d1_pkt.c revision 277195
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> 124 125/* mod 128 saturating subtract of two 64-bit values in big-endian order */ 126static int satsub64be(const unsigned char *v1,const unsigned char *v2) 127{ int ret,sat,brw,i; 128 129 if (sizeof(long) == 8) do 130 { const union { long one; char little; } is_endian = {1}; 131 long l; 132 133 if (is_endian.little) break; 134 /* not reached on little-endians */ 135 /* following test is redundant, because input is 136 * always aligned, but I take no chances... */ 137 if (((size_t)v1|(size_t)v2)&0x7) break; 138 139 l = *((long *)v1); 140 l -= *((long *)v2); 141 if (l>128) return 128; 142 else if (l<-128) return -128; 143 else return (int)l; 144 } while (0); 145 146 ret = (int)v1[7]-(int)v2[7]; 147 sat = 0; 148 brw = ret>>8; /* brw is either 0 or -1 */ 149 if (ret & 0x80) 150 { for (i=6;i>=0;i--) 151 { brw += (int)v1[i]-(int)v2[i]; 152 sat |= ~brw; 153 brw >>= 8; 154 } 155 } 156 else 157 { for (i=6;i>=0;i--) 158 { brw += (int)v1[i]-(int)v2[i]; 159 sat |= brw; 160 brw >>= 8; 161 } 162 } 163 brw <<= 8; /* brw is either 0 or -256 */ 164 165 if (sat&0xff) return brw | 0x80; 166 else return brw + (ret&0xFF); 167} 168 169static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 170 int len, int peek); 171static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 172static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 173static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 174 unsigned int *is_next_epoch); 175#if 0 176static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 177 unsigned short *priority, unsigned long *offset); 178#endif 179static int dtls1_buffer_record(SSL *s, record_pqueue *q, 180 unsigned char *priority); 181static int dtls1_process_record(SSL *s); 182 183/* copy buffered record into SSL structure */ 184static int 185dtls1_copy_record(SSL *s, pitem *item) 186 { 187 DTLS1_RECORD_DATA *rdata; 188 189 rdata = (DTLS1_RECORD_DATA *)item->data; 190 191 if (s->s3->rbuf.buf != NULL) 192 OPENSSL_free(s->s3->rbuf.buf); 193 194 s->packet = rdata->packet; 195 s->packet_length = rdata->packet_length; 196 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 197 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 198 199 /* Set proper sequence number for mac calculation */ 200 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 201 202 return(1); 203 } 204 205 206static int 207dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 208 { 209 DTLS1_RECORD_DATA *rdata; 210 pitem *item; 211 212 /* Limit the size of the queue to prevent DOS attacks */ 213 if (pqueue_size(queue->q) >= 100) 214 return 0; 215 216 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 217 item = pitem_new(priority, rdata); 218 if (rdata == NULL || item == NULL) 219 { 220 if (rdata != NULL) OPENSSL_free(rdata); 221 if (item != NULL) pitem_free(item); 222 223 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 224 return(0); 225 } 226 227 rdata->packet = s->packet; 228 rdata->packet_length = s->packet_length; 229 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 230 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 231 232 item->data = rdata; 233 234#ifndef OPENSSL_NO_SCTP 235 /* Store bio_dgram_sctp_rcvinfo struct */ 236 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 237 (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) { 238 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 239 } 240#endif 241 242 s->packet = NULL; 243 s->packet_length = 0; 244 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 245 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 246 247 if (!ssl3_setup_buffers(s)) 248 { 249 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 250 if (rdata->rbuf.buf != NULL) 251 OPENSSL_free(rdata->rbuf.buf); 252 OPENSSL_free(rdata); 253 pitem_free(item); 254 return(-1); 255 } 256 257 /* insert should not fail, since duplicates are dropped */ 258 if (pqueue_insert(queue->q, item) == NULL) 259 { 260 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 261 if (rdata->rbuf.buf != NULL) 262 OPENSSL_free(rdata->rbuf.buf); 263 OPENSSL_free(rdata); 264 pitem_free(item); 265 return(-1); 266 } 267 268 return(1); 269 } 270 271 272static int 273dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 274 { 275 pitem *item; 276 277 item = pqueue_pop(queue->q); 278 if (item) 279 { 280 dtls1_copy_record(s, item); 281 282 OPENSSL_free(item->data); 283 pitem_free(item); 284 285 return(1); 286 } 287 288 return(0); 289 } 290 291 292/* retrieve a buffered record that belongs to the new epoch, i.e., not processed 293 * yet */ 294#define dtls1_get_unprocessed_record(s) \ 295 dtls1_retrieve_buffered_record((s), \ 296 &((s)->d1->unprocessed_rcds)) 297 298/* retrieve a buffered record that belongs to the current epoch, ie, processed */ 299#define dtls1_get_processed_record(s) \ 300 dtls1_retrieve_buffered_record((s), \ 301 &((s)->d1->processed_rcds)) 302 303static int 304dtls1_process_buffered_records(SSL *s) 305 { 306 pitem *item; 307 308 item = pqueue_peek(s->d1->unprocessed_rcds.q); 309 if (item) 310 { 311 /* Check if epoch is current. */ 312 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 313 return(1); /* Nothing to do. */ 314 315 /* Process all the records. */ 316 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 317 { 318 dtls1_get_unprocessed_record(s); 319 if ( ! dtls1_process_record(s)) 320 return(0); 321 if(dtls1_buffer_record(s, &(s->d1->processed_rcds), 322 s->s3->rrec.seq_num)<0) 323 return -1; 324 } 325 } 326 327 /* sync epoch numbers once all the unprocessed records 328 * have been processed */ 329 s->d1->processed_rcds.epoch = s->d1->r_epoch; 330 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 331 332 return(1); 333 } 334 335 336#if 0 337 338static int 339dtls1_get_buffered_record(SSL *s) 340 { 341 pitem *item; 342 PQ_64BIT priority = 343 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 344 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 345 346 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 347 nothing buffered */ 348 return 0; 349 350 351 item = pqueue_peek(s->d1->rcvd_records); 352 if (item && item->priority == priority) 353 { 354 /* Check if we've received the record of interest. It must be 355 * a handshake record, since data records as passed up without 356 * buffering */ 357 DTLS1_RECORD_DATA *rdata; 358 item = pqueue_pop(s->d1->rcvd_records); 359 rdata = (DTLS1_RECORD_DATA *)item->data; 360 361 if (s->s3->rbuf.buf != NULL) 362 OPENSSL_free(s->s3->rbuf.buf); 363 364 s->packet = rdata->packet; 365 s->packet_length = rdata->packet_length; 366 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 367 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 368 369 OPENSSL_free(item->data); 370 pitem_free(item); 371 372 /* s->d1->next_expected_seq_num++; */ 373 return(1); 374 } 375 376 return 0; 377 } 378 379#endif 380 381static int 382dtls1_process_record(SSL *s) 383{ 384 int i,al; 385 int enc_err; 386 SSL_SESSION *sess; 387 SSL3_RECORD *rr; 388 unsigned int mac_size, orig_len; 389 unsigned char md[EVP_MAX_MD_SIZE]; 390 391 rr= &(s->s3->rrec); 392 sess = s->session; 393 394 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 395 * and we have that many bytes in s->packet 396 */ 397 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 398 399 /* ok, we can now read from 's->packet' data into 'rr' 400 * rr->input points at rr->length bytes, which 401 * need to be copied into rr->data by either 402 * the decryption or by the decompression 403 * When the data is 'copied' into the rr->data buffer, 404 * rr->input will be pointed at the new buffer */ 405 406 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 407 * rr->length bytes of encrypted compressed stuff. */ 408 409 /* check is not needed I believe */ 410 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 411 { 412 al=SSL_AD_RECORD_OVERFLOW; 413 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 414 goto f_err; 415 } 416 417 /* decrypt in place in 'rr->input' */ 418 rr->data=rr->input; 419 420 enc_err = s->method->ssl3_enc->enc(s,0); 421 /* enc_err is: 422 * 0: (in non-constant time) if the record is publically invalid. 423 * 1: if the padding is valid 424 * -1: if the padding is invalid */ 425 if (enc_err == 0) 426 { 427 /* For DTLS we simply ignore bad packets. */ 428 rr->length = 0; 429 s->packet_length = 0; 430 goto err; 431 } 432 433#ifdef TLS_DEBUG 434printf("dec %d\n",rr->length); 435{ unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 436printf("\n"); 437#endif 438 439 /* r->length is now the compressed data plus mac */ 440 if ((sess != NULL) && 441 (s->enc_read_ctx != NULL) && 442 (EVP_MD_CTX_md(s->read_hash) != NULL)) 443 { 444 /* s->read_hash != NULL => mac_size != -1 */ 445 unsigned char *mac = NULL; 446 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 447 mac_size=EVP_MD_CTX_size(s->read_hash); 448 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 449 450 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 451 orig_len = rr->length+((unsigned int)rr->type>>8); 452 453 /* orig_len is the length of the record before any padding was 454 * removed. This is public information, as is the MAC in use, 455 * therefore we can safely process the record in a different 456 * amount of time if it's too short to possibly contain a MAC. 457 */ 458 if (orig_len < mac_size || 459 /* CBC records must have a padding length byte too. */ 460 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 461 orig_len < mac_size+1)) 462 { 463 al=SSL_AD_DECODE_ERROR; 464 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT); 465 goto f_err; 466 } 467 468 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) 469 { 470 /* We update the length so that the TLS header bytes 471 * can be constructed correctly but we need to extract 472 * the MAC in constant time from within the record, 473 * without leaking the contents of the padding bytes. 474 * */ 475 mac = mac_tmp; 476 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 477 rr->length -= mac_size; 478 } 479 else 480 { 481 /* In this case there's no padding, so |orig_len| 482 * equals |rec->length| and we checked that there's 483 * enough bytes for |mac_size| above. */ 484 rr->length -= mac_size; 485 mac = &rr->data[rr->length]; 486 } 487 488 i=s->method->ssl3_enc->mac(s,md,0 /* not send */); 489 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 490 enc_err = -1; 491 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 492 enc_err = -1; 493 } 494 495 if (enc_err < 0) 496 { 497 /* decryption failed, silently discard message */ 498 rr->length = 0; 499 s->packet_length = 0; 500 goto err; 501 } 502 503 /* r->length is now just compressed */ 504 if (s->expand != NULL) 505 { 506 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 507 { 508 al=SSL_AD_RECORD_OVERFLOW; 509 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 510 goto f_err; 511 } 512 if (!ssl3_do_uncompress(s)) 513 { 514 al=SSL_AD_DECOMPRESSION_FAILURE; 515 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 516 goto f_err; 517 } 518 } 519 520 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 521 { 522 al=SSL_AD_RECORD_OVERFLOW; 523 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 524 goto f_err; 525 } 526 527 rr->off=0; 528 /* So at this point the following is true 529 * ssl->s3->rrec.type is the type of record 530 * ssl->s3->rrec.length == number of bytes in record 531 * ssl->s3->rrec.off == offset to first valid byte 532 * ssl->s3->rrec.data == where to take bytes from, increment 533 * after use :-). 534 */ 535 536 /* we have pulled in a full packet so zero things */ 537 s->packet_length=0; 538 return(1); 539 540f_err: 541 ssl3_send_alert(s,SSL3_AL_FATAL,al); 542err: 543 return(0); 544} 545 546 547/* Call this to get a new input record. 548 * It will return <= 0 if more data is needed, normally due to an error 549 * or non-blocking IO. 550 * When it finishes, one packet has been decoded and can be found in 551 * ssl->s3->rrec.type - is the type of record 552 * ssl->s3->rrec.data, - data 553 * ssl->s3->rrec.length, - number of bytes 554 */ 555/* used only by dtls1_read_bytes */ 556int dtls1_get_record(SSL *s) 557 { 558 int ssl_major,ssl_minor; 559 int i,n; 560 SSL3_RECORD *rr; 561 unsigned char *p = NULL; 562 unsigned short version; 563 DTLS1_BITMAP *bitmap; 564 unsigned int is_next_epoch; 565 566 rr= &(s->s3->rrec); 567 568 /* The epoch may have changed. If so, process all the 569 * pending records. This is a non-blocking operation. */ 570 if(dtls1_process_buffered_records(s)<0) 571 return -1; 572 573 /* if we're renegotiating, then there may be buffered records */ 574 if (dtls1_get_processed_record(s)) 575 return 1; 576 577 /* get something from the wire */ 578again: 579 /* check if we have the header */ 580 if ( (s->rstate != SSL_ST_READ_BODY) || 581 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 582 { 583 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 584 /* read timeout is handled by dtls1_read_bytes */ 585 if (n <= 0) return(n); /* error or non-blocking */ 586 587 /* this packet contained a partial record, dump it */ 588 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 589 { 590 s->packet_length = 0; 591 goto again; 592 } 593 594 s->rstate=SSL_ST_READ_BODY; 595 596 p=s->packet; 597 598 /* Pull apart the header into the DTLS1_RECORD */ 599 rr->type= *(p++); 600 ssl_major= *(p++); 601 ssl_minor= *(p++); 602 version=(ssl_major<<8)|ssl_minor; 603 604 /* sequence number is 64 bits, with top 2 bytes = epoch */ 605 n2s(p,rr->epoch); 606 607 memcpy(&(s->s3->read_sequence[2]), p, 6); 608 p+=6; 609 610 n2s(p,rr->length); 611 612 /* Lets check version */ 613 if (!s->first_packet) 614 { 615 if (version != s->version) 616 { 617 /* unexpected version, silently discard */ 618 rr->length = 0; 619 s->packet_length = 0; 620 goto again; 621 } 622 } 623 624 if ((version & 0xff00) != (s->version & 0xff00)) 625 { 626 /* wrong version, silently discard record */ 627 rr->length = 0; 628 s->packet_length = 0; 629 goto again; 630 } 631 632 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 633 { 634 /* record too long, silently discard it */ 635 rr->length = 0; 636 s->packet_length = 0; 637 goto again; 638 } 639 640 /* now s->rstate == SSL_ST_READ_BODY */ 641 } 642 643 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 644 645 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 646 { 647 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 648 i=rr->length; 649 n=ssl3_read_n(s,i,i,1); 650 /* this packet contained a partial record, dump it */ 651 if ( n != i) 652 { 653 rr->length = 0; 654 s->packet_length = 0; 655 goto again; 656 } 657 658 /* now n == rr->length, 659 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 660 } 661 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 662 663 /* match epochs. NULL means the packet is dropped on the floor */ 664 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 665 if ( bitmap == NULL) 666 { 667 rr->length = 0; 668 s->packet_length = 0; /* dump this record */ 669 goto again; /* get another record */ 670 } 671 672#ifndef OPENSSL_NO_SCTP 673 /* Only do replay check if no SCTP bio */ 674 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) 675 { 676#endif 677 /* Check whether this is a repeat, or aged record. 678 * Don't check if we're listening and this message is 679 * a ClientHello. They can look as if they're replayed, 680 * since they arrive from different connections and 681 * would be dropped unnecessarily. 682 */ 683 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 684 s->packet_length > DTLS1_RT_HEADER_LENGTH && 685 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) && 686 !dtls1_record_replay_check(s, bitmap)) 687 { 688 rr->length = 0; 689 s->packet_length=0; /* dump this record */ 690 goto again; /* get another record */ 691 } 692#ifndef OPENSSL_NO_SCTP 693 } 694#endif 695 696 /* just read a 0 length packet */ 697 if (rr->length == 0) goto again; 698 699 /* If this record is from the next epoch (either HM or ALERT), 700 * and a handshake is currently in progress, buffer it since it 701 * cannot be processed at this time. However, do not buffer 702 * anything while listening. 703 */ 704 if (is_next_epoch) 705 { 706 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) 707 { 708 if(dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num)<0) 709 return -1; 710 dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */ 711 } 712 rr->length = 0; 713 s->packet_length = 0; 714 goto again; 715 } 716 717 if (!dtls1_process_record(s)) 718 { 719 rr->length = 0; 720 s->packet_length = 0; /* dump this record */ 721 goto again; /* get another record */ 722 } 723 dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */ 724 725 return(1); 726 727 } 728 729/* Return up to 'len' payload bytes received in 'type' records. 730 * 'type' is one of the following: 731 * 732 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 733 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 734 * - 0 (during a shutdown, no data has to be returned) 735 * 736 * If we don't have stored data to work from, read a SSL/TLS record first 737 * (possibly multiple records if we still don't have anything to return). 738 * 739 * This function must handle any surprises the peer may have for us, such as 740 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 741 * a surprise, but handled as if it were), or renegotiation requests. 742 * Also if record payloads contain fragments too small to process, we store 743 * them until there is enough for the respective protocol (the record protocol 744 * may use arbitrary fragmentation and even interleaving): 745 * Change cipher spec protocol 746 * just 1 byte needed, no need for keeping anything stored 747 * Alert protocol 748 * 2 bytes needed (AlertLevel, AlertDescription) 749 * Handshake protocol 750 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 751 * to detect unexpected Client Hello and Hello Request messages 752 * here, anything else is handled by higher layers 753 * Application data protocol 754 * none of our business 755 */ 756int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 757 { 758 int al,i,j,ret; 759 unsigned int n; 760 SSL3_RECORD *rr; 761 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 762 763 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 764 if (!ssl3_setup_buffers(s)) 765 return(-1); 766 767 /* XXX: check what the second '&& type' is about */ 768 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 769 (type != SSL3_RT_HANDSHAKE) && type) || 770 (peek && (type != SSL3_RT_APPLICATION_DATA))) 771 { 772 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 773 return -1; 774 } 775 776 /* check whether there's a handshake message (client hello?) waiting */ 777 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 778 return ret; 779 780 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 781 782#ifndef OPENSSL_NO_SCTP 783 /* Continue handshake if it had to be interrupted to read 784 * app data with SCTP. 785 */ 786 if ((!s->in_handshake && SSL_in_init(s)) || 787 (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 788 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) && 789 s->s3->in_read_app_data != 2)) 790#else 791 if (!s->in_handshake && SSL_in_init(s)) 792#endif 793 { 794 /* type == SSL3_RT_APPLICATION_DATA */ 795 i=s->handshake_func(s); 796 if (i < 0) return(i); 797 if (i == 0) 798 { 799 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 800 return(-1); 801 } 802 } 803 804start: 805 s->rwstate=SSL_NOTHING; 806 807 /* s->s3->rrec.type - is the type of record 808 * s->s3->rrec.data, - data 809 * s->s3->rrec.off, - offset into 'data' for next read 810 * s->s3->rrec.length, - number of bytes. */ 811 rr = &(s->s3->rrec); 812 813 /* We are not handshaking and have no data yet, 814 * so process data buffered during the last handshake 815 * in advance, if any. 816 */ 817 if (s->state == SSL_ST_OK && rr->length == 0) 818 { 819 pitem *item; 820 item = pqueue_pop(s->d1->buffered_app_data.q); 821 if (item) 822 { 823#ifndef OPENSSL_NO_SCTP 824 /* Restore bio_dgram_sctp_rcvinfo struct */ 825 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) 826 { 827 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data; 828 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 829 } 830#endif 831 832 dtls1_copy_record(s, item); 833 834 OPENSSL_free(item->data); 835 pitem_free(item); 836 } 837 } 838 839 /* Check for timeout */ 840 if (dtls1_handle_timeout(s) > 0) 841 goto start; 842 843 /* get new packet if necessary */ 844 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 845 { 846 ret=dtls1_get_record(s); 847 if (ret <= 0) 848 { 849 ret = dtls1_read_failed(s, ret); 850 /* anything other than a timeout is an error */ 851 if (ret <= 0) 852 return(ret); 853 else 854 goto start; 855 } 856 } 857 858 /* we now have a packet which can be read and processed */ 859 860 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 861 * reset by ssl3_get_finished */ 862 && (rr->type != SSL3_RT_HANDSHAKE)) 863 { 864 /* We now have application data between CCS and Finished. 865 * Most likely the packets were reordered on their way, so 866 * buffer the application data for later processing rather 867 * than dropping the connection. 868 */ 869 if(dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num)<0) 870 { 871 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 872 return -1; 873 } 874 rr->length = 0; 875 goto start; 876 } 877 878 /* If the other end has shut down, throw anything we read away 879 * (even in 'peek' mode) */ 880 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 881 { 882 rr->length=0; 883 s->rwstate=SSL_NOTHING; 884 return(0); 885 } 886 887 888 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 889 { 890 /* make sure that we are not getting application data when we 891 * are doing a handshake for the first time */ 892 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 893 (s->enc_read_ctx == NULL)) 894 { 895 al=SSL_AD_UNEXPECTED_MESSAGE; 896 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 897 goto f_err; 898 } 899 900 if (len <= 0) return(len); 901 902 if ((unsigned int)len > rr->length) 903 n = rr->length; 904 else 905 n = (unsigned int)len; 906 907 memcpy(buf,&(rr->data[rr->off]),n); 908 if (!peek) 909 { 910 rr->length-=n; 911 rr->off+=n; 912 if (rr->length == 0) 913 { 914 s->rstate=SSL_ST_READ_HEADER; 915 rr->off=0; 916 } 917 } 918 919#ifndef OPENSSL_NO_SCTP 920 /* We were about to renegotiate but had to read 921 * belated application data first, so retry. 922 */ 923 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 924 rr->type == SSL3_RT_APPLICATION_DATA && 925 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) 926 { 927 s->rwstate=SSL_READING; 928 BIO_clear_retry_flags(SSL_get_rbio(s)); 929 BIO_set_retry_read(SSL_get_rbio(s)); 930 } 931 932 /* We might had to delay a close_notify alert because 933 * of reordered app data. If there was an alert and there 934 * is no message to read anymore, finally set shutdown. 935 */ 936 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 937 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 938 { 939 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 940 return(0); 941 } 942#endif 943 return(n); 944 } 945 946 947 /* If we get here, then type != rr->type; if we have a handshake 948 * message, then it was unexpected (Hello Request or Client Hello). */ 949 950 /* In case of record types for which we have 'fragment' storage, 951 * fill that so that we can process the data at a fixed place. 952 */ 953 { 954 unsigned int k, dest_maxlen = 0; 955 unsigned char *dest = NULL; 956 unsigned int *dest_len = NULL; 957 958 if (rr->type == SSL3_RT_HANDSHAKE) 959 { 960 dest_maxlen = sizeof s->d1->handshake_fragment; 961 dest = s->d1->handshake_fragment; 962 dest_len = &s->d1->handshake_fragment_len; 963 } 964 else if (rr->type == SSL3_RT_ALERT) 965 { 966 dest_maxlen = sizeof(s->d1->alert_fragment); 967 dest = s->d1->alert_fragment; 968 dest_len = &s->d1->alert_fragment_len; 969 } 970#ifndef OPENSSL_NO_HEARTBEATS 971 else if (rr->type == TLS1_RT_HEARTBEAT) 972 { 973 dtls1_process_heartbeat(s); 974 975 /* Exit and notify application to read again */ 976 rr->length = 0; 977 s->rwstate=SSL_READING; 978 BIO_clear_retry_flags(SSL_get_rbio(s)); 979 BIO_set_retry_read(SSL_get_rbio(s)); 980 return(-1); 981 } 982#endif 983 /* else it's a CCS message, or application data or wrong */ 984 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 985 { 986 /* Application data while renegotiating 987 * is allowed. Try again reading. 988 */ 989 if (rr->type == SSL3_RT_APPLICATION_DATA) 990 { 991 BIO *bio; 992 s->s3->in_read_app_data=2; 993 bio=SSL_get_rbio(s); 994 s->rwstate=SSL_READING; 995 BIO_clear_retry_flags(bio); 996 BIO_set_retry_read(bio); 997 return(-1); 998 } 999 1000 /* Not certain if this is the right error handling */ 1001 al=SSL_AD_UNEXPECTED_MESSAGE; 1002 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1003 goto f_err; 1004 } 1005 1006 if (dest_maxlen > 0) 1007 { 1008 /* XDTLS: In a pathalogical case, the Client Hello 1009 * may be fragmented--don't always expect dest_maxlen bytes */ 1010 if ( rr->length < dest_maxlen) 1011 { 1012#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1013 /* 1014 * for normal alerts rr->length is 2, while 1015 * dest_maxlen is 7 if we were to handle this 1016 * non-existing alert... 1017 */ 1018 FIX ME 1019#endif 1020 s->rstate=SSL_ST_READ_HEADER; 1021 rr->length = 0; 1022 goto start; 1023 } 1024 1025 /* now move 'n' bytes: */ 1026 for ( k = 0; k < dest_maxlen; k++) 1027 { 1028 dest[k] = rr->data[rr->off++]; 1029 rr->length--; 1030 } 1031 *dest_len = dest_maxlen; 1032 } 1033 } 1034 1035 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 1036 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 1037 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 1038 1039 /* If we are a client, check for an incoming 'Hello Request': */ 1040 if ((!s->server) && 1041 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1042 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1043 (s->session != NULL) && (s->session->cipher != NULL)) 1044 { 1045 s->d1->handshake_fragment_len = 0; 1046 1047 if ((s->d1->handshake_fragment[1] != 0) || 1048 (s->d1->handshake_fragment[2] != 0) || 1049 (s->d1->handshake_fragment[3] != 0)) 1050 { 1051 al=SSL_AD_DECODE_ERROR; 1052 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 1053 goto err; 1054 } 1055 1056 /* no need to check sequence number on HELLO REQUEST messages */ 1057 1058 if (s->msg_callback) 1059 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1060 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 1061 1062 if (SSL_is_init_finished(s) && 1063 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1064 !s->s3->renegotiate) 1065 { 1066 s->new_session = 1; 1067 ssl3_renegotiate(s); 1068 if (ssl3_renegotiate_check(s)) 1069 { 1070 i=s->handshake_func(s); 1071 if (i < 0) return(i); 1072 if (i == 0) 1073 { 1074 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1075 return(-1); 1076 } 1077 1078 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1079 { 1080 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1081 { 1082 BIO *bio; 1083 /* In the case where we try to read application data, 1084 * but we trigger an SSL handshake, we return -1 with 1085 * the retry option set. Otherwise renegotiation may 1086 * cause nasty problems in the blocking world */ 1087 s->rwstate=SSL_READING; 1088 bio=SSL_get_rbio(s); 1089 BIO_clear_retry_flags(bio); 1090 BIO_set_retry_read(bio); 1091 return(-1); 1092 } 1093 } 1094 } 1095 } 1096 /* we either finished a handshake or ignored the request, 1097 * now try again to obtain the (application) data we were asked for */ 1098 goto start; 1099 } 1100 1101 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1102 { 1103 int alert_level = s->d1->alert_fragment[0]; 1104 int alert_descr = s->d1->alert_fragment[1]; 1105 1106 s->d1->alert_fragment_len = 0; 1107 1108 if (s->msg_callback) 1109 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1110 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1111 1112 if (s->info_callback != NULL) 1113 cb=s->info_callback; 1114 else if (s->ctx->info_callback != NULL) 1115 cb=s->ctx->info_callback; 1116 1117 if (cb != NULL) 1118 { 1119 j = (alert_level << 8) | alert_descr; 1120 cb(s, SSL_CB_READ_ALERT, j); 1121 } 1122 1123 if (alert_level == 1) /* warning */ 1124 { 1125 s->s3->warn_alert = alert_descr; 1126 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1127 { 1128#ifndef OPENSSL_NO_SCTP 1129 /* With SCTP and streams the socket may deliver app data 1130 * after a close_notify alert. We have to check this 1131 * first so that nothing gets discarded. 1132 */ 1133 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1134 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 1135 { 1136 s->d1->shutdown_received = 1; 1137 s->rwstate=SSL_READING; 1138 BIO_clear_retry_flags(SSL_get_rbio(s)); 1139 BIO_set_retry_read(SSL_get_rbio(s)); 1140 return -1; 1141 } 1142#endif 1143 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1144 return(0); 1145 } 1146#if 0 1147 /* XXX: this is a possible improvement in the future */ 1148 /* now check if it's a missing record */ 1149 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1150 { 1151 unsigned short seq; 1152 unsigned int frag_off; 1153 unsigned char *p = &(s->d1->alert_fragment[2]); 1154 1155 n2s(p, seq); 1156 n2l3(p, frag_off); 1157 1158 dtls1_retransmit_message(s, 1159 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1160 frag_off, &found); 1161 if ( ! found && SSL_in_init(s)) 1162 { 1163 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1164 /* requested a message not yet sent, 1165 send an alert ourselves */ 1166 ssl3_send_alert(s,SSL3_AL_WARNING, 1167 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1168 } 1169 } 1170#endif 1171 } 1172 else if (alert_level == 2) /* fatal */ 1173 { 1174 char tmp[16]; 1175 1176 s->rwstate=SSL_NOTHING; 1177 s->s3->fatal_alert = alert_descr; 1178 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1179 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1180 ERR_add_error_data(2,"SSL alert number ",tmp); 1181 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1182 SSL_CTX_remove_session(s->ctx,s->session); 1183 return(0); 1184 } 1185 else 1186 { 1187 al=SSL_AD_ILLEGAL_PARAMETER; 1188 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1189 goto f_err; 1190 } 1191 1192 goto start; 1193 } 1194 1195 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1196 { 1197 s->rwstate=SSL_NOTHING; 1198 rr->length=0; 1199 return(0); 1200 } 1201 1202 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1203 { 1204 struct ccs_header_st ccs_hdr; 1205 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1206 1207 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1208 1209 if (s->version == DTLS1_BAD_VER) 1210 ccs_hdr_len = 3; 1211 1212 /* 'Change Cipher Spec' is just a single byte, so we know 1213 * exactly what the record payload has to look like */ 1214 /* XDTLS: check that epoch is consistent */ 1215 if ( (rr->length != ccs_hdr_len) || 1216 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1217 { 1218 i=SSL_AD_ILLEGAL_PARAMETER; 1219 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1220 goto err; 1221 } 1222 1223 rr->length=0; 1224 1225 if (s->msg_callback) 1226 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1227 rr->data, 1, s, s->msg_callback_arg); 1228 1229 /* We can't process a CCS now, because previous handshake 1230 * messages are still missing, so just drop it. 1231 */ 1232 if (!s->d1->change_cipher_spec_ok) 1233 { 1234 goto start; 1235 } 1236 1237 s->d1->change_cipher_spec_ok = 0; 1238 1239 s->s3->change_cipher_spec=1; 1240 if (!ssl3_do_change_cipher_spec(s)) 1241 goto err; 1242 1243 /* do this whenever CCS is processed */ 1244 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1245 1246 if (s->version == DTLS1_BAD_VER) 1247 s->d1->handshake_read_seq++; 1248 1249#ifndef OPENSSL_NO_SCTP 1250 /* Remember that a CCS has been received, 1251 * so that an old key of SCTP-Auth can be 1252 * deleted when a CCS is sent. Will be ignored 1253 * if no SCTP is used 1254 */ 1255 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1256#endif 1257 1258 goto start; 1259 } 1260 1261 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1262 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1263 !s->in_handshake) 1264 { 1265 struct hm_header_st msg_hdr; 1266 1267 /* this may just be a stale retransmit */ 1268 dtls1_get_message_header(rr->data, &msg_hdr); 1269 if( rr->epoch != s->d1->r_epoch) 1270 { 1271 rr->length = 0; 1272 goto start; 1273 } 1274 1275 /* If we are server, we may have a repeated FINISHED of the 1276 * client here, then retransmit our CCS and FINISHED. 1277 */ 1278 if (msg_hdr.type == SSL3_MT_FINISHED) 1279 { 1280 if (dtls1_check_timeout_num(s) < 0) 1281 return -1; 1282 1283 dtls1_retransmit_buffered_messages(s); 1284 rr->length = 0; 1285 goto start; 1286 } 1287 1288 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1289 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1290 { 1291#if 0 /* worked only because C operator preferences are not as expected (and 1292 * because this is not really needed for clients except for detecting 1293 * protocol violations): */ 1294 s->state=SSL_ST_BEFORE|(s->server) 1295 ?SSL_ST_ACCEPT 1296 :SSL_ST_CONNECT; 1297#else 1298 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1299#endif 1300 s->renegotiate=1; 1301 s->new_session=1; 1302 } 1303 i=s->handshake_func(s); 1304 if (i < 0) return(i); 1305 if (i == 0) 1306 { 1307 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1308 return(-1); 1309 } 1310 1311 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1312 { 1313 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1314 { 1315 BIO *bio; 1316 /* In the case where we try to read application data, 1317 * but we trigger an SSL handshake, we return -1 with 1318 * the retry option set. Otherwise renegotiation may 1319 * cause nasty problems in the blocking world */ 1320 s->rwstate=SSL_READING; 1321 bio=SSL_get_rbio(s); 1322 BIO_clear_retry_flags(bio); 1323 BIO_set_retry_read(bio); 1324 return(-1); 1325 } 1326 } 1327 goto start; 1328 } 1329 1330 switch (rr->type) 1331 { 1332 default: 1333#ifndef OPENSSL_NO_TLS 1334 /* TLS just ignores unknown message types */ 1335 if (s->version == TLS1_VERSION) 1336 { 1337 rr->length = 0; 1338 goto start; 1339 } 1340#endif 1341 al=SSL_AD_UNEXPECTED_MESSAGE; 1342 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1343 goto f_err; 1344 case SSL3_RT_CHANGE_CIPHER_SPEC: 1345 case SSL3_RT_ALERT: 1346 case SSL3_RT_HANDSHAKE: 1347 /* we already handled all of these, with the possible exception 1348 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1349 * should not happen when type != rr->type */ 1350 al=SSL_AD_UNEXPECTED_MESSAGE; 1351 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1352 goto f_err; 1353 case SSL3_RT_APPLICATION_DATA: 1354 /* At this point, we were expecting handshake data, 1355 * but have application data. If the library was 1356 * running inside ssl3_read() (i.e. in_read_app_data 1357 * is set) and it makes sense to read application data 1358 * at this point (session renegotiation not yet started), 1359 * we will indulge it. 1360 */ 1361 if (s->s3->in_read_app_data && 1362 (s->s3->total_renegotiations != 0) && 1363 (( 1364 (s->state & SSL_ST_CONNECT) && 1365 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1366 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1367 ) || ( 1368 (s->state & SSL_ST_ACCEPT) && 1369 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1370 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1371 ) 1372 )) 1373 { 1374 s->s3->in_read_app_data=2; 1375 return(-1); 1376 } 1377 else 1378 { 1379 al=SSL_AD_UNEXPECTED_MESSAGE; 1380 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1381 goto f_err; 1382 } 1383 } 1384 /* not reached */ 1385 1386f_err: 1387 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1388err: 1389 return(-1); 1390 } 1391 1392int 1393dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1394 { 1395 int i; 1396 1397#ifndef OPENSSL_NO_SCTP 1398 /* Check if we have to continue an interrupted handshake 1399 * for reading belated app data with SCTP. 1400 */ 1401 if ((SSL_in_init(s) && !s->in_handshake) || 1402 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1403 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1404#else 1405 if (SSL_in_init(s) && !s->in_handshake) 1406#endif 1407 { 1408 i=s->handshake_func(s); 1409 if (i < 0) return(i); 1410 if (i == 0) 1411 { 1412 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1413 return -1; 1414 } 1415 } 1416 1417 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1418 { 1419 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1420 return -1; 1421 } 1422 1423 i = dtls1_write_bytes(s, type, buf_, len); 1424 return i; 1425 } 1426 1427 1428 /* this only happens when a client hello is received and a handshake 1429 * is started. */ 1430static int 1431have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1432 int len, int peek) 1433 { 1434 1435 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1436 /* (partially) satisfy request from storage */ 1437 { 1438 unsigned char *src = s->d1->handshake_fragment; 1439 unsigned char *dst = buf; 1440 unsigned int k,n; 1441 1442 /* peek == 0 */ 1443 n = 0; 1444 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1445 { 1446 *dst++ = *src++; 1447 len--; s->d1->handshake_fragment_len--; 1448 n++; 1449 } 1450 /* move any remaining fragment bytes: */ 1451 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1452 s->d1->handshake_fragment[k] = *src++; 1453 return n; 1454 } 1455 1456 return 0; 1457 } 1458 1459 1460 1461 1462/* Call this to write data in records of type 'type' 1463 * It will return <= 0 if not all data has been sent or non-blocking IO. 1464 */ 1465int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1466 { 1467 int i; 1468 1469 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1470 s->rwstate=SSL_NOTHING; 1471 i=do_dtls1_write(s, type, buf, len, 0); 1472 return i; 1473 } 1474 1475int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1476 { 1477 unsigned char *p,*pseq; 1478 int i,mac_size,clear=0; 1479 int prefix_len = 0; 1480 SSL3_RECORD *wr; 1481 SSL3_BUFFER *wb; 1482 SSL_SESSION *sess; 1483 int bs; 1484 1485 /* first check if there is a SSL3_BUFFER still being written 1486 * out. This will happen with non blocking IO */ 1487 if (s->s3->wbuf.left != 0) 1488 { 1489 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1490 return(ssl3_write_pending(s,type,buf,len)); 1491 } 1492 1493 /* If we have an alert to send, lets send it */ 1494 if (s->s3->alert_dispatch) 1495 { 1496 i=s->method->ssl_dispatch_alert(s); 1497 if (i <= 0) 1498 return(i); 1499 /* if it went, fall through and send more stuff */ 1500 } 1501 1502 if (len == 0 && !create_empty_fragment) 1503 return 0; 1504 1505 wr= &(s->s3->wrec); 1506 wb= &(s->s3->wbuf); 1507 sess=s->session; 1508 1509 if ( (sess == NULL) || 1510 (s->enc_write_ctx == NULL) || 1511 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1512 clear=1; 1513 1514 if (clear) 1515 mac_size=0; 1516 else 1517 { 1518 mac_size=EVP_MD_CTX_size(s->write_hash); 1519 if (mac_size < 0) 1520 goto err; 1521 } 1522 1523 /* DTLS implements explicit IV, so no need for empty fragments */ 1524#if 0 1525 /* 'create_empty_fragment' is true only when this function calls itself */ 1526 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1527 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1528 { 1529 /* countermeasure against known-IV weakness in CBC ciphersuites 1530 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1531 */ 1532 1533 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1534 { 1535 /* recursive function call with 'create_empty_fragment' set; 1536 * this prepares and buffers the data for an empty fragment 1537 * (these 'prefix_len' bytes are sent out later 1538 * together with the actual payload) */ 1539 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1540 if (prefix_len <= 0) 1541 goto err; 1542 1543 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1544 { 1545 /* insufficient space */ 1546 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1547 goto err; 1548 } 1549 } 1550 1551 s->s3->empty_fragment_done = 1; 1552 } 1553#endif 1554 p = wb->buf + prefix_len; 1555 1556 /* write the header */ 1557 1558 *(p++)=type&0xff; 1559 wr->type=type; 1560 1561 *(p++)=(s->version>>8); 1562 *(p++)=s->version&0xff; 1563 1564 /* field where we are to write out packet epoch, seq num and len */ 1565 pseq=p; 1566 p+=10; 1567 1568 /* lets setup the record stuff. */ 1569 1570 /* Make space for the explicit IV in case of CBC. 1571 * (this is a bit of a boundary violation, but what the heck). 1572 */ 1573 if ( s->enc_write_ctx && 1574 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1575 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1576 else 1577 bs = 0; 1578 1579 wr->data=p + bs; /* make room for IV in case of CBC */ 1580 wr->length=(int)len; 1581 wr->input=(unsigned char *)buf; 1582 1583 /* we now 'read' from wr->input, wr->length bytes into 1584 * wr->data */ 1585 1586 /* first we compress */ 1587 if (s->compress != NULL) 1588 { 1589 if (!ssl3_do_compress(s)) 1590 { 1591 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1592 goto err; 1593 } 1594 } 1595 else 1596 { 1597 memcpy(wr->data,wr->input,wr->length); 1598 wr->input=wr->data; 1599 } 1600 1601 /* we should still have the output to wr->data and the input 1602 * from wr->input. Length should be wr->length. 1603 * wr->data still points in the wb->buf */ 1604 1605 if (mac_size != 0) 1606 { 1607 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0) 1608 goto err; 1609 wr->length+=mac_size; 1610 } 1611 1612 /* this is true regardless of mac size */ 1613 wr->input=p; 1614 wr->data=p; 1615 1616 1617 /* ssl3_enc can only have an error on read */ 1618 if (bs) /* bs != 0 in case of CBC */ 1619 { 1620 RAND_pseudo_bytes(p,bs); 1621 /* master IV and last CBC residue stand for 1622 * the rest of randomness */ 1623 wr->length += bs; 1624 } 1625 1626 s->method->ssl3_enc->enc(s,1); 1627 1628 /* record length after mac and block padding */ 1629/* if (type == SSL3_RT_APPLICATION_DATA || 1630 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1631 1632 /* there's only one epoch between handshake and app data */ 1633 1634 s2n(s->d1->w_epoch, pseq); 1635 1636 /* XDTLS: ?? */ 1637/* else 1638 s2n(s->d1->handshake_epoch, pseq); */ 1639 1640 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1641 pseq+=6; 1642 s2n(wr->length,pseq); 1643 1644 /* we should now have 1645 * wr->data pointing to the encrypted data, which is 1646 * wr->length long */ 1647 wr->type=type; /* not needed but helps for debugging */ 1648 wr->length+=DTLS1_RT_HEADER_LENGTH; 1649 1650#if 0 /* this is now done at the message layer */ 1651 /* buffer the record, making it easy to handle retransmits */ 1652 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1653 dtls1_buffer_record(s, wr->data, wr->length, 1654 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1655#endif 1656 1657 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1658 1659 if (create_empty_fragment) 1660 { 1661 /* we are in a recursive call; 1662 * just return the length, don't write out anything here 1663 */ 1664 return wr->length; 1665 } 1666 1667 /* now let's set up wb */ 1668 wb->left = prefix_len + wr->length; 1669 wb->offset = 0; 1670 1671 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1672 s->s3->wpend_tot=len; 1673 s->s3->wpend_buf=buf; 1674 s->s3->wpend_type=type; 1675 s->s3->wpend_ret=len; 1676 1677 /* we now just need to write the buffer */ 1678 return ssl3_write_pending(s,type,buf,len); 1679err: 1680 return -1; 1681 } 1682 1683 1684 1685static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1686 { 1687 int cmp; 1688 unsigned int shift; 1689 const unsigned char *seq = s->s3->read_sequence; 1690 1691 cmp = satsub64be(seq,bitmap->max_seq_num); 1692 if (cmp > 0) 1693 { 1694 memcpy (s->s3->rrec.seq_num,seq,8); 1695 return 1; /* this record in new */ 1696 } 1697 shift = -cmp; 1698 if (shift >= sizeof(bitmap->map)*8) 1699 return 0; /* stale, outside the window */ 1700 else if (bitmap->map & (1UL<<shift)) 1701 return 0; /* record previously received */ 1702 1703 memcpy (s->s3->rrec.seq_num,seq,8); 1704 return 1; 1705 } 1706 1707 1708static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1709 { 1710 int cmp; 1711 unsigned int shift; 1712 const unsigned char *seq = s->s3->read_sequence; 1713 1714 cmp = satsub64be(seq,bitmap->max_seq_num); 1715 if (cmp > 0) 1716 { 1717 shift = cmp; 1718 if (shift < sizeof(bitmap->map)*8) 1719 bitmap->map <<= shift, bitmap->map |= 1UL; 1720 else 1721 bitmap->map = 1UL; 1722 memcpy(bitmap->max_seq_num,seq,8); 1723 } 1724 else { 1725 shift = -cmp; 1726 if (shift < sizeof(bitmap->map)*8) 1727 bitmap->map |= 1UL<<shift; 1728 } 1729 } 1730 1731 1732int dtls1_dispatch_alert(SSL *s) 1733 { 1734 int i,j; 1735 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1736 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1737 unsigned char *ptr = &buf[0]; 1738 1739 s->s3->alert_dispatch=0; 1740 1741 memset(buf, 0x00, sizeof(buf)); 1742 *ptr++ = s->s3->send_alert[0]; 1743 *ptr++ = s->s3->send_alert[1]; 1744 1745#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1746 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1747 { 1748 s2n(s->d1->handshake_read_seq, ptr); 1749#if 0 1750 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1751 1752 else 1753 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1754#endif 1755 1756#if 0 1757 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); 1758#endif 1759 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1760 } 1761#endif 1762 1763 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1764 if (i <= 0) 1765 { 1766 s->s3->alert_dispatch=1; 1767 /* fprintf( stderr, "not done with alert\n" ); */ 1768 } 1769 else 1770 { 1771 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1772#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1773 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1774#endif 1775 ) 1776 (void)BIO_flush(s->wbio); 1777 1778 if (s->msg_callback) 1779 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1780 2, s, s->msg_callback_arg); 1781 1782 if (s->info_callback != NULL) 1783 cb=s->info_callback; 1784 else if (s->ctx->info_callback != NULL) 1785 cb=s->ctx->info_callback; 1786 1787 if (cb != NULL) 1788 { 1789 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1790 cb(s,SSL_CB_WRITE_ALERT,j); 1791 } 1792 } 1793 return(i); 1794 } 1795 1796 1797static DTLS1_BITMAP * 1798dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1799 { 1800 1801 *is_next_epoch = 0; 1802 1803 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1804 if (rr->epoch == s->d1->r_epoch) 1805 return &s->d1->bitmap; 1806 1807 /* Only HM and ALERT messages can be from the next epoch */ 1808 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1809 (rr->type == SSL3_RT_HANDSHAKE || 1810 rr->type == SSL3_RT_ALERT)) 1811 { 1812 *is_next_epoch = 1; 1813 return &s->d1->next_bitmap; 1814 } 1815 1816 return NULL; 1817 } 1818 1819#if 0 1820static int 1821dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1822 unsigned long *offset) 1823 { 1824 1825 /* alerts are passed up immediately */ 1826 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1827 rr->type == SSL3_RT_ALERT) 1828 return 0; 1829 1830 /* Only need to buffer if a handshake is underway. 1831 * (this implies that Hello Request and Client Hello are passed up 1832 * immediately) */ 1833 if ( SSL_in_init(s)) 1834 { 1835 unsigned char *data = rr->data; 1836 /* need to extract the HM/CCS sequence number here */ 1837 if ( rr->type == SSL3_RT_HANDSHAKE || 1838 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1839 { 1840 unsigned short seq_num; 1841 struct hm_header_st msg_hdr; 1842 struct ccs_header_st ccs_hdr; 1843 1844 if ( rr->type == SSL3_RT_HANDSHAKE) 1845 { 1846 dtls1_get_message_header(data, &msg_hdr); 1847 seq_num = msg_hdr.seq; 1848 *offset = msg_hdr.frag_off; 1849 } 1850 else 1851 { 1852 dtls1_get_ccs_header(data, &ccs_hdr); 1853 seq_num = ccs_hdr.seq; 1854 *offset = 0; 1855 } 1856 1857 /* this is either a record we're waiting for, or a 1858 * retransmit of something we happened to previously 1859 * receive (higher layers will drop the repeat silently */ 1860 if ( seq_num < s->d1->handshake_read_seq) 1861 return 0; 1862 if (rr->type == SSL3_RT_HANDSHAKE && 1863 seq_num == s->d1->handshake_read_seq && 1864 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1865 return 0; 1866 else if ( seq_num == s->d1->handshake_read_seq && 1867 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1868 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1869 return 0; 1870 else 1871 { 1872 *priority = seq_num; 1873 return 1; 1874 } 1875 } 1876 else /* unknown record type */ 1877 return 0; 1878 } 1879 1880 return 0; 1881 } 1882#endif 1883 1884void 1885dtls1_reset_seq_numbers(SSL *s, int rw) 1886 { 1887 unsigned char *seq; 1888 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1889 1890 if ( rw & SSL3_CC_READ) 1891 { 1892 seq = s->s3->read_sequence; 1893 s->d1->r_epoch++; 1894 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1895 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1896 } 1897 else 1898 { 1899 seq = s->s3->write_sequence; 1900 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1901 s->d1->w_epoch++; 1902 } 1903 1904 memset(seq, 0x00, seq_bytes); 1905 } 1906