1 /* $OpenBSD: d1_pkt.c,v 1.109 2021/08/31 13:34:55 jsing 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 <machine/endian.h> 117 118 #include <errno.h> 119 #include <stdio.h> 120 121 #include <openssl/buffer.h> 122 #include <openssl/evp.h> 123 124 #include "bytestring.h" 125 #include "dtls_locl.h" 126 #include "pqueue.h" 127 #include "ssl_locl.h" 128 129 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 130 static int 131 satsub64be(const unsigned char *v1, const unsigned char *v2) 132 { 133 int ret, sat, brw, i; 134 135 if (sizeof(long) == 8) 136 do { 137 long l; 138 139 if (BYTE_ORDER == LITTLE_ENDIAN) 140 break; 141 /* not reached on little-endians */ 142 /* following test is redundant, because input is 143 * always aligned, but I take no chances... */ 144 if (((size_t)v1 | (size_t)v2) & 0x7) 145 break; 146 147 l = *((long *)v1); 148 l -= *((long *)v2); 149 if (l > 128) 150 return 128; 151 else if (l<-128) 152 return -128; 153 else 154 return (int)l; 155 } while (0); 156 157 ret = (int)v1[7] - (int)v2[7]; 158 sat = 0; 159 brw = ret >> 8; /* brw is either 0 or -1 */ 160 if (ret & 0x80) { 161 for (i = 6; i >= 0; i--) { 162 brw += (int)v1[i]-(int)v2[i]; 163 sat |= ~brw; 164 brw >>= 8; 165 } 166 } else { 167 for (i = 6; i >= 0; i--) { 168 brw += (int)v1[i]-(int)v2[i]; 169 sat |= brw; 170 brw >>= 8; 171 } 172 } 173 brw <<= 8; /* brw is either 0 or -256 */ 174 175 if (sat & 0xff) 176 return brw | 0x80; 177 else 178 return brw + (ret & 0xFF); 179 } 180 181 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 182 const unsigned char *seq); 183 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 184 const unsigned char *seq); 185 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, 186 unsigned int *is_next_epoch); 187 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 188 unsigned char *priority); 189 static int dtls1_process_record(SSL *s); 190 191 /* copy buffered record into SSL structure */ 192 static int 193 dtls1_copy_record(SSL *s, DTLS1_RECORD_DATA_INTERNAL *rdata) 194 { 195 ssl3_release_buffer(&S3I(s)->rbuf); 196 197 s->internal->packet = rdata->packet; 198 s->internal->packet_length = rdata->packet_length; 199 memcpy(&(S3I(s)->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 200 memcpy(&(S3I(s)->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL)); 201 202 return (1); 203 } 204 205 static int 206 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 207 { 208 DTLS1_RECORD_DATA_INTERNAL *rdata; 209 pitem *item; 210 211 /* Limit the size of the queue to prevent DOS attacks */ 212 if (pqueue_size(queue->q) >= 100) 213 return 0; 214 215 rdata = malloc(sizeof(DTLS1_RECORD_DATA_INTERNAL)); 216 item = pitem_new(priority, rdata); 217 if (rdata == NULL || item == NULL) 218 goto init_err; 219 220 rdata->packet = s->internal->packet; 221 rdata->packet_length = s->internal->packet_length; 222 memcpy(&(rdata->rbuf), &(S3I(s)->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 223 memcpy(&(rdata->rrec), &(S3I(s)->rrec), sizeof(SSL3_RECORD_INTERNAL)); 224 225 item->data = rdata; 226 227 s->internal->packet = NULL; 228 s->internal->packet_length = 0; 229 memset(&(S3I(s)->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL)); 230 memset(&(S3I(s)->rrec), 0, sizeof(SSL3_RECORD_INTERNAL)); 231 232 if (!ssl3_setup_buffers(s)) 233 goto err; 234 235 /* insert should not fail, since duplicates are dropped */ 236 if (pqueue_insert(queue->q, item) == NULL) 237 goto err; 238 239 return (1); 240 241 err: 242 ssl3_release_buffer(&rdata->rbuf); 243 244 init_err: 245 SSLerror(s, ERR_R_INTERNAL_ERROR); 246 free(rdata); 247 pitem_free(item); 248 return (-1); 249 } 250 251 252 static int 253 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 254 { 255 pitem *item; 256 257 item = pqueue_pop(queue->q); 258 if (item) { 259 dtls1_copy_record(s, item->data); 260 261 free(item->data); 262 pitem_free(item); 263 264 return (1); 265 } 266 267 return (0); 268 } 269 270 static int 271 dtls1_process_buffered_record(SSL *s) 272 { 273 /* Check if epoch is current. */ 274 if (D1I(s)->unprocessed_rcds.epoch != 275 tls12_record_layer_read_epoch(s->internal->rl)) 276 return (0); 277 278 /* Update epoch once all unprocessed records have been processed. */ 279 if (pqueue_peek(D1I(s)->unprocessed_rcds.q) == NULL) { 280 D1I(s)->unprocessed_rcds.epoch = 281 tls12_record_layer_read_epoch(s->internal->rl) + 1; 282 return (0); 283 } 284 285 /* Process one of the records. */ 286 if (!dtls1_retrieve_buffered_record(s, &D1I(s)->unprocessed_rcds)) 287 return (-1); 288 if (!dtls1_process_record(s)) 289 return (-1); 290 291 return (1); 292 } 293 294 static int 295 dtls1_process_record(SSL *s) 296 { 297 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 298 uint8_t alert_desc; 299 uint8_t *out; 300 size_t out_len; 301 302 tls12_record_layer_set_version(s->internal->rl, s->version); 303 304 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet, 305 s->internal->packet_length, &out, &out_len)) { 306 tls12_record_layer_alert(s->internal->rl, &alert_desc); 307 308 if (alert_desc == 0) 309 goto err; 310 311 /* 312 * DTLS should silently discard invalid records, including those 313 * with a bad MAC, as per RFC 6347 section 4.1.2.1. 314 */ 315 if (alert_desc == SSL_AD_BAD_RECORD_MAC) { 316 out_len = 0; 317 goto done; 318 } 319 320 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 321 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 322 323 goto fatal_err; 324 } 325 326 done: 327 rr->data = out; 328 rr->length = out_len; 329 rr->off = 0; 330 331 s->internal->packet_length = 0; 332 333 return (1); 334 335 fatal_err: 336 ssl3_send_alert(s, SSL3_AL_FATAL, alert_desc); 337 err: 338 return (0); 339 } 340 341 /* Call this to get a new input record. 342 * It will return <= 0 if more data is needed, normally due to an error 343 * or non-blocking IO. 344 * When it finishes, one packet has been decoded and can be found in 345 * ssl->s3->internal->rrec.type - is the type of record 346 * ssl->s3->internal->rrec.data, - data 347 * ssl->s3->internal->rrec.length, - number of bytes 348 */ 349 /* used only by dtls1_read_bytes */ 350 int 351 dtls1_get_record(SSL *s) 352 { 353 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 354 unsigned char *p = NULL; 355 DTLS1_BITMAP *bitmap; 356 unsigned int is_next_epoch; 357 int ret, n; 358 359 /* See if there are pending records that can now be processed. */ 360 if ((ret = dtls1_process_buffered_record(s)) != 0) 361 return (ret); 362 363 /* get something from the wire */ 364 if (0) { 365 again: 366 /* dump this record on all retries */ 367 rr->length = 0; 368 s->internal->packet_length = 0; 369 } 370 371 /* check if we have the header */ 372 if ((s->internal->rstate != SSL_ST_READ_BODY) || 373 (s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) { 374 CBS header, seq_no; 375 uint16_t epoch, len, ssl_version; 376 uint8_t type; 377 378 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH); 379 if (n <= 0) 380 return (n); 381 382 /* If this packet contained a partial record, dump it. */ 383 if (n != DTLS1_RT_HEADER_LENGTH) 384 goto again; 385 386 s->internal->rstate = SSL_ST_READ_BODY; 387 388 CBS_init(&header, s->internal->packet, s->internal->packet_length); 389 390 /* Pull apart the header into the DTLS1_RECORD */ 391 if (!CBS_get_u8(&header, &type)) 392 goto again; 393 if (!CBS_get_u16(&header, &ssl_version)) 394 goto again; 395 396 /* sequence number is 64 bits, with top 2 bytes = epoch */ 397 if (!CBS_get_u16(&header, &epoch) || 398 !CBS_get_bytes(&header, &seq_no, 6)) 399 goto again; 400 401 if (!CBS_get_u16(&header, &len)) 402 goto again; 403 404 if (!CBS_write_bytes(&seq_no, &rr->seq_num[2], 405 sizeof(rr->seq_num) - 2, NULL)) 406 goto again; 407 408 rr->type = type; 409 rr->epoch = epoch; 410 rr->length = len; 411 412 /* unexpected version, silently discard */ 413 if (!s->internal->first_packet && ssl_version != s->version) 414 goto again; 415 416 /* wrong version, silently discard record */ 417 if ((ssl_version & 0xff00) != (s->version & 0xff00)) 418 goto again; 419 420 /* record too long, silently discard it */ 421 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 422 goto again; 423 424 /* now s->internal->rstate == SSL_ST_READ_BODY */ 425 p = (unsigned char *)CBS_data(&header); 426 } 427 428 /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */ 429 430 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length); 431 if (n <= 0) 432 return (n); 433 434 /* If this packet contained a partial record, dump it. */ 435 if (n != DTLS1_RT_HEADER_LENGTH + rr->length) 436 goto again; 437 438 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 439 440 /* match epochs. NULL means the packet is dropped on the floor */ 441 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 442 if (bitmap == NULL) 443 goto again; 444 445 /* 446 * Check whether this is a repeat, or aged record. 447 * Don't check if we're listening and this message is 448 * a ClientHello. They can look as if they're replayed, 449 * since they arrive from different connections and 450 * would be dropped unnecessarily. 451 */ 452 if (!(D1I(s)->listen && rr->type == SSL3_RT_HANDSHAKE && 453 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 454 !dtls1_record_replay_check(s, bitmap, rr->seq_num)) 455 goto again; 456 457 /* just read a 0 length packet */ 458 if (rr->length == 0) 459 goto again; 460 461 /* If this record is from the next epoch (either HM or ALERT), 462 * and a handshake is currently in progress, buffer it since it 463 * cannot be processed at this time. However, do not buffer 464 * anything while listening. 465 */ 466 if (is_next_epoch) { 467 if ((SSL_in_init(s) || s->internal->in_handshake) && !D1I(s)->listen) { 468 if (dtls1_buffer_record(s, &(D1I(s)->unprocessed_rcds), 469 rr->seq_num) < 0) 470 return (-1); 471 /* Mark receipt of record. */ 472 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 473 } 474 goto again; 475 } 476 477 if (!dtls1_process_record(s)) 478 goto again; 479 480 /* Mark receipt of record. */ 481 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 482 483 return (1); 484 } 485 486 /* Return up to 'len' payload bytes received in 'type' records. 487 * 'type' is one of the following: 488 * 489 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 490 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 491 * - 0 (during a shutdown, no data has to be returned) 492 * 493 * If we don't have stored data to work from, read a SSL/TLS record first 494 * (possibly multiple records if we still don't have anything to return). 495 * 496 * This function must handle any surprises the peer may have for us, such as 497 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 498 * a surprise, but handled as if it were), or renegotiation requests. 499 * Also if record payloads contain fragments too small to process, we store 500 * them until there is enough for the respective protocol (the record protocol 501 * may use arbitrary fragmentation and even interleaving): 502 * Change cipher spec protocol 503 * just 1 byte needed, no need for keeping anything stored 504 * Alert protocol 505 * 2 bytes needed (AlertLevel, AlertDescription) 506 * Handshake protocol 507 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 508 * to detect unexpected Client Hello and Hello Request messages 509 * here, anything else is handled by higher layers 510 * Application data protocol 511 * none of our business 512 */ 513 int 514 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 515 { 516 int al, i, ret; 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 s->internal->rwstate = SSL_NOTHING; 543 544 /* S3I(s)->rrec.type - is the type of record 545 * S3I(s)->rrec.data, - data 546 * S3I(s)->rrec.off, - offset into 'data' for next read 547 * S3I(s)->rrec.length, - number of bytes. */ 548 rr = &(S3I(s)->rrec); 549 550 /* We are not handshaking and have no data yet, 551 * so process data buffered during the last handshake 552 * in advance, if any. 553 */ 554 if (S3I(s)->hs.state == SSL_ST_OK && rr->length == 0) 555 dtls1_retrieve_buffered_record(s, &(D1I(s)->buffered_app_data)); 556 557 /* Check for timeout */ 558 if (dtls1_handle_timeout(s) > 0) 559 goto start; 560 561 /* get new packet if necessary */ 562 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 563 ret = dtls1_get_record(s); 564 if (ret <= 0) { 565 ret = dtls1_read_failed(s, ret); 566 /* anything other than a timeout is an error */ 567 if (ret <= 0) 568 return (ret); 569 else 570 goto start; 571 } 572 } 573 574 if (D1I(s)->listen && rr->type != SSL3_RT_HANDSHAKE) { 575 rr->length = 0; 576 goto start; 577 } 578 579 /* we now have a packet which can be read and processed */ 580 581 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 582 * reset by ssl3_get_finished */ 583 && (rr->type != SSL3_RT_HANDSHAKE)) { 584 /* We now have application data between CCS and Finished. 585 * Most likely the packets were reordered on their way, so 586 * buffer the application data for later processing rather 587 * than dropping the connection. 588 */ 589 if (dtls1_buffer_record(s, &(D1I(s)->buffered_app_data), 590 rr->seq_num) < 0) { 591 SSLerror(s, ERR_R_INTERNAL_ERROR); 592 return (-1); 593 } 594 rr->length = 0; 595 goto start; 596 } 597 598 /* If the other end has shut down, throw anything we read away 599 * (even in 'peek' mode) */ 600 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 601 rr->length = 0; 602 s->internal->rwstate = SSL_NOTHING; 603 return (0); 604 } 605 606 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 607 if (type == rr->type) { 608 /* make sure that we are not getting application data when we 609 * are doing a handshake for the first time */ 610 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 611 !tls12_record_layer_read_protected(s->internal->rl)) { 612 al = SSL_AD_UNEXPECTED_MESSAGE; 613 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 614 goto fatal_err; 615 } 616 617 if (len <= 0) 618 return (len); 619 620 if ((unsigned int)len > rr->length) 621 n = rr->length; 622 else 623 n = (unsigned int)len; 624 625 memcpy(buf, &(rr->data[rr->off]), n); 626 if (!peek) { 627 rr->length -= n; 628 rr->off += n; 629 if (rr->length == 0) { 630 s->internal->rstate = SSL_ST_READ_HEADER; 631 rr->off = 0; 632 } 633 } 634 635 return (n); 636 } 637 638 /* 639 * If we get here, then type != rr->type; if we have a handshake 640 * message, then it was unexpected (Hello Request or Client Hello). 641 */ 642 643 { 644 unsigned int record_min_len = 0; 645 646 if (rr->type == SSL3_RT_HANDSHAKE) { 647 record_min_len = DTLS1_HM_HEADER_LENGTH; 648 } else if (rr->type == SSL3_RT_ALERT) { 649 record_min_len = DTLS1_AL_HEADER_LENGTH; 650 } else if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 651 record_min_len = DTLS1_CCS_HEADER_LENGTH; 652 } else if (rr->type == SSL3_RT_APPLICATION_DATA) { 653 /* 654 * Application data while renegotiating is allowed. 655 * Try reading again. 656 */ 657 BIO *bio; 658 659 S3I(s)->in_read_app_data = 2; 660 bio = SSL_get_rbio(s); 661 s->internal->rwstate = SSL_READING; 662 BIO_clear_retry_flags(bio); 663 BIO_set_retry_read(bio); 664 return (-1); 665 } else { 666 /* Not certain if this is the right error handling */ 667 al = SSL_AD_UNEXPECTED_MESSAGE; 668 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 669 goto fatal_err; 670 } 671 672 if (record_min_len > 0 && rr->length < record_min_len) { 673 s->internal->rstate = SSL_ST_READ_HEADER; 674 rr->length = 0; 675 goto start; 676 } 677 } 678 679 /* If we are a client, check for an incoming 'Hello Request': */ 680 if (!s->server && rr->type == SSL3_RT_HANDSHAKE && 681 rr->length >= DTLS1_HM_HEADER_LENGTH && rr->off == 0 && 682 rr->data[0] == SSL3_MT_HELLO_REQUEST && 683 s->session != NULL && s->session->cipher != NULL) { 684 if (rr->data[1] != 0 || rr->data[2] != 0 || rr->data[3] != 0) { 685 al = SSL_AD_DECODE_ERROR; 686 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 687 goto fatal_err; 688 } 689 rr->length = 0; 690 691 /* no need to check sequence number on HELLO REQUEST messages */ 692 693 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE, rr->data, 4); 694 695 if (SSL_is_init_finished(s) && 696 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 697 !S3I(s)->renegotiate) { 698 D1I(s)->handshake_read_seq++; 699 s->internal->new_session = 1; 700 ssl3_renegotiate(s); 701 if (ssl3_renegotiate_check(s)) { 702 i = s->internal->handshake_func(s); 703 if (i < 0) 704 return (i); 705 if (i == 0) { 706 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 707 return (-1); 708 } 709 710 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 711 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */ 712 { 713 BIO *bio; 714 /* In the case where we try to read application data, 715 * but we trigger an SSL handshake, we return -1 with 716 * the retry option set. Otherwise renegotiation may 717 * cause nasty problems in the blocking world */ 718 s->internal->rwstate = SSL_READING; 719 bio = SSL_get_rbio(s); 720 BIO_clear_retry_flags(bio); 721 BIO_set_retry_read(bio); 722 return (-1); 723 } 724 } 725 } 726 } 727 /* we either finished a handshake or ignored the request, 728 * now try again to obtain the (application) data we were asked for */ 729 rr->length = 0; 730 goto start; 731 } 732 733 if (rr->type == SSL3_RT_ALERT && rr->length >= DTLS1_AL_HEADER_LENGTH && 734 rr->off == 0) { 735 int alert_level = rr->data[0]; 736 int alert_descr = rr->data[1]; 737 738 ssl_msg_callback(s, 0, SSL3_RT_ALERT, rr->data, 2); 739 740 ssl_info_callback(s, SSL_CB_READ_ALERT, 741 (alert_level << 8) | alert_descr); 742 743 if (alert_level == SSL3_AL_WARNING) { 744 S3I(s)->warn_alert = alert_descr; 745 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 746 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 747 return (0); 748 } 749 } else if (alert_level == SSL3_AL_FATAL) { 750 s->internal->rwstate = SSL_NOTHING; 751 S3I(s)->fatal_alert = alert_descr; 752 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 753 ERR_asprintf_error_data("SSL alert number %d", 754 alert_descr); 755 s->internal->shutdown|=SSL_RECEIVED_SHUTDOWN; 756 SSL_CTX_remove_session(s->ctx, s->session); 757 return (0); 758 } else { 759 al = SSL_AD_ILLEGAL_PARAMETER; 760 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 761 goto fatal_err; 762 } 763 764 rr->length = 0; 765 goto start; 766 } 767 768 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 769 s->internal->rwstate = SSL_NOTHING; 770 rr->length = 0; 771 return (0); 772 } 773 774 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 775 /* 'Change Cipher Spec' is just a single byte, so we know 776 * exactly what the record payload has to look like */ 777 /* XDTLS: check that epoch is consistent */ 778 if ((rr->length != DTLS1_CCS_HEADER_LENGTH) || 779 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 780 al = SSL_AD_DECODE_ERROR; 781 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 782 goto fatal_err; 783 } 784 785 ssl_msg_callback(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1); 786 787 /* We can't process a CCS now, because previous handshake 788 * messages are still missing, so just drop it. 789 */ 790 if (!D1I(s)->change_cipher_spec_ok) { 791 rr->length = 0; 792 goto start; 793 } 794 795 D1I(s)->change_cipher_spec_ok = 0; 796 797 S3I(s)->change_cipher_spec = 1; 798 if (!ssl3_do_change_cipher_spec(s)) 799 goto err; 800 801 rr->length = 0; 802 goto start; 803 } 804 805 /* Unexpected handshake message (Client Hello, or protocol violation) */ 806 if (rr->type == SSL3_RT_HANDSHAKE && 807 rr->length >= DTLS1_HM_HEADER_LENGTH && rr->off == 0 && 808 !s->internal->in_handshake) { 809 struct hm_header_st msg_hdr; 810 811 /* this may just be a stale retransmit */ 812 if (!dtls1_get_message_header(rr->data, &msg_hdr)) 813 return -1; 814 if (rr->epoch != tls12_record_layer_read_epoch(s->internal->rl)) { 815 rr->length = 0; 816 goto start; 817 } 818 819 /* If we are server, we may have a repeated FINISHED of the 820 * client here, then retransmit our CCS and FINISHED. 821 */ 822 if (msg_hdr.type == SSL3_MT_FINISHED) { 823 if (dtls1_check_timeout_num(s) < 0) 824 return -1; 825 826 dtls1_retransmit_buffered_messages(s); 827 rr->length = 0; 828 goto start; 829 } 830 831 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 832 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 833 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 834 s->internal->renegotiate = 1; 835 s->internal->new_session = 1; 836 } 837 i = s->internal->handshake_func(s); 838 if (i < 0) 839 return (i); 840 if (i == 0) { 841 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 842 return (-1); 843 } 844 845 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 846 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */ 847 { 848 BIO *bio; 849 /* In the case where we try to read application data, 850 * but we trigger an SSL handshake, we return -1 with 851 * the retry option set. Otherwise renegotiation may 852 * cause nasty problems in the blocking world */ 853 s->internal->rwstate = SSL_READING; 854 bio = SSL_get_rbio(s); 855 BIO_clear_retry_flags(bio); 856 BIO_set_retry_read(bio); 857 return (-1); 858 } 859 } 860 rr->length = 0; 861 goto start; 862 } 863 864 switch (rr->type) { 865 default: 866 al = SSL_AD_UNEXPECTED_MESSAGE; 867 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 868 goto fatal_err; 869 case SSL3_RT_CHANGE_CIPHER_SPEC: 870 case SSL3_RT_ALERT: 871 case SSL3_RT_HANDSHAKE: 872 /* we already handled all of these, with the possible exception 873 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 874 * should not happen when type != rr->type */ 875 al = SSL_AD_UNEXPECTED_MESSAGE; 876 SSLerror(s, ERR_R_INTERNAL_ERROR); 877 goto fatal_err; 878 case SSL3_RT_APPLICATION_DATA: 879 /* At this point, we were expecting handshake data, 880 * but have application data. If the library was 881 * running inside ssl3_read() (i.e. in_read_app_data 882 * is set) and it makes sense to read application data 883 * at this point (session renegotiation not yet started), 884 * we will indulge it. 885 */ 886 if (S3I(s)->in_read_app_data && 887 (S3I(s)->total_renegotiations != 0) && 888 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 889 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 890 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 891 (S3I(s)->hs.state & SSL_ST_ACCEPT) && 892 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 893 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 894 S3I(s)->in_read_app_data = 2; 895 return (-1); 896 } else { 897 al = SSL_AD_UNEXPECTED_MESSAGE; 898 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 899 goto fatal_err; 900 } 901 } 902 /* not reached */ 903 904 fatal_err: 905 ssl3_send_alert(s, SSL3_AL_FATAL, al); 906 err: 907 return (-1); 908 } 909 910 int 911 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 912 { 913 int i; 914 915 if (SSL_in_init(s) && !s->internal->in_handshake) 916 { 917 i = s->internal->handshake_func(s); 918 if (i < 0) 919 return (i); 920 if (i == 0) { 921 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 922 return -1; 923 } 924 } 925 926 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 927 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); 928 return -1; 929 } 930 931 i = dtls1_write_bytes(s, type, buf_, len); 932 return i; 933 } 934 935 /* Call this to write data in records of type 'type' 936 * It will return <= 0 if not all data has been sent or non-blocking IO. 937 */ 938 int 939 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 940 { 941 int i; 942 943 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 944 s->internal->rwstate = SSL_NOTHING; 945 i = do_dtls1_write(s, type, buf, len); 946 return i; 947 } 948 949 int 950 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 951 { 952 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 953 size_t out_len; 954 CBB cbb; 955 int ret; 956 957 memset(&cbb, 0, sizeof(cbb)); 958 959 /* 960 * First check if there is a SSL3_BUFFER_INTERNAL still being written 961 * out. This will happen with non blocking IO. 962 */ 963 if (wb->left != 0) { 964 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 965 return (ssl3_write_pending(s, type, buf, len)); 966 } 967 968 /* If we have an alert to send, let's send it */ 969 if (S3I(s)->alert_dispatch) { 970 if ((ret = ssl3_dispatch_alert(s)) <= 0) 971 return (ret); 972 /* If it went, fall through and send more stuff. */ 973 } 974 975 if (len == 0) 976 return 0; 977 978 wb->offset = 0; 979 980 if (!CBB_init_fixed(&cbb, wb->buf, wb->len)) 981 goto err; 982 983 tls12_record_layer_set_version(s->internal->rl, s->version); 984 985 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 986 goto err; 987 988 if (!CBB_finish(&cbb, NULL, &out_len)) 989 goto err; 990 991 wb->left = out_len; 992 993 /* 994 * Memorize arguments so that ssl3_write_pending can detect 995 * bad write retries later. 996 */ 997 S3I(s)->wpend_tot = len; 998 S3I(s)->wpend_buf = buf; 999 S3I(s)->wpend_type = type; 1000 S3I(s)->wpend_ret = len; 1001 1002 /* We now just need to write the buffer. */ 1003 return ssl3_write_pending(s, type, buf, len); 1004 1005 err: 1006 CBB_cleanup(&cbb); 1007 1008 return -1; 1009 } 1010 1011 static int 1012 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 1013 const unsigned char *seq) 1014 { 1015 unsigned int shift; 1016 int cmp; 1017 1018 cmp = satsub64be(seq, bitmap->max_seq_num); 1019 if (cmp > 0) 1020 return 1; /* this record in new */ 1021 shift = -cmp; 1022 if (shift >= sizeof(bitmap->map)*8) 1023 return 0; /* stale, outside the window */ 1024 else if (bitmap->map & (1UL << shift)) 1025 return 0; /* record previously received */ 1026 1027 return 1; 1028 } 1029 1030 static void 1031 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 1032 const unsigned char *seq) 1033 { 1034 unsigned int shift; 1035 int cmp; 1036 1037 cmp = satsub64be(seq, bitmap->max_seq_num); 1038 if (cmp > 0) { 1039 shift = cmp; 1040 if (shift < sizeof(bitmap->map)*8) 1041 bitmap->map <<= shift, bitmap->map |= 1UL; 1042 else 1043 bitmap->map = 1UL; 1044 memcpy(bitmap->max_seq_num, seq, 8); 1045 } else { 1046 shift = -cmp; 1047 if (shift < sizeof(bitmap->map) * 8) 1048 bitmap->map |= 1UL << shift; 1049 } 1050 } 1051 1052 static DTLS1_BITMAP * 1053 dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch) 1054 { 1055 uint16_t read_epoch, read_epoch_next; 1056 1057 *is_next_epoch = 0; 1058 1059 read_epoch = tls12_record_layer_read_epoch(s->internal->rl); 1060 read_epoch_next = read_epoch + 1; 1061 1062 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1063 if (rr->epoch == read_epoch) 1064 return &D1I(s)->bitmap; 1065 1066 /* Only HM and ALERT messages can be from the next epoch */ 1067 if (rr->epoch == read_epoch_next && 1068 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1069 *is_next_epoch = 1; 1070 return &D1I(s)->next_bitmap; 1071 } 1072 1073 return NULL; 1074 } 1075 1076 void 1077 dtls1_reset_read_seq_numbers(SSL *s) 1078 { 1079 memcpy(&(D1I(s)->bitmap), &(D1I(s)->next_bitmap), sizeof(DTLS1_BITMAP)); 1080 memset(&(D1I(s)->next_bitmap), 0, sizeof(DTLS1_BITMAP)); 1081 } 1082