d1_both.c revision 306196
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 mac_size = EVP_MD_CTX_size(s->write_hash); 284 else 285 mac_size = 0; 286 287 if (s->enc_write_ctx && 288 (EVP_CIPHER_mode(s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 289 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 290 else 291 blocksize = 0; 292 293 frag_off = 0; 294 s->rwstate = SSL_NOTHING; 295 296 /* s->init_num shouldn't ever be < 0...but just in case */ 297 while (s->init_num > 0) { 298 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) { 299 /* We must be writing a fragment other than the first one */ 300 301 if (frag_off > 0) { 302 /* This is the first attempt at writing out this fragment */ 303 304 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) { 305 /* 306 * Each fragment that was already sent must at least have 307 * contained the message header plus one other byte. 308 * Therefore |init_off| must have progressed by at least 309 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went 310 * wrong. 311 */ 312 return -1; 313 } 314 315 /* 316 * Adjust |init_off| and |init_num| to allow room for a new 317 * message header for this fragment. 318 */ 319 s->init_off -= DTLS1_HM_HEADER_LENGTH; 320 s->init_num += DTLS1_HM_HEADER_LENGTH; 321 } else { 322 /* 323 * We must have been called again after a retry so use the 324 * fragment offset from our last attempt. We do not need 325 * to adjust |init_off| and |init_num| as above, because 326 * that should already have been done before the retry. 327 */ 328 frag_off = s->d1->w_msg_hdr.frag_off; 329 } 330 } 331 332 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH 333 + mac_size + blocksize; 334 if (s->d1->mtu > used_len) 335 curr_mtu = s->d1->mtu - used_len; 336 else 337 curr_mtu = 0; 338 339 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 340 /* 341 * grr.. we could get an error if MTU picked was wrong 342 */ 343 ret = BIO_flush(SSL_get_wbio(s)); 344 if (ret <= 0) { 345 s->rwstate = SSL_WRITING; 346 return ret; 347 } 348 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 349 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) { 350 curr_mtu = s->d1->mtu - used_len; 351 } else { 352 /* Shouldn't happen */ 353 return -1; 354 } 355 } 356 357 /* 358 * We just checked that s->init_num > 0 so this cast should be safe 359 */ 360 if (((unsigned int)s->init_num) > curr_mtu) 361 len = curr_mtu; 362 else 363 len = s->init_num; 364 365 /* Shouldn't ever happen */ 366 if (len > INT_MAX) 367 len = INT_MAX; 368 369 /* 370 * XDTLS: this function is too long. split out the CCS part 371 */ 372 if (type == SSL3_RT_HANDSHAKE) { 373 if (len < DTLS1_HM_HEADER_LENGTH) { 374 /* 375 * len is so small that we really can't do anything sensible 376 * so fail 377 */ 378 return -1; 379 } 380 dtls1_fix_message_header(s, frag_off, 381 len - DTLS1_HM_HEADER_LENGTH); 382 383 dtls1_write_message_header(s, 384 (unsigned char *)&s->init_buf-> 385 data[s->init_off]); 386 } 387 388 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], 389 len); 390 if (ret < 0) { 391 /* 392 * might need to update MTU here, but we don't know which 393 * previous packet caused the failure -- so can't really 394 * retransmit anything. continue as if everything is fine and 395 * wait for an alert to handle the retransmit 396 */ 397 if (retry && BIO_ctrl(SSL_get_wbio(s), 398 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) { 399 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 400 if (!dtls1_query_mtu(s)) 401 return -1; 402 /* Have one more go */ 403 retry = 0; 404 } else 405 return -1; 406 } else { 407 return (-1); 408 } 409 } else { 410 411 /* 412 * bad if this assert fails, only part of the handshake message 413 * got sent. but why would this happen? 414 */ 415 OPENSSL_assert(len == (unsigned int)ret); 416 417 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 418 /* 419 * should not be done for 'Hello Request's, but in that case 420 * we'll ignore the result anyway 421 */ 422 unsigned char *p = 423 (unsigned char *)&s->init_buf->data[s->init_off]; 424 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 425 int xlen; 426 427 if (frag_off == 0 && s->version != DTLS1_BAD_VER) { 428 /* 429 * reconstruct message header is if it is being sent in 430 * single fragment 431 */ 432 *p++ = msg_hdr->type; 433 l2n3(msg_hdr->msg_len, p); 434 s2n(msg_hdr->seq, p); 435 l2n3(0, p); 436 l2n3(msg_hdr->msg_len, p); 437 p -= DTLS1_HM_HEADER_LENGTH; 438 xlen = ret; 439 } else { 440 p += DTLS1_HM_HEADER_LENGTH; 441 xlen = ret - DTLS1_HM_HEADER_LENGTH; 442 } 443 444 ssl3_finish_mac(s, p, xlen); 445 } 446 447 if (ret == s->init_num) { 448 if (s->msg_callback) 449 s->msg_callback(1, s->version, type, s->init_buf->data, 450 (size_t)(s->init_off + s->init_num), s, 451 s->msg_callback_arg); 452 453 s->init_off = 0; /* done writing this message */ 454 s->init_num = 0; 455 456 return (1); 457 } 458 s->init_off += ret; 459 s->init_num -= ret; 460 ret -= DTLS1_HM_HEADER_LENGTH; 461 frag_off += ret; 462 463 /* 464 * We save the fragment offset for the next fragment so we have it 465 * available in case of an IO retry. We don't know the length of the 466 * next fragment yet so just set that to 0 for now. It will be 467 * updated again later. 468 */ 469 dtls1_fix_message_header(s, frag_off, 0); 470 } 471 } 472 return (0); 473} 474 475/* 476 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum 477 * acceptable body length 'max'. Read an entire handshake message. Handshake 478 * messages arrive in fragments. 479 */ 480long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 481{ 482 int i, al; 483 struct hm_header_st *msg_hdr; 484 unsigned char *p; 485 unsigned long msg_len; 486 487 /* 488 * s3->tmp is used to store messages that are unexpected, caused by the 489 * absence of an optional handshake message 490 */ 491 if (s->s3->tmp.reuse_message) { 492 s->s3->tmp.reuse_message = 0; 493 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 494 al = SSL_AD_UNEXPECTED_MESSAGE; 495 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 496 goto f_err; 497 } 498 *ok = 1; 499 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 500 s->init_num = (int)s->s3->tmp.message_size; 501 return s->init_num; 502 } 503 504 msg_hdr = &s->d1->r_msg_hdr; 505 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 506 507 again: 508 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 509 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) { 510 /* bad fragment received */ 511 goto again; 512 } else if (i <= 0 && !*ok) { 513 return i; 514 } 515 516 if (mt >= 0 && s->s3->tmp.message_type != mt) { 517 al = SSL_AD_UNEXPECTED_MESSAGE; 518 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 519 goto f_err; 520 } 521 522 p = (unsigned char *)s->init_buf->data; 523 msg_len = msg_hdr->msg_len; 524 525 /* reconstruct message header */ 526 *(p++) = msg_hdr->type; 527 l2n3(msg_len, p); 528 s2n(msg_hdr->seq, p); 529 l2n3(0, p); 530 l2n3(msg_len, p); 531 if (s->version != DTLS1_BAD_VER) { 532 p -= DTLS1_HM_HEADER_LENGTH; 533 msg_len += DTLS1_HM_HEADER_LENGTH; 534 } 535 536 ssl3_finish_mac(s, p, msg_len); 537 if (s->msg_callback) 538 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 539 p, msg_len, s, s->msg_callback_arg); 540 541 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 542 543 /* Don't change sequence numbers while listening */ 544 if (!s->d1->listen) 545 s->d1->handshake_read_seq++; 546 547 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 548 return s->init_num; 549 550 f_err: 551 ssl3_send_alert(s, SSL3_AL_FATAL, al); 552 *ok = 0; 553 return -1; 554} 555 556static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 557 int max) 558{ 559 size_t frag_off, frag_len, msg_len; 560 561 msg_len = msg_hdr->msg_len; 562 frag_off = msg_hdr->frag_off; 563 frag_len = msg_hdr->frag_len; 564 565 /* sanity checking */ 566 if ((frag_off + frag_len) > msg_len) { 567 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 568 return SSL_AD_ILLEGAL_PARAMETER; 569 } 570 571 if ((frag_off + frag_len) > (unsigned long)max) { 572 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 573 return SSL_AD_ILLEGAL_PARAMETER; 574 } 575 576 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 577 /* 578 * msg_len is limited to 2^24, but is effectively checked against max 579 * above 580 * 581 * Make buffer slightly larger than message length as a precaution 582 * against small OOB reads e.g. CVE-2016-6306 583 */ 584 if (!BUF_MEM_grow_clean 585 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH + 16)) { 586 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 587 return SSL_AD_INTERNAL_ERROR; 588 } 589 590 s->s3->tmp.message_size = msg_len; 591 s->d1->r_msg_hdr.msg_len = msg_len; 592 s->s3->tmp.message_type = msg_hdr->type; 593 s->d1->r_msg_hdr.type = msg_hdr->type; 594 s->d1->r_msg_hdr.seq = msg_hdr->seq; 595 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 596 /* 597 * They must be playing with us! BTW, failure to enforce upper limit 598 * would open possibility for buffer overrun. 599 */ 600 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 601 return SSL_AD_ILLEGAL_PARAMETER; 602 } 603 604 return 0; /* no error */ 605} 606 607static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 608{ 609 /*- 610 * (0) check whether the desired fragment is available 611 * if so: 612 * (1) copy over the fragment to s->init_buf->data[] 613 * (2) update s->init_num 614 */ 615 pitem *item; 616 hm_fragment *frag; 617 int al; 618 619 *ok = 0; 620 do { 621 item = pqueue_peek(s->d1->buffered_messages); 622 if (item == NULL) 623 return 0; 624 625 frag = (hm_fragment *)item->data; 626 627 if (frag->msg_header.seq < s->d1->handshake_read_seq) { 628 /* This is a stale message that has been buffered so clear it */ 629 pqueue_pop(s->d1->buffered_messages); 630 dtls1_hm_fragment_free(frag); 631 pitem_free(item); 632 item = NULL; 633 frag = NULL; 634 } 635 } while (item == NULL); 636 637 638 /* Don't return if reassembly still in progress */ 639 if (frag->reassembly != NULL) 640 return 0; 641 642 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 643 unsigned long frag_len = frag->msg_header.frag_len; 644 pqueue_pop(s->d1->buffered_messages); 645 646 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 647 648 if (al == 0) { /* no alert */ 649 unsigned char *p = 650 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 651 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 652 frag->msg_header.frag_len); 653 } 654 655 dtls1_hm_fragment_free(frag); 656 pitem_free(item); 657 658 if (al == 0) { 659 *ok = 1; 660 return frag_len; 661 } 662 663 ssl3_send_alert(s, SSL3_AL_FATAL, al); 664 s->init_num = 0; 665 *ok = 0; 666 return -1; 667 } else 668 return 0; 669} 670 671/* 672 * dtls1_max_handshake_message_len returns the maximum number of bytes 673 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 674 * may be greater if the maximum certificate list size requires it. 675 */ 676static unsigned long dtls1_max_handshake_message_len(const SSL *s) 677{ 678 unsigned long max_len = 679 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 680 if (max_len < (unsigned long)s->max_cert_list) 681 return s->max_cert_list; 682 return max_len; 683} 684 685static int 686dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 687{ 688 hm_fragment *frag = NULL; 689 pitem *item = NULL; 690 int i = -1, is_complete; 691 unsigned char seq64be[8]; 692 unsigned long frag_len = msg_hdr->frag_len; 693 694 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 695 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 696 goto err; 697 698 if (frag_len == 0) 699 return DTLS1_HM_FRAGMENT_RETRY; 700 701 /* Try to find item in queue */ 702 memset(seq64be, 0, sizeof(seq64be)); 703 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 704 seq64be[7] = (unsigned char)msg_hdr->seq; 705 item = pqueue_find(s->d1->buffered_messages, seq64be); 706 707 if (item == NULL) { 708 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 709 if (frag == NULL) 710 goto err; 711 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 712 frag->msg_header.frag_len = frag->msg_header.msg_len; 713 frag->msg_header.frag_off = 0; 714 } else { 715 frag = (hm_fragment *)item->data; 716 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 717 item = NULL; 718 frag = NULL; 719 goto err; 720 } 721 } 722 723 /* 724 * If message is already reassembled, this must be a retransmit and can 725 * be dropped. In this case item != NULL and so frag does not need to be 726 * freed. 727 */ 728 if (frag->reassembly == NULL) { 729 unsigned char devnull[256]; 730 731 while (frag_len) { 732 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 733 devnull, 734 frag_len > 735 sizeof(devnull) ? sizeof(devnull) : 736 frag_len, 0); 737 if (i <= 0) 738 goto err; 739 frag_len -= i; 740 } 741 return DTLS1_HM_FRAGMENT_RETRY; 742 } 743 744 /* read the body of the fragment (header has already been read */ 745 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 746 frag->fragment + msg_hdr->frag_off, 747 frag_len, 0); 748 if ((unsigned long)i != frag_len) 749 i = -1; 750 if (i <= 0) 751 goto err; 752 753 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 754 (long)(msg_hdr->frag_off + frag_len)); 755 756 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 757 is_complete); 758 759 if (is_complete) { 760 OPENSSL_free(frag->reassembly); 761 frag->reassembly = NULL; 762 } 763 764 if (item == NULL) { 765 item = pitem_new(seq64be, frag); 766 if (item == NULL) { 767 i = -1; 768 goto err; 769 } 770 771 item = pqueue_insert(s->d1->buffered_messages, item); 772 /* 773 * pqueue_insert fails iff a duplicate item is inserted. However, 774 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 775 * would have returned it and control would never have reached this 776 * branch. 777 */ 778 OPENSSL_assert(item != NULL); 779 } 780 781 return DTLS1_HM_FRAGMENT_RETRY; 782 783 err: 784 if (frag != NULL && item == NULL) 785 dtls1_hm_fragment_free(frag); 786 *ok = 0; 787 return i; 788} 789 790static int 791dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 792 int *ok) 793{ 794 int i = -1; 795 hm_fragment *frag = NULL; 796 pitem *item = NULL; 797 unsigned char seq64be[8]; 798 unsigned long frag_len = msg_hdr->frag_len; 799 800 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 801 goto err; 802 803 /* Try to find item in queue, to prevent duplicate entries */ 804 memset(seq64be, 0, sizeof(seq64be)); 805 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 806 seq64be[7] = (unsigned char)msg_hdr->seq; 807 item = pqueue_find(s->d1->buffered_messages, seq64be); 808 809 /* 810 * If we already have an entry and this one is a fragment, don't discard 811 * it and rather try to reassemble it. 812 */ 813 if (item != NULL && frag_len != msg_hdr->msg_len) 814 item = NULL; 815 816 /* 817 * Discard the message if sequence number was already there, is too far 818 * in the future, already in the queue or if we received a FINISHED 819 * before the SERVER_HELLO, which then must be a stale retransmit. 820 */ 821 if (msg_hdr->seq <= s->d1->handshake_read_seq || 822 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 823 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 824 { 825 unsigned char devnull[256]; 826 827 while (frag_len) { 828 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 829 devnull, 830 frag_len > 831 sizeof(devnull) ? sizeof(devnull) : 832 frag_len, 0); 833 if (i <= 0) 834 goto err; 835 frag_len -= i; 836 } 837 } else { 838 if (frag_len != msg_hdr->msg_len) 839 return dtls1_reassemble_fragment(s, msg_hdr, ok); 840 841 if (frag_len > dtls1_max_handshake_message_len(s)) 842 goto err; 843 844 frag = dtls1_hm_fragment_new(frag_len, 0); 845 if (frag == NULL) 846 goto err; 847 848 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 849 850 if (frag_len) { 851 /* 852 * read the body of the fragment (header has already been read 853 */ 854 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 855 frag->fragment, frag_len, 0); 856 if ((unsigned long)i != frag_len) 857 i = -1; 858 if (i <= 0) 859 goto err; 860 } 861 862 item = pitem_new(seq64be, frag); 863 if (item == NULL) 864 goto err; 865 866 item = pqueue_insert(s->d1->buffered_messages, item); 867 /* 868 * pqueue_insert fails iff a duplicate item is inserted. However, 869 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 870 * would have returned it. Then, either |frag_len| != 871 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 872 * have been processed with |dtls1_reassemble_fragment|, above, or 873 * the record will have been discarded. 874 */ 875 OPENSSL_assert(item != NULL); 876 } 877 878 return DTLS1_HM_FRAGMENT_RETRY; 879 880 err: 881 if (frag != NULL && item == NULL) 882 dtls1_hm_fragment_free(frag); 883 *ok = 0; 884 return i; 885} 886 887static long 888dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 889{ 890 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 891 unsigned long len, frag_off, frag_len; 892 int i, al; 893 struct hm_header_st msg_hdr; 894 895 redo: 896 /* see if we have the required fragment already */ 897 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 898 if (*ok) 899 s->init_num = frag_len; 900 return frag_len; 901 } 902 903 /* read handshake message header */ 904 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 905 DTLS1_HM_HEADER_LENGTH, 0); 906 if (i <= 0) { /* nbio, or an error */ 907 s->rwstate = SSL_READING; 908 *ok = 0; 909 return i; 910 } 911 /* Handshake fails if message header is incomplete */ 912 if (i != DTLS1_HM_HEADER_LENGTH) { 913 al = SSL_AD_UNEXPECTED_MESSAGE; 914 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 915 goto f_err; 916 } 917 918 /* parse the message fragment header */ 919 dtls1_get_message_header(wire, &msg_hdr); 920 921 len = msg_hdr.msg_len; 922 frag_off = msg_hdr.frag_off; 923 frag_len = msg_hdr.frag_len; 924 925 /* 926 * We must have at least frag_len bytes left in the record to be read. 927 * Fragments must not span records. 928 */ 929 if (frag_len > s->s3->rrec.length) { 930 al = SSL3_AD_ILLEGAL_PARAMETER; 931 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 932 goto f_err; 933 } 934 935 /* 936 * if this is a future (or stale) message it gets buffered 937 * (or dropped)--no further processing at this time 938 * While listening, we accept seq 1 (ClientHello with cookie) 939 * although we're still expecting seq 0 (ClientHello) 940 */ 941 if (msg_hdr.seq != s->d1->handshake_read_seq 942 && !(s->d1->listen && msg_hdr.seq == 1)) 943 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 944 945 if (frag_len && frag_len < len) 946 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 947 948 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 949 wire[0] == SSL3_MT_HELLO_REQUEST) { 950 /* 951 * The server may always send 'Hello Request' messages -- we are 952 * doing a handshake anyway now, so ignore them if their format is 953 * correct. Does not count for 'Finished' MAC. 954 */ 955 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 956 if (s->msg_callback) 957 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 958 wire, DTLS1_HM_HEADER_LENGTH, s, 959 s->msg_callback_arg); 960 961 s->init_num = 0; 962 goto redo; 963 } else { /* Incorrectly formated Hello request */ 964 965 al = SSL_AD_UNEXPECTED_MESSAGE; 966 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 967 SSL_R_UNEXPECTED_MESSAGE); 968 goto f_err; 969 } 970 } 971 972 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 973 goto f_err; 974 975 if (frag_len > 0) { 976 unsigned char *p = 977 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 978 979 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 980 &p[frag_off], frag_len, 0); 981 982 /* 983 * This shouldn't ever fail due to NBIO because we already checked 984 * that we have enough data in the record 985 */ 986 if (i <= 0) { 987 s->rwstate = SSL_READING; 988 *ok = 0; 989 return i; 990 } 991 } else 992 i = 0; 993 994 /* 995 * XDTLS: an incorrectly formatted fragment should cause the handshake 996 * to fail 997 */ 998 if (i != (int)frag_len) { 999 al = SSL3_AD_ILLEGAL_PARAMETER; 1000 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 1001 goto f_err; 1002 } 1003 1004 *ok = 1; 1005 s->state = stn; 1006 1007 /* 1008 * Note that s->init_num is *not* used as current offset in 1009 * s->init_buf->data, but as a counter summing up fragments' lengths: as 1010 * soon as they sum up to handshake packet length, we assume we have got 1011 * all the fragments. 1012 */ 1013 s->init_num = frag_len; 1014 return frag_len; 1015 1016 f_err: 1017 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1018 s->init_num = 0; 1019 1020 *ok = 0; 1021 return (-1); 1022} 1023 1024int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 1025{ 1026 unsigned char *p, *d; 1027 int i; 1028 unsigned long l; 1029 1030 if (s->state == a) { 1031 d = (unsigned char *)s->init_buf->data; 1032 p = &(d[DTLS1_HM_HEADER_LENGTH]); 1033 1034 i = s->method->ssl3_enc->final_finish_mac(s, 1035 sender, slen, 1036 s->s3->tmp.finish_md); 1037 s->s3->tmp.finish_md_len = i; 1038 memcpy(p, s->s3->tmp.finish_md, i); 1039 p += i; 1040 l = i; 1041 1042 /* 1043 * Copy the finished so we can use it for renegotiation checks 1044 */ 1045 if (s->type == SSL_ST_CONNECT) { 1046 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1047 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i); 1048 s->s3->previous_client_finished_len = i; 1049 } else { 1050 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1051 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i); 1052 s->s3->previous_server_finished_len = i; 1053 } 1054 1055#ifdef OPENSSL_SYS_WIN16 1056 /* 1057 * MSVC 1.5 does not clear the top bytes of the word unless I do 1058 * this. 1059 */ 1060 l &= 0xffff; 1061#endif 1062 1063 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 1064 s->init_num = (int)l + DTLS1_HM_HEADER_LENGTH; 1065 s->init_off = 0; 1066 1067 /* buffer the message to handle re-xmits */ 1068 dtls1_buffer_message(s, 0); 1069 1070 s->state = b; 1071 } 1072 1073 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 1074 return (dtls1_do_write(s, SSL3_RT_HANDSHAKE)); 1075} 1076 1077/*- 1078 * for these 2 messages, we need to 1079 * ssl->enc_read_ctx re-init 1080 * ssl->s3->read_sequence zero 1081 * ssl->s3->read_mac_secret re-init 1082 * ssl->session->read_sym_enc assign 1083 * ssl->session->read_compression assign 1084 * ssl->session->read_hash assign 1085 */ 1086int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1087{ 1088 unsigned char *p; 1089 1090 if (s->state == a) { 1091 p = (unsigned char *)s->init_buf->data; 1092 *p++ = SSL3_MT_CCS; 1093 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1094 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1095 1096 if (s->version == DTLS1_BAD_VER) { 1097 s->d1->next_handshake_write_seq++; 1098 s2n(s->d1->handshake_write_seq, p); 1099 s->init_num += 2; 1100 } 1101 1102 s->init_off = 0; 1103 1104 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1105 s->d1->handshake_write_seq, 0, 0); 1106 1107 /* buffer the message to handle re-xmits */ 1108 dtls1_buffer_message(s, 1); 1109 1110 s->state = b; 1111 } 1112 1113 /* SSL3_ST_CW_CHANGE_B */ 1114 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1115} 1116 1117static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1118{ 1119 int n; 1120 unsigned char *p; 1121 1122 n = i2d_X509(x, NULL); 1123 if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) { 1124 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB); 1125 return 0; 1126 } 1127 p = (unsigned char *)&(buf->data[*l]); 1128 l2n3(n, p); 1129 i2d_X509(x, &p); 1130 *l += n + 3; 1131 1132 return 1; 1133} 1134 1135unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1136{ 1137 unsigned char *p; 1138 int i; 1139 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH; 1140 BUF_MEM *buf; 1141 1142 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1143 buf = s->init_buf; 1144 if (!BUF_MEM_grow_clean(buf, 10)) { 1145 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB); 1146 return (0); 1147 } 1148 if (x != NULL) { 1149 X509_STORE_CTX xs_ctx; 1150 1151 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, x, NULL)) { 1152 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB); 1153 return (0); 1154 } 1155 1156 X509_verify_cert(&xs_ctx); 1157 /* Don't leave errors in the queue */ 1158 ERR_clear_error(); 1159 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) { 1160 x = sk_X509_value(xs_ctx.chain, i); 1161 1162 if (!dtls1_add_cert_to_buf(buf, &l, x)) { 1163 X509_STORE_CTX_cleanup(&xs_ctx); 1164 return 0; 1165 } 1166 } 1167 X509_STORE_CTX_cleanup(&xs_ctx); 1168 } 1169 /* Thawte special :-) */ 1170 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) { 1171 x = sk_X509_value(s->ctx->extra_certs, i); 1172 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1173 return 0; 1174 } 1175 1176 l -= (3 + DTLS1_HM_HEADER_LENGTH); 1177 1178 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1179 l2n3(l, p); 1180 l += 3; 1181 p = (unsigned char *)&(buf->data[0]); 1182 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1183 1184 l += DTLS1_HM_HEADER_LENGTH; 1185 return (l); 1186} 1187 1188int dtls1_read_failed(SSL *s, int code) 1189{ 1190 if (code > 0) { 1191 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1192 return 1; 1193 } 1194 1195 if (!dtls1_is_timer_expired(s)) { 1196 /* 1197 * not a timeout, none of our business, let higher layers handle 1198 * this. in fact it's probably an error 1199 */ 1200 return code; 1201 } 1202#ifndef OPENSSL_NO_HEARTBEATS 1203 /* done, no need to send a retransmit */ 1204 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1205#else 1206 /* done, no need to send a retransmit */ 1207 if (!SSL_in_init(s)) 1208#endif 1209 { 1210 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1211 return code; 1212 } 1213#if 0 /* for now, each alert contains only one 1214 * record number */ 1215 item = pqueue_peek(state->rcvd_records); 1216 if (item) { 1217 /* send an alert immediately for all the missing records */ 1218 } else 1219#endif 1220 1221#if 0 /* no more alert sending, just retransmit the 1222 * last set of messages */ 1223 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1224 ssl3_send_alert(s, SSL3_AL_WARNING, 1225 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1226#endif 1227 1228 return dtls1_handle_timeout(s); 1229} 1230 1231int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1232{ 1233 /* 1234 * The index of the retransmission queue actually is the message sequence 1235 * number, since the queue only contains messages of a single handshake. 1236 * However, the ChangeCipherSpec has no message sequence number and so 1237 * using only the sequence will result in the CCS and Finished having the 1238 * same index. To prevent this, the sequence number is multiplied by 2. 1239 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1240 * Finished, it also maintains the order of the index (important for 1241 * priority queues) and fits in the unsigned short variable. 1242 */ 1243 return seq * 2 - is_ccs; 1244} 1245 1246int dtls1_retransmit_buffered_messages(SSL *s) 1247{ 1248 pqueue sent = s->d1->sent_messages; 1249 piterator iter; 1250 pitem *item; 1251 hm_fragment *frag; 1252 int found = 0; 1253 1254 iter = pqueue_iterator(sent); 1255 1256 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1257 frag = (hm_fragment *)item->data; 1258 if (dtls1_retransmit_message(s, (unsigned short) 1259 dtls1_get_queue_priority 1260 (frag->msg_header.seq, 1261 frag->msg_header.is_ccs), 0, 1262 &found) <= 0 && found) { 1263 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1264 return -1; 1265 } 1266 } 1267 1268 return 1; 1269} 1270 1271int dtls1_buffer_message(SSL *s, int is_ccs) 1272{ 1273 pitem *item; 1274 hm_fragment *frag; 1275 unsigned char seq64be[8]; 1276 1277 /* 1278 * this function is called immediately after a message has been 1279 * serialized 1280 */ 1281 OPENSSL_assert(s->init_off == 0); 1282 1283 frag = dtls1_hm_fragment_new(s->init_num, 0); 1284 if (!frag) 1285 return 0; 1286 1287 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1288 1289 if (is_ccs) { 1290 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1291 ((s->version == 1292 DTLS1_VERSION) ? DTLS1_CCS_HEADER_LENGTH : 3) == 1293 (unsigned int)s->init_num); 1294 } else { 1295 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1296 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1297 } 1298 1299 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1300 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1301 frag->msg_header.type = s->d1->w_msg_hdr.type; 1302 frag->msg_header.frag_off = 0; 1303 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1304 frag->msg_header.is_ccs = is_ccs; 1305 1306 /* save current state */ 1307 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1308 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1309 frag->msg_header.saved_retransmit_state.compress = s->compress; 1310 frag->msg_header.saved_retransmit_state.session = s->session; 1311 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1312 1313 memset(seq64be, 0, sizeof(seq64be)); 1314 seq64be[6] = 1315 (unsigned 1316 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1317 frag->msg_header.is_ccs) >> 8); 1318 seq64be[7] = 1319 (unsigned 1320 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1321 frag->msg_header.is_ccs)); 1322 1323 item = pitem_new(seq64be, frag); 1324 if (item == NULL) { 1325 dtls1_hm_fragment_free(frag); 1326 return 0; 1327 } 1328#if 0 1329 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1330 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1331 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1332#endif 1333 1334 pqueue_insert(s->d1->sent_messages, item); 1335 return 1; 1336} 1337 1338int 1339dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1340 int *found) 1341{ 1342 int ret; 1343 /* XDTLS: for now assuming that read/writes are blocking */ 1344 pitem *item; 1345 hm_fragment *frag; 1346 unsigned long header_length; 1347 unsigned char seq64be[8]; 1348 struct dtls1_retransmit_state saved_state; 1349 unsigned char save_write_sequence[8]; 1350 1351 /*- 1352 OPENSSL_assert(s->init_num == 0); 1353 OPENSSL_assert(s->init_off == 0); 1354 */ 1355 1356 /* XDTLS: the requested message ought to be found, otherwise error */ 1357 memset(seq64be, 0, sizeof(seq64be)); 1358 seq64be[6] = (unsigned char)(seq >> 8); 1359 seq64be[7] = (unsigned char)seq; 1360 1361 item = pqueue_find(s->d1->sent_messages, seq64be); 1362 if (item == NULL) { 1363 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1364 *found = 0; 1365 return 0; 1366 } 1367 1368 *found = 1; 1369 frag = (hm_fragment *)item->data; 1370 1371 if (frag->msg_header.is_ccs) 1372 header_length = DTLS1_CCS_HEADER_LENGTH; 1373 else 1374 header_length = DTLS1_HM_HEADER_LENGTH; 1375 1376 memcpy(s->init_buf->data, frag->fragment, 1377 frag->msg_header.msg_len + header_length); 1378 s->init_num = frag->msg_header.msg_len + header_length; 1379 1380 dtls1_set_message_header_int(s, frag->msg_header.type, 1381 frag->msg_header.msg_len, 1382 frag->msg_header.seq, 0, 1383 frag->msg_header.frag_len); 1384 1385 /* save current state */ 1386 saved_state.enc_write_ctx = s->enc_write_ctx; 1387 saved_state.write_hash = s->write_hash; 1388 saved_state.compress = s->compress; 1389 saved_state.session = s->session; 1390 saved_state.epoch = s->d1->w_epoch; 1391 saved_state.epoch = s->d1->w_epoch; 1392 1393 s->d1->retransmitting = 1; 1394 1395 /* restore state in which the message was originally sent */ 1396 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1397 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1398 s->compress = frag->msg_header.saved_retransmit_state.compress; 1399 s->session = frag->msg_header.saved_retransmit_state.session; 1400 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1401 1402 if (frag->msg_header.saved_retransmit_state.epoch == 1403 saved_state.epoch - 1) { 1404 memcpy(save_write_sequence, s->s3->write_sequence, 1405 sizeof(s->s3->write_sequence)); 1406 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1407 sizeof(s->s3->write_sequence)); 1408 } 1409 1410 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1411 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1412 1413 /* restore current state */ 1414 s->enc_write_ctx = saved_state.enc_write_ctx; 1415 s->write_hash = saved_state.write_hash; 1416 s->compress = saved_state.compress; 1417 s->session = saved_state.session; 1418 s->d1->w_epoch = saved_state.epoch; 1419 1420 if (frag->msg_header.saved_retransmit_state.epoch == 1421 saved_state.epoch - 1) { 1422 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1423 sizeof(s->s3->write_sequence)); 1424 memcpy(s->s3->write_sequence, save_write_sequence, 1425 sizeof(s->s3->write_sequence)); 1426 } 1427 1428 s->d1->retransmitting = 0; 1429 1430 (void)BIO_flush(SSL_get_wbio(s)); 1431 return ret; 1432} 1433 1434unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1435 unsigned char mt, unsigned long len, 1436 unsigned long frag_off, 1437 unsigned long frag_len) 1438{ 1439 /* Don't change sequence numbers while listening */ 1440 if (frag_off == 0 && !s->d1->listen) { 1441 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1442 s->d1->next_handshake_write_seq++; 1443 } 1444 1445 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1446 frag_off, frag_len); 1447 1448 return p += DTLS1_HM_HEADER_LENGTH; 1449} 1450 1451/* don't actually do the writing, wait till the MTU has been retrieved */ 1452static void 1453dtls1_set_message_header_int(SSL *s, unsigned char mt, 1454 unsigned long len, unsigned short seq_num, 1455 unsigned long frag_off, unsigned long frag_len) 1456{ 1457 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1458 1459 msg_hdr->type = mt; 1460 msg_hdr->msg_len = len; 1461 msg_hdr->seq = seq_num; 1462 msg_hdr->frag_off = frag_off; 1463 msg_hdr->frag_len = frag_len; 1464} 1465 1466static void 1467dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1468 unsigned long frag_len) 1469{ 1470 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1471 1472 msg_hdr->frag_off = frag_off; 1473 msg_hdr->frag_len = frag_len; 1474} 1475 1476static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1477{ 1478 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1479 1480 *p++ = msg_hdr->type; 1481 l2n3(msg_hdr->msg_len, p); 1482 1483 s2n(msg_hdr->seq, p); 1484 l2n3(msg_hdr->frag_off, p); 1485 l2n3(msg_hdr->frag_len, p); 1486 1487 return p; 1488} 1489 1490unsigned int dtls1_link_min_mtu(void) 1491{ 1492 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1493 sizeof(g_probable_mtu[0])) - 1]); 1494} 1495 1496unsigned int dtls1_min_mtu(SSL *s) 1497{ 1498 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1499} 1500 1501void 1502dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1503{ 1504 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1505 msg_hdr->type = *(data++); 1506 n2l3(data, msg_hdr->msg_len); 1507 1508 n2s(data, msg_hdr->seq); 1509 n2l3(data, msg_hdr->frag_off); 1510 n2l3(data, msg_hdr->frag_len); 1511} 1512 1513void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1514{ 1515 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1516 1517 ccs_hdr->type = *(data++); 1518} 1519 1520int dtls1_shutdown(SSL *s) 1521{ 1522 int ret; 1523#ifndef OPENSSL_NO_SCTP 1524 BIO *wbio; 1525 1526 wbio = SSL_get_wbio(s); 1527 if (wbio != NULL && BIO_dgram_is_sctp(wbio) && 1528 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1529 ret = BIO_dgram_sctp_wait_for_dry(wbio); 1530 if (ret < 0) 1531 return -1; 1532 1533 if (ret == 0) 1534 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1535 NULL); 1536 } 1537#endif 1538 ret = ssl3_shutdown(s); 1539#ifndef OPENSSL_NO_SCTP 1540 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1541#endif 1542 return ret; 1543} 1544 1545#ifndef OPENSSL_NO_HEARTBEATS 1546int dtls1_process_heartbeat(SSL *s) 1547{ 1548 unsigned char *p = &s->s3->rrec.data[0], *pl; 1549 unsigned short hbtype; 1550 unsigned int payload; 1551 unsigned int padding = 16; /* Use minimum padding */ 1552 1553 if (s->msg_callback) 1554 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1555 &s->s3->rrec.data[0], s->s3->rrec.length, 1556 s, s->msg_callback_arg); 1557 1558 /* Read type and payload length first */ 1559 if (1 + 2 + 16 > s->s3->rrec.length) 1560 return 0; /* silently discard */ 1561 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1562 return 0; /* silently discard per RFC 6520 sec. 4 */ 1563 1564 hbtype = *p++; 1565 n2s(p, payload); 1566 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1567 return 0; /* silently discard per RFC 6520 sec. 4 */ 1568 pl = p; 1569 1570 if (hbtype == TLS1_HB_REQUEST) { 1571 unsigned char *buffer, *bp; 1572 unsigned int write_length = 1 /* heartbeat type */ + 1573 2 /* heartbeat length */ + 1574 payload + padding; 1575 int r; 1576 1577 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1578 return 0; 1579 1580 /* 1581 * Allocate memory for the response, size is 1 byte message type, 1582 * plus 2 bytes payload length, plus payload, plus padding 1583 */ 1584 buffer = OPENSSL_malloc(write_length); 1585 if (buffer == NULL) 1586 return -1; 1587 bp = buffer; 1588 1589 /* Enter response type, length and copy payload */ 1590 *bp++ = TLS1_HB_RESPONSE; 1591 s2n(payload, bp); 1592 memcpy(bp, pl, payload); 1593 bp += payload; 1594 /* Random padding */ 1595 if (RAND_bytes(bp, padding) <= 0) { 1596 OPENSSL_free(buffer); 1597 return -1; 1598 } 1599 1600 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1601 1602 if (r >= 0 && s->msg_callback) 1603 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1604 buffer, write_length, s, s->msg_callback_arg); 1605 1606 OPENSSL_free(buffer); 1607 1608 if (r < 0) 1609 return r; 1610 } else if (hbtype == TLS1_HB_RESPONSE) { 1611 unsigned int seq; 1612 1613 /* 1614 * We only send sequence numbers (2 bytes unsigned int), and 16 1615 * random bytes, so we just try to read the sequence number 1616 */ 1617 n2s(pl, seq); 1618 1619 if (payload == 18 && seq == s->tlsext_hb_seq) { 1620 dtls1_stop_timer(s); 1621 s->tlsext_hb_seq++; 1622 s->tlsext_hb_pending = 0; 1623 } 1624 } 1625 1626 return 0; 1627} 1628 1629int dtls1_heartbeat(SSL *s) 1630{ 1631 unsigned char *buf, *p; 1632 int ret = -1; 1633 unsigned int payload = 18; /* Sequence number + random bytes */ 1634 unsigned int padding = 16; /* Use minimum padding */ 1635 1636 /* Only send if peer supports and accepts HB requests... */ 1637 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1638 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1639 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1640 return -1; 1641 } 1642 1643 /* ...and there is none in flight yet... */ 1644 if (s->tlsext_hb_pending) { 1645 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1646 return -1; 1647 } 1648 1649 /* ...and no handshake in progress. */ 1650 if (SSL_in_init(s) || s->in_handshake) { 1651 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1652 return -1; 1653 } 1654 1655 /* 1656 * Check if padding is too long, payload and padding must not exceed 2^14 1657 * - 3 = 16381 bytes in total. 1658 */ 1659 OPENSSL_assert(payload + padding <= 16381); 1660 1661 /*- 1662 * Create HeartBeat message, we just use a sequence number 1663 * as payload to distuingish different messages and add 1664 * some random stuff. 1665 * - Message Type, 1 byte 1666 * - Payload Length, 2 bytes (unsigned int) 1667 * - Payload, the sequence number (2 bytes uint) 1668 * - Payload, random bytes (16 bytes uint) 1669 * - Padding 1670 */ 1671 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1672 p = buf; 1673 /* Message Type */ 1674 *p++ = TLS1_HB_REQUEST; 1675 /* Payload length (18 bytes here) */ 1676 s2n(payload, p); 1677 /* Sequence number */ 1678 s2n(s->tlsext_hb_seq, p); 1679 /* 16 random bytes */ 1680 if (RAND_bytes(p, 16) <= 0) 1681 goto err; 1682 p += 16; 1683 /* Random padding */ 1684 if (RAND_bytes(p, padding) <= 0) 1685 goto err; 1686 1687 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1688 if (ret >= 0) { 1689 if (s->msg_callback) 1690 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1691 buf, 3 + payload + padding, 1692 s, s->msg_callback_arg); 1693 1694 dtls1_start_timer(s); 1695 s->tlsext_hb_pending = 1; 1696 } 1697 1698err: 1699 OPENSSL_free(buf); 1700 1701 return ret; 1702} 1703#endif 1704