d1_pkt.c revision 296341
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); 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; 322 323 item = pqueue_peek(s->d1->unprocessed_rcds.q); 324 if (item) { 325 /* Check if epoch is current. */ 326 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 327 return (1); /* Nothing to do. */ 328 329 /* Process all the records. */ 330 while (pqueue_peek(s->d1->unprocessed_rcds.q)) { 331 dtls1_get_unprocessed_record(s); 332 if (!dtls1_process_record(s)) 333 return (0); 334 if (dtls1_buffer_record(s, &(s->d1->processed_rcds), 335 s->s3->rrec.seq_num) < 0) 336 return -1; 337 } 338 } 339 340 /* 341 * sync epoch numbers once all the unprocessed records have been 342 * processed 343 */ 344 s->d1->processed_rcds.epoch = s->d1->r_epoch; 345 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 346 347 return (1); 348} 349 350#if 0 351 352static int dtls1_get_buffered_record(SSL *s) 353{ 354 pitem *item; 355 PQ_64BIT priority = 356 (((PQ_64BIT) s->d1->handshake_read_seq) << 32) | 357 ((PQ_64BIT) s->d1->r_msg_hdr.frag_off); 358 359 /* if we're not (re)negotiating, nothing buffered */ 360 if (!SSL_in_init(s)) 361 return 0; 362 363 item = pqueue_peek(s->d1->rcvd_records); 364 if (item && item->priority == priority) { 365 /* 366 * Check if we've received the record of interest. It must be a 367 * handshake record, since data records as passed up without 368 * buffering 369 */ 370 DTLS1_RECORD_DATA *rdata; 371 item = pqueue_pop(s->d1->rcvd_records); 372 rdata = (DTLS1_RECORD_DATA *)item->data; 373 374 if (s->s3->rbuf.buf != NULL) 375 OPENSSL_free(s->s3->rbuf.buf); 376 377 s->packet = rdata->packet; 378 s->packet_length = rdata->packet_length; 379 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 380 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 381 382 OPENSSL_free(item->data); 383 pitem_free(item); 384 385 /* s->d1->next_expected_seq_num++; */ 386 return (1); 387 } 388 389 return 0; 390} 391 392#endif 393 394static int dtls1_process_record(SSL *s) 395{ 396 int i, al; 397 int enc_err; 398 SSL_SESSION *sess; 399 SSL3_RECORD *rr; 400 unsigned int mac_size, orig_len; 401 unsigned char md[EVP_MAX_MD_SIZE]; 402 403 rr = &(s->s3->rrec); 404 sess = s->session; 405 406 /* 407 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 408 * and we have that many bytes in s->packet 409 */ 410 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]); 411 412 /* 413 * ok, we can now read from 's->packet' data into 'rr' rr->input points 414 * at rr->length bytes, which need to be copied into rr->data by either 415 * the decryption or by the decompression When the data is 'copied' into 416 * the rr->data buffer, rr->input will be pointed at the new buffer 417 */ 418 419 /* 420 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length 421 * bytes of encrypted compressed stuff. 422 */ 423 424 /* check is not needed I believe */ 425 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 426 al = SSL_AD_RECORD_OVERFLOW; 427 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 428 goto f_err; 429 } 430 431 /* decrypt in place in 'rr->input' */ 432 rr->data = rr->input; 433 434 enc_err = s->method->ssl3_enc->enc(s, 0); 435 /*- 436 * enc_err is: 437 * 0: (in non-constant time) if the record is publically invalid. 438 * 1: if the padding is valid 439 * -1: if the padding is invalid 440 */ 441 if (enc_err == 0) { 442 /* For DTLS we simply ignore bad packets. */ 443 rr->length = 0; 444 s->packet_length = 0; 445 goto err; 446 } 447#ifdef TLS_DEBUG 448 printf("dec %d\n", rr->length); 449 { 450 unsigned int z; 451 for (z = 0; z < rr->length; z++) 452 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); 453 } 454 printf("\n"); 455#endif 456 457 /* r->length is now the compressed data plus mac */ 458 if ((sess != NULL) && 459 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) { 460 /* s->read_hash != NULL => mac_size != -1 */ 461 unsigned char *mac = NULL; 462 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 463 mac_size = EVP_MD_CTX_size(s->read_hash); 464 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 465 466 /* 467 * kludge: *_cbc_remove_padding passes padding length in rr->type 468 */ 469 orig_len = rr->length + ((unsigned int)rr->type >> 8); 470 471 /* 472 * orig_len is the length of the record before any padding was 473 * removed. This is public information, as is the MAC in use, 474 * therefore we can safely process the record in a different amount 475 * of time if it's too short to possibly contain a MAC. 476 */ 477 if (orig_len < mac_size || 478 /* CBC records must have a padding length byte too. */ 479 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 480 orig_len < mac_size + 1)) { 481 al = SSL_AD_DECODE_ERROR; 482 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT); 483 goto f_err; 484 } 485 486 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 487 /* 488 * We update the length so that the TLS header bytes can be 489 * constructed correctly but we need to extract the MAC in 490 * constant time from within the record, without leaking the 491 * contents of the padding bytes. 492 */ 493 mac = mac_tmp; 494 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 495 rr->length -= mac_size; 496 } else { 497 /* 498 * In this case there's no padding, so |orig_len| equals 499 * |rec->length| and we checked that there's enough bytes for 500 * |mac_size| above. 501 */ 502 rr->length -= mac_size; 503 mac = &rr->data[rr->length]; 504 } 505 506 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ ); 507 if (i < 0 || mac == NULL 508 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 509 enc_err = -1; 510 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 511 enc_err = -1; 512 } 513 514 if (enc_err < 0) { 515 /* decryption failed, silently discard message */ 516 rr->length = 0; 517 s->packet_length = 0; 518 goto err; 519 } 520 521 /* r->length is now just compressed */ 522 if (s->expand != NULL) { 523 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) { 524 al = SSL_AD_RECORD_OVERFLOW; 525 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, 526 SSL_R_COMPRESSED_LENGTH_TOO_LONG); 527 goto f_err; 528 } 529 if (!ssl3_do_uncompress(s)) { 530 al = SSL_AD_DECOMPRESSION_FAILURE; 531 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION); 532 goto f_err; 533 } 534 } 535 536 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 537 al = SSL_AD_RECORD_OVERFLOW; 538 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); 539 goto f_err; 540 } 541 542 rr->off = 0; 543 /*- 544 * So at this point the following is true 545 * ssl->s3->rrec.type is the type of record 546 * ssl->s3->rrec.length == number of bytes in record 547 * ssl->s3->rrec.off == offset to first valid byte 548 * ssl->s3->rrec.data == where to take bytes from, increment 549 * after use :-). 550 */ 551 552 /* we have pulled in a full packet so zero things */ 553 s->packet_length = 0; 554 return (1); 555 556 f_err: 557 ssl3_send_alert(s, SSL3_AL_FATAL, al); 558 err: 559 return (0); 560} 561 562/*- 563 * Call this to get a new input record. 564 * It will return <= 0 if more data is needed, normally due to an error 565 * or non-blocking IO. 566 * When it finishes, one packet has been decoded and can be found in 567 * ssl->s3->rrec.type - is the type of record 568 * ssl->s3->rrec.data, - data 569 * ssl->s3->rrec.length, - number of bytes 570 */ 571/* used only by dtls1_read_bytes */ 572int dtls1_get_record(SSL *s) 573{ 574 int ssl_major, ssl_minor; 575 int i, n; 576 SSL3_RECORD *rr; 577 unsigned char *p = NULL; 578 unsigned short version; 579 DTLS1_BITMAP *bitmap; 580 unsigned int is_next_epoch; 581 582 rr = &(s->s3->rrec); 583 584 /* 585 * The epoch may have changed. If so, process all the pending records. 586 * This is a non-blocking operation. 587 */ 588 if (dtls1_process_buffered_records(s) < 0) 589 return -1; 590 591 /* if we're renegotiating, then there may be buffered records */ 592 if (dtls1_get_processed_record(s)) 593 return 1; 594 595 /* get something from the wire */ 596 again: 597 /* check if we have the header */ 598 if ((s->rstate != SSL_ST_READ_BODY) || 599 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { 600 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 601 /* read timeout is handled by dtls1_read_bytes */ 602 if (n <= 0) 603 return (n); /* error or non-blocking */ 604 605 /* this packet contained a partial record, dump it */ 606 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) { 607 s->packet_length = 0; 608 goto again; 609 } 610 611 s->rstate = SSL_ST_READ_BODY; 612 613 p = s->packet; 614 615 /* Pull apart the header into the DTLS1_RECORD */ 616 rr->type = *(p++); 617 ssl_major = *(p++); 618 ssl_minor = *(p++); 619 version = (ssl_major << 8) | ssl_minor; 620 621 /* sequence number is 64 bits, with top 2 bytes = epoch */ 622 n2s(p, rr->epoch); 623 624 memcpy(&(s->s3->read_sequence[2]), p, 6); 625 p += 6; 626 627 n2s(p, rr->length); 628 629 /* Lets check version */ 630 if (!s->first_packet) { 631 if (version != s->version) { 632 /* unexpected version, silently discard */ 633 rr->length = 0; 634 s->packet_length = 0; 635 goto again; 636 } 637 } 638 639 if ((version & 0xff00) != (s->version & 0xff00)) { 640 /* wrong version, silently discard record */ 641 rr->length = 0; 642 s->packet_length = 0; 643 goto again; 644 } 645 646 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 647 /* record too long, silently discard it */ 648 rr->length = 0; 649 s->packet_length = 0; 650 goto again; 651 } 652 653 /* now s->rstate == SSL_ST_READ_BODY */ 654 } 655 656 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 657 658 if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) { 659 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 660 i = rr->length; 661 n = ssl3_read_n(s, i, i, 1); 662 /* this packet contained a partial record, dump it */ 663 if (n != i) { 664 rr->length = 0; 665 s->packet_length = 0; 666 goto again; 667 } 668 669 /* 670 * now n == rr->length, and s->packet_length == 671 * DTLS1_RT_HEADER_LENGTH + rr->length 672 */ 673 } 674 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 675 676 /* match epochs. NULL means the packet is dropped on the floor */ 677 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 678 if (bitmap == NULL) { 679 rr->length = 0; 680 s->packet_length = 0; /* dump this record */ 681 goto again; /* get another record */ 682 } 683#ifndef OPENSSL_NO_SCTP 684 /* Only do replay check if no SCTP bio */ 685 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) { 686#endif 687 /* 688 * Check whether this is a repeat, or aged record. Don't check if 689 * we're listening and this message is a ClientHello. They can look 690 * as if they're replayed, since they arrive from different 691 * connections and would be dropped unnecessarily. 692 */ 693 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 694 s->packet_length > DTLS1_RT_HEADER_LENGTH && 695 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) && 696 !dtls1_record_replay_check(s, bitmap)) { 697 rr->length = 0; 698 s->packet_length = 0; /* dump this record */ 699 goto again; /* get another record */ 700 } 701#ifndef OPENSSL_NO_SCTP 702 } 703#endif 704 705 /* just read a 0 length packet */ 706 if (rr->length == 0) 707 goto again; 708 709 /* 710 * If this record is from the next epoch (either HM or ALERT), and a 711 * handshake is currently in progress, buffer it since it cannot be 712 * processed at this time. However, do not buffer anything while 713 * listening. 714 */ 715 if (is_next_epoch) { 716 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) { 717 if (dtls1_buffer_record 718 (s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0) 719 return -1; 720 /* Mark receipt of record. */ 721 dtls1_record_bitmap_update(s, bitmap); 722 } 723 rr->length = 0; 724 s->packet_length = 0; 725 goto again; 726 } 727 728 if (!dtls1_process_record(s)) { 729 rr->length = 0; 730 s->packet_length = 0; /* dump this record */ 731 goto again; /* get another record */ 732 } 733 dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */ 734 735 return (1); 736 737} 738 739/*- 740 * Return up to 'len' payload bytes received in 'type' records. 741 * 'type' is one of the following: 742 * 743 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 744 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 745 * - 0 (during a shutdown, no data has to be returned) 746 * 747 * If we don't have stored data to work from, read a SSL/TLS record first 748 * (possibly multiple records if we still don't have anything to return). 749 * 750 * This function must handle any surprises the peer may have for us, such as 751 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 752 * a surprise, but handled as if it were), or renegotiation requests. 753 * Also if record payloads contain fragments too small to process, we store 754 * them until there is enough for the respective protocol (the record protocol 755 * may use arbitrary fragmentation and even interleaving): 756 * Change cipher spec protocol 757 * just 1 byte needed, no need for keeping anything stored 758 * Alert protocol 759 * 2 bytes needed (AlertLevel, AlertDescription) 760 * Handshake protocol 761 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 762 * to detect unexpected Client Hello and Hello Request messages 763 * here, anything else is handled by higher layers 764 * Application data protocol 765 * none of our business 766 */ 767int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 768{ 769 int al, i, j, ret; 770 unsigned int n; 771 SSL3_RECORD *rr; 772 void (*cb) (const SSL *ssl, int type2, int val) = NULL; 773 774 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 775 if (!ssl3_setup_buffers(s)) 776 return (-1); 777 778 /* XXX: check what the second '&& type' is about */ 779 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 780 (type != SSL3_RT_HANDSHAKE) && type) || 781 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 782 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 783 return -1; 784 } 785 786 /* 787 * check whether there's a handshake message (client hello?) waiting 788 */ 789 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 790 return ret; 791 792 /* 793 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. 794 */ 795 796#ifndef OPENSSL_NO_SCTP 797 /* 798 * Continue handshake if it had to be interrupted to read app data with 799 * SCTP. 800 */ 801 if ((!s->in_handshake && SSL_in_init(s)) || 802 (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 803 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK 804 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) 805 && s->s3->in_read_app_data != 2)) 806#else 807 if (!s->in_handshake && SSL_in_init(s)) 808#endif 809 { 810 /* type == SSL3_RT_APPLICATION_DATA */ 811 i = s->handshake_func(s); 812 if (i < 0) 813 return (i); 814 if (i == 0) { 815 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 816 return (-1); 817 } 818 } 819 820 start: 821 s->rwstate = SSL_NOTHING; 822 823 /*- 824 * s->s3->rrec.type - is the type of record 825 * s->s3->rrec.data, - data 826 * s->s3->rrec.off, - offset into 'data' for next read 827 * s->s3->rrec.length, - number of bytes. 828 */ 829 rr = &(s->s3->rrec); 830 831 /* 832 * We are not handshaking and have no data yet, so process data buffered 833 * during the last handshake in advance, if any. 834 */ 835 if (s->state == SSL_ST_OK && rr->length == 0) { 836 pitem *item; 837 item = pqueue_pop(s->d1->buffered_app_data.q); 838 if (item) { 839#ifndef OPENSSL_NO_SCTP 840 /* Restore bio_dgram_sctp_rcvinfo struct */ 841 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) { 842 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data; 843 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, 844 sizeof(rdata->recordinfo), &rdata->recordinfo); 845 } 846#endif 847 848 dtls1_copy_record(s, item); 849 850 OPENSSL_free(item->data); 851 pitem_free(item); 852 } 853 } 854 855 /* Check for timeout */ 856 if (dtls1_handle_timeout(s) > 0) 857 goto start; 858 859 /* get new packet if necessary */ 860 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) { 861 ret = dtls1_get_record(s); 862 if (ret <= 0) { 863 ret = dtls1_read_failed(s, ret); 864 /* anything other than a timeout is an error */ 865 if (ret <= 0) 866 return (ret); 867 else 868 goto start; 869 } 870 } 871 872 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) { 873 rr->length = 0; 874 goto start; 875 } 876 877 /* we now have a packet which can be read and processed */ 878 879 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 880 * reset by ssl3_get_finished */ 881 && (rr->type != SSL3_RT_HANDSHAKE)) { 882 /* 883 * We now have application data between CCS and Finished. Most likely 884 * the packets were reordered on their way, so buffer the application 885 * data for later processing rather than dropping the connection. 886 */ 887 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) < 888 0) { 889 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 890 return -1; 891 } 892 rr->length = 0; 893 goto start; 894 } 895 896 /* 897 * If the other end has shut down, throw anything we read away (even in 898 * 'peek' mode) 899 */ 900 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 901 rr->length = 0; 902 s->rwstate = SSL_NOTHING; 903 return (0); 904 } 905 906 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or 907 * SSL3_RT_HANDSHAKE */ 908 /* 909 * make sure that we are not getting application data when we are 910 * doing a handshake for the first time 911 */ 912 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 913 (s->enc_read_ctx == NULL)) { 914 al = SSL_AD_UNEXPECTED_MESSAGE; 915 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE); 916 goto f_err; 917 } 918 919 if (len <= 0) 920 return (len); 921 922 if ((unsigned int)len > rr->length) 923 n = rr->length; 924 else 925 n = (unsigned int)len; 926 927 memcpy(buf, &(rr->data[rr->off]), n); 928 if (!peek) { 929 rr->length -= n; 930 rr->off += n; 931 if (rr->length == 0) { 932 s->rstate = SSL_ST_READ_HEADER; 933 rr->off = 0; 934 } 935 } 936#ifndef OPENSSL_NO_SCTP 937 /* 938 * We were about to renegotiate but had to read belated application 939 * data first, so retry. 940 */ 941 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 942 rr->type == SSL3_RT_APPLICATION_DATA && 943 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK 944 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) { 945 s->rwstate = SSL_READING; 946 BIO_clear_retry_flags(SSL_get_rbio(s)); 947 BIO_set_retry_read(SSL_get_rbio(s)); 948 } 949 950 /* 951 * We might had to delay a close_notify alert because of reordered 952 * app data. If there was an alert and there is no message to read 953 * anymore, finally set shutdown. 954 */ 955 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 956 s->d1->shutdown_received 957 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 958 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 959 return (0); 960 } 961#endif 962 return (n); 963 } 964 965 /* 966 * If we get here, then type != rr->type; if we have a handshake message, 967 * then it was unexpected (Hello Request or Client Hello). 968 */ 969 970 /* 971 * In case of record types for which we have 'fragment' storage, fill 972 * that so that we can process the data at a fixed place. 973 */ 974 { 975 unsigned int k, dest_maxlen = 0; 976 unsigned char *dest = NULL; 977 unsigned int *dest_len = NULL; 978 979 if (rr->type == SSL3_RT_HANDSHAKE) { 980 dest_maxlen = sizeof s->d1->handshake_fragment; 981 dest = s->d1->handshake_fragment; 982 dest_len = &s->d1->handshake_fragment_len; 983 } else if (rr->type == SSL3_RT_ALERT) { 984 dest_maxlen = sizeof(s->d1->alert_fragment); 985 dest = s->d1->alert_fragment; 986 dest_len = &s->d1->alert_fragment_len; 987 } 988#ifndef OPENSSL_NO_HEARTBEATS 989 else if (rr->type == TLS1_RT_HEARTBEAT) { 990 dtls1_process_heartbeat(s); 991 992 /* Exit and notify application to read again */ 993 rr->length = 0; 994 s->rwstate = SSL_READING; 995 BIO_clear_retry_flags(SSL_get_rbio(s)); 996 BIO_set_retry_read(SSL_get_rbio(s)); 997 return (-1); 998 } 999#endif 1000 /* else it's a CCS message, or application data or wrong */ 1001 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 1002 /* 1003 * Application data while renegotiating is allowed. Try again 1004 * reading. 1005 */ 1006 if (rr->type == SSL3_RT_APPLICATION_DATA) { 1007 BIO *bio; 1008 s->s3->in_read_app_data = 2; 1009 bio = SSL_get_rbio(s); 1010 s->rwstate = SSL_READING; 1011 BIO_clear_retry_flags(bio); 1012 BIO_set_retry_read(bio); 1013 return (-1); 1014 } 1015 1016 /* Not certain if this is the right error handling */ 1017 al = SSL_AD_UNEXPECTED_MESSAGE; 1018 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1019 goto f_err; 1020 } 1021 1022 if (dest_maxlen > 0) { 1023 /* 1024 * XDTLS: In a pathalogical case, the Client Hello may be 1025 * fragmented--don't always expect dest_maxlen bytes 1026 */ 1027 if (rr->length < dest_maxlen) { 1028#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1029 /* 1030 * for normal alerts rr->length is 2, while 1031 * dest_maxlen is 7 if we were to handle this 1032 * non-existing alert... 1033 */ 1034 FIX ME 1035#endif 1036 s->rstate = SSL_ST_READ_HEADER; 1037 rr->length = 0; 1038 goto start; 1039 } 1040 1041 /* now move 'n' bytes: */ 1042 for (k = 0; k < dest_maxlen; k++) { 1043 dest[k] = rr->data[rr->off++]; 1044 rr->length--; 1045 } 1046 *dest_len = dest_maxlen; 1047 } 1048 } 1049 1050 /*- 1051 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 1052 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 1053 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) 1054 */ 1055 1056 /* If we are a client, check for an incoming 'Hello Request': */ 1057 if ((!s->server) && 1058 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1059 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1060 (s->session != NULL) && (s->session->cipher != NULL)) { 1061 s->d1->handshake_fragment_len = 0; 1062 1063 if ((s->d1->handshake_fragment[1] != 0) || 1064 (s->d1->handshake_fragment[2] != 0) || 1065 (s->d1->handshake_fragment[3] != 0)) { 1066 al = SSL_AD_DECODE_ERROR; 1067 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST); 1068 goto f_err; 1069 } 1070 1071 /* 1072 * no need to check sequence number on HELLO REQUEST messages 1073 */ 1074 1075 if (s->msg_callback) 1076 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1077 s->d1->handshake_fragment, 4, s, 1078 s->msg_callback_arg); 1079 1080 if (SSL_is_init_finished(s) && 1081 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1082 !s->s3->renegotiate) { 1083 s->d1->handshake_read_seq++; 1084 s->new_session = 1; 1085 ssl3_renegotiate(s); 1086 if (ssl3_renegotiate_check(s)) { 1087 i = s->handshake_func(s); 1088 if (i < 0) 1089 return (i); 1090 if (i == 0) { 1091 SSLerr(SSL_F_DTLS1_READ_BYTES, 1092 SSL_R_SSL_HANDSHAKE_FAILURE); 1093 return (-1); 1094 } 1095 1096 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1097 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1098 BIO *bio; 1099 /* 1100 * In the case where we try to read application data, 1101 * but we trigger an SSL handshake, we return -1 with 1102 * the retry option set. Otherwise renegotiation may 1103 * cause nasty problems in the blocking world 1104 */ 1105 s->rwstate = SSL_READING; 1106 bio = SSL_get_rbio(s); 1107 BIO_clear_retry_flags(bio); 1108 BIO_set_retry_read(bio); 1109 return (-1); 1110 } 1111 } 1112 } 1113 } 1114 /* 1115 * we either finished a handshake or ignored the request, now try 1116 * again to obtain the (application) data we were asked for 1117 */ 1118 goto start; 1119 } 1120 1121 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 1122 int alert_level = s->d1->alert_fragment[0]; 1123 int alert_descr = s->d1->alert_fragment[1]; 1124 1125 s->d1->alert_fragment_len = 0; 1126 1127 if (s->msg_callback) 1128 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1129 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1130 1131 if (s->info_callback != NULL) 1132 cb = s->info_callback; 1133 else if (s->ctx->info_callback != NULL) 1134 cb = s->ctx->info_callback; 1135 1136 if (cb != NULL) { 1137 j = (alert_level << 8) | alert_descr; 1138 cb(s, SSL_CB_READ_ALERT, j); 1139 } 1140 1141 if (alert_level == SSL3_AL_WARNING) { 1142 s->s3->warn_alert = alert_descr; 1143 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 1144#ifndef OPENSSL_NO_SCTP 1145 /* 1146 * With SCTP and streams the socket may deliver app data 1147 * after a close_notify alert. We have to check this first so 1148 * that nothing gets discarded. 1149 */ 1150 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1151 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 1152 s->d1->shutdown_received = 1; 1153 s->rwstate = SSL_READING; 1154 BIO_clear_retry_flags(SSL_get_rbio(s)); 1155 BIO_set_retry_read(SSL_get_rbio(s)); 1156 return -1; 1157 } 1158#endif 1159 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1160 return (0); 1161 } 1162#if 0 1163 /* XXX: this is a possible improvement in the future */ 1164 /* now check if it's a missing record */ 1165 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1166 unsigned short seq; 1167 unsigned int frag_off; 1168 unsigned char *p = &(s->d1->alert_fragment[2]); 1169 1170 n2s(p, seq); 1171 n2l3(p, frag_off); 1172 1173 dtls1_retransmit_message(s, 1174 dtls1_get_queue_priority 1175 (frag->msg_header.seq, 0), frag_off, 1176 &found); 1177 if (!found && SSL_in_init(s)) { 1178 /* 1179 * fprintf( stderr,"in init = %d\n", SSL_in_init(s)); 1180 */ 1181 /* 1182 * requested a message not yet sent, send an alert 1183 * ourselves 1184 */ 1185 ssl3_send_alert(s, SSL3_AL_WARNING, 1186 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1187 } 1188 } 1189#endif 1190 } else if (alert_level == SSL3_AL_FATAL) { 1191 char tmp[16]; 1192 1193 s->rwstate = SSL_NOTHING; 1194 s->s3->fatal_alert = alert_descr; 1195 SSLerr(SSL_F_DTLS1_READ_BYTES, 1196 SSL_AD_REASON_OFFSET + alert_descr); 1197 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); 1198 ERR_add_error_data(2, "SSL alert number ", tmp); 1199 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1200 SSL_CTX_remove_session(s->ctx, s->session); 1201 return (0); 1202 } else { 1203 al = SSL_AD_ILLEGAL_PARAMETER; 1204 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE); 1205 goto f_err; 1206 } 1207 1208 goto start; 1209 } 1210 1211 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a 1212 * shutdown */ 1213 s->rwstate = SSL_NOTHING; 1214 rr->length = 0; 1215 return (0); 1216 } 1217 1218 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1219 struct ccs_header_st ccs_hdr; 1220 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1221 1222 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1223 1224 if (s->version == DTLS1_BAD_VER) 1225 ccs_hdr_len = 3; 1226 1227 /* 1228 * 'Change Cipher Spec' is just a single byte, so we know exactly 1229 * what the record payload has to look like 1230 */ 1231 /* XDTLS: check that epoch is consistent */ 1232 if ((rr->length != ccs_hdr_len) || 1233 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 1234 i = SSL_AD_ILLEGAL_PARAMETER; 1235 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1236 goto err; 1237 } 1238 1239 rr->length = 0; 1240 1241 if (s->msg_callback) 1242 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1243 rr->data, 1, s, s->msg_callback_arg); 1244 1245 /* 1246 * We can't process a CCS now, because previous handshake messages 1247 * are still missing, so just drop it. 1248 */ 1249 if (!s->d1->change_cipher_spec_ok) { 1250 goto start; 1251 } 1252 1253 s->d1->change_cipher_spec_ok = 0; 1254 1255 s->s3->change_cipher_spec = 1; 1256 if (!ssl3_do_change_cipher_spec(s)) 1257 goto err; 1258 1259 /* do this whenever CCS is processed */ 1260 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1261 1262 if (s->version == DTLS1_BAD_VER) 1263 s->d1->handshake_read_seq++; 1264 1265#ifndef OPENSSL_NO_SCTP 1266 /* 1267 * Remember that a CCS has been received, so that an old key of 1268 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no 1269 * SCTP is used 1270 */ 1271 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1272#endif 1273 1274 goto start; 1275 } 1276 1277 /* 1278 * Unexpected handshake message (Client Hello, or protocol violation) 1279 */ 1280 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1281 !s->in_handshake) { 1282 struct hm_header_st msg_hdr; 1283 1284 /* this may just be a stale retransmit */ 1285 dtls1_get_message_header(rr->data, &msg_hdr); 1286 if (rr->epoch != s->d1->r_epoch) { 1287 rr->length = 0; 1288 goto start; 1289 } 1290 1291 /* 1292 * If we are server, we may have a repeated FINISHED of the client 1293 * here, then retransmit our CCS and FINISHED. 1294 */ 1295 if (msg_hdr.type == SSL3_MT_FINISHED) { 1296 if (dtls1_check_timeout_num(s) < 0) 1297 return -1; 1298 1299 dtls1_retransmit_buffered_messages(s); 1300 rr->length = 0; 1301 goto start; 1302 } 1303 1304 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) && 1305 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1306#if 0 /* worked only because C operator preferences 1307 * are not as expected (and because this is 1308 * not really needed for clients except for 1309 * detecting protocol violations): */ 1310 s->state = SSL_ST_BEFORE | (s->server) 1311 ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1312#else 1313 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1314#endif 1315 s->renegotiate = 1; 1316 s->new_session = 1; 1317 } 1318 i = s->handshake_func(s); 1319 if (i < 0) 1320 return (i); 1321 if (i == 0) { 1322 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1323 return (-1); 1324 } 1325 1326 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1327 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1328 BIO *bio; 1329 /* 1330 * In the case where we try to read application data, but we 1331 * trigger an SSL handshake, we return -1 with the retry 1332 * option set. Otherwise renegotiation may cause nasty 1333 * problems in the blocking world 1334 */ 1335 s->rwstate = SSL_READING; 1336 bio = SSL_get_rbio(s); 1337 BIO_clear_retry_flags(bio); 1338 BIO_set_retry_read(bio); 1339 return (-1); 1340 } 1341 } 1342 goto start; 1343 } 1344 1345 switch (rr->type) { 1346 default: 1347#ifndef OPENSSL_NO_TLS 1348 /* TLS just ignores unknown message types */ 1349 if (s->version == TLS1_VERSION) { 1350 rr->length = 0; 1351 goto start; 1352 } 1353#endif 1354 al = SSL_AD_UNEXPECTED_MESSAGE; 1355 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1356 goto f_err; 1357 case SSL3_RT_CHANGE_CIPHER_SPEC: 1358 case SSL3_RT_ALERT: 1359 case SSL3_RT_HANDSHAKE: 1360 /* 1361 * we already handled all of these, with the possible exception of 1362 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not 1363 * happen when type != rr->type 1364 */ 1365 al = SSL_AD_UNEXPECTED_MESSAGE; 1366 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 1367 goto f_err; 1368 case SSL3_RT_APPLICATION_DATA: 1369 /* 1370 * At this point, we were expecting handshake data, but have 1371 * application data. If the library was running inside ssl3_read() 1372 * (i.e. in_read_app_data is set) and it makes sense to read 1373 * application data at this point (session renegotiation not yet 1374 * started), we will indulge it. 1375 */ 1376 if (s->s3->in_read_app_data && 1377 (s->s3->total_renegotiations != 0) && 1378 (((s->state & SSL_ST_CONNECT) && 1379 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1380 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1381 ) || ((s->state & SSL_ST_ACCEPT) && 1382 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1383 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1384 ) 1385 )) { 1386 s->s3->in_read_app_data = 2; 1387 return (-1); 1388 } else { 1389 al = SSL_AD_UNEXPECTED_MESSAGE; 1390 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1391 goto f_err; 1392 } 1393 } 1394 /* not reached */ 1395 1396 f_err: 1397 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1398 err: 1399 return (-1); 1400} 1401 1402int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1403{ 1404 int i; 1405 1406#ifndef OPENSSL_NO_SCTP 1407 /* 1408 * Check if we have to continue an interrupted handshake for reading 1409 * belated app data with SCTP. 1410 */ 1411 if ((SSL_in_init(s) && !s->in_handshake) || 1412 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1413 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK 1414 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1415#else 1416 if (SSL_in_init(s) && !s->in_handshake) 1417#endif 1418 { 1419 i = s->handshake_func(s); 1420 if (i < 0) 1421 return (i); 1422 if (i == 0) { 1423 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, 1424 SSL_R_SSL_HANDSHAKE_FAILURE); 1425 return -1; 1426 } 1427 } 1428 1429 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 1430 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG); 1431 return -1; 1432 } 1433 1434 i = dtls1_write_bytes(s, type, buf_, len); 1435 return i; 1436} 1437 1438 /* 1439 * this only happens when a client hello is received and a handshake 1440 * is started. 1441 */ 1442static int 1443have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1444 int len, int peek) 1445{ 1446 1447 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1448 /* (partially) satisfy request from storage */ 1449 { 1450 unsigned char *src = s->d1->handshake_fragment; 1451 unsigned char *dst = buf; 1452 unsigned int k, n; 1453 1454 /* peek == 0 */ 1455 n = 0; 1456 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) { 1457 *dst++ = *src++; 1458 len--; 1459 s->d1->handshake_fragment_len--; 1460 n++; 1461 } 1462 /* move any remaining fragment bytes: */ 1463 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1464 s->d1->handshake_fragment[k] = *src++; 1465 return n; 1466 } 1467 1468 return 0; 1469} 1470 1471/* 1472 * Call this to write data in records of type 'type' It will return <= 0 if 1473 * not all data has been sent or non-blocking IO. 1474 */ 1475int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1476{ 1477 int i; 1478 1479 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1480 s->rwstate = SSL_NOTHING; 1481 i = do_dtls1_write(s, type, buf, len, 0); 1482 return i; 1483} 1484 1485int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 1486 unsigned int len, int create_empty_fragment) 1487{ 1488 unsigned char *p, *pseq; 1489 int i, mac_size, clear = 0; 1490 int prefix_len = 0; 1491 SSL3_RECORD *wr; 1492 SSL3_BUFFER *wb; 1493 SSL_SESSION *sess; 1494 int bs; 1495 1496 /* 1497 * first check if there is a SSL3_BUFFER still being written out. This 1498 * will happen with non blocking IO 1499 */ 1500 if (s->s3->wbuf.left != 0) { 1501 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1502 return (ssl3_write_pending(s, type, buf, len)); 1503 } 1504 1505 /* If we have an alert to send, lets send it */ 1506 if (s->s3->alert_dispatch) { 1507 i = s->method->ssl_dispatch_alert(s); 1508 if (i <= 0) 1509 return (i); 1510 /* if it went, fall through and send more stuff */ 1511 } 1512 1513 if (len == 0 && !create_empty_fragment) 1514 return 0; 1515 1516 wr = &(s->s3->wrec); 1517 wb = &(s->s3->wbuf); 1518 sess = s->session; 1519 1520 if ((sess == NULL) || 1521 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL)) 1522 clear = 1; 1523 1524 if (clear) 1525 mac_size = 0; 1526 else { 1527 mac_size = EVP_MD_CTX_size(s->write_hash); 1528 if (mac_size < 0) 1529 goto err; 1530 } 1531 1532 /* DTLS implements explicit IV, so no need for empty fragments */ 1533#if 0 1534 /* 1535 * 'create_empty_fragment' is true only when this function calls itself 1536 */ 1537 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1538 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1539 { 1540 /* 1541 * countermeasure against known-IV weakness in CBC ciphersuites (see 1542 * http://www.openssl.org/~bodo/tls-cbc.txt) 1543 */ 1544 1545 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) { 1546 /* 1547 * recursive function call with 'create_empty_fragment' set; this 1548 * prepares and buffers the data for an empty fragment (these 1549 * 'prefix_len' bytes are sent out later together with the actual 1550 * payload) 1551 */ 1552 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1553 if (prefix_len <= 0) 1554 goto err; 1555 1556 if (s->s3->wbuf.len < 1557 (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) { 1558 /* insufficient space */ 1559 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1560 goto err; 1561 } 1562 } 1563 1564 s->s3->empty_fragment_done = 1; 1565 } 1566#endif 1567 p = wb->buf + prefix_len; 1568 1569 /* write the header */ 1570 1571 *(p++) = type & 0xff; 1572 wr->type = type; 1573 1574 *(p++) = (s->version >> 8); 1575 *(p++) = s->version & 0xff; 1576 1577 /* field where we are to write out packet epoch, seq num and len */ 1578 pseq = p; 1579 p += 10; 1580 1581 /* lets setup the record stuff. */ 1582 1583 /* 1584 * Make space for the explicit IV in case of CBC. (this is a bit of a 1585 * boundary violation, but what the heck). 1586 */ 1587 if (s->enc_write_ctx && 1588 (EVP_CIPHER_mode(s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 1589 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1590 else 1591 bs = 0; 1592 1593 wr->data = p + bs; /* make room for IV in case of CBC */ 1594 wr->length = (int)len; 1595 wr->input = (unsigned char *)buf; 1596 1597 /* 1598 * we now 'read' from wr->input, wr->length bytes into wr->data 1599 */ 1600 1601 /* first we compress */ 1602 if (s->compress != NULL) { 1603 if (!ssl3_do_compress(s)) { 1604 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE); 1605 goto err; 1606 } 1607 } else { 1608 memcpy(wr->data, wr->input, wr->length); 1609 wr->input = wr->data; 1610 } 1611 1612 /* 1613 * we should still have the output to wr->data and the input from 1614 * wr->input. Length should be wr->length. wr->data still points in the 1615 * wb->buf 1616 */ 1617 1618 if (mac_size != 0) { 1619 if (s->method->ssl3_enc->mac(s, &(p[wr->length + bs]), 1) < 0) 1620 goto err; 1621 wr->length += mac_size; 1622 } 1623 1624 /* this is true regardless of mac size */ 1625 wr->input = p; 1626 wr->data = p; 1627 1628 /* ssl3_enc can only have an error on read */ 1629 if (bs) { /* bs != 0 in case of CBC */ 1630 RAND_pseudo_bytes(p, bs); 1631 /* 1632 * master IV and last CBC residue stand for the rest of randomness 1633 */ 1634 wr->length += bs; 1635 } 1636 1637 if (s->method->ssl3_enc->enc(s, 1) < 1) 1638 goto err; 1639 1640 /* record length after mac and block padding */ 1641 /* 1642 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && ! 1643 * SSL_in_init(s))) 1644 */ 1645 1646 /* there's only one epoch between handshake and app data */ 1647 1648 s2n(s->d1->w_epoch, pseq); 1649 1650 /* XDTLS: ?? */ 1651 /* 1652 * else s2n(s->d1->handshake_epoch, pseq); 1653 */ 1654 1655 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1656 pseq += 6; 1657 s2n(wr->length, pseq); 1658 1659 /* 1660 * we should now have wr->data pointing to the encrypted data, which is 1661 * wr->length long 1662 */ 1663 wr->type = type; /* not needed but helps for debugging */ 1664 wr->length += DTLS1_RT_HEADER_LENGTH; 1665 1666#if 0 /* this is now done at the message layer */ 1667 /* buffer the record, making it easy to handle retransmits */ 1668 if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1669 dtls1_buffer_record(s, wr->data, wr->length, 1670 *((PQ_64BIT *) & (s->s3->write_sequence[0]))); 1671#endif 1672 1673 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1674 1675 if (create_empty_fragment) { 1676 /* 1677 * we are in a recursive call; just return the length, don't write 1678 * out anything here 1679 */ 1680 return wr->length; 1681 } 1682 1683 /* now let's set up wb */ 1684 wb->left = prefix_len + wr->length; 1685 wb->offset = 0; 1686 1687 /* 1688 * memorize arguments so that ssl3_write_pending can detect bad write 1689 * retries later 1690 */ 1691 s->s3->wpend_tot = len; 1692 s->s3->wpend_buf = buf; 1693 s->s3->wpend_type = type; 1694 s->s3->wpend_ret = len; 1695 1696 /* we now just need to write the buffer */ 1697 return ssl3_write_pending(s, type, buf, len); 1698 err: 1699 return -1; 1700} 1701 1702static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1703{ 1704 int cmp; 1705 unsigned int shift; 1706 const unsigned char *seq = s->s3->read_sequence; 1707 1708 cmp = satsub64be(seq, bitmap->max_seq_num); 1709 if (cmp > 0) { 1710 memcpy(s->s3->rrec.seq_num, seq, 8); 1711 return 1; /* this record in new */ 1712 } 1713 shift = -cmp; 1714 if (shift >= sizeof(bitmap->map) * 8) 1715 return 0; /* stale, outside the window */ 1716 else if (bitmap->map & (1UL << shift)) 1717 return 0; /* record previously received */ 1718 1719 memcpy(s->s3->rrec.seq_num, seq, 8); 1720 return 1; 1721} 1722 1723static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1724{ 1725 int cmp; 1726 unsigned int shift; 1727 const unsigned char *seq = s->s3->read_sequence; 1728 1729 cmp = satsub64be(seq, bitmap->max_seq_num); 1730 if (cmp > 0) { 1731 shift = cmp; 1732 if (shift < sizeof(bitmap->map) * 8) 1733 bitmap->map <<= shift, bitmap->map |= 1UL; 1734 else 1735 bitmap->map = 1UL; 1736 memcpy(bitmap->max_seq_num, seq, 8); 1737 } else { 1738 shift = -cmp; 1739 if (shift < sizeof(bitmap->map) * 8) 1740 bitmap->map |= 1UL << shift; 1741 } 1742} 1743 1744int dtls1_dispatch_alert(SSL *s) 1745{ 1746 int i, j; 1747 void (*cb) (const SSL *ssl, int type, int val) = NULL; 1748 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1749 unsigned char *ptr = &buf[0]; 1750 1751 s->s3->alert_dispatch = 0; 1752 1753 memset(buf, 0x00, sizeof(buf)); 1754 *ptr++ = s->s3->send_alert[0]; 1755 *ptr++ = s->s3->send_alert[1]; 1756 1757#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1758 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1759 s2n(s->d1->handshake_read_seq, ptr); 1760# if 0 1761 if (s->d1->r_msg_hdr.frag_off == 0) 1762 /* 1763 * waiting for a new msg 1764 */ 1765 else 1766 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1767# endif 1768 1769# if 0 1770 fprintf(stderr, 1771 "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n", 1772 s->d1->handshake_read_seq, s->d1->r_msg_hdr.seq); 1773# endif 1774 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1775 } 1776#endif 1777 1778 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1779 if (i <= 0) { 1780 s->s3->alert_dispatch = 1; 1781 /* fprintf( stderr, "not done with alert\n" ); */ 1782 } else { 1783 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1784#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1785 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1786#endif 1787 ) 1788 (void)BIO_flush(s->wbio); 1789 1790 if (s->msg_callback) 1791 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1792 2, s, s->msg_callback_arg); 1793 1794 if (s->info_callback != NULL) 1795 cb = s->info_callback; 1796 else if (s->ctx->info_callback != NULL) 1797 cb = s->ctx->info_callback; 1798 1799 if (cb != NULL) { 1800 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]; 1801 cb(s, SSL_CB_WRITE_ALERT, j); 1802 } 1803 } 1804 return (i); 1805} 1806 1807static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 1808 unsigned int *is_next_epoch) 1809{ 1810 1811 *is_next_epoch = 0; 1812 1813 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1814 if (rr->epoch == s->d1->r_epoch) 1815 return &s->d1->bitmap; 1816 1817 /* Only HM and ALERT messages can be from the next epoch */ 1818 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1819 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1820 *is_next_epoch = 1; 1821 return &s->d1->next_bitmap; 1822 } 1823 1824 return NULL; 1825} 1826 1827#if 0 1828static int 1829dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 1830 unsigned short *priority, unsigned long *offset) 1831{ 1832 1833 /* alerts are passed up immediately */ 1834 if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT) 1835 return 0; 1836 1837 /* 1838 * Only need to buffer if a handshake is underway. (this implies that 1839 * Hello Request and Client Hello are passed up immediately) 1840 */ 1841 if (SSL_in_init(s)) { 1842 unsigned char *data = rr->data; 1843 /* need to extract the HM/CCS sequence number here */ 1844 if (rr->type == SSL3_RT_HANDSHAKE || 1845 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1846 unsigned short seq_num; 1847 struct hm_header_st msg_hdr; 1848 struct ccs_header_st ccs_hdr; 1849 1850 if (rr->type == SSL3_RT_HANDSHAKE) { 1851 dtls1_get_message_header(data, &msg_hdr); 1852 seq_num = msg_hdr.seq; 1853 *offset = msg_hdr.frag_off; 1854 } else { 1855 dtls1_get_ccs_header(data, &ccs_hdr); 1856 seq_num = ccs_hdr.seq; 1857 *offset = 0; 1858 } 1859 1860 /* 1861 * this is either a record we're waiting for, or a retransmit of 1862 * something we happened to previously receive (higher layers 1863 * will drop the repeat silently 1864 */ 1865 if (seq_num < s->d1->handshake_read_seq) 1866 return 0; 1867 if (rr->type == SSL3_RT_HANDSHAKE && 1868 seq_num == s->d1->handshake_read_seq && 1869 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1870 return 0; 1871 else if (seq_num == s->d1->handshake_read_seq && 1872 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1873 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1874 return 0; 1875 else { 1876 *priority = seq_num; 1877 return 1; 1878 } 1879 } else /* unknown record type */ 1880 return 0; 1881 } 1882 1883 return 0; 1884} 1885#endif 1886 1887void dtls1_reset_seq_numbers(SSL *s, int rw) 1888{ 1889 unsigned char *seq; 1890 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1891 1892 if (rw & SSL3_CC_READ) { 1893 seq = s->s3->read_sequence; 1894 s->d1->r_epoch++; 1895 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1896 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1897 } else { 1898 seq = s->s3->write_sequence; 1899 memcpy(s->d1->last_write_sequence, seq, 1900 sizeof(s->s3->write_sequence)); 1901 s->d1->w_epoch++; 1902 } 1903 1904 memset(seq, 0x00, seq_bytes); 1905} 1906