d1_pkt.c revision 284295
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 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) 859 { 860 rr->length = 0; 861 goto start; 862 } 863 864 /* we now have a packet which can be read and processed */ 865 866 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 867 * reset by ssl3_get_finished */ 868 && (rr->type != SSL3_RT_HANDSHAKE)) 869 { 870 /* We now have application data between CCS and Finished. 871 * Most likely the packets were reordered on their way, so 872 * buffer the application data for later processing rather 873 * than dropping the connection. 874 */ 875 if(dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num)<0) 876 { 877 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 878 return -1; 879 } 880 rr->length = 0; 881 goto start; 882 } 883 884 /* If the other end has shut down, throw anything we read away 885 * (even in 'peek' mode) */ 886 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 887 { 888 rr->length=0; 889 s->rwstate=SSL_NOTHING; 890 return(0); 891 } 892 893 894 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 895 { 896 /* make sure that we are not getting application data when we 897 * are doing a handshake for the first time */ 898 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 899 (s->enc_read_ctx == NULL)) 900 { 901 al=SSL_AD_UNEXPECTED_MESSAGE; 902 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 903 goto f_err; 904 } 905 906 if (len <= 0) return(len); 907 908 if ((unsigned int)len > rr->length) 909 n = rr->length; 910 else 911 n = (unsigned int)len; 912 913 memcpy(buf,&(rr->data[rr->off]),n); 914 if (!peek) 915 { 916 rr->length-=n; 917 rr->off+=n; 918 if (rr->length == 0) 919 { 920 s->rstate=SSL_ST_READ_HEADER; 921 rr->off=0; 922 } 923 } 924 925#ifndef OPENSSL_NO_SCTP 926 /* We were about to renegotiate but had to read 927 * belated application data first, so retry. 928 */ 929 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 930 rr->type == SSL3_RT_APPLICATION_DATA && 931 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) 932 { 933 s->rwstate=SSL_READING; 934 BIO_clear_retry_flags(SSL_get_rbio(s)); 935 BIO_set_retry_read(SSL_get_rbio(s)); 936 } 937 938 /* We might had to delay a close_notify alert because 939 * of reordered app data. If there was an alert and there 940 * is no message to read anymore, finally set shutdown. 941 */ 942 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 943 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 944 { 945 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 946 return(0); 947 } 948#endif 949 return(n); 950 } 951 952 953 /* If we get here, then type != rr->type; if we have a handshake 954 * message, then it was unexpected (Hello Request or Client Hello). */ 955 956 /* In case of record types for which we have 'fragment' storage, 957 * fill that so that we can process the data at a fixed place. 958 */ 959 { 960 unsigned int k, dest_maxlen = 0; 961 unsigned char *dest = NULL; 962 unsigned int *dest_len = NULL; 963 964 if (rr->type == SSL3_RT_HANDSHAKE) 965 { 966 dest_maxlen = sizeof s->d1->handshake_fragment; 967 dest = s->d1->handshake_fragment; 968 dest_len = &s->d1->handshake_fragment_len; 969 } 970 else if (rr->type == SSL3_RT_ALERT) 971 { 972 dest_maxlen = sizeof(s->d1->alert_fragment); 973 dest = s->d1->alert_fragment; 974 dest_len = &s->d1->alert_fragment_len; 975 } 976#ifndef OPENSSL_NO_HEARTBEATS 977 else if (rr->type == TLS1_RT_HEARTBEAT) 978 { 979 dtls1_process_heartbeat(s); 980 981 /* Exit and notify application to read again */ 982 rr->length = 0; 983 s->rwstate=SSL_READING; 984 BIO_clear_retry_flags(SSL_get_rbio(s)); 985 BIO_set_retry_read(SSL_get_rbio(s)); 986 return(-1); 987 } 988#endif 989 /* else it's a CCS message, or application data or wrong */ 990 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 991 { 992 /* Application data while renegotiating 993 * is allowed. Try again reading. 994 */ 995 if (rr->type == SSL3_RT_APPLICATION_DATA) 996 { 997 BIO *bio; 998 s->s3->in_read_app_data=2; 999 bio=SSL_get_rbio(s); 1000 s->rwstate=SSL_READING; 1001 BIO_clear_retry_flags(bio); 1002 BIO_set_retry_read(bio); 1003 return(-1); 1004 } 1005 1006 /* Not certain if this is the right error handling */ 1007 al=SSL_AD_UNEXPECTED_MESSAGE; 1008 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1009 goto f_err; 1010 } 1011 1012 if (dest_maxlen > 0) 1013 { 1014 /* XDTLS: In a pathalogical case, the Client Hello 1015 * may be fragmented--don't always expect dest_maxlen bytes */ 1016 if ( rr->length < dest_maxlen) 1017 { 1018#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1019 /* 1020 * for normal alerts rr->length is 2, while 1021 * dest_maxlen is 7 if we were to handle this 1022 * non-existing alert... 1023 */ 1024 FIX ME 1025#endif 1026 s->rstate=SSL_ST_READ_HEADER; 1027 rr->length = 0; 1028 goto start; 1029 } 1030 1031 /* now move 'n' bytes: */ 1032 for ( k = 0; k < dest_maxlen; k++) 1033 { 1034 dest[k] = rr->data[rr->off++]; 1035 rr->length--; 1036 } 1037 *dest_len = dest_maxlen; 1038 } 1039 } 1040 1041 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 1042 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 1043 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 1044 1045 /* If we are a client, check for an incoming 'Hello Request': */ 1046 if ((!s->server) && 1047 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1048 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1049 (s->session != NULL) && (s->session->cipher != NULL)) 1050 { 1051 s->d1->handshake_fragment_len = 0; 1052 1053 if ((s->d1->handshake_fragment[1] != 0) || 1054 (s->d1->handshake_fragment[2] != 0) || 1055 (s->d1->handshake_fragment[3] != 0)) 1056 { 1057 al=SSL_AD_DECODE_ERROR; 1058 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 1059 goto f_err; 1060 } 1061 1062 /* no need to check sequence number on HELLO REQUEST messages */ 1063 1064 if (s->msg_callback) 1065 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1066 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 1067 1068 if (SSL_is_init_finished(s) && 1069 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1070 !s->s3->renegotiate) 1071 { 1072 s->d1->handshake_read_seq++; 1073 s->new_session = 1; 1074 ssl3_renegotiate(s); 1075 if (ssl3_renegotiate_check(s)) 1076 { 1077 i=s->handshake_func(s); 1078 if (i < 0) return(i); 1079 if (i == 0) 1080 { 1081 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1082 return(-1); 1083 } 1084 1085 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1086 { 1087 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1088 { 1089 BIO *bio; 1090 /* In the case where we try to read application data, 1091 * but we trigger an SSL handshake, we return -1 with 1092 * the retry option set. Otherwise renegotiation may 1093 * cause nasty problems in the blocking world */ 1094 s->rwstate=SSL_READING; 1095 bio=SSL_get_rbio(s); 1096 BIO_clear_retry_flags(bio); 1097 BIO_set_retry_read(bio); 1098 return(-1); 1099 } 1100 } 1101 } 1102 } 1103 /* we either finished a handshake or ignored the request, 1104 * now try again to obtain the (application) data we were asked for */ 1105 goto start; 1106 } 1107 1108 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1109 { 1110 int alert_level = s->d1->alert_fragment[0]; 1111 int alert_descr = s->d1->alert_fragment[1]; 1112 1113 s->d1->alert_fragment_len = 0; 1114 1115 if (s->msg_callback) 1116 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1117 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1118 1119 if (s->info_callback != NULL) 1120 cb=s->info_callback; 1121 else if (s->ctx->info_callback != NULL) 1122 cb=s->ctx->info_callback; 1123 1124 if (cb != NULL) 1125 { 1126 j = (alert_level << 8) | alert_descr; 1127 cb(s, SSL_CB_READ_ALERT, j); 1128 } 1129 1130 if (alert_level == 1) /* warning */ 1131 { 1132 s->s3->warn_alert = alert_descr; 1133 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1134 { 1135#ifndef OPENSSL_NO_SCTP 1136 /* With SCTP and streams the socket may deliver app data 1137 * after a close_notify alert. We have to check this 1138 * first so that nothing gets discarded. 1139 */ 1140 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1141 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 1142 { 1143 s->d1->shutdown_received = 1; 1144 s->rwstate=SSL_READING; 1145 BIO_clear_retry_flags(SSL_get_rbio(s)); 1146 BIO_set_retry_read(SSL_get_rbio(s)); 1147 return -1; 1148 } 1149#endif 1150 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1151 return(0); 1152 } 1153#if 0 1154 /* XXX: this is a possible improvement in the future */ 1155 /* now check if it's a missing record */ 1156 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1157 { 1158 unsigned short seq; 1159 unsigned int frag_off; 1160 unsigned char *p = &(s->d1->alert_fragment[2]); 1161 1162 n2s(p, seq); 1163 n2l3(p, frag_off); 1164 1165 dtls1_retransmit_message(s, 1166 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1167 frag_off, &found); 1168 if ( ! found && SSL_in_init(s)) 1169 { 1170 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1171 /* requested a message not yet sent, 1172 send an alert ourselves */ 1173 ssl3_send_alert(s,SSL3_AL_WARNING, 1174 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1175 } 1176 } 1177#endif 1178 } 1179 else if (alert_level == 2) /* fatal */ 1180 { 1181 char tmp[16]; 1182 1183 s->rwstate=SSL_NOTHING; 1184 s->s3->fatal_alert = alert_descr; 1185 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1186 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1187 ERR_add_error_data(2,"SSL alert number ",tmp); 1188 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1189 SSL_CTX_remove_session(s->ctx,s->session); 1190 return(0); 1191 } 1192 else 1193 { 1194 al=SSL_AD_ILLEGAL_PARAMETER; 1195 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1196 goto f_err; 1197 } 1198 1199 goto start; 1200 } 1201 1202 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1203 { 1204 s->rwstate=SSL_NOTHING; 1205 rr->length=0; 1206 return(0); 1207 } 1208 1209 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1210 { 1211 struct ccs_header_st ccs_hdr; 1212 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1213 1214 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1215 1216 if (s->version == DTLS1_BAD_VER) 1217 ccs_hdr_len = 3; 1218 1219 /* 'Change Cipher Spec' is just a single byte, so we know 1220 * exactly what the record payload has to look like */ 1221 /* XDTLS: check that epoch is consistent */ 1222 if ( (rr->length != ccs_hdr_len) || 1223 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1224 { 1225 i=SSL_AD_ILLEGAL_PARAMETER; 1226 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1227 goto err; 1228 } 1229 1230 rr->length=0; 1231 1232 if (s->msg_callback) 1233 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1234 rr->data, 1, s, s->msg_callback_arg); 1235 1236 /* We can't process a CCS now, because previous handshake 1237 * messages are still missing, so just drop it. 1238 */ 1239 if (!s->d1->change_cipher_spec_ok) 1240 { 1241 goto start; 1242 } 1243 1244 s->d1->change_cipher_spec_ok = 0; 1245 1246 s->s3->change_cipher_spec=1; 1247 if (!ssl3_do_change_cipher_spec(s)) 1248 goto err; 1249 1250 /* do this whenever CCS is processed */ 1251 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1252 1253 if (s->version == DTLS1_BAD_VER) 1254 s->d1->handshake_read_seq++; 1255 1256#ifndef OPENSSL_NO_SCTP 1257 /* Remember that a CCS has been received, 1258 * so that an old key of SCTP-Auth can be 1259 * deleted when a CCS is sent. Will be ignored 1260 * if no SCTP is used 1261 */ 1262 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1263#endif 1264 1265 goto start; 1266 } 1267 1268 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1269 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1270 !s->in_handshake) 1271 { 1272 struct hm_header_st msg_hdr; 1273 1274 /* this may just be a stale retransmit */ 1275 dtls1_get_message_header(rr->data, &msg_hdr); 1276 if( rr->epoch != s->d1->r_epoch) 1277 { 1278 rr->length = 0; 1279 goto start; 1280 } 1281 1282 /* If we are server, we may have a repeated FINISHED of the 1283 * client here, then retransmit our CCS and FINISHED. 1284 */ 1285 if (msg_hdr.type == SSL3_MT_FINISHED) 1286 { 1287 if (dtls1_check_timeout_num(s) < 0) 1288 return -1; 1289 1290 dtls1_retransmit_buffered_messages(s); 1291 rr->length = 0; 1292 goto start; 1293 } 1294 1295 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1296 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1297 { 1298#if 0 /* worked only because C operator preferences are not as expected (and 1299 * because this is not really needed for clients except for detecting 1300 * protocol violations): */ 1301 s->state=SSL_ST_BEFORE|(s->server) 1302 ?SSL_ST_ACCEPT 1303 :SSL_ST_CONNECT; 1304#else 1305 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1306#endif 1307 s->renegotiate=1; 1308 s->new_session=1; 1309 } 1310 i=s->handshake_func(s); 1311 if (i < 0) return(i); 1312 if (i == 0) 1313 { 1314 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1315 return(-1); 1316 } 1317 1318 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1319 { 1320 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1321 { 1322 BIO *bio; 1323 /* In the case where we try to read application data, 1324 * but we trigger an SSL handshake, we return -1 with 1325 * the retry option set. Otherwise renegotiation may 1326 * cause nasty problems in the blocking world */ 1327 s->rwstate=SSL_READING; 1328 bio=SSL_get_rbio(s); 1329 BIO_clear_retry_flags(bio); 1330 BIO_set_retry_read(bio); 1331 return(-1); 1332 } 1333 } 1334 goto start; 1335 } 1336 1337 switch (rr->type) 1338 { 1339 default: 1340#ifndef OPENSSL_NO_TLS 1341 /* TLS just ignores unknown message types */ 1342 if (s->version == TLS1_VERSION) 1343 { 1344 rr->length = 0; 1345 goto start; 1346 } 1347#endif 1348 al=SSL_AD_UNEXPECTED_MESSAGE; 1349 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1350 goto f_err; 1351 case SSL3_RT_CHANGE_CIPHER_SPEC: 1352 case SSL3_RT_ALERT: 1353 case SSL3_RT_HANDSHAKE: 1354 /* we already handled all of these, with the possible exception 1355 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1356 * should not happen when type != rr->type */ 1357 al=SSL_AD_UNEXPECTED_MESSAGE; 1358 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1359 goto f_err; 1360 case SSL3_RT_APPLICATION_DATA: 1361 /* At this point, we were expecting handshake data, 1362 * but have application data. If the library was 1363 * running inside ssl3_read() (i.e. in_read_app_data 1364 * is set) and it makes sense to read application data 1365 * at this point (session renegotiation not yet started), 1366 * we will indulge it. 1367 */ 1368 if (s->s3->in_read_app_data && 1369 (s->s3->total_renegotiations != 0) && 1370 (( 1371 (s->state & SSL_ST_CONNECT) && 1372 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1373 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1374 ) || ( 1375 (s->state & SSL_ST_ACCEPT) && 1376 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1377 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1378 ) 1379 )) 1380 { 1381 s->s3->in_read_app_data=2; 1382 return(-1); 1383 } 1384 else 1385 { 1386 al=SSL_AD_UNEXPECTED_MESSAGE; 1387 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1388 goto f_err; 1389 } 1390 } 1391 /* not reached */ 1392 1393f_err: 1394 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1395err: 1396 return(-1); 1397 } 1398 1399int 1400dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1401 { 1402 int i; 1403 1404#ifndef OPENSSL_NO_SCTP 1405 /* Check if we have to continue an interrupted handshake 1406 * for reading belated app data with SCTP. 1407 */ 1408 if ((SSL_in_init(s) && !s->in_handshake) || 1409 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1410 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1411#else 1412 if (SSL_in_init(s) && !s->in_handshake) 1413#endif 1414 { 1415 i=s->handshake_func(s); 1416 if (i < 0) return(i); 1417 if (i == 0) 1418 { 1419 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1420 return -1; 1421 } 1422 } 1423 1424 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1425 { 1426 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1427 return -1; 1428 } 1429 1430 i = dtls1_write_bytes(s, type, buf_, len); 1431 return i; 1432 } 1433 1434 1435 /* this only happens when a client hello is received and a handshake 1436 * is started. */ 1437static int 1438have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1439 int len, int peek) 1440 { 1441 1442 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1443 /* (partially) satisfy request from storage */ 1444 { 1445 unsigned char *src = s->d1->handshake_fragment; 1446 unsigned char *dst = buf; 1447 unsigned int k,n; 1448 1449 /* peek == 0 */ 1450 n = 0; 1451 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1452 { 1453 *dst++ = *src++; 1454 len--; s->d1->handshake_fragment_len--; 1455 n++; 1456 } 1457 /* move any remaining fragment bytes: */ 1458 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1459 s->d1->handshake_fragment[k] = *src++; 1460 return n; 1461 } 1462 1463 return 0; 1464 } 1465 1466 1467 1468 1469/* Call this to write data in records of type 'type' 1470 * It will return <= 0 if not all data has been sent or non-blocking IO. 1471 */ 1472int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1473 { 1474 int i; 1475 1476 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1477 s->rwstate=SSL_NOTHING; 1478 i=do_dtls1_write(s, type, buf, len, 0); 1479 return i; 1480 } 1481 1482int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1483 { 1484 unsigned char *p,*pseq; 1485 int i,mac_size,clear=0; 1486 int prefix_len = 0; 1487 SSL3_RECORD *wr; 1488 SSL3_BUFFER *wb; 1489 SSL_SESSION *sess; 1490 int bs; 1491 1492 /* first check if there is a SSL3_BUFFER still being written 1493 * out. This will happen with non blocking IO */ 1494 if (s->s3->wbuf.left != 0) 1495 { 1496 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1497 return(ssl3_write_pending(s,type,buf,len)); 1498 } 1499 1500 /* If we have an alert to send, lets send it */ 1501 if (s->s3->alert_dispatch) 1502 { 1503 i=s->method->ssl_dispatch_alert(s); 1504 if (i <= 0) 1505 return(i); 1506 /* if it went, fall through and send more stuff */ 1507 } 1508 1509 if (len == 0 && !create_empty_fragment) 1510 return 0; 1511 1512 wr= &(s->s3->wrec); 1513 wb= &(s->s3->wbuf); 1514 sess=s->session; 1515 1516 if ( (sess == NULL) || 1517 (s->enc_write_ctx == NULL) || 1518 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1519 clear=1; 1520 1521 if (clear) 1522 mac_size=0; 1523 else 1524 { 1525 mac_size=EVP_MD_CTX_size(s->write_hash); 1526 if (mac_size < 0) 1527 goto err; 1528 } 1529 1530 /* DTLS implements explicit IV, so no need for empty fragments */ 1531#if 0 1532 /* 'create_empty_fragment' is true only when this function calls itself */ 1533 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1534 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1535 { 1536 /* countermeasure against known-IV weakness in CBC ciphersuites 1537 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1538 */ 1539 1540 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1541 { 1542 /* recursive function call with 'create_empty_fragment' set; 1543 * this prepares and buffers the data for an empty fragment 1544 * (these 'prefix_len' bytes are sent out later 1545 * together with the actual payload) */ 1546 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1547 if (prefix_len <= 0) 1548 goto err; 1549 1550 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1551 { 1552 /* insufficient space */ 1553 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1554 goto err; 1555 } 1556 } 1557 1558 s->s3->empty_fragment_done = 1; 1559 } 1560#endif 1561 p = wb->buf + prefix_len; 1562 1563 /* write the header */ 1564 1565 *(p++)=type&0xff; 1566 wr->type=type; 1567 1568 *(p++)=(s->version>>8); 1569 *(p++)=s->version&0xff; 1570 1571 /* field where we are to write out packet epoch, seq num and len */ 1572 pseq=p; 1573 p+=10; 1574 1575 /* lets setup the record stuff. */ 1576 1577 /* Make space for the explicit IV in case of CBC. 1578 * (this is a bit of a boundary violation, but what the heck). 1579 */ 1580 if ( s->enc_write_ctx && 1581 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1582 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1583 else 1584 bs = 0; 1585 1586 wr->data=p + bs; /* make room for IV in case of CBC */ 1587 wr->length=(int)len; 1588 wr->input=(unsigned char *)buf; 1589 1590 /* we now 'read' from wr->input, wr->length bytes into 1591 * wr->data */ 1592 1593 /* first we compress */ 1594 if (s->compress != NULL) 1595 { 1596 if (!ssl3_do_compress(s)) 1597 { 1598 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1599 goto err; 1600 } 1601 } 1602 else 1603 { 1604 memcpy(wr->data,wr->input,wr->length); 1605 wr->input=wr->data; 1606 } 1607 1608 /* we should still have the output to wr->data and the input 1609 * from wr->input. Length should be wr->length. 1610 * wr->data still points in the wb->buf */ 1611 1612 if (mac_size != 0) 1613 { 1614 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0) 1615 goto err; 1616 wr->length+=mac_size; 1617 } 1618 1619 /* this is true regardless of mac size */ 1620 wr->input=p; 1621 wr->data=p; 1622 1623 1624 /* ssl3_enc can only have an error on read */ 1625 if (bs) /* bs != 0 in case of CBC */ 1626 { 1627 RAND_pseudo_bytes(p,bs); 1628 /* master IV and last CBC residue stand for 1629 * the rest of randomness */ 1630 wr->length += bs; 1631 } 1632 1633 if(s->method->ssl3_enc->enc(s,1) < 1) goto err; 1634 1635 /* record length after mac and block padding */ 1636/* if (type == SSL3_RT_APPLICATION_DATA || 1637 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1638 1639 /* there's only one epoch between handshake and app data */ 1640 1641 s2n(s->d1->w_epoch, pseq); 1642 1643 /* XDTLS: ?? */ 1644/* else 1645 s2n(s->d1->handshake_epoch, pseq); */ 1646 1647 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1648 pseq+=6; 1649 s2n(wr->length,pseq); 1650 1651 /* we should now have 1652 * wr->data pointing to the encrypted data, which is 1653 * wr->length long */ 1654 wr->type=type; /* not needed but helps for debugging */ 1655 wr->length+=DTLS1_RT_HEADER_LENGTH; 1656 1657#if 0 /* this is now done at the message layer */ 1658 /* buffer the record, making it easy to handle retransmits */ 1659 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1660 dtls1_buffer_record(s, wr->data, wr->length, 1661 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1662#endif 1663 1664 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1665 1666 if (create_empty_fragment) 1667 { 1668 /* we are in a recursive call; 1669 * just return the length, don't write out anything here 1670 */ 1671 return wr->length; 1672 } 1673 1674 /* now let's set up wb */ 1675 wb->left = prefix_len + wr->length; 1676 wb->offset = 0; 1677 1678 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1679 s->s3->wpend_tot=len; 1680 s->s3->wpend_buf=buf; 1681 s->s3->wpend_type=type; 1682 s->s3->wpend_ret=len; 1683 1684 /* we now just need to write the buffer */ 1685 return ssl3_write_pending(s,type,buf,len); 1686err: 1687 return -1; 1688 } 1689 1690 1691 1692static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1693 { 1694 int cmp; 1695 unsigned int shift; 1696 const unsigned char *seq = s->s3->read_sequence; 1697 1698 cmp = satsub64be(seq,bitmap->max_seq_num); 1699 if (cmp > 0) 1700 { 1701 memcpy (s->s3->rrec.seq_num,seq,8); 1702 return 1; /* this record in new */ 1703 } 1704 shift = -cmp; 1705 if (shift >= sizeof(bitmap->map)*8) 1706 return 0; /* stale, outside the window */ 1707 else if (bitmap->map & (1UL<<shift)) 1708 return 0; /* record previously received */ 1709 1710 memcpy (s->s3->rrec.seq_num,seq,8); 1711 return 1; 1712 } 1713 1714 1715static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1716 { 1717 int cmp; 1718 unsigned int shift; 1719 const unsigned char *seq = s->s3->read_sequence; 1720 1721 cmp = satsub64be(seq,bitmap->max_seq_num); 1722 if (cmp > 0) 1723 { 1724 shift = cmp; 1725 if (shift < sizeof(bitmap->map)*8) 1726 bitmap->map <<= shift, bitmap->map |= 1UL; 1727 else 1728 bitmap->map = 1UL; 1729 memcpy(bitmap->max_seq_num,seq,8); 1730 } 1731 else { 1732 shift = -cmp; 1733 if (shift < sizeof(bitmap->map)*8) 1734 bitmap->map |= 1UL<<shift; 1735 } 1736 } 1737 1738 1739int dtls1_dispatch_alert(SSL *s) 1740 { 1741 int i,j; 1742 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1743 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1744 unsigned char *ptr = &buf[0]; 1745 1746 s->s3->alert_dispatch=0; 1747 1748 memset(buf, 0x00, sizeof(buf)); 1749 *ptr++ = s->s3->send_alert[0]; 1750 *ptr++ = s->s3->send_alert[1]; 1751 1752#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1753 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1754 { 1755 s2n(s->d1->handshake_read_seq, ptr); 1756#if 0 1757 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1758 1759 else 1760 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1761#endif 1762 1763#if 0 1764 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); 1765#endif 1766 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1767 } 1768#endif 1769 1770 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1771 if (i <= 0) 1772 { 1773 s->s3->alert_dispatch=1; 1774 /* fprintf( stderr, "not done with alert\n" ); */ 1775 } 1776 else 1777 { 1778 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1779#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1780 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1781#endif 1782 ) 1783 (void)BIO_flush(s->wbio); 1784 1785 if (s->msg_callback) 1786 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1787 2, s, s->msg_callback_arg); 1788 1789 if (s->info_callback != NULL) 1790 cb=s->info_callback; 1791 else if (s->ctx->info_callback != NULL) 1792 cb=s->ctx->info_callback; 1793 1794 if (cb != NULL) 1795 { 1796 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1797 cb(s,SSL_CB_WRITE_ALERT,j); 1798 } 1799 } 1800 return(i); 1801 } 1802 1803 1804static DTLS1_BITMAP * 1805dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1806 { 1807 1808 *is_next_epoch = 0; 1809 1810 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1811 if (rr->epoch == s->d1->r_epoch) 1812 return &s->d1->bitmap; 1813 1814 /* Only HM and ALERT messages can be from the next epoch */ 1815 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1816 (rr->type == SSL3_RT_HANDSHAKE || 1817 rr->type == SSL3_RT_ALERT)) 1818 { 1819 *is_next_epoch = 1; 1820 return &s->d1->next_bitmap; 1821 } 1822 1823 return NULL; 1824 } 1825 1826#if 0 1827static int 1828dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1829 unsigned long *offset) 1830 { 1831 1832 /* alerts are passed up immediately */ 1833 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1834 rr->type == SSL3_RT_ALERT) 1835 return 0; 1836 1837 /* Only need to buffer if a handshake is underway. 1838 * (this implies that Hello Request and Client Hello are passed up 1839 * immediately) */ 1840 if ( SSL_in_init(s)) 1841 { 1842 unsigned char *data = rr->data; 1843 /* need to extract the HM/CCS sequence number here */ 1844 if ( rr->type == SSL3_RT_HANDSHAKE || 1845 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1846 { 1847 unsigned short seq_num; 1848 struct hm_header_st msg_hdr; 1849 struct ccs_header_st ccs_hdr; 1850 1851 if ( rr->type == SSL3_RT_HANDSHAKE) 1852 { 1853 dtls1_get_message_header(data, &msg_hdr); 1854 seq_num = msg_hdr.seq; 1855 *offset = msg_hdr.frag_off; 1856 } 1857 else 1858 { 1859 dtls1_get_ccs_header(data, &ccs_hdr); 1860 seq_num = ccs_hdr.seq; 1861 *offset = 0; 1862 } 1863 1864 /* this is either a record we're waiting for, or a 1865 * retransmit of something we happened to previously 1866 * receive (higher layers will drop the repeat silently */ 1867 if ( seq_num < s->d1->handshake_read_seq) 1868 return 0; 1869 if (rr->type == SSL3_RT_HANDSHAKE && 1870 seq_num == s->d1->handshake_read_seq && 1871 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1872 return 0; 1873 else if ( seq_num == s->d1->handshake_read_seq && 1874 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1875 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1876 return 0; 1877 else 1878 { 1879 *priority = seq_num; 1880 return 1; 1881 } 1882 } 1883 else /* unknown record type */ 1884 return 0; 1885 } 1886 1887 return 0; 1888 } 1889#endif 1890 1891void 1892dtls1_reset_seq_numbers(SSL *s, int rw) 1893 { 1894 unsigned char *seq; 1895 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1896 1897 if ( rw & SSL3_CC_READ) 1898 { 1899 seq = s->s3->read_sequence; 1900 s->d1->r_epoch++; 1901 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1902 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1903 } 1904 else 1905 { 1906 seq = s->s3->write_sequence; 1907 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1908 s->d1->w_epoch++; 1909 } 1910 1911 memset(seq, 0x00, seq_bytes); 1912 } 1913