1 /* $OpenBSD: d1_both.c,v 1.38 2015/09/11 18:08:21 jsing Exp $ */ 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 <stdio.h> 118 #include <string.h> 119 120 #include "ssl_locl.h" 121 122 #include <openssl/buffer.h> 123 #include <openssl/evp.h> 124 #include <openssl/objects.h> 125 #include <openssl/x509.h> 126 127 #include "pqueue.h" 128 #include "bytestring.h" 129 130 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 131 132 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 133 if ((end) - (start) <= 8) { \ 134 long ii; \ 135 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 136 } else { \ 137 long ii; \ 138 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 139 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 140 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 141 } } 142 143 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 144 long ii; \ 145 OPENSSL_assert((msg_len) > 0); \ 146 is_complete = 1; \ 147 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 148 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 149 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 150 151 static unsigned char bitmask_start_values[] = { 152 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 153 }; 154 static unsigned char bitmask_end_values[] = { 155 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f 156 }; 157 158 /* XDTLS: figure out the right values */ 159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 160 161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 163 unsigned long frag_len); 164 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p); 165 static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 166 unsigned long len, unsigned short seq_num, unsigned long frag_off, 167 unsigned long frag_len); 168 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, 169 int *ok); 170 171 static hm_fragment * 172 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly) 173 { 174 hm_fragment *frag = NULL; 175 unsigned char *buf = NULL; 176 unsigned char *bitmask = NULL; 177 178 frag = malloc(sizeof(hm_fragment)); 179 if (frag == NULL) 180 return NULL; 181 182 if (frag_len) { 183 buf = malloc(frag_len); 184 if (buf == NULL) { 185 free(frag); 186 return NULL; 187 } 188 } 189 190 /* zero length fragment gets zero frag->fragment */ 191 frag->fragment = buf; 192 193 /* Initialize reassembly bitmask if necessary */ 194 if (reassembly) { 195 bitmask = malloc(RSMBLY_BITMASK_SIZE(frag_len)); 196 if (bitmask == NULL) { 197 free(buf); 198 free(frag); 199 return NULL; 200 } 201 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 202 } 203 204 frag->reassembly = bitmask; 205 206 return frag; 207 } 208 209 static void 210 dtls1_hm_fragment_free(hm_fragment *frag) 211 { 212 if (frag == NULL) 213 return; 214 215 if (frag->msg_header.is_ccs) { 216 EVP_CIPHER_CTX_free( 217 frag->msg_header.saved_retransmit_state.enc_write_ctx); 218 EVP_MD_CTX_destroy( 219 frag->msg_header.saved_retransmit_state.write_hash); 220 } 221 free(frag->fragment); 222 free(frag->reassembly); 223 free(frag); 224 } 225 226 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 227 int 228 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 = BIO_ctrl(SSL_get_wbio(s), 238 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 239 240 /* 241 * I've seen the kernel return bogus numbers when it 242 * doesn't know the MTU (ie., the initial write), so just 243 * make sure we have a reasonable number 244 */ 245 if (s->d1->mtu < dtls1_min_mtu()) { 246 s->d1->mtu = 0; 247 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 248 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 249 s->d1->mtu, NULL); 250 } 251 } 252 253 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); 254 /* should have something reasonable now */ 255 256 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 257 OPENSSL_assert(s->init_num == 258 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 259 260 if (s->write_hash) 261 mac_size = EVP_MD_CTX_size(s->write_hash); 262 else 263 mac_size = 0; 264 265 if (s->enc_write_ctx && 266 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 267 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 268 else 269 blocksize = 0; 270 271 frag_off = 0; 272 while (s->init_num) { 273 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 274 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; 275 276 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 277 /* grr.. we could get an error if MTU picked was wrong */ 278 ret = BIO_flush(SSL_get_wbio(s)); 279 if (ret <= 0) 280 return ret; 281 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 282 mac_size - blocksize; 283 } 284 285 if (s->init_num > curr_mtu) 286 len = curr_mtu; 287 else 288 len = s->init_num; 289 290 291 /* XDTLS: this function is too long. split out the CCS part */ 292 if (type == SSL3_RT_HANDSHAKE) { 293 if (s->init_off != 0) { 294 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 295 s->init_off -= DTLS1_HM_HEADER_LENGTH; 296 s->init_num += DTLS1_HM_HEADER_LENGTH; 297 298 if (s->init_num > curr_mtu) 299 len = curr_mtu; 300 else 301 len = s->init_num; 302 } 303 304 dtls1_fix_message_header(s, frag_off, 305 len - DTLS1_HM_HEADER_LENGTH); 306 307 dtls1_write_message_header(s, 308 (unsigned char *)&s->init_buf->data[s->init_off]); 309 310 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 311 } 312 313 ret = dtls1_write_bytes(s, type, 314 &s->init_buf->data[s->init_off], len); 315 if (ret < 0) { 316 /* 317 * Might need to update MTU here, but we don't know 318 * which previous packet caused the failure -- so 319 * can't really retransmit anything. continue as 320 * if everything is fine and wait for an alert to 321 * handle the retransmit 322 */ 323 if (BIO_ctrl(SSL_get_wbio(s), 324 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) 325 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 326 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 327 else 328 return (-1); 329 } else { 330 331 /* 332 * Bad if this assert fails, only part of the 333 * handshake message got sent. but why would 334 * this happen? 335 */ 336 OPENSSL_assert(len == (unsigned int)ret); 337 338 if (type == SSL3_RT_HANDSHAKE && 339 !s->d1->retransmitting) { 340 /* 341 * Should not be done for 'Hello Request's, 342 * but in that case we'll ignore the result 343 * anyway 344 */ 345 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 346 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 347 int xlen; 348 349 if (frag_off == 0) { 350 /* 351 * Reconstruct message header is if it 352 * is being sent in single fragment 353 */ 354 *p++ = msg_hdr->type; 355 l2n3(msg_hdr->msg_len, p); 356 s2n (msg_hdr->seq, p); 357 l2n3(0, p); 358 l2n3(msg_hdr->msg_len, p); 359 p -= DTLS1_HM_HEADER_LENGTH; 360 xlen = ret; 361 } else { 362 p += DTLS1_HM_HEADER_LENGTH; 363 xlen = ret - DTLS1_HM_HEADER_LENGTH; 364 } 365 366 tls1_finish_mac(s, p, xlen); 367 } 368 369 if (ret == s->init_num) { 370 if (s->msg_callback) 371 s->msg_callback(1, s->version, type, 372 s->init_buf->data, 373 (size_t)(s->init_off + s->init_num), 374 s, s->msg_callback_arg); 375 376 s->init_off = 0; 377 /* done writing this message */ 378 s->init_num = 0; 379 380 return (1); 381 } 382 s->init_off += ret; 383 s->init_num -= ret; 384 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 385 } 386 } 387 return (0); 388 } 389 390 391 /* 392 * Obtain handshake message of message type 'mt' (any if mt == -1), 393 * maximum acceptable body length 'max'. 394 * Read an entire handshake message. Handshake messages arrive in 395 * fragments. 396 */ 397 long 398 dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 399 { 400 int i, al; 401 struct hm_header_st *msg_hdr; 402 unsigned char *p; 403 unsigned long msg_len; 404 405 /* 406 * s3->tmp is used to store messages that are unexpected, caused 407 * by the absence of an optional handshake message 408 */ 409 if (s->s3->tmp.reuse_message) { 410 s->s3->tmp.reuse_message = 0; 411 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 412 al = SSL_AD_UNEXPECTED_MESSAGE; 413 SSLerr(SSL_F_DTLS1_GET_MESSAGE, 414 SSL_R_UNEXPECTED_MESSAGE); 415 goto f_err; 416 } 417 *ok = 1; 418 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 419 s->init_num = (int)s->s3->tmp.message_size; 420 return s->init_num; 421 } 422 423 msg_hdr = &s->d1->r_msg_hdr; 424 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 425 426 again: 427 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 428 if (i == DTLS1_HM_BAD_FRAGMENT || 429 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 430 goto again; 431 else if (i <= 0 && !*ok) 432 return i; 433 434 p = (unsigned char *)s->init_buf->data; 435 msg_len = msg_hdr->msg_len; 436 437 /* reconstruct message header */ 438 *(p++) = msg_hdr->type; 439 l2n3(msg_len, p); 440 s2n (msg_hdr->seq, p); 441 l2n3(0, p); 442 l2n3(msg_len, p); 443 444 p -= DTLS1_HM_HEADER_LENGTH; 445 msg_len += DTLS1_HM_HEADER_LENGTH; 446 447 tls1_finish_mac(s, p, msg_len); 448 if (s->msg_callback) 449 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, p, msg_len, 450 s, s->msg_callback_arg); 451 452 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 453 454 /* Don't change sequence numbers while listening */ 455 if (!s->d1->listen) 456 s->d1->handshake_read_seq++; 457 458 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 459 return s->init_num; 460 461 f_err: 462 ssl3_send_alert(s, SSL3_AL_FATAL, al); 463 *ok = 0; 464 return -1; 465 } 466 467 468 static int 469 dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, int max) 470 { 471 size_t frag_off, frag_len, msg_len; 472 473 msg_len = msg_hdr->msg_len; 474 frag_off = msg_hdr->frag_off; 475 frag_len = msg_hdr->frag_len; 476 477 /* sanity checking */ 478 if ((frag_off + frag_len) > msg_len) { 479 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, 480 SSL_R_EXCESSIVE_MESSAGE_SIZE); 481 return SSL_AD_ILLEGAL_PARAMETER; 482 } 483 484 if ((frag_off + frag_len) > (unsigned long)max) { 485 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, 486 SSL_R_EXCESSIVE_MESSAGE_SIZE); 487 return SSL_AD_ILLEGAL_PARAMETER; 488 } 489 490 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 491 { 492 /* 493 * msg_len is limited to 2^24, but is effectively checked 494 * against max above 495 */ 496 if (!BUF_MEM_grow_clean(s->init_buf, 497 msg_len + DTLS1_HM_HEADER_LENGTH)) { 498 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 499 return SSL_AD_INTERNAL_ERROR; 500 } 501 502 s->s3->tmp.message_size = msg_len; 503 s->d1->r_msg_hdr.msg_len = msg_len; 504 s->s3->tmp.message_type = msg_hdr->type; 505 s->d1->r_msg_hdr.type = msg_hdr->type; 506 s->d1->r_msg_hdr.seq = msg_hdr->seq; 507 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 508 /* 509 * They must be playing with us! BTW, failure to enforce 510 * upper limit would open possibility for buffer overrun. 511 */ 512 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, 513 SSL_R_EXCESSIVE_MESSAGE_SIZE); 514 return SSL_AD_ILLEGAL_PARAMETER; 515 } 516 517 return 0; /* no error */ 518 } 519 520 static int 521 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 522 { 523 /* 524 * (0) check whether the desired fragment is available 525 * if so: 526 * (1) copy over the fragment to s->init_buf->data[] 527 * (2) update s->init_num 528 */ 529 pitem *item; 530 hm_fragment *frag; 531 int al; 532 533 *ok = 0; 534 item = pqueue_peek(s->d1->buffered_messages); 535 if (item == NULL) 536 return 0; 537 538 frag = (hm_fragment *)item->data; 539 540 /* Don't return if reassembly still in progress */ 541 if (frag->reassembly != NULL) 542 return 0; 543 544 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 545 unsigned long frag_len = frag->msg_header.frag_len; 546 pqueue_pop(s->d1->buffered_messages); 547 548 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 549 550 if (al == 0) /* no alert */ 551 { 552 unsigned char *p = (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 553 memcpy(&p[frag->msg_header.frag_off], 554 frag->fragment, frag->msg_header.frag_len); 555 } 556 557 dtls1_hm_fragment_free(frag); 558 pitem_free(item); 559 560 if (al == 0) { 561 *ok = 1; 562 return frag_len; 563 } 564 565 ssl3_send_alert(s, SSL3_AL_FATAL, al); 566 s->init_num = 0; 567 *ok = 0; 568 return -1; 569 } else 570 return 0; 571 } 572 573 /* 574 * dtls1_max_handshake_message_len returns the maximum number of bytes 575 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, 576 * but may be greater if the maximum certificate list size requires it. 577 */ 578 static unsigned long 579 dtls1_max_handshake_message_len(const SSL *s) 580 { 581 unsigned long max_len; 582 583 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 584 if (max_len < (unsigned long)s->max_cert_list) 585 return s->max_cert_list; 586 return max_len; 587 } 588 589 static int 590 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok) 591 { 592 hm_fragment *frag = NULL; 593 pitem *item = NULL; 594 int i = -1, is_complete; 595 unsigned char seq64be[8]; 596 unsigned long frag_len = msg_hdr->frag_len; 597 598 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || 599 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 600 goto err; 601 602 if (frag_len == 0) { 603 i = DTLS1_HM_FRAGMENT_RETRY; 604 goto err; 605 } 606 607 /* Try to find item in queue */ 608 memset(seq64be, 0, sizeof(seq64be)); 609 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 610 seq64be[7] = (unsigned char)msg_hdr->seq; 611 item = pqueue_find(s->d1->buffered_messages, seq64be); 612 613 if (item == NULL) { 614 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 615 if (frag == NULL) 616 goto err; 617 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 618 frag->msg_header.frag_len = frag->msg_header.msg_len; 619 frag->msg_header.frag_off = 0; 620 } else { 621 frag = (hm_fragment*)item->data; 622 if (frag->msg_header.msg_len != msg_hdr->msg_len) { 623 item = NULL; 624 frag = NULL; 625 goto err; 626 } 627 } 628 629 /* 630 * If message is already reassembled, this must be a 631 * retransmit and can be dropped. 632 */ 633 if (frag->reassembly == NULL) { 634 unsigned char devnull [256]; 635 636 while (frag_len) { 637 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 638 devnull, frag_len > sizeof(devnull) ? 639 sizeof(devnull) : frag_len, 0); 640 if (i <= 0) 641 goto err; 642 frag_len -= i; 643 } 644 i = DTLS1_HM_FRAGMENT_RETRY; 645 goto err; 646 } 647 648 /* read the body of the fragment (header has already been read */ 649 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 650 frag->fragment + msg_hdr->frag_off, frag_len, 0); 651 if (i <= 0 || (unsigned long)i != frag_len) 652 goto err; 653 654 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 655 (long)(msg_hdr->frag_off + frag_len)); 656 657 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 658 is_complete); 659 660 if (is_complete) { 661 free(frag->reassembly); 662 frag->reassembly = NULL; 663 } 664 665 if (item == NULL) { 666 memset(seq64be, 0, sizeof(seq64be)); 667 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 668 seq64be[7] = (unsigned char)(msg_hdr->seq); 669 670 item = pitem_new(seq64be, frag); 671 if (item == NULL) { 672 i = -1; 673 goto err; 674 } 675 676 pqueue_insert(s->d1->buffered_messages, item); 677 } 678 679 return DTLS1_HM_FRAGMENT_RETRY; 680 681 err: 682 if (item == NULL && frag != NULL) 683 dtls1_hm_fragment_free(frag); 684 *ok = 0; 685 return i; 686 } 687 688 689 static int 690 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 691 { 692 int i = -1; 693 hm_fragment *frag = NULL; 694 pitem *item = NULL; 695 unsigned char seq64be[8]; 696 unsigned long frag_len = msg_hdr->frag_len; 697 698 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 699 goto err; 700 701 /* Try to find item in queue, to prevent duplicate entries */ 702 memset(seq64be, 0, sizeof(seq64be)); 703 seq64be[6] = (unsigned char) (msg_hdr->seq >> 8); 704 seq64be[7] = (unsigned char) msg_hdr->seq; 705 item = pqueue_find(s->d1->buffered_messages, seq64be); 706 707 /* 708 * If we already have an entry and this one is a fragment, 709 * don't discard it and rather try to reassemble it. 710 */ 711 if (item != NULL && frag_len < msg_hdr->msg_len) 712 item = NULL; 713 714 /* 715 * Discard the message if sequence number was already there, is 716 * too far in the future, already in the queue or if we received 717 * a FINISHED before the SERVER_HELLO, which then must be a stale 718 * retransmit. 719 */ 720 if (msg_hdr->seq <= s->d1->handshake_read_seq || 721 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 722 (s->d1->handshake_read_seq == 0 && 723 msg_hdr->type == SSL3_MT_FINISHED)) { 724 unsigned char devnull [256]; 725 726 while (frag_len) { 727 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 728 devnull, frag_len > sizeof(devnull) ? 729 sizeof(devnull) : frag_len, 0); 730 if (i <= 0) 731 goto err; 732 frag_len -= i; 733 } 734 } else { 735 if (frag_len < msg_hdr->msg_len) 736 return dtls1_reassemble_fragment(s, msg_hdr, ok); 737 738 if (frag_len > dtls1_max_handshake_message_len(s)) 739 goto err; 740 741 frag = dtls1_hm_fragment_new(frag_len, 0); 742 if (frag == NULL) 743 goto err; 744 745 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 746 747 if (frag_len) { 748 /* read the body of the fragment (header has already been read */ 749 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 750 frag->fragment, frag_len, 0); 751 if (i <= 0 || (unsigned long)i != frag_len) 752 goto err; 753 } 754 755 memset(seq64be, 0, sizeof(seq64be)); 756 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 757 seq64be[7] = (unsigned char)(msg_hdr->seq); 758 759 item = pitem_new(seq64be, frag); 760 if (item == NULL) 761 goto err; 762 763 pqueue_insert(s->d1->buffered_messages, item); 764 } 765 766 return DTLS1_HM_FRAGMENT_RETRY; 767 768 err: 769 if (item == NULL && frag != NULL) 770 dtls1_hm_fragment_free(frag); 771 *ok = 0; 772 return i; 773 } 774 775 776 static long 777 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 778 { 779 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 780 unsigned long len, frag_off, frag_len; 781 int i, al; 782 struct hm_header_st msg_hdr; 783 784 again: 785 /* see if we have the required fragment already */ 786 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 787 if (*ok) 788 s->init_num = frag_len; 789 return frag_len; 790 } 791 792 /* read handshake message header */ 793 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 794 DTLS1_HM_HEADER_LENGTH, 0); 795 if (i <= 0) /* nbio, or an error */ 796 { 797 s->rwstate = SSL_READING; 798 *ok = 0; 799 return i; 800 } 801 /* Handshake fails if message header is incomplete */ 802 if (i != DTLS1_HM_HEADER_LENGTH || 803 /* parse the message fragment header */ 804 dtls1_get_message_header(wire, &msg_hdr) == 0) { 805 al = SSL_AD_UNEXPECTED_MESSAGE; 806 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 807 SSL_R_UNEXPECTED_MESSAGE); 808 goto f_err; 809 } 810 811 /* 812 * if this is a future (or stale) message it gets buffered 813 * (or dropped)--no further processing at this time 814 * While listening, we accept seq 1 (ClientHello with cookie) 815 * although we're still expecting seq 0 (ClientHello) 816 */ 817 if (msg_hdr.seq != s->d1->handshake_read_seq && 818 !(s->d1->listen && msg_hdr.seq == 1)) 819 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 820 821 len = msg_hdr.msg_len; 822 frag_off = msg_hdr.frag_off; 823 frag_len = msg_hdr.frag_len; 824 825 if (frag_len && frag_len < len) 826 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 827 828 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 829 wire[0] == SSL3_MT_HELLO_REQUEST) { 830 /* 831 * The server may always send 'Hello Request' messages -- 832 * we are doing a handshake anyway now, so ignore them 833 * if their format is correct. Does not count for 834 * 'Finished' MAC. 835 */ 836 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 837 if (s->msg_callback) 838 s->msg_callback(0, s->version, 839 SSL3_RT_HANDSHAKE, wire, 840 DTLS1_HM_HEADER_LENGTH, s, 841 s->msg_callback_arg); 842 843 s->init_num = 0; 844 goto again; 845 } 846 else /* Incorrectly formated Hello request */ 847 { 848 al = SSL_AD_UNEXPECTED_MESSAGE; 849 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 850 SSL_R_UNEXPECTED_MESSAGE); 851 goto f_err; 852 } 853 } 854 855 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 856 goto f_err; 857 858 /* XDTLS: ressurect this when restart is in place */ 859 s->state = stn; 860 861 if (frag_len > 0) { 862 unsigned char *p = (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 863 864 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 865 &p[frag_off], frag_len, 0); 866 /* XDTLS: fix this--message fragments cannot span multiple packets */ 867 if (i <= 0) { 868 s->rwstate = SSL_READING; 869 *ok = 0; 870 return i; 871 } 872 } else 873 i = 0; 874 875 /* 876 * XDTLS: an incorrectly formatted fragment should cause the 877 * handshake to fail 878 */ 879 if (i != (int)frag_len) { 880 al = SSL3_AD_ILLEGAL_PARAMETER; 881 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 882 SSL3_AD_ILLEGAL_PARAMETER); 883 goto f_err; 884 } 885 886 *ok = 1; 887 888 /* 889 * Note that s->init_num is *not* used as current offset in 890 * s->init_buf->data, but as a counter summing up fragments' 891 * lengths: as soon as they sum up to handshake packet 892 * length, we assume we have got all the fragments. 893 */ 894 s->init_num = frag_len; 895 return frag_len; 896 897 f_err: 898 ssl3_send_alert(s, SSL3_AL_FATAL, al); 899 s->init_num = 0; 900 901 *ok = 0; 902 return (-1); 903 } 904 905 /* 906 * for these 2 messages, we need to 907 * ssl->enc_read_ctx re-init 908 * ssl->s3->read_sequence zero 909 * ssl->s3->read_mac_secret re-init 910 * ssl->session->read_sym_enc assign 911 * ssl->session->read_hash assign 912 */ 913 int 914 dtls1_send_change_cipher_spec(SSL *s, int a, int b) 915 { 916 unsigned char *p; 917 918 if (s->state == a) { 919 p = (unsigned char *)s->init_buf->data; 920 *p++=SSL3_MT_CCS; 921 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 922 s->init_num = DTLS1_CCS_HEADER_LENGTH; 923 924 s->init_off = 0; 925 926 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 927 s->d1->handshake_write_seq, 0, 0); 928 929 /* buffer the message to handle re-xmits */ 930 dtls1_buffer_message(s, 1); 931 932 s->state = b; 933 } 934 935 /* SSL3_ST_CW_CHANGE_B */ 936 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 937 } 938 939 static int 940 dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 941 { 942 int n; 943 unsigned char *p; 944 945 n = i2d_X509(x, NULL); 946 if (!BUF_MEM_grow_clean(buf, n + (*l) + 3)) { 947 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB); 948 return 0; 949 } 950 p = (unsigned char *)&(buf->data[*l]); 951 l2n3(n, p); 952 i2d_X509(x, &p); 953 *l += n + 3; 954 955 return 1; 956 } 957 958 unsigned long 959 dtls1_output_cert_chain(SSL *s, X509 *x) 960 { 961 unsigned char *p; 962 int i; 963 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH; 964 BUF_MEM *buf; 965 966 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 967 buf = s->init_buf; 968 if (!BUF_MEM_grow_clean(buf, 10)) { 969 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB); 970 return (0); 971 } 972 if (x != NULL) { 973 X509_STORE_CTX xs_ctx; 974 975 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, 976 x, NULL)) { 977 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB); 978 return (0); 979 } 980 981 X509_verify_cert(&xs_ctx); 982 /* Don't leave errors in the queue */ 983 ERR_clear_error(); 984 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) { 985 x = sk_X509_value(xs_ctx.chain, i); 986 987 if (!dtls1_add_cert_to_buf(buf, &l, x)) { 988 X509_STORE_CTX_cleanup(&xs_ctx); 989 return 0; 990 } 991 } 992 X509_STORE_CTX_cleanup(&xs_ctx); 993 } 994 /* Thawte special :-) */ 995 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) { 996 x = sk_X509_value(s->ctx->extra_certs, i); 997 if (!dtls1_add_cert_to_buf(buf, &l, x)) 998 return 0; 999 } 1000 1001 l -= (3 + DTLS1_HM_HEADER_LENGTH); 1002 1003 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1004 l2n3(l, p); 1005 l += 3; 1006 p = (unsigned char *)&(buf->data[0]); 1007 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1008 1009 l += DTLS1_HM_HEADER_LENGTH; 1010 return (l); 1011 } 1012 1013 int 1014 dtls1_read_failed(SSL *s, int code) 1015 { 1016 if (code > 0) { 1017 #ifdef DEBUG 1018 fprintf(stderr, "invalid state reached %s:%d", 1019 __FILE__, __LINE__); 1020 #endif 1021 return 1; 1022 } 1023 1024 if (!dtls1_is_timer_expired(s)) { 1025 /* 1026 * not a timeout, none of our business, let higher layers 1027 * handle this. in fact it's probably an error 1028 */ 1029 return code; 1030 } 1031 1032 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1033 { 1034 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1035 return code; 1036 } 1037 1038 return dtls1_handle_timeout(s); 1039 } 1040 1041 int 1042 dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1043 { 1044 /* 1045 * The index of the retransmission queue actually is the message 1046 * sequence number, since the queue only contains messages of a 1047 * single handshake. However, the ChangeCipherSpec has no message 1048 * sequence number and so using only the sequence will result in 1049 * the CCS and Finished having the same index. To prevent this, the 1050 * sequence number is multiplied by 2. In case of a CCS 1 is 1051 * subtracted. This does not only differ CSS and Finished, it also 1052 * maintains the order of the index (important for priority queues) 1053 * and fits in the unsigned short variable. 1054 */ 1055 return seq * 2 - is_ccs; 1056 } 1057 1058 int 1059 dtls1_retransmit_buffered_messages(SSL *s) 1060 { 1061 pqueue sent = s->d1->sent_messages; 1062 piterator iter; 1063 pitem *item; 1064 hm_fragment *frag; 1065 int found = 0; 1066 1067 iter = pqueue_iterator(sent); 1068 1069 for (item = pqueue_next(&iter); item != NULL; 1070 item = pqueue_next(&iter)) { 1071 frag = (hm_fragment *)item->data; 1072 if (dtls1_retransmit_message(s, 1073 (unsigned short)dtls1_get_queue_priority( 1074 frag->msg_header.seq, frag->msg_header.is_ccs), 0, 1075 &found) <= 0 && found) { 1076 #ifdef DEBUG 1077 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1078 #endif 1079 return -1; 1080 } 1081 } 1082 1083 return 1; 1084 } 1085 1086 int 1087 dtls1_buffer_message(SSL *s, int is_ccs) 1088 { 1089 pitem *item; 1090 hm_fragment *frag; 1091 unsigned char seq64be[8]; 1092 1093 /* Buffer the messsage in order to handle DTLS retransmissions. */ 1094 1095 /* 1096 * This function is called immediately after a message has 1097 * been serialized 1098 */ 1099 OPENSSL_assert(s->init_off == 0); 1100 1101 frag = dtls1_hm_fragment_new(s->init_num, 0); 1102 if (frag == NULL) 1103 return 0; 1104 1105 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1106 1107 if (is_ccs) { 1108 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1109 ((s->version == DTLS1_VERSION) ? 1110 DTLS1_CCS_HEADER_LENGTH : 3) == (unsigned int)s->init_num); 1111 } else { 1112 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1113 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1114 } 1115 1116 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1117 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1118 frag->msg_header.type = s->d1->w_msg_hdr.type; 1119 frag->msg_header.frag_off = 0; 1120 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1121 frag->msg_header.is_ccs = is_ccs; 1122 1123 /* save current state*/ 1124 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1125 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1126 frag->msg_header.saved_retransmit_state.session = s->session; 1127 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1128 1129 memset(seq64be, 0, sizeof(seq64be)); 1130 seq64be[6] = (unsigned char)(dtls1_get_queue_priority( 1131 frag->msg_header.seq, frag->msg_header.is_ccs) >> 8); 1132 seq64be[7] = (unsigned char)(dtls1_get_queue_priority( 1133 frag->msg_header.seq, frag->msg_header.is_ccs)); 1134 1135 item = pitem_new(seq64be, frag); 1136 if (item == NULL) { 1137 dtls1_hm_fragment_free(frag); 1138 return 0; 1139 } 1140 1141 pqueue_insert(s->d1->sent_messages, item); 1142 return 1; 1143 } 1144 1145 int 1146 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1147 int *found) 1148 { 1149 int ret; 1150 /* XDTLS: for now assuming that read/writes are blocking */ 1151 pitem *item; 1152 hm_fragment *frag; 1153 unsigned long header_length; 1154 unsigned char seq64be[8]; 1155 struct dtls1_retransmit_state saved_state; 1156 unsigned char save_write_sequence[8]; 1157 1158 /* 1159 OPENSSL_assert(s->init_num == 0); 1160 OPENSSL_assert(s->init_off == 0); 1161 */ 1162 1163 /* XDTLS: the requested message ought to be found, otherwise error */ 1164 memset(seq64be, 0, sizeof(seq64be)); 1165 seq64be[6] = (unsigned char)(seq >> 8); 1166 seq64be[7] = (unsigned char)seq; 1167 1168 item = pqueue_find(s->d1->sent_messages, seq64be); 1169 if (item == NULL) { 1170 #ifdef DEBUG 1171 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1172 #endif 1173 *found = 0; 1174 return 0; 1175 } 1176 1177 *found = 1; 1178 frag = (hm_fragment *)item->data; 1179 1180 if (frag->msg_header.is_ccs) 1181 header_length = DTLS1_CCS_HEADER_LENGTH; 1182 else 1183 header_length = DTLS1_HM_HEADER_LENGTH; 1184 1185 memcpy(s->init_buf->data, frag->fragment, 1186 frag->msg_header.msg_len + header_length); 1187 s->init_num = frag->msg_header.msg_len + header_length; 1188 1189 dtls1_set_message_header_int(s, frag->msg_header.type, 1190 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1191 frag->msg_header.frag_len); 1192 1193 /* save current state */ 1194 saved_state.enc_write_ctx = s->enc_write_ctx; 1195 saved_state.write_hash = s->write_hash; 1196 saved_state.session = s->session; 1197 saved_state.epoch = s->d1->w_epoch; 1198 1199 s->d1->retransmitting = 1; 1200 1201 /* restore state in which the message was originally sent */ 1202 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1203 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1204 s->session = frag->msg_header.saved_retransmit_state.session; 1205 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1206 1207 if (frag->msg_header.saved_retransmit_state.epoch == 1208 saved_state.epoch - 1) { 1209 memcpy(save_write_sequence, s->s3->write_sequence, 1210 sizeof(s->s3->write_sequence)); 1211 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1212 sizeof(s->s3->write_sequence)); 1213 } 1214 1215 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1216 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1217 1218 /* restore current state */ 1219 s->enc_write_ctx = saved_state.enc_write_ctx; 1220 s->write_hash = saved_state.write_hash; 1221 s->session = saved_state.session; 1222 s->d1->w_epoch = saved_state.epoch; 1223 1224 if (frag->msg_header.saved_retransmit_state.epoch == 1225 saved_state.epoch - 1) { 1226 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1227 sizeof(s->s3->write_sequence)); 1228 memcpy(s->s3->write_sequence, save_write_sequence, 1229 sizeof(s->s3->write_sequence)); 1230 } 1231 1232 s->d1->retransmitting = 0; 1233 1234 (void)BIO_flush(SSL_get_wbio(s)); 1235 return ret; 1236 } 1237 1238 /* call this function when the buffered messages are no longer needed */ 1239 void 1240 dtls1_clear_record_buffer(SSL *s) 1241 { 1242 pitem *item; 1243 1244 for(item = pqueue_pop(s->d1->sent_messages); item != NULL; 1245 item = pqueue_pop(s->d1->sent_messages)) { 1246 dtls1_hm_fragment_free((hm_fragment *)item->data); 1247 pitem_free(item); 1248 } 1249 } 1250 1251 unsigned char * 1252 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1253 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1254 { 1255 /* Don't change sequence numbers while listening */ 1256 if (frag_off == 0 && !s->d1->listen) { 1257 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1258 s->d1->next_handshake_write_seq++; 1259 } 1260 1261 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1262 frag_off, frag_len); 1263 1264 return p += DTLS1_HM_HEADER_LENGTH; 1265 } 1266 1267 /* don't actually do the writing, wait till the MTU has been retrieved */ 1268 static void 1269 dtls1_set_message_header_int(SSL *s, unsigned char mt, unsigned long len, 1270 unsigned short seq_num, unsigned long frag_off, unsigned long frag_len) 1271 { 1272 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1273 1274 msg_hdr->type = mt; 1275 msg_hdr->msg_len = len; 1276 msg_hdr->seq = seq_num; 1277 msg_hdr->frag_off = frag_off; 1278 msg_hdr->frag_len = frag_len; 1279 } 1280 1281 static void 1282 dtls1_fix_message_header(SSL *s, unsigned long frag_off, unsigned long frag_len) 1283 { 1284 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1285 1286 msg_hdr->frag_off = frag_off; 1287 msg_hdr->frag_len = frag_len; 1288 } 1289 1290 static unsigned char * 1291 dtls1_write_message_header(SSL *s, unsigned char *p) 1292 { 1293 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1294 1295 *p++ = msg_hdr->type; 1296 l2n3(msg_hdr->msg_len, p); 1297 1298 s2n(msg_hdr->seq, p); 1299 l2n3(msg_hdr->frag_off, p); 1300 l2n3(msg_hdr->frag_len, p); 1301 1302 return p; 1303 } 1304 1305 unsigned int 1306 dtls1_min_mtu(void) 1307 { 1308 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1309 sizeof(g_probable_mtu[0])) - 1]); 1310 } 1311 1312 static unsigned int 1313 dtls1_guess_mtu(unsigned int curr_mtu) 1314 { 1315 unsigned int i; 1316 1317 if (curr_mtu == 0) 1318 return g_probable_mtu[0]; 1319 1320 for (i = 0; i < sizeof(g_probable_mtu) / sizeof(g_probable_mtu[0]); i++) 1321 if (curr_mtu > g_probable_mtu[i]) 1322 return g_probable_mtu[i]; 1323 1324 return curr_mtu; 1325 } 1326 1327 int 1328 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1329 { 1330 CBS header; 1331 uint32_t msg_len, frag_off, frag_len; 1332 uint16_t seq; 1333 uint8_t type; 1334 1335 CBS_init(&header, data, sizeof(*msg_hdr)); 1336 1337 memset(msg_hdr, 0, sizeof(*msg_hdr)); 1338 1339 if (!CBS_get_u8(&header, &type)) 1340 return 0; 1341 if (!CBS_get_u24(&header, &msg_len)) 1342 return 0; 1343 if (!CBS_get_u16(&header, &seq)) 1344 return 0; 1345 if (!CBS_get_u24(&header, &frag_off)) 1346 return 0; 1347 if (!CBS_get_u24(&header, &frag_len)) 1348 return 0; 1349 1350 msg_hdr->type = type; 1351 msg_hdr->msg_len = msg_len; 1352 msg_hdr->seq = seq; 1353 msg_hdr->frag_off = frag_off; 1354 msg_hdr->frag_len = frag_len; 1355 1356 return 1; 1357 } 1358 1359 void 1360 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1361 { 1362 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1363 1364 ccs_hdr->type = *(data++); 1365 } 1366 1367 int 1368 dtls1_shutdown(SSL *s) 1369 { 1370 int ret; 1371 1372 ret = ssl3_shutdown(s); 1373 return ret; 1374 } 1375