d1_both.c revision 295016
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 if (!BUF_MEM_grow_clean 582 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { 583 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 584 return SSL_AD_INTERNAL_ERROR; 585 } 586 587 s->s3->tmp.message_size = msg_len; 588 s->d1->r_msg_hdr.msg_len = msg_len; 589 s->s3->tmp.message_type = msg_hdr->type; 590 s->d1->r_msg_hdr.type = msg_hdr->type; 591 s->d1->r_msg_hdr.seq = msg_hdr->seq; 592 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 593 /* 594 * They must be playing with us! BTW, failure to enforce upper limit 595 * would open possibility for buffer overrun. 596 */ 597 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 598 return SSL_AD_ILLEGAL_PARAMETER; 599 } 600 601 return 0; /* no error */ 602} 603 604static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 605{ 606 /*- 607 * (0) check whether the desired fragment is available 608 * if so: 609 * (1) copy over the fragment to s->init_buf->data[] 610 * (2) update s->init_num 611 */ 612 pitem *item; 613 hm_fragment *frag; 614 int al; 615 616 *ok = 0; 617 item = pqueue_peek(s->d1->buffered_messages); 618 if (item == NULL) 619 return 0; 620 621 frag = (hm_fragment *)item->data; 622 623 /* Don't return if reassembly still in progress */ 624 if (frag->reassembly != NULL) 625 return 0; 626 627 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 628 unsigned long frag_len = frag->msg_header.frag_len; 629 pqueue_pop(s->d1->buffered_messages); 630 631 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 632 633 if (al == 0) { /* no alert */ 634 unsigned char *p = 635 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 636 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 637 frag->msg_header.frag_len); 638 } 639 640 dtls1_hm_fragment_free(frag); 641 pitem_free(item); 642 643 if (al == 0) { 644 *ok = 1; 645 return frag_len; 646 } 647 648 ssl3_send_alert(s, SSL3_AL_FATAL, al); 649 s->init_num = 0; 650 *ok = 0; 651 return -1; 652 } else 653 return 0; 654} 655 656/* 657 * dtls1_max_handshake_message_len returns the maximum number of bytes 658 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 659 * may be greater if the maximum certificate list size requires it. 660 */ 661static unsigned long dtls1_max_handshake_message_len(const SSL *s) 662{ 663 unsigned long max_len = 664 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 665 if (max_len < (unsigned long)s->max_cert_list) 666 return s->max_cert_list; 667 return max_len; 668} 669 670static int 671dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 672{ 673 hm_fragment *frag = NULL; 674 pitem *item = NULL; 675 int i = -1, is_complete; 676 unsigned char seq64be[8]; 677 unsigned long frag_len = msg_hdr->frag_len; 678 679 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 680 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 681 goto err; 682 683 if (frag_len == 0) 684 return DTLS1_HM_FRAGMENT_RETRY; 685 686 /* Try to find item in queue */ 687 memset(seq64be, 0, sizeof(seq64be)); 688 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 689 seq64be[7] = (unsigned char)msg_hdr->seq; 690 item = pqueue_find(s->d1->buffered_messages, seq64be); 691 692 if (item == NULL) { 693 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 694 if (frag == NULL) 695 goto err; 696 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 697 frag->msg_header.frag_len = frag->msg_header.msg_len; 698 frag->msg_header.frag_off = 0; 699 } else { 700 frag = (hm_fragment *)item->data; 701 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 702 item = NULL; 703 frag = NULL; 704 goto err; 705 } 706 } 707 708 /* 709 * If message is already reassembled, this must be a retransmit and can 710 * be dropped. In this case item != NULL and so frag does not need to be 711 * freed. 712 */ 713 if (frag->reassembly == NULL) { 714 unsigned char devnull[256]; 715 716 while (frag_len) { 717 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 718 devnull, 719 frag_len > 720 sizeof(devnull) ? sizeof(devnull) : 721 frag_len, 0); 722 if (i <= 0) 723 goto err; 724 frag_len -= i; 725 } 726 return DTLS1_HM_FRAGMENT_RETRY; 727 } 728 729 /* read the body of the fragment (header has already been read */ 730 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 731 frag->fragment + msg_hdr->frag_off, 732 frag_len, 0); 733 if ((unsigned long)i != frag_len) 734 i = -1; 735 if (i <= 0) 736 goto err; 737 738 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 739 (long)(msg_hdr->frag_off + frag_len)); 740 741 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 742 is_complete); 743 744 if (is_complete) { 745 OPENSSL_free(frag->reassembly); 746 frag->reassembly = NULL; 747 } 748 749 if (item == NULL) { 750 item = pitem_new(seq64be, frag); 751 if (item == NULL) { 752 i = -1; 753 goto err; 754 } 755 756 item = pqueue_insert(s->d1->buffered_messages, item); 757 /* 758 * pqueue_insert fails iff a duplicate item is inserted. However, 759 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 760 * would have returned it and control would never have reached this 761 * branch. 762 */ 763 OPENSSL_assert(item != NULL); 764 } 765 766 return DTLS1_HM_FRAGMENT_RETRY; 767 768 err: 769 if (frag != NULL && item == NULL) 770 dtls1_hm_fragment_free(frag); 771 *ok = 0; 772 return i; 773} 774 775static int 776dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 777 int *ok) 778{ 779 int i = -1; 780 hm_fragment *frag = NULL; 781 pitem *item = NULL; 782 unsigned char seq64be[8]; 783 unsigned long frag_len = msg_hdr->frag_len; 784 785 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 786 goto err; 787 788 /* Try to find item in queue, to prevent duplicate entries */ 789 memset(seq64be, 0, sizeof(seq64be)); 790 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 791 seq64be[7] = (unsigned char)msg_hdr->seq; 792 item = pqueue_find(s->d1->buffered_messages, seq64be); 793 794 /* 795 * If we already have an entry and this one is a fragment, don't discard 796 * it and rather try to reassemble it. 797 */ 798 if (item != NULL && frag_len != msg_hdr->msg_len) 799 item = NULL; 800 801 /* 802 * Discard the message if sequence number was already there, is too far 803 * in the future, already in the queue or if we received a FINISHED 804 * before the SERVER_HELLO, which then must be a stale retransmit. 805 */ 806 if (msg_hdr->seq <= s->d1->handshake_read_seq || 807 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 808 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 809 { 810 unsigned char devnull[256]; 811 812 while (frag_len) { 813 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 814 devnull, 815 frag_len > 816 sizeof(devnull) ? sizeof(devnull) : 817 frag_len, 0); 818 if (i <= 0) 819 goto err; 820 frag_len -= i; 821 } 822 } else { 823 if (frag_len != msg_hdr->msg_len) 824 return dtls1_reassemble_fragment(s, msg_hdr, ok); 825 826 if (frag_len > dtls1_max_handshake_message_len(s)) 827 goto err; 828 829 frag = dtls1_hm_fragment_new(frag_len, 0); 830 if (frag == NULL) 831 goto err; 832 833 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 834 835 if (frag_len) { 836 /* 837 * read the body of the fragment (header has already been read 838 */ 839 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 840 frag->fragment, frag_len, 0); 841 if ((unsigned long)i != frag_len) 842 i = -1; 843 if (i <= 0) 844 goto err; 845 } 846 847 item = pitem_new(seq64be, frag); 848 if (item == NULL) 849 goto err; 850 851 item = pqueue_insert(s->d1->buffered_messages, item); 852 /* 853 * pqueue_insert fails iff a duplicate item is inserted. However, 854 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 855 * would have returned it. Then, either |frag_len| != 856 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 857 * have been processed with |dtls1_reassemble_fragment|, above, or 858 * the record will have been discarded. 859 */ 860 OPENSSL_assert(item != NULL); 861 } 862 863 return DTLS1_HM_FRAGMENT_RETRY; 864 865 err: 866 if (frag != NULL && item == NULL) 867 dtls1_hm_fragment_free(frag); 868 *ok = 0; 869 return i; 870} 871 872static long 873dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 874{ 875 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 876 unsigned long len, frag_off, frag_len; 877 int i, al; 878 struct hm_header_st msg_hdr; 879 880 redo: 881 /* see if we have the required fragment already */ 882 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 883 if (*ok) 884 s->init_num = frag_len; 885 return frag_len; 886 } 887 888 /* read handshake message header */ 889 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 890 DTLS1_HM_HEADER_LENGTH, 0); 891 if (i <= 0) { /* nbio, or an error */ 892 s->rwstate = SSL_READING; 893 *ok = 0; 894 return i; 895 } 896 /* Handshake fails if message header is incomplete */ 897 if (i != DTLS1_HM_HEADER_LENGTH) { 898 al = SSL_AD_UNEXPECTED_MESSAGE; 899 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 900 goto f_err; 901 } 902 903 /* parse the message fragment header */ 904 dtls1_get_message_header(wire, &msg_hdr); 905 906 len = msg_hdr.msg_len; 907 frag_off = msg_hdr.frag_off; 908 frag_len = msg_hdr.frag_len; 909 910 /* 911 * We must have at least frag_len bytes left in the record to be read. 912 * Fragments must not span records. 913 */ 914 if (frag_len > s->s3->rrec.length) { 915 al = SSL3_AD_ILLEGAL_PARAMETER; 916 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 917 goto f_err; 918 } 919 920 /* 921 * if this is a future (or stale) message it gets buffered 922 * (or dropped)--no further processing at this time 923 * While listening, we accept seq 1 (ClientHello with cookie) 924 * although we're still expecting seq 0 (ClientHello) 925 */ 926 if (msg_hdr.seq != s->d1->handshake_read_seq 927 && !(s->d1->listen && msg_hdr.seq == 1)) 928 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 929 930 if (frag_len && frag_len < len) 931 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 932 933 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 934 wire[0] == SSL3_MT_HELLO_REQUEST) { 935 /* 936 * The server may always send 'Hello Request' messages -- we are 937 * doing a handshake anyway now, so ignore them if their format is 938 * correct. Does not count for 'Finished' MAC. 939 */ 940 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 941 if (s->msg_callback) 942 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 943 wire, DTLS1_HM_HEADER_LENGTH, s, 944 s->msg_callback_arg); 945 946 s->init_num = 0; 947 goto redo; 948 } else { /* Incorrectly formated Hello request */ 949 950 al = SSL_AD_UNEXPECTED_MESSAGE; 951 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 952 SSL_R_UNEXPECTED_MESSAGE); 953 goto f_err; 954 } 955 } 956 957 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 958 goto f_err; 959 960 if (frag_len > 0) { 961 unsigned char *p = 962 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 963 964 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 965 &p[frag_off], frag_len, 0); 966 967 /* 968 * This shouldn't ever fail due to NBIO because we already checked 969 * that we have enough data in the record 970 */ 971 if (i <= 0) { 972 s->rwstate = SSL_READING; 973 *ok = 0; 974 return i; 975 } 976 } else 977 i = 0; 978 979 /* 980 * XDTLS: an incorrectly formatted fragment should cause the handshake 981 * to fail 982 */ 983 if (i != (int)frag_len) { 984 al = SSL3_AD_ILLEGAL_PARAMETER; 985 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 986 goto f_err; 987 } 988 989 *ok = 1; 990 s->state = stn; 991 992 /* 993 * Note that s->init_num is *not* used as current offset in 994 * s->init_buf->data, but as a counter summing up fragments' lengths: as 995 * soon as they sum up to handshake packet length, we assume we have got 996 * all the fragments. 997 */ 998 s->init_num = frag_len; 999 return frag_len; 1000 1001 f_err: 1002 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1003 s->init_num = 0; 1004 1005 *ok = 0; 1006 return (-1); 1007} 1008 1009int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 1010{ 1011 unsigned char *p, *d; 1012 int i; 1013 unsigned long l; 1014 1015 if (s->state == a) { 1016 d = (unsigned char *)s->init_buf->data; 1017 p = &(d[DTLS1_HM_HEADER_LENGTH]); 1018 1019 i = s->method->ssl3_enc->final_finish_mac(s, 1020 sender, slen, 1021 s->s3->tmp.finish_md); 1022 s->s3->tmp.finish_md_len = i; 1023 memcpy(p, s->s3->tmp.finish_md, i); 1024 p += i; 1025 l = i; 1026 1027 /* 1028 * Copy the finished so we can use it for renegotiation checks 1029 */ 1030 if (s->type == SSL_ST_CONNECT) { 1031 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1032 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i); 1033 s->s3->previous_client_finished_len = i; 1034 } else { 1035 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1036 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i); 1037 s->s3->previous_server_finished_len = i; 1038 } 1039 1040#ifdef OPENSSL_SYS_WIN16 1041 /* 1042 * MSVC 1.5 does not clear the top bytes of the word unless I do 1043 * this. 1044 */ 1045 l &= 0xffff; 1046#endif 1047 1048 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 1049 s->init_num = (int)l + DTLS1_HM_HEADER_LENGTH; 1050 s->init_off = 0; 1051 1052 /* buffer the message to handle re-xmits */ 1053 dtls1_buffer_message(s, 0); 1054 1055 s->state = b; 1056 } 1057 1058 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 1059 return (dtls1_do_write(s, SSL3_RT_HANDSHAKE)); 1060} 1061 1062/*- 1063 * for these 2 messages, we need to 1064 * ssl->enc_read_ctx re-init 1065 * ssl->s3->read_sequence zero 1066 * ssl->s3->read_mac_secret re-init 1067 * ssl->session->read_sym_enc assign 1068 * ssl->session->read_compression assign 1069 * ssl->session->read_hash assign 1070 */ 1071int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1072{ 1073 unsigned char *p; 1074 1075 if (s->state == a) { 1076 p = (unsigned char *)s->init_buf->data; 1077 *p++ = SSL3_MT_CCS; 1078 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1079 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1080 1081 if (s->version == DTLS1_BAD_VER) { 1082 s->d1->next_handshake_write_seq++; 1083 s2n(s->d1->handshake_write_seq, p); 1084 s->init_num += 2; 1085 } 1086 1087 s->init_off = 0; 1088 1089 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1090 s->d1->handshake_write_seq, 0, 0); 1091 1092 /* buffer the message to handle re-xmits */ 1093 dtls1_buffer_message(s, 1); 1094 1095 s->state = b; 1096 } 1097 1098 /* SSL3_ST_CW_CHANGE_B */ 1099 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1100} 1101 1102static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1103{ 1104 int n; 1105 unsigned char *p; 1106 1107 n = i2d_X509(x, NULL); 1108 if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) { 1109 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB); 1110 return 0; 1111 } 1112 p = (unsigned char *)&(buf->data[*l]); 1113 l2n3(n, p); 1114 i2d_X509(x, &p); 1115 *l += n + 3; 1116 1117 return 1; 1118} 1119 1120unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1121{ 1122 unsigned char *p; 1123 int i; 1124 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH; 1125 BUF_MEM *buf; 1126 1127 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1128 buf = s->init_buf; 1129 if (!BUF_MEM_grow_clean(buf, 10)) { 1130 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB); 1131 return (0); 1132 } 1133 if (x != NULL) { 1134 X509_STORE_CTX xs_ctx; 1135 1136 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, x, NULL)) { 1137 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB); 1138 return (0); 1139 } 1140 1141 X509_verify_cert(&xs_ctx); 1142 /* Don't leave errors in the queue */ 1143 ERR_clear_error(); 1144 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) { 1145 x = sk_X509_value(xs_ctx.chain, i); 1146 1147 if (!dtls1_add_cert_to_buf(buf, &l, x)) { 1148 X509_STORE_CTX_cleanup(&xs_ctx); 1149 return 0; 1150 } 1151 } 1152 X509_STORE_CTX_cleanup(&xs_ctx); 1153 } 1154 /* Thawte special :-) */ 1155 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) { 1156 x = sk_X509_value(s->ctx->extra_certs, i); 1157 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1158 return 0; 1159 } 1160 1161 l -= (3 + DTLS1_HM_HEADER_LENGTH); 1162 1163 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1164 l2n3(l, p); 1165 l += 3; 1166 p = (unsigned char *)&(buf->data[0]); 1167 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1168 1169 l += DTLS1_HM_HEADER_LENGTH; 1170 return (l); 1171} 1172 1173int dtls1_read_failed(SSL *s, int code) 1174{ 1175 if (code > 0) { 1176 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1177 return 1; 1178 } 1179 1180 if (!dtls1_is_timer_expired(s)) { 1181 /* 1182 * not a timeout, none of our business, let higher layers handle 1183 * this. in fact it's probably an error 1184 */ 1185 return code; 1186 } 1187#ifndef OPENSSL_NO_HEARTBEATS 1188 /* done, no need to send a retransmit */ 1189 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1190#else 1191 /* done, no need to send a retransmit */ 1192 if (!SSL_in_init(s)) 1193#endif 1194 { 1195 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1196 return code; 1197 } 1198#if 0 /* for now, each alert contains only one 1199 * record number */ 1200 item = pqueue_peek(state->rcvd_records); 1201 if (item) { 1202 /* send an alert immediately for all the missing records */ 1203 } else 1204#endif 1205 1206#if 0 /* no more alert sending, just retransmit the 1207 * last set of messages */ 1208 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1209 ssl3_send_alert(s, SSL3_AL_WARNING, 1210 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1211#endif 1212 1213 return dtls1_handle_timeout(s); 1214} 1215 1216int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1217{ 1218 /* 1219 * The index of the retransmission queue actually is the message sequence 1220 * number, since the queue only contains messages of a single handshake. 1221 * However, the ChangeCipherSpec has no message sequence number and so 1222 * using only the sequence will result in the CCS and Finished having the 1223 * same index. To prevent this, the sequence number is multiplied by 2. 1224 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1225 * Finished, it also maintains the order of the index (important for 1226 * priority queues) and fits in the unsigned short variable. 1227 */ 1228 return seq * 2 - is_ccs; 1229} 1230 1231int dtls1_retransmit_buffered_messages(SSL *s) 1232{ 1233 pqueue sent = s->d1->sent_messages; 1234 piterator iter; 1235 pitem *item; 1236 hm_fragment *frag; 1237 int found = 0; 1238 1239 iter = pqueue_iterator(sent); 1240 1241 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1242 frag = (hm_fragment *)item->data; 1243 if (dtls1_retransmit_message(s, (unsigned short) 1244 dtls1_get_queue_priority 1245 (frag->msg_header.seq, 1246 frag->msg_header.is_ccs), 0, 1247 &found) <= 0 && found) { 1248 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1249 return -1; 1250 } 1251 } 1252 1253 return 1; 1254} 1255 1256int dtls1_buffer_message(SSL *s, int is_ccs) 1257{ 1258 pitem *item; 1259 hm_fragment *frag; 1260 unsigned char seq64be[8]; 1261 1262 /* 1263 * this function is called immediately after a message has been 1264 * serialized 1265 */ 1266 OPENSSL_assert(s->init_off == 0); 1267 1268 frag = dtls1_hm_fragment_new(s->init_num, 0); 1269 if (!frag) 1270 return 0; 1271 1272 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1273 1274 if (is_ccs) { 1275 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1276 ((s->version == 1277 DTLS1_VERSION) ? DTLS1_CCS_HEADER_LENGTH : 3) == 1278 (unsigned int)s->init_num); 1279 } else { 1280 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1281 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1282 } 1283 1284 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1285 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1286 frag->msg_header.type = s->d1->w_msg_hdr.type; 1287 frag->msg_header.frag_off = 0; 1288 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1289 frag->msg_header.is_ccs = is_ccs; 1290 1291 /* save current state */ 1292 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1293 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1294 frag->msg_header.saved_retransmit_state.compress = s->compress; 1295 frag->msg_header.saved_retransmit_state.session = s->session; 1296 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1297 1298 memset(seq64be, 0, sizeof(seq64be)); 1299 seq64be[6] = 1300 (unsigned 1301 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1302 frag->msg_header.is_ccs) >> 8); 1303 seq64be[7] = 1304 (unsigned 1305 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1306 frag->msg_header.is_ccs)); 1307 1308 item = pitem_new(seq64be, frag); 1309 if (item == NULL) { 1310 dtls1_hm_fragment_free(frag); 1311 return 0; 1312 } 1313#if 0 1314 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1315 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1316 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1317#endif 1318 1319 pqueue_insert(s->d1->sent_messages, item); 1320 return 1; 1321} 1322 1323int 1324dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1325 int *found) 1326{ 1327 int ret; 1328 /* XDTLS: for now assuming that read/writes are blocking */ 1329 pitem *item; 1330 hm_fragment *frag; 1331 unsigned long header_length; 1332 unsigned char seq64be[8]; 1333 struct dtls1_retransmit_state saved_state; 1334 unsigned char save_write_sequence[8]; 1335 1336 /*- 1337 OPENSSL_assert(s->init_num == 0); 1338 OPENSSL_assert(s->init_off == 0); 1339 */ 1340 1341 /* XDTLS: the requested message ought to be found, otherwise error */ 1342 memset(seq64be, 0, sizeof(seq64be)); 1343 seq64be[6] = (unsigned char)(seq >> 8); 1344 seq64be[7] = (unsigned char)seq; 1345 1346 item = pqueue_find(s->d1->sent_messages, seq64be); 1347 if (item == NULL) { 1348 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1349 *found = 0; 1350 return 0; 1351 } 1352 1353 *found = 1; 1354 frag = (hm_fragment *)item->data; 1355 1356 if (frag->msg_header.is_ccs) 1357 header_length = DTLS1_CCS_HEADER_LENGTH; 1358 else 1359 header_length = DTLS1_HM_HEADER_LENGTH; 1360 1361 memcpy(s->init_buf->data, frag->fragment, 1362 frag->msg_header.msg_len + header_length); 1363 s->init_num = frag->msg_header.msg_len + header_length; 1364 1365 dtls1_set_message_header_int(s, frag->msg_header.type, 1366 frag->msg_header.msg_len, 1367 frag->msg_header.seq, 0, 1368 frag->msg_header.frag_len); 1369 1370 /* save current state */ 1371 saved_state.enc_write_ctx = s->enc_write_ctx; 1372 saved_state.write_hash = s->write_hash; 1373 saved_state.compress = s->compress; 1374 saved_state.session = s->session; 1375 saved_state.epoch = s->d1->w_epoch; 1376 saved_state.epoch = s->d1->w_epoch; 1377 1378 s->d1->retransmitting = 1; 1379 1380 /* restore state in which the message was originally sent */ 1381 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1382 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1383 s->compress = frag->msg_header.saved_retransmit_state.compress; 1384 s->session = frag->msg_header.saved_retransmit_state.session; 1385 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1386 1387 if (frag->msg_header.saved_retransmit_state.epoch == 1388 saved_state.epoch - 1) { 1389 memcpy(save_write_sequence, s->s3->write_sequence, 1390 sizeof(s->s3->write_sequence)); 1391 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1392 sizeof(s->s3->write_sequence)); 1393 } 1394 1395 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1396 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1397 1398 /* restore current state */ 1399 s->enc_write_ctx = saved_state.enc_write_ctx; 1400 s->write_hash = saved_state.write_hash; 1401 s->compress = saved_state.compress; 1402 s->session = saved_state.session; 1403 s->d1->w_epoch = saved_state.epoch; 1404 1405 if (frag->msg_header.saved_retransmit_state.epoch == 1406 saved_state.epoch - 1) { 1407 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1408 sizeof(s->s3->write_sequence)); 1409 memcpy(s->s3->write_sequence, save_write_sequence, 1410 sizeof(s->s3->write_sequence)); 1411 } 1412 1413 s->d1->retransmitting = 0; 1414 1415 (void)BIO_flush(SSL_get_wbio(s)); 1416 return ret; 1417} 1418 1419/* call this function when the buffered messages are no longer needed */ 1420void dtls1_clear_record_buffer(SSL *s) 1421{ 1422 pitem *item; 1423 1424 for (item = pqueue_pop(s->d1->sent_messages); 1425 item != NULL; item = pqueue_pop(s->d1->sent_messages)) { 1426 dtls1_hm_fragment_free((hm_fragment *)item->data); 1427 pitem_free(item); 1428 } 1429} 1430 1431unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1432 unsigned char mt, unsigned long len, 1433 unsigned long frag_off, 1434 unsigned long frag_len) 1435{ 1436 /* Don't change sequence numbers while listening */ 1437 if (frag_off == 0 && !s->d1->listen) { 1438 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1439 s->d1->next_handshake_write_seq++; 1440 } 1441 1442 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1443 frag_off, frag_len); 1444 1445 return p += DTLS1_HM_HEADER_LENGTH; 1446} 1447 1448/* don't actually do the writing, wait till the MTU has been retrieved */ 1449static void 1450dtls1_set_message_header_int(SSL *s, unsigned char mt, 1451 unsigned long len, unsigned short seq_num, 1452 unsigned long frag_off, unsigned long frag_len) 1453{ 1454 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1455 1456 msg_hdr->type = mt; 1457 msg_hdr->msg_len = len; 1458 msg_hdr->seq = seq_num; 1459 msg_hdr->frag_off = frag_off; 1460 msg_hdr->frag_len = frag_len; 1461} 1462 1463static void 1464dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1465 unsigned long frag_len) 1466{ 1467 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1468 1469 msg_hdr->frag_off = frag_off; 1470 msg_hdr->frag_len = frag_len; 1471} 1472 1473static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1474{ 1475 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1476 1477 *p++ = msg_hdr->type; 1478 l2n3(msg_hdr->msg_len, p); 1479 1480 s2n(msg_hdr->seq, p); 1481 l2n3(msg_hdr->frag_off, p); 1482 l2n3(msg_hdr->frag_len, p); 1483 1484 return p; 1485} 1486 1487unsigned int dtls1_link_min_mtu(void) 1488{ 1489 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1490 sizeof(g_probable_mtu[0])) - 1]); 1491} 1492 1493unsigned int dtls1_min_mtu(SSL *s) 1494{ 1495 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1496} 1497 1498void 1499dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1500{ 1501 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1502 msg_hdr->type = *(data++); 1503 n2l3(data, msg_hdr->msg_len); 1504 1505 n2s(data, msg_hdr->seq); 1506 n2l3(data, msg_hdr->frag_off); 1507 n2l3(data, msg_hdr->frag_len); 1508} 1509 1510void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1511{ 1512 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1513 1514 ccs_hdr->type = *(data++); 1515} 1516 1517int dtls1_shutdown(SSL *s) 1518{ 1519 int ret; 1520#ifndef OPENSSL_NO_SCTP 1521 BIO *wbio; 1522 1523 wbio = SSL_get_wbio(s); 1524 if (wbio != NULL && BIO_dgram_is_sctp(wbio) && 1525 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1526 ret = BIO_dgram_sctp_wait_for_dry(wbio); 1527 if (ret < 0) 1528 return -1; 1529 1530 if (ret == 0) 1531 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1532 NULL); 1533 } 1534#endif 1535 ret = ssl3_shutdown(s); 1536#ifndef OPENSSL_NO_SCTP 1537 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1538#endif 1539 return ret; 1540} 1541 1542#ifndef OPENSSL_NO_HEARTBEATS 1543int dtls1_process_heartbeat(SSL *s) 1544{ 1545 unsigned char *p = &s->s3->rrec.data[0], *pl; 1546 unsigned short hbtype; 1547 unsigned int payload; 1548 unsigned int padding = 16; /* Use minimum padding */ 1549 1550 if (s->msg_callback) 1551 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1552 &s->s3->rrec.data[0], s->s3->rrec.length, 1553 s, s->msg_callback_arg); 1554 1555 /* Read type and payload length first */ 1556 if (1 + 2 + 16 > s->s3->rrec.length) 1557 return 0; /* silently discard */ 1558 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1559 return 0; /* silently discard per RFC 6520 sec. 4 */ 1560 1561 hbtype = *p++; 1562 n2s(p, payload); 1563 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1564 return 0; /* silently discard per RFC 6520 sec. 4 */ 1565 pl = p; 1566 1567 if (hbtype == TLS1_HB_REQUEST) { 1568 unsigned char *buffer, *bp; 1569 unsigned int write_length = 1 /* heartbeat type */ + 1570 2 /* heartbeat length */ + 1571 payload + padding; 1572 int r; 1573 1574 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1575 return 0; 1576 1577 /* 1578 * Allocate memory for the response, size is 1 byte message type, 1579 * plus 2 bytes payload length, plus payload, plus padding 1580 */ 1581 buffer = OPENSSL_malloc(write_length); 1582 bp = buffer; 1583 1584 /* Enter response type, length and copy payload */ 1585 *bp++ = TLS1_HB_RESPONSE; 1586 s2n(payload, bp); 1587 memcpy(bp, pl, payload); 1588 bp += payload; 1589 /* Random padding */ 1590 if (RAND_pseudo_bytes(bp, padding) < 0) { 1591 OPENSSL_free(buffer); 1592 return -1; 1593 } 1594 1595 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1596 1597 if (r >= 0 && s->msg_callback) 1598 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1599 buffer, write_length, s, s->msg_callback_arg); 1600 1601 OPENSSL_free(buffer); 1602 1603 if (r < 0) 1604 return r; 1605 } else if (hbtype == TLS1_HB_RESPONSE) { 1606 unsigned int seq; 1607 1608 /* 1609 * We only send sequence numbers (2 bytes unsigned int), and 16 1610 * random bytes, so we just try to read the sequence number 1611 */ 1612 n2s(pl, seq); 1613 1614 if (payload == 18 && seq == s->tlsext_hb_seq) { 1615 dtls1_stop_timer(s); 1616 s->tlsext_hb_seq++; 1617 s->tlsext_hb_pending = 0; 1618 } 1619 } 1620 1621 return 0; 1622} 1623 1624int dtls1_heartbeat(SSL *s) 1625{ 1626 unsigned char *buf, *p; 1627 int ret = -1; 1628 unsigned int payload = 18; /* Sequence number + random bytes */ 1629 unsigned int padding = 16; /* Use minimum padding */ 1630 1631 /* Only send if peer supports and accepts HB requests... */ 1632 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1633 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1634 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1635 return -1; 1636 } 1637 1638 /* ...and there is none in flight yet... */ 1639 if (s->tlsext_hb_pending) { 1640 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1641 return -1; 1642 } 1643 1644 /* ...and no handshake in progress. */ 1645 if (SSL_in_init(s) || s->in_handshake) { 1646 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1647 return -1; 1648 } 1649 1650 /* 1651 * Check if padding is too long, payload and padding must not exceed 2^14 1652 * - 3 = 16381 bytes in total. 1653 */ 1654 OPENSSL_assert(payload + padding <= 16381); 1655 1656 /*- 1657 * Create HeartBeat message, we just use a sequence number 1658 * as payload to distuingish different messages and add 1659 * some random stuff. 1660 * - Message Type, 1 byte 1661 * - Payload Length, 2 bytes (unsigned int) 1662 * - Payload, the sequence number (2 bytes uint) 1663 * - Payload, random bytes (16 bytes uint) 1664 * - Padding 1665 */ 1666 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1667 p = buf; 1668 /* Message Type */ 1669 *p++ = TLS1_HB_REQUEST; 1670 /* Payload length (18 bytes here) */ 1671 s2n(payload, p); 1672 /* Sequence number */ 1673 s2n(s->tlsext_hb_seq, p); 1674 /* 16 random bytes */ 1675 if (RAND_pseudo_bytes(p, 16) < 0) 1676 goto err; 1677 p += 16; 1678 /* Random padding */ 1679 if (RAND_pseudo_bytes(p, padding) < 0) 1680 goto err; 1681 1682 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1683 if (ret >= 0) { 1684 if (s->msg_callback) 1685 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1686 buf, 3 + payload + padding, 1687 s, s->msg_callback_arg); 1688 1689 dtls1_start_timer(s); 1690 s->tlsext_hb_pending = 1; 1691 } 1692 1693err: 1694 OPENSSL_free(buf); 1695 1696 return ret; 1697} 1698#endif 1699