d1_both.c revision 280304
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->init_num shouldn't ever be < 0...but just in case */ 295 while (s->init_num > 0) { 296 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH 297 + mac_size + blocksize; 298 if (s->d1->mtu > used_len) 299 curr_mtu = s->d1->mtu - used_len; 300 else 301 curr_mtu = 0; 302 303 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 304 /* 305 * grr.. we could get an error if MTU picked was wrong 306 */ 307 ret = BIO_flush(SSL_get_wbio(s)); 308 if (ret <= 0) 309 return ret; 310 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 311 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) { 312 curr_mtu = s->d1->mtu - used_len; 313 } else { 314 /* Shouldn't happen */ 315 return -1; 316 } 317 } 318 319 /* 320 * We just checked that s->init_num > 0 so this cast should be safe 321 */ 322 if (((unsigned int)s->init_num) > curr_mtu) 323 len = curr_mtu; 324 else 325 len = s->init_num; 326 327 /* Shouldn't ever happen */ 328 if (len > INT_MAX) 329 len = INT_MAX; 330 331 /* 332 * XDTLS: this function is too long. split out the CCS part 333 */ 334 if (type == SSL3_RT_HANDSHAKE) { 335 if (s->init_off != 0) { 336 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 337 s->init_off -= DTLS1_HM_HEADER_LENGTH; 338 s->init_num += DTLS1_HM_HEADER_LENGTH; 339 340 /* 341 * We just checked that s->init_num > 0 so this cast should 342 * be safe 343 */ 344 if (((unsigned int)s->init_num) > curr_mtu) 345 len = curr_mtu; 346 else 347 len = s->init_num; 348 } 349 350 /* Shouldn't ever happen */ 351 if (len > INT_MAX) 352 len = INT_MAX; 353 354 if (len < DTLS1_HM_HEADER_LENGTH) { 355 /* 356 * len is so small that we really can't do anything sensible 357 * so fail 358 */ 359 return -1; 360 } 361 dtls1_fix_message_header(s, frag_off, 362 len - DTLS1_HM_HEADER_LENGTH); 363 364 dtls1_write_message_header(s, 365 (unsigned char *)&s->init_buf-> 366 data[s->init_off]); 367 } 368 369 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], 370 len); 371 if (ret < 0) { 372 /* 373 * might need to update MTU here, but we don't know which 374 * previous packet caused the failure -- so can't really 375 * retransmit anything. continue as if everything is fine and 376 * wait for an alert to handle the retransmit 377 */ 378 if (retry && BIO_ctrl(SSL_get_wbio(s), 379 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) { 380 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 381 if (!dtls1_query_mtu(s)) 382 return -1; 383 /* Have one more go */ 384 retry = 0; 385 } else 386 return -1; 387 } else { 388 return (-1); 389 } 390 } else { 391 392 /* 393 * bad if this assert fails, only part of the handshake message 394 * got sent. but why would this happen? 395 */ 396 OPENSSL_assert(len == (unsigned int)ret); 397 398 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 399 /* 400 * should not be done for 'Hello Request's, but in that case 401 * we'll ignore the result anyway 402 */ 403 unsigned char *p = 404 (unsigned char *)&s->init_buf->data[s->init_off]; 405 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 406 int xlen; 407 408 if (frag_off == 0 && s->version != DTLS1_BAD_VER) { 409 /* 410 * reconstruct message header is if it is being sent in 411 * single fragment 412 */ 413 *p++ = msg_hdr->type; 414 l2n3(msg_hdr->msg_len, p); 415 s2n(msg_hdr->seq, p); 416 l2n3(0, p); 417 l2n3(msg_hdr->msg_len, p); 418 p -= DTLS1_HM_HEADER_LENGTH; 419 xlen = ret; 420 } else { 421 p += DTLS1_HM_HEADER_LENGTH; 422 xlen = ret - DTLS1_HM_HEADER_LENGTH; 423 } 424 425 ssl3_finish_mac(s, p, xlen); 426 } 427 428 if (ret == s->init_num) { 429 if (s->msg_callback) 430 s->msg_callback(1, s->version, type, s->init_buf->data, 431 (size_t)(s->init_off + s->init_num), s, 432 s->msg_callback_arg); 433 434 s->init_off = 0; /* done writing this message */ 435 s->init_num = 0; 436 437 return (1); 438 } 439 s->init_off += ret; 440 s->init_num -= ret; 441 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 442 } 443 } 444 return (0); 445} 446 447/* 448 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum 449 * acceptable body length 'max'. Read an entire handshake message. Handshake 450 * messages arrive in fragments. 451 */ 452long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 453{ 454 int i, al; 455 struct hm_header_st *msg_hdr; 456 unsigned char *p; 457 unsigned long msg_len; 458 459 /* 460 * s3->tmp is used to store messages that are unexpected, caused by the 461 * absence of an optional handshake message 462 */ 463 if (s->s3->tmp.reuse_message) { 464 s->s3->tmp.reuse_message = 0; 465 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 466 al = SSL_AD_UNEXPECTED_MESSAGE; 467 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 468 goto f_err; 469 } 470 *ok = 1; 471 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 472 s->init_num = (int)s->s3->tmp.message_size; 473 return s->init_num; 474 } 475 476 msg_hdr = &s->d1->r_msg_hdr; 477 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 478 479 again: 480 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 481 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) { 482 /* bad fragment received */ 483 goto again; 484 } else if (i <= 0 && !*ok) { 485 return i; 486 } 487 488 p = (unsigned char *)s->init_buf->data; 489 msg_len = msg_hdr->msg_len; 490 491 /* reconstruct message header */ 492 *(p++) = msg_hdr->type; 493 l2n3(msg_len, p); 494 s2n(msg_hdr->seq, p); 495 l2n3(0, p); 496 l2n3(msg_len, p); 497 if (s->version != DTLS1_BAD_VER) { 498 p -= DTLS1_HM_HEADER_LENGTH; 499 msg_len += DTLS1_HM_HEADER_LENGTH; 500 } 501 502 ssl3_finish_mac(s, p, msg_len); 503 if (s->msg_callback) 504 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 505 p, msg_len, s, s->msg_callback_arg); 506 507 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 508 509 /* Don't change sequence numbers while listening */ 510 if (!s->d1->listen) 511 s->d1->handshake_read_seq++; 512 513 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 514 return s->init_num; 515 516 f_err: 517 ssl3_send_alert(s, SSL3_AL_FATAL, al); 518 *ok = 0; 519 return -1; 520} 521 522static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 523 int max) 524{ 525 size_t frag_off, frag_len, msg_len; 526 527 msg_len = msg_hdr->msg_len; 528 frag_off = msg_hdr->frag_off; 529 frag_len = msg_hdr->frag_len; 530 531 /* sanity checking */ 532 if ((frag_off + frag_len) > msg_len) { 533 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 534 return SSL_AD_ILLEGAL_PARAMETER; 535 } 536 537 if ((frag_off + frag_len) > (unsigned long)max) { 538 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 539 return SSL_AD_ILLEGAL_PARAMETER; 540 } 541 542 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 543 /* 544 * msg_len is limited to 2^24, but is effectively checked against max 545 * above 546 */ 547 if (!BUF_MEM_grow_clean 548 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { 549 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 550 return SSL_AD_INTERNAL_ERROR; 551 } 552 553 s->s3->tmp.message_size = msg_len; 554 s->d1->r_msg_hdr.msg_len = msg_len; 555 s->s3->tmp.message_type = msg_hdr->type; 556 s->d1->r_msg_hdr.type = msg_hdr->type; 557 s->d1->r_msg_hdr.seq = msg_hdr->seq; 558 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 559 /* 560 * They must be playing with us! BTW, failure to enforce upper limit 561 * would open possibility for buffer overrun. 562 */ 563 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 564 return SSL_AD_ILLEGAL_PARAMETER; 565 } 566 567 return 0; /* no error */ 568} 569 570static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 571{ 572 /*- 573 * (0) check whether the desired fragment is available 574 * if so: 575 * (1) copy over the fragment to s->init_buf->data[] 576 * (2) update s->init_num 577 */ 578 pitem *item; 579 hm_fragment *frag; 580 int al; 581 582 *ok = 0; 583 item = pqueue_peek(s->d1->buffered_messages); 584 if (item == NULL) 585 return 0; 586 587 frag = (hm_fragment *)item->data; 588 589 /* Don't return if reassembly still in progress */ 590 if (frag->reassembly != NULL) 591 return 0; 592 593 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 594 unsigned long frag_len = frag->msg_header.frag_len; 595 pqueue_pop(s->d1->buffered_messages); 596 597 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 598 599 if (al == 0) { /* no alert */ 600 unsigned char *p = 601 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 602 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 603 frag->msg_header.frag_len); 604 } 605 606 dtls1_hm_fragment_free(frag); 607 pitem_free(item); 608 609 if (al == 0) { 610 *ok = 1; 611 return frag_len; 612 } 613 614 ssl3_send_alert(s, SSL3_AL_FATAL, al); 615 s->init_num = 0; 616 *ok = 0; 617 return -1; 618 } else 619 return 0; 620} 621 622/* 623 * dtls1_max_handshake_message_len returns the maximum number of bytes 624 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 625 * may be greater if the maximum certificate list size requires it. 626 */ 627static unsigned long dtls1_max_handshake_message_len(const SSL *s) 628{ 629 unsigned long max_len = 630 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 631 if (max_len < (unsigned long)s->max_cert_list) 632 return s->max_cert_list; 633 return max_len; 634} 635 636static int 637dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 638{ 639 hm_fragment *frag = NULL; 640 pitem *item = NULL; 641 int i = -1, is_complete; 642 unsigned char seq64be[8]; 643 unsigned long frag_len = msg_hdr->frag_len; 644 645 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 646 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 647 goto err; 648 649 if (frag_len == 0) 650 return DTLS1_HM_FRAGMENT_RETRY; 651 652 /* Try to find item in queue */ 653 memset(seq64be, 0, sizeof(seq64be)); 654 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 655 seq64be[7] = (unsigned char)msg_hdr->seq; 656 item = pqueue_find(s->d1->buffered_messages, seq64be); 657 658 if (item == NULL) { 659 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 660 if (frag == NULL) 661 goto err; 662 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 663 frag->msg_header.frag_len = frag->msg_header.msg_len; 664 frag->msg_header.frag_off = 0; 665 } else { 666 frag = (hm_fragment *)item->data; 667 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 668 item = NULL; 669 frag = NULL; 670 goto err; 671 } 672 } 673 674 /* 675 * If message is already reassembled, this must be a retransmit and can 676 * be dropped. In this case item != NULL and so frag does not need to be 677 * freed. 678 */ 679 if (frag->reassembly == NULL) { 680 unsigned char devnull[256]; 681 682 while (frag_len) { 683 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 684 devnull, 685 frag_len > 686 sizeof(devnull) ? sizeof(devnull) : 687 frag_len, 0); 688 if (i <= 0) 689 goto err; 690 frag_len -= i; 691 } 692 return DTLS1_HM_FRAGMENT_RETRY; 693 } 694 695 /* read the body of the fragment (header has already been read */ 696 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 697 frag->fragment + msg_hdr->frag_off, 698 frag_len, 0); 699 if ((unsigned long)i != frag_len) 700 i = -1; 701 if (i <= 0) 702 goto err; 703 704 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 705 (long)(msg_hdr->frag_off + frag_len)); 706 707 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 708 is_complete); 709 710 if (is_complete) { 711 OPENSSL_free(frag->reassembly); 712 frag->reassembly = NULL; 713 } 714 715 if (item == NULL) { 716 item = pitem_new(seq64be, frag); 717 if (item == NULL) { 718 i = -1; 719 goto err; 720 } 721 722 item = pqueue_insert(s->d1->buffered_messages, item); 723 /* 724 * pqueue_insert fails iff a duplicate item is inserted. However, 725 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 726 * would have returned it and control would never have reached this 727 * branch. 728 */ 729 OPENSSL_assert(item != NULL); 730 } 731 732 return DTLS1_HM_FRAGMENT_RETRY; 733 734 err: 735 if (frag != NULL && item == NULL) 736 dtls1_hm_fragment_free(frag); 737 *ok = 0; 738 return i; 739} 740 741static int 742dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 743 int *ok) 744{ 745 int i = -1; 746 hm_fragment *frag = NULL; 747 pitem *item = NULL; 748 unsigned char seq64be[8]; 749 unsigned long frag_len = msg_hdr->frag_len; 750 751 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 752 goto err; 753 754 /* Try to find item in queue, to prevent duplicate entries */ 755 memset(seq64be, 0, sizeof(seq64be)); 756 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 757 seq64be[7] = (unsigned char)msg_hdr->seq; 758 item = pqueue_find(s->d1->buffered_messages, seq64be); 759 760 /* 761 * If we already have an entry and this one is a fragment, don't discard 762 * it and rather try to reassemble it. 763 */ 764 if (item != NULL && frag_len != msg_hdr->msg_len) 765 item = NULL; 766 767 /* 768 * Discard the message if sequence number was already there, is too far 769 * in the future, already in the queue or if we received a FINISHED 770 * before the SERVER_HELLO, which then must be a stale retransmit. 771 */ 772 if (msg_hdr->seq <= s->d1->handshake_read_seq || 773 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 774 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 775 { 776 unsigned char devnull[256]; 777 778 while (frag_len) { 779 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 780 devnull, 781 frag_len > 782 sizeof(devnull) ? sizeof(devnull) : 783 frag_len, 0); 784 if (i <= 0) 785 goto err; 786 frag_len -= i; 787 } 788 } else { 789 if (frag_len != msg_hdr->msg_len) 790 return dtls1_reassemble_fragment(s, msg_hdr, ok); 791 792 if (frag_len > dtls1_max_handshake_message_len(s)) 793 goto err; 794 795 frag = dtls1_hm_fragment_new(frag_len, 0); 796 if (frag == NULL) 797 goto err; 798 799 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 800 801 if (frag_len) { 802 /* 803 * read the body of the fragment (header has already been read 804 */ 805 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 806 frag->fragment, frag_len, 0); 807 if ((unsigned long)i != frag_len) 808 i = -1; 809 if (i <= 0) 810 goto err; 811 } 812 813 item = pitem_new(seq64be, frag); 814 if (item == NULL) 815 goto err; 816 817 item = pqueue_insert(s->d1->buffered_messages, item); 818 /* 819 * pqueue_insert fails iff a duplicate item is inserted. However, 820 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 821 * would have returned it. Then, either |frag_len| != 822 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 823 * have been processed with |dtls1_reassemble_fragment|, above, or 824 * the record will have been discarded. 825 */ 826 OPENSSL_assert(item != NULL); 827 } 828 829 return DTLS1_HM_FRAGMENT_RETRY; 830 831 err: 832 if (frag != NULL && item == NULL) 833 dtls1_hm_fragment_free(frag); 834 *ok = 0; 835 return i; 836} 837 838static long 839dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 840{ 841 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 842 unsigned long len, frag_off, frag_len; 843 int i, al; 844 struct hm_header_st msg_hdr; 845 846 redo: 847 /* see if we have the required fragment already */ 848 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 849 if (*ok) 850 s->init_num = frag_len; 851 return frag_len; 852 } 853 854 /* read handshake message header */ 855 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 856 DTLS1_HM_HEADER_LENGTH, 0); 857 if (i <= 0) { /* nbio, or an error */ 858 s->rwstate = SSL_READING; 859 *ok = 0; 860 return i; 861 } 862 /* Handshake fails if message header is incomplete */ 863 if (i != DTLS1_HM_HEADER_LENGTH) { 864 al = SSL_AD_UNEXPECTED_MESSAGE; 865 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 866 goto f_err; 867 } 868 869 /* parse the message fragment header */ 870 dtls1_get_message_header(wire, &msg_hdr); 871 872 /* 873 * if this is a future (or stale) message it gets buffered 874 * (or dropped)--no further processing at this time 875 * While listening, we accept seq 1 (ClientHello with cookie) 876 * although we're still expecting seq 0 (ClientHello) 877 */ 878 if (msg_hdr.seq != s->d1->handshake_read_seq 879 && !(s->d1->listen && msg_hdr.seq == 1)) 880 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 881 882 len = msg_hdr.msg_len; 883 frag_off = msg_hdr.frag_off; 884 frag_len = msg_hdr.frag_len; 885 886 if (frag_len && frag_len < len) 887 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 888 889 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 890 wire[0] == SSL3_MT_HELLO_REQUEST) { 891 /* 892 * The server may always send 'Hello Request' messages -- we are 893 * doing a handshake anyway now, so ignore them if their format is 894 * correct. Does not count for 'Finished' MAC. 895 */ 896 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 897 if (s->msg_callback) 898 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 899 wire, DTLS1_HM_HEADER_LENGTH, s, 900 s->msg_callback_arg); 901 902 s->init_num = 0; 903 goto redo; 904 } else { /* Incorrectly formated Hello request */ 905 906 al = SSL_AD_UNEXPECTED_MESSAGE; 907 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 908 SSL_R_UNEXPECTED_MESSAGE); 909 goto f_err; 910 } 911 } 912 913 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 914 goto f_err; 915 916 /* XDTLS: ressurect this when restart is in place */ 917 s->state = stn; 918 919 if (frag_len > 0) { 920 unsigned char *p = 921 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 922 923 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 924 &p[frag_off], frag_len, 0); 925 /* 926 * XDTLS: fix this--message fragments cannot span multiple packets 927 */ 928 if (i <= 0) { 929 s->rwstate = SSL_READING; 930 *ok = 0; 931 return i; 932 } 933 } else 934 i = 0; 935 936 /* 937 * XDTLS: an incorrectly formatted fragment should cause the handshake 938 * to fail 939 */ 940 if (i != (int)frag_len) { 941 al = SSL3_AD_ILLEGAL_PARAMETER; 942 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 943 goto f_err; 944 } 945 946 *ok = 1; 947 948 /* 949 * Note that s->init_num is *not* used as current offset in 950 * s->init_buf->data, but as a counter summing up fragments' lengths: as 951 * soon as they sum up to handshake packet length, we assume we have got 952 * all the fragments. 953 */ 954 s->init_num = frag_len; 955 return frag_len; 956 957 f_err: 958 ssl3_send_alert(s, SSL3_AL_FATAL, al); 959 s->init_num = 0; 960 961 *ok = 0; 962 return (-1); 963} 964 965int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 966{ 967 unsigned char *p, *d; 968 int i; 969 unsigned long l; 970 971 if (s->state == a) { 972 d = (unsigned char *)s->init_buf->data; 973 p = &(d[DTLS1_HM_HEADER_LENGTH]); 974 975 i = s->method->ssl3_enc->final_finish_mac(s, 976 sender, slen, 977 s->s3->tmp.finish_md); 978 s->s3->tmp.finish_md_len = i; 979 memcpy(p, s->s3->tmp.finish_md, i); 980 p += i; 981 l = i; 982 983 /* 984 * Copy the finished so we can use it for renegotiation checks 985 */ 986 if (s->type == SSL_ST_CONNECT) { 987 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 988 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i); 989 s->s3->previous_client_finished_len = i; 990 } else { 991 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 992 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i); 993 s->s3->previous_server_finished_len = i; 994 } 995 996#ifdef OPENSSL_SYS_WIN16 997 /* 998 * MSVC 1.5 does not clear the top bytes of the word unless I do 999 * this. 1000 */ 1001 l &= 0xffff; 1002#endif 1003 1004 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 1005 s->init_num = (int)l + DTLS1_HM_HEADER_LENGTH; 1006 s->init_off = 0; 1007 1008 /* buffer the message to handle re-xmits */ 1009 dtls1_buffer_message(s, 0); 1010 1011 s->state = b; 1012 } 1013 1014 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 1015 return (dtls1_do_write(s, SSL3_RT_HANDSHAKE)); 1016} 1017 1018/*- 1019 * for these 2 messages, we need to 1020 * ssl->enc_read_ctx re-init 1021 * ssl->s3->read_sequence zero 1022 * ssl->s3->read_mac_secret re-init 1023 * ssl->session->read_sym_enc assign 1024 * ssl->session->read_compression assign 1025 * ssl->session->read_hash assign 1026 */ 1027int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1028{ 1029 unsigned char *p; 1030 1031 if (s->state == a) { 1032 p = (unsigned char *)s->init_buf->data; 1033 *p++ = SSL3_MT_CCS; 1034 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1035 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1036 1037 if (s->version == DTLS1_BAD_VER) { 1038 s->d1->next_handshake_write_seq++; 1039 s2n(s->d1->handshake_write_seq, p); 1040 s->init_num += 2; 1041 } 1042 1043 s->init_off = 0; 1044 1045 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1046 s->d1->handshake_write_seq, 0, 0); 1047 1048 /* buffer the message to handle re-xmits */ 1049 dtls1_buffer_message(s, 1); 1050 1051 s->state = b; 1052 } 1053 1054 /* SSL3_ST_CW_CHANGE_B */ 1055 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1056} 1057 1058static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1059{ 1060 int n; 1061 unsigned char *p; 1062 1063 n = i2d_X509(x, NULL); 1064 if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) { 1065 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB); 1066 return 0; 1067 } 1068 p = (unsigned char *)&(buf->data[*l]); 1069 l2n3(n, p); 1070 i2d_X509(x, &p); 1071 *l += n + 3; 1072 1073 return 1; 1074} 1075 1076unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1077{ 1078 unsigned char *p; 1079 int i; 1080 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH; 1081 BUF_MEM *buf; 1082 1083 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1084 buf = s->init_buf; 1085 if (!BUF_MEM_grow_clean(buf, 10)) { 1086 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB); 1087 return (0); 1088 } 1089 if (x != NULL) { 1090 X509_STORE_CTX xs_ctx; 1091 1092 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, x, NULL)) { 1093 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB); 1094 return (0); 1095 } 1096 1097 X509_verify_cert(&xs_ctx); 1098 /* Don't leave errors in the queue */ 1099 ERR_clear_error(); 1100 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) { 1101 x = sk_X509_value(xs_ctx.chain, i); 1102 1103 if (!dtls1_add_cert_to_buf(buf, &l, x)) { 1104 X509_STORE_CTX_cleanup(&xs_ctx); 1105 return 0; 1106 } 1107 } 1108 X509_STORE_CTX_cleanup(&xs_ctx); 1109 } 1110 /* Thawte special :-) */ 1111 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) { 1112 x = sk_X509_value(s->ctx->extra_certs, i); 1113 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1114 return 0; 1115 } 1116 1117 l -= (3 + DTLS1_HM_HEADER_LENGTH); 1118 1119 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1120 l2n3(l, p); 1121 l += 3; 1122 p = (unsigned char *)&(buf->data[0]); 1123 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1124 1125 l += DTLS1_HM_HEADER_LENGTH; 1126 return (l); 1127} 1128 1129int dtls1_read_failed(SSL *s, int code) 1130{ 1131 if (code > 0) { 1132 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1133 return 1; 1134 } 1135 1136 if (!dtls1_is_timer_expired(s)) { 1137 /* 1138 * not a timeout, none of our business, let higher layers handle 1139 * this. in fact it's probably an error 1140 */ 1141 return code; 1142 } 1143#ifndef OPENSSL_NO_HEARTBEATS 1144 /* done, no need to send a retransmit */ 1145 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1146#else 1147 /* done, no need to send a retransmit */ 1148 if (!SSL_in_init(s)) 1149#endif 1150 { 1151 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1152 return code; 1153 } 1154#if 0 /* for now, each alert contains only one 1155 * record number */ 1156 item = pqueue_peek(state->rcvd_records); 1157 if (item) { 1158 /* send an alert immediately for all the missing records */ 1159 } else 1160#endif 1161 1162#if 0 /* no more alert sending, just retransmit the 1163 * last set of messages */ 1164 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1165 ssl3_send_alert(s, SSL3_AL_WARNING, 1166 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1167#endif 1168 1169 return dtls1_handle_timeout(s); 1170} 1171 1172int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1173{ 1174 /* 1175 * The index of the retransmission queue actually is the message sequence 1176 * number, since the queue only contains messages of a single handshake. 1177 * However, the ChangeCipherSpec has no message sequence number and so 1178 * using only the sequence will result in the CCS and Finished having the 1179 * same index. To prevent this, the sequence number is multiplied by 2. 1180 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1181 * Finished, it also maintains the order of the index (important for 1182 * priority queues) and fits in the unsigned short variable. 1183 */ 1184 return seq * 2 - is_ccs; 1185} 1186 1187int dtls1_retransmit_buffered_messages(SSL *s) 1188{ 1189 pqueue sent = s->d1->sent_messages; 1190 piterator iter; 1191 pitem *item; 1192 hm_fragment *frag; 1193 int found = 0; 1194 1195 iter = pqueue_iterator(sent); 1196 1197 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1198 frag = (hm_fragment *)item->data; 1199 if (dtls1_retransmit_message(s, (unsigned short) 1200 dtls1_get_queue_priority 1201 (frag->msg_header.seq, 1202 frag->msg_header.is_ccs), 0, 1203 &found) <= 0 && found) { 1204 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1205 return -1; 1206 } 1207 } 1208 1209 return 1; 1210} 1211 1212int dtls1_buffer_message(SSL *s, int is_ccs) 1213{ 1214 pitem *item; 1215 hm_fragment *frag; 1216 unsigned char seq64be[8]; 1217 1218 /* 1219 * this function is called immediately after a message has been 1220 * serialized 1221 */ 1222 OPENSSL_assert(s->init_off == 0); 1223 1224 frag = dtls1_hm_fragment_new(s->init_num, 0); 1225 if (!frag) 1226 return 0; 1227 1228 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1229 1230 if (is_ccs) { 1231 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1232 ((s->version == 1233 DTLS1_VERSION) ? DTLS1_CCS_HEADER_LENGTH : 3) == 1234 (unsigned int)s->init_num); 1235 } else { 1236 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1237 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1238 } 1239 1240 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1241 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1242 frag->msg_header.type = s->d1->w_msg_hdr.type; 1243 frag->msg_header.frag_off = 0; 1244 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1245 frag->msg_header.is_ccs = is_ccs; 1246 1247 /* save current state */ 1248 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1249 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1250 frag->msg_header.saved_retransmit_state.compress = s->compress; 1251 frag->msg_header.saved_retransmit_state.session = s->session; 1252 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1253 1254 memset(seq64be, 0, sizeof(seq64be)); 1255 seq64be[6] = 1256 (unsigned 1257 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1258 frag->msg_header.is_ccs) >> 8); 1259 seq64be[7] = 1260 (unsigned 1261 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1262 frag->msg_header.is_ccs)); 1263 1264 item = pitem_new(seq64be, frag); 1265 if (item == NULL) { 1266 dtls1_hm_fragment_free(frag); 1267 return 0; 1268 } 1269#if 0 1270 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1271 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1272 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1273#endif 1274 1275 pqueue_insert(s->d1->sent_messages, item); 1276 return 1; 1277} 1278 1279int 1280dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1281 int *found) 1282{ 1283 int ret; 1284 /* XDTLS: for now assuming that read/writes are blocking */ 1285 pitem *item; 1286 hm_fragment *frag; 1287 unsigned long header_length; 1288 unsigned char seq64be[8]; 1289 struct dtls1_retransmit_state saved_state; 1290 unsigned char save_write_sequence[8]; 1291 1292 /*- 1293 OPENSSL_assert(s->init_num == 0); 1294 OPENSSL_assert(s->init_off == 0); 1295 */ 1296 1297 /* XDTLS: the requested message ought to be found, otherwise error */ 1298 memset(seq64be, 0, sizeof(seq64be)); 1299 seq64be[6] = (unsigned char)(seq >> 8); 1300 seq64be[7] = (unsigned char)seq; 1301 1302 item = pqueue_find(s->d1->sent_messages, seq64be); 1303 if (item == NULL) { 1304 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1305 *found = 0; 1306 return 0; 1307 } 1308 1309 *found = 1; 1310 frag = (hm_fragment *)item->data; 1311 1312 if (frag->msg_header.is_ccs) 1313 header_length = DTLS1_CCS_HEADER_LENGTH; 1314 else 1315 header_length = DTLS1_HM_HEADER_LENGTH; 1316 1317 memcpy(s->init_buf->data, frag->fragment, 1318 frag->msg_header.msg_len + header_length); 1319 s->init_num = frag->msg_header.msg_len + header_length; 1320 1321 dtls1_set_message_header_int(s, frag->msg_header.type, 1322 frag->msg_header.msg_len, 1323 frag->msg_header.seq, 0, 1324 frag->msg_header.frag_len); 1325 1326 /* save current state */ 1327 saved_state.enc_write_ctx = s->enc_write_ctx; 1328 saved_state.write_hash = s->write_hash; 1329 saved_state.compress = s->compress; 1330 saved_state.session = s->session; 1331 saved_state.epoch = s->d1->w_epoch; 1332 saved_state.epoch = s->d1->w_epoch; 1333 1334 s->d1->retransmitting = 1; 1335 1336 /* restore state in which the message was originally sent */ 1337 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1338 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1339 s->compress = frag->msg_header.saved_retransmit_state.compress; 1340 s->session = frag->msg_header.saved_retransmit_state.session; 1341 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1342 1343 if (frag->msg_header.saved_retransmit_state.epoch == 1344 saved_state.epoch - 1) { 1345 memcpy(save_write_sequence, s->s3->write_sequence, 1346 sizeof(s->s3->write_sequence)); 1347 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1348 sizeof(s->s3->write_sequence)); 1349 } 1350 1351 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1352 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1353 1354 /* restore current state */ 1355 s->enc_write_ctx = saved_state.enc_write_ctx; 1356 s->write_hash = saved_state.write_hash; 1357 s->compress = saved_state.compress; 1358 s->session = saved_state.session; 1359 s->d1->w_epoch = saved_state.epoch; 1360 1361 if (frag->msg_header.saved_retransmit_state.epoch == 1362 saved_state.epoch - 1) { 1363 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1364 sizeof(s->s3->write_sequence)); 1365 memcpy(s->s3->write_sequence, save_write_sequence, 1366 sizeof(s->s3->write_sequence)); 1367 } 1368 1369 s->d1->retransmitting = 0; 1370 1371 (void)BIO_flush(SSL_get_wbio(s)); 1372 return ret; 1373} 1374 1375/* call this function when the buffered messages are no longer needed */ 1376void dtls1_clear_record_buffer(SSL *s) 1377{ 1378 pitem *item; 1379 1380 for (item = pqueue_pop(s->d1->sent_messages); 1381 item != NULL; item = pqueue_pop(s->d1->sent_messages)) { 1382 dtls1_hm_fragment_free((hm_fragment *)item->data); 1383 pitem_free(item); 1384 } 1385} 1386 1387unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1388 unsigned char mt, unsigned long len, 1389 unsigned long frag_off, 1390 unsigned long frag_len) 1391{ 1392 /* Don't change sequence numbers while listening */ 1393 if (frag_off == 0 && !s->d1->listen) { 1394 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1395 s->d1->next_handshake_write_seq++; 1396 } 1397 1398 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1399 frag_off, frag_len); 1400 1401 return p += DTLS1_HM_HEADER_LENGTH; 1402} 1403 1404/* don't actually do the writing, wait till the MTU has been retrieved */ 1405static void 1406dtls1_set_message_header_int(SSL *s, unsigned char mt, 1407 unsigned long len, unsigned short seq_num, 1408 unsigned long frag_off, unsigned long frag_len) 1409{ 1410 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1411 1412 msg_hdr->type = mt; 1413 msg_hdr->msg_len = len; 1414 msg_hdr->seq = seq_num; 1415 msg_hdr->frag_off = frag_off; 1416 msg_hdr->frag_len = frag_len; 1417} 1418 1419static void 1420dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1421 unsigned long frag_len) 1422{ 1423 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1424 1425 msg_hdr->frag_off = frag_off; 1426 msg_hdr->frag_len = frag_len; 1427} 1428 1429static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1430{ 1431 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1432 1433 *p++ = msg_hdr->type; 1434 l2n3(msg_hdr->msg_len, p); 1435 1436 s2n(msg_hdr->seq, p); 1437 l2n3(msg_hdr->frag_off, p); 1438 l2n3(msg_hdr->frag_len, p); 1439 1440 return p; 1441} 1442 1443unsigned int dtls1_link_min_mtu(void) 1444{ 1445 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1446 sizeof(g_probable_mtu[0])) - 1]); 1447} 1448 1449unsigned int dtls1_min_mtu(SSL *s) 1450{ 1451 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1452} 1453 1454void 1455dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1456{ 1457 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1458 msg_hdr->type = *(data++); 1459 n2l3(data, msg_hdr->msg_len); 1460 1461 n2s(data, msg_hdr->seq); 1462 n2l3(data, msg_hdr->frag_off); 1463 n2l3(data, msg_hdr->frag_len); 1464} 1465 1466void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1467{ 1468 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1469 1470 ccs_hdr->type = *(data++); 1471} 1472 1473int dtls1_shutdown(SSL *s) 1474{ 1475 int ret; 1476#ifndef OPENSSL_NO_SCTP 1477 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1478 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1479 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1480 if (ret < 0) 1481 return -1; 1482 1483 if (ret == 0) 1484 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1485 NULL); 1486 } 1487#endif 1488 ret = ssl3_shutdown(s); 1489#ifndef OPENSSL_NO_SCTP 1490 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1491#endif 1492 return ret; 1493} 1494 1495#ifndef OPENSSL_NO_HEARTBEATS 1496int dtls1_process_heartbeat(SSL *s) 1497{ 1498 unsigned char *p = &s->s3->rrec.data[0], *pl; 1499 unsigned short hbtype; 1500 unsigned int payload; 1501 unsigned int padding = 16; /* Use minimum padding */ 1502 1503 if (s->msg_callback) 1504 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1505 &s->s3->rrec.data[0], s->s3->rrec.length, 1506 s, s->msg_callback_arg); 1507 1508 /* Read type and payload length first */ 1509 if (1 + 2 + 16 > s->s3->rrec.length) 1510 return 0; /* silently discard */ 1511 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1512 return 0; /* silently discard per RFC 6520 sec. 4 */ 1513 1514 hbtype = *p++; 1515 n2s(p, payload); 1516 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1517 return 0; /* silently discard per RFC 6520 sec. 4 */ 1518 pl = p; 1519 1520 if (hbtype == TLS1_HB_REQUEST) { 1521 unsigned char *buffer, *bp; 1522 unsigned int write_length = 1 /* heartbeat type */ + 1523 2 /* heartbeat length */ + 1524 payload + padding; 1525 int r; 1526 1527 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1528 return 0; 1529 1530 /* 1531 * Allocate memory for the response, size is 1 byte message type, 1532 * plus 2 bytes payload length, plus payload, plus padding 1533 */ 1534 buffer = OPENSSL_malloc(write_length); 1535 bp = buffer; 1536 1537 /* Enter response type, length and copy payload */ 1538 *bp++ = TLS1_HB_RESPONSE; 1539 s2n(payload, bp); 1540 memcpy(bp, pl, payload); 1541 bp += payload; 1542 /* Random padding */ 1543 RAND_pseudo_bytes(bp, padding); 1544 1545 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1546 1547 if (r >= 0 && s->msg_callback) 1548 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1549 buffer, write_length, s, s->msg_callback_arg); 1550 1551 OPENSSL_free(buffer); 1552 1553 if (r < 0) 1554 return r; 1555 } else if (hbtype == TLS1_HB_RESPONSE) { 1556 unsigned int seq; 1557 1558 /* 1559 * We only send sequence numbers (2 bytes unsigned int), and 16 1560 * random bytes, so we just try to read the sequence number 1561 */ 1562 n2s(pl, seq); 1563 1564 if (payload == 18 && seq == s->tlsext_hb_seq) { 1565 dtls1_stop_timer(s); 1566 s->tlsext_hb_seq++; 1567 s->tlsext_hb_pending = 0; 1568 } 1569 } 1570 1571 return 0; 1572} 1573 1574int dtls1_heartbeat(SSL *s) 1575{ 1576 unsigned char *buf, *p; 1577 int ret; 1578 unsigned int payload = 18; /* Sequence number + random bytes */ 1579 unsigned int padding = 16; /* Use minimum padding */ 1580 1581 /* Only send if peer supports and accepts HB requests... */ 1582 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1583 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1584 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1585 return -1; 1586 } 1587 1588 /* ...and there is none in flight yet... */ 1589 if (s->tlsext_hb_pending) { 1590 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1591 return -1; 1592 } 1593 1594 /* ...and no handshake in progress. */ 1595 if (SSL_in_init(s) || s->in_handshake) { 1596 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1597 return -1; 1598 } 1599 1600 /* 1601 * Check if padding is too long, payload and padding must not exceed 2^14 1602 * - 3 = 16381 bytes in total. 1603 */ 1604 OPENSSL_assert(payload + padding <= 16381); 1605 1606 /*- 1607 * Create HeartBeat message, we just use a sequence number 1608 * as payload to distuingish different messages and add 1609 * some random stuff. 1610 * - Message Type, 1 byte 1611 * - Payload Length, 2 bytes (unsigned int) 1612 * - Payload, the sequence number (2 bytes uint) 1613 * - Payload, random bytes (16 bytes uint) 1614 * - Padding 1615 */ 1616 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1617 p = buf; 1618 /* Message Type */ 1619 *p++ = TLS1_HB_REQUEST; 1620 /* Payload length (18 bytes here) */ 1621 s2n(payload, p); 1622 /* Sequence number */ 1623 s2n(s->tlsext_hb_seq, p); 1624 /* 16 random bytes */ 1625 RAND_pseudo_bytes(p, 16); 1626 p += 16; 1627 /* Random padding */ 1628 RAND_pseudo_bytes(p, padding); 1629 1630 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1631 if (ret >= 0) { 1632 if (s->msg_callback) 1633 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1634 buf, 3 + payload + padding, 1635 s, s->msg_callback_arg); 1636 1637 dtls1_start_timer(s); 1638 s->tlsext_hb_pending = 1; 1639 } 1640 1641 OPENSSL_free(buf); 1642 1643 return ret; 1644} 1645#endif 1646