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 if (frag->msg_header.is_ccs) { 99 EVP_CIPHER_CTX_free(frag->msg_header. 100 saved_retransmit_state.enc_write_ctx); 101 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash); 102 } 103 OPENSSL_free(frag->fragment); 104 OPENSSL_free(frag->reassembly); 105 OPENSSL_free(frag); 106} 107 108/* 109 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or 110 * SSL3_RT_CHANGE_CIPHER_SPEC) 111 */ 112int dtls1_do_write(SSL *s, int type) 113{ 114 int ret; 115 size_t written; 116 size_t curr_mtu; 117 int retry = 1; 118 size_t len, frag_off, mac_size, blocksize, used_len; 119 120 if (!dtls1_query_mtu(s)) 121 return -1; 122 123 if (s->d1->mtu < dtls1_min_mtu(s)) 124 /* should have something reasonable now */ 125 return -1; 126 127 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) { 128 if (!ossl_assert(s->init_num == 129 s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH)) 130 return -1; 131 } 132 133 if (s->write_hash) { 134 if (s->enc_write_ctx 135 && (EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(s->enc_write_ctx)) & 136 EVP_CIPH_FLAG_AEAD_CIPHER) != 0) 137 mac_size = 0; 138 else 139 mac_size = EVP_MD_CTX_get_size(s->write_hash); 140 } else 141 mac_size = 0; 142 143 if (s->enc_write_ctx && 144 (EVP_CIPHER_CTX_get_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE)) 145 blocksize = 2 * EVP_CIPHER_CTX_get_block_size(s->enc_write_ctx); 146 else 147 blocksize = 0; 148 149 frag_off = 0; 150 s->rwstate = SSL_NOTHING; 151 152 /* s->init_num shouldn't ever be < 0...but just in case */ 153 while (s->init_num > 0) { 154 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) { 155 /* We must be writing a fragment other than the first one */ 156 157 if (frag_off > 0) { 158 /* This is the first attempt at writing out this fragment */ 159 160 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) { 161 /* 162 * Each fragment that was already sent must at least have 163 * contained the message header plus one other byte. 164 * Therefore |init_off| must have progressed by at least 165 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went 166 * wrong. 167 */ 168 return -1; 169 } 170 171 /* 172 * Adjust |init_off| and |init_num| to allow room for a new 173 * message header for this fragment. 174 */ 175 s->init_off -= DTLS1_HM_HEADER_LENGTH; 176 s->init_num += DTLS1_HM_HEADER_LENGTH; 177 } else { 178 /* 179 * We must have been called again after a retry so use the 180 * fragment offset from our last attempt. We do not need 181 * to adjust |init_off| and |init_num| as above, because 182 * that should already have been done before the retry. 183 */ 184 frag_off = s->d1->w_msg_hdr.frag_off; 185 } 186 } 187 188 used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH 189 + mac_size + blocksize; 190 if (s->d1->mtu > used_len) 191 curr_mtu = s->d1->mtu - used_len; 192 else 193 curr_mtu = 0; 194 195 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 196 /* 197 * grr.. we could get an error if MTU picked was wrong 198 */ 199 ret = BIO_flush(s->wbio); 200 if (ret <= 0) { 201 s->rwstate = SSL_WRITING; 202 return ret; 203 } 204 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 205 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) { 206 curr_mtu = s->d1->mtu - used_len; 207 } else { 208 /* Shouldn't happen */ 209 return -1; 210 } 211 } 212 213 /* 214 * We just checked that s->init_num > 0 so this cast should be safe 215 */ 216 if (((unsigned int)s->init_num) > curr_mtu) 217 len = curr_mtu; 218 else 219 len = s->init_num; 220 221 if (len > ssl_get_max_send_fragment(s)) 222 len = ssl_get_max_send_fragment(s); 223 224 /* 225 * XDTLS: this function is too long. split out the CCS part 226 */ 227 if (type == SSL3_RT_HANDSHAKE) { 228 if (len < DTLS1_HM_HEADER_LENGTH) { 229 /* 230 * len is so small that we really can't do anything sensible 231 * so fail 232 */ 233 return -1; 234 } 235 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH); 236 237 dtls1_write_message_header(s, 238 (unsigned char *)&s->init_buf-> 239 data[s->init_off]); 240 } 241 242 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len, 243 &written); 244 if (ret <= 0) { 245 /* 246 * might need to update MTU here, but we don't know which 247 * previous packet caused the failure -- so can't really 248 * retransmit anything. continue as if everything is fine and 249 * wait for an alert to handle the retransmit 250 */ 251 if (retry && BIO_ctrl(SSL_get_wbio(s), 252 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) { 253 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 254 if (!dtls1_query_mtu(s)) 255 return -1; 256 /* Have one more go */ 257 retry = 0; 258 } else 259 return -1; 260 } else { 261 return -1; 262 } 263 } else { 264 265 /* 266 * bad if this assert fails, only part of the handshake message 267 * got sent. but why would this happen? 268 */ 269 if (!ossl_assert(len == written)) 270 return -1; 271 272 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 273 /* 274 * should not be done for 'Hello Request's, but in that case 275 * we'll ignore the result anyway 276 */ 277 unsigned char *p = 278 (unsigned char *)&s->init_buf->data[s->init_off]; 279 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 280 size_t xlen; 281 282 if (frag_off == 0 && s->version != DTLS1_BAD_VER) { 283 /* 284 * reconstruct message header is if it is being sent in 285 * single fragment 286 */ 287 *p++ = msg_hdr->type; 288 l2n3(msg_hdr->msg_len, p); 289 s2n(msg_hdr->seq, p); 290 l2n3(0, p); 291 l2n3(msg_hdr->msg_len, p); 292 p -= DTLS1_HM_HEADER_LENGTH; 293 xlen = written; 294 } else { 295 p += DTLS1_HM_HEADER_LENGTH; 296 xlen = written - DTLS1_HM_HEADER_LENGTH; 297 } 298 299 if (!ssl3_finish_mac(s, p, xlen)) 300 return -1; 301 } 302 303 if (written == s->init_num) { 304 if (s->msg_callback) 305 s->msg_callback(1, s->version, type, s->init_buf->data, 306 (size_t)(s->init_off + s->init_num), s, 307 s->msg_callback_arg); 308 309 s->init_off = 0; /* done writing this message */ 310 s->init_num = 0; 311 312 return 1; 313 } 314 s->init_off += written; 315 s->init_num -= written; 316 written -= DTLS1_HM_HEADER_LENGTH; 317 frag_off += written; 318 319 /* 320 * We save the fragment offset for the next fragment so we have it 321 * available in case of an IO retry. We don't know the length of the 322 * next fragment yet so just set that to 0 for now. It will be 323 * updated again later. 324 */ 325 dtls1_fix_message_header(s, frag_off, 0); 326 } 327 } 328 return 0; 329} 330 331int dtls_get_message(SSL *s, int *mt) 332{ 333 struct hm_header_st *msg_hdr; 334 unsigned char *p; 335 size_t msg_len; 336 size_t tmplen; 337 int errtype; 338 339 msg_hdr = &s->d1->r_msg_hdr; 340 memset(msg_hdr, 0, sizeof(*msg_hdr)); 341 342 again: 343 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) { 344 if (errtype == DTLS1_HM_BAD_FRAGMENT 345 || errtype == DTLS1_HM_FRAGMENT_RETRY) { 346 /* bad fragment received */ 347 goto again; 348 } 349 return 0; 350 } 351 352 *mt = s->s3.tmp.message_type; 353 354 p = (unsigned char *)s->init_buf->data; 355 356 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) { 357 if (s->msg_callback) { 358 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 359 p, 1, s, s->msg_callback_arg); 360 } 361 /* 362 * This isn't a real handshake message so skip the processing below. 363 */ 364 return 1; 365 } 366 367 msg_len = msg_hdr->msg_len; 368 369 /* reconstruct message header */ 370 *(p++) = msg_hdr->type; 371 l2n3(msg_len, p); 372 s2n(msg_hdr->seq, p); 373 l2n3(0, p); 374 l2n3(msg_len, p); 375 376 memset(msg_hdr, 0, sizeof(*msg_hdr)); 377 378 s->d1->handshake_read_seq++; 379 380 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 381 382 return 1; 383} 384 385/* 386 * Actually we already have the message body - but this is an opportunity for 387 * DTLS to do any further processing it wants at the same point that TLS would 388 * be asked for the message body. 389 */ 390int dtls_get_message_body(SSL *s, size_t *len) 391{ 392 unsigned char *msg = (unsigned char *)s->init_buf->data; 393 size_t msg_len = s->init_num + DTLS1_HM_HEADER_LENGTH; 394 395 if (s->s3.tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) { 396 /* Nothing to be done */ 397 goto end; 398 } 399 /* 400 * If receiving Finished, record MAC of prior handshake messages for 401 * Finished verification. 402 */ 403 if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) { 404 /* SSLfatal() already called */ 405 return 0; 406 } 407 408 if (s->version == DTLS1_BAD_VER) { 409 msg += DTLS1_HM_HEADER_LENGTH; 410 msg_len -= DTLS1_HM_HEADER_LENGTH; 411 } 412 413 if (!ssl3_finish_mac(s, msg, msg_len)) 414 return 0; 415 416 if (s->msg_callback) 417 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 418 s->init_buf->data, s->init_num + DTLS1_HM_HEADER_LENGTH, 419 s, s->msg_callback_arg); 420 421 end: 422 *len = s->init_num; 423 return 1; 424} 425 426/* 427 * dtls1_max_handshake_message_len returns the maximum number of bytes 428 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 429 * may be greater if the maximum certificate list size requires it. 430 */ 431static size_t dtls1_max_handshake_message_len(const SSL *s) 432{ 433 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 434 if (max_len < s->max_cert_list) 435 return s->max_cert_list; 436 return max_len; 437} 438 439static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr) 440{ 441 size_t frag_off, frag_len, msg_len; 442 443 msg_len = msg_hdr->msg_len; 444 frag_off = msg_hdr->frag_off; 445 frag_len = msg_hdr->frag_len; 446 447 /* sanity checking */ 448 if ((frag_off + frag_len) > msg_len 449 || msg_len > dtls1_max_handshake_message_len(s)) { 450 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE); 451 return 0; 452 } 453 454 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 455 /* 456 * msg_len is limited to 2^24, but is effectively checked against 457 * dtls_max_handshake_message_len(s) above 458 */ 459 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { 460 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB); 461 return 0; 462 } 463 464 s->s3.tmp.message_size = msg_len; 465 s->d1->r_msg_hdr.msg_len = msg_len; 466 s->s3.tmp.message_type = msg_hdr->type; 467 s->d1->r_msg_hdr.type = msg_hdr->type; 468 s->d1->r_msg_hdr.seq = msg_hdr->seq; 469 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 470 /* 471 * They must be playing with us! BTW, failure to enforce upper limit 472 * would open possibility for buffer overrun. 473 */ 474 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE); 475 return 0; 476 } 477 478 return 1; 479} 480 481/* 482 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a 483 * fatal error. 484 */ 485static int dtls1_retrieve_buffered_fragment(SSL *s, size_t *len) 486{ 487 /*- 488 * (0) check whether the desired fragment is available 489 * if so: 490 * (1) copy over the fragment to s->init_buf->data[] 491 * (2) update s->init_num 492 */ 493 pitem *item; 494 piterator iter; 495 hm_fragment *frag; 496 int ret; 497 int chretran = 0; 498 499 iter = pqueue_iterator(s->d1->buffered_messages); 500 do { 501 item = pqueue_next(&iter); 502 if (item == NULL) 503 return 0; 504 505 frag = (hm_fragment *)item->data; 506 507 if (frag->msg_header.seq < s->d1->handshake_read_seq) { 508 pitem *next; 509 hm_fragment *nextfrag; 510 511 if (!s->server 512 || frag->msg_header.seq != 0 513 || s->d1->handshake_read_seq != 1 514 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) { 515 /* 516 * This is a stale message that has been buffered so clear it. 517 * It is safe to pop this message from the queue even though 518 * we have an active iterator 519 */ 520 pqueue_pop(s->d1->buffered_messages); 521 dtls1_hm_fragment_free(frag); 522 pitem_free(item); 523 item = NULL; 524 frag = NULL; 525 } else { 526 /* 527 * We have fragments for a ClientHello without a cookie, 528 * even though we have sent a HelloVerifyRequest. It is possible 529 * that the HelloVerifyRequest got lost and this is a 530 * retransmission of the original ClientHello 531 */ 532 next = pqueue_next(&iter); 533 if (next != NULL) { 534 nextfrag = (hm_fragment *)next->data; 535 if (nextfrag->msg_header.seq == s->d1->handshake_read_seq) { 536 /* 537 * We have fragments for both a ClientHello without 538 * cookie and one with. Ditch the one without. 539 */ 540 pqueue_pop(s->d1->buffered_messages); 541 dtls1_hm_fragment_free(frag); 542 pitem_free(item); 543 item = next; 544 frag = nextfrag; 545 } else { 546 chretran = 1; 547 } 548 } else { 549 chretran = 1; 550 } 551 } 552 } 553 } while (item == NULL); 554 555 /* Don't return if reassembly still in progress */ 556 if (frag->reassembly != NULL) 557 return 0; 558 559 if (s->d1->handshake_read_seq == frag->msg_header.seq || chretran) { 560 size_t frag_len = frag->msg_header.frag_len; 561 pqueue_pop(s->d1->buffered_messages); 562 563 /* Calls SSLfatal() as required */ 564 ret = dtls1_preprocess_fragment(s, &frag->msg_header); 565 566 if (ret && frag->msg_header.frag_len > 0) { 567 unsigned char *p = 568 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 569 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 570 frag->msg_header.frag_len); 571 } 572 573 dtls1_hm_fragment_free(frag); 574 pitem_free(item); 575 576 if (ret) { 577 if (chretran) { 578 /* 579 * We got a new ClientHello with a message sequence of 0. 580 * Reset the read/write sequences back to the beginning. 581 * We process it like this is the first time we've seen a 582 * ClientHello from the client. 583 */ 584 s->d1->handshake_read_seq = 0; 585 s->d1->next_handshake_write_seq = 0; 586 } 587 *len = frag_len; 588 return 1; 589 } 590 591 /* Fatal error */ 592 s->init_num = 0; 593 return -1; 594 } else { 595 return 0; 596 } 597} 598 599static int 600dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr) 601{ 602 hm_fragment *frag = NULL; 603 pitem *item = NULL; 604 int i = -1, is_complete; 605 unsigned char seq64be[8]; 606 size_t frag_len = msg_hdr->frag_len; 607 size_t readbytes; 608 609 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 610 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 611 goto err; 612 613 if (frag_len == 0) { 614 return DTLS1_HM_FRAGMENT_RETRY; 615 } 616 617 /* Try to find item in queue */ 618 memset(seq64be, 0, sizeof(seq64be)); 619 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 620 seq64be[7] = (unsigned char)msg_hdr->seq; 621 item = pqueue_find(s->d1->buffered_messages, seq64be); 622 623 if (item == NULL) { 624 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 625 if (frag == NULL) 626 goto err; 627 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 628 frag->msg_header.frag_len = frag->msg_header.msg_len; 629 frag->msg_header.frag_off = 0; 630 } else { 631 frag = (hm_fragment *)item->data; 632 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 633 item = NULL; 634 frag = NULL; 635 goto err; 636 } 637 } 638 639 /* 640 * If message is already reassembled, this must be a retransmit and can 641 * be dropped. In this case item != NULL and so frag does not need to be 642 * freed. 643 */ 644 if (frag->reassembly == NULL) { 645 unsigned char devnull[256]; 646 647 while (frag_len) { 648 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 649 devnull, 650 frag_len > 651 sizeof(devnull) ? sizeof(devnull) : 652 frag_len, 0, &readbytes); 653 if (i <= 0) 654 goto err; 655 frag_len -= readbytes; 656 } 657 return DTLS1_HM_FRAGMENT_RETRY; 658 } 659 660 /* read the body of the fragment (header has already been read */ 661 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 662 frag->fragment + msg_hdr->frag_off, 663 frag_len, 0, &readbytes); 664 if (i <= 0 || readbytes != frag_len) 665 i = -1; 666 if (i <= 0) 667 goto err; 668 669 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 670 (long)(msg_hdr->frag_off + frag_len)); 671 672 if (!ossl_assert(msg_hdr->msg_len > 0)) 673 goto err; 674 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 675 is_complete); 676 677 if (is_complete) { 678 OPENSSL_free(frag->reassembly); 679 frag->reassembly = NULL; 680 } 681 682 if (item == NULL) { 683 item = pitem_new(seq64be, frag); 684 if (item == NULL) { 685 i = -1; 686 goto err; 687 } 688 689 item = pqueue_insert(s->d1->buffered_messages, item); 690 /* 691 * pqueue_insert fails iff a duplicate item is inserted. However, 692 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 693 * would have returned it and control would never have reached this 694 * branch. 695 */ 696 if (!ossl_assert(item != NULL)) 697 goto err; 698 } 699 700 return DTLS1_HM_FRAGMENT_RETRY; 701 702 err: 703 if (item == NULL) 704 dtls1_hm_fragment_free(frag); 705 return -1; 706} 707 708static int 709dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr) 710{ 711 int i = -1; 712 hm_fragment *frag = NULL; 713 pitem *item = NULL; 714 unsigned char seq64be[8]; 715 size_t frag_len = msg_hdr->frag_len; 716 size_t readbytes; 717 718 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 719 goto err; 720 721 /* Try to find item in queue, to prevent duplicate entries */ 722 memset(seq64be, 0, sizeof(seq64be)); 723 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 724 seq64be[7] = (unsigned char)msg_hdr->seq; 725 item = pqueue_find(s->d1->buffered_messages, seq64be); 726 727 /* 728 * If we already have an entry and this one is a fragment, don't discard 729 * it and rather try to reassemble it. 730 */ 731 if (item != NULL && frag_len != msg_hdr->msg_len) 732 item = NULL; 733 734 /* 735 * Discard the message if sequence number was already there, is too far 736 * in the future, already in the queue or if we received a FINISHED 737 * before the SERVER_HELLO, which then must be a stale retransmit. 738 */ 739 if (msg_hdr->seq <= s->d1->handshake_read_seq || 740 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 741 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) { 742 unsigned char devnull[256]; 743 744 while (frag_len) { 745 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 746 devnull, 747 frag_len > 748 sizeof(devnull) ? sizeof(devnull) : 749 frag_len, 0, &readbytes); 750 if (i <= 0) 751 goto err; 752 frag_len -= readbytes; 753 } 754 } else { 755 if (frag_len != msg_hdr->msg_len) { 756 return dtls1_reassemble_fragment(s, msg_hdr); 757 } 758 759 if (frag_len > dtls1_max_handshake_message_len(s)) 760 goto err; 761 762 frag = dtls1_hm_fragment_new(frag_len, 0); 763 if (frag == NULL) 764 goto err; 765 766 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 767 768 if (frag_len) { 769 /* 770 * read the body of the fragment (header has already been read 771 */ 772 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 773 frag->fragment, frag_len, 0, 774 &readbytes); 775 if (i<=0 || readbytes != frag_len) 776 i = -1; 777 if (i <= 0) 778 goto err; 779 } 780 781 item = pitem_new(seq64be, frag); 782 if (item == NULL) 783 goto err; 784 785 item = pqueue_insert(s->d1->buffered_messages, item); 786 /* 787 * pqueue_insert fails iff a duplicate item is inserted. However, 788 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 789 * would have returned it. Then, either |frag_len| != 790 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 791 * have been processed with |dtls1_reassemble_fragment|, above, or 792 * the record will have been discarded. 793 */ 794 if (!ossl_assert(item != NULL)) 795 goto err; 796 } 797 798 return DTLS1_HM_FRAGMENT_RETRY; 799 800 err: 801 if (item == NULL) 802 dtls1_hm_fragment_free(frag); 803 return 0; 804} 805 806static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len) 807{ 808 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 809 size_t mlen, frag_off, frag_len; 810 int i, ret, recvd_type; 811 struct hm_header_st msg_hdr; 812 size_t readbytes; 813 int chretran = 0; 814 815 *errtype = 0; 816 817 redo: 818 /* see if we have the required fragment already */ 819 ret = dtls1_retrieve_buffered_fragment(s, &frag_len); 820 if (ret < 0) { 821 /* SSLfatal() already called */ 822 return 0; 823 } 824 if (ret > 0) { 825 s->init_num = frag_len; 826 *len = frag_len; 827 return 1; 828 } 829 830 /* read handshake message header */ 831 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire, 832 DTLS1_HM_HEADER_LENGTH, 0, &readbytes); 833 if (i <= 0) { /* nbio, or an error */ 834 s->rwstate = SSL_READING; 835 *len = 0; 836 return 0; 837 } 838 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) { 839 if (wire[0] != SSL3_MT_CCS) { 840 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, 841 SSL_R_BAD_CHANGE_CIPHER_SPEC); 842 goto f_err; 843 } 844 845 memcpy(s->init_buf->data, wire, readbytes); 846 s->init_num = readbytes - 1; 847 s->init_msg = s->init_buf->data + 1; 848 s->s3.tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC; 849 s->s3.tmp.message_size = readbytes - 1; 850 *len = readbytes - 1; 851 return 1; 852 } 853 854 /* Handshake fails if message header is incomplete */ 855 if (readbytes != DTLS1_HM_HEADER_LENGTH) { 856 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 857 goto f_err; 858 } 859 860 /* parse the message fragment header */ 861 dtls1_get_message_header(wire, &msg_hdr); 862 863 mlen = msg_hdr.msg_len; 864 frag_off = msg_hdr.frag_off; 865 frag_len = msg_hdr.frag_len; 866 867 /* 868 * We must have at least frag_len bytes left in the record to be read. 869 * Fragments must not span records. 870 */ 871 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) { 872 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH); 873 goto f_err; 874 } 875 876 /* 877 * if this is a future (or stale) message it gets buffered 878 * (or dropped)--no further processing at this time 879 * While listening, we accept seq 1 (ClientHello with cookie) 880 * although we're still expecting seq 0 (ClientHello) 881 */ 882 if (msg_hdr.seq != s->d1->handshake_read_seq) { 883 if (!s->server 884 || msg_hdr.seq != 0 885 || s->d1->handshake_read_seq != 1 886 || wire[0] != SSL3_MT_CLIENT_HELLO 887 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) { 888 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr); 889 return 0; 890 } 891 /* 892 * We received a ClientHello and sent back a HelloVerifyRequest. We 893 * now seem to have received a retransmitted initial ClientHello. That 894 * is allowed (possibly our HelloVerifyRequest got lost). 895 */ 896 chretran = 1; 897 } 898 899 if (frag_len && frag_len < mlen) { 900 *errtype = dtls1_reassemble_fragment(s, &msg_hdr); 901 return 0; 902 } 903 904 if (!s->server 905 && s->d1->r_msg_hdr.frag_off == 0 906 && s->statem.hand_state != TLS_ST_OK 907 && wire[0] == SSL3_MT_HELLO_REQUEST) { 908 /* 909 * The server may always send 'Hello Request' messages -- we are 910 * doing a handshake anyway now, so ignore them if their format is 911 * correct. Does not count for 'Finished' MAC. 912 */ 913 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 914 if (s->msg_callback) 915 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 916 wire, DTLS1_HM_HEADER_LENGTH, s, 917 s->msg_callback_arg); 918 919 s->init_num = 0; 920 goto redo; 921 } else { /* Incorrectly formatted Hello request */ 922 923 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 924 goto f_err; 925 } 926 } 927 928 if (!dtls1_preprocess_fragment(s, &msg_hdr)) { 929 /* SSLfatal() already called */ 930 goto f_err; 931 } 932 933 if (frag_len > 0) { 934 unsigned char *p = 935 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 936 937 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, 938 &p[frag_off], frag_len, 0, &readbytes); 939 940 /* 941 * This shouldn't ever fail due to NBIO because we already checked 942 * that we have enough data in the record 943 */ 944 if (i <= 0) { 945 s->rwstate = SSL_READING; 946 *len = 0; 947 return 0; 948 } 949 } else { 950 readbytes = 0; 951 } 952 953 /* 954 * XDTLS: an incorrectly formatted fragment should cause the handshake 955 * to fail 956 */ 957 if (readbytes != frag_len) { 958 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH); 959 goto f_err; 960 } 961 962 if (chretran) { 963 /* 964 * We got a new ClientHello with a message sequence of 0. 965 * Reset the read/write sequences back to the beginning. 966 * We process it like this is the first time we've seen a ClientHello 967 * from the client. 968 */ 969 s->d1->handshake_read_seq = 0; 970 s->d1->next_handshake_write_seq = 0; 971 } 972 973 /* 974 * Note that s->init_num is *not* used as current offset in 975 * s->init_buf->data, but as a counter summing up fragments' lengths: as 976 * soon as they sum up to handshake packet length, we assume we have got 977 * all the fragments. 978 */ 979 *len = s->init_num = frag_len; 980 return 1; 981 982 f_err: 983 s->init_num = 0; 984 *len = 0; 985 return 0; 986} 987 988/*- 989 * for these 2 messages, we need to 990 * ssl->enc_read_ctx re-init 991 * ssl->rlayer.read_sequence zero 992 * ssl->s3.read_mac_secret re-init 993 * ssl->session->read_sym_enc assign 994 * ssl->session->read_compression assign 995 * ssl->session->read_hash assign 996 */ 997int dtls_construct_change_cipher_spec(SSL *s, WPACKET *pkt) 998{ 999 if (s->version == DTLS1_BAD_VER) { 1000 s->d1->next_handshake_write_seq++; 1001 1002 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) { 1003 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1004 return 0; 1005 } 1006 } 1007 1008 return 1; 1009} 1010 1011#ifndef OPENSSL_NO_SCTP 1012/* 1013 * Wait for a dry event. Should only be called at a point in the handshake 1014 * where we are not expecting any data from the peer except an alert. 1015 */ 1016WORK_STATE dtls_wait_for_dry(SSL *s) 1017{ 1018 int ret, errtype; 1019 size_t len; 1020 1021 /* read app data until dry event */ 1022 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1023 if (ret < 0) { 1024 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1025 return WORK_ERROR; 1026 } 1027 1028 if (ret == 0) { 1029 /* 1030 * We're not expecting any more messages from the peer at this point - 1031 * but we could get an alert. If an alert is waiting then we will never 1032 * return successfully. Therefore we attempt to read a message. This 1033 * should never succeed but will process any waiting alerts. 1034 */ 1035 if (dtls_get_reassembled_message(s, &errtype, &len)) { 1036 /* The call succeeded! This should never happen */ 1037 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 1038 return WORK_ERROR; 1039 } 1040 1041 s->s3.in_read_app_data = 2; 1042 s->rwstate = SSL_READING; 1043 BIO_clear_retry_flags(SSL_get_rbio(s)); 1044 BIO_set_retry_read(SSL_get_rbio(s)); 1045 return WORK_MORE_A; 1046 } 1047 return WORK_FINISHED_CONTINUE; 1048} 1049#endif 1050 1051int dtls1_read_failed(SSL *s, int code) 1052{ 1053 if (code > 0) { 1054 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1055 return 0; 1056 } 1057 1058 if (!dtls1_is_timer_expired(s) || ossl_statem_in_error(s)) { 1059 /* 1060 * not a timeout, none of our business, let higher layers handle 1061 * this. in fact it's probably an error 1062 */ 1063 return code; 1064 } 1065 /* done, no need to send a retransmit */ 1066 if (!SSL_in_init(s)) 1067 { 1068 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1069 return code; 1070 } 1071 1072 return dtls1_handle_timeout(s); 1073} 1074 1075int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1076{ 1077 /* 1078 * The index of the retransmission queue actually is the message sequence 1079 * number, since the queue only contains messages of a single handshake. 1080 * However, the ChangeCipherSpec has no message sequence number and so 1081 * using only the sequence will result in the CCS and Finished having the 1082 * same index. To prevent this, the sequence number is multiplied by 2. 1083 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1084 * Finished, it also maintains the order of the index (important for 1085 * priority queues) and fits in the unsigned short variable. 1086 */ 1087 return seq * 2 - is_ccs; 1088} 1089 1090int dtls1_retransmit_buffered_messages(SSL *s) 1091{ 1092 pqueue *sent = s->d1->sent_messages; 1093 piterator iter; 1094 pitem *item; 1095 hm_fragment *frag; 1096 int found = 0; 1097 1098 iter = pqueue_iterator(sent); 1099 1100 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1101 frag = (hm_fragment *)item->data; 1102 if (dtls1_retransmit_message(s, (unsigned short) 1103 dtls1_get_queue_priority 1104 (frag->msg_header.seq, 1105 frag->msg_header.is_ccs), &found) <= 0) 1106 return -1; 1107 } 1108 1109 return 1; 1110} 1111 1112int dtls1_buffer_message(SSL *s, int is_ccs) 1113{ 1114 pitem *item; 1115 hm_fragment *frag; 1116 unsigned char seq64be[8]; 1117 1118 /* 1119 * this function is called immediately after a message has been 1120 * serialized 1121 */ 1122 if (!ossl_assert(s->init_off == 0)) 1123 return 0; 1124 1125 frag = dtls1_hm_fragment_new(s->init_num, 0); 1126 if (frag == NULL) 1127 return 0; 1128 1129 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1130 1131 if (is_ccs) { 1132 /* For DTLS1_BAD_VER the header length is non-standard */ 1133 if (!ossl_assert(s->d1->w_msg_hdr.msg_len + 1134 ((s->version == 1135 DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH) 1136 == (unsigned int)s->init_num)) { 1137 dtls1_hm_fragment_free(frag); 1138 return 0; 1139 } 1140 } else { 1141 if (!ossl_assert(s->d1->w_msg_hdr.msg_len + 1142 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num)) { 1143 dtls1_hm_fragment_free(frag); 1144 return 0; 1145 } 1146 } 1147 1148 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1149 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1150 frag->msg_header.type = s->d1->w_msg_hdr.type; 1151 frag->msg_header.frag_off = 0; 1152 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1153 frag->msg_header.is_ccs = is_ccs; 1154 1155 /* save current state */ 1156 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1157 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1158 frag->msg_header.saved_retransmit_state.compress = s->compress; 1159 frag->msg_header.saved_retransmit_state.session = s->session; 1160 frag->msg_header.saved_retransmit_state.epoch = 1161 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer); 1162 1163 memset(seq64be, 0, sizeof(seq64be)); 1164 seq64be[6] = 1165 (unsigned 1166 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1167 frag->msg_header.is_ccs) >> 8); 1168 seq64be[7] = 1169 (unsigned 1170 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1171 frag->msg_header.is_ccs)); 1172 1173 item = pitem_new(seq64be, frag); 1174 if (item == NULL) { 1175 dtls1_hm_fragment_free(frag); 1176 return 0; 1177 } 1178 1179 pqueue_insert(s->d1->sent_messages, item); 1180 return 1; 1181} 1182 1183int dtls1_retransmit_message(SSL *s, unsigned short seq, int *found) 1184{ 1185 int ret; 1186 /* XDTLS: for now assuming that read/writes are blocking */ 1187 pitem *item; 1188 hm_fragment *frag; 1189 unsigned long header_length; 1190 unsigned char seq64be[8]; 1191 struct dtls1_retransmit_state saved_state; 1192 1193 /* XDTLS: the requested message ought to be found, otherwise error */ 1194 memset(seq64be, 0, sizeof(seq64be)); 1195 seq64be[6] = (unsigned char)(seq >> 8); 1196 seq64be[7] = (unsigned char)seq; 1197 1198 item = pqueue_find(s->d1->sent_messages, seq64be); 1199 if (item == NULL) { 1200 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 1201 *found = 0; 1202 return 0; 1203 } 1204 1205 *found = 1; 1206 frag = (hm_fragment *)item->data; 1207 1208 if (frag->msg_header.is_ccs) 1209 header_length = DTLS1_CCS_HEADER_LENGTH; 1210 else 1211 header_length = DTLS1_HM_HEADER_LENGTH; 1212 1213 memcpy(s->init_buf->data, frag->fragment, 1214 frag->msg_header.msg_len + header_length); 1215 s->init_num = frag->msg_header.msg_len + header_length; 1216 1217 dtls1_set_message_header_int(s, frag->msg_header.type, 1218 frag->msg_header.msg_len, 1219 frag->msg_header.seq, 0, 1220 frag->msg_header.frag_len); 1221 1222 /* save current state */ 1223 saved_state.enc_write_ctx = s->enc_write_ctx; 1224 saved_state.write_hash = s->write_hash; 1225 saved_state.compress = s->compress; 1226 saved_state.session = s->session; 1227 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer); 1228 1229 s->d1->retransmitting = 1; 1230 1231 /* restore state in which the message was originally sent */ 1232 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1233 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1234 s->compress = frag->msg_header.saved_retransmit_state.compress; 1235 s->session = frag->msg_header.saved_retransmit_state.session; 1236 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, 1237 frag->msg_header. 1238 saved_retransmit_state.epoch); 1239 1240 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1241 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1242 1243 /* restore current state */ 1244 s->enc_write_ctx = saved_state.enc_write_ctx; 1245 s->write_hash = saved_state.write_hash; 1246 s->compress = saved_state.compress; 1247 s->session = saved_state.session; 1248 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch); 1249 1250 s->d1->retransmitting = 0; 1251 1252 (void)BIO_flush(s->wbio); 1253 return ret; 1254} 1255 1256void dtls1_set_message_header(SSL *s, 1257 unsigned char mt, size_t len, 1258 size_t frag_off, size_t frag_len) 1259{ 1260 if (frag_off == 0) { 1261 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1262 s->d1->next_handshake_write_seq++; 1263 } 1264 1265 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1266 frag_off, frag_len); 1267} 1268 1269/* don't actually do the writing, wait till the MTU has been retrieved */ 1270static void 1271dtls1_set_message_header_int(SSL *s, unsigned char mt, 1272 size_t len, unsigned short seq_num, 1273 size_t frag_off, size_t frag_len) 1274{ 1275 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1276 1277 msg_hdr->type = mt; 1278 msg_hdr->msg_len = len; 1279 msg_hdr->seq = seq_num; 1280 msg_hdr->frag_off = frag_off; 1281 msg_hdr->frag_len = frag_len; 1282} 1283 1284static void 1285dtls1_fix_message_header(SSL *s, size_t frag_off, size_t frag_len) 1286{ 1287 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1288 1289 msg_hdr->frag_off = frag_off; 1290 msg_hdr->frag_len = frag_len; 1291} 1292 1293static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1294{ 1295 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1296 1297 *p++ = msg_hdr->type; 1298 l2n3(msg_hdr->msg_len, p); 1299 1300 s2n(msg_hdr->seq, p); 1301 l2n3(msg_hdr->frag_off, p); 1302 l2n3(msg_hdr->frag_len, p); 1303 1304 return p; 1305} 1306 1307void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1308{ 1309 memset(msg_hdr, 0, sizeof(*msg_hdr)); 1310 msg_hdr->type = *(data++); 1311 n2l3(data, msg_hdr->msg_len); 1312 1313 n2s(data, msg_hdr->seq); 1314 n2l3(data, msg_hdr->frag_off); 1315 n2l3(data, msg_hdr->frag_len); 1316} 1317 1318int dtls1_set_handshake_header(SSL *s, WPACKET *pkt, int htype) 1319{ 1320 unsigned char *header; 1321 1322 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) { 1323 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1324 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1325 s->d1->handshake_write_seq, 0, 0); 1326 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS)) 1327 return 0; 1328 } else { 1329 dtls1_set_message_header(s, htype, 0, 0, 0); 1330 /* 1331 * We allocate space at the start for the message header. This gets 1332 * filled in later 1333 */ 1334 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header) 1335 || !WPACKET_start_sub_packet(pkt)) 1336 return 0; 1337 } 1338 1339 return 1; 1340} 1341 1342int dtls1_close_construct_packet(SSL *s, WPACKET *pkt, int htype) 1343{ 1344 size_t msglen; 1345 1346 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt)) 1347 || !WPACKET_get_length(pkt, &msglen) 1348 || msglen > INT_MAX) 1349 return 0; 1350 1351 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) { 1352 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH; 1353 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH; 1354 } 1355 s->init_num = (int)msglen; 1356 s->init_off = 0; 1357 1358 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) { 1359 /* Buffer the message to handle re-xmits */ 1360 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC 1361 ? 1 : 0)) 1362 return 0; 1363 } 1364 1365 return 1; 1366} 1367