d1_both.c revision 306195
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) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core@openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116#include <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 if (mt >= 0 && s->s3->tmp.message_type != mt) { 521 al = SSL_AD_UNEXPECTED_MESSAGE; 522 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 523 goto f_err; 524 } 525 526 p = (unsigned char *)s->init_buf->data; 527 msg_len = msg_hdr->msg_len; 528 529 /* reconstruct message header */ 530 *(p++) = msg_hdr->type; 531 l2n3(msg_len, p); 532 s2n(msg_hdr->seq, p); 533 l2n3(0, p); 534 l2n3(msg_len, p); 535 if (s->version != DTLS1_BAD_VER) { 536 p -= DTLS1_HM_HEADER_LENGTH; 537 msg_len += DTLS1_HM_HEADER_LENGTH; 538 } 539 540 ssl3_finish_mac(s, p, msg_len); 541 if (s->msg_callback) 542 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 543 p, msg_len, s, s->msg_callback_arg); 544 545 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 546 547 /* Don't change sequence numbers while listening */ 548 if (!s->d1->listen) 549 s->d1->handshake_read_seq++; 550 551 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 552 return s->init_num; 553 554 f_err: 555 ssl3_send_alert(s, SSL3_AL_FATAL, al); 556 *ok = 0; 557 return -1; 558} 559 560static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 561 int max) 562{ 563 size_t frag_off, frag_len, msg_len; 564 565 msg_len = msg_hdr->msg_len; 566 frag_off = msg_hdr->frag_off; 567 frag_len = msg_hdr->frag_len; 568 569 /* sanity checking */ 570 if ((frag_off + frag_len) > msg_len) { 571 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 572 return SSL_AD_ILLEGAL_PARAMETER; 573 } 574 575 if ((frag_off + frag_len) > (unsigned long)max) { 576 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 577 return SSL_AD_ILLEGAL_PARAMETER; 578 } 579 580 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 581 /* 582 * msg_len is limited to 2^24, but is effectively checked against max 583 * above 584 * 585 * Make buffer slightly larger than message length as a precaution 586 * against small OOB reads e.g. CVE-2016-6306 587 */ 588 if (!BUF_MEM_grow_clean 589 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH + 16)) { 590 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 591 return SSL_AD_INTERNAL_ERROR; 592 } 593 594 s->s3->tmp.message_size = msg_len; 595 s->d1->r_msg_hdr.msg_len = msg_len; 596 s->s3->tmp.message_type = msg_hdr->type; 597 s->d1->r_msg_hdr.type = msg_hdr->type; 598 s->d1->r_msg_hdr.seq = msg_hdr->seq; 599 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 600 /* 601 * They must be playing with us! BTW, failure to enforce upper limit 602 * would open possibility for buffer overrun. 603 */ 604 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 605 return SSL_AD_ILLEGAL_PARAMETER; 606 } 607 608 return 0; /* no error */ 609} 610 611static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 612{ 613 /*- 614 * (0) check whether the desired fragment is available 615 * if so: 616 * (1) copy over the fragment to s->init_buf->data[] 617 * (2) update s->init_num 618 */ 619 pitem *item; 620 hm_fragment *frag; 621 int al; 622 623 *ok = 0; 624 do { 625 item = pqueue_peek(s->d1->buffered_messages); 626 if (item == NULL) 627 return 0; 628 629 frag = (hm_fragment *)item->data; 630 631 if (frag->msg_header.seq < s->d1->handshake_read_seq) { 632 /* This is a stale message that has been buffered so clear it */ 633 pqueue_pop(s->d1->buffered_messages); 634 dtls1_hm_fragment_free(frag); 635 pitem_free(item); 636 item = NULL; 637 frag = NULL; 638 } 639 } while (item == NULL); 640 641 642 /* Don't return if reassembly still in progress */ 643 if (frag->reassembly != NULL) 644 return 0; 645 646 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 647 unsigned long frag_len = frag->msg_header.frag_len; 648 pqueue_pop(s->d1->buffered_messages); 649 650 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 651 652 if (al == 0) { /* no alert */ 653 unsigned char *p = 654 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 655 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 656 frag->msg_header.frag_len); 657 } 658 659 dtls1_hm_fragment_free(frag); 660 pitem_free(item); 661 662 if (al == 0) { 663 *ok = 1; 664 return frag_len; 665 } 666 667 ssl3_send_alert(s, SSL3_AL_FATAL, al); 668 s->init_num = 0; 669 *ok = 0; 670 return -1; 671 } else 672 return 0; 673} 674 675/* 676 * dtls1_max_handshake_message_len returns the maximum number of bytes 677 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 678 * may be greater if the maximum certificate list size requires it. 679 */ 680static unsigned long dtls1_max_handshake_message_len(const SSL *s) 681{ 682 unsigned long max_len = 683 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 684 if (max_len < (unsigned long)s->max_cert_list) 685 return s->max_cert_list; 686 return max_len; 687} 688 689static int 690dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 691{ 692 hm_fragment *frag = NULL; 693 pitem *item = NULL; 694 int i = -1, is_complete; 695 unsigned char seq64be[8]; 696 unsigned long frag_len = msg_hdr->frag_len; 697 698 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 699 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 700 goto err; 701 702 if (frag_len == 0) 703 return DTLS1_HM_FRAGMENT_RETRY; 704 705 /* Try to find item in queue */ 706 memset(seq64be, 0, sizeof(seq64be)); 707 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 708 seq64be[7] = (unsigned char)msg_hdr->seq; 709 item = pqueue_find(s->d1->buffered_messages, seq64be); 710 711 if (item == NULL) { 712 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 713 if (frag == NULL) 714 goto err; 715 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 716 frag->msg_header.frag_len = frag->msg_header.msg_len; 717 frag->msg_header.frag_off = 0; 718 } else { 719 frag = (hm_fragment *)item->data; 720 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 721 item = NULL; 722 frag = NULL; 723 goto err; 724 } 725 } 726 727 /* 728 * If message is already reassembled, this must be a retransmit and can 729 * be dropped. In this case item != NULL and so frag does not need to be 730 * freed. 731 */ 732 if (frag->reassembly == NULL) { 733 unsigned char devnull[256]; 734 735 while (frag_len) { 736 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 737 devnull, 738 frag_len > 739 sizeof(devnull) ? sizeof(devnull) : 740 frag_len, 0); 741 if (i <= 0) 742 goto err; 743 frag_len -= i; 744 } 745 return DTLS1_HM_FRAGMENT_RETRY; 746 } 747 748 /* read the body of the fragment (header has already been read */ 749 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 750 frag->fragment + msg_hdr->frag_off, 751 frag_len, 0); 752 if ((unsigned long)i != frag_len) 753 i = -1; 754 if (i <= 0) 755 goto err; 756 757 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 758 (long)(msg_hdr->frag_off + frag_len)); 759 760 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 761 is_complete); 762 763 if (is_complete) { 764 OPENSSL_free(frag->reassembly); 765 frag->reassembly = NULL; 766 } 767 768 if (item == NULL) { 769 item = pitem_new(seq64be, frag); 770 if (item == NULL) { 771 i = -1; 772 goto err; 773 } 774 775 item = pqueue_insert(s->d1->buffered_messages, item); 776 /* 777 * pqueue_insert fails iff a duplicate item is inserted. However, 778 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 779 * would have returned it and control would never have reached this 780 * branch. 781 */ 782 OPENSSL_assert(item != NULL); 783 } 784 785 return DTLS1_HM_FRAGMENT_RETRY; 786 787 err: 788 if (frag != NULL && item == NULL) 789 dtls1_hm_fragment_free(frag); 790 *ok = 0; 791 return i; 792} 793 794static int 795dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 796 int *ok) 797{ 798 int i = -1; 799 hm_fragment *frag = NULL; 800 pitem *item = NULL; 801 unsigned char seq64be[8]; 802 unsigned long frag_len = msg_hdr->frag_len; 803 804 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 805 goto err; 806 807 /* Try to find item in queue, to prevent duplicate entries */ 808 memset(seq64be, 0, sizeof(seq64be)); 809 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 810 seq64be[7] = (unsigned char)msg_hdr->seq; 811 item = pqueue_find(s->d1->buffered_messages, seq64be); 812 813 /* 814 * If we already have an entry and this one is a fragment, don't discard 815 * it and rather try to reassemble it. 816 */ 817 if (item != NULL && frag_len != msg_hdr->msg_len) 818 item = NULL; 819 820 /* 821 * Discard the message if sequence number was already there, is too far 822 * in the future, already in the queue or if we received a FINISHED 823 * before the SERVER_HELLO, which then must be a stale retransmit. 824 */ 825 if (msg_hdr->seq <= s->d1->handshake_read_seq || 826 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 827 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 828 { 829 unsigned char devnull[256]; 830 831 while (frag_len) { 832 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 833 devnull, 834 frag_len > 835 sizeof(devnull) ? sizeof(devnull) : 836 frag_len, 0); 837 if (i <= 0) 838 goto err; 839 frag_len -= i; 840 } 841 } else { 842 if (frag_len != msg_hdr->msg_len) 843 return dtls1_reassemble_fragment(s, msg_hdr, ok); 844 845 if (frag_len > dtls1_max_handshake_message_len(s)) 846 goto err; 847 848 frag = dtls1_hm_fragment_new(frag_len, 0); 849 if (frag == NULL) 850 goto err; 851 852 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 853 854 if (frag_len) { 855 /* 856 * read the body of the fragment (header has already been read 857 */ 858 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 859 frag->fragment, frag_len, 0); 860 if ((unsigned long)i != frag_len) 861 i = -1; 862 if (i <= 0) 863 goto err; 864 } 865 866 item = pitem_new(seq64be, frag); 867 if (item == NULL) 868 goto err; 869 870 item = pqueue_insert(s->d1->buffered_messages, item); 871 /* 872 * pqueue_insert fails iff a duplicate item is inserted. However, 873 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 874 * would have returned it. Then, either |frag_len| != 875 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 876 * have been processed with |dtls1_reassemble_fragment|, above, or 877 * the record will have been discarded. 878 */ 879 OPENSSL_assert(item != NULL); 880 } 881 882 return DTLS1_HM_FRAGMENT_RETRY; 883 884 err: 885 if (frag != NULL && item == NULL) 886 dtls1_hm_fragment_free(frag); 887 *ok = 0; 888 return i; 889} 890 891static long 892dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 893{ 894 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 895 unsigned long len, frag_off, frag_len; 896 int i, al; 897 struct hm_header_st msg_hdr; 898 899 redo: 900 /* see if we have the required fragment already */ 901 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 902 if (*ok) 903 s->init_num = frag_len; 904 return frag_len; 905 } 906 907 /* read handshake message header */ 908 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 909 DTLS1_HM_HEADER_LENGTH, 0); 910 if (i <= 0) { /* nbio, or an error */ 911 s->rwstate = SSL_READING; 912 *ok = 0; 913 return i; 914 } 915 /* Handshake fails if message header is incomplete */ 916 if (i != DTLS1_HM_HEADER_LENGTH) { 917 al = SSL_AD_UNEXPECTED_MESSAGE; 918 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 919 goto f_err; 920 } 921 922 /* parse the message fragment header */ 923 dtls1_get_message_header(wire, &msg_hdr); 924 925 len = msg_hdr.msg_len; 926 frag_off = msg_hdr.frag_off; 927 frag_len = msg_hdr.frag_len; 928 929 /* 930 * We must have at least frag_len bytes left in the record to be read. 931 * Fragments must not span records. 932 */ 933 if (frag_len > s->s3->rrec.length) { 934 al = SSL3_AD_ILLEGAL_PARAMETER; 935 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 936 goto f_err; 937 } 938 939 /* 940 * if this is a future (or stale) message it gets buffered 941 * (or dropped)--no further processing at this time 942 * While listening, we accept seq 1 (ClientHello with cookie) 943 * although we're still expecting seq 0 (ClientHello) 944 */ 945 if (msg_hdr.seq != s->d1->handshake_read_seq 946 && !(s->d1->listen && msg_hdr.seq == 1)) 947 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 948 949 if (frag_len && frag_len < len) 950 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 951 952 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 953 wire[0] == SSL3_MT_HELLO_REQUEST) { 954 /* 955 * The server may always send 'Hello Request' messages -- we are 956 * doing a handshake anyway now, so ignore them if their format is 957 * correct. Does not count for 'Finished' MAC. 958 */ 959 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 960 if (s->msg_callback) 961 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 962 wire, DTLS1_HM_HEADER_LENGTH, s, 963 s->msg_callback_arg); 964 965 s->init_num = 0; 966 goto redo; 967 } else { /* Incorrectly formated Hello request */ 968 969 al = SSL_AD_UNEXPECTED_MESSAGE; 970 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 971 SSL_R_UNEXPECTED_MESSAGE); 972 goto f_err; 973 } 974 } 975 976 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 977 goto f_err; 978 979 if (frag_len > 0) { 980 unsigned char *p = 981 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 982 983 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 984 &p[frag_off], frag_len, 0); 985 986 /* 987 * This shouldn't ever fail due to NBIO because we already checked 988 * that we have enough data in the record 989 */ 990 if (i <= 0) { 991 s->rwstate = SSL_READING; 992 *ok = 0; 993 return i; 994 } 995 } else 996 i = 0; 997 998 /* 999 * XDTLS: an incorrectly formatted fragment should cause the handshake 1000 * to fail 1001 */ 1002 if (i != (int)frag_len) { 1003 al = SSL3_AD_ILLEGAL_PARAMETER; 1004 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 1005 goto f_err; 1006 } 1007 1008 *ok = 1; 1009 s->state = stn; 1010 1011 /* 1012 * Note that s->init_num is *not* used as current offset in 1013 * s->init_buf->data, but as a counter summing up fragments' lengths: as 1014 * soon as they sum up to handshake packet length, we assume we have got 1015 * all the fragments. 1016 */ 1017 s->init_num = frag_len; 1018 return frag_len; 1019 1020 f_err: 1021 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1022 s->init_num = 0; 1023 1024 *ok = 0; 1025 return (-1); 1026} 1027 1028/*- 1029 * for these 2 messages, we need to 1030 * ssl->enc_read_ctx re-init 1031 * ssl->s3->read_sequence zero 1032 * ssl->s3->read_mac_secret re-init 1033 * ssl->session->read_sym_enc assign 1034 * ssl->session->read_compression assign 1035 * ssl->session->read_hash assign 1036 */ 1037int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1038{ 1039 unsigned char *p; 1040 1041 if (s->state == a) { 1042 p = (unsigned char *)s->init_buf->data; 1043 *p++ = SSL3_MT_CCS; 1044 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1045 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1046 1047 if (s->version == DTLS1_BAD_VER) { 1048 s->d1->next_handshake_write_seq++; 1049 s2n(s->d1->handshake_write_seq, p); 1050 s->init_num += 2; 1051 } 1052 1053 s->init_off = 0; 1054 1055 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1056 s->d1->handshake_write_seq, 0, 0); 1057 1058 /* buffer the message to handle re-xmits */ 1059 dtls1_buffer_message(s, 1); 1060 1061 s->state = b; 1062 } 1063 1064 /* SSL3_ST_CW_CHANGE_B */ 1065 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1066} 1067 1068int dtls1_read_failed(SSL *s, int code) 1069{ 1070 if (code > 0) { 1071 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1072 return 1; 1073 } 1074 1075 if (!dtls1_is_timer_expired(s)) { 1076 /* 1077 * not a timeout, none of our business, let higher layers handle 1078 * this. in fact it's probably an error 1079 */ 1080 return code; 1081 } 1082#ifndef OPENSSL_NO_HEARTBEATS 1083 /* done, no need to send a retransmit */ 1084 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1085#else 1086 /* done, no need to send a retransmit */ 1087 if (!SSL_in_init(s)) 1088#endif 1089 { 1090 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1091 return code; 1092 } 1093#if 0 /* for now, each alert contains only one 1094 * record number */ 1095 item = pqueue_peek(state->rcvd_records); 1096 if (item) { 1097 /* send an alert immediately for all the missing records */ 1098 } else 1099#endif 1100 1101#if 0 /* no more alert sending, just retransmit the 1102 * last set of messages */ 1103 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1104 ssl3_send_alert(s, SSL3_AL_WARNING, 1105 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1106#endif 1107 1108 return dtls1_handle_timeout(s); 1109} 1110 1111int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1112{ 1113 /* 1114 * The index of the retransmission queue actually is the message sequence 1115 * number, since the queue only contains messages of a single handshake. 1116 * However, the ChangeCipherSpec has no message sequence number and so 1117 * using only the sequence will result in the CCS and Finished having the 1118 * same index. To prevent this, the sequence number is multiplied by 2. 1119 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1120 * Finished, it also maintains the order of the index (important for 1121 * priority queues) and fits in the unsigned short variable. 1122 */ 1123 return seq * 2 - is_ccs; 1124} 1125 1126int dtls1_retransmit_buffered_messages(SSL *s) 1127{ 1128 pqueue sent = s->d1->sent_messages; 1129 piterator iter; 1130 pitem *item; 1131 hm_fragment *frag; 1132 int found = 0; 1133 1134 iter = pqueue_iterator(sent); 1135 1136 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1137 frag = (hm_fragment *)item->data; 1138 if (dtls1_retransmit_message(s, (unsigned short) 1139 dtls1_get_queue_priority 1140 (frag->msg_header.seq, 1141 frag->msg_header.is_ccs), 0, 1142 &found) <= 0 && found) { 1143 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1144 return -1; 1145 } 1146 } 1147 1148 return 1; 1149} 1150 1151int dtls1_buffer_message(SSL *s, int is_ccs) 1152{ 1153 pitem *item; 1154 hm_fragment *frag; 1155 unsigned char seq64be[8]; 1156 1157 /* 1158 * this function is called immediately after a message has been 1159 * serialized 1160 */ 1161 OPENSSL_assert(s->init_off == 0); 1162 1163 frag = dtls1_hm_fragment_new(s->init_num, 0); 1164 if (!frag) 1165 return 0; 1166 1167 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1168 1169 if (is_ccs) { 1170 /* For DTLS1_BAD_VER the header length is non-standard */ 1171 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1172 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH) 1173 == (unsigned int)s->init_num); 1174 } else { 1175 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1176 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1177 } 1178 1179 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1180 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1181 frag->msg_header.type = s->d1->w_msg_hdr.type; 1182 frag->msg_header.frag_off = 0; 1183 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1184 frag->msg_header.is_ccs = is_ccs; 1185 1186 /* save current state */ 1187 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1188 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1189 frag->msg_header.saved_retransmit_state.compress = s->compress; 1190 frag->msg_header.saved_retransmit_state.session = s->session; 1191 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1192 1193 memset(seq64be, 0, sizeof(seq64be)); 1194 seq64be[6] = 1195 (unsigned 1196 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1197 frag->msg_header.is_ccs) >> 8); 1198 seq64be[7] = 1199 (unsigned 1200 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1201 frag->msg_header.is_ccs)); 1202 1203 item = pitem_new(seq64be, frag); 1204 if (item == NULL) { 1205 dtls1_hm_fragment_free(frag); 1206 return 0; 1207 } 1208#if 0 1209 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1210 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1211 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1212#endif 1213 1214 pqueue_insert(s->d1->sent_messages, item); 1215 return 1; 1216} 1217 1218int 1219dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1220 int *found) 1221{ 1222 int ret; 1223 /* XDTLS: for now assuming that read/writes are blocking */ 1224 pitem *item; 1225 hm_fragment *frag; 1226 unsigned long header_length; 1227 unsigned char seq64be[8]; 1228 struct dtls1_retransmit_state saved_state; 1229 unsigned char save_write_sequence[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 1230 1231 /*- 1232 OPENSSL_assert(s->init_num == 0); 1233 OPENSSL_assert(s->init_off == 0); 1234 */ 1235 1236 /* XDTLS: the requested message ought to be found, otherwise error */ 1237 memset(seq64be, 0, sizeof(seq64be)); 1238 seq64be[6] = (unsigned char)(seq >> 8); 1239 seq64be[7] = (unsigned char)seq; 1240 1241 item = pqueue_find(s->d1->sent_messages, seq64be); 1242 if (item == NULL) { 1243 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1244 *found = 0; 1245 return 0; 1246 } 1247 1248 *found = 1; 1249 frag = (hm_fragment *)item->data; 1250 1251 if (frag->msg_header.is_ccs) 1252 header_length = DTLS1_CCS_HEADER_LENGTH; 1253 else 1254 header_length = DTLS1_HM_HEADER_LENGTH; 1255 1256 memcpy(s->init_buf->data, frag->fragment, 1257 frag->msg_header.msg_len + header_length); 1258 s->init_num = frag->msg_header.msg_len + header_length; 1259 1260 dtls1_set_message_header_int(s, frag->msg_header.type, 1261 frag->msg_header.msg_len, 1262 frag->msg_header.seq, 0, 1263 frag->msg_header.frag_len); 1264 1265 /* save current state */ 1266 saved_state.enc_write_ctx = s->enc_write_ctx; 1267 saved_state.write_hash = s->write_hash; 1268 saved_state.compress = s->compress; 1269 saved_state.session = s->session; 1270 saved_state.epoch = s->d1->w_epoch; 1271 saved_state.epoch = s->d1->w_epoch; 1272 1273 s->d1->retransmitting = 1; 1274 1275 /* restore state in which the message was originally sent */ 1276 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1277 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1278 s->compress = frag->msg_header.saved_retransmit_state.compress; 1279 s->session = frag->msg_header.saved_retransmit_state.session; 1280 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1281 1282 if (frag->msg_header.saved_retransmit_state.epoch == 1283 saved_state.epoch - 1) { 1284 memcpy(save_write_sequence, s->s3->write_sequence, 1285 sizeof(s->s3->write_sequence)); 1286 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1287 sizeof(s->s3->write_sequence)); 1288 } 1289 1290 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1291 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1292 1293 /* restore current state */ 1294 s->enc_write_ctx = saved_state.enc_write_ctx; 1295 s->write_hash = saved_state.write_hash; 1296 s->compress = saved_state.compress; 1297 s->session = saved_state.session; 1298 s->d1->w_epoch = saved_state.epoch; 1299 1300 if (frag->msg_header.saved_retransmit_state.epoch == 1301 saved_state.epoch - 1) { 1302 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1303 sizeof(s->s3->write_sequence)); 1304 memcpy(s->s3->write_sequence, save_write_sequence, 1305 sizeof(s->s3->write_sequence)); 1306 } 1307 1308 s->d1->retransmitting = 0; 1309 1310 (void)BIO_flush(SSL_get_wbio(s)); 1311 return ret; 1312} 1313 1314unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1315 unsigned char mt, unsigned long len, 1316 unsigned long frag_off, 1317 unsigned long frag_len) 1318{ 1319 /* Don't change sequence numbers while listening */ 1320 if (frag_off == 0 && !s->d1->listen) { 1321 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1322 s->d1->next_handshake_write_seq++; 1323 } 1324 1325 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1326 frag_off, frag_len); 1327 1328 return p += DTLS1_HM_HEADER_LENGTH; 1329} 1330 1331/* don't actually do the writing, wait till the MTU has been retrieved */ 1332static void 1333dtls1_set_message_header_int(SSL *s, unsigned char mt, 1334 unsigned long len, unsigned short seq_num, 1335 unsigned long frag_off, unsigned long frag_len) 1336{ 1337 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1338 1339 msg_hdr->type = mt; 1340 msg_hdr->msg_len = len; 1341 msg_hdr->seq = seq_num; 1342 msg_hdr->frag_off = frag_off; 1343 msg_hdr->frag_len = frag_len; 1344} 1345 1346static void 1347dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1348 unsigned long frag_len) 1349{ 1350 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1351 1352 msg_hdr->frag_off = frag_off; 1353 msg_hdr->frag_len = frag_len; 1354} 1355 1356static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1357{ 1358 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1359 1360 *p++ = msg_hdr->type; 1361 l2n3(msg_hdr->msg_len, p); 1362 1363 s2n(msg_hdr->seq, p); 1364 l2n3(msg_hdr->frag_off, p); 1365 l2n3(msg_hdr->frag_len, p); 1366 1367 return p; 1368} 1369 1370unsigned int dtls1_link_min_mtu(void) 1371{ 1372 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1373 sizeof(g_probable_mtu[0])) - 1]); 1374} 1375 1376unsigned int dtls1_min_mtu(SSL *s) 1377{ 1378 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1379} 1380 1381void 1382dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1383{ 1384 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1385 msg_hdr->type = *(data++); 1386 n2l3(data, msg_hdr->msg_len); 1387 1388 n2s(data, msg_hdr->seq); 1389 n2l3(data, msg_hdr->frag_off); 1390 n2l3(data, msg_hdr->frag_len); 1391} 1392 1393void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1394{ 1395 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1396 1397 ccs_hdr->type = *(data++); 1398} 1399 1400int dtls1_shutdown(SSL *s) 1401{ 1402 int ret; 1403#ifndef OPENSSL_NO_SCTP 1404 BIO *wbio; 1405 1406 wbio = SSL_get_wbio(s); 1407 if (wbio != NULL && BIO_dgram_is_sctp(wbio) && 1408 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1409 ret = BIO_dgram_sctp_wait_for_dry(wbio); 1410 if (ret < 0) 1411 return -1; 1412 1413 if (ret == 0) 1414 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1415 NULL); 1416 } 1417#endif 1418 ret = ssl3_shutdown(s); 1419#ifndef OPENSSL_NO_SCTP 1420 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1421#endif 1422 return ret; 1423} 1424 1425#ifndef OPENSSL_NO_HEARTBEATS 1426int dtls1_process_heartbeat(SSL *s) 1427{ 1428 unsigned char *p = &s->s3->rrec.data[0], *pl; 1429 unsigned short hbtype; 1430 unsigned int payload; 1431 unsigned int padding = 16; /* Use minimum padding */ 1432 1433 if (s->msg_callback) 1434 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1435 &s->s3->rrec.data[0], s->s3->rrec.length, 1436 s, s->msg_callback_arg); 1437 1438 /* Read type and payload length first */ 1439 if (1 + 2 + 16 > s->s3->rrec.length) 1440 return 0; /* silently discard */ 1441 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1442 return 0; /* silently discard per RFC 6520 sec. 4 */ 1443 1444 hbtype = *p++; 1445 n2s(p, payload); 1446 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1447 return 0; /* silently discard per RFC 6520 sec. 4 */ 1448 pl = p; 1449 1450 if (hbtype == TLS1_HB_REQUEST) { 1451 unsigned char *buffer, *bp; 1452 unsigned int write_length = 1 /* heartbeat type */ + 1453 2 /* heartbeat length */ + 1454 payload + padding; 1455 int r; 1456 1457 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1458 return 0; 1459 1460 /* 1461 * Allocate memory for the response, size is 1 byte message type, 1462 * plus 2 bytes payload length, plus payload, plus padding 1463 */ 1464 buffer = OPENSSL_malloc(write_length); 1465 if (buffer == NULL) 1466 return -1; 1467 bp = buffer; 1468 1469 /* Enter response type, length and copy payload */ 1470 *bp++ = TLS1_HB_RESPONSE; 1471 s2n(payload, bp); 1472 memcpy(bp, pl, payload); 1473 bp += payload; 1474 /* Random padding */ 1475 if (RAND_bytes(bp, padding) <= 0) { 1476 OPENSSL_free(buffer); 1477 return -1; 1478 } 1479 1480 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1481 1482 if (r >= 0 && s->msg_callback) 1483 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1484 buffer, write_length, s, s->msg_callback_arg); 1485 1486 OPENSSL_free(buffer); 1487 1488 if (r < 0) 1489 return r; 1490 } else if (hbtype == TLS1_HB_RESPONSE) { 1491 unsigned int seq; 1492 1493 /* 1494 * We only send sequence numbers (2 bytes unsigned int), and 16 1495 * random bytes, so we just try to read the sequence number 1496 */ 1497 n2s(pl, seq); 1498 1499 if (payload == 18 && seq == s->tlsext_hb_seq) { 1500 dtls1_stop_timer(s); 1501 s->tlsext_hb_seq++; 1502 s->tlsext_hb_pending = 0; 1503 } 1504 } 1505 1506 return 0; 1507} 1508 1509int dtls1_heartbeat(SSL *s) 1510{ 1511 unsigned char *buf, *p; 1512 int ret = -1; 1513 unsigned int payload = 18; /* Sequence number + random bytes */ 1514 unsigned int padding = 16; /* Use minimum padding */ 1515 1516 /* Only send if peer supports and accepts HB requests... */ 1517 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1518 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1519 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1520 return -1; 1521 } 1522 1523 /* ...and there is none in flight yet... */ 1524 if (s->tlsext_hb_pending) { 1525 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1526 return -1; 1527 } 1528 1529 /* ...and no handshake in progress. */ 1530 if (SSL_in_init(s) || s->in_handshake) { 1531 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1532 return -1; 1533 } 1534 1535 /* 1536 * Check if padding is too long, payload and padding must not exceed 2^14 1537 * - 3 = 16381 bytes in total. 1538 */ 1539 OPENSSL_assert(payload + padding <= 16381); 1540 1541 /*- 1542 * Create HeartBeat message, we just use a sequence number 1543 * as payload to distuingish different messages and add 1544 * some random stuff. 1545 * - Message Type, 1 byte 1546 * - Payload Length, 2 bytes (unsigned int) 1547 * - Payload, the sequence number (2 bytes uint) 1548 * - Payload, random bytes (16 bytes uint) 1549 * - Padding 1550 */ 1551 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1552 if (buf == NULL) 1553 goto err; 1554 p = buf; 1555 /* Message Type */ 1556 *p++ = TLS1_HB_REQUEST; 1557 /* Payload length (18 bytes here) */ 1558 s2n(payload, p); 1559 /* Sequence number */ 1560 s2n(s->tlsext_hb_seq, p); 1561 /* 16 random bytes */ 1562 if (RAND_bytes(p, 16) <= 0) 1563 goto err; 1564 p += 16; 1565 /* Random padding */ 1566 if (RAND_bytes(p, padding) <= 0) 1567 goto err; 1568 1569 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1570 if (ret >= 0) { 1571 if (s->msg_callback) 1572 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1573 buf, 3 + payload + padding, 1574 s, s->msg_callback_arg); 1575 1576 dtls1_start_timer(s); 1577 s->tlsext_hb_pending = 1; 1578 } 1579 1580err: 1581 OPENSSL_free(buf); 1582 1583 return ret; 1584} 1585#endif 1586