d1_both.c revision 271304
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 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */ 323 if ( len <= DTLS1_HM_HEADER_LENGTH) 324 len += DTLS1_HM_HEADER_LENGTH; 325 } 326 327 dtls1_fix_message_header(s, frag_off, 328 len - DTLS1_HM_HEADER_LENGTH); 329 330 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 331 332 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 333 } 334 335 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 336 len); 337 if (ret < 0) 338 { 339 /* might need to update MTU here, but we don't know 340 * which previous packet caused the failure -- so can't 341 * really retransmit anything. continue as if everything 342 * is fine and wait for an alert to handle the 343 * retransmit 344 */ 345 if ( BIO_ctrl(SSL_get_wbio(s), 346 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 ) 347 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 348 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 349 else 350 return(-1); 351 } 352 else 353 { 354 355 /* bad if this assert fails, only part of the handshake 356 * message got sent. but why would this happen? */ 357 OPENSSL_assert(len == (unsigned int)ret); 358 359 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 360 { 361 /* should not be done for 'Hello Request's, but in that case 362 * we'll ignore the result anyway */ 363 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 364 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 365 int xlen; 366 367 if (frag_off == 0 && s->version != DTLS1_BAD_VER) 368 { 369 /* reconstruct message header is if it 370 * is being sent in single fragment */ 371 *p++ = msg_hdr->type; 372 l2n3(msg_hdr->msg_len,p); 373 s2n (msg_hdr->seq,p); 374 l2n3(0,p); 375 l2n3(msg_hdr->msg_len,p); 376 p -= DTLS1_HM_HEADER_LENGTH; 377 xlen = ret; 378 } 379 else 380 { 381 p += DTLS1_HM_HEADER_LENGTH; 382 xlen = ret - DTLS1_HM_HEADER_LENGTH; 383 } 384 385 ssl3_finish_mac(s, p, xlen); 386 } 387 388 if (ret == s->init_num) 389 { 390 if (s->msg_callback) 391 s->msg_callback(1, s->version, type, s->init_buf->data, 392 (size_t)(s->init_off + s->init_num), s, 393 s->msg_callback_arg); 394 395 s->init_off = 0; /* done writing this message */ 396 s->init_num = 0; 397 398 return(1); 399 } 400 s->init_off+=ret; 401 s->init_num-=ret; 402 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 403 } 404 } 405 return(0); 406 } 407 408 409/* Obtain handshake message of message type 'mt' (any if mt == -1), 410 * maximum acceptable body length 'max'. 411 * Read an entire handshake message. Handshake messages arrive in 412 * fragments. 413 */ 414long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 415 { 416 int i, al; 417 struct hm_header_st *msg_hdr; 418 unsigned char *p; 419 unsigned long msg_len; 420 421 /* s3->tmp is used to store messages that are unexpected, caused 422 * by the absence of an optional handshake message */ 423 if (s->s3->tmp.reuse_message) 424 { 425 s->s3->tmp.reuse_message=0; 426 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 427 { 428 al=SSL_AD_UNEXPECTED_MESSAGE; 429 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 430 goto f_err; 431 } 432 *ok=1; 433 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 434 s->init_num = (int)s->s3->tmp.message_size; 435 return s->init_num; 436 } 437 438 msg_hdr = &s->d1->r_msg_hdr; 439 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 440 441again: 442 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 443 if ( i == DTLS1_HM_BAD_FRAGMENT || 444 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 445 goto again; 446 else if ( i <= 0 && !*ok) 447 return i; 448 449 p = (unsigned char *)s->init_buf->data; 450 msg_len = msg_hdr->msg_len; 451 452 /* reconstruct message header */ 453 *(p++) = msg_hdr->type; 454 l2n3(msg_len,p); 455 s2n (msg_hdr->seq,p); 456 l2n3(0,p); 457 l2n3(msg_len,p); 458 if (s->version != DTLS1_BAD_VER) { 459 p -= DTLS1_HM_HEADER_LENGTH; 460 msg_len += DTLS1_HM_HEADER_LENGTH; 461 } 462 463 ssl3_finish_mac(s, p, msg_len); 464 if (s->msg_callback) 465 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 466 p, msg_len, 467 s, s->msg_callback_arg); 468 469 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 470 471 /* Don't change sequence numbers while listening */ 472 if (!s->d1->listen) 473 s->d1->handshake_read_seq++; 474 475 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 476 return s->init_num; 477 478f_err: 479 ssl3_send_alert(s,SSL3_AL_FATAL,al); 480 *ok = 0; 481 return -1; 482 } 483 484 485static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 486 { 487 size_t frag_off,frag_len,msg_len; 488 489 msg_len = msg_hdr->msg_len; 490 frag_off = msg_hdr->frag_off; 491 frag_len = msg_hdr->frag_len; 492 493 /* sanity checking */ 494 if ( (frag_off+frag_len) > msg_len) 495 { 496 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 497 return SSL_AD_ILLEGAL_PARAMETER; 498 } 499 500 if ( (frag_off+frag_len) > (unsigned long)max) 501 { 502 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 503 return SSL_AD_ILLEGAL_PARAMETER; 504 } 505 506 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 507 { 508 /* msg_len is limited to 2^24, but is effectively checked 509 * against max above */ 510 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH)) 511 { 512 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 513 return SSL_AD_INTERNAL_ERROR; 514 } 515 516 s->s3->tmp.message_size = msg_len; 517 s->d1->r_msg_hdr.msg_len = msg_len; 518 s->s3->tmp.message_type = msg_hdr->type; 519 s->d1->r_msg_hdr.type = msg_hdr->type; 520 s->d1->r_msg_hdr.seq = msg_hdr->seq; 521 } 522 else if (msg_len != s->d1->r_msg_hdr.msg_len) 523 { 524 /* They must be playing with us! BTW, failure to enforce 525 * upper limit would open possibility for buffer overrun. */ 526 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 527 return SSL_AD_ILLEGAL_PARAMETER; 528 } 529 530 return 0; /* no error */ 531 } 532 533 534static int 535dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 536 { 537 /* (0) check whether the desired fragment is available 538 * if so: 539 * (1) copy over the fragment to s->init_buf->data[] 540 * (2) update s->init_num 541 */ 542 pitem *item; 543 hm_fragment *frag; 544 int al; 545 546 *ok = 0; 547 item = pqueue_peek(s->d1->buffered_messages); 548 if ( item == NULL) 549 return 0; 550 551 frag = (hm_fragment *)item->data; 552 553 /* Don't return if reassembly still in progress */ 554 if (frag->reassembly != NULL) 555 return 0; 556 557 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 558 { 559 unsigned long frag_len = frag->msg_header.frag_len; 560 pqueue_pop(s->d1->buffered_messages); 561 562 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 563 564 if (al==0) /* no alert */ 565 { 566 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 567 memcpy(&p[frag->msg_header.frag_off], 568 frag->fragment,frag->msg_header.frag_len); 569 } 570 571 dtls1_hm_fragment_free(frag); 572 pitem_free(item); 573 574 if (al==0) 575 { 576 *ok = 1; 577 return frag_len; 578 } 579 580 ssl3_send_alert(s,SSL3_AL_FATAL,al); 581 s->init_num = 0; 582 *ok = 0; 583 return -1; 584 } 585 else 586 return 0; 587 } 588 589/* dtls1_max_handshake_message_len returns the maximum number of bytes 590 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may 591 * be greater if the maximum certificate list size requires it. */ 592static unsigned long dtls1_max_handshake_message_len(const SSL *s) 593 { 594 unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 595 if (max_len < (unsigned long)s->max_cert_list) 596 return s->max_cert_list; 597 return max_len; 598 } 599 600static int 601dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 602 { 603 hm_fragment *frag = NULL; 604 pitem *item = NULL; 605 int i = -1, is_complete; 606 unsigned char seq64be[8]; 607 unsigned long frag_len = msg_hdr->frag_len; 608 609 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len || 610 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 611 goto err; 612 613 if (frag_len == 0) 614 return DTLS1_HM_FRAGMENT_RETRY; 615 616 /* Try to find item in queue */ 617 memset(seq64be,0,sizeof(seq64be)); 618 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 619 seq64be[7] = (unsigned char) msg_hdr->seq; 620 item = pqueue_find(s->d1->buffered_messages, seq64be); 621 622 if (item == NULL) 623 { 624 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 625 if ( frag == NULL) 626 goto err; 627 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 628 frag->msg_header.frag_len = frag->msg_header.msg_len; 629 frag->msg_header.frag_off = 0; 630 } 631 else 632 { 633 frag = (hm_fragment*) item->data; 634 if (frag->msg_header.msg_len != msg_hdr->msg_len) 635 { 636 item = NULL; 637 frag = NULL; 638 goto err; 639 } 640 } 641 642 643 /* If message is already reassembled, this must be a 644 * retransmit and can be dropped. In this case item != NULL and so frag 645 * does not need to be freed. 646 */ 647 if (frag->reassembly == NULL) 648 { 649 unsigned char devnull [256]; 650 651 while (frag_len) 652 { 653 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 654 devnull, 655 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 656 if (i<=0) goto err; 657 frag_len -= i; 658 } 659 return DTLS1_HM_FRAGMENT_RETRY; 660 } 661 662 /* read the body of the fragment (header has already been read */ 663 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 664 frag->fragment + msg_hdr->frag_off,frag_len,0); 665 if ((unsigned long)i!=frag_len) 666 i=-1; 667 if (i<=0) 668 goto err; 669 670 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 671 (long)(msg_hdr->frag_off + frag_len)); 672 673 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 674 is_complete); 675 676 if (is_complete) 677 { 678 OPENSSL_free(frag->reassembly); 679 frag->reassembly = NULL; 680 } 681 682 if (item == NULL) 683 { 684 item = pitem_new(seq64be, frag); 685 if (item == NULL) 686 { 687 goto err; 688 i = -1; 689 } 690 691 item = pqueue_insert(s->d1->buffered_messages, item); 692 /* pqueue_insert fails iff a duplicate item is inserted. 693 * However, |item| cannot be a duplicate. If it were, 694 * |pqueue_find|, above, would have returned it and control 695 * would never have reached this branch. */ 696 OPENSSL_assert(item != NULL); 697 } 698 699 return DTLS1_HM_FRAGMENT_RETRY; 700 701err: 702 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 703 *ok = 0; 704 return i; 705 } 706 707 708static int 709dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 710{ 711 int i=-1; 712 hm_fragment *frag = NULL; 713 pitem *item = NULL; 714 unsigned char seq64be[8]; 715 unsigned long frag_len = msg_hdr->frag_len; 716 717 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 718 goto err; 719 720 /* Try to find item in queue, to prevent duplicate entries */ 721 memset(seq64be,0,sizeof(seq64be)); 722 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 723 seq64be[7] = (unsigned char) msg_hdr->seq; 724 item = pqueue_find(s->d1->buffered_messages, seq64be); 725 726 /* If we already have an entry and this one is a fragment, 727 * don't discard it and rather try to reassemble it. 728 */ 729 if (item != NULL && frag_len != msg_hdr->msg_len) 730 item = NULL; 731 732 /* Discard the message if sequence number was already there, is 733 * too far in the future, already in the queue or if we received 734 * a FINISHED before the SERVER_HELLO, which then must be a stale 735 * retransmit. 736 */ 737 if (msg_hdr->seq <= s->d1->handshake_read_seq || 738 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 739 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 740 { 741 unsigned char devnull [256]; 742 743 while (frag_len) 744 { 745 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 746 devnull, 747 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 748 if (i<=0) goto err; 749 frag_len -= i; 750 } 751 } 752 else 753 { 754 if (frag_len != msg_hdr->msg_len) 755 return dtls1_reassemble_fragment(s, msg_hdr, ok); 756 757 if (frag_len > dtls1_max_handshake_message_len(s)) 758 goto err; 759 760 frag = dtls1_hm_fragment_new(frag_len, 0); 761 if ( frag == NULL) 762 goto err; 763 764 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 765 766 if (frag_len) 767 { 768 /* read the body of the fragment (header has already been read */ 769 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 770 frag->fragment,frag_len,0); 771 if ((unsigned long)i!=frag_len) 772 i = -1; 773 if (i<=0) 774 goto err; 775 } 776 777 item = pitem_new(seq64be, frag); 778 if ( item == NULL) 779 goto err; 780 781 item = pqueue_insert(s->d1->buffered_messages, item); 782 /* pqueue_insert fails iff a duplicate item is inserted. 783 * However, |item| cannot be a duplicate. If it were, 784 * |pqueue_find|, above, would have returned it. Then, either 785 * |frag_len| != |msg_hdr->msg_len| in which case |item| is set 786 * to NULL and it will have been processed with 787 * |dtls1_reassemble_fragment|, above, or the record will have 788 * been discarded. */ 789 OPENSSL_assert(item != NULL); 790 } 791 792 return DTLS1_HM_FRAGMENT_RETRY; 793 794err: 795 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 796 *ok = 0; 797 return i; 798 } 799 800 801static long 802dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 803 { 804 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 805 unsigned long len, frag_off, frag_len; 806 int i,al; 807 struct hm_header_st msg_hdr; 808 809 redo: 810 /* see if we have the required fragment already */ 811 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 812 { 813 if (*ok) s->init_num = frag_len; 814 return frag_len; 815 } 816 817 /* read handshake message header */ 818 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 819 DTLS1_HM_HEADER_LENGTH, 0); 820 if (i <= 0) /* nbio, or an error */ 821 { 822 s->rwstate=SSL_READING; 823 *ok = 0; 824 return i; 825 } 826 /* Handshake fails if message header is incomplete */ 827 if (i != DTLS1_HM_HEADER_LENGTH) 828 { 829 al=SSL_AD_UNEXPECTED_MESSAGE; 830 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 831 goto f_err; 832 } 833 834 /* parse the message fragment header */ 835 dtls1_get_message_header(wire, &msg_hdr); 836 837 /* 838 * if this is a future (or stale) message it gets buffered 839 * (or dropped)--no further processing at this time 840 * While listening, we accept seq 1 (ClientHello with cookie) 841 * although we're still expecting seq 0 (ClientHello) 842 */ 843 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 844 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 845 846 len = msg_hdr.msg_len; 847 frag_off = msg_hdr.frag_off; 848 frag_len = msg_hdr.frag_len; 849 850 if (frag_len && frag_len < len) 851 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 852 853 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 854 wire[0] == SSL3_MT_HELLO_REQUEST) 855 { 856 /* The server may always send 'Hello Request' messages -- 857 * we are doing a handshake anyway now, so ignore them 858 * if their format is correct. Does not count for 859 * 'Finished' MAC. */ 860 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 861 { 862 if (s->msg_callback) 863 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 864 wire, DTLS1_HM_HEADER_LENGTH, s, 865 s->msg_callback_arg); 866 867 s->init_num = 0; 868 goto redo; 869 } 870 else /* Incorrectly formated Hello request */ 871 { 872 al=SSL_AD_UNEXPECTED_MESSAGE; 873 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 874 goto f_err; 875 } 876 } 877 878 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 879 goto f_err; 880 881 /* XDTLS: ressurect this when restart is in place */ 882 s->state=stn; 883 884 if ( frag_len > 0) 885 { 886 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 887 888 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 889 &p[frag_off],frag_len,0); 890 /* XDTLS: fix this--message fragments cannot span multiple packets */ 891 if (i <= 0) 892 { 893 s->rwstate=SSL_READING; 894 *ok = 0; 895 return i; 896 } 897 } 898 else 899 i = 0; 900 901 /* XDTLS: an incorrectly formatted fragment should cause the 902 * handshake to fail */ 903 if (i != (int)frag_len) 904 { 905 al=SSL3_AD_ILLEGAL_PARAMETER; 906 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 907 goto f_err; 908 } 909 910 *ok = 1; 911 912 /* Note that s->init_num is *not* used as current offset in 913 * s->init_buf->data, but as a counter summing up fragments' 914 * lengths: as soon as they sum up to handshake packet 915 * length, we assume we have got all the fragments. */ 916 s->init_num = frag_len; 917 return frag_len; 918 919f_err: 920 ssl3_send_alert(s,SSL3_AL_FATAL,al); 921 s->init_num = 0; 922 923 *ok=0; 924 return(-1); 925 } 926 927int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 928 { 929 unsigned char *p,*d; 930 int i; 931 unsigned long l; 932 933 if (s->state == a) 934 { 935 d=(unsigned char *)s->init_buf->data; 936 p= &(d[DTLS1_HM_HEADER_LENGTH]); 937 938 i=s->method->ssl3_enc->final_finish_mac(s, 939 sender,slen,s->s3->tmp.finish_md); 940 s->s3->tmp.finish_md_len = i; 941 memcpy(p, s->s3->tmp.finish_md, i); 942 p+=i; 943 l=i; 944 945 /* Copy the finished so we can use it for 946 * renegotiation checks 947 */ 948 if(s->type == SSL_ST_CONNECT) 949 { 950 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 951 memcpy(s->s3->previous_client_finished, 952 s->s3->tmp.finish_md, i); 953 s->s3->previous_client_finished_len=i; 954 } 955 else 956 { 957 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 958 memcpy(s->s3->previous_server_finished, 959 s->s3->tmp.finish_md, i); 960 s->s3->previous_server_finished_len=i; 961 } 962 963#ifdef OPENSSL_SYS_WIN16 964 /* MSVC 1.5 does not clear the top bytes of the word unless 965 * I do this. 966 */ 967 l&=0xffff; 968#endif 969 970 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 971 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 972 s->init_off=0; 973 974 /* buffer the message to handle re-xmits */ 975 dtls1_buffer_message(s, 0); 976 977 s->state=b; 978 } 979 980 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 981 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 982 } 983 984/* for these 2 messages, we need to 985 * ssl->enc_read_ctx re-init 986 * ssl->s3->read_sequence zero 987 * ssl->s3->read_mac_secret re-init 988 * ssl->session->read_sym_enc assign 989 * ssl->session->read_compression assign 990 * ssl->session->read_hash assign 991 */ 992int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 993 { 994 unsigned char *p; 995 996 if (s->state == a) 997 { 998 p=(unsigned char *)s->init_buf->data; 999 *p++=SSL3_MT_CCS; 1000 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1001 s->init_num=DTLS1_CCS_HEADER_LENGTH; 1002 1003 if (s->version == DTLS1_BAD_VER) { 1004 s->d1->next_handshake_write_seq++; 1005 s2n(s->d1->handshake_write_seq,p); 1006 s->init_num+=2; 1007 } 1008 1009 s->init_off=0; 1010 1011 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1012 s->d1->handshake_write_seq, 0, 0); 1013 1014 /* buffer the message to handle re-xmits */ 1015 dtls1_buffer_message(s, 1); 1016 1017 s->state=b; 1018 } 1019 1020 /* SSL3_ST_CW_CHANGE_B */ 1021 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1022 } 1023 1024static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1025 { 1026 int n; 1027 unsigned char *p; 1028 1029 n=i2d_X509(x,NULL); 1030 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1031 { 1032 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1033 return 0; 1034 } 1035 p=(unsigned char *)&(buf->data[*l]); 1036 l2n3(n,p); 1037 i2d_X509(x,&p); 1038 *l+=n+3; 1039 1040 return 1; 1041 } 1042unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1043 { 1044 unsigned char *p; 1045 int i; 1046 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1047 BUF_MEM *buf; 1048 1049 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1050 buf=s->init_buf; 1051 if (!BUF_MEM_grow_clean(buf,10)) 1052 { 1053 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1054 return(0); 1055 } 1056 if (x != NULL) 1057 { 1058 X509_STORE_CTX xs_ctx; 1059 1060 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1061 { 1062 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1063 return(0); 1064 } 1065 1066 X509_verify_cert(&xs_ctx); 1067 /* Don't leave errors in the queue */ 1068 ERR_clear_error(); 1069 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1070 { 1071 x = sk_X509_value(xs_ctx.chain, i); 1072 1073 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1074 { 1075 X509_STORE_CTX_cleanup(&xs_ctx); 1076 return 0; 1077 } 1078 } 1079 X509_STORE_CTX_cleanup(&xs_ctx); 1080 } 1081 /* Thawte special :-) */ 1082 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1083 { 1084 x=sk_X509_value(s->ctx->extra_certs,i); 1085 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1086 return 0; 1087 } 1088 1089 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1090 1091 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1092 l2n3(l,p); 1093 l+=3; 1094 p=(unsigned char *)&(buf->data[0]); 1095 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1096 1097 l+=DTLS1_HM_HEADER_LENGTH; 1098 return(l); 1099 } 1100 1101int dtls1_read_failed(SSL *s, int code) 1102 { 1103 if ( code > 0) 1104 { 1105 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1106 return 1; 1107 } 1108 1109 if (!dtls1_is_timer_expired(s)) 1110 { 1111 /* not a timeout, none of our business, 1112 let higher layers handle this. in fact it's probably an error */ 1113 return code; 1114 } 1115 1116#ifndef OPENSSL_NO_HEARTBEATS 1117 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1118#else 1119 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1120#endif 1121 { 1122 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1123 return code; 1124 } 1125 1126#if 0 /* for now, each alert contains only one record number */ 1127 item = pqueue_peek(state->rcvd_records); 1128 if ( item ) 1129 { 1130 /* send an alert immediately for all the missing records */ 1131 } 1132 else 1133#endif 1134 1135#if 0 /* no more alert sending, just retransmit the last set of messages */ 1136 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1137 ssl3_send_alert(s,SSL3_AL_WARNING, 1138 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1139#endif 1140 1141 return dtls1_handle_timeout(s); 1142 } 1143 1144int 1145dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1146 { 1147 /* The index of the retransmission queue actually is the message sequence number, 1148 * since the queue only contains messages of a single handshake. However, the 1149 * ChangeCipherSpec has no message sequence number and so using only the sequence 1150 * will result in the CCS and Finished having the same index. To prevent this, 1151 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1152 * This does not only differ CSS and Finished, it also maintains the order of the 1153 * index (important for priority queues) and fits in the unsigned short variable. 1154 */ 1155 return seq * 2 - is_ccs; 1156 } 1157 1158int 1159dtls1_retransmit_buffered_messages(SSL *s) 1160 { 1161 pqueue sent = s->d1->sent_messages; 1162 piterator iter; 1163 pitem *item; 1164 hm_fragment *frag; 1165 int found = 0; 1166 1167 iter = pqueue_iterator(sent); 1168 1169 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1170 { 1171 frag = (hm_fragment *)item->data; 1172 if ( dtls1_retransmit_message(s, 1173 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1174 0, &found) <= 0 && found) 1175 { 1176 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1177 return -1; 1178 } 1179 } 1180 1181 return 1; 1182 } 1183 1184int 1185dtls1_buffer_message(SSL *s, int is_ccs) 1186 { 1187 pitem *item; 1188 hm_fragment *frag; 1189 unsigned char seq64be[8]; 1190 1191 /* this function is called immediately after a message has 1192 * been serialized */ 1193 OPENSSL_assert(s->init_off == 0); 1194 1195 frag = dtls1_hm_fragment_new(s->init_num, 0); 1196 1197 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1198 1199 if ( is_ccs) 1200 { 1201 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1202 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1203 } 1204 else 1205 { 1206 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1207 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1208 } 1209 1210 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1211 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1212 frag->msg_header.type = s->d1->w_msg_hdr.type; 1213 frag->msg_header.frag_off = 0; 1214 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1215 frag->msg_header.is_ccs = is_ccs; 1216 1217 /* save current state*/ 1218 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1219 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1220 frag->msg_header.saved_retransmit_state.compress = s->compress; 1221 frag->msg_header.saved_retransmit_state.session = s->session; 1222 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1223 1224 memset(seq64be,0,sizeof(seq64be)); 1225 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1226 frag->msg_header.is_ccs)>>8); 1227 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1228 frag->msg_header.is_ccs)); 1229 1230 item = pitem_new(seq64be, frag); 1231 if ( item == NULL) 1232 { 1233 dtls1_hm_fragment_free(frag); 1234 return 0; 1235 } 1236 1237#if 0 1238 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1239 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1240 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1241#endif 1242 1243 pqueue_insert(s->d1->sent_messages, item); 1244 return 1; 1245 } 1246 1247int 1248dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1249 int *found) 1250 { 1251 int ret; 1252 /* XDTLS: for now assuming that read/writes are blocking */ 1253 pitem *item; 1254 hm_fragment *frag ; 1255 unsigned long header_length; 1256 unsigned char seq64be[8]; 1257 struct dtls1_retransmit_state saved_state; 1258 unsigned char save_write_sequence[8]; 1259 1260 /* 1261 OPENSSL_assert(s->init_num == 0); 1262 OPENSSL_assert(s->init_off == 0); 1263 */ 1264 1265 /* XDTLS: the requested message ought to be found, otherwise error */ 1266 memset(seq64be,0,sizeof(seq64be)); 1267 seq64be[6] = (unsigned char)(seq>>8); 1268 seq64be[7] = (unsigned char)seq; 1269 1270 item = pqueue_find(s->d1->sent_messages, seq64be); 1271 if ( item == NULL) 1272 { 1273 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1274 *found = 0; 1275 return 0; 1276 } 1277 1278 *found = 1; 1279 frag = (hm_fragment *)item->data; 1280 1281 if ( frag->msg_header.is_ccs) 1282 header_length = DTLS1_CCS_HEADER_LENGTH; 1283 else 1284 header_length = DTLS1_HM_HEADER_LENGTH; 1285 1286 memcpy(s->init_buf->data, frag->fragment, 1287 frag->msg_header.msg_len + header_length); 1288 s->init_num = frag->msg_header.msg_len + header_length; 1289 1290 dtls1_set_message_header_int(s, frag->msg_header.type, 1291 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1292 frag->msg_header.frag_len); 1293 1294 /* save current state */ 1295 saved_state.enc_write_ctx = s->enc_write_ctx; 1296 saved_state.write_hash = s->write_hash; 1297 saved_state.compress = s->compress; 1298 saved_state.session = s->session; 1299 saved_state.epoch = s->d1->w_epoch; 1300 saved_state.epoch = s->d1->w_epoch; 1301 1302 s->d1->retransmitting = 1; 1303 1304 /* restore state in which the message was originally sent */ 1305 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1306 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1307 s->compress = frag->msg_header.saved_retransmit_state.compress; 1308 s->session = frag->msg_header.saved_retransmit_state.session; 1309 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1310 1311 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1312 { 1313 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1314 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1315 } 1316 1317 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1318 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1319 1320 /* restore current state */ 1321 s->enc_write_ctx = saved_state.enc_write_ctx; 1322 s->write_hash = saved_state.write_hash; 1323 s->compress = saved_state.compress; 1324 s->session = saved_state.session; 1325 s->d1->w_epoch = saved_state.epoch; 1326 1327 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1328 { 1329 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1330 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1331 } 1332 1333 s->d1->retransmitting = 0; 1334 1335 (void)BIO_flush(SSL_get_wbio(s)); 1336 return ret; 1337 } 1338 1339/* call this function when the buffered messages are no longer needed */ 1340void 1341dtls1_clear_record_buffer(SSL *s) 1342 { 1343 pitem *item; 1344 1345 for(item = pqueue_pop(s->d1->sent_messages); 1346 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1347 { 1348 dtls1_hm_fragment_free((hm_fragment *)item->data); 1349 pitem_free(item); 1350 } 1351 } 1352 1353 1354unsigned char * 1355dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1356 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1357 { 1358 /* Don't change sequence numbers while listening */ 1359 if (frag_off == 0 && !s->d1->listen) 1360 { 1361 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1362 s->d1->next_handshake_write_seq++; 1363 } 1364 1365 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1366 frag_off, frag_len); 1367 1368 return p += DTLS1_HM_HEADER_LENGTH; 1369 } 1370 1371 1372/* don't actually do the writing, wait till the MTU has been retrieved */ 1373static void 1374dtls1_set_message_header_int(SSL *s, unsigned char mt, 1375 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1376 unsigned long frag_len) 1377 { 1378 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1379 1380 msg_hdr->type = mt; 1381 msg_hdr->msg_len = len; 1382 msg_hdr->seq = seq_num; 1383 msg_hdr->frag_off = frag_off; 1384 msg_hdr->frag_len = frag_len; 1385 } 1386 1387static void 1388dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1389 unsigned long frag_len) 1390 { 1391 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1392 1393 msg_hdr->frag_off = frag_off; 1394 msg_hdr->frag_len = frag_len; 1395 } 1396 1397static unsigned char * 1398dtls1_write_message_header(SSL *s, unsigned char *p) 1399 { 1400 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1401 1402 *p++ = msg_hdr->type; 1403 l2n3(msg_hdr->msg_len, p); 1404 1405 s2n(msg_hdr->seq, p); 1406 l2n3(msg_hdr->frag_off, p); 1407 l2n3(msg_hdr->frag_len, p); 1408 1409 return p; 1410 } 1411 1412unsigned int 1413dtls1_min_mtu(void) 1414 { 1415 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1416 sizeof(g_probable_mtu[0])) - 1]); 1417 } 1418 1419static unsigned int 1420dtls1_guess_mtu(unsigned int curr_mtu) 1421 { 1422 unsigned int i; 1423 1424 if ( curr_mtu == 0 ) 1425 return g_probable_mtu[0] ; 1426 1427 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1428 if ( curr_mtu > g_probable_mtu[i]) 1429 return g_probable_mtu[i]; 1430 1431 return curr_mtu; 1432 } 1433 1434void 1435dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1436 { 1437 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1438 msg_hdr->type = *(data++); 1439 n2l3(data, msg_hdr->msg_len); 1440 1441 n2s(data, msg_hdr->seq); 1442 n2l3(data, msg_hdr->frag_off); 1443 n2l3(data, msg_hdr->frag_len); 1444 } 1445 1446void 1447dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1448 { 1449 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1450 1451 ccs_hdr->type = *(data++); 1452 } 1453 1454int dtls1_shutdown(SSL *s) 1455 { 1456 int ret; 1457#ifndef OPENSSL_NO_SCTP 1458 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1459 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1460 { 1461 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1462 if (ret < 0) return -1; 1463 1464 if (ret == 0) 1465 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1466 } 1467#endif 1468 ret = ssl3_shutdown(s); 1469#ifndef OPENSSL_NO_SCTP 1470 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1471#endif 1472 return ret; 1473 } 1474 1475#ifndef OPENSSL_NO_HEARTBEATS 1476int 1477dtls1_process_heartbeat(SSL *s) 1478 { 1479 unsigned char *p = &s->s3->rrec.data[0], *pl; 1480 unsigned short hbtype; 1481 unsigned int payload; 1482 unsigned int padding = 16; /* Use minimum padding */ 1483 1484 if (s->msg_callback) 1485 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1486 &s->s3->rrec.data[0], s->s3->rrec.length, 1487 s, s->msg_callback_arg); 1488 1489 /* Read type and payload length first */ 1490 if (1 + 2 + 16 > s->s3->rrec.length) 1491 return 0; /* silently discard */ 1492 hbtype = *p++; 1493 n2s(p, payload); 1494 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1495 return 0; /* silently discard per RFC 6520 sec. 4 */ 1496 pl = p; 1497 1498 if (hbtype == TLS1_HB_REQUEST) 1499 { 1500 unsigned char *buffer, *bp; 1501 unsigned int write_length = 1 /* heartbeat type */ + 1502 2 /* heartbeat length */ + 1503 payload + padding; 1504 int r; 1505 1506 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1507 return 0; 1508 1509 /* Allocate memory for the response, size is 1 byte 1510 * message type, plus 2 bytes payload length, plus 1511 * payload, plus padding 1512 */ 1513 buffer = OPENSSL_malloc(write_length); 1514 bp = buffer; 1515 1516 /* Enter response type, length and copy payload */ 1517 *bp++ = TLS1_HB_RESPONSE; 1518 s2n(payload, bp); 1519 memcpy(bp, pl, payload); 1520 bp += payload; 1521 /* Random padding */ 1522 RAND_pseudo_bytes(bp, padding); 1523 1524 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1525 1526 if (r >= 0 && s->msg_callback) 1527 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1528 buffer, write_length, 1529 s, s->msg_callback_arg); 1530 1531 OPENSSL_free(buffer); 1532 1533 if (r < 0) 1534 return r; 1535 } 1536 else if (hbtype == TLS1_HB_RESPONSE) 1537 { 1538 unsigned int seq; 1539 1540 /* We only send sequence numbers (2 bytes unsigned int), 1541 * and 16 random bytes, so we just try to read the 1542 * sequence number */ 1543 n2s(pl, seq); 1544 1545 if (payload == 18 && seq == s->tlsext_hb_seq) 1546 { 1547 dtls1_stop_timer(s); 1548 s->tlsext_hb_seq++; 1549 s->tlsext_hb_pending = 0; 1550 } 1551 } 1552 1553 return 0; 1554 } 1555 1556int 1557dtls1_heartbeat(SSL *s) 1558 { 1559 unsigned char *buf, *p; 1560 int ret; 1561 unsigned int payload = 18; /* Sequence number + random bytes */ 1562 unsigned int padding = 16; /* Use minimum padding */ 1563 1564 /* Only send if peer supports and accepts HB requests... */ 1565 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1566 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1567 { 1568 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1569 return -1; 1570 } 1571 1572 /* ...and there is none in flight yet... */ 1573 if (s->tlsext_hb_pending) 1574 { 1575 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1576 return -1; 1577 } 1578 1579 /* ...and no handshake in progress. */ 1580 if (SSL_in_init(s) || s->in_handshake) 1581 { 1582 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1583 return -1; 1584 } 1585 1586 /* Check if padding is too long, payload and padding 1587 * must not exceed 2^14 - 3 = 16381 bytes in total. 1588 */ 1589 OPENSSL_assert(payload + padding <= 16381); 1590 1591 /* Create HeartBeat message, we just use a sequence number 1592 * as payload to distuingish different messages and add 1593 * some random stuff. 1594 * - Message Type, 1 byte 1595 * - Payload Length, 2 bytes (unsigned int) 1596 * - Payload, the sequence number (2 bytes uint) 1597 * - Payload, random bytes (16 bytes uint) 1598 * - Padding 1599 */ 1600 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1601 p = buf; 1602 /* Message Type */ 1603 *p++ = TLS1_HB_REQUEST; 1604 /* Payload length (18 bytes here) */ 1605 s2n(payload, p); 1606 /* Sequence number */ 1607 s2n(s->tlsext_hb_seq, p); 1608 /* 16 random bytes */ 1609 RAND_pseudo_bytes(p, 16); 1610 p += 16; 1611 /* Random padding */ 1612 RAND_pseudo_bytes(p, padding); 1613 1614 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1615 if (ret >= 0) 1616 { 1617 if (s->msg_callback) 1618 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1619 buf, 3 + payload + padding, 1620 s, s->msg_callback_arg); 1621 1622 dtls1_start_timer(s); 1623 s->tlsext_hb_pending = 1; 1624 } 1625 1626 OPENSSL_free(buf); 1627 1628 return ret; 1629 } 1630#endif 1631