d1_both.c revision 302408
1/* ssl/d1_both.c */ 2/* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core@openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116#include <limits.h> 117#include <string.h> 118#include <stdio.h> 119#include "ssl_locl.h" 120#include <openssl/buffer.h> 121#include <openssl/rand.h> 122#include <openssl/objects.h> 123#include <openssl/evp.h> 124#include <openssl/x509.h> 125 126#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 127 128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 129 if ((end) - (start) <= 8) { \ 130 long ii; \ 131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 132 } else { \ 133 long ii; \ 134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 137 } } 138 139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 140 long ii; \ 141 OPENSSL_assert((msg_len) > 0); \ 142 is_complete = 1; \ 143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 146 147#if 0 148# define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \ 149 long ii; \ 150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \ 151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \ 152 printf("\n"); } 153#endif 154 155static unsigned char bitmask_start_values[] = 156 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 }; 157static unsigned char bitmask_end_values[] = 158 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f }; 159 160/* XDTLS: figure out the right values */ 161static const unsigned int g_probable_mtu[] = { 1500, 512, 256 }; 162 163static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 164 unsigned long frag_len); 165static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p); 166static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 167 unsigned long len, 168 unsigned short seq_num, 169 unsigned long frag_off, 170 unsigned long frag_len); 171static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, 172 int *ok); 173 174static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len, 175 int reassembly) 176{ 177 hm_fragment *frag = NULL; 178 unsigned char *buf = NULL; 179 unsigned char *bitmask = NULL; 180 181 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 182 if (frag == NULL) 183 return NULL; 184 185 if (frag_len) { 186 buf = (unsigned char *)OPENSSL_malloc(frag_len); 187 if (buf == NULL) { 188 OPENSSL_free(frag); 189 return NULL; 190 } 191 } 192 193 /* zero length fragment gets zero frag->fragment */ 194 frag->fragment = buf; 195 196 /* Initialize reassembly bitmask if necessary */ 197 if (reassembly) { 198 bitmask = 199 (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) { 201 if (buf != NULL) 202 OPENSSL_free(buf); 203 OPENSSL_free(frag); 204 return NULL; 205 } 206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 207 } 208 209 frag->reassembly = bitmask; 210 211 return frag; 212} 213 214void dtls1_hm_fragment_free(hm_fragment *frag) 215{ 216 217 if (frag->msg_header.is_ccs) { 218 EVP_CIPHER_CTX_free(frag->msg_header. 219 saved_retransmit_state.enc_write_ctx); 220 EVP_MD_CTX_destroy(frag->msg_header. 221 saved_retransmit_state.write_hash); 222 } 223 if (frag->fragment) 224 OPENSSL_free(frag->fragment); 225 if (frag->reassembly) 226 OPENSSL_free(frag->reassembly); 227 OPENSSL_free(frag); 228} 229 230static int dtls1_query_mtu(SSL *s) 231{ 232 if (s->d1->link_mtu) { 233 s->d1->mtu = 234 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 235 s->d1->link_mtu = 0; 236 } 237 238 /* AHA! Figure out the MTU, and stick to the right size */ 239 if (s->d1->mtu < dtls1_min_mtu(s)) { 240 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 241 s->d1->mtu = 242 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 243 244 /* 245 * I've seen the kernel return bogus numbers when it doesn't know 246 * (initial write), so just make sure we have a reasonable number 247 */ 248 if (s->d1->mtu < dtls1_min_mtu(s)) { 249 /* Set to min mtu */ 250 s->d1->mtu = dtls1_min_mtu(s); 251 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 252 s->d1->mtu, NULL); 253 } 254 } else 255 return 0; 256 } 257 return 1; 258} 259 260/* 261 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or 262 * SSL3_RT_CHANGE_CIPHER_SPEC) 263 */ 264int dtls1_do_write(SSL *s, int type) 265{ 266 int ret; 267 unsigned int curr_mtu; 268 int retry = 1; 269 unsigned int len, frag_off, mac_size, blocksize, used_len; 270 271 if (!dtls1_query_mtu(s)) 272 return -1; 273 274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something 275 * reasonable now */ 276 277 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 278 OPENSSL_assert(s->init_num == 279 (int)s->d1->w_msg_hdr.msg_len + 280 DTLS1_HM_HEADER_LENGTH); 281 282 if (s->write_hash) { 283 if (s->enc_write_ctx 284 && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE) 285 mac_size = 0; 286 else 287 mac_size = EVP_MD_CTX_size(s->write_hash); 288 } else 289 mac_size = 0; 290 291 if (s->enc_write_ctx && 292 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE)) 293 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 294 else 295 blocksize = 0; 296 297 frag_off = 0; 298 s->rwstate = SSL_NOTHING; 299 300 /* s->init_num shouldn't ever be < 0...but just in case */ 301 while (s->init_num > 0) { 302 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) { 303 /* We must be writing a fragment other than the first one */ 304 305 if (frag_off > 0) { 306 /* This is the first attempt at writing out this fragment */ 307 308 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) { 309 /* 310 * Each fragment that was already sent must at least have 311 * contained the message header plus one other byte. 312 * Therefore |init_off| must have progressed by at least 313 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went 314 * wrong. 315 */ 316 return -1; 317 } 318 319 /* 320 * Adjust |init_off| and |init_num| to allow room for a new 321 * message header for this fragment. 322 */ 323 s->init_off -= DTLS1_HM_HEADER_LENGTH; 324 s->init_num += DTLS1_HM_HEADER_LENGTH; 325 } else { 326 /* 327 * We must have been called again after a retry so use the 328 * fragment offset from our last attempt. We do not need 329 * to adjust |init_off| and |init_num| as above, because 330 * that should already have been done before the retry. 331 */ 332 frag_off = s->d1->w_msg_hdr.frag_off; 333 } 334 } 335 336 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH 337 + mac_size + blocksize; 338 if (s->d1->mtu > used_len) 339 curr_mtu = s->d1->mtu - used_len; 340 else 341 curr_mtu = 0; 342 343 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 344 /* 345 * grr.. we could get an error if MTU picked was wrong 346 */ 347 ret = BIO_flush(SSL_get_wbio(s)); 348 if (ret <= 0) { 349 s->rwstate = SSL_WRITING; 350 return ret; 351 } 352 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 353 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) { 354 curr_mtu = s->d1->mtu - used_len; 355 } else { 356 /* Shouldn't happen */ 357 return -1; 358 } 359 } 360 361 /* 362 * We just checked that s->init_num > 0 so this cast should be safe 363 */ 364 if (((unsigned int)s->init_num) > curr_mtu) 365 len = curr_mtu; 366 else 367 len = s->init_num; 368 369 /* Shouldn't ever happen */ 370 if (len > INT_MAX) 371 len = INT_MAX; 372 373 /* 374 * XDTLS: this function is too long. split out the CCS part 375 */ 376 if (type == SSL3_RT_HANDSHAKE) { 377 if (len < DTLS1_HM_HEADER_LENGTH) { 378 /* 379 * len is so small that we really can't do anything sensible 380 * so fail 381 */ 382 return -1; 383 } 384 dtls1_fix_message_header(s, frag_off, 385 len - DTLS1_HM_HEADER_LENGTH); 386 387 dtls1_write_message_header(s, 388 (unsigned char *)&s->init_buf-> 389 data[s->init_off]); 390 } 391 392 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], 393 len); 394 if (ret < 0) { 395 /* 396 * might need to update MTU here, but we don't know which 397 * previous packet caused the failure -- so can't really 398 * retransmit anything. continue as if everything is fine and 399 * wait for an alert to handle the retransmit 400 */ 401 if (retry && BIO_ctrl(SSL_get_wbio(s), 402 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) { 403 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 404 if (!dtls1_query_mtu(s)) 405 return -1; 406 /* Have one more go */ 407 retry = 0; 408 } else 409 return -1; 410 } else { 411 return (-1); 412 } 413 } else { 414 415 /* 416 * bad if this assert fails, only part of the handshake message 417 * got sent. but why would this happen? 418 */ 419 OPENSSL_assert(len == (unsigned int)ret); 420 421 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 422 /* 423 * should not be done for 'Hello Request's, but in that case 424 * we'll ignore the result anyway 425 */ 426 unsigned char *p = 427 (unsigned char *)&s->init_buf->data[s->init_off]; 428 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 429 int xlen; 430 431 if (frag_off == 0 && s->version != DTLS1_BAD_VER) { 432 /* 433 * reconstruct message header is if it is being sent in 434 * single fragment 435 */ 436 *p++ = msg_hdr->type; 437 l2n3(msg_hdr->msg_len, p); 438 s2n(msg_hdr->seq, p); 439 l2n3(0, p); 440 l2n3(msg_hdr->msg_len, p); 441 p -= DTLS1_HM_HEADER_LENGTH; 442 xlen = ret; 443 } else { 444 p += DTLS1_HM_HEADER_LENGTH; 445 xlen = ret - DTLS1_HM_HEADER_LENGTH; 446 } 447 448 ssl3_finish_mac(s, p, xlen); 449 } 450 451 if (ret == s->init_num) { 452 if (s->msg_callback) 453 s->msg_callback(1, s->version, type, s->init_buf->data, 454 (size_t)(s->init_off + s->init_num), s, 455 s->msg_callback_arg); 456 457 s->init_off = 0; /* done writing this message */ 458 s->init_num = 0; 459 460 return (1); 461 } 462 s->init_off += ret; 463 s->init_num -= ret; 464 ret -= DTLS1_HM_HEADER_LENGTH; 465 frag_off += ret; 466 467 /* 468 * We save the fragment offset for the next fragment so we have it 469 * available in case of an IO retry. We don't know the length of the 470 * next fragment yet so just set that to 0 for now. It will be 471 * updated again later. 472 */ 473 dtls1_fix_message_header(s, frag_off, 0); 474 } 475 } 476 return (0); 477} 478 479/* 480 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum 481 * acceptable body length 'max'. Read an entire handshake message. Handshake 482 * messages arrive in fragments. 483 */ 484long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 485{ 486 int i, al; 487 struct hm_header_st *msg_hdr; 488 unsigned char *p; 489 unsigned long msg_len; 490 491 /* 492 * s3->tmp is used to store messages that are unexpected, caused by the 493 * absence of an optional handshake message 494 */ 495 if (s->s3->tmp.reuse_message) { 496 s->s3->tmp.reuse_message = 0; 497 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 498 al = SSL_AD_UNEXPECTED_MESSAGE; 499 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 500 goto f_err; 501 } 502 *ok = 1; 503 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 504 s->init_num = (int)s->s3->tmp.message_size; 505 return s->init_num; 506 } 507 508 msg_hdr = &s->d1->r_msg_hdr; 509 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 510 511 again: 512 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 513 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) { 514 /* bad fragment received */ 515 goto again; 516 } else if (i <= 0 && !*ok) { 517 return i; 518 } 519 520 if (mt >= 0 && s->s3->tmp.message_type != mt) { 521 al = SSL_AD_UNEXPECTED_MESSAGE; 522 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 523 goto f_err; 524 } 525 526 p = (unsigned char *)s->init_buf->data; 527 msg_len = msg_hdr->msg_len; 528 529 /* reconstruct message header */ 530 *(p++) = msg_hdr->type; 531 l2n3(msg_len, p); 532 s2n(msg_hdr->seq, p); 533 l2n3(0, p); 534 l2n3(msg_len, p); 535 if (s->version != DTLS1_BAD_VER) { 536 p -= DTLS1_HM_HEADER_LENGTH; 537 msg_len += DTLS1_HM_HEADER_LENGTH; 538 } 539 540 ssl3_finish_mac(s, p, msg_len); 541 if (s->msg_callback) 542 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 543 p, msg_len, s, s->msg_callback_arg); 544 545 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 546 547 /* Don't change sequence numbers while listening */ 548 if (!s->d1->listen) 549 s->d1->handshake_read_seq++; 550 551 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 552 return s->init_num; 553 554 f_err: 555 ssl3_send_alert(s, SSL3_AL_FATAL, al); 556 *ok = 0; 557 return -1; 558} 559 560static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 561 int max) 562{ 563 size_t frag_off, frag_len, msg_len; 564 565 msg_len = msg_hdr->msg_len; 566 frag_off = msg_hdr->frag_off; 567 frag_len = msg_hdr->frag_len; 568 569 /* sanity checking */ 570 if ((frag_off + frag_len) > msg_len) { 571 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 572 return SSL_AD_ILLEGAL_PARAMETER; 573 } 574 575 if ((frag_off + frag_len) > (unsigned long)max) { 576 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 577 return SSL_AD_ILLEGAL_PARAMETER; 578 } 579 580 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 581 /* 582 * msg_len is limited to 2^24, but is effectively checked against max 583 * above 584 */ 585 if (!BUF_MEM_grow_clean 586 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { 587 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 588 return SSL_AD_INTERNAL_ERROR; 589 } 590 591 s->s3->tmp.message_size = msg_len; 592 s->d1->r_msg_hdr.msg_len = msg_len; 593 s->s3->tmp.message_type = msg_hdr->type; 594 s->d1->r_msg_hdr.type = msg_hdr->type; 595 s->d1->r_msg_hdr.seq = msg_hdr->seq; 596 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 597 /* 598 * They must be playing with us! BTW, failure to enforce upper limit 599 * would open possibility for buffer overrun. 600 */ 601 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 602 return SSL_AD_ILLEGAL_PARAMETER; 603 } 604 605 return 0; /* no error */ 606} 607 608static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 609{ 610 /*- 611 * (0) check whether the desired fragment is available 612 * if so: 613 * (1) copy over the fragment to s->init_buf->data[] 614 * (2) update s->init_num 615 */ 616 pitem *item; 617 hm_fragment *frag; 618 int al; 619 620 *ok = 0; 621 item = pqueue_peek(s->d1->buffered_messages); 622 if (item == NULL) 623 return 0; 624 625 frag = (hm_fragment *)item->data; 626 627 /* Don't return if reassembly still in progress */ 628 if (frag->reassembly != NULL) 629 return 0; 630 631 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 632 unsigned long frag_len = frag->msg_header.frag_len; 633 pqueue_pop(s->d1->buffered_messages); 634 635 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 636 637 if (al == 0) { /* no alert */ 638 unsigned char *p = 639 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 640 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 641 frag->msg_header.frag_len); 642 } 643 644 dtls1_hm_fragment_free(frag); 645 pitem_free(item); 646 647 if (al == 0) { 648 *ok = 1; 649 return frag_len; 650 } 651 652 ssl3_send_alert(s, SSL3_AL_FATAL, al); 653 s->init_num = 0; 654 *ok = 0; 655 return -1; 656 } else 657 return 0; 658} 659 660/* 661 * dtls1_max_handshake_message_len returns the maximum number of bytes 662 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 663 * may be greater if the maximum certificate list size requires it. 664 */ 665static unsigned long dtls1_max_handshake_message_len(const SSL *s) 666{ 667 unsigned long max_len = 668 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 669 if (max_len < (unsigned long)s->max_cert_list) 670 return s->max_cert_list; 671 return max_len; 672} 673 674static int 675dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 676{ 677 hm_fragment *frag = NULL; 678 pitem *item = NULL; 679 int i = -1, is_complete; 680 unsigned char seq64be[8]; 681 unsigned long frag_len = msg_hdr->frag_len; 682 683 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 684 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 685 goto err; 686 687 if (frag_len == 0) 688 return DTLS1_HM_FRAGMENT_RETRY; 689 690 /* Try to find item in queue */ 691 memset(seq64be, 0, sizeof(seq64be)); 692 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 693 seq64be[7] = (unsigned char)msg_hdr->seq; 694 item = pqueue_find(s->d1->buffered_messages, seq64be); 695 696 if (item == NULL) { 697 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 698 if (frag == NULL) 699 goto err; 700 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 701 frag->msg_header.frag_len = frag->msg_header.msg_len; 702 frag->msg_header.frag_off = 0; 703 } else { 704 frag = (hm_fragment *)item->data; 705 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 706 item = NULL; 707 frag = NULL; 708 goto err; 709 } 710 } 711 712 /* 713 * If message is already reassembled, this must be a retransmit and can 714 * be dropped. In this case item != NULL and so frag does not need to be 715 * freed. 716 */ 717 if (frag->reassembly == NULL) { 718 unsigned char devnull[256]; 719 720 while (frag_len) { 721 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 722 devnull, 723 frag_len > 724 sizeof(devnull) ? sizeof(devnull) : 725 frag_len, 0); 726 if (i <= 0) 727 goto err; 728 frag_len -= i; 729 } 730 return DTLS1_HM_FRAGMENT_RETRY; 731 } 732 733 /* read the body of the fragment (header has already been read */ 734 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 735 frag->fragment + msg_hdr->frag_off, 736 frag_len, 0); 737 if ((unsigned long)i != frag_len) 738 i = -1; 739 if (i <= 0) 740 goto err; 741 742 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 743 (long)(msg_hdr->frag_off + frag_len)); 744 745 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 746 is_complete); 747 748 if (is_complete) { 749 OPENSSL_free(frag->reassembly); 750 frag->reassembly = NULL; 751 } 752 753 if (item == NULL) { 754 item = pitem_new(seq64be, frag); 755 if (item == NULL) { 756 i = -1; 757 goto err; 758 } 759 760 item = pqueue_insert(s->d1->buffered_messages, item); 761 /* 762 * pqueue_insert fails iff a duplicate item is inserted. However, 763 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 764 * would have returned it and control would never have reached this 765 * branch. 766 */ 767 OPENSSL_assert(item != NULL); 768 } 769 770 return DTLS1_HM_FRAGMENT_RETRY; 771 772 err: 773 if (frag != NULL && item == NULL) 774 dtls1_hm_fragment_free(frag); 775 *ok = 0; 776 return i; 777} 778 779static int 780dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 781 int *ok) 782{ 783 int i = -1; 784 hm_fragment *frag = NULL; 785 pitem *item = NULL; 786 unsigned char seq64be[8]; 787 unsigned long frag_len = msg_hdr->frag_len; 788 789 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 790 goto err; 791 792 /* Try to find item in queue, to prevent duplicate entries */ 793 memset(seq64be, 0, sizeof(seq64be)); 794 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 795 seq64be[7] = (unsigned char)msg_hdr->seq; 796 item = pqueue_find(s->d1->buffered_messages, seq64be); 797 798 /* 799 * If we already have an entry and this one is a fragment, don't discard 800 * it and rather try to reassemble it. 801 */ 802 if (item != NULL && frag_len != msg_hdr->msg_len) 803 item = NULL; 804 805 /* 806 * Discard the message if sequence number was already there, is too far 807 * in the future, already in the queue or if we received a FINISHED 808 * before the SERVER_HELLO, which then must be a stale retransmit. 809 */ 810 if (msg_hdr->seq <= s->d1->handshake_read_seq || 811 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 812 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 813 { 814 unsigned char devnull[256]; 815 816 while (frag_len) { 817 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 818 devnull, 819 frag_len > 820 sizeof(devnull) ? sizeof(devnull) : 821 frag_len, 0); 822 if (i <= 0) 823 goto err; 824 frag_len -= i; 825 } 826 } else { 827 if (frag_len != msg_hdr->msg_len) 828 return dtls1_reassemble_fragment(s, msg_hdr, ok); 829 830 if (frag_len > dtls1_max_handshake_message_len(s)) 831 goto err; 832 833 frag = dtls1_hm_fragment_new(frag_len, 0); 834 if (frag == NULL) 835 goto err; 836 837 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 838 839 if (frag_len) { 840 /* 841 * read the body of the fragment (header has already been read 842 */ 843 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 844 frag->fragment, frag_len, 0); 845 if ((unsigned long)i != frag_len) 846 i = -1; 847 if (i <= 0) 848 goto err; 849 } 850 851 item = pitem_new(seq64be, frag); 852 if (item == NULL) 853 goto err; 854 855 item = pqueue_insert(s->d1->buffered_messages, item); 856 /* 857 * pqueue_insert fails iff a duplicate item is inserted. However, 858 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 859 * would have returned it. Then, either |frag_len| != 860 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 861 * have been processed with |dtls1_reassemble_fragment|, above, or 862 * the record will have been discarded. 863 */ 864 OPENSSL_assert(item != NULL); 865 } 866 867 return DTLS1_HM_FRAGMENT_RETRY; 868 869 err: 870 if (frag != NULL && item == NULL) 871 dtls1_hm_fragment_free(frag); 872 *ok = 0; 873 return i; 874} 875 876static long 877dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 878{ 879 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 880 unsigned long len, frag_off, frag_len; 881 int i, al; 882 struct hm_header_st msg_hdr; 883 884 redo: 885 /* see if we have the required fragment already */ 886 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 887 if (*ok) 888 s->init_num = frag_len; 889 return frag_len; 890 } 891 892 /* read handshake message header */ 893 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 894 DTLS1_HM_HEADER_LENGTH, 0); 895 if (i <= 0) { /* nbio, or an error */ 896 s->rwstate = SSL_READING; 897 *ok = 0; 898 return i; 899 } 900 /* Handshake fails if message header is incomplete */ 901 if (i != DTLS1_HM_HEADER_LENGTH) { 902 al = SSL_AD_UNEXPECTED_MESSAGE; 903 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 904 goto f_err; 905 } 906 907 /* parse the message fragment header */ 908 dtls1_get_message_header(wire, &msg_hdr); 909 910 len = msg_hdr.msg_len; 911 frag_off = msg_hdr.frag_off; 912 frag_len = msg_hdr.frag_len; 913 914 /* 915 * We must have at least frag_len bytes left in the record to be read. 916 * Fragments must not span records. 917 */ 918 if (frag_len > s->s3->rrec.length) { 919 al = SSL3_AD_ILLEGAL_PARAMETER; 920 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 921 goto f_err; 922 } 923 924 /* 925 * if this is a future (or stale) message it gets buffered 926 * (or dropped)--no further processing at this time 927 * While listening, we accept seq 1 (ClientHello with cookie) 928 * although we're still expecting seq 0 (ClientHello) 929 */ 930 if (msg_hdr.seq != s->d1->handshake_read_seq 931 && !(s->d1->listen && msg_hdr.seq == 1)) 932 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 933 934 if (frag_len && frag_len < len) 935 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 936 937 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 938 wire[0] == SSL3_MT_HELLO_REQUEST) { 939 /* 940 * The server may always send 'Hello Request' messages -- we are 941 * doing a handshake anyway now, so ignore them if their format is 942 * correct. Does not count for 'Finished' MAC. 943 */ 944 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 945 if (s->msg_callback) 946 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 947 wire, DTLS1_HM_HEADER_LENGTH, s, 948 s->msg_callback_arg); 949 950 s->init_num = 0; 951 goto redo; 952 } else { /* Incorrectly formated Hello request */ 953 954 al = SSL_AD_UNEXPECTED_MESSAGE; 955 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 956 SSL_R_UNEXPECTED_MESSAGE); 957 goto f_err; 958 } 959 } 960 961 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 962 goto f_err; 963 964 if (frag_len > 0) { 965 unsigned char *p = 966 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 967 968 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 969 &p[frag_off], frag_len, 0); 970 971 /* 972 * This shouldn't ever fail due to NBIO because we already checked 973 * that we have enough data in the record 974 */ 975 if (i <= 0) { 976 s->rwstate = SSL_READING; 977 *ok = 0; 978 return i; 979 } 980 } else 981 i = 0; 982 983 /* 984 * XDTLS: an incorrectly formatted fragment should cause the handshake 985 * to fail 986 */ 987 if (i != (int)frag_len) { 988 al = SSL3_AD_ILLEGAL_PARAMETER; 989 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 990 goto f_err; 991 } 992 993 *ok = 1; 994 s->state = stn; 995 996 /* 997 * Note that s->init_num is *not* used as current offset in 998 * s->init_buf->data, but as a counter summing up fragments' lengths: as 999 * soon as they sum up to handshake packet length, we assume we have got 1000 * all the fragments. 1001 */ 1002 s->init_num = frag_len; 1003 return frag_len; 1004 1005 f_err: 1006 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1007 s->init_num = 0; 1008 1009 *ok = 0; 1010 return (-1); 1011} 1012 1013/*- 1014 * for these 2 messages, we need to 1015 * ssl->enc_read_ctx re-init 1016 * ssl->s3->read_sequence zero 1017 * ssl->s3->read_mac_secret re-init 1018 * ssl->session->read_sym_enc assign 1019 * ssl->session->read_compression assign 1020 * ssl->session->read_hash assign 1021 */ 1022int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1023{ 1024 unsigned char *p; 1025 1026 if (s->state == a) { 1027 p = (unsigned char *)s->init_buf->data; 1028 *p++ = SSL3_MT_CCS; 1029 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1030 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1031 1032 if (s->version == DTLS1_BAD_VER) { 1033 s->d1->next_handshake_write_seq++; 1034 s2n(s->d1->handshake_write_seq, p); 1035 s->init_num += 2; 1036 } 1037 1038 s->init_off = 0; 1039 1040 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1041 s->d1->handshake_write_seq, 0, 0); 1042 1043 /* buffer the message to handle re-xmits */ 1044 dtls1_buffer_message(s, 1); 1045 1046 s->state = b; 1047 } 1048 1049 /* SSL3_ST_CW_CHANGE_B */ 1050 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1051} 1052 1053int dtls1_read_failed(SSL *s, int code) 1054{ 1055 if (code > 0) { 1056 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1057 return 1; 1058 } 1059 1060 if (!dtls1_is_timer_expired(s)) { 1061 /* 1062 * not a timeout, none of our business, let higher layers handle 1063 * this. in fact it's probably an error 1064 */ 1065 return code; 1066 } 1067#ifndef OPENSSL_NO_HEARTBEATS 1068 /* done, no need to send a retransmit */ 1069 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1070#else 1071 /* done, no need to send a retransmit */ 1072 if (!SSL_in_init(s)) 1073#endif 1074 { 1075 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1076 return code; 1077 } 1078#if 0 /* for now, each alert contains only one 1079 * record number */ 1080 item = pqueue_peek(state->rcvd_records); 1081 if (item) { 1082 /* send an alert immediately for all the missing records */ 1083 } else 1084#endif 1085 1086#if 0 /* no more alert sending, just retransmit the 1087 * last set of messages */ 1088 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1089 ssl3_send_alert(s, SSL3_AL_WARNING, 1090 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1091#endif 1092 1093 return dtls1_handle_timeout(s); 1094} 1095 1096int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1097{ 1098 /* 1099 * The index of the retransmission queue actually is the message sequence 1100 * number, since the queue only contains messages of a single handshake. 1101 * However, the ChangeCipherSpec has no message sequence number and so 1102 * using only the sequence will result in the CCS and Finished having the 1103 * same index. To prevent this, the sequence number is multiplied by 2. 1104 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1105 * Finished, it also maintains the order of the index (important for 1106 * priority queues) and fits in the unsigned short variable. 1107 */ 1108 return seq * 2 - is_ccs; 1109} 1110 1111int dtls1_retransmit_buffered_messages(SSL *s) 1112{ 1113 pqueue sent = s->d1->sent_messages; 1114 piterator iter; 1115 pitem *item; 1116 hm_fragment *frag; 1117 int found = 0; 1118 1119 iter = pqueue_iterator(sent); 1120 1121 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1122 frag = (hm_fragment *)item->data; 1123 if (dtls1_retransmit_message(s, (unsigned short) 1124 dtls1_get_queue_priority 1125 (frag->msg_header.seq, 1126 frag->msg_header.is_ccs), 0, 1127 &found) <= 0 && found) { 1128 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1129 return -1; 1130 } 1131 } 1132 1133 return 1; 1134} 1135 1136int dtls1_buffer_message(SSL *s, int is_ccs) 1137{ 1138 pitem *item; 1139 hm_fragment *frag; 1140 unsigned char seq64be[8]; 1141 1142 /* 1143 * this function is called immediately after a message has been 1144 * serialized 1145 */ 1146 OPENSSL_assert(s->init_off == 0); 1147 1148 frag = dtls1_hm_fragment_new(s->init_num, 0); 1149 if (!frag) 1150 return 0; 1151 1152 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1153 1154 if (is_ccs) { 1155 /* For DTLS1_BAD_VER the header length is non-standard */ 1156 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1157 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH) 1158 == (unsigned int)s->init_num); 1159 } else { 1160 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1161 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1162 } 1163 1164 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1165 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1166 frag->msg_header.type = s->d1->w_msg_hdr.type; 1167 frag->msg_header.frag_off = 0; 1168 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1169 frag->msg_header.is_ccs = is_ccs; 1170 1171 /* save current state */ 1172 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1173 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1174 frag->msg_header.saved_retransmit_state.compress = s->compress; 1175 frag->msg_header.saved_retransmit_state.session = s->session; 1176 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1177 1178 memset(seq64be, 0, sizeof(seq64be)); 1179 seq64be[6] = 1180 (unsigned 1181 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1182 frag->msg_header.is_ccs) >> 8); 1183 seq64be[7] = 1184 (unsigned 1185 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1186 frag->msg_header.is_ccs)); 1187 1188 item = pitem_new(seq64be, frag); 1189 if (item == NULL) { 1190 dtls1_hm_fragment_free(frag); 1191 return 0; 1192 } 1193#if 0 1194 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1195 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1196 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1197#endif 1198 1199 pqueue_insert(s->d1->sent_messages, item); 1200 return 1; 1201} 1202 1203int 1204dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1205 int *found) 1206{ 1207 int ret; 1208 /* XDTLS: for now assuming that read/writes are blocking */ 1209 pitem *item; 1210 hm_fragment *frag; 1211 unsigned long header_length; 1212 unsigned char seq64be[8]; 1213 struct dtls1_retransmit_state saved_state; 1214 unsigned char save_write_sequence[8]; 1215 1216 /*- 1217 OPENSSL_assert(s->init_num == 0); 1218 OPENSSL_assert(s->init_off == 0); 1219 */ 1220 1221 /* XDTLS: the requested message ought to be found, otherwise error */ 1222 memset(seq64be, 0, sizeof(seq64be)); 1223 seq64be[6] = (unsigned char)(seq >> 8); 1224 seq64be[7] = (unsigned char)seq; 1225 1226 item = pqueue_find(s->d1->sent_messages, seq64be); 1227 if (item == NULL) { 1228 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1229 *found = 0; 1230 return 0; 1231 } 1232 1233 *found = 1; 1234 frag = (hm_fragment *)item->data; 1235 1236 if (frag->msg_header.is_ccs) 1237 header_length = DTLS1_CCS_HEADER_LENGTH; 1238 else 1239 header_length = DTLS1_HM_HEADER_LENGTH; 1240 1241 memcpy(s->init_buf->data, frag->fragment, 1242 frag->msg_header.msg_len + header_length); 1243 s->init_num = frag->msg_header.msg_len + header_length; 1244 1245 dtls1_set_message_header_int(s, frag->msg_header.type, 1246 frag->msg_header.msg_len, 1247 frag->msg_header.seq, 0, 1248 frag->msg_header.frag_len); 1249 1250 /* save current state */ 1251 saved_state.enc_write_ctx = s->enc_write_ctx; 1252 saved_state.write_hash = s->write_hash; 1253 saved_state.compress = s->compress; 1254 saved_state.session = s->session; 1255 saved_state.epoch = s->d1->w_epoch; 1256 saved_state.epoch = s->d1->w_epoch; 1257 1258 s->d1->retransmitting = 1; 1259 1260 /* restore state in which the message was originally sent */ 1261 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1262 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1263 s->compress = frag->msg_header.saved_retransmit_state.compress; 1264 s->session = frag->msg_header.saved_retransmit_state.session; 1265 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1266 1267 if (frag->msg_header.saved_retransmit_state.epoch == 1268 saved_state.epoch - 1) { 1269 memcpy(save_write_sequence, s->s3->write_sequence, 1270 sizeof(s->s3->write_sequence)); 1271 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1272 sizeof(s->s3->write_sequence)); 1273 } 1274 1275 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1276 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1277 1278 /* restore current state */ 1279 s->enc_write_ctx = saved_state.enc_write_ctx; 1280 s->write_hash = saved_state.write_hash; 1281 s->compress = saved_state.compress; 1282 s->session = saved_state.session; 1283 s->d1->w_epoch = saved_state.epoch; 1284 1285 if (frag->msg_header.saved_retransmit_state.epoch == 1286 saved_state.epoch - 1) { 1287 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1288 sizeof(s->s3->write_sequence)); 1289 memcpy(s->s3->write_sequence, save_write_sequence, 1290 sizeof(s->s3->write_sequence)); 1291 } 1292 1293 s->d1->retransmitting = 0; 1294 1295 (void)BIO_flush(SSL_get_wbio(s)); 1296 return ret; 1297} 1298 1299/* call this function when the buffered messages are no longer needed */ 1300void dtls1_clear_record_buffer(SSL *s) 1301{ 1302 pitem *item; 1303 1304 for (item = pqueue_pop(s->d1->sent_messages); 1305 item != NULL; item = pqueue_pop(s->d1->sent_messages)) { 1306 dtls1_hm_fragment_free((hm_fragment *)item->data); 1307 pitem_free(item); 1308 } 1309} 1310 1311unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1312 unsigned char mt, unsigned long len, 1313 unsigned long frag_off, 1314 unsigned long frag_len) 1315{ 1316 /* Don't change sequence numbers while listening */ 1317 if (frag_off == 0 && !s->d1->listen) { 1318 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1319 s->d1->next_handshake_write_seq++; 1320 } 1321 1322 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1323 frag_off, frag_len); 1324 1325 return p += DTLS1_HM_HEADER_LENGTH; 1326} 1327 1328/* don't actually do the writing, wait till the MTU has been retrieved */ 1329static void 1330dtls1_set_message_header_int(SSL *s, unsigned char mt, 1331 unsigned long len, unsigned short seq_num, 1332 unsigned long frag_off, unsigned long frag_len) 1333{ 1334 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1335 1336 msg_hdr->type = mt; 1337 msg_hdr->msg_len = len; 1338 msg_hdr->seq = seq_num; 1339 msg_hdr->frag_off = frag_off; 1340 msg_hdr->frag_len = frag_len; 1341} 1342 1343static void 1344dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1345 unsigned long frag_len) 1346{ 1347 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1348 1349 msg_hdr->frag_off = frag_off; 1350 msg_hdr->frag_len = frag_len; 1351} 1352 1353static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1354{ 1355 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1356 1357 *p++ = msg_hdr->type; 1358 l2n3(msg_hdr->msg_len, p); 1359 1360 s2n(msg_hdr->seq, p); 1361 l2n3(msg_hdr->frag_off, p); 1362 l2n3(msg_hdr->frag_len, p); 1363 1364 return p; 1365} 1366 1367unsigned int dtls1_link_min_mtu(void) 1368{ 1369 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1370 sizeof(g_probable_mtu[0])) - 1]); 1371} 1372 1373unsigned int dtls1_min_mtu(SSL *s) 1374{ 1375 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1376} 1377 1378void 1379dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1380{ 1381 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1382 msg_hdr->type = *(data++); 1383 n2l3(data, msg_hdr->msg_len); 1384 1385 n2s(data, msg_hdr->seq); 1386 n2l3(data, msg_hdr->frag_off); 1387 n2l3(data, msg_hdr->frag_len); 1388} 1389 1390void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1391{ 1392 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1393 1394 ccs_hdr->type = *(data++); 1395} 1396 1397int dtls1_shutdown(SSL *s) 1398{ 1399 int ret; 1400#ifndef OPENSSL_NO_SCTP 1401 BIO *wbio; 1402 1403 wbio = SSL_get_wbio(s); 1404 if (wbio != NULL && BIO_dgram_is_sctp(wbio) && 1405 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1406 ret = BIO_dgram_sctp_wait_for_dry(wbio); 1407 if (ret < 0) 1408 return -1; 1409 1410 if (ret == 0) 1411 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1412 NULL); 1413 } 1414#endif 1415 ret = ssl3_shutdown(s); 1416#ifndef OPENSSL_NO_SCTP 1417 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1418#endif 1419 return ret; 1420} 1421 1422#ifndef OPENSSL_NO_HEARTBEATS 1423int dtls1_process_heartbeat(SSL *s) 1424{ 1425 unsigned char *p = &s->s3->rrec.data[0], *pl; 1426 unsigned short hbtype; 1427 unsigned int payload; 1428 unsigned int padding = 16; /* Use minimum padding */ 1429 1430 if (s->msg_callback) 1431 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1432 &s->s3->rrec.data[0], s->s3->rrec.length, 1433 s, s->msg_callback_arg); 1434 1435 /* Read type and payload length first */ 1436 if (1 + 2 + 16 > s->s3->rrec.length) 1437 return 0; /* silently discard */ 1438 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1439 return 0; /* silently discard per RFC 6520 sec. 4 */ 1440 1441 hbtype = *p++; 1442 n2s(p, payload); 1443 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1444 return 0; /* silently discard per RFC 6520 sec. 4 */ 1445 pl = p; 1446 1447 if (hbtype == TLS1_HB_REQUEST) { 1448 unsigned char *buffer, *bp; 1449 unsigned int write_length = 1 /* heartbeat type */ + 1450 2 /* heartbeat length */ + 1451 payload + padding; 1452 int r; 1453 1454 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1455 return 0; 1456 1457 /* 1458 * Allocate memory for the response, size is 1 byte message type, 1459 * plus 2 bytes payload length, plus payload, plus padding 1460 */ 1461 buffer = OPENSSL_malloc(write_length); 1462 if (buffer == NULL) 1463 return -1; 1464 bp = buffer; 1465 1466 /* Enter response type, length and copy payload */ 1467 *bp++ = TLS1_HB_RESPONSE; 1468 s2n(payload, bp); 1469 memcpy(bp, pl, payload); 1470 bp += payload; 1471 /* Random padding */ 1472 if (RAND_pseudo_bytes(bp, padding) < 0) { 1473 OPENSSL_free(buffer); 1474 return -1; 1475 } 1476 1477 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1478 1479 if (r >= 0 && s->msg_callback) 1480 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1481 buffer, write_length, s, s->msg_callback_arg); 1482 1483 OPENSSL_free(buffer); 1484 1485 if (r < 0) 1486 return r; 1487 } else if (hbtype == TLS1_HB_RESPONSE) { 1488 unsigned int seq; 1489 1490 /* 1491 * We only send sequence numbers (2 bytes unsigned int), and 16 1492 * random bytes, so we just try to read the sequence number 1493 */ 1494 n2s(pl, seq); 1495 1496 if (payload == 18 && seq == s->tlsext_hb_seq) { 1497 dtls1_stop_timer(s); 1498 s->tlsext_hb_seq++; 1499 s->tlsext_hb_pending = 0; 1500 } 1501 } 1502 1503 return 0; 1504} 1505 1506int dtls1_heartbeat(SSL *s) 1507{ 1508 unsigned char *buf, *p; 1509 int ret = -1; 1510 unsigned int payload = 18; /* Sequence number + random bytes */ 1511 unsigned int padding = 16; /* Use minimum padding */ 1512 1513 /* Only send if peer supports and accepts HB requests... */ 1514 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1515 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1516 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1517 return -1; 1518 } 1519 1520 /* ...and there is none in flight yet... */ 1521 if (s->tlsext_hb_pending) { 1522 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1523 return -1; 1524 } 1525 1526 /* ...and no handshake in progress. */ 1527 if (SSL_in_init(s) || s->in_handshake) { 1528 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1529 return -1; 1530 } 1531 1532 /* 1533 * Check if padding is too long, payload and padding must not exceed 2^14 1534 * - 3 = 16381 bytes in total. 1535 */ 1536 OPENSSL_assert(payload + padding <= 16381); 1537 1538 /*- 1539 * Create HeartBeat message, we just use a sequence number 1540 * as payload to distuingish different messages and add 1541 * some random stuff. 1542 * - Message Type, 1 byte 1543 * - Payload Length, 2 bytes (unsigned int) 1544 * - Payload, the sequence number (2 bytes uint) 1545 * - Payload, random bytes (16 bytes uint) 1546 * - Padding 1547 */ 1548 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1549 p = buf; 1550 /* Message Type */ 1551 *p++ = TLS1_HB_REQUEST; 1552 /* Payload length (18 bytes here) */ 1553 s2n(payload, p); 1554 /* Sequence number */ 1555 s2n(s->tlsext_hb_seq, p); 1556 /* 16 random bytes */ 1557 if (RAND_pseudo_bytes(p, 16) < 0) 1558 goto err; 1559 p += 16; 1560 /* Random padding */ 1561 if (RAND_pseudo_bytes(p, padding) < 0) 1562 goto err; 1563 1564 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1565 if (ret >= 0) { 1566 if (s->msg_callback) 1567 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1568 buf, 3 + payload + padding, 1569 s, s->msg_callback_arg); 1570 1571 dtls1_start_timer(s); 1572 s->tlsext_hb_pending = 1; 1573 } 1574 1575err: 1576 OPENSSL_free(buf); 1577 1578 return ret; 1579} 1580#endif 1581