d1_both.c revision 276864
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 p = (unsigned char *)s->init_buf->data; 485 msg_len = msg_hdr->msg_len; 486 487 /* reconstruct message header */ 488 *(p++) = msg_hdr->type; 489 l2n3(msg_len,p); 490 s2n (msg_hdr->seq,p); 491 l2n3(0,p); 492 l2n3(msg_len,p); 493 if (s->version != DTLS1_BAD_VER) { 494 p -= DTLS1_HM_HEADER_LENGTH; 495 msg_len += DTLS1_HM_HEADER_LENGTH; 496 } 497 498 ssl3_finish_mac(s, p, msg_len); 499 if (s->msg_callback) 500 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 501 p, msg_len, 502 s, s->msg_callback_arg); 503 504 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 505 506 /* Don't change sequence numbers while listening */ 507 if (!s->d1->listen) 508 s->d1->handshake_read_seq++; 509 510 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 511 return s->init_num; 512 513f_err: 514 ssl3_send_alert(s,SSL3_AL_FATAL,al); 515 *ok = 0; 516 return -1; 517 } 518 519 520static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 521 { 522 size_t frag_off,frag_len,msg_len; 523 524 msg_len = msg_hdr->msg_len; 525 frag_off = msg_hdr->frag_off; 526 frag_len = msg_hdr->frag_len; 527 528 /* sanity checking */ 529 if ( (frag_off+frag_len) > msg_len) 530 { 531 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 532 return SSL_AD_ILLEGAL_PARAMETER; 533 } 534 535 if ( (frag_off+frag_len) > (unsigned long)max) 536 { 537 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 538 return SSL_AD_ILLEGAL_PARAMETER; 539 } 540 541 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 542 { 543 /* msg_len is limited to 2^24, but is effectively checked 544 * against max above */ 545 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH)) 546 { 547 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 548 return SSL_AD_INTERNAL_ERROR; 549 } 550 551 s->s3->tmp.message_size = msg_len; 552 s->d1->r_msg_hdr.msg_len = msg_len; 553 s->s3->tmp.message_type = msg_hdr->type; 554 s->d1->r_msg_hdr.type = msg_hdr->type; 555 s->d1->r_msg_hdr.seq = msg_hdr->seq; 556 } 557 else if (msg_len != s->d1->r_msg_hdr.msg_len) 558 { 559 /* They must be playing with us! BTW, failure to enforce 560 * upper limit would open possibility for buffer overrun. */ 561 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 562 return SSL_AD_ILLEGAL_PARAMETER; 563 } 564 565 return 0; /* no error */ 566 } 567 568 569static int 570dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 571 { 572 /* (0) check whether the desired fragment is available 573 * if so: 574 * (1) copy over the fragment to s->init_buf->data[] 575 * (2) update s->init_num 576 */ 577 pitem *item; 578 hm_fragment *frag; 579 int al; 580 581 *ok = 0; 582 item = pqueue_peek(s->d1->buffered_messages); 583 if ( item == NULL) 584 return 0; 585 586 frag = (hm_fragment *)item->data; 587 588 /* Don't return if reassembly still in progress */ 589 if (frag->reassembly != NULL) 590 return 0; 591 592 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 593 { 594 unsigned long frag_len = frag->msg_header.frag_len; 595 pqueue_pop(s->d1->buffered_messages); 596 597 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 598 599 if (al==0) /* no alert */ 600 { 601 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 602 memcpy(&p[frag->msg_header.frag_off], 603 frag->fragment,frag->msg_header.frag_len); 604 } 605 606 dtls1_hm_fragment_free(frag); 607 pitem_free(item); 608 609 if (al==0) 610 { 611 *ok = 1; 612 return frag_len; 613 } 614 615 ssl3_send_alert(s,SSL3_AL_FATAL,al); 616 s->init_num = 0; 617 *ok = 0; 618 return -1; 619 } 620 else 621 return 0; 622 } 623 624/* dtls1_max_handshake_message_len returns the maximum number of bytes 625 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may 626 * be greater if the maximum certificate list size requires it. */ 627static unsigned long dtls1_max_handshake_message_len(const SSL *s) 628 { 629 unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 630 if (max_len < (unsigned long)s->max_cert_list) 631 return s->max_cert_list; 632 return max_len; 633 } 634 635static int 636dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 637 { 638 hm_fragment *frag = NULL; 639 pitem *item = NULL; 640 int i = -1, is_complete; 641 unsigned char seq64be[8]; 642 unsigned long frag_len = msg_hdr->frag_len; 643 644 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len || 645 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 646 goto err; 647 648 if (frag_len == 0) 649 return DTLS1_HM_FRAGMENT_RETRY; 650 651 /* Try to find item in queue */ 652 memset(seq64be,0,sizeof(seq64be)); 653 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 654 seq64be[7] = (unsigned char) msg_hdr->seq; 655 item = pqueue_find(s->d1->buffered_messages, seq64be); 656 657 if (item == NULL) 658 { 659 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 660 if ( frag == NULL) 661 goto err; 662 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 663 frag->msg_header.frag_len = frag->msg_header.msg_len; 664 frag->msg_header.frag_off = 0; 665 } 666 else 667 { 668 frag = (hm_fragment*) item->data; 669 if (frag->msg_header.msg_len != msg_hdr->msg_len) 670 { 671 item = NULL; 672 frag = NULL; 673 goto err; 674 } 675 } 676 677 678 /* If message is already reassembled, this must be a 679 * retransmit and can be dropped. In this case item != NULL and so frag 680 * does not need to be freed. 681 */ 682 if (frag->reassembly == NULL) 683 { 684 unsigned char devnull [256]; 685 686 while (frag_len) 687 { 688 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 689 devnull, 690 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 691 if (i<=0) goto err; 692 frag_len -= i; 693 } 694 return DTLS1_HM_FRAGMENT_RETRY; 695 } 696 697 /* read the body of the fragment (header has already been read */ 698 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 699 frag->fragment + msg_hdr->frag_off,frag_len,0); 700 if ((unsigned long)i!=frag_len) 701 i=-1; 702 if (i<=0) 703 goto err; 704 705 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 706 (long)(msg_hdr->frag_off + frag_len)); 707 708 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 709 is_complete); 710 711 if (is_complete) 712 { 713 OPENSSL_free(frag->reassembly); 714 frag->reassembly = NULL; 715 } 716 717 if (item == NULL) 718 { 719 item = pitem_new(seq64be, frag); 720 if (item == NULL) 721 { 722 i = -1; 723 goto err; 724 } 725 726 item = pqueue_insert(s->d1->buffered_messages, item); 727 /* pqueue_insert fails iff a duplicate item is inserted. 728 * However, |item| cannot be a duplicate. If it were, 729 * |pqueue_find|, above, would have returned it and control 730 * would never have reached this branch. */ 731 OPENSSL_assert(item != NULL); 732 } 733 734 return DTLS1_HM_FRAGMENT_RETRY; 735 736err: 737 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 738 *ok = 0; 739 return i; 740 } 741 742 743static int 744dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 745{ 746 int i=-1; 747 hm_fragment *frag = NULL; 748 pitem *item = NULL; 749 unsigned char seq64be[8]; 750 unsigned long frag_len = msg_hdr->frag_len; 751 752 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 753 goto err; 754 755 /* Try to find item in queue, to prevent duplicate entries */ 756 memset(seq64be,0,sizeof(seq64be)); 757 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 758 seq64be[7] = (unsigned char) msg_hdr->seq; 759 item = pqueue_find(s->d1->buffered_messages, seq64be); 760 761 /* If we already have an entry and this one is a fragment, 762 * don't discard it and rather try to reassemble it. 763 */ 764 if (item != NULL && frag_len != msg_hdr->msg_len) 765 item = NULL; 766 767 /* Discard the message if sequence number was already there, is 768 * too far in the future, already in the queue or if we received 769 * a FINISHED before the SERVER_HELLO, which then must be a stale 770 * retransmit. 771 */ 772 if (msg_hdr->seq <= s->d1->handshake_read_seq || 773 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 774 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 775 { 776 unsigned char devnull [256]; 777 778 while (frag_len) 779 { 780 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 781 devnull, 782 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 783 if (i<=0) goto err; 784 frag_len -= i; 785 } 786 } 787 else 788 { 789 if (frag_len != msg_hdr->msg_len) 790 return dtls1_reassemble_fragment(s, msg_hdr, ok); 791 792 if (frag_len > dtls1_max_handshake_message_len(s)) 793 goto err; 794 795 frag = dtls1_hm_fragment_new(frag_len, 0); 796 if ( frag == NULL) 797 goto err; 798 799 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 800 801 if (frag_len) 802 { 803 /* read the body of the fragment (header has already been read */ 804 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 805 frag->fragment,frag_len,0); 806 if ((unsigned long)i!=frag_len) 807 i = -1; 808 if (i<=0) 809 goto err; 810 } 811 812 item = pitem_new(seq64be, frag); 813 if ( item == NULL) 814 goto err; 815 816 item = pqueue_insert(s->d1->buffered_messages, item); 817 /* pqueue_insert fails iff a duplicate item is inserted. 818 * However, |item| cannot be a duplicate. If it were, 819 * |pqueue_find|, above, would have returned it. Then, either 820 * |frag_len| != |msg_hdr->msg_len| in which case |item| is set 821 * to NULL and it will have been processed with 822 * |dtls1_reassemble_fragment|, above, or the record will have 823 * been discarded. */ 824 OPENSSL_assert(item != NULL); 825 } 826 827 return DTLS1_HM_FRAGMENT_RETRY; 828 829err: 830 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 831 *ok = 0; 832 return i; 833 } 834 835 836static long 837dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 838 { 839 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 840 unsigned long len, frag_off, frag_len; 841 int i,al; 842 struct hm_header_st msg_hdr; 843 844 redo: 845 /* see if we have the required fragment already */ 846 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 847 { 848 if (*ok) s->init_num = frag_len; 849 return frag_len; 850 } 851 852 /* read handshake message header */ 853 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 854 DTLS1_HM_HEADER_LENGTH, 0); 855 if (i <= 0) /* nbio, or an error */ 856 { 857 s->rwstate=SSL_READING; 858 *ok = 0; 859 return i; 860 } 861 /* Handshake fails if message header is incomplete */ 862 if (i != DTLS1_HM_HEADER_LENGTH) 863 { 864 al=SSL_AD_UNEXPECTED_MESSAGE; 865 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 866 goto f_err; 867 } 868 869 /* parse the message fragment header */ 870 dtls1_get_message_header(wire, &msg_hdr); 871 872 /* 873 * if this is a future (or stale) message it gets buffered 874 * (or dropped)--no further processing at this time 875 * While listening, we accept seq 1 (ClientHello with cookie) 876 * although we're still expecting seq 0 (ClientHello) 877 */ 878 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 879 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 880 881 len = msg_hdr.msg_len; 882 frag_off = msg_hdr.frag_off; 883 frag_len = msg_hdr.frag_len; 884 885 if (frag_len && frag_len < len) 886 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 887 888 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 889 wire[0] == SSL3_MT_HELLO_REQUEST) 890 { 891 /* The server may always send 'Hello Request' messages -- 892 * we are doing a handshake anyway now, so ignore them 893 * if their format is correct. Does not count for 894 * 'Finished' MAC. */ 895 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 896 { 897 if (s->msg_callback) 898 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 899 wire, DTLS1_HM_HEADER_LENGTH, s, 900 s->msg_callback_arg); 901 902 s->init_num = 0; 903 goto redo; 904 } 905 else /* Incorrectly formated Hello request */ 906 { 907 al=SSL_AD_UNEXPECTED_MESSAGE; 908 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 909 goto f_err; 910 } 911 } 912 913 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 914 goto f_err; 915 916 /* XDTLS: ressurect this when restart is in place */ 917 s->state=stn; 918 919 if ( frag_len > 0) 920 { 921 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 922 923 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 924 &p[frag_off],frag_len,0); 925 /* XDTLS: fix this--message fragments cannot span multiple packets */ 926 if (i <= 0) 927 { 928 s->rwstate=SSL_READING; 929 *ok = 0; 930 return i; 931 } 932 } 933 else 934 i = 0; 935 936 /* XDTLS: an incorrectly formatted fragment should cause the 937 * handshake to fail */ 938 if (i != (int)frag_len) 939 { 940 al=SSL3_AD_ILLEGAL_PARAMETER; 941 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 942 goto f_err; 943 } 944 945 *ok = 1; 946 947 /* Note that s->init_num is *not* used as current offset in 948 * s->init_buf->data, but as a counter summing up fragments' 949 * lengths: as soon as they sum up to handshake packet 950 * length, we assume we have got all the fragments. */ 951 s->init_num = frag_len; 952 return frag_len; 953 954f_err: 955 ssl3_send_alert(s,SSL3_AL_FATAL,al); 956 s->init_num = 0; 957 958 *ok=0; 959 return(-1); 960 } 961 962int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 963 { 964 unsigned char *p,*d; 965 int i; 966 unsigned long l; 967 968 if (s->state == a) 969 { 970 d=(unsigned char *)s->init_buf->data; 971 p= &(d[DTLS1_HM_HEADER_LENGTH]); 972 973 i=s->method->ssl3_enc->final_finish_mac(s, 974 sender,slen,s->s3->tmp.finish_md); 975 s->s3->tmp.finish_md_len = i; 976 memcpy(p, s->s3->tmp.finish_md, i); 977 p+=i; 978 l=i; 979 980 /* Copy the finished so we can use it for 981 * renegotiation checks 982 */ 983 if(s->type == SSL_ST_CONNECT) 984 { 985 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 986 memcpy(s->s3->previous_client_finished, 987 s->s3->tmp.finish_md, i); 988 s->s3->previous_client_finished_len=i; 989 } 990 else 991 { 992 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 993 memcpy(s->s3->previous_server_finished, 994 s->s3->tmp.finish_md, i); 995 s->s3->previous_server_finished_len=i; 996 } 997 998#ifdef OPENSSL_SYS_WIN16 999 /* MSVC 1.5 does not clear the top bytes of the word unless 1000 * I do this. 1001 */ 1002 l&=0xffff; 1003#endif 1004 1005 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 1006 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 1007 s->init_off=0; 1008 1009 /* buffer the message to handle re-xmits */ 1010 dtls1_buffer_message(s, 0); 1011 1012 s->state=b; 1013 } 1014 1015 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 1016 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 1017 } 1018 1019/* for these 2 messages, we need to 1020 * ssl->enc_read_ctx re-init 1021 * ssl->s3->read_sequence zero 1022 * ssl->s3->read_mac_secret re-init 1023 * ssl->session->read_sym_enc assign 1024 * ssl->session->read_compression assign 1025 * ssl->session->read_hash assign 1026 */ 1027int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 1028 { 1029 unsigned char *p; 1030 1031 if (s->state == a) 1032 { 1033 p=(unsigned char *)s->init_buf->data; 1034 *p++=SSL3_MT_CCS; 1035 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1036 s->init_num=DTLS1_CCS_HEADER_LENGTH; 1037 1038 if (s->version == DTLS1_BAD_VER) { 1039 s->d1->next_handshake_write_seq++; 1040 s2n(s->d1->handshake_write_seq,p); 1041 s->init_num+=2; 1042 } 1043 1044 s->init_off=0; 1045 1046 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1047 s->d1->handshake_write_seq, 0, 0); 1048 1049 /* buffer the message to handle re-xmits */ 1050 dtls1_buffer_message(s, 1); 1051 1052 s->state=b; 1053 } 1054 1055 /* SSL3_ST_CW_CHANGE_B */ 1056 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1057 } 1058 1059static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1060 { 1061 int n; 1062 unsigned char *p; 1063 1064 n=i2d_X509(x,NULL); 1065 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1066 { 1067 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1068 return 0; 1069 } 1070 p=(unsigned char *)&(buf->data[*l]); 1071 l2n3(n,p); 1072 i2d_X509(x,&p); 1073 *l+=n+3; 1074 1075 return 1; 1076 } 1077unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1078 { 1079 unsigned char *p; 1080 int i; 1081 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1082 BUF_MEM *buf; 1083 1084 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1085 buf=s->init_buf; 1086 if (!BUF_MEM_grow_clean(buf,10)) 1087 { 1088 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1089 return(0); 1090 } 1091 if (x != NULL) 1092 { 1093 X509_STORE_CTX xs_ctx; 1094 1095 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1096 { 1097 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1098 return(0); 1099 } 1100 1101 X509_verify_cert(&xs_ctx); 1102 /* Don't leave errors in the queue */ 1103 ERR_clear_error(); 1104 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1105 { 1106 x = sk_X509_value(xs_ctx.chain, i); 1107 1108 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1109 { 1110 X509_STORE_CTX_cleanup(&xs_ctx); 1111 return 0; 1112 } 1113 } 1114 X509_STORE_CTX_cleanup(&xs_ctx); 1115 } 1116 /* Thawte special :-) */ 1117 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1118 { 1119 x=sk_X509_value(s->ctx->extra_certs,i); 1120 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1121 return 0; 1122 } 1123 1124 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1125 1126 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1127 l2n3(l,p); 1128 l+=3; 1129 p=(unsigned char *)&(buf->data[0]); 1130 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1131 1132 l+=DTLS1_HM_HEADER_LENGTH; 1133 return(l); 1134 } 1135 1136int dtls1_read_failed(SSL *s, int code) 1137 { 1138 if ( code > 0) 1139 { 1140 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1141 return 1; 1142 } 1143 1144 if (!dtls1_is_timer_expired(s)) 1145 { 1146 /* not a timeout, none of our business, 1147 let higher layers handle this. in fact it's probably an error */ 1148 return code; 1149 } 1150 1151#ifndef OPENSSL_NO_HEARTBEATS 1152 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1153#else 1154 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1155#endif 1156 { 1157 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1158 return code; 1159 } 1160 1161#if 0 /* for now, each alert contains only one record number */ 1162 item = pqueue_peek(state->rcvd_records); 1163 if ( item ) 1164 { 1165 /* send an alert immediately for all the missing records */ 1166 } 1167 else 1168#endif 1169 1170#if 0 /* no more alert sending, just retransmit the last set of messages */ 1171 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1172 ssl3_send_alert(s,SSL3_AL_WARNING, 1173 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1174#endif 1175 1176 return dtls1_handle_timeout(s); 1177 } 1178 1179int 1180dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1181 { 1182 /* The index of the retransmission queue actually is the message sequence number, 1183 * since the queue only contains messages of a single handshake. However, the 1184 * ChangeCipherSpec has no message sequence number and so using only the sequence 1185 * will result in the CCS and Finished having the same index. To prevent this, 1186 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1187 * This does not only differ CSS and Finished, it also maintains the order of the 1188 * index (important for priority queues) and fits in the unsigned short variable. 1189 */ 1190 return seq * 2 - is_ccs; 1191 } 1192 1193int 1194dtls1_retransmit_buffered_messages(SSL *s) 1195 { 1196 pqueue sent = s->d1->sent_messages; 1197 piterator iter; 1198 pitem *item; 1199 hm_fragment *frag; 1200 int found = 0; 1201 1202 iter = pqueue_iterator(sent); 1203 1204 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1205 { 1206 frag = (hm_fragment *)item->data; 1207 if ( dtls1_retransmit_message(s, 1208 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1209 0, &found) <= 0 && found) 1210 { 1211 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1212 return -1; 1213 } 1214 } 1215 1216 return 1; 1217 } 1218 1219int 1220dtls1_buffer_message(SSL *s, int is_ccs) 1221 { 1222 pitem *item; 1223 hm_fragment *frag; 1224 unsigned char seq64be[8]; 1225 1226 /* this function is called immediately after a message has 1227 * been serialized */ 1228 OPENSSL_assert(s->init_off == 0); 1229 1230 frag = dtls1_hm_fragment_new(s->init_num, 0); 1231 if (!frag) 1232 return 0; 1233 1234 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1235 1236 if ( is_ccs) 1237 { 1238 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1239 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1240 } 1241 else 1242 { 1243 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1244 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1245 } 1246 1247 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1248 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1249 frag->msg_header.type = s->d1->w_msg_hdr.type; 1250 frag->msg_header.frag_off = 0; 1251 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1252 frag->msg_header.is_ccs = is_ccs; 1253 1254 /* save current state*/ 1255 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1256 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1257 frag->msg_header.saved_retransmit_state.compress = s->compress; 1258 frag->msg_header.saved_retransmit_state.session = s->session; 1259 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1260 1261 memset(seq64be,0,sizeof(seq64be)); 1262 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1263 frag->msg_header.is_ccs)>>8); 1264 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1265 frag->msg_header.is_ccs)); 1266 1267 item = pitem_new(seq64be, frag); 1268 if ( item == NULL) 1269 { 1270 dtls1_hm_fragment_free(frag); 1271 return 0; 1272 } 1273 1274#if 0 1275 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1276 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1277 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1278#endif 1279 1280 pqueue_insert(s->d1->sent_messages, item); 1281 return 1; 1282 } 1283 1284int 1285dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1286 int *found) 1287 { 1288 int ret; 1289 /* XDTLS: for now assuming that read/writes are blocking */ 1290 pitem *item; 1291 hm_fragment *frag ; 1292 unsigned long header_length; 1293 unsigned char seq64be[8]; 1294 struct dtls1_retransmit_state saved_state; 1295 unsigned char save_write_sequence[8]; 1296 1297 /* 1298 OPENSSL_assert(s->init_num == 0); 1299 OPENSSL_assert(s->init_off == 0); 1300 */ 1301 1302 /* XDTLS: the requested message ought to be found, otherwise error */ 1303 memset(seq64be,0,sizeof(seq64be)); 1304 seq64be[6] = (unsigned char)(seq>>8); 1305 seq64be[7] = (unsigned char)seq; 1306 1307 item = pqueue_find(s->d1->sent_messages, seq64be); 1308 if ( item == NULL) 1309 { 1310 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1311 *found = 0; 1312 return 0; 1313 } 1314 1315 *found = 1; 1316 frag = (hm_fragment *)item->data; 1317 1318 if ( frag->msg_header.is_ccs) 1319 header_length = DTLS1_CCS_HEADER_LENGTH; 1320 else 1321 header_length = DTLS1_HM_HEADER_LENGTH; 1322 1323 memcpy(s->init_buf->data, frag->fragment, 1324 frag->msg_header.msg_len + header_length); 1325 s->init_num = frag->msg_header.msg_len + header_length; 1326 1327 dtls1_set_message_header_int(s, frag->msg_header.type, 1328 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1329 frag->msg_header.frag_len); 1330 1331 /* save current state */ 1332 saved_state.enc_write_ctx = s->enc_write_ctx; 1333 saved_state.write_hash = s->write_hash; 1334 saved_state.compress = s->compress; 1335 saved_state.session = s->session; 1336 saved_state.epoch = s->d1->w_epoch; 1337 saved_state.epoch = s->d1->w_epoch; 1338 1339 s->d1->retransmitting = 1; 1340 1341 /* restore state in which the message was originally sent */ 1342 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1343 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1344 s->compress = frag->msg_header.saved_retransmit_state.compress; 1345 s->session = frag->msg_header.saved_retransmit_state.session; 1346 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1347 1348 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1349 { 1350 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1351 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1352 } 1353 1354 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1355 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1356 1357 /* restore current state */ 1358 s->enc_write_ctx = saved_state.enc_write_ctx; 1359 s->write_hash = saved_state.write_hash; 1360 s->compress = saved_state.compress; 1361 s->session = saved_state.session; 1362 s->d1->w_epoch = saved_state.epoch; 1363 1364 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1365 { 1366 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1367 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1368 } 1369 1370 s->d1->retransmitting = 0; 1371 1372 (void)BIO_flush(SSL_get_wbio(s)); 1373 return ret; 1374 } 1375 1376/* call this function when the buffered messages are no longer needed */ 1377void 1378dtls1_clear_record_buffer(SSL *s) 1379 { 1380 pitem *item; 1381 1382 for(item = pqueue_pop(s->d1->sent_messages); 1383 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1384 { 1385 dtls1_hm_fragment_free((hm_fragment *)item->data); 1386 pitem_free(item); 1387 } 1388 } 1389 1390 1391unsigned char * 1392dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1393 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1394 { 1395 /* Don't change sequence numbers while listening */ 1396 if (frag_off == 0 && !s->d1->listen) 1397 { 1398 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1399 s->d1->next_handshake_write_seq++; 1400 } 1401 1402 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1403 frag_off, frag_len); 1404 1405 return p += DTLS1_HM_HEADER_LENGTH; 1406 } 1407 1408 1409/* don't actually do the writing, wait till the MTU has been retrieved */ 1410static void 1411dtls1_set_message_header_int(SSL *s, unsigned char mt, 1412 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1413 unsigned long frag_len) 1414 { 1415 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1416 1417 msg_hdr->type = mt; 1418 msg_hdr->msg_len = len; 1419 msg_hdr->seq = seq_num; 1420 msg_hdr->frag_off = frag_off; 1421 msg_hdr->frag_len = frag_len; 1422 } 1423 1424static void 1425dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1426 unsigned long frag_len) 1427 { 1428 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1429 1430 msg_hdr->frag_off = frag_off; 1431 msg_hdr->frag_len = frag_len; 1432 } 1433 1434static unsigned char * 1435dtls1_write_message_header(SSL *s, unsigned char *p) 1436 { 1437 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1438 1439 *p++ = msg_hdr->type; 1440 l2n3(msg_hdr->msg_len, p); 1441 1442 s2n(msg_hdr->seq, p); 1443 l2n3(msg_hdr->frag_off, p); 1444 l2n3(msg_hdr->frag_len, p); 1445 1446 return p; 1447 } 1448 1449unsigned int 1450dtls1_link_min_mtu(void) 1451 { 1452 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1453 sizeof(g_probable_mtu[0])) - 1]); 1454 } 1455 1456unsigned int 1457dtls1_min_mtu(SSL *s) 1458 { 1459 return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); 1460 } 1461 1462 1463void 1464dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1465 { 1466 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1467 msg_hdr->type = *(data++); 1468 n2l3(data, msg_hdr->msg_len); 1469 1470 n2s(data, msg_hdr->seq); 1471 n2l3(data, msg_hdr->frag_off); 1472 n2l3(data, msg_hdr->frag_len); 1473 } 1474 1475void 1476dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1477 { 1478 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1479 1480 ccs_hdr->type = *(data++); 1481 } 1482 1483int dtls1_shutdown(SSL *s) 1484 { 1485 int ret; 1486#ifndef OPENSSL_NO_SCTP 1487 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1488 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1489 { 1490 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1491 if (ret < 0) return -1; 1492 1493 if (ret == 0) 1494 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1495 } 1496#endif 1497 ret = ssl3_shutdown(s); 1498#ifndef OPENSSL_NO_SCTP 1499 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1500#endif 1501 return ret; 1502 } 1503 1504#ifndef OPENSSL_NO_HEARTBEATS 1505int 1506dtls1_process_heartbeat(SSL *s) 1507 { 1508 unsigned char *p = &s->s3->rrec.data[0], *pl; 1509 unsigned short hbtype; 1510 unsigned int payload; 1511 unsigned int padding = 16; /* Use minimum padding */ 1512 1513 if (s->msg_callback) 1514 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1515 &s->s3->rrec.data[0], s->s3->rrec.length, 1516 s, s->msg_callback_arg); 1517 1518 /* Read type and payload length first */ 1519 if (1 + 2 + 16 > s->s3->rrec.length) 1520 return 0; /* silently discard */ 1521 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1522 return 0; /* silently discard per RFC 6520 sec. 4 */ 1523 1524 hbtype = *p++; 1525 n2s(p, payload); 1526 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1527 return 0; /* silently discard per RFC 6520 sec. 4 */ 1528 pl = p; 1529 1530 if (hbtype == TLS1_HB_REQUEST) 1531 { 1532 unsigned char *buffer, *bp; 1533 unsigned int write_length = 1 /* heartbeat type */ + 1534 2 /* heartbeat length */ + 1535 payload + padding; 1536 int r; 1537 1538 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1539 return 0; 1540 1541 /* Allocate memory for the response, size is 1 byte 1542 * message type, plus 2 bytes payload length, plus 1543 * payload, plus padding 1544 */ 1545 buffer = OPENSSL_malloc(write_length); 1546 bp = buffer; 1547 1548 /* Enter response type, length and copy payload */ 1549 *bp++ = TLS1_HB_RESPONSE; 1550 s2n(payload, bp); 1551 memcpy(bp, pl, payload); 1552 bp += payload; 1553 /* Random padding */ 1554 RAND_pseudo_bytes(bp, padding); 1555 1556 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1557 1558 if (r >= 0 && s->msg_callback) 1559 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1560 buffer, write_length, 1561 s, s->msg_callback_arg); 1562 1563 OPENSSL_free(buffer); 1564 1565 if (r < 0) 1566 return r; 1567 } 1568 else if (hbtype == TLS1_HB_RESPONSE) 1569 { 1570 unsigned int seq; 1571 1572 /* We only send sequence numbers (2 bytes unsigned int), 1573 * and 16 random bytes, so we just try to read the 1574 * sequence number */ 1575 n2s(pl, seq); 1576 1577 if (payload == 18 && seq == s->tlsext_hb_seq) 1578 { 1579 dtls1_stop_timer(s); 1580 s->tlsext_hb_seq++; 1581 s->tlsext_hb_pending = 0; 1582 } 1583 } 1584 1585 return 0; 1586 } 1587 1588int 1589dtls1_heartbeat(SSL *s) 1590 { 1591 unsigned char *buf, *p; 1592 int ret; 1593 unsigned int payload = 18; /* Sequence number + random bytes */ 1594 unsigned int padding = 16; /* Use minimum padding */ 1595 1596 /* Only send if peer supports and accepts HB requests... */ 1597 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1598 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1599 { 1600 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1601 return -1; 1602 } 1603 1604 /* ...and there is none in flight yet... */ 1605 if (s->tlsext_hb_pending) 1606 { 1607 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1608 return -1; 1609 } 1610 1611 /* ...and no handshake in progress. */ 1612 if (SSL_in_init(s) || s->in_handshake) 1613 { 1614 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1615 return -1; 1616 } 1617 1618 /* Check if padding is too long, payload and padding 1619 * must not exceed 2^14 - 3 = 16381 bytes in total. 1620 */ 1621 OPENSSL_assert(payload + padding <= 16381); 1622 1623 /* Create HeartBeat message, we just use a sequence number 1624 * as payload to distuingish different messages and add 1625 * some random stuff. 1626 * - Message Type, 1 byte 1627 * - Payload Length, 2 bytes (unsigned int) 1628 * - Payload, the sequence number (2 bytes uint) 1629 * - Payload, random bytes (16 bytes uint) 1630 * - Padding 1631 */ 1632 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1633 p = buf; 1634 /* Message Type */ 1635 *p++ = TLS1_HB_REQUEST; 1636 /* Payload length (18 bytes here) */ 1637 s2n(payload, p); 1638 /* Sequence number */ 1639 s2n(s->tlsext_hb_seq, p); 1640 /* 16 random bytes */ 1641 RAND_pseudo_bytes(p, 16); 1642 p += 16; 1643 /* Random padding */ 1644 RAND_pseudo_bytes(p, padding); 1645 1646 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1647 if (ret >= 0) 1648 { 1649 if (s->msg_callback) 1650 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1651 buf, 3 + payload + padding, 1652 s, s->msg_callback_arg); 1653 1654 dtls1_start_timer(s); 1655 s->tlsext_hb_pending = 1; 1656 } 1657 1658 OPENSSL_free(buf); 1659 1660 return ret; 1661 } 1662#endif 1663