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[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80}; 156static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f}; 157 158/* XDTLS: figure out the right values */ 159static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 160 161static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 162static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 163 unsigned long frag_len); 164static unsigned char *dtls1_write_message_header(SSL *s, 165 unsigned char *p); 166static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 167 unsigned long len, unsigned short seq_num, unsigned long frag_off, 168 unsigned long frag_len); 169static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 170 long max, int *ok); 171 172static hm_fragment * 173dtls1_hm_fragment_new(unsigned long frag_len, int reassembly) 174 { 175 hm_fragment *frag = NULL; 176 unsigned char *buf = NULL; 177 unsigned char *bitmask = NULL; 178 179 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 180 if ( frag == NULL) 181 return NULL; 182 183 if (frag_len) 184 { 185 buf = (unsigned char *)OPENSSL_malloc(frag_len); 186 if ( buf == NULL) 187 { 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 { 199 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) 201 { 202 if (buf != NULL) 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 214static void 215dtls1_hm_fragment_free(hm_fragment *frag) 216 { 217 if (frag->fragment) OPENSSL_free(frag->fragment); 218 if (frag->reassembly) OPENSSL_free(frag->reassembly); 219 OPENSSL_free(frag); 220 } 221 222/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 223int dtls1_do_write(SSL *s, int type) 224 { 225 int ret; 226 int curr_mtu; 227 unsigned int len, frag_off, mac_size, blocksize; 228 229 /* AHA! Figure out the MTU, and stick to the right size */ 230 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 231 { 232 s->d1->mtu = 233 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 234 235 /* I've seen the kernel return bogus numbers when it doesn't know 236 * (initial write), so just make sure we have a reasonable number */ 237 if (s->d1->mtu < dtls1_min_mtu()) 238 { 239 s->d1->mtu = 0; 240 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 241 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 242 s->d1->mtu, NULL); 243 } 244 } 245#if 0 246 mtu = s->d1->mtu; 247 248 fprintf(stderr, "using MTU = %d\n", mtu); 249 250 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 251 252 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 253 254 if ( curr_mtu > 0) 255 mtu = curr_mtu; 256 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0) 257 return ret; 258 259 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) 260 { 261 ret = BIO_flush(SSL_get_wbio(s)); 262 if ( ret <= 0) 263 return ret; 264 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 265 } 266#endif 267 268 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */ 269 270 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 271 OPENSSL_assert(s->init_num == 272 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 273 274 if (s->write_hash) 275 mac_size = EVP_MD_size(s->write_hash); 276 else 277 mac_size = 0; 278 279 if (s->enc_write_ctx && 280 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 281 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 282 else 283 blocksize = 0; 284 285 frag_off = 0; 286 while( s->init_num) 287 { 288 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 289 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; 290 291 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH) 292 { 293 /* grr.. we could get an error if MTU picked was wrong */ 294 ret = BIO_flush(SSL_get_wbio(s)); 295 if ( ret <= 0) 296 return ret; 297 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 298 mac_size - blocksize; 299 } 300 301 if ( s->init_num > curr_mtu) 302 len = curr_mtu; 303 else 304 len = s->init_num; 305 306 307 /* XDTLS: this function is too long. split out the CCS part */ 308 if ( type == SSL3_RT_HANDSHAKE) 309 { 310 if ( s->init_off != 0) 311 { 312 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 313 s->init_off -= DTLS1_HM_HEADER_LENGTH; 314 s->init_num += DTLS1_HM_HEADER_LENGTH; 315 316 if ( s->init_num > curr_mtu) 317 len = curr_mtu; 318 else 319 len = s->init_num; 320 } 321 322 dtls1_fix_message_header(s, frag_off, 323 len - DTLS1_HM_HEADER_LENGTH); 324 325 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 326 327 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 328 } 329 330 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 331 len); 332 if (ret < 0) 333 { 334 /* might need to update MTU here, but we don't know 335 * which previous packet caused the failure -- so can't 336 * really retransmit anything. continue as if everything 337 * is fine and wait for an alert to handle the 338 * retransmit 339 */ 340 if ( BIO_ctrl(SSL_get_wbio(s), 341 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 ) 342 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 343 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 344 else 345 return(-1); 346 } 347 else 348 { 349 350 /* bad if this assert fails, only part of the handshake 351 * message got sent. but why would this happen? */ 352 OPENSSL_assert(len == (unsigned int)ret); 353 354 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 355 { 356 /* should not be done for 'Hello Request's, but in that case 357 * we'll ignore the result anyway */ 358 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 359 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 360 int xlen; 361 362 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER) 363 { 364 /* reconstruct message header is if it 365 * is being sent in single fragment */ 366 *p++ = msg_hdr->type; 367 l2n3(msg_hdr->msg_len,p); 368 s2n (msg_hdr->seq,p); 369 l2n3(0,p); 370 l2n3(msg_hdr->msg_len,p); 371 p -= DTLS1_HM_HEADER_LENGTH; 372 xlen = ret; 373 } 374 else 375 { 376 p += DTLS1_HM_HEADER_LENGTH; 377 xlen = ret - DTLS1_HM_HEADER_LENGTH; 378 } 379 380 ssl3_finish_mac(s, p, xlen); 381 } 382 383 if (ret == s->init_num) 384 { 385 if (s->msg_callback) 386 s->msg_callback(1, s->version, type, s->init_buf->data, 387 (size_t)(s->init_off + s->init_num), s, 388 s->msg_callback_arg); 389 390 s->init_off = 0; /* done writing this message */ 391 s->init_num = 0; 392 393 return(1); 394 } 395 s->init_off+=ret; 396 s->init_num-=ret; 397 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 398 } 399 } 400 return(0); 401 } 402 403 404/* Obtain handshake message of message type 'mt' (any if mt == -1), 405 * maximum acceptable body length 'max'. 406 * Read an entire handshake message. Handshake messages arrive in 407 * fragments. 408 */ 409long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 410 { 411 int i, al; 412 struct hm_header_st *msg_hdr; 413 unsigned char *p; 414 unsigned long msg_len; 415 416 /* s3->tmp is used to store messages that are unexpected, caused 417 * by the absence of an optional handshake message */ 418 if (s->s3->tmp.reuse_message) 419 { 420 s->s3->tmp.reuse_message=0; 421 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 422 { 423 al=SSL_AD_UNEXPECTED_MESSAGE; 424 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 425 goto f_err; 426 } 427 *ok=1; 428 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 429 s->init_num = (int)s->s3->tmp.message_size; 430 return s->init_num; 431 } 432 433 msg_hdr = &s->d1->r_msg_hdr; 434 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 435 436again: 437 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 438 if ( i == DTLS1_HM_BAD_FRAGMENT || 439 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 440 goto again; 441 else if ( i <= 0 && !*ok) 442 return i; 443 444 p = (unsigned char *)s->init_buf->data; 445 msg_len = msg_hdr->msg_len; 446 447 /* reconstruct message header */ 448 *(p++) = msg_hdr->type; 449 l2n3(msg_len,p); 450 s2n (msg_hdr->seq,p); 451 l2n3(0,p); 452 l2n3(msg_len,p); 453 if (s->version != DTLS1_BAD_VER) { 454 p -= DTLS1_HM_HEADER_LENGTH; 455 msg_len += DTLS1_HM_HEADER_LENGTH; 456 } 457 458 ssl3_finish_mac(s, p, msg_len); 459 if (s->msg_callback) 460 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 461 p, msg_len, 462 s, s->msg_callback_arg); 463 464 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 465 466 /* Don't change sequence numbers while listening */ 467 if (!s->d1->listen) 468 s->d1->handshake_read_seq++; 469 470 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 471 return s->init_num; 472 473f_err: 474 ssl3_send_alert(s,SSL3_AL_FATAL,al); 475 *ok = 0; 476 return -1; 477 } 478 479 480static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 481 { 482 size_t frag_off,frag_len,msg_len; 483 484 msg_len = msg_hdr->msg_len; 485 frag_off = msg_hdr->frag_off; 486 frag_len = msg_hdr->frag_len; 487 488 /* sanity checking */ 489 if ( (frag_off+frag_len) > msg_len) 490 { 491 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 492 return SSL_AD_ILLEGAL_PARAMETER; 493 } 494 495 if ( (frag_off+frag_len) > (unsigned long)max) 496 { 497 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 498 return SSL_AD_ILLEGAL_PARAMETER; 499 } 500 501 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 502 { 503 /* msg_len is limited to 2^24, but is effectively checked 504 * against max above */ 505 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH)) 506 { 507 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 508 return SSL_AD_INTERNAL_ERROR; 509 } 510 511 s->s3->tmp.message_size = msg_len; 512 s->d1->r_msg_hdr.msg_len = msg_len; 513 s->s3->tmp.message_type = msg_hdr->type; 514 s->d1->r_msg_hdr.type = msg_hdr->type; 515 s->d1->r_msg_hdr.seq = msg_hdr->seq; 516 } 517 else if (msg_len != s->d1->r_msg_hdr.msg_len) 518 { 519 /* They must be playing with us! BTW, failure to enforce 520 * upper limit would open possibility for buffer overrun. */ 521 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 522 return SSL_AD_ILLEGAL_PARAMETER; 523 } 524 525 return 0; /* no error */ 526 } 527 528 529static int 530dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 531 { 532 /* (0) check whether the desired fragment is available 533 * if so: 534 * (1) copy over the fragment to s->init_buf->data[] 535 * (2) update s->init_num 536 */ 537 pitem *item; 538 hm_fragment *frag; 539 int al; 540 541 *ok = 0; 542 item = pqueue_peek(s->d1->buffered_messages); 543 if ( item == NULL) 544 return 0; 545 546 frag = (hm_fragment *)item->data; 547 548 /* Don't return if reassembly still in progress */ 549 if (frag->reassembly != NULL) 550 return 0; 551 552 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 553 { 554 unsigned long frag_len = frag->msg_header.frag_len; 555 pqueue_pop(s->d1->buffered_messages); 556 557 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 558 559 if (al==0) /* no alert */ 560 { 561 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 562 memcpy(&p[frag->msg_header.frag_off], 563 frag->fragment,frag->msg_header.frag_len); 564 } 565 566 dtls1_hm_fragment_free(frag); 567 pitem_free(item); 568 569 if (al==0) 570 { 571 *ok = 1; 572 return frag_len; 573 } 574 575 ssl3_send_alert(s,SSL3_AL_FATAL,al); 576 s->init_num = 0; 577 *ok = 0; 578 return -1; 579 } 580 else 581 return 0; 582 } 583 584 585static int 586dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok) 587 { 588 hm_fragment *frag = NULL; 589 pitem *item = NULL; 590 int i = -1, is_complete; 591 PQ_64BIT seq64; 592 unsigned long frag_len = msg_hdr->frag_len, max_len; 593 594 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 595 goto err; 596 597 /* Determine maximum allowed message size. Depends on (user set) 598 * maximum certificate length, but 16k is minimum. 599 */ 600 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list) 601 max_len = s->max_cert_list; 602 else 603 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 604 605 if ((msg_hdr->frag_off+frag_len) > max_len) 606 goto err; 607 608 /* Try to find item in queue */ 609 pq_64bit_init(&seq64); 610 pq_64bit_assign_word(&seq64, msg_hdr->seq); 611 item = pqueue_find(s->d1->buffered_messages, seq64); 612 pq_64bit_free(&seq64); 613 614 if (item == NULL) 615 { 616 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 617 if ( frag == NULL) 618 goto err; 619 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 620 frag->msg_header.frag_len = frag->msg_header.msg_len; 621 frag->msg_header.frag_off = 0; 622 } 623 else 624 { 625 frag = (hm_fragment*) item->data; 626 if (frag->msg_header.msg_len != msg_hdr->msg_len) 627 { 628 item = NULL; 629 frag = NULL; 630 goto err; 631 } 632 } 633 634 635 /* If message is already reassembled, this must be a 636 * retransmit and can be dropped. 637 */ 638 if (frag->reassembly == NULL) 639 { 640 unsigned char devnull [256]; 641 642 while (frag_len) 643 { 644 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 645 devnull, 646 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 647 if (i<=0) goto err; 648 frag_len -= i; 649 } 650 return DTLS1_HM_FRAGMENT_RETRY; 651 } 652 653 /* read the body of the fragment (header has already been read */ 654 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 655 frag->fragment + msg_hdr->frag_off,frag_len,0); 656 if (i<=0 || (unsigned long)i!=frag_len) 657 goto err; 658 659 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 660 (long)(msg_hdr->frag_off + frag_len)); 661 662 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 663 is_complete); 664 665 if (is_complete) 666 { 667 OPENSSL_free(frag->reassembly); 668 frag->reassembly = NULL; 669 } 670 671 if (item == NULL) 672 { 673 pq_64bit_init(&seq64); 674 pq_64bit_assign_word(&seq64, msg_hdr->seq); 675 item = pitem_new(seq64, frag); 676 pq_64bit_free(&seq64); 677 678 if (item == NULL) 679 { 680 i = -1; 681 goto err; 682 } 683 684 pqueue_insert(s->d1->buffered_messages, item); 685 } 686 687 return DTLS1_HM_FRAGMENT_RETRY; 688 689err: 690 if (frag != NULL) dtls1_hm_fragment_free(frag); 691 if (item != NULL) OPENSSL_free(item); 692 *ok = 0; 693 return i; 694 } 695 696 697static int 698dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 699{ 700 int i=-1; 701 hm_fragment *frag = NULL; 702 pitem *item = NULL; 703 PQ_64BIT seq64; 704 unsigned long frag_len = msg_hdr->frag_len; 705 706 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 707 goto err; 708 709 /* Try to find item in queue, to prevent duplicate entries */ 710 pq_64bit_init(&seq64); 711 pq_64bit_assign_word(&seq64, msg_hdr->seq); 712 item = pqueue_find(s->d1->buffered_messages, seq64); 713 pq_64bit_free(&seq64); 714 715 /* If we already have an entry and this one is a fragment, 716 * don't discard it and rather try to reassemble it. 717 */ 718 if (item != NULL && frag_len < msg_hdr->msg_len) 719 item = NULL; 720 721 /* Discard the message if sequence number was already there, is 722 * too far in the future, already in the queue or if we received 723 * a FINISHED before the SERVER_HELLO, which then must be a stale 724 * retransmit. 725 */ 726 if (msg_hdr->seq <= s->d1->handshake_read_seq || 727 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 728 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 729 { 730 unsigned char devnull [256]; 731 732 while (frag_len) 733 { 734 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 735 devnull, 736 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 737 if (i<=0) goto err; 738 frag_len -= i; 739 } 740 } 741 else 742 { 743 if (frag_len && frag_len < msg_hdr->msg_len) 744 return dtls1_reassemble_fragment(s, msg_hdr, ok); 745 746 frag = dtls1_hm_fragment_new(frag_len, 0); 747 if ( frag == NULL) 748 goto err; 749 750 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 751 752 if (frag_len) 753 { 754 /* read the body of the fragment (header has already been read) */ 755 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 756 frag->fragment,frag_len,0); 757 if (i<=0 || (unsigned long)i!=frag_len) 758 goto err; 759 } 760 761 pq_64bit_init(&seq64); 762 pq_64bit_assign_word(&seq64, msg_hdr->seq); 763 764 item = pitem_new(seq64, frag); 765 pq_64bit_free(&seq64); 766 if ( item == NULL) 767 goto err; 768 769 pqueue_insert(s->d1->buffered_messages, item); 770 } 771 772 return DTLS1_HM_FRAGMENT_RETRY; 773 774err: 775 if ( frag != NULL) dtls1_hm_fragment_free(frag); 776 if ( item != NULL) OPENSSL_free(item); 777 *ok = 0; 778 return i; 779 } 780 781 782static long 783dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 784 { 785 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 786 unsigned long len, frag_off, frag_len; 787 int i,al; 788 struct hm_header_st msg_hdr; 789 790 redo: 791 /* see if we have the required fragment already */ 792 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 793 { 794 if (*ok) s->init_num = frag_len; 795 return frag_len; 796 } 797 798 /* read handshake message header */ 799 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 800 DTLS1_HM_HEADER_LENGTH, 0); 801 if (i <= 0) /* nbio, or an error */ 802 { 803 s->rwstate=SSL_READING; 804 *ok = 0; 805 return i; 806 } 807 /* Handshake fails if message header is incomplete */ 808 if (i != DTLS1_HM_HEADER_LENGTH) 809 { 810 al=SSL_AD_UNEXPECTED_MESSAGE; 811 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 812 goto f_err; 813 } 814 815 /* parse the message fragment header */ 816 dtls1_get_message_header(wire, &msg_hdr); 817 818 /* 819 * if this is a future (or stale) message it gets buffered 820 * (or dropped)--no further processing at this time 821 * While listening, we accept seq 1 (ClientHello with cookie) 822 * although we're still expecting seq 0 (ClientHello) 823 */ 824 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 825 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 826 827 len = msg_hdr.msg_len; 828 frag_off = msg_hdr.frag_off; 829 frag_len = msg_hdr.frag_len; 830 831 if (frag_len && frag_len < len) 832 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 833 834 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 835 wire[0] == SSL3_MT_HELLO_REQUEST) 836 { 837 /* The server may always send 'Hello Request' messages -- 838 * we are doing a handshake anyway now, so ignore them 839 * if their format is correct. Does not count for 840 * 'Finished' MAC. */ 841 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 842 { 843 if (s->msg_callback) 844 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 845 wire, DTLS1_HM_HEADER_LENGTH, s, 846 s->msg_callback_arg); 847 848 s->init_num = 0; 849 goto redo; 850 } 851 else /* Incorrectly formated Hello request */ 852 { 853 al=SSL_AD_UNEXPECTED_MESSAGE; 854 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 855 goto f_err; 856 } 857 } 858 859 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 860 goto f_err; 861 862 /* XDTLS: ressurect this when restart is in place */ 863 s->state=stn; 864 865 if ( frag_len > 0) 866 { 867 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 868 869 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 870 &p[frag_off],frag_len,0); 871 /* XDTLS: fix this--message fragments cannot span multiple packets */ 872 if (i <= 0) 873 { 874 s->rwstate=SSL_READING; 875 *ok = 0; 876 return i; 877 } 878 } 879 else 880 i = 0; 881 882 /* XDTLS: an incorrectly formatted fragment should cause the 883 * handshake to fail */ 884 if (i != (int)frag_len) 885 { 886 al=SSL3_AD_ILLEGAL_PARAMETER; 887 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 888 goto f_err; 889 } 890 891 *ok = 1; 892 893 /* Note that s->init_num is *not* used as current offset in 894 * s->init_buf->data, but as a counter summing up fragments' 895 * lengths: as soon as they sum up to handshake packet 896 * length, we assume we have got all the fragments. */ 897 s->init_num = frag_len; 898 return frag_len; 899 900f_err: 901 ssl3_send_alert(s,SSL3_AL_FATAL,al); 902 s->init_num = 0; 903 904 *ok=0; 905 return(-1); 906 } 907 908int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 909 { 910 unsigned char *p,*d; 911 int i; 912 unsigned long l; 913 914 if (s->state == a) 915 { 916 d=(unsigned char *)s->init_buf->data; 917 p= &(d[DTLS1_HM_HEADER_LENGTH]); 918 919 i=s->method->ssl3_enc->final_finish_mac(s, 920 &(s->s3->finish_dgst1), 921 &(s->s3->finish_dgst2), 922 sender,slen,s->s3->tmp.finish_md); 923 s->s3->tmp.finish_md_len = i; 924 memcpy(p, s->s3->tmp.finish_md, i); 925 p+=i; 926 l=i; 927 928 /* Copy the finished so we can use it for 929 * renegotiation checks 930 */ 931 if(s->type == SSL_ST_CONNECT) 932 { 933 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 934 memcpy(s->s3->previous_client_finished, 935 s->s3->tmp.finish_md, i); 936 s->s3->previous_client_finished_len=i; 937 } 938 else 939 { 940 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 941 memcpy(s->s3->previous_server_finished, 942 s->s3->tmp.finish_md, i); 943 s->s3->previous_server_finished_len=i; 944 } 945 946#ifdef OPENSSL_SYS_WIN16 947 /* MSVC 1.5 does not clear the top bytes of the word unless 948 * I do this. 949 */ 950 l&=0xffff; 951#endif 952 953 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 954 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 955 s->init_off=0; 956 957 /* buffer the message to handle re-xmits */ 958 dtls1_buffer_message(s, 0); 959 960 s->state=b; 961 } 962 963 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 964 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 965 } 966 967/* for these 2 messages, we need to 968 * ssl->enc_read_ctx re-init 969 * ssl->s3->read_sequence zero 970 * ssl->s3->read_mac_secret re-init 971 * ssl->session->read_sym_enc assign 972 * ssl->session->read_compression assign 973 * ssl->session->read_hash assign 974 */ 975int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 976 { 977 unsigned char *p; 978 979 if (s->state == a) 980 { 981 p=(unsigned char *)s->init_buf->data; 982 *p++=SSL3_MT_CCS; 983 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 984 s->init_num=DTLS1_CCS_HEADER_LENGTH; 985 986 if (s->client_version == DTLS1_BAD_VER) 987 { 988 s->d1->next_handshake_write_seq++; 989 s2n(s->d1->handshake_write_seq,p); 990 s->init_num+=2; 991 } 992 993 s->init_off=0; 994 995 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 996 s->d1->handshake_write_seq, 0, 0); 997 998 /* buffer the message to handle re-xmits */ 999 dtls1_buffer_message(s, 1); 1000 1001 s->state=b; 1002 } 1003 1004 /* SSL3_ST_CW_CHANGE_B */ 1005 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1006 } 1007 1008static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1009 { 1010 int n; 1011 unsigned char *p; 1012 1013 n=i2d_X509(x,NULL); 1014 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1015 { 1016 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1017 return 0; 1018 } 1019 p=(unsigned char *)&(buf->data[*l]); 1020 l2n3(n,p); 1021 i2d_X509(x,&p); 1022 *l+=n+3; 1023 1024 return 1; 1025 } 1026unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1027 { 1028 unsigned char *p; 1029 int i; 1030 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1031 BUF_MEM *buf; 1032 1033 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1034 buf=s->init_buf; 1035 if (!BUF_MEM_grow_clean(buf,10)) 1036 { 1037 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1038 return(0); 1039 } 1040 if (x != NULL) 1041 { 1042 X509_STORE_CTX xs_ctx; 1043 1044 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1045 { 1046 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1047 return(0); 1048 } 1049 1050 X509_verify_cert(&xs_ctx); 1051 /* Don't leave errors in the queue */ 1052 ERR_clear_error(); 1053 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1054 { 1055 x = sk_X509_value(xs_ctx.chain, i); 1056 1057 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1058 { 1059 X509_STORE_CTX_cleanup(&xs_ctx); 1060 return 0; 1061 } 1062 } 1063 X509_STORE_CTX_cleanup(&xs_ctx); 1064 } 1065 /* Thawte special :-) */ 1066 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1067 { 1068 x=sk_X509_value(s->ctx->extra_certs,i); 1069 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1070 return 0; 1071 } 1072 1073 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1074 1075 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1076 l2n3(l,p); 1077 l+=3; 1078 p=(unsigned char *)&(buf->data[0]); 1079 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1080 1081 l+=DTLS1_HM_HEADER_LENGTH; 1082 return(l); 1083 } 1084 1085int dtls1_read_failed(SSL *s, int code) 1086 { 1087 if ( code > 0) 1088 { 1089 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1090 return 1; 1091 } 1092 1093 if (!dtls1_is_timer_expired(s)) 1094 { 1095 /* not a timeout, none of our business, 1096 let higher layers handle this. in fact it's probably an error */ 1097 return code; 1098 } 1099 1100 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */ 1101 { 1102 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1103 return code; 1104 } 1105 1106#if 0 /* for now, each alert contains only one record number */ 1107 item = pqueue_peek(state->rcvd_records); 1108 if ( item ) 1109 { 1110 /* send an alert immediately for all the missing records */ 1111 } 1112 else 1113#endif 1114 1115#if 0 /* no more alert sending, just retransmit the last set of messages */ 1116 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1117 ssl3_send_alert(s,SSL3_AL_WARNING, 1118 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1119#endif 1120 1121 return dtls1_handle_timeout(s); 1122 } 1123 1124int 1125dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1126 { 1127 /* The index of the retransmission queue actually is the message sequence number, 1128 * since the queue only contains messages of a single handshake. However, the 1129 * ChangeCipherSpec has no message sequence number and so using only the sequence 1130 * will result in the CCS and Finished having the same index. To prevent this, 1131 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1132 * This does not only differ CSS and Finished, it also maintains the order of the 1133 * index (important for priority queues) and fits in the unsigned short variable. 1134 */ 1135 return seq * 2 - is_ccs; 1136 } 1137 1138int 1139dtls1_retransmit_buffered_messages(SSL *s) 1140 { 1141 pqueue sent = s->d1->sent_messages; 1142 piterator iter; 1143 pitem *item; 1144 hm_fragment *frag; 1145 int found = 0; 1146 1147 iter = pqueue_iterator(sent); 1148 1149 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1150 { 1151 frag = (hm_fragment *)item->data; 1152 if ( dtls1_retransmit_message(s, 1153 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1154 0, &found) <= 0 && found) 1155 { 1156 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1157 return -1; 1158 } 1159 } 1160 1161 return 1; 1162 } 1163 1164int 1165dtls1_buffer_message(SSL *s, int is_ccs) 1166 { 1167 pitem *item; 1168 hm_fragment *frag; 1169 PQ_64BIT seq64; 1170 1171 /* this function is called immediately after a message has 1172 * been serialized */ 1173 OPENSSL_assert(s->init_off == 0); 1174 1175 frag = dtls1_hm_fragment_new(s->init_num, 0); 1176 1177 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1178 1179 if ( is_ccs) 1180 { 1181 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1182 DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num); 1183 } 1184 else 1185 { 1186 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1187 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1188 } 1189 1190 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1191 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1192 frag->msg_header.type = s->d1->w_msg_hdr.type; 1193 frag->msg_header.frag_off = 0; 1194 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1195 frag->msg_header.is_ccs = is_ccs; 1196 1197 /* save current state*/ 1198 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1199 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1200 frag->msg_header.saved_retransmit_state.compress = s->compress; 1201 frag->msg_header.saved_retransmit_state.session = s->session; 1202 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1203 1204 pq_64bit_init(&seq64); 1205 1206 pq_64bit_assign_word(&seq64, 1207 dtls1_get_queue_priority(frag->msg_header.seq, 1208 frag->msg_header.is_ccs)); 1209 1210 item = pitem_new(seq64, frag); 1211 pq_64bit_free(&seq64); 1212 if ( item == NULL) 1213 { 1214 dtls1_hm_fragment_free(frag); 1215 return 0; 1216 } 1217 1218#if 0 1219 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1220 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1221 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1222#endif 1223 1224 pqueue_insert(s->d1->sent_messages, item); 1225 return 1; 1226 } 1227 1228int 1229dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1230 int *found) 1231 { 1232 int ret; 1233 /* XDTLS: for now assuming that read/writes are blocking */ 1234 pitem *item; 1235 hm_fragment *frag ; 1236 unsigned long header_length; 1237 PQ_64BIT seq64; 1238 struct dtls1_retransmit_state saved_state; 1239 unsigned char save_write_sequence[8]; 1240 1241 /* 1242 OPENSSL_assert(s->init_num == 0); 1243 OPENSSL_assert(s->init_off == 0); 1244 */ 1245 1246 /* XDTLS: the requested message ought to be found, otherwise error */ 1247 pq_64bit_init(&seq64); 1248 pq_64bit_assign_word(&seq64, seq); 1249 1250 item = pqueue_find(s->d1->sent_messages, seq64); 1251 pq_64bit_free(&seq64); 1252 if ( item == NULL) 1253 { 1254 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1255 *found = 0; 1256 return 0; 1257 } 1258 1259 *found = 1; 1260 frag = (hm_fragment *)item->data; 1261 1262 if ( frag->msg_header.is_ccs) 1263 header_length = DTLS1_CCS_HEADER_LENGTH; 1264 else 1265 header_length = DTLS1_HM_HEADER_LENGTH; 1266 1267 memcpy(s->init_buf->data, frag->fragment, 1268 frag->msg_header.msg_len + header_length); 1269 s->init_num = frag->msg_header.msg_len + header_length; 1270 1271 dtls1_set_message_header_int(s, frag->msg_header.type, 1272 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1273 frag->msg_header.frag_len); 1274 1275 /* save current state */ 1276 saved_state.enc_write_ctx = s->enc_write_ctx; 1277 saved_state.write_hash = s->write_hash; 1278 saved_state.compress = s->compress; 1279 saved_state.session = s->session; 1280 saved_state.epoch = s->d1->w_epoch; 1281 saved_state.epoch = s->d1->w_epoch; 1282 1283 s->d1->retransmitting = 1; 1284 1285 /* restore state in which the message was originally sent */ 1286 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1287 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1288 s->compress = frag->msg_header.saved_retransmit_state.compress; 1289 s->session = frag->msg_header.saved_retransmit_state.session; 1290 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1291 1292 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1293 { 1294 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1295 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1296 } 1297 1298 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1299 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1300 1301 /* restore current state */ 1302 s->enc_write_ctx = saved_state.enc_write_ctx; 1303 s->write_hash = saved_state.write_hash; 1304 s->compress = saved_state.compress; 1305 s->session = saved_state.session; 1306 s->d1->w_epoch = saved_state.epoch; 1307 1308 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1309 { 1310 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1311 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1312 } 1313 1314 s->d1->retransmitting = 0; 1315 1316 (void)BIO_flush(SSL_get_wbio(s)); 1317 return ret; 1318 } 1319 1320/* call this function when the buffered messages are no longer needed */ 1321void 1322dtls1_clear_record_buffer(SSL *s) 1323 { 1324 pitem *item; 1325 1326 for(item = pqueue_pop(s->d1->sent_messages); 1327 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1328 { 1329 dtls1_hm_fragment_free((hm_fragment *)item->data); 1330 pitem_free(item); 1331 } 1332 } 1333 1334 1335unsigned char * 1336dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1337 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1338 { 1339 /* Don't change sequence numbers while listening */ 1340 if (frag_off == 0 && !s->d1->listen) 1341 { 1342 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1343 s->d1->next_handshake_write_seq++; 1344 } 1345 1346 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1347 frag_off, frag_len); 1348 1349 return p += DTLS1_HM_HEADER_LENGTH; 1350 } 1351 1352 1353/* don't actually do the writing, wait till the MTU has been retrieved */ 1354static void 1355dtls1_set_message_header_int(SSL *s, unsigned char mt, 1356 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1357 unsigned long frag_len) 1358 { 1359 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1360 1361 msg_hdr->type = mt; 1362 msg_hdr->msg_len = len; 1363 msg_hdr->seq = seq_num; 1364 msg_hdr->frag_off = frag_off; 1365 msg_hdr->frag_len = frag_len; 1366 } 1367 1368static void 1369dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1370 unsigned long frag_len) 1371 { 1372 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1373 1374 msg_hdr->frag_off = frag_off; 1375 msg_hdr->frag_len = frag_len; 1376 } 1377 1378static unsigned char * 1379dtls1_write_message_header(SSL *s, unsigned char *p) 1380 { 1381 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1382 1383 *p++ = msg_hdr->type; 1384 l2n3(msg_hdr->msg_len, p); 1385 1386 s2n(msg_hdr->seq, p); 1387 l2n3(msg_hdr->frag_off, p); 1388 l2n3(msg_hdr->frag_len, p); 1389 1390 return p; 1391 } 1392 1393unsigned int 1394dtls1_min_mtu(void) 1395 { 1396 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1397 sizeof(g_probable_mtu[0])) - 1]); 1398 } 1399 1400static unsigned int 1401dtls1_guess_mtu(unsigned int curr_mtu) 1402 { 1403 size_t i; 1404 1405 if ( curr_mtu == 0 ) 1406 return g_probable_mtu[0] ; 1407 1408 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1409 if ( curr_mtu > g_probable_mtu[i]) 1410 return g_probable_mtu[i]; 1411 1412 return curr_mtu; 1413 } 1414 1415void 1416dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1417 { 1418 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1419 msg_hdr->type = *(data++); 1420 n2l3(data, msg_hdr->msg_len); 1421 1422 n2s(data, msg_hdr->seq); 1423 n2l3(data, msg_hdr->frag_off); 1424 n2l3(data, msg_hdr->frag_len); 1425 } 1426 1427void 1428dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1429 { 1430 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1431 1432 ccs_hdr->type = *(data++); 1433 } 1434