d1_both.c revision 306230
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 unsigned int g_probable_mtu[] = { 1500 - 28, 512 - 28, 256 - 28 }; 162 163static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 164static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 165 unsigned long frag_len); 166static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p); 167static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 168 unsigned long len, 169 unsigned short seq_num, 170 unsigned long frag_off, 171 unsigned long frag_len); 172static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, 173 int *ok); 174 175static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len, 176 int reassembly) 177{ 178 hm_fragment *frag = NULL; 179 unsigned char *buf = NULL; 180 unsigned char *bitmask = NULL; 181 182 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 183 if (frag == NULL) 184 return NULL; 185 186 if (frag_len) { 187 buf = (unsigned char *)OPENSSL_malloc(frag_len); 188 if (buf == NULL) { 189 OPENSSL_free(frag); 190 return NULL; 191 } 192 } 193 194 /* zero length fragment gets zero frag->fragment */ 195 frag->fragment = buf; 196 197 /* Initialize reassembly bitmask if necessary */ 198 if (reassembly) { 199 bitmask = 200 (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 201 if (bitmask == NULL) { 202 if (buf != NULL) 203 OPENSSL_free(buf); 204 OPENSSL_free(frag); 205 return NULL; 206 } 207 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 208 } 209 210 frag->reassembly = bitmask; 211 212 return frag; 213} 214 215static void dtls1_hm_fragment_free(hm_fragment *frag) 216{ 217 if (frag->fragment) 218 OPENSSL_free(frag->fragment); 219 if (frag->reassembly) 220 OPENSSL_free(frag->reassembly); 221 OPENSSL_free(frag); 222} 223 224/* 225 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or 226 * SSL3_RT_CHANGE_CIPHER_SPEC) 227 */ 228int dtls1_do_write(SSL *s, int type) 229{ 230 int ret; 231 int curr_mtu; 232 unsigned int len, frag_off, mac_size, blocksize; 233 234 /* AHA! Figure out the MTU, and stick to the right size */ 235 if (s->d1->mtu < dtls1_min_mtu() 236 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 237 s->d1->mtu = 238 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 239 240 /* 241 * I've seen the kernel return bogus numbers when it doesn't know 242 * (initial write), so just make sure we have a reasonable number 243 */ 244 if (s->d1->mtu < dtls1_min_mtu()) { 245 s->d1->mtu = 0; 246 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 247 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 248 s->d1->mtu, NULL); 249 } 250 } 251#if 0 252 mtu = s->d1->mtu; 253 254 fprintf(stderr, "using MTU = %d\n", mtu); 255 256 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 257 258 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 259 260 if (curr_mtu > 0) 261 mtu = curr_mtu; 262 else if ((ret = BIO_flush(SSL_get_wbio(s))) <= 0) 263 return ret; 264 265 if (BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) { 266 ret = BIO_flush(SSL_get_wbio(s)); 267 if (ret <= 0) 268 return ret; 269 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 270 } 271#endif 272 273 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something 274 * reasonable now */ 275 276 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 277 OPENSSL_assert(s->init_num == 278 (int)s->d1->w_msg_hdr.msg_len + 279 DTLS1_HM_HEADER_LENGTH); 280 281 if (s->write_hash) 282 mac_size = EVP_MD_size(s->write_hash); 283 else 284 mac_size = 0; 285 286 if (s->enc_write_ctx && 287 (EVP_CIPHER_mode(s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 288 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 289 else 290 blocksize = 0; 291 292 frag_off = 0; 293 while (s->init_num) { 294 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 295 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; 296 297 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 298 /* 299 * grr.. we could get an error if MTU picked was wrong 300 */ 301 ret = BIO_flush(SSL_get_wbio(s)); 302 if (ret <= 0) 303 return ret; 304 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 305 mac_size - blocksize; 306 } 307 308 if (s->init_num > curr_mtu) 309 len = curr_mtu; 310 else 311 len = s->init_num; 312 313 /* 314 * XDTLS: this function is too long. split out the CCS part 315 */ 316 if (type == SSL3_RT_HANDSHAKE) { 317 if (s->init_off != 0) { 318 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 319 s->init_off -= DTLS1_HM_HEADER_LENGTH; 320 s->init_num += DTLS1_HM_HEADER_LENGTH; 321 322 if (s->init_num > curr_mtu) 323 len = curr_mtu; 324 else 325 len = s->init_num; 326 } 327 328 dtls1_fix_message_header(s, frag_off, 329 len - DTLS1_HM_HEADER_LENGTH); 330 331 dtls1_write_message_header(s, 332 (unsigned char *)&s->init_buf-> 333 data[s->init_off]); 334 335 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 336 } 337 338 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], 339 len); 340 if (ret < 0) { 341 /* 342 * might need to update MTU here, but we don't know which 343 * previous packet caused the failure -- so can't really 344 * retransmit anything. continue as if everything is fine and 345 * wait for an alert to handle the retransmit 346 */ 347 if (BIO_ctrl(SSL_get_wbio(s), 348 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) 349 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 350 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 351 else 352 return (-1); 353 } else { 354 355 /* 356 * bad if this assert fails, only part of the handshake message 357 * got sent. but why would this happen? 358 */ 359 OPENSSL_assert(len == (unsigned int)ret); 360 361 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) { 362 /* 363 * should not be done for 'Hello Request's, but in that case 364 * we'll ignore the result anyway 365 */ 366 unsigned char *p = 367 (unsigned char *)&s->init_buf->data[s->init_off]; 368 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 369 int xlen; 370 371 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER) { 372 /* 373 * reconstruct message header is if it is being sent in 374 * single fragment 375 */ 376 *p++ = msg_hdr->type; 377 l2n3(msg_hdr->msg_len, p); 378 s2n(msg_hdr->seq, p); 379 l2n3(0, p); 380 l2n3(msg_hdr->msg_len, p); 381 p -= DTLS1_HM_HEADER_LENGTH; 382 xlen = ret; 383 } else { 384 p += DTLS1_HM_HEADER_LENGTH; 385 xlen = ret - DTLS1_HM_HEADER_LENGTH; 386 } 387 388 ssl3_finish_mac(s, p, xlen); 389 } 390 391 if (ret == s->init_num) { 392 if (s->msg_callback) 393 s->msg_callback(1, s->version, type, s->init_buf->data, 394 (size_t)(s->init_off + s->init_num), s, 395 s->msg_callback_arg); 396 397 s->init_off = 0; /* done writing this message */ 398 s->init_num = 0; 399 400 return (1); 401 } 402 s->init_off += ret; 403 s->init_num -= ret; 404 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 405 } 406 } 407 return (0); 408} 409 410/* 411 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum 412 * acceptable body length 'max'. Read an entire handshake message. Handshake 413 * messages arrive in fragments. 414 */ 415long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 416{ 417 int i, al; 418 struct hm_header_st *msg_hdr; 419 unsigned char *p; 420 unsigned long msg_len; 421 422 /* 423 * s3->tmp is used to store messages that are unexpected, caused by the 424 * absence of an optional handshake message 425 */ 426 if (s->s3->tmp.reuse_message) { 427 s->s3->tmp.reuse_message = 0; 428 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 429 al = SSL_AD_UNEXPECTED_MESSAGE; 430 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 431 goto f_err; 432 } 433 *ok = 1; 434 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 435 s->init_num = (int)s->s3->tmp.message_size; 436 return s->init_num; 437 } 438 439 msg_hdr = &s->d1->r_msg_hdr; 440 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 441 442 again: 443 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 444 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) { 445 /* bad fragment received */ 446 goto again; 447 } else if (i <= 0 && !*ok) { 448 return i; 449 } 450 451 p = (unsigned char *)s->init_buf->data; 452 msg_len = msg_hdr->msg_len; 453 454 /* reconstruct message header */ 455 *(p++) = msg_hdr->type; 456 l2n3(msg_len, p); 457 s2n(msg_hdr->seq, p); 458 l2n3(0, p); 459 l2n3(msg_len, p); 460 if (s->version != DTLS1_BAD_VER) { 461 p -= DTLS1_HM_HEADER_LENGTH; 462 msg_len += DTLS1_HM_HEADER_LENGTH; 463 } 464 465 ssl3_finish_mac(s, p, msg_len); 466 if (s->msg_callback) 467 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 468 p, msg_len, s, s->msg_callback_arg); 469 470 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 471 472 /* Don't change sequence numbers while listening */ 473 if (!s->d1->listen) 474 s->d1->handshake_read_seq++; 475 476 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 477 return s->init_num; 478 479 f_err: 480 ssl3_send_alert(s, SSL3_AL_FATAL, al); 481 *ok = 0; 482 return -1; 483} 484 485static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, 486 int max) 487{ 488 size_t frag_off, frag_len, msg_len; 489 490 msg_len = msg_hdr->msg_len; 491 frag_off = msg_hdr->frag_off; 492 frag_len = msg_hdr->frag_len; 493 494 /* sanity checking */ 495 if ((frag_off + frag_len) > msg_len) { 496 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 497 return SSL_AD_ILLEGAL_PARAMETER; 498 } 499 500 if ((frag_off + frag_len) > (unsigned long)max) { 501 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 502 return SSL_AD_ILLEGAL_PARAMETER; 503 } 504 505 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */ 506 /* 507 * msg_len is limited to 2^24, but is effectively checked against max 508 * above 509 */ 510 if (!BUF_MEM_grow_clean 511 (s->init_buf, (int)msg_len + DTLS1_HM_HEADER_LENGTH)) { 512 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 513 return SSL_AD_INTERNAL_ERROR; 514 } 515 516 s->s3->tmp.message_size = msg_len; 517 s->d1->r_msg_hdr.msg_len = msg_len; 518 s->s3->tmp.message_type = msg_hdr->type; 519 s->d1->r_msg_hdr.type = msg_hdr->type; 520 s->d1->r_msg_hdr.seq = msg_hdr->seq; 521 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 522 /* 523 * They must be playing with us! BTW, failure to enforce upper limit 524 * would open possibility for buffer overrun. 525 */ 526 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE); 527 return SSL_AD_ILLEGAL_PARAMETER; 528 } 529 530 return 0; /* no error */ 531} 532 533static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 534{ 535 /*- 536 * (0) check whether the desired fragment is available 537 * if so: 538 * (1) copy over the fragment to s->init_buf->data[] 539 * (2) update s->init_num 540 */ 541 pitem *item; 542 hm_fragment *frag; 543 int al; 544 545 *ok = 0; 546 do { 547 item = pqueue_peek(s->d1->buffered_messages); 548 if (item == NULL) 549 return 0; 550 551 frag = (hm_fragment *)item->data; 552 553 if (frag->msg_header.seq < s->d1->handshake_read_seq) { 554 /* This is a stale message that has been buffered so clear it */ 555 pqueue_pop(s->d1->buffered_messages); 556 dtls1_hm_fragment_free(frag); 557 pitem_free(item); 558 item = NULL; 559 frag = NULL; 560 } 561 } while (item == NULL); 562 563 564 /* Don't return if reassembly still in progress */ 565 if (frag->reassembly != NULL) 566 return 0; 567 568 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 569 unsigned long frag_len = frag->msg_header.frag_len; 570 pqueue_pop(s->d1->buffered_messages); 571 572 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 573 574 if (al == 0) { /* no alert */ 575 unsigned char *p = 576 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 577 memcpy(&p[frag->msg_header.frag_off], frag->fragment, 578 frag->msg_header.frag_len); 579 } 580 581 dtls1_hm_fragment_free(frag); 582 pitem_free(item); 583 584 if (al == 0) { 585 *ok = 1; 586 return frag_len; 587 } 588 589 ssl3_send_alert(s, SSL3_AL_FATAL, al); 590 s->init_num = 0; 591 *ok = 0; 592 return -1; 593 } else 594 return 0; 595} 596 597/* 598 * dtls1_max_handshake_message_len returns the maximum number of bytes 599 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but 600 * may be greater if the maximum certificate list size requires it. 601 */ 602static unsigned long dtls1_max_handshake_message_len(const SSL *s) 603{ 604 unsigned long max_len = 605 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 606 if (max_len < (unsigned long)s->max_cert_list) 607 return s->max_cert_list; 608 return max_len; 609} 610 611static int 612dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok) 613{ 614 hm_fragment *frag = NULL; 615 pitem *item = NULL; 616 int i = -1, is_complete; 617 PQ_64BIT seq64; 618 unsigned long frag_len = msg_hdr->frag_len; 619 620 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 621 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 622 goto err; 623 624 if (frag_len == 0) 625 return DTLS1_HM_FRAGMENT_RETRY; 626 627 /* Try to find item in queue */ 628 pq_64bit_init(&seq64); 629 pq_64bit_assign_word(&seq64, msg_hdr->seq); 630 item = pqueue_find(s->d1->buffered_messages, seq64); 631 pq_64bit_free(&seq64); 632 633 if (item == NULL) { 634 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 635 if (frag == NULL) 636 goto err; 637 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 638 frag->msg_header.frag_len = frag->msg_header.msg_len; 639 frag->msg_header.frag_off = 0; 640 } else { 641 frag = (hm_fragment *)item->data; 642 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 643 item = NULL; 644 frag = NULL; 645 goto err; 646 } 647 } 648 649 /* 650 * If message is already reassembled, this must be a retransmit and can 651 * be dropped. In this case item != NULL and so frag does not need to be 652 * freed. 653 */ 654 if (frag->reassembly == NULL) { 655 unsigned char devnull[256]; 656 657 while (frag_len) { 658 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 659 devnull, 660 frag_len > 661 sizeof(devnull) ? sizeof(devnull) : 662 frag_len, 0); 663 if (i <= 0) 664 goto err; 665 frag_len -= i; 666 } 667 return DTLS1_HM_FRAGMENT_RETRY; 668 } 669 670 /* read the body of the fragment (header has already been read */ 671 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 672 frag->fragment + msg_hdr->frag_off, 673 frag_len, 0); 674 if ((unsigned long)i != frag_len) 675 i = -1; 676 if (i <= 0) 677 goto err; 678 679 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 680 (long)(msg_hdr->frag_off + frag_len)); 681 682 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 683 is_complete); 684 685 if (is_complete) { 686 OPENSSL_free(frag->reassembly); 687 frag->reassembly = NULL; 688 } 689 690 if (item == NULL) { 691 pq_64bit_init(&seq64); 692 pq_64bit_assign_word(&seq64, msg_hdr->seq); 693 item = pitem_new(seq64, frag); 694 pq_64bit_free(&seq64); 695 696 if (item == NULL) { 697 i = -1; 698 goto err; 699 } 700 701 item = pqueue_insert(s->d1->buffered_messages, item); 702 /* 703 * pqueue_insert fails iff a duplicate item is inserted. However, 704 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 705 * would have returned it and control would never have reached this 706 * branch. 707 */ 708 OPENSSL_assert(item != NULL); 709 } 710 711 return DTLS1_HM_FRAGMENT_RETRY; 712 713 err: 714 if (frag != NULL && item == NULL) 715 dtls1_hm_fragment_free(frag); 716 *ok = 0; 717 return i; 718} 719 720static int 721dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr, 722 int *ok) 723{ 724 int i = -1; 725 hm_fragment *frag = NULL; 726 pitem *item = NULL; 727 PQ_64BIT seq64; 728 unsigned long frag_len = msg_hdr->frag_len; 729 730 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 731 goto err; 732 733 /* Try to find item in queue, to prevent duplicate entries */ 734 pq_64bit_init(&seq64); 735 pq_64bit_assign_word(&seq64, msg_hdr->seq); 736 item = pqueue_find(s->d1->buffered_messages, seq64); 737 pq_64bit_free(&seq64); 738 739 /* 740 * If we already have an entry and this one is a fragment, don't discard 741 * it and rather try to reassemble it. 742 */ 743 if (item != NULL && frag_len != msg_hdr->msg_len) 744 item = NULL; 745 746 /* 747 * Discard the message if sequence number was already there, is too far 748 * in the future, already in the queue or if we received a FINISHED 749 * before the SERVER_HELLO, which then must be a stale retransmit. 750 */ 751 if (msg_hdr->seq <= s->d1->handshake_read_seq || 752 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 753 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 754 { 755 unsigned char devnull[256]; 756 757 while (frag_len) { 758 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 759 devnull, 760 frag_len > 761 sizeof(devnull) ? sizeof(devnull) : 762 frag_len, 0); 763 if (i <= 0) 764 goto err; 765 frag_len -= i; 766 } 767 } else { 768 if (frag_len != msg_hdr->msg_len) 769 return dtls1_reassemble_fragment(s, msg_hdr, ok); 770 771 if (frag_len > dtls1_max_handshake_message_len(s)) 772 goto err; 773 774 frag = dtls1_hm_fragment_new(frag_len, 0); 775 if (frag == NULL) 776 goto err; 777 778 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 779 780 if (frag_len) { 781 /* 782 * read the body of the fragment (header has already been read) 783 */ 784 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 785 frag->fragment, frag_len, 0); 786 if ((unsigned long)i != frag_len) 787 i = -1; 788 if (i <= 0) 789 goto err; 790 } 791 792 pq_64bit_init(&seq64); 793 pq_64bit_assign_word(&seq64, msg_hdr->seq); 794 795 item = pitem_new(seq64, frag); 796 pq_64bit_free(&seq64); 797 if (item == NULL) 798 goto err; 799 800 item = pqueue_insert(s->d1->buffered_messages, item); 801 /* 802 * pqueue_insert fails iff a duplicate item is inserted. However, 803 * |item| cannot be a duplicate. If it were, |pqueue_find|, above, 804 * would have returned it. Then, either |frag_len| != 805 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will 806 * have been processed with |dtls1_reassemble_fragment|, above, or 807 * the record will have been discarded. 808 */ 809 OPENSSL_assert(item != NULL); 810 } 811 812 return DTLS1_HM_FRAGMENT_RETRY; 813 814 err: 815 if (frag != NULL && item == NULL) 816 dtls1_hm_fragment_free(frag); 817 *ok = 0; 818 return i; 819} 820 821static long 822dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 823{ 824 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 825 unsigned long len, frag_off, frag_len; 826 int i, al; 827 struct hm_header_st msg_hdr; 828 829 redo: 830 /* see if we have the required fragment already */ 831 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 832 if (*ok) 833 s->init_num = frag_len; 834 return frag_len; 835 } 836 837 /* read handshake message header */ 838 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 839 DTLS1_HM_HEADER_LENGTH, 0); 840 if (i <= 0) { /* nbio, or an error */ 841 s->rwstate = SSL_READING; 842 *ok = 0; 843 return i; 844 } 845 /* Handshake fails if message header is incomplete */ 846 if (i != DTLS1_HM_HEADER_LENGTH) { 847 al = SSL_AD_UNEXPECTED_MESSAGE; 848 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE); 849 goto f_err; 850 } 851 852 /* parse the message fragment header */ 853 dtls1_get_message_header(wire, &msg_hdr); 854 855 /* 856 * if this is a future (or stale) message it gets buffered 857 * (or dropped)--no further processing at this time 858 * While listening, we accept seq 1 (ClientHello with cookie) 859 * although we're still expecting seq 0 (ClientHello) 860 */ 861 if (msg_hdr.seq != s->d1->handshake_read_seq 862 && !(s->d1->listen && msg_hdr.seq == 1)) 863 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 864 865 len = msg_hdr.msg_len; 866 frag_off = msg_hdr.frag_off; 867 frag_len = msg_hdr.frag_len; 868 869 if (frag_len && frag_len < len) 870 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 871 872 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 873 wire[0] == SSL3_MT_HELLO_REQUEST) { 874 /* 875 * The server may always send 'Hello Request' messages -- we are 876 * doing a handshake anyway now, so ignore them if their format is 877 * correct. Does not count for 'Finished' MAC. 878 */ 879 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 880 if (s->msg_callback) 881 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 882 wire, DTLS1_HM_HEADER_LENGTH, s, 883 s->msg_callback_arg); 884 885 s->init_num = 0; 886 goto redo; 887 } else { /* Incorrectly formated Hello request */ 888 889 al = SSL_AD_UNEXPECTED_MESSAGE; 890 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 891 SSL_R_UNEXPECTED_MESSAGE); 892 goto f_err; 893 } 894 } 895 896 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 897 goto f_err; 898 899 /* XDTLS: ressurect this when restart is in place */ 900 s->state = stn; 901 902 if (frag_len > 0) { 903 unsigned char *p = 904 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 905 906 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 907 &p[frag_off], frag_len, 0); 908 /* 909 * XDTLS: fix this--message fragments cannot span multiple packets 910 */ 911 if (i <= 0) { 912 s->rwstate = SSL_READING; 913 *ok = 0; 914 return i; 915 } 916 } else 917 i = 0; 918 919 /* 920 * XDTLS: an incorrectly formatted fragment should cause the handshake 921 * to fail 922 */ 923 if (i != (int)frag_len) { 924 al = SSL3_AD_ILLEGAL_PARAMETER; 925 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER); 926 goto f_err; 927 } 928 929 *ok = 1; 930 931 /* 932 * Note that s->init_num is *not* used as current offset in 933 * s->init_buf->data, but as a counter summing up fragments' lengths: as 934 * soon as they sum up to handshake packet length, we assume we have got 935 * all the fragments. 936 */ 937 s->init_num = frag_len; 938 return frag_len; 939 940 f_err: 941 ssl3_send_alert(s, SSL3_AL_FATAL, al); 942 s->init_num = 0; 943 944 *ok = 0; 945 return (-1); 946} 947 948int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 949{ 950 unsigned char *p, *d; 951 int i; 952 unsigned long l; 953 954 if (s->state == a) { 955 d = (unsigned char *)s->init_buf->data; 956 p = &(d[DTLS1_HM_HEADER_LENGTH]); 957 958 i = s->method->ssl3_enc->final_finish_mac(s, 959 &(s->s3->finish_dgst1), 960 &(s->s3->finish_dgst2), 961 sender, slen, 962 s->s3->tmp.finish_md); 963 s->s3->tmp.finish_md_len = i; 964 memcpy(p, s->s3->tmp.finish_md, i); 965 p += i; 966 l = i; 967 968 /* 969 * Copy the finished so we can use it for renegotiation checks 970 */ 971 if (s->type == SSL_ST_CONNECT) { 972 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 973 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i); 974 s->s3->previous_client_finished_len = i; 975 } else { 976 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 977 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i); 978 s->s3->previous_server_finished_len = i; 979 } 980 981#ifdef OPENSSL_SYS_WIN16 982 /* 983 * MSVC 1.5 does not clear the top bytes of the word unless I do 984 * this. 985 */ 986 l &= 0xffff; 987#endif 988 989 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 990 s->init_num = (int)l + DTLS1_HM_HEADER_LENGTH; 991 s->init_off = 0; 992 993 /* buffer the message to handle re-xmits */ 994 dtls1_buffer_message(s, 0); 995 996 s->state = b; 997 } 998 999 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 1000 return (dtls1_do_write(s, SSL3_RT_HANDSHAKE)); 1001} 1002 1003/*- 1004 * for these 2 messages, we need to 1005 * ssl->enc_read_ctx re-init 1006 * ssl->s3->read_sequence zero 1007 * ssl->s3->read_mac_secret re-init 1008 * ssl->session->read_sym_enc assign 1009 * ssl->session->read_compression assign 1010 * ssl->session->read_hash assign 1011 */ 1012int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1013{ 1014 unsigned char *p; 1015 1016 if (s->state == a) { 1017 p = (unsigned char *)s->init_buf->data; 1018 *p++ = SSL3_MT_CCS; 1019 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1020 s->init_num = DTLS1_CCS_HEADER_LENGTH; 1021 1022 if (s->client_version == DTLS1_BAD_VER) { 1023 s->d1->next_handshake_write_seq++; 1024 s2n(s->d1->handshake_write_seq, p); 1025 s->init_num += 2; 1026 } 1027 1028 s->init_off = 0; 1029 1030 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1031 s->d1->handshake_write_seq, 0, 0); 1032 1033 /* buffer the message to handle re-xmits */ 1034 dtls1_buffer_message(s, 1); 1035 1036 s->state = b; 1037 } 1038 1039 /* SSL3_ST_CW_CHANGE_B */ 1040 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 1041} 1042 1043static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1044{ 1045 int n; 1046 unsigned char *p; 1047 1048 n = i2d_X509(x, NULL); 1049 if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) { 1050 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB); 1051 return 0; 1052 } 1053 p = (unsigned char *)&(buf->data[*l]); 1054 l2n3(n, p); 1055 i2d_X509(x, &p); 1056 *l += n + 3; 1057 1058 return 1; 1059} 1060 1061unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1062{ 1063 unsigned char *p; 1064 int i; 1065 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH; 1066 BUF_MEM *buf; 1067 1068 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1069 buf = s->init_buf; 1070 if (!BUF_MEM_grow_clean(buf, 10)) { 1071 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB); 1072 return (0); 1073 } 1074 if (x != NULL) { 1075 X509_STORE_CTX xs_ctx; 1076 1077 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, x, NULL)) { 1078 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB); 1079 return (0); 1080 } 1081 1082 X509_verify_cert(&xs_ctx); 1083 /* Don't leave errors in the queue */ 1084 ERR_clear_error(); 1085 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) { 1086 x = sk_X509_value(xs_ctx.chain, i); 1087 1088 if (!dtls1_add_cert_to_buf(buf, &l, x)) { 1089 X509_STORE_CTX_cleanup(&xs_ctx); 1090 return 0; 1091 } 1092 } 1093 X509_STORE_CTX_cleanup(&xs_ctx); 1094 } 1095 /* Thawte special :-) */ 1096 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) { 1097 x = sk_X509_value(s->ctx->extra_certs, i); 1098 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1099 return 0; 1100 } 1101 1102 l -= (3 + DTLS1_HM_HEADER_LENGTH); 1103 1104 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1105 l2n3(l, p); 1106 l += 3; 1107 p = (unsigned char *)&(buf->data[0]); 1108 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1109 1110 l += DTLS1_HM_HEADER_LENGTH; 1111 return (l); 1112} 1113 1114int dtls1_read_failed(SSL *s, int code) 1115{ 1116 if (code > 0) { 1117 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1118 return 1; 1119 } 1120 1121 if (!dtls1_is_timer_expired(s)) { 1122 /* 1123 * not a timeout, none of our business, let higher layers handle 1124 * this. in fact it's probably an error 1125 */ 1126 return code; 1127 } 1128 1129 /* done, no need to send a retransmit */ 1130 if (!SSL_in_init(s)) { 1131 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1132 return code; 1133 } 1134#if 0 /* for now, each alert contains only one 1135 * record number */ 1136 item = pqueue_peek(state->rcvd_records); 1137 if (item) { 1138 /* send an alert immediately for all the missing records */ 1139 } else 1140#endif 1141 1142#if 0 /* no more alert sending, just retransmit the 1143 * last set of messages */ 1144 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1145 ssl3_send_alert(s, SSL3_AL_WARNING, 1146 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1147#endif 1148 1149 return dtls1_handle_timeout(s); 1150} 1151 1152int dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1153{ 1154 /* 1155 * The index of the retransmission queue actually is the message sequence 1156 * number, since the queue only contains messages of a single handshake. 1157 * However, the ChangeCipherSpec has no message sequence number and so 1158 * using only the sequence will result in the CCS and Finished having the 1159 * same index. To prevent this, the sequence number is multiplied by 2. 1160 * In case of a CCS 1 is subtracted. This does not only differ CSS and 1161 * Finished, it also maintains the order of the index (important for 1162 * priority queues) and fits in the unsigned short variable. 1163 */ 1164 return seq * 2 - is_ccs; 1165} 1166 1167int dtls1_retransmit_buffered_messages(SSL *s) 1168{ 1169 pqueue sent = s->d1->sent_messages; 1170 piterator iter; 1171 pitem *item; 1172 hm_fragment *frag; 1173 int found = 0; 1174 1175 iter = pqueue_iterator(sent); 1176 1177 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { 1178 frag = (hm_fragment *)item->data; 1179 if (dtls1_retransmit_message(s, (unsigned short) 1180 dtls1_get_queue_priority 1181 (frag->msg_header.seq, 1182 frag->msg_header.is_ccs), 0, 1183 &found) <= 0 && found) { 1184 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1185 return -1; 1186 } 1187 } 1188 1189 return 1; 1190} 1191 1192int dtls1_buffer_message(SSL *s, int is_ccs) 1193{ 1194 pitem *item; 1195 hm_fragment *frag; 1196 PQ_64BIT seq64; 1197 1198 /* 1199 * this function is called immediately after a message has been 1200 * serialized 1201 */ 1202 OPENSSL_assert(s->init_off == 0); 1203 1204 frag = dtls1_hm_fragment_new(s->init_num, 0); 1205 if (!frag) 1206 return 0; 1207 1208 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1209 1210 if (is_ccs) { 1211 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1212 DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num); 1213 } else { 1214 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1215 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1216 } 1217 1218 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1219 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1220 frag->msg_header.type = s->d1->w_msg_hdr.type; 1221 frag->msg_header.frag_off = 0; 1222 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1223 frag->msg_header.is_ccs = is_ccs; 1224 1225 /* save current state */ 1226 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1227 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1228 frag->msg_header.saved_retransmit_state.compress = s->compress; 1229 frag->msg_header.saved_retransmit_state.session = s->session; 1230 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1231 1232 pq_64bit_init(&seq64); 1233 1234 pq_64bit_assign_word(&seq64, 1235 dtls1_get_queue_priority(frag->msg_header.seq, 1236 frag->msg_header.is_ccs)); 1237 1238 item = pitem_new(seq64, frag); 1239 pq_64bit_free(&seq64); 1240 if (item == NULL) { 1241 dtls1_hm_fragment_free(frag); 1242 return 0; 1243 } 1244#if 0 1245 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1246 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1247 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1248#endif 1249 1250 pqueue_insert(s->d1->sent_messages, item); 1251 return 1; 1252} 1253 1254int 1255dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1256 int *found) 1257{ 1258 int ret; 1259 /* XDTLS: for now assuming that read/writes are blocking */ 1260 pitem *item; 1261 hm_fragment *frag; 1262 unsigned long header_length; 1263 PQ_64BIT seq64; 1264 struct dtls1_retransmit_state saved_state; 1265 unsigned char save_write_sequence[8]; 1266 1267 /*- 1268 OPENSSL_assert(s->init_num == 0); 1269 OPENSSL_assert(s->init_off == 0); 1270 */ 1271 1272 /* XDTLS: the requested message ought to be found, otherwise error */ 1273 pq_64bit_init(&seq64); 1274 pq_64bit_assign_word(&seq64, seq); 1275 1276 item = pqueue_find(s->d1->sent_messages, seq64); 1277 pq_64bit_free(&seq64); 1278 if (item == NULL) { 1279 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1280 *found = 0; 1281 return 0; 1282 } 1283 1284 *found = 1; 1285 frag = (hm_fragment *)item->data; 1286 1287 if (frag->msg_header.is_ccs) 1288 header_length = DTLS1_CCS_HEADER_LENGTH; 1289 else 1290 header_length = DTLS1_HM_HEADER_LENGTH; 1291 1292 memcpy(s->init_buf->data, frag->fragment, 1293 frag->msg_header.msg_len + header_length); 1294 s->init_num = frag->msg_header.msg_len + header_length; 1295 1296 dtls1_set_message_header_int(s, frag->msg_header.type, 1297 frag->msg_header.msg_len, 1298 frag->msg_header.seq, 0, 1299 frag->msg_header.frag_len); 1300 1301 /* save current state */ 1302 saved_state.enc_write_ctx = s->enc_write_ctx; 1303 saved_state.write_hash = s->write_hash; 1304 saved_state.compress = s->compress; 1305 saved_state.session = s->session; 1306 saved_state.epoch = s->d1->w_epoch; 1307 saved_state.epoch = s->d1->w_epoch; 1308 1309 s->d1->retransmitting = 1; 1310 1311 /* restore state in which the message was originally sent */ 1312 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1313 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1314 s->compress = frag->msg_header.saved_retransmit_state.compress; 1315 s->session = frag->msg_header.saved_retransmit_state.session; 1316 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1317 1318 if (frag->msg_header.saved_retransmit_state.epoch == 1319 saved_state.epoch - 1) { 1320 memcpy(save_write_sequence, s->s3->write_sequence, 1321 sizeof(s->s3->write_sequence)); 1322 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1323 sizeof(s->s3->write_sequence)); 1324 } 1325 1326 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1327 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1328 1329 /* restore current state */ 1330 s->enc_write_ctx = saved_state.enc_write_ctx; 1331 s->write_hash = saved_state.write_hash; 1332 s->compress = saved_state.compress; 1333 s->session = saved_state.session; 1334 s->d1->w_epoch = saved_state.epoch; 1335 1336 if (frag->msg_header.saved_retransmit_state.epoch == 1337 saved_state.epoch - 1) { 1338 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1339 sizeof(s->s3->write_sequence)); 1340 memcpy(s->s3->write_sequence, save_write_sequence, 1341 sizeof(s->s3->write_sequence)); 1342 } 1343 1344 s->d1->retransmitting = 0; 1345 1346 (void)BIO_flush(SSL_get_wbio(s)); 1347 return ret; 1348} 1349 1350unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p, 1351 unsigned char mt, unsigned long len, 1352 unsigned long frag_off, 1353 unsigned long frag_len) 1354{ 1355 /* Don't change sequence numbers while listening */ 1356 if (frag_off == 0 && !s->d1->listen) { 1357 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1358 s->d1->next_handshake_write_seq++; 1359 } 1360 1361 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1362 frag_off, frag_len); 1363 1364 return p += DTLS1_HM_HEADER_LENGTH; 1365} 1366 1367/* don't actually do the writing, wait till the MTU has been retrieved */ 1368static void 1369dtls1_set_message_header_int(SSL *s, unsigned char mt, 1370 unsigned long len, unsigned short seq_num, 1371 unsigned long frag_off, unsigned long frag_len) 1372{ 1373 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1374 1375 msg_hdr->type = mt; 1376 msg_hdr->msg_len = len; 1377 msg_hdr->seq = seq_num; 1378 msg_hdr->frag_off = frag_off; 1379 msg_hdr->frag_len = frag_len; 1380} 1381 1382static void 1383dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1384 unsigned long frag_len) 1385{ 1386 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1387 1388 msg_hdr->frag_off = frag_off; 1389 msg_hdr->frag_len = frag_len; 1390} 1391 1392static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p) 1393{ 1394 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1395 1396 *p++ = msg_hdr->type; 1397 l2n3(msg_hdr->msg_len, p); 1398 1399 s2n(msg_hdr->seq, p); 1400 l2n3(msg_hdr->frag_off, p); 1401 l2n3(msg_hdr->frag_len, p); 1402 1403 return p; 1404} 1405 1406unsigned int dtls1_min_mtu(void) 1407{ 1408 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1409 sizeof(g_probable_mtu[0])) - 1]); 1410} 1411 1412static unsigned int dtls1_guess_mtu(unsigned int curr_mtu) 1413{ 1414 size_t i; 1415 1416 if (curr_mtu == 0) 1417 return g_probable_mtu[0]; 1418 1419 for (i = 0; i < sizeof(g_probable_mtu) / sizeof(g_probable_mtu[0]); i++) 1420 if (curr_mtu > g_probable_mtu[i]) 1421 return g_probable_mtu[i]; 1422 1423 return curr_mtu; 1424} 1425 1426void 1427dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1428{ 1429 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1430 msg_hdr->type = *(data++); 1431 n2l3(data, msg_hdr->msg_len); 1432 1433 n2s(data, msg_hdr->seq); 1434 n2l3(data, msg_hdr->frag_off); 1435 n2l3(data, msg_hdr->frag_len); 1436} 1437 1438void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1439{ 1440 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1441 1442 ccs_hdr->type = *(data++); 1443} 1444