1 /* $OpenBSD: d1_pkt.c,v 1.82 2020/09/24 17:59:54 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 "ssl_locl.h" 122 123 #include <openssl/buffer.h> 124 #include <openssl/evp.h> 125 126 #include "pqueue.h" 127 #include "bytestring.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 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 189 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, 190 unsigned int *is_next_epoch); 191 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 192 unsigned char *priority); 193 static int dtls1_process_record(SSL *s); 194 195 /* copy buffered record into SSL structure */ 196 static int 197 dtls1_copy_record(SSL *s, pitem *item) 198 { 199 DTLS1_RECORD_DATA_INTERNAL *rdata; 200 201 rdata = (DTLS1_RECORD_DATA_INTERNAL *)item->data; 202 203 ssl3_release_buffer(&S3I(s)->rbuf); 204 205 s->internal->packet = rdata->packet; 206 s->internal->packet_length = rdata->packet_length; 207 memcpy(&(S3I(s)->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 208 memcpy(&(S3I(s)->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL)); 209 210 /* Set proper sequence number for mac calculation */ 211 memcpy(&(S3I(s)->read_sequence[2]), &(rdata->packet[5]), 6); 212 213 return (1); 214 } 215 216 217 static int 218 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 219 { 220 DTLS1_RECORD_DATA_INTERNAL *rdata; 221 pitem *item; 222 223 /* Limit the size of the queue to prevent DOS attacks */ 224 if (pqueue_size(queue->q) >= 100) 225 return 0; 226 227 rdata = malloc(sizeof(DTLS1_RECORD_DATA_INTERNAL)); 228 item = pitem_new(priority, rdata); 229 if (rdata == NULL || item == NULL) 230 goto init_err; 231 232 rdata->packet = s->internal->packet; 233 rdata->packet_length = s->internal->packet_length; 234 memcpy(&(rdata->rbuf), &(S3I(s)->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); 235 memcpy(&(rdata->rrec), &(S3I(s)->rrec), sizeof(SSL3_RECORD_INTERNAL)); 236 237 item->data = rdata; 238 239 s->internal->packet = NULL; 240 s->internal->packet_length = 0; 241 memset(&(S3I(s)->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL)); 242 memset(&(S3I(s)->rrec), 0, sizeof(SSL3_RECORD_INTERNAL)); 243 244 if (!ssl3_setup_buffers(s)) 245 goto err; 246 247 /* insert should not fail, since duplicates are dropped */ 248 if (pqueue_insert(queue->q, item) == NULL) 249 goto err; 250 251 return (1); 252 253 err: 254 ssl3_release_buffer(&rdata->rbuf); 255 256 init_err: 257 SSLerror(s, ERR_R_INTERNAL_ERROR); 258 free(rdata); 259 pitem_free(item); 260 return (-1); 261 } 262 263 264 static int 265 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 266 { 267 pitem *item; 268 269 item = pqueue_pop(queue->q); 270 if (item) { 271 dtls1_copy_record(s, item); 272 273 free(item->data); 274 pitem_free(item); 275 276 return (1); 277 } 278 279 return (0); 280 } 281 282 283 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 284 * yet */ 285 #define dtls1_get_unprocessed_record(s) \ 286 dtls1_retrieve_buffered_record((s), \ 287 &((D1I(s))->unprocessed_rcds)) 288 289 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 290 #define dtls1_get_processed_record(s) \ 291 dtls1_retrieve_buffered_record((s), \ 292 &((D1I(s))->processed_rcds)) 293 294 static int 295 dtls1_process_buffered_records(SSL *s) 296 { 297 pitem *item; 298 299 item = pqueue_peek(D1I(s)->unprocessed_rcds.q); 300 if (item) { 301 /* Check if epoch is current. */ 302 if (D1I(s)->unprocessed_rcds.epoch != D1I(s)->r_epoch) 303 return (1); 304 /* Nothing to do. */ 305 306 /* Process all the records. */ 307 while (pqueue_peek(D1I(s)->unprocessed_rcds.q)) { 308 dtls1_get_unprocessed_record(s); 309 if (! dtls1_process_record(s)) 310 return (0); 311 if (dtls1_buffer_record(s, &(D1I(s)->processed_rcds), 312 S3I(s)->rrec.seq_num) < 0) 313 return (-1); 314 } 315 } 316 317 /* sync epoch numbers once all the unprocessed records 318 * have been processed */ 319 D1I(s)->processed_rcds.epoch = D1I(s)->r_epoch; 320 D1I(s)->unprocessed_rcds.epoch = D1I(s)->r_epoch + 1; 321 322 return (1); 323 } 324 325 static int 326 dtls1_process_record(SSL *s) 327 { 328 int i, al; 329 int enc_err; 330 SSL_SESSION *sess; 331 SSL3_RECORD_INTERNAL *rr; 332 unsigned int mac_size, orig_len; 333 unsigned char md[EVP_MAX_MD_SIZE]; 334 335 rr = &(S3I(s)->rrec); 336 sess = s->session; 337 338 /* At this point, s->internal->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 339 * and we have that many bytes in s->internal->packet 340 */ 341 rr->input = &(s->internal->packet[DTLS1_RT_HEADER_LENGTH]); 342 343 /* ok, we can now read from 's->internal->packet' data into 'rr' 344 * rr->input points at rr->length bytes, which 345 * need to be copied into rr->data by either 346 * the decryption or by the decompression 347 * When the data is 'copied' into the rr->data buffer, 348 * rr->input will be pointed at the new buffer */ 349 350 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 351 * rr->length bytes of encrypted compressed stuff. */ 352 353 /* check is not needed I believe */ 354 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 355 al = SSL_AD_RECORD_OVERFLOW; 356 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 357 goto f_err; 358 } 359 360 /* decrypt in place in 'rr->input' */ 361 rr->data = rr->input; 362 363 /* enc_err is: 364 * 0: (in non-constant time) if the record is publically invalid. 365 * 1: if the padding is valid 366 * -1: if the padding is invalid */ 367 if ((enc_err = tls1_enc(s, 0)) == 0) { 368 /* For DTLS we simply ignore bad packets. */ 369 rr->length = 0; 370 s->internal->packet_length = 0; 371 goto err; 372 } 373 374 /* r->length is now the compressed data plus mac */ 375 if ((sess != NULL) && (s->enc_read_ctx != NULL) && 376 (EVP_MD_CTX_md(s->read_hash) != NULL)) { 377 /* s->read_hash != NULL => mac_size != -1 */ 378 unsigned char *mac = NULL; 379 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 380 mac_size = EVP_MD_CTX_size(s->read_hash); 381 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 382 383 orig_len = rr->length + rr->padding_length; 384 385 /* orig_len is the length of the record before any padding was 386 * removed. This is public information, as is the MAC in use, 387 * therefore we can safely process the record in a different 388 * amount of time if it's too short to possibly contain a MAC. 389 */ 390 if (orig_len < mac_size || 391 /* CBC records must have a padding length byte too. */ 392 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 393 orig_len < mac_size + 1)) { 394 al = SSL_AD_DECODE_ERROR; 395 SSLerror(s, SSL_R_LENGTH_TOO_SHORT); 396 goto f_err; 397 } 398 399 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 400 /* We update the length so that the TLS header bytes 401 * can be constructed correctly but we need to extract 402 * the MAC in constant time from within the record, 403 * without leaking the contents of the padding bytes. 404 * */ 405 mac = mac_tmp; 406 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 407 rr->length -= mac_size; 408 } else { 409 /* In this case there's no padding, so |orig_len| 410 * equals |rec->length| and we checked that there's 411 * enough bytes for |mac_size| above. */ 412 rr->length -= mac_size; 413 mac = &rr->data[rr->length]; 414 } 415 416 i = tls1_mac(s, md, 0 /* not send */); 417 if (i < 0 || mac == NULL || timingsafe_memcmp(md, mac, (size_t)mac_size) != 0) 418 enc_err = -1; 419 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 420 enc_err = -1; 421 } 422 423 if (enc_err < 0) { 424 /* decryption failed, silently discard message */ 425 rr->length = 0; 426 s->internal->packet_length = 0; 427 goto err; 428 } 429 430 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 431 al = SSL_AD_RECORD_OVERFLOW; 432 SSLerror(s, SSL_R_DATA_LENGTH_TOO_LONG); 433 goto f_err; 434 } 435 436 rr->off = 0; 437 /* So at this point the following is true 438 * ssl->s3->internal->rrec.type is the type of record 439 * ssl->s3->internal->rrec.length == number of bytes in record 440 * ssl->s3->internal->rrec.off == offset to first valid byte 441 * ssl->s3->internal->rrec.data == where to take bytes from, increment 442 * after use :-). 443 */ 444 445 /* we have pulled in a full packet so zero things */ 446 s->internal->packet_length = 0; 447 return (1); 448 449 f_err: 450 ssl3_send_alert(s, SSL3_AL_FATAL, al); 451 err: 452 return (0); 453 } 454 455 456 /* Call this to get a new input record. 457 * It will return <= 0 if more data is needed, normally due to an error 458 * or non-blocking IO. 459 * When it finishes, one packet has been decoded and can be found in 460 * ssl->s3->internal->rrec.type - is the type of record 461 * ssl->s3->internal->rrec.data, - data 462 * ssl->s3->internal->rrec.length, - number of bytes 463 */ 464 /* used only by dtls1_read_bytes */ 465 int 466 dtls1_get_record(SSL *s) 467 { 468 SSL3_RECORD_INTERNAL *rr; 469 unsigned char *p = NULL; 470 DTLS1_BITMAP *bitmap; 471 unsigned int is_next_epoch; 472 int n; 473 474 rr = &(S3I(s)->rrec); 475 476 /* The epoch may have changed. If so, process all the 477 * pending records. This is a non-blocking operation. */ 478 if (dtls1_process_buffered_records(s) < 0) 479 return (-1); 480 481 /* if we're renegotiating, then there may be buffered records */ 482 if (dtls1_get_processed_record(s)) 483 return 1; 484 485 /* get something from the wire */ 486 if (0) { 487 again: 488 /* dump this record on all retries */ 489 rr->length = 0; 490 s->internal->packet_length = 0; 491 } 492 493 /* check if we have the header */ 494 if ((s->internal->rstate != SSL_ST_READ_BODY) || 495 (s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) { 496 CBS header, seq_no; 497 uint16_t epoch, len, ssl_version; 498 uint8_t type; 499 500 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH); 501 if (n <= 0) 502 return (n); 503 504 /* If this packet contained a partial record, dump it. */ 505 if (n != DTLS1_RT_HEADER_LENGTH) 506 goto again; 507 508 s->internal->rstate = SSL_ST_READ_BODY; 509 510 CBS_init(&header, s->internal->packet, s->internal->packet_length); 511 512 /* Pull apart the header into the DTLS1_RECORD */ 513 if (!CBS_get_u8(&header, &type)) 514 goto again; 515 if (!CBS_get_u16(&header, &ssl_version)) 516 goto again; 517 518 /* sequence number is 64 bits, with top 2 bytes = epoch */ 519 if (!CBS_get_u16(&header, &epoch) || 520 !CBS_get_bytes(&header, &seq_no, 6)) 521 goto again; 522 523 if (!CBS_write_bytes(&seq_no, &(S3I(s)->read_sequence[2]), 524 sizeof(S3I(s)->read_sequence) - 2, NULL)) 525 goto again; 526 if (!CBS_get_u16(&header, &len)) 527 goto again; 528 529 rr->type = type; 530 rr->epoch = epoch; 531 rr->length = len; 532 533 /* unexpected version, silently discard */ 534 if (!s->internal->first_packet && ssl_version != s->version) 535 goto again; 536 537 /* wrong version, silently discard record */ 538 if ((ssl_version & 0xff00) != (s->version & 0xff00)) 539 goto again; 540 541 /* record too long, silently discard it */ 542 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 543 goto again; 544 545 /* now s->internal->rstate == SSL_ST_READ_BODY */ 546 p = (unsigned char *)CBS_data(&header); 547 } 548 549 /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */ 550 551 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length); 552 if (n <= 0) 553 return (n); 554 555 /* If this packet contained a partial record, dump it. */ 556 if (n != DTLS1_RT_HEADER_LENGTH + rr->length) 557 goto again; 558 559 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 560 561 /* match epochs. NULL means the packet is dropped on the floor */ 562 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 563 if (bitmap == NULL) 564 goto again; 565 566 /* 567 * Check whether this is a repeat, or aged record. 568 * Don't check if we're listening and this message is 569 * a ClientHello. They can look as if they're replayed, 570 * since they arrive from different connections and 571 * would be dropped unnecessarily. 572 */ 573 if (!(D1I(s)->listen && rr->type == SSL3_RT_HANDSHAKE && 574 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 575 !dtls1_record_replay_check(s, bitmap)) 576 goto again; 577 578 /* just read a 0 length packet */ 579 if (rr->length == 0) 580 goto again; 581 582 /* If this record is from the next epoch (either HM or ALERT), 583 * and a handshake is currently in progress, buffer it since it 584 * cannot be processed at this time. However, do not buffer 585 * anything while listening. 586 */ 587 if (is_next_epoch) { 588 if ((SSL_in_init(s) || s->internal->in_handshake) && !D1I(s)->listen) { 589 if (dtls1_buffer_record(s, &(D1I(s)->unprocessed_rcds), 590 rr->seq_num) < 0) 591 return (-1); 592 /* Mark receipt of record. */ 593 dtls1_record_bitmap_update(s, bitmap); 594 } 595 goto again; 596 } 597 598 if (!dtls1_process_record(s)) 599 goto again; 600 601 /* Mark receipt of record. */ 602 dtls1_record_bitmap_update(s, bitmap); 603 604 return (1); 605 } 606 607 /* Return up to 'len' payload bytes received in 'type' records. 608 * 'type' is one of the following: 609 * 610 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 611 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 612 * - 0 (during a shutdown, no data has to be returned) 613 * 614 * If we don't have stored data to work from, read a SSL/TLS record first 615 * (possibly multiple records if we still don't have anything to return). 616 * 617 * This function must handle any surprises the peer may have for us, such as 618 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 619 * a surprise, but handled as if it were), or renegotiation requests. 620 * Also if record payloads contain fragments too small to process, we store 621 * them until there is enough for the respective protocol (the record protocol 622 * may use arbitrary fragmentation and even interleaving): 623 * Change cipher spec protocol 624 * just 1 byte needed, no need for keeping anything stored 625 * Alert protocol 626 * 2 bytes needed (AlertLevel, AlertDescription) 627 * Handshake protocol 628 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 629 * to detect unexpected Client Hello and Hello Request messages 630 * here, anything else is handled by higher layers 631 * Application data protocol 632 * none of our business 633 */ 634 int 635 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 636 { 637 int al, i, j, ret; 638 unsigned int n; 639 SSL3_RECORD_INTERNAL *rr; 640 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 641 642 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */ 643 if (!ssl3_setup_buffers(s)) 644 return (-1); 645 646 if ((type && 647 type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || 648 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 649 SSLerror(s, ERR_R_INTERNAL_ERROR); 650 return -1; 651 } 652 653 /* check whether there's a handshake message (client hello?) waiting */ 654 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 655 return ret; 656 657 /* Now D1I(s)->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 658 659 if (!s->internal->in_handshake && SSL_in_init(s)) 660 { 661 /* type == SSL3_RT_APPLICATION_DATA */ 662 i = s->internal->handshake_func(s); 663 if (i < 0) 664 return (i); 665 if (i == 0) { 666 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 667 return (-1); 668 } 669 } 670 671 start: 672 s->internal->rwstate = SSL_NOTHING; 673 674 /* S3I(s)->rrec.type - is the type of record 675 * S3I(s)->rrec.data, - data 676 * S3I(s)->rrec.off, - offset into 'data' for next read 677 * S3I(s)->rrec.length, - number of bytes. */ 678 rr = &(S3I(s)->rrec); 679 680 /* We are not handshaking and have no data yet, 681 * so process data buffered during the last handshake 682 * in advance, if any. 683 */ 684 if (S3I(s)->hs.state == SSL_ST_OK && rr->length == 0) { 685 pitem *item; 686 item = pqueue_pop(D1I(s)->buffered_app_data.q); 687 if (item) { 688 689 dtls1_copy_record(s, item); 690 691 free(item->data); 692 pitem_free(item); 693 } 694 } 695 696 /* Check for timeout */ 697 if (dtls1_handle_timeout(s) > 0) 698 goto start; 699 700 /* get new packet if necessary */ 701 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 702 ret = dtls1_get_record(s); 703 if (ret <= 0) { 704 ret = dtls1_read_failed(s, ret); 705 /* anything other than a timeout is an error */ 706 if (ret <= 0) 707 return (ret); 708 else 709 goto start; 710 } 711 } 712 713 if (D1I(s)->listen && rr->type != SSL3_RT_HANDSHAKE) { 714 rr->length = 0; 715 goto start; 716 } 717 718 /* we now have a packet which can be read and processed */ 719 720 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 721 * reset by ssl3_get_finished */ 722 && (rr->type != SSL3_RT_HANDSHAKE)) { 723 /* We now have application data between CCS and Finished. 724 * Most likely the packets were reordered on their way, so 725 * buffer the application data for later processing rather 726 * than dropping the connection. 727 */ 728 if (dtls1_buffer_record(s, &(D1I(s)->buffered_app_data), 729 rr->seq_num) < 0) { 730 SSLerror(s, ERR_R_INTERNAL_ERROR); 731 return (-1); 732 } 733 rr->length = 0; 734 goto start; 735 } 736 737 /* If the other end has shut down, throw anything we read away 738 * (even in 'peek' mode) */ 739 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 740 rr->length = 0; 741 s->internal->rwstate = SSL_NOTHING; 742 return (0); 743 } 744 745 746 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 747 { 748 /* make sure that we are not getting application data when we 749 * are doing a handshake for the first time */ 750 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 751 (s->enc_read_ctx == NULL)) { 752 al = SSL_AD_UNEXPECTED_MESSAGE; 753 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 754 goto f_err; 755 } 756 757 if (len <= 0) 758 return (len); 759 760 if ((unsigned int)len > rr->length) 761 n = rr->length; 762 else 763 n = (unsigned int)len; 764 765 memcpy(buf, &(rr->data[rr->off]), n); 766 if (!peek) { 767 rr->length -= n; 768 rr->off += n; 769 if (rr->length == 0) { 770 s->internal->rstate = SSL_ST_READ_HEADER; 771 rr->off = 0; 772 } 773 } 774 775 return (n); 776 } 777 778 779 /* If we get here, then type != rr->type; if we have a handshake 780 * message, then it was unexpected (Hello Request or Client Hello). */ 781 782 /* In case of record types for which we have 'fragment' storage, 783 * fill that so that we can process the data at a fixed place. 784 */ 785 { 786 unsigned int k, dest_maxlen = 0; 787 unsigned char *dest = NULL; 788 unsigned int *dest_len = NULL; 789 790 if (rr->type == SSL3_RT_HANDSHAKE) { 791 dest_maxlen = sizeof D1I(s)->handshake_fragment; 792 dest = D1I(s)->handshake_fragment; 793 dest_len = &D1I(s)->handshake_fragment_len; 794 } else if (rr->type == SSL3_RT_ALERT) { 795 dest_maxlen = sizeof(D1I(s)->alert_fragment); 796 dest = D1I(s)->alert_fragment; 797 dest_len = &D1I(s)->alert_fragment_len; 798 } 799 /* else it's a CCS message, or application data or wrong */ 800 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 801 /* Application data while renegotiating 802 * is allowed. Try again reading. 803 */ 804 if (rr->type == SSL3_RT_APPLICATION_DATA) { 805 BIO *bio; 806 S3I(s)->in_read_app_data = 2; 807 bio = SSL_get_rbio(s); 808 s->internal->rwstate = SSL_READING; 809 BIO_clear_retry_flags(bio); 810 BIO_set_retry_read(bio); 811 return (-1); 812 } 813 814 /* Not certain if this is the right error handling */ 815 al = SSL_AD_UNEXPECTED_MESSAGE; 816 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 817 goto f_err; 818 } 819 820 if (dest_maxlen > 0) { 821 /* XDTLS: In a pathalogical case, the Client Hello 822 * may be fragmented--don't always expect dest_maxlen bytes */ 823 if (rr->length < dest_maxlen) { 824 s->internal->rstate = SSL_ST_READ_HEADER; 825 rr->length = 0; 826 goto start; 827 } 828 829 /* now move 'n' bytes: */ 830 for ( k = 0; k < dest_maxlen; k++) { 831 dest[k] = rr->data[rr->off++]; 832 rr->length--; 833 } 834 *dest_len = dest_maxlen; 835 } 836 } 837 838 /* D1I(s)->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 839 * D1I(s)->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 840 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 841 842 /* If we are a client, check for an incoming 'Hello Request': */ 843 if ((!s->server) && 844 (D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 845 (D1I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 846 (s->session != NULL) && (s->session->cipher != NULL)) { 847 D1I(s)->handshake_fragment_len = 0; 848 849 if ((D1I(s)->handshake_fragment[1] != 0) || 850 (D1I(s)->handshake_fragment[2] != 0) || 851 (D1I(s)->handshake_fragment[3] != 0)) { 852 al = SSL_AD_DECODE_ERROR; 853 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 854 goto f_err; 855 } 856 857 /* no need to check sequence number on HELLO REQUEST messages */ 858 859 if (s->internal->msg_callback) 860 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 861 D1I(s)->handshake_fragment, 4, s, s->internal->msg_callback_arg); 862 863 if (SSL_is_init_finished(s) && 864 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 865 !S3I(s)->renegotiate) { 866 D1I(s)->handshake_read_seq++; 867 s->internal->new_session = 1; 868 ssl3_renegotiate(s); 869 if (ssl3_renegotiate_check(s)) { 870 i = s->internal->handshake_func(s); 871 if (i < 0) 872 return (i); 873 if (i == 0) { 874 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 875 return (-1); 876 } 877 878 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 879 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */ 880 { 881 BIO *bio; 882 /* In the case where we try to read application data, 883 * but we trigger an SSL handshake, we return -1 with 884 * the retry option set. Otherwise renegotiation may 885 * cause nasty problems in the blocking world */ 886 s->internal->rwstate = SSL_READING; 887 bio = SSL_get_rbio(s); 888 BIO_clear_retry_flags(bio); 889 BIO_set_retry_read(bio); 890 return (-1); 891 } 892 } 893 } 894 } 895 /* we either finished a handshake or ignored the request, 896 * now try again to obtain the (application) data we were asked for */ 897 goto start; 898 } 899 900 if (D1I(s)->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 901 int alert_level = D1I(s)->alert_fragment[0]; 902 int alert_descr = D1I(s)->alert_fragment[1]; 903 904 D1I(s)->alert_fragment_len = 0; 905 906 if (s->internal->msg_callback) 907 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT, 908 D1I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg); 909 910 if (s->internal->info_callback != NULL) 911 cb = s->internal->info_callback; 912 else if (s->ctx->internal->info_callback != NULL) 913 cb = s->ctx->internal->info_callback; 914 915 if (cb != NULL) { 916 j = (alert_level << 8) | alert_descr; 917 cb(s, SSL_CB_READ_ALERT, j); 918 } 919 920 if (alert_level == 1) /* warning */ 921 { 922 S3I(s)->warn_alert = alert_descr; 923 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 924 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 925 return (0); 926 } 927 } else if (alert_level == 2) /* fatal */ 928 { 929 s->internal->rwstate = SSL_NOTHING; 930 S3I(s)->fatal_alert = alert_descr; 931 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 932 ERR_asprintf_error_data("SSL alert number %d", 933 alert_descr); 934 s->internal->shutdown|=SSL_RECEIVED_SHUTDOWN; 935 SSL_CTX_remove_session(s->ctx, s->session); 936 return (0); 937 } else { 938 al = SSL_AD_ILLEGAL_PARAMETER; 939 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 940 goto f_err; 941 } 942 943 goto start; 944 } 945 946 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 947 { 948 s->internal->rwstate = SSL_NOTHING; 949 rr->length = 0; 950 return (0); 951 } 952 953 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 954 struct ccs_header_st ccs_hdr; 955 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 956 957 dtls1_get_ccs_header(rr->data, &ccs_hdr); 958 959 /* 'Change Cipher Spec' is just a single byte, so we know 960 * exactly what the record payload has to look like */ 961 /* XDTLS: check that epoch is consistent */ 962 if ((rr->length != ccs_hdr_len) || 963 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 964 al = SSL_AD_DECODE_ERROR; 965 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 966 goto f_err; 967 } 968 969 rr->length = 0; 970 971 if (s->internal->msg_callback) 972 s->internal->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 973 rr->data, 1, s, s->internal->msg_callback_arg); 974 975 /* We can't process a CCS now, because previous handshake 976 * messages are still missing, so just drop it. 977 */ 978 if (!D1I(s)->change_cipher_spec_ok) { 979 goto start; 980 } 981 982 D1I(s)->change_cipher_spec_ok = 0; 983 984 S3I(s)->change_cipher_spec = 1; 985 if (!ssl3_do_change_cipher_spec(s)) 986 goto err; 987 988 /* do this whenever CCS is processed */ 989 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 990 991 goto start; 992 } 993 994 /* Unexpected handshake message (Client Hello, or protocol violation) */ 995 if ((D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 996 !s->internal->in_handshake) { 997 struct hm_header_st msg_hdr; 998 999 /* this may just be a stale retransmit */ 1000 if (!dtls1_get_message_header(rr->data, &msg_hdr)) 1001 return -1; 1002 if (rr->epoch != D1I(s)->r_epoch) { 1003 rr->length = 0; 1004 goto start; 1005 } 1006 1007 /* If we are server, we may have a repeated FINISHED of the 1008 * client here, then retransmit our CCS and FINISHED. 1009 */ 1010 if (msg_hdr.type == SSL3_MT_FINISHED) { 1011 if (dtls1_check_timeout_num(s) < 0) 1012 return -1; 1013 1014 dtls1_retransmit_buffered_messages(s); 1015 rr->length = 0; 1016 goto start; 1017 } 1018 1019 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 1020 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1021 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1022 s->internal->renegotiate = 1; 1023 s->internal->new_session = 1; 1024 } 1025 i = s->internal->handshake_func(s); 1026 if (i < 0) 1027 return (i); 1028 if (i == 0) { 1029 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1030 return (-1); 1031 } 1032 1033 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1034 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */ 1035 { 1036 BIO *bio; 1037 /* In the case where we try to read application data, 1038 * but we trigger an SSL handshake, we return -1 with 1039 * the retry option set. Otherwise renegotiation may 1040 * cause nasty problems in the blocking world */ 1041 s->internal->rwstate = SSL_READING; 1042 bio = SSL_get_rbio(s); 1043 BIO_clear_retry_flags(bio); 1044 BIO_set_retry_read(bio); 1045 return (-1); 1046 } 1047 } 1048 goto start; 1049 } 1050 1051 switch (rr->type) { 1052 default: 1053 /* TLS just ignores unknown message types */ 1054 if (s->version == TLS1_VERSION) { 1055 rr->length = 0; 1056 goto start; 1057 } 1058 al = SSL_AD_UNEXPECTED_MESSAGE; 1059 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1060 goto f_err; 1061 case SSL3_RT_CHANGE_CIPHER_SPEC: 1062 case SSL3_RT_ALERT: 1063 case SSL3_RT_HANDSHAKE: 1064 /* we already handled all of these, with the possible exception 1065 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 1066 * should not happen when type != rr->type */ 1067 al = SSL_AD_UNEXPECTED_MESSAGE; 1068 SSLerror(s, ERR_R_INTERNAL_ERROR); 1069 goto f_err; 1070 case SSL3_RT_APPLICATION_DATA: 1071 /* At this point, we were expecting handshake data, 1072 * but have application data. If the library was 1073 * running inside ssl3_read() (i.e. in_read_app_data 1074 * is set) and it makes sense to read application data 1075 * at this point (session renegotiation not yet started), 1076 * we will indulge it. 1077 */ 1078 if (S3I(s)->in_read_app_data && 1079 (S3I(s)->total_renegotiations != 0) && 1080 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 1081 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1082 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 1083 (S3I(s)->hs.state & SSL_ST_ACCEPT) && 1084 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1085 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1086 S3I(s)->in_read_app_data = 2; 1087 return (-1); 1088 } else { 1089 al = SSL_AD_UNEXPECTED_MESSAGE; 1090 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1091 goto f_err; 1092 } 1093 } 1094 /* not reached */ 1095 1096 f_err: 1097 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1098 err: 1099 return (-1); 1100 } 1101 1102 int 1103 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1104 { 1105 int i; 1106 1107 if (SSL_in_init(s) && !s->internal->in_handshake) 1108 { 1109 i = s->internal->handshake_func(s); 1110 if (i < 0) 1111 return (i); 1112 if (i == 0) { 1113 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1114 return -1; 1115 } 1116 } 1117 1118 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 1119 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); 1120 return -1; 1121 } 1122 1123 i = dtls1_write_bytes(s, type, buf_, len); 1124 return i; 1125 } 1126 1127 1128 /* this only happens when a client hello is received and a handshake 1129 * is started. */ 1130 static int 1131 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1132 int len, int peek) 1133 { 1134 1135 if ((type == SSL3_RT_HANDSHAKE) && (D1I(s)->handshake_fragment_len > 0)) 1136 /* (partially) satisfy request from storage */ 1137 { 1138 unsigned char *src = D1I(s)->handshake_fragment; 1139 unsigned char *dst = buf; 1140 unsigned int k, n; 1141 1142 /* peek == 0 */ 1143 n = 0; 1144 while ((len > 0) && (D1I(s)->handshake_fragment_len > 0)) { 1145 *dst++ = *src++; 1146 len--; 1147 D1I(s)->handshake_fragment_len--; 1148 n++; 1149 } 1150 /* move any remaining fragment bytes: */ 1151 for (k = 0; k < D1I(s)->handshake_fragment_len; k++) 1152 D1I(s)->handshake_fragment[k] = *src++; 1153 return n; 1154 } 1155 1156 return 0; 1157 } 1158 1159 1160 /* Call this to write data in records of type 'type' 1161 * It will return <= 0 if not all data has been sent or non-blocking IO. 1162 */ 1163 int 1164 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1165 { 1166 int i; 1167 1168 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1169 s->internal->rwstate = SSL_NOTHING; 1170 i = do_dtls1_write(s, type, buf, len); 1171 return i; 1172 } 1173 1174 int 1175 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 1176 { 1177 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 1178 size_t out_len; 1179 CBB cbb; 1180 int ret; 1181 1182 memset(&cbb, 0, sizeof(cbb)); 1183 1184 /* 1185 * First check if there is a SSL3_BUFFER_INTERNAL still being written 1186 * out. This will happen with non blocking IO. 1187 */ 1188 if (wb->left != 0) { 1189 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1190 return (ssl3_write_pending(s, type, buf, len)); 1191 } 1192 1193 /* If we have an alert to send, let's send it */ 1194 if (S3I(s)->alert_dispatch) { 1195 if ((ret = s->method->ssl_dispatch_alert(s)) <= 0) 1196 return (ret); 1197 /* If it went, fall through and send more stuff. */ 1198 } 1199 1200 if (len == 0) 1201 return 0; 1202 1203 wb->offset = 0; 1204 1205 if (!CBB_init_fixed(&cbb, wb->buf, wb->len)) 1206 goto err; 1207 1208 tls12_record_layer_set_version(s->internal->rl, s->version); 1209 tls12_record_layer_set_write_epoch(s->internal->rl, D1I(s)->w_epoch); 1210 1211 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 1212 goto err; 1213 1214 if (!CBB_finish(&cbb, NULL, &out_len)) 1215 goto err; 1216 1217 wb->left = out_len; 1218 1219 /* 1220 * Memorize arguments so that ssl3_write_pending can detect 1221 * bad write retries later. 1222 */ 1223 S3I(s)->wpend_tot = len; 1224 S3I(s)->wpend_buf = buf; 1225 S3I(s)->wpend_type = type; 1226 S3I(s)->wpend_ret = len; 1227 1228 /* We now just need to write the buffer. */ 1229 return ssl3_write_pending(s, type, buf, len); 1230 1231 err: 1232 CBB_cleanup(&cbb); 1233 1234 return -1; 1235 } 1236 1237 static int 1238 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1239 { 1240 int cmp; 1241 unsigned int shift; 1242 const unsigned char *seq = S3I(s)->read_sequence; 1243 1244 cmp = satsub64be(seq, bitmap->max_seq_num); 1245 if (cmp > 0) { 1246 memcpy (S3I(s)->rrec.seq_num, seq, 8); 1247 return 1; /* this record in new */ 1248 } 1249 shift = -cmp; 1250 if (shift >= sizeof(bitmap->map)*8) 1251 return 0; /* stale, outside the window */ 1252 else if (bitmap->map & (1UL << shift)) 1253 return 0; /* record previously received */ 1254 1255 memcpy(S3I(s)->rrec.seq_num, seq, 8); 1256 return 1; 1257 } 1258 1259 1260 static void 1261 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1262 { 1263 int cmp; 1264 unsigned int shift; 1265 const unsigned char *seq = S3I(s)->read_sequence; 1266 1267 cmp = satsub64be(seq, bitmap->max_seq_num); 1268 if (cmp > 0) { 1269 shift = cmp; 1270 if (shift < sizeof(bitmap->map)*8) 1271 bitmap->map <<= shift, bitmap->map |= 1UL; 1272 else 1273 bitmap->map = 1UL; 1274 memcpy(bitmap->max_seq_num, seq, 8); 1275 } else { 1276 shift = -cmp; 1277 if (shift < sizeof(bitmap->map) * 8) 1278 bitmap->map |= 1UL << shift; 1279 } 1280 } 1281 1282 1283 int 1284 dtls1_dispatch_alert(SSL *s) 1285 { 1286 int i, j; 1287 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1288 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1289 unsigned char *ptr = &buf[0]; 1290 1291 S3I(s)->alert_dispatch = 0; 1292 1293 memset(buf, 0, sizeof(buf)); 1294 *ptr++ = S3I(s)->send_alert[0]; 1295 *ptr++ = S3I(s)->send_alert[1]; 1296 1297 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf)); 1298 if (i <= 0) { 1299 S3I(s)->alert_dispatch = 1; 1300 /* fprintf( stderr, "not done with alert\n" ); */ 1301 } else { 1302 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL) 1303 (void)BIO_flush(s->wbio); 1304 1305 if (s->internal->msg_callback) 1306 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT, 1307 S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg); 1308 1309 if (s->internal->info_callback != NULL) 1310 cb = s->internal->info_callback; 1311 else if (s->ctx->internal->info_callback != NULL) 1312 cb = s->ctx->internal->info_callback; 1313 1314 if (cb != NULL) { 1315 j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1]; 1316 cb(s, SSL_CB_WRITE_ALERT, j); 1317 } 1318 } 1319 return (i); 1320 } 1321 1322 1323 static DTLS1_BITMAP * 1324 dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch) 1325 { 1326 1327 *is_next_epoch = 0; 1328 1329 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1330 if (rr->epoch == D1I(s)->r_epoch) 1331 return &D1I(s)->bitmap; 1332 1333 /* Only HM and ALERT messages can be from the next epoch */ 1334 else if (rr->epoch == (unsigned long)(D1I(s)->r_epoch + 1) && 1335 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1336 *is_next_epoch = 1; 1337 return &D1I(s)->next_bitmap; 1338 } 1339 1340 return NULL; 1341 } 1342 1343 void 1344 dtls1_reset_seq_numbers(SSL *s, int rw) 1345 { 1346 unsigned char *seq; 1347 unsigned int seq_bytes = sizeof(S3I(s)->read_sequence); 1348 1349 if (rw & SSL3_CC_READ) { 1350 D1I(s)->r_epoch++; 1351 seq = S3I(s)->read_sequence; 1352 memcpy(&(D1I(s)->bitmap), &(D1I(s)->next_bitmap), sizeof(DTLS1_BITMAP)); 1353 memset(&(D1I(s)->next_bitmap), 0, sizeof(DTLS1_BITMAP)); 1354 } else { 1355 D1I(s)->w_epoch++; 1356 seq = S3I(s)->write_sequence; 1357 memcpy(D1I(s)->last_write_sequence, seq, sizeof(S3I(s)->write_sequence)); 1358 } 1359 1360 memset(seq, 0, seq_bytes); 1361 } 1362