d1_both.c revision 337982
1/* ssl/d1_both.c */ 2/* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1998-2018 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 <limits.h> 117#include <string.h> 118#include <stdio.h> 119#include "ssl_locl.h" 120#include <openssl/buffer.h> 121#include <openssl/rand.h> 122#include <openssl/objects.h> 123#include <openssl/evp.h> 124#include <openssl/x509.h> 125 126#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 127 128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 129 if ((end) - (start) <= 8) { \ 130 long ii; \ 131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 132 } else { \ 133 long ii; \ 134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 137 } } 138 139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 140 long ii; \ 141 OPENSSL_assert((msg_len) > 0); \ 142 is_complete = 1; \ 143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 146 147#if 0 148# define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \ 149 long ii; \ 150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \ 151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \ 152 printf("\n"); } 153#endif 154 155static unsigned char bitmask_start_values[] = 156 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 }; 157static unsigned char bitmask_end_values[] = 158 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f }; 159 160/* XDTLS: figure out the right values */ 161static const unsigned int g_probable_mtu[] = { 1500, 512, 256 }; 162 163static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 164 unsigned long frag_len); 165static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p); 166static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 167 unsigned long len, 168 unsigned short seq_num, 169 unsigned long frag_off, 170 unsigned long frag_len); 171static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, 172 int *ok); 173 174static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len, 175 int reassembly) 176{ 177 hm_fragment *frag = NULL; 178 unsigned char *buf = NULL; 179 unsigned char *bitmask = NULL; 180 181 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 182 if (frag == NULL) 183 return NULL; 184 185 if (frag_len) { 186 buf = (unsigned char *)OPENSSL_malloc(frag_len); 187 if (buf == NULL) { 188 OPENSSL_free(frag); 189 return NULL; 190 } 191 } 192 193 /* zero length fragment gets zero frag->fragment */ 194 frag->fragment = buf; 195 196 /* Initialize reassembly bitmask if necessary */ 197 if (reassembly) { 198 bitmask = 199 (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) { 201 if (buf != NULL) 202 OPENSSL_free(buf); 203 OPENSSL_free(frag); 204 return NULL; 205 } 206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 207 } 208 209 frag->reassembly = bitmask; 210 211 return frag; 212} 213 214void dtls1_hm_fragment_free(hm_fragment *frag) 215{ 216 217 if (frag->msg_header.is_ccs) { 218 EVP_CIPHER_CTX_free(frag->msg_header. 219 saved_retransmit_state.enc_write_ctx); 220 EVP_MD_CTX_destroy(frag->msg_header. 221 saved_retransmit_state.write_hash); 222 } 223 if (frag->fragment) 224 OPENSSL_free(frag->fragment); 225 if (frag->reassembly) 226 OPENSSL_free(frag->reassembly); 227 OPENSSL_free(frag); 228} 229 230static int dtls1_query_mtu(SSL *s) 231{ 232 if (s->d1->link_mtu) { 233 s->d1->mtu = 234 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 235 s->d1->link_mtu = 0; 236 } 237 238 /* AHA! Figure out the MTU, and stick to the right size */ 239 if (s->d1->mtu < dtls1_min_mtu(s)) { 240 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 241 s->d1->mtu = 242 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 243 244 /* 245 * I've seen the kernel return bogus numbers when it doesn't know 246 * (initial write), so just make sure we have a reasonable number 247 */ 248 if (s->d1->mtu < dtls1_min_mtu(s)) { 249 /* Set to min mtu */ 250 s->d1->mtu = dtls1_min_mtu(s); 251 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 252 s->d1->mtu, NULL); 253 } 254 } else 255 return 0; 256 } 257 return 1; 258} 259 260/* 261 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or 262 * SSL3_RT_CHANGE_CIPHER_SPEC) 263 */ 264int dtls1_do_write(SSL *s, int type) 265{ 266 int ret; 267 unsigned int curr_mtu; 268 int retry = 1; 269 unsigned int len, frag_off, mac_size, blocksize, used_len; 270 271 if (!dtls1_query_mtu(s)) 272 return -1; 273 274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something 275 * reasonable now */ 276 277 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 278 OPENSSL_assert(s->init_num == 279 (int)s->d1->w_msg_hdr.msg_len + 280 DTLS1_HM_HEADER_LENGTH); 281 282 if (s->write_hash) { 283 if (s->enc_write_ctx 284 && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE) 285 mac_size = 0; 286 else 287 mac_size = EVP_MD_CTX_size(s->write_hash); 288 } else 289 mac_size = 0; 290 291 if (s->enc_write_ctx && 292 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE)) 293 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 294 else 295 blocksize = 0; 296 297 frag_off = 0; 298 s->rwstate = SSL_NOTHING; 299 300 /* s->init_num shouldn't ever be < 0...but just in case */ 301 while (s->init_num > 0) { 302 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) { 303 /* We must be writing a fragment other than the first one */ 304 305 if (frag_off > 0) { 306 /* This is the first attempt at writing out this fragment */ 307 308 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) { 309 /* 310 * Each fragment that was already sent must at least have 311 * contained the message header plus one other byte. 312 * Therefore |init_off| must have progressed by at least 313 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went 314 * wrong. 315 */ 316 return -1; 317 } 318 319 /* 320 * Adjust |init_off| and |init_num| to allow room for a new 321 * message header for this fragment. 322 */ 323 s->init_off -= DTLS1_HM_HEADER_LENGTH; 324 s->init_num += DTLS1_HM_HEADER_LENGTH; 325 } else { 326 /* 327 * We must have been called again after a retry so use the 328 * fragment offset from our last attempt. We do not need 329 * to adjust |init_off| and |init_num| as above, because 330 * that should already have been done before the retry. 331 */ 332 frag_off = s->d1->w_msg_hdr.frag_off; 333 } 334 } 335 336 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH 337 + mac_size + blocksize; 338 if (s->d1->mtu > used_len) 339 curr_mtu = s->d1->mtu - used_len; 340 else 341 curr_mtu = 0; 342 343 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 344 /* 345 * grr.. we could get an error if MTU picked was wrong 346 */ 347 ret = BIO_flush(SSL_get_wbio(s)); 348 if (ret <= 0) { 349 s->rwstate = SSL_WRITING; 350 return ret; 351 } 352 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 353 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) { 354 curr_mtu = s->d1->mtu - used_len; 355 } else { 356 /* Shouldn't happen */ 357 return -1; 358 } 359 } 360 361 /* 362 * We just checked that s->init_num > 0 so this cast should be safe 363 */ 364 if (((unsigned int)s->init_num) > curr_mtu) 365 len = curr_mtu; 366 else 367 len = s->init_num; 368 369 /* Shouldn't ever happen */ 370 if (len > INT_MAX) 371 len = INT_MAX; 372 373 /* 374 * XDTLS: this function is too long. split out the CCS part 375 */ 376 if (type == SSL3_RT_HANDSHAKE) { 377 if (len < DTLS1_HM_HEADER_LENGTH) { 378 /* 379 * len is so small that we really can't do anything sensible 380 * so fail 381 */ 382 return -1; 383 } 384 dtls1_fix_message_header(s, frag_off, 385 len - DTLS1_HM_HEADER_LENGTH); 386 387 dtls1_write_message_header(s, 388 (unsigned char *)&s->init_buf-> 389 data[s->init_off]); 390 } 391 392 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], 393 len); 394 if (ret < 0) { 395 /* 396 * might need to update MTU here, but we don't know which 397 * previous packet caused the failure -- so can't really 398 * retransmit anything. continue as if everything is fine and 399 * wait for an alert to handle the retransmit 400 */ 401 if (retry && BIO_ctrl(SSL_get_wbio(s), 402 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) { 403 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 404 if (!dtls1_query_mtu(s)) 405 return -1; 406 /* Have one more go */ 407 retry = 0; 408 } else 409 return -1; 410 } else { 411 return (-1); 412 } 413 } else { 414 415 /* 416 * bad if this assert fails, only part of the handshake message 417 * got sent. but why would this happen? 418 */ 419 OPENSSL_assert(len == (unsigned int)ret); 420 421 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 422 /* 423 * should not be done for 'Hello Request's, but in that case 424 * we'll ignore the result anyway 425 */ 426 unsigned char *p = 427 (unsigned char *)&s->init_buf->data[s->init_off]; 428 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 429 int xlen; 430 431 if (frag_off == 0 && s->version != DTLS1_BAD_VER) { 432 /* 433 * reconstruct message header is if it is being sent in 434 * single fragment 435 */ 436 *p++ = msg_hdr->type; 437 l2n3(msg_hdr->msg_len, p); 438 s2n(msg_hdr->seq, p); 439 l2n3(0, p); 440 l2n3(msg_hdr->msg_len, p); 441 p -= DTLS1_HM_HEADER_LENGTH; 442 xlen = ret; 443 } else { 444 p += DTLS1_HM_HEADER_LENGTH; 445 xlen = ret - DTLS1_HM_HEADER_LENGTH; 446 } 447 448 ssl3_finish_mac(s, p, xlen); 449 } 450 451 if (ret == s->init_num) { 452 if (s->msg_callback) 453 s->msg_callback(1, s->version, type, s->init_buf->data, 454 (size_t)(s->init_off + s->init_num), s, 455 s->msg_callback_arg); 456 457 s->init_off = 0; /* done writing this message */ 458 s->init_num = 0; 459 460 return (1); 461 } 462 s->init_off += ret; 463 s->init_num -= ret; 464 ret -= DTLS1_HM_HEADER_LENGTH; 465 frag_off += ret; 466 467 /* 468 * We save the fragment offset for the next fragment so we have it 469 * available in case of an IO retry. We don't know the length of the 470 * next fragment yet so just set that to 0 for now. It will be 471 * updated again later. 472 */ 473 dtls1_fix_message_header(s, frag_off, 0); 474 } 475 } 476 return (0); 477} 478 479/* 480 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum 481 * acceptable body length 'max'. Read an entire handshake message. Handshake 482 * messages arrive in fragments. 483 */ 484long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 485{ 486 int i, al; 487 struct hm_header_st *msg_hdr; 488 unsigned char *p; 489 unsigned long msg_len; 490 491 /* 492 * s3->tmp is used to store messages that are unexpected, caused by the 493 * absence of an optional handshake message 494 */ 495 if (s->s3->tmp.reuse_message) { 496 s->s3->tmp.reuse_message = 0; 497 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 498 al = SSL_AD_UNEXPECTED_MESSAGE; 499 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 500 goto f_err; 501 } 502 *ok = 1; 503 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 504 s->init_num = (int)s->s3->tmp.message_size; 505 return s->init_num; 506 } 507 508 msg_hdr = &s->d1->r_msg_hdr; 509 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 510 511 again: 512 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 513 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) { 514 /* bad fragment received */ 515 goto again; 516 } else if (i <= 0 && !*ok) { 517 return i; 518 } 519 520 /* 521 * Don't change the *message* read sequence number while listening. For 522 * the *record* write sequence we reflect the ClientHello sequence number 523 * when listening. 524 */ 525 if (s->d1->listen) 526 memcpy(s->s3->write_sequence, s->s3->read_sequence, 527 sizeof(s->s3->write_sequence)); 528 else 529 s->d1->handshake_read_seq++; 530 531 if (mt >= 0 && s->s3->tmp.message_type != mt) { 532 al = SSL_AD_UNEXPECTED_MESSAGE; 533 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 534 goto f_err; 535 } 536 537 p = (unsigned char *)s->init_buf->data; 538 msg_len = msg_hdr->msg_len; 539 540 /* reconstruct message header */ 541 *(p++) = msg_hdr->type; 542 l2n3(msg_len, p); 543 s2n(msg_hdr->seq, p); 544 l2n3(0, p); 545 l2n3(msg_len, p); 546 if (s->version != DTLS1_BAD_VER) { 547 p -= DTLS1_HM_HEADER_LENGTH; 548 msg_len += DTLS1_HM_HEADER_LENGTH; 549 } 550 551 ssl3_finish_mac(s, p, msg_len); 552 if (s->msg_callback) 553 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 554 p, msg_len, s, s->msg_callback_arg); 555 556 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 557 558 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 559 return s->init_num; 560 561 f_err: 562 ssl3_send_alert(s, SSL3_AL_FATAL, al); 563 *ok = 0; 564 return -1; 565} 566 567static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 568 int max) 569{ 570 size_t frag_off, frag_len, msg_len; 571 572 msg_len = msg_hdr->msg_len; 573 frag_off = msg_hdr->frag_off; 574 frag_len = msg_hdr->frag_len; 575 576 /* sanity checking */ 577 if ((frag_off + frag_len) > msg_len) { 578 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 579 return SSL_AD_ILLEGAL_PARAMETER; 580 } 581 582 if ((frag_off + frag_len) > (unsigned long)max) { 583 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 584 return SSL_AD_ILLEGAL_PARAMETER; 585 } 586 587 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 588 /* 589 * msg_len is limited to 2^24, but is effectively checked against max 590 * above 591 * 592 * Make buffer slightly larger than message length as a precaution 593 * against small OOB reads e.g. CVE-2016-6306 594 */ 595 if (!BUF_MEM_grow_clean 596 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH + 16)) { 597 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 598 return SSL_AD_INTERNAL_ERROR; 599 } 600 601 s->s3->tmp.message_size = msg_len; 602 s->d1->r_msg_hdr.msg_len = msg_len; 603 s->s3->tmp.message_type = msg_hdr->type; 604 s->d1->r_msg_hdr.type = msg_hdr->type; 605 s->d1->r_msg_hdr.seq = msg_hdr->seq; 606 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 607 /* 608 * They must be playing with us! BTW, failure to enforce upper limit 609 * would open possibility for buffer overrun. 610 */ 611 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 612 return SSL_AD_ILLEGAL_PARAMETER; 613 } 614 615 return 0; /* no error */ 616} 617 618static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 619{ 620 /*- 621 * (0) check whether the desired fragment is available 622 * if so: 623 * (1) copy over the fragment to s->init_buf->data[] 624 * (2) update s->init_num 625 */ 626 pitem *item; 627 hm_fragment *frag; 628 int al; 629 630 *ok = 0; 631 do { 632 item = pqueue_peek(s->d1->buffered_messages); 633 if (item == NULL) 634 return 0; 635 636 frag = (hm_fragment *)item->data; 637 638 if (frag->msg_header.seq < s->d1->handshake_read_seq) { 639 /* This is a stale message that has been buffered so clear it */ 640 pqueue_pop(s->d1->buffered_messages); 641 dtls1_hm_fragment_free(frag); 642 pitem_free(item); 643 item = NULL; 644 frag = NULL; 645 } 646 } while (item == NULL); 647 648 649 /* Don't return if reassembly still in progress */ 650 if (frag->reassembly != NULL) 651 return 0; 652 653 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 654 unsigned long frag_len = frag->msg_header.frag_len; 655 pqueue_pop(s->d1->buffered_messages); 656 657 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 658 659 /* al will be 0 if no alert */ 660 if (al == 0 && frag->msg_header.frag_len > 0) { 661 unsigned char *p = 662 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 663 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 664 frag->msg_header.frag_len); 665 } 666 667 dtls1_hm_fragment_free(frag); 668 pitem_free(item); 669 670 if (al == 0) { 671 *ok = 1; 672 return frag_len; 673 } 674 675 ssl3_send_alert(s, SSL3_AL_FATAL, al); 676 s->init_num = 0; 677 *ok = 0; 678 return -1; 679 } else 680 return 0; 681} 682 683/* 684 * dtls1_max_handshake_message_len returns the maximum number of bytes 685 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 686 * may be greater if the maximum certificate list size requires it. 687 */ 688static unsigned long dtls1_max_handshake_message_len(const SSL *s) 689{ 690 unsigned long max_len = 691 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 692 if (max_len < (unsigned long)s->max_cert_list) 693 return s->max_cert_list; 694 return max_len; 695} 696 697static int 698dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 699{ 700 hm_fragment *frag = NULL; 701 pitem *item = NULL; 702 int i = -1, is_complete; 703 unsigned char seq64be[8]; 704 unsigned long frag_len = msg_hdr->frag_len; 705 706 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 707 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 708 goto err; 709 710 if (frag_len == 0) 711 return DTLS1_HM_FRAGMENT_RETRY; 712 713 /* Try to find item in queue */ 714 memset(seq64be, 0, sizeof(seq64be)); 715 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 716 seq64be[7] = (unsigned char)msg_hdr->seq; 717 item = pqueue_find(s->d1->buffered_messages, seq64be); 718 719 if (item == NULL) { 720 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 721 if (frag == NULL) 722 goto err; 723 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 724 frag->msg_header.frag_len = frag->msg_header.msg_len; 725 frag->msg_header.frag_off = 0; 726 } else { 727 frag = (hm_fragment *)item->data; 728 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 729 item = NULL; 730 frag = NULL; 731 goto err; 732 } 733 } 734 735 /* 736 * If message is already reassembled, this must be a retransmit and can 737 * be dropped. In this case item != NULL and so frag does not need to be 738 * freed. 739 */ 740 if (frag->reassembly == NULL) { 741 unsigned char devnull[256]; 742 743 while (frag_len) { 744 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 745 devnull, 746 frag_len > 747 sizeof(devnull) ? sizeof(devnull) : 748 frag_len, 0); 749 if (i <= 0) 750 goto err; 751 frag_len -= i; 752 } 753 return DTLS1_HM_FRAGMENT_RETRY; 754 } 755 756 /* read the body of the fragment (header has already been read */ 757 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 758 frag->fragment + msg_hdr->frag_off, 759 frag_len, 0); 760 if ((unsigned long)i != frag_len) 761 i = -1; 762 if (i <= 0) 763 goto err; 764 765 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 766 (long)(msg_hdr->frag_off + frag_len)); 767 768 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 769 is_complete); 770 771 if (is_complete) { 772 OPENSSL_free(frag->reassembly); 773 frag->reassembly = NULL; 774 } 775 776 if (item == NULL) { 777 item = pitem_new(seq64be, frag); 778 if (item == NULL) { 779 i = -1; 780 goto err; 781 } 782 783 item = pqueue_insert(s->d1->buffered_messages, item); 784 /* 785 * pqueue_insert fails iff a duplicate item is inserted. However, 786 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 787 * would have returned it and control would never have reached this 788 * branch. 789 */ 790 OPENSSL_assert(item != NULL); 791 } 792 793 return DTLS1_HM_FRAGMENT_RETRY; 794 795 err: 796 if (frag != NULL && item == NULL) 797 dtls1_hm_fragment_free(frag); 798 *ok = 0; 799 return i; 800} 801 802static int 803dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 804 int *ok) 805{ 806 int i = -1; 807 hm_fragment *frag = NULL; 808 pitem *item = NULL; 809 unsigned char seq64be[8]; 810 unsigned long frag_len = msg_hdr->frag_len; 811 812 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 813 goto err; 814 815 /* Try to find item in queue, to prevent duplicate entries */ 816 memset(seq64be, 0, sizeof(seq64be)); 817 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 818 seq64be[7] = (unsigned char)msg_hdr->seq; 819 item = pqueue_find(s->d1->buffered_messages, seq64be); 820 821 /* 822 * If we already have an entry and this one is a fragment, don't discard 823 * it and rather try to reassemble it. 824 */ 825 if (item != NULL && frag_len != msg_hdr->msg_len) 826 item = NULL; 827 828 /* 829 * Discard the message if sequence number was already there, is too far 830 * in the future, already in the queue or if we received a FINISHED 831 * before the SERVER_HELLO, which then must be a stale retransmit. 832 */ 833 if (msg_hdr->seq <= s->d1->handshake_read_seq || 834 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 835 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 836 { 837 unsigned char devnull[256]; 838 839 while (frag_len) { 840 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 841 devnull, 842 frag_len > 843 sizeof(devnull) ? sizeof(devnull) : 844 frag_len, 0); 845 if (i <= 0) 846 goto err; 847 frag_len -= i; 848 } 849 } else { 850 if (frag_len != msg_hdr->msg_len) 851 return dtls1_reassemble_fragment(s, msg_hdr, ok); 852 853 if (frag_len > dtls1_max_handshake_message_len(s)) 854 goto err; 855 856 frag = dtls1_hm_fragment_new(frag_len, 0); 857 if (frag == NULL) 858 goto err; 859 860 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 861 862 if (frag_len) { 863 /* 864 * read the body of the fragment (header has already been read 865 */ 866 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 867 frag->fragment, frag_len, 0); 868 if ((unsigned long)i != frag_len) 869 i = -1; 870 if (i <= 0) 871 goto err; 872 } 873 874 item = pitem_new(seq64be, frag); 875 if (item == NULL) 876 goto err; 877 878 item = pqueue_insert(s->d1->buffered_messages, item); 879 /* 880 * pqueue_insert fails iff a duplicate item is inserted. However, 881 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 882 * would have returned it. Then, either |frag_len| != 883 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 884 * have been processed with |dtls1_reassemble_fragment|, above, or 885 * the record will have been discarded. 886 */ 887 OPENSSL_assert(item != NULL); 888 } 889 890 return DTLS1_HM_FRAGMENT_RETRY; 891 892 err: 893 if (frag != NULL && item == NULL) 894 dtls1_hm_fragment_free(frag); 895 *ok = 0; 896 return i; 897} 898 899static long 900dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 901{ 902 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 903 unsigned long len, frag_off, frag_len; 904 int i, al; 905 struct hm_header_st msg_hdr; 906 907 redo: 908 /* see if we have the required fragment already */ 909 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 910 if (*ok) 911 s->init_num = frag_len; 912 return frag_len; 913 } 914 915 /* read handshake message header */ 916 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 917 DTLS1_HM_HEADER_LENGTH, 0); 918 if (i <= 0) { /* nbio, or an error */ 919 s->rwstate = SSL_READING; 920 *ok = 0; 921 return i; 922 } 923 /* Handshake fails if message header is incomplete */ 924 if (i != DTLS1_HM_HEADER_LENGTH) { 925 al = SSL_AD_UNEXPECTED_MESSAGE; 926 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 927 goto f_err; 928 } 929 930 /* parse the message fragment header */ 931 dtls1_get_message_header(wire, &msg_hdr); 932 933 len = msg_hdr.msg_len; 934 frag_off = msg_hdr.frag_off; 935 frag_len = msg_hdr.frag_len; 936 937 /* 938 * We must have at least frag_len bytes left in the record to be read. 939 * Fragments must not span records. 940 */ 941 if (frag_len > s->s3->rrec.length) { 942 al = SSL3_AD_ILLEGAL_PARAMETER; 943 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 944 goto f_err; 945 } 946 947 /* 948 * if this is a future (or stale) message it gets buffered 949 * (or dropped)--no further processing at this time 950 * While listening, we accept seq 1 (ClientHello with cookie) 951 * although we're still expecting seq 0 (ClientHello) 952 */ 953 if (msg_hdr.seq != s->d1->handshake_read_seq 954 && !(s->d1->listen && msg_hdr.seq == 1)) 955 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 956 957 if (frag_len && frag_len < len) 958 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 959 960 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 961 wire[0] == SSL3_MT_HELLO_REQUEST) { 962 /* 963 * The server may always send 'Hello Request' messages -- we are 964 * doing a handshake anyway now, so ignore them if their format is 965 * correct. Does not count for 'Finished' MAC. 966 */ 967 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 968 if (s->msg_callback) 969 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 970 wire, DTLS1_HM_HEADER_LENGTH, s, 971 s->msg_callback_arg); 972 973 s->init_num = 0; 974 goto redo; 975 } else { /* Incorrectly formated Hello request */ 976 977 al = SSL_AD_UNEXPECTED_MESSAGE; 978 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 979 SSL_R_UNEXPECTED_MESSAGE); 980 goto f_err; 981 } 982 } 983 984 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 985 goto f_err; 986 987 if (frag_len > 0) { 988 unsigned char *p = 989 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 990 991 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 992 &p[frag_off], frag_len, 0); 993 994 /* 995 * This shouldn't ever fail due to NBIO because we already checked 996 * that we have enough data in the record 997 */ 998 if (i <= 0) { 999 s->rwstate = SSL_READING; 1000 *ok = 0; 1001 return i; 1002 } 1003 } else 1004 i = 0; 1005 1006 /* 1007 * XDTLS: an incorrectly formatted fragment should cause the handshake 1008 * to fail 1009 */ 1010 if (i != (int)frag_len) { 1011 al = SSL3_AD_ILLEGAL_PARAMETER; 1012 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 1013 goto f_err; 1014 } 1015 1016 *ok = 1; 1017 s->state = stn; 1018 1019 /* 1020 * Note that s->init_num is *not* used as current offset in 1021 * s->init_buf->data, but as a counter summing up fragments' lengths: as 1022 * soon as they sum up to handshake packet length, we assume we have got 1023 * all the fragments. 1024 */ 1025 s->init_num = frag_len; 1026 return frag_len; 1027 1028 f_err: 1029 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1030 s->init_num = 0; 1031 1032 *ok = 0; 1033 return (-1); 1034} 1035 1036/*- 1037 * for these 2 messages, we need to 1038 * ssl->enc_read_ctx re-init 1039 * ssl->s3->read_sequence zero 1040 * ssl->s3->read_mac_secret re-init 1041 * ssl->session->read_sym_enc assign 1042 * ssl->session->read_compression assign 1043 * ssl->session->read_hash assign 1044 */ 1045int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1046{ 1047 unsigned char *p; 1048 1049 if (s->state == a) { 1050 p = (unsigned char *)s->init_buf->data; 1051 *p++ = SSL3_MT_CCS; 1052 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1053 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1054 1055 if (s->version == DTLS1_BAD_VER) { 1056 s->d1->next_handshake_write_seq++; 1057 s2n(s->d1->handshake_write_seq, p); 1058 s->init_num += 2; 1059 } 1060 1061 s->init_off = 0; 1062 1063 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1064 s->d1->handshake_write_seq, 0, 0); 1065 1066 /* buffer the message to handle re-xmits */ 1067 dtls1_buffer_message(s, 1); 1068 1069 s->state = b; 1070 } 1071 1072 /* SSL3_ST_CW_CHANGE_B */ 1073 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1074} 1075 1076int dtls1_read_failed(SSL *s, int code) 1077{ 1078 if (code > 0) { 1079#ifdef TLS_DEBUG 1080 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1081#endif 1082 return 1; 1083 } 1084 1085 if (!dtls1_is_timer_expired(s)) { 1086 /* 1087 * not a timeout, none of our business, let higher layers handle 1088 * this. in fact it's probably an error 1089 */ 1090 return code; 1091 } 1092#ifndef OPENSSL_NO_HEARTBEATS 1093 /* done, no need to send a retransmit */ 1094 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1095#else 1096 /* done, no need to send a retransmit */ 1097 if (!SSL_in_init(s)) 1098#endif 1099 { 1100 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1101 return code; 1102 } 1103#if 0 /* for now, each alert contains only one 1104 * record number */ 1105 item = pqueue_peek(state->rcvd_records); 1106 if (item) { 1107 /* send an alert immediately for all the missing records */ 1108 } else 1109#endif 1110 1111#if 0 /* no more alert sending, just retransmit the 1112 * last set of messages */ 1113 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1114 ssl3_send_alert(s, SSL3_AL_WARNING, 1115 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1116#endif 1117 1118 return dtls1_handle_timeout(s); 1119} 1120 1121int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1122{ 1123 /* 1124 * The index of the retransmission queue actually is the message sequence 1125 * number, since the queue only contains messages of a single handshake. 1126 * However, the ChangeCipherSpec has no message sequence number and so 1127 * using only the sequence will result in the CCS and Finished having the 1128 * same index. To prevent this, the sequence number is multiplied by 2. 1129 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1130 * Finished, it also maintains the order of the index (important for 1131 * priority queues) and fits in the unsigned short variable. 1132 */ 1133 return seq * 2 - is_ccs; 1134} 1135 1136int dtls1_retransmit_buffered_messages(SSL *s) 1137{ 1138 pqueue sent = s->d1->sent_messages; 1139 piterator iter; 1140 pitem *item; 1141 hm_fragment *frag; 1142 int found = 0; 1143 1144 iter = pqueue_iterator(sent); 1145 1146 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1147 frag = (hm_fragment *)item->data; 1148 if (dtls1_retransmit_message(s, (unsigned short) 1149 dtls1_get_queue_priority 1150 (frag->msg_header.seq, 1151 frag->msg_header.is_ccs), 0, 1152 &found) <= 0 && found) { 1153#ifdef TLS_DEBUG 1154 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1155#endif 1156 return -1; 1157 } 1158 } 1159 1160 return 1; 1161} 1162 1163int dtls1_buffer_message(SSL *s, int is_ccs) 1164{ 1165 pitem *item; 1166 hm_fragment *frag; 1167 unsigned char seq64be[8]; 1168 1169 /* 1170 * this function is called immediately after a message has been 1171 * serialized 1172 */ 1173 OPENSSL_assert(s->init_off == 0); 1174 1175 frag = dtls1_hm_fragment_new(s->init_num, 0); 1176 if (!frag) 1177 return 0; 1178 1179 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1180 1181 if (is_ccs) { 1182 /* For DTLS1_BAD_VER the header length is non-standard */ 1183 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1184 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH) 1185 == (unsigned int)s->init_num); 1186 } else { 1187 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1188 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1189 } 1190 1191 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1192 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1193 frag->msg_header.type = s->d1->w_msg_hdr.type; 1194 frag->msg_header.frag_off = 0; 1195 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1196 frag->msg_header.is_ccs = is_ccs; 1197 1198 /* save current state */ 1199 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1200 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1201 frag->msg_header.saved_retransmit_state.compress = s->compress; 1202 frag->msg_header.saved_retransmit_state.session = s->session; 1203 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1204 1205 memset(seq64be, 0, sizeof(seq64be)); 1206 seq64be[6] = 1207 (unsigned 1208 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1209 frag->msg_header.is_ccs) >> 8); 1210 seq64be[7] = 1211 (unsigned 1212 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1213 frag->msg_header.is_ccs)); 1214 1215 item = pitem_new(seq64be, frag); 1216 if (item == NULL) { 1217 dtls1_hm_fragment_free(frag); 1218 return 0; 1219 } 1220#if 0 1221 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1222 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1223 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1224#endif 1225 1226 pqueue_insert(s->d1->sent_messages, item); 1227 return 1; 1228} 1229 1230int 1231dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1232 int *found) 1233{ 1234 int ret; 1235 /* XDTLS: for now assuming that read/writes are blocking */ 1236 pitem *item; 1237 hm_fragment *frag; 1238 unsigned long header_length; 1239 unsigned char seq64be[8]; 1240 struct dtls1_retransmit_state saved_state; 1241 unsigned char save_write_sequence[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 1242 1243 /*- 1244 OPENSSL_assert(s->init_num == 0); 1245 OPENSSL_assert(s->init_off == 0); 1246 */ 1247 1248 /* XDTLS: the requested message ought to be found, otherwise error */ 1249 memset(seq64be, 0, sizeof(seq64be)); 1250 seq64be[6] = (unsigned char)(seq >> 8); 1251 seq64be[7] = (unsigned char)seq; 1252 1253 item = pqueue_find(s->d1->sent_messages, seq64be); 1254 if (item == NULL) { 1255#ifdef TLS_DEBUG 1256 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1257#endif 1258 *found = 0; 1259 return 0; 1260 } 1261 1262 *found = 1; 1263 frag = (hm_fragment *)item->data; 1264 1265 if (frag->msg_header.is_ccs) 1266 header_length = DTLS1_CCS_HEADER_LENGTH; 1267 else 1268 header_length = DTLS1_HM_HEADER_LENGTH; 1269 1270 memcpy(s->init_buf->data, frag->fragment, 1271 frag->msg_header.msg_len + header_length); 1272 s->init_num = frag->msg_header.msg_len + header_length; 1273 1274 dtls1_set_message_header_int(s, frag->msg_header.type, 1275 frag->msg_header.msg_len, 1276 frag->msg_header.seq, 0, 1277 frag->msg_header.frag_len); 1278 1279 /* save current state */ 1280 saved_state.enc_write_ctx = s->enc_write_ctx; 1281 saved_state.write_hash = s->write_hash; 1282 saved_state.compress = s->compress; 1283 saved_state.session = s->session; 1284 saved_state.epoch = s->d1->w_epoch; 1285 saved_state.epoch = s->d1->w_epoch; 1286 1287 s->d1->retransmitting = 1; 1288 1289 /* restore state in which the message was originally sent */ 1290 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1291 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1292 s->compress = frag->msg_header.saved_retransmit_state.compress; 1293 s->session = frag->msg_header.saved_retransmit_state.session; 1294 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1295 1296 if (frag->msg_header.saved_retransmit_state.epoch == 1297 saved_state.epoch - 1) { 1298 memcpy(save_write_sequence, s->s3->write_sequence, 1299 sizeof(s->s3->write_sequence)); 1300 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1301 sizeof(s->s3->write_sequence)); 1302 } 1303 1304 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1305 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1306 1307 /* restore current state */ 1308 s->enc_write_ctx = saved_state.enc_write_ctx; 1309 s->write_hash = saved_state.write_hash; 1310 s->compress = saved_state.compress; 1311 s->session = saved_state.session; 1312 s->d1->w_epoch = saved_state.epoch; 1313 1314 if (frag->msg_header.saved_retransmit_state.epoch == 1315 saved_state.epoch - 1) { 1316 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1317 sizeof(s->s3->write_sequence)); 1318 memcpy(s->s3->write_sequence, save_write_sequence, 1319 sizeof(s->s3->write_sequence)); 1320 } 1321 1322 s->d1->retransmitting = 0; 1323 1324 (void)BIO_flush(SSL_get_wbio(s)); 1325 return ret; 1326} 1327 1328unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1329 unsigned char mt, unsigned long len, 1330 unsigned long frag_off, 1331 unsigned long frag_len) 1332{ 1333 /* Don't change sequence numbers while listening */ 1334 if (frag_off == 0 && !s->d1->listen) { 1335 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1336 s->d1->next_handshake_write_seq++; 1337 } 1338 1339 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1340 frag_off, frag_len); 1341 1342 return p += DTLS1_HM_HEADER_LENGTH; 1343} 1344 1345/* don't actually do the writing, wait till the MTU has been retrieved */ 1346static void 1347dtls1_set_message_header_int(SSL *s, unsigned char mt, 1348 unsigned long len, unsigned short seq_num, 1349 unsigned long frag_off, unsigned long frag_len) 1350{ 1351 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1352 1353 msg_hdr->type = mt; 1354 msg_hdr->msg_len = len; 1355 msg_hdr->seq = seq_num; 1356 msg_hdr->frag_off = frag_off; 1357 msg_hdr->frag_len = frag_len; 1358} 1359 1360static void 1361dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1362 unsigned long frag_len) 1363{ 1364 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1365 1366 msg_hdr->frag_off = frag_off; 1367 msg_hdr->frag_len = frag_len; 1368} 1369 1370static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1371{ 1372 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1373 1374 *p++ = msg_hdr->type; 1375 l2n3(msg_hdr->msg_len, p); 1376 1377 s2n(msg_hdr->seq, p); 1378 l2n3(msg_hdr->frag_off, p); 1379 l2n3(msg_hdr->frag_len, p); 1380 1381 return p; 1382} 1383 1384unsigned int dtls1_link_min_mtu(void) 1385{ 1386 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1387 sizeof(g_probable_mtu[0])) - 1]); 1388} 1389 1390unsigned int dtls1_min_mtu(SSL *s) 1391{ 1392 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1393} 1394 1395void 1396dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1397{ 1398 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1399 msg_hdr->type = *(data++); 1400 n2l3(data, msg_hdr->msg_len); 1401 1402 n2s(data, msg_hdr->seq); 1403 n2l3(data, msg_hdr->frag_off); 1404 n2l3(data, msg_hdr->frag_len); 1405} 1406 1407void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1408{ 1409 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1410 1411 ccs_hdr->type = *(data++); 1412} 1413 1414int dtls1_shutdown(SSL *s) 1415{ 1416 int ret; 1417#ifndef OPENSSL_NO_SCTP 1418 BIO *wbio; 1419 1420 wbio = SSL_get_wbio(s); 1421 if (wbio != NULL && BIO_dgram_is_sctp(wbio) && 1422 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1423 ret = BIO_dgram_sctp_wait_for_dry(wbio); 1424 if (ret < 0) 1425 return -1; 1426 1427 if (ret == 0) 1428 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1429 NULL); 1430 } 1431#endif 1432 ret = ssl3_shutdown(s); 1433#ifndef OPENSSL_NO_SCTP 1434 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1435#endif 1436 return ret; 1437} 1438 1439#ifndef OPENSSL_NO_HEARTBEATS 1440int dtls1_process_heartbeat(SSL *s) 1441{ 1442 unsigned char *p = &s->s3->rrec.data[0], *pl; 1443 unsigned short hbtype; 1444 unsigned int payload; 1445 unsigned int padding = 16; /* Use minimum padding */ 1446 1447 if (s->msg_callback) 1448 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1449 &s->s3->rrec.data[0], s->s3->rrec.length, 1450 s, s->msg_callback_arg); 1451 1452 /* Read type and payload length first */ 1453 if (1 + 2 + 16 > s->s3->rrec.length) 1454 return 0; /* silently discard */ 1455 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1456 return 0; /* silently discard per RFC 6520 sec. 4 */ 1457 1458 hbtype = *p++; 1459 n2s(p, payload); 1460 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1461 return 0; /* silently discard per RFC 6520 sec. 4 */ 1462 pl = p; 1463 1464 if (hbtype == TLS1_HB_REQUEST) { 1465 unsigned char *buffer, *bp; 1466 unsigned int write_length = 1 /* heartbeat type */ + 1467 2 /* heartbeat length */ + 1468 payload + padding; 1469 int r; 1470 1471 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1472 return 0; 1473 1474 /* 1475 * Allocate memory for the response, size is 1 byte message type, 1476 * plus 2 bytes payload length, plus payload, plus padding 1477 */ 1478 buffer = OPENSSL_malloc(write_length); 1479 if (buffer == NULL) 1480 return -1; 1481 bp = buffer; 1482 1483 /* Enter response type, length and copy payload */ 1484 *bp++ = TLS1_HB_RESPONSE; 1485 s2n(payload, bp); 1486 memcpy(bp, pl, payload); 1487 bp += payload; 1488 /* Random padding */ 1489 if (RAND_bytes(bp, padding) <= 0) { 1490 OPENSSL_free(buffer); 1491 return -1; 1492 } 1493 1494 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1495 1496 if (r >= 0 && s->msg_callback) 1497 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1498 buffer, write_length, s, s->msg_callback_arg); 1499 1500 OPENSSL_free(buffer); 1501 1502 if (r < 0) 1503 return r; 1504 } else if (hbtype == TLS1_HB_RESPONSE) { 1505 unsigned int seq; 1506 1507 /* 1508 * We only send sequence numbers (2 bytes unsigned int), and 16 1509 * random bytes, so we just try to read the sequence number 1510 */ 1511 n2s(pl, seq); 1512 1513 if (payload == 18 && seq == s->tlsext_hb_seq) { 1514 dtls1_stop_timer(s); 1515 s->tlsext_hb_seq++; 1516 s->tlsext_hb_pending = 0; 1517 } 1518 } 1519 1520 return 0; 1521} 1522 1523int dtls1_heartbeat(SSL *s) 1524{ 1525 unsigned char *buf, *p; 1526 int ret = -1; 1527 unsigned int payload = 18; /* Sequence number + random bytes */ 1528 unsigned int padding = 16; /* Use minimum padding */ 1529 1530 /* Only send if peer supports and accepts HB requests... */ 1531 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1532 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1533 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1534 return -1; 1535 } 1536 1537 /* ...and there is none in flight yet... */ 1538 if (s->tlsext_hb_pending) { 1539 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1540 return -1; 1541 } 1542 1543 /* ...and no handshake in progress. */ 1544 if (SSL_in_init(s) || s->in_handshake) { 1545 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1546 return -1; 1547 } 1548 1549 /* 1550 * Check if padding is too long, payload and padding must not exceed 2^14 1551 * - 3 = 16381 bytes in total. 1552 */ 1553 OPENSSL_assert(payload + padding <= 16381); 1554 1555 /*- 1556 * Create HeartBeat message, we just use a sequence number 1557 * as payload to distuingish different messages and add 1558 * some random stuff. 1559 * - Message Type, 1 byte 1560 * - Payload Length, 2 bytes (unsigned int) 1561 * - Payload, the sequence number (2 bytes uint) 1562 * - Payload, random bytes (16 bytes uint) 1563 * - Padding 1564 */ 1565 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1566 if (buf == NULL) 1567 goto err; 1568 p = buf; 1569 /* Message Type */ 1570 *p++ = TLS1_HB_REQUEST; 1571 /* Payload length (18 bytes here) */ 1572 s2n(payload, p); 1573 /* Sequence number */ 1574 s2n(s->tlsext_hb_seq, p); 1575 /* 16 random bytes */ 1576 if (RAND_bytes(p, 16) <= 0) 1577 goto err; 1578 p += 16; 1579 /* Random padding */ 1580 if (RAND_bytes(p, padding) <= 0) 1581 goto err; 1582 1583 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1584 if (ret >= 0) { 1585 if (s->msg_callback) 1586 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1587 buf, 3 + payload + padding, 1588 s, s->msg_callback_arg); 1589 1590 dtls1_start_timer(s); 1591 s->tlsext_hb_pending = 1; 1592 } 1593 1594err: 1595 OPENSSL_free(buf); 1596 1597 return ret; 1598} 1599#endif 1600