d1_both.c revision 264267
1/* ssl/d1_both.c */ 2/* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core@openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116#include <limits.h> 117#include <string.h> 118#include <stdio.h> 119#include "ssl_locl.h" 120#include <openssl/buffer.h> 121#include <openssl/rand.h> 122#include <openssl/objects.h> 123#include <openssl/evp.h> 124#include <openssl/x509.h> 125 126#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 127 128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 129 if ((end) - (start) <= 8) { \ 130 long ii; \ 131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 132 } else { \ 133 long ii; \ 134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 137 } } 138 139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 140 long ii; \ 141 OPENSSL_assert((msg_len) > 0); \ 142 is_complete = 1; \ 143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 146 147#if 0 148#define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \ 149 long ii; \ 150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \ 151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \ 152 printf("\n"); } 153#endif 154 155static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80}; 156static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f}; 157 158/* XDTLS: figure out the right values */ 159static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 160 161static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 162static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 163 unsigned long frag_len); 164static unsigned char *dtls1_write_message_header(SSL *s, 165 unsigned char *p); 166static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 167 unsigned long len, unsigned short seq_num, unsigned long frag_off, 168 unsigned long frag_len); 169static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 170 long max, int *ok); 171 172static hm_fragment * 173dtls1_hm_fragment_new(unsigned long frag_len, int reassembly) 174 { 175 hm_fragment *frag = NULL; 176 unsigned char *buf = NULL; 177 unsigned char *bitmask = NULL; 178 179 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 180 if ( frag == NULL) 181 return NULL; 182 183 if (frag_len) 184 { 185 buf = (unsigned char *)OPENSSL_malloc(frag_len); 186 if ( buf == NULL) 187 { 188 OPENSSL_free(frag); 189 return NULL; 190 } 191 } 192 193 /* zero length fragment gets zero frag->fragment */ 194 frag->fragment = buf; 195 196 /* Initialize reassembly bitmask if necessary */ 197 if (reassembly) 198 { 199 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) 201 { 202 if (buf != NULL) OPENSSL_free(buf); 203 OPENSSL_free(frag); 204 return NULL; 205 } 206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 207 } 208 209 frag->reassembly = bitmask; 210 211 return frag; 212 } 213 214static void 215dtls1_hm_fragment_free(hm_fragment *frag) 216 { 217 218 if (frag->msg_header.is_ccs) 219 { 220 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx); 221 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash); 222 } 223 if (frag->fragment) OPENSSL_free(frag->fragment); 224 if (frag->reassembly) OPENSSL_free(frag->reassembly); 225 OPENSSL_free(frag); 226 } 227 228/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 229int dtls1_do_write(SSL *s, int type) 230 { 231 int ret; 232 int curr_mtu; 233 unsigned int len, frag_off, mac_size, blocksize; 234 235 /* AHA! Figure out the MTU, and stick to the right size */ 236 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 237 { 238 s->d1->mtu = 239 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 240 241 /* I've seen the kernel return bogus numbers when it doesn't know 242 * (initial write), so just make sure we have a reasonable number */ 243 if (s->d1->mtu < dtls1_min_mtu()) 244 { 245 s->d1->mtu = 0; 246 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 247 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 248 s->d1->mtu, NULL); 249 } 250 } 251#if 0 252 mtu = s->d1->mtu; 253 254 fprintf(stderr, "using MTU = %d\n", mtu); 255 256 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 257 258 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 259 260 if ( curr_mtu > 0) 261 mtu = curr_mtu; 262 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0) 263 return ret; 264 265 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) 266 { 267 ret = BIO_flush(SSL_get_wbio(s)); 268 if ( ret <= 0) 269 return ret; 270 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 271 } 272#endif 273 274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */ 275 276 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 277 OPENSSL_assert(s->init_num == 278 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 279 280 if (s->write_hash) 281 mac_size = EVP_MD_CTX_size(s->write_hash); 282 else 283 mac_size = 0; 284 285 if (s->enc_write_ctx && 286 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 287 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 288 else 289 blocksize = 0; 290 291 frag_off = 0; 292 while( s->init_num) 293 { 294 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 295 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; 296 297 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH) 298 { 299 /* grr.. we could get an error if MTU picked was wrong */ 300 ret = BIO_flush(SSL_get_wbio(s)); 301 if ( ret <= 0) 302 return ret; 303 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 304 mac_size - blocksize; 305 } 306 307 if ( s->init_num > curr_mtu) 308 len = curr_mtu; 309 else 310 len = s->init_num; 311 312 313 /* XDTLS: this function is too long. split out the CCS part */ 314 if ( type == SSL3_RT_HANDSHAKE) 315 { 316 if ( s->init_off != 0) 317 { 318 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 319 s->init_off -= DTLS1_HM_HEADER_LENGTH; 320 s->init_num += DTLS1_HM_HEADER_LENGTH; 321 322 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */ 323 if ( len <= DTLS1_HM_HEADER_LENGTH) 324 len += DTLS1_HM_HEADER_LENGTH; 325 } 326 327 dtls1_fix_message_header(s, frag_off, 328 len - DTLS1_HM_HEADER_LENGTH); 329 330 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 331 332 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 333 } 334 335 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 336 len); 337 if (ret < 0) 338 { 339 /* might need to update MTU here, but we don't know 340 * which previous packet caused the failure -- so can't 341 * really retransmit anything. continue as if everything 342 * is fine and wait for an alert to handle the 343 * retransmit 344 */ 345 if ( BIO_ctrl(SSL_get_wbio(s), 346 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 ) 347 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 348 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 349 else 350 return(-1); 351 } 352 else 353 { 354 355 /* bad if this assert fails, only part of the handshake 356 * message got sent. but why would this happen? */ 357 OPENSSL_assert(len == (unsigned int)ret); 358 359 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 360 { 361 /* should not be done for 'Hello Request's, but in that case 362 * we'll ignore the result anyway */ 363 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 364 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 365 int xlen; 366 367 if (frag_off == 0 && s->version != DTLS1_BAD_VER) 368 { 369 /* reconstruct message header is if it 370 * is being sent in single fragment */ 371 *p++ = msg_hdr->type; 372 l2n3(msg_hdr->msg_len,p); 373 s2n (msg_hdr->seq,p); 374 l2n3(0,p); 375 l2n3(msg_hdr->msg_len,p); 376 p -= DTLS1_HM_HEADER_LENGTH; 377 xlen = ret; 378 } 379 else 380 { 381 p += DTLS1_HM_HEADER_LENGTH; 382 xlen = ret - DTLS1_HM_HEADER_LENGTH; 383 } 384 385 ssl3_finish_mac(s, p, xlen); 386 } 387 388 if (ret == s->init_num) 389 { 390 if (s->msg_callback) 391 s->msg_callback(1, s->version, type, s->init_buf->data, 392 (size_t)(s->init_off + s->init_num), s, 393 s->msg_callback_arg); 394 395 s->init_off = 0; /* done writing this message */ 396 s->init_num = 0; 397 398 return(1); 399 } 400 s->init_off+=ret; 401 s->init_num-=ret; 402 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 403 } 404 } 405 return(0); 406 } 407 408 409/* Obtain handshake message of message type 'mt' (any if mt == -1), 410 * maximum acceptable body length 'max'. 411 * Read an entire handshake message. Handshake messages arrive in 412 * fragments. 413 */ 414long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 415 { 416 int i, al; 417 struct hm_header_st *msg_hdr; 418 unsigned char *p; 419 unsigned long msg_len; 420 421 /* s3->tmp is used to store messages that are unexpected, caused 422 * by the absence of an optional handshake message */ 423 if (s->s3->tmp.reuse_message) 424 { 425 s->s3->tmp.reuse_message=0; 426 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 427 { 428 al=SSL_AD_UNEXPECTED_MESSAGE; 429 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 430 goto f_err; 431 } 432 *ok=1; 433 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 434 s->init_num = (int)s->s3->tmp.message_size; 435 return s->init_num; 436 } 437 438 msg_hdr = &s->d1->r_msg_hdr; 439 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 440 441again: 442 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 443 if ( i == DTLS1_HM_BAD_FRAGMENT || 444 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 445 goto again; 446 else if ( i <= 0 && !*ok) 447 return i; 448 449 p = (unsigned char *)s->init_buf->data; 450 msg_len = msg_hdr->msg_len; 451 452 /* reconstruct message header */ 453 *(p++) = msg_hdr->type; 454 l2n3(msg_len,p); 455 s2n (msg_hdr->seq,p); 456 l2n3(0,p); 457 l2n3(msg_len,p); 458 if (s->version != DTLS1_BAD_VER) { 459 p -= DTLS1_HM_HEADER_LENGTH; 460 msg_len += DTLS1_HM_HEADER_LENGTH; 461 } 462 463 ssl3_finish_mac(s, p, msg_len); 464 if (s->msg_callback) 465 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 466 p, msg_len, 467 s, s->msg_callback_arg); 468 469 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 470 471 /* Don't change sequence numbers while listening */ 472 if (!s->d1->listen) 473 s->d1->handshake_read_seq++; 474 475 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 476 return s->init_num; 477 478f_err: 479 ssl3_send_alert(s,SSL3_AL_FATAL,al); 480 *ok = 0; 481 return -1; 482 } 483 484 485static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 486 { 487 size_t frag_off,frag_len,msg_len; 488 489 msg_len = msg_hdr->msg_len; 490 frag_off = msg_hdr->frag_off; 491 frag_len = msg_hdr->frag_len; 492 493 /* sanity checking */ 494 if ( (frag_off+frag_len) > msg_len) 495 { 496 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 497 return SSL_AD_ILLEGAL_PARAMETER; 498 } 499 500 if ( (frag_off+frag_len) > (unsigned long)max) 501 { 502 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 503 return SSL_AD_ILLEGAL_PARAMETER; 504 } 505 506 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 507 { 508 /* msg_len is limited to 2^24, but is effectively checked 509 * against max above */ 510 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH)) 511 { 512 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 513 return SSL_AD_INTERNAL_ERROR; 514 } 515 516 s->s3->tmp.message_size = msg_len; 517 s->d1->r_msg_hdr.msg_len = msg_len; 518 s->s3->tmp.message_type = msg_hdr->type; 519 s->d1->r_msg_hdr.type = msg_hdr->type; 520 s->d1->r_msg_hdr.seq = msg_hdr->seq; 521 } 522 else if (msg_len != s->d1->r_msg_hdr.msg_len) 523 { 524 /* They must be playing with us! BTW, failure to enforce 525 * upper limit would open possibility for buffer overrun. */ 526 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 527 return SSL_AD_ILLEGAL_PARAMETER; 528 } 529 530 return 0; /* no error */ 531 } 532 533 534static int 535dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 536 { 537 /* (0) check whether the desired fragment is available 538 * if so: 539 * (1) copy over the fragment to s->init_buf->data[] 540 * (2) update s->init_num 541 */ 542 pitem *item; 543 hm_fragment *frag; 544 int al; 545 546 *ok = 0; 547 item = pqueue_peek(s->d1->buffered_messages); 548 if ( item == NULL) 549 return 0; 550 551 frag = (hm_fragment *)item->data; 552 553 /* Don't return if reassembly still in progress */ 554 if (frag->reassembly != NULL) 555 return 0; 556 557 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 558 { 559 unsigned long frag_len = frag->msg_header.frag_len; 560 pqueue_pop(s->d1->buffered_messages); 561 562 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 563 564 if (al==0) /* no alert */ 565 { 566 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 567 memcpy(&p[frag->msg_header.frag_off], 568 frag->fragment,frag->msg_header.frag_len); 569 } 570 571 dtls1_hm_fragment_free(frag); 572 pitem_free(item); 573 574 if (al==0) 575 { 576 *ok = 1; 577 return frag_len; 578 } 579 580 ssl3_send_alert(s,SSL3_AL_FATAL,al); 581 s->init_num = 0; 582 *ok = 0; 583 return -1; 584 } 585 else 586 return 0; 587 } 588 589 590static int 591dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok) 592 { 593 hm_fragment *frag = NULL; 594 pitem *item = NULL; 595 int i = -1, is_complete; 596 unsigned char seq64be[8]; 597 unsigned long frag_len = msg_hdr->frag_len, max_len; 598 599 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 600 goto err; 601 602 /* Determine maximum allowed message size. Depends on (user set) 603 * maximum certificate length, but 16k is minimum. 604 */ 605 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list) 606 max_len = s->max_cert_list; 607 else 608 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 609 610 if ((msg_hdr->frag_off+frag_len) > max_len) 611 goto err; 612 613 /* Try to find item in queue */ 614 memset(seq64be,0,sizeof(seq64be)); 615 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 616 seq64be[7] = (unsigned char) msg_hdr->seq; 617 item = pqueue_find(s->d1->buffered_messages, seq64be); 618 619 if (item == NULL) 620 { 621 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 622 if ( frag == NULL) 623 goto err; 624 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 625 frag->msg_header.frag_len = frag->msg_header.msg_len; 626 frag->msg_header.frag_off = 0; 627 } 628 else 629 frag = (hm_fragment*) item->data; 630 631 /* If message is already reassembled, this must be a 632 * retransmit and can be dropped. 633 */ 634 if (frag->reassembly == NULL) 635 { 636 unsigned char devnull [256]; 637 638 while (frag_len) 639 { 640 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 641 devnull, 642 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 643 if (i<=0) goto err; 644 frag_len -= i; 645 } 646 return DTLS1_HM_FRAGMENT_RETRY; 647 } 648 649 /* read the body of the fragment (header has already been read */ 650 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 651 frag->fragment + msg_hdr->frag_off,frag_len,0); 652 if (i<=0 || (unsigned long)i!=frag_len) 653 goto err; 654 655 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 656 (long)(msg_hdr->frag_off + frag_len)); 657 658 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 659 is_complete); 660 661 if (is_complete) 662 { 663 OPENSSL_free(frag->reassembly); 664 frag->reassembly = NULL; 665 } 666 667 if (item == NULL) 668 { 669 memset(seq64be,0,sizeof(seq64be)); 670 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 671 seq64be[7] = (unsigned char)(msg_hdr->seq); 672 673 item = pitem_new(seq64be, frag); 674 if (item == NULL) 675 { 676 goto err; 677 i = -1; 678 } 679 680 pqueue_insert(s->d1->buffered_messages, item); 681 } 682 683 return DTLS1_HM_FRAGMENT_RETRY; 684 685err: 686 if (frag != NULL) dtls1_hm_fragment_free(frag); 687 if (item != NULL) OPENSSL_free(item); 688 *ok = 0; 689 return i; 690 } 691 692 693static int 694dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 695{ 696 int i=-1; 697 hm_fragment *frag = NULL; 698 pitem *item = NULL; 699 unsigned char seq64be[8]; 700 unsigned long frag_len = msg_hdr->frag_len; 701 702 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 703 goto err; 704 705 /* Try to find item in queue, to prevent duplicate entries */ 706 memset(seq64be,0,sizeof(seq64be)); 707 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 708 seq64be[7] = (unsigned char) msg_hdr->seq; 709 item = pqueue_find(s->d1->buffered_messages, seq64be); 710 711 /* If we already have an entry and this one is a fragment, 712 * don't discard it and rather try to reassemble it. 713 */ 714 if (item != NULL && frag_len < msg_hdr->msg_len) 715 item = NULL; 716 717 /* Discard the message if sequence number was already there, is 718 * too far in the future, already in the queue or if we received 719 * a FINISHED before the SERVER_HELLO, which then must be a stale 720 * retransmit. 721 */ 722 if (msg_hdr->seq <= s->d1->handshake_read_seq || 723 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 724 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 725 { 726 unsigned char devnull [256]; 727 728 while (frag_len) 729 { 730 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 731 devnull, 732 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 733 if (i<=0) goto err; 734 frag_len -= i; 735 } 736 } 737 else 738 { 739 if (frag_len && frag_len < msg_hdr->msg_len) 740 return dtls1_reassemble_fragment(s, msg_hdr, ok); 741 742 frag = dtls1_hm_fragment_new(frag_len, 0); 743 if ( frag == NULL) 744 goto err; 745 746 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 747 748 if (frag_len) 749 { 750 /* read the body of the fragment (header has already been read */ 751 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 752 frag->fragment,frag_len,0); 753 if (i<=0 || (unsigned long)i!=frag_len) 754 goto err; 755 } 756 757 memset(seq64be,0,sizeof(seq64be)); 758 seq64be[6] = (unsigned char)(msg_hdr->seq>>8); 759 seq64be[7] = (unsigned char)(msg_hdr->seq); 760 761 item = pitem_new(seq64be, frag); 762 if ( item == NULL) 763 goto err; 764 765 pqueue_insert(s->d1->buffered_messages, item); 766 } 767 768 return DTLS1_HM_FRAGMENT_RETRY; 769 770err: 771 if ( frag != NULL) dtls1_hm_fragment_free(frag); 772 if ( item != NULL) OPENSSL_free(item); 773 *ok = 0; 774 return i; 775 } 776 777 778static long 779dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 780 { 781 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 782 unsigned long len, frag_off, frag_len; 783 int i,al; 784 struct hm_header_st msg_hdr; 785 786 /* see if we have the required fragment already */ 787 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 788 { 789 if (*ok) s->init_num = frag_len; 790 return frag_len; 791 } 792 793 /* read handshake message header */ 794 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 795 DTLS1_HM_HEADER_LENGTH, 0); 796 if (i <= 0) /* nbio, or an error */ 797 { 798 s->rwstate=SSL_READING; 799 *ok = 0; 800 return i; 801 } 802 /* Handshake fails if message header is incomplete */ 803 if (i != DTLS1_HM_HEADER_LENGTH) 804 { 805 al=SSL_AD_UNEXPECTED_MESSAGE; 806 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 807 goto f_err; 808 } 809 810 /* parse the message fragment header */ 811 dtls1_get_message_header(wire, &msg_hdr); 812 813 /* 814 * if this is a future (or stale) message it gets buffered 815 * (or dropped)--no further processing at this time 816 * While listening, we accept seq 1 (ClientHello with cookie) 817 * although we're still expecting seq 0 (ClientHello) 818 */ 819 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 820 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 821 822 len = msg_hdr.msg_len; 823 frag_off = msg_hdr.frag_off; 824 frag_len = msg_hdr.frag_len; 825 826 if (frag_len && frag_len < len) 827 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 828 829 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 830 wire[0] == SSL3_MT_HELLO_REQUEST) 831 { 832 /* The server may always send 'Hello Request' messages -- 833 * we are doing a handshake anyway now, so ignore them 834 * if their format is correct. Does not count for 835 * 'Finished' MAC. */ 836 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 837 { 838 if (s->msg_callback) 839 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 840 wire, DTLS1_HM_HEADER_LENGTH, s, 841 s->msg_callback_arg); 842 843 s->init_num = 0; 844 return dtls1_get_message_fragment(s, st1, stn, 845 max, ok); 846 } 847 else /* Incorrectly formated Hello request */ 848 { 849 al=SSL_AD_UNEXPECTED_MESSAGE; 850 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 851 goto f_err; 852 } 853 } 854 855 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 856 goto f_err; 857 858 /* XDTLS: ressurect this when restart is in place */ 859 s->state=stn; 860 861 if ( frag_len > 0) 862 { 863 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 864 865 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 866 &p[frag_off],frag_len,0); 867 /* XDTLS: fix this--message fragments cannot span multiple packets */ 868 if (i <= 0) 869 { 870 s->rwstate=SSL_READING; 871 *ok = 0; 872 return i; 873 } 874 } 875 else 876 i = 0; 877 878 /* XDTLS: an incorrectly formatted fragment should cause the 879 * handshake to fail */ 880 if (i != (int)frag_len) 881 { 882 al=SSL3_AD_ILLEGAL_PARAMETER; 883 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 884 goto f_err; 885 } 886 887 *ok = 1; 888 889 /* Note that s->init_num is *not* used as current offset in 890 * s->init_buf->data, but as a counter summing up fragments' 891 * lengths: as soon as they sum up to handshake packet 892 * length, we assume we have got all the fragments. */ 893 s->init_num = frag_len; 894 return frag_len; 895 896f_err: 897 ssl3_send_alert(s,SSL3_AL_FATAL,al); 898 s->init_num = 0; 899 900 *ok=0; 901 return(-1); 902 } 903 904int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 905 { 906 unsigned char *p,*d; 907 int i; 908 unsigned long l; 909 910 if (s->state == a) 911 { 912 d=(unsigned char *)s->init_buf->data; 913 p= &(d[DTLS1_HM_HEADER_LENGTH]); 914 915 i=s->method->ssl3_enc->final_finish_mac(s, 916 sender,slen,s->s3->tmp.finish_md); 917 s->s3->tmp.finish_md_len = i; 918 memcpy(p, s->s3->tmp.finish_md, i); 919 p+=i; 920 l=i; 921 922 /* Copy the finished so we can use it for 923 * renegotiation checks 924 */ 925 if(s->type == SSL_ST_CONNECT) 926 { 927 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 928 memcpy(s->s3->previous_client_finished, 929 s->s3->tmp.finish_md, i); 930 s->s3->previous_client_finished_len=i; 931 } 932 else 933 { 934 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 935 memcpy(s->s3->previous_server_finished, 936 s->s3->tmp.finish_md, i); 937 s->s3->previous_server_finished_len=i; 938 } 939 940#ifdef OPENSSL_SYS_WIN16 941 /* MSVC 1.5 does not clear the top bytes of the word unless 942 * I do this. 943 */ 944 l&=0xffff; 945#endif 946 947 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 948 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 949 s->init_off=0; 950 951 /* buffer the message to handle re-xmits */ 952 dtls1_buffer_message(s, 0); 953 954 s->state=b; 955 } 956 957 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 958 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 959 } 960 961/* for these 2 messages, we need to 962 * ssl->enc_read_ctx re-init 963 * ssl->s3->read_sequence zero 964 * ssl->s3->read_mac_secret re-init 965 * ssl->session->read_sym_enc assign 966 * ssl->session->read_compression assign 967 * ssl->session->read_hash assign 968 */ 969int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 970 { 971 unsigned char *p; 972 973 if (s->state == a) 974 { 975 p=(unsigned char *)s->init_buf->data; 976 *p++=SSL3_MT_CCS; 977 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 978 s->init_num=DTLS1_CCS_HEADER_LENGTH; 979 980 if (s->version == DTLS1_BAD_VER) { 981 s->d1->next_handshake_write_seq++; 982 s2n(s->d1->handshake_write_seq,p); 983 s->init_num+=2; 984 } 985 986 s->init_off=0; 987 988 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 989 s->d1->handshake_write_seq, 0, 0); 990 991 /* buffer the message to handle re-xmits */ 992 dtls1_buffer_message(s, 1); 993 994 s->state=b; 995 } 996 997 /* SSL3_ST_CW_CHANGE_B */ 998 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 999 } 1000 1001static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1002 { 1003 int n; 1004 unsigned char *p; 1005 1006 n=i2d_X509(x,NULL); 1007 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1008 { 1009 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1010 return 0; 1011 } 1012 p=(unsigned char *)&(buf->data[*l]); 1013 l2n3(n,p); 1014 i2d_X509(x,&p); 1015 *l+=n+3; 1016 1017 return 1; 1018 } 1019unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1020 { 1021 unsigned char *p; 1022 int i; 1023 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1024 BUF_MEM *buf; 1025 1026 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1027 buf=s->init_buf; 1028 if (!BUF_MEM_grow_clean(buf,10)) 1029 { 1030 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1031 return(0); 1032 } 1033 if (x != NULL) 1034 { 1035 X509_STORE_CTX xs_ctx; 1036 1037 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1038 { 1039 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1040 return(0); 1041 } 1042 1043 X509_verify_cert(&xs_ctx); 1044 /* Don't leave errors in the queue */ 1045 ERR_clear_error(); 1046 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1047 { 1048 x = sk_X509_value(xs_ctx.chain, i); 1049 1050 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1051 { 1052 X509_STORE_CTX_cleanup(&xs_ctx); 1053 return 0; 1054 } 1055 } 1056 X509_STORE_CTX_cleanup(&xs_ctx); 1057 } 1058 /* Thawte special :-) */ 1059 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1060 { 1061 x=sk_X509_value(s->ctx->extra_certs,i); 1062 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1063 return 0; 1064 } 1065 1066 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1067 1068 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1069 l2n3(l,p); 1070 l+=3; 1071 p=(unsigned char *)&(buf->data[0]); 1072 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1073 1074 l+=DTLS1_HM_HEADER_LENGTH; 1075 return(l); 1076 } 1077 1078int dtls1_read_failed(SSL *s, int code) 1079 { 1080 if ( code > 0) 1081 { 1082 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1083 return 1; 1084 } 1085 1086 if (!dtls1_is_timer_expired(s)) 1087 { 1088 /* not a timeout, none of our business, 1089 let higher layers handle this. in fact it's probably an error */ 1090 return code; 1091 } 1092 1093#ifndef OPENSSL_NO_HEARTBEATS 1094 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1095#else 1096 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1097#endif 1098 { 1099 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1100 return code; 1101 } 1102 1103#if 0 /* for now, each alert contains only one record number */ 1104 item = pqueue_peek(state->rcvd_records); 1105 if ( item ) 1106 { 1107 /* send an alert immediately for all the missing records */ 1108 } 1109 else 1110#endif 1111 1112#if 0 /* no more alert sending, just retransmit the last set of messages */ 1113 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1114 ssl3_send_alert(s,SSL3_AL_WARNING, 1115 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1116#endif 1117 1118 return dtls1_handle_timeout(s); 1119 } 1120 1121int 1122dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1123 { 1124 /* The index of the retransmission queue actually is the message sequence number, 1125 * since the queue only contains messages of a single handshake. However, the 1126 * ChangeCipherSpec has no message sequence number and so using only the sequence 1127 * will result in the CCS and Finished having the same index. To prevent this, 1128 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1129 * This does not only differ CSS and Finished, it also maintains the order of the 1130 * index (important for priority queues) and fits in the unsigned short variable. 1131 */ 1132 return seq * 2 - is_ccs; 1133 } 1134 1135int 1136dtls1_retransmit_buffered_messages(SSL *s) 1137 { 1138 pqueue sent = s->d1->sent_messages; 1139 piterator iter; 1140 pitem *item; 1141 hm_fragment *frag; 1142 int found = 0; 1143 1144 iter = pqueue_iterator(sent); 1145 1146 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1147 { 1148 frag = (hm_fragment *)item->data; 1149 if ( dtls1_retransmit_message(s, 1150 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1151 0, &found) <= 0 && found) 1152 { 1153 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1154 return -1; 1155 } 1156 } 1157 1158 return 1; 1159 } 1160 1161int 1162dtls1_buffer_message(SSL *s, int is_ccs) 1163 { 1164 pitem *item; 1165 hm_fragment *frag; 1166 unsigned char seq64be[8]; 1167 1168 /* this function is called immediately after a message has 1169 * been serialized */ 1170 OPENSSL_assert(s->init_off == 0); 1171 1172 frag = dtls1_hm_fragment_new(s->init_num, 0); 1173 1174 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1175 1176 if ( is_ccs) 1177 { 1178 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1179 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1180 } 1181 else 1182 { 1183 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1184 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1185 } 1186 1187 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1188 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1189 frag->msg_header.type = s->d1->w_msg_hdr.type; 1190 frag->msg_header.frag_off = 0; 1191 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1192 frag->msg_header.is_ccs = is_ccs; 1193 1194 /* save current state*/ 1195 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1196 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1197 frag->msg_header.saved_retransmit_state.compress = s->compress; 1198 frag->msg_header.saved_retransmit_state.session = s->session; 1199 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1200 1201 memset(seq64be,0,sizeof(seq64be)); 1202 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1203 frag->msg_header.is_ccs)>>8); 1204 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1205 frag->msg_header.is_ccs)); 1206 1207 item = pitem_new(seq64be, frag); 1208 if ( item == NULL) 1209 { 1210 dtls1_hm_fragment_free(frag); 1211 return 0; 1212 } 1213 1214#if 0 1215 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1216 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1217 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1218#endif 1219 1220 pqueue_insert(s->d1->sent_messages, item); 1221 return 1; 1222 } 1223 1224int 1225dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1226 int *found) 1227 { 1228 int ret; 1229 /* XDTLS: for now assuming that read/writes are blocking */ 1230 pitem *item; 1231 hm_fragment *frag ; 1232 unsigned long header_length; 1233 unsigned char seq64be[8]; 1234 struct dtls1_retransmit_state saved_state; 1235 unsigned char save_write_sequence[8]; 1236 1237 /* 1238 OPENSSL_assert(s->init_num == 0); 1239 OPENSSL_assert(s->init_off == 0); 1240 */ 1241 1242 /* XDTLS: the requested message ought to be found, otherwise error */ 1243 memset(seq64be,0,sizeof(seq64be)); 1244 seq64be[6] = (unsigned char)(seq>>8); 1245 seq64be[7] = (unsigned char)seq; 1246 1247 item = pqueue_find(s->d1->sent_messages, seq64be); 1248 if ( item == NULL) 1249 { 1250 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1251 *found = 0; 1252 return 0; 1253 } 1254 1255 *found = 1; 1256 frag = (hm_fragment *)item->data; 1257 1258 if ( frag->msg_header.is_ccs) 1259 header_length = DTLS1_CCS_HEADER_LENGTH; 1260 else 1261 header_length = DTLS1_HM_HEADER_LENGTH; 1262 1263 memcpy(s->init_buf->data, frag->fragment, 1264 frag->msg_header.msg_len + header_length); 1265 s->init_num = frag->msg_header.msg_len + header_length; 1266 1267 dtls1_set_message_header_int(s, frag->msg_header.type, 1268 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1269 frag->msg_header.frag_len); 1270 1271 /* save current state */ 1272 saved_state.enc_write_ctx = s->enc_write_ctx; 1273 saved_state.write_hash = s->write_hash; 1274 saved_state.compress = s->compress; 1275 saved_state.session = s->session; 1276 saved_state.epoch = s->d1->w_epoch; 1277 saved_state.epoch = s->d1->w_epoch; 1278 1279 s->d1->retransmitting = 1; 1280 1281 /* restore state in which the message was originally sent */ 1282 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1283 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1284 s->compress = frag->msg_header.saved_retransmit_state.compress; 1285 s->session = frag->msg_header.saved_retransmit_state.session; 1286 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1287 1288 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1289 { 1290 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1291 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1292 } 1293 1294 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1295 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1296 1297 /* restore current state */ 1298 s->enc_write_ctx = saved_state.enc_write_ctx; 1299 s->write_hash = saved_state.write_hash; 1300 s->compress = saved_state.compress; 1301 s->session = saved_state.session; 1302 s->d1->w_epoch = saved_state.epoch; 1303 1304 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1305 { 1306 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1307 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1308 } 1309 1310 s->d1->retransmitting = 0; 1311 1312 (void)BIO_flush(SSL_get_wbio(s)); 1313 return ret; 1314 } 1315 1316/* call this function when the buffered messages are no longer needed */ 1317void 1318dtls1_clear_record_buffer(SSL *s) 1319 { 1320 pitem *item; 1321 1322 for(item = pqueue_pop(s->d1->sent_messages); 1323 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1324 { 1325 dtls1_hm_fragment_free((hm_fragment *)item->data); 1326 pitem_free(item); 1327 } 1328 } 1329 1330 1331unsigned char * 1332dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1333 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1334 { 1335 /* Don't change sequence numbers while listening */ 1336 if (frag_off == 0 && !s->d1->listen) 1337 { 1338 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1339 s->d1->next_handshake_write_seq++; 1340 } 1341 1342 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1343 frag_off, frag_len); 1344 1345 return p += DTLS1_HM_HEADER_LENGTH; 1346 } 1347 1348 1349/* don't actually do the writing, wait till the MTU has been retrieved */ 1350static void 1351dtls1_set_message_header_int(SSL *s, unsigned char mt, 1352 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1353 unsigned long frag_len) 1354 { 1355 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1356 1357 msg_hdr->type = mt; 1358 msg_hdr->msg_len = len; 1359 msg_hdr->seq = seq_num; 1360 msg_hdr->frag_off = frag_off; 1361 msg_hdr->frag_len = frag_len; 1362 } 1363 1364static void 1365dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1366 unsigned long frag_len) 1367 { 1368 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1369 1370 msg_hdr->frag_off = frag_off; 1371 msg_hdr->frag_len = frag_len; 1372 } 1373 1374static unsigned char * 1375dtls1_write_message_header(SSL *s, unsigned char *p) 1376 { 1377 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1378 1379 *p++ = msg_hdr->type; 1380 l2n3(msg_hdr->msg_len, p); 1381 1382 s2n(msg_hdr->seq, p); 1383 l2n3(msg_hdr->frag_off, p); 1384 l2n3(msg_hdr->frag_len, p); 1385 1386 return p; 1387 } 1388 1389unsigned int 1390dtls1_min_mtu(void) 1391 { 1392 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1393 sizeof(g_probable_mtu[0])) - 1]); 1394 } 1395 1396static unsigned int 1397dtls1_guess_mtu(unsigned int curr_mtu) 1398 { 1399 unsigned int i; 1400 1401 if ( curr_mtu == 0 ) 1402 return g_probable_mtu[0] ; 1403 1404 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1405 if ( curr_mtu > g_probable_mtu[i]) 1406 return g_probable_mtu[i]; 1407 1408 return curr_mtu; 1409 } 1410 1411void 1412dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1413 { 1414 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1415 msg_hdr->type = *(data++); 1416 n2l3(data, msg_hdr->msg_len); 1417 1418 n2s(data, msg_hdr->seq); 1419 n2l3(data, msg_hdr->frag_off); 1420 n2l3(data, msg_hdr->frag_len); 1421 } 1422 1423void 1424dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1425 { 1426 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1427 1428 ccs_hdr->type = *(data++); 1429 } 1430 1431int dtls1_shutdown(SSL *s) 1432 { 1433 int ret; 1434#ifndef OPENSSL_NO_SCTP 1435 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1436 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1437 { 1438 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1439 if (ret < 0) return -1; 1440 1441 if (ret == 0) 1442 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1443 } 1444#endif 1445 ret = ssl3_shutdown(s); 1446#ifndef OPENSSL_NO_SCTP 1447 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1448#endif 1449 return ret; 1450 } 1451 1452#ifndef OPENSSL_NO_HEARTBEATS 1453int 1454dtls1_process_heartbeat(SSL *s) 1455 { 1456 unsigned char *p = &s->s3->rrec.data[0], *pl; 1457 unsigned short hbtype; 1458 unsigned int payload; 1459 unsigned int padding = 16; /* Use minimum padding */ 1460 1461 if (s->msg_callback) 1462 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1463 &s->s3->rrec.data[0], s->s3->rrec.length, 1464 s, s->msg_callback_arg); 1465 1466 /* Read type and payload length first */ 1467 if (1 + 2 + 16 > s->s3->rrec.length) 1468 return 0; /* silently discard */ 1469 hbtype = *p++; 1470 n2s(p, payload); 1471 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1472 return 0; /* silently discard per RFC 6520 sec. 4 */ 1473 pl = p; 1474 1475 if (hbtype == TLS1_HB_REQUEST) 1476 { 1477 unsigned char *buffer, *bp; 1478 unsigned int write_length = 1 /* heartbeat type */ + 1479 2 /* heartbeat length */ + 1480 payload + padding; 1481 int r; 1482 1483 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1484 return 0; 1485 1486 /* Allocate memory for the response, size is 1 byte 1487 * message type, plus 2 bytes payload length, plus 1488 * payload, plus padding 1489 */ 1490 buffer = OPENSSL_malloc(write_length); 1491 bp = buffer; 1492 1493 /* Enter response type, length and copy payload */ 1494 *bp++ = TLS1_HB_RESPONSE; 1495 s2n(payload, bp); 1496 memcpy(bp, pl, payload); 1497 bp += payload; 1498 /* Random padding */ 1499 RAND_pseudo_bytes(bp, padding); 1500 1501 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1502 1503 if (r >= 0 && s->msg_callback) 1504 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1505 buffer, write_length, 1506 s, s->msg_callback_arg); 1507 1508 OPENSSL_free(buffer); 1509 1510 if (r < 0) 1511 return r; 1512 } 1513 else if (hbtype == TLS1_HB_RESPONSE) 1514 { 1515 unsigned int seq; 1516 1517 /* We only send sequence numbers (2 bytes unsigned int), 1518 * and 16 random bytes, so we just try to read the 1519 * sequence number */ 1520 n2s(pl, seq); 1521 1522 if (payload == 18 && seq == s->tlsext_hb_seq) 1523 { 1524 dtls1_stop_timer(s); 1525 s->tlsext_hb_seq++; 1526 s->tlsext_hb_pending = 0; 1527 } 1528 } 1529 1530 return 0; 1531 } 1532 1533int 1534dtls1_heartbeat(SSL *s) 1535 { 1536 unsigned char *buf, *p; 1537 int ret; 1538 unsigned int payload = 18; /* Sequence number + random bytes */ 1539 unsigned int padding = 16; /* Use minimum padding */ 1540 1541 /* Only send if peer supports and accepts HB requests... */ 1542 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1543 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1544 { 1545 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1546 return -1; 1547 } 1548 1549 /* ...and there is none in flight yet... */ 1550 if (s->tlsext_hb_pending) 1551 { 1552 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1553 return -1; 1554 } 1555 1556 /* ...and no handshake in progress. */ 1557 if (SSL_in_init(s) || s->in_handshake) 1558 { 1559 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1560 return -1; 1561 } 1562 1563 /* Check if padding is too long, payload and padding 1564 * must not exceed 2^14 - 3 = 16381 bytes in total. 1565 */ 1566 OPENSSL_assert(payload + padding <= 16381); 1567 1568 /* Create HeartBeat message, we just use a sequence number 1569 * as payload to distuingish different messages and add 1570 * some random stuff. 1571 * - Message Type, 1 byte 1572 * - Payload Length, 2 bytes (unsigned int) 1573 * - Payload, the sequence number (2 bytes uint) 1574 * - Payload, random bytes (16 bytes uint) 1575 * - Padding 1576 */ 1577 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1578 p = buf; 1579 /* Message Type */ 1580 *p++ = TLS1_HB_REQUEST; 1581 /* Payload length (18 bytes here) */ 1582 s2n(payload, p); 1583 /* Sequence number */ 1584 s2n(s->tlsext_hb_seq, p); 1585 /* 16 random bytes */ 1586 RAND_pseudo_bytes(p, 16); 1587 p += 16; 1588 /* Random padding */ 1589 RAND_pseudo_bytes(p, padding); 1590 1591 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1592 if (ret >= 0) 1593 { 1594 if (s->msg_callback) 1595 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1596 buf, 3 + payload + padding, 1597 s, s->msg_callback_arg); 1598 1599 dtls1_start_timer(s); 1600 s->tlsext_hb_pending = 1; 1601 } 1602 1603 OPENSSL_free(buf); 1604 1605 return ret; 1606 } 1607#endif 1608