d1_both.c revision 284295
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 const unsigned int g_probable_mtu[] = {1500, 512, 256}; 160 161static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 162 unsigned long frag_len); 163static unsigned char *dtls1_write_message_header(SSL *s, 164 unsigned char *p); 165static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 166 unsigned long len, unsigned short seq_num, unsigned long frag_off, 167 unsigned long frag_len); 168static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 169 long max, int *ok); 170 171static hm_fragment * 172dtls1_hm_fragment_new(unsigned long frag_len, int reassembly) 173 { 174 hm_fragment *frag = NULL; 175 unsigned char *buf = NULL; 176 unsigned char *bitmask = NULL; 177 178 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 179 if ( frag == NULL) 180 return NULL; 181 182 if (frag_len) 183 { 184 buf = (unsigned char *)OPENSSL_malloc(frag_len); 185 if ( buf == NULL) 186 { 187 OPENSSL_free(frag); 188 return NULL; 189 } 190 } 191 192 /* zero length fragment gets zero frag->fragment */ 193 frag->fragment = buf; 194 195 /* Initialize reassembly bitmask if necessary */ 196 if (reassembly) 197 { 198 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 199 if (bitmask == NULL) 200 { 201 if (buf != NULL) OPENSSL_free(buf); 202 OPENSSL_free(frag); 203 return NULL; 204 } 205 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 206 } 207 208 frag->reassembly = bitmask; 209 210 return frag; 211 } 212 213void dtls1_hm_fragment_free(hm_fragment *frag) 214 { 215 216 if (frag->msg_header.is_ccs) 217 { 218 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx); 219 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash); 220 } 221 if (frag->fragment) OPENSSL_free(frag->fragment); 222 if (frag->reassembly) OPENSSL_free(frag->reassembly); 223 OPENSSL_free(frag); 224 } 225 226static int dtls1_query_mtu(SSL *s) 227{ 228 if(s->d1->link_mtu) 229 { 230 s->d1->mtu = s->d1->link_mtu-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 231 s->d1->link_mtu = 0; 232 } 233 234 /* AHA! Figure out the MTU, and stick to the right size */ 235 if (s->d1->mtu < dtls1_min_mtu(s)) 236 { 237 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 238 { 239 s->d1->mtu = 240 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 241 242 /* I've seen the kernel return bogus numbers when it doesn't know 243 * (initial write), so just make sure we have a reasonable number */ 244 if (s->d1->mtu < dtls1_min_mtu(s)) 245 { 246 /* Set to min mtu */ 247 s->d1->mtu = dtls1_min_mtu(s); 248 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 249 s->d1->mtu, NULL); 250 } 251 } 252 else 253 return 0; 254 } 255 return 1; 256} 257 258/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 259int dtls1_do_write(SSL *s, int type) 260 { 261 int ret; 262 unsigned int curr_mtu; 263 int retry = 1; 264 unsigned int len, frag_off, mac_size, blocksize, used_len; 265 266 if(!dtls1_query_mtu(s)) 267 return -1; 268 269 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something reasonable now */ 270 271 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 272 OPENSSL_assert(s->init_num == 273 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 274 275 if (s->write_hash) 276 mac_size = EVP_MD_CTX_size(s->write_hash); 277 else 278 mac_size = 0; 279 280 if (s->enc_write_ctx && 281 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 282 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 283 else 284 blocksize = 0; 285 286 frag_off = 0; 287 /* s->init_num shouldn't ever be < 0...but just in case */ 288 while(s->init_num > 0) 289 { 290 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH 291 + mac_size + blocksize; 292 if(s->d1->mtu > used_len) 293 curr_mtu = s->d1->mtu - used_len; 294 else 295 curr_mtu = 0; 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 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize; 304 if(s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) 305 { 306 curr_mtu = s->d1->mtu - used_len; 307 } 308 else 309 { 310 /* Shouldn't happen */ 311 return -1; 312 } 313 } 314 315 /* We just checked that s->init_num > 0 so this cast should be safe */ 316 if (((unsigned int)s->init_num) > curr_mtu) 317 len = curr_mtu; 318 else 319 len = s->init_num; 320 321 /* Shouldn't ever happen */ 322 if(len > INT_MAX) 323 len = INT_MAX; 324 325 /* XDTLS: this function is too long. split out the CCS part */ 326 if ( type == SSL3_RT_HANDSHAKE) 327 { 328 if ( s->init_off != 0) 329 { 330 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 331 s->init_off -= DTLS1_HM_HEADER_LENGTH; 332 s->init_num += DTLS1_HM_HEADER_LENGTH; 333 334 /* We just checked that s->init_num > 0 so this cast should be safe */ 335 if (((unsigned int)s->init_num) > curr_mtu) 336 len = curr_mtu; 337 else 338 len = s->init_num; 339 } 340 341 /* Shouldn't ever happen */ 342 if(len > INT_MAX) 343 len = INT_MAX; 344 345 if ( len < DTLS1_HM_HEADER_LENGTH ) 346 { 347 /* 348 * len is so small that we really can't do anything sensible 349 * so fail 350 */ 351 return -1; 352 } 353 dtls1_fix_message_header(s, frag_off, 354 len - DTLS1_HM_HEADER_LENGTH); 355 356 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 357 } 358 359 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 360 len); 361 if (ret < 0) 362 { 363 /* might need to update MTU here, but we don't know 364 * which previous packet caused the failure -- so can't 365 * really retransmit anything. continue as if everything 366 * is fine and wait for an alert to handle the 367 * retransmit 368 */ 369 if ( retry && BIO_ctrl(SSL_get_wbio(s), 370 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 ) 371 { 372 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 373 { 374 if(!dtls1_query_mtu(s)) 375 return -1; 376 /* Have one more go */ 377 retry = 0; 378 } 379 else 380 return -1; 381 } 382 else 383 { 384 return(-1); 385 } 386 } 387 else 388 { 389 390 /* bad if this assert fails, only part of the handshake 391 * message got sent. but why would this happen? */ 392 OPENSSL_assert(len == (unsigned int)ret); 393 394 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 395 { 396 /* should not be done for 'Hello Request's, but in that case 397 * we'll ignore the result anyway */ 398 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 399 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 400 int xlen; 401 402 if (frag_off == 0 && s->version != DTLS1_BAD_VER) 403 { 404 /* reconstruct message header is if it 405 * is being sent in single fragment */ 406 *p++ = msg_hdr->type; 407 l2n3(msg_hdr->msg_len,p); 408 s2n (msg_hdr->seq,p); 409 l2n3(0,p); 410 l2n3(msg_hdr->msg_len,p); 411 p -= DTLS1_HM_HEADER_LENGTH; 412 xlen = ret; 413 } 414 else 415 { 416 p += DTLS1_HM_HEADER_LENGTH; 417 xlen = ret - DTLS1_HM_HEADER_LENGTH; 418 } 419 420 ssl3_finish_mac(s, p, xlen); 421 } 422 423 if (ret == s->init_num) 424 { 425 if (s->msg_callback) 426 s->msg_callback(1, s->version, type, s->init_buf->data, 427 (size_t)(s->init_off + s->init_num), s, 428 s->msg_callback_arg); 429 430 s->init_off = 0; /* done writing this message */ 431 s->init_num = 0; 432 433 return(1); 434 } 435 s->init_off+=ret; 436 s->init_num-=ret; 437 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 438 } 439 } 440 return(0); 441 } 442 443 444/* Obtain handshake message of message type 'mt' (any if mt == -1), 445 * maximum acceptable body length 'max'. 446 * Read an entire handshake message. Handshake messages arrive in 447 * fragments. 448 */ 449long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 450 { 451 int i, al; 452 struct hm_header_st *msg_hdr; 453 unsigned char *p; 454 unsigned long msg_len; 455 456 /* s3->tmp is used to store messages that are unexpected, caused 457 * by the absence of an optional handshake message */ 458 if (s->s3->tmp.reuse_message) 459 { 460 s->s3->tmp.reuse_message=0; 461 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 462 { 463 al=SSL_AD_UNEXPECTED_MESSAGE; 464 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 465 goto f_err; 466 } 467 *ok=1; 468 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 469 s->init_num = (int)s->s3->tmp.message_size; 470 return s->init_num; 471 } 472 473 msg_hdr = &s->d1->r_msg_hdr; 474 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 475 476again: 477 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 478 if ( i == DTLS1_HM_BAD_FRAGMENT || 479 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 480 goto again; 481 else if ( i <= 0 && !*ok) 482 return i; 483 484 if (mt >= 0 && s->s3->tmp.message_type != mt) { 485 al = SSL_AD_UNEXPECTED_MESSAGE; 486 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE); 487 goto f_err; 488 } 489 490 p = (unsigned char *)s->init_buf->data; 491 msg_len = msg_hdr->msg_len; 492 493 /* reconstruct message header */ 494 *(p++) = msg_hdr->type; 495 l2n3(msg_len,p); 496 s2n (msg_hdr->seq,p); 497 l2n3(0,p); 498 l2n3(msg_len,p); 499 if (s->version != DTLS1_BAD_VER) { 500 p -= DTLS1_HM_HEADER_LENGTH; 501 msg_len += DTLS1_HM_HEADER_LENGTH; 502 } 503 504 ssl3_finish_mac(s, p, msg_len); 505 if (s->msg_callback) 506 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 507 p, msg_len, 508 s, s->msg_callback_arg); 509 510 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 511 512 /* Don't change sequence numbers while listening */ 513 if (!s->d1->listen) 514 s->d1->handshake_read_seq++; 515 516 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 517 return s->init_num; 518 519f_err: 520 ssl3_send_alert(s,SSL3_AL_FATAL,al); 521 *ok = 0; 522 return -1; 523 } 524 525 526static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 527 { 528 size_t frag_off,frag_len,msg_len; 529 530 msg_len = msg_hdr->msg_len; 531 frag_off = msg_hdr->frag_off; 532 frag_len = msg_hdr->frag_len; 533 534 /* sanity checking */ 535 if ( (frag_off+frag_len) > msg_len) 536 { 537 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 538 return SSL_AD_ILLEGAL_PARAMETER; 539 } 540 541 if ( (frag_off+frag_len) > (unsigned long)max) 542 { 543 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 544 return SSL_AD_ILLEGAL_PARAMETER; 545 } 546 547 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 548 { 549 /* msg_len is limited to 2^24, but is effectively checked 550 * against max above */ 551 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH)) 552 { 553 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 554 return SSL_AD_INTERNAL_ERROR; 555 } 556 557 s->s3->tmp.message_size = msg_len; 558 s->d1->r_msg_hdr.msg_len = msg_len; 559 s->s3->tmp.message_type = msg_hdr->type; 560 s->d1->r_msg_hdr.type = msg_hdr->type; 561 s->d1->r_msg_hdr.seq = msg_hdr->seq; 562 } 563 else if (msg_len != s->d1->r_msg_hdr.msg_len) 564 { 565 /* They must be playing with us! BTW, failure to enforce 566 * upper limit would open possibility for buffer overrun. */ 567 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 568 return SSL_AD_ILLEGAL_PARAMETER; 569 } 570 571 return 0; /* no error */ 572 } 573 574 575static int 576dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 577 { 578 /* (0) check whether the desired fragment is available 579 * if so: 580 * (1) copy over the fragment to s->init_buf->data[] 581 * (2) update s->init_num 582 */ 583 pitem *item; 584 hm_fragment *frag; 585 int al; 586 587 *ok = 0; 588 item = pqueue_peek(s->d1->buffered_messages); 589 if ( item == NULL) 590 return 0; 591 592 frag = (hm_fragment *)item->data; 593 594 /* Don't return if reassembly still in progress */ 595 if (frag->reassembly != NULL) 596 return 0; 597 598 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 599 { 600 unsigned long frag_len = frag->msg_header.frag_len; 601 pqueue_pop(s->d1->buffered_messages); 602 603 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 604 605 if (al==0) /* no alert */ 606 { 607 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 608 memcpy(&p[frag->msg_header.frag_off], 609 frag->fragment,frag->msg_header.frag_len); 610 } 611 612 dtls1_hm_fragment_free(frag); 613 pitem_free(item); 614 615 if (al==0) 616 { 617 *ok = 1; 618 return frag_len; 619 } 620 621 ssl3_send_alert(s,SSL3_AL_FATAL,al); 622 s->init_num = 0; 623 *ok = 0; 624 return -1; 625 } 626 else 627 return 0; 628 } 629 630/* dtls1_max_handshake_message_len returns the maximum number of bytes 631 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may 632 * be greater if the maximum certificate list size requires it. */ 633static unsigned long dtls1_max_handshake_message_len(const SSL *s) 634 { 635 unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 636 if (max_len < (unsigned long)s->max_cert_list) 637 return s->max_cert_list; 638 return max_len; 639 } 640 641static int 642dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 643 { 644 hm_fragment *frag = NULL; 645 pitem *item = NULL; 646 int i = -1, is_complete; 647 unsigned char seq64be[8]; 648 unsigned long frag_len = msg_hdr->frag_len; 649 650 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len || 651 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 652 goto err; 653 654 if (frag_len == 0) 655 return DTLS1_HM_FRAGMENT_RETRY; 656 657 /* Try to find item in queue */ 658 memset(seq64be,0,sizeof(seq64be)); 659 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 660 seq64be[7] = (unsigned char) msg_hdr->seq; 661 item = pqueue_find(s->d1->buffered_messages, seq64be); 662 663 if (item == NULL) 664 { 665 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 666 if ( frag == NULL) 667 goto err; 668 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 669 frag->msg_header.frag_len = frag->msg_header.msg_len; 670 frag->msg_header.frag_off = 0; 671 } 672 else 673 { 674 frag = (hm_fragment*) item->data; 675 if (frag->msg_header.msg_len != msg_hdr->msg_len) 676 { 677 item = NULL; 678 frag = NULL; 679 goto err; 680 } 681 } 682 683 684 /* If message is already reassembled, this must be a 685 * retransmit and can be dropped. In this case item != NULL and so frag 686 * does not need to be freed. 687 */ 688 if (frag->reassembly == NULL) 689 { 690 unsigned char devnull [256]; 691 692 while (frag_len) 693 { 694 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 695 devnull, 696 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 697 if (i<=0) goto err; 698 frag_len -= i; 699 } 700 return DTLS1_HM_FRAGMENT_RETRY; 701 } 702 703 /* read the body of the fragment (header has already been read */ 704 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 705 frag->fragment + msg_hdr->frag_off,frag_len,0); 706 if ((unsigned long)i!=frag_len) 707 i=-1; 708 if (i<=0) 709 goto err; 710 711 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 712 (long)(msg_hdr->frag_off + frag_len)); 713 714 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 715 is_complete); 716 717 if (is_complete) 718 { 719 OPENSSL_free(frag->reassembly); 720 frag->reassembly = NULL; 721 } 722 723 if (item == NULL) 724 { 725 item = pitem_new(seq64be, frag); 726 if (item == NULL) 727 { 728 i = -1; 729 goto err; 730 } 731 732 item = pqueue_insert(s->d1->buffered_messages, item); 733 /* pqueue_insert fails iff a duplicate item is inserted. 734 * However, |item| cannot be a duplicate. If it were, 735 * |pqueue_find|, above, would have returned it and control 736 * would never have reached this branch. */ 737 OPENSSL_assert(item != NULL); 738 } 739 740 return DTLS1_HM_FRAGMENT_RETRY; 741 742err: 743 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 744 *ok = 0; 745 return i; 746 } 747 748 749static int 750dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 751{ 752 int i=-1; 753 hm_fragment *frag = NULL; 754 pitem *item = NULL; 755 unsigned char seq64be[8]; 756 unsigned long frag_len = msg_hdr->frag_len; 757 758 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 759 goto err; 760 761 /* Try to find item in queue, to prevent duplicate entries */ 762 memset(seq64be,0,sizeof(seq64be)); 763 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 764 seq64be[7] = (unsigned char) msg_hdr->seq; 765 item = pqueue_find(s->d1->buffered_messages, seq64be); 766 767 /* If we already have an entry and this one is a fragment, 768 * don't discard it and rather try to reassemble it. 769 */ 770 if (item != NULL && frag_len != msg_hdr->msg_len) 771 item = NULL; 772 773 /* Discard the message if sequence number was already there, is 774 * too far in the future, already in the queue or if we received 775 * a FINISHED before the SERVER_HELLO, which then must be a stale 776 * retransmit. 777 */ 778 if (msg_hdr->seq <= s->d1->handshake_read_seq || 779 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 780 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 781 { 782 unsigned char devnull [256]; 783 784 while (frag_len) 785 { 786 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 787 devnull, 788 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 789 if (i<=0) goto err; 790 frag_len -= i; 791 } 792 } 793 else 794 { 795 if (frag_len != msg_hdr->msg_len) 796 return dtls1_reassemble_fragment(s, msg_hdr, ok); 797 798 if (frag_len > dtls1_max_handshake_message_len(s)) 799 goto err; 800 801 frag = dtls1_hm_fragment_new(frag_len, 0); 802 if ( frag == NULL) 803 goto err; 804 805 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 806 807 if (frag_len) 808 { 809 /* read the body of the fragment (header has already been read */ 810 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 811 frag->fragment,frag_len,0); 812 if ((unsigned long)i!=frag_len) 813 i = -1; 814 if (i<=0) 815 goto err; 816 } 817 818 item = pitem_new(seq64be, frag); 819 if ( item == NULL) 820 goto err; 821 822 item = pqueue_insert(s->d1->buffered_messages, item); 823 /* pqueue_insert fails iff a duplicate item is inserted. 824 * However, |item| cannot be a duplicate. If it were, 825 * |pqueue_find|, above, would have returned it. Then, either 826 * |frag_len| != |msg_hdr->msg_len| in which case |item| is set 827 * to NULL and it will have been processed with 828 * |dtls1_reassemble_fragment|, above, or the record will have 829 * been discarded. */ 830 OPENSSL_assert(item != NULL); 831 } 832 833 return DTLS1_HM_FRAGMENT_RETRY; 834 835err: 836 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 837 *ok = 0; 838 return i; 839 } 840 841 842static long 843dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 844 { 845 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 846 unsigned long len, frag_off, frag_len; 847 int i,al; 848 struct hm_header_st msg_hdr; 849 850 redo: 851 /* see if we have the required fragment already */ 852 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 853 { 854 if (*ok) s->init_num = frag_len; 855 return frag_len; 856 } 857 858 /* read handshake message header */ 859 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 860 DTLS1_HM_HEADER_LENGTH, 0); 861 if (i <= 0) /* nbio, or an error */ 862 { 863 s->rwstate=SSL_READING; 864 *ok = 0; 865 return i; 866 } 867 /* Handshake fails if message header is incomplete */ 868 if (i != DTLS1_HM_HEADER_LENGTH) 869 { 870 al=SSL_AD_UNEXPECTED_MESSAGE; 871 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 872 goto f_err; 873 } 874 875 /* parse the message fragment header */ 876 dtls1_get_message_header(wire, &msg_hdr); 877 878 len = msg_hdr.msg_len; 879 frag_off = msg_hdr.frag_off; 880 frag_len = msg_hdr.frag_len; 881 882 /* 883 * We must have at least frag_len bytes left in the record to be read. 884 * Fragments must not span records. 885 */ 886 if (frag_len > s->s3->rrec.length) { 887 al = SSL3_AD_ILLEGAL_PARAMETER; 888 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH); 889 goto f_err; 890 } 891 892 /* 893 * if this is a future (or stale) message it gets buffered 894 * (or dropped)--no further processing at this time 895 * While listening, we accept seq 1 (ClientHello with cookie) 896 * although we're still expecting seq 0 (ClientHello) 897 */ 898 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 899 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 900 901 if (frag_len && frag_len < len) 902 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 903 904 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 905 wire[0] == SSL3_MT_HELLO_REQUEST) 906 { 907 /* The server may always send 'Hello Request' messages -- 908 * we are doing a handshake anyway now, so ignore them 909 * if their format is correct. Does not count for 910 * 'Finished' MAC. */ 911 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 912 { 913 if (s->msg_callback) 914 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 915 wire, DTLS1_HM_HEADER_LENGTH, s, 916 s->msg_callback_arg); 917 918 s->init_num = 0; 919 goto redo; 920 } 921 else /* Incorrectly formated Hello request */ 922 { 923 al=SSL_AD_UNEXPECTED_MESSAGE; 924 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 925 goto f_err; 926 } 927 } 928 929 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 930 goto f_err; 931 932 if ( frag_len > 0) 933 { 934 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 935 936 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 937 &p[frag_off],frag_len,0); 938 /* 939 * This shouldn't ever fail due to NBIO because we already checked 940 * that we have enough data in the record 941 */ 942 if (i <= 0) 943 { 944 s->rwstate=SSL_READING; 945 *ok = 0; 946 return i; 947 } 948 } 949 else 950 i = 0; 951 952 /* XDTLS: an incorrectly formatted fragment should cause the 953 * handshake to fail */ 954 if (i != (int)frag_len) 955 { 956 al=SSL3_AD_ILLEGAL_PARAMETER; 957 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 958 goto f_err; 959 } 960 961 *ok = 1; 962 s->state = stn; 963 964 /* Note that s->init_num is *not* used as current offset in 965 * s->init_buf->data, but as a counter summing up fragments' 966 * lengths: as soon as they sum up to handshake packet 967 * length, we assume we have got all the fragments. */ 968 s->init_num = frag_len; 969 return frag_len; 970 971f_err: 972 ssl3_send_alert(s,SSL3_AL_FATAL,al); 973 s->init_num = 0; 974 975 *ok=0; 976 return(-1); 977 } 978 979int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 980 { 981 unsigned char *p,*d; 982 int i; 983 unsigned long l; 984 985 if (s->state == a) 986 { 987 d=(unsigned char *)s->init_buf->data; 988 p= &(d[DTLS1_HM_HEADER_LENGTH]); 989 990 i=s->method->ssl3_enc->final_finish_mac(s, 991 sender,slen,s->s3->tmp.finish_md); 992 s->s3->tmp.finish_md_len = i; 993 memcpy(p, s->s3->tmp.finish_md, i); 994 p+=i; 995 l=i; 996 997 /* Copy the finished so we can use it for 998 * renegotiation checks 999 */ 1000 if(s->type == SSL_ST_CONNECT) 1001 { 1002 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1003 memcpy(s->s3->previous_client_finished, 1004 s->s3->tmp.finish_md, i); 1005 s->s3->previous_client_finished_len=i; 1006 } 1007 else 1008 { 1009 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 1010 memcpy(s->s3->previous_server_finished, 1011 s->s3->tmp.finish_md, i); 1012 s->s3->previous_server_finished_len=i; 1013 } 1014 1015#ifdef OPENSSL_SYS_WIN16 1016 /* MSVC 1.5 does not clear the top bytes of the word unless 1017 * I do this. 1018 */ 1019 l&=0xffff; 1020#endif 1021 1022 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 1023 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 1024 s->init_off=0; 1025 1026 /* buffer the message to handle re-xmits */ 1027 dtls1_buffer_message(s, 0); 1028 1029 s->state=b; 1030 } 1031 1032 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 1033 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 1034 } 1035 1036/* for these 2 messages, we need to 1037 * ssl->enc_read_ctx re-init 1038 * ssl->s3->read_sequence zero 1039 * ssl->s3->read_mac_secret re-init 1040 * ssl->session->read_sym_enc assign 1041 * ssl->session->read_compression assign 1042 * ssl->session->read_hash assign 1043 */ 1044int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1045 { 1046 unsigned char *p; 1047 1048 if (s->state == a) 1049 { 1050 p=(unsigned char *)s->init_buf->data; 1051 *p++=SSL3_MT_CCS; 1052 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1053 s->init_num=DTLS1_CCS_HEADER_LENGTH; 1054 1055 if (s->version == DTLS1_BAD_VER) { 1056 s->d1->next_handshake_write_seq++; 1057 s2n(s->d1->handshake_write_seq,p); 1058 s->init_num+=2; 1059 } 1060 1061 s->init_off=0; 1062 1063 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1064 s->d1->handshake_write_seq, 0, 0); 1065 1066 /* buffer the message to handle re-xmits */ 1067 dtls1_buffer_message(s, 1); 1068 1069 s->state=b; 1070 } 1071 1072 /* SSL3_ST_CW_CHANGE_B */ 1073 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1074 } 1075 1076static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1077 { 1078 int n; 1079 unsigned char *p; 1080 1081 n=i2d_X509(x,NULL); 1082 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1083 { 1084 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1085 return 0; 1086 } 1087 p=(unsigned char *)&(buf->data[*l]); 1088 l2n3(n,p); 1089 i2d_X509(x,&p); 1090 *l+=n+3; 1091 1092 return 1; 1093 } 1094unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1095 { 1096 unsigned char *p; 1097 int i; 1098 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1099 BUF_MEM *buf; 1100 1101 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1102 buf=s->init_buf; 1103 if (!BUF_MEM_grow_clean(buf,10)) 1104 { 1105 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1106 return(0); 1107 } 1108 if (x != NULL) 1109 { 1110 X509_STORE_CTX xs_ctx; 1111 1112 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1113 { 1114 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1115 return(0); 1116 } 1117 1118 X509_verify_cert(&xs_ctx); 1119 /* Don't leave errors in the queue */ 1120 ERR_clear_error(); 1121 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1122 { 1123 x = sk_X509_value(xs_ctx.chain, i); 1124 1125 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1126 { 1127 X509_STORE_CTX_cleanup(&xs_ctx); 1128 return 0; 1129 } 1130 } 1131 X509_STORE_CTX_cleanup(&xs_ctx); 1132 } 1133 /* Thawte special :-) */ 1134 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1135 { 1136 x=sk_X509_value(s->ctx->extra_certs,i); 1137 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1138 return 0; 1139 } 1140 1141 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1142 1143 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1144 l2n3(l,p); 1145 l+=3; 1146 p=(unsigned char *)&(buf->data[0]); 1147 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1148 1149 l+=DTLS1_HM_HEADER_LENGTH; 1150 return(l); 1151 } 1152 1153int dtls1_read_failed(SSL *s, int code) 1154 { 1155 if ( code > 0) 1156 { 1157 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1158 return 1; 1159 } 1160 1161 if (!dtls1_is_timer_expired(s)) 1162 { 1163 /* not a timeout, none of our business, 1164 let higher layers handle this. in fact it's probably an error */ 1165 return code; 1166 } 1167 1168#ifndef OPENSSL_NO_HEARTBEATS 1169 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1170#else 1171 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1172#endif 1173 { 1174 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1175 return code; 1176 } 1177 1178#if 0 /* for now, each alert contains only one record number */ 1179 item = pqueue_peek(state->rcvd_records); 1180 if ( item ) 1181 { 1182 /* send an alert immediately for all the missing records */ 1183 } 1184 else 1185#endif 1186 1187#if 0 /* no more alert sending, just retransmit the last set of messages */ 1188 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1189 ssl3_send_alert(s,SSL3_AL_WARNING, 1190 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1191#endif 1192 1193 return dtls1_handle_timeout(s); 1194 } 1195 1196int 1197dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1198 { 1199 /* The index of the retransmission queue actually is the message sequence number, 1200 * since the queue only contains messages of a single handshake. However, the 1201 * ChangeCipherSpec has no message sequence number and so using only the sequence 1202 * will result in the CCS and Finished having the same index. To prevent this, 1203 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1204 * This does not only differ CSS and Finished, it also maintains the order of the 1205 * index (important for priority queues) and fits in the unsigned short variable. 1206 */ 1207 return seq * 2 - is_ccs; 1208 } 1209 1210int 1211dtls1_retransmit_buffered_messages(SSL *s) 1212 { 1213 pqueue sent = s->d1->sent_messages; 1214 piterator iter; 1215 pitem *item; 1216 hm_fragment *frag; 1217 int found = 0; 1218 1219 iter = pqueue_iterator(sent); 1220 1221 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1222 { 1223 frag = (hm_fragment *)item->data; 1224 if ( dtls1_retransmit_message(s, 1225 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1226 0, &found) <= 0 && found) 1227 { 1228 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1229 return -1; 1230 } 1231 } 1232 1233 return 1; 1234 } 1235 1236int 1237dtls1_buffer_message(SSL *s, int is_ccs) 1238 { 1239 pitem *item; 1240 hm_fragment *frag; 1241 unsigned char seq64be[8]; 1242 1243 /* this function is called immediately after a message has 1244 * been serialized */ 1245 OPENSSL_assert(s->init_off == 0); 1246 1247 frag = dtls1_hm_fragment_new(s->init_num, 0); 1248 if (!frag) 1249 return 0; 1250 1251 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1252 1253 if ( is_ccs) 1254 { 1255 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1256 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1257 } 1258 else 1259 { 1260 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1261 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1262 } 1263 1264 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1265 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1266 frag->msg_header.type = s->d1->w_msg_hdr.type; 1267 frag->msg_header.frag_off = 0; 1268 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1269 frag->msg_header.is_ccs = is_ccs; 1270 1271 /* save current state*/ 1272 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1273 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1274 frag->msg_header.saved_retransmit_state.compress = s->compress; 1275 frag->msg_header.saved_retransmit_state.session = s->session; 1276 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1277 1278 memset(seq64be,0,sizeof(seq64be)); 1279 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1280 frag->msg_header.is_ccs)>>8); 1281 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1282 frag->msg_header.is_ccs)); 1283 1284 item = pitem_new(seq64be, frag); 1285 if ( item == NULL) 1286 { 1287 dtls1_hm_fragment_free(frag); 1288 return 0; 1289 } 1290 1291#if 0 1292 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1293 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1294 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1295#endif 1296 1297 pqueue_insert(s->d1->sent_messages, item); 1298 return 1; 1299 } 1300 1301int 1302dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1303 int *found) 1304 { 1305 int ret; 1306 /* XDTLS: for now assuming that read/writes are blocking */ 1307 pitem *item; 1308 hm_fragment *frag ; 1309 unsigned long header_length; 1310 unsigned char seq64be[8]; 1311 struct dtls1_retransmit_state saved_state; 1312 unsigned char save_write_sequence[8]; 1313 1314 /* 1315 OPENSSL_assert(s->init_num == 0); 1316 OPENSSL_assert(s->init_off == 0); 1317 */ 1318 1319 /* XDTLS: the requested message ought to be found, otherwise error */ 1320 memset(seq64be,0,sizeof(seq64be)); 1321 seq64be[6] = (unsigned char)(seq>>8); 1322 seq64be[7] = (unsigned char)seq; 1323 1324 item = pqueue_find(s->d1->sent_messages, seq64be); 1325 if ( item == NULL) 1326 { 1327 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1328 *found = 0; 1329 return 0; 1330 } 1331 1332 *found = 1; 1333 frag = (hm_fragment *)item->data; 1334 1335 if ( frag->msg_header.is_ccs) 1336 header_length = DTLS1_CCS_HEADER_LENGTH; 1337 else 1338 header_length = DTLS1_HM_HEADER_LENGTH; 1339 1340 memcpy(s->init_buf->data, frag->fragment, 1341 frag->msg_header.msg_len + header_length); 1342 s->init_num = frag->msg_header.msg_len + header_length; 1343 1344 dtls1_set_message_header_int(s, frag->msg_header.type, 1345 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1346 frag->msg_header.frag_len); 1347 1348 /* save current state */ 1349 saved_state.enc_write_ctx = s->enc_write_ctx; 1350 saved_state.write_hash = s->write_hash; 1351 saved_state.compress = s->compress; 1352 saved_state.session = s->session; 1353 saved_state.epoch = s->d1->w_epoch; 1354 saved_state.epoch = s->d1->w_epoch; 1355 1356 s->d1->retransmitting = 1; 1357 1358 /* restore state in which the message was originally sent */ 1359 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1360 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1361 s->compress = frag->msg_header.saved_retransmit_state.compress; 1362 s->session = frag->msg_header.saved_retransmit_state.session; 1363 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1364 1365 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1366 { 1367 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1368 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1369 } 1370 1371 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1372 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1373 1374 /* restore current state */ 1375 s->enc_write_ctx = saved_state.enc_write_ctx; 1376 s->write_hash = saved_state.write_hash; 1377 s->compress = saved_state.compress; 1378 s->session = saved_state.session; 1379 s->d1->w_epoch = saved_state.epoch; 1380 1381 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1382 { 1383 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1384 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1385 } 1386 1387 s->d1->retransmitting = 0; 1388 1389 (void)BIO_flush(SSL_get_wbio(s)); 1390 return ret; 1391 } 1392 1393/* call this function when the buffered messages are no longer needed */ 1394void 1395dtls1_clear_record_buffer(SSL *s) 1396 { 1397 pitem *item; 1398 1399 for(item = pqueue_pop(s->d1->sent_messages); 1400 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1401 { 1402 dtls1_hm_fragment_free((hm_fragment *)item->data); 1403 pitem_free(item); 1404 } 1405 } 1406 1407 1408unsigned char * 1409dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1410 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1411 { 1412 /* Don't change sequence numbers while listening */ 1413 if (frag_off == 0 && !s->d1->listen) 1414 { 1415 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1416 s->d1->next_handshake_write_seq++; 1417 } 1418 1419 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1420 frag_off, frag_len); 1421 1422 return p += DTLS1_HM_HEADER_LENGTH; 1423 } 1424 1425 1426/* don't actually do the writing, wait till the MTU has been retrieved */ 1427static void 1428dtls1_set_message_header_int(SSL *s, unsigned char mt, 1429 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1430 unsigned long frag_len) 1431 { 1432 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1433 1434 msg_hdr->type = mt; 1435 msg_hdr->msg_len = len; 1436 msg_hdr->seq = seq_num; 1437 msg_hdr->frag_off = frag_off; 1438 msg_hdr->frag_len = frag_len; 1439 } 1440 1441static void 1442dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1443 unsigned long frag_len) 1444 { 1445 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1446 1447 msg_hdr->frag_off = frag_off; 1448 msg_hdr->frag_len = frag_len; 1449 } 1450 1451static unsigned char * 1452dtls1_write_message_header(SSL *s, unsigned char *p) 1453 { 1454 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1455 1456 *p++ = msg_hdr->type; 1457 l2n3(msg_hdr->msg_len, p); 1458 1459 s2n(msg_hdr->seq, p); 1460 l2n3(msg_hdr->frag_off, p); 1461 l2n3(msg_hdr->frag_len, p); 1462 1463 return p; 1464 } 1465 1466unsigned int 1467dtls1_link_min_mtu(void) 1468 { 1469 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1470 sizeof(g_probable_mtu[0])) - 1]); 1471 } 1472 1473unsigned int 1474dtls1_min_mtu(SSL *s) 1475 { 1476 return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1477 } 1478 1479 1480void 1481dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1482 { 1483 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1484 msg_hdr->type = *(data++); 1485 n2l3(data, msg_hdr->msg_len); 1486 1487 n2s(data, msg_hdr->seq); 1488 n2l3(data, msg_hdr->frag_off); 1489 n2l3(data, msg_hdr->frag_len); 1490 } 1491 1492void 1493dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1494 { 1495 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1496 1497 ccs_hdr->type = *(data++); 1498 } 1499 1500int dtls1_shutdown(SSL *s) 1501 { 1502 int ret; 1503#ifndef OPENSSL_NO_SCTP 1504 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1505 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1506 { 1507 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1508 if (ret < 0) return -1; 1509 1510 if (ret == 0) 1511 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1512 } 1513#endif 1514 ret = ssl3_shutdown(s); 1515#ifndef OPENSSL_NO_SCTP 1516 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1517#endif 1518 return ret; 1519 } 1520 1521#ifndef OPENSSL_NO_HEARTBEATS 1522int 1523dtls1_process_heartbeat(SSL *s) 1524 { 1525 unsigned char *p = &s->s3->rrec.data[0], *pl; 1526 unsigned short hbtype; 1527 unsigned int payload; 1528 unsigned int padding = 16; /* Use minimum padding */ 1529 1530 if (s->msg_callback) 1531 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1532 &s->s3->rrec.data[0], s->s3->rrec.length, 1533 s, s->msg_callback_arg); 1534 1535 /* Read type and payload length first */ 1536 if (1 + 2 + 16 > s->s3->rrec.length) 1537 return 0; /* silently discard */ 1538 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1539 return 0; /* silently discard per RFC 6520 sec. 4 */ 1540 1541 hbtype = *p++; 1542 n2s(p, payload); 1543 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1544 return 0; /* silently discard per RFC 6520 sec. 4 */ 1545 pl = p; 1546 1547 if (hbtype == TLS1_HB_REQUEST) 1548 { 1549 unsigned char *buffer, *bp; 1550 unsigned int write_length = 1 /* heartbeat type */ + 1551 2 /* heartbeat length */ + 1552 payload + padding; 1553 int r; 1554 1555 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1556 return 0; 1557 1558 /* Allocate memory for the response, size is 1 byte 1559 * message type, plus 2 bytes payload length, plus 1560 * payload, plus padding 1561 */ 1562 buffer = OPENSSL_malloc(write_length); 1563 bp = buffer; 1564 1565 /* Enter response type, length and copy payload */ 1566 *bp++ = TLS1_HB_RESPONSE; 1567 s2n(payload, bp); 1568 memcpy(bp, pl, payload); 1569 bp += payload; 1570 /* Random padding */ 1571 RAND_pseudo_bytes(bp, padding); 1572 1573 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1574 1575 if (r >= 0 && s->msg_callback) 1576 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1577 buffer, write_length, 1578 s, s->msg_callback_arg); 1579 1580 OPENSSL_free(buffer); 1581 1582 if (r < 0) 1583 return r; 1584 } 1585 else if (hbtype == TLS1_HB_RESPONSE) 1586 { 1587 unsigned int seq; 1588 1589 /* We only send sequence numbers (2 bytes unsigned int), 1590 * and 16 random bytes, so we just try to read the 1591 * sequence number */ 1592 n2s(pl, seq); 1593 1594 if (payload == 18 && seq == s->tlsext_hb_seq) 1595 { 1596 dtls1_stop_timer(s); 1597 s->tlsext_hb_seq++; 1598 s->tlsext_hb_pending = 0; 1599 } 1600 } 1601 1602 return 0; 1603 } 1604 1605int 1606dtls1_heartbeat(SSL *s) 1607 { 1608 unsigned char *buf, *p; 1609 int ret; 1610 unsigned int payload = 18; /* Sequence number + random bytes */ 1611 unsigned int padding = 16; /* Use minimum padding */ 1612 1613 /* Only send if peer supports and accepts HB requests... */ 1614 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1615 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1616 { 1617 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1618 return -1; 1619 } 1620 1621 /* ...and there is none in flight yet... */ 1622 if (s->tlsext_hb_pending) 1623 { 1624 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1625 return -1; 1626 } 1627 1628 /* ...and no handshake in progress. */ 1629 if (SSL_in_init(s) || s->in_handshake) 1630 { 1631 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1632 return -1; 1633 } 1634 1635 /* Check if padding is too long, payload and padding 1636 * must not exceed 2^14 - 3 = 16381 bytes in total. 1637 */ 1638 OPENSSL_assert(payload + padding <= 16381); 1639 1640 /* Create HeartBeat message, we just use a sequence number 1641 * as payload to distuingish different messages and add 1642 * some random stuff. 1643 * - Message Type, 1 byte 1644 * - Payload Length, 2 bytes (unsigned int) 1645 * - Payload, the sequence number (2 bytes uint) 1646 * - Payload, random bytes (16 bytes uint) 1647 * - Padding 1648 */ 1649 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1650 p = buf; 1651 /* Message Type */ 1652 *p++ = TLS1_HB_REQUEST; 1653 /* Payload length (18 bytes here) */ 1654 s2n(payload, p); 1655 /* Sequence number */ 1656 s2n(s->tlsext_hb_seq, p); 1657 /* 16 random bytes */ 1658 RAND_pseudo_bytes(p, 16); 1659 p += 16; 1660 /* Random padding */ 1661 RAND_pseudo_bytes(p, padding); 1662 1663 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1664 if (ret >= 0) 1665 { 1666 if (s->msg_callback) 1667 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1668 buf, 3 + payload + padding, 1669 s, s->msg_callback_arg); 1670 1671 dtls1_start_timer(s); 1672 s->tlsext_hb_pending = 1; 1673 } 1674 1675 OPENSSL_free(buf); 1676 1677 return ret; 1678 } 1679#endif 1680