1/* 2 * Copyright 2005-2022 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10#include <limits.h> 11#include <string.h> 12#include <stdio.h> 13#include "../ssl_local.h" 14#include "statem_local.h" 15#include "internal/cryptlib.h" 16#include <openssl/buffer.h> 17#include <openssl/objects.h> 18#include <openssl/evp.h> 19#include <openssl/x509.h> 20 21#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 22 23#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 24 if ((end) - (start) <= 8) { \ 25 long ii; \ 26 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 27 } else { \ 28 long ii; \ 29 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 30 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 31 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 32 } } 33 34#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 35 long ii; \ 36 is_complete = 1; \ 37 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 38 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 39 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 40 41static unsigned char bitmask_start_values[] = 42 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 }; 43static unsigned char bitmask_end_values[] = 44 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f }; 45 46static void dtls1_fix_message_header(SSL *s, size_t frag_off, 47 size_t frag_len); 48static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p); 49static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 50 size_t len, 51 unsigned short seq_num, 52 size_t frag_off, 53 size_t frag_len); 54static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len); 55 56static hm_fragment *dtls1_hm_fragment_new(size_t frag_len, int reassembly) 57{ 58 hm_fragment *frag = NULL; 59 unsigned char *buf = NULL; 60 unsigned char *bitmask = NULL; 61 62 if ((frag = OPENSSL_zalloc(sizeof(*frag))) == NULL) { 63 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE); 64 return NULL; 65 } 66 67 if (frag_len) { 68 if ((buf = OPENSSL_malloc(frag_len)) == NULL) { 69 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE); 70 OPENSSL_free(frag); 71 return NULL; 72 } 73 } 74 75 /* zero length fragment gets zero frag->fragment */ 76 frag->fragment = buf; 77 78 /* Initialize reassembly bitmask if necessary */ 79 if (reassembly) { 80 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len)); 81 if (bitmask == NULL) { 82 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE); 83 OPENSSL_free(buf); 84 OPENSSL_free(frag); 85 return NULL; 86 } 87 } 88 89 frag->reassembly = bitmask; 90 91 return frag; 92} 93 94void dtls1_hm_fragment_free(hm_fragment *frag) 95{ 96 if (!frag) 97 return; 98 99 OPENSSL_free(frag->fragment); 100 OPENSSL_free(frag->reassembly); 101 OPENSSL_free(frag); 102} 103 104/* 105 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or 106 * SSL3_RT_CHANGE_CIPHER_SPEC) 107 */ 108int dtls1_do_write(SSL *s, int type) 109{ 110 int ret; 111 size_t written; 112 size_t curr_mtu; 113 int retry = 1; 114 size_t len, frag_off, mac_size, blocksize, used_len; 115 116 if (!dtls1_query_mtu(s)) 117 return -1; 118 119 if (s->d1->mtu < dtls1_min_mtu(s)) 120 /* should have something reasonable now */ 121 return -1; 122 123 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) { 124 if (!ossl_assert(s->init_num == 125 s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH)) 126 return -1; 127 } 128 129 if (s->write_hash) { 130 if (s->enc_write_ctx 131 && (EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(s->enc_write_ctx)) & 132 EVP_CIPH_FLAG_AEAD_CIPHER) != 0) 133 mac_size = 0; 134 else 135 mac_size = EVP_MD_CTX_get_size(s->write_hash); 136 } else 137 mac_size = 0; 138 139 if (s->enc_write_ctx && 140 (EVP_CIPHER_CTX_get_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE)) 141 blocksize = 2 * EVP_CIPHER_CTX_get_block_size(s->enc_write_ctx); 142 else 143 blocksize = 0; 144 145 frag_off = 0; 146 s->rwstate = SSL_NOTHING; 147 148 /* s->init_num shouldn't ever be < 0...but just in case */ 149 while (s->init_num > 0) { 150 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) { 151 /* We must be writing a fragment other than the first one */ 152 153 if (frag_off > 0) { 154 /* This is the first attempt at writing out this fragment */ 155 156 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) { 157 /* 158 * Each fragment that was already sent must at least have 159 * contained the message header plus one other byte. 160 * Therefore |init_off| must have progressed by at least 161 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went 162 * wrong. 163 */ 164 return -1; 165 } 166 167 /* 168 * Adjust |init_off| and |init_num| to allow room for a new 169 * message header for this fragment. 170 */ 171 s->init_off -= DTLS1_HM_HEADER_LENGTH; 172 s->init_num += DTLS1_HM_HEADER_LENGTH; 173 } else { 174 /* 175 * We must have been called again after a retry so use the 176 * fragment offset from our last attempt. We do not need 177 * to adjust |init_off| and |init_num| as above, because 178 * that should already have been done before the retry. 179 */ 180 frag_off = s->d1->w_msg_hdr.frag_off; 181 } 182 } 183 184 used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH 185 + mac_size + blocksize; 186 if (s->d1->mtu > used_len) 187 curr_mtu = s->d1->mtu - used_len; 188 else 189 curr_mtu = 0; 190 191 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 192 /* 193 * grr.. we could get an error if MTU picked was wrong 194 */ 195 ret = BIO_flush(s->wbio); 196 if (ret <= 0) { 197 s->rwstate = SSL_WRITING; 198 return ret; 199 } 200 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 201 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) { 202 curr_mtu = s->d1->mtu - used_len; 203 } else { 204 /* Shouldn't happen */ 205 return -1; 206 } 207 } 208 209 /* 210 * We just checked that s->init_num > 0 so this cast should be safe 211 */ 212 if (((unsigned int)s->init_num) > curr_mtu) 213 len = curr_mtu; 214 else 215 len = s->init_num; 216 217 if (len > ssl_get_max_send_fragment(s)) 218 len = ssl_get_max_send_fragment(s); 219 220 /* 221 * XDTLS: this function is too long. split out the CCS part 222 */ 223 if (type == SSL3_RT_HANDSHAKE) { 224 if (len < DTLS1_HM_HEADER_LENGTH) { 225 /* 226 * len is so small that we really can't do anything sensible 227 * so fail 228 */ 229 return -1; 230 } 231 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH); 232 233 dtls1_write_message_header(s, 234 (unsigned char *)&s->init_buf-> 235 data[s->init_off]); 236 } 237 238 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len, 239 &written); 240 if (ret <= 0) { 241 /* 242 * might need to update MTU here, but we don't know which 243 * previous packet caused the failure -- so can't really 244 * retransmit anything. continue as if everything is fine and 245 * wait for an alert to handle the retransmit 246 */ 247 if (retry && BIO_ctrl(SSL_get_wbio(s), 248 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) { 249 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 250 if (!dtls1_query_mtu(s)) 251 return -1; 252 /* Have one more go */ 253 retry = 0; 254 } else 255 return -1; 256 } else { 257 return -1; 258 } 259 } else { 260 261 /* 262 * bad if this assert fails, only part of the handshake message 263 * got sent. but why would this happen? 264 */ 265 if (!ossl_assert(len == written)) 266 return -1; 267 268 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 269 /* 270 * should not be done for 'Hello Request's, but in that case 271 * we'll ignore the result anyway 272 */ 273 unsigned char *p = 274 (unsigned char *)&s->init_buf->data[s->init_off]; 275 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 276 size_t xlen; 277 278 if (frag_off == 0 && s->version != DTLS1_BAD_VER) { 279 /* 280 * reconstruct message header is if it is being sent in 281 * single fragment 282 */ 283 *p++ = msg_hdr->type; 284 l2n3(msg_hdr->msg_len, p); 285 s2n(msg_hdr->seq, p); 286 l2n3(0, p); 287 l2n3(msg_hdr->msg_len, p); 288 p -= DTLS1_HM_HEADER_LENGTH; 289 xlen = written; 290 } else { 291 p += DTLS1_HM_HEADER_LENGTH; 292 xlen = written - DTLS1_HM_HEADER_LENGTH; 293 } 294 295 if (!ssl3_finish_mac(s, p, xlen)) 296 return -1; 297 } 298 299 if (written == s->init_num) { 300 if (s->msg_callback) 301 s->msg_callback(1, s->version, type, s->init_buf->data, 302 (size_t)(s->init_off + s->init_num), s, 303 s->msg_callback_arg); 304 305 s->init_off = 0; /* done writing this message */ 306 s->init_num = 0; 307 308 return 1; 309 } 310 s->init_off += written; 311 s->init_num -= written; 312 written -= DTLS1_HM_HEADER_LENGTH; 313 frag_off += written; 314 315 /* 316 * We save the fragment offset for the next fragment so we have it 317 * available in case of an IO retry. We don't know the length of the 318 * next fragment yet so just set that to 0 for now. It will be 319 * updated again later. 320 */ 321 dtls1_fix_message_header(s, frag_off, 0); 322 } 323 } 324 return 0; 325} 326 327int dtls_get_message(SSL *s, int *mt) 328{ 329 struct hm_header_st *msg_hdr; 330 unsigned char *p; 331 size_t msg_len; 332 size_t tmplen; 333 int errtype; 334 335 msg_hdr = &s->d1->r_msg_hdr; 336 memset(msg_hdr, 0, sizeof(*msg_hdr)); 337 338 again: 339 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) { 340 if (errtype == DTLS1_HM_BAD_FRAGMENT 341 || errtype == DTLS1_HM_FRAGMENT_RETRY) { 342 /* bad fragment received */ 343 goto again; 344 } 345 return 0; 346 } 347 348 *mt = s->s3.tmp.message_type; 349 350 p = (unsigned char *)s->init_buf->data; 351 352 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) { 353 if (s->msg_callback) { 354 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 355 p, 1, s, s->msg_callback_arg); 356 } 357 /* 358 * This isn't a real handshake message so skip the processing below. 359 */ 360 return 1; 361 } 362 363 msg_len = msg_hdr->msg_len; 364 365 /* reconstruct message header */ 366 *(p++) = msg_hdr->type; 367 l2n3(msg_len, p); 368 s2n(msg_hdr->seq, p); 369 l2n3(0, p); 370 l2n3(msg_len, p); 371 372 memset(msg_hdr, 0, sizeof(*msg_hdr)); 373 374 s->d1->handshake_read_seq++; 375 376 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 377 378 return 1; 379} 380 381/* 382 * Actually we already have the message body - but this is an opportunity for 383 * DTLS to do any further processing it wants at the same point that TLS would 384 * be asked for the message body. 385 */ 386int dtls_get_message_body(SSL *s, size_t *len) 387{ 388 unsigned char *msg = (unsigned char *)s->init_buf->data; 389 size_t msg_len = s->init_num + DTLS1_HM_HEADER_LENGTH; 390 391 if (s->s3.tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) { 392 /* Nothing to be done */ 393 goto end; 394 } 395 /* 396 * If receiving Finished, record MAC of prior handshake messages for 397 * Finished verification. 398 */ 399 if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) { 400 /* SSLfatal() already called */ 401 return 0; 402 } 403 404 if (s->version == DTLS1_BAD_VER) { 405 msg += DTLS1_HM_HEADER_LENGTH; 406 msg_len -= DTLS1_HM_HEADER_LENGTH; 407 } 408 409 if (!ssl3_finish_mac(s, msg, msg_len)) 410 return 0; 411 412 if (s->msg_callback) 413 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 414 s->init_buf->data, s->init_num + DTLS1_HM_HEADER_LENGTH, 415 s, s->msg_callback_arg); 416 417 end: 418 *len = s->init_num; 419 return 1; 420} 421 422/* 423 * dtls1_max_handshake_message_len returns the maximum number of bytes 424 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 425 * may be greater if the maximum certificate list size requires it. 426 */ 427static size_t dtls1_max_handshake_message_len(const SSL *s) 428{ 429 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 430 if (max_len < s->max_cert_list) 431 return s->max_cert_list; 432 return max_len; 433} 434 435static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr) 436{ 437 size_t frag_off, frag_len, msg_len; 438 439 msg_len = msg_hdr->msg_len; 440 frag_off = msg_hdr->frag_off; 441 frag_len = msg_hdr->frag_len; 442 443 /* sanity checking */ 444 if ((frag_off + frag_len) > msg_len 445 || msg_len > dtls1_max_handshake_message_len(s)) { 446 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE); 447 return 0; 448 } 449 450 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 451 /* 452 * msg_len is limited to 2^24, but is effectively checked against 453 * dtls_max_handshake_message_len(s) above 454 */ 455 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { 456 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB); 457 return 0; 458 } 459 460 s->s3.tmp.message_size = msg_len; 461 s->d1->r_msg_hdr.msg_len = msg_len; 462 s->s3.tmp.message_type = msg_hdr->type; 463 s->d1->r_msg_hdr.type = msg_hdr->type; 464 s->d1->r_msg_hdr.seq = msg_hdr->seq; 465 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 466 /* 467 * They must be playing with us! BTW, failure to enforce upper limit 468 * would open possibility for buffer overrun. 469 */ 470 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE); 471 return 0; 472 } 473 474 return 1; 475} 476 477/* 478 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a 479 * fatal error. 480 */ 481static int dtls1_retrieve_buffered_fragment(SSL *s, size_t *len) 482{ 483 /*- 484 * (0) check whether the desired fragment is available 485 * if so: 486 * (1) copy over the fragment to s->init_buf->data[] 487 * (2) update s->init_num 488 */ 489 pitem *item; 490 piterator iter; 491 hm_fragment *frag; 492 int ret; 493 int chretran = 0; 494 495 iter = pqueue_iterator(s->d1->buffered_messages); 496 do { 497 item = pqueue_next(&iter); 498 if (item == NULL) 499 return 0; 500 501 frag = (hm_fragment *)item->data; 502 503 if (frag->msg_header.seq < s->d1->handshake_read_seq) { 504 pitem *next; 505 hm_fragment *nextfrag; 506 507 if (!s->server 508 || frag->msg_header.seq != 0 509 || s->d1->handshake_read_seq != 1 510 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) { 511 /* 512 * This is a stale message that has been buffered so clear it. 513 * It is safe to pop this message from the queue even though 514 * we have an active iterator 515 */ 516 pqueue_pop(s->d1->buffered_messages); 517 dtls1_hm_fragment_free(frag); 518 pitem_free(item); 519 item = NULL; 520 frag = NULL; 521 } else { 522 /* 523 * We have fragments for a ClientHello without a cookie, 524 * even though we have sent a HelloVerifyRequest. It is possible 525 * that the HelloVerifyRequest got lost and this is a 526 * retransmission of the original ClientHello 527 */ 528 next = pqueue_next(&iter); 529 if (next != NULL) { 530 nextfrag = (hm_fragment *)next->data; 531 if (nextfrag->msg_header.seq == s->d1->handshake_read_seq) { 532 /* 533 * We have fragments for both a ClientHello without 534 * cookie and one with. Ditch the one without. 535 */ 536 pqueue_pop(s->d1->buffered_messages); 537 dtls1_hm_fragment_free(frag); 538 pitem_free(item); 539 item = next; 540 frag = nextfrag; 541 } else { 542 chretran = 1; 543 } 544 } else { 545 chretran = 1; 546 } 547 } 548 } 549 } while (item == NULL); 550 551 /* Don't return if reassembly still in progress */ 552 if (frag->reassembly != NULL) 553 return 0; 554 555 if (s->d1->handshake_read_seq == frag->msg_header.seq || chretran) { 556 size_t frag_len = frag->msg_header.frag_len; 557 pqueue_pop(s->d1->buffered_messages); 558 559 /* Calls SSLfatal() as required */ 560 ret = dtls1_preprocess_fragment(s, &frag->msg_header); 561 562 if (ret && frag->msg_header.frag_len > 0) { 563 unsigned char *p = 564 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 565 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 566 frag->msg_header.frag_len); 567 } 568 569 dtls1_hm_fragment_free(frag); 570 pitem_free(item); 571 572 if (ret) { 573 if (chretran) { 574 /* 575 * We got a new ClientHello with a message sequence of 0. 576 * Reset the read/write sequences back to the beginning. 577 * We process it like this is the first time we've seen a 578 * ClientHello from the client. 579 */ 580 s->d1->handshake_read_seq = 0; 581 s->d1->next_handshake_write_seq = 0; 582 } 583 *len = frag_len; 584 return 1; 585 } 586 587 /* Fatal error */ 588 s->init_num = 0; 589 return -1; 590 } else { 591 return 0; 592 } 593} 594 595static int 596dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr) 597{ 598 hm_fragment *frag = NULL; 599 pitem *item = NULL; 600 int i = -1, is_complete; 601 unsigned char seq64be[8]; 602 size_t frag_len = msg_hdr->frag_len; 603 size_t readbytes; 604 605 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 606 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 607 goto err; 608 609 if (frag_len == 0) { 610 return DTLS1_HM_FRAGMENT_RETRY; 611 } 612 613 /* Try to find item in queue */ 614 memset(seq64be, 0, sizeof(seq64be)); 615 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 616 seq64be[7] = (unsigned char)msg_hdr->seq; 617 item = pqueue_find(s->d1->buffered_messages, seq64be); 618 619 if (item == NULL) { 620 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 621 if (frag == NULL) 622 goto err; 623 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 624 frag->msg_header.frag_len = frag->msg_header.msg_len; 625 frag->msg_header.frag_off = 0; 626 } else { 627 frag = (hm_fragment *)item->data; 628 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 629 item = NULL; 630 frag = NULL; 631 goto err; 632 } 633 } 634 635 /* 636 * If message is already reassembled, this must be a retransmit and can 637 * be dropped. In this case item != NULL and so frag does not need to be 638 * freed. 639 */ 640 if (frag->reassembly == NULL) { 641 unsigned char devnull[256]; 642 643 while (frag_len) { 644 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 645 devnull, 646 frag_len > 647 sizeof(devnull) ? sizeof(devnull) : 648 frag_len, 0, &readbytes); 649 if (i <= 0) 650 goto err; 651 frag_len -= readbytes; 652 } 653 return DTLS1_HM_FRAGMENT_RETRY; 654 } 655 656 /* read the body of the fragment (header has already been read */ 657 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 658 frag->fragment + msg_hdr->frag_off, 659 frag_len, 0, &readbytes); 660 if (i <= 0 || readbytes != frag_len) 661 i = -1; 662 if (i <= 0) 663 goto err; 664 665 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 666 (long)(msg_hdr->frag_off + frag_len)); 667 668 if (!ossl_assert(msg_hdr->msg_len > 0)) 669 goto err; 670 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 671 is_complete); 672 673 if (is_complete) { 674 OPENSSL_free(frag->reassembly); 675 frag->reassembly = NULL; 676 } 677 678 if (item == NULL) { 679 item = pitem_new(seq64be, frag); 680 if (item == NULL) { 681 i = -1; 682 goto err; 683 } 684 685 item = pqueue_insert(s->d1->buffered_messages, item); 686 /* 687 * pqueue_insert fails iff a duplicate item is inserted. However, 688 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 689 * would have returned it and control would never have reached this 690 * branch. 691 */ 692 if (!ossl_assert(item != NULL)) 693 goto err; 694 } 695 696 return DTLS1_HM_FRAGMENT_RETRY; 697 698 err: 699 if (item == NULL) 700 dtls1_hm_fragment_free(frag); 701 return -1; 702} 703 704static int 705dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr) 706{ 707 int i = -1; 708 hm_fragment *frag = NULL; 709 pitem *item = NULL; 710 unsigned char seq64be[8]; 711 size_t frag_len = msg_hdr->frag_len; 712 size_t readbytes; 713 714 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 715 goto err; 716 717 /* Try to find item in queue, to prevent duplicate entries */ 718 memset(seq64be, 0, sizeof(seq64be)); 719 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 720 seq64be[7] = (unsigned char)msg_hdr->seq; 721 item = pqueue_find(s->d1->buffered_messages, seq64be); 722 723 /* 724 * If we already have an entry and this one is a fragment, don't discard 725 * it and rather try to reassemble it. 726 */ 727 if (item != NULL && frag_len != msg_hdr->msg_len) 728 item = NULL; 729 730 /* 731 * Discard the message if sequence number was already there, is too far 732 * in the future, already in the queue or if we received a FINISHED 733 * before the SERVER_HELLO, which then must be a stale retransmit. 734 */ 735 if (msg_hdr->seq <= s->d1->handshake_read_seq || 736 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 737 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) { 738 unsigned char devnull[256]; 739 740 while (frag_len) { 741 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 742 devnull, 743 frag_len > 744 sizeof(devnull) ? sizeof(devnull) : 745 frag_len, 0, &readbytes); 746 if (i <= 0) 747 goto err; 748 frag_len -= readbytes; 749 } 750 } else { 751 if (frag_len != msg_hdr->msg_len) { 752 return dtls1_reassemble_fragment(s, msg_hdr); 753 } 754 755 if (frag_len > dtls1_max_handshake_message_len(s)) 756 goto err; 757 758 frag = dtls1_hm_fragment_new(frag_len, 0); 759 if (frag == NULL) 760 goto err; 761 762 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 763 764 if (frag_len) { 765 /* 766 * read the body of the fragment (header has already been read 767 */ 768 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 769 frag->fragment, frag_len, 0, 770 &readbytes); 771 if (i<=0 || readbytes != frag_len) 772 i = -1; 773 if (i <= 0) 774 goto err; 775 } 776 777 item = pitem_new(seq64be, frag); 778 if (item == NULL) 779 goto err; 780 781 item = pqueue_insert(s->d1->buffered_messages, item); 782 /* 783 * pqueue_insert fails iff a duplicate item is inserted. However, 784 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 785 * would have returned it. Then, either |frag_len| != 786 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 787 * have been processed with |dtls1_reassemble_fragment|, above, or 788 * the record will have been discarded. 789 */ 790 if (!ossl_assert(item != NULL)) 791 goto err; 792 } 793 794 return DTLS1_HM_FRAGMENT_RETRY; 795 796 err: 797 if (item == NULL) 798 dtls1_hm_fragment_free(frag); 799 return 0; 800} 801 802static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len) 803{ 804 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 805 size_t mlen, frag_off, frag_len; 806 int i, ret, recvd_type; 807 struct hm_header_st msg_hdr; 808 size_t readbytes; 809 int chretran = 0; 810 811 *errtype = 0; 812 813 redo: 814 /* see if we have the required fragment already */ 815 ret = dtls1_retrieve_buffered_fragment(s, &frag_len); 816 if (ret < 0) { 817 /* SSLfatal() already called */ 818 return 0; 819 } 820 if (ret > 0) { 821 s->init_num = frag_len; 822 *len = frag_len; 823 return 1; 824 } 825 826 /* read handshake message header */ 827 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire, 828 DTLS1_HM_HEADER_LENGTH, 0, &readbytes); 829 if (i <= 0) { /* nbio, or an error */ 830 s->rwstate = SSL_READING; 831 *len = 0; 832 return 0; 833 } 834 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) { 835 if (wire[0] != SSL3_MT_CCS) { 836 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, 837 SSL_R_BAD_CHANGE_CIPHER_SPEC); 838 goto f_err; 839 } 840 841 memcpy(s->init_buf->data, wire, readbytes); 842 s->init_num = readbytes - 1; 843 s->init_msg = s->init_buf->data + 1; 844 s->s3.tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC; 845 s->s3.tmp.message_size = readbytes - 1; 846 *len = readbytes - 1; 847 return 1; 848 } 849 850 /* Handshake fails if message header is incomplete */ 851 if (readbytes != DTLS1_HM_HEADER_LENGTH) { 852 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 853 goto f_err; 854 } 855 856 /* parse the message fragment header */ 857 dtls1_get_message_header(wire, &msg_hdr); 858 859 mlen = msg_hdr.msg_len; 860 frag_off = msg_hdr.frag_off; 861 frag_len = msg_hdr.frag_len; 862 863 /* 864 * We must have at least frag_len bytes left in the record to be read. 865 * Fragments must not span records. 866 */ 867 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) { 868 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH); 869 goto f_err; 870 } 871 872 /* 873 * if this is a future (or stale) message it gets buffered 874 * (or dropped)--no further processing at this time 875 * While listening, we accept seq 1 (ClientHello with cookie) 876 * although we're still expecting seq 0 (ClientHello) 877 */ 878 if (msg_hdr.seq != s->d1->handshake_read_seq) { 879 if (!s->server 880 || msg_hdr.seq != 0 881 || s->d1->handshake_read_seq != 1 882 || wire[0] != SSL3_MT_CLIENT_HELLO 883 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) { 884 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr); 885 return 0; 886 } 887 /* 888 * We received a ClientHello and sent back a HelloVerifyRequest. We 889 * now seem to have received a retransmitted initial ClientHello. That 890 * is allowed (possibly our HelloVerifyRequest got lost). 891 */ 892 chretran = 1; 893 } 894 895 if (frag_len && frag_len < mlen) { 896 *errtype = dtls1_reassemble_fragment(s, &msg_hdr); 897 return 0; 898 } 899 900 if (!s->server 901 && s->d1->r_msg_hdr.frag_off == 0 902 && s->statem.hand_state != TLS_ST_OK 903 && wire[0] == SSL3_MT_HELLO_REQUEST) { 904 /* 905 * The server may always send 'Hello Request' messages -- we are 906 * doing a handshake anyway now, so ignore them if their format is 907 * correct. Does not count for 'Finished' MAC. 908 */ 909 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 910 if (s->msg_callback) 911 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 912 wire, DTLS1_HM_HEADER_LENGTH, s, 913 s->msg_callback_arg); 914 915 s->init_num = 0; 916 goto redo; 917 } else { /* Incorrectly formatted Hello request */ 918 919 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 920 goto f_err; 921 } 922 } 923 924 if (!dtls1_preprocess_fragment(s, &msg_hdr)) { 925 /* SSLfatal() already called */ 926 goto f_err; 927 } 928 929 if (frag_len > 0) { 930 unsigned char *p = 931 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 932 933 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 934 &p[frag_off], frag_len, 0, &readbytes); 935 936 /* 937 * This shouldn't ever fail due to NBIO because we already checked 938 * that we have enough data in the record 939 */ 940 if (i <= 0) { 941 s->rwstate = SSL_READING; 942 *len = 0; 943 return 0; 944 } 945 } else { 946 readbytes = 0; 947 } 948 949 /* 950 * XDTLS: an incorrectly formatted fragment should cause the handshake 951 * to fail 952 */ 953 if (readbytes != frag_len) { 954 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH); 955 goto f_err; 956 } 957 958 if (chretran) { 959 /* 960 * We got a new ClientHello with a message sequence of 0. 961 * Reset the read/write sequences back to the beginning. 962 * We process it like this is the first time we've seen a ClientHello 963 * from the client. 964 */ 965 s->d1->handshake_read_seq = 0; 966 s->d1->next_handshake_write_seq = 0; 967 } 968 969 /* 970 * Note that s->init_num is *not* used as current offset in 971 * s->init_buf->data, but as a counter summing up fragments' lengths: as 972 * soon as they sum up to handshake packet length, we assume we have got 973 * all the fragments. 974 */ 975 *len = s->init_num = frag_len; 976 return 1; 977 978 f_err: 979 s->init_num = 0; 980 *len = 0; 981 return 0; 982} 983 984/*- 985 * for these 2 messages, we need to 986 * ssl->enc_read_ctx re-init 987 * ssl->rlayer.read_sequence zero 988 * ssl->s3.read_mac_secret re-init 989 * ssl->session->read_sym_enc assign 990 * ssl->session->read_compression assign 991 * ssl->session->read_hash assign 992 */ 993int dtls_construct_change_cipher_spec(SSL *s, WPACKET *pkt) 994{ 995 if (s->version == DTLS1_BAD_VER) { 996 s->d1->next_handshake_write_seq++; 997 998 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) { 999 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1000 return 0; 1001 } 1002 } 1003 1004 return 1; 1005} 1006 1007#ifndef OPENSSL_NO_SCTP 1008/* 1009 * Wait for a dry event. Should only be called at a point in the handshake 1010 * where we are not expecting any data from the peer except an alert. 1011 */ 1012WORK_STATE dtls_wait_for_dry(SSL *s) 1013{ 1014 int ret, errtype; 1015 size_t len; 1016 1017 /* read app data until dry event */ 1018 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1019 if (ret < 0) { 1020 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1021 return WORK_ERROR; 1022 } 1023 1024 if (ret == 0) { 1025 /* 1026 * We're not expecting any more messages from the peer at this point - 1027 * but we could get an alert. If an alert is waiting then we will never 1028 * return successfully. Therefore we attempt to read a message. This 1029 * should never succeed but will process any waiting alerts. 1030 */ 1031 if (dtls_get_reassembled_message(s, &errtype, &len)) { 1032 /* The call succeeded! This should never happen */ 1033 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 1034 return WORK_ERROR; 1035 } 1036 1037 s->s3.in_read_app_data = 2; 1038 s->rwstate = SSL_READING; 1039 BIO_clear_retry_flags(SSL_get_rbio(s)); 1040 BIO_set_retry_read(SSL_get_rbio(s)); 1041 return WORK_MORE_A; 1042 } 1043 return WORK_FINISHED_CONTINUE; 1044} 1045#endif 1046 1047int dtls1_read_failed(SSL *s, int code) 1048{ 1049 if (code > 0) { 1050 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1051 return 0; 1052 } 1053 1054 if (!dtls1_is_timer_expired(s) || ossl_statem_in_error(s)) { 1055 /* 1056 * not a timeout, none of our business, let higher layers handle 1057 * this. in fact it's probably an error 1058 */ 1059 return code; 1060 } 1061 /* done, no need to send a retransmit */ 1062 if (!SSL_in_init(s)) 1063 { 1064 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1065 return code; 1066 } 1067 1068 return dtls1_handle_timeout(s); 1069} 1070 1071int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1072{ 1073 /* 1074 * The index of the retransmission queue actually is the message sequence 1075 * number, since the queue only contains messages of a single handshake. 1076 * However, the ChangeCipherSpec has no message sequence number and so 1077 * using only the sequence will result in the CCS and Finished having the 1078 * same index. To prevent this, the sequence number is multiplied by 2. 1079 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1080 * Finished, it also maintains the order of the index (important for 1081 * priority queues) and fits in the unsigned short variable. 1082 */ 1083 return seq * 2 - is_ccs; 1084} 1085 1086int dtls1_retransmit_buffered_messages(SSL *s) 1087{ 1088 pqueue *sent = s->d1->sent_messages; 1089 piterator iter; 1090 pitem *item; 1091 hm_fragment *frag; 1092 int found = 0; 1093 1094 iter = pqueue_iterator(sent); 1095 1096 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1097 frag = (hm_fragment *)item->data; 1098 if (dtls1_retransmit_message(s, (unsigned short) 1099 dtls1_get_queue_priority 1100 (frag->msg_header.seq, 1101 frag->msg_header.is_ccs), &found) <= 0) 1102 return -1; 1103 } 1104 1105 return 1; 1106} 1107 1108int dtls1_buffer_message(SSL *s, int is_ccs) 1109{ 1110 pitem *item; 1111 hm_fragment *frag; 1112 unsigned char seq64be[8]; 1113 1114 /* 1115 * this function is called immediately after a message has been 1116 * serialized 1117 */ 1118 if (!ossl_assert(s->init_off == 0)) 1119 return 0; 1120 1121 frag = dtls1_hm_fragment_new(s->init_num, 0); 1122 if (frag == NULL) 1123 return 0; 1124 1125 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1126 1127 if (is_ccs) { 1128 /* For DTLS1_BAD_VER the header length is non-standard */ 1129 if (!ossl_assert(s->d1->w_msg_hdr.msg_len + 1130 ((s->version == 1131 DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH) 1132 == (unsigned int)s->init_num)) { 1133 dtls1_hm_fragment_free(frag); 1134 return 0; 1135 } 1136 } else { 1137 if (!ossl_assert(s->d1->w_msg_hdr.msg_len + 1138 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num)) { 1139 dtls1_hm_fragment_free(frag); 1140 return 0; 1141 } 1142 } 1143 1144 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1145 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1146 frag->msg_header.type = s->d1->w_msg_hdr.type; 1147 frag->msg_header.frag_off = 0; 1148 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1149 frag->msg_header.is_ccs = is_ccs; 1150 1151 /* save current state */ 1152 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1153 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1154 frag->msg_header.saved_retransmit_state.compress = s->compress; 1155 frag->msg_header.saved_retransmit_state.session = s->session; 1156 frag->msg_header.saved_retransmit_state.epoch = 1157 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer); 1158 1159 memset(seq64be, 0, sizeof(seq64be)); 1160 seq64be[6] = 1161 (unsigned 1162 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1163 frag->msg_header.is_ccs) >> 8); 1164 seq64be[7] = 1165 (unsigned 1166 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1167 frag->msg_header.is_ccs)); 1168 1169 item = pitem_new(seq64be, frag); 1170 if (item == NULL) { 1171 dtls1_hm_fragment_free(frag); 1172 return 0; 1173 } 1174 1175 pqueue_insert(s->d1->sent_messages, item); 1176 return 1; 1177} 1178 1179int dtls1_retransmit_message(SSL *s, unsigned short seq, int *found) 1180{ 1181 int ret; 1182 /* XDTLS: for now assuming that read/writes are blocking */ 1183 pitem *item; 1184 hm_fragment *frag; 1185 unsigned long header_length; 1186 unsigned char seq64be[8]; 1187 struct dtls1_retransmit_state saved_state; 1188 1189 /* XDTLS: the requested message ought to be found, otherwise error */ 1190 memset(seq64be, 0, sizeof(seq64be)); 1191 seq64be[6] = (unsigned char)(seq >> 8); 1192 seq64be[7] = (unsigned char)seq; 1193 1194 item = pqueue_find(s->d1->sent_messages, seq64be); 1195 if (item == NULL) { 1196 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1197 *found = 0; 1198 return 0; 1199 } 1200 1201 *found = 1; 1202 frag = (hm_fragment *)item->data; 1203 1204 if (frag->msg_header.is_ccs) 1205 header_length = DTLS1_CCS_HEADER_LENGTH; 1206 else 1207 header_length = DTLS1_HM_HEADER_LENGTH; 1208 1209 memcpy(s->init_buf->data, frag->fragment, 1210 frag->msg_header.msg_len + header_length); 1211 s->init_num = frag->msg_header.msg_len + header_length; 1212 1213 dtls1_set_message_header_int(s, frag->msg_header.type, 1214 frag->msg_header.msg_len, 1215 frag->msg_header.seq, 0, 1216 frag->msg_header.frag_len); 1217 1218 /* save current state */ 1219 saved_state.enc_write_ctx = s->enc_write_ctx; 1220 saved_state.write_hash = s->write_hash; 1221 saved_state.compress = s->compress; 1222 saved_state.session = s->session; 1223 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer); 1224 1225 s->d1->retransmitting = 1; 1226 1227 /* restore state in which the message was originally sent */ 1228 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1229 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1230 s->compress = frag->msg_header.saved_retransmit_state.compress; 1231 s->session = frag->msg_header.saved_retransmit_state.session; 1232 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, 1233 frag->msg_header. 1234 saved_retransmit_state.epoch); 1235 1236 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1237 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1238 1239 /* restore current state */ 1240 s->enc_write_ctx = saved_state.enc_write_ctx; 1241 s->write_hash = saved_state.write_hash; 1242 s->compress = saved_state.compress; 1243 s->session = saved_state.session; 1244 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch); 1245 1246 s->d1->retransmitting = 0; 1247 1248 (void)BIO_flush(s->wbio); 1249 return ret; 1250} 1251 1252void dtls1_set_message_header(SSL *s, 1253 unsigned char mt, size_t len, 1254 size_t frag_off, size_t frag_len) 1255{ 1256 if (frag_off == 0) { 1257 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1258 s->d1->next_handshake_write_seq++; 1259 } 1260 1261 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1262 frag_off, frag_len); 1263} 1264 1265/* don't actually do the writing, wait till the MTU has been retrieved */ 1266static void 1267dtls1_set_message_header_int(SSL *s, unsigned char mt, 1268 size_t len, unsigned short seq_num, 1269 size_t frag_off, size_t frag_len) 1270{ 1271 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1272 1273 msg_hdr->type = mt; 1274 msg_hdr->msg_len = len; 1275 msg_hdr->seq = seq_num; 1276 msg_hdr->frag_off = frag_off; 1277 msg_hdr->frag_len = frag_len; 1278} 1279 1280static void 1281dtls1_fix_message_header(SSL *s, size_t frag_off, size_t frag_len) 1282{ 1283 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1284 1285 msg_hdr->frag_off = frag_off; 1286 msg_hdr->frag_len = frag_len; 1287} 1288 1289static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1290{ 1291 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1292 1293 *p++ = msg_hdr->type; 1294 l2n3(msg_hdr->msg_len, p); 1295 1296 s2n(msg_hdr->seq, p); 1297 l2n3(msg_hdr->frag_off, p); 1298 l2n3(msg_hdr->frag_len, p); 1299 1300 return p; 1301} 1302 1303void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1304{ 1305 memset(msg_hdr, 0, sizeof(*msg_hdr)); 1306 msg_hdr->type = *(data++); 1307 n2l3(data, msg_hdr->msg_len); 1308 1309 n2s(data, msg_hdr->seq); 1310 n2l3(data, msg_hdr->frag_off); 1311 n2l3(data, msg_hdr->frag_len); 1312} 1313 1314int dtls1_set_handshake_header(SSL *s, WPACKET *pkt, int htype) 1315{ 1316 unsigned char *header; 1317 1318 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) { 1319 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1320 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1321 s->d1->handshake_write_seq, 0, 0); 1322 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS)) 1323 return 0; 1324 } else { 1325 dtls1_set_message_header(s, htype, 0, 0, 0); 1326 /* 1327 * We allocate space at the start for the message header. This gets 1328 * filled in later 1329 */ 1330 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header) 1331 || !WPACKET_start_sub_packet(pkt)) 1332 return 0; 1333 } 1334 1335 return 1; 1336} 1337 1338int dtls1_close_construct_packet(SSL *s, WPACKET *pkt, int htype) 1339{ 1340 size_t msglen; 1341 1342 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt)) 1343 || !WPACKET_get_length(pkt, &msglen) 1344 || msglen > INT_MAX) 1345 return 0; 1346 1347 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) { 1348 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH; 1349 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH; 1350 } 1351 s->init_num = (int)msglen; 1352 s->init_off = 0; 1353 1354 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) { 1355 /* Buffer the message to handle re-xmits */ 1356 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC 1357 ? 1 : 0)) 1358 return 0; 1359 } 1360 1361 return 1; 1362} 1363