1672 } 1673 1674 /* this is true regardless of mac size */ 1675 wr->input = p; 1676 wr->data = p; 1677 1678 /* ssl3_enc can only have an error on read */ 1679 if (bs) { /* bs != 0 in case of CBC */ 1680 RAND_pseudo_bytes(p, bs); 1681 /* 1682 * master IV and last CBC residue stand for the rest of randomness 1683 */ 1684 wr->length += bs; 1685 } 1686 1687 if (s->method->ssl3_enc->enc(s, 1) < 1) 1688 goto err; 1689 1690 /* record length after mac and block padding */ 1691 /* 1692 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && ! 1693 * SSL_in_init(s))) 1694 */ 1695 1696 /* there's only one epoch between handshake and app data */ 1697 1698 s2n(s->d1->w_epoch, pseq); 1699 1700 /* XDTLS: ?? */ 1701 /* 1702 * else s2n(s->d1->handshake_epoch, pseq); 1703 */ 1704 1705 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1706 pseq += 6; 1707 s2n(wr->length, pseq); 1708 1709 /* 1710 * we should now have wr->data pointing to the encrypted data, which is 1711 * wr->length long 1712 */ 1713 wr->type = type; /* not needed but helps for debugging */ 1714 wr->length += DTLS1_RT_HEADER_LENGTH; 1715 1716#if 0 /* this is now done at the message layer */ 1717 /* buffer the record, making it easy to handle retransmits */ 1718 if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1719 dtls1_buffer_record(s, wr->data, wr->length, 1720 *((PQ_64BIT *) & (s->s3->write_sequence[0]))); 1721#endif 1722 1723 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1724 1725 if (create_empty_fragment) { 1726 /* 1727 * we are in a recursive call; just return the length, don't write 1728 * out anything here 1729 */ 1730 return wr->length; 1731 } 1732 1733 /* now let's set up wb */ 1734 wb->left = prefix_len + wr->length; 1735 wb->offset = 0; 1736 1737 /* 1738 * memorize arguments so that ssl3_write_pending can detect bad write 1739 * retries later 1740 */ 1741 s->s3->wpend_tot = len; 1742 s->s3->wpend_buf = buf; 1743 s->s3->wpend_type = type; 1744 s->s3->wpend_ret = len; 1745 1746 /* we now just need to write the buffer */ 1747 return ssl3_write_pending(s, type, buf, len); 1748 err: 1749 return -1; 1750} 1751 1752static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1753{ 1754 int cmp; 1755 unsigned int shift; 1756 const unsigned char *seq = s->s3->read_sequence; 1757 1758 cmp = satsub64be(seq, bitmap->max_seq_num); 1759 if (cmp > 0) { 1760 memcpy(s->s3->rrec.seq_num, seq, 8); 1761 return 1; /* this record in new */ 1762 } 1763 shift = -cmp; 1764 if (shift >= sizeof(bitmap->map) * 8) 1765 return 0; /* stale, outside the window */ 1766 else if (bitmap->map & (1UL << shift)) 1767 return 0; /* record previously received */ 1768 1769 memcpy(s->s3->rrec.seq_num, seq, 8); 1770 return 1; 1771} 1772 1773static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1774{ 1775 int cmp; 1776 unsigned int shift; 1777 const unsigned char *seq = s->s3->read_sequence; 1778 1779 cmp = satsub64be(seq, bitmap->max_seq_num); 1780 if (cmp > 0) { 1781 shift = cmp; 1782 if (shift < sizeof(bitmap->map) * 8) 1783 bitmap->map <<= shift, bitmap->map |= 1UL; 1784 else 1785 bitmap->map = 1UL; 1786 memcpy(bitmap->max_seq_num, seq, 8); 1787 } else { 1788 shift = -cmp; 1789 if (shift < sizeof(bitmap->map) * 8) 1790 bitmap->map |= 1UL << shift; 1791 } 1792} 1793 1794int dtls1_dispatch_alert(SSL *s) 1795{ 1796 int i, j; 1797 void (*cb) (const SSL *ssl, int type, int val) = NULL; 1798 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1799 unsigned char *ptr = &buf[0]; 1800 1801 s->s3->alert_dispatch = 0; 1802 1803 memset(buf, 0x00, sizeof(buf)); 1804 *ptr++ = s->s3->send_alert[0]; 1805 *ptr++ = s->s3->send_alert[1]; 1806 1807#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1808 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1809 s2n(s->d1->handshake_read_seq, ptr); 1810# if 0 1811 if (s->d1->r_msg_hdr.frag_off == 0) 1812 /* 1813 * waiting for a new msg 1814 */ 1815 else 1816 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1817# endif 1818 1819# if 0 1820 fprintf(stderr, 1821 "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n", 1822 s->d1->handshake_read_seq, s->d1->r_msg_hdr.seq); 1823# endif 1824 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1825 } 1826#endif 1827 1828 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1829 if (i <= 0) { 1830 s->s3->alert_dispatch = 1; 1831 /* fprintf( stderr, "not done with alert\n" ); */ 1832 } else { 1833 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1834#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1835 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1836#endif 1837 ) 1838 (void)BIO_flush(s->wbio); 1839 1840 if (s->msg_callback) 1841 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1842 2, s, s->msg_callback_arg); 1843 1844 if (s->info_callback != NULL) 1845 cb = s->info_callback; 1846 else if (s->ctx->info_callback != NULL) 1847 cb = s->ctx->info_callback; 1848 1849 if (cb != NULL) { 1850 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]; 1851 cb(s, SSL_CB_WRITE_ALERT, j); 1852 } 1853 } 1854 return (i); 1855} 1856 1857static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 1858 unsigned int *is_next_epoch) 1859{ 1860 1861 *is_next_epoch = 0; 1862 1863 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1864 if (rr->epoch == s->d1->r_epoch) 1865 return &s->d1->bitmap; 1866 1867 /* 1868 * Only HM and ALERT messages can be from the next epoch and only if we 1869 * have already processed all of the unprocessed records from the last 1870 * epoch 1871 */ 1872 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1873 s->d1->unprocessed_rcds.epoch != s->d1->r_epoch && 1874 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1875 *is_next_epoch = 1; 1876 return &s->d1->next_bitmap; 1877 } 1878 1879 return NULL; 1880} 1881 1882#if 0 1883static int 1884dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 1885 unsigned short *priority, unsigned long *offset) 1886{ 1887 1888 /* alerts are passed up immediately */ 1889 if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT) 1890 return 0; 1891 1892 /* 1893 * Only need to buffer if a handshake is underway. (this implies that 1894 * Hello Request and Client Hello are passed up immediately) 1895 */ 1896 if (SSL_in_init(s)) { 1897 unsigned char *data = rr->data; 1898 /* need to extract the HM/CCS sequence number here */ 1899 if (rr->type == SSL3_RT_HANDSHAKE || 1900 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1901 unsigned short seq_num; 1902 struct hm_header_st msg_hdr; 1903 struct ccs_header_st ccs_hdr; 1904 1905 if (rr->type == SSL3_RT_HANDSHAKE) { 1906 dtls1_get_message_header(data, &msg_hdr); 1907 seq_num = msg_hdr.seq; 1908 *offset = msg_hdr.frag_off; 1909 } else { 1910 dtls1_get_ccs_header(data, &ccs_hdr); 1911 seq_num = ccs_hdr.seq; 1912 *offset = 0; 1913 } 1914 1915 /* 1916 * this is either a record we're waiting for, or a retransmit of 1917 * something we happened to previously receive (higher layers 1918 * will drop the repeat silently 1919 */ 1920 if (seq_num < s->d1->handshake_read_seq) 1921 return 0; 1922 if (rr->type == SSL3_RT_HANDSHAKE && 1923 seq_num == s->d1->handshake_read_seq && 1924 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1925 return 0; 1926 else if (seq_num == s->d1->handshake_read_seq && 1927 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1928 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1929 return 0; 1930 else { 1931 *priority = seq_num; 1932 return 1; 1933 } 1934 } else /* unknown record type */ 1935 return 0; 1936 } 1937 1938 return 0; 1939} 1940#endif 1941 1942void dtls1_reset_seq_numbers(SSL *s, int rw) 1943{ 1944 unsigned char *seq; 1945 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1946 1947 if (rw & SSL3_CC_READ) { 1948 seq = s->s3->read_sequence; 1949 s->d1->r_epoch++; 1950 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1951 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1952 1953 /* 1954 * We must not use any buffered messages received from the previous 1955 * epoch 1956 */ 1957 dtls1_clear_received_buffer(s); 1958 } else { 1959 seq = s->s3->write_sequence; 1960 memcpy(s->d1->last_write_sequence, seq, 1961 sizeof(s->s3->write_sequence)); 1962 s->d1->w_epoch++; 1963 } 1964 1965 memset(seq, 0x00, seq_bytes); 1966} 1967