1 /* $OpenBSD: d1_pkt.c,v 1.47 2015/09/10 17:57:50 jsing 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 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 130 static int 131 satsub64be(const unsigned char *v1, const unsigned char *v2) 132 { 133 int ret, sat, brw, i; 134 135 if (sizeof(long) == 8) 136 do { 137 long l; 138 139 if (BYTE_ORDER == LITTLE_ENDIAN) 140 break; 141 /* not reached on little-endians */ 142 /* following test is redundant, because input is 143 * always aligned, but I take no chances... */ 144 if (((size_t)v1 | (size_t)v2) & 0x7) 145 break; 146 147 l = *((long *)v1); 148 l -= *((long *)v2); 149 if (l > 128) 150 return 128; 151 else if (l<-128) 152 return -128; 153 else 154 return (int)l; 155 } while (0); 156 157 ret = (int)v1[7] - (int)v2[7]; 158 sat = 0; 159 brw = ret >> 8; /* brw is either 0 or -1 */ 160 if (ret & 0x80) { 161 for (i = 6; i >= 0; i--) { 162 brw += (int)v1[i]-(int)v2[i]; 163 sat |= ~brw; 164 brw >>= 8; 165 } 166 } else { 167 for (i = 6; i >= 0; i--) { 168 brw += (int)v1[i]-(int)v2[i]; 169 sat |= brw; 170 brw >>= 8; 171 } 172 } 173 brw <<= 8; /* brw is either 0 or -256 */ 174 175 if (sat & 0xff) 176 return brw | 0x80; 177 else 178 return brw + (ret & 0xFF); 179 } 180 181 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 182 int len, int peek); 183 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 184 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 185 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 186 unsigned int *is_next_epoch); 187 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 188 unsigned char *priority); 189 static int dtls1_process_record(SSL *s); 190 191 /* copy buffered record into SSL structure */ 192 static int 193 dtls1_copy_record(SSL *s, pitem *item) 194 { 195 DTLS1_RECORD_DATA *rdata; 196 197 rdata = (DTLS1_RECORD_DATA *)item->data; 198 199 free(s->s3->rbuf.buf); 200 201 s->packet = rdata->packet; 202 s->packet_length = rdata->packet_length; 203 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 204 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 205 206 /* Set proper sequence number for mac calculation */ 207 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 208 209 return (1); 210 } 211 212 213 static int 214 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 215 { 216 DTLS1_RECORD_DATA *rdata; 217 pitem *item; 218 219 /* Limit the size of the queue to prevent DOS attacks */ 220 if (pqueue_size(queue->q) >= 100) 221 return 0; 222 223 rdata = malloc(sizeof(DTLS1_RECORD_DATA)); 224 item = pitem_new(priority, rdata); 225 if (rdata == NULL || item == NULL) 226 goto init_err; 227 228 rdata->packet = s->packet; 229 rdata->packet_length = s->packet_length; 230 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 231 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 232 233 item->data = rdata; 234 235 236 s->packet = NULL; 237 s->packet_length = 0; 238 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 239 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 240 241 if (!ssl3_setup_buffers(s)) 242 goto err; 243 244 /* insert should not fail, since duplicates are dropped */ 245 if (pqueue_insert(queue->q, item) == NULL) 246 goto err; 247 248 return (1); 249 250 err: 251 free(rdata->rbuf.buf); 252 253 init_err: 254 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 255 free(rdata); 256 pitem_free(item); 257 return (-1); 258 } 259 260 261 static int 262 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 263 { 264 pitem *item; 265 266 item = pqueue_pop(queue->q); 267 if (item) { 268 dtls1_copy_record(s, item); 269 270 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)) 290 291 static int 292 dtls1_process_buffered_records(SSL *s) 293 { 294 pitem *item; 295 296 item = pqueue_peek(s->d1->unprocessed_rcds.q); 297 if (item) { 298 /* Check if epoch is current. */ 299 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 300 return (1); 301 /* Nothing to do. */ 302 303 /* Process all the records. */ 304 while (pqueue_peek(s->d1->unprocessed_rcds.q)) { 305 dtls1_get_unprocessed_record(s); 306 if (! dtls1_process_record(s)) 307 return (0); 308 if (dtls1_buffer_record(s, &(s->d1->processed_rcds), 309 s->s3->rrec.seq_num) < 0) 310 return (-1); 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 static int 323 dtls1_process_record(SSL *s) 324 { 325 int i, al; 326 int enc_err; 327 SSL_SESSION *sess; 328 SSL3_RECORD *rr; 329 unsigned int mac_size, orig_len; 330 unsigned char md[EVP_MAX_MD_SIZE]; 331 332 rr = &(s->s3->rrec); 333 sess = s->session; 334 335 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 336 * and we have that many bytes in s->packet 337 */ 338 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]); 339 340 /* ok, we can now read from 's->packet' data into 'rr' 341 * rr->input points at rr->length bytes, which 342 * need to be copied into rr->data by either 343 * the decryption or by the decompression 344 * When the data is 'copied' into the rr->data buffer, 345 * rr->input will be pointed at the new buffer */ 346 347 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 348 * rr->length bytes of encrypted compressed stuff. */ 349 350 /* check is not needed I believe */ 351 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 352 al = SSL_AD_RECORD_OVERFLOW; 353 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 354 goto f_err; 355 } 356 357 /* decrypt in place in 'rr->input' */ 358 rr->data = rr->input; 359 360 enc_err = s->method->ssl3_enc->enc(s, 0); 361 /* enc_err is: 362 * 0: (in non-constant time) if the record is publically invalid. 363 * 1: if the padding is valid 364 * -1: if the padding is invalid */ 365 if (enc_err == 0) { 366 /* For DTLS we simply ignore bad packets. */ 367 rr->length = 0; 368 s->packet_length = 0; 369 goto err; 370 } 371 372 373 /* r->length is now the compressed data plus mac */ 374 if ((sess != NULL) && (s->enc_read_ctx != NULL) && 375 (EVP_MD_CTX_md(s->read_hash) != NULL)) { 376 /* s->read_hash != NULL => mac_size != -1 */ 377 unsigned char *mac = NULL; 378 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 379 mac_size = EVP_MD_CTX_size(s->read_hash); 380 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 381 382 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 383 orig_len = rr->length + ((unsigned int)rr->type >> 8); 384 385 /* orig_len is the length of the record before any padding was 386 * removed. This is public information, as is the MAC in use, 387 * therefore we can safely process the record in a different 388 * amount of time if it's too short to possibly contain a MAC. 389 */ 390 if (orig_len < mac_size || 391 /* CBC records must have a padding length byte too. */ 392 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 393 orig_len < mac_size + 1)) { 394 al = SSL_AD_DECODE_ERROR; 395 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT); 396 goto f_err; 397 } 398 399 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 400 /* We update the length so that the TLS header bytes 401 * can be constructed correctly but we need to extract 402 * the MAC in constant time from within the record, 403 * without leaking the contents of the padding bytes. 404 * */ 405 mac = mac_tmp; 406 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 407 rr->length -= mac_size; 408 } else { 409 /* In this case there's no padding, so |orig_len| 410 * equals |rec->length| and we checked that there's 411 * enough bytes for |mac_size| above. */ 412 rr->length -= mac_size; 413 mac = &rr->data[rr->length]; 414 } 415 416 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */); 417 if (i < 0 || mac == NULL || timingsafe_memcmp(md, mac, (size_t)mac_size) != 0) 418 enc_err = -1; 419 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 420 enc_err = -1; 421 } 422 423 if (enc_err < 0) { 424 /* decryption failed, silently discard message */ 425 rr->length = 0; 426 s->packet_length = 0; 427 goto err; 428 } 429 430 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 431 al = SSL_AD_RECORD_OVERFLOW; 432 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); 433 goto f_err; 434 } 435 436 rr->off = 0; 437 /* So at this point the following is true 438 * ssl->s3->rrec.type is the type of record 439 * ssl->s3->rrec.length == number of bytes in record 440 * ssl->s3->rrec.off == offset to first valid byte 441 * ssl->s3->rrec.data == where to take bytes from, increment 442 * after use :-). 443 */ 444 445 /* we have pulled in a full packet so zero things */ 446 s->packet_length = 0; 447 return (1); 448 449 f_err: 450 ssl3_send_alert(s, SSL3_AL_FATAL, al); 451 err: 452 return (0); 453 } 454 455 456 /* Call this to get a new input record. 457 * It will return <= 0 if more data is needed, normally due to an error 458 * or non-blocking IO. 459 * When it finishes, one packet has been decoded and can be found in 460 * ssl->s3->rrec.type - is the type of record 461 * ssl->s3->rrec.data, - data 462 * ssl->s3->rrec.length, - number of bytes 463 */ 464 /* used only by dtls1_read_bytes */ 465 int 466 dtls1_get_record(SSL *s) 467 { 468 int i, n; 469 SSL3_RECORD *rr; 470 unsigned char *p = NULL; 471 DTLS1_BITMAP *bitmap; 472 unsigned int is_next_epoch; 473 474 rr = &(s->s3->rrec); 475 476 /* The epoch may have changed. If so, process all the 477 * pending records. This is a non-blocking operation. */ 478 if (dtls1_process_buffered_records(s) < 0) 479 return (-1); 480 481 /* if we're renegotiating, then there may be buffered records */ 482 if (dtls1_get_processed_record(s)) 483 return 1; 484 485 /* get something from the wire */ 486 if (0) { 487 again: 488 /* dump this record on all retries */ 489 rr->length = 0; 490 s->packet_length = 0; 491 } 492 493 /* check if we have the header */ 494 if ((s->rstate != SSL_ST_READ_BODY) || 495 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { 496 CBS header, seq_no; 497 uint16_t epoch, len, ssl_version; 498 uint8_t type; 499 500 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 501 /* read timeout is handled by dtls1_read_bytes */ 502 if (n <= 0) 503 return(n); /* error or non-blocking */ 504 505 /* this packet contained a partial record, dump it */ 506 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 507 goto again; 508 509 s->rstate = SSL_ST_READ_BODY; 510 511 CBS_init(&header, s->packet, s->packet_length); 512 513 /* Pull apart the header into the DTLS1_RECORD */ 514 if (!CBS_get_u8(&header, &type)) 515 goto again; 516 if (!CBS_get_u16(&header, &ssl_version)) 517 goto again; 518 519 /* sequence number is 64 bits, with top 2 bytes = epoch */ 520 if (!CBS_get_u16(&header, &epoch) || 521 !CBS_get_bytes(&header, &seq_no, 6)) 522 goto again; 523 524 if (!CBS_write_bytes(&seq_no, &(s->s3->read_sequence[2]), 525 sizeof(s->s3->read_sequence) - 2, NULL)) 526 goto again; 527 if (!CBS_get_u16(&header, &len)) 528 goto again; 529 530 rr->type = type; 531 rr->epoch = epoch; 532 rr->length = len; 533 534 /* unexpected version, silently discard */ 535 if (!s->first_packet && ssl_version != s->version) 536 goto again; 537 538 /* wrong version, silently discard record */ 539 if ((ssl_version & 0xff00) != (s->version & 0xff00)) 540 goto again; 541 542 /* record too long, silently discard it */ 543 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 544 goto again; 545 546 /* now s->rstate == SSL_ST_READ_BODY */ 547 p = (unsigned char *)CBS_data(&header); 548 } 549 550 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 551 552 if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) { 553 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 554 i = rr->length; 555 n = ssl3_read_n(s, i, i, 1); 556 if (n <= 0) 557 return(n); /* error or non-blocking io */ 558 559 /* this packet contained a partial record, dump it */ 560 if (n != i) 561 goto again; 562 563 /* now n == rr->length, 564 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 565 } 566 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 567 568 /* match epochs. NULL means the packet is dropped on the floor */ 569 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 570 if (bitmap == NULL) 571 goto again; 572 573 /* 574 * Check whether this is a repeat, or aged record. 575 * Don't check if we're listening and this message is 576 * a ClientHello. They can look as if they're replayed, 577 * since they arrive from different connections and 578 * would be dropped unnecessarily. 579 */ 580 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 581 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 582 !dtls1_record_replay_check(s, bitmap)) 583 goto again; 584 585 /* just read a 0 length packet */ 586 if (rr->length == 0) 587 goto again; 588 589 /* If this record is from the next epoch (either HM or ALERT), 590 * and a handshake is currently in progress, buffer it since it 591 * cannot be processed at this time. However, do not buffer 592 * anything while listening. 593 */ 594 if (is_next_epoch) { 595 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) { 596 if (dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), 597 rr->seq_num) < 0) 598 return (-1); 599 /* Mark receipt of record. */ 600 dtls1_record_bitmap_update(s, bitmap); 601 } 602 goto again; 603 } 604 605 if (!dtls1_process_record(s)) 606 goto again; 607 608 /* Mark receipt of record. */ 609 dtls1_record_bitmap_update(s, bitmap); 610 611 return (1); 612 } 613 614 /* Return up to 'len' payload bytes received in 'type' records. 615 * 'type' is one of the following: 616 * 617 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 618 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 619 * - 0 (during a shutdown, no data has to be returned) 620 * 621 * If we don't have stored data to work from, read a SSL/TLS record first 622 * (possibly multiple records if we still don't have anything to return). 623 * 624 * This function must handle any surprises the peer may have for us, such as 625 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 626 * a surprise, but handled as if it were), or renegotiation requests. 627 * Also if record payloads contain fragments too small to process, we store 628 * them until there is enough for the respective protocol (the record protocol 629 * may use arbitrary fragmentation and even interleaving): 630 * Change cipher spec protocol 631 * just 1 byte needed, no need for keeping anything stored 632 * Alert protocol 633 * 2 bytes needed (AlertLevel, AlertDescription) 634 * Handshake protocol 635 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 636 * to detect unexpected Client Hello and Hello Request messages 637 * here, anything else is handled by higher layers 638 * Application data protocol 639 * none of our business 640 */ 641 int 642 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 643 { 644 int al, i, j, ret; 645 unsigned int n; 646 SSL3_RECORD *rr; 647 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 648 649 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 650 if (!ssl3_setup_buffers(s)) 651 return (-1); 652 653 if ((type && 654 type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || 655 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 656 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 657 return -1; 658 } 659 660 /* check whether there's a handshake message (client hello?) waiting */ 661 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 662 return ret; 663 664 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 665 666 if (!s->in_handshake && SSL_in_init(s)) 667 { 668 /* type == SSL3_RT_APPLICATION_DATA */ 669 i = s->handshake_func(s); 670 if (i < 0) 671 return (i); 672 if (i == 0) { 673 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 674 return (-1); 675 } 676 } 677 678 start: 679 s->rwstate = SSL_NOTHING; 680 681 /* s->s3->rrec.type - is the type of record 682 * s->s3->rrec.data, - data 683 * s->s3->rrec.off, - offset into 'data' for next read 684 * s->s3->rrec.length, - number of bytes. */ 685 rr = &(s->s3->rrec); 686 687 /* We are not handshaking and have no data yet, 688 * so process data buffered during the last handshake 689 * in advance, if any. 690 */ 691 if (s->state == SSL_ST_OK && rr->length == 0) { 692 pitem *item; 693 item = pqueue_pop(s->d1->buffered_app_data.q); 694 if (item) { 695 696 dtls1_copy_record(s, item); 697 698 free(item->data); 699 pitem_free(item); 700 } 701 } 702 703 /* Check for timeout */ 704 if (dtls1_handle_timeout(s) > 0) 705 goto start; 706 707 /* get new packet if necessary */ 708 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) { 709 ret = dtls1_get_record(s); 710 if (ret <= 0) { 711 ret = dtls1_read_failed(s, ret); 712 /* anything other than a timeout is an error */ 713 if (ret <= 0) 714 return (ret); 715 else 716 goto start; 717 } 718 } 719 720 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) { 721 rr->length = 0; 722 goto start; 723 } 724 725 /* we now have a packet which can be read and processed */ 726 727 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 728 * reset by ssl3_get_finished */ 729 && (rr->type != SSL3_RT_HANDSHAKE)) { 730 /* We now have application data between CCS and Finished. 731 * Most likely the packets were reordered on their way, so 732 * buffer the application data for later processing rather 733 * than dropping the connection. 734 */ 735 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), 736 rr->seq_num) < 0) { 737 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 738 return (-1); 739 } 740 rr->length = 0; 741 goto start; 742 } 743 744 /* If the other end has shut down, throw anything we read away 745 * (even in 'peek' mode) */ 746 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 747 rr->length = 0; 748 s->rwstate = SSL_NOTHING; 749 return (0); 750 } 751 752 753 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 754 { 755 /* make sure that we are not getting application data when we 756 * are doing a handshake for the first time */ 757 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 758 (s->enc_read_ctx == NULL)) { 759 al = SSL_AD_UNEXPECTED_MESSAGE; 760 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE); 761 goto f_err; 762 } 763 764 if (len <= 0) 765 return (len); 766 767 if ((unsigned int)len > rr->length) 768 n = rr->length; 769 else 770 n = (unsigned int)len; 771 772 memcpy(buf, &(rr->data[rr->off]), n); 773 if (!peek) { 774 rr->length -= n; 775 rr->off += n; 776 if (rr->length == 0) { 777 s->rstate = SSL_ST_READ_HEADER; 778 rr->off = 0; 779 } 780 } 781 782 return (n); 783 } 784 785 786 /* If we get here, then type != rr->type; if we have a handshake 787 * message, then it was unexpected (Hello Request or Client Hello). */ 788 789 /* In case of record types for which we have 'fragment' storage, 790 * fill that so that we can process the data at a fixed place. 791 */ 792 { 793 unsigned int k, dest_maxlen = 0; 794 unsigned char *dest = NULL; 795 unsigned int *dest_len = NULL; 796 797 if (rr->type == SSL3_RT_HANDSHAKE) { 798 dest_maxlen = sizeof s->d1->handshake_fragment; 799 dest = s->d1->handshake_fragment; 800 dest_len = &s->d1->handshake_fragment_len; 801 } else if (rr->type == SSL3_RT_ALERT) { 802 dest_maxlen = sizeof(s->d1->alert_fragment); 803 dest = s->d1->alert_fragment; 804 dest_len = &s->d1->alert_fragment_len; 805 } 806 /* else it's a CCS message, or application data or wrong */ 807 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 808 /* Application data while renegotiating 809 * is allowed. Try again reading. 810 */ 811 if (rr->type == SSL3_RT_APPLICATION_DATA) { 812 BIO *bio; 813 s->s3->in_read_app_data = 2; 814 bio = SSL_get_rbio(s); 815 s->rwstate = SSL_READING; 816 BIO_clear_retry_flags(bio); 817 BIO_set_retry_read(bio); 818 return (-1); 819 } 820 821 /* Not certain if this is the right error handling */ 822 al = SSL_AD_UNEXPECTED_MESSAGE; 823 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 824 goto f_err; 825 } 826 827 if (dest_maxlen > 0) { 828 /* XDTLS: In a pathalogical case, the Client Hello 829 * may be fragmented--don't always expect dest_maxlen bytes */ 830 if (rr->length < dest_maxlen) { 831 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 832 /* 833 * for normal alerts rr->length is 2, while 834 * dest_maxlen is 7 if we were to handle this 835 * non-existing alert... 836 */ 837 FIX ME 838 #endif 839 s->rstate = SSL_ST_READ_HEADER; 840 rr->length = 0; 841 goto start; 842 } 843 844 /* now move 'n' bytes: */ 845 for ( k = 0; k < dest_maxlen; k++) { 846 dest[k] = rr->data[rr->off++]; 847 rr->length--; 848 } 849 *dest_len = dest_maxlen; 850 } 851 } 852 853 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 854 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 855 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 856 857 /* If we are a client, check for an incoming 'Hello Request': */ 858 if ((!s->server) && 859 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 860 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 861 (s->session != NULL) && (s->session->cipher != NULL)) { 862 s->d1->handshake_fragment_len = 0; 863 864 if ((s->d1->handshake_fragment[1] != 0) || 865 (s->d1->handshake_fragment[2] != 0) || 866 (s->d1->handshake_fragment[3] != 0)) { 867 al = SSL_AD_DECODE_ERROR; 868 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST); 869 goto err; 870 } 871 872 /* no need to check sequence number on HELLO REQUEST messages */ 873 874 if (s->msg_callback) 875 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 876 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 877 878 if (SSL_is_init_finished(s) && 879 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 880 !s->s3->renegotiate) { 881 s->d1->handshake_read_seq++; 882 s->new_session = 1; 883 ssl3_renegotiate(s); 884 if (ssl3_renegotiate_check(s)) { 885 i = s->handshake_func(s); 886 if (i < 0) 887 return (i); 888 if (i == 0) { 889 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 890 return (-1); 891 } 892 893 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 894 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 895 { 896 BIO *bio; 897 /* In the case where we try to read application data, 898 * but we trigger an SSL handshake, we return -1 with 899 * the retry option set. Otherwise renegotiation may 900 * cause nasty problems in the blocking world */ 901 s->rwstate = SSL_READING; 902 bio = SSL_get_rbio(s); 903 BIO_clear_retry_flags(bio); 904 BIO_set_retry_read(bio); 905 return (-1); 906 } 907 } 908 } 909 } 910 /* we either finished a handshake or ignored the request, 911 * now try again to obtain the (application) data we were asked for */ 912 goto start; 913 } 914 915 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 916 int alert_level = s->d1->alert_fragment[0]; 917 int alert_descr = s->d1->alert_fragment[1]; 918 919 s->d1->alert_fragment_len = 0; 920 921 if (s->msg_callback) 922 s->msg_callback(0, s->version, SSL3_RT_ALERT, 923 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 924 925 if (s->info_callback != NULL) 926 cb = s->info_callback; 927 else if (s->ctx->info_callback != NULL) 928 cb = s->ctx->info_callback; 929 930 if (cb != NULL) { 931 j = (alert_level << 8) | alert_descr; 932 cb(s, SSL_CB_READ_ALERT, j); 933 } 934 935 if (alert_level == 1) /* warning */ 936 { 937 s->s3->warn_alert = alert_descr; 938 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 939 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 940 return (0); 941 } 942 } else if (alert_level == 2) /* fatal */ 943 { 944 s->rwstate = SSL_NOTHING; 945 s->s3->fatal_alert = alert_descr; 946 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 947 ERR_asprintf_error_data("SSL alert number %d", 948 alert_descr); 949 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 950 SSL_CTX_remove_session(s->ctx, s->session); 951 return (0); 952 } else { 953 al = SSL_AD_ILLEGAL_PARAMETER; 954 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE); 955 goto f_err; 956 } 957 958 goto start; 959 } 960 961 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 962 { 963 s->rwstate = SSL_NOTHING; 964 rr->length = 0; 965 return (0); 966 } 967 968 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 969 struct ccs_header_st ccs_hdr; 970 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 971 972 dtls1_get_ccs_header(rr->data, &ccs_hdr); 973 974 /* 'Change Cipher Spec' is just a single byte, so we know 975 * exactly what the record payload has to look like */ 976 /* XDTLS: check that epoch is consistent */ 977 if ((rr->length != ccs_hdr_len) || 978 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 979 i = SSL_AD_ILLEGAL_PARAMETER; 980 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC); 981 goto err; 982 } 983 984 rr->length = 0; 985 986 if (s->msg_callback) 987 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 988 rr->data, 1, s, s->msg_callback_arg); 989 990 /* We can't process a CCS now, because previous handshake 991 * messages are still missing, so just drop it. 992 */ 993 if (!s->d1->change_cipher_spec_ok) { 994 goto start; 995 } 996 997 s->d1->change_cipher_spec_ok = 0; 998 999 s->s3->change_cipher_spec = 1; 1000 if (!ssl3_do_change_cipher_spec(s)) 1001 goto err; 1002 1003 /* do this whenever CCS is processed */ 1004 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1005 1006 goto start; 1007 } 1008 1009 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1010 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1011 !s->in_handshake) { 1012 struct hm_header_st msg_hdr; 1013 1014 /* this may just be a stale retransmit */ 1015 if (!dtls1_get_message_header(rr->data, &msg_hdr)) 1016 return -1; 1017 if (rr->epoch != s->d1->r_epoch) { 1018 rr->length = 0; 1019 goto start; 1020 } 1021 1022 /* If we are server, we may have a repeated FINISHED of the 1023 * client here, then retransmit our CCS and FINISHED. 1024 */ 1025 if (msg_hdr.type == SSL3_MT_FINISHED) { 1026 if (dtls1_check_timeout_num(s) < 0) 1027 return -1; 1028 1029 dtls1_retransmit_buffered_messages(s); 1030 rr->length = 0; 1031 goto start; 1032 } 1033 1034 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1035 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1036 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1037 s->renegotiate = 1; 1038 s->new_session = 1; 1039 } 1040 i = s->handshake_func(s); 1041 if (i < 0) 1042 return (i); 1043 if (i == 0) { 1044 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1045 return (-1); 1046 } 1047 1048 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1049 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1050 { 1051 BIO *bio; 1052 /* In the case where we try to read application data, 1053 * but we trigger an SSL handshake, we return -1 with 1054 * the retry option set. Otherwise renegotiation may 1055 * cause nasty problems in the blocking world */ 1056 s->rwstate = SSL_READING; 1057 bio = SSL_get_rbio(s); 1058 BIO_clear_retry_flags(bio); 1059 BIO_set_retry_read(bio); 1060 return (-1); 1061 } 1062 } 1063 goto start; 1064 } 1065 1066 switch (rr->type) { 1067 default: 1068 /* TLS just ignores unknown message types */ 1069 if (s->version == TLS1_VERSION) { 1070 rr->length = 0; 1071 goto start; 1072 } 1073 al = SSL_AD_UNEXPECTED_MESSAGE; 1074 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1075 goto f_err; 1076 case SSL3_RT_CHANGE_CIPHER_SPEC: 1077 case SSL3_RT_ALERT: 1078 case SSL3_RT_HANDSHAKE: 1079 /* we already handled all of these, with the possible exception 1080 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1081 * should not happen when type != rr->type */ 1082 al = SSL_AD_UNEXPECTED_MESSAGE; 1083 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 1084 goto f_err; 1085 case SSL3_RT_APPLICATION_DATA: 1086 /* At this point, we were expecting handshake data, 1087 * but have application data. If the library was 1088 * running inside ssl3_read() (i.e. in_read_app_data 1089 * is set) and it makes sense to read application data 1090 * at this point (session renegotiation not yet started), 1091 * we will indulge it. 1092 */ 1093 if (s->s3->in_read_app_data && 1094 (s->s3->total_renegotiations != 0) && 1095 (((s->state & SSL_ST_CONNECT) && 1096 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1097 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 1098 (s->state & SSL_ST_ACCEPT) && 1099 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1100 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1101 s->s3->in_read_app_data = 2; 1102 return (-1); 1103 } else { 1104 al = SSL_AD_UNEXPECTED_MESSAGE; 1105 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1106 goto f_err; 1107 } 1108 } 1109 /* not reached */ 1110 1111 f_err: 1112 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1113 err: 1114 return (-1); 1115 } 1116 1117 int 1118 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1119 { 1120 int i; 1121 1122 if (SSL_in_init(s) && !s->in_handshake) 1123 { 1124 i = s->handshake_func(s); 1125 if (i < 0) 1126 return (i); 1127 if (i == 0) { 1128 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1129 return -1; 1130 } 1131 } 1132 1133 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 1134 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG); 1135 return -1; 1136 } 1137 1138 i = dtls1_write_bytes(s, type, buf_, len); 1139 return i; 1140 } 1141 1142 1143 /* this only happens when a client hello is received and a handshake 1144 * is started. */ 1145 static int 1146 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1147 int len, int peek) 1148 { 1149 1150 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1151 /* (partially) satisfy request from storage */ 1152 { 1153 unsigned char *src = s->d1->handshake_fragment; 1154 unsigned char *dst = buf; 1155 unsigned int k, n; 1156 1157 /* peek == 0 */ 1158 n = 0; 1159 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) { 1160 *dst++ = *src++; 1161 len--; 1162 s->d1->handshake_fragment_len--; 1163 n++; 1164 } 1165 /* move any remaining fragment bytes: */ 1166 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1167 s->d1->handshake_fragment[k] = *src++; 1168 return n; 1169 } 1170 1171 return 0; 1172 } 1173 1174 1175 /* Call this to write data in records of type 'type' 1176 * It will return <= 0 if not all data has been sent or non-blocking IO. 1177 */ 1178 int 1179 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1180 { 1181 int i; 1182 1183 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1184 s->rwstate = SSL_NOTHING; 1185 i = do_dtls1_write(s, type, buf, len); 1186 return i; 1187 } 1188 1189 int 1190 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 1191 { 1192 unsigned char *p, *pseq; 1193 int i, mac_size, clear = 0; 1194 int prefix_len = 0; 1195 SSL3_RECORD *wr; 1196 SSL3_BUFFER *wb; 1197 SSL_SESSION *sess; 1198 int bs; 1199 1200 /* first check if there is a SSL3_BUFFER still being written 1201 * out. This will happen with non blocking IO */ 1202 if (s->s3->wbuf.left != 0) { 1203 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1204 return (ssl3_write_pending(s, type, buf, len)); 1205 } 1206 1207 /* If we have an alert to send, lets send it */ 1208 if (s->s3->alert_dispatch) { 1209 i = s->method->ssl_dispatch_alert(s); 1210 if (i <= 0) 1211 return (i); 1212 /* if it went, fall through and send more stuff */ 1213 } 1214 1215 if (len == 0) 1216 return 0; 1217 1218 wr = &(s->s3->wrec); 1219 wb = &(s->s3->wbuf); 1220 sess = s->session; 1221 1222 if ((sess == NULL) || (s->enc_write_ctx == NULL) || 1223 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1224 clear = 1; 1225 1226 if (clear) 1227 mac_size = 0; 1228 else { 1229 mac_size = EVP_MD_CTX_size(s->write_hash); 1230 if (mac_size < 0) 1231 goto err; 1232 } 1233 1234 /* DTLS implements explicit IV, so no need for empty fragments. */ 1235 1236 p = wb->buf + prefix_len; 1237 1238 /* write the header */ 1239 1240 *(p++) = type&0xff; 1241 wr->type = type; 1242 1243 *(p++) = (s->version >> 8); 1244 *(p++) = s->version&0xff; 1245 1246 /* field where we are to write out packet epoch, seq num and len */ 1247 pseq = p; 1248 1249 p += 10; 1250 1251 /* lets setup the record stuff. */ 1252 1253 /* Make space for the explicit IV in case of CBC. 1254 * (this is a bit of a boundary violation, but what the heck). 1255 */ 1256 if (s->enc_write_ctx && 1257 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1258 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1259 else 1260 bs = 0; 1261 1262 wr->data = p + bs; 1263 /* make room for IV in case of CBC */ 1264 wr->length = (int)len; 1265 wr->input = (unsigned char *)buf; 1266 1267 /* we now 'read' from wr->input, wr->length bytes into 1268 * wr->data */ 1269 1270 memcpy(wr->data, wr->input, wr->length); 1271 wr->input = wr->data; 1272 1273 /* we should still have the output to wr->data and the input 1274 * from wr->input. Length should be wr->length. 1275 * wr->data still points in the wb->buf */ 1276 1277 if (mac_size != 0) { 1278 if (s->method->ssl3_enc->mac(s, &(p[wr->length + bs]), 1) < 0) 1279 goto err; 1280 wr->length += mac_size; 1281 } 1282 1283 /* this is true regardless of mac size */ 1284 wr->input = p; 1285 wr->data = p; 1286 1287 1288 /* ssl3_enc can only have an error on read */ 1289 if (bs) /* bs != 0 in case of CBC */ 1290 { 1291 arc4random_buf(p, bs); 1292 /* master IV and last CBC residue stand for 1293 * the rest of randomness */ 1294 wr->length += bs; 1295 } 1296 1297 s->method->ssl3_enc->enc(s, 1); 1298 1299 /* record length after mac and block padding */ 1300 /* if (type == SSL3_RT_APPLICATION_DATA || 1301 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1302 1303 /* there's only one epoch between handshake and app data */ 1304 1305 s2n(s->d1->w_epoch, pseq); 1306 1307 /* XDTLS: ?? */ 1308 /* else 1309 s2n(s->d1->handshake_epoch, pseq); 1310 */ 1311 1312 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1313 pseq += 6; 1314 s2n(wr->length, pseq); 1315 1316 /* we should now have 1317 * wr->data pointing to the encrypted data, which is 1318 * wr->length long */ 1319 wr->type=type; /* not needed but helps for debugging */ 1320 wr->length += DTLS1_RT_HEADER_LENGTH; 1321 1322 tls1_record_sequence_increment(s->s3->write_sequence); 1323 1324 /* now let's set up wb */ 1325 wb->left = prefix_len + wr->length; 1326 wb->offset = 0; 1327 1328 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1329 s->s3->wpend_tot = len; 1330 s->s3->wpend_buf = buf; 1331 s->s3->wpend_type = type; 1332 s->s3->wpend_ret = len; 1333 1334 /* we now just need to write the buffer */ 1335 return ssl3_write_pending(s, type, buf, len); 1336 err: 1337 return -1; 1338 } 1339 1340 1341 1342 static int 1343 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1344 { 1345 int cmp; 1346 unsigned int shift; 1347 const unsigned char *seq = s->s3->read_sequence; 1348 1349 cmp = satsub64be(seq, bitmap->max_seq_num); 1350 if (cmp > 0) { 1351 memcpy (s->s3->rrec.seq_num, seq, 8); 1352 return 1; /* this record in new */ 1353 } 1354 shift = -cmp; 1355 if (shift >= sizeof(bitmap->map)*8) 1356 return 0; /* stale, outside the window */ 1357 else if (bitmap->map & (1UL << shift)) 1358 return 0; /* record previously received */ 1359 1360 memcpy(s->s3->rrec.seq_num, seq, 8); 1361 return 1; 1362 } 1363 1364 1365 static void 1366 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1367 { 1368 int cmp; 1369 unsigned int shift; 1370 const unsigned char *seq = s->s3->read_sequence; 1371 1372 cmp = satsub64be(seq, bitmap->max_seq_num); 1373 if (cmp > 0) { 1374 shift = cmp; 1375 if (shift < sizeof(bitmap->map)*8) 1376 bitmap->map <<= shift, bitmap->map |= 1UL; 1377 else 1378 bitmap->map = 1UL; 1379 memcpy(bitmap->max_seq_num, seq, 8); 1380 } else { 1381 shift = -cmp; 1382 if (shift < sizeof(bitmap->map) * 8) 1383 bitmap->map |= 1UL << shift; 1384 } 1385 } 1386 1387 1388 int 1389 dtls1_dispatch_alert(SSL *s) 1390 { 1391 int i, j; 1392 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1393 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1394 unsigned char *ptr = &buf[0]; 1395 1396 s->s3->alert_dispatch = 0; 1397 1398 memset(buf, 0x00, sizeof(buf)); 1399 *ptr++ = s->s3->send_alert[0]; 1400 *ptr++ = s->s3->send_alert[1]; 1401 1402 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1403 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1404 s2n(s->d1->handshake_read_seq, ptr); 1405 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1406 } 1407 #endif 1408 1409 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf)); 1410 if (i <= 0) { 1411 s->s3->alert_dispatch = 1; 1412 /* fprintf( stderr, "not done with alert\n" ); */ 1413 } else { 1414 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1415 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1416 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1417 #endif 1418 ) 1419 (void)BIO_flush(s->wbio); 1420 1421 if (s->msg_callback) 1422 s->msg_callback(1, s->version, SSL3_RT_ALERT, 1423 s->s3->send_alert, 2, s, s->msg_callback_arg); 1424 1425 if (s->info_callback != NULL) 1426 cb = s->info_callback; 1427 else if (s->ctx->info_callback != NULL) 1428 cb = s->ctx->info_callback; 1429 1430 if (cb != NULL) { 1431 j = (s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1432 cb(s, SSL_CB_WRITE_ALERT, j); 1433 } 1434 } 1435 return (i); 1436 } 1437 1438 1439 static DTLS1_BITMAP * 1440 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1441 { 1442 1443 *is_next_epoch = 0; 1444 1445 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1446 if (rr->epoch == s->d1->r_epoch) 1447 return &s->d1->bitmap; 1448 1449 /* Only HM and ALERT messages can be from the next epoch */ 1450 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1451 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1452 *is_next_epoch = 1; 1453 return &s->d1->next_bitmap; 1454 } 1455 1456 return NULL; 1457 } 1458 1459 void 1460 dtls1_reset_seq_numbers(SSL *s, int rw) 1461 { 1462 unsigned char *seq; 1463 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1464 1465 if (rw & SSL3_CC_READ) { 1466 seq = s->s3->read_sequence; 1467 s->d1->r_epoch++; 1468 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1469 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1470 } else { 1471 seq = s->s3->write_sequence; 1472 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1473 s->d1->w_epoch++; 1474 } 1475 1476 memset(seq, 0x00, seq_bytes); 1477 } 1478