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