d1_both.c revision 325335
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 /* 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 if (al == 0) { /* no alert */ 660 unsigned char *p = 661 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 662 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 663 frag->msg_header.frag_len); 664 } 665 666 dtls1_hm_fragment_free(frag); 667 pitem_free(item); 668 669 if (al == 0) { 670 *ok = 1; 671 return frag_len; 672 } 673 674 ssl3_send_alert(s, SSL3_AL_FATAL, al); 675 s->init_num = 0; 676 *ok = 0; 677 return -1; 678 } else 679 return 0; 680} 681 682/* 683 * dtls1_max_handshake_message_len returns the maximum number of bytes 684 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 685 * may be greater if the maximum certificate list size requires it. 686 */ 687static unsigned long dtls1_max_handshake_message_len(const SSL *s) 688{ 689 unsigned long max_len = 690 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 691 if (max_len < (unsigned long)s->max_cert_list) 692 return s->max_cert_list; 693 return max_len; 694} 695 696static int 697dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 698{ 699 hm_fragment *frag = NULL; 700 pitem *item = NULL; 701 int i = -1, is_complete; 702 unsigned char seq64be[8]; 703 unsigned long frag_len = msg_hdr->frag_len; 704 705 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 706 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 707 goto err; 708 709 if (frag_len == 0) 710 return DTLS1_HM_FRAGMENT_RETRY; 711 712 /* Try to find item in queue */ 713 memset(seq64be, 0, sizeof(seq64be)); 714 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 715 seq64be[7] = (unsigned char)msg_hdr->seq; 716 item = pqueue_find(s->d1->buffered_messages, seq64be); 717 718 if (item == NULL) { 719 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 720 if (frag == NULL) 721 goto err; 722 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 723 frag->msg_header.frag_len = frag->msg_header.msg_len; 724 frag->msg_header.frag_off = 0; 725 } else { 726 frag = (hm_fragment *)item->data; 727 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 728 item = NULL; 729 frag = NULL; 730 goto err; 731 } 732 } 733 734 /* 735 * If message is already reassembled, this must be a retransmit and can 736 * be dropped. In this case item != NULL and so frag does not need to be 737 * freed. 738 */ 739 if (frag->reassembly == NULL) { 740 unsigned char devnull[256]; 741 742 while (frag_len) { 743 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 744 devnull, 745 frag_len > 746 sizeof(devnull) ? sizeof(devnull) : 747 frag_len, 0); 748 if (i <= 0) 749 goto err; 750 frag_len -= i; 751 } 752 return DTLS1_HM_FRAGMENT_RETRY; 753 } 754 755 /* read the body of the fragment (header has already been read */ 756 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 757 frag->fragment + msg_hdr->frag_off, 758 frag_len, 0); 759 if ((unsigned long)i != frag_len) 760 i = -1; 761 if (i <= 0) 762 goto err; 763 764 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 765 (long)(msg_hdr->frag_off + frag_len)); 766 767 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 768 is_complete); 769 770 if (is_complete) { 771 OPENSSL_free(frag->reassembly); 772 frag->reassembly = NULL; 773 } 774 775 if (item == NULL) { 776 item = pitem_new(seq64be, frag); 777 if (item == NULL) { 778 i = -1; 779 goto err; 780 } 781 782 item = pqueue_insert(s->d1->buffered_messages, item); 783 /* 784 * pqueue_insert fails iff a duplicate item is inserted. However, 785 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 786 * would have returned it and control would never have reached this 787 * branch. 788 */ 789 OPENSSL_assert(item != NULL); 790 } 791 792 return DTLS1_HM_FRAGMENT_RETRY; 793 794 err: 795 if (frag != NULL && item == NULL) 796 dtls1_hm_fragment_free(frag); 797 *ok = 0; 798 return i; 799} 800 801static int 802dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 803 int *ok) 804{ 805 int i = -1; 806 hm_fragment *frag = NULL; 807 pitem *item = NULL; 808 unsigned char seq64be[8]; 809 unsigned long frag_len = msg_hdr->frag_len; 810 811 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 812 goto err; 813 814 /* Try to find item in queue, to prevent duplicate entries */ 815 memset(seq64be, 0, sizeof(seq64be)); 816 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 817 seq64be[7] = (unsigned char)msg_hdr->seq; 818 item = pqueue_find(s->d1->buffered_messages, seq64be); 819 820 /* 821 * If we already have an entry and this one is a fragment, don't discard 822 * it and rather try to reassemble it. 823 */ 824 if (item != NULL && frag_len != msg_hdr->msg_len) 825 item = NULL; 826 827 /* 828 * Discard the message if sequence number was already there, is too far 829 * in the future, already in the queue or if we received a FINISHED 830 * before the SERVER_HELLO, which then must be a stale retransmit. 831 */ 832 if (msg_hdr->seq <= s->d1->handshake_read_seq || 833 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 834 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 835 { 836 unsigned char devnull[256]; 837 838 while (frag_len) { 839 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 840 devnull, 841 frag_len > 842 sizeof(devnull) ? sizeof(devnull) : 843 frag_len, 0); 844 if (i <= 0) 845 goto err; 846 frag_len -= i; 847 } 848 } else { 849 if (frag_len != msg_hdr->msg_len) 850 return dtls1_reassemble_fragment(s, msg_hdr, ok); 851 852 if (frag_len > dtls1_max_handshake_message_len(s)) 853 goto err; 854 855 frag = dtls1_hm_fragment_new(frag_len, 0); 856 if (frag == NULL) 857 goto err; 858 859 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 860 861 if (frag_len) { 862 /* 863 * read the body of the fragment (header has already been read 864 */ 865 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 866 frag->fragment, frag_len, 0); 867 if ((unsigned long)i != frag_len) 868 i = -1; 869 if (i <= 0) 870 goto err; 871 } 872 873 item = pitem_new(seq64be, frag); 874 if (item == NULL) 875 goto err; 876 877 item = pqueue_insert(s->d1->buffered_messages, item); 878 /* 879 * pqueue_insert fails iff a duplicate item is inserted. However, 880 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 881 * would have returned it. Then, either |frag_len| != 882 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 883 * have been processed with |dtls1_reassemble_fragment|, above, or 884 * the record will have been discarded. 885 */ 886 OPENSSL_assert(item != NULL); 887 } 888 889 return DTLS1_HM_FRAGMENT_RETRY; 890 891 err: 892 if (frag != NULL && item == NULL) 893 dtls1_hm_fragment_free(frag); 894 *ok = 0; 895 return i; 896} 897 898static long 899dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 900{ 901 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 902 unsigned long len, frag_off, frag_len; 903 int i, al; 904 struct hm_header_st msg_hdr; 905 906 redo: 907 /* see if we have the required fragment already */ 908 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 909 if (*ok) 910 s->init_num = frag_len; 911 return frag_len; 912 } 913 914 /* read handshake message header */ 915 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 916 DTLS1_HM_HEADER_LENGTH, 0); 917 if (i <= 0) { /* nbio, or an error */ 918 s->rwstate = SSL_READING; 919 *ok = 0; 920 return i; 921 } 922 /* Handshake fails if message header is incomplete */ 923 if (i != DTLS1_HM_HEADER_LENGTH) { 924 al = SSL_AD_UNEXPECTED_MESSAGE; 925 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 926 goto f_err; 927 } 928 929 /* parse the message fragment header */ 930 dtls1_get_message_header(wire, &msg_hdr); 931 932 len = msg_hdr.msg_len; 933 frag_off = msg_hdr.frag_off; 934 frag_len = msg_hdr.frag_len; 935 936 /* 937 * We must have at least frag_len bytes left in the record to be read. 938 * Fragments must not span records. 939 */ 940 if (frag_len > s->s3->rrec.length) { 941 al = SSL3_AD_ILLEGAL_PARAMETER; 942 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 943 goto f_err; 944 } 945 946 /* 947 * if this is a future (or stale) message it gets buffered 948 * (or dropped)--no further processing at this time 949 * While listening, we accept seq 1 (ClientHello with cookie) 950 * although we're still expecting seq 0 (ClientHello) 951 */ 952 if (msg_hdr.seq != s->d1->handshake_read_seq 953 && !(s->d1->listen && msg_hdr.seq == 1)) 954 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 955 956 if (frag_len && frag_len < len) 957 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 958 959 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 960 wire[0] == SSL3_MT_HELLO_REQUEST) { 961 /* 962 * The server may always send 'Hello Request' messages -- we are 963 * doing a handshake anyway now, so ignore them if their format is 964 * correct. Does not count for 'Finished' MAC. 965 */ 966 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 967 if (s->msg_callback) 968 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 969 wire, DTLS1_HM_HEADER_LENGTH, s, 970 s->msg_callback_arg); 971 972 s->init_num = 0; 973 goto redo; 974 } else { /* Incorrectly formated Hello request */ 975 976 al = SSL_AD_UNEXPECTED_MESSAGE; 977 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 978 SSL_R_UNEXPECTED_MESSAGE); 979 goto f_err; 980 } 981 } 982 983 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 984 goto f_err; 985 986 if (frag_len > 0) { 987 unsigned char *p = 988 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 989 990 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 991 &p[frag_off], frag_len, 0); 992 993 /* 994 * This shouldn't ever fail due to NBIO because we already checked 995 * that we have enough data in the record 996 */ 997 if (i <= 0) { 998 s->rwstate = SSL_READING; 999 *ok = 0; 1000 return i; 1001 } 1002 } else 1003 i = 0; 1004 1005 /* 1006 * XDTLS: an incorrectly formatted fragment should cause the handshake 1007 * to fail 1008 */ 1009 if (i != (int)frag_len) { 1010 al = SSL3_AD_ILLEGAL_PARAMETER; 1011 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 1012 goto f_err; 1013 } 1014 1015 *ok = 1; 1016 s->state = stn; 1017 1018 /* 1019 * Note that s->init_num is *not* used as current offset in 1020 * s->init_buf->data, but as a counter summing up fragments' lengths: as 1021 * soon as they sum up to handshake packet length, we assume we have got 1022 * all the fragments. 1023 */ 1024 s->init_num = frag_len; 1025 return frag_len; 1026 1027 f_err: 1028 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1029 s->init_num = 0; 1030 1031 *ok = 0; 1032 return (-1); 1033} 1034 1035/*- 1036 * for these 2 messages, we need to 1037 * ssl->enc_read_ctx re-init 1038 * ssl->s3->read_sequence zero 1039 * ssl->s3->read_mac_secret re-init 1040 * ssl->session->read_sym_enc assign 1041 * ssl->session->read_compression assign 1042 * ssl->session->read_hash assign 1043 */ 1044int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1045{ 1046 unsigned char *p; 1047 1048 if (s->state == a) { 1049 p = (unsigned char *)s->init_buf->data; 1050 *p++ = SSL3_MT_CCS; 1051 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1052 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1053 1054 if (s->version == DTLS1_BAD_VER) { 1055 s->d1->next_handshake_write_seq++; 1056 s2n(s->d1->handshake_write_seq, p); 1057 s->init_num += 2; 1058 } 1059 1060 s->init_off = 0; 1061 1062 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1063 s->d1->handshake_write_seq, 0, 0); 1064 1065 /* buffer the message to handle re-xmits */ 1066 dtls1_buffer_message(s, 1); 1067 1068 s->state = b; 1069 } 1070 1071 /* SSL3_ST_CW_CHANGE_B */ 1072 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1073} 1074 1075int dtls1_read_failed(SSL *s, int code) 1076{ 1077 if (code > 0) { 1078#ifdef TLS_DEBUG 1079 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1080#endif 1081 return 1; 1082 } 1083 1084 if (!dtls1_is_timer_expired(s)) { 1085 /* 1086 * not a timeout, none of our business, let higher layers handle 1087 * this. in fact it's probably an error 1088 */ 1089 return code; 1090 } 1091#ifndef OPENSSL_NO_HEARTBEATS 1092 /* done, no need to send a retransmit */ 1093 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1094#else 1095 /* done, no need to send a retransmit */ 1096 if (!SSL_in_init(s)) 1097#endif 1098 { 1099 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1100 return code; 1101 } 1102#if 0 /* for now, each alert contains only one 1103 * record number */ 1104 item = pqueue_peek(state->rcvd_records); 1105 if (item) { 1106 /* send an alert immediately for all the missing records */ 1107 } else 1108#endif 1109 1110#if 0 /* no more alert sending, just retransmit the 1111 * last set of messages */ 1112 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1113 ssl3_send_alert(s, SSL3_AL_WARNING, 1114 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1115#endif 1116 1117 return dtls1_handle_timeout(s); 1118} 1119 1120int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1121{ 1122 /* 1123 * The index of the retransmission queue actually is the message sequence 1124 * number, since the queue only contains messages of a single handshake. 1125 * However, the ChangeCipherSpec has no message sequence number and so 1126 * using only the sequence will result in the CCS and Finished having the 1127 * same index. To prevent this, the sequence number is multiplied by 2. 1128 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1129 * Finished, it also maintains the order of the index (important for 1130 * priority queues) and fits in the unsigned short variable. 1131 */ 1132 return seq * 2 - is_ccs; 1133} 1134 1135int dtls1_retransmit_buffered_messages(SSL *s) 1136{ 1137 pqueue sent = s->d1->sent_messages; 1138 piterator iter; 1139 pitem *item; 1140 hm_fragment *frag; 1141 int found = 0; 1142 1143 iter = pqueue_iterator(sent); 1144 1145 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1146 frag = (hm_fragment *)item->data; 1147 if (dtls1_retransmit_message(s, (unsigned short) 1148 dtls1_get_queue_priority 1149 (frag->msg_header.seq, 1150 frag->msg_header.is_ccs), 0, 1151 &found) <= 0 && found) { 1152#ifdef TLS_DEBUG 1153 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1154#endif 1155 return -1; 1156 } 1157 } 1158 1159 return 1; 1160} 1161 1162int dtls1_buffer_message(SSL *s, int is_ccs) 1163{ 1164 pitem *item; 1165 hm_fragment *frag; 1166 unsigned char seq64be[8]; 1167 1168 /* 1169 * this function is called immediately after a message has been 1170 * serialized 1171 */ 1172 OPENSSL_assert(s->init_off == 0); 1173 1174 frag = dtls1_hm_fragment_new(s->init_num, 0); 1175 if (!frag) 1176 return 0; 1177 1178 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1179 1180 if (is_ccs) { 1181 /* For DTLS1_BAD_VER the header length is non-standard */ 1182 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1183 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH) 1184 == (unsigned int)s->init_num); 1185 } else { 1186 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1187 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1188 } 1189 1190 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1191 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1192 frag->msg_header.type = s->d1->w_msg_hdr.type; 1193 frag->msg_header.frag_off = 0; 1194 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1195 frag->msg_header.is_ccs = is_ccs; 1196 1197 /* save current state */ 1198 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1199 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1200 frag->msg_header.saved_retransmit_state.compress = s->compress; 1201 frag->msg_header.saved_retransmit_state.session = s->session; 1202 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1203 1204 memset(seq64be, 0, sizeof(seq64be)); 1205 seq64be[6] = 1206 (unsigned 1207 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1208 frag->msg_header.is_ccs) >> 8); 1209 seq64be[7] = 1210 (unsigned 1211 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1212 frag->msg_header.is_ccs)); 1213 1214 item = pitem_new(seq64be, frag); 1215 if (item == NULL) { 1216 dtls1_hm_fragment_free(frag); 1217 return 0; 1218 } 1219#if 0 1220 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1221 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1222 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1223#endif 1224 1225 pqueue_insert(s->d1->sent_messages, item); 1226 return 1; 1227} 1228 1229int 1230dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1231 int *found) 1232{ 1233 int ret; 1234 /* XDTLS: for now assuming that read/writes are blocking */ 1235 pitem *item; 1236 hm_fragment *frag; 1237 unsigned long header_length; 1238 unsigned char seq64be[8]; 1239 struct dtls1_retransmit_state saved_state; 1240 unsigned char save_write_sequence[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 1241 1242 /*- 1243 OPENSSL_assert(s->init_num == 0); 1244 OPENSSL_assert(s->init_off == 0); 1245 */ 1246 1247 /* XDTLS: the requested message ought to be found, otherwise error */ 1248 memset(seq64be, 0, sizeof(seq64be)); 1249 seq64be[6] = (unsigned char)(seq >> 8); 1250 seq64be[7] = (unsigned char)seq; 1251 1252 item = pqueue_find(s->d1->sent_messages, seq64be); 1253 if (item == NULL) { 1254#ifdef TLS_DEBUG 1255 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1256#endif 1257 *found = 0; 1258 return 0; 1259 } 1260 1261 *found = 1; 1262 frag = (hm_fragment *)item->data; 1263 1264 if (frag->msg_header.is_ccs) 1265 header_length = DTLS1_CCS_HEADER_LENGTH; 1266 else 1267 header_length = DTLS1_HM_HEADER_LENGTH; 1268 1269 memcpy(s->init_buf->data, frag->fragment, 1270 frag->msg_header.msg_len + header_length); 1271 s->init_num = frag->msg_header.msg_len + header_length; 1272 1273 dtls1_set_message_header_int(s, frag->msg_header.type, 1274 frag->msg_header.msg_len, 1275 frag->msg_header.seq, 0, 1276 frag->msg_header.frag_len); 1277 1278 /* save current state */ 1279 saved_state.enc_write_ctx = s->enc_write_ctx; 1280 saved_state.write_hash = s->write_hash; 1281 saved_state.compress = s->compress; 1282 saved_state.session = s->session; 1283 saved_state.epoch = s->d1->w_epoch; 1284 saved_state.epoch = s->d1->w_epoch; 1285 1286 s->d1->retransmitting = 1; 1287 1288 /* restore state in which the message was originally sent */ 1289 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1290 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1291 s->compress = frag->msg_header.saved_retransmit_state.compress; 1292 s->session = frag->msg_header.saved_retransmit_state.session; 1293 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1294 1295 if (frag->msg_header.saved_retransmit_state.epoch == 1296 saved_state.epoch - 1) { 1297 memcpy(save_write_sequence, s->s3->write_sequence, 1298 sizeof(s->s3->write_sequence)); 1299 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1300 sizeof(s->s3->write_sequence)); 1301 } 1302 1303 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1304 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1305 1306 /* restore current state */ 1307 s->enc_write_ctx = saved_state.enc_write_ctx; 1308 s->write_hash = saved_state.write_hash; 1309 s->compress = saved_state.compress; 1310 s->session = saved_state.session; 1311 s->d1->w_epoch = saved_state.epoch; 1312 1313 if (frag->msg_header.saved_retransmit_state.epoch == 1314 saved_state.epoch - 1) { 1315 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1316 sizeof(s->s3->write_sequence)); 1317 memcpy(s->s3->write_sequence, save_write_sequence, 1318 sizeof(s->s3->write_sequence)); 1319 } 1320 1321 s->d1->retransmitting = 0; 1322 1323 (void)BIO_flush(SSL_get_wbio(s)); 1324 return ret; 1325} 1326 1327unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1328 unsigned char mt, unsigned long len, 1329 unsigned long frag_off, 1330 unsigned long frag_len) 1331{ 1332 /* Don't change sequence numbers while listening */ 1333 if (frag_off == 0 && !s->d1->listen) { 1334 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1335 s->d1->next_handshake_write_seq++; 1336 } 1337 1338 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1339 frag_off, frag_len); 1340 1341 return p += DTLS1_HM_HEADER_LENGTH; 1342} 1343 1344/* don't actually do the writing, wait till the MTU has been retrieved */ 1345static void 1346dtls1_set_message_header_int(SSL *s, unsigned char mt, 1347 unsigned long len, unsigned short seq_num, 1348 unsigned long frag_off, unsigned long frag_len) 1349{ 1350 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1351 1352 msg_hdr->type = mt; 1353 msg_hdr->msg_len = len; 1354 msg_hdr->seq = seq_num; 1355 msg_hdr->frag_off = frag_off; 1356 msg_hdr->frag_len = frag_len; 1357} 1358 1359static void 1360dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1361 unsigned long frag_len) 1362{ 1363 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1364 1365 msg_hdr->frag_off = frag_off; 1366 msg_hdr->frag_len = frag_len; 1367} 1368 1369static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1370{ 1371 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1372 1373 *p++ = msg_hdr->type; 1374 l2n3(msg_hdr->msg_len, p); 1375 1376 s2n(msg_hdr->seq, p); 1377 l2n3(msg_hdr->frag_off, p); 1378 l2n3(msg_hdr->frag_len, p); 1379 1380 return p; 1381} 1382 1383unsigned int dtls1_link_min_mtu(void) 1384{ 1385 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1386 sizeof(g_probable_mtu[0])) - 1]); 1387} 1388 1389unsigned int dtls1_min_mtu(SSL *s) 1390{ 1391 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1392} 1393 1394void 1395dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1396{ 1397 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1398 msg_hdr->type = *(data++); 1399 n2l3(data, msg_hdr->msg_len); 1400 1401 n2s(data, msg_hdr->seq); 1402 n2l3(data, msg_hdr->frag_off); 1403 n2l3(data, msg_hdr->frag_len); 1404} 1405 1406void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1407{ 1408 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1409 1410 ccs_hdr->type = *(data++); 1411} 1412 1413int dtls1_shutdown(SSL *s) 1414{ 1415 int ret; 1416#ifndef OPENSSL_NO_SCTP 1417 BIO *wbio; 1418 1419 wbio = SSL_get_wbio(s); 1420 if (wbio != NULL && BIO_dgram_is_sctp(wbio) && 1421 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1422 ret = BIO_dgram_sctp_wait_for_dry(wbio); 1423 if (ret < 0) 1424 return -1; 1425 1426 if (ret == 0) 1427 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1428 NULL); 1429 } 1430#endif 1431 ret = ssl3_shutdown(s); 1432#ifndef OPENSSL_NO_SCTP 1433 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1434#endif 1435 return ret; 1436} 1437 1438#ifndef OPENSSL_NO_HEARTBEATS 1439int dtls1_process_heartbeat(SSL *s) 1440{ 1441 unsigned char *p = &s->s3->rrec.data[0], *pl; 1442 unsigned short hbtype; 1443 unsigned int payload; 1444 unsigned int padding = 16; /* Use minimum padding */ 1445 1446 if (s->msg_callback) 1447 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1448 &s->s3->rrec.data[0], s->s3->rrec.length, 1449 s, s->msg_callback_arg); 1450 1451 /* Read type and payload length first */ 1452 if (1 + 2 + 16 > s->s3->rrec.length) 1453 return 0; /* silently discard */ 1454 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1455 return 0; /* silently discard per RFC 6520 sec. 4 */ 1456 1457 hbtype = *p++; 1458 n2s(p, payload); 1459 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1460 return 0; /* silently discard per RFC 6520 sec. 4 */ 1461 pl = p; 1462 1463 if (hbtype == TLS1_HB_REQUEST) { 1464 unsigned char *buffer, *bp; 1465 unsigned int write_length = 1 /* heartbeat type */ + 1466 2 /* heartbeat length */ + 1467 payload + padding; 1468 int r; 1469 1470 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1471 return 0; 1472 1473 /* 1474 * Allocate memory for the response, size is 1 byte message type, 1475 * plus 2 bytes payload length, plus payload, plus padding 1476 */ 1477 buffer = OPENSSL_malloc(write_length); 1478 if (buffer == NULL) 1479 return -1; 1480 bp = buffer; 1481 1482 /* Enter response type, length and copy payload */ 1483 *bp++ = TLS1_HB_RESPONSE; 1484 s2n(payload, bp); 1485 memcpy(bp, pl, payload); 1486 bp += payload; 1487 /* Random padding */ 1488 if (RAND_bytes(bp, padding) <= 0) { 1489 OPENSSL_free(buffer); 1490 return -1; 1491 } 1492 1493 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1494 1495 if (r >= 0 && s->msg_callback) 1496 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1497 buffer, write_length, s, s->msg_callback_arg); 1498 1499 OPENSSL_free(buffer); 1500 1501 if (r < 0) 1502 return r; 1503 } else if (hbtype == TLS1_HB_RESPONSE) { 1504 unsigned int seq; 1505 1506 /* 1507 * We only send sequence numbers (2 bytes unsigned int), and 16 1508 * random bytes, so we just try to read the sequence number 1509 */ 1510 n2s(pl, seq); 1511 1512 if (payload == 18 && seq == s->tlsext_hb_seq) { 1513 dtls1_stop_timer(s); 1514 s->tlsext_hb_seq++; 1515 s->tlsext_hb_pending = 0; 1516 } 1517 } 1518 1519 return 0; 1520} 1521 1522int dtls1_heartbeat(SSL *s) 1523{ 1524 unsigned char *buf, *p; 1525 int ret = -1; 1526 unsigned int payload = 18; /* Sequence number + random bytes */ 1527 unsigned int padding = 16; /* Use minimum padding */ 1528 1529 /* Only send if peer supports and accepts HB requests... */ 1530 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1531 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1532 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1533 return -1; 1534 } 1535 1536 /* ...and there is none in flight yet... */ 1537 if (s->tlsext_hb_pending) { 1538 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1539 return -1; 1540 } 1541 1542 /* ...and no handshake in progress. */ 1543 if (SSL_in_init(s) || s->in_handshake) { 1544 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1545 return -1; 1546 } 1547 1548 /* 1549 * Check if padding is too long, payload and padding must not exceed 2^14 1550 * - 3 = 16381 bytes in total. 1551 */ 1552 OPENSSL_assert(payload + padding <= 16381); 1553 1554 /*- 1555 * Create HeartBeat message, we just use a sequence number 1556 * as payload to distuingish different messages and add 1557 * some random stuff. 1558 * - Message Type, 1 byte 1559 * - Payload Length, 2 bytes (unsigned int) 1560 * - Payload, the sequence number (2 bytes uint) 1561 * - Payload, random bytes (16 bytes uint) 1562 * - Padding 1563 */ 1564 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1565 if (buf == NULL) 1566 goto err; 1567 p = buf; 1568 /* Message Type */ 1569 *p++ = TLS1_HB_REQUEST; 1570 /* Payload length (18 bytes here) */ 1571 s2n(payload, p); 1572 /* Sequence number */ 1573 s2n(s->tlsext_hb_seq, p); 1574 /* 16 random bytes */ 1575 if (RAND_bytes(p, 16) <= 0) 1576 goto err; 1577 p += 16; 1578 /* Random padding */ 1579 if (RAND_bytes(p, padding) <= 0) 1580 goto err; 1581 1582 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1583 if (ret >= 0) { 1584 if (s->msg_callback) 1585 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1586 buf, 3 + payload + padding, 1587 s, s->msg_callback_arg); 1588 1589 dtls1_start_timer(s); 1590 s->tlsext_hb_pending = 1; 1591 } 1592 1593err: 1594 OPENSSL_free(buf); 1595 1596 return ret; 1597} 1598#endif 1599