d1_both.c revision 267258
1/* ssl/d1_both.c */ 2/* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core@openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116#include <limits.h> 117#include <string.h> 118#include <stdio.h> 119#include "ssl_locl.h" 120#include <openssl/buffer.h> 121#include <openssl/rand.h> 122#include <openssl/objects.h> 123#include <openssl/evp.h> 124#include <openssl/x509.h> 125 126#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 127 128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 129 if ((end) - (start) <= 8) { \ 130 long ii; \ 131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 132 } else { \ 133 long ii; \ 134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 137 } } 138 139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 140 long ii; \ 141 OPENSSL_assert((msg_len) > 0); \ 142 is_complete = 1; \ 143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 146 147#if 0 148#define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \ 149 long ii; \ 150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \ 151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \ 152 printf("\n"); } 153#endif 154 155static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80}; 156static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f}; 157 158/* XDTLS: figure out the right values */ 159static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 160 161static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 162static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 163 unsigned long frag_len); 164static unsigned char *dtls1_write_message_header(SSL *s, 165 unsigned char *p); 166static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 167 unsigned long len, unsigned short seq_num, unsigned long frag_off, 168 unsigned long frag_len); 169static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 170 long max, int *ok); 171 172static hm_fragment * 173dtls1_hm_fragment_new(unsigned long frag_len, int reassembly) 174 { 175 hm_fragment *frag = NULL; 176 unsigned char *buf = NULL; 177 unsigned char *bitmask = NULL; 178 179 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 180 if ( frag == NULL) 181 return NULL; 182 183 if (frag_len) 184 { 185 buf = (unsigned char *)OPENSSL_malloc(frag_len); 186 if ( buf == NULL) 187 { 188 OPENSSL_free(frag); 189 return NULL; 190 } 191 } 192 193 /* zero length fragment gets zero frag->fragment */ 194 frag->fragment = buf; 195 196 /* Initialize reassembly bitmask if necessary */ 197 if (reassembly) 198 { 199 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) 201 { 202 if (buf != NULL) OPENSSL_free(buf); 203 OPENSSL_free(frag); 204 return NULL; 205 } 206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 207 } 208 209 frag->reassembly = bitmask; 210 211 return frag; 212 } 213 214static void 215dtls1_hm_fragment_free(hm_fragment *frag) 216 { 217 218 if (frag->msg_header.is_ccs) 219 { 220 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx); 221 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash); 222 } 223 if (frag->fragment) OPENSSL_free(frag->fragment); 224 if (frag->reassembly) OPENSSL_free(frag->reassembly); 225 OPENSSL_free(frag); 226 } 227 228/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 229int dtls1_do_write(SSL *s, int type) 230 { 231 int ret; 232 int curr_mtu; 233 unsigned int len, frag_off, mac_size, blocksize; 234 235 /* AHA! Figure out the MTU, and stick to the right size */ 236 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 237 { 238 s->d1->mtu = 239 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 240 241 /* I've seen the kernel return bogus numbers when it doesn't know 242 * (initial write), so just make sure we have a reasonable number */ 243 if (s->d1->mtu < dtls1_min_mtu()) 244 { 245 s->d1->mtu = 0; 246 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 247 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 248 s->d1->mtu, NULL); 249 } 250 } 251#if 0 252 mtu = s->d1->mtu; 253 254 fprintf(stderr, "using MTU = %d\n", mtu); 255 256 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 257 258 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 259 260 if ( curr_mtu > 0) 261 mtu = curr_mtu; 262 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0) 263 return ret; 264 265 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) 266 { 267 ret = BIO_flush(SSL_get_wbio(s)); 268 if ( ret <= 0) 269 return ret; 270 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 271 } 272#endif 273 274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */ 275 276 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 277 OPENSSL_assert(s->init_num == 278 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 279 280 if (s->write_hash) 281 mac_size = EVP_MD_CTX_size(s->write_hash); 282 else 283 mac_size = 0; 284 285 if (s->enc_write_ctx && 286 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 287 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 288 else 289 blocksize = 0; 290 291 frag_off = 0; 292 while( s->init_num) 293 { 294 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 295 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; 296 297 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH) 298 { 299 /* grr.. we could get an error if MTU picked was wrong */ 300 ret = BIO_flush(SSL_get_wbio(s)); 301 if ( ret <= 0) 302 return ret; 303 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 304 mac_size - blocksize; 305 } 306 307 if ( s->init_num > curr_mtu) 308 len = curr_mtu; 309 else 310 len = s->init_num; 311 312 313 /* XDTLS: this function is too long. split out the CCS part */ 314 if ( type == SSL3_RT_HANDSHAKE) 315 { 316 if ( s->init_off != 0) 317 { 318 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 319 s->init_off -= DTLS1_HM_HEADER_LENGTH; 320 s->init_num += DTLS1_HM_HEADER_LENGTH; 321 322 if ( s->init_num > curr_mtu) 323 len = curr_mtu; 324 else 325 len = s->init_num; 326 } 327 328 dtls1_fix_message_header(s, frag_off, 329 len - DTLS1_HM_HEADER_LENGTH); 330 331 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 332 333 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 334 } 335 336 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 337 len); 338 if (ret < 0) 339 { 340 /* might need to update MTU here, but we don't know 341 * which previous packet caused the failure -- so can't 342 * really retransmit anything. continue as if everything 343 * is fine and wait for an alert to handle the 344 * retransmit 345 */ 346 if ( BIO_ctrl(SSL_get_wbio(s), 347 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 ) 348 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 349 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 350 else 351 return(-1); 352 } 353 else 354 { 355 356 /* bad if this assert fails, only part of the handshake 357 * message got sent. but why would this happen? */ 358 OPENSSL_assert(len == (unsigned int)ret); 359 360 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 361 { 362 /* should not be done for 'Hello Request's, but in that case 363 * we'll ignore the result anyway */ 364 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 365 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 366 int xlen; 367 368 if (frag_off == 0 && s->version != DTLS1_BAD_VER) 369 { 370 /* reconstruct message header is if it 371 * is being sent in single fragment */ 372 *p++ = msg_hdr->type; 373 l2n3(msg_hdr->msg_len,p); 374 s2n (msg_hdr->seq,p); 375 l2n3(0,p); 376 l2n3(msg_hdr->msg_len,p); 377 p -= DTLS1_HM_HEADER_LENGTH; 378 xlen = ret; 379 } 380 else 381 { 382 p += DTLS1_HM_HEADER_LENGTH; 383 xlen = ret - DTLS1_HM_HEADER_LENGTH; 384 } 385 386 ssl3_finish_mac(s, p, xlen); 387 } 388 389 if (ret == s->init_num) 390 { 391 if (s->msg_callback) 392 s->msg_callback(1, s->version, type, s->init_buf->data, 393 (size_t)(s->init_off + s->init_num), s, 394 s->msg_callback_arg); 395 396 s->init_off = 0; /* done writing this message */ 397 s->init_num = 0; 398 399 return(1); 400 } 401 s->init_off+=ret; 402 s->init_num-=ret; 403 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 404 } 405 } 406 return(0); 407 } 408 409 410/* Obtain handshake message of message type 'mt' (any if mt == -1), 411 * maximum acceptable body length 'max'. 412 * Read an entire handshake message. Handshake messages arrive in 413 * fragments. 414 */ 415long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 416 { 417 int i, al; 418 struct hm_header_st *msg_hdr; 419 unsigned char *p; 420 unsigned long msg_len; 421 422 /* s3->tmp is used to store messages that are unexpected, caused 423 * by the absence of an optional handshake message */ 424 if (s->s3->tmp.reuse_message) 425 { 426 s->s3->tmp.reuse_message=0; 427 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 428 { 429 al=SSL_AD_UNEXPECTED_MESSAGE; 430 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 431 goto f_err; 432 } 433 *ok=1; 434 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 435 s->init_num = (int)s->s3->tmp.message_size; 436 return s->init_num; 437 } 438 439 msg_hdr = &s->d1->r_msg_hdr; 440 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 441 442again: 443 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 444 if ( i == DTLS1_HM_BAD_FRAGMENT || 445 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 446 goto again; 447 else if ( i <= 0 && !*ok) 448 return i; 449 450 p = (unsigned char *)s->init_buf->data; 451 msg_len = msg_hdr->msg_len; 452 453 /* reconstruct message header */ 454 *(p++) = msg_hdr->type; 455 l2n3(msg_len,p); 456 s2n (msg_hdr->seq,p); 457 l2n3(0,p); 458 l2n3(msg_len,p); 459 if (s->version != DTLS1_BAD_VER) { 460 p -= DTLS1_HM_HEADER_LENGTH; 461 msg_len += DTLS1_HM_HEADER_LENGTH; 462 } 463 464 ssl3_finish_mac(s, p, msg_len); 465 if (s->msg_callback) 466 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 467 p, msg_len, 468 s, s->msg_callback_arg); 469 470 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 471 472 /* Don't change sequence numbers while listening */ 473 if (!s->d1->listen) 474 s->d1->handshake_read_seq++; 475 476 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 477 return s->init_num; 478 479f_err: 480 ssl3_send_alert(s,SSL3_AL_FATAL,al); 481 *ok = 0; 482 return -1; 483 } 484 485 486static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 487 { 488 size_t frag_off,frag_len,msg_len; 489 490 msg_len = msg_hdr->msg_len; 491 frag_off = msg_hdr->frag_off; 492 frag_len = msg_hdr->frag_len; 493 494 /* sanity checking */ 495 if ( (frag_off+frag_len) > msg_len) 496 { 497 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 498 return SSL_AD_ILLEGAL_PARAMETER; 499 } 500 501 if ( (frag_off+frag_len) > (unsigned long)max) 502 { 503 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 504 return SSL_AD_ILLEGAL_PARAMETER; 505 } 506 507 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 508 { 509 /* msg_len is limited to 2^24, but is effectively checked 510 * against max above */ 511 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH)) 512 { 513 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 514 return SSL_AD_INTERNAL_ERROR; 515 } 516 517 s->s3->tmp.message_size = msg_len; 518 s->d1->r_msg_hdr.msg_len = msg_len; 519 s->s3->tmp.message_type = msg_hdr->type; 520 s->d1->r_msg_hdr.type = msg_hdr->type; 521 s->d1->r_msg_hdr.seq = msg_hdr->seq; 522 } 523 else if (msg_len != s->d1->r_msg_hdr.msg_len) 524 { 525 /* They must be playing with us! BTW, failure to enforce 526 * upper limit would open possibility for buffer overrun. */ 527 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 528 return SSL_AD_ILLEGAL_PARAMETER; 529 } 530 531 return 0; /* no error */ 532 } 533 534 535static int 536dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 537 { 538 /* (0) check whether the desired fragment is available 539 * if so: 540 * (1) copy over the fragment to s->init_buf->data[] 541 * (2) update s->init_num 542 */ 543 pitem *item; 544 hm_fragment *frag; 545 int al; 546 547 *ok = 0; 548 item = pqueue_peek(s->d1->buffered_messages); 549 if ( item == NULL) 550 return 0; 551 552 frag = (hm_fragment *)item->data; 553 554 /* Don't return if reassembly still in progress */ 555 if (frag->reassembly != NULL) 556 return 0; 557 558 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 559 { 560 unsigned long frag_len = frag->msg_header.frag_len; 561 pqueue_pop(s->d1->buffered_messages); 562 563 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 564 565 if (al==0) /* no alert */ 566 { 567 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 568 memcpy(&p[frag->msg_header.frag_off], 569 frag->fragment,frag->msg_header.frag_len); 570 } 571 572 dtls1_hm_fragment_free(frag); 573 pitem_free(item); 574 575 if (al==0) 576 { 577 *ok = 1; 578 return frag_len; 579 } 580 581 ssl3_send_alert(s,SSL3_AL_FATAL,al); 582 s->init_num = 0; 583 *ok = 0; 584 return -1; 585 } 586 else 587 return 0; 588 } 589 590 591static int 592dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok) 593 { 594 hm_fragment *frag = NULL; 595 pitem *item = NULL; 596 int i = -1, is_complete; 597 unsigned char seq64be[8]; 598 unsigned long frag_len = msg_hdr->frag_len, max_len; 599 600 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 601 goto err; 602 603 /* Determine maximum allowed message size. Depends on (user set) 604 * maximum certificate length, but 16k is minimum. 605 */ 606 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list) 607 max_len = s->max_cert_list; 608 else 609 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 610 611 if ((msg_hdr->frag_off+frag_len) > max_len) 612 goto err; 613 614 /* Try to find item in queue */ 615 memset(seq64be,0,sizeof(seq64be)); 616 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 617 seq64be[7] = (unsigned char) msg_hdr->seq; 618 item = pqueue_find(s->d1->buffered_messages, seq64be); 619 620 if (item == NULL) 621 { 622 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 623 if ( frag == NULL) 624 goto err; 625 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 626 frag->msg_header.frag_len = frag->msg_header.msg_len; 627 frag->msg_header.frag_off = 0; 628 } 629 else 630 { 631 frag = (hm_fragment*) item->data; 632 if (frag->msg_header.msg_len != msg_hdr->msg_len) 633 { 634 item = NULL; 635 frag = NULL; 636 goto err; 637 } 638 } 639 640 641 /* If message is already reassembled, this must be a 642 * retransmit and can be dropped. 643 */ 644 if (frag->reassembly == NULL) 645 { 646 unsigned char devnull [256]; 647 648 while (frag_len) 649 { 650 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 651 devnull, 652 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 653 if (i<=0) goto err; 654 frag_len -= i; 655 } 656 return DTLS1_HM_FRAGMENT_RETRY; 657 } 658 659 /* read the body of the fragment (header has already been read */ 660 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 661 frag->fragment + msg_hdr->frag_off,frag_len,0); 662 if (i<=0 || (unsigned long)i!=frag_len) 663 goto err; 664 665 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 666 (long)(msg_hdr->frag_off + frag_len)); 667 668 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 669 is_complete); 670 671 if (is_complete) 672 { 673 OPENSSL_free(frag->reassembly); 674 frag->reassembly = NULL; 675 } 676 677 if (item == NULL) 678 { 679 memset(seq64be,0,sizeof(seq64be)); 680 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 681 seq64be[7] = (unsigned char)(msg_hdr->seq); 682 683 item = pitem_new(seq64be, frag); 684 if (item == NULL) 685 { 686 i = -1; 687 goto err; 688 } 689 690 pqueue_insert(s->d1->buffered_messages, item); 691 } 692 693 return DTLS1_HM_FRAGMENT_RETRY; 694 695err: 696 if (frag != NULL) dtls1_hm_fragment_free(frag); 697 if (item != NULL) OPENSSL_free(item); 698 *ok = 0; 699 return i; 700 } 701 702 703static int 704dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 705{ 706 int i=-1; 707 hm_fragment *frag = NULL; 708 pitem *item = NULL; 709 unsigned char seq64be[8]; 710 unsigned long frag_len = msg_hdr->frag_len; 711 712 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 713 goto err; 714 715 /* Try to find item in queue, to prevent duplicate entries */ 716 memset(seq64be,0,sizeof(seq64be)); 717 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 718 seq64be[7] = (unsigned char) msg_hdr->seq; 719 item = pqueue_find(s->d1->buffered_messages, seq64be); 720 721 /* If we already have an entry and this one is a fragment, 722 * don't discard it and rather try to reassemble it. 723 */ 724 if (item != NULL && frag_len < msg_hdr->msg_len) 725 item = NULL; 726 727 /* Discard the message if sequence number was already there, is 728 * too far in the future, already in the queue or if we received 729 * a FINISHED before the SERVER_HELLO, which then must be a stale 730 * retransmit. 731 */ 732 if (msg_hdr->seq <= s->d1->handshake_read_seq || 733 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 734 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 735 { 736 unsigned char devnull [256]; 737 738 while (frag_len) 739 { 740 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 741 devnull, 742 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 743 if (i<=0) goto err; 744 frag_len -= i; 745 } 746 } 747 else 748 { 749 if (frag_len && frag_len < msg_hdr->msg_len) 750 return dtls1_reassemble_fragment(s, msg_hdr, ok); 751 752 frag = dtls1_hm_fragment_new(frag_len, 0); 753 if ( frag == NULL) 754 goto err; 755 756 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 757 758 if (frag_len) 759 { 760 /* read the body of the fragment (header has already been read */ 761 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 762 frag->fragment,frag_len,0); 763 if (i<=0 || (unsigned long)i!=frag_len) 764 goto err; 765 } 766 767 memset(seq64be,0,sizeof(seq64be)); 768 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 769 seq64be[7] = (unsigned char)(msg_hdr->seq); 770 771 item = pitem_new(seq64be, frag); 772 if ( item == NULL) 773 goto err; 774 775 pqueue_insert(s->d1->buffered_messages, item); 776 } 777 778 return DTLS1_HM_FRAGMENT_RETRY; 779 780err: 781 if ( frag != NULL) dtls1_hm_fragment_free(frag); 782 if ( item != NULL) OPENSSL_free(item); 783 *ok = 0; 784 return i; 785 } 786 787 788static long 789dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 790 { 791 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 792 unsigned long len, frag_off, frag_len; 793 int i,al; 794 struct hm_header_st msg_hdr; 795 796 redo: 797 /* see if we have the required fragment already */ 798 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 799 { 800 if (*ok) s->init_num = frag_len; 801 return frag_len; 802 } 803 804 /* read handshake message header */ 805 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 806 DTLS1_HM_HEADER_LENGTH, 0); 807 if (i <= 0) /* nbio, or an error */ 808 { 809 s->rwstate=SSL_READING; 810 *ok = 0; 811 return i; 812 } 813 /* Handshake fails if message header is incomplete */ 814 if (i != DTLS1_HM_HEADER_LENGTH) 815 { 816 al=SSL_AD_UNEXPECTED_MESSAGE; 817 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 818 goto f_err; 819 } 820 821 /* parse the message fragment header */ 822 dtls1_get_message_header(wire, &msg_hdr); 823 824 /* 825 * if this is a future (or stale) message it gets buffered 826 * (or dropped)--no further processing at this time 827 * While listening, we accept seq 1 (ClientHello with cookie) 828 * although we're still expecting seq 0 (ClientHello) 829 */ 830 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 831 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 832 833 len = msg_hdr.msg_len; 834 frag_off = msg_hdr.frag_off; 835 frag_len = msg_hdr.frag_len; 836 837 if (frag_len && frag_len < len) 838 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 839 840 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 841 wire[0] == SSL3_MT_HELLO_REQUEST) 842 { 843 /* The server may always send 'Hello Request' messages -- 844 * we are doing a handshake anyway now, so ignore them 845 * if their format is correct. Does not count for 846 * 'Finished' MAC. */ 847 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 848 { 849 if (s->msg_callback) 850 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 851 wire, DTLS1_HM_HEADER_LENGTH, s, 852 s->msg_callback_arg); 853 854 s->init_num = 0; 855 goto redo; 856 } 857 else /* Incorrectly formated Hello request */ 858 { 859 al=SSL_AD_UNEXPECTED_MESSAGE; 860 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 861 goto f_err; 862 } 863 } 864 865 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 866 goto f_err; 867 868 /* XDTLS: ressurect this when restart is in place */ 869 s->state=stn; 870 871 if ( frag_len > 0) 872 { 873 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 874 875 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 876 &p[frag_off],frag_len,0); 877 /* XDTLS: fix this--message fragments cannot span multiple packets */ 878 if (i <= 0) 879 { 880 s->rwstate=SSL_READING; 881 *ok = 0; 882 return i; 883 } 884 } 885 else 886 i = 0; 887 888 /* XDTLS: an incorrectly formatted fragment should cause the 889 * handshake to fail */ 890 if (i != (int)frag_len) 891 { 892 al=SSL3_AD_ILLEGAL_PARAMETER; 893 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 894 goto f_err; 895 } 896 897 *ok = 1; 898 899 /* Note that s->init_num is *not* used as current offset in 900 * s->init_buf->data, but as a counter summing up fragments' 901 * lengths: as soon as they sum up to handshake packet 902 * length, we assume we have got all the fragments. */ 903 s->init_num = frag_len; 904 return frag_len; 905 906f_err: 907 ssl3_send_alert(s,SSL3_AL_FATAL,al); 908 s->init_num = 0; 909 910 *ok=0; 911 return(-1); 912 } 913 914int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 915 { 916 unsigned char *p,*d; 917 int i; 918 unsigned long l; 919 920 if (s->state == a) 921 { 922 d=(unsigned char *)s->init_buf->data; 923 p= &(d[DTLS1_HM_HEADER_LENGTH]); 924 925 i=s->method->ssl3_enc->final_finish_mac(s, 926 sender,slen,s->s3->tmp.finish_md); 927 s->s3->tmp.finish_md_len = i; 928 memcpy(p, s->s3->tmp.finish_md, i); 929 p+=i; 930 l=i; 931 932 /* Copy the finished so we can use it for 933 * renegotiation checks 934 */ 935 if(s->type == SSL_ST_CONNECT) 936 { 937 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 938 memcpy(s->s3->previous_client_finished, 939 s->s3->tmp.finish_md, i); 940 s->s3->previous_client_finished_len=i; 941 } 942 else 943 { 944 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 945 memcpy(s->s3->previous_server_finished, 946 s->s3->tmp.finish_md, i); 947 s->s3->previous_server_finished_len=i; 948 } 949 950#ifdef OPENSSL_SYS_WIN16 951 /* MSVC 1.5 does not clear the top bytes of the word unless 952 * I do this. 953 */ 954 l&=0xffff; 955#endif 956 957 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 958 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 959 s->init_off=0; 960 961 /* buffer the message to handle re-xmits */ 962 dtls1_buffer_message(s, 0); 963 964 s->state=b; 965 } 966 967 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 968 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 969 } 970 971/* for these 2 messages, we need to 972 * ssl->enc_read_ctx re-init 973 * ssl->s3->read_sequence zero 974 * ssl->s3->read_mac_secret re-init 975 * ssl->session->read_sym_enc assign 976 * ssl->session->read_compression assign 977 * ssl->session->read_hash assign 978 */ 979int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 980 { 981 unsigned char *p; 982 983 if (s->state == a) 984 { 985 p=(unsigned char *)s->init_buf->data; 986 *p++=SSL3_MT_CCS; 987 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 988 s->init_num=DTLS1_CCS_HEADER_LENGTH; 989 990 if (s->version == DTLS1_BAD_VER) { 991 s->d1->next_handshake_write_seq++; 992 s2n(s->d1->handshake_write_seq,p); 993 s->init_num+=2; 994 } 995 996 s->init_off=0; 997 998 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 999 s->d1->handshake_write_seq, 0, 0); 1000 1001 /* buffer the message to handle re-xmits */ 1002 dtls1_buffer_message(s, 1); 1003 1004 s->state=b; 1005 } 1006 1007 /* SSL3_ST_CW_CHANGE_B */ 1008 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1009 } 1010 1011static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1012 { 1013 int n; 1014 unsigned char *p; 1015 1016 n=i2d_X509(x,NULL); 1017 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1018 { 1019 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1020 return 0; 1021 } 1022 p=(unsigned char *)&(buf->data[*l]); 1023 l2n3(n,p); 1024 i2d_X509(x,&p); 1025 *l+=n+3; 1026 1027 return 1; 1028 } 1029unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1030 { 1031 unsigned char *p; 1032 int i; 1033 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1034 BUF_MEM *buf; 1035 1036 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1037 buf=s->init_buf; 1038 if (!BUF_MEM_grow_clean(buf,10)) 1039 { 1040 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1041 return(0); 1042 } 1043 if (x != NULL) 1044 { 1045 X509_STORE_CTX xs_ctx; 1046 1047 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1048 { 1049 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1050 return(0); 1051 } 1052 1053 X509_verify_cert(&xs_ctx); 1054 /* Don't leave errors in the queue */ 1055 ERR_clear_error(); 1056 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1057 { 1058 x = sk_X509_value(xs_ctx.chain, i); 1059 1060 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1061 { 1062 X509_STORE_CTX_cleanup(&xs_ctx); 1063 return 0; 1064 } 1065 } 1066 X509_STORE_CTX_cleanup(&xs_ctx); 1067 } 1068 /* Thawte special :-) */ 1069 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1070 { 1071 x=sk_X509_value(s->ctx->extra_certs,i); 1072 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1073 return 0; 1074 } 1075 1076 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1077 1078 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1079 l2n3(l,p); 1080 l+=3; 1081 p=(unsigned char *)&(buf->data[0]); 1082 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1083 1084 l+=DTLS1_HM_HEADER_LENGTH; 1085 return(l); 1086 } 1087 1088int dtls1_read_failed(SSL *s, int code) 1089 { 1090 if ( code > 0) 1091 { 1092 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1093 return 1; 1094 } 1095 1096 if (!dtls1_is_timer_expired(s)) 1097 { 1098 /* not a timeout, none of our business, 1099 let higher layers handle this. in fact it's probably an error */ 1100 return code; 1101 } 1102 1103#ifndef OPENSSL_NO_HEARTBEATS 1104 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1105#else 1106 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1107#endif 1108 { 1109 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1110 return code; 1111 } 1112 1113#if 0 /* for now, each alert contains only one record number */ 1114 item = pqueue_peek(state->rcvd_records); 1115 if ( item ) 1116 { 1117 /* send an alert immediately for all the missing records */ 1118 } 1119 else 1120#endif 1121 1122#if 0 /* no more alert sending, just retransmit the last set of messages */ 1123 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1124 ssl3_send_alert(s,SSL3_AL_WARNING, 1125 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1126#endif 1127 1128 return dtls1_handle_timeout(s); 1129 } 1130 1131int 1132dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1133 { 1134 /* The index of the retransmission queue actually is the message sequence number, 1135 * since the queue only contains messages of a single handshake. However, the 1136 * ChangeCipherSpec has no message sequence number and so using only the sequence 1137 * will result in the CCS and Finished having the same index. To prevent this, 1138 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1139 * This does not only differ CSS and Finished, it also maintains the order of the 1140 * index (important for priority queues) and fits in the unsigned short variable. 1141 */ 1142 return seq * 2 - is_ccs; 1143 } 1144 1145int 1146dtls1_retransmit_buffered_messages(SSL *s) 1147 { 1148 pqueue sent = s->d1->sent_messages; 1149 piterator iter; 1150 pitem *item; 1151 hm_fragment *frag; 1152 int found = 0; 1153 1154 iter = pqueue_iterator(sent); 1155 1156 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1157 { 1158 frag = (hm_fragment *)item->data; 1159 if ( dtls1_retransmit_message(s, 1160 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1161 0, &found) <= 0 && found) 1162 { 1163 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1164 return -1; 1165 } 1166 } 1167 1168 return 1; 1169 } 1170 1171int 1172dtls1_buffer_message(SSL *s, int is_ccs) 1173 { 1174 pitem *item; 1175 hm_fragment *frag; 1176 unsigned char seq64be[8]; 1177 1178 /* this function is called immediately after a message has 1179 * been serialized */ 1180 OPENSSL_assert(s->init_off == 0); 1181 1182 frag = dtls1_hm_fragment_new(s->init_num, 0); 1183 1184 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1185 1186 if ( is_ccs) 1187 { 1188 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1189 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1190 } 1191 else 1192 { 1193 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1194 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1195 } 1196 1197 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1198 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1199 frag->msg_header.type = s->d1->w_msg_hdr.type; 1200 frag->msg_header.frag_off = 0; 1201 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1202 frag->msg_header.is_ccs = is_ccs; 1203 1204 /* save current state*/ 1205 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1206 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1207 frag->msg_header.saved_retransmit_state.compress = s->compress; 1208 frag->msg_header.saved_retransmit_state.session = s->session; 1209 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1210 1211 memset(seq64be,0,sizeof(seq64be)); 1212 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1213 frag->msg_header.is_ccs)>>8); 1214 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1215 frag->msg_header.is_ccs)); 1216 1217 item = pitem_new(seq64be, frag); 1218 if ( item == NULL) 1219 { 1220 dtls1_hm_fragment_free(frag); 1221 return 0; 1222 } 1223 1224#if 0 1225 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1226 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1227 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1228#endif 1229 1230 pqueue_insert(s->d1->sent_messages, item); 1231 return 1; 1232 } 1233 1234int 1235dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1236 int *found) 1237 { 1238 int ret; 1239 /* XDTLS: for now assuming that read/writes are blocking */ 1240 pitem *item; 1241 hm_fragment *frag ; 1242 unsigned long header_length; 1243 unsigned char seq64be[8]; 1244 struct dtls1_retransmit_state saved_state; 1245 unsigned char save_write_sequence[8]; 1246 1247 /* 1248 OPENSSL_assert(s->init_num == 0); 1249 OPENSSL_assert(s->init_off == 0); 1250 */ 1251 1252 /* XDTLS: the requested message ought to be found, otherwise error */ 1253 memset(seq64be,0,sizeof(seq64be)); 1254 seq64be[6] = (unsigned char)(seq>>8); 1255 seq64be[7] = (unsigned char)seq; 1256 1257 item = pqueue_find(s->d1->sent_messages, seq64be); 1258 if ( item == NULL) 1259 { 1260 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1261 *found = 0; 1262 return 0; 1263 } 1264 1265 *found = 1; 1266 frag = (hm_fragment *)item->data; 1267 1268 if ( frag->msg_header.is_ccs) 1269 header_length = DTLS1_CCS_HEADER_LENGTH; 1270 else 1271 header_length = DTLS1_HM_HEADER_LENGTH; 1272 1273 memcpy(s->init_buf->data, frag->fragment, 1274 frag->msg_header.msg_len + header_length); 1275 s->init_num = frag->msg_header.msg_len + header_length; 1276 1277 dtls1_set_message_header_int(s, frag->msg_header.type, 1278 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1279 frag->msg_header.frag_len); 1280 1281 /* save current state */ 1282 saved_state.enc_write_ctx = s->enc_write_ctx; 1283 saved_state.write_hash = s->write_hash; 1284 saved_state.compress = s->compress; 1285 saved_state.session = s->session; 1286 saved_state.epoch = s->d1->w_epoch; 1287 saved_state.epoch = s->d1->w_epoch; 1288 1289 s->d1->retransmitting = 1; 1290 1291 /* restore state in which the message was originally sent */ 1292 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1293 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1294 s->compress = frag->msg_header.saved_retransmit_state.compress; 1295 s->session = frag->msg_header.saved_retransmit_state.session; 1296 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1297 1298 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1299 { 1300 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1301 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1302 } 1303 1304 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1305 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1306 1307 /* restore current state */ 1308 s->enc_write_ctx = saved_state.enc_write_ctx; 1309 s->write_hash = saved_state.write_hash; 1310 s->compress = saved_state.compress; 1311 s->session = saved_state.session; 1312 s->d1->w_epoch = saved_state.epoch; 1313 1314 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1315 { 1316 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1317 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1318 } 1319 1320 s->d1->retransmitting = 0; 1321 1322 (void)BIO_flush(SSL_get_wbio(s)); 1323 return ret; 1324 } 1325 1326/* call this function when the buffered messages are no longer needed */ 1327void 1328dtls1_clear_record_buffer(SSL *s) 1329 { 1330 pitem *item; 1331 1332 for(item = pqueue_pop(s->d1->sent_messages); 1333 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1334 { 1335 dtls1_hm_fragment_free((hm_fragment *)item->data); 1336 pitem_free(item); 1337 } 1338 } 1339 1340 1341unsigned char * 1342dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1343 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1344 { 1345 /* Don't change sequence numbers while listening */ 1346 if (frag_off == 0 && !s->d1->listen) 1347 { 1348 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1349 s->d1->next_handshake_write_seq++; 1350 } 1351 1352 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1353 frag_off, frag_len); 1354 1355 return p += DTLS1_HM_HEADER_LENGTH; 1356 } 1357 1358 1359/* don't actually do the writing, wait till the MTU has been retrieved */ 1360static void 1361dtls1_set_message_header_int(SSL *s, unsigned char mt, 1362 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1363 unsigned long frag_len) 1364 { 1365 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1366 1367 msg_hdr->type = mt; 1368 msg_hdr->msg_len = len; 1369 msg_hdr->seq = seq_num; 1370 msg_hdr->frag_off = frag_off; 1371 msg_hdr->frag_len = frag_len; 1372 } 1373 1374static void 1375dtls1_fix_message_header(SSL *s, 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->frag_off = frag_off; 1381 msg_hdr->frag_len = frag_len; 1382 } 1383 1384static unsigned char * 1385dtls1_write_message_header(SSL *s, unsigned char *p) 1386 { 1387 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1388 1389 *p++ = msg_hdr->type; 1390 l2n3(msg_hdr->msg_len, p); 1391 1392 s2n(msg_hdr->seq, p); 1393 l2n3(msg_hdr->frag_off, p); 1394 l2n3(msg_hdr->frag_len, p); 1395 1396 return p; 1397 } 1398 1399unsigned int 1400dtls1_min_mtu(void) 1401 { 1402 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1403 sizeof(g_probable_mtu[0])) - 1]); 1404 } 1405 1406static unsigned int 1407dtls1_guess_mtu(unsigned int curr_mtu) 1408 { 1409 unsigned int i; 1410 1411 if ( curr_mtu == 0 ) 1412 return g_probable_mtu[0] ; 1413 1414 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1415 if ( curr_mtu > g_probable_mtu[i]) 1416 return g_probable_mtu[i]; 1417 1418 return curr_mtu; 1419 } 1420 1421void 1422dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1423 { 1424 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1425 msg_hdr->type = *(data++); 1426 n2l3(data, msg_hdr->msg_len); 1427 1428 n2s(data, msg_hdr->seq); 1429 n2l3(data, msg_hdr->frag_off); 1430 n2l3(data, msg_hdr->frag_len); 1431 } 1432 1433void 1434dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1435 { 1436 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1437 1438 ccs_hdr->type = *(data++); 1439 } 1440 1441int dtls1_shutdown(SSL *s) 1442 { 1443 int ret; 1444#ifndef OPENSSL_NO_SCTP 1445 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1446 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1447 { 1448 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1449 if (ret < 0) return -1; 1450 1451 if (ret == 0) 1452 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1453 } 1454#endif 1455 ret = ssl3_shutdown(s); 1456#ifndef OPENSSL_NO_SCTP 1457 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1458#endif 1459 return ret; 1460 } 1461 1462#ifndef OPENSSL_NO_HEARTBEATS 1463int 1464dtls1_process_heartbeat(SSL *s) 1465 { 1466 unsigned char *p = &s->s3->rrec.data[0], *pl; 1467 unsigned short hbtype; 1468 unsigned int payload; 1469 unsigned int padding = 16; /* Use minimum padding */ 1470 1471 if (s->msg_callback) 1472 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1473 &s->s3->rrec.data[0], s->s3->rrec.length, 1474 s, s->msg_callback_arg); 1475 1476 /* Read type and payload length first */ 1477 if (1 + 2 + 16 > s->s3->rrec.length) 1478 return 0; /* silently discard */ 1479 hbtype = *p++; 1480 n2s(p, payload); 1481 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1482 return 0; /* silently discard per RFC 6520 sec. 4 */ 1483 pl = p; 1484 1485 if (hbtype == TLS1_HB_REQUEST) 1486 { 1487 unsigned char *buffer, *bp; 1488 unsigned int write_length = 1 /* heartbeat type */ + 1489 2 /* heartbeat length */ + 1490 payload + padding; 1491 int r; 1492 1493 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1494 return 0; 1495 1496 /* Allocate memory for the response, size is 1 byte 1497 * message type, plus 2 bytes payload length, plus 1498 * payload, plus padding 1499 */ 1500 buffer = OPENSSL_malloc(write_length); 1501 bp = buffer; 1502 1503 /* Enter response type, length and copy payload */ 1504 *bp++ = TLS1_HB_RESPONSE; 1505 s2n(payload, bp); 1506 memcpy(bp, pl, payload); 1507 bp += payload; 1508 /* Random padding */ 1509 RAND_pseudo_bytes(bp, padding); 1510 1511 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1512 1513 if (r >= 0 && s->msg_callback) 1514 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1515 buffer, write_length, 1516 s, s->msg_callback_arg); 1517 1518 OPENSSL_free(buffer); 1519 1520 if (r < 0) 1521 return r; 1522 } 1523 else if (hbtype == TLS1_HB_RESPONSE) 1524 { 1525 unsigned int seq; 1526 1527 /* We only send sequence numbers (2 bytes unsigned int), 1528 * and 16 random bytes, so we just try to read the 1529 * sequence number */ 1530 n2s(pl, seq); 1531 1532 if (payload == 18 && seq == s->tlsext_hb_seq) 1533 { 1534 dtls1_stop_timer(s); 1535 s->tlsext_hb_seq++; 1536 s->tlsext_hb_pending = 0; 1537 } 1538 } 1539 1540 return 0; 1541 } 1542 1543int 1544dtls1_heartbeat(SSL *s) 1545 { 1546 unsigned char *buf, *p; 1547 int ret; 1548 unsigned int payload = 18; /* Sequence number + random bytes */ 1549 unsigned int padding = 16; /* Use minimum padding */ 1550 1551 /* Only send if peer supports and accepts HB requests... */ 1552 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1553 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1554 { 1555 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1556 return -1; 1557 } 1558 1559 /* ...and there is none in flight yet... */ 1560 if (s->tlsext_hb_pending) 1561 { 1562 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1563 return -1; 1564 } 1565 1566 /* ...and no handshake in progress. */ 1567 if (SSL_in_init(s) || s->in_handshake) 1568 { 1569 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1570 return -1; 1571 } 1572 1573 /* Check if padding is too long, payload and padding 1574 * must not exceed 2^14 - 3 = 16381 bytes in total. 1575 */ 1576 OPENSSL_assert(payload + padding <= 16381); 1577 1578 /* Create HeartBeat message, we just use a sequence number 1579 * as payload to distuingish different messages and add 1580 * some random stuff. 1581 * - Message Type, 1 byte 1582 * - Payload Length, 2 bytes (unsigned int) 1583 * - Payload, the sequence number (2 bytes uint) 1584 * - Payload, random bytes (16 bytes uint) 1585 * - Padding 1586 */ 1587 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1588 p = buf; 1589 /* Message Type */ 1590 *p++ = TLS1_HB_REQUEST; 1591 /* Payload length (18 bytes here) */ 1592 s2n(payload, p); 1593 /* Sequence number */ 1594 s2n(s->tlsext_hb_seq, p); 1595 /* 16 random bytes */ 1596 RAND_pseudo_bytes(p, 16); 1597 p += 16; 1598 /* Random padding */ 1599 RAND_pseudo_bytes(p, padding); 1600 1601 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1602 if (ret >= 0) 1603 { 1604 if (s->msg_callback) 1605 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1606 buf, 3 + payload + padding, 1607 s, s->msg_callback_arg); 1608 1609 dtls1_start_timer(s); 1610 s->tlsext_hb_pending = 1; 1611 } 1612 1613 OPENSSL_free(buf); 1614 1615 return ret; 1616 } 1617#endif 1618