d1_both.c revision 296341
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 if (mt >= 0 && s->s3->tmp.message_type != mt) { 489 al = SSL_AD_UNEXPECTED_MESSAGE; 490 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 491 goto f_err; 492 } 493 494 p = (unsigned char *)s->init_buf->data; 495 msg_len = msg_hdr->msg_len; 496 497 /* reconstruct message header */ 498 *(p++) = msg_hdr->type; 499 l2n3(msg_len, p); 500 s2n(msg_hdr->seq, p); 501 l2n3(0, p); 502 l2n3(msg_len, p); 503 if (s->version != DTLS1_BAD_VER) { 504 p -= DTLS1_HM_HEADER_LENGTH; 505 msg_len += DTLS1_HM_HEADER_LENGTH; 506 } 507 508 ssl3_finish_mac(s, p, msg_len); 509 if (s->msg_callback) 510 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 511 p, msg_len, s, s->msg_callback_arg); 512 513 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 514 515 /* Don't change sequence numbers while listening */ 516 if (!s->d1->listen) 517 s->d1->handshake_read_seq++; 518 519 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 520 return s->init_num; 521 522 f_err: 523 ssl3_send_alert(s, SSL3_AL_FATAL, al); 524 *ok = 0; 525 return -1; 526} 527 528static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 529 int max) 530{ 531 size_t frag_off, frag_len, msg_len; 532 533 msg_len = msg_hdr->msg_len; 534 frag_off = msg_hdr->frag_off; 535 frag_len = msg_hdr->frag_len; 536 537 /* sanity checking */ 538 if ((frag_off + frag_len) > msg_len) { 539 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 540 return SSL_AD_ILLEGAL_PARAMETER; 541 } 542 543 if ((frag_off + frag_len) > (unsigned long)max) { 544 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 545 return SSL_AD_ILLEGAL_PARAMETER; 546 } 547 548 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 549 /* 550 * msg_len is limited to 2^24, but is effectively checked against max 551 * above 552 */ 553 if (!BUF_MEM_grow_clean 554 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { 555 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 556 return SSL_AD_INTERNAL_ERROR; 557 } 558 559 s->s3->tmp.message_size = msg_len; 560 s->d1->r_msg_hdr.msg_len = msg_len; 561 s->s3->tmp.message_type = msg_hdr->type; 562 s->d1->r_msg_hdr.type = msg_hdr->type; 563 s->d1->r_msg_hdr.seq = msg_hdr->seq; 564 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 565 /* 566 * They must be playing with us! BTW, failure to enforce upper limit 567 * would open possibility for buffer overrun. 568 */ 569 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 570 return SSL_AD_ILLEGAL_PARAMETER; 571 } 572 573 return 0; /* no error */ 574} 575 576static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 577{ 578 /*- 579 * (0) check whether the desired fragment is available 580 * if so: 581 * (1) copy over the fragment to s->init_buf->data[] 582 * (2) update s->init_num 583 */ 584 pitem *item; 585 hm_fragment *frag; 586 int al; 587 588 *ok = 0; 589 item = pqueue_peek(s->d1->buffered_messages); 590 if (item == NULL) 591 return 0; 592 593 frag = (hm_fragment *)item->data; 594 595 /* Don't return if reassembly still in progress */ 596 if (frag->reassembly != NULL) 597 return 0; 598 599 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 600 unsigned long frag_len = frag->msg_header.frag_len; 601 pqueue_pop(s->d1->buffered_messages); 602 603 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 604 605 if (al == 0) { /* no alert */ 606 unsigned char *p = 607 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 608 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 609 frag->msg_header.frag_len); 610 } 611 612 dtls1_hm_fragment_free(frag); 613 pitem_free(item); 614 615 if (al == 0) { 616 *ok = 1; 617 return frag_len; 618 } 619 620 ssl3_send_alert(s, SSL3_AL_FATAL, al); 621 s->init_num = 0; 622 *ok = 0; 623 return -1; 624 } else 625 return 0; 626} 627 628/* 629 * dtls1_max_handshake_message_len returns the maximum number of bytes 630 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 631 * may be greater if the maximum certificate list size requires it. 632 */ 633static unsigned long dtls1_max_handshake_message_len(const SSL *s) 634{ 635 unsigned long max_len = 636 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 637 if (max_len < (unsigned long)s->max_cert_list) 638 return s->max_cert_list; 639 return max_len; 640} 641 642static int 643dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 644{ 645 hm_fragment *frag = NULL; 646 pitem *item = NULL; 647 int i = -1, is_complete; 648 unsigned char seq64be[8]; 649 unsigned long frag_len = msg_hdr->frag_len; 650 651 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 652 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 653 goto err; 654 655 if (frag_len == 0) 656 return DTLS1_HM_FRAGMENT_RETRY; 657 658 /* Try to find item in queue */ 659 memset(seq64be, 0, sizeof(seq64be)); 660 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 661 seq64be[7] = (unsigned char)msg_hdr->seq; 662 item = pqueue_find(s->d1->buffered_messages, seq64be); 663 664 if (item == NULL) { 665 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 666 if (frag == NULL) 667 goto err; 668 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 669 frag->msg_header.frag_len = frag->msg_header.msg_len; 670 frag->msg_header.frag_off = 0; 671 } else { 672 frag = (hm_fragment *)item->data; 673 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 674 item = NULL; 675 frag = NULL; 676 goto err; 677 } 678 } 679 680 /* 681 * If message is already reassembled, this must be a retransmit and can 682 * be dropped. In this case item != NULL and so frag does not need to be 683 * freed. 684 */ 685 if (frag->reassembly == NULL) { 686 unsigned char devnull[256]; 687 688 while (frag_len) { 689 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 690 devnull, 691 frag_len > 692 sizeof(devnull) ? sizeof(devnull) : 693 frag_len, 0); 694 if (i <= 0) 695 goto err; 696 frag_len -= i; 697 } 698 return DTLS1_HM_FRAGMENT_RETRY; 699 } 700 701 /* read the body of the fragment (header has already been read */ 702 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 703 frag->fragment + msg_hdr->frag_off, 704 frag_len, 0); 705 if ((unsigned long)i != frag_len) 706 i = -1; 707 if (i <= 0) 708 goto err; 709 710 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 711 (long)(msg_hdr->frag_off + frag_len)); 712 713 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 714 is_complete); 715 716 if (is_complete) { 717 OPENSSL_free(frag->reassembly); 718 frag->reassembly = NULL; 719 } 720 721 if (item == NULL) { 722 item = pitem_new(seq64be, frag); 723 if (item == NULL) { 724 i = -1; 725 goto err; 726 } 727 728 item = pqueue_insert(s->d1->buffered_messages, item); 729 /* 730 * pqueue_insert fails iff a duplicate item is inserted. However, 731 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 732 * would have returned it and control would never have reached this 733 * branch. 734 */ 735 OPENSSL_assert(item != NULL); 736 } 737 738 return DTLS1_HM_FRAGMENT_RETRY; 739 740 err: 741 if (frag != NULL && item == NULL) 742 dtls1_hm_fragment_free(frag); 743 *ok = 0; 744 return i; 745} 746 747static int 748dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 749 int *ok) 750{ 751 int i = -1; 752 hm_fragment *frag = NULL; 753 pitem *item = NULL; 754 unsigned char seq64be[8]; 755 unsigned long frag_len = msg_hdr->frag_len; 756 757 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 758 goto err; 759 760 /* Try to find item in queue, to prevent duplicate entries */ 761 memset(seq64be, 0, sizeof(seq64be)); 762 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 763 seq64be[7] = (unsigned char)msg_hdr->seq; 764 item = pqueue_find(s->d1->buffered_messages, seq64be); 765 766 /* 767 * If we already have an entry and this one is a fragment, don't discard 768 * it and rather try to reassemble it. 769 */ 770 if (item != NULL && frag_len != msg_hdr->msg_len) 771 item = NULL; 772 773 /* 774 * Discard the message if sequence number was already there, is too far 775 * in the future, already in the queue or if we received a FINISHED 776 * before the SERVER_HELLO, which then must be a stale retransmit. 777 */ 778 if (msg_hdr->seq <= s->d1->handshake_read_seq || 779 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 780 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 781 { 782 unsigned char devnull[256]; 783 784 while (frag_len) { 785 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 786 devnull, 787 frag_len > 788 sizeof(devnull) ? sizeof(devnull) : 789 frag_len, 0); 790 if (i <= 0) 791 goto err; 792 frag_len -= i; 793 } 794 } else { 795 if (frag_len != msg_hdr->msg_len) 796 return dtls1_reassemble_fragment(s, msg_hdr, ok); 797 798 if (frag_len > dtls1_max_handshake_message_len(s)) 799 goto err; 800 801 frag = dtls1_hm_fragment_new(frag_len, 0); 802 if (frag == NULL) 803 goto err; 804 805 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 806 807 if (frag_len) { 808 /* 809 * read the body of the fragment (header has already been read 810 */ 811 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 812 frag->fragment, frag_len, 0); 813 if ((unsigned long)i != frag_len) 814 i = -1; 815 if (i <= 0) 816 goto err; 817 } 818 819 item = pitem_new(seq64be, frag); 820 if (item == NULL) 821 goto err; 822 823 item = pqueue_insert(s->d1->buffered_messages, item); 824 /* 825 * pqueue_insert fails iff a duplicate item is inserted. However, 826 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 827 * would have returned it. Then, either |frag_len| != 828 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 829 * have been processed with |dtls1_reassemble_fragment|, above, or 830 * the record will have been discarded. 831 */ 832 OPENSSL_assert(item != NULL); 833 } 834 835 return DTLS1_HM_FRAGMENT_RETRY; 836 837 err: 838 if (frag != NULL && item == NULL) 839 dtls1_hm_fragment_free(frag); 840 *ok = 0; 841 return i; 842} 843 844static long 845dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 846{ 847 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 848 unsigned long len, frag_off, frag_len; 849 int i, al; 850 struct hm_header_st msg_hdr; 851 852 redo: 853 /* see if we have the required fragment already */ 854 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 855 if (*ok) 856 s->init_num = frag_len; 857 return frag_len; 858 } 859 860 /* read handshake message header */ 861 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 862 DTLS1_HM_HEADER_LENGTH, 0); 863 if (i <= 0) { /* nbio, or an error */ 864 s->rwstate = SSL_READING; 865 *ok = 0; 866 return i; 867 } 868 /* Handshake fails if message header is incomplete */ 869 if (i != DTLS1_HM_HEADER_LENGTH) { 870 al = SSL_AD_UNEXPECTED_MESSAGE; 871 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 872 goto f_err; 873 } 874 875 /* parse the message fragment header */ 876 dtls1_get_message_header(wire, &msg_hdr); 877 878 len = msg_hdr.msg_len; 879 frag_off = msg_hdr.frag_off; 880 frag_len = msg_hdr.frag_len; 881 882 /* 883 * We must have at least frag_len bytes left in the record to be read. 884 * Fragments must not span records. 885 */ 886 if (frag_len > s->s3->rrec.length) { 887 al = SSL3_AD_ILLEGAL_PARAMETER; 888 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 889 goto f_err; 890 } 891 892 /* 893 * if this is a future (or stale) message it gets buffered 894 * (or dropped)--no further processing at this time 895 * While listening, we accept seq 1 (ClientHello with cookie) 896 * although we're still expecting seq 0 (ClientHello) 897 */ 898 if (msg_hdr.seq != s->d1->handshake_read_seq 899 && !(s->d1->listen && msg_hdr.seq == 1)) 900 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 901 902 if (frag_len && frag_len < len) 903 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 904 905 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 906 wire[0] == SSL3_MT_HELLO_REQUEST) { 907 /* 908 * The server may always send 'Hello Request' messages -- we are 909 * doing a handshake anyway now, so ignore them if their format is 910 * correct. Does not count for 'Finished' MAC. 911 */ 912 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 913 if (s->msg_callback) 914 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 915 wire, DTLS1_HM_HEADER_LENGTH, s, 916 s->msg_callback_arg); 917 918 s->init_num = 0; 919 goto redo; 920 } else { /* Incorrectly formated Hello request */ 921 922 al = SSL_AD_UNEXPECTED_MESSAGE; 923 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 924 SSL_R_UNEXPECTED_MESSAGE); 925 goto f_err; 926 } 927 } 928 929 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 930 goto f_err; 931 932 if (frag_len > 0) { 933 unsigned char *p = 934 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 935 936 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 937 &p[frag_off], frag_len, 0); 938 939 /* 940 * This shouldn't ever fail due to NBIO because we already checked 941 * that we have enough data in the record 942 */ 943 if (i <= 0) { 944 s->rwstate = SSL_READING; 945 *ok = 0; 946 return i; 947 } 948 } else 949 i = 0; 950 951 /* 952 * XDTLS: an incorrectly formatted fragment should cause the handshake 953 * to fail 954 */ 955 if (i != (int)frag_len) { 956 al = SSL3_AD_ILLEGAL_PARAMETER; 957 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 958 goto f_err; 959 } 960 961 *ok = 1; 962 s->state = stn; 963 964 /* 965 * Note that s->init_num is *not* used as current offset in 966 * s->init_buf->data, but as a counter summing up fragments' lengths: as 967 * soon as they sum up to handshake packet length, we assume we have got 968 * all the fragments. 969 */ 970 s->init_num = frag_len; 971 return frag_len; 972 973 f_err: 974 ssl3_send_alert(s, SSL3_AL_FATAL, al); 975 s->init_num = 0; 976 977 *ok = 0; 978 return (-1); 979} 980 981int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 982{ 983 unsigned char *p, *d; 984 int i; 985 unsigned long l; 986 987 if (s->state == a) { 988 d = (unsigned char *)s->init_buf->data; 989 p = &(d[DTLS1_HM_HEADER_LENGTH]); 990 991 i = s->method->ssl3_enc->final_finish_mac(s, 992 sender, slen, 993 s->s3->tmp.finish_md); 994 s->s3->tmp.finish_md_len = i; 995 memcpy(p, s->s3->tmp.finish_md, i); 996 p += i; 997 l = i; 998 999 /* 1000 * Copy the finished so we can use it for renegotiation checks 1001 */ 1002 if (s->type == SSL_ST_CONNECT) { 1003 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1004 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i); 1005 s->s3->previous_client_finished_len = i; 1006 } else { 1007 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1008 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i); 1009 s->s3->previous_server_finished_len = i; 1010 } 1011 1012#ifdef OPENSSL_SYS_WIN16 1013 /* 1014 * MSVC 1.5 does not clear the top bytes of the word unless I do 1015 * this. 1016 */ 1017 l &= 0xffff; 1018#endif 1019 1020 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 1021 s->init_num = (int)l + DTLS1_HM_HEADER_LENGTH; 1022 s->init_off = 0; 1023 1024 /* buffer the message to handle re-xmits */ 1025 dtls1_buffer_message(s, 0); 1026 1027 s->state = b; 1028 } 1029 1030 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 1031 return (dtls1_do_write(s, SSL3_RT_HANDSHAKE)); 1032} 1033 1034/*- 1035 * for these 2 messages, we need to 1036 * ssl->enc_read_ctx re-init 1037 * ssl->s3->read_sequence zero 1038 * ssl->s3->read_mac_secret re-init 1039 * ssl->session->read_sym_enc assign 1040 * ssl->session->read_compression assign 1041 * ssl->session->read_hash assign 1042 */ 1043int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1044{ 1045 unsigned char *p; 1046 1047 if (s->state == a) { 1048 p = (unsigned char *)s->init_buf->data; 1049 *p++ = SSL3_MT_CCS; 1050 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1051 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1052 1053 if (s->version == DTLS1_BAD_VER) { 1054 s->d1->next_handshake_write_seq++; 1055 s2n(s->d1->handshake_write_seq, p); 1056 s->init_num += 2; 1057 } 1058 1059 s->init_off = 0; 1060 1061 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1062 s->d1->handshake_write_seq, 0, 0); 1063 1064 /* buffer the message to handle re-xmits */ 1065 dtls1_buffer_message(s, 1); 1066 1067 s->state = b; 1068 } 1069 1070 /* SSL3_ST_CW_CHANGE_B */ 1071 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1072} 1073 1074static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1075{ 1076 int n; 1077 unsigned char *p; 1078 1079 n = i2d_X509(x, NULL); 1080 if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) { 1081 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB); 1082 return 0; 1083 } 1084 p = (unsigned char *)&(buf->data[*l]); 1085 l2n3(n, p); 1086 i2d_X509(x, &p); 1087 *l += n + 3; 1088 1089 return 1; 1090} 1091 1092unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1093{ 1094 unsigned char *p; 1095 int i; 1096 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH; 1097 BUF_MEM *buf; 1098 1099 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1100 buf = s->init_buf; 1101 if (!BUF_MEM_grow_clean(buf, 10)) { 1102 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB); 1103 return (0); 1104 } 1105 if (x != NULL) { 1106 X509_STORE_CTX xs_ctx; 1107 1108 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, x, NULL)) { 1109 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB); 1110 return (0); 1111 } 1112 1113 X509_verify_cert(&xs_ctx); 1114 /* Don't leave errors in the queue */ 1115 ERR_clear_error(); 1116 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) { 1117 x = sk_X509_value(xs_ctx.chain, i); 1118 1119 if (!dtls1_add_cert_to_buf(buf, &l, x)) { 1120 X509_STORE_CTX_cleanup(&xs_ctx); 1121 return 0; 1122 } 1123 } 1124 X509_STORE_CTX_cleanup(&xs_ctx); 1125 } 1126 /* Thawte special :-) */ 1127 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) { 1128 x = sk_X509_value(s->ctx->extra_certs, i); 1129 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1130 return 0; 1131 } 1132 1133 l -= (3 + DTLS1_HM_HEADER_LENGTH); 1134 1135 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1136 l2n3(l, p); 1137 l += 3; 1138 p = (unsigned char *)&(buf->data[0]); 1139 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1140 1141 l += DTLS1_HM_HEADER_LENGTH; 1142 return (l); 1143} 1144 1145int dtls1_read_failed(SSL *s, int code) 1146{ 1147 if (code > 0) { 1148 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1149 return 1; 1150 } 1151 1152 if (!dtls1_is_timer_expired(s)) { 1153 /* 1154 * not a timeout, none of our business, let higher layers handle 1155 * this. in fact it's probably an error 1156 */ 1157 return code; 1158 } 1159#ifndef OPENSSL_NO_HEARTBEATS 1160 /* done, no need to send a retransmit */ 1161 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1162#else 1163 /* done, no need to send a retransmit */ 1164 if (!SSL_in_init(s)) 1165#endif 1166 { 1167 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1168 return code; 1169 } 1170#if 0 /* for now, each alert contains only one 1171 * record number */ 1172 item = pqueue_peek(state->rcvd_records); 1173 if (item) { 1174 /* send an alert immediately for all the missing records */ 1175 } else 1176#endif 1177 1178#if 0 /* no more alert sending, just retransmit the 1179 * last set of messages */ 1180 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1181 ssl3_send_alert(s, SSL3_AL_WARNING, 1182 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1183#endif 1184 1185 return dtls1_handle_timeout(s); 1186} 1187 1188int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1189{ 1190 /* 1191 * The index of the retransmission queue actually is the message sequence 1192 * number, since the queue only contains messages of a single handshake. 1193 * However, the ChangeCipherSpec has no message sequence number and so 1194 * using only the sequence will result in the CCS and Finished having the 1195 * same index. To prevent this, the sequence number is multiplied by 2. 1196 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1197 * Finished, it also maintains the order of the index (important for 1198 * priority queues) and fits in the unsigned short variable. 1199 */ 1200 return seq * 2 - is_ccs; 1201} 1202 1203int dtls1_retransmit_buffered_messages(SSL *s) 1204{ 1205 pqueue sent = s->d1->sent_messages; 1206 piterator iter; 1207 pitem *item; 1208 hm_fragment *frag; 1209 int found = 0; 1210 1211 iter = pqueue_iterator(sent); 1212 1213 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1214 frag = (hm_fragment *)item->data; 1215 if (dtls1_retransmit_message(s, (unsigned short) 1216 dtls1_get_queue_priority 1217 (frag->msg_header.seq, 1218 frag->msg_header.is_ccs), 0, 1219 &found) <= 0 && found) { 1220 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1221 return -1; 1222 } 1223 } 1224 1225 return 1; 1226} 1227 1228int dtls1_buffer_message(SSL *s, int is_ccs) 1229{ 1230 pitem *item; 1231 hm_fragment *frag; 1232 unsigned char seq64be[8]; 1233 1234 /* 1235 * this function is called immediately after a message has been 1236 * serialized 1237 */ 1238 OPENSSL_assert(s->init_off == 0); 1239 1240 frag = dtls1_hm_fragment_new(s->init_num, 0); 1241 if (!frag) 1242 return 0; 1243 1244 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1245 1246 if (is_ccs) { 1247 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1248 ((s->version == 1249 DTLS1_VERSION) ? DTLS1_CCS_HEADER_LENGTH : 3) == 1250 (unsigned int)s->init_num); 1251 } else { 1252 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1253 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1254 } 1255 1256 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1257 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1258 frag->msg_header.type = s->d1->w_msg_hdr.type; 1259 frag->msg_header.frag_off = 0; 1260 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1261 frag->msg_header.is_ccs = is_ccs; 1262 1263 /* save current state */ 1264 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1265 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1266 frag->msg_header.saved_retransmit_state.compress = s->compress; 1267 frag->msg_header.saved_retransmit_state.session = s->session; 1268 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1269 1270 memset(seq64be, 0, sizeof(seq64be)); 1271 seq64be[6] = 1272 (unsigned 1273 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1274 frag->msg_header.is_ccs) >> 8); 1275 seq64be[7] = 1276 (unsigned 1277 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1278 frag->msg_header.is_ccs)); 1279 1280 item = pitem_new(seq64be, frag); 1281 if (item == NULL) { 1282 dtls1_hm_fragment_free(frag); 1283 return 0; 1284 } 1285#if 0 1286 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1287 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1288 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1289#endif 1290 1291 pqueue_insert(s->d1->sent_messages, item); 1292 return 1; 1293} 1294 1295int 1296dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1297 int *found) 1298{ 1299 int ret; 1300 /* XDTLS: for now assuming that read/writes are blocking */ 1301 pitem *item; 1302 hm_fragment *frag; 1303 unsigned long header_length; 1304 unsigned char seq64be[8]; 1305 struct dtls1_retransmit_state saved_state; 1306 unsigned char save_write_sequence[8]; 1307 1308 /*- 1309 OPENSSL_assert(s->init_num == 0); 1310 OPENSSL_assert(s->init_off == 0); 1311 */ 1312 1313 /* XDTLS: the requested message ought to be found, otherwise error */ 1314 memset(seq64be, 0, sizeof(seq64be)); 1315 seq64be[6] = (unsigned char)(seq >> 8); 1316 seq64be[7] = (unsigned char)seq; 1317 1318 item = pqueue_find(s->d1->sent_messages, seq64be); 1319 if (item == NULL) { 1320 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1321 *found = 0; 1322 return 0; 1323 } 1324 1325 *found = 1; 1326 frag = (hm_fragment *)item->data; 1327 1328 if (frag->msg_header.is_ccs) 1329 header_length = DTLS1_CCS_HEADER_LENGTH; 1330 else 1331 header_length = DTLS1_HM_HEADER_LENGTH; 1332 1333 memcpy(s->init_buf->data, frag->fragment, 1334 frag->msg_header.msg_len + header_length); 1335 s->init_num = frag->msg_header.msg_len + header_length; 1336 1337 dtls1_set_message_header_int(s, frag->msg_header.type, 1338 frag->msg_header.msg_len, 1339 frag->msg_header.seq, 0, 1340 frag->msg_header.frag_len); 1341 1342 /* save current state */ 1343 saved_state.enc_write_ctx = s->enc_write_ctx; 1344 saved_state.write_hash = s->write_hash; 1345 saved_state.compress = s->compress; 1346 saved_state.session = s->session; 1347 saved_state.epoch = s->d1->w_epoch; 1348 saved_state.epoch = s->d1->w_epoch; 1349 1350 s->d1->retransmitting = 1; 1351 1352 /* restore state in which the message was originally sent */ 1353 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1354 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1355 s->compress = frag->msg_header.saved_retransmit_state.compress; 1356 s->session = frag->msg_header.saved_retransmit_state.session; 1357 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1358 1359 if (frag->msg_header.saved_retransmit_state.epoch == 1360 saved_state.epoch - 1) { 1361 memcpy(save_write_sequence, s->s3->write_sequence, 1362 sizeof(s->s3->write_sequence)); 1363 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1364 sizeof(s->s3->write_sequence)); 1365 } 1366 1367 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1368 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1369 1370 /* restore current state */ 1371 s->enc_write_ctx = saved_state.enc_write_ctx; 1372 s->write_hash = saved_state.write_hash; 1373 s->compress = saved_state.compress; 1374 s->session = saved_state.session; 1375 s->d1->w_epoch = saved_state.epoch; 1376 1377 if (frag->msg_header.saved_retransmit_state.epoch == 1378 saved_state.epoch - 1) { 1379 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1380 sizeof(s->s3->write_sequence)); 1381 memcpy(s->s3->write_sequence, save_write_sequence, 1382 sizeof(s->s3->write_sequence)); 1383 } 1384 1385 s->d1->retransmitting = 0; 1386 1387 (void)BIO_flush(SSL_get_wbio(s)); 1388 return ret; 1389} 1390 1391/* call this function when the buffered messages are no longer needed */ 1392void dtls1_clear_record_buffer(SSL *s) 1393{ 1394 pitem *item; 1395 1396 for (item = pqueue_pop(s->d1->sent_messages); 1397 item != NULL; item = pqueue_pop(s->d1->sent_messages)) { 1398 dtls1_hm_fragment_free((hm_fragment *)item->data); 1399 pitem_free(item); 1400 } 1401} 1402 1403unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1404 unsigned char mt, unsigned long len, 1405 unsigned long frag_off, 1406 unsigned long frag_len) 1407{ 1408 /* Don't change sequence numbers while listening */ 1409 if (frag_off == 0 && !s->d1->listen) { 1410 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1411 s->d1->next_handshake_write_seq++; 1412 } 1413 1414 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1415 frag_off, frag_len); 1416 1417 return p += DTLS1_HM_HEADER_LENGTH; 1418} 1419 1420/* don't actually do the writing, wait till the MTU has been retrieved */ 1421static void 1422dtls1_set_message_header_int(SSL *s, unsigned char mt, 1423 unsigned long len, unsigned short seq_num, 1424 unsigned long frag_off, unsigned long frag_len) 1425{ 1426 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1427 1428 msg_hdr->type = mt; 1429 msg_hdr->msg_len = len; 1430 msg_hdr->seq = seq_num; 1431 msg_hdr->frag_off = frag_off; 1432 msg_hdr->frag_len = frag_len; 1433} 1434 1435static void 1436dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1437 unsigned long frag_len) 1438{ 1439 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1440 1441 msg_hdr->frag_off = frag_off; 1442 msg_hdr->frag_len = frag_len; 1443} 1444 1445static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1446{ 1447 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1448 1449 *p++ = msg_hdr->type; 1450 l2n3(msg_hdr->msg_len, p); 1451 1452 s2n(msg_hdr->seq, p); 1453 l2n3(msg_hdr->frag_off, p); 1454 l2n3(msg_hdr->frag_len, p); 1455 1456 return p; 1457} 1458 1459unsigned int dtls1_link_min_mtu(void) 1460{ 1461 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1462 sizeof(g_probable_mtu[0])) - 1]); 1463} 1464 1465unsigned int dtls1_min_mtu(SSL *s) 1466{ 1467 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1468} 1469 1470void 1471dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1472{ 1473 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1474 msg_hdr->type = *(data++); 1475 n2l3(data, msg_hdr->msg_len); 1476 1477 n2s(data, msg_hdr->seq); 1478 n2l3(data, msg_hdr->frag_off); 1479 n2l3(data, msg_hdr->frag_len); 1480} 1481 1482void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1483{ 1484 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1485 1486 ccs_hdr->type = *(data++); 1487} 1488 1489int dtls1_shutdown(SSL *s) 1490{ 1491 int ret; 1492#ifndef OPENSSL_NO_SCTP 1493 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1494 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1495 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1496 if (ret < 0) 1497 return -1; 1498 1499 if (ret == 0) 1500 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1501 NULL); 1502 } 1503#endif 1504 ret = ssl3_shutdown(s); 1505#ifndef OPENSSL_NO_SCTP 1506 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1507#endif 1508 return ret; 1509} 1510 1511#ifndef OPENSSL_NO_HEARTBEATS 1512int dtls1_process_heartbeat(SSL *s) 1513{ 1514 unsigned char *p = &s->s3->rrec.data[0], *pl; 1515 unsigned short hbtype; 1516 unsigned int payload; 1517 unsigned int padding = 16; /* Use minimum padding */ 1518 1519 if (s->msg_callback) 1520 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1521 &s->s3->rrec.data[0], s->s3->rrec.length, 1522 s, s->msg_callback_arg); 1523 1524 /* Read type and payload length first */ 1525 if (1 + 2 + 16 > s->s3->rrec.length) 1526 return 0; /* silently discard */ 1527 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1528 return 0; /* silently discard per RFC 6520 sec. 4 */ 1529 1530 hbtype = *p++; 1531 n2s(p, payload); 1532 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1533 return 0; /* silently discard per RFC 6520 sec. 4 */ 1534 pl = p; 1535 1536 if (hbtype == TLS1_HB_REQUEST) { 1537 unsigned char *buffer, *bp; 1538 unsigned int write_length = 1 /* heartbeat type */ + 1539 2 /* heartbeat length */ + 1540 payload + padding; 1541 int r; 1542 1543 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1544 return 0; 1545 1546 /* 1547 * Allocate memory for the response, size is 1 byte message type, 1548 * plus 2 bytes payload length, plus payload, plus padding 1549 */ 1550 buffer = OPENSSL_malloc(write_length); 1551 bp = buffer; 1552 1553 /* Enter response type, length and copy payload */ 1554 *bp++ = TLS1_HB_RESPONSE; 1555 s2n(payload, bp); 1556 memcpy(bp, pl, payload); 1557 bp += payload; 1558 /* Random padding */ 1559 if (RAND_pseudo_bytes(bp, padding) < 0) { 1560 OPENSSL_free(buffer); 1561 return -1; 1562 } 1563 1564 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1565 1566 if (r >= 0 && s->msg_callback) 1567 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1568 buffer, write_length, s, s->msg_callback_arg); 1569 1570 OPENSSL_free(buffer); 1571 1572 if (r < 0) 1573 return r; 1574 } else if (hbtype == TLS1_HB_RESPONSE) { 1575 unsigned int seq; 1576 1577 /* 1578 * We only send sequence numbers (2 bytes unsigned int), and 16 1579 * random bytes, so we just try to read the sequence number 1580 */ 1581 n2s(pl, seq); 1582 1583 if (payload == 18 && seq == s->tlsext_hb_seq) { 1584 dtls1_stop_timer(s); 1585 s->tlsext_hb_seq++; 1586 s->tlsext_hb_pending = 0; 1587 } 1588 } 1589 1590 return 0; 1591} 1592 1593int dtls1_heartbeat(SSL *s) 1594{ 1595 unsigned char *buf, *p; 1596 int ret = -1; 1597 unsigned int payload = 18; /* Sequence number + random bytes */ 1598 unsigned int padding = 16; /* Use minimum padding */ 1599 1600 /* Only send if peer supports and accepts HB requests... */ 1601 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1602 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1603 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1604 return -1; 1605 } 1606 1607 /* ...and there is none in flight yet... */ 1608 if (s->tlsext_hb_pending) { 1609 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1610 return -1; 1611 } 1612 1613 /* ...and no handshake in progress. */ 1614 if (SSL_in_init(s) || s->in_handshake) { 1615 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1616 return -1; 1617 } 1618 1619 /* 1620 * Check if padding is too long, payload and padding must not exceed 2^14 1621 * - 3 = 16381 bytes in total. 1622 */ 1623 OPENSSL_assert(payload + padding <= 16381); 1624 1625 /*- 1626 * Create HeartBeat message, we just use a sequence number 1627 * as payload to distuingish different messages and add 1628 * some random stuff. 1629 * - Message Type, 1 byte 1630 * - Payload Length, 2 bytes (unsigned int) 1631 * - Payload, the sequence number (2 bytes uint) 1632 * - Payload, random bytes (16 bytes uint) 1633 * - Padding 1634 */ 1635 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1636 p = buf; 1637 /* Message Type */ 1638 *p++ = TLS1_HB_REQUEST; 1639 /* Payload length (18 bytes here) */ 1640 s2n(payload, p); 1641 /* Sequence number */ 1642 s2n(s->tlsext_hb_seq, p); 1643 /* 16 random bytes */ 1644 if (RAND_pseudo_bytes(p, 16) < 0) 1645 goto err; 1646 p += 16; 1647 /* Random padding */ 1648 if (RAND_pseudo_bytes(p, padding) < 0) 1649 goto err; 1650 1651 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1652 if (ret >= 0) { 1653 if (s->msg_callback) 1654 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1655 buf, 3 + payload + padding, 1656 s, s->msg_callback_arg); 1657 1658 dtls1_start_timer(s); 1659 s->tlsext_hb_pending = 1; 1660 } 1661 1662err: 1663 OPENSSL_free(buf); 1664 1665 return ret; 1666} 1667#endif 1668