1 /* $OpenBSD: d1_pkt.c,v 1.116 2021/11/09 18:40:21 bcook 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 <stdio.h> 119 120 #include <openssl/buffer.h> 121 #include <openssl/evp.h> 122 123 #include "bytestring.h" 124 #include "dtls_locl.h" 125 #include "pqueue.h" 126 #include "ssl_locl.h" 127 128 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 129 static int 130 satsub64be(const unsigned char *v1, const unsigned char *v2) 131 { 132 int ret, sat, brw, i; 133 134 if (sizeof(long) == 8) 135 do { 136 long l; 137 138 if (BYTE_ORDER == LITTLE_ENDIAN) 139 break; 140 /* not reached on little-endians */ 141 /* following test is redundant, because input is 142 * always aligned, but I take no chances... */ 143 if (((size_t)v1 | (size_t)v2) & 0x7) 144 break; 145 146 l = *((long *)v1); 147 l -= *((long *)v2); 148 if (l > 128) 149 return 128; 150 else if (l<-128) 151 return -128; 152 else 153 return (int)l; 154 } while (0); 155 156 ret = (int)v1[7] - (int)v2[7]; 157 sat = 0; 158 brw = ret >> 8; /* brw is either 0 or -1 */ 159 if (ret & 0x80) { 160 for (i = 6; i >= 0; i--) { 161 brw += (int)v1[i]-(int)v2[i]; 162 sat |= ~brw; 163 brw >>= 8; 164 } 165 } else { 166 for (i = 6; i >= 0; i--) { 167 brw += (int)v1[i]-(int)v2[i]; 168 sat |= brw; 169 brw >>= 8; 170 } 171 } 172 brw <<= 8; /* brw is either 0 or -256 */ 173 174 if (sat & 0xff) 175 return brw | 0x80; 176 else 177 return brw + (ret & 0xFF); 178 } 179 180 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 181 const unsigned char *seq); 182 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 183 const unsigned char *seq); 184 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, 185 unsigned int *is_next_epoch); 186 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 187 unsigned char *priority); 188 static int dtls1_process_record(SSL *s); 189 190 /* copy buffered record into SSL structure */ 191 static int 192 dtls1_copy_record(SSL *s, DTLS1_RECORD_DATA_INTERNAL *rdata) 193 { 194 ssl3_release_buffer(&S3I(s)->rbuf); 195 196 s->internal->packet = rdata->packet; 197 s->internal->packet_length = rdata->packet_length; 198 memcpy(&(S3I(s)->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 199 memcpy(&(S3I(s)->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL)); 200 201 return (1); 202 } 203 204 static int 205 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 206 { 207 DTLS1_RECORD_DATA_INTERNAL *rdata; 208 pitem *item; 209 210 /* Limit the size of the queue to prevent DOS attacks */ 211 if (pqueue_size(queue->q) >= 100) 212 return 0; 213 214 rdata = malloc(sizeof(DTLS1_RECORD_DATA_INTERNAL)); 215 item = pitem_new(priority, rdata); 216 if (rdata == NULL || item == NULL) 217 goto init_err; 218 219 rdata->packet = s->internal->packet; 220 rdata->packet_length = s->internal->packet_length; 221 memcpy(&(rdata->rbuf), &(S3I(s)->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 222 memcpy(&(rdata->rrec), &(S3I(s)->rrec), sizeof(SSL3_RECORD_INTERNAL)); 223 224 item->data = rdata; 225 226 s->internal->packet = NULL; 227 s->internal->packet_length = 0; 228 memset(&(S3I(s)->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL)); 229 memset(&(S3I(s)->rrec), 0, sizeof(SSL3_RECORD_INTERNAL)); 230 231 if (!ssl3_setup_buffers(s)) 232 goto err; 233 234 /* insert should not fail, since duplicates are dropped */ 235 if (pqueue_insert(queue->q, item) == NULL) 236 goto err; 237 238 return (1); 239 240 err: 241 ssl3_release_buffer(&rdata->rbuf); 242 243 init_err: 244 SSLerror(s, ERR_R_INTERNAL_ERROR); 245 free(rdata); 246 pitem_free(item); 247 return (-1); 248 } 249 250 251 static int 252 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 253 { 254 pitem *item; 255 256 item = pqueue_pop(queue->q); 257 if (item) { 258 dtls1_copy_record(s, item->data); 259 260 free(item->data); 261 pitem_free(item); 262 263 return (1); 264 } 265 266 return (0); 267 } 268 269 static int 270 dtls1_process_buffered_record(SSL *s) 271 { 272 /* Check if epoch is current. */ 273 if (s->d1->unprocessed_rcds.epoch != 274 tls12_record_layer_read_epoch(s->internal->rl)) 275 return (0); 276 277 /* Update epoch once all unprocessed records have been processed. */ 278 if (pqueue_peek(s->d1->unprocessed_rcds.q) == NULL) { 279 s->d1->unprocessed_rcds.epoch = 280 tls12_record_layer_read_epoch(s->internal->rl) + 1; 281 return (0); 282 } 283 284 /* Process one of the records. */ 285 if (!dtls1_retrieve_buffered_record(s, &s->d1->unprocessed_rcds)) 286 return (-1); 287 if (!dtls1_process_record(s)) 288 return (-1); 289 290 return (1); 291 } 292 293 static int 294 dtls1_process_record(SSL *s) 295 { 296 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 297 uint8_t alert_desc; 298 uint8_t *out; 299 size_t out_len; 300 301 tls12_record_layer_set_version(s->internal->rl, s->version); 302 303 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet, 304 s->internal->packet_length, &out, &out_len)) { 305 tls12_record_layer_alert(s->internal->rl, &alert_desc); 306 307 if (alert_desc == 0) 308 goto err; 309 310 /* 311 * DTLS should silently discard invalid records, including those 312 * with a bad MAC, as per RFC 6347 section 4.1.2.1. 313 */ 314 if (alert_desc == SSL_AD_BAD_RECORD_MAC) { 315 out_len = 0; 316 goto done; 317 } 318 319 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 320 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 321 322 goto fatal_err; 323 } 324 325 done: 326 rr->data = out; 327 rr->length = out_len; 328 rr->off = 0; 329 330 s->internal->packet_length = 0; 331 332 return (1); 333 334 fatal_err: 335 ssl3_send_alert(s, SSL3_AL_FATAL, alert_desc); 336 err: 337 return (0); 338 } 339 340 /* Call this to get a new input record. 341 * It will return <= 0 if more data is needed, normally due to an error 342 * or non-blocking IO. 343 * When it finishes, one packet has been decoded and can be found in 344 * ssl->s3->internal->rrec.type - is the type of record 345 * ssl->s3->internal->rrec.data, - data 346 * ssl->s3->internal->rrec.length, - number of bytes 347 */ 348 /* used only by dtls1_read_bytes */ 349 int 350 dtls1_get_record(SSL *s) 351 { 352 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 353 unsigned char *p = NULL; 354 DTLS1_BITMAP *bitmap; 355 unsigned int is_next_epoch; 356 int ret, n; 357 358 /* See if there are pending records that can now be processed. */ 359 if ((ret = dtls1_process_buffered_record(s)) != 0) 360 return (ret); 361 362 /* get something from the wire */ 363 if (0) { 364 again: 365 /* dump this record on all retries */ 366 rr->length = 0; 367 s->internal->packet_length = 0; 368 } 369 370 /* check if we have the header */ 371 if ((s->internal->rstate != SSL_ST_READ_BODY) || 372 (s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) { 373 CBS header, seq_no; 374 uint16_t epoch, len, ssl_version; 375 uint8_t type; 376 377 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH); 378 if (n <= 0) 379 return (n); 380 381 /* If this packet contained a partial record, dump it. */ 382 if (n != DTLS1_RT_HEADER_LENGTH) 383 goto again; 384 385 s->internal->rstate = SSL_ST_READ_BODY; 386 387 CBS_init(&header, s->internal->packet, s->internal->packet_length); 388 389 /* Pull apart the header into the DTLS1_RECORD */ 390 if (!CBS_get_u8(&header, &type)) 391 goto again; 392 if (!CBS_get_u16(&header, &ssl_version)) 393 goto again; 394 395 /* Sequence number is 64 bits, with top 2 bytes = epoch. */ 396 if (!CBS_get_bytes(&header, &seq_no, SSL3_SEQUENCE_SIZE)) 397 goto again; 398 if (!CBS_get_u16(&seq_no, &epoch)) 399 goto again; 400 if (!CBS_write_bytes(&seq_no, &rr->seq_num[2], 401 sizeof(rr->seq_num) - 2, NULL)) 402 goto again; 403 404 if (!CBS_get_u16(&header, &len)) 405 goto again; 406 407 rr->type = type; 408 rr->epoch = epoch; 409 rr->length = len; 410 411 /* unexpected version, silently discard */ 412 if (!s->internal->first_packet && ssl_version != s->version) 413 goto again; 414 415 /* wrong version, silently discard record */ 416 if ((ssl_version & 0xff00) != (s->version & 0xff00)) 417 goto again; 418 419 /* record too long, silently discard it */ 420 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 421 goto again; 422 423 /* now s->internal->rstate == SSL_ST_READ_BODY */ 424 p = (unsigned char *)CBS_data(&header); 425 } 426 427 /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */ 428 429 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length); 430 if (n <= 0) 431 return (n); 432 433 /* If this packet contained a partial record, dump it. */ 434 if (n != DTLS1_RT_HEADER_LENGTH + rr->length) 435 goto again; 436 437 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 438 439 /* match epochs. NULL means the packet is dropped on the floor */ 440 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 441 if (bitmap == NULL) 442 goto again; 443 444 /* 445 * Check whether this is a repeat, or aged record. 446 * Don't check if we're listening and this message is 447 * a ClientHello. They can look as if they're replayed, 448 * since they arrive from different connections and 449 * would be dropped unnecessarily. 450 */ 451 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 452 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 453 !dtls1_record_replay_check(s, bitmap, rr->seq_num)) 454 goto again; 455 456 /* just read a 0 length packet */ 457 if (rr->length == 0) 458 goto again; 459 460 /* If this record is from the next epoch (either HM or ALERT), 461 * and a handshake is currently in progress, buffer it since it 462 * cannot be processed at this time. However, do not buffer 463 * anything while listening. 464 */ 465 if (is_next_epoch) { 466 if ((SSL_in_init(s) || s->internal->in_handshake) && !s->d1->listen) { 467 if (dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), 468 rr->seq_num) < 0) 469 return (-1); 470 /* Mark receipt of record. */ 471 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 472 } 473 goto again; 474 } 475 476 if (!dtls1_process_record(s)) 477 goto again; 478 479 /* Mark receipt of record. */ 480 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 481 482 return (1); 483 } 484 485 /* Return up to 'len' payload bytes received in 'type' records. 486 * 'type' is one of the following: 487 * 488 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 489 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 490 * - 0 (during a shutdown, no data has to be returned) 491 * 492 * If we don't have stored data to work from, read a SSL/TLS record first 493 * (possibly multiple records if we still don't have anything to return). 494 * 495 * This function must handle any surprises the peer may have for us, such as 496 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 497 * a surprise, but handled as if it were), or renegotiation requests. 498 * Also if record payloads contain fragments too small to process, we store 499 * them until there is enough for the respective protocol (the record protocol 500 * may use arbitrary fragmentation and even interleaving): 501 * Change cipher spec protocol 502 * just 1 byte needed, no need for keeping anything stored 503 * Alert protocol 504 * 2 bytes needed (AlertLevel, AlertDescription) 505 * Handshake protocol 506 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 507 * to detect unexpected Client Hello and Hello Request messages 508 * here, anything else is handled by higher layers 509 * Application data protocol 510 * none of our business 511 */ 512 int 513 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 514 { 515 int al, i, ret; 516 int rrcount = 0; 517 unsigned int n; 518 SSL3_RECORD_INTERNAL *rr; 519 520 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */ 521 if (!ssl3_setup_buffers(s)) 522 return (-1); 523 524 if ((type && 525 type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || 526 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 527 SSLerror(s, ERR_R_INTERNAL_ERROR); 528 return -1; 529 } 530 531 if (!s->internal->in_handshake && SSL_in_init(s)) { 532 i = s->internal->handshake_func(s); 533 if (i < 0) 534 return (i); 535 if (i == 0) { 536 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 537 return (-1); 538 } 539 } 540 541 start: 542 /* 543 * Do not process more than three consecutive records, otherwise the 544 * peer can cause us to loop indefinitely. Instead, return with an 545 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 546 * processing. In the future, the total number of non-handshake and 547 * non-application data records per connection should probably also be 548 * limited... 549 */ 550 if (rrcount++ >= 3) { 551 ssl_force_want_read(s); 552 return -1; 553 } 554 555 s->internal->rwstate = SSL_NOTHING; 556 557 /* S3I(s)->rrec.type - is the type of record 558 * S3I(s)->rrec.data, - data 559 * S3I(s)->rrec.off, - offset into 'data' for next read 560 * S3I(s)->rrec.length, - number of bytes. */ 561 rr = &(S3I(s)->rrec); 562 563 /* We are not handshaking and have no data yet, 564 * so process data buffered during the last handshake 565 * in advance, if any. 566 */ 567 if (S3I(s)->hs.state == SSL_ST_OK && rr->length == 0) 568 dtls1_retrieve_buffered_record(s, &(s->d1->buffered_app_data)); 569 570 /* Check for timeout */ 571 if (dtls1_handle_timeout(s) > 0) 572 goto start; 573 574 /* get new packet if necessary */ 575 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 576 ret = dtls1_get_record(s); 577 if (ret <= 0) { 578 ret = dtls1_read_failed(s, ret); 579 /* anything other than a timeout is an error */ 580 if (ret <= 0) 581 return (ret); 582 else 583 goto start; 584 } 585 } 586 587 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) { 588 rr->length = 0; 589 goto start; 590 } 591 592 /* we now have a packet which can be read and processed */ 593 594 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 595 * reset by ssl3_get_finished */ 596 && (rr->type != SSL3_RT_HANDSHAKE)) { 597 /* We now have application data between CCS and Finished. 598 * Most likely the packets were reordered on their way, so 599 * buffer the application data for later processing rather 600 * than dropping the connection. 601 */ 602 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), 603 rr->seq_num) < 0) { 604 SSLerror(s, ERR_R_INTERNAL_ERROR); 605 return (-1); 606 } 607 rr->length = 0; 608 goto start; 609 } 610 611 /* If the other end has shut down, throw anything we read away 612 * (even in 'peek' mode) */ 613 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 614 rr->length = 0; 615 s->internal->rwstate = SSL_NOTHING; 616 return (0); 617 } 618 619 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 620 if (type == rr->type) { 621 /* make sure that we are not getting application data when we 622 * are doing a handshake for the first time */ 623 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 624 !tls12_record_layer_read_protected(s->internal->rl)) { 625 al = SSL_AD_UNEXPECTED_MESSAGE; 626 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 627 goto fatal_err; 628 } 629 630 if (len <= 0) 631 return (len); 632 633 if ((unsigned int)len > rr->length) 634 n = rr->length; 635 else 636 n = (unsigned int)len; 637 638 memcpy(buf, &(rr->data[rr->off]), n); 639 if (!peek) { 640 rr->length -= n; 641 rr->off += n; 642 if (rr->length == 0) { 643 s->internal->rstate = SSL_ST_READ_HEADER; 644 rr->off = 0; 645 } 646 } 647 648 return (n); 649 } 650 651 /* 652 * If we get here, then type != rr->type; if we have a handshake 653 * message, then it was unexpected (Hello Request or Client Hello). 654 */ 655 656 { 657 unsigned int record_min_len = 0; 658 659 if (rr->type == SSL3_RT_HANDSHAKE) { 660 record_min_len = DTLS1_HM_HEADER_LENGTH; 661 } else if (rr->type == SSL3_RT_ALERT) { 662 record_min_len = DTLS1_AL_HEADER_LENGTH; 663 } else if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 664 record_min_len = DTLS1_CCS_HEADER_LENGTH; 665 } else if (rr->type == SSL3_RT_APPLICATION_DATA) { 666 /* 667 * Application data while renegotiating is allowed. 668 * Try reading again. 669 */ 670 S3I(s)->in_read_app_data = 2; 671 ssl_force_want_read(s); 672 return -1; 673 } else { 674 /* Not certain if this is the right error handling */ 675 al = SSL_AD_UNEXPECTED_MESSAGE; 676 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 677 goto fatal_err; 678 } 679 680 if (record_min_len > 0 && rr->length < record_min_len) { 681 s->internal->rstate = SSL_ST_READ_HEADER; 682 rr->length = 0; 683 goto start; 684 } 685 } 686 687 /* If we are a client, check for an incoming 'Hello Request': */ 688 if (!s->server && rr->type == SSL3_RT_HANDSHAKE && 689 rr->length >= DTLS1_HM_HEADER_LENGTH && rr->off == 0 && 690 rr->data[0] == SSL3_MT_HELLO_REQUEST && 691 s->session != NULL && s->session->cipher != NULL) { 692 struct hm_header_st msg_hdr; 693 CBS cbs; 694 695 CBS_init(&cbs, rr->data, rr->length); 696 if (!dtls1_get_message_header(&cbs, &msg_hdr)) 697 return -1; 698 if (msg_hdr.msg_len != 0) { 699 al = SSL_AD_DECODE_ERROR; 700 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 701 goto fatal_err; 702 } 703 rr->length = 0; 704 705 /* no need to check sequence number on HELLO REQUEST messages */ 706 707 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE, rr->data, 4); 708 709 if (SSL_is_init_finished(s) && 710 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 711 !S3I(s)->renegotiate) { 712 s->d1->handshake_read_seq++; 713 s->internal->new_session = 1; 714 ssl3_renegotiate(s); 715 if (ssl3_renegotiate_check(s)) { 716 i = s->internal->handshake_func(s); 717 if (i < 0) 718 return (i); 719 if (i == 0) { 720 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 721 return (-1); 722 } 723 724 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 725 if (S3I(s)->rbuf.left == 0) { 726 ssl_force_want_read(s); 727 return (-1); 728 } 729 } 730 } 731 } 732 /* we either finished a handshake or ignored the request, 733 * now try again to obtain the (application) data we were asked for */ 734 rr->length = 0; 735 goto start; 736 } 737 738 if (rr->type == SSL3_RT_ALERT && rr->length >= DTLS1_AL_HEADER_LENGTH && 739 rr->off == 0) { 740 int alert_level = rr->data[0]; 741 int alert_descr = rr->data[1]; 742 743 ssl_msg_callback(s, 0, SSL3_RT_ALERT, rr->data, 2); 744 745 ssl_info_callback(s, SSL_CB_READ_ALERT, 746 (alert_level << 8) | alert_descr); 747 748 if (alert_level == SSL3_AL_WARNING) { 749 S3I(s)->warn_alert = alert_descr; 750 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 751 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 752 return (0); 753 } 754 } else if (alert_level == SSL3_AL_FATAL) { 755 s->internal->rwstate = SSL_NOTHING; 756 S3I(s)->fatal_alert = alert_descr; 757 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 758 ERR_asprintf_error_data("SSL alert number %d", 759 alert_descr); 760 s->internal->shutdown|=SSL_RECEIVED_SHUTDOWN; 761 SSL_CTX_remove_session(s->ctx, s->session); 762 return (0); 763 } else { 764 al = SSL_AD_ILLEGAL_PARAMETER; 765 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 766 goto fatal_err; 767 } 768 769 rr->length = 0; 770 goto start; 771 } 772 773 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 774 s->internal->rwstate = SSL_NOTHING; 775 rr->length = 0; 776 return (0); 777 } 778 779 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 780 /* 'Change Cipher Spec' is just a single byte, so we know 781 * exactly what the record payload has to look like */ 782 /* XDTLS: check that epoch is consistent */ 783 if ((rr->length != DTLS1_CCS_HEADER_LENGTH) || 784 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 785 al = SSL_AD_DECODE_ERROR; 786 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 787 goto fatal_err; 788 } 789 790 ssl_msg_callback(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1); 791 792 /* We can't process a CCS now, because previous handshake 793 * messages are still missing, so just drop it. 794 */ 795 if (!s->d1->change_cipher_spec_ok) { 796 rr->length = 0; 797 goto start; 798 } 799 800 s->d1->change_cipher_spec_ok = 0; 801 802 S3I(s)->change_cipher_spec = 1; 803 if (!ssl3_do_change_cipher_spec(s)) 804 goto err; 805 806 rr->length = 0; 807 goto start; 808 } 809 810 /* Unexpected handshake message (Client Hello, or protocol violation) */ 811 if (rr->type == SSL3_RT_HANDSHAKE && 812 rr->length >= DTLS1_HM_HEADER_LENGTH && rr->off == 0 && 813 !s->internal->in_handshake) { 814 struct hm_header_st msg_hdr; 815 CBS cbs; 816 817 /* this may just be a stale retransmit */ 818 CBS_init(&cbs, rr->data, rr->length); 819 if (!dtls1_get_message_header(&cbs, &msg_hdr)) 820 return -1; 821 if (rr->epoch != tls12_record_layer_read_epoch(s->internal->rl)) { 822 rr->length = 0; 823 goto start; 824 } 825 826 /* If we are server, we may have a repeated FINISHED of the 827 * client here, then retransmit our CCS and FINISHED. 828 */ 829 if (msg_hdr.type == SSL3_MT_FINISHED) { 830 if (dtls1_check_timeout_num(s) < 0) 831 return -1; 832 833 dtls1_retransmit_buffered_messages(s); 834 rr->length = 0; 835 goto start; 836 } 837 838 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 839 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 840 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 841 s->internal->renegotiate = 1; 842 s->internal->new_session = 1; 843 } 844 i = s->internal->handshake_func(s); 845 if (i < 0) 846 return (i); 847 if (i == 0) { 848 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 849 return (-1); 850 } 851 852 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 853 if (S3I(s)->rbuf.left == 0) { 854 ssl_force_want_read(s); 855 return (-1); 856 } 857 } 858 rr->length = 0; 859 goto start; 860 } 861 862 switch (rr->type) { 863 default: 864 al = SSL_AD_UNEXPECTED_MESSAGE; 865 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 866 goto fatal_err; 867 case SSL3_RT_CHANGE_CIPHER_SPEC: 868 case SSL3_RT_ALERT: 869 case SSL3_RT_HANDSHAKE: 870 /* we already handled all of these, with the possible exception 871 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 872 * should not happen when type != rr->type */ 873 al = SSL_AD_UNEXPECTED_MESSAGE; 874 SSLerror(s, ERR_R_INTERNAL_ERROR); 875 goto fatal_err; 876 case SSL3_RT_APPLICATION_DATA: 877 /* At this point, we were expecting handshake data, 878 * but have application data. If the library was 879 * running inside ssl3_read() (i.e. in_read_app_data 880 * is set) and it makes sense to read application data 881 * at this point (session renegotiation not yet started), 882 * we will indulge it. 883 */ 884 if (S3I(s)->in_read_app_data && 885 (S3I(s)->total_renegotiations != 0) && 886 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 887 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 888 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 889 (S3I(s)->hs.state & SSL_ST_ACCEPT) && 890 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 891 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 892 S3I(s)->in_read_app_data = 2; 893 return (-1); 894 } else { 895 al = SSL_AD_UNEXPECTED_MESSAGE; 896 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 897 goto fatal_err; 898 } 899 } 900 /* not reached */ 901 902 fatal_err: 903 ssl3_send_alert(s, SSL3_AL_FATAL, al); 904 err: 905 return (-1); 906 } 907 908 int 909 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 910 { 911 int i; 912 913 if (SSL_in_init(s) && !s->internal->in_handshake) 914 { 915 i = s->internal->handshake_func(s); 916 if (i < 0) 917 return (i); 918 if (i == 0) { 919 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 920 return -1; 921 } 922 } 923 924 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 925 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); 926 return -1; 927 } 928 929 i = dtls1_write_bytes(s, type, buf_, len); 930 return i; 931 } 932 933 /* Call this to write data in records of type 'type' 934 * It will return <= 0 if not all data has been sent or non-blocking IO. 935 */ 936 int 937 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 938 { 939 int i; 940 941 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 942 s->internal->rwstate = SSL_NOTHING; 943 i = do_dtls1_write(s, type, buf, len); 944 return i; 945 } 946 947 int 948 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 949 { 950 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 951 size_t out_len; 952 CBB cbb; 953 int ret; 954 955 memset(&cbb, 0, sizeof(cbb)); 956 957 /* 958 * First check if there is a SSL3_BUFFER_INTERNAL still being written 959 * out. This will happen with non blocking IO. 960 */ 961 if (wb->left != 0) { 962 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 963 return (ssl3_write_pending(s, type, buf, len)); 964 } 965 966 /* If we have an alert to send, let's send it */ 967 if (S3I(s)->alert_dispatch) { 968 if ((ret = ssl3_dispatch_alert(s)) <= 0) 969 return (ret); 970 /* If it went, fall through and send more stuff. */ 971 } 972 973 if (len == 0) 974 return 0; 975 976 wb->offset = 0; 977 978 if (!CBB_init_fixed(&cbb, wb->buf, wb->len)) 979 goto err; 980 981 tls12_record_layer_set_version(s->internal->rl, s->version); 982 983 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 984 goto err; 985 986 if (!CBB_finish(&cbb, NULL, &out_len)) 987 goto err; 988 989 wb->left = out_len; 990 991 /* 992 * Memorize arguments so that ssl3_write_pending can detect 993 * bad write retries later. 994 */ 995 S3I(s)->wpend_tot = len; 996 S3I(s)->wpend_buf = buf; 997 S3I(s)->wpend_type = type; 998 S3I(s)->wpend_ret = len; 999 1000 /* We now just need to write the buffer. */ 1001 return ssl3_write_pending(s, type, buf, len); 1002 1003 err: 1004 CBB_cleanup(&cbb); 1005 1006 return -1; 1007 } 1008 1009 static int 1010 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 1011 const unsigned char *seq) 1012 { 1013 unsigned int shift; 1014 int cmp; 1015 1016 cmp = satsub64be(seq, bitmap->max_seq_num); 1017 if (cmp > 0) 1018 return 1; /* this record in new */ 1019 shift = -cmp; 1020 if (shift >= sizeof(bitmap->map)*8) 1021 return 0; /* stale, outside the window */ 1022 else if (bitmap->map & (1UL << shift)) 1023 return 0; /* record previously received */ 1024 1025 return 1; 1026 } 1027 1028 static void 1029 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 1030 const unsigned char *seq) 1031 { 1032 unsigned int shift; 1033 int cmp; 1034 1035 cmp = satsub64be(seq, bitmap->max_seq_num); 1036 if (cmp > 0) { 1037 shift = cmp; 1038 if (shift < sizeof(bitmap->map)*8) 1039 bitmap->map <<= shift, bitmap->map |= 1UL; 1040 else 1041 bitmap->map = 1UL; 1042 memcpy(bitmap->max_seq_num, seq, 8); 1043 } else { 1044 shift = -cmp; 1045 if (shift < sizeof(bitmap->map) * 8) 1046 bitmap->map |= 1UL << shift; 1047 } 1048 } 1049 1050 static DTLS1_BITMAP * 1051 dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch) 1052 { 1053 uint16_t read_epoch, read_epoch_next; 1054 1055 *is_next_epoch = 0; 1056 1057 read_epoch = tls12_record_layer_read_epoch(s->internal->rl); 1058 read_epoch_next = read_epoch + 1; 1059 1060 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1061 if (rr->epoch == read_epoch) 1062 return &s->d1->bitmap; 1063 1064 /* Only HM and ALERT messages can be from the next epoch */ 1065 if (rr->epoch == read_epoch_next && 1066 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1067 *is_next_epoch = 1; 1068 return &s->d1->next_bitmap; 1069 } 1070 1071 return NULL; 1072 } 1073 1074 void 1075 dtls1_reset_read_seq_numbers(SSL *s) 1076 { 1077 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1078 memset(&(s->d1->next_bitmap), 0, sizeof(DTLS1_BITMAP)); 1079 } 1080