d1_both.c revision 264331
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 { 217 218 if (frag->msg_header.is_ccs) 219 { 220 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx); 221 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash); 222 } 223 if (frag->fragment) OPENSSL_free(frag->fragment); 224 if (frag->reassembly) OPENSSL_free(frag->reassembly); 225 OPENSSL_free(frag); 226 } 227 228/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 229int dtls1_do_write(SSL *s, int type) 230 { 231 int ret; 232 int curr_mtu; 233 unsigned int len, frag_off, mac_size, blocksize; 234 235 /* AHA! Figure out the MTU, and stick to the right size */ 236 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 237 { 238 s->d1->mtu = 239 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 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 if (s->d1->mtu < dtls1_min_mtu()) 244 { 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 { 267 ret = BIO_flush(SSL_get_wbio(s)); 268 if ( ret <= 0) 269 return ret; 270 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 271 } 272#endif 273 274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something 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 + DTLS1_HM_HEADER_LENGTH); 279 280 if (s->write_hash) 281 mac_size = EVP_MD_CTX_size(s->write_hash); 282 else 283 mac_size = 0; 284 285 if (s->enc_write_ctx && 286 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 287 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 288 else 289 blocksize = 0; 290 291 frag_off = 0; 292 while( s->init_num) 293 { 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 ret = BIO_flush(SSL_get_wbio(s)); 301 if ( ret <= 0) 302 return ret; 303 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 304 mac_size - blocksize; 305 } 306 307 if ( s->init_num > curr_mtu) 308 len = curr_mtu; 309 else 310 len = s->init_num; 311 312 313 /* XDTLS: this function is too long. split out the CCS part */ 314 if ( type == SSL3_RT_HANDSHAKE) 315 { 316 if ( s->init_off != 0) 317 { 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, (unsigned char *)&s->init_buf->data[s->init_off]); 332 333 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 334 } 335 336 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 337 len); 338 if (ret < 0) 339 { 340 /* might need to update MTU here, but we don't know 341 * which previous packet caused the failure -- so can't 342 * really retransmit anything. continue as if everything 343 * is fine and wait for an alert to handle the 344 * retransmit 345 */ 346 if ( BIO_ctrl(SSL_get_wbio(s), 347 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 ) 348 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 349 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 350 else 351 return(-1); 352 } 353 else 354 { 355 356 /* bad if this assert fails, only part of the handshake 357 * message got sent. but why would this happen? */ 358 OPENSSL_assert(len == (unsigned int)ret); 359 360 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 361 { 362 /* should not be done for 'Hello Request's, but in that case 363 * we'll ignore the result anyway */ 364 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 365 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 366 int xlen; 367 368 if (frag_off == 0 && s->version != DTLS1_BAD_VER) 369 { 370 /* reconstruct message header is if it 371 * is being sent in single fragment */ 372 *p++ = msg_hdr->type; 373 l2n3(msg_hdr->msg_len,p); 374 s2n (msg_hdr->seq,p); 375 l2n3(0,p); 376 l2n3(msg_hdr->msg_len,p); 377 p -= DTLS1_HM_HEADER_LENGTH; 378 xlen = ret; 379 } 380 else 381 { 382 p += DTLS1_HM_HEADER_LENGTH; 383 xlen = ret - DTLS1_HM_HEADER_LENGTH; 384 } 385 386 ssl3_finish_mac(s, p, xlen); 387 } 388 389 if (ret == s->init_num) 390 { 391 if (s->msg_callback) 392 s->msg_callback(1, s->version, type, s->init_buf->data, 393 (size_t)(s->init_off + s->init_num), s, 394 s->msg_callback_arg); 395 396 s->init_off = 0; /* done writing this message */ 397 s->init_num = 0; 398 399 return(1); 400 } 401 s->init_off+=ret; 402 s->init_num-=ret; 403 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 404 } 405 } 406 return(0); 407 } 408 409 410/* Obtain handshake message of message type 'mt' (any if mt == -1), 411 * maximum acceptable body length 'max'. 412 * Read an entire handshake message. Handshake messages arrive in 413 * 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 /* s3->tmp is used to store messages that are unexpected, caused 423 * by the absence of an optional handshake message */ 424 if (s->s3->tmp.reuse_message) 425 { 426 s->s3->tmp.reuse_message=0; 427 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 428 { 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 442again: 443 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 444 if ( i == DTLS1_HM_BAD_FRAGMENT || 445 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 446 goto again; 447 else if ( i <= 0 && !*ok) 448 return i; 449 450 p = (unsigned char *)s->init_buf->data; 451 msg_len = msg_hdr->msg_len; 452 453 /* reconstruct message header */ 454 *(p++) = msg_hdr->type; 455 l2n3(msg_len,p); 456 s2n (msg_hdr->seq,p); 457 l2n3(0,p); 458 l2n3(msg_len,p); 459 if (s->version != DTLS1_BAD_VER) { 460 p -= DTLS1_HM_HEADER_LENGTH; 461 msg_len += DTLS1_HM_HEADER_LENGTH; 462 } 463 464 ssl3_finish_mac(s, p, msg_len); 465 if (s->msg_callback) 466 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 467 p, msg_len, 468 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 479f_err: 480 ssl3_send_alert(s,SSL3_AL_FATAL,al); 481 *ok = 0; 482 return -1; 483 } 484 485 486static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,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 { 497 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 498 return SSL_AD_ILLEGAL_PARAMETER; 499 } 500 501 if ( (frag_off+frag_len) > (unsigned long)max) 502 { 503 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 504 return SSL_AD_ILLEGAL_PARAMETER; 505 } 506 507 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 508 { 509 /* msg_len is limited to 2^24, but is effectively checked 510 * against max above */ 511 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH)) 512 { 513 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 514 return SSL_AD_INTERNAL_ERROR; 515 } 516 517 s->s3->tmp.message_size = msg_len; 518 s->d1->r_msg_hdr.msg_len = msg_len; 519 s->s3->tmp.message_type = msg_hdr->type; 520 s->d1->r_msg_hdr.type = msg_hdr->type; 521 s->d1->r_msg_hdr.seq = msg_hdr->seq; 522 } 523 else if (msg_len != s->d1->r_msg_hdr.msg_len) 524 { 525 /* They must be playing with us! BTW, failure to enforce 526 * upper limit would open possibility for buffer overrun. */ 527 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 528 return SSL_AD_ILLEGAL_PARAMETER; 529 } 530 531 return 0; /* no error */ 532 } 533 534 535static int 536dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 537 { 538 /* (0) check whether the desired fragment is available 539 * if so: 540 * (1) copy over the fragment to s->init_buf->data[] 541 * (2) update s->init_num 542 */ 543 pitem *item; 544 hm_fragment *frag; 545 int al; 546 547 *ok = 0; 548 item = pqueue_peek(s->d1->buffered_messages); 549 if ( item == NULL) 550 return 0; 551 552 frag = (hm_fragment *)item->data; 553 554 /* Don't return if reassembly still in progress */ 555 if (frag->reassembly != NULL) 556 return 0; 557 558 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 559 { 560 unsigned long frag_len = frag->msg_header.frag_len; 561 pqueue_pop(s->d1->buffered_messages); 562 563 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 564 565 if (al==0) /* no alert */ 566 { 567 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 568 memcpy(&p[frag->msg_header.frag_off], 569 frag->fragment,frag->msg_header.frag_len); 570 } 571 572 dtls1_hm_fragment_free(frag); 573 pitem_free(item); 574 575 if (al==0) 576 { 577 *ok = 1; 578 return frag_len; 579 } 580 581 ssl3_send_alert(s,SSL3_AL_FATAL,al); 582 s->init_num = 0; 583 *ok = 0; 584 return -1; 585 } 586 else 587 return 0; 588 } 589 590 591static int 592dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok) 593 { 594 hm_fragment *frag = NULL; 595 pitem *item = NULL; 596 int i = -1, is_complete; 597 unsigned char seq64be[8]; 598 unsigned long frag_len = msg_hdr->frag_len, max_len; 599 600 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 601 goto err; 602 603 /* Determine maximum allowed message size. Depends on (user set) 604 * maximum certificate length, but 16k is minimum. 605 */ 606 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list) 607 max_len = s->max_cert_list; 608 else 609 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 610 611 if ((msg_hdr->frag_off+frag_len) > max_len) 612 goto err; 613 614 /* Try to find item in queue */ 615 memset(seq64be,0,sizeof(seq64be)); 616 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 617 seq64be[7] = (unsigned char) msg_hdr->seq; 618 item = pqueue_find(s->d1->buffered_messages, seq64be); 619 620 if (item == NULL) 621 { 622 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 623 if ( frag == NULL) 624 goto err; 625 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 626 frag->msg_header.frag_len = frag->msg_header.msg_len; 627 frag->msg_header.frag_off = 0; 628 } 629 else 630 frag = (hm_fragment*) item->data; 631 632 /* If message is already reassembled, this must be a 633 * retransmit and can be dropped. 634 */ 635 if (frag->reassembly == NULL) 636 { 637 unsigned char devnull [256]; 638 639 while (frag_len) 640 { 641 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 642 devnull, 643 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 644 if (i<=0) goto err; 645 frag_len -= i; 646 } 647 return DTLS1_HM_FRAGMENT_RETRY; 648 } 649 650 /* read the body of the fragment (header has already been read */ 651 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 652 frag->fragment + msg_hdr->frag_off,frag_len,0); 653 if (i<=0 || (unsigned long)i!=frag_len) 654 goto err; 655 656 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 657 (long)(msg_hdr->frag_off + frag_len)); 658 659 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 660 is_complete); 661 662 if (is_complete) 663 { 664 OPENSSL_free(frag->reassembly); 665 frag->reassembly = NULL; 666 } 667 668 if (item == NULL) 669 { 670 memset(seq64be,0,sizeof(seq64be)); 671 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 672 seq64be[7] = (unsigned char)(msg_hdr->seq); 673 674 item = pitem_new(seq64be, frag); 675 if (item == NULL) 676 { 677 goto err; 678 i = -1; 679 } 680 681 pqueue_insert(s->d1->buffered_messages, item); 682 } 683 684 return DTLS1_HM_FRAGMENT_RETRY; 685 686err: 687 if (frag != NULL) dtls1_hm_fragment_free(frag); 688 if (item != NULL) OPENSSL_free(item); 689 *ok = 0; 690 return i; 691 } 692 693 694static int 695dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 696{ 697 int i=-1; 698 hm_fragment *frag = NULL; 699 pitem *item = NULL; 700 unsigned char seq64be[8]; 701 unsigned long frag_len = msg_hdr->frag_len; 702 703 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 704 goto err; 705 706 /* Try to find item in queue, to prevent duplicate entries */ 707 memset(seq64be,0,sizeof(seq64be)); 708 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 709 seq64be[7] = (unsigned char) msg_hdr->seq; 710 item = pqueue_find(s->d1->buffered_messages, seq64be); 711 712 /* If we already have an entry and this one is a fragment, 713 * don't discard it and rather try to reassemble it. 714 */ 715 if (item != NULL && frag_len < msg_hdr->msg_len) 716 item = NULL; 717 718 /* Discard the message if sequence number was already there, is 719 * too far in the future, already in the queue or if we received 720 * a FINISHED before the SERVER_HELLO, which then must be a stale 721 * retransmit. 722 */ 723 if (msg_hdr->seq <= s->d1->handshake_read_seq || 724 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 725 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 726 { 727 unsigned char devnull [256]; 728 729 while (frag_len) 730 { 731 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 732 devnull, 733 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 734 if (i<=0) goto err; 735 frag_len -= i; 736 } 737 } 738 else 739 { 740 if (frag_len && frag_len < msg_hdr->msg_len) 741 return dtls1_reassemble_fragment(s, msg_hdr, ok); 742 743 frag = dtls1_hm_fragment_new(frag_len, 0); 744 if ( frag == NULL) 745 goto err; 746 747 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 748 749 if (frag_len) 750 { 751 /* read the body of the fragment (header has already been read */ 752 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 753 frag->fragment,frag_len,0); 754 if (i<=0 || (unsigned long)i!=frag_len) 755 goto err; 756 } 757 758 memset(seq64be,0,sizeof(seq64be)); 759 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 760 seq64be[7] = (unsigned char)(msg_hdr->seq); 761 762 item = pitem_new(seq64be, frag); 763 if ( item == NULL) 764 goto err; 765 766 pqueue_insert(s->d1->buffered_messages, item); 767 } 768 769 return DTLS1_HM_FRAGMENT_RETRY; 770 771err: 772 if ( frag != NULL) dtls1_hm_fragment_free(frag); 773 if ( item != NULL) OPENSSL_free(item); 774 *ok = 0; 775 return i; 776 } 777 778 779static long 780dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 781 { 782 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 783 unsigned long len, frag_off, frag_len; 784 int i,al; 785 struct hm_header_st msg_hdr; 786 787 /* see if we have the required fragment already */ 788 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 789 { 790 if (*ok) s->init_num = frag_len; 791 return frag_len; 792 } 793 794 /* read handshake message header */ 795 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 796 DTLS1_HM_HEADER_LENGTH, 0); 797 if (i <= 0) /* nbio, or an error */ 798 { 799 s->rwstate=SSL_READING; 800 *ok = 0; 801 return i; 802 } 803 /* Handshake fails if message header is incomplete */ 804 if (i != DTLS1_HM_HEADER_LENGTH) 805 { 806 al=SSL_AD_UNEXPECTED_MESSAGE; 807 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 808 goto f_err; 809 } 810 811 /* parse the message fragment header */ 812 dtls1_get_message_header(wire, &msg_hdr); 813 814 /* 815 * if this is a future (or stale) message it gets buffered 816 * (or dropped)--no further processing at this time 817 * While listening, we accept seq 1 (ClientHello with cookie) 818 * although we're still expecting seq 0 (ClientHello) 819 */ 820 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 821 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 822 823 len = msg_hdr.msg_len; 824 frag_off = msg_hdr.frag_off; 825 frag_len = msg_hdr.frag_len; 826 827 if (frag_len && frag_len < len) 828 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 829 830 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 831 wire[0] == SSL3_MT_HELLO_REQUEST) 832 { 833 /* The server may always send 'Hello Request' messages -- 834 * we are doing a handshake anyway now, so ignore them 835 * if their format is correct. Does not count for 836 * 'Finished' MAC. */ 837 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 838 { 839 if (s->msg_callback) 840 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 841 wire, DTLS1_HM_HEADER_LENGTH, s, 842 s->msg_callback_arg); 843 844 s->init_num = 0; 845 return dtls1_get_message_fragment(s, st1, stn, 846 max, ok); 847 } 848 else /* Incorrectly formated Hello request */ 849 { 850 al=SSL_AD_UNEXPECTED_MESSAGE; 851 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 852 goto f_err; 853 } 854 } 855 856 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 857 goto f_err; 858 859 /* XDTLS: ressurect this when restart is in place */ 860 s->state=stn; 861 862 if ( frag_len > 0) 863 { 864 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 865 866 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 867 &p[frag_off],frag_len,0); 868 /* XDTLS: fix this--message fragments cannot span multiple packets */ 869 if (i <= 0) 870 { 871 s->rwstate=SSL_READING; 872 *ok = 0; 873 return i; 874 } 875 } 876 else 877 i = 0; 878 879 /* XDTLS: an incorrectly formatted fragment should cause the 880 * handshake to fail */ 881 if (i != (int)frag_len) 882 { 883 al=SSL3_AD_ILLEGAL_PARAMETER; 884 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 885 goto f_err; 886 } 887 888 *ok = 1; 889 890 /* Note that s->init_num is *not* used as current offset in 891 * s->init_buf->data, but as a counter summing up fragments' 892 * lengths: as soon as they sum up to handshake packet 893 * length, we assume we have got all the fragments. */ 894 s->init_num = frag_len; 895 return frag_len; 896 897f_err: 898 ssl3_send_alert(s,SSL3_AL_FATAL,al); 899 s->init_num = 0; 900 901 *ok=0; 902 return(-1); 903 } 904 905int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 906 { 907 unsigned char *p,*d; 908 int i; 909 unsigned long l; 910 911 if (s->state == a) 912 { 913 d=(unsigned char *)s->init_buf->data; 914 p= &(d[DTLS1_HM_HEADER_LENGTH]); 915 916 i=s->method->ssl3_enc->final_finish_mac(s, 917 sender,slen,s->s3->tmp.finish_md); 918 s->s3->tmp.finish_md_len = i; 919 memcpy(p, s->s3->tmp.finish_md, i); 920 p+=i; 921 l=i; 922 923 /* Copy the finished so we can use it for 924 * renegotiation checks 925 */ 926 if(s->type == SSL_ST_CONNECT) 927 { 928 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 929 memcpy(s->s3->previous_client_finished, 930 s->s3->tmp.finish_md, i); 931 s->s3->previous_client_finished_len=i; 932 } 933 else 934 { 935 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 936 memcpy(s->s3->previous_server_finished, 937 s->s3->tmp.finish_md, i); 938 s->s3->previous_server_finished_len=i; 939 } 940 941#ifdef OPENSSL_SYS_WIN16 942 /* MSVC 1.5 does not clear the top bytes of the word unless 943 * I do this. 944 */ 945 l&=0xffff; 946#endif 947 948 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 949 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 950 s->init_off=0; 951 952 /* buffer the message to handle re-xmits */ 953 dtls1_buffer_message(s, 0); 954 955 s->state=b; 956 } 957 958 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 959 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 960 } 961 962/* for these 2 messages, we need to 963 * ssl->enc_read_ctx re-init 964 * ssl->s3->read_sequence zero 965 * ssl->s3->read_mac_secret re-init 966 * ssl->session->read_sym_enc assign 967 * ssl->session->read_compression assign 968 * ssl->session->read_hash assign 969 */ 970int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 971 { 972 unsigned char *p; 973 974 if (s->state == a) 975 { 976 p=(unsigned char *)s->init_buf->data; 977 *p++=SSL3_MT_CCS; 978 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 979 s->init_num=DTLS1_CCS_HEADER_LENGTH; 980 981 if (s->version == DTLS1_BAD_VER) { 982 s->d1->next_handshake_write_seq++; 983 s2n(s->d1->handshake_write_seq,p); 984 s->init_num+=2; 985 } 986 987 s->init_off=0; 988 989 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 990 s->d1->handshake_write_seq, 0, 0); 991 992 /* buffer the message to handle re-xmits */ 993 dtls1_buffer_message(s, 1); 994 995 s->state=b; 996 } 997 998 /* SSL3_ST_CW_CHANGE_B */ 999 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1000 } 1001 1002static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1003 { 1004 int n; 1005 unsigned char *p; 1006 1007 n=i2d_X509(x,NULL); 1008 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1009 { 1010 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1011 return 0; 1012 } 1013 p=(unsigned char *)&(buf->data[*l]); 1014 l2n3(n,p); 1015 i2d_X509(x,&p); 1016 *l+=n+3; 1017 1018 return 1; 1019 } 1020unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1021 { 1022 unsigned char *p; 1023 int i; 1024 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1025 BUF_MEM *buf; 1026 1027 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1028 buf=s->init_buf; 1029 if (!BUF_MEM_grow_clean(buf,10)) 1030 { 1031 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1032 return(0); 1033 } 1034 if (x != NULL) 1035 { 1036 X509_STORE_CTX xs_ctx; 1037 1038 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1039 { 1040 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1041 return(0); 1042 } 1043 1044 X509_verify_cert(&xs_ctx); 1045 /* Don't leave errors in the queue */ 1046 ERR_clear_error(); 1047 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1048 { 1049 x = sk_X509_value(xs_ctx.chain, i); 1050 1051 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1052 { 1053 X509_STORE_CTX_cleanup(&xs_ctx); 1054 return 0; 1055 } 1056 } 1057 X509_STORE_CTX_cleanup(&xs_ctx); 1058 } 1059 /* Thawte special :-) */ 1060 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1061 { 1062 x=sk_X509_value(s->ctx->extra_certs,i); 1063 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1064 return 0; 1065 } 1066 1067 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1068 1069 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1070 l2n3(l,p); 1071 l+=3; 1072 p=(unsigned char *)&(buf->data[0]); 1073 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1074 1075 l+=DTLS1_HM_HEADER_LENGTH; 1076 return(l); 1077 } 1078 1079int dtls1_read_failed(SSL *s, int code) 1080 { 1081 if ( code > 0) 1082 { 1083 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1084 return 1; 1085 } 1086 1087 if (!dtls1_is_timer_expired(s)) 1088 { 1089 /* not a timeout, none of our business, 1090 let higher layers handle this. in fact it's probably an error */ 1091 return code; 1092 } 1093 1094#ifndef OPENSSL_NO_HEARTBEATS 1095 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1096#else 1097 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1098#endif 1099 { 1100 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1101 return code; 1102 } 1103 1104#if 0 /* for now, each alert contains only one record number */ 1105 item = pqueue_peek(state->rcvd_records); 1106 if ( item ) 1107 { 1108 /* send an alert immediately for all the missing records */ 1109 } 1110 else 1111#endif 1112 1113#if 0 /* no more alert sending, just retransmit the last set of messages */ 1114 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1115 ssl3_send_alert(s,SSL3_AL_WARNING, 1116 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1117#endif 1118 1119 return dtls1_handle_timeout(s); 1120 } 1121 1122int 1123dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1124 { 1125 /* The index of the retransmission queue actually is the message sequence number, 1126 * since the queue only contains messages of a single handshake. However, the 1127 * ChangeCipherSpec has no message sequence number and so using only the sequence 1128 * will result in the CCS and Finished having the same index. To prevent this, 1129 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1130 * This does not only differ CSS and Finished, it also maintains the order of the 1131 * index (important for priority queues) and fits in the unsigned short variable. 1132 */ 1133 return seq * 2 - is_ccs; 1134 } 1135 1136int 1137dtls1_retransmit_buffered_messages(SSL *s) 1138 { 1139 pqueue sent = s->d1->sent_messages; 1140 piterator iter; 1141 pitem *item; 1142 hm_fragment *frag; 1143 int found = 0; 1144 1145 iter = pqueue_iterator(sent); 1146 1147 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1148 { 1149 frag = (hm_fragment *)item->data; 1150 if ( dtls1_retransmit_message(s, 1151 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1152 0, &found) <= 0 && found) 1153 { 1154 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1155 return -1; 1156 } 1157 } 1158 1159 return 1; 1160 } 1161 1162int 1163dtls1_buffer_message(SSL *s, int is_ccs) 1164 { 1165 pitem *item; 1166 hm_fragment *frag; 1167 unsigned char seq64be[8]; 1168 1169 /* this function is called immediately after a message has 1170 * been serialized */ 1171 OPENSSL_assert(s->init_off == 0); 1172 1173 frag = dtls1_hm_fragment_new(s->init_num, 0); 1174 1175 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1176 1177 if ( is_ccs) 1178 { 1179 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1180 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1181 } 1182 else 1183 { 1184 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1185 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1186 } 1187 1188 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1189 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1190 frag->msg_header.type = s->d1->w_msg_hdr.type; 1191 frag->msg_header.frag_off = 0; 1192 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1193 frag->msg_header.is_ccs = is_ccs; 1194 1195 /* save current state*/ 1196 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1197 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1198 frag->msg_header.saved_retransmit_state.compress = s->compress; 1199 frag->msg_header.saved_retransmit_state.session = s->session; 1200 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1201 1202 memset(seq64be,0,sizeof(seq64be)); 1203 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1204 frag->msg_header.is_ccs)>>8); 1205 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1206 frag->msg_header.is_ccs)); 1207 1208 item = pitem_new(seq64be, frag); 1209 if ( item == NULL) 1210 { 1211 dtls1_hm_fragment_free(frag); 1212 return 0; 1213 } 1214 1215#if 0 1216 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1217 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1218 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1219#endif 1220 1221 pqueue_insert(s->d1->sent_messages, item); 1222 return 1; 1223 } 1224 1225int 1226dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1227 int *found) 1228 { 1229 int ret; 1230 /* XDTLS: for now assuming that read/writes are blocking */ 1231 pitem *item; 1232 hm_fragment *frag ; 1233 unsigned long header_length; 1234 unsigned char seq64be[8]; 1235 struct dtls1_retransmit_state saved_state; 1236 unsigned char save_write_sequence[8]; 1237 1238 /* 1239 OPENSSL_assert(s->init_num == 0); 1240 OPENSSL_assert(s->init_off == 0); 1241 */ 1242 1243 /* XDTLS: the requested message ought to be found, otherwise error */ 1244 memset(seq64be,0,sizeof(seq64be)); 1245 seq64be[6] = (unsigned char)(seq>>8); 1246 seq64be[7] = (unsigned char)seq; 1247 1248 item = pqueue_find(s->d1->sent_messages, seq64be); 1249 if ( item == NULL) 1250 { 1251 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1252 *found = 0; 1253 return 0; 1254 } 1255 1256 *found = 1; 1257 frag = (hm_fragment *)item->data; 1258 1259 if ( frag->msg_header.is_ccs) 1260 header_length = DTLS1_CCS_HEADER_LENGTH; 1261 else 1262 header_length = DTLS1_HM_HEADER_LENGTH; 1263 1264 memcpy(s->init_buf->data, frag->fragment, 1265 frag->msg_header.msg_len + header_length); 1266 s->init_num = frag->msg_header.msg_len + header_length; 1267 1268 dtls1_set_message_header_int(s, frag->msg_header.type, 1269 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1270 frag->msg_header.frag_len); 1271 1272 /* save current state */ 1273 saved_state.enc_write_ctx = s->enc_write_ctx; 1274 saved_state.write_hash = s->write_hash; 1275 saved_state.compress = s->compress; 1276 saved_state.session = s->session; 1277 saved_state.epoch = s->d1->w_epoch; 1278 saved_state.epoch = s->d1->w_epoch; 1279 1280 s->d1->retransmitting = 1; 1281 1282 /* restore state in which the message was originally sent */ 1283 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1284 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1285 s->compress = frag->msg_header.saved_retransmit_state.compress; 1286 s->session = frag->msg_header.saved_retransmit_state.session; 1287 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1288 1289 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1290 { 1291 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1292 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1293 } 1294 1295 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1296 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1297 1298 /* restore current state */ 1299 s->enc_write_ctx = saved_state.enc_write_ctx; 1300 s->write_hash = saved_state.write_hash; 1301 s->compress = saved_state.compress; 1302 s->session = saved_state.session; 1303 s->d1->w_epoch = saved_state.epoch; 1304 1305 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1306 { 1307 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1308 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1309 } 1310 1311 s->d1->retransmitting = 0; 1312 1313 (void)BIO_flush(SSL_get_wbio(s)); 1314 return ret; 1315 } 1316 1317/* call this function when the buffered messages are no longer needed */ 1318void 1319dtls1_clear_record_buffer(SSL *s) 1320 { 1321 pitem *item; 1322 1323 for(item = pqueue_pop(s->d1->sent_messages); 1324 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1325 { 1326 dtls1_hm_fragment_free((hm_fragment *)item->data); 1327 pitem_free(item); 1328 } 1329 } 1330 1331 1332unsigned char * 1333dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1334 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1335 { 1336 /* Don't change sequence numbers while listening */ 1337 if (frag_off == 0 && !s->d1->listen) 1338 { 1339 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1340 s->d1->next_handshake_write_seq++; 1341 } 1342 1343 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1344 frag_off, frag_len); 1345 1346 return p += DTLS1_HM_HEADER_LENGTH; 1347 } 1348 1349 1350/* don't actually do the writing, wait till the MTU has been retrieved */ 1351static void 1352dtls1_set_message_header_int(SSL *s, unsigned char mt, 1353 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1354 unsigned long frag_len) 1355 { 1356 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1357 1358 msg_hdr->type = mt; 1359 msg_hdr->msg_len = len; 1360 msg_hdr->seq = seq_num; 1361 msg_hdr->frag_off = frag_off; 1362 msg_hdr->frag_len = frag_len; 1363 } 1364 1365static void 1366dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1367 unsigned long frag_len) 1368 { 1369 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1370 1371 msg_hdr->frag_off = frag_off; 1372 msg_hdr->frag_len = frag_len; 1373 } 1374 1375static unsigned char * 1376dtls1_write_message_header(SSL *s, unsigned char *p) 1377 { 1378 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1379 1380 *p++ = msg_hdr->type; 1381 l2n3(msg_hdr->msg_len, p); 1382 1383 s2n(msg_hdr->seq, p); 1384 l2n3(msg_hdr->frag_off, p); 1385 l2n3(msg_hdr->frag_len, p); 1386 1387 return p; 1388 } 1389 1390unsigned int 1391dtls1_min_mtu(void) 1392 { 1393 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1394 sizeof(g_probable_mtu[0])) - 1]); 1395 } 1396 1397static unsigned int 1398dtls1_guess_mtu(unsigned int curr_mtu) 1399 { 1400 unsigned int i; 1401 1402 if ( curr_mtu == 0 ) 1403 return g_probable_mtu[0] ; 1404 1405 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1406 if ( curr_mtu > g_probable_mtu[i]) 1407 return g_probable_mtu[i]; 1408 1409 return curr_mtu; 1410 } 1411 1412void 1413dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1414 { 1415 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1416 msg_hdr->type = *(data++); 1417 n2l3(data, msg_hdr->msg_len); 1418 1419 n2s(data, msg_hdr->seq); 1420 n2l3(data, msg_hdr->frag_off); 1421 n2l3(data, msg_hdr->frag_len); 1422 } 1423 1424void 1425dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1426 { 1427 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1428 1429 ccs_hdr->type = *(data++); 1430 } 1431 1432int dtls1_shutdown(SSL *s) 1433 { 1434 int ret; 1435#ifndef OPENSSL_NO_SCTP 1436 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1437 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1438 { 1439 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1440 if (ret < 0) return -1; 1441 1442 if (ret == 0) 1443 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1444 } 1445#endif 1446 ret = ssl3_shutdown(s); 1447#ifndef OPENSSL_NO_SCTP 1448 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1449#endif 1450 return ret; 1451 } 1452 1453#ifndef OPENSSL_NO_HEARTBEATS 1454int 1455dtls1_process_heartbeat(SSL *s) 1456 { 1457 unsigned char *p = &s->s3->rrec.data[0], *pl; 1458 unsigned short hbtype; 1459 unsigned int payload; 1460 unsigned int padding = 16; /* Use minimum padding */ 1461 1462 if (s->msg_callback) 1463 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1464 &s->s3->rrec.data[0], s->s3->rrec.length, 1465 s, s->msg_callback_arg); 1466 1467 /* Read type and payload length first */ 1468 if (1 + 2 + 16 > s->s3->rrec.length) 1469 return 0; /* silently discard */ 1470 hbtype = *p++; 1471 n2s(p, payload); 1472 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1473 return 0; /* silently discard per RFC 6520 sec. 4 */ 1474 pl = p; 1475 1476 if (hbtype == TLS1_HB_REQUEST) 1477 { 1478 unsigned char *buffer, *bp; 1479 unsigned int write_length = 1 /* heartbeat type */ + 1480 2 /* heartbeat length */ + 1481 payload + padding; 1482 int r; 1483 1484 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1485 return 0; 1486 1487 /* Allocate memory for the response, size is 1 byte 1488 * message type, plus 2 bytes payload length, plus 1489 * payload, plus padding 1490 */ 1491 buffer = OPENSSL_malloc(write_length); 1492 bp = buffer; 1493 1494 /* Enter response type, length and copy payload */ 1495 *bp++ = TLS1_HB_RESPONSE; 1496 s2n(payload, bp); 1497 memcpy(bp, pl, payload); 1498 bp += payload; 1499 /* Random padding */ 1500 RAND_pseudo_bytes(bp, padding); 1501 1502 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1503 1504 if (r >= 0 && s->msg_callback) 1505 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1506 buffer, write_length, 1507 s, s->msg_callback_arg); 1508 1509 OPENSSL_free(buffer); 1510 1511 if (r < 0) 1512 return r; 1513 } 1514 else if (hbtype == TLS1_HB_RESPONSE) 1515 { 1516 unsigned int seq; 1517 1518 /* We only send sequence numbers (2 bytes unsigned int), 1519 * and 16 random bytes, so we just try to read the 1520 * sequence number */ 1521 n2s(pl, seq); 1522 1523 if (payload == 18 && seq == s->tlsext_hb_seq) 1524 { 1525 dtls1_stop_timer(s); 1526 s->tlsext_hb_seq++; 1527 s->tlsext_hb_pending = 0; 1528 } 1529 } 1530 1531 return 0; 1532 } 1533 1534int 1535dtls1_heartbeat(SSL *s) 1536 { 1537 unsigned char *buf, *p; 1538 int ret; 1539 unsigned int payload = 18; /* Sequence number + random bytes */ 1540 unsigned int padding = 16; /* Use minimum padding */ 1541 1542 /* Only send if peer supports and accepts HB requests... */ 1543 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1544 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1545 { 1546 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1547 return -1; 1548 } 1549 1550 /* ...and there is none in flight yet... */ 1551 if (s->tlsext_hb_pending) 1552 { 1553 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1554 return -1; 1555 } 1556 1557 /* ...and no handshake in progress. */ 1558 if (SSL_in_init(s) || s->in_handshake) 1559 { 1560 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1561 return -1; 1562 } 1563 1564 /* Check if padding is too long, payload and padding 1565 * must not exceed 2^14 - 3 = 16381 bytes in total. 1566 */ 1567 OPENSSL_assert(payload + padding <= 16381); 1568 1569 /* Create HeartBeat message, we just use a sequence number 1570 * as payload to distuingish different messages and add 1571 * some random stuff. 1572 * - Message Type, 1 byte 1573 * - Payload Length, 2 bytes (unsigned int) 1574 * - Payload, the sequence number (2 bytes uint) 1575 * - Payload, random bytes (16 bytes uint) 1576 * - Padding 1577 */ 1578 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1579 p = buf; 1580 /* Message Type */ 1581 *p++ = TLS1_HB_REQUEST; 1582 /* Payload length (18 bytes here) */ 1583 s2n(payload, p); 1584 /* Sequence number */ 1585 s2n(s->tlsext_hb_seq, p); 1586 /* 16 random bytes */ 1587 RAND_pseudo_bytes(p, 16); 1588 p += 16; 1589 /* Random padding */ 1590 RAND_pseudo_bytes(p, padding); 1591 1592 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1593 if (ret >= 0) 1594 { 1595 if (s->msg_callback) 1596 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1597 buf, 3 + payload + padding, 1598 s, s->msg_callback_arg); 1599 1600 dtls1_start_timer(s); 1601 s->tlsext_hb_pending = 1; 1602 } 1603 1604 OPENSSL_free(buf); 1605 1606 return ret; 1607 } 1608#endif 1609