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 154 155 static unsigned char bitmask_start_values[] = { 156 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 157 }; 158 static unsigned char bitmask_end_values[] = { 159 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f 160 }; 161 162 /* XDTLS: figure out the right values */ 163 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 164 165 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 166 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 167 unsigned long frag_len); 168 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p); 169 static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 170 unsigned long len, unsigned short seq_num, unsigned long frag_off, 171 unsigned long frag_len); 172 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, 173 int *ok); 174 175 static hm_fragment * 176 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly) 177 { 178 hm_fragment *frag = NULL; 179 unsigned char *buf = NULL; 180 unsigned char *bitmask = NULL; 181 182 frag = malloc(sizeof(hm_fragment)); 183 if (frag == NULL) 184 return NULL; 185 186 if (frag_len) { 187 buf = malloc(frag_len); 188 if (buf == NULL) { 189 free(frag); 190 return NULL; 191 } 192 } 193 194 /* zero length fragment gets zero frag->fragment */ 195 frag->fragment = buf; 196 197 /* Initialize reassembly bitmask if necessary */ 198 if (reassembly) { 199 bitmask = malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) { 201 if (buf != NULL) 202 free(buf); 203 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 } 213 214 static void 215 dtls1_hm_fragment_free(hm_fragment *frag) 216 { 217 218 if (frag->msg_header.is_ccs) { 219 EVP_CIPHER_CTX_free( 220 frag->msg_header.saved_retransmit_state.enc_write_ctx); 221 EVP_MD_CTX_destroy( 222 frag->msg_header.saved_retransmit_state.write_hash); 223 } 224 if (frag->fragment) 225 free(frag->fragment); 226 if (frag->reassembly) 227 free(frag->reassembly); 228 free(frag); 229 } 230 231 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 232 int 233 dtls1_do_write(SSL *s, int type) 234 { 235 int ret; 236 int curr_mtu; 237 unsigned int len, frag_off, mac_size, blocksize; 238 239 /* AHA! Figure out the MTU, and stick to the right size */ 240 if (s->d1->mtu < dtls1_min_mtu() && 241 !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { 242 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 243 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 244 245 /* I've seen the kernel return bogus numbers when it doesn't know 246 * (initial write), so just make sure we have a reasonable number */ 247 if (s->d1->mtu < dtls1_min_mtu()) { 248 s->d1->mtu = 0; 249 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 250 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 251 s->d1->mtu, NULL); 252 } 253 } 254 #if 0 255 mtu = s->d1->mtu; 256 257 fprintf(stderr, "using MTU = %d\n", mtu); 258 259 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 260 261 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 262 263 if (curr_mtu > 0) 264 mtu = curr_mtu; 265 else if (( ret = BIO_flush(SSL_get_wbio(s))) <= 0) 266 return ret; 267 268 if (BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) { 269 ret = BIO_flush(SSL_get_wbio(s)); 270 if (ret <= 0) 271 return ret; 272 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + 273 DTLS1_RT_HEADER_LENGTH); 274 } 275 #endif 276 277 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); 278 /* should have something reasonable now */ 279 280 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 281 OPENSSL_assert(s->init_num == 282 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 283 284 if (s->write_hash) 285 mac_size = EVP_MD_CTX_size(s->write_hash); 286 else 287 mac_size = 0; 288 289 if (s->enc_write_ctx && 290 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 291 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 292 else 293 blocksize = 0; 294 295 frag_off = 0; 296 while (s->init_num) { 297 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 298 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; 299 300 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) { 301 /* grr.. we could get an error if MTU picked was wrong */ 302 ret = BIO_flush(SSL_get_wbio(s)); 303 if (ret <= 0) 304 return ret; 305 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 306 mac_size - blocksize; 307 } 308 309 if (s->init_num > curr_mtu) 310 len = curr_mtu; 311 else 312 len = s->init_num; 313 314 315 /* XDTLS: this function is too long. split out the CCS part */ 316 if (type == SSL3_RT_HANDSHAKE) { 317 if (s->init_off != 0) { 318 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 319 s->init_off -= DTLS1_HM_HEADER_LENGTH; 320 s->init_num += DTLS1_HM_HEADER_LENGTH; 321 322 if (s->init_num > curr_mtu) 323 len = curr_mtu; 324 else 325 len = s->init_num; 326 } 327 328 dtls1_fix_message_header(s, frag_off, 329 len - DTLS1_HM_HEADER_LENGTH); 330 331 dtls1_write_message_header(s, 332 (unsigned char *)&s->init_buf->data[s->init_off]); 333 334 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 335 } 336 337 ret = dtls1_write_bytes(s, type, 338 &s->init_buf->data[s->init_off], len); 339 if (ret < 0) { 340 /* might need to update MTU here, but we don't know 341 * which previous packet caused the failure -- so can't 342 * really retransmit anything. continue as if everything 343 * is fine and wait for an alert to handle the 344 * retransmit 345 */ 346 if (BIO_ctrl(SSL_get_wbio(s), 347 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) 348 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 349 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 350 else 351 return (-1); 352 } else { 353 354 /* bad if this assert fails, only part of the handshake 355 * message got sent. but why would this happen? */ 356 OPENSSL_assert(len == (unsigned int)ret); 357 358 if (type == SSL3_RT_HANDSHAKE && 359 !s->d1->retransmitting) { 360 /* should not be done for 'Hello Request's, but in that case 361 * we'll ignore the result anyway */ 362 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 363 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 364 int xlen; 365 366 if (frag_off == 0 && 367 s->version != DTLS1_BAD_VER) { 368 /* reconstruct message header is if it 369 * is being sent in single fragment */ 370 *p++ = msg_hdr->type; 371 l2n3(msg_hdr->msg_len, p); 372 s2n (msg_hdr->seq, p); 373 l2n3(0, p); 374 l2n3(msg_hdr->msg_len, p); 375 p -= DTLS1_HM_HEADER_LENGTH; 376 xlen = ret; 377 } else { 378 p += DTLS1_HM_HEADER_LENGTH; 379 xlen = ret - DTLS1_HM_HEADER_LENGTH; 380 } 381 382 ssl3_finish_mac(s, p, xlen); 383 } 384 385 if (ret == s->init_num) { 386 if (s->msg_callback) 387 s->msg_callback(1, s->version, type, 388 s->init_buf->data, 389 (size_t)(s->init_off + s->init_num), 390 s, s->msg_callback_arg); 391 392 s->init_off = 0; 393 /* done writing this message */ 394 s->init_num = 0; 395 396 return (1); 397 } 398 s->init_off += ret; 399 s->init_num -= ret; 400 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 401 } 402 } 403 return (0); 404 } 405 406 407 /* Obtain handshake message of message type 'mt' (any if mt == -1), 408 * maximum acceptable body length 'max'. 409 * Read an entire handshake message. Handshake messages arrive in 410 * fragments. 411 */ 412 long 413 dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 414 { 415 int i, al; 416 struct hm_header_st *msg_hdr; 417 unsigned char *p; 418 unsigned long msg_len; 419 420 /* s3->tmp is used to store messages that are unexpected, caused 421 * by the absence of an optional handshake message */ 422 if (s->s3->tmp.reuse_message) { 423 s->s3->tmp.reuse_message = 0; 424 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) { 425 al = SSL_AD_UNEXPECTED_MESSAGE; 426 SSLerr(SSL_F_DTLS1_GET_MESSAGE, 427 SSL_R_UNEXPECTED_MESSAGE); 428 goto f_err; 429 } 430 *ok = 1; 431 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 432 s->init_num = (int)s->s3->tmp.message_size; 433 return s->init_num; 434 } 435 436 msg_hdr = &s->d1->r_msg_hdr; 437 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 438 439 again: 440 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 441 if (i == DTLS1_HM_BAD_FRAGMENT || 442 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 443 goto again; 444 else if (i <= 0 && !*ok) 445 return i; 446 447 p = (unsigned char *)s->init_buf->data; 448 msg_len = msg_hdr->msg_len; 449 450 /* reconstruct message header */ 451 *(p++) = msg_hdr->type; 452 l2n3(msg_len, p); 453 s2n (msg_hdr->seq, p); 454 l2n3(0, p); 455 l2n3(msg_len, p); 456 if (s->version != DTLS1_BAD_VER) { 457 p -= DTLS1_HM_HEADER_LENGTH; 458 msg_len += DTLS1_HM_HEADER_LENGTH; 459 } 460 461 ssl3_finish_mac(s, p, msg_len); 462 if (s->msg_callback) 463 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, p, msg_len, 464 s, s->msg_callback_arg); 465 466 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 467 468 /* Don't change sequence numbers while listening */ 469 if (!s->d1->listen) 470 s->d1->handshake_read_seq++; 471 472 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 473 return s->init_num; 474 475 f_err: 476 ssl3_send_alert(s, SSL3_AL_FATAL, al); 477 *ok = 0; 478 return -1; 479 } 480 481 482 static int 483 dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, int max) 484 { 485 size_t frag_off, frag_len, msg_len; 486 487 msg_len = msg_hdr->msg_len; 488 frag_off = msg_hdr->frag_off; 489 frag_len = msg_hdr->frag_len; 490 491 /* sanity checking */ 492 if ((frag_off + frag_len) > msg_len) { 493 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, 494 SSL_R_EXCESSIVE_MESSAGE_SIZE); 495 return SSL_AD_ILLEGAL_PARAMETER; 496 } 497 498 if ((frag_off + frag_len) > (unsigned long)max) { 499 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, 500 SSL_R_EXCESSIVE_MESSAGE_SIZE); 501 return SSL_AD_ILLEGAL_PARAMETER; 502 } 503 504 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 505 { 506 /* msg_len is limited to 2^24, but is effectively checked 507 * against max above */ 508 if (!BUF_MEM_grow_clean(s->init_buf, 509 msg_len + DTLS1_HM_HEADER_LENGTH)) { 510 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB); 511 return SSL_AD_INTERNAL_ERROR; 512 } 513 514 s->s3->tmp.message_size = msg_len; 515 s->d1->r_msg_hdr.msg_len = msg_len; 516 s->s3->tmp.message_type = msg_hdr->type; 517 s->d1->r_msg_hdr.type = msg_hdr->type; 518 s->d1->r_msg_hdr.seq = msg_hdr->seq; 519 } else if (msg_len != s->d1->r_msg_hdr.msg_len) { 520 /* They must be playing with us! BTW, failure to enforce 521 * upper limit would open possibility for buffer overrun. */ 522 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, 523 SSL_R_EXCESSIVE_MESSAGE_SIZE); 524 return SSL_AD_ILLEGAL_PARAMETER; 525 } 526 527 return 0; /* no error */ 528 } 529 530 static int 531 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 532 { 533 /* (0) check whether the desired fragment is available 534 * if so: 535 * (1) copy over the fragment to s->init_buf->data[] 536 * (2) update s->init_num 537 */ 538 pitem *item; 539 hm_fragment *frag; 540 int al; 541 542 *ok = 0; 543 item = pqueue_peek(s->d1->buffered_messages); 544 if (item == NULL) 545 return 0; 546 547 frag = (hm_fragment *)item->data; 548 549 /* Don't return if reassembly still in progress */ 550 if (frag->reassembly != NULL) 551 return 0; 552 553 if (s->d1->handshake_read_seq == frag->msg_header.seq) { 554 unsigned long frag_len = frag->msg_header.frag_len; 555 pqueue_pop(s->d1->buffered_messages); 556 557 al = dtls1_preprocess_fragment(s, &frag->msg_header, max); 558 559 if (al == 0) /* no alert */ 560 { 561 unsigned char *p = (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 562 memcpy(&p[frag->msg_header.frag_off], 563 frag->fragment, frag->msg_header.frag_len); 564 } 565 566 dtls1_hm_fragment_free(frag); 567 pitem_free(item); 568 569 if (al == 0) { 570 *ok = 1; 571 return frag_len; 572 } 573 574 ssl3_send_alert(s, SSL3_AL_FATAL, al); 575 s->init_num = 0; 576 *ok = 0; 577 return -1; 578 } else 579 return 0; 580 } 581 582 583 static int 584 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok) 585 { 586 hm_fragment *frag = NULL; 587 pitem *item = NULL; 588 int i = -1, is_complete; 589 unsigned char seq64be[8]; 590 unsigned long frag_len = msg_hdr->frag_len, max_len; 591 592 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 593 goto err; 594 595 /* Determine maximum allowed message size. Depends on (user set) 596 * maximum certificate length, but 16k is minimum. 597 */ 598 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < 599 s->max_cert_list) 600 max_len = s->max_cert_list; 601 else 602 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 603 604 if ((msg_hdr->frag_off + frag_len) > max_len) 605 goto err; 606 607 /* Try to find item in queue */ 608 memset(seq64be, 0, sizeof(seq64be)); 609 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 610 seq64be[7] = (unsigned char)msg_hdr->seq; 611 item = pqueue_find(s->d1->buffered_messages, seq64be); 612 613 if (item == NULL) { 614 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 615 if (frag == NULL) 616 goto err; 617 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 618 frag->msg_header.frag_len = frag->msg_header.msg_len; 619 frag->msg_header.frag_off = 0; 620 } else 621 frag = (hm_fragment*)item->data; 622 623 /* If message is already reassembled, this must be a 624 * retransmit and can be dropped. 625 */ 626 if (frag->reassembly == NULL) { 627 unsigned char devnull [256]; 628 629 while (frag_len) { 630 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 631 devnull, frag_len > sizeof(devnull) ? 632 sizeof(devnull) : frag_len, 0); 633 if (i <= 0) 634 goto err; 635 frag_len -= i; 636 } 637 return DTLS1_HM_FRAGMENT_RETRY; 638 } 639 640 /* read the body of the fragment (header has already been read */ 641 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 642 frag->fragment + msg_hdr->frag_off, frag_len, 0); 643 if (i <= 0 || (unsigned long)i != frag_len) 644 goto err; 645 646 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 647 (long)(msg_hdr->frag_off + frag_len)); 648 649 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 650 is_complete); 651 652 if (is_complete) { 653 free(frag->reassembly); 654 frag->reassembly = NULL; 655 } 656 657 if (item == NULL) { 658 memset(seq64be, 0, sizeof(seq64be)); 659 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 660 seq64be[7] = (unsigned char)(msg_hdr->seq); 661 662 item = pitem_new(seq64be, frag); 663 if (item == NULL) { 664 i = -1; 665 goto err; 666 } 667 668 pqueue_insert(s->d1->buffered_messages, item); 669 } 670 671 return DTLS1_HM_FRAGMENT_RETRY; 672 673 err: 674 if (item == NULL && frag != NULL) 675 dtls1_hm_fragment_free(frag); 676 *ok = 0; 677 return i; 678 } 679 680 681 static int 682 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 683 { 684 int i = -1; 685 hm_fragment *frag = NULL; 686 pitem *item = NULL; 687 unsigned char seq64be[8]; 688 unsigned long frag_len = msg_hdr->frag_len; 689 690 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) 691 goto err; 692 693 /* Try to find item in queue, to prevent duplicate entries */ 694 memset(seq64be, 0, sizeof(seq64be)); 695 seq64be[6] = (unsigned char) (msg_hdr->seq >> 8); 696 seq64be[7] = (unsigned char) msg_hdr->seq; 697 item = pqueue_find(s->d1->buffered_messages, seq64be); 698 699 /* If we already have an entry and this one is a fragment, 700 * don't discard it and rather try to reassemble it. 701 */ 702 if (item != NULL && frag_len < msg_hdr->msg_len) 703 item = NULL; 704 705 /* Discard the message if sequence number was already there, is 706 * too far in the future, already in the queue or if we received 707 * a FINISHED before the SERVER_HELLO, which then must be a stale 708 * retransmit. 709 */ 710 if (msg_hdr->seq <= s->d1->handshake_read_seq || 711 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 712 (s->d1->handshake_read_seq == 0 && 713 msg_hdr->type == SSL3_MT_FINISHED)) { 714 unsigned char devnull [256]; 715 716 while (frag_len) { 717 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 718 devnull, frag_len > sizeof(devnull) ? 719 sizeof(devnull) : frag_len, 0); 720 if (i <= 0) 721 goto err; 722 frag_len -= i; 723 } 724 } else { 725 if (frag_len && frag_len < msg_hdr->msg_len) 726 return dtls1_reassemble_fragment(s, msg_hdr, ok); 727 728 frag = dtls1_hm_fragment_new(frag_len, 0); 729 if (frag == NULL) 730 goto err; 731 732 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 733 734 if (frag_len) { 735 /* read the body of the fragment (header has already been read */ 736 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 737 frag->fragment, frag_len, 0); 738 if (i <= 0 || (unsigned long)i != frag_len) 739 goto err; 740 } 741 742 memset(seq64be, 0, sizeof(seq64be)); 743 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); 744 seq64be[7] = (unsigned char)(msg_hdr->seq); 745 746 item = pitem_new(seq64be, frag); 747 if (item == NULL) 748 goto err; 749 750 pqueue_insert(s->d1->buffered_messages, item); 751 } 752 753 return DTLS1_HM_FRAGMENT_RETRY; 754 755 err: 756 if (item == NULL && frag != NULL) 757 dtls1_hm_fragment_free(frag); 758 *ok = 0; 759 return i; 760 } 761 762 763 static long 764 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 765 { 766 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 767 unsigned long len, frag_off, frag_len; 768 int i, al; 769 struct hm_header_st msg_hdr; 770 771 /* see if we have the required fragment already */ 772 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { 773 if (*ok) 774 s->init_num = frag_len; 775 return frag_len; 776 } 777 778 /* read handshake message header */ 779 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, 780 DTLS1_HM_HEADER_LENGTH, 0); 781 if (i <= 0) /* nbio, or an error */ 782 { 783 s->rwstate = SSL_READING; 784 *ok = 0; 785 return i; 786 } 787 /* Handshake fails if message header is incomplete */ 788 if (i != DTLS1_HM_HEADER_LENGTH) { 789 al = SSL_AD_UNEXPECTED_MESSAGE; 790 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 791 SSL_R_UNEXPECTED_MESSAGE); 792 goto f_err; 793 } 794 795 /* parse the message fragment header */ 796 dtls1_get_message_header(wire, &msg_hdr); 797 798 /* 799 * if this is a future (or stale) message it gets buffered 800 * (or dropped)--no further processing at this time 801 * While listening, we accept seq 1 (ClientHello with cookie) 802 * although we're still expecting seq 0 (ClientHello) 803 */ 804 if (msg_hdr.seq != s->d1->handshake_read_seq && 805 !(s->d1->listen && msg_hdr.seq == 1)) 806 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 807 808 len = msg_hdr.msg_len; 809 frag_off = msg_hdr.frag_off; 810 frag_len = msg_hdr.frag_len; 811 812 if (frag_len && frag_len < len) 813 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 814 815 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 816 wire[0] == SSL3_MT_HELLO_REQUEST) { 817 /* The server may always send 'Hello Request' messages -- 818 * we are doing a handshake anyway now, so ignore them 819 * if their format is correct. Does not count for 820 * 'Finished' MAC. */ 821 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { 822 if (s->msg_callback) 823 s->msg_callback(0, s->version, 824 SSL3_RT_HANDSHAKE, wire, 825 DTLS1_HM_HEADER_LENGTH, s, 826 s->msg_callback_arg); 827 828 s->init_num = 0; 829 return dtls1_get_message_fragment(s, st1, stn, max, ok); 830 } 831 else /* Incorrectly formated Hello request */ 832 { 833 al = SSL_AD_UNEXPECTED_MESSAGE; 834 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 835 SSL_R_UNEXPECTED_MESSAGE); 836 goto f_err; 837 } 838 } 839 840 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) 841 goto f_err; 842 843 /* XDTLS: ressurect this when restart is in place */ 844 s->state = stn; 845 846 if (frag_len > 0) { 847 unsigned char *p = (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 848 849 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, 850 &p[frag_off], frag_len, 0); 851 /* XDTLS: fix this--message fragments cannot span multiple packets */ 852 if (i <= 0) { 853 s->rwstate = SSL_READING; 854 *ok = 0; 855 return i; 856 } 857 } else 858 i = 0; 859 860 /* XDTLS: an incorrectly formatted fragment should cause the 861 * handshake to fail */ 862 if (i != (int)frag_len) { 863 al = SSL3_AD_ILLEGAL_PARAMETER; 864 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, 865 SSL3_AD_ILLEGAL_PARAMETER); 866 goto f_err; 867 } 868 869 *ok = 1; 870 871 /* Note that s->init_num is *not* used as current offset in 872 * s->init_buf->data, but as a counter summing up fragments' 873 * lengths: as soon as they sum up to handshake packet 874 * length, we assume we have got all the fragments. */ 875 s->init_num = frag_len; 876 return frag_len; 877 878 f_err: 879 ssl3_send_alert(s, SSL3_AL_FATAL, al); 880 s->init_num = 0; 881 882 *ok = 0; 883 return (-1); 884 } 885 886 int 887 dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 888 { 889 unsigned char *p, *d; 890 int i; 891 unsigned long l; 892 893 if (s->state == a) { 894 d = (unsigned char *)s->init_buf->data; 895 p = &(d[DTLS1_HM_HEADER_LENGTH]); 896 897 i = s->method->ssl3_enc->final_finish_mac(s, sender, slen, 898 s->s3->tmp.finish_md); 899 s->s3->tmp.finish_md_len = i; 900 memcpy(p, s->s3->tmp.finish_md, i); 901 p += i; 902 l = i; 903 904 /* Copy the finished so we can use it for 905 * renegotiation checks 906 */ 907 if (s->type == SSL_ST_CONNECT) { 908 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 909 memcpy(s->s3->previous_client_finished, 910 s->s3->tmp.finish_md, i); 911 s->s3->previous_client_finished_len = i; 912 } else { 913 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 914 memcpy(s->s3->previous_server_finished, 915 s->s3->tmp.finish_md, i); 916 s->s3->previous_server_finished_len = i; 917 } 918 919 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 920 s->init_num = (int)l + DTLS1_HM_HEADER_LENGTH; 921 s->init_off = 0; 922 923 /* buffer the message to handle re-xmits */ 924 dtls1_buffer_message(s, 0); 925 926 s->state = b; 927 } 928 929 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 930 return (dtls1_do_write(s, SSL3_RT_HANDSHAKE)); 931 } 932 933 /* for these 2 messages, we need to 934 * ssl->enc_read_ctx re-init 935 * ssl->s3->read_sequence zero 936 * ssl->s3->read_mac_secret re-init 937 * ssl->session->read_sym_enc assign 938 * ssl->session->read_compression assign 939 * ssl->session->read_hash assign 940 */ 941 int 942 dtls1_send_change_cipher_spec(SSL *s, int a, int b) 943 { 944 unsigned char *p; 945 946 if (s->state == a) { 947 p = (unsigned char *)s->init_buf->data; 948 *p++=SSL3_MT_CCS; 949 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 950 s->init_num = DTLS1_CCS_HEADER_LENGTH; 951 952 if (s->version == DTLS1_BAD_VER) { 953 s->d1->next_handshake_write_seq++; 954 s2n(s->d1->handshake_write_seq, p); 955 s->init_num += 2; 956 } 957 958 s->init_off = 0; 959 960 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 961 s->d1->handshake_write_seq, 0, 0); 962 963 /* buffer the message to handle re-xmits */ 964 dtls1_buffer_message(s, 1); 965 966 s->state = b; 967 } 968 969 /* SSL3_ST_CW_CHANGE_B */ 970 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC)); 971 } 972 973 static int 974 dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 975 { 976 int n; 977 unsigned char *p; 978 979 n = i2d_X509(x, NULL); 980 if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) { 981 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB); 982 return 0; 983 } 984 p = (unsigned char *)&(buf->data[*l]); 985 l2n3(n, p); 986 i2d_X509(x, &p); 987 *l += n + 3; 988 989 return 1; 990 } 991 992 unsigned long 993 dtls1_output_cert_chain(SSL *s, X509 *x) 994 { 995 unsigned char *p; 996 int i; 997 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH; 998 BUF_MEM *buf; 999 1000 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1001 buf = s->init_buf; 1002 if (!BUF_MEM_grow_clean(buf, 10)) { 1003 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB); 1004 return (0); 1005 } 1006 if (x != NULL) { 1007 X509_STORE_CTX xs_ctx; 1008 1009 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, 1010 x, NULL)) { 1011 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB); 1012 return (0); 1013 } 1014 1015 X509_verify_cert(&xs_ctx); 1016 /* Don't leave errors in the queue */ 1017 ERR_clear_error(); 1018 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) { 1019 x = sk_X509_value(xs_ctx.chain, i); 1020 1021 if (!dtls1_add_cert_to_buf(buf, &l, x)) { 1022 X509_STORE_CTX_cleanup(&xs_ctx); 1023 return 0; 1024 } 1025 } 1026 X509_STORE_CTX_cleanup(&xs_ctx); 1027 } 1028 /* Thawte special :-) */ 1029 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) { 1030 x = sk_X509_value(s->ctx->extra_certs, i); 1031 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1032 return 0; 1033 } 1034 1035 l -= (3 + DTLS1_HM_HEADER_LENGTH); 1036 1037 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1038 l2n3(l, p); 1039 l += 3; 1040 p = (unsigned char *)&(buf->data[0]); 1041 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1042 1043 l += DTLS1_HM_HEADER_LENGTH; 1044 return (l); 1045 } 1046 1047 int 1048 dtls1_read_failed(SSL *s, int code) 1049 { 1050 if (code > 0) { 1051 fprintf(stderr, "invalid state reached %s:%d", 1052 __FILE__, __LINE__); 1053 return 1; 1054 } 1055 1056 if (!dtls1_is_timer_expired(s)) { 1057 /* not a timeout, none of our business, 1058 let higher layers handle this. in fact it's probably an error */ 1059 return code; 1060 } 1061 1062 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1063 { 1064 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1065 return code; 1066 } 1067 1068 #if 0 /* for now, each alert contains only one record number */ 1069 item = pqueue_peek(state->rcvd_records); 1070 if (item ) { 1071 /* send an alert immediately for all the missing records */ 1072 } else 1073 #endif 1074 1075 #if 0 /* no more alert sending, just retransmit the last set of messages */ 1076 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1077 ssl3_send_alert(s, SSL3_AL_WARNING, 1078 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1079 #endif 1080 1081 return dtls1_handle_timeout(s); 1082 } 1083 1084 int 1085 dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1086 { 1087 /* The index of the retransmission queue actually is the message sequence number, 1088 * since the queue only contains messages of a single handshake. However, the 1089 * ChangeCipherSpec has no message sequence number and so using only the sequence 1090 * will result in the CCS and Finished having the same index. To prevent this, 1091 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1092 * This does not only differ CSS and Finished, it also maintains the order of the 1093 * index (important for priority queues) and fits in the unsigned short variable. 1094 */ 1095 return seq * 2 - is_ccs; 1096 } 1097 1098 int 1099 dtls1_retransmit_buffered_messages(SSL *s) 1100 { 1101 pqueue sent = s->d1->sent_messages; 1102 piterator iter; 1103 pitem *item; 1104 hm_fragment *frag; 1105 int found = 0; 1106 1107 iter = pqueue_iterator(sent); 1108 1109 for (item = pqueue_next(&iter); item != NULL; 1110 item = pqueue_next(&iter)) { 1111 frag = (hm_fragment *)item->data; 1112 if (dtls1_retransmit_message(s, 1113 (unsigned short)dtls1_get_queue_priority( 1114 frag->msg_header.seq, frag->msg_header.is_ccs), 0, 1115 &found) <= 0 && found) { 1116 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1117 return -1; 1118 } 1119 } 1120 1121 return 1; 1122 } 1123 1124 int 1125 dtls1_buffer_message(SSL *s, int is_ccs) 1126 { 1127 pitem *item; 1128 hm_fragment *frag; 1129 unsigned char seq64be[8]; 1130 1131 /* this function is called immediately after a message has 1132 * been serialized */ 1133 OPENSSL_assert(s->init_off == 0); 1134 1135 frag = dtls1_hm_fragment_new(s->init_num, 0); 1136 if (frag == NULL) 1137 return 0; 1138 1139 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1140 1141 if (is_ccs) { 1142 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1143 ((s->version == DTLS1_VERSION) ? 1144 DTLS1_CCS_HEADER_LENGTH : 3) == (unsigned int)s->init_num); 1145 } else { 1146 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1147 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1148 } 1149 1150 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1151 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1152 frag->msg_header.type = s->d1->w_msg_hdr.type; 1153 frag->msg_header.frag_off = 0; 1154 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1155 frag->msg_header.is_ccs = is_ccs; 1156 1157 /* save current state*/ 1158 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1159 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1160 frag->msg_header.saved_retransmit_state.compress = s->compress; 1161 frag->msg_header.saved_retransmit_state.session = s->session; 1162 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1163 1164 memset(seq64be, 0, sizeof(seq64be)); 1165 seq64be[6] = (unsigned char)(dtls1_get_queue_priority( 1166 frag->msg_header.seq, frag->msg_header.is_ccs) >> 8); 1167 seq64be[7] = (unsigned char)(dtls1_get_queue_priority( 1168 frag->msg_header.seq, frag->msg_header.is_ccs)); 1169 1170 item = pitem_new(seq64be, frag); 1171 if (item == NULL) { 1172 dtls1_hm_fragment_free(frag); 1173 return 0; 1174 } 1175 1176 #if 0 1177 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1178 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1179 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1180 #endif 1181 1182 pqueue_insert(s->d1->sent_messages, item); 1183 return 1; 1184 } 1185 1186 int 1187 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1188 int *found) 1189 { 1190 int ret; 1191 /* XDTLS: for now assuming that read/writes are blocking */ 1192 pitem *item; 1193 hm_fragment *frag; 1194 unsigned long header_length; 1195 unsigned char seq64be[8]; 1196 struct dtls1_retransmit_state saved_state; 1197 unsigned char save_write_sequence[8]; 1198 1199 /* 1200 OPENSSL_assert(s->init_num == 0); 1201 OPENSSL_assert(s->init_off == 0); 1202 */ 1203 1204 /* XDTLS: the requested message ought to be found, otherwise error */ 1205 memset(seq64be, 0, sizeof(seq64be)); 1206 seq64be[6] = (unsigned char)(seq >> 8); 1207 seq64be[7] = (unsigned char)seq; 1208 1209 item = pqueue_find(s->d1->sent_messages, seq64be); 1210 if (item == NULL) { 1211 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1212 *found = 0; 1213 return 0; 1214 } 1215 1216 *found = 1; 1217 frag = (hm_fragment *)item->data; 1218 1219 if (frag->msg_header.is_ccs) 1220 header_length = DTLS1_CCS_HEADER_LENGTH; 1221 else 1222 header_length = DTLS1_HM_HEADER_LENGTH; 1223 1224 memcpy(s->init_buf->data, frag->fragment, 1225 frag->msg_header.msg_len + header_length); 1226 s->init_num = frag->msg_header.msg_len + header_length; 1227 1228 dtls1_set_message_header_int(s, frag->msg_header.type, 1229 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1230 frag->msg_header.frag_len); 1231 1232 /* save current state */ 1233 saved_state.enc_write_ctx = s->enc_write_ctx; 1234 saved_state.write_hash = s->write_hash; 1235 saved_state.compress = s->compress; 1236 saved_state.session = s->session; 1237 saved_state.epoch = s->d1->w_epoch; 1238 1239 s->d1->retransmitting = 1; 1240 1241 /* restore state in which the message was originally sent */ 1242 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1243 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1244 s->compress = frag->msg_header.saved_retransmit_state.compress; 1245 s->session = frag->msg_header.saved_retransmit_state.session; 1246 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1247 1248 if (frag->msg_header.saved_retransmit_state.epoch == 1249 saved_state.epoch - 1) { 1250 memcpy(save_write_sequence, s->s3->write_sequence, 1251 sizeof(s->s3->write_sequence)); 1252 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, 1253 sizeof(s->s3->write_sequence)); 1254 } 1255 1256 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1257 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1258 1259 /* restore current state */ 1260 s->enc_write_ctx = saved_state.enc_write_ctx; 1261 s->write_hash = saved_state.write_hash; 1262 s->compress = saved_state.compress; 1263 s->session = saved_state.session; 1264 s->d1->w_epoch = saved_state.epoch; 1265 1266 if (frag->msg_header.saved_retransmit_state.epoch == 1267 saved_state.epoch - 1) { 1268 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, 1269 sizeof(s->s3->write_sequence)); 1270 memcpy(s->s3->write_sequence, save_write_sequence, 1271 sizeof(s->s3->write_sequence)); 1272 } 1273 1274 s->d1->retransmitting = 0; 1275 1276 (void)BIO_flush(SSL_get_wbio(s)); 1277 return ret; 1278 } 1279 1280 /* call this function when the buffered messages are no longer needed */ 1281 void 1282 dtls1_clear_record_buffer(SSL *s) 1283 { 1284 pitem *item; 1285 1286 for(item = pqueue_pop(s->d1->sent_messages); item != NULL; 1287 item = pqueue_pop(s->d1->sent_messages)) { 1288 dtls1_hm_fragment_free((hm_fragment *)item->data); 1289 pitem_free(item); 1290 } 1291 } 1292 1293 unsigned char * 1294 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1295 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1296 { 1297 /* Don't change sequence numbers while listening */ 1298 if (frag_off == 0 && !s->d1->listen) { 1299 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1300 s->d1->next_handshake_write_seq++; 1301 } 1302 1303 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1304 frag_off, frag_len); 1305 1306 return p += DTLS1_HM_HEADER_LENGTH; 1307 } 1308 1309 /* don't actually do the writing, wait till the MTU has been retrieved */ 1310 static void 1311 dtls1_set_message_header_int(SSL *s, unsigned char mt, unsigned long len, 1312 unsigned short seq_num, unsigned long frag_off, unsigned long frag_len) 1313 { 1314 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1315 1316 msg_hdr->type = mt; 1317 msg_hdr->msg_len = len; 1318 msg_hdr->seq = seq_num; 1319 msg_hdr->frag_off = frag_off; 1320 msg_hdr->frag_len = frag_len; 1321 } 1322 1323 static void 1324 dtls1_fix_message_header(SSL *s, unsigned long frag_off, unsigned long frag_len) 1325 { 1326 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1327 1328 msg_hdr->frag_off = frag_off; 1329 msg_hdr->frag_len = frag_len; 1330 } 1331 1332 static unsigned char * 1333 dtls1_write_message_header(SSL *s, unsigned char *p) 1334 { 1335 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1336 1337 *p++ = msg_hdr->type; 1338 l2n3(msg_hdr->msg_len, p); 1339 1340 s2n(msg_hdr->seq, p); 1341 l2n3(msg_hdr->frag_off, p); 1342 l2n3(msg_hdr->frag_len, p); 1343 1344 return p; 1345 } 1346 1347 unsigned int 1348 dtls1_min_mtu(void) 1349 { 1350 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1351 sizeof(g_probable_mtu[0])) - 1]); 1352 } 1353 1354 static unsigned int 1355 dtls1_guess_mtu(unsigned int curr_mtu) 1356 { 1357 unsigned int i; 1358 1359 if (curr_mtu == 0) 1360 return g_probable_mtu[0]; 1361 1362 for (i = 0; i < sizeof(g_probable_mtu) / sizeof(g_probable_mtu[0]); i++) 1363 if (curr_mtu > g_probable_mtu[i]) 1364 return g_probable_mtu[i]; 1365 1366 return curr_mtu; 1367 } 1368 1369 void 1370 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1371 { 1372 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1373 msg_hdr->type = *(data++); 1374 n2l3(data, msg_hdr->msg_len); 1375 1376 n2s(data, msg_hdr->seq); 1377 n2l3(data, msg_hdr->frag_off); 1378 n2l3(data, msg_hdr->frag_len); 1379 } 1380 1381 void 1382 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1383 { 1384 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1385 1386 ccs_hdr->type = *(data++); 1387 } 1388 1389 int 1390 dtls1_shutdown(SSL *s) 1391 { 1392 int ret; 1393 1394 #ifndef OPENSSL_NO_SCTP 1395 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1396 !(s->shutdown & SSL_SENT_SHUTDOWN)) { 1397 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1398 if (ret < 0) 1399 return -1; 1400 1401 if (ret == 0) 1402 BIO_ctrl(SSL_get_wbio(s), 1403 BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1404 } 1405 #endif 1406 ret = ssl3_shutdown(s); 1407 #ifndef OPENSSL_NO_SCTP 1408 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1409 #endif 1410 return ret; 1411 } 1412