1/* $OpenBSD: d1_pkt.c,v 1.128 2023/07/02 20:16:47 tb Exp $ */ 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 <endian.h> 117#include <errno.h> 118#include <limits.h> 119#include <stdio.h> 120 121#include <openssl/buffer.h> 122#include <openssl/evp.h> 123 124#include "bytestring.h" 125#include "dtls_local.h" 126#include "pqueue.h" 127#include "ssl_local.h" 128#include "tls_content.h" 129 130/* mod 128 saturating subtract of two 64-bit values in big-endian order */ 131static int 132satsub64be(const unsigned char *v1, const unsigned char *v2) 133{ 134 int ret, sat, brw, i; 135 136 if (sizeof(long) == 8) 137 do { 138 long l; 139 140 if (BYTE_ORDER == LITTLE_ENDIAN) 141 break; 142 /* not reached on little-endians */ 143 /* following test is redundant, because input is 144 * always aligned, but I take no chances... */ 145 if (((size_t)v1 | (size_t)v2) & 0x7) 146 break; 147 148 l = *((long *)v1); 149 l -= *((long *)v2); 150 if (l > 128) 151 return 128; 152 else if (l<-128) 153 return -128; 154 else 155 return (int)l; 156 } while (0); 157 158 ret = (int)v1[7] - (int)v2[7]; 159 sat = 0; 160 brw = ret >> 8; /* brw is either 0 or -1 */ 161 if (ret & 0x80) { 162 for (i = 6; i >= 0; i--) { 163 brw += (int)v1[i]-(int)v2[i]; 164 sat |= ~brw; 165 brw >>= 8; 166 } 167 } else { 168 for (i = 6; i >= 0; i--) { 169 brw += (int)v1[i]-(int)v2[i]; 170 sat |= brw; 171 brw >>= 8; 172 } 173 } 174 brw <<= 8; /* brw is either 0 or -256 */ 175 176 if (sat & 0xff) 177 return brw | 0x80; 178 else 179 return brw + (ret & 0xFF); 180} 181 182static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 183 const unsigned char *seq); 184static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 185 const unsigned char *seq); 186static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, 187 unsigned int *is_next_epoch); 188static int dtls1_buffer_record(SSL *s, record_pqueue *q, 189 unsigned char *priority); 190static int dtls1_process_record(SSL *s); 191 192/* copy buffered record into SSL structure */ 193static int 194dtls1_copy_record(SSL *s, DTLS1_RECORD_DATA_INTERNAL *rdata) 195{ 196 ssl3_release_buffer(&s->s3->rbuf); 197 198 s->packet = rdata->packet; 199 s->packet_length = rdata->packet_length; 200 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 201 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL)); 202 203 return (1); 204} 205 206static int 207dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 208{ 209 DTLS1_RECORD_DATA_INTERNAL *rdata = NULL; 210 pitem *item = NULL; 211 212 /* Limit the size of the queue to prevent DOS attacks */ 213 if (pqueue_size(queue->q) >= 100) 214 return 0; 215 216 if ((rdata = malloc(sizeof(*rdata))) == NULL) 217 goto init_err; 218 if ((item = pitem_new(priority, rdata)) == NULL) 219 goto init_err; 220 221 rdata->packet = s->packet; 222 rdata->packet_length = s->packet_length; 223 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 224 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD_INTERNAL)); 225 226 item->data = rdata; 227 228 s->packet = NULL; 229 s->packet_length = 0; 230 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL)); 231 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD_INTERNAL)); 232 233 if (!ssl3_setup_buffers(s)) 234 goto err; 235 236 /* insert should not fail, since duplicates are dropped */ 237 if (pqueue_insert(queue->q, item) == NULL) 238 goto err; 239 240 return (1); 241 242 err: 243 ssl3_release_buffer(&rdata->rbuf); 244 245 init_err: 246 SSLerror(s, ERR_R_INTERNAL_ERROR); 247 free(rdata); 248 pitem_free(item); 249 return (-1); 250} 251 252static int 253dtls1_buffer_rcontent(SSL *s, rcontent_pqueue *queue, unsigned char *priority) 254{ 255 DTLS1_RCONTENT_DATA_INTERNAL *rdata = NULL; 256 pitem *item = NULL; 257 258 /* Limit the size of the queue to prevent DOS attacks */ 259 if (pqueue_size(queue->q) >= 100) 260 return 0; 261 262 if ((rdata = malloc(sizeof(*rdata))) == NULL) 263 goto init_err; 264 if ((item = pitem_new(priority, rdata)) == NULL) 265 goto init_err; 266 267 rdata->rcontent = s->s3->rcontent; 268 s->s3->rcontent = NULL; 269 270 item->data = rdata; 271 272 /* insert should not fail, since duplicates are dropped */ 273 if (pqueue_insert(queue->q, item) == NULL) 274 goto err; 275 276 if ((s->s3->rcontent = tls_content_new()) == NULL) 277 goto err; 278 279 return (1); 280 281 err: 282 tls_content_free(rdata->rcontent); 283 284 init_err: 285 SSLerror(s, ERR_R_INTERNAL_ERROR); 286 free(rdata); 287 pitem_free(item); 288 return (-1); 289} 290 291static int 292dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 293{ 294 pitem *item; 295 296 item = pqueue_pop(queue->q); 297 if (item) { 298 dtls1_copy_record(s, item->data); 299 300 free(item->data); 301 pitem_free(item); 302 303 return (1); 304 } 305 306 return (0); 307} 308 309static int 310dtls1_retrieve_buffered_rcontent(SSL *s, rcontent_pqueue *queue) 311{ 312 DTLS1_RCONTENT_DATA_INTERNAL *rdata; 313 pitem *item; 314 315 item = pqueue_pop(queue->q); 316 if (item) { 317 rdata = item->data; 318 319 tls_content_free(s->s3->rcontent); 320 s->s3->rcontent = rdata->rcontent; 321 s->s3->rrec.epoch = tls_content_epoch(s->s3->rcontent); 322 323 free(item->data); 324 pitem_free(item); 325 326 return (1); 327 } 328 329 return (0); 330} 331 332static int 333dtls1_process_buffered_record(SSL *s) 334{ 335 /* Check if epoch is current. */ 336 if (s->d1->unprocessed_rcds.epoch != 337 tls12_record_layer_read_epoch(s->rl)) 338 return (0); 339 340 /* Update epoch once all unprocessed records have been processed. */ 341 if (pqueue_peek(s->d1->unprocessed_rcds.q) == NULL) { 342 s->d1->unprocessed_rcds.epoch = 343 tls12_record_layer_read_epoch(s->rl) + 1; 344 return (0); 345 } 346 347 /* Process one of the records. */ 348 if (!dtls1_retrieve_buffered_record(s, &s->d1->unprocessed_rcds)) 349 return (-1); 350 if (!dtls1_process_record(s)) 351 return (-1); 352 353 return (1); 354} 355 356static int 357dtls1_process_record(SSL *s) 358{ 359 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec); 360 uint8_t alert_desc; 361 362 tls12_record_layer_set_version(s->rl, s->version); 363 364 if (!tls12_record_layer_open_record(s->rl, s->packet, s->packet_length, 365 s->s3->rcontent)) { 366 tls12_record_layer_alert(s->rl, &alert_desc); 367 368 if (alert_desc == 0) 369 goto err; 370 371 /* 372 * DTLS should silently discard invalid records, including those 373 * with a bad MAC, as per RFC 6347 section 4.1.2.1. 374 */ 375 if (alert_desc == SSL_AD_BAD_RECORD_MAC) 376 goto done; 377 378 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 379 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 380 381 goto fatal_err; 382 } 383 384 /* XXX move to record layer. */ 385 tls_content_set_epoch(s->s3->rcontent, rr->epoch); 386 387 done: 388 s->packet_length = 0; 389 390 return (1); 391 392 fatal_err: 393 ssl3_send_alert(s, SSL3_AL_FATAL, alert_desc); 394 err: 395 return (0); 396} 397 398/* Call this to get a new input record. 399 * It will return <= 0 if more data is needed, normally due to an error 400 * or non-blocking IO. 401 * When it finishes, one packet has been decoded and can be found in 402 * ssl->s3->rrec.type - is the type of record 403 * ssl->s3->rrec.data, - data 404 * ssl->s3->rrec.length, - number of bytes 405 */ 406/* used only by dtls1_read_bytes */ 407int 408dtls1_get_record(SSL *s) 409{ 410 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec); 411 unsigned char *p = NULL; 412 DTLS1_BITMAP *bitmap; 413 unsigned int is_next_epoch; 414 int ret, n; 415 416 /* See if there are pending records that can now be processed. */ 417 if ((ret = dtls1_process_buffered_record(s)) != 0) 418 return (ret); 419 420 /* get something from the wire */ 421 if (0) { 422 again: 423 /* dump this record on all retries */ 424 rr->length = 0; 425 s->packet_length = 0; 426 } 427 428 /* check if we have the header */ 429 if ((s->rstate != SSL_ST_READ_BODY) || 430 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { 431 CBS header, seq_no; 432 uint16_t epoch, len, ssl_version; 433 uint8_t type; 434 435 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH); 436 if (n <= 0) 437 return (n); 438 439 /* If this packet contained a partial record, dump it. */ 440 if (n != DTLS1_RT_HEADER_LENGTH) 441 goto again; 442 443 s->rstate = SSL_ST_READ_BODY; 444 445 CBS_init(&header, s->packet, s->packet_length); 446 447 /* Pull apart the header into the DTLS1_RECORD */ 448 if (!CBS_get_u8(&header, &type)) 449 goto again; 450 if (!CBS_get_u16(&header, &ssl_version)) 451 goto again; 452 453 /* Sequence number is 64 bits, with top 2 bytes = epoch. */ 454 if (!CBS_get_bytes(&header, &seq_no, SSL3_SEQUENCE_SIZE)) 455 goto again; 456 if (!CBS_get_u16(&seq_no, &epoch)) 457 goto again; 458 if (!CBS_write_bytes(&seq_no, &rr->seq_num[2], 459 sizeof(rr->seq_num) - 2, NULL)) 460 goto again; 461 462 if (!CBS_get_u16(&header, &len)) 463 goto again; 464 465 rr->type = type; 466 rr->epoch = epoch; 467 rr->length = len; 468 469 /* unexpected version, silently discard */ 470 if (!s->first_packet && ssl_version != s->version) 471 goto again; 472 473 /* wrong version, silently discard record */ 474 if ((ssl_version & 0xff00) != (s->version & 0xff00)) 475 goto again; 476 477 /* record too long, silently discard it */ 478 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 479 goto again; 480 481 /* now s->rstate == SSL_ST_READ_BODY */ 482 p = (unsigned char *)CBS_data(&header); 483 } 484 485 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 486 487 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length); 488 if (n <= 0) 489 return (n); 490 491 /* If this packet contained a partial record, dump it. */ 492 if (n != DTLS1_RT_HEADER_LENGTH + rr->length) 493 goto again; 494 495 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 496 497 /* match epochs. NULL means the packet is dropped on the floor */ 498 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 499 if (bitmap == NULL) 500 goto again; 501 502 /* 503 * Check whether this is a repeat, or aged record. 504 * Don't check if we're listening and this message is 505 * a ClientHello. They can look as if they're replayed, 506 * since they arrive from different connections and 507 * would be dropped unnecessarily. 508 */ 509 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 510 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 511 !dtls1_record_replay_check(s, bitmap, rr->seq_num)) 512 goto again; 513 514 /* just read a 0 length packet */ 515 if (rr->length == 0) 516 goto again; 517 518 /* If this record is from the next epoch (either HM or ALERT), 519 * and a handshake is currently in progress, buffer it since it 520 * cannot be processed at this time. However, do not buffer 521 * anything while listening. 522 */ 523 if (is_next_epoch) { 524 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) { 525 if (dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), 526 rr->seq_num) < 0) 527 return (-1); 528 /* Mark receipt of record. */ 529 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 530 } 531 goto again; 532 } 533 534 if (!dtls1_process_record(s)) 535 goto again; 536 537 /* Mark receipt of record. */ 538 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 539 540 return (1); 541} 542 543static int 544dtls1_read_handshake_unexpected(SSL *s) 545{ 546 struct hm_header_st hs_msg_hdr; 547 CBS cbs; 548 int ret; 549 550 if (s->in_handshake) { 551 SSLerror(s, ERR_R_INTERNAL_ERROR); 552 return -1; 553 } 554 555 /* Parse handshake message header. */ 556 CBS_dup(tls_content_cbs(s->s3->rcontent), &cbs); 557 if (!dtls1_get_message_header(&cbs, &hs_msg_hdr)) 558 return -1; /* XXX - probably should drop/continue. */ 559 560 /* This may just be a stale retransmit. */ 561 if (tls_content_epoch(s->s3->rcontent) != 562 tls12_record_layer_read_epoch(s->rl)) { 563 tls_content_clear(s->s3->rcontent); 564 s->s3->rrec.length = 0; 565 return 1; 566 } 567 568 if (hs_msg_hdr.type == SSL3_MT_HELLO_REQUEST) { 569 /* 570 * Incoming HelloRequest messages should only be received by a 571 * client. A server may send these at any time - a client should 572 * ignore the message if received in the middle of a handshake. 573 * See RFC 5246 sections 7.4 and 7.4.1.1. 574 */ 575 if (s->server) { 576 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 577 ssl3_send_alert(s, SSL3_AL_FATAL, 578 SSL_AD_UNEXPECTED_MESSAGE); 579 return -1; 580 } 581 582 /* XXX - should also check frag offset/length. */ 583 if (hs_msg_hdr.msg_len != 0) { 584 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 585 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 586 return -1; 587 } 588 589 ssl_msg_callback_cbs(s, 0, SSL3_RT_HANDSHAKE, 590 tls_content_cbs(s->s3->rcontent)); 591 592 tls_content_clear(s->s3->rcontent); 593 s->s3->rrec.length = 0; 594 595 /* 596 * It should be impossible to hit this, but keep the safety 597 * harness for now... 598 */ 599 if (s->session == NULL || s->session->cipher == NULL) 600 return 1; 601 602 /* 603 * Ignore this message if we're currently handshaking, 604 * renegotiation is already pending or renegotiation is disabled 605 * via flags. 606 */ 607 if (!SSL_is_init_finished(s) || s->s3->renegotiate || 608 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) 609 return 1; 610 611 s->d1->handshake_read_seq++; 612 613 /* XXX - why is this set here but not in ssl3? */ 614 s->new_session = 1; 615 616 if (!ssl3_renegotiate(s)) 617 return 1; 618 if (!ssl3_renegotiate_check(s)) 619 return 1; 620 621 } else if (hs_msg_hdr.type == SSL3_MT_CLIENT_HELLO) { 622 /* 623 * Incoming ClientHello messages should only be received by a 624 * server. A client may send these in response to server 625 * initiated renegotiation (HelloRequest) or in order to 626 * initiate renegotiation by the client. See RFC 5246 section 627 * 7.4.1.2. 628 */ 629 if (!s->server) { 630 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 631 ssl3_send_alert(s, SSL3_AL_FATAL, 632 SSL_AD_UNEXPECTED_MESSAGE); 633 return -1; 634 } 635 636 /* 637 * A client should not be sending a ClientHello unless we're not 638 * currently handshaking. 639 */ 640 if (!SSL_is_init_finished(s)) { 641 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 642 ssl3_send_alert(s, SSL3_AL_FATAL, 643 SSL_AD_UNEXPECTED_MESSAGE); 644 return -1; 645 } 646 647 if ((s->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) { 648 ssl3_send_alert(s, SSL3_AL_FATAL, 649 SSL_AD_NO_RENEGOTIATION); 650 return -1; 651 } 652 653 if (s->session == NULL || s->session->cipher == NULL) { 654 SSLerror(s, ERR_R_INTERNAL_ERROR); 655 return -1; 656 } 657 658 /* Client requested renegotiation but it is not permitted. */ 659 if (!s->s3->send_connection_binding || 660 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) { 661 ssl3_send_alert(s, SSL3_AL_WARNING, 662 SSL_AD_NO_RENEGOTIATION); 663 return 1; 664 } 665 666 s->s3->hs.state = SSL_ST_ACCEPT; 667 s->renegotiate = 1; 668 s->new_session = 1; 669 670 } else if (hs_msg_hdr.type == SSL3_MT_FINISHED && s->server) { 671 /* 672 * If we are server, we may have a repeated FINISHED of the 673 * client here, then retransmit our CCS and FINISHED. 674 */ 675 if (dtls1_check_timeout_num(s) < 0) 676 return -1; 677 678 /* XXX - should this be calling ssl_msg_callback()? */ 679 680 dtls1_retransmit_buffered_messages(s); 681 682 tls_content_clear(s->s3->rcontent); 683 s->s3->rrec.length = 0; 684 685 return 1; 686 687 } else { 688 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 689 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 690 return -1; 691 } 692 693 if ((ret = s->handshake_func(s)) < 0) 694 return ret; 695 if (ret == 0) { 696 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 697 return -1; 698 } 699 700 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 701 if (s->s3->rbuf.left == 0) { 702 ssl_force_want_read(s); 703 return -1; 704 } 705 } 706 707 /* 708 * We either finished a handshake or ignored the request, now try again 709 * to obtain the (application) data we were asked for. 710 */ 711 return 1; 712} 713 714/* Return up to 'len' payload bytes received in 'type' records. 715 * 'type' is one of the following: 716 * 717 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 718 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 719 * - 0 (during a shutdown, no data has to be returned) 720 * 721 * If we don't have stored data to work from, read a SSL/TLS record first 722 * (possibly multiple records if we still don't have anything to return). 723 * 724 * This function must handle any surprises the peer may have for us, such as 725 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 726 * a surprise, but handled as if it were), or renegotiation requests. 727 * Also if record payloads contain fragments too small to process, we store 728 * them until there is enough for the respective protocol (the record protocol 729 * may use arbitrary fragmentation and even interleaving): 730 * Change cipher spec protocol 731 * just 1 byte needed, no need for keeping anything stored 732 * Alert protocol 733 * 2 bytes needed (AlertLevel, AlertDescription) 734 * Handshake protocol 735 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 736 * to detect unexpected Client Hello and Hello Request messages 737 * here, anything else is handled by higher layers 738 * Application data protocol 739 * none of our business 740 */ 741int 742dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 743{ 744 int rrcount = 0; 745 ssize_t ssret; 746 int ret; 747 748 if (s->s3->rbuf.buf == NULL) { 749 if (!ssl3_setup_buffers(s)) 750 return -1; 751 } 752 753 if (s->s3->rcontent == NULL) { 754 if ((s->s3->rcontent = tls_content_new()) == NULL) 755 return -1; 756 } 757 758 if (len < 0) { 759 SSLerror(s, ERR_R_INTERNAL_ERROR); 760 return -1; 761 } 762 763 if (type != 0 && type != SSL3_RT_APPLICATION_DATA && 764 type != SSL3_RT_HANDSHAKE) { 765 SSLerror(s, ERR_R_INTERNAL_ERROR); 766 return -1; 767 } 768 if (peek && type != SSL3_RT_APPLICATION_DATA) { 769 SSLerror(s, ERR_R_INTERNAL_ERROR); 770 return -1; 771 } 772 773 if (SSL_in_init(s) && !s->in_handshake) { 774 if ((ret = s->handshake_func(s)) < 0) 775 return ret; 776 if (ret == 0) { 777 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 778 return -1; 779 } 780 } 781 782 start: 783 /* 784 * Do not process more than three consecutive records, otherwise the 785 * peer can cause us to loop indefinitely. Instead, return with an 786 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 787 * processing. In the future, the total number of non-handshake and 788 * non-application data records per connection should probably also be 789 * limited... 790 */ 791 if (rrcount++ >= 3) { 792 ssl_force_want_read(s); 793 return -1; 794 } 795 796 s->rwstate = SSL_NOTHING; 797 798 /* 799 * We are not handshaking and have no data yet, so process data buffered 800 * during the last handshake in advance, if any. 801 */ 802 if (s->s3->hs.state == SSL_ST_OK && 803 tls_content_remaining(s->s3->rcontent) == 0) 804 dtls1_retrieve_buffered_rcontent(s, &s->d1->buffered_app_data); 805 806 if (dtls1_handle_timeout(s) > 0) 807 goto start; 808 809 if (tls_content_remaining(s->s3->rcontent) == 0) { 810 if ((ret = dtls1_get_record(s)) <= 0) { 811 /* Anything other than a timeout is an error. */ 812 if ((ret = dtls1_read_failed(s, ret)) <= 0) 813 return ret; 814 goto start; 815 } 816 } 817 818 if (s->d1->listen && 819 tls_content_type(s->s3->rcontent) != SSL3_RT_HANDSHAKE) { 820 tls_content_clear(s->s3->rcontent); 821 s->s3->rrec.length = 0; 822 goto start; 823 } 824 825 /* We now have a packet which can be read and processed. */ 826 827 if (s->s3->change_cipher_spec && 828 tls_content_type(s->s3->rcontent) != SSL3_RT_HANDSHAKE) { 829 /* 830 * We now have application data between CCS and Finished. 831 * Most likely the packets were reordered on their way, so 832 * buffer the application data for later processing rather 833 * than dropping the connection. 834 */ 835 if (dtls1_buffer_rcontent(s, &s->d1->buffered_app_data, 836 s->s3->rrec.seq_num) < 0) { 837 SSLerror(s, ERR_R_INTERNAL_ERROR); 838 return (-1); 839 } 840 tls_content_clear(s->s3->rcontent); 841 s->s3->rrec.length = 0; 842 goto start; 843 } 844 845 /* 846 * If the other end has shut down, throw anything we read away (even in 847 * 'peek' mode). 848 */ 849 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 850 s->rwstate = SSL_NOTHING; 851 tls_content_clear(s->s3->rcontent); 852 s->s3->rrec.length = 0; 853 return 0; 854 } 855 856 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 857 if (tls_content_type(s->s3->rcontent) == type) { 858 /* 859 * Make sure that we are not getting application data when we 860 * are doing a handshake for the first time. 861 */ 862 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 863 !tls12_record_layer_read_protected(s->rl)) { 864 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 865 ssl3_send_alert(s, SSL3_AL_FATAL, 866 SSL_AD_UNEXPECTED_MESSAGE); 867 return -1; 868 } 869 870 if (len <= 0) 871 return len; 872 873 if (peek) { 874 ssret = tls_content_peek(s->s3->rcontent, buf, len); 875 } else { 876 ssret = tls_content_read(s->s3->rcontent, buf, len); 877 } 878 if (ssret < INT_MIN || ssret > INT_MAX) 879 return -1; 880 if (ssret < 0) 881 return (int)ssret; 882 883 if (tls_content_remaining(s->s3->rcontent) == 0) 884 s->rstate = SSL_ST_READ_HEADER; 885 886 return (int)ssret; 887 } 888 889 if (tls_content_type(s->s3->rcontent) == SSL3_RT_ALERT) { 890 if ((ret = ssl3_read_alert(s)) <= 0) 891 return ret; 892 goto start; 893 } 894 895 if (s->shutdown & SSL_SENT_SHUTDOWN) { 896 s->rwstate = SSL_NOTHING; 897 tls_content_clear(s->s3->rcontent); 898 s->s3->rrec.length = 0; 899 return (0); 900 } 901 902 if (tls_content_type(s->s3->rcontent) == SSL3_RT_APPLICATION_DATA) { 903 /* 904 * At this point, we were expecting handshake data, but have 905 * application data. If the library was running inside 906 * ssl3_read() (i.e. in_read_app_data is set) and it makes 907 * sense to read application data at this point (session 908 * renegotiation not yet started), we will indulge it. 909 */ 910 if (s->s3->in_read_app_data != 0 && 911 s->s3->total_renegotiations != 0 && 912 (((s->s3->hs.state & SSL_ST_CONNECT) && 913 (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 914 (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 915 (s->s3->hs.state & SSL_ST_ACCEPT) && 916 (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 917 (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 918 s->s3->in_read_app_data = 2; 919 return -1; 920 } else { 921 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 922 ssl3_send_alert(s, SSL3_AL_FATAL, 923 SSL_AD_UNEXPECTED_MESSAGE); 924 return -1; 925 } 926 } 927 928 if (tls_content_type(s->s3->rcontent) == SSL3_RT_CHANGE_CIPHER_SPEC) { 929 if ((ret = ssl3_read_change_cipher_spec(s)) <= 0) 930 return ret; 931 goto start; 932 } 933 934 if (tls_content_type(s->s3->rcontent) == SSL3_RT_HANDSHAKE) { 935 if ((ret = dtls1_read_handshake_unexpected(s)) <= 0) 936 return ret; 937 goto start; 938 } 939 940 /* Unknown record type. */ 941 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 942 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 943 return -1; 944} 945 946int 947dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 948{ 949 int i; 950 951 if (SSL_in_init(s) && !s->in_handshake) { 952 i = s->handshake_func(s); 953 if (i < 0) 954 return (i); 955 if (i == 0) { 956 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 957 return -1; 958 } 959 } 960 961 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 962 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); 963 return -1; 964 } 965 966 i = dtls1_write_bytes(s, type, buf_, len); 967 return i; 968} 969 970/* Call this to write data in records of type 'type' 971 * It will return <= 0 if not all data has been sent or non-blocking IO. 972 */ 973int 974dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 975{ 976 int i; 977 978 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 979 s->rwstate = SSL_NOTHING; 980 i = do_dtls1_write(s, type, buf, len); 981 return i; 982} 983 984int 985do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 986{ 987 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); 988 size_t out_len; 989 CBB cbb; 990 int ret; 991 992 memset(&cbb, 0, sizeof(cbb)); 993 994 /* 995 * First check if there is a SSL3_BUFFER_INTERNAL still being written 996 * out. This will happen with non blocking IO. 997 */ 998 if (wb->left != 0) { 999 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1000 return (ssl3_write_pending(s, type, buf, len)); 1001 } 1002 1003 /* If we have an alert to send, let's send it */ 1004 if (s->s3->alert_dispatch) { 1005 if ((ret = ssl3_dispatch_alert(s)) <= 0) 1006 return (ret); 1007 /* If it went, fall through and send more stuff. */ 1008 } 1009 1010 if (len == 0) 1011 return 0; 1012 1013 wb->offset = 0; 1014 1015 if (!CBB_init_fixed(&cbb, wb->buf, wb->len)) 1016 goto err; 1017 1018 tls12_record_layer_set_version(s->rl, s->version); 1019 1020 if (!tls12_record_layer_seal_record(s->rl, type, buf, len, &cbb)) 1021 goto err; 1022 1023 if (!CBB_finish(&cbb, NULL, &out_len)) 1024 goto err; 1025 1026 wb->left = out_len; 1027 1028 /* 1029 * Memorize arguments so that ssl3_write_pending can detect 1030 * bad write retries later. 1031 */ 1032 s->s3->wpend_tot = len; 1033 s->s3->wpend_buf = buf; 1034 s->s3->wpend_type = type; 1035 s->s3->wpend_ret = len; 1036 1037 /* We now just need to write the buffer. */ 1038 return ssl3_write_pending(s, type, buf, len); 1039 1040 err: 1041 CBB_cleanup(&cbb); 1042 1043 return -1; 1044} 1045 1046static int 1047dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 1048 const unsigned char *seq) 1049{ 1050 unsigned int shift; 1051 int cmp; 1052 1053 cmp = satsub64be(seq, bitmap->max_seq_num); 1054 if (cmp > 0) 1055 return 1; /* this record in new */ 1056 shift = -cmp; 1057 if (shift >= sizeof(bitmap->map)*8) 1058 return 0; /* stale, outside the window */ 1059 else if (bitmap->map & (1UL << shift)) 1060 return 0; /* record previously received */ 1061 1062 return 1; 1063} 1064 1065static void 1066dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 1067 const unsigned char *seq) 1068{ 1069 unsigned int shift; 1070 int cmp; 1071 1072 cmp = satsub64be(seq, bitmap->max_seq_num); 1073 if (cmp > 0) { 1074 shift = cmp; 1075 if (shift < sizeof(bitmap->map)*8) 1076 bitmap->map <<= shift, bitmap->map |= 1UL; 1077 else 1078 bitmap->map = 1UL; 1079 memcpy(bitmap->max_seq_num, seq, 8); 1080 } else { 1081 shift = -cmp; 1082 if (shift < sizeof(bitmap->map) * 8) 1083 bitmap->map |= 1UL << shift; 1084 } 1085} 1086 1087static DTLS1_BITMAP * 1088dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch) 1089{ 1090 uint16_t read_epoch, read_epoch_next; 1091 1092 *is_next_epoch = 0; 1093 1094 read_epoch = tls12_record_layer_read_epoch(s->rl); 1095 read_epoch_next = read_epoch + 1; 1096 1097 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1098 if (rr->epoch == read_epoch) 1099 return &s->d1->bitmap; 1100 1101 /* Only HM and ALERT messages can be from the next epoch */ 1102 if (rr->epoch == read_epoch_next && 1103 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1104 *is_next_epoch = 1; 1105 return &s->d1->next_bitmap; 1106 } 1107 1108 return NULL; 1109} 1110 1111void 1112dtls1_reset_read_seq_numbers(SSL *s) 1113{ 1114 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1115 memset(&(s->d1->next_bitmap), 0, sizeof(DTLS1_BITMAP)); 1116} 1117