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