d1_pkt.c revision 308205
1/* ssl/d1_pkt.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 <stdio.h> 117#include <errno.h> 118#define USE_SOCKETS 119#include "ssl_locl.h" 120#include <openssl/evp.h> 121#include <openssl/buffer.h> 122#include <openssl/pqueue.h> 123#include <openssl/rand.h> 124 125static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 126 int len, int peek); 127static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 128static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 129static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 130 unsigned int *is_next_epoch); 131#if 0 132static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 133 unsigned short *priority, 134 unsigned long *offset); 135#endif 136static int dtls1_buffer_record(SSL *s, record_pqueue *q, PQ_64BIT * priority); 137static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap); 138#if PQ_64BIT_IS_INTEGER 139static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT * num); 140#endif 141 142/* copy buffered record into SSL structure */ 143static int dtls1_copy_record(SSL *s, pitem *item) 144{ 145 DTLS1_RECORD_DATA *rdata; 146 147 rdata = (DTLS1_RECORD_DATA *)item->data; 148 149 if (s->s3->rbuf.buf != NULL) 150 OPENSSL_free(s->s3->rbuf.buf); 151 152 s->packet = rdata->packet; 153 s->packet_length = rdata->packet_length; 154 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 155 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 156 157 /* Set proper sequence number for mac calculation */ 158 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 159 160 return (1); 161} 162 163static int 164dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT * priority) 165{ 166 DTLS1_RECORD_DATA *rdata; 167 pitem *item; 168 169 /* Limit the size of the queue to prevent DOS attacks */ 170 if (pqueue_size(queue->q) >= 100) 171 return 0; 172 173 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 174 item = pitem_new(*priority, rdata); 175 if (rdata == NULL || item == NULL) { 176 if (rdata != NULL) 177 OPENSSL_free(rdata); 178 if (item != NULL) 179 pitem_free(item); 180 181 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 182 return (0); 183 } 184 185 rdata->packet = s->packet; 186 rdata->packet_length = s->packet_length; 187 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 188 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 189 190 item->data = rdata; 191 192 /* insert should not fail, since duplicates are dropped */ 193 if (pqueue_insert(queue->q, item) == NULL) { 194 OPENSSL_free(rdata); 195 pitem_free(item); 196 return (0); 197 } 198 199 s->packet = NULL; 200 s->packet_length = 0; 201 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 202 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 203 204 if (!ssl3_setup_buffers(s)) { 205 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 206 OPENSSL_free(rdata); 207 pitem_free(item); 208 return (0); 209 } 210 211 return (1); 212} 213 214static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 215{ 216 pitem *item; 217 218 item = pqueue_pop(queue->q); 219 if (item) { 220 dtls1_copy_record(s, item); 221 222 OPENSSL_free(item->data); 223 pitem_free(item); 224 225 return (1); 226 } 227 228 return (0); 229} 230 231/* 232 * retrieve a buffered record that belongs to the new epoch, i.e., not 233 * processed yet 234 */ 235#define dtls1_get_unprocessed_record(s) \ 236 dtls1_retrieve_buffered_record((s), \ 237 &((s)->d1->unprocessed_rcds)) 238 239/* 240 * retrieve a buffered record that belongs to the current epoch, ie, 241 * processed 242 */ 243#define dtls1_get_processed_record(s) \ 244 dtls1_retrieve_buffered_record((s), \ 245 &((s)->d1->processed_rcds)) 246 247static int dtls1_process_buffered_records(SSL *s) 248{ 249 pitem *item; 250 SSL3_BUFFER *rb; 251 SSL3_RECORD *rr; 252 DTLS1_BITMAP *bitmap; 253 unsigned int is_next_epoch; 254 int replayok = 1; 255 256 item = pqueue_peek(s->d1->unprocessed_rcds.q); 257 if (item) { 258 /* Check if epoch is current. */ 259 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 260 return 1; /* Nothing to do. */ 261 262 rr = &s->s3->rrec; 263 rb = &s->s3->rbuf; 264 265 if (rb->left > 0) { 266 /* 267 * We've still got data from the current packet to read. There could 268 * be a record from the new epoch in it - so don't overwrite it 269 * with the unprocessed records yet (we'll do it when we've 270 * finished reading the current packet). 271 */ 272 return 1; 273 } 274 275 276 /* Process all the records. */ 277 while (pqueue_peek(s->d1->unprocessed_rcds.q)) { 278 dtls1_get_unprocessed_record(s); 279 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 280 if (bitmap == NULL) { 281 /* 282 * Should not happen. This will only ever be NULL when the 283 * current record is from a different epoch. But that cannot 284 * be the case because we already checked the epoch above 285 */ 286 SSLerr(SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS, 287 ERR_R_INTERNAL_ERROR); 288 return 0; 289 } 290 { 291 /* 292 * Check whether this is a repeat, or aged record. We did this 293 * check once already when we first received the record - but 294 * we might have updated the window since then due to 295 * records we subsequently processed. 296 */ 297 replayok = dtls1_record_replay_check(s, bitmap); 298 } 299 300 if (!replayok || !dtls1_process_record(s, bitmap)) { 301 /* dump this record */ 302 rr->length = 0; 303 s->packet_length = 0; 304 continue; 305 } 306 307 if (dtls1_buffer_record(s, &(s->d1->processed_rcds), 308 &s->s3->rrec.seq_num) < 0) 309 return 0; 310 } 311 } 312 313 /* 314 * sync epoch numbers once all the unprocessed records have been 315 * processed 316 */ 317 s->d1->processed_rcds.epoch = s->d1->r_epoch; 318 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 319 320 return 1; 321} 322 323#if 0 324 325static int dtls1_get_buffered_record(SSL *s) 326{ 327 pitem *item; 328 PQ_64BIT priority = 329 (((PQ_64BIT) s->d1->handshake_read_seq) << 32) | 330 ((PQ_64BIT) s->d1->r_msg_hdr.frag_off); 331 332 /* if we're not (re)negotiating, nothing buffered */ 333 if (!SSL_in_init(s)) 334 return 0; 335 336 item = pqueue_peek(s->d1->rcvd_records); 337 if (item && item->priority == priority) { 338 /* 339 * Check if we've received the record of interest. It must be a 340 * handshake record, since data records as passed up without 341 * buffering 342 */ 343 DTLS1_RECORD_DATA *rdata; 344 item = pqueue_pop(s->d1->rcvd_records); 345 rdata = (DTLS1_RECORD_DATA *)item->data; 346 347 if (s->s3->rbuf.buf != NULL) 348 OPENSSL_free(s->s3->rbuf.buf); 349 350 s->packet = rdata->packet; 351 s->packet_length = rdata->packet_length; 352 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 353 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 354 355 OPENSSL_free(item->data); 356 pitem_free(item); 357 358 /* s->d1->next_expected_seq_num++; */ 359 return (1); 360 } 361 362 return 0; 363} 364 365#endif 366 367static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap) 368{ 369 int i, al; 370 int enc_err; 371 SSL_SESSION *sess; 372 SSL3_RECORD *rr; 373 unsigned int mac_size, orig_len; 374 unsigned char md[EVP_MAX_MD_SIZE]; 375 376 rr = &(s->s3->rrec); 377 sess = s->session; 378 379 /* 380 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 381 * and we have that many bytes in s->packet 382 */ 383 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]); 384 385 /* 386 * ok, we can now read from 's->packet' data into 'rr' rr->input points 387 * at rr->length bytes, which need to be copied into rr->data by either 388 * the decryption or by the decompression When the data is 'copied' into 389 * the rr->data buffer, rr->input will be pointed at the new buffer 390 */ 391 392 /* 393 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length 394 * bytes of encrypted compressed stuff. 395 */ 396 397 /* check is not needed I believe */ 398 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 399 al = SSL_AD_RECORD_OVERFLOW; 400 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 401 goto f_err; 402 } 403 404 /* decrypt in place in 'rr->input' */ 405 rr->data = rr->input; 406 407 enc_err = s->method->ssl3_enc->enc(s, 0); 408 /*- 409 * enc_err is: 410 * 0: (in non-constant time) if the record is publically invalid. 411 * 1: if the padding is valid 412 * -1: if the padding is invalid 413 */ 414 if (enc_err == 0) { 415 /* For DTLS we simply ignore bad packets. */ 416 rr->length = 0; 417 s->packet_length = 0; 418 goto err; 419 } 420#ifdef TLS_DEBUG 421 printf("dec %d\n", rr->length); 422 { 423 unsigned int z; 424 for (z = 0; z < rr->length; z++) 425 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); 426 } 427 printf("\n"); 428#endif 429 430 /* r->length is now the compressed data plus mac */ 431 if ((sess != NULL) && (s->enc_read_ctx != NULL) && (s->read_hash != NULL)) { 432 /* s->read_hash != NULL => mac_size != -1 */ 433 unsigned char *mac = NULL; 434 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 435 mac_size = EVP_MD_size(s->read_hash); 436 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 437 438 /* 439 * kludge: *_cbc_remove_padding passes padding length in rr->type 440 */ 441 orig_len = rr->length + ((unsigned int)rr->type >> 8); 442 443 /* 444 * orig_len is the length of the record before any padding was 445 * removed. This is public information, as is the MAC in use, 446 * therefore we can safely process the record in a different amount 447 * of time if it's too short to possibly contain a MAC. 448 */ 449 if (orig_len < mac_size || 450 /* CBC records must have a padding length byte too. */ 451 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 452 orig_len < mac_size + 1)) { 453 al = SSL_AD_DECODE_ERROR; 454 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT); 455 goto f_err; 456 } 457 458 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 459 /* 460 * We update the length so that the TLS header bytes can be 461 * constructed correctly but we need to extract the MAC in 462 * constant time from within the record, without leaking the 463 * contents of the padding bytes. 464 */ 465 mac = mac_tmp; 466 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 467 rr->length -= mac_size; 468 } else { 469 /* 470 * In this case there's no padding, so |orig_len| equals 471 * |rec->length| and we checked that there's enough bytes for 472 * |mac_size| above. 473 */ 474 rr->length -= mac_size; 475 mac = &rr->data[rr->length]; 476 } 477 478 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ ); 479 if (i < 0 || mac == NULL 480 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 481 enc_err = -1; 482 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 483 enc_err = -1; 484 } 485 486 if (enc_err < 0) { 487 /* decryption failed, silently discard message */ 488 rr->length = 0; 489 s->packet_length = 0; 490 goto err; 491 } 492 493 /* r->length is now just compressed */ 494 if (s->expand != NULL) { 495 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) { 496 al = SSL_AD_RECORD_OVERFLOW; 497 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, 498 SSL_R_COMPRESSED_LENGTH_TOO_LONG); 499 goto f_err; 500 } 501 if (!ssl3_do_uncompress(s)) { 502 al = SSL_AD_DECOMPRESSION_FAILURE; 503 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION); 504 goto f_err; 505 } 506 } 507 508 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 509 al = SSL_AD_RECORD_OVERFLOW; 510 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); 511 goto f_err; 512 } 513 514 rr->off = 0; 515 /*- 516 * So at this point the following is true 517 * ssl->s3->rrec.type is the type of record 518 * ssl->s3->rrec.length == number of bytes in record 519 * ssl->s3->rrec.off == offset to first valid byte 520 * ssl->s3->rrec.data == where to take bytes from, increment 521 * after use :-). 522 */ 523 524 /* we have pulled in a full packet so zero things */ 525 s->packet_length = 0; 526 527 /* Mark receipt of record. */ 528 dtls1_record_bitmap_update(s, bitmap); 529 530 return (1); 531 532 f_err: 533 ssl3_send_alert(s, SSL3_AL_FATAL, al); 534 err: 535 return (0); 536} 537 538/*- 539 * Call this to get a new input record. 540 * It will return <= 0 if more data is needed, normally due to an error 541 * or non-blocking IO. 542 * When it finishes, one packet has been decoded and can be found in 543 * ssl->s3->rrec.type - is the type of record 544 * ssl->s3->rrec.data, - data 545 * ssl->s3->rrec.length, - number of bytes 546 */ 547/* used only by dtls1_read_bytes */ 548int dtls1_get_record(SSL *s) 549{ 550 int ssl_major, ssl_minor; 551 int i, n; 552 SSL3_RECORD *rr; 553 unsigned char *p = NULL; 554 unsigned short version; 555 DTLS1_BITMAP *bitmap; 556 unsigned int is_next_epoch; 557 558 rr = &(s->s3->rrec); 559 560 again: 561 /* 562 * The epoch may have changed. If so, process all the pending records. 563 * This is a non-blocking operation. 564 */ 565 dtls1_process_buffered_records(s); 566 567 /* if we're renegotiating, then there may be buffered records */ 568 if (dtls1_get_processed_record(s)) 569 return 1; 570 571 /* get something from the wire */ 572 /* check if we have the header */ 573 if ((s->rstate != SSL_ST_READ_BODY) || 574 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { 575 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 576 /* read timeout is handled by dtls1_read_bytes */ 577 if (n <= 0) 578 return (n); /* error or non-blocking */ 579 580 /* this packet contained a partial record, dump it */ 581 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) { 582 s->packet_length = 0; 583 goto again; 584 } 585 586 s->rstate = SSL_ST_READ_BODY; 587 588 p = s->packet; 589 590 /* Pull apart the header into the DTLS1_RECORD */ 591 rr->type = *(p++); 592 ssl_major = *(p++); 593 ssl_minor = *(p++); 594 version = (ssl_major << 8) | ssl_minor; 595 596 /* sequence number is 64 bits, with top 2 bytes = epoch */ 597 n2s(p, rr->epoch); 598 599 memcpy(&(s->s3->read_sequence[2]), p, 6); 600 p += 6; 601 602 n2s(p, rr->length); 603 604 /* Lets check version */ 605 if (!s->first_packet) { 606 if (version != s->version && version != DTLS1_BAD_VER) { 607 /* unexpected version, silently discard */ 608 rr->length = 0; 609 s->packet_length = 0; 610 goto again; 611 } 612 } 613 614 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) && 615 (version & 0xff00) != (DTLS1_BAD_VER & 0xff00)) { 616 /* wrong version, silently discard record */ 617 rr->length = 0; 618 s->packet_length = 0; 619 goto again; 620 } 621 622 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 623 /* record too long, silently discard it */ 624 rr->length = 0; 625 s->packet_length = 0; 626 goto again; 627 } 628 629 s->client_version = version; 630 /* now s->rstate == SSL_ST_READ_BODY */ 631 } 632 633 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 634 635 if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) { 636 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 637 i = rr->length; 638 n = ssl3_read_n(s, i, i, 1); 639 /* this packet contained a partial record, dump it */ 640 if (n != i) { 641 rr->length = 0; 642 s->packet_length = 0; 643 goto again; 644 } 645 646 /* 647 * now n == rr->length, and s->packet_length == 648 * DTLS1_RT_HEADER_LENGTH + rr->length 649 */ 650 } 651 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 652 653 /* match epochs. NULL means the packet is dropped on the floor */ 654 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 655 if (bitmap == NULL) { 656 rr->length = 0; 657 s->packet_length = 0; /* dump this record */ 658 goto again; /* get another record */ 659 } 660 661 /* 662 * Check whether this is a repeat, or aged record. Don't check if we're 663 * listening and this message is a ClientHello. They can look as if 664 * they're replayed, since they arrive from different connections and 665 * would be dropped unnecessarily. 666 */ 667 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 668 s->packet_length > DTLS1_RT_HEADER_LENGTH && 669 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) && 670 !dtls1_record_replay_check(s, bitmap)) { 671 rr->length = 0; 672 s->packet_length = 0; /* dump this record */ 673 goto again; /* get another record */ 674 } 675 676 /* just read a 0 length packet */ 677 if (rr->length == 0) 678 goto again; 679 680 /* 681 * If this record is from the next epoch (either HM or ALERT), and a 682 * handshake is currently in progress, buffer it since it cannot be 683 * processed at this time. However, do not buffer anything while 684 * listening. 685 */ 686 if (is_next_epoch) { 687 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) { 688 if (dtls1_buffer_record 689 (s, &(s->d1->unprocessed_rcds), &rr->seq_num) < 0) 690 return -1; 691 } 692 rr->length = 0; 693 s->packet_length = 0; 694 goto again; 695 } 696 697 if (!dtls1_process_record(s, bitmap)) { 698 rr->length = 0; 699 s->packet_length = 0; /* dump this record */ 700 goto again; /* get another record */ 701 } 702 703 return (1); 704 705} 706 707/*- 708 * Return up to 'len' payload bytes received in 'type' records. 709 * 'type' is one of the following: 710 * 711 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 712 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 713 * - 0 (during a shutdown, no data has to be returned) 714 * 715 * If we don't have stored data to work from, read a SSL/TLS record first 716 * (possibly multiple records if we still don't have anything to return). 717 * 718 * This function must handle any surprises the peer may have for us, such as 719 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 720 * a surprise, but handled as if it were), or renegotiation requests. 721 * Also if record payloads contain fragments too small to process, we store 722 * them until there is enough for the respective protocol (the record protocol 723 * may use arbitrary fragmentation and even interleaving): 724 * Change cipher spec protocol 725 * just 1 byte needed, no need for keeping anything stored 726 * Alert protocol 727 * 2 bytes needed (AlertLevel, AlertDescription) 728 * Handshake protocol 729 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 730 * to detect unexpected Client Hello and Hello Request messages 731 * here, anything else is handled by higher layers 732 * Application data protocol 733 * none of our business 734 */ 735int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 736{ 737 int al, i, j, ret; 738 unsigned int n; 739 SSL3_RECORD *rr; 740 void (*cb) (const SSL *ssl, int type2, int val) = NULL; 741 742 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 743 if (!ssl3_setup_buffers(s)) 744 return (-1); 745 746 /* XXX: check what the second '&& type' is about */ 747 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 748 (type != SSL3_RT_HANDSHAKE) && type) || 749 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 750 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 751 return -1; 752 } 753 754 /* 755 * check whether there's a handshake message (client hello?) waiting 756 */ 757 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 758 return ret; 759 760 /* 761 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. 762 */ 763 764 if (!s->in_handshake && SSL_in_init(s)) { 765 /* type == SSL3_RT_APPLICATION_DATA */ 766 i = s->handshake_func(s); 767 if (i < 0) 768 return (i); 769 if (i == 0) { 770 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 771 return (-1); 772 } 773 } 774 775 start: 776 s->rwstate = SSL_NOTHING; 777 778 /*- 779 * s->s3->rrec.type - is the type of record 780 * s->s3->rrec.data, - data 781 * s->s3->rrec.off, - offset into 'data' for next read 782 * s->s3->rrec.length, - number of bytes. 783 */ 784 rr = &(s->s3->rrec); 785 786 /* 787 * We are not handshaking and have no data yet, so process data buffered 788 * during the last handshake in advance, if any. 789 */ 790 if (s->state == SSL_ST_OK && rr->length == 0) { 791 pitem *item; 792 item = pqueue_pop(s->d1->buffered_app_data.q); 793 if (item) { 794 dtls1_copy_record(s, item); 795 796 OPENSSL_free(item->data); 797 pitem_free(item); 798 } 799 } 800 801 /* Check for timeout */ 802 if (dtls1_handle_timeout(s) > 0) 803 goto start; 804 805 /* get new packet if necessary */ 806 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) { 807 ret = dtls1_get_record(s); 808 if (ret <= 0) { 809 ret = dtls1_read_failed(s, ret); 810 /* anything other than a timeout is an error */ 811 if (ret <= 0) 812 return (ret); 813 else 814 goto start; 815 } 816 } 817 818 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) { 819 rr->length = 0; 820 goto start; 821 } 822 823 /* 824 * Reset the count of consecutive warning alerts if we've got a non-empty 825 * record that isn't an alert. 826 */ 827 if (rr->type != SSL3_RT_ALERT && rr->length != 0) 828 s->s3->alert_count = 0; 829 830 /* we now have a packet which can be read and processed */ 831 832 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 833 * reset by ssl3_get_finished */ 834 && (rr->type != SSL3_RT_HANDSHAKE)) { 835 /* 836 * We now have application data between CCS and Finished. Most likely 837 * the packets were reordered on their way, so buffer the application 838 * data for later processing rather than dropping the connection. 839 */ 840 dtls1_buffer_record(s, &(s->d1->buffered_app_data), &rr->seq_num); 841 rr->length = 0; 842 goto start; 843 } 844 845 /* 846 * If the other end has shut down, throw anything we read away (even in 847 * 'peek' mode) 848 */ 849 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 850 rr->length = 0; 851 s->rwstate = SSL_NOTHING; 852 return (0); 853 } 854 855 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or 856 * SSL3_RT_HANDSHAKE */ 857 /* 858 * make sure that we are not getting application data when we are 859 * doing a handshake for the first time 860 */ 861 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 862 (s->enc_read_ctx == NULL)) { 863 al = SSL_AD_UNEXPECTED_MESSAGE; 864 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE); 865 goto f_err; 866 } 867 868 if (len <= 0) 869 return (len); 870 871 if ((unsigned int)len > rr->length) 872 n = rr->length; 873 else 874 n = (unsigned int)len; 875 876 memcpy(buf, &(rr->data[rr->off]), n); 877 if (!peek) { 878 rr->length -= n; 879 rr->off += n; 880 if (rr->length == 0) { 881 s->rstate = SSL_ST_READ_HEADER; 882 rr->off = 0; 883 } 884 } 885 return (n); 886 } 887 888 /* 889 * If we get here, then type != rr->type; if we have a handshake message, 890 * then it was unexpected (Hello Request or Client Hello). 891 */ 892 893 /* 894 * In case of record types for which we have 'fragment' storage, fill 895 * that so that we can process the data at a fixed place. 896 */ 897 { 898 unsigned int k, dest_maxlen = 0; 899 unsigned char *dest = NULL; 900 unsigned int *dest_len = NULL; 901 902 if (rr->type == SSL3_RT_HANDSHAKE) { 903 dest_maxlen = sizeof s->d1->handshake_fragment; 904 dest = s->d1->handshake_fragment; 905 dest_len = &s->d1->handshake_fragment_len; 906 } else if (rr->type == SSL3_RT_ALERT) { 907 dest_maxlen = sizeof(s->d1->alert_fragment); 908 dest = s->d1->alert_fragment; 909 dest_len = &s->d1->alert_fragment_len; 910 } 911 /* else it's a CCS message, or application data or wrong */ 912 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 913 /* 914 * Application data while renegotiating is allowed. Try again 915 * reading. 916 */ 917 if (rr->type == SSL3_RT_APPLICATION_DATA) { 918 BIO *bio; 919 s->s3->in_read_app_data = 2; 920 bio = SSL_get_rbio(s); 921 s->rwstate = SSL_READING; 922 BIO_clear_retry_flags(bio); 923 BIO_set_retry_read(bio); 924 return (-1); 925 } 926 927 /* Not certain if this is the right error handling */ 928 al = SSL_AD_UNEXPECTED_MESSAGE; 929 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 930 goto f_err; 931 } 932 933 if (dest_maxlen > 0) { 934 /* 935 * XDTLS: In a pathalogical case, the Client Hello may be 936 * fragmented--don't always expect dest_maxlen bytes 937 */ 938 if (rr->length < dest_maxlen) { 939#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 940 /* 941 * for normal alerts rr->length is 2, while 942 * dest_maxlen is 7 if we were to handle this 943 * non-existing alert... 944 */ 945 FIX ME 946#endif 947 s->rstate = SSL_ST_READ_HEADER; 948 rr->length = 0; 949 goto start; 950 } 951 952 /* now move 'n' bytes: */ 953 for (k = 0; k < dest_maxlen; k++) { 954 dest[k] = rr->data[rr->off++]; 955 rr->length--; 956 } 957 *dest_len = dest_maxlen; 958 } 959 } 960 961 /*- 962 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 963 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 964 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) 965 */ 966 967 /* If we are a client, check for an incoming 'Hello Request': */ 968 if ((!s->server) && 969 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 970 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 971 (s->session != NULL) && (s->session->cipher != NULL)) { 972 s->d1->handshake_fragment_len = 0; 973 974 if ((s->d1->handshake_fragment[1] != 0) || 975 (s->d1->handshake_fragment[2] != 0) || 976 (s->d1->handshake_fragment[3] != 0)) { 977 al = SSL_AD_DECODE_ERROR; 978 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST); 979 goto err; 980 } 981 982 /* 983 * no need to check sequence number on HELLO REQUEST messages 984 */ 985 986 if (s->msg_callback) 987 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 988 s->d1->handshake_fragment, 4, s, 989 s->msg_callback_arg); 990 991 if (SSL_is_init_finished(s) && 992 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 993 !s->s3->renegotiate) { 994 s->d1->handshake_read_seq++; 995 ssl3_renegotiate(s); 996 if (ssl3_renegotiate_check(s)) { 997 i = s->handshake_func(s); 998 if (i < 0) 999 return (i); 1000 if (i == 0) { 1001 SSLerr(SSL_F_DTLS1_READ_BYTES, 1002 SSL_R_SSL_HANDSHAKE_FAILURE); 1003 return (-1); 1004 } 1005 1006 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1007 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1008 BIO *bio; 1009 /* 1010 * In the case where we try to read application data, 1011 * but we trigger an SSL handshake, we return -1 with 1012 * the retry option set. Otherwise renegotiation may 1013 * cause nasty problems in the blocking world 1014 */ 1015 s->rwstate = SSL_READING; 1016 bio = SSL_get_rbio(s); 1017 BIO_clear_retry_flags(bio); 1018 BIO_set_retry_read(bio); 1019 return (-1); 1020 } 1021 } 1022 } 1023 } 1024 /* 1025 * we either finished a handshake or ignored the request, now try 1026 * again to obtain the (application) data we were asked for 1027 */ 1028 goto start; 1029 } 1030 1031 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 1032 int alert_level = s->d1->alert_fragment[0]; 1033 int alert_descr = s->d1->alert_fragment[1]; 1034 1035 s->d1->alert_fragment_len = 0; 1036 1037 if (s->msg_callback) 1038 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1039 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1040 1041 if (s->info_callback != NULL) 1042 cb = s->info_callback; 1043 else if (s->ctx->info_callback != NULL) 1044 cb = s->ctx->info_callback; 1045 1046 if (cb != NULL) { 1047 j = (alert_level << 8) | alert_descr; 1048 cb(s, SSL_CB_READ_ALERT, j); 1049 } 1050 1051 if (alert_level == 1) { /* warning */ 1052 s->s3->warn_alert = alert_descr; 1053 1054 s->s3->alert_count++; 1055 if (s->s3->alert_count == MAX_WARN_ALERT_COUNT) { 1056 al = SSL_AD_UNEXPECTED_MESSAGE; 1057 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS); 1058 goto f_err; 1059 } 1060 1061 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 1062 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1063 return (0); 1064 } 1065#if 0 1066 /* XXX: this is a possible improvement in the future */ 1067 /* now check if it's a missing record */ 1068 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1069 unsigned short seq; 1070 unsigned int frag_off; 1071 unsigned char *p = &(s->d1->alert_fragment[2]); 1072 1073 n2s(p, seq); 1074 n2l3(p, frag_off); 1075 1076 dtls1_retransmit_message(s, 1077 dtls1_get_queue_priority 1078 (frag->msg_header.seq, 0), frag_off, 1079 &found); 1080 if (!found && SSL_in_init(s)) { 1081 /* 1082 * fprintf( stderr,"in init = %d\n", SSL_in_init(s)); 1083 */ 1084 /* 1085 * requested a message not yet sent, send an alert 1086 * ourselves 1087 */ 1088 ssl3_send_alert(s, SSL3_AL_WARNING, 1089 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1090 } 1091 } 1092#endif 1093 } else if (alert_level == 2) { /* fatal */ 1094 char tmp[16]; 1095 1096 s->rwstate = SSL_NOTHING; 1097 s->s3->fatal_alert = alert_descr; 1098 SSLerr(SSL_F_DTLS1_READ_BYTES, 1099 SSL_AD_REASON_OFFSET + alert_descr); 1100 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); 1101 ERR_add_error_data(2, "SSL alert number ", tmp); 1102 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1103 SSL_CTX_remove_session(s->ctx, s->session); 1104 return (0); 1105 } else { 1106 al = SSL_AD_ILLEGAL_PARAMETER; 1107 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE); 1108 goto f_err; 1109 } 1110 1111 goto start; 1112 } 1113 1114 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a 1115 * shutdown */ 1116 s->rwstate = SSL_NOTHING; 1117 rr->length = 0; 1118 return (0); 1119 } 1120 1121 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1122 struct ccs_header_st ccs_hdr; 1123 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1124 1125 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1126 1127 /* 1128 * 'Change Cipher Spec' is just a single byte, so we know exactly 1129 * what the record payload has to look like 1130 */ 1131 /* XDTLS: check that epoch is consistent */ 1132 if (s->client_version == DTLS1_BAD_VER || s->version == DTLS1_BAD_VER) 1133 ccs_hdr_len = 3; 1134 1135 if ((rr->length != ccs_hdr_len) || (rr->off != 0) 1136 || (rr->data[0] != SSL3_MT_CCS)) { 1137 i = SSL_AD_ILLEGAL_PARAMETER; 1138 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1139 goto err; 1140 } 1141 1142 rr->length = 0; 1143 1144 if (s->msg_callback) 1145 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1146 rr->data, 1, s, s->msg_callback_arg); 1147 1148 /* 1149 * We can't process a CCS now, because previous handshake messages 1150 * are still missing, so just drop it. 1151 */ 1152 if (!s->d1->change_cipher_spec_ok) { 1153 goto start; 1154 } 1155 1156 s->d1->change_cipher_spec_ok = 0; 1157 1158 s->s3->change_cipher_spec = 1; 1159 if (!ssl3_do_change_cipher_spec(s)) 1160 goto err; 1161 1162 /* do this whenever CCS is processed */ 1163 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1164 1165 if (s->client_version == DTLS1_BAD_VER) 1166 s->d1->handshake_read_seq++; 1167 1168 goto start; 1169 } 1170 1171 /* 1172 * Unexpected handshake message (Client Hello, or protocol violation) 1173 */ 1174 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1175 !s->in_handshake) { 1176 struct hm_header_st msg_hdr; 1177 1178 /* this may just be a stale retransmit */ 1179 dtls1_get_message_header(rr->data, &msg_hdr); 1180 if (rr->epoch != s->d1->r_epoch) { 1181 rr->length = 0; 1182 goto start; 1183 } 1184 1185 /* 1186 * If we are server, we may have a repeated FINISHED of the client 1187 * here, then retransmit our CCS and FINISHED. 1188 */ 1189 if (msg_hdr.type == SSL3_MT_FINISHED) { 1190 if (dtls1_check_timeout_num(s) < 0) 1191 return -1; 1192 1193 dtls1_retransmit_buffered_messages(s); 1194 rr->length = 0; 1195 goto start; 1196 } 1197 1198 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) && 1199 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1200#if 0 /* worked only because C operator preferences 1201 * are not as expected (and because this is 1202 * not really needed for clients except for 1203 * detecting protocol violations): */ 1204 s->state = SSL_ST_BEFORE | (s->server) 1205 ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1206#else 1207 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1208#endif 1209 s->new_session = 1; 1210 } 1211 i = s->handshake_func(s); 1212 if (i < 0) 1213 return (i); 1214 if (i == 0) { 1215 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1216 return (-1); 1217 } 1218 1219 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1220 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1221 BIO *bio; 1222 /* 1223 * In the case where we try to read application data, but we 1224 * trigger an SSL handshake, we return -1 with the retry 1225 * option set. Otherwise renegotiation may cause nasty 1226 * problems in the blocking world 1227 */ 1228 s->rwstate = SSL_READING; 1229 bio = SSL_get_rbio(s); 1230 BIO_clear_retry_flags(bio); 1231 BIO_set_retry_read(bio); 1232 return (-1); 1233 } 1234 } 1235 goto start; 1236 } 1237 1238 switch (rr->type) { 1239 default: 1240#ifndef OPENSSL_NO_TLS 1241 /* TLS just ignores unknown message types */ 1242 if (s->version == TLS1_VERSION) { 1243 rr->length = 0; 1244 goto start; 1245 } 1246#endif 1247 al = SSL_AD_UNEXPECTED_MESSAGE; 1248 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1249 goto f_err; 1250 case SSL3_RT_CHANGE_CIPHER_SPEC: 1251 case SSL3_RT_ALERT: 1252 case SSL3_RT_HANDSHAKE: 1253 /* 1254 * we already handled all of these, with the possible exception of 1255 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not 1256 * happen when type != rr->type 1257 */ 1258 al = SSL_AD_UNEXPECTED_MESSAGE; 1259 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 1260 goto f_err; 1261 case SSL3_RT_APPLICATION_DATA: 1262 /* 1263 * At this point, we were expecting handshake data, but have 1264 * application data. If the library was running inside ssl3_read() 1265 * (i.e. in_read_app_data is set) and it makes sense to read 1266 * application data at this point (session renegotiation not yet 1267 * started), we will indulge it. 1268 */ 1269 if (s->s3->in_read_app_data && 1270 (s->s3->total_renegotiations != 0) && 1271 (((s->state & SSL_ST_CONNECT) && 1272 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1273 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1274 ) || ((s->state & SSL_ST_ACCEPT) && 1275 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1276 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1277 ) 1278 )) { 1279 s->s3->in_read_app_data = 2; 1280 return (-1); 1281 } else { 1282 al = SSL_AD_UNEXPECTED_MESSAGE; 1283 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1284 goto f_err; 1285 } 1286 } 1287 /* not reached */ 1288 1289 f_err: 1290 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1291 err: 1292 return (-1); 1293} 1294 1295int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1296{ 1297 int i; 1298 1299 if (SSL_in_init(s) && !s->in_handshake) { 1300 i = s->handshake_func(s); 1301 if (i < 0) 1302 return (i); 1303 if (i == 0) { 1304 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, 1305 SSL_R_SSL_HANDSHAKE_FAILURE); 1306 return -1; 1307 } 1308 } 1309 1310 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 1311 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG); 1312 return -1; 1313 } 1314 1315 i = dtls1_write_bytes(s, type, buf_, len); 1316 return i; 1317} 1318 1319 /* 1320 * this only happens when a client hello is received and a handshake 1321 * is started. 1322 */ 1323static int 1324have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1325 int len, int peek) 1326{ 1327 1328 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1329 /* (partially) satisfy request from storage */ 1330 { 1331 unsigned char *src = s->d1->handshake_fragment; 1332 unsigned char *dst = buf; 1333 unsigned int k, n; 1334 1335 /* peek == 0 */ 1336 n = 0; 1337 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) { 1338 *dst++ = *src++; 1339 len--; 1340 s->d1->handshake_fragment_len--; 1341 n++; 1342 } 1343 /* move any remaining fragment bytes: */ 1344 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1345 s->d1->handshake_fragment[k] = *src++; 1346 return n; 1347 } 1348 1349 return 0; 1350} 1351 1352/* 1353 * Call this to write data in records of type 'type' It will return <= 0 if 1354 * not all data has been sent or non-blocking IO. 1355 */ 1356int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1357{ 1358 int i; 1359 1360 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1361 s->rwstate = SSL_NOTHING; 1362 i = do_dtls1_write(s, type, buf, len, 0); 1363 return i; 1364} 1365 1366int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 1367 unsigned int len, int create_empty_fragment) 1368{ 1369 unsigned char *p, *pseq; 1370 int i, mac_size, clear = 0; 1371 int prefix_len = 0; 1372 SSL3_RECORD *wr; 1373 SSL3_BUFFER *wb; 1374 SSL_SESSION *sess; 1375 int bs; 1376 1377 /* 1378 * first check if there is a SSL3_BUFFER still being written out. This 1379 * will happen with non blocking IO 1380 */ 1381 if (s->s3->wbuf.left != 0) { 1382 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1383 return (ssl3_write_pending(s, type, buf, len)); 1384 } 1385 1386 /* If we have an alert to send, lets send it */ 1387 if (s->s3->alert_dispatch) { 1388 i = s->method->ssl_dispatch_alert(s); 1389 if (i <= 0) 1390 return (i); 1391 /* if it went, fall through and send more stuff */ 1392 } 1393 1394 if (len == 0 && !create_empty_fragment) 1395 return 0; 1396 1397 wr = &(s->s3->wrec); 1398 wb = &(s->s3->wbuf); 1399 sess = s->session; 1400 1401 if ((sess == NULL) || 1402 (s->enc_write_ctx == NULL) || (s->write_hash == NULL)) 1403 clear = 1; 1404 1405 if (clear) 1406 mac_size = 0; 1407 else 1408 mac_size = EVP_MD_size(s->write_hash); 1409 1410 /* DTLS implements explicit IV, so no need for empty fragments */ 1411#if 0 1412 /* 1413 * 'create_empty_fragment' is true only when this function calls itself 1414 */ 1415 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1416 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1417 { 1418 /* 1419 * countermeasure against known-IV weakness in CBC ciphersuites (see 1420 * http://www.openssl.org/~bodo/tls-cbc.txt) 1421 */ 1422 1423 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) { 1424 /* 1425 * recursive function call with 'create_empty_fragment' set; this 1426 * prepares and buffers the data for an empty fragment (these 1427 * 'prefix_len' bytes are sent out later together with the actual 1428 * payload) 1429 */ 1430 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1431 if (prefix_len <= 0) 1432 goto err; 1433 1434 if (s->s3->wbuf.len < 1435 (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) { 1436 /* insufficient space */ 1437 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1438 goto err; 1439 } 1440 } 1441 1442 s->s3->empty_fragment_done = 1; 1443 } 1444#endif 1445 1446 p = wb->buf + prefix_len; 1447 1448 /* write the header */ 1449 1450 *(p++) = type & 0xff; 1451 wr->type = type; 1452 1453 if (s->client_version == DTLS1_BAD_VER) 1454 *(p++) = DTLS1_BAD_VER >> 8, *(p++) = DTLS1_BAD_VER & 0xff; 1455 else 1456 *(p++) = (s->version >> 8), *(p++) = s->version & 0xff; 1457 1458 /* field where we are to write out packet epoch, seq num and len */ 1459 pseq = p; 1460 p += 10; 1461 1462 /* lets setup the record stuff. */ 1463 1464 /* 1465 * Make space for the explicit IV in case of CBC. (this is a bit of a 1466 * boundary violation, but what the heck). 1467 */ 1468 if (s->enc_write_ctx && 1469 (EVP_CIPHER_mode(s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 1470 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1471 else 1472 bs = 0; 1473 1474 wr->data = p + bs; /* make room for IV in case of CBC */ 1475 wr->length = (int)len; 1476 wr->input = (unsigned char *)buf; 1477 1478 /* 1479 * we now 'read' from wr->input, wr->length bytes into wr->data 1480 */ 1481 1482 /* first we compress */ 1483 if (s->compress != NULL) { 1484 if (!ssl3_do_compress(s)) { 1485 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE); 1486 goto err; 1487 } 1488 } else { 1489 memcpy(wr->data, wr->input, wr->length); 1490 wr->input = wr->data; 1491 } 1492 1493 /* 1494 * we should still have the output to wr->data and the input from 1495 * wr->input. Length should be wr->length. wr->data still points in the 1496 * wb->buf 1497 */ 1498 1499 if (mac_size != 0) { 1500 s->method->ssl3_enc->mac(s, &(p[wr->length + bs]), 1); 1501 wr->length += mac_size; 1502 } 1503 1504 /* this is true regardless of mac size */ 1505 wr->input = p; 1506 wr->data = p; 1507 1508 /* ssl3_enc can only have an error on read */ 1509 if (bs) { /* bs != 0 in case of CBC */ 1510 RAND_pseudo_bytes(p, bs); 1511 /* 1512 * master IV and last CBC residue stand for the rest of randomness 1513 */ 1514 wr->length += bs; 1515 } 1516 1517 s->method->ssl3_enc->enc(s, 1); 1518 1519 /* record length after mac and block padding */ 1520 /* 1521 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && ! 1522 * SSL_in_init(s))) 1523 */ 1524 1525 /* there's only one epoch between handshake and app data */ 1526 1527 s2n(s->d1->w_epoch, pseq); 1528 1529 /* XDTLS: ?? */ 1530 /* 1531 * else s2n(s->d1->handshake_epoch, pseq); 1532 */ 1533 1534 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1535 pseq += 6; 1536 s2n(wr->length, pseq); 1537 1538 /* 1539 * we should now have wr->data pointing to the encrypted data, which is 1540 * wr->length long 1541 */ 1542 wr->type = type; /* not needed but helps for debugging */ 1543 wr->length += DTLS1_RT_HEADER_LENGTH; 1544 1545#if 0 /* this is now done at the message layer */ 1546 /* buffer the record, making it easy to handle retransmits */ 1547 if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1548 dtls1_buffer_record(s, wr->data, wr->length, 1549 *((PQ_64BIT *) & (s->s3->write_sequence[0]))); 1550#endif 1551 1552 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1553 1554 if (create_empty_fragment) { 1555 /* 1556 * we are in a recursive call; just return the length, don't write 1557 * out anything here 1558 */ 1559 return wr->length; 1560 } 1561 1562 /* now let's set up wb */ 1563 wb->left = prefix_len + wr->length; 1564 wb->offset = 0; 1565 1566 /* 1567 * memorize arguments so that ssl3_write_pending can detect bad write 1568 * retries later 1569 */ 1570 s->s3->wpend_tot = len; 1571 s->s3->wpend_buf = buf; 1572 s->s3->wpend_type = type; 1573 s->s3->wpend_ret = len; 1574 1575 /* we now just need to write the buffer */ 1576 return ssl3_write_pending(s, type, buf, len); 1577 err: 1578 return -1; 1579} 1580 1581static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1582{ 1583#if PQ_64BIT_IS_INTEGER 1584 PQ_64BIT mask = 0x0000000000000001L; 1585#endif 1586 PQ_64BIT rcd_num, tmp; 1587 1588 pq_64bit_init(&rcd_num); 1589 pq_64bit_init(&tmp); 1590 1591 /* this is the sequence number for the record just read */ 1592 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1593 1594 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1595 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) { 1596 pq_64bit_assign(&s->s3->rrec.seq_num, &rcd_num); 1597 pq_64bit_free(&rcd_num); 1598 pq_64bit_free(&tmp); 1599 return 1; /* this record is new */ 1600 } 1601 1602 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1603 1604 if (pq_64bit_get_word(&tmp) > bitmap->length) { 1605 pq_64bit_free(&rcd_num); 1606 pq_64bit_free(&tmp); 1607 return 0; /* stale, outside the window */ 1608 } 1609#if PQ_64BIT_IS_BIGNUM 1610 { 1611 int offset; 1612 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1613 pq_64bit_sub_word(&tmp, 1); 1614 offset = pq_64bit_get_word(&tmp); 1615 if (pq_64bit_is_bit_set(&(bitmap->map), offset)) { 1616 pq_64bit_free(&rcd_num); 1617 pq_64bit_free(&tmp); 1618 return 0; 1619 } 1620 } 1621#else 1622 mask <<= (bitmap->max_seq_num - rcd_num - 1); 1623 if (bitmap->map & mask) 1624 return 0; /* record previously received */ 1625#endif 1626 1627 pq_64bit_assign(&s->s3->rrec.seq_num, &rcd_num); 1628 pq_64bit_free(&rcd_num); 1629 pq_64bit_free(&tmp); 1630 return 1; 1631} 1632 1633static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1634{ 1635 unsigned int shift; 1636 PQ_64BIT rcd_num; 1637 PQ_64BIT tmp; 1638 PQ_64BIT_CTX *ctx; 1639 1640 pq_64bit_init(&rcd_num); 1641 pq_64bit_init(&tmp); 1642 1643 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1644 1645 /* 1646 * unfortunate code complexity due to 64-bit manipulation support on 1647 * 32-bit machines 1648 */ 1649 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1650 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) { 1651 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num)); 1652 pq_64bit_add_word(&tmp, 1); 1653 1654 shift = (unsigned int)pq_64bit_get_word(&tmp); 1655 1656 pq_64bit_lshift(&(tmp), &(bitmap->map), shift); 1657 pq_64bit_assign(&(bitmap->map), &tmp); 1658 1659 pq_64bit_set_bit(&(bitmap->map), 0); 1660 pq_64bit_add_word(&rcd_num, 1); 1661 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num); 1662 1663 pq_64bit_assign_word(&tmp, 1); 1664 pq_64bit_lshift(&tmp, &tmp, bitmap->length); 1665 ctx = pq_64bit_ctx_new(&ctx); 1666 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx); 1667 pq_64bit_ctx_free(ctx); 1668 } else { 1669 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1670 pq_64bit_sub_word(&tmp, 1); 1671 shift = (unsigned int)pq_64bit_get_word(&tmp); 1672 1673 pq_64bit_set_bit(&(bitmap->map), shift); 1674 } 1675 1676 pq_64bit_free(&rcd_num); 1677 pq_64bit_free(&tmp); 1678} 1679 1680int dtls1_dispatch_alert(SSL *s) 1681{ 1682 int i, j; 1683 void (*cb) (const SSL *ssl, int type, int val) = NULL; 1684 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1685 unsigned char *ptr = &buf[0]; 1686 1687 s->s3->alert_dispatch = 0; 1688 1689 memset(buf, 0x00, sizeof(buf)); 1690 *ptr++ = s->s3->send_alert[0]; 1691 *ptr++ = s->s3->send_alert[1]; 1692 1693#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1694 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1695 s2n(s->d1->handshake_read_seq, ptr); 1696# if 0 1697 if (s->d1->r_msg_hdr.frag_off == 0) 1698 /* 1699 * waiting for a new msg 1700 */ 1701 else 1702 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1703# endif 1704 1705# if 0 1706 fprintf(stderr, 1707 "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n", 1708 s->d1->handshake_read_seq, s->d1->r_msg_hdr.seq); 1709# endif 1710 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1711 } 1712#endif 1713 1714 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1715 if (i <= 0) { 1716 s->s3->alert_dispatch = 1; 1717 /* fprintf( stderr, "not done with alert\n" ); */ 1718 } else { 1719 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1720#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1721 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1722#endif 1723 ) 1724 (void)BIO_flush(s->wbio); 1725 1726 if (s->msg_callback) 1727 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1728 2, s, s->msg_callback_arg); 1729 1730 if (s->info_callback != NULL) 1731 cb = s->info_callback; 1732 else if (s->ctx->info_callback != NULL) 1733 cb = s->ctx->info_callback; 1734 1735 if (cb != NULL) { 1736 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]; 1737 cb(s, SSL_CB_WRITE_ALERT, j); 1738 } 1739 } 1740 return (i); 1741} 1742 1743static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 1744 unsigned int *is_next_epoch) 1745{ 1746 1747 *is_next_epoch = 0; 1748 1749 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1750 if (rr->epoch == s->d1->r_epoch) 1751 return &s->d1->bitmap; 1752 1753 /* 1754 * Only HM and ALERT messages can be from the next epoch and only if we 1755 * have already processed all of the unprocessed records from the last 1756 * epoch 1757 */ 1758 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1759 s->d1->unprocessed_rcds.epoch != s->d1->r_epoch && 1760 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1761 *is_next_epoch = 1; 1762 return &s->d1->next_bitmap; 1763 } 1764 1765 return NULL; 1766} 1767 1768#if 0 1769static int 1770dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 1771 unsigned short *priority, unsigned long *offset) 1772{ 1773 1774 /* alerts are passed up immediately */ 1775 if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT) 1776 return 0; 1777 1778 /* 1779 * Only need to buffer if a handshake is underway. (this implies that 1780 * Hello Request and Client Hello are passed up immediately) 1781 */ 1782 if (SSL_in_init(s)) { 1783 unsigned char *data = rr->data; 1784 /* need to extract the HM/CCS sequence number here */ 1785 if (rr->type == SSL3_RT_HANDSHAKE || 1786 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1787 unsigned short seq_num; 1788 struct hm_header_st msg_hdr; 1789 struct ccs_header_st ccs_hdr; 1790 1791 if (rr->type == SSL3_RT_HANDSHAKE) { 1792 dtls1_get_message_header(data, &msg_hdr); 1793 seq_num = msg_hdr.seq; 1794 *offset = msg_hdr.frag_off; 1795 } else { 1796 dtls1_get_ccs_header(data, &ccs_hdr); 1797 seq_num = ccs_hdr.seq; 1798 *offset = 0; 1799 } 1800 1801 /* 1802 * this is either a record we're waiting for, or a retransmit of 1803 * something we happened to previously receive (higher layers 1804 * will drop the repeat silently 1805 */ 1806 if (seq_num < s->d1->handshake_read_seq) 1807 return 0; 1808 if (rr->type == SSL3_RT_HANDSHAKE && 1809 seq_num == s->d1->handshake_read_seq && 1810 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1811 return 0; 1812 else if (seq_num == s->d1->handshake_read_seq && 1813 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1814 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1815 return 0; 1816 else { 1817 *priority = seq_num; 1818 return 1; 1819 } 1820 } else /* unknown record type */ 1821 return 0; 1822 } 1823 1824 return 0; 1825} 1826#endif 1827 1828void dtls1_reset_seq_numbers(SSL *s, int rw) 1829{ 1830 unsigned char *seq; 1831 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1832 1833 if (rw & SSL3_CC_READ) { 1834 seq = s->s3->read_sequence; 1835 s->d1->r_epoch++; 1836 1837 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map)); 1838 s->d1->bitmap.length = s->d1->next_bitmap.length; 1839 pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 1840 &(s->d1->next_bitmap.max_seq_num)); 1841 1842 pq_64bit_free(&(s->d1->next_bitmap.map)); 1843 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num)); 1844 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1845 pq_64bit_init(&(s->d1->next_bitmap.map)); 1846 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num)); 1847 1848 /* 1849 * We must not use any buffered messages received from the previous 1850 * epoch 1851 */ 1852 dtls1_clear_received_buffer(s); 1853 } else { 1854 seq = s->s3->write_sequence; 1855 memcpy(s->d1->last_write_sequence, seq, 1856 sizeof(s->s3->write_sequence)); 1857 s->d1->w_epoch++; 1858 } 1859 1860 memset(seq, 0x00, seq_bytes); 1861} 1862 1863#if PQ_64BIT_IS_INTEGER 1864static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT * num) 1865{ 1866 PQ_64BIT _num; 1867 1868 _num = (((PQ_64BIT) bytes[0]) << 56) | 1869 (((PQ_64BIT) bytes[1]) << 48) | 1870 (((PQ_64BIT) bytes[2]) << 40) | 1871 (((PQ_64BIT) bytes[3]) << 32) | 1872 (((PQ_64BIT) bytes[4]) << 24) | 1873 (((PQ_64BIT) bytes[5]) << 16) | 1874 (((PQ_64BIT) bytes[6]) << 8) | (((PQ_64BIT) bytes[7])); 1875 1876 *num = _num; 1877 return _num; 1878} 1879#endif 1880