1/* DTLS implementation written by Nagendra Modadugu 2 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. */ 3/* ==================================================================== 4 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 18 * 3. All advertising materials mentioning features or use of this 19 * software must display the following acknowledgment: 20 * "This product includes software developed by the OpenSSL Project 21 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 22 * 23 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 24 * endorse or promote products derived from this software without 25 * prior written permission. For written permission, please contact 26 * openssl-core@openssl.org. 27 * 28 * 5. Products derived from this software may not be called "OpenSSL" 29 * nor may "OpenSSL" appear in their names without prior written 30 * permission of the OpenSSL Project. 31 * 32 * 6. Redistributions of any form whatsoever must retain the following 33 * acknowledgment: 34 * "This product includes software developed by the OpenSSL Project 35 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 36 * 37 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 38 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 40 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 43 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 44 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 46 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 47 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 48 * OF THE POSSIBILITY OF SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This product includes cryptographic software written by Eric Young 52 * (eay@cryptsoft.com). This product includes software written by Tim 53 * Hudson (tjh@cryptsoft.com). 54 * 55 */ 56/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 57 * All rights reserved. 58 * 59 * This package is an SSL implementation written 60 * by Eric Young (eay@cryptsoft.com). 61 * The implementation was written so as to conform with Netscapes SSL. 62 * 63 * This library is free for commercial and non-commercial use as long as 64 * the following conditions are aheared to. The following conditions 65 * apply to all code found in this distribution, be it the RC4, RSA, 66 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 67 * included with this distribution is covered by the same copyright terms 68 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 69 * 70 * Copyright remains Eric Young's, and as such any Copyright notices in 71 * the code are not to be removed. 72 * If this package is used in a product, Eric Young should be given attribution 73 * as the author of the parts of the library used. 74 * This can be in the form of a textual message at program startup or 75 * in documentation (online or textual) provided with the package. 76 * 77 * Redistribution and use in source and binary forms, with or without 78 * modification, are permitted provided that the following conditions 79 * are met: 80 * 1. Redistributions of source code must retain the copyright 81 * notice, this list of conditions and the following disclaimer. 82 * 2. Redistributions in binary form must reproduce the above copyright 83 * notice, this list of conditions and the following disclaimer in the 84 * documentation and/or other materials provided with the distribution. 85 * 3. All advertising materials mentioning features or use of this software 86 * must display the following acknowledgement: 87 * "This product includes cryptographic software written by 88 * Eric Young (eay@cryptsoft.com)" 89 * The word 'cryptographic' can be left out if the rouines from the library 90 * being used are not cryptographic related :-). 91 * 4. If you include any Windows specific code (or a derivative thereof) from 92 * the apps directory (application code) you must include an acknowledgement: 93 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 94 * 95 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 96 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 97 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 98 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 99 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 100 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 101 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 102 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 103 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 104 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 105 * SUCH DAMAGE. 106 * 107 * The licence and distribution terms for any publically available version or 108 * derivative of this code cannot be changed. i.e. this code cannot simply be 109 * copied and put under another distribution licence 110 * [including the GNU Public Licence.] */ 111 112#include <stdio.h> 113#include <errno.h> 114#include <assert.h> 115 116#include <openssl/buf.h> 117#include <openssl/mem.h> 118#include <openssl/evp.h> 119#include <openssl/err.h> 120#include <openssl/rand.h> 121 122#include "ssl_locl.h" 123/* mod 128 saturating subtract of two 64-bit values in big-endian order */ 124static int satsub64be(const unsigned char *v1,const unsigned char *v2) 125{ int ret,sat,brw,i; 126 127 if (sizeof(long) == 8) do 128 { const union { long one; char little; } is_endian = {1}; 129 long l; 130 131 if (is_endian.little) break; 132 /* not reached on little-endians */ 133 /* following test is redundant, because input is 134 * always aligned, but I take no chances... */ 135 if (((size_t)v1|(size_t)v2)&0x7) break; 136 137 l = *((long *)v1); 138 l -= *((long *)v2); 139 if (l>128) return 128; 140 else if (l<-128) return -128; 141 else return (int)l; 142 } while (0); 143 144 ret = (int)v1[7]-(int)v2[7]; 145 sat = 0; 146 brw = ret>>8; /* brw is either 0 or -1 */ 147 if (ret & 0x80) 148 { for (i=6;i>=0;i--) 149 { brw += (int)v1[i]-(int)v2[i]; 150 sat |= ~brw; 151 brw >>= 8; 152 } 153 } 154 else 155 { for (i=6;i>=0;i--) 156 { brw += (int)v1[i]-(int)v2[i]; 157 sat |= brw; 158 brw >>= 8; 159 } 160 } 161 brw <<= 8; /* brw is either 0 or -256 */ 162 163 if (sat&0xff) return brw | 0x80; 164 else return brw + (ret&0xFF); 165} 166 167static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 168 int len, int peek); 169static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 170static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 171static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 172 unsigned int *is_next_epoch); 173#if 0 174static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 175 unsigned short *priority, unsigned long *offset); 176#endif 177static int dtls1_buffer_record(SSL *s, record_pqueue *q, 178 unsigned char *priority); 179static int dtls1_process_record(SSL *s); 180static int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 181 unsigned int len); 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 OPENSSL_PUT_ERROR(SSL, 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 s->packet = NULL; 235 s->packet_length = 0; 236 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 237 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 238 239 if (!ssl3_setup_buffers(s)) 240 { 241 OPENSSL_PUT_ERROR(SSL, dtls1_buffer_record, ERR_R_INTERNAL_ERROR); 242 OPENSSL_free(rdata); 243 pitem_free(item); 244 return(0); 245 } 246 247 /* insert should not fail, since duplicates are dropped */ 248 if (pqueue_insert(queue->q, item) == NULL) 249 { 250 OPENSSL_PUT_ERROR(SSL, dtls1_buffer_record, ERR_R_INTERNAL_ERROR); 251 OPENSSL_free(rdata); 252 pitem_free(item); 253 return(0); 254 } 255 256 return(1); 257 } 258 259 260static int 261dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 262 { 263 pitem *item; 264 265 item = pqueue_pop(queue->q); 266 if (item) 267 { 268 dtls1_copy_record(s, item); 269 270 OPENSSL_free(item->data); 271 pitem_free(item); 272 273 return(1); 274 } 275 276 return(0); 277 } 278 279 280/* retrieve a buffered record that belongs to the new epoch, i.e., not processed 281 * yet */ 282#define dtls1_get_unprocessed_record(s) \ 283 dtls1_retrieve_buffered_record((s), \ 284 &((s)->d1->unprocessed_rcds)) 285 286/* retrieve a buffered record that belongs to the current epoch, ie, processed */ 287#define dtls1_get_processed_record(s) \ 288 dtls1_retrieve_buffered_record((s), \ 289 &((s)->d1->processed_rcds)) 290 291static int 292dtls1_process_buffered_records(SSL *s) 293 { 294 pitem *item; 295 296 item = pqueue_peek(s->d1->unprocessed_rcds.q); 297 if (item) 298 { 299 /* Check if epoch is current. */ 300 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 301 return(1); /* Nothing to do. */ 302 303 /* Process all the records. */ 304 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 305 { 306 dtls1_get_unprocessed_record(s); 307 if ( ! dtls1_process_record(s)) 308 return(0); 309 dtls1_buffer_record(s, &(s->d1->processed_rcds), 310 s->s3->rrec.seq_num); 311 } 312 } 313 314 /* sync epoch numbers once all the unprocessed records 315 * have been processed */ 316 s->d1->processed_rcds.epoch = s->d1->r_epoch; 317 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 318 319 return(1); 320 } 321 322 323#if 0 324 325static int 326dtls1_get_buffered_record(SSL *s) 327 { 328 pitem *item; 329 PQ_64BIT priority = 330 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 331 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 332 333 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 334 nothing buffered */ 335 return 0; 336 337 338 item = pqueue_peek(s->d1->rcvd_records); 339 if (item && item->priority == priority) 340 { 341 /* Check if we've received the record of interest. It must be 342 * a handshake record, since data records as passed up without 343 * buffering */ 344 DTLS1_RECORD_DATA *rdata; 345 item = pqueue_pop(s->d1->rcvd_records); 346 rdata = (DTLS1_RECORD_DATA *)item->data; 347 348 if (s->s3->rbuf.buf != NULL) 349 OPENSSL_free(s->s3->rbuf.buf); 350 351 s->packet = rdata->packet; 352 s->packet_length = rdata->packet_length; 353 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 354 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 355 356 OPENSSL_free(item->data); 357 pitem_free(item); 358 359 /* s->d1->next_expected_seq_num++; */ 360 return(1); 361 } 362 363 return 0; 364 } 365 366#endif 367 368static int 369dtls1_process_record(SSL *s) 370{ 371 int i,al; 372 int enc_err; 373 SSL_SESSION *sess; 374 SSL3_RECORD *rr; 375 unsigned int mac_size, orig_len; 376 unsigned char md[EVP_MAX_MD_SIZE]; 377 378 rr= &(s->s3->rrec); 379 sess = s->session; 380 381 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 382 * and we have that many bytes in s->packet 383 */ 384 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 385 386 /* ok, we can now read from 's->packet' data into 'rr' 387 * rr->input points at rr->length bytes, which 388 * need to be copied into rr->data by either 389 * the decryption or by the decompression 390 * When the data is 'copied' into the rr->data buffer, 391 * rr->input will be pointed at the new buffer */ 392 393 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 394 * rr->length bytes of encrypted compressed stuff. */ 395 396 /* check is not needed I believe */ 397 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 398 { 399 al=SSL_AD_RECORD_OVERFLOW; 400 OPENSSL_PUT_ERROR(SSL, dtls1_process_record, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 401 goto f_err; 402 } 403 404 /* decrypt in place in 'rr->input' */ 405 rr->data=rr->input; 406 407 enc_err = s->method->ssl3_enc->enc(s,0); 408 /* enc_err is: 409 * 0: (in non-constant time) if the record is publically invalid. 410 * 1: if the padding is valid 411 * -1: if the padding is invalid */ 412 if (enc_err == 0) 413 { 414 /* For DTLS we simply ignore bad packets. */ 415 rr->length = 0; 416 s->packet_length = 0; 417 goto err; 418 } 419 420#ifdef TLS_DEBUG 421printf("dec %d\n",rr->length); 422{ unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 423printf("\n"); 424#endif 425 426 /* r->length is now the compressed data plus mac */ 427 if ((sess != NULL) && 428 (s->enc_read_ctx != NULL) && 429 (EVP_MD_CTX_md(s->read_hash) != NULL)) 430 { 431 /* s->read_hash != NULL => mac_size != -1 */ 432 unsigned char *mac = NULL; 433 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 434 mac_size=EVP_MD_CTX_size(s->read_hash); 435 assert(mac_size <= EVP_MAX_MD_SIZE); 436 437 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 438 orig_len = rr->length+((unsigned int)rr->type>>8); 439 440 /* orig_len is the length of the record before any padding was 441 * removed. This is public information, as is the MAC in use, 442 * therefore we can safely process the record in a different 443 * amount of time if it's too short to possibly contain a MAC. 444 */ 445 if (orig_len < mac_size || 446 /* CBC records must have a padding length byte too. */ 447 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 448 orig_len < mac_size+1)) 449 { 450 al=SSL_AD_DECODE_ERROR; 451 OPENSSL_PUT_ERROR(SSL, dtls1_process_record, SSL_R_LENGTH_TOO_SHORT); 452 goto f_err; 453 } 454 455 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) 456 { 457 /* We update the length so that the TLS header bytes 458 * can be constructed correctly but we need to extract 459 * the MAC in constant time from within the record, 460 * without leaking the contents of the padding bytes. 461 * */ 462 mac = mac_tmp; 463 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 464 rr->length -= mac_size; 465 } 466 else 467 { 468 /* In this case there's no padding, so |orig_len| 469 * equals |rec->length| and we checked that there's 470 * enough bytes for |mac_size| above. */ 471 rr->length -= mac_size; 472 mac = &rr->data[rr->length]; 473 } 474 475 i=s->method->ssl3_enc->mac(s,md,0 /* not send */); 476 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 477 enc_err = -1; 478 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 479 enc_err = -1; 480 } 481 482 if (enc_err < 0) 483 { 484 /* decryption failed, silently discard message */ 485 rr->length = 0; 486 s->packet_length = 0; 487 goto err; 488 } 489 490 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 491 { 492 al=SSL_AD_RECORD_OVERFLOW; 493 OPENSSL_PUT_ERROR(SSL, dtls1_process_record, SSL_R_DATA_LENGTH_TOO_LONG); 494 goto f_err; 495 } 496 497 rr->off=0; 498 /* So at this point the following is true 499 * ssl->s3->rrec.type is the type of record 500 * ssl->s3->rrec.length == number of bytes in record 501 * ssl->s3->rrec.off == offset to first valid byte 502 * ssl->s3->rrec.data == where to take bytes from, increment 503 * after use :-). 504 */ 505 506 /* we have pulled in a full packet so zero things */ 507 s->packet_length=0; 508 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 509 return(1); 510 511f_err: 512 ssl3_send_alert(s,SSL3_AL_FATAL,al); 513err: 514 return(0); 515} 516 517 518/* Call this to get a new input record. 519 * It will return <= 0 if more data is needed, normally due to an error 520 * or non-blocking IO. 521 * When it finishes, one packet has been decoded and can be found in 522 * ssl->s3->rrec.type - is the type of record 523 * ssl->s3->rrec.data, - data 524 * ssl->s3->rrec.length, - number of bytes 525 */ 526/* used only by dtls1_read_bytes */ 527int dtls1_get_record(SSL *s) 528 { 529 int ssl_major,ssl_minor; 530 int i,n; 531 SSL3_RECORD *rr; 532 unsigned char *p = NULL; 533 unsigned short version; 534 DTLS1_BITMAP *bitmap; 535 unsigned int is_next_epoch; 536 537 rr= &(s->s3->rrec); 538 539 /* The epoch may have changed. If so, process all the 540 * pending records. This is a non-blocking operation. */ 541 dtls1_process_buffered_records(s); 542 543 /* if we're renegotiating, then there may be buffered records */ 544 if (dtls1_get_processed_record(s)) 545 return 1; 546 547 /* get something from the wire */ 548again: 549 /* check if we have the header */ 550 if ( (s->rstate != SSL_ST_READ_BODY) || 551 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 552 { 553 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 554 /* read timeout is handled by dtls1_read_bytes */ 555 if (n <= 0) return(n); /* error or non-blocking */ 556 557 /* this packet contained a partial record, dump it */ 558 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 559 { 560 s->packet_length = 0; 561 goto again; 562 } 563 564 s->rstate=SSL_ST_READ_BODY; 565 566 p=s->packet; 567 568 if (s->msg_callback) 569 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg); 570 571 /* Pull apart the header into the DTLS1_RECORD */ 572 rr->type= *(p++); 573 ssl_major= *(p++); 574 ssl_minor= *(p++); 575 version=(ssl_major<<8)|ssl_minor; 576 577 /* sequence number is 64 bits, with top 2 bytes = epoch */ 578 n2s(p,rr->epoch); 579 580 memcpy(&(s->s3->read_sequence[2]), p, 6); 581 p+=6; 582 583 n2s(p,rr->length); 584 585 /* Lets check version */ 586 if (!s->first_packet) 587 { 588 if (version != s->version) 589 { 590 /* unexpected version, silently discard */ 591 rr->length = 0; 592 s->packet_length = 0; 593 goto again; 594 } 595 } 596 597 if ((version & 0xff00) != (s->version & 0xff00)) 598 { 599 /* wrong version, silently discard record */ 600 rr->length = 0; 601 s->packet_length = 0; 602 goto again; 603 } 604 605 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 606 { 607 /* record too long, silently discard it */ 608 rr->length = 0; 609 s->packet_length = 0; 610 goto again; 611 } 612 613 /* now s->rstate == SSL_ST_READ_BODY */ 614 } 615 616 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 617 618 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 619 { 620 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 621 i=rr->length; 622 n=ssl3_read_n(s,i,i,1); 623 if (n <= 0) return(n); /* error or non-blocking io */ 624 625 /* this packet contained a partial record, dump it */ 626 if ( n != i) 627 { 628 rr->length = 0; 629 s->packet_length = 0; 630 goto again; 631 } 632 633 /* now n == rr->length, 634 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 635 } 636 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 637 638 /* match epochs. NULL means the packet is dropped on the floor */ 639 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 640 if ( bitmap == NULL) 641 { 642 rr->length = 0; 643 s->packet_length = 0; /* dump this record */ 644 goto again; /* get another record */ 645 } 646 647 /* Check whether this is a repeat, or aged record. 648 * Don't check if we're listening and this message is 649 * a ClientHello. They can look as if they're replayed, 650 * since they arrive from different connections and 651 * would be dropped unnecessarily. 652 */ 653 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 654 *p == SSL3_MT_CLIENT_HELLO) && 655 !dtls1_record_replay_check(s, bitmap)) 656 { 657 rr->length = 0; 658 s->packet_length=0; /* dump this record */ 659 goto again; /* get another record */ 660 } 661 662 /* just read a 0 length packet */ 663 if (rr->length == 0) goto again; 664 665 /* If this record is from the next epoch (either HM or ALERT), 666 * and a handshake is currently in progress, buffer it since it 667 * cannot be processed at this time. However, do not buffer 668 * anything while listening. 669 */ 670 if (is_next_epoch) 671 { 672 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) 673 { 674 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 675 } 676 rr->length = 0; 677 s->packet_length = 0; 678 goto again; 679 } 680 681 if (!dtls1_process_record(s)) 682 { 683 rr->length = 0; 684 s->packet_length = 0; /* dump this record */ 685 goto again; /* get another record */ 686 } 687 688 return(1); 689 690 } 691 692/* Return up to 'len' payload bytes received in 'type' records. 693 * 'type' is one of the following: 694 * 695 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 696 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 697 * - 0 (during a shutdown, no data has to be returned) 698 * 699 * If we don't have stored data to work from, read a SSL/TLS record first 700 * (possibly multiple records if we still don't have anything to return). 701 * 702 * This function must handle any surprises the peer may have for us, such as 703 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 704 * a surprise, but handled as if it were), or renegotiation requests. 705 * Also if record payloads contain fragments too small to process, we store 706 * them until there is enough for the respective protocol (the record protocol 707 * may use arbitrary fragmentation and even interleaving): 708 * Change cipher spec protocol 709 * just 1 byte needed, no need for keeping anything stored 710 * Alert protocol 711 * 2 bytes needed (AlertLevel, AlertDescription) 712 * Handshake protocol 713 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 714 * to detect unexpected Client Hello and Hello Request messages 715 * here, anything else is handled by higher layers 716 * Application data protocol 717 * none of our business 718 */ 719int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 720 { 721 int al,i,j,ret; 722 unsigned int n; 723 SSL3_RECORD *rr; 724 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 725 726 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 727 if (!ssl3_setup_buffers(s)) 728 return(-1); 729 730 /* XXX: check what the second '&& type' is about */ 731 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 732 (type != SSL3_RT_HANDSHAKE) && type) || 733 (peek && (type != SSL3_RT_APPLICATION_DATA))) 734 { 735 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, ERR_R_INTERNAL_ERROR); 736 return -1; 737 } 738 739 /* check whether there's a handshake message (client hello?) waiting */ 740 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 741 return ret; 742 743 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 744 745 if (!s->in_handshake && SSL_in_init(s)) 746 { 747 /* type == SSL3_RT_APPLICATION_DATA */ 748 i=s->handshake_func(s); 749 if (i < 0) return(i); 750 if (i == 0) 751 { 752 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); 753 return(-1); 754 } 755 } 756 757start: 758 s->rwstate=SSL_NOTHING; 759 760 /* s->s3->rrec.type - is the type of record 761 * s->s3->rrec.data, - data 762 * s->s3->rrec.off, - offset into 'data' for next read 763 * s->s3->rrec.length, - number of bytes. */ 764 rr = &(s->s3->rrec); 765 766 /* We are not handshaking and have no data yet, 767 * so process data buffered during the last handshake 768 * in advance, if any. 769 */ 770 if (s->state == SSL_ST_OK && rr->length == 0) 771 { 772 pitem *item; 773 item = pqueue_pop(s->d1->buffered_app_data.q); 774 if (item) 775 { 776 dtls1_copy_record(s, item); 777 778 OPENSSL_free(item->data); 779 pitem_free(item); 780 } 781 } 782 783 /* Check for timeout */ 784 if (dtls1_handle_timeout(s) > 0) 785 goto start; 786 787 /* get new packet if necessary */ 788 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 789 { 790 ret=dtls1_get_record(s); 791 if (ret <= 0) 792 { 793 ret = dtls1_read_failed(s, ret); 794 /* anything other than a timeout is an error */ 795 if (ret <= 0) 796 return(ret); 797 else 798 goto start; 799 } 800 } 801 802 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) 803 { 804 rr->length = 0; 805 goto start; 806 } 807 808 /* we now have a packet which can be read and processed */ 809 810 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 811 * reset by ssl3_get_finished */ 812 && (rr->type != SSL3_RT_HANDSHAKE)) 813 { 814 /* We now have application data between CCS and Finished. 815 * Most likely the packets were reordered on their way, so 816 * buffer the application data for later processing rather 817 * than dropping the connection. 818 */ 819 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num); 820 rr->length = 0; 821 goto start; 822 } 823 824 /* If the other end has shut down, throw anything we read away 825 * (even in 'peek' mode) */ 826 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 827 { 828 rr->length=0; 829 s->rwstate=SSL_NOTHING; 830 return(0); 831 } 832 833 834 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 835 { 836 /* make sure that we are not getting application data when we 837 * are doing a handshake for the first time */ 838 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 839 (s->enc_read_ctx == NULL)) 840 { 841 al=SSL_AD_UNEXPECTED_MESSAGE; 842 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_APP_DATA_IN_HANDSHAKE); 843 goto f_err; 844 } 845 846 if (len <= 0) return(len); 847 848 if ((unsigned int)len > rr->length) 849 n = rr->length; 850 else 851 n = (unsigned int)len; 852 853 memcpy(buf,&(rr->data[rr->off]),n); 854 if (!peek) 855 { 856 rr->length-=n; 857 rr->off+=n; 858 if (rr->length == 0) 859 { 860 s->rstate=SSL_ST_READ_HEADER; 861 rr->off=0; 862 } 863 } 864 865 return(n); 866 } 867 868 869 /* If we get here, then type != rr->type; if we have a handshake 870 * message, then it was unexpected (Hello Request or Client Hello). */ 871 872 /* In case of record types for which we have 'fragment' storage, 873 * fill that so that we can process the data at a fixed place. 874 */ 875 { 876 unsigned int k, dest_maxlen = 0; 877 unsigned char *dest = NULL; 878 unsigned int *dest_len = NULL; 879 880 if (rr->type == SSL3_RT_HANDSHAKE) 881 { 882 dest_maxlen = sizeof s->d1->handshake_fragment; 883 dest = s->d1->handshake_fragment; 884 dest_len = &s->d1->handshake_fragment_len; 885 } 886 else if (rr->type == SSL3_RT_ALERT) 887 { 888 dest_maxlen = sizeof(s->d1->alert_fragment); 889 dest = s->d1->alert_fragment; 890 dest_len = &s->d1->alert_fragment_len; 891 } 892 /* else it's a CCS message, or application data or wrong */ 893 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 894 { 895 /* Application data while renegotiating 896 * is allowed. Try again reading. 897 */ 898 if (rr->type == SSL3_RT_APPLICATION_DATA) 899 { 900 BIO *bio; 901 s->s3->in_read_app_data=2; 902 bio=SSL_get_rbio(s); 903 s->rwstate=SSL_READING; 904 BIO_clear_retry_flags(bio); 905 BIO_set_retry_read(bio); 906 return(-1); 907 } 908 909 /* Not certain if this is the right error handling */ 910 al=SSL_AD_UNEXPECTED_MESSAGE; 911 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD); 912 goto f_err; 913 } 914 915 if (dest_maxlen > 0) 916 { 917 /* XDTLS: In a pathalogical case, the Client Hello 918 * may be fragmented--don't always expect dest_maxlen bytes */ 919 if ( rr->length < dest_maxlen) 920 { 921#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 922 /* 923 * for normal alerts rr->length is 2, while 924 * dest_maxlen is 7 if we were to handle this 925 * non-existing alert... 926 */ 927 FIX ME 928#endif 929 s->rstate=SSL_ST_READ_HEADER; 930 rr->length = 0; 931 goto start; 932 } 933 934 /* now move 'n' bytes: */ 935 for ( k = 0; k < dest_maxlen; k++) 936 { 937 dest[k] = rr->data[rr->off++]; 938 rr->length--; 939 } 940 *dest_len = dest_maxlen; 941 } 942 } 943 944 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 945 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 946 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 947 948 /* If we are a client, check for an incoming 'Hello Request': */ 949 if ((!s->server) && 950 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 951 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 952 (s->session != NULL) && (s->session->cipher != NULL)) 953 { 954 s->d1->handshake_fragment_len = 0; 955 956 if ((s->d1->handshake_fragment[1] != 0) || 957 (s->d1->handshake_fragment[2] != 0) || 958 (s->d1->handshake_fragment[3] != 0)) 959 { 960 al=SSL_AD_DECODE_ERROR; 961 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_HELLO_REQUEST); 962 goto f_err; 963 } 964 965 /* no need to check sequence number on HELLO REQUEST messages */ 966 967 if (s->msg_callback) 968 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 969 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 970 971 if (SSL_is_init_finished(s) && 972 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 973 !s->s3->renegotiate) 974 { 975 s->d1->handshake_read_seq++; 976 s->new_session = 1; 977 ssl3_renegotiate(s); 978 if (ssl3_renegotiate_check(s)) 979 { 980 i=s->handshake_func(s); 981 if (i < 0) return(i); 982 if (i == 0) 983 { 984 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); 985 return(-1); 986 } 987 988 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 989 { 990 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 991 { 992 BIO *bio; 993 /* In the case where we try to read application data, 994 * but we trigger an SSL handshake, we return -1 with 995 * the retry option set. Otherwise renegotiation may 996 * cause nasty problems in the blocking world */ 997 s->rwstate=SSL_READING; 998 bio=SSL_get_rbio(s); 999 BIO_clear_retry_flags(bio); 1000 BIO_set_retry_read(bio); 1001 return(-1); 1002 } 1003 } 1004 } 1005 } 1006 /* we either finished a handshake or ignored the request, 1007 * now try again to obtain the (application) data we were asked for */ 1008 goto start; 1009 } 1010 1011 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1012 { 1013 int alert_level = s->d1->alert_fragment[0]; 1014 int alert_descr = s->d1->alert_fragment[1]; 1015 1016 s->d1->alert_fragment_len = 0; 1017 1018 if (s->msg_callback) 1019 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1020 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1021 1022 if (s->info_callback != NULL) 1023 cb=s->info_callback; 1024 else if (s->ctx->info_callback != NULL) 1025 cb=s->ctx->info_callback; 1026 1027 if (cb != NULL) 1028 { 1029 j = (alert_level << 8) | alert_descr; 1030 cb(s, SSL_CB_READ_ALERT, j); 1031 } 1032 1033 if (alert_level == 1) /* warning */ 1034 { 1035 s->s3->warn_alert = alert_descr; 1036 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1037 { 1038 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1039 return(0); 1040 } 1041#if 0 1042 /* XXX: this is a possible improvement in the future */ 1043 /* now check if it's a missing record */ 1044 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1045 { 1046 unsigned short seq; 1047 unsigned int frag_off; 1048 unsigned char *p = &(s->d1->alert_fragment[2]); 1049 1050 n2s(p, seq); 1051 n2l3(p, frag_off); 1052 1053 dtls1_retransmit_message(s, 1054 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1055 frag_off, &found); 1056 if ( ! found && SSL_in_init(s)) 1057 { 1058 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1059 /* requested a message not yet sent, 1060 send an alert ourselves */ 1061 ssl3_send_alert(s,SSL3_AL_WARNING, 1062 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1063 } 1064 } 1065#endif 1066 } 1067 else if (alert_level == 2) /* fatal */ 1068 { 1069 char tmp[16]; 1070 1071 s->rwstate=SSL_NOTHING; 1072 s->s3->fatal_alert = alert_descr; 1073 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_AD_REASON_OFFSET + alert_descr); 1074 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1075 ERR_add_error_data(2,"SSL alert number ",tmp); 1076 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1077 SSL_CTX_remove_session(s->ctx,s->session); 1078 return(0); 1079 } 1080 else 1081 { 1082 al=SSL_AD_ILLEGAL_PARAMETER; 1083 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNKNOWN_ALERT_TYPE); 1084 goto f_err; 1085 } 1086 1087 goto start; 1088 } 1089 1090 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1091 { 1092 s->rwstate=SSL_NOTHING; 1093 rr->length=0; 1094 return(0); 1095 } 1096 1097 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1098 { 1099 struct ccs_header_st ccs_hdr; 1100 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1101 1102 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1103 1104 /* 'Change Cipher Spec' is just a single byte, so we know 1105 * exactly what the record payload has to look like */ 1106 /* XDTLS: check that epoch is consistent */ 1107 if ( (rr->length != ccs_hdr_len) || 1108 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1109 { 1110 al=SSL_AD_ILLEGAL_PARAMETER; 1111 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1112 goto f_err; 1113 } 1114 1115 rr->length=0; 1116 1117 if (s->msg_callback) 1118 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1119 rr->data, 1, s, s->msg_callback_arg); 1120 1121 /* We can't process a CCS now, because previous handshake 1122 * messages are still missing, so just drop it. 1123 */ 1124 if (!s->d1->change_cipher_spec_ok) 1125 { 1126 goto start; 1127 } 1128 1129 s->d1->change_cipher_spec_ok = 0; 1130 1131 s->s3->change_cipher_spec=1; 1132 if (!ssl3_do_change_cipher_spec(s)) 1133 goto err; 1134 1135 /* do this whenever CCS is processed */ 1136 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1137 1138 goto start; 1139 } 1140 1141 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1142 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1143 !s->in_handshake) 1144 { 1145 struct hm_header_st msg_hdr; 1146 1147 /* this may just be a stale retransmit */ 1148 dtls1_get_message_header(rr->data, &msg_hdr); 1149 if( rr->epoch != s->d1->r_epoch) 1150 { 1151 rr->length = 0; 1152 goto start; 1153 } 1154 1155 /* If we are server, we may have a repeated FINISHED of the 1156 * client here, then retransmit our CCS and FINISHED. 1157 */ 1158 if (msg_hdr.type == SSL3_MT_FINISHED) 1159 { 1160 if (dtls1_check_timeout_num(s) < 0) 1161 return -1; 1162 1163 dtls1_retransmit_buffered_messages(s); 1164 rr->length = 0; 1165 goto start; 1166 } 1167 1168 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1169 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1170 { 1171#if 0 /* worked only because C operator preferences are not as expected (and 1172 * because this is not really needed for clients except for detecting 1173 * protocol violations): */ 1174 s->state=SSL_ST_BEFORE|(s->server) 1175 ?SSL_ST_ACCEPT 1176 :SSL_ST_CONNECT; 1177#else 1178 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1179#endif 1180 s->renegotiate=1; 1181 s->new_session=1; 1182 } 1183 i=s->handshake_func(s); 1184 if (i < 0) return(i); 1185 if (i == 0) 1186 { 1187 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); 1188 return(-1); 1189 } 1190 1191 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1192 { 1193 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1194 { 1195 BIO *bio; 1196 /* In the case where we try to read application data, 1197 * but we trigger an SSL handshake, we return -1 with 1198 * the retry option set. Otherwise renegotiation may 1199 * cause nasty problems in the blocking world */ 1200 s->rwstate=SSL_READING; 1201 bio=SSL_get_rbio(s); 1202 BIO_clear_retry_flags(bio); 1203 BIO_set_retry_read(bio); 1204 return(-1); 1205 } 1206 } 1207 goto start; 1208 } 1209 1210 switch (rr->type) 1211 { 1212 default: 1213 /* TLS just ignores unknown message types */ 1214 if (s->version == TLS1_VERSION) 1215 { 1216 rr->length = 0; 1217 goto start; 1218 } 1219 al=SSL_AD_UNEXPECTED_MESSAGE; 1220 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD); 1221 goto f_err; 1222 case SSL3_RT_CHANGE_CIPHER_SPEC: 1223 case SSL3_RT_ALERT: 1224 case SSL3_RT_HANDSHAKE: 1225 /* we already handled all of these, with the possible exception 1226 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1227 * should not happen when type != rr->type */ 1228 al=SSL_AD_UNEXPECTED_MESSAGE; 1229 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, ERR_R_INTERNAL_ERROR); 1230 goto f_err; 1231 case SSL3_RT_APPLICATION_DATA: 1232 /* At this point, we were expecting handshake data, 1233 * but have application data. If the library was 1234 * running inside ssl3_read() (i.e. in_read_app_data 1235 * is set) and it makes sense to read application data 1236 * at this point (session renegotiation not yet started), 1237 * we will indulge it. 1238 */ 1239 if (s->s3->in_read_app_data && 1240 (s->s3->total_renegotiations != 0) && 1241 (( 1242 (s->state & SSL_ST_CONNECT) && 1243 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1244 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1245 ) || ( 1246 (s->state & SSL_ST_ACCEPT) && 1247 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1248 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1249 ) 1250 )) 1251 { 1252 s->s3->in_read_app_data=2; 1253 return(-1); 1254 } 1255 else 1256 { 1257 al=SSL_AD_UNEXPECTED_MESSAGE; 1258 OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD); 1259 goto f_err; 1260 } 1261 } 1262 /* not reached */ 1263 1264f_err: 1265 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1266err: 1267 return(-1); 1268 } 1269 1270int 1271dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1272 { 1273 int i; 1274 1275 if (SSL_in_init(s) && !s->in_handshake) 1276 { 1277 i=s->handshake_func(s); 1278 if (i < 0) return(i); 1279 if (i == 0) 1280 { 1281 OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); 1282 return -1; 1283 } 1284 } 1285 1286 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1287 { 1288 OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data_bytes, SSL_R_DTLS_MESSAGE_TOO_BIG); 1289 return -1; 1290 } 1291 1292 i = dtls1_write_bytes(s, type, buf_, len); 1293 return i; 1294 } 1295 1296 1297 /* this only happens when a client hello is received and a handshake 1298 * is started. */ 1299static int 1300have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1301 int len, int peek) 1302 { 1303 1304 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1305 /* (partially) satisfy request from storage */ 1306 { 1307 unsigned char *src = s->d1->handshake_fragment; 1308 unsigned char *dst = buf; 1309 unsigned int k,n; 1310 1311 /* peek == 0 */ 1312 n = 0; 1313 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1314 { 1315 *dst++ = *src++; 1316 len--; s->d1->handshake_fragment_len--; 1317 n++; 1318 } 1319 /* move any remaining fragment bytes: */ 1320 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1321 s->d1->handshake_fragment[k] = *src++; 1322 return n; 1323 } 1324 1325 return 0; 1326 } 1327 1328 1329 1330 1331/* Call this to write data in records of type 'type' 1332 * It will return <= 0 if not all data has been sent or non-blocking IO. 1333 */ 1334int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1335 { 1336 int i; 1337 1338 assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1339 s->rwstate=SSL_NOTHING; 1340 i=do_dtls1_write(s, type, buf, len); 1341 return i; 1342 } 1343 1344static int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 1345 unsigned int len) 1346 { 1347 unsigned char *p,*pseq; 1348 int i,mac_size,clear=0; 1349 int prefix_len = 0; 1350 int eivlen; 1351 SSL3_RECORD *wr; 1352 SSL3_BUFFER *wb; 1353 SSL_SESSION *sess; 1354 1355 /* first check if there is a SSL3_BUFFER still being written 1356 * out. This will happen with non blocking IO */ 1357 if (s->s3->wbuf.left != 0) 1358 { 1359 assert(0); /* XDTLS: want to see if we ever get here */ 1360 return(ssl3_write_pending(s,type,buf,len)); 1361 } 1362 1363 /* If we have an alert to send, lets send it */ 1364 if (s->s3->alert_dispatch) 1365 { 1366 i=s->method->ssl_dispatch_alert(s); 1367 if (i <= 0) 1368 return(i); 1369 /* if it went, fall through and send more stuff */ 1370 } 1371 1372 if (len == 0) 1373 return 0; 1374 1375 wr= &(s->s3->wrec); 1376 wb= &(s->s3->wbuf); 1377 sess=s->session; 1378 1379 if ( (sess == NULL) || 1380 (s->enc_write_ctx == NULL) || 1381 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1382 clear=1; 1383 1384 if (clear) 1385 mac_size=0; 1386 else 1387 { 1388 mac_size=EVP_MD_CTX_size(s->write_hash); 1389 if (mac_size < 0) 1390 goto err; 1391 } 1392 1393 p = wb->buf + prefix_len; 1394 1395 /* write the header */ 1396 1397 *(p++)=type&0xff; 1398 wr->type=type; 1399 /* Special case: for hello verify request, client version 1.0 and 1400 * we haven't decided which version to use yet send back using 1401 * version 1.0 header: otherwise some clients will ignore it. 1402 */ 1403 if (s->method->version == DTLS_ANY_VERSION) 1404 { 1405 *(p++)=DTLS1_VERSION>>8; 1406 *(p++)=DTLS1_VERSION&0xff; 1407 } 1408 else 1409 { 1410 *(p++)=s->version>>8; 1411 *(p++)=s->version&0xff; 1412 } 1413 1414 /* field where we are to write out packet epoch, seq num and len */ 1415 pseq=p; 1416 p+=10; 1417 1418 /* Explicit IV length, block ciphers appropriate version flag */ 1419 if (s->enc_write_ctx) 1420 { 1421 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx); 1422 if (mode == EVP_CIPH_CBC_MODE) 1423 { 1424 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx); 1425 if (eivlen <= 1) 1426 eivlen = 0; 1427 } 1428 /* Need explicit part of IV for GCM mode */ 1429 else if (mode == EVP_CIPH_GCM_MODE) 1430 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN; 1431 else 1432 eivlen = 0; 1433 } 1434 else 1435 eivlen = 0; 1436 1437 /* lets setup the record stuff. */ 1438 wr->data=p + eivlen; /* make room for IV in case of CBC */ 1439 wr->length=(int)len; 1440 wr->input=(unsigned char *)buf; 1441 1442 /* we now 'read' from wr->input, wr->length bytes into 1443 * wr->data */ 1444 1445 memcpy(wr->data,wr->input,wr->length); 1446 wr->input=wr->data; 1447 1448 /* we should still have the output to wr->data and the input 1449 * from wr->input. Length should be wr->length. 1450 * wr->data still points in the wb->buf */ 1451 1452 if (mac_size != 0) 1453 { 1454 if(s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0) 1455 goto err; 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 if (eivlen) 1464 wr->length += eivlen; 1465 1466 s->method->ssl3_enc->enc(s,1); 1467 1468 /* record length after mac and block padding */ 1469/* if (type == SSL3_RT_APPLICATION_DATA || 1470 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1471 1472 /* there's only one epoch between handshake and app data */ 1473 1474 s2n(s->d1->w_epoch, pseq); 1475 1476 /* XDTLS: ?? */ 1477/* else 1478 s2n(s->d1->handshake_epoch, pseq); */ 1479 1480 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1481 pseq+=6; 1482 s2n(wr->length,pseq); 1483 1484 if (s->msg_callback) 1485 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg); 1486 1487 /* we should now have 1488 * wr->data pointing to the encrypted data, which is 1489 * wr->length long */ 1490 wr->type=type; /* not needed but helps for debugging */ 1491 wr->length+=DTLS1_RT_HEADER_LENGTH; 1492 1493#if 0 /* this is now done at the message layer */ 1494 /* buffer the record, making it easy to handle retransmits */ 1495 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1496 dtls1_buffer_record(s, wr->data, wr->length, 1497 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1498#endif 1499 1500 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1501 1502 /* now let's set up wb */ 1503 wb->left = prefix_len + wr->length; 1504 wb->offset = 0; 1505 1506 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1507 s->s3->wpend_tot=len; 1508 s->s3->wpend_buf=buf; 1509 s->s3->wpend_type=type; 1510 s->s3->wpend_ret=len; 1511 1512 /* we now just need to write the buffer */ 1513 return ssl3_write_pending(s,type,buf,len); 1514err: 1515 return -1; 1516 } 1517 1518 1519 1520static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1521 { 1522 int cmp; 1523 unsigned int shift; 1524 const unsigned char *seq = s->s3->read_sequence; 1525 1526 cmp = satsub64be(seq,bitmap->max_seq_num); 1527 if (cmp > 0) 1528 { 1529 memcpy (s->s3->rrec.seq_num,seq,8); 1530 return 1; /* this record in new */ 1531 } 1532 shift = -cmp; 1533 if (shift >= sizeof(bitmap->map)*8) 1534 return 0; /* stale, outside the window */ 1535 else if (bitmap->map & (1UL<<shift)) 1536 return 0; /* record previously received */ 1537 1538 memcpy (s->s3->rrec.seq_num,seq,8); 1539 return 1; 1540 } 1541 1542 1543static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1544 { 1545 int cmp; 1546 unsigned int shift; 1547 const unsigned char *seq = s->s3->read_sequence; 1548 1549 cmp = satsub64be(seq,bitmap->max_seq_num); 1550 if (cmp > 0) 1551 { 1552 shift = cmp; 1553 if (shift < sizeof(bitmap->map)*8) 1554 bitmap->map <<= shift, bitmap->map |= 1UL; 1555 else 1556 bitmap->map = 1UL; 1557 memcpy(bitmap->max_seq_num,seq,8); 1558 } 1559 else { 1560 shift = -cmp; 1561 if (shift < sizeof(bitmap->map)*8) 1562 bitmap->map |= 1UL<<shift; 1563 } 1564 } 1565 1566 1567int dtls1_dispatch_alert(SSL *s) 1568 { 1569 int i,j; 1570 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1571 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1572 unsigned char *ptr = &buf[0]; 1573 1574 s->s3->alert_dispatch=0; 1575 1576 memset(buf, 0x00, sizeof(buf)); 1577 *ptr++ = s->s3->send_alert[0]; 1578 *ptr++ = s->s3->send_alert[1]; 1579 1580#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1581 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1582 { 1583 s2n(s->d1->handshake_read_seq, ptr); 1584#if 0 1585 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1586 1587 else 1588 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1589#endif 1590 1591#if 0 1592 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); 1593#endif 1594 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1595 } 1596#endif 1597 1598 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf)); 1599 if (i <= 0) 1600 { 1601 s->s3->alert_dispatch=1; 1602 /* fprintf( stderr, "not done with alert\n" ); */ 1603 } 1604 else 1605 { 1606 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1607#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1608 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1609#endif 1610 ) 1611 (void)BIO_flush(s->wbio); 1612 1613 if (s->msg_callback) 1614 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1615 2, s, s->msg_callback_arg); 1616 1617 if (s->info_callback != NULL) 1618 cb=s->info_callback; 1619 else if (s->ctx->info_callback != NULL) 1620 cb=s->ctx->info_callback; 1621 1622 if (cb != NULL) 1623 { 1624 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1625 cb(s,SSL_CB_WRITE_ALERT,j); 1626 } 1627 } 1628 return(i); 1629 } 1630 1631 1632static DTLS1_BITMAP * 1633dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1634 { 1635 1636 *is_next_epoch = 0; 1637 1638 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1639 if (rr->epoch == s->d1->r_epoch) 1640 return &s->d1->bitmap; 1641 1642 /* Only HM and ALERT messages can be from the next epoch */ 1643 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1644 (rr->type == SSL3_RT_HANDSHAKE || 1645 rr->type == SSL3_RT_ALERT)) 1646 { 1647 *is_next_epoch = 1; 1648 return &s->d1->next_bitmap; 1649 } 1650 1651 return NULL; 1652 } 1653 1654#if 0 1655static int 1656dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1657 unsigned long *offset) 1658 { 1659 1660 /* alerts are passed up immediately */ 1661 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1662 rr->type == SSL3_RT_ALERT) 1663 return 0; 1664 1665 /* Only need to buffer if a handshake is underway. 1666 * (this implies that Hello Request and Client Hello are passed up 1667 * immediately) */ 1668 if ( SSL_in_init(s)) 1669 { 1670 unsigned char *data = rr->data; 1671 /* need to extract the HM/CCS sequence number here */ 1672 if ( rr->type == SSL3_RT_HANDSHAKE || 1673 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1674 { 1675 unsigned short seq_num; 1676 struct hm_header_st msg_hdr; 1677 struct ccs_header_st ccs_hdr; 1678 1679 if ( rr->type == SSL3_RT_HANDSHAKE) 1680 { 1681 dtls1_get_message_header(data, &msg_hdr); 1682 seq_num = msg_hdr.seq; 1683 *offset = msg_hdr.frag_off; 1684 } 1685 else 1686 { 1687 dtls1_get_ccs_header(data, &ccs_hdr); 1688 seq_num = ccs_hdr.seq; 1689 *offset = 0; 1690 } 1691 1692 /* this is either a record we're waiting for, or a 1693 * retransmit of something we happened to previously 1694 * receive (higher layers will drop the repeat silently */ 1695 if ( seq_num < s->d1->handshake_read_seq) 1696 return 0; 1697 if (rr->type == SSL3_RT_HANDSHAKE && 1698 seq_num == s->d1->handshake_read_seq && 1699 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1700 return 0; 1701 else if ( seq_num == s->d1->handshake_read_seq && 1702 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1703 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1704 return 0; 1705 else 1706 { 1707 *priority = seq_num; 1708 return 1; 1709 } 1710 } 1711 else /* unknown record type */ 1712 return 0; 1713 } 1714 1715 return 0; 1716 } 1717#endif 1718 1719void 1720dtls1_reset_seq_numbers(SSL *s, int rw) 1721 { 1722 unsigned char *seq; 1723 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1724 1725 if ( rw & SSL3_CC_READ) 1726 { 1727 seq = s->s3->read_sequence; 1728 s->d1->r_epoch++; 1729 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1730 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1731 } 1732 else 1733 { 1734 seq = s->s3->write_sequence; 1735 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1736 s->d1->w_epoch++; 1737 } 1738 1739 memset(seq, 0x00, seq_bytes); 1740 } 1741