1 /* $OpenBSD: d1_pkt.c,v 1.103 2021/07/21 08:42:14 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 static int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 130 unsigned int len); 131 132 133 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 134 static int 135 satsub64be(const unsigned char *v1, const unsigned char *v2) 136 { 137 int ret, sat, brw, i; 138 139 if (sizeof(long) == 8) 140 do { 141 long l; 142 143 if (BYTE_ORDER == LITTLE_ENDIAN) 144 break; 145 /* not reached on little-endians */ 146 /* following test is redundant, because input is 147 * always aligned, but I take no chances... */ 148 if (((size_t)v1 | (size_t)v2) & 0x7) 149 break; 150 151 l = *((long *)v1); 152 l -= *((long *)v2); 153 if (l > 128) 154 return 128; 155 else if (l<-128) 156 return -128; 157 else 158 return (int)l; 159 } while (0); 160 161 ret = (int)v1[7] - (int)v2[7]; 162 sat = 0; 163 brw = ret >> 8; /* brw is either 0 or -1 */ 164 if (ret & 0x80) { 165 for (i = 6; i >= 0; i--) { 166 brw += (int)v1[i]-(int)v2[i]; 167 sat |= ~brw; 168 brw >>= 8; 169 } 170 } else { 171 for (i = 6; i >= 0; i--) { 172 brw += (int)v1[i]-(int)v2[i]; 173 sat |= brw; 174 brw >>= 8; 175 } 176 } 177 brw <<= 8; /* brw is either 0 or -256 */ 178 179 if (sat & 0xff) 180 return brw | 0x80; 181 else 182 return brw + (ret & 0xFF); 183 } 184 185 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 186 int len, int peek); 187 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 188 const unsigned char *seq); 189 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 190 const unsigned char *seq); 191 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, 192 unsigned int *is_next_epoch); 193 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 194 unsigned char *priority); 195 static int dtls1_process_record(SSL *s); 196 197 /* copy buffered record into SSL structure */ 198 static int 199 dtls1_copy_record(SSL *s, DTLS1_RECORD_DATA_INTERNAL *rdata) 200 { 201 ssl3_release_buffer(&S3I(s)->rbuf); 202 203 s->internal->packet = rdata->packet; 204 s->internal->packet_length = rdata->packet_length; 205 memcpy(&(S3I(s)->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 206 memcpy(&(S3I(s)->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL)); 207 208 return (1); 209 } 210 211 static int 212 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 213 { 214 DTLS1_RECORD_DATA_INTERNAL *rdata; 215 pitem *item; 216 217 /* Limit the size of the queue to prevent DOS attacks */ 218 if (pqueue_size(queue->q) >= 100) 219 return 0; 220 221 rdata = malloc(sizeof(DTLS1_RECORD_DATA_INTERNAL)); 222 item = pitem_new(priority, rdata); 223 if (rdata == NULL || item == NULL) 224 goto init_err; 225 226 rdata->packet = s->internal->packet; 227 rdata->packet_length = s->internal->packet_length; 228 memcpy(&(rdata->rbuf), &(S3I(s)->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 229 memcpy(&(rdata->rrec), &(S3I(s)->rrec), sizeof(SSL3_RECORD_INTERNAL)); 230 231 item->data = rdata; 232 233 s->internal->packet = NULL; 234 s->internal->packet_length = 0; 235 memset(&(S3I(s)->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL)); 236 memset(&(S3I(s)->rrec), 0, sizeof(SSL3_RECORD_INTERNAL)); 237 238 if (!ssl3_setup_buffers(s)) 239 goto err; 240 241 /* insert should not fail, since duplicates are dropped */ 242 if (pqueue_insert(queue->q, item) == NULL) 243 goto err; 244 245 return (1); 246 247 err: 248 ssl3_release_buffer(&rdata->rbuf); 249 250 init_err: 251 SSLerror(s, ERR_R_INTERNAL_ERROR); 252 free(rdata); 253 pitem_free(item); 254 return (-1); 255 } 256 257 258 static int 259 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 260 { 261 pitem *item; 262 263 item = pqueue_pop(queue->q); 264 if (item) { 265 dtls1_copy_record(s, item->data); 266 267 free(item->data); 268 pitem_free(item); 269 270 return (1); 271 } 272 273 return (0); 274 } 275 276 static int 277 dtls1_process_buffered_record(SSL *s) 278 { 279 /* Check if epoch is current. */ 280 if (D1I(s)->unprocessed_rcds.epoch != D1I(s)->r_epoch) 281 return (0); 282 283 /* Update epoch once all unprocessed records have been processed. */ 284 if (pqueue_peek(D1I(s)->unprocessed_rcds.q) == NULL) { 285 D1I(s)->unprocessed_rcds.epoch = D1I(s)->r_epoch + 1; 286 return (0); 287 } 288 289 /* Process one of the records. */ 290 if (!dtls1_retrieve_buffered_record(s, &D1I(s)->unprocessed_rcds)) 291 return (-1); 292 if (!dtls1_process_record(s)) 293 return (-1); 294 295 return (1); 296 } 297 298 static int 299 dtls1_process_record(SSL *s) 300 { 301 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 302 uint8_t alert_desc; 303 uint8_t *out; 304 size_t out_len; 305 306 tls12_record_layer_set_version(s->internal->rl, s->version); 307 308 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet, 309 s->internal->packet_length, &out, &out_len)) { 310 tls12_record_layer_alert(s->internal->rl, &alert_desc); 311 312 if (alert_desc == 0) 313 goto err; 314 315 /* 316 * DTLS should silently discard invalid records, including those 317 * with a bad MAC, as per RFC 6347 section 4.1.2.1. 318 */ 319 if (alert_desc == SSL_AD_BAD_RECORD_MAC) { 320 out_len = 0; 321 goto done; 322 } 323 324 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 325 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 326 327 goto fatal_err; 328 } 329 330 done: 331 rr->data = out; 332 rr->length = out_len; 333 rr->off = 0; 334 335 s->internal->packet_length = 0; 336 337 return (1); 338 339 fatal_err: 340 ssl3_send_alert(s, SSL3_AL_FATAL, alert_desc); 341 err: 342 return (0); 343 } 344 345 /* Call this to get a new input record. 346 * It will return <= 0 if more data is needed, normally due to an error 347 * or non-blocking IO. 348 * When it finishes, one packet has been decoded and can be found in 349 * ssl->s3->internal->rrec.type - is the type of record 350 * ssl->s3->internal->rrec.data, - data 351 * ssl->s3->internal->rrec.length, - number of bytes 352 */ 353 /* used only by dtls1_read_bytes */ 354 int 355 dtls1_get_record(SSL *s) 356 { 357 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 358 unsigned char *p = NULL; 359 DTLS1_BITMAP *bitmap; 360 unsigned int is_next_epoch; 361 int ret, n; 362 363 /* See if there are pending records that can now be processed. */ 364 if ((ret = dtls1_process_buffered_record(s)) != 0) 365 return (ret); 366 367 /* get something from the wire */ 368 if (0) { 369 again: 370 /* dump this record on all retries */ 371 rr->length = 0; 372 s->internal->packet_length = 0; 373 } 374 375 /* check if we have the header */ 376 if ((s->internal->rstate != SSL_ST_READ_BODY) || 377 (s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) { 378 CBS header, seq_no; 379 uint16_t epoch, len, ssl_version; 380 uint8_t type; 381 382 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH); 383 if (n <= 0) 384 return (n); 385 386 /* If this packet contained a partial record, dump it. */ 387 if (n != DTLS1_RT_HEADER_LENGTH) 388 goto again; 389 390 s->internal->rstate = SSL_ST_READ_BODY; 391 392 CBS_init(&header, s->internal->packet, s->internal->packet_length); 393 394 /* Pull apart the header into the DTLS1_RECORD */ 395 if (!CBS_get_u8(&header, &type)) 396 goto again; 397 if (!CBS_get_u16(&header, &ssl_version)) 398 goto again; 399 400 /* sequence number is 64 bits, with top 2 bytes = epoch */ 401 if (!CBS_get_u16(&header, &epoch) || 402 !CBS_get_bytes(&header, &seq_no, 6)) 403 goto again; 404 405 if (!CBS_get_u16(&header, &len)) 406 goto again; 407 408 if (!CBS_write_bytes(&seq_no, &rr->seq_num[2], 409 sizeof(rr->seq_num) - 2, NULL)) 410 goto again; 411 412 rr->type = type; 413 rr->epoch = epoch; 414 rr->length = len; 415 416 /* unexpected version, silently discard */ 417 if (!s->internal->first_packet && ssl_version != s->version) 418 goto again; 419 420 /* wrong version, silently discard record */ 421 if ((ssl_version & 0xff00) != (s->version & 0xff00)) 422 goto again; 423 424 /* record too long, silently discard it */ 425 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 426 goto again; 427 428 /* now s->internal->rstate == SSL_ST_READ_BODY */ 429 p = (unsigned char *)CBS_data(&header); 430 } 431 432 /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */ 433 434 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length); 435 if (n <= 0) 436 return (n); 437 438 /* If this packet contained a partial record, dump it. */ 439 if (n != DTLS1_RT_HEADER_LENGTH + rr->length) 440 goto again; 441 442 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 443 444 /* match epochs. NULL means the packet is dropped on the floor */ 445 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 446 if (bitmap == NULL) 447 goto again; 448 449 /* 450 * Check whether this is a repeat, or aged record. 451 * Don't check if we're listening and this message is 452 * a ClientHello. They can look as if they're replayed, 453 * since they arrive from different connections and 454 * would be dropped unnecessarily. 455 */ 456 if (!(D1I(s)->listen && rr->type == SSL3_RT_HANDSHAKE && 457 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 458 !dtls1_record_replay_check(s, bitmap, rr->seq_num)) 459 goto again; 460 461 /* just read a 0 length packet */ 462 if (rr->length == 0) 463 goto again; 464 465 /* If this record is from the next epoch (either HM or ALERT), 466 * and a handshake is currently in progress, buffer it since it 467 * cannot be processed at this time. However, do not buffer 468 * anything while listening. 469 */ 470 if (is_next_epoch) { 471 if ((SSL_in_init(s) || s->internal->in_handshake) && !D1I(s)->listen) { 472 if (dtls1_buffer_record(s, &(D1I(s)->unprocessed_rcds), 473 rr->seq_num) < 0) 474 return (-1); 475 /* Mark receipt of record. */ 476 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 477 } 478 goto again; 479 } 480 481 if (!dtls1_process_record(s)) 482 goto again; 483 484 /* Mark receipt of record. */ 485 dtls1_record_bitmap_update(s, bitmap, rr->seq_num); 486 487 return (1); 488 } 489 490 /* Return up to 'len' payload bytes received in 'type' records. 491 * 'type' is one of the following: 492 * 493 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 494 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 495 * - 0 (during a shutdown, no data has to be returned) 496 * 497 * If we don't have stored data to work from, read a SSL/TLS record first 498 * (possibly multiple records if we still don't have anything to return). 499 * 500 * This function must handle any surprises the peer may have for us, such as 501 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 502 * a surprise, but handled as if it were), or renegotiation requests. 503 * Also if record payloads contain fragments too small to process, we store 504 * them until there is enough for the respective protocol (the record protocol 505 * may use arbitrary fragmentation and even interleaving): 506 * Change cipher spec protocol 507 * just 1 byte needed, no need for keeping anything stored 508 * Alert protocol 509 * 2 bytes needed (AlertLevel, AlertDescription) 510 * Handshake protocol 511 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 512 * to detect unexpected Client Hello and Hello Request messages 513 * here, anything else is handled by higher layers 514 * Application data protocol 515 * none of our business 516 */ 517 int 518 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 519 { 520 int al, i, j, ret; 521 unsigned int n; 522 SSL3_RECORD_INTERNAL *rr; 523 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 524 525 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */ 526 if (!ssl3_setup_buffers(s)) 527 return (-1); 528 529 if ((type && 530 type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || 531 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 532 SSLerror(s, ERR_R_INTERNAL_ERROR); 533 return -1; 534 } 535 536 /* check whether there's a handshake message (client hello?) waiting */ 537 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 538 return ret; 539 540 /* Now D1I(s)->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 541 542 if (!s->internal->in_handshake && SSL_in_init(s)) 543 { 544 /* type == SSL3_RT_APPLICATION_DATA */ 545 i = s->internal->handshake_func(s); 546 if (i < 0) 547 return (i); 548 if (i == 0) { 549 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 550 return (-1); 551 } 552 } 553 554 start: 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, &(D1I(s)->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 (D1I(s)->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, &(D1I(s)->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 /* In case of record types for which we have 'fragment' storage, 656 * fill that so that we can process the data at a fixed place. 657 */ 658 { 659 unsigned int k, dest_maxlen = 0; 660 unsigned char *dest = NULL; 661 unsigned int *dest_len = NULL; 662 663 if (rr->type == SSL3_RT_HANDSHAKE) { 664 dest_maxlen = sizeof D1I(s)->handshake_fragment; 665 dest = D1I(s)->handshake_fragment; 666 dest_len = &D1I(s)->handshake_fragment_len; 667 } else if (rr->type == SSL3_RT_ALERT) { 668 dest_maxlen = sizeof(D1I(s)->alert_fragment); 669 dest = D1I(s)->alert_fragment; 670 dest_len = &D1I(s)->alert_fragment_len; 671 } 672 /* else it's a CCS message, or application data or wrong */ 673 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 674 /* Application data while renegotiating 675 * is allowed. Try again reading. 676 */ 677 if (rr->type == SSL3_RT_APPLICATION_DATA) { 678 BIO *bio; 679 S3I(s)->in_read_app_data = 2; 680 bio = SSL_get_rbio(s); 681 s->internal->rwstate = SSL_READING; 682 BIO_clear_retry_flags(bio); 683 BIO_set_retry_read(bio); 684 return (-1); 685 } 686 687 /* Not certain if this is the right error handling */ 688 al = SSL_AD_UNEXPECTED_MESSAGE; 689 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 690 goto fatal_err; 691 } 692 693 if (dest_maxlen > 0) { 694 /* XDTLS: In a pathalogical case, the Client Hello 695 * may be fragmented--don't always expect dest_maxlen bytes */ 696 if (rr->length < dest_maxlen) { 697 s->internal->rstate = SSL_ST_READ_HEADER; 698 rr->length = 0; 699 goto start; 700 } 701 702 /* now move 'n' bytes: */ 703 for ( k = 0; k < dest_maxlen; k++) { 704 dest[k] = rr->data[rr->off++]; 705 rr->length--; 706 } 707 *dest_len = dest_maxlen; 708 } 709 } 710 711 /* D1I(s)->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 712 * D1I(s)->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 713 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 714 715 /* If we are a client, check for an incoming 'Hello Request': */ 716 if ((!s->server) && 717 (D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 718 (D1I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 719 (s->session != NULL) && (s->session->cipher != NULL)) { 720 D1I(s)->handshake_fragment_len = 0; 721 722 if ((D1I(s)->handshake_fragment[1] != 0) || 723 (D1I(s)->handshake_fragment[2] != 0) || 724 (D1I(s)->handshake_fragment[3] != 0)) { 725 al = SSL_AD_DECODE_ERROR; 726 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 727 goto fatal_err; 728 } 729 730 /* no need to check sequence number on HELLO REQUEST messages */ 731 732 if (s->internal->msg_callback) 733 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 734 D1I(s)->handshake_fragment, 4, s, s->internal->msg_callback_arg); 735 736 if (SSL_is_init_finished(s) && 737 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 738 !S3I(s)->renegotiate) { 739 D1I(s)->handshake_read_seq++; 740 s->internal->new_session = 1; 741 ssl3_renegotiate(s); 742 if (ssl3_renegotiate_check(s)) { 743 i = s->internal->handshake_func(s); 744 if (i < 0) 745 return (i); 746 if (i == 0) { 747 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 748 return (-1); 749 } 750 751 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 752 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */ 753 { 754 BIO *bio; 755 /* In the case where we try to read application data, 756 * but we trigger an SSL handshake, we return -1 with 757 * the retry option set. Otherwise renegotiation may 758 * cause nasty problems in the blocking world */ 759 s->internal->rwstate = SSL_READING; 760 bio = SSL_get_rbio(s); 761 BIO_clear_retry_flags(bio); 762 BIO_set_retry_read(bio); 763 return (-1); 764 } 765 } 766 } 767 } 768 /* we either finished a handshake or ignored the request, 769 * now try again to obtain the (application) data we were asked for */ 770 goto start; 771 } 772 773 if (D1I(s)->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 774 int alert_level = D1I(s)->alert_fragment[0]; 775 int alert_descr = D1I(s)->alert_fragment[1]; 776 777 D1I(s)->alert_fragment_len = 0; 778 779 if (s->internal->msg_callback) 780 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT, 781 D1I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg); 782 783 if (s->internal->info_callback != NULL) 784 cb = s->internal->info_callback; 785 else if (s->ctx->internal->info_callback != NULL) 786 cb = s->ctx->internal->info_callback; 787 788 if (cb != NULL) { 789 j = (alert_level << 8) | alert_descr; 790 cb(s, SSL_CB_READ_ALERT, j); 791 } 792 793 if (alert_level == 1) /* warning */ 794 { 795 S3I(s)->warn_alert = alert_descr; 796 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 797 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 798 return (0); 799 } 800 } else if (alert_level == 2) /* fatal */ 801 { 802 s->internal->rwstate = SSL_NOTHING; 803 S3I(s)->fatal_alert = alert_descr; 804 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 805 ERR_asprintf_error_data("SSL alert number %d", 806 alert_descr); 807 s->internal->shutdown|=SSL_RECEIVED_SHUTDOWN; 808 SSL_CTX_remove_session(s->ctx, s->session); 809 return (0); 810 } else { 811 al = SSL_AD_ILLEGAL_PARAMETER; 812 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 813 goto fatal_err; 814 } 815 816 goto start; 817 } 818 819 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 820 { 821 s->internal->rwstate = SSL_NOTHING; 822 rr->length = 0; 823 return (0); 824 } 825 826 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 827 /* 'Change Cipher Spec' is just a single byte, so we know 828 * exactly what the record payload has to look like */ 829 /* XDTLS: check that epoch is consistent */ 830 if ((rr->length != DTLS1_CCS_HEADER_LENGTH) || 831 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 832 al = SSL_AD_DECODE_ERROR; 833 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 834 goto fatal_err; 835 } 836 837 rr->length = 0; 838 839 if (s->internal->msg_callback) 840 s->internal->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 841 rr->data, 1, s, s->internal->msg_callback_arg); 842 843 /* We can't process a CCS now, because previous handshake 844 * messages are still missing, so just drop it. 845 */ 846 if (!D1I(s)->change_cipher_spec_ok) { 847 goto start; 848 } 849 850 D1I(s)->change_cipher_spec_ok = 0; 851 852 S3I(s)->change_cipher_spec = 1; 853 if (!ssl3_do_change_cipher_spec(s)) 854 goto err; 855 856 goto start; 857 } 858 859 /* Unexpected handshake message (Client Hello, or protocol violation) */ 860 if ((D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 861 !s->internal->in_handshake) { 862 struct hm_header_st msg_hdr; 863 864 /* this may just be a stale retransmit */ 865 if (!dtls1_get_message_header(rr->data, &msg_hdr)) 866 return -1; 867 if (rr->epoch != D1I(s)->r_epoch) { 868 rr->length = 0; 869 goto start; 870 } 871 872 /* If we are server, we may have a repeated FINISHED of the 873 * client here, then retransmit our CCS and FINISHED. 874 */ 875 if (msg_hdr.type == SSL3_MT_FINISHED) { 876 if (dtls1_check_timeout_num(s) < 0) 877 return -1; 878 879 dtls1_retransmit_buffered_messages(s); 880 rr->length = 0; 881 goto start; 882 } 883 884 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 885 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 886 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 887 s->internal->renegotiate = 1; 888 s->internal->new_session = 1; 889 } 890 i = s->internal->handshake_func(s); 891 if (i < 0) 892 return (i); 893 if (i == 0) { 894 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 895 return (-1); 896 } 897 898 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 899 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */ 900 { 901 BIO *bio; 902 /* In the case where we try to read application data, 903 * but we trigger an SSL handshake, we return -1 with 904 * the retry option set. Otherwise renegotiation may 905 * cause nasty problems in the blocking world */ 906 s->internal->rwstate = SSL_READING; 907 bio = SSL_get_rbio(s); 908 BIO_clear_retry_flags(bio); 909 BIO_set_retry_read(bio); 910 return (-1); 911 } 912 } 913 goto start; 914 } 915 916 switch (rr->type) { 917 default: 918 /* TLS just ignores unknown message types */ 919 if (s->version == TLS1_VERSION) { 920 rr->length = 0; 921 goto start; 922 } 923 al = SSL_AD_UNEXPECTED_MESSAGE; 924 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 925 goto fatal_err; 926 case SSL3_RT_CHANGE_CIPHER_SPEC: 927 case SSL3_RT_ALERT: 928 case SSL3_RT_HANDSHAKE: 929 /* we already handled all of these, with the possible exception 930 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 931 * should not happen when type != rr->type */ 932 al = SSL_AD_UNEXPECTED_MESSAGE; 933 SSLerror(s, ERR_R_INTERNAL_ERROR); 934 goto fatal_err; 935 case SSL3_RT_APPLICATION_DATA: 936 /* At this point, we were expecting handshake data, 937 * but have application data. If the library was 938 * running inside ssl3_read() (i.e. in_read_app_data 939 * is set) and it makes sense to read application data 940 * at this point (session renegotiation not yet started), 941 * we will indulge it. 942 */ 943 if (S3I(s)->in_read_app_data && 944 (S3I(s)->total_renegotiations != 0) && 945 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 946 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 947 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 948 (S3I(s)->hs.state & SSL_ST_ACCEPT) && 949 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 950 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 951 S3I(s)->in_read_app_data = 2; 952 return (-1); 953 } else { 954 al = SSL_AD_UNEXPECTED_MESSAGE; 955 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 956 goto fatal_err; 957 } 958 } 959 /* not reached */ 960 961 fatal_err: 962 ssl3_send_alert(s, SSL3_AL_FATAL, al); 963 err: 964 return (-1); 965 } 966 967 int 968 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 969 { 970 int i; 971 972 if (SSL_in_init(s) && !s->internal->in_handshake) 973 { 974 i = s->internal->handshake_func(s); 975 if (i < 0) 976 return (i); 977 if (i == 0) { 978 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 979 return -1; 980 } 981 } 982 983 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 984 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); 985 return -1; 986 } 987 988 i = dtls1_write_bytes(s, type, buf_, len); 989 return i; 990 } 991 992 993 /* this only happens when a client hello is received and a handshake 994 * is started. */ 995 static int 996 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 997 int len, int peek) 998 { 999 1000 if ((type == SSL3_RT_HANDSHAKE) && (D1I(s)->handshake_fragment_len > 0)) 1001 /* (partially) satisfy request from storage */ 1002 { 1003 unsigned char *src = D1I(s)->handshake_fragment; 1004 unsigned char *dst = buf; 1005 unsigned int k, n; 1006 1007 /* peek == 0 */ 1008 n = 0; 1009 while ((len > 0) && (D1I(s)->handshake_fragment_len > 0)) { 1010 *dst++ = *src++; 1011 len--; 1012 D1I(s)->handshake_fragment_len--; 1013 n++; 1014 } 1015 /* move any remaining fragment bytes: */ 1016 for (k = 0; k < D1I(s)->handshake_fragment_len; k++) 1017 D1I(s)->handshake_fragment[k] = *src++; 1018 return n; 1019 } 1020 1021 return 0; 1022 } 1023 1024 1025 /* Call this to write data in records of type 'type' 1026 * It will return <= 0 if not all data has been sent or non-blocking IO. 1027 */ 1028 int 1029 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1030 { 1031 int i; 1032 1033 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1034 s->internal->rwstate = SSL_NOTHING; 1035 i = do_dtls1_write(s, type, buf, len); 1036 return i; 1037 } 1038 1039 int 1040 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 1041 { 1042 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 1043 size_t out_len; 1044 CBB cbb; 1045 int ret; 1046 1047 memset(&cbb, 0, sizeof(cbb)); 1048 1049 /* 1050 * First check if there is a SSL3_BUFFER_INTERNAL still being written 1051 * out. This will happen with non blocking IO. 1052 */ 1053 if (wb->left != 0) { 1054 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1055 return (ssl3_write_pending(s, type, buf, len)); 1056 } 1057 1058 /* If we have an alert to send, let's send it */ 1059 if (S3I(s)->alert_dispatch) { 1060 if ((ret = s->method->ssl_dispatch_alert(s)) <= 0) 1061 return (ret); 1062 /* If it went, fall through and send more stuff. */ 1063 } 1064 1065 if (len == 0) 1066 return 0; 1067 1068 wb->offset = 0; 1069 1070 if (!CBB_init_fixed(&cbb, wb->buf, wb->len)) 1071 goto err; 1072 1073 tls12_record_layer_set_version(s->internal->rl, s->version); 1074 1075 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 1076 goto err; 1077 1078 if (!CBB_finish(&cbb, NULL, &out_len)) 1079 goto err; 1080 1081 wb->left = out_len; 1082 1083 /* 1084 * Memorize arguments so that ssl3_write_pending can detect 1085 * bad write retries later. 1086 */ 1087 S3I(s)->wpend_tot = len; 1088 S3I(s)->wpend_buf = buf; 1089 S3I(s)->wpend_type = type; 1090 S3I(s)->wpend_ret = len; 1091 1092 /* We now just need to write the buffer. */ 1093 return ssl3_write_pending(s, type, buf, len); 1094 1095 err: 1096 CBB_cleanup(&cbb); 1097 1098 return -1; 1099 } 1100 1101 static int 1102 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 1103 const unsigned char *seq) 1104 { 1105 unsigned int shift; 1106 int cmp; 1107 1108 cmp = satsub64be(seq, bitmap->max_seq_num); 1109 if (cmp > 0) 1110 return 1; /* this record in new */ 1111 shift = -cmp; 1112 if (shift >= sizeof(bitmap->map)*8) 1113 return 0; /* stale, outside the window */ 1114 else if (bitmap->map & (1UL << shift)) 1115 return 0; /* record previously received */ 1116 1117 return 1; 1118 } 1119 1120 static void 1121 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, 1122 const unsigned char *seq) 1123 { 1124 unsigned int shift; 1125 int cmp; 1126 1127 cmp = satsub64be(seq, bitmap->max_seq_num); 1128 if (cmp > 0) { 1129 shift = cmp; 1130 if (shift < sizeof(bitmap->map)*8) 1131 bitmap->map <<= shift, bitmap->map |= 1UL; 1132 else 1133 bitmap->map = 1UL; 1134 memcpy(bitmap->max_seq_num, seq, 8); 1135 } else { 1136 shift = -cmp; 1137 if (shift < sizeof(bitmap->map) * 8) 1138 bitmap->map |= 1UL << shift; 1139 } 1140 } 1141 1142 int 1143 dtls1_dispatch_alert(SSL *s) 1144 { 1145 int i, j; 1146 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1147 1148 S3I(s)->alert_dispatch = 0; 1149 1150 i = do_dtls1_write(s, SSL3_RT_ALERT, &S3I(s)->send_alert[0], 2); 1151 if (i <= 0) { 1152 S3I(s)->alert_dispatch = 1; 1153 } else { 1154 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL) 1155 (void)BIO_flush(s->wbio); 1156 1157 if (s->internal->msg_callback) 1158 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT, 1159 S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg); 1160 1161 if (s->internal->info_callback != NULL) 1162 cb = s->internal->info_callback; 1163 else if (s->ctx->internal->info_callback != NULL) 1164 cb = s->ctx->internal->info_callback; 1165 1166 if (cb != NULL) { 1167 j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1]; 1168 cb(s, SSL_CB_WRITE_ALERT, j); 1169 } 1170 } 1171 return (i); 1172 } 1173 1174 static DTLS1_BITMAP * 1175 dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch) 1176 { 1177 uint16_t next_epoch = D1I(s)->r_epoch + 1; 1178 1179 *is_next_epoch = 0; 1180 1181 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1182 if (rr->epoch == D1I(s)->r_epoch) 1183 return &D1I(s)->bitmap; 1184 1185 /* Only HM and ALERT messages can be from the next epoch */ 1186 else if (rr->epoch == next_epoch && 1187 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1188 *is_next_epoch = 1; 1189 return &D1I(s)->next_bitmap; 1190 } 1191 1192 return NULL; 1193 } 1194 1195 void 1196 dtls1_reset_read_seq_numbers(SSL *s) 1197 { 1198 D1I(s)->r_epoch++; 1199 memcpy(&(D1I(s)->bitmap), &(D1I(s)->next_bitmap), sizeof(DTLS1_BITMAP)); 1200 memset(&(D1I(s)->next_bitmap), 0, sizeof(DTLS1_BITMAP)); 1201 } 1202