d1_both.c revision 267104
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 590static int 591dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok) 592 { 593 hm_fragment *frag = NULL; 594 pitem *item = NULL; 595 int i = -1, is_complete; 596 unsigned char seq64be[8]; 597 unsigned long frag_len = msg_hdr->frag_len, max_len; 598 599 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 600 goto err; 601 602 /* Determine maximum allowed message size. Depends on (user set) 603 * maximum certificate length, but 16k is minimum. 604 */ 605 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list) 606 max_len = s->max_cert_list; 607 else 608 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 609 610 if ((msg_hdr->frag_off+frag_len) > max_len) 611 goto err; 612 613 /* Try to find item in queue */ 614 memset(seq64be,0,sizeof(seq64be)); 615 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 616 seq64be[7] = (unsigned char) msg_hdr->seq; 617 item = pqueue_find(s->d1->buffered_messages, seq64be); 618 619 if (item == NULL) 620 { 621 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 622 if ( frag == NULL) 623 goto err; 624 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 625 frag->msg_header.frag_len = frag->msg_header.msg_len; 626 frag->msg_header.frag_off = 0; 627 } 628 else 629 { 630 frag = (hm_fragment*) item->data; 631 if (frag->msg_header.msg_len != msg_hdr->msg_len) 632 { 633 item = NULL; 634 frag = NULL; 635 goto err; 636 } 637 } 638 639 640 /* If message is already reassembled, this must be a 641 * retransmit and can be dropped. 642 */ 643 if (frag->reassembly == NULL) 644 { 645 unsigned char devnull [256]; 646 647 while (frag_len) 648 { 649 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 650 devnull, 651 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 652 if (i<=0) goto err; 653 frag_len -= i; 654 } 655 return DTLS1_HM_FRAGMENT_RETRY; 656 } 657 658 /* read the body of the fragment (header has already been read */ 659 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 660 frag->fragment + msg_hdr->frag_off,frag_len,0); 661 if (i<=0 || (unsigned long)i!=frag_len) 662 goto err; 663 664 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 665 (long)(msg_hdr->frag_off + frag_len)); 666 667 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 668 is_complete); 669 670 if (is_complete) 671 { 672 OPENSSL_free(frag->reassembly); 673 frag->reassembly = NULL; 674 } 675 676 if (item == NULL) 677 { 678 memset(seq64be,0,sizeof(seq64be)); 679 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 680 seq64be[7] = (unsigned char)(msg_hdr->seq); 681 682 item = pitem_new(seq64be, frag); 683 if (item == NULL) 684 { 685 goto err; 686 i = -1; 687 } 688 689 pqueue_insert(s->d1->buffered_messages, item); 690 } 691 692 return DTLS1_HM_FRAGMENT_RETRY; 693 694err: 695 if (frag != NULL) dtls1_hm_fragment_free(frag); 696 if (item != NULL) OPENSSL_free(item); 697 *ok = 0; 698 return i; 699 } 700 701 702static int 703dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 704{ 705 int i=-1; 706 hm_fragment *frag = NULL; 707 pitem *item = NULL; 708 unsigned char seq64be[8]; 709 unsigned long frag_len = msg_hdr->frag_len; 710 711 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 712 goto err; 713 714 /* Try to find item in queue, to prevent duplicate entries */ 715 memset(seq64be,0,sizeof(seq64be)); 716 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 717 seq64be[7] = (unsigned char) msg_hdr->seq; 718 item = pqueue_find(s->d1->buffered_messages, seq64be); 719 720 /* If we already have an entry and this one is a fragment, 721 * don't discard it and rather try to reassemble it. 722 */ 723 if (item != NULL && frag_len < msg_hdr->msg_len) 724 item = NULL; 725 726 /* Discard the message if sequence number was already there, is 727 * too far in the future, already in the queue or if we received 728 * a FINISHED before the SERVER_HELLO, which then must be a stale 729 * retransmit. 730 */ 731 if (msg_hdr->seq <= s->d1->handshake_read_seq || 732 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 733 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 734 { 735 unsigned char devnull [256]; 736 737 while (frag_len) 738 { 739 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 740 devnull, 741 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 742 if (i<=0) goto err; 743 frag_len -= i; 744 } 745 } 746 else 747 { 748 if (frag_len && frag_len < msg_hdr->msg_len) 749 return dtls1_reassemble_fragment(s, msg_hdr, ok); 750 751 frag = dtls1_hm_fragment_new(frag_len, 0); 752 if ( frag == NULL) 753 goto err; 754 755 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 756 757 if (frag_len) 758 { 759 /* read the body of the fragment (header has already been read */ 760 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 761 frag->fragment,frag_len,0); 762 if (i<=0 || (unsigned long)i!=frag_len) 763 goto err; 764 } 765 766 memset(seq64be,0,sizeof(seq64be)); 767 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 768 seq64be[7] = (unsigned char)(msg_hdr->seq); 769 770 item = pitem_new(seq64be, frag); 771 if ( item == NULL) 772 goto err; 773 774 pqueue_insert(s->d1->buffered_messages, item); 775 } 776 777 return DTLS1_HM_FRAGMENT_RETRY; 778 779err: 780 if ( frag != NULL) dtls1_hm_fragment_free(frag); 781 if ( item != NULL) OPENSSL_free(item); 782 *ok = 0; 783 return i; 784 } 785 786 787static long 788dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 789 { 790 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 791 unsigned long len, frag_off, frag_len; 792 int i,al; 793 struct hm_header_st msg_hdr; 794 795 redo: 796 /* see if we have the required fragment already */ 797 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 798 { 799 if (*ok) s->init_num = frag_len; 800 return frag_len; 801 } 802 803 /* read handshake message header */ 804 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 805 DTLS1_HM_HEADER_LENGTH, 0); 806 if (i <= 0) /* nbio, or an error */ 807 { 808 s->rwstate=SSL_READING; 809 *ok = 0; 810 return i; 811 } 812 /* Handshake fails if message header is incomplete */ 813 if (i != DTLS1_HM_HEADER_LENGTH) 814 { 815 al=SSL_AD_UNEXPECTED_MESSAGE; 816 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 817 goto f_err; 818 } 819 820 /* parse the message fragment header */ 821 dtls1_get_message_header(wire, &msg_hdr); 822 823 /* 824 * if this is a future (or stale) message it gets buffered 825 * (or dropped)--no further processing at this time 826 * While listening, we accept seq 1 (ClientHello with cookie) 827 * although we're still expecting seq 0 (ClientHello) 828 */ 829 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 830 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 831 832 len = msg_hdr.msg_len; 833 frag_off = msg_hdr.frag_off; 834 frag_len = msg_hdr.frag_len; 835 836 if (frag_len && frag_len < len) 837 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 838 839 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 840 wire[0] == SSL3_MT_HELLO_REQUEST) 841 { 842 /* The server may always send 'Hello Request' messages -- 843 * we are doing a handshake anyway now, so ignore them 844 * if their format is correct. Does not count for 845 * 'Finished' MAC. */ 846 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 847 { 848 if (s->msg_callback) 849 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 850 wire, DTLS1_HM_HEADER_LENGTH, s, 851 s->msg_callback_arg); 852 853 s->init_num = 0; 854 goto redo; 855 } 856 else /* Incorrectly formated Hello request */ 857 { 858 al=SSL_AD_UNEXPECTED_MESSAGE; 859 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 860 goto f_err; 861 } 862 } 863 864 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 865 goto f_err; 866 867 /* XDTLS: ressurect this when restart is in place */ 868 s->state=stn; 869 870 if ( frag_len > 0) 871 { 872 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 873 874 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 875 &p[frag_off],frag_len,0); 876 /* XDTLS: fix this--message fragments cannot span multiple packets */ 877 if (i <= 0) 878 { 879 s->rwstate=SSL_READING; 880 *ok = 0; 881 return i; 882 } 883 } 884 else 885 i = 0; 886 887 /* XDTLS: an incorrectly formatted fragment should cause the 888 * handshake to fail */ 889 if (i != (int)frag_len) 890 { 891 al=SSL3_AD_ILLEGAL_PARAMETER; 892 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 893 goto f_err; 894 } 895 896 *ok = 1; 897 898 /* Note that s->init_num is *not* used as current offset in 899 * s->init_buf->data, but as a counter summing up fragments' 900 * lengths: as soon as they sum up to handshake packet 901 * length, we assume we have got all the fragments. */ 902 s->init_num = frag_len; 903 return frag_len; 904 905f_err: 906 ssl3_send_alert(s,SSL3_AL_FATAL,al); 907 s->init_num = 0; 908 909 *ok=0; 910 return(-1); 911 } 912 913int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 914 { 915 unsigned char *p,*d; 916 int i; 917 unsigned long l; 918 919 if (s->state == a) 920 { 921 d=(unsigned char *)s->init_buf->data; 922 p= &(d[DTLS1_HM_HEADER_LENGTH]); 923 924 i=s->method->ssl3_enc->final_finish_mac(s, 925 sender,slen,s->s3->tmp.finish_md); 926 s->s3->tmp.finish_md_len = i; 927 memcpy(p, s->s3->tmp.finish_md, i); 928 p+=i; 929 l=i; 930 931 /* Copy the finished so we can use it for 932 * renegotiation checks 933 */ 934 if(s->type == SSL_ST_CONNECT) 935 { 936 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 937 memcpy(s->s3->previous_client_finished, 938 s->s3->tmp.finish_md, i); 939 s->s3->previous_client_finished_len=i; 940 } 941 else 942 { 943 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 944 memcpy(s->s3->previous_server_finished, 945 s->s3->tmp.finish_md, i); 946 s->s3->previous_server_finished_len=i; 947 } 948 949#ifdef OPENSSL_SYS_WIN16 950 /* MSVC 1.5 does not clear the top bytes of the word unless 951 * I do this. 952 */ 953 l&=0xffff; 954#endif 955 956 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 957 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 958 s->init_off=0; 959 960 /* buffer the message to handle re-xmits */ 961 dtls1_buffer_message(s, 0); 962 963 s->state=b; 964 } 965 966 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 967 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 968 } 969 970/* for these 2 messages, we need to 971 * ssl->enc_read_ctx re-init 972 * ssl->s3->read_sequence zero 973 * ssl->s3->read_mac_secret re-init 974 * ssl->session->read_sym_enc assign 975 * ssl->session->read_compression assign 976 * ssl->session->read_hash assign 977 */ 978int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 979 { 980 unsigned char *p; 981 982 if (s->state == a) 983 { 984 p=(unsigned char *)s->init_buf->data; 985 *p++=SSL3_MT_CCS; 986 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 987 s->init_num=DTLS1_CCS_HEADER_LENGTH; 988 989 if (s->version == DTLS1_BAD_VER) { 990 s->d1->next_handshake_write_seq++; 991 s2n(s->d1->handshake_write_seq,p); 992 s->init_num+=2; 993 } 994 995 s->init_off=0; 996 997 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 998 s->d1->handshake_write_seq, 0, 0); 999 1000 /* buffer the message to handle re-xmits */ 1001 dtls1_buffer_message(s, 1); 1002 1003 s->state=b; 1004 } 1005 1006 /* SSL3_ST_CW_CHANGE_B */ 1007 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1008 } 1009 1010static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1011 { 1012 int n; 1013 unsigned char *p; 1014 1015 n=i2d_X509(x,NULL); 1016 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1017 { 1018 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1019 return 0; 1020 } 1021 p=(unsigned char *)&(buf->data[*l]); 1022 l2n3(n,p); 1023 i2d_X509(x,&p); 1024 *l+=n+3; 1025 1026 return 1; 1027 } 1028unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1029 { 1030 unsigned char *p; 1031 int i; 1032 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1033 BUF_MEM *buf; 1034 1035 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1036 buf=s->init_buf; 1037 if (!BUF_MEM_grow_clean(buf,10)) 1038 { 1039 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1040 return(0); 1041 } 1042 if (x != NULL) 1043 { 1044 X509_STORE_CTX xs_ctx; 1045 1046 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1047 { 1048 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1049 return(0); 1050 } 1051 1052 X509_verify_cert(&xs_ctx); 1053 /* Don't leave errors in the queue */ 1054 ERR_clear_error(); 1055 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1056 { 1057 x = sk_X509_value(xs_ctx.chain, i); 1058 1059 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1060 { 1061 X509_STORE_CTX_cleanup(&xs_ctx); 1062 return 0; 1063 } 1064 } 1065 X509_STORE_CTX_cleanup(&xs_ctx); 1066 } 1067 /* Thawte special :-) */ 1068 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1069 { 1070 x=sk_X509_value(s->ctx->extra_certs,i); 1071 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1072 return 0; 1073 } 1074 1075 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1076 1077 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1078 l2n3(l,p); 1079 l+=3; 1080 p=(unsigned char *)&(buf->data[0]); 1081 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1082 1083 l+=DTLS1_HM_HEADER_LENGTH; 1084 return(l); 1085 } 1086 1087int dtls1_read_failed(SSL *s, int code) 1088 { 1089 if ( code > 0) 1090 { 1091 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1092 return 1; 1093 } 1094 1095 if (!dtls1_is_timer_expired(s)) 1096 { 1097 /* not a timeout, none of our business, 1098 let higher layers handle this. in fact it's probably an error */ 1099 return code; 1100 } 1101 1102#ifndef OPENSSL_NO_HEARTBEATS 1103 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1104#else 1105 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1106#endif 1107 { 1108 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1109 return code; 1110 } 1111 1112#if 0 /* for now, each alert contains only one record number */ 1113 item = pqueue_peek(state->rcvd_records); 1114 if ( item ) 1115 { 1116 /* send an alert immediately for all the missing records */ 1117 } 1118 else 1119#endif 1120 1121#if 0 /* no more alert sending, just retransmit the last set of messages */ 1122 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1123 ssl3_send_alert(s,SSL3_AL_WARNING, 1124 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1125#endif 1126 1127 return dtls1_handle_timeout(s); 1128 } 1129 1130int 1131dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1132 { 1133 /* The index of the retransmission queue actually is the message sequence number, 1134 * since the queue only contains messages of a single handshake. However, the 1135 * ChangeCipherSpec has no message sequence number and so using only the sequence 1136 * will result in the CCS and Finished having the same index. To prevent this, 1137 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1138 * This does not only differ CSS and Finished, it also maintains the order of the 1139 * index (important for priority queues) and fits in the unsigned short variable. 1140 */ 1141 return seq * 2 - is_ccs; 1142 } 1143 1144int 1145dtls1_retransmit_buffered_messages(SSL *s) 1146 { 1147 pqueue sent = s->d1->sent_messages; 1148 piterator iter; 1149 pitem *item; 1150 hm_fragment *frag; 1151 int found = 0; 1152 1153 iter = pqueue_iterator(sent); 1154 1155 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1156 { 1157 frag = (hm_fragment *)item->data; 1158 if ( dtls1_retransmit_message(s, 1159 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1160 0, &found) <= 0 && found) 1161 { 1162 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1163 return -1; 1164 } 1165 } 1166 1167 return 1; 1168 } 1169 1170int 1171dtls1_buffer_message(SSL *s, int is_ccs) 1172 { 1173 pitem *item; 1174 hm_fragment *frag; 1175 unsigned char seq64be[8]; 1176 1177 /* this function is called immediately after a message has 1178 * been serialized */ 1179 OPENSSL_assert(s->init_off == 0); 1180 1181 frag = dtls1_hm_fragment_new(s->init_num, 0); 1182 1183 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1184 1185 if ( is_ccs) 1186 { 1187 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1188 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1189 } 1190 else 1191 { 1192 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1193 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1194 } 1195 1196 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1197 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1198 frag->msg_header.type = s->d1->w_msg_hdr.type; 1199 frag->msg_header.frag_off = 0; 1200 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1201 frag->msg_header.is_ccs = is_ccs; 1202 1203 /* save current state*/ 1204 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1205 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1206 frag->msg_header.saved_retransmit_state.compress = s->compress; 1207 frag->msg_header.saved_retransmit_state.session = s->session; 1208 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1209 1210 memset(seq64be,0,sizeof(seq64be)); 1211 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1212 frag->msg_header.is_ccs)>>8); 1213 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1214 frag->msg_header.is_ccs)); 1215 1216 item = pitem_new(seq64be, frag); 1217 if ( item == NULL) 1218 { 1219 dtls1_hm_fragment_free(frag); 1220 return 0; 1221 } 1222 1223#if 0 1224 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1225 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1226 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1227#endif 1228 1229 pqueue_insert(s->d1->sent_messages, item); 1230 return 1; 1231 } 1232 1233int 1234dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1235 int *found) 1236 { 1237 int ret; 1238 /* XDTLS: for now assuming that read/writes are blocking */ 1239 pitem *item; 1240 hm_fragment *frag ; 1241 unsigned long header_length; 1242 unsigned char seq64be[8]; 1243 struct dtls1_retransmit_state saved_state; 1244 unsigned char save_write_sequence[8]; 1245 1246 /* 1247 OPENSSL_assert(s->init_num == 0); 1248 OPENSSL_assert(s->init_off == 0); 1249 */ 1250 1251 /* XDTLS: the requested message ought to be found, otherwise error */ 1252 memset(seq64be,0,sizeof(seq64be)); 1253 seq64be[6] = (unsigned char)(seq>>8); 1254 seq64be[7] = (unsigned char)seq; 1255 1256 item = pqueue_find(s->d1->sent_messages, seq64be); 1257 if ( item == NULL) 1258 { 1259 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1260 *found = 0; 1261 return 0; 1262 } 1263 1264 *found = 1; 1265 frag = (hm_fragment *)item->data; 1266 1267 if ( frag->msg_header.is_ccs) 1268 header_length = DTLS1_CCS_HEADER_LENGTH; 1269 else 1270 header_length = DTLS1_HM_HEADER_LENGTH; 1271 1272 memcpy(s->init_buf->data, frag->fragment, 1273 frag->msg_header.msg_len + header_length); 1274 s->init_num = frag->msg_header.msg_len + header_length; 1275 1276 dtls1_set_message_header_int(s, frag->msg_header.type, 1277 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1278 frag->msg_header.frag_len); 1279 1280 /* save current state */ 1281 saved_state.enc_write_ctx = s->enc_write_ctx; 1282 saved_state.write_hash = s->write_hash; 1283 saved_state.compress = s->compress; 1284 saved_state.session = s->session; 1285 saved_state.epoch = s->d1->w_epoch; 1286 saved_state.epoch = s->d1->w_epoch; 1287 1288 s->d1->retransmitting = 1; 1289 1290 /* restore state in which the message was originally sent */ 1291 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1292 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1293 s->compress = frag->msg_header.saved_retransmit_state.compress; 1294 s->session = frag->msg_header.saved_retransmit_state.session; 1295 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1296 1297 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1298 { 1299 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1300 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1301 } 1302 1303 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1304 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1305 1306 /* restore current state */ 1307 s->enc_write_ctx = saved_state.enc_write_ctx; 1308 s->write_hash = saved_state.write_hash; 1309 s->compress = saved_state.compress; 1310 s->session = saved_state.session; 1311 s->d1->w_epoch = saved_state.epoch; 1312 1313 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1314 { 1315 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1316 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1317 } 1318 1319 s->d1->retransmitting = 0; 1320 1321 (void)BIO_flush(SSL_get_wbio(s)); 1322 return ret; 1323 } 1324 1325/* call this function when the buffered messages are no longer needed */ 1326void 1327dtls1_clear_record_buffer(SSL *s) 1328 { 1329 pitem *item; 1330 1331 for(item = pqueue_pop(s->d1->sent_messages); 1332 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1333 { 1334 dtls1_hm_fragment_free((hm_fragment *)item->data); 1335 pitem_free(item); 1336 } 1337 } 1338 1339 1340unsigned char * 1341dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1342 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1343 { 1344 /* Don't change sequence numbers while listening */ 1345 if (frag_off == 0 && !s->d1->listen) 1346 { 1347 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1348 s->d1->next_handshake_write_seq++; 1349 } 1350 1351 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1352 frag_off, frag_len); 1353 1354 return p += DTLS1_HM_HEADER_LENGTH; 1355 } 1356 1357 1358/* don't actually do the writing, wait till the MTU has been retrieved */ 1359static void 1360dtls1_set_message_header_int(SSL *s, unsigned char mt, 1361 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1362 unsigned long frag_len) 1363 { 1364 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1365 1366 msg_hdr->type = mt; 1367 msg_hdr->msg_len = len; 1368 msg_hdr->seq = seq_num; 1369 msg_hdr->frag_off = frag_off; 1370 msg_hdr->frag_len = frag_len; 1371 } 1372 1373static void 1374dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1375 unsigned long frag_len) 1376 { 1377 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1378 1379 msg_hdr->frag_off = frag_off; 1380 msg_hdr->frag_len = frag_len; 1381 } 1382 1383static unsigned char * 1384dtls1_write_message_header(SSL *s, unsigned char *p) 1385 { 1386 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1387 1388 *p++ = msg_hdr->type; 1389 l2n3(msg_hdr->msg_len, p); 1390 1391 s2n(msg_hdr->seq, p); 1392 l2n3(msg_hdr->frag_off, p); 1393 l2n3(msg_hdr->frag_len, p); 1394 1395 return p; 1396 } 1397 1398unsigned int 1399dtls1_min_mtu(void) 1400 { 1401 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1402 sizeof(g_probable_mtu[0])) - 1]); 1403 } 1404 1405static unsigned int 1406dtls1_guess_mtu(unsigned int curr_mtu) 1407 { 1408 unsigned int i; 1409 1410 if ( curr_mtu == 0 ) 1411 return g_probable_mtu[0] ; 1412 1413 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1414 if ( curr_mtu > g_probable_mtu[i]) 1415 return g_probable_mtu[i]; 1416 1417 return curr_mtu; 1418 } 1419 1420void 1421dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1422 { 1423 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1424 msg_hdr->type = *(data++); 1425 n2l3(data, msg_hdr->msg_len); 1426 1427 n2s(data, msg_hdr->seq); 1428 n2l3(data, msg_hdr->frag_off); 1429 n2l3(data, msg_hdr->frag_len); 1430 } 1431 1432void 1433dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1434 { 1435 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1436 1437 ccs_hdr->type = *(data++); 1438 } 1439 1440int dtls1_shutdown(SSL *s) 1441 { 1442 int ret; 1443#ifndef OPENSSL_NO_SCTP 1444 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1445 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1446 { 1447 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1448 if (ret < 0) return -1; 1449 1450 if (ret == 0) 1451 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1452 } 1453#endif 1454 ret = ssl3_shutdown(s); 1455#ifndef OPENSSL_NO_SCTP 1456 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1457#endif 1458 return ret; 1459 } 1460 1461#ifndef OPENSSL_NO_HEARTBEATS 1462int 1463dtls1_process_heartbeat(SSL *s) 1464 { 1465 unsigned char *p = &s->s3->rrec.data[0], *pl; 1466 unsigned short hbtype; 1467 unsigned int payload; 1468 unsigned int padding = 16; /* Use minimum padding */ 1469 1470 if (s->msg_callback) 1471 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1472 &s->s3->rrec.data[0], s->s3->rrec.length, 1473 s, s->msg_callback_arg); 1474 1475 /* Read type and payload length first */ 1476 if (1 + 2 + 16 > s->s3->rrec.length) 1477 return 0; /* silently discard */ 1478 hbtype = *p++; 1479 n2s(p, payload); 1480 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1481 return 0; /* silently discard per RFC 6520 sec. 4 */ 1482 pl = p; 1483 1484 if (hbtype == TLS1_HB_REQUEST) 1485 { 1486 unsigned char *buffer, *bp; 1487 unsigned int write_length = 1 /* heartbeat type */ + 1488 2 /* heartbeat length */ + 1489 payload + padding; 1490 int r; 1491 1492 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1493 return 0; 1494 1495 /* Allocate memory for the response, size is 1 byte 1496 * message type, plus 2 bytes payload length, plus 1497 * payload, plus padding 1498 */ 1499 buffer = OPENSSL_malloc(write_length); 1500 bp = buffer; 1501 1502 /* Enter response type, length and copy payload */ 1503 *bp++ = TLS1_HB_RESPONSE; 1504 s2n(payload, bp); 1505 memcpy(bp, pl, payload); 1506 bp += payload; 1507 /* Random padding */ 1508 RAND_pseudo_bytes(bp, padding); 1509 1510 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1511 1512 if (r >= 0 && s->msg_callback) 1513 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1514 buffer, write_length, 1515 s, s->msg_callback_arg); 1516 1517 OPENSSL_free(buffer); 1518 1519 if (r < 0) 1520 return r; 1521 } 1522 else if (hbtype == TLS1_HB_RESPONSE) 1523 { 1524 unsigned int seq; 1525 1526 /* We only send sequence numbers (2 bytes unsigned int), 1527 * and 16 random bytes, so we just try to read the 1528 * sequence number */ 1529 n2s(pl, seq); 1530 1531 if (payload == 18 && seq == s->tlsext_hb_seq) 1532 { 1533 dtls1_stop_timer(s); 1534 s->tlsext_hb_seq++; 1535 s->tlsext_hb_pending = 0; 1536 } 1537 } 1538 1539 return 0; 1540 } 1541 1542int 1543dtls1_heartbeat(SSL *s) 1544 { 1545 unsigned char *buf, *p; 1546 int ret; 1547 unsigned int payload = 18; /* Sequence number + random bytes */ 1548 unsigned int padding = 16; /* Use minimum padding */ 1549 1550 /* Only send if peer supports and accepts HB requests... */ 1551 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1552 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1553 { 1554 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1555 return -1; 1556 } 1557 1558 /* ...and there is none in flight yet... */ 1559 if (s->tlsext_hb_pending) 1560 { 1561 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1562 return -1; 1563 } 1564 1565 /* ...and no handshake in progress. */ 1566 if (SSL_in_init(s) || s->in_handshake) 1567 { 1568 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1569 return -1; 1570 } 1571 1572 /* Check if padding is too long, payload and padding 1573 * must not exceed 2^14 - 3 = 16381 bytes in total. 1574 */ 1575 OPENSSL_assert(payload + padding <= 16381); 1576 1577 /* Create HeartBeat message, we just use a sequence number 1578 * as payload to distuingish different messages and add 1579 * some random stuff. 1580 * - Message Type, 1 byte 1581 * - Payload Length, 2 bytes (unsigned int) 1582 * - Payload, the sequence number (2 bytes uint) 1583 * - Payload, random bytes (16 bytes uint) 1584 * - Padding 1585 */ 1586 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1587 p = buf; 1588 /* Message Type */ 1589 *p++ = TLS1_HB_REQUEST; 1590 /* Payload length (18 bytes here) */ 1591 s2n(payload, p); 1592 /* Sequence number */ 1593 s2n(s->tlsext_hb_seq, p); 1594 /* 16 random bytes */ 1595 RAND_pseudo_bytes(p, 16); 1596 p += 16; 1597 /* Random padding */ 1598 RAND_pseudo_bytes(p, padding); 1599 1600 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1601 if (ret >= 0) 1602 { 1603 if (s->msg_callback) 1604 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1605 buf, 3 + payload + padding, 1606 s, s->msg_callback_arg); 1607 1608 dtls1_start_timer(s); 1609 s->tlsext_hb_pending = 1; 1610 } 1611 1612 OPENSSL_free(buf); 1613 1614 return ret; 1615 } 1616#endif 1617