1 /* $OpenBSD: d1_pkt.c,v 1.63 2017/05/07 04:22:24 beck Exp $ */ 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 <machine/endian.h> 117 118 #include <errno.h> 119 #include <stdio.h> 120 121 #include "ssl_locl.h" 122 123 #include <openssl/buffer.h> 124 #include <openssl/evp.h> 125 126 #include "pqueue.h" 127 #include "bytestring.h" 128 129 static int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 130 unsigned int len); 131 132 133 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 134 static int 135 satsub64be(const unsigned char *v1, const unsigned char *v2) 136 { 137 int ret, sat, brw, i; 138 139 if (sizeof(long) == 8) 140 do { 141 long l; 142 143 if (BYTE_ORDER == LITTLE_ENDIAN) 144 break; 145 /* not reached on little-endians */ 146 /* following test is redundant, because input is 147 * always aligned, but I take no chances... */ 148 if (((size_t)v1 | (size_t)v2) & 0x7) 149 break; 150 151 l = *((long *)v1); 152 l -= *((long *)v2); 153 if (l > 128) 154 return 128; 155 else if (l<-128) 156 return -128; 157 else 158 return (int)l; 159 } while (0); 160 161 ret = (int)v1[7] - (int)v2[7]; 162 sat = 0; 163 brw = ret >> 8; /* brw is either 0 or -1 */ 164 if (ret & 0x80) { 165 for (i = 6; i >= 0; i--) { 166 brw += (int)v1[i]-(int)v2[i]; 167 sat |= ~brw; 168 brw >>= 8; 169 } 170 } else { 171 for (i = 6; i >= 0; i--) { 172 brw += (int)v1[i]-(int)v2[i]; 173 sat |= brw; 174 brw >>= 8; 175 } 176 } 177 brw <<= 8; /* brw is either 0 or -256 */ 178 179 if (sat & 0xff) 180 return brw | 0x80; 181 else 182 return brw + (ret & 0xFF); 183 } 184 185 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 186 int len, int peek); 187 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 188 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 189 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 190 unsigned int *is_next_epoch); 191 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 192 unsigned char *priority); 193 static int dtls1_process_record(SSL *s); 194 195 /* copy buffered record into SSL structure */ 196 static int 197 dtls1_copy_record(SSL *s, pitem *item) 198 { 199 DTLS1_RECORD_DATA *rdata; 200 201 rdata = (DTLS1_RECORD_DATA *)item->data; 202 203 free(s->s3->rbuf.buf); 204 205 s->internal->packet = rdata->packet; 206 s->internal->packet_length = rdata->packet_length; 207 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 208 memcpy(&(S3I(s)->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 209 210 /* Set proper sequence number for mac calculation */ 211 memcpy(&(S3I(s)->read_sequence[2]), &(rdata->packet[5]), 6); 212 213 return (1); 214 } 215 216 217 static int 218 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 219 { 220 DTLS1_RECORD_DATA *rdata; 221 pitem *item; 222 223 /* Limit the size of the queue to prevent DOS attacks */ 224 if (pqueue_size(queue->q) >= 100) 225 return 0; 226 227 rdata = malloc(sizeof(DTLS1_RECORD_DATA)); 228 item = pitem_new(priority, rdata); 229 if (rdata == NULL || item == NULL) 230 goto init_err; 231 232 rdata->packet = s->internal->packet; 233 rdata->packet_length = s->internal->packet_length; 234 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 235 memcpy(&(rdata->rrec), &(S3I(s)->rrec), sizeof(SSL3_RECORD)); 236 237 item->data = rdata; 238 239 240 s->internal->packet = NULL; 241 s->internal->packet_length = 0; 242 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 243 memset(&(S3I(s)->rrec), 0, sizeof(SSL3_RECORD)); 244 245 if (!ssl3_setup_buffers(s)) 246 goto err; 247 248 /* insert should not fail, since duplicates are dropped */ 249 if (pqueue_insert(queue->q, item) == NULL) 250 goto err; 251 252 return (1); 253 254 err: 255 free(rdata->rbuf.buf); 256 257 init_err: 258 SSLerror(s, ERR_R_INTERNAL_ERROR); 259 free(rdata); 260 pitem_free(item); 261 return (-1); 262 } 263 264 265 static int 266 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 267 { 268 pitem *item; 269 270 item = pqueue_pop(queue->q); 271 if (item) { 272 dtls1_copy_record(s, item); 273 274 free(item->data); 275 pitem_free(item); 276 277 return (1); 278 } 279 280 return (0); 281 } 282 283 284 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 285 * yet */ 286 #define dtls1_get_unprocessed_record(s) \ 287 dtls1_retrieve_buffered_record((s), \ 288 &((D1I(s))->unprocessed_rcds)) 289 290 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 291 #define dtls1_get_processed_record(s) \ 292 dtls1_retrieve_buffered_record((s), \ 293 &((D1I(s))->processed_rcds)) 294 295 static int 296 dtls1_process_buffered_records(SSL *s) 297 { 298 pitem *item; 299 300 item = pqueue_peek(D1I(s)->unprocessed_rcds.q); 301 if (item) { 302 /* Check if epoch is current. */ 303 if (D1I(s)->unprocessed_rcds.epoch != D1I(s)->r_epoch) 304 return (1); 305 /* Nothing to do. */ 306 307 /* Process all the records. */ 308 while (pqueue_peek(D1I(s)->unprocessed_rcds.q)) { 309 dtls1_get_unprocessed_record(s); 310 if (! dtls1_process_record(s)) 311 return (0); 312 if (dtls1_buffer_record(s, &(D1I(s)->processed_rcds), 313 S3I(s)->rrec.seq_num) < 0) 314 return (-1); 315 } 316 } 317 318 /* sync epoch numbers once all the unprocessed records 319 * have been processed */ 320 D1I(s)->processed_rcds.epoch = D1I(s)->r_epoch; 321 D1I(s)->unprocessed_rcds.epoch = D1I(s)->r_epoch + 1; 322 323 return (1); 324 } 325 326 static int 327 dtls1_process_record(SSL *s) 328 { 329 int i, al; 330 int enc_err; 331 SSL_SESSION *sess; 332 SSL3_RECORD *rr; 333 unsigned int mac_size, orig_len; 334 unsigned char md[EVP_MAX_MD_SIZE]; 335 336 rr = &(S3I(s)->rrec); 337 sess = s->session; 338 339 /* At this point, s->internal->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 340 * and we have that many bytes in s->internal->packet 341 */ 342 rr->input = &(s->internal->packet[DTLS1_RT_HEADER_LENGTH]); 343 344 /* ok, we can now read from 's->internal->packet' data into 'rr' 345 * rr->input points at rr->length bytes, which 346 * need to be copied into rr->data by either 347 * the decryption or by the decompression 348 * When the data is 'copied' into the rr->data buffer, 349 * rr->input will be pointed at the new buffer */ 350 351 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 352 * rr->length bytes of encrypted compressed stuff. */ 353 354 /* check is not needed I believe */ 355 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 356 al = SSL_AD_RECORD_OVERFLOW; 357 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 358 goto f_err; 359 } 360 361 /* decrypt in place in 'rr->input' */ 362 rr->data = rr->input; 363 364 enc_err = s->method->internal->ssl3_enc->enc(s, 0); 365 /* enc_err is: 366 * 0: (in non-constant time) if the record is publically invalid. 367 * 1: if the padding is valid 368 * -1: if the padding is invalid */ 369 if (enc_err == 0) { 370 /* For DTLS we simply ignore bad packets. */ 371 rr->length = 0; 372 s->internal->packet_length = 0; 373 goto err; 374 } 375 376 377 /* r->length is now the compressed data plus mac */ 378 if ((sess != NULL) && (s->enc_read_ctx != NULL) && 379 (EVP_MD_CTX_md(s->read_hash) != NULL)) { 380 /* s->read_hash != NULL => mac_size != -1 */ 381 unsigned char *mac = NULL; 382 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 383 mac_size = EVP_MD_CTX_size(s->read_hash); 384 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 385 386 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 387 orig_len = rr->length + ((unsigned int)rr->type >> 8); 388 389 /* orig_len is the length of the record before any padding was 390 * removed. This is public information, as is the MAC in use, 391 * therefore we can safely process the record in a different 392 * amount of time if it's too short to possibly contain a MAC. 393 */ 394 if (orig_len < mac_size || 395 /* CBC records must have a padding length byte too. */ 396 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 397 orig_len < mac_size + 1)) { 398 al = SSL_AD_DECODE_ERROR; 399 SSLerror(s, SSL_R_LENGTH_TOO_SHORT); 400 goto f_err; 401 } 402 403 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 404 /* We update the length so that the TLS header bytes 405 * can be constructed correctly but we need to extract 406 * the MAC in constant time from within the record, 407 * without leaking the contents of the padding bytes. 408 * */ 409 mac = mac_tmp; 410 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 411 rr->length -= mac_size; 412 } else { 413 /* In this case there's no padding, so |orig_len| 414 * equals |rec->length| and we checked that there's 415 * enough bytes for |mac_size| above. */ 416 rr->length -= mac_size; 417 mac = &rr->data[rr->length]; 418 } 419 420 i = tls1_mac(s, md, 0 /* not send */); 421 if (i < 0 || mac == NULL || timingsafe_memcmp(md, mac, (size_t)mac_size) != 0) 422 enc_err = -1; 423 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 424 enc_err = -1; 425 } 426 427 if (enc_err < 0) { 428 /* decryption failed, silently discard message */ 429 rr->length = 0; 430 s->internal->packet_length = 0; 431 goto err; 432 } 433 434 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 435 al = SSL_AD_RECORD_OVERFLOW; 436 SSLerror(s, SSL_R_DATA_LENGTH_TOO_LONG); 437 goto f_err; 438 } 439 440 rr->off = 0; 441 /* So at this point the following is true 442 * ssl->s3->internal->rrec.type is the type of record 443 * ssl->s3->internal->rrec.length == number of bytes in record 444 * ssl->s3->internal->rrec.off == offset to first valid byte 445 * ssl->s3->internal->rrec.data == where to take bytes from, increment 446 * after use :-). 447 */ 448 449 /* we have pulled in a full packet so zero things */ 450 s->internal->packet_length = 0; 451 return (1); 452 453 f_err: 454 ssl3_send_alert(s, SSL3_AL_FATAL, al); 455 err: 456 return (0); 457 } 458 459 460 /* Call this to get a new input record. 461 * It will return <= 0 if more data is needed, normally due to an error 462 * or non-blocking IO. 463 * When it finishes, one packet has been decoded and can be found in 464 * ssl->s3->internal->rrec.type - is the type of record 465 * ssl->s3->internal->rrec.data, - data 466 * ssl->s3->internal->rrec.length, - number of bytes 467 */ 468 /* used only by dtls1_read_bytes */ 469 int 470 dtls1_get_record(SSL *s) 471 { 472 SSL3_RECORD *rr; 473 unsigned char *p = NULL; 474 DTLS1_BITMAP *bitmap; 475 unsigned int is_next_epoch; 476 int n; 477 478 rr = &(S3I(s)->rrec); 479 480 /* The epoch may have changed. If so, process all the 481 * pending records. This is a non-blocking operation. */ 482 if (dtls1_process_buffered_records(s) < 0) 483 return (-1); 484 485 /* if we're renegotiating, then there may be buffered records */ 486 if (dtls1_get_processed_record(s)) 487 return 1; 488 489 /* get something from the wire */ 490 if (0) { 491 again: 492 /* dump this record on all retries */ 493 rr->length = 0; 494 s->internal->packet_length = 0; 495 } 496 497 /* check if we have the header */ 498 if ((s->internal->rstate != SSL_ST_READ_BODY) || 499 (s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) { 500 CBS header, seq_no; 501 uint16_t epoch, len, ssl_version; 502 uint8_t type; 503 504 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH); 505 if (n <= 0) 506 return (n); 507 508 /* If this packet contained a partial record, dump it. */ 509 if (n != DTLS1_RT_HEADER_LENGTH) 510 goto again; 511 512 s->internal->rstate = SSL_ST_READ_BODY; 513 514 CBS_init(&header, s->internal->packet, s->internal->packet_length); 515 516 /* Pull apart the header into the DTLS1_RECORD */ 517 if (!CBS_get_u8(&header, &type)) 518 goto again; 519 if (!CBS_get_u16(&header, &ssl_version)) 520 goto again; 521 522 /* sequence number is 64 bits, with top 2 bytes = epoch */ 523 if (!CBS_get_u16(&header, &epoch) || 524 !CBS_get_bytes(&header, &seq_no, 6)) 525 goto again; 526 527 if (!CBS_write_bytes(&seq_no, &(S3I(s)->read_sequence[2]), 528 sizeof(S3I(s)->read_sequence) - 2, NULL)) 529 goto again; 530 if (!CBS_get_u16(&header, &len)) 531 goto again; 532 533 rr->type = type; 534 rr->epoch = epoch; 535 rr->length = len; 536 537 /* unexpected version, silently discard */ 538 if (!s->internal->first_packet && ssl_version != s->version) 539 goto again; 540 541 /* wrong version, silently discard record */ 542 if ((ssl_version & 0xff00) != (s->version & 0xff00)) 543 goto again; 544 545 /* record too long, silently discard it */ 546 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 547 goto again; 548 549 /* now s->internal->rstate == SSL_ST_READ_BODY */ 550 p = (unsigned char *)CBS_data(&header); 551 } 552 553 /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */ 554 555 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length); 556 if (n <= 0) 557 return (n); 558 559 /* If this packet contained a partial record, dump it. */ 560 if (n != DTLS1_RT_HEADER_LENGTH + rr->length) 561 goto again; 562 563 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 564 565 /* match epochs. NULL means the packet is dropped on the floor */ 566 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 567 if (bitmap == NULL) 568 goto again; 569 570 /* 571 * Check whether this is a repeat, or aged record. 572 * Don't check if we're listening and this message is 573 * a ClientHello. They can look as if they're replayed, 574 * since they arrive from different connections and 575 * would be dropped unnecessarily. 576 */ 577 if (!(D1I(s)->listen && rr->type == SSL3_RT_HANDSHAKE && 578 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 579 !dtls1_record_replay_check(s, bitmap)) 580 goto again; 581 582 /* just read a 0 length packet */ 583 if (rr->length == 0) 584 goto again; 585 586 /* If this record is from the next epoch (either HM or ALERT), 587 * and a handshake is currently in progress, buffer it since it 588 * cannot be processed at this time. However, do not buffer 589 * anything while listening. 590 */ 591 if (is_next_epoch) { 592 if ((SSL_in_init(s) || s->internal->in_handshake) && !D1I(s)->listen) { 593 if (dtls1_buffer_record(s, &(D1I(s)->unprocessed_rcds), 594 rr->seq_num) < 0) 595 return (-1); 596 /* Mark receipt of record. */ 597 dtls1_record_bitmap_update(s, bitmap); 598 } 599 goto again; 600 } 601 602 if (!dtls1_process_record(s)) 603 goto again; 604 605 /* Mark receipt of record. */ 606 dtls1_record_bitmap_update(s, bitmap); 607 608 return (1); 609 } 610 611 /* Return up to 'len' payload bytes received in 'type' records. 612 * 'type' is one of the following: 613 * 614 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 615 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 616 * - 0 (during a shutdown, no data has to be returned) 617 * 618 * If we don't have stored data to work from, read a SSL/TLS record first 619 * (possibly multiple records if we still don't have anything to return). 620 * 621 * This function must handle any surprises the peer may have for us, such as 622 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 623 * a surprise, but handled as if it were), or renegotiation requests. 624 * Also if record payloads contain fragments too small to process, we store 625 * them until there is enough for the respective protocol (the record protocol 626 * may use arbitrary fragmentation and even interleaving): 627 * Change cipher spec protocol 628 * just 1 byte needed, no need for keeping anything stored 629 * Alert protocol 630 * 2 bytes needed (AlertLevel, AlertDescription) 631 * Handshake protocol 632 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 633 * to detect unexpected Client Hello and Hello Request messages 634 * here, anything else is handled by higher layers 635 * Application data protocol 636 * none of our business 637 */ 638 int 639 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 640 { 641 int al, i, j, ret; 642 unsigned int n; 643 SSL3_RECORD *rr; 644 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 645 646 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 647 if (!ssl3_setup_buffers(s)) 648 return (-1); 649 650 if ((type && 651 type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || 652 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 653 SSLerror(s, ERR_R_INTERNAL_ERROR); 654 return -1; 655 } 656 657 /* check whether there's a handshake message (client hello?) waiting */ 658 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 659 return ret; 660 661 /* Now D1I(s)->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 662 663 if (!s->internal->in_handshake && SSL_in_init(s)) 664 { 665 /* type == SSL3_RT_APPLICATION_DATA */ 666 i = s->internal->handshake_func(s); 667 if (i < 0) 668 return (i); 669 if (i == 0) { 670 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 671 return (-1); 672 } 673 } 674 675 start: 676 s->internal->rwstate = SSL_NOTHING; 677 678 /* S3I(s)->rrec.type - is the type of record 679 * S3I(s)->rrec.data, - data 680 * S3I(s)->rrec.off, - offset into 'data' for next read 681 * S3I(s)->rrec.length, - number of bytes. */ 682 rr = &(S3I(s)->rrec); 683 684 /* We are not handshaking and have no data yet, 685 * so process data buffered during the last handshake 686 * in advance, if any. 687 */ 688 if (S3I(s)->hs.state == SSL_ST_OK && rr->length == 0) { 689 pitem *item; 690 item = pqueue_pop(D1I(s)->buffered_app_data.q); 691 if (item) { 692 693 dtls1_copy_record(s, item); 694 695 free(item->data); 696 pitem_free(item); 697 } 698 } 699 700 /* Check for timeout */ 701 if (dtls1_handle_timeout(s) > 0) 702 goto start; 703 704 /* get new packet if necessary */ 705 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 706 ret = dtls1_get_record(s); 707 if (ret <= 0) { 708 ret = dtls1_read_failed(s, ret); 709 /* anything other than a timeout is an error */ 710 if (ret <= 0) 711 return (ret); 712 else 713 goto start; 714 } 715 } 716 717 if (D1I(s)->listen && rr->type != SSL3_RT_HANDSHAKE) { 718 rr->length = 0; 719 goto start; 720 } 721 722 /* we now have a packet which can be read and processed */ 723 724 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 725 * reset by ssl3_get_finished */ 726 && (rr->type != SSL3_RT_HANDSHAKE)) { 727 /* We now have application data between CCS and Finished. 728 * Most likely the packets were reordered on their way, so 729 * buffer the application data for later processing rather 730 * than dropping the connection. 731 */ 732 if (dtls1_buffer_record(s, &(D1I(s)->buffered_app_data), 733 rr->seq_num) < 0) { 734 SSLerror(s, ERR_R_INTERNAL_ERROR); 735 return (-1); 736 } 737 rr->length = 0; 738 goto start; 739 } 740 741 /* If the other end has shut down, throw anything we read away 742 * (even in 'peek' mode) */ 743 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 744 rr->length = 0; 745 s->internal->rwstate = SSL_NOTHING; 746 return (0); 747 } 748 749 750 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 751 { 752 /* make sure that we are not getting application data when we 753 * are doing a handshake for the first time */ 754 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 755 (s->enc_read_ctx == NULL)) { 756 al = SSL_AD_UNEXPECTED_MESSAGE; 757 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 758 goto f_err; 759 } 760 761 if (len <= 0) 762 return (len); 763 764 if ((unsigned int)len > rr->length) 765 n = rr->length; 766 else 767 n = (unsigned int)len; 768 769 memcpy(buf, &(rr->data[rr->off]), n); 770 if (!peek) { 771 rr->length -= n; 772 rr->off += n; 773 if (rr->length == 0) { 774 s->internal->rstate = SSL_ST_READ_HEADER; 775 rr->off = 0; 776 } 777 } 778 779 return (n); 780 } 781 782 783 /* If we get here, then type != rr->type; if we have a handshake 784 * message, then it was unexpected (Hello Request or Client Hello). */ 785 786 /* In case of record types for which we have 'fragment' storage, 787 * fill that so that we can process the data at a fixed place. 788 */ 789 { 790 unsigned int k, dest_maxlen = 0; 791 unsigned char *dest = NULL; 792 unsigned int *dest_len = NULL; 793 794 if (rr->type == SSL3_RT_HANDSHAKE) { 795 dest_maxlen = sizeof D1I(s)->handshake_fragment; 796 dest = D1I(s)->handshake_fragment; 797 dest_len = &D1I(s)->handshake_fragment_len; 798 } else if (rr->type == SSL3_RT_ALERT) { 799 dest_maxlen = sizeof(D1I(s)->alert_fragment); 800 dest = D1I(s)->alert_fragment; 801 dest_len = &D1I(s)->alert_fragment_len; 802 } 803 /* else it's a CCS message, or application data or wrong */ 804 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 805 /* Application data while renegotiating 806 * is allowed. Try again reading. 807 */ 808 if (rr->type == SSL3_RT_APPLICATION_DATA) { 809 BIO *bio; 810 S3I(s)->in_read_app_data = 2; 811 bio = SSL_get_rbio(s); 812 s->internal->rwstate = SSL_READING; 813 BIO_clear_retry_flags(bio); 814 BIO_set_retry_read(bio); 815 return (-1); 816 } 817 818 /* Not certain if this is the right error handling */ 819 al = SSL_AD_UNEXPECTED_MESSAGE; 820 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 821 goto f_err; 822 } 823 824 if (dest_maxlen > 0) { 825 /* XDTLS: In a pathalogical case, the Client Hello 826 * may be fragmented--don't always expect dest_maxlen bytes */ 827 if (rr->length < dest_maxlen) { 828 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 829 /* 830 * for normal alerts rr->length is 2, while 831 * dest_maxlen is 7 if we were to handle this 832 * non-existing alert... 833 */ 834 FIX ME 835 #endif 836 s->internal->rstate = SSL_ST_READ_HEADER; 837 rr->length = 0; 838 goto start; 839 } 840 841 /* now move 'n' bytes: */ 842 for ( k = 0; k < dest_maxlen; k++) { 843 dest[k] = rr->data[rr->off++]; 844 rr->length--; 845 } 846 *dest_len = dest_maxlen; 847 } 848 } 849 850 /* D1I(s)->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 851 * D1I(s)->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 852 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 853 854 /* If we are a client, check for an incoming 'Hello Request': */ 855 if ((!s->server) && 856 (D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 857 (D1I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 858 (s->session != NULL) && (s->session->cipher != NULL)) { 859 D1I(s)->handshake_fragment_len = 0; 860 861 if ((D1I(s)->handshake_fragment[1] != 0) || 862 (D1I(s)->handshake_fragment[2] != 0) || 863 (D1I(s)->handshake_fragment[3] != 0)) { 864 al = SSL_AD_DECODE_ERROR; 865 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 866 goto err; 867 } 868 869 /* no need to check sequence number on HELLO REQUEST messages */ 870 871 if (s->internal->msg_callback) 872 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 873 D1I(s)->handshake_fragment, 4, s, s->internal->msg_callback_arg); 874 875 if (SSL_is_init_finished(s) && 876 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 877 !S3I(s)->renegotiate) { 878 D1I(s)->handshake_read_seq++; 879 s->internal->new_session = 1; 880 ssl3_renegotiate(s); 881 if (ssl3_renegotiate_check(s)) { 882 i = s->internal->handshake_func(s); 883 if (i < 0) 884 return (i); 885 if (i == 0) { 886 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 887 return (-1); 888 } 889 890 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 891 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 892 { 893 BIO *bio; 894 /* In the case where we try to read application data, 895 * but we trigger an SSL handshake, we return -1 with 896 * the retry option set. Otherwise renegotiation may 897 * cause nasty problems in the blocking world */ 898 s->internal->rwstate = SSL_READING; 899 bio = SSL_get_rbio(s); 900 BIO_clear_retry_flags(bio); 901 BIO_set_retry_read(bio); 902 return (-1); 903 } 904 } 905 } 906 } 907 /* we either finished a handshake or ignored the request, 908 * now try again to obtain the (application) data we were asked for */ 909 goto start; 910 } 911 912 if (D1I(s)->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 913 int alert_level = D1I(s)->alert_fragment[0]; 914 int alert_descr = D1I(s)->alert_fragment[1]; 915 916 D1I(s)->alert_fragment_len = 0; 917 918 if (s->internal->msg_callback) 919 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT, 920 D1I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg); 921 922 if (s->internal->info_callback != NULL) 923 cb = s->internal->info_callback; 924 else if (s->ctx->internal->info_callback != NULL) 925 cb = s->ctx->internal->info_callback; 926 927 if (cb != NULL) { 928 j = (alert_level << 8) | alert_descr; 929 cb(s, SSL_CB_READ_ALERT, j); 930 } 931 932 if (alert_level == 1) /* warning */ 933 { 934 S3I(s)->warn_alert = alert_descr; 935 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 936 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 937 return (0); 938 } 939 } else if (alert_level == 2) /* fatal */ 940 { 941 s->internal->rwstate = SSL_NOTHING; 942 S3I(s)->fatal_alert = alert_descr; 943 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 944 ERR_asprintf_error_data("SSL alert number %d", 945 alert_descr); 946 s->internal->shutdown|=SSL_RECEIVED_SHUTDOWN; 947 SSL_CTX_remove_session(s->ctx, s->session); 948 return (0); 949 } else { 950 al = SSL_AD_ILLEGAL_PARAMETER; 951 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 952 goto f_err; 953 } 954 955 goto start; 956 } 957 958 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 959 { 960 s->internal->rwstate = SSL_NOTHING; 961 rr->length = 0; 962 return (0); 963 } 964 965 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 966 struct ccs_header_st ccs_hdr; 967 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 968 969 dtls1_get_ccs_header(rr->data, &ccs_hdr); 970 971 /* 'Change Cipher Spec' is just a single byte, so we know 972 * exactly what the record payload has to look like */ 973 /* XDTLS: check that epoch is consistent */ 974 if ((rr->length != ccs_hdr_len) || 975 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 976 i = SSL_AD_ILLEGAL_PARAMETER; 977 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 978 goto err; 979 } 980 981 rr->length = 0; 982 983 if (s->internal->msg_callback) 984 s->internal->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 985 rr->data, 1, s, s->internal->msg_callback_arg); 986 987 /* We can't process a CCS now, because previous handshake 988 * messages are still missing, so just drop it. 989 */ 990 if (!D1I(s)->change_cipher_spec_ok) { 991 goto start; 992 } 993 994 D1I(s)->change_cipher_spec_ok = 0; 995 996 S3I(s)->change_cipher_spec = 1; 997 if (!ssl3_do_change_cipher_spec(s)) 998 goto err; 999 1000 /* do this whenever CCS is processed */ 1001 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1002 1003 goto start; 1004 } 1005 1006 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1007 if ((D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1008 !s->internal->in_handshake) { 1009 struct hm_header_st msg_hdr; 1010 1011 /* this may just be a stale retransmit */ 1012 if (!dtls1_get_message_header(rr->data, &msg_hdr)) 1013 return -1; 1014 if (rr->epoch != D1I(s)->r_epoch) { 1015 rr->length = 0; 1016 goto start; 1017 } 1018 1019 /* If we are server, we may have a repeated FINISHED of the 1020 * client here, then retransmit our CCS and FINISHED. 1021 */ 1022 if (msg_hdr.type == SSL3_MT_FINISHED) { 1023 if (dtls1_check_timeout_num(s) < 0) 1024 return -1; 1025 1026 dtls1_retransmit_buffered_messages(s); 1027 rr->length = 0; 1028 goto start; 1029 } 1030 1031 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 1032 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1033 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1034 s->internal->renegotiate = 1; 1035 s->internal->new_session = 1; 1036 } 1037 i = s->internal->handshake_func(s); 1038 if (i < 0) 1039 return (i); 1040 if (i == 0) { 1041 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1042 return (-1); 1043 } 1044 1045 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1046 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1047 { 1048 BIO *bio; 1049 /* In the case where we try to read application data, 1050 * but we trigger an SSL handshake, we return -1 with 1051 * the retry option set. Otherwise renegotiation may 1052 * cause nasty problems in the blocking world */ 1053 s->internal->rwstate = SSL_READING; 1054 bio = SSL_get_rbio(s); 1055 BIO_clear_retry_flags(bio); 1056 BIO_set_retry_read(bio); 1057 return (-1); 1058 } 1059 } 1060 goto start; 1061 } 1062 1063 switch (rr->type) { 1064 default: 1065 /* TLS just ignores unknown message types */ 1066 if (s->version == TLS1_VERSION) { 1067 rr->length = 0; 1068 goto start; 1069 } 1070 al = SSL_AD_UNEXPECTED_MESSAGE; 1071 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1072 goto f_err; 1073 case SSL3_RT_CHANGE_CIPHER_SPEC: 1074 case SSL3_RT_ALERT: 1075 case SSL3_RT_HANDSHAKE: 1076 /* we already handled all of these, with the possible exception 1077 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 1078 * should not happen when type != rr->type */ 1079 al = SSL_AD_UNEXPECTED_MESSAGE; 1080 SSLerror(s, ERR_R_INTERNAL_ERROR); 1081 goto f_err; 1082 case SSL3_RT_APPLICATION_DATA: 1083 /* At this point, we were expecting handshake data, 1084 * but have application data. If the library was 1085 * running inside ssl3_read() (i.e. in_read_app_data 1086 * is set) and it makes sense to read application data 1087 * at this point (session renegotiation not yet started), 1088 * we will indulge it. 1089 */ 1090 if (S3I(s)->in_read_app_data && 1091 (S3I(s)->total_renegotiations != 0) && 1092 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 1093 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1094 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 1095 (S3I(s)->hs.state & SSL_ST_ACCEPT) && 1096 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1097 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1098 S3I(s)->in_read_app_data = 2; 1099 return (-1); 1100 } else { 1101 al = SSL_AD_UNEXPECTED_MESSAGE; 1102 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1103 goto f_err; 1104 } 1105 } 1106 /* not reached */ 1107 1108 f_err: 1109 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1110 err: 1111 return (-1); 1112 } 1113 1114 int 1115 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1116 { 1117 int i; 1118 1119 if (SSL_in_init(s) && !s->internal->in_handshake) 1120 { 1121 i = s->internal->handshake_func(s); 1122 if (i < 0) 1123 return (i); 1124 if (i == 0) { 1125 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1126 return -1; 1127 } 1128 } 1129 1130 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 1131 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); 1132 return -1; 1133 } 1134 1135 i = dtls1_write_bytes(s, type, buf_, len); 1136 return i; 1137 } 1138 1139 1140 /* this only happens when a client hello is received and a handshake 1141 * is started. */ 1142 static int 1143 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1144 int len, int peek) 1145 { 1146 1147 if ((type == SSL3_RT_HANDSHAKE) && (D1I(s)->handshake_fragment_len > 0)) 1148 /* (partially) satisfy request from storage */ 1149 { 1150 unsigned char *src = D1I(s)->handshake_fragment; 1151 unsigned char *dst = buf; 1152 unsigned int k, n; 1153 1154 /* peek == 0 */ 1155 n = 0; 1156 while ((len > 0) && (D1I(s)->handshake_fragment_len > 0)) { 1157 *dst++ = *src++; 1158 len--; 1159 D1I(s)->handshake_fragment_len--; 1160 n++; 1161 } 1162 /* move any remaining fragment bytes: */ 1163 for (k = 0; k < D1I(s)->handshake_fragment_len; k++) 1164 D1I(s)->handshake_fragment[k] = *src++; 1165 return n; 1166 } 1167 1168 return 0; 1169 } 1170 1171 1172 /* Call this to write data in records of type 'type' 1173 * It will return <= 0 if not all data has been sent or non-blocking IO. 1174 */ 1175 int 1176 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1177 { 1178 int i; 1179 1180 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1181 s->internal->rwstate = SSL_NOTHING; 1182 i = do_dtls1_write(s, type, buf, len); 1183 return i; 1184 } 1185 1186 int 1187 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 1188 { 1189 unsigned char *p, *pseq; 1190 int i, mac_size, clear = 0; 1191 int prefix_len = 0; 1192 SSL3_RECORD *wr; 1193 SSL3_BUFFER *wb; 1194 SSL_SESSION *sess; 1195 int bs; 1196 1197 /* first check if there is a SSL3_BUFFER still being written 1198 * out. This will happen with non blocking IO */ 1199 if (s->s3->wbuf.left != 0) { 1200 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1201 return (ssl3_write_pending(s, type, buf, len)); 1202 } 1203 1204 /* If we have an alert to send, lets send it */ 1205 if (s->s3->alert_dispatch) { 1206 i = s->method->ssl_dispatch_alert(s); 1207 if (i <= 0) 1208 return (i); 1209 /* if it went, fall through and send more stuff */ 1210 } 1211 1212 if (len == 0) 1213 return 0; 1214 1215 wr = &(S3I(s)->wrec); 1216 wb = &(s->s3->wbuf); 1217 sess = s->session; 1218 1219 if ((sess == NULL) || (s->internal->enc_write_ctx == NULL) || 1220 (EVP_MD_CTX_md(s->internal->write_hash) == NULL)) 1221 clear = 1; 1222 1223 if (clear) 1224 mac_size = 0; 1225 else { 1226 mac_size = EVP_MD_CTX_size(s->internal->write_hash); 1227 if (mac_size < 0) 1228 goto err; 1229 } 1230 1231 /* DTLS implements explicit IV, so no need for empty fragments. */ 1232 1233 p = wb->buf + prefix_len; 1234 1235 /* write the header */ 1236 1237 *(p++) = type&0xff; 1238 wr->type = type; 1239 1240 *(p++) = (s->version >> 8); 1241 *(p++) = s->version&0xff; 1242 1243 /* field where we are to write out packet epoch, seq num and len */ 1244 pseq = p; 1245 1246 p += 10; 1247 1248 /* lets setup the record stuff. */ 1249 1250 /* Make space for the explicit IV in case of CBC. 1251 * (this is a bit of a boundary violation, but what the heck). 1252 */ 1253 if (s->internal->enc_write_ctx && 1254 (EVP_CIPHER_mode(s->internal->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 1255 bs = EVP_CIPHER_block_size(s->internal->enc_write_ctx->cipher); 1256 else 1257 bs = 0; 1258 1259 wr->data = p + bs; 1260 /* make room for IV in case of CBC */ 1261 wr->length = (int)len; 1262 wr->input = (unsigned char *)buf; 1263 1264 /* we now 'read' from wr->input, wr->length bytes into 1265 * wr->data */ 1266 1267 memcpy(wr->data, wr->input, wr->length); 1268 wr->input = wr->data; 1269 1270 /* we should still have the output to wr->data and the input 1271 * from wr->input. Length should be wr->length. 1272 * wr->data still points in the wb->buf */ 1273 1274 if (mac_size != 0) { 1275 if (tls1_mac(s, &(p[wr->length + bs]), 1) < 0) 1276 goto err; 1277 wr->length += mac_size; 1278 } 1279 1280 /* this is true regardless of mac size */ 1281 wr->input = p; 1282 wr->data = p; 1283 1284 1285 /* ssl3_enc can only have an error on read */ 1286 if (bs) /* bs != 0 in case of CBC */ 1287 { 1288 arc4random_buf(p, bs); 1289 /* master IV and last CBC residue stand for 1290 * the rest of randomness */ 1291 wr->length += bs; 1292 } 1293 1294 s->method->internal->ssl3_enc->enc(s, 1); 1295 1296 /* record length after mac and block padding */ 1297 /* if (type == SSL3_RT_APPLICATION_DATA || 1298 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1299 1300 /* there's only one epoch between handshake and app data */ 1301 1302 s2n(D1I(s)->w_epoch, pseq); 1303 1304 /* XDTLS: ?? */ 1305 /* else 1306 s2n(D1I(s)->handshake_epoch, pseq); 1307 */ 1308 1309 memcpy(pseq, &(S3I(s)->write_sequence[2]), 6); 1310 pseq += 6; 1311 s2n(wr->length, pseq); 1312 1313 /* we should now have 1314 * wr->data pointing to the encrypted data, which is 1315 * wr->length long */ 1316 wr->type=type; /* not needed but helps for debugging */ 1317 wr->length += DTLS1_RT_HEADER_LENGTH; 1318 1319 tls1_record_sequence_increment(S3I(s)->write_sequence); 1320 1321 /* now let's set up wb */ 1322 wb->left = prefix_len + wr->length; 1323 wb->offset = 0; 1324 1325 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1326 S3I(s)->wpend_tot = len; 1327 S3I(s)->wpend_buf = buf; 1328 S3I(s)->wpend_type = type; 1329 S3I(s)->wpend_ret = len; 1330 1331 /* we now just need to write the buffer */ 1332 return ssl3_write_pending(s, type, buf, len); 1333 err: 1334 return -1; 1335 } 1336 1337 1338 1339 static int 1340 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1341 { 1342 int cmp; 1343 unsigned int shift; 1344 const unsigned char *seq = S3I(s)->read_sequence; 1345 1346 cmp = satsub64be(seq, bitmap->max_seq_num); 1347 if (cmp > 0) { 1348 memcpy (S3I(s)->rrec.seq_num, seq, 8); 1349 return 1; /* this record in new */ 1350 } 1351 shift = -cmp; 1352 if (shift >= sizeof(bitmap->map)*8) 1353 return 0; /* stale, outside the window */ 1354 else if (bitmap->map & (1UL << shift)) 1355 return 0; /* record previously received */ 1356 1357 memcpy(S3I(s)->rrec.seq_num, seq, 8); 1358 return 1; 1359 } 1360 1361 1362 static void 1363 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1364 { 1365 int cmp; 1366 unsigned int shift; 1367 const unsigned char *seq = S3I(s)->read_sequence; 1368 1369 cmp = satsub64be(seq, bitmap->max_seq_num); 1370 if (cmp > 0) { 1371 shift = cmp; 1372 if (shift < sizeof(bitmap->map)*8) 1373 bitmap->map <<= shift, bitmap->map |= 1UL; 1374 else 1375 bitmap->map = 1UL; 1376 memcpy(bitmap->max_seq_num, seq, 8); 1377 } else { 1378 shift = -cmp; 1379 if (shift < sizeof(bitmap->map) * 8) 1380 bitmap->map |= 1UL << shift; 1381 } 1382 } 1383 1384 1385 int 1386 dtls1_dispatch_alert(SSL *s) 1387 { 1388 int i, j; 1389 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1390 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1391 unsigned char *ptr = &buf[0]; 1392 1393 s->s3->alert_dispatch = 0; 1394 1395 memset(buf, 0x00, sizeof(buf)); 1396 *ptr++ = s->s3->send_alert[0]; 1397 *ptr++ = s->s3->send_alert[1]; 1398 1399 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1400 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1401 s2n(D1I(s)->handshake_read_seq, ptr); 1402 l2n3(D1I(s)->r_msg_hdr.frag_off, ptr); 1403 } 1404 #endif 1405 1406 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf)); 1407 if (i <= 0) { 1408 s->s3->alert_dispatch = 1; 1409 /* fprintf( stderr, "not done with alert\n" ); */ 1410 } else { 1411 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1412 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1413 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1414 #endif 1415 ) 1416 (void)BIO_flush(s->wbio); 1417 1418 if (s->internal->msg_callback) 1419 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT, 1420 s->s3->send_alert, 2, s, s->internal->msg_callback_arg); 1421 1422 if (s->internal->info_callback != NULL) 1423 cb = s->internal->info_callback; 1424 else if (s->ctx->internal->info_callback != NULL) 1425 cb = s->ctx->internal->info_callback; 1426 1427 if (cb != NULL) { 1428 j = (s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1429 cb(s, SSL_CB_WRITE_ALERT, j); 1430 } 1431 } 1432 return (i); 1433 } 1434 1435 1436 static DTLS1_BITMAP * 1437 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1438 { 1439 1440 *is_next_epoch = 0; 1441 1442 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1443 if (rr->epoch == D1I(s)->r_epoch) 1444 return &D1I(s)->bitmap; 1445 1446 /* Only HM and ALERT messages can be from the next epoch */ 1447 else if (rr->epoch == (unsigned long)(D1I(s)->r_epoch + 1) && 1448 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1449 *is_next_epoch = 1; 1450 return &D1I(s)->next_bitmap; 1451 } 1452 1453 return NULL; 1454 } 1455 1456 void 1457 dtls1_reset_seq_numbers(SSL *s, int rw) 1458 { 1459 unsigned char *seq; 1460 unsigned int seq_bytes = sizeof(S3I(s)->read_sequence); 1461 1462 if (rw & SSL3_CC_READ) { 1463 seq = S3I(s)->read_sequence; 1464 D1I(s)->r_epoch++; 1465 memcpy(&(D1I(s)->bitmap), &(D1I(s)->next_bitmap), sizeof(DTLS1_BITMAP)); 1466 memset(&(D1I(s)->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1467 } else { 1468 seq = S3I(s)->write_sequence; 1469 memcpy(D1I(s)->last_write_sequence, seq, sizeof(S3I(s)->write_sequence)); 1470 D1I(s)->w_epoch++; 1471 } 1472 1473 memset(seq, 0x00, seq_bytes); 1474 } 1475