1 /* $OpenBSD: d1_pkt.c,v 1.123 2022/03/26 15:05:53 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 <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(&s->s3->rbuf); 195 196 s->internal->packet = rdata->packet; 197 s->internal->packet_length = rdata->packet_length; 198 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 199 memcpy(&(s->s3->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), &(s->s3->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 222 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD_INTERNAL)); 223 224 item->data = rdata; 225 226 s->internal->packet = NULL; 227 s->internal->packet_length = 0; 228 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL)); 229 memset(&(s->s3->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 = &(s->s3->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 = &(s->s3->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 static int 486 dtls1_read_handshake_unexpected(SSL *s) 487 { 488 SSL3_RECORD_INTERNAL *rr = &s->s3->rrec; 489 struct hm_header_st hs_msg_hdr; 490 CBS cbs; 491 int ret; 492 493 if (s->internal->in_handshake) { 494 SSLerror(s, ERR_R_INTERNAL_ERROR); 495 return -1; 496 } 497 498 if (rr->off != 0) { 499 SSLerror(s, ERR_R_INTERNAL_ERROR); 500 return -1; 501 } 502 503 /* Parse handshake message header. */ 504 CBS_init(&cbs, rr->data, rr->length); 505 if (!dtls1_get_message_header(&cbs, &hs_msg_hdr)) 506 return -1; /* XXX - probably should drop/continue. */ 507 508 /* This may just be a stale retransmit. */ 509 if (rr->epoch != tls12_record_layer_read_epoch(s->internal->rl)) { 510 rr->length = 0; 511 return 1; 512 } 513 514 if (hs_msg_hdr.type == SSL3_MT_HELLO_REQUEST) { 515 /* 516 * Incoming HelloRequest messages should only be received by a 517 * client. A server may send these at any time - a client should 518 * ignore the message if received in the middle of a handshake. 519 * See RFC 5246 sections 7.4 and 7.4.1.1. 520 */ 521 if (s->server) { 522 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 523 ssl3_send_alert(s, SSL3_AL_FATAL, 524 SSL_AD_UNEXPECTED_MESSAGE); 525 return -1; 526 } 527 528 /* XXX - should also check frag offset/length. */ 529 if (hs_msg_hdr.msg_len != 0) { 530 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 531 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 532 return -1; 533 } 534 535 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE, rr->data, 536 DTLS1_HM_HEADER_LENGTH); 537 538 rr->length = 0; 539 540 /* 541 * It should be impossible to hit this, but keep the safety 542 * harness for now... 543 */ 544 if (s->session == NULL || s->session->cipher == NULL) 545 return 1; 546 547 /* 548 * Ignore this message if we're currently handshaking, 549 * renegotiation is already pending or renegotiation is disabled 550 * via flags. 551 */ 552 if (!SSL_is_init_finished(s) || s->s3->renegotiate || 553 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) 554 return 1; 555 556 s->d1->handshake_read_seq++; 557 558 /* XXX - why is this set here but not in ssl3? */ 559 s->internal->new_session = 1; 560 561 if (!ssl3_renegotiate(s)) 562 return 1; 563 if (!ssl3_renegotiate_check(s)) 564 return 1; 565 566 } else if (hs_msg_hdr.type == SSL3_MT_CLIENT_HELLO) { 567 /* 568 * Incoming ClientHello messages should only be received by a 569 * server. A client may send these in response to server 570 * initiated renegotiation (HelloRequest) or in order to 571 * initiate renegotiation by the client. See RFC 5246 section 572 * 7.4.1.2. 573 */ 574 if (!s->server) { 575 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 576 ssl3_send_alert(s, SSL3_AL_FATAL, 577 SSL_AD_UNEXPECTED_MESSAGE); 578 return -1; 579 } 580 581 /* 582 * A client should not be sending a ClientHello unless we're not 583 * currently handshaking. 584 */ 585 if (!SSL_is_init_finished(s)) { 586 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 587 ssl3_send_alert(s, SSL3_AL_FATAL, 588 SSL_AD_UNEXPECTED_MESSAGE); 589 return -1; 590 } 591 592 if ((s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) { 593 ssl3_send_alert(s, SSL3_AL_FATAL, 594 SSL_AD_NO_RENEGOTIATION); 595 return -1; 596 } 597 598 if (s->session == NULL || s->session->cipher == NULL) { 599 SSLerror(s, ERR_R_INTERNAL_ERROR); 600 return -1; 601 } 602 603 /* Client requested renegotiation but it is not permitted. */ 604 if (!s->s3->send_connection_binding || 605 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) { 606 ssl3_send_alert(s, SSL3_AL_WARNING, 607 SSL_AD_NO_RENEGOTIATION); 608 return 1; 609 } 610 611 s->s3->hs.state = SSL_ST_ACCEPT; 612 s->internal->renegotiate = 1; 613 s->internal->new_session = 1; 614 615 } else if (hs_msg_hdr.type == SSL3_MT_FINISHED && s->server) { 616 /* 617 * If we are server, we may have a repeated FINISHED of the 618 * client here, then retransmit our CCS and FINISHED. 619 */ 620 if (dtls1_check_timeout_num(s) < 0) 621 return -1; 622 623 /* XXX - should this be calling ssl_msg_callback()? */ 624 625 dtls1_retransmit_buffered_messages(s); 626 627 rr->length = 0; 628 629 return 1; 630 631 } else { 632 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 633 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 634 return -1; 635 } 636 637 if ((ret = s->internal->handshake_func(s)) < 0) 638 return ret; 639 if (ret == 0) { 640 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 641 return -1; 642 } 643 644 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 645 if (s->s3->rbuf.left == 0) { 646 ssl_force_want_read(s); 647 return -1; 648 } 649 } 650 651 /* 652 * We either finished a handshake or ignored the request, now try again 653 * to obtain the (application) data we were asked for. 654 */ 655 return 1; 656 } 657 658 /* Return up to 'len' payload bytes received in 'type' records. 659 * 'type' is one of the following: 660 * 661 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 662 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 663 * - 0 (during a shutdown, no data has to be returned) 664 * 665 * If we don't have stored data to work from, read a SSL/TLS record first 666 * (possibly multiple records if we still don't have anything to return). 667 * 668 * This function must handle any surprises the peer may have for us, such as 669 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 670 * a surprise, but handled as if it were), or renegotiation requests. 671 * Also if record payloads contain fragments too small to process, we store 672 * them until there is enough for the respective protocol (the record protocol 673 * may use arbitrary fragmentation and even interleaving): 674 * Change cipher spec protocol 675 * just 1 byte needed, no need for keeping anything stored 676 * Alert protocol 677 * 2 bytes needed (AlertLevel, AlertDescription) 678 * Handshake protocol 679 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 680 * to detect unexpected Client Hello and Hello Request messages 681 * here, anything else is handled by higher layers 682 * Application data protocol 683 * none of our business 684 */ 685 int 686 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 687 { 688 SSL3_RECORD_INTERNAL *rr; 689 int rrcount = 0; 690 unsigned int n; 691 int ret; 692 693 if (s->s3->rbuf.buf == NULL) { 694 if (!ssl3_setup_buffers(s)) 695 return -1; 696 } 697 698 if (len < 0) { 699 SSLerror(s, ERR_R_INTERNAL_ERROR); 700 return -1; 701 } 702 703 if (type != 0 && type != SSL3_RT_APPLICATION_DATA && 704 type != SSL3_RT_HANDSHAKE) { 705 SSLerror(s, ERR_R_INTERNAL_ERROR); 706 return -1; 707 } 708 if (peek && type != SSL3_RT_APPLICATION_DATA) { 709 SSLerror(s, ERR_R_INTERNAL_ERROR); 710 return -1; 711 } 712 713 if (SSL_in_init(s) && !s->internal->in_handshake) { 714 if ((ret = s->internal->handshake_func(s)) < 0) 715 return ret; 716 if (ret == 0) { 717 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 718 return -1; 719 } 720 } 721 722 start: 723 /* 724 * Do not process more than three consecutive records, otherwise the 725 * peer can cause us to loop indefinitely. Instead, return with an 726 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 727 * processing. In the future, the total number of non-handshake and 728 * non-application data records per connection should probably also be 729 * limited... 730 */ 731 if (rrcount++ >= 3) { 732 ssl_force_want_read(s); 733 return -1; 734 } 735 736 s->internal->rwstate = SSL_NOTHING; 737 738 rr = &s->s3->rrec; 739 740 /* 741 * We are not handshaking and have no data yet, so process data buffered 742 * during the last handshake in advance, if any. 743 */ 744 if (s->s3->hs.state == SSL_ST_OK && rr->length == 0) 745 dtls1_retrieve_buffered_record(s, &s->d1->buffered_app_data); 746 747 if (dtls1_handle_timeout(s) > 0) 748 goto start; 749 750 if (rr->length == 0 || s->internal->rstate == SSL_ST_READ_BODY) { 751 if ((ret = dtls1_get_record(s)) <= 0) { 752 /* Anything other than a timeout is an error. */ 753 if ((ret = dtls1_read_failed(s, ret)) <= 0) 754 return ret; 755 goto start; 756 } 757 } 758 759 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) { 760 rr->length = 0; 761 goto start; 762 } 763 764 /* We now have a packet which can be read and processed. */ 765 766 if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE) { 767 /* 768 * We now have application data between CCS and Finished. 769 * Most likely the packets were reordered on their way, so 770 * buffer the application data for later processing rather 771 * than dropping the connection. 772 */ 773 if (dtls1_buffer_record(s, &s->d1->buffered_app_data, 774 rr->seq_num) < 0) { 775 SSLerror(s, ERR_R_INTERNAL_ERROR); 776 return (-1); 777 } 778 rr->length = 0; 779 goto start; 780 } 781 782 /* 783 * If the other end has shut down, throw anything we read away (even in 784 * 'peek' mode). 785 */ 786 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 787 s->internal->rwstate = SSL_NOTHING; 788 rr->length = 0; 789 return 0; 790 } 791 792 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 793 if (type == rr->type) { 794 /* 795 * Make sure that we are not getting application data when we 796 * are doing a handshake for the first time. 797 */ 798 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 799 !tls12_record_layer_read_protected(s->internal->rl)) { 800 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 801 ssl3_send_alert(s, SSL3_AL_FATAL, 802 SSL_AD_UNEXPECTED_MESSAGE); 803 return -1; 804 } 805 806 if (len <= 0) 807 return len; 808 809 if ((unsigned int)len > rr->length) 810 n = rr->length; 811 else 812 n = (unsigned int)len; 813 814 memcpy(buf, &rr->data[rr->off], n); 815 if (!peek) { 816 memset(&rr->data[rr->off], 0, n); 817 rr->length -= n; 818 rr->off += n; 819 if (rr->length == 0) { 820 s->internal->rstate = SSL_ST_READ_HEADER; 821 rr->off = 0; 822 } 823 } 824 825 return n; 826 } 827 828 /* 829 * If we get here, then type != rr->type; if we have a handshake 830 * message, then it was unexpected (Hello Request or Client Hello). 831 */ 832 833 if (rr->type == SSL3_RT_ALERT) { 834 if ((ret = ssl3_read_alert(s)) <= 0) 835 return ret; 836 goto start; 837 } 838 839 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 840 s->internal->rwstate = SSL_NOTHING; 841 rr->length = 0; 842 return (0); 843 } 844 845 if (rr->type == SSL3_RT_APPLICATION_DATA) { 846 /* 847 * At this point, we were expecting handshake data, but have 848 * application data. If the library was running inside 849 * ssl3_read() (i.e. in_read_app_data is set) and it makes 850 * sense to read application data at this point (session 851 * renegotiation not yet started), we will indulge it. 852 */ 853 if (s->s3->in_read_app_data != 0 && 854 s->s3->total_renegotiations != 0 && 855 (((s->s3->hs.state & SSL_ST_CONNECT) && 856 (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 857 (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 858 (s->s3->hs.state & SSL_ST_ACCEPT) && 859 (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 860 (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 861 s->s3->in_read_app_data = 2; 862 return -1; 863 } else { 864 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 865 ssl3_send_alert(s, SSL3_AL_FATAL, 866 SSL_AD_UNEXPECTED_MESSAGE); 867 return -1; 868 } 869 } 870 871 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 872 if ((ret = ssl3_read_change_cipher_spec(s)) <= 0) 873 return ret; 874 goto start; 875 } 876 877 if (rr->type == SSL3_RT_HANDSHAKE) { 878 if ((ret = dtls1_read_handshake_unexpected(s)) <= 0) 879 return ret; 880 goto start; 881 } 882 883 /* Unknown record type. */ 884 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 885 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 886 return -1; 887 } 888 889 int 890 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 891 { 892 int i; 893 894 if (SSL_in_init(s) && !s->internal->in_handshake) 895 { 896 i = s->internal->handshake_func(s); 897 if (i < 0) 898 return (i); 899 if (i == 0) { 900 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 901 return -1; 902 } 903 } 904 905 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 906 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); 907 return -1; 908 } 909 910 i = dtls1_write_bytes(s, type, buf_, len); 911 return i; 912 } 913 914 /* Call this to write data in records of type 'type' 915 * It will return <= 0 if not all data has been sent or non-blocking IO. 916 */ 917 int 918 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 919 { 920 int i; 921 922 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 923 s->internal->rwstate = SSL_NOTHING; 924 i = do_dtls1_write(s, type, buf, len); 925 return i; 926 } 927 928 int 929 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 930 { 931 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); 932 size_t out_len; 933 CBB cbb; 934 int ret; 935 936 memset(&cbb, 0, sizeof(cbb)); 937 938 /* 939 * First check if there is a SSL3_BUFFER_INTERNAL still being written 940 * out. This will happen with non blocking IO. 941 */ 942 if (wb->left != 0) { 943 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 944 return (ssl3_write_pending(s, type, buf, len)); 945 } 946 947 /* If we have an alert to send, let's send it */ 948 if (s->s3->alert_dispatch) { 949 if ((ret = ssl3_dispatch_alert(s)) <= 0) 950 return (ret); 951 /* If it went, fall through and send more stuff. */ 952 } 953 954 if (len == 0) 955 return 0; 956 957 wb->offset = 0; 958 959 if (!CBB_init_fixed(&cbb, wb->buf, wb->len)) 960 goto err; 961 962 tls12_record_layer_set_version(s->internal->rl, s->version); 963 964 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 965 goto err; 966 967 if (!CBB_finish(&cbb, NULL, &out_len)) 968 goto err; 969 970 wb->left = out_len; 971 972 /* 973 * Memorize arguments so that ssl3_write_pending can detect 974 * bad write retries later. 975 */ 976 s->s3->wpend_tot = len; 977 s->s3->wpend_buf = buf; 978 s->s3->wpend_type = type; 979 s->s3->wpend_ret = len; 980 981 /* We now just need to write the buffer. */ 982 return ssl3_write_pending(s, type, buf, len); 983 984 err: 985 CBB_cleanup(&cbb); 986 987 return -1; 988 } 989 990 static int 991 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 992 const unsigned char *seq) 993 { 994 unsigned int shift; 995 int cmp; 996 997 cmp = satsub64be(seq, bitmap->max_seq_num); 998 if (cmp > 0) 999 return 1; /* this record in new */ 1000 shift = -cmp; 1001 if (shift >= sizeof(bitmap->map)*8) 1002 return 0; /* stale, outside the window */ 1003 else if (bitmap->map & (1UL << shift)) 1004 return 0; /* record previously received */ 1005 1006 return 1; 1007 } 1008 1009 static void 1010 dtls1_record_bitmap_update(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 shift = cmp; 1019 if (shift < sizeof(bitmap->map)*8) 1020 bitmap->map <<= shift, bitmap->map |= 1UL; 1021 else 1022 bitmap->map = 1UL; 1023 memcpy(bitmap->max_seq_num, seq, 8); 1024 } else { 1025 shift = -cmp; 1026 if (shift < sizeof(bitmap->map) * 8) 1027 bitmap->map |= 1UL << shift; 1028 } 1029 } 1030 1031 static DTLS1_BITMAP * 1032 dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch) 1033 { 1034 uint16_t read_epoch, read_epoch_next; 1035 1036 *is_next_epoch = 0; 1037 1038 read_epoch = tls12_record_layer_read_epoch(s->internal->rl); 1039 read_epoch_next = read_epoch + 1; 1040 1041 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1042 if (rr->epoch == read_epoch) 1043 return &s->d1->bitmap; 1044 1045 /* Only HM and ALERT messages can be from the next epoch */ 1046 if (rr->epoch == read_epoch_next && 1047 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1048 *is_next_epoch = 1; 1049 return &s->d1->next_bitmap; 1050 } 1051 1052 return NULL; 1053 } 1054 1055 void 1056 dtls1_reset_read_seq_numbers(SSL *s) 1057 { 1058 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1059 memset(&(s->d1->next_bitmap), 0, sizeof(DTLS1_BITMAP)); 1060 } 1061