d1_both.c revision 290207
1/* ssl/d1_both.c */ 2/* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core@openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116#include <limits.h> 117#include <string.h> 118#include <stdio.h> 119#include "ssl_locl.h" 120#include <openssl/buffer.h> 121#include <openssl/rand.h> 122#include <openssl/objects.h> 123#include <openssl/evp.h> 124#include <openssl/x509.h> 125 126#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 127 128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 129 if ((end) - (start) <= 8) { \ 130 long ii; \ 131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 132 } else { \ 133 long ii; \ 134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 137 } } 138 139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 140 long ii; \ 141 OPENSSL_assert((msg_len) > 0); \ 142 is_complete = 1; \ 143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 146 147#if 0 148# define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \ 149 long ii; \ 150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \ 151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \ 152 printf("\n"); } 153#endif 154 155static unsigned char bitmask_start_values[] = 156 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 }; 157static unsigned char bitmask_end_values[] = 158 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f }; 159 160/* XDTLS: figure out the right values */ 161static const unsigned int g_probable_mtu[] = { 1500, 512, 256 }; 162 163static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 164 unsigned long frag_len); 165static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p); 166static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 167 unsigned long len, 168 unsigned short seq_num, 169 unsigned long frag_off, 170 unsigned long frag_len); 171static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, 172 int *ok); 173 174static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len, 175 int reassembly) 176{ 177 hm_fragment *frag = NULL; 178 unsigned char *buf = NULL; 179 unsigned char *bitmask = NULL; 180 181 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 182 if (frag == NULL) 183 return NULL; 184 185 if (frag_len) { 186 buf = (unsigned char *)OPENSSL_malloc(frag_len); 187 if (buf == NULL) { 188 OPENSSL_free(frag); 189 return NULL; 190 } 191 } 192 193 /* zero length fragment gets zero frag->fragment */ 194 frag->fragment = buf; 195 196 /* Initialize reassembly bitmask if necessary */ 197 if (reassembly) { 198 bitmask = 199 (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) { 201 if (buf != NULL) 202 OPENSSL_free(buf); 203 OPENSSL_free(frag); 204 return NULL; 205 } 206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 207 } 208 209 frag->reassembly = bitmask; 210 211 return frag; 212} 213 214void dtls1_hm_fragment_free(hm_fragment *frag) 215{ 216 217 if (frag->msg_header.is_ccs) { 218 EVP_CIPHER_CTX_free(frag->msg_header. 219 saved_retransmit_state.enc_write_ctx); 220 EVP_MD_CTX_destroy(frag->msg_header. 221 saved_retransmit_state.write_hash); 222 } 223 if (frag->fragment) 224 OPENSSL_free(frag->fragment); 225 if (frag->reassembly) 226 OPENSSL_free(frag->reassembly); 227 OPENSSL_free(frag); 228} 229 230static int dtls1_query_mtu(SSL *s) 231{ 232 if (s->d1->link_mtu) { 233 s->d1->mtu = 234 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 235 s->d1->link_mtu = 0; 236 } 237 238 /* AHA! Figure out the MTU, and stick to the right size */ 239 if (s->d1->mtu < dtls1_min_mtu(s)) { 240 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 241 s->d1->mtu = 242 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 243 244 /* 245 * I've seen the kernel return bogus numbers when it doesn't know 246 * (initial write), so just make sure we have a reasonable number 247 */ 248 if (s->d1->mtu < dtls1_min_mtu(s)) { 249 /* Set to min mtu */ 250 s->d1->mtu = dtls1_min_mtu(s); 251 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 252 s->d1->mtu, NULL); 253 } 254 } else 255 return 0; 256 } 257 return 1; 258} 259 260/* 261 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or 262 * SSL3_RT_CHANGE_CIPHER_SPEC) 263 */ 264int dtls1_do_write(SSL *s, int type) 265{ 266 int ret; 267 unsigned int curr_mtu; 268 int retry = 1; 269 unsigned int len, frag_off, mac_size, blocksize, used_len; 270 271 if (!dtls1_query_mtu(s)) 272 return -1; 273 274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something 275 * reasonable now */ 276 277 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 278 OPENSSL_assert(s->init_num == 279 (int)s->d1->w_msg_hdr.msg_len + 280 DTLS1_HM_HEADER_LENGTH); 281 282 if (s->write_hash) { 283 if (s->enc_write_ctx 284 && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE) 285 mac_size = 0; 286 else 287 mac_size = EVP_MD_CTX_size(s->write_hash); 288 } else 289 mac_size = 0; 290 291 if (s->enc_write_ctx && 292 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE)) 293 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 294 else 295 blocksize = 0; 296 297 frag_off = 0; 298 /* s->init_num shouldn't ever be < 0...but just in case */ 299 while (s->init_num > 0) { 300 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH 301 + mac_size + blocksize; 302 if (s->d1->mtu > used_len) 303 curr_mtu = s->d1->mtu - used_len; 304 else 305 curr_mtu = 0; 306 307 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 308 /* 309 * grr.. we could get an error if MTU picked was wrong 310 */ 311 ret = BIO_flush(SSL_get_wbio(s)); 312 if (ret <= 0) 313 return ret; 314 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 315 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) { 316 curr_mtu = s->d1->mtu - used_len; 317 } else { 318 /* Shouldn't happen */ 319 return -1; 320 } 321 } 322 323 /* 324 * We just checked that s->init_num > 0 so this cast should be safe 325 */ 326 if (((unsigned int)s->init_num) > curr_mtu) 327 len = curr_mtu; 328 else 329 len = s->init_num; 330 331 /* Shouldn't ever happen */ 332 if (len > INT_MAX) 333 len = INT_MAX; 334 335 /* 336 * XDTLS: this function is too long. split out the CCS part 337 */ 338 if (type == SSL3_RT_HANDSHAKE) { 339 if (s->init_off != 0) { 340 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 341 s->init_off -= DTLS1_HM_HEADER_LENGTH; 342 s->init_num += DTLS1_HM_HEADER_LENGTH; 343 344 /* 345 * We just checked that s->init_num > 0 so this cast should 346 * be safe 347 */ 348 if (((unsigned int)s->init_num) > curr_mtu) 349 len = curr_mtu; 350 else 351 len = s->init_num; 352 } 353 354 /* Shouldn't ever happen */ 355 if (len > INT_MAX) 356 len = INT_MAX; 357 358 if (len < DTLS1_HM_HEADER_LENGTH) { 359 /* 360 * len is so small that we really can't do anything sensible 361 * so fail 362 */ 363 return -1; 364 } 365 dtls1_fix_message_header(s, frag_off, 366 len - DTLS1_HM_HEADER_LENGTH); 367 368 dtls1_write_message_header(s, 369 (unsigned char *)&s->init_buf-> 370 data[s->init_off]); 371 } 372 373 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], 374 len); 375 if (ret < 0) { 376 /* 377 * might need to update MTU here, but we don't know which 378 * previous packet caused the failure -- so can't really 379 * retransmit anything. continue as if everything is fine and 380 * wait for an alert to handle the retransmit 381 */ 382 if (retry && BIO_ctrl(SSL_get_wbio(s), 383 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) { 384 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 385 if (!dtls1_query_mtu(s)) 386 return -1; 387 /* Have one more go */ 388 retry = 0; 389 } else 390 return -1; 391 } else { 392 return (-1); 393 } 394 } else { 395 396 /* 397 * bad if this assert fails, only part of the handshake message 398 * got sent. but why would this happen? 399 */ 400 OPENSSL_assert(len == (unsigned int)ret); 401 402 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 403 /* 404 * should not be done for 'Hello Request's, but in that case 405 * we'll ignore the result anyway 406 */ 407 unsigned char *p = 408 (unsigned char *)&s->init_buf->data[s->init_off]; 409 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 410 int xlen; 411 412 if (frag_off == 0 && s->version != DTLS1_BAD_VER) { 413 /* 414 * reconstruct message header is if it is being sent in 415 * single fragment 416 */ 417 *p++ = msg_hdr->type; 418 l2n3(msg_hdr->msg_len, p); 419 s2n(msg_hdr->seq, p); 420 l2n3(0, p); 421 l2n3(msg_hdr->msg_len, p); 422 p -= DTLS1_HM_HEADER_LENGTH; 423 xlen = ret; 424 } else { 425 p += DTLS1_HM_HEADER_LENGTH; 426 xlen = ret - DTLS1_HM_HEADER_LENGTH; 427 } 428 429 ssl3_finish_mac(s, p, xlen); 430 } 431 432 if (ret == s->init_num) { 433 if (s->msg_callback) 434 s->msg_callback(1, s->version, type, s->init_buf->data, 435 (size_t)(s->init_off + s->init_num), s, 436 s->msg_callback_arg); 437 438 s->init_off = 0; /* done writing this message */ 439 s->init_num = 0; 440 441 return (1); 442 } 443 s->init_off += ret; 444 s->init_num -= ret; 445 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 446 } 447 } 448 return (0); 449} 450 451/* 452 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum 453 * acceptable body length 'max'. Read an entire handshake message. Handshake 454 * messages arrive in fragments. 455 */ 456long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 457{ 458 int i, al; 459 struct hm_header_st *msg_hdr; 460 unsigned char *p; 461 unsigned long msg_len; 462 463 /* 464 * s3->tmp is used to store messages that are unexpected, caused by the 465 * absence of an optional handshake message 466 */ 467 if (s->s3->tmp.reuse_message) { 468 s->s3->tmp.reuse_message = 0; 469 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 470 al = SSL_AD_UNEXPECTED_MESSAGE; 471 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 472 goto f_err; 473 } 474 *ok = 1; 475 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 476 s->init_num = (int)s->s3->tmp.message_size; 477 return s->init_num; 478 } 479 480 msg_hdr = &s->d1->r_msg_hdr; 481 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 482 483 again: 484 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 485 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) { 486 /* bad fragment received */ 487 goto again; 488 } else if (i <= 0 && !*ok) { 489 return i; 490 } 491 492 if (mt >= 0 && s->s3->tmp.message_type != mt) { 493 al = SSL_AD_UNEXPECTED_MESSAGE; 494 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 495 goto f_err; 496 } 497 498 p = (unsigned char *)s->init_buf->data; 499 msg_len = msg_hdr->msg_len; 500 501 /* reconstruct message header */ 502 *(p++) = msg_hdr->type; 503 l2n3(msg_len, p); 504 s2n(msg_hdr->seq, p); 505 l2n3(0, p); 506 l2n3(msg_len, p); 507 if (s->version != DTLS1_BAD_VER) { 508 p -= DTLS1_HM_HEADER_LENGTH; 509 msg_len += DTLS1_HM_HEADER_LENGTH; 510 } 511 512 ssl3_finish_mac(s, p, msg_len); 513 if (s->msg_callback) 514 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 515 p, msg_len, s, s->msg_callback_arg); 516 517 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 518 519 /* Don't change sequence numbers while listening */ 520 if (!s->d1->listen) 521 s->d1->handshake_read_seq++; 522 523 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 524 return s->init_num; 525 526 f_err: 527 ssl3_send_alert(s, SSL3_AL_FATAL, al); 528 *ok = 0; 529 return -1; 530} 531 532static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 533 int max) 534{ 535 size_t frag_off, frag_len, msg_len; 536 537 msg_len = msg_hdr->msg_len; 538 frag_off = msg_hdr->frag_off; 539 frag_len = msg_hdr->frag_len; 540 541 /* sanity checking */ 542 if ((frag_off + frag_len) > msg_len) { 543 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 544 return SSL_AD_ILLEGAL_PARAMETER; 545 } 546 547 if ((frag_off + frag_len) > (unsigned long)max) { 548 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 549 return SSL_AD_ILLEGAL_PARAMETER; 550 } 551 552 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 553 /* 554 * msg_len is limited to 2^24, but is effectively checked against max 555 * above 556 */ 557 if (!BUF_MEM_grow_clean 558 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { 559 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 560 return SSL_AD_INTERNAL_ERROR; 561 } 562 563 s->s3->tmp.message_size = msg_len; 564 s->d1->r_msg_hdr.msg_len = msg_len; 565 s->s3->tmp.message_type = msg_hdr->type; 566 s->d1->r_msg_hdr.type = msg_hdr->type; 567 s->d1->r_msg_hdr.seq = msg_hdr->seq; 568 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 569 /* 570 * They must be playing with us! BTW, failure to enforce upper limit 571 * would open possibility for buffer overrun. 572 */ 573 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 574 return SSL_AD_ILLEGAL_PARAMETER; 575 } 576 577 return 0; /* no error */ 578} 579 580static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 581{ 582 /*- 583 * (0) check whether the desired fragment is available 584 * if so: 585 * (1) copy over the fragment to s->init_buf->data[] 586 * (2) update s->init_num 587 */ 588 pitem *item; 589 hm_fragment *frag; 590 int al; 591 592 *ok = 0; 593 item = pqueue_peek(s->d1->buffered_messages); 594 if (item == NULL) 595 return 0; 596 597 frag = (hm_fragment *)item->data; 598 599 /* Don't return if reassembly still in progress */ 600 if (frag->reassembly != NULL) 601 return 0; 602 603 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 604 unsigned long frag_len = frag->msg_header.frag_len; 605 pqueue_pop(s->d1->buffered_messages); 606 607 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 608 609 if (al == 0) { /* no alert */ 610 unsigned char *p = 611 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 612 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 613 frag->msg_header.frag_len); 614 } 615 616 dtls1_hm_fragment_free(frag); 617 pitem_free(item); 618 619 if (al == 0) { 620 *ok = 1; 621 return frag_len; 622 } 623 624 ssl3_send_alert(s, SSL3_AL_FATAL, al); 625 s->init_num = 0; 626 *ok = 0; 627 return -1; 628 } else 629 return 0; 630} 631 632/* 633 * dtls1_max_handshake_message_len returns the maximum number of bytes 634 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 635 * may be greater if the maximum certificate list size requires it. 636 */ 637static unsigned long dtls1_max_handshake_message_len(const SSL *s) 638{ 639 unsigned long max_len = 640 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 641 if (max_len < (unsigned long)s->max_cert_list) 642 return s->max_cert_list; 643 return max_len; 644} 645 646static int 647dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 648{ 649 hm_fragment *frag = NULL; 650 pitem *item = NULL; 651 int i = -1, is_complete; 652 unsigned char seq64be[8]; 653 unsigned long frag_len = msg_hdr->frag_len; 654 655 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 656 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 657 goto err; 658 659 if (frag_len == 0) 660 return DTLS1_HM_FRAGMENT_RETRY; 661 662 /* Try to find item in queue */ 663 memset(seq64be, 0, sizeof(seq64be)); 664 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 665 seq64be[7] = (unsigned char)msg_hdr->seq; 666 item = pqueue_find(s->d1->buffered_messages, seq64be); 667 668 if (item == NULL) { 669 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 670 if (frag == NULL) 671 goto err; 672 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 673 frag->msg_header.frag_len = frag->msg_header.msg_len; 674 frag->msg_header.frag_off = 0; 675 } else { 676 frag = (hm_fragment *)item->data; 677 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 678 item = NULL; 679 frag = NULL; 680 goto err; 681 } 682 } 683 684 /* 685 * If message is already reassembled, this must be a retransmit and can 686 * be dropped. In this case item != NULL and so frag does not need to be 687 * freed. 688 */ 689 if (frag->reassembly == NULL) { 690 unsigned char devnull[256]; 691 692 while (frag_len) { 693 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 694 devnull, 695 frag_len > 696 sizeof(devnull) ? sizeof(devnull) : 697 frag_len, 0); 698 if (i <= 0) 699 goto err; 700 frag_len -= i; 701 } 702 return DTLS1_HM_FRAGMENT_RETRY; 703 } 704 705 /* read the body of the fragment (header has already been read */ 706 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 707 frag->fragment + msg_hdr->frag_off, 708 frag_len, 0); 709 if ((unsigned long)i != frag_len) 710 i = -1; 711 if (i <= 0) 712 goto err; 713 714 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 715 (long)(msg_hdr->frag_off + frag_len)); 716 717 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 718 is_complete); 719 720 if (is_complete) { 721 OPENSSL_free(frag->reassembly); 722 frag->reassembly = NULL; 723 } 724 725 if (item == NULL) { 726 item = pitem_new(seq64be, frag); 727 if (item == NULL) { 728 i = -1; 729 goto err; 730 } 731 732 item = pqueue_insert(s->d1->buffered_messages, item); 733 /* 734 * pqueue_insert fails iff a duplicate item is inserted. However, 735 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 736 * would have returned it and control would never have reached this 737 * branch. 738 */ 739 OPENSSL_assert(item != NULL); 740 } 741 742 return DTLS1_HM_FRAGMENT_RETRY; 743 744 err: 745 if (frag != NULL && item == NULL) 746 dtls1_hm_fragment_free(frag); 747 *ok = 0; 748 return i; 749} 750 751static int 752dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 753 int *ok) 754{ 755 int i = -1; 756 hm_fragment *frag = NULL; 757 pitem *item = NULL; 758 unsigned char seq64be[8]; 759 unsigned long frag_len = msg_hdr->frag_len; 760 761 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 762 goto err; 763 764 /* Try to find item in queue, to prevent duplicate entries */ 765 memset(seq64be, 0, sizeof(seq64be)); 766 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 767 seq64be[7] = (unsigned char)msg_hdr->seq; 768 item = pqueue_find(s->d1->buffered_messages, seq64be); 769 770 /* 771 * If we already have an entry and this one is a fragment, don't discard 772 * it and rather try to reassemble it. 773 */ 774 if (item != NULL && frag_len != msg_hdr->msg_len) 775 item = NULL; 776 777 /* 778 * Discard the message if sequence number was already there, is too far 779 * in the future, already in the queue or if we received a FINISHED 780 * before the SERVER_HELLO, which then must be a stale retransmit. 781 */ 782 if (msg_hdr->seq <= s->d1->handshake_read_seq || 783 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 784 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 785 { 786 unsigned char devnull[256]; 787 788 while (frag_len) { 789 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 790 devnull, 791 frag_len > 792 sizeof(devnull) ? sizeof(devnull) : 793 frag_len, 0); 794 if (i <= 0) 795 goto err; 796 frag_len -= i; 797 } 798 } else { 799 if (frag_len != msg_hdr->msg_len) 800 return dtls1_reassemble_fragment(s, msg_hdr, ok); 801 802 if (frag_len > dtls1_max_handshake_message_len(s)) 803 goto err; 804 805 frag = dtls1_hm_fragment_new(frag_len, 0); 806 if (frag == NULL) 807 goto err; 808 809 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 810 811 if (frag_len) { 812 /* 813 * read the body of the fragment (header has already been read 814 */ 815 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 816 frag->fragment, frag_len, 0); 817 if ((unsigned long)i != frag_len) 818 i = -1; 819 if (i <= 0) 820 goto err; 821 } 822 823 item = pitem_new(seq64be, frag); 824 if (item == NULL) 825 goto err; 826 827 item = pqueue_insert(s->d1->buffered_messages, item); 828 /* 829 * pqueue_insert fails iff a duplicate item is inserted. However, 830 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 831 * would have returned it. Then, either |frag_len| != 832 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 833 * have been processed with |dtls1_reassemble_fragment|, above, or 834 * the record will have been discarded. 835 */ 836 OPENSSL_assert(item != NULL); 837 } 838 839 return DTLS1_HM_FRAGMENT_RETRY; 840 841 err: 842 if (frag != NULL && item == NULL) 843 dtls1_hm_fragment_free(frag); 844 *ok = 0; 845 return i; 846} 847 848static long 849dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 850{ 851 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 852 unsigned long len, frag_off, frag_len; 853 int i, al; 854 struct hm_header_st msg_hdr; 855 856 redo: 857 /* see if we have the required fragment already */ 858 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 859 if (*ok) 860 s->init_num = frag_len; 861 return frag_len; 862 } 863 864 /* read handshake message header */ 865 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 866 DTLS1_HM_HEADER_LENGTH, 0); 867 if (i <= 0) { /* nbio, or an error */ 868 s->rwstate = SSL_READING; 869 *ok = 0; 870 return i; 871 } 872 /* Handshake fails if message header is incomplete */ 873 if (i != DTLS1_HM_HEADER_LENGTH) { 874 al = SSL_AD_UNEXPECTED_MESSAGE; 875 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 876 goto f_err; 877 } 878 879 /* parse the message fragment header */ 880 dtls1_get_message_header(wire, &msg_hdr); 881 882 len = msg_hdr.msg_len; 883 frag_off = msg_hdr.frag_off; 884 frag_len = msg_hdr.frag_len; 885 886 /* 887 * We must have at least frag_len bytes left in the record to be read. 888 * Fragments must not span records. 889 */ 890 if (frag_len > s->s3->rrec.length) { 891 al = SSL3_AD_ILLEGAL_PARAMETER; 892 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 893 goto f_err; 894 } 895 896 /* 897 * if this is a future (or stale) message it gets buffered 898 * (or dropped)--no further processing at this time 899 * While listening, we accept seq 1 (ClientHello with cookie) 900 * although we're still expecting seq 0 (ClientHello) 901 */ 902 if (msg_hdr.seq != s->d1->handshake_read_seq 903 && !(s->d1->listen && msg_hdr.seq == 1)) 904 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 905 906 if (frag_len && frag_len < len) 907 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 908 909 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 910 wire[0] == SSL3_MT_HELLO_REQUEST) { 911 /* 912 * The server may always send 'Hello Request' messages -- we are 913 * doing a handshake anyway now, so ignore them if their format is 914 * correct. Does not count for 'Finished' MAC. 915 */ 916 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 917 if (s->msg_callback) 918 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 919 wire, DTLS1_HM_HEADER_LENGTH, s, 920 s->msg_callback_arg); 921 922 s->init_num = 0; 923 goto redo; 924 } else { /* Incorrectly formated Hello request */ 925 926 al = SSL_AD_UNEXPECTED_MESSAGE; 927 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 928 SSL_R_UNEXPECTED_MESSAGE); 929 goto f_err; 930 } 931 } 932 933 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 934 goto f_err; 935 936 if (frag_len > 0) { 937 unsigned char *p = 938 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 939 940 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 941 &p[frag_off], frag_len, 0); 942 943 /* 944 * This shouldn't ever fail due to NBIO because we already checked 945 * that we have enough data in the record 946 */ 947 if (i <= 0) { 948 s->rwstate = SSL_READING; 949 *ok = 0; 950 return i; 951 } 952 } else 953 i = 0; 954 955 /* 956 * XDTLS: an incorrectly formatted fragment should cause the handshake 957 * to fail 958 */ 959 if (i != (int)frag_len) { 960 al = SSL3_AD_ILLEGAL_PARAMETER; 961 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 962 goto f_err; 963 } 964 965 *ok = 1; 966 s->state = stn; 967 968 /* 969 * Note that s->init_num is *not* used as current offset in 970 * s->init_buf->data, but as a counter summing up fragments' lengths: as 971 * soon as they sum up to handshake packet length, we assume we have got 972 * all the fragments. 973 */ 974 s->init_num = frag_len; 975 return frag_len; 976 977 f_err: 978 ssl3_send_alert(s, SSL3_AL_FATAL, al); 979 s->init_num = 0; 980 981 *ok = 0; 982 return (-1); 983} 984 985/*- 986 * for these 2 messages, we need to 987 * ssl->enc_read_ctx re-init 988 * ssl->s3->read_sequence zero 989 * ssl->s3->read_mac_secret re-init 990 * ssl->session->read_sym_enc assign 991 * ssl->session->read_compression assign 992 * ssl->session->read_hash assign 993 */ 994int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 995{ 996 unsigned char *p; 997 998 if (s->state == a) { 999 p = (unsigned char *)s->init_buf->data; 1000 *p++ = SSL3_MT_CCS; 1001 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1002 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1003 1004 if (s->version == DTLS1_BAD_VER) { 1005 s->d1->next_handshake_write_seq++; 1006 s2n(s->d1->handshake_write_seq, p); 1007 s->init_num += 2; 1008 } 1009 1010 s->init_off = 0; 1011 1012 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1013 s->d1->handshake_write_seq, 0, 0); 1014 1015 /* buffer the message to handle re-xmits */ 1016 dtls1_buffer_message(s, 1); 1017 1018 s->state = b; 1019 } 1020 1021 /* SSL3_ST_CW_CHANGE_B */ 1022 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1023} 1024 1025int dtls1_read_failed(SSL *s, int code) 1026{ 1027 if (code > 0) { 1028 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1029 return 1; 1030 } 1031 1032 if (!dtls1_is_timer_expired(s)) { 1033 /* 1034 * not a timeout, none of our business, let higher layers handle 1035 * this. in fact it's probably an error 1036 */ 1037 return code; 1038 } 1039#ifndef OPENSSL_NO_HEARTBEATS 1040 /* done, no need to send a retransmit */ 1041 if (!SSL_in_init(s) && !s->tlsext_hb_pending) 1042#else 1043 /* done, no need to send a retransmit */ 1044 if (!SSL_in_init(s)) 1045#endif 1046 { 1047 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1048 return code; 1049 } 1050#if 0 /* for now, each alert contains only one 1051 * record number */ 1052 item = pqueue_peek(state->rcvd_records); 1053 if (item) { 1054 /* send an alert immediately for all the missing records */ 1055 } else 1056#endif 1057 1058#if 0 /* no more alert sending, just retransmit the 1059 * last set of messages */ 1060 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1061 ssl3_send_alert(s, SSL3_AL_WARNING, 1062 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1063#endif 1064 1065 return dtls1_handle_timeout(s); 1066} 1067 1068int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1069{ 1070 /* 1071 * The index of the retransmission queue actually is the message sequence 1072 * number, since the queue only contains messages of a single handshake. 1073 * However, the ChangeCipherSpec has no message sequence number and so 1074 * using only the sequence will result in the CCS and Finished having the 1075 * same index. To prevent this, the sequence number is multiplied by 2. 1076 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1077 * Finished, it also maintains the order of the index (important for 1078 * priority queues) and fits in the unsigned short variable. 1079 */ 1080 return seq * 2 - is_ccs; 1081} 1082 1083int dtls1_retransmit_buffered_messages(SSL *s) 1084{ 1085 pqueue sent = s->d1->sent_messages; 1086 piterator iter; 1087 pitem *item; 1088 hm_fragment *frag; 1089 int found = 0; 1090 1091 iter = pqueue_iterator(sent); 1092 1093 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1094 frag = (hm_fragment *)item->data; 1095 if (dtls1_retransmit_message(s, (unsigned short) 1096 dtls1_get_queue_priority 1097 (frag->msg_header.seq, 1098 frag->msg_header.is_ccs), 0, 1099 &found) <= 0 && found) { 1100 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1101 return -1; 1102 } 1103 } 1104 1105 return 1; 1106} 1107 1108int dtls1_buffer_message(SSL *s, int is_ccs) 1109{ 1110 pitem *item; 1111 hm_fragment *frag; 1112 unsigned char seq64be[8]; 1113 1114 /* 1115 * this function is called immediately after a message has been 1116 * serialized 1117 */ 1118 OPENSSL_assert(s->init_off == 0); 1119 1120 frag = dtls1_hm_fragment_new(s->init_num, 0); 1121 if (!frag) 1122 return 0; 1123 1124 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1125 1126 if (is_ccs) { 1127 /* For DTLS1_BAD_VER the header length is non-standard */ 1128 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1129 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH) 1130 == (unsigned int)s->init_num); 1131 } else { 1132 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1133 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1134 } 1135 1136 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1137 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1138 frag->msg_header.type = s->d1->w_msg_hdr.type; 1139 frag->msg_header.frag_off = 0; 1140 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1141 frag->msg_header.is_ccs = is_ccs; 1142 1143 /* save current state */ 1144 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1145 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1146 frag->msg_header.saved_retransmit_state.compress = s->compress; 1147 frag->msg_header.saved_retransmit_state.session = s->session; 1148 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1149 1150 memset(seq64be, 0, sizeof(seq64be)); 1151 seq64be[6] = 1152 (unsigned 1153 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1154 frag->msg_header.is_ccs) >> 8); 1155 seq64be[7] = 1156 (unsigned 1157 char)(dtls1_get_queue_priority(frag->msg_header.seq, 1158 frag->msg_header.is_ccs)); 1159 1160 item = pitem_new(seq64be, frag); 1161 if (item == NULL) { 1162 dtls1_hm_fragment_free(frag); 1163 return 0; 1164 } 1165#if 0 1166 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1167 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1168 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1169#endif 1170 1171 pqueue_insert(s->d1->sent_messages, item); 1172 return 1; 1173} 1174 1175int 1176dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1177 int *found) 1178{ 1179 int ret; 1180 /* XDTLS: for now assuming that read/writes are blocking */ 1181 pitem *item; 1182 hm_fragment *frag; 1183 unsigned long header_length; 1184 unsigned char seq64be[8]; 1185 struct dtls1_retransmit_state saved_state; 1186 unsigned char save_write_sequence[8]; 1187 1188 /*- 1189 OPENSSL_assert(s->init_num == 0); 1190 OPENSSL_assert(s->init_off == 0); 1191 */ 1192 1193 /* XDTLS: the requested message ought to be found, otherwise error */ 1194 memset(seq64be, 0, sizeof(seq64be)); 1195 seq64be[6] = (unsigned char)(seq >> 8); 1196 seq64be[7] = (unsigned char)seq; 1197 1198 item = pqueue_find(s->d1->sent_messages, seq64be); 1199 if (item == NULL) { 1200 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1201 *found = 0; 1202 return 0; 1203 } 1204 1205 *found = 1; 1206 frag = (hm_fragment *)item->data; 1207 1208 if (frag->msg_header.is_ccs) 1209 header_length = DTLS1_CCS_HEADER_LENGTH; 1210 else 1211 header_length = DTLS1_HM_HEADER_LENGTH; 1212 1213 memcpy(s->init_buf->data, frag->fragment, 1214 frag->msg_header.msg_len + header_length); 1215 s->init_num = frag->msg_header.msg_len + header_length; 1216 1217 dtls1_set_message_header_int(s, frag->msg_header.type, 1218 frag->msg_header.msg_len, 1219 frag->msg_header.seq, 0, 1220 frag->msg_header.frag_len); 1221 1222 /* save current state */ 1223 saved_state.enc_write_ctx = s->enc_write_ctx; 1224 saved_state.write_hash = s->write_hash; 1225 saved_state.compress = s->compress; 1226 saved_state.session = s->session; 1227 saved_state.epoch = s->d1->w_epoch; 1228 saved_state.epoch = s->d1->w_epoch; 1229 1230 s->d1->retransmitting = 1; 1231 1232 /* restore state in which the message was originally sent */ 1233 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1234 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1235 s->compress = frag->msg_header.saved_retransmit_state.compress; 1236 s->session = frag->msg_header.saved_retransmit_state.session; 1237 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1238 1239 if (frag->msg_header.saved_retransmit_state.epoch == 1240 saved_state.epoch - 1) { 1241 memcpy(save_write_sequence, s->s3->write_sequence, 1242 sizeof(s->s3->write_sequence)); 1243 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1244 sizeof(s->s3->write_sequence)); 1245 } 1246 1247 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1248 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1249 1250 /* restore current state */ 1251 s->enc_write_ctx = saved_state.enc_write_ctx; 1252 s->write_hash = saved_state.write_hash; 1253 s->compress = saved_state.compress; 1254 s->session = saved_state.session; 1255 s->d1->w_epoch = saved_state.epoch; 1256 1257 if (frag->msg_header.saved_retransmit_state.epoch == 1258 saved_state.epoch - 1) { 1259 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1260 sizeof(s->s3->write_sequence)); 1261 memcpy(s->s3->write_sequence, save_write_sequence, 1262 sizeof(s->s3->write_sequence)); 1263 } 1264 1265 s->d1->retransmitting = 0; 1266 1267 (void)BIO_flush(SSL_get_wbio(s)); 1268 return ret; 1269} 1270 1271/* call this function when the buffered messages are no longer needed */ 1272void dtls1_clear_record_buffer(SSL *s) 1273{ 1274 pitem *item; 1275 1276 for (item = pqueue_pop(s->d1->sent_messages); 1277 item != NULL; item = pqueue_pop(s->d1->sent_messages)) { 1278 dtls1_hm_fragment_free((hm_fragment *)item->data); 1279 pitem_free(item); 1280 } 1281} 1282 1283unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1284 unsigned char mt, unsigned long len, 1285 unsigned long frag_off, 1286 unsigned long frag_len) 1287{ 1288 /* Don't change sequence numbers while listening */ 1289 if (frag_off == 0 && !s->d1->listen) { 1290 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1291 s->d1->next_handshake_write_seq++; 1292 } 1293 1294 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1295 frag_off, frag_len); 1296 1297 return p += DTLS1_HM_HEADER_LENGTH; 1298} 1299 1300/* don't actually do the writing, wait till the MTU has been retrieved */ 1301static void 1302dtls1_set_message_header_int(SSL *s, unsigned char mt, 1303 unsigned long len, unsigned short seq_num, 1304 unsigned long frag_off, unsigned long frag_len) 1305{ 1306 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1307 1308 msg_hdr->type = mt; 1309 msg_hdr->msg_len = len; 1310 msg_hdr->seq = seq_num; 1311 msg_hdr->frag_off = frag_off; 1312 msg_hdr->frag_len = frag_len; 1313} 1314 1315static void 1316dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1317 unsigned long frag_len) 1318{ 1319 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1320 1321 msg_hdr->frag_off = frag_off; 1322 msg_hdr->frag_len = frag_len; 1323} 1324 1325static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1326{ 1327 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1328 1329 *p++ = msg_hdr->type; 1330 l2n3(msg_hdr->msg_len, p); 1331 1332 s2n(msg_hdr->seq, p); 1333 l2n3(msg_hdr->frag_off, p); 1334 l2n3(msg_hdr->frag_len, p); 1335 1336 return p; 1337} 1338 1339unsigned int dtls1_link_min_mtu(void) 1340{ 1341 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1342 sizeof(g_probable_mtu[0])) - 1]); 1343} 1344 1345unsigned int dtls1_min_mtu(SSL *s) 1346{ 1347 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1348} 1349 1350void 1351dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1352{ 1353 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1354 msg_hdr->type = *(data++); 1355 n2l3(data, msg_hdr->msg_len); 1356 1357 n2s(data, msg_hdr->seq); 1358 n2l3(data, msg_hdr->frag_off); 1359 n2l3(data, msg_hdr->frag_len); 1360} 1361 1362void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1363{ 1364 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1365 1366 ccs_hdr->type = *(data++); 1367} 1368 1369int dtls1_shutdown(SSL *s) 1370{ 1371 int ret; 1372#ifndef OPENSSL_NO_SCTP 1373 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1374 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1375 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1376 if (ret < 0) 1377 return -1; 1378 1379 if (ret == 0) 1380 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, 1381 NULL); 1382 } 1383#endif 1384 ret = ssl3_shutdown(s); 1385#ifndef OPENSSL_NO_SCTP 1386 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1387#endif 1388 return ret; 1389} 1390 1391#ifndef OPENSSL_NO_HEARTBEATS 1392int dtls1_process_heartbeat(SSL *s) 1393{ 1394 unsigned char *p = &s->s3->rrec.data[0], *pl; 1395 unsigned short hbtype; 1396 unsigned int payload; 1397 unsigned int padding = 16; /* Use minimum padding */ 1398 1399 if (s->msg_callback) 1400 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1401 &s->s3->rrec.data[0], s->s3->rrec.length, 1402 s, s->msg_callback_arg); 1403 1404 /* Read type and payload length first */ 1405 if (1 + 2 + 16 > s->s3->rrec.length) 1406 return 0; /* silently discard */ 1407 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1408 return 0; /* silently discard per RFC 6520 sec. 4 */ 1409 1410 hbtype = *p++; 1411 n2s(p, payload); 1412 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1413 return 0; /* silently discard per RFC 6520 sec. 4 */ 1414 pl = p; 1415 1416 if (hbtype == TLS1_HB_REQUEST) { 1417 unsigned char *buffer, *bp; 1418 unsigned int write_length = 1 /* heartbeat type */ + 1419 2 /* heartbeat length */ + 1420 payload + padding; 1421 int r; 1422 1423 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1424 return 0; 1425 1426 /* 1427 * Allocate memory for the response, size is 1 byte message type, 1428 * plus 2 bytes payload length, plus payload, plus padding 1429 */ 1430 buffer = OPENSSL_malloc(write_length); 1431 bp = buffer; 1432 1433 /* Enter response type, length and copy payload */ 1434 *bp++ = TLS1_HB_RESPONSE; 1435 s2n(payload, bp); 1436 memcpy(bp, pl, payload); 1437 bp += payload; 1438 /* Random padding */ 1439 if (RAND_pseudo_bytes(bp, padding) < 0) { 1440 OPENSSL_free(buffer); 1441 return -1; 1442 } 1443 1444 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1445 1446 if (r >= 0 && s->msg_callback) 1447 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1448 buffer, write_length, s, s->msg_callback_arg); 1449 1450 OPENSSL_free(buffer); 1451 1452 if (r < 0) 1453 return r; 1454 } else if (hbtype == TLS1_HB_RESPONSE) { 1455 unsigned int seq; 1456 1457 /* 1458 * We only send sequence numbers (2 bytes unsigned int), and 16 1459 * random bytes, so we just try to read the sequence number 1460 */ 1461 n2s(pl, seq); 1462 1463 if (payload == 18 && seq == s->tlsext_hb_seq) { 1464 dtls1_stop_timer(s); 1465 s->tlsext_hb_seq++; 1466 s->tlsext_hb_pending = 0; 1467 } 1468 } 1469 1470 return 0; 1471} 1472 1473int dtls1_heartbeat(SSL *s) 1474{ 1475 unsigned char *buf, *p; 1476 int ret = -1; 1477 unsigned int payload = 18; /* Sequence number + random bytes */ 1478 unsigned int padding = 16; /* Use minimum padding */ 1479 1480 /* Only send if peer supports and accepts HB requests... */ 1481 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1482 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) { 1483 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1484 return -1; 1485 } 1486 1487 /* ...and there is none in flight yet... */ 1488 if (s->tlsext_hb_pending) { 1489 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING); 1490 return -1; 1491 } 1492 1493 /* ...and no handshake in progress. */ 1494 if (SSL_in_init(s) || s->in_handshake) { 1495 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE); 1496 return -1; 1497 } 1498 1499 /* 1500 * Check if padding is too long, payload and padding must not exceed 2^14 1501 * - 3 = 16381 bytes in total. 1502 */ 1503 OPENSSL_assert(payload + padding <= 16381); 1504 1505 /*- 1506 * Create HeartBeat message, we just use a sequence number 1507 * as payload to distuingish different messages and add 1508 * some random stuff. 1509 * - Message Type, 1 byte 1510 * - Payload Length, 2 bytes (unsigned int) 1511 * - Payload, the sequence number (2 bytes uint) 1512 * - Payload, random bytes (16 bytes uint) 1513 * - Padding 1514 */ 1515 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1516 p = buf; 1517 /* Message Type */ 1518 *p++ = TLS1_HB_REQUEST; 1519 /* Payload length (18 bytes here) */ 1520 s2n(payload, p); 1521 /* Sequence number */ 1522 s2n(s->tlsext_hb_seq, p); 1523 /* 16 random bytes */ 1524 if (RAND_pseudo_bytes(p, 16) < 0) 1525 goto err; 1526 p += 16; 1527 /* Random padding */ 1528 if (RAND_pseudo_bytes(p, padding) < 0) 1529 goto err; 1530 1531 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1532 if (ret >= 0) { 1533 if (s->msg_callback) 1534 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1535 buf, 3 + payload + padding, 1536 s, s->msg_callback_arg); 1537 1538 dtls1_start_timer(s); 1539 s->tlsext_hb_pending = 1; 1540 } 1541 1542err: 1543 OPENSSL_free(buf); 1544 1545 return ret; 1546} 1547#endif 1548