1 /* $OpenBSD: d1_pkt.c,v 1.37 2014/11/16 14:12:47 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" 127 128 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 129 static int 130 satsub64be(const unsigned char *v1, const unsigned char *v2) 131 { 132 int ret, sat, brw, i; 133 134 if (sizeof(long) == 8) 135 do { 136 long l; 137 138 if (BYTE_ORDER == LITTLE_ENDIAN) 139 break; 140 /* not reached on little-endians */ 141 /* following test is redundant, because input is 142 * always aligned, but I take no chances... */ 143 if (((size_t)v1 | (size_t)v2) & 0x7) 144 break; 145 146 l = *((long *)v1); 147 l -= *((long *)v2); 148 if (l > 128) 149 return 128; 150 else if (l<-128) 151 return -128; 152 else 153 return (int)l; 154 } while (0); 155 156 ret = (int)v1[7] - (int)v2[7]; 157 sat = 0; 158 brw = ret >> 8; /* brw is either 0 or -1 */ 159 if (ret & 0x80) { 160 for (i = 6; i >= 0; i--) { 161 brw += (int)v1[i]-(int)v2[i]; 162 sat |= ~brw; 163 brw >>= 8; 164 } 165 } else { 166 for (i = 6; i >= 0; i--) { 167 brw += (int)v1[i]-(int)v2[i]; 168 sat |= brw; 169 brw >>= 8; 170 } 171 } 172 brw <<= 8; /* brw is either 0 or -256 */ 173 174 if (sat & 0xff) 175 return brw | 0x80; 176 else 177 return brw + (ret & 0xFF); 178 } 179 180 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 181 int len, int peek); 182 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 183 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 184 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 185 unsigned int *is_next_epoch); 186 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 187 unsigned char *priority); 188 static int dtls1_process_record(SSL *s); 189 190 /* copy buffered record into SSL structure */ 191 static int 192 dtls1_copy_record(SSL *s, pitem *item) 193 { 194 DTLS1_RECORD_DATA *rdata; 195 196 rdata = (DTLS1_RECORD_DATA *)item->data; 197 198 free(s->s3->rbuf.buf); 199 200 s->packet = rdata->packet; 201 s->packet_length = rdata->packet_length; 202 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 203 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 204 205 /* Set proper sequence number for mac calculation */ 206 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 207 208 return (1); 209 } 210 211 212 static int 213 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 214 { 215 DTLS1_RECORD_DATA *rdata; 216 pitem *item; 217 218 /* Limit the size of the queue to prevent DOS attacks */ 219 if (pqueue_size(queue->q) >= 100) 220 return 0; 221 222 rdata = malloc(sizeof(DTLS1_RECORD_DATA)); 223 item = pitem_new(priority, rdata); 224 if (rdata == NULL || item == NULL) 225 goto err; 226 227 rdata->packet = s->packet; 228 rdata->packet_length = s->packet_length; 229 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 230 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 231 232 item->data = rdata; 233 234 #ifndef OPENSSL_NO_SCTP 235 /* Store bio_dgram_sctp_rcvinfo struct */ 236 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 237 (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) { 238 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 239 } 240 #endif 241 242 s->packet = NULL; 243 s->packet_length = 0; 244 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 245 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 246 247 if (!ssl3_setup_buffers(s)) 248 goto err; 249 250 /* insert should not fail, since duplicates are dropped */ 251 if (pqueue_insert(queue->q, item) == NULL) 252 goto err; 253 254 return (1); 255 256 err: 257 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 258 free(rdata); 259 pitem_free(item); 260 return (0); 261 } 262 263 264 static int 265 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 266 { 267 pitem *item; 268 269 item = pqueue_pop(queue->q); 270 if (item) { 271 dtls1_copy_record(s, item); 272 273 free(item->data); 274 pitem_free(item); 275 276 return (1); 277 } 278 279 return (0); 280 } 281 282 283 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 284 * yet */ 285 #define dtls1_get_unprocessed_record(s) \ 286 dtls1_retrieve_buffered_record((s), \ 287 &((s)->d1->unprocessed_rcds)) 288 289 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 290 #define dtls1_get_processed_record(s) \ 291 dtls1_retrieve_buffered_record((s), \ 292 &((s)->d1->processed_rcds)) 293 294 static int 295 dtls1_process_buffered_records(SSL *s) 296 { 297 pitem *item; 298 299 item = pqueue_peek(s->d1->unprocessed_rcds.q); 300 if (item) { 301 /* Check if epoch is current. */ 302 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 303 return (1); 304 /* Nothing to do. */ 305 306 /* Process all the records. */ 307 while (pqueue_peek(s->d1->unprocessed_rcds.q)) { 308 dtls1_get_unprocessed_record(s); 309 if (! dtls1_process_record(s)) 310 return (0); 311 dtls1_buffer_record(s, &(s->d1->processed_rcds), 312 s->s3->rrec.seq_num); 313 } 314 } 315 316 /* sync epoch numbers once all the unprocessed records 317 * have been processed */ 318 s->d1->processed_rcds.epoch = s->d1->r_epoch; 319 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 320 321 return (1); 322 } 323 324 static int 325 dtls1_process_record(SSL *s) 326 { 327 int i, al; 328 int enc_err; 329 SSL_SESSION *sess; 330 SSL3_RECORD *rr; 331 unsigned int mac_size, orig_len; 332 unsigned char md[EVP_MAX_MD_SIZE]; 333 334 rr = &(s->s3->rrec); 335 sess = s->session; 336 337 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 338 * and we have that many bytes in s->packet 339 */ 340 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]); 341 342 /* ok, we can now read from 's->packet' data into 'rr' 343 * rr->input points at rr->length bytes, which 344 * need to be copied into rr->data by either 345 * the decryption or by the decompression 346 * When the data is 'copied' into the rr->data buffer, 347 * rr->input will be pointed at the new buffer */ 348 349 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 350 * rr->length bytes of encrypted compressed stuff. */ 351 352 /* check is not needed I believe */ 353 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 354 al = SSL_AD_RECORD_OVERFLOW; 355 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 356 goto f_err; 357 } 358 359 /* decrypt in place in 'rr->input' */ 360 rr->data = rr->input; 361 362 enc_err = s->method->ssl3_enc->enc(s, 0); 363 /* enc_err is: 364 * 0: (in non-constant time) if the record is publically invalid. 365 * 1: if the padding is valid 366 * -1: if the padding is invalid */ 367 if (enc_err == 0) { 368 /* For DTLS we simply ignore bad packets. */ 369 rr->length = 0; 370 s->packet_length = 0; 371 goto err; 372 } 373 374 375 /* r->length is now the compressed data plus mac */ 376 if ((sess != NULL) && (s->enc_read_ctx != NULL) && 377 (EVP_MD_CTX_md(s->read_hash) != NULL)) { 378 /* s->read_hash != NULL => mac_size != -1 */ 379 unsigned char *mac = NULL; 380 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 381 mac_size = EVP_MD_CTX_size(s->read_hash); 382 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 383 384 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 385 orig_len = rr->length + ((unsigned int)rr->type >> 8); 386 387 /* orig_len is the length of the record before any padding was 388 * removed. This is public information, as is the MAC in use, 389 * therefore we can safely process the record in a different 390 * amount of time if it's too short to possibly contain a MAC. 391 */ 392 if (orig_len < mac_size || 393 /* CBC records must have a padding length byte too. */ 394 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 395 orig_len < mac_size + 1)) { 396 al = SSL_AD_DECODE_ERROR; 397 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT); 398 goto f_err; 399 } 400 401 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 402 /* We update the length so that the TLS header bytes 403 * can be constructed correctly but we need to extract 404 * the MAC in constant time from within the record, 405 * without leaking the contents of the padding bytes. 406 * */ 407 mac = mac_tmp; 408 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 409 rr->length -= mac_size; 410 } else { 411 /* In this case there's no padding, so |orig_len| 412 * equals |rec->length| and we checked that there's 413 * enough bytes for |mac_size| above. */ 414 rr->length -= mac_size; 415 mac = &rr->data[rr->length]; 416 } 417 418 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */); 419 if (i < 0 || mac == NULL || timingsafe_memcmp(md, mac, (size_t)mac_size) != 0) 420 enc_err = -1; 421 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 422 enc_err = -1; 423 } 424 425 if (enc_err < 0) { 426 /* decryption failed, silently discard message */ 427 rr->length = 0; 428 s->packet_length = 0; 429 goto err; 430 } 431 432 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 433 al = SSL_AD_RECORD_OVERFLOW; 434 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); 435 goto f_err; 436 } 437 438 rr->off = 0; 439 /* So at this point the following is true 440 * ssl->s3->rrec.type is the type of record 441 * ssl->s3->rrec.length == number of bytes in record 442 * ssl->s3->rrec.off == offset to first valid byte 443 * ssl->s3->rrec.data == where to take bytes from, increment 444 * after use :-). 445 */ 446 447 /* we have pulled in a full packet so zero things */ 448 s->packet_length = 0; 449 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 450 return (1); 451 452 f_err: 453 ssl3_send_alert(s, SSL3_AL_FATAL, al); 454 err: 455 return (0); 456 } 457 458 459 /* Call this to get a new input record. 460 * It will return <= 0 if more data is needed, normally due to an error 461 * or non-blocking IO. 462 * When it finishes, one packet has been decoded and can be found in 463 * ssl->s3->rrec.type - is the type of record 464 * ssl->s3->rrec.data, - data 465 * ssl->s3->rrec.length, - number of bytes 466 */ 467 /* used only by dtls1_read_bytes */ 468 int 469 dtls1_get_record(SSL *s) 470 { 471 int ssl_major, ssl_minor; 472 int i, n; 473 SSL3_RECORD *rr; 474 unsigned char *p = NULL; 475 unsigned short version; 476 DTLS1_BITMAP *bitmap; 477 unsigned int is_next_epoch; 478 479 rr = &(s->s3->rrec); 480 481 /* The epoch may have changed. If so, process all the 482 * pending records. This is a non-blocking operation. */ 483 dtls1_process_buffered_records(s); 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 again: 491 /* check if we have the header */ 492 if ((s->rstate != SSL_ST_READ_BODY) || 493 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { 494 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 495 /* read timeout is handled by dtls1_read_bytes */ 496 if (n <= 0) 497 return(n); /* error or non-blocking */ 498 499 /* this packet contained a partial record, dump it */ 500 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) { 501 s->packet_length = 0; 502 goto again; 503 } 504 505 s->rstate = SSL_ST_READ_BODY; 506 507 p = s->packet; 508 509 /* Pull apart the header into the DTLS1_RECORD */ 510 rr->type= *(p++); 511 ssl_major= *(p++); 512 ssl_minor= *(p++); 513 version = (ssl_major << 8)|ssl_minor; 514 515 /* sequence number is 64 bits, with top 2 bytes = epoch */ 516 n2s(p, rr->epoch); 517 518 memcpy(&(s->s3->read_sequence[2]), p, 6); 519 p += 6; 520 521 n2s(p, rr->length); 522 523 /* Lets check version */ 524 if (!s->first_packet) { 525 if (version != s->version) { 526 /* unexpected version, silently discard */ 527 rr->length = 0; 528 s->packet_length = 0; 529 goto again; 530 } 531 } 532 533 if ((version & 0xff00) != (s->version & 0xff00)) { 534 /* wrong version, silently discard record */ 535 rr->length = 0; 536 s->packet_length = 0; 537 goto again; 538 } 539 540 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 541 /* record too long, silently discard it */ 542 rr->length = 0; 543 s->packet_length = 0; 544 goto again; 545 } 546 547 /* now s->rstate == SSL_ST_READ_BODY */ 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 rr->length = 0; 562 s->packet_length = 0; 563 goto again; 564 } 565 566 /* now n == rr->length, 567 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 568 } 569 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 570 571 /* match epochs. NULL means the packet is dropped on the floor */ 572 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 573 if (bitmap == NULL) { 574 rr->length = 0; 575 s->packet_length = 0; 576 /* dump this record */ 577 goto again; 578 /* get another record */ 579 } 580 581 #ifndef OPENSSL_NO_SCTP 582 /* Only do replay check if no SCTP bio */ 583 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) { 584 #endif 585 /* Check whether this is a repeat, or aged record. 586 * Don't check if we're listening and this message is 587 * a ClientHello. They can look as if they're replayed, 588 * since they arrive from different connections and 589 * would be dropped unnecessarily. 590 */ 591 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 592 p != NULL && *p == SSL3_MT_CLIENT_HELLO) && 593 !dtls1_record_replay_check(s, bitmap)) { 594 rr->length = 0; 595 s->packet_length=0; /* dump this record */ 596 goto again; 597 /* get another record */ 598 } 599 #ifndef OPENSSL_NO_SCTP 600 } 601 #endif 602 603 /* just read a 0 length packet */ 604 if (rr->length == 0) 605 goto again; 606 607 /* If this record is from the next epoch (either HM or ALERT), 608 * and a handshake is currently in progress, buffer it since it 609 * cannot be processed at this time. However, do not buffer 610 * anything while listening. 611 */ 612 if (is_next_epoch) { 613 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) { 614 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 615 } 616 rr->length = 0; 617 s->packet_length = 0; 618 goto again; 619 } 620 621 if (!dtls1_process_record(s)) { 622 rr->length = 0; 623 s->packet_length = 0; 624 /* dump this record */ 625 goto again; 626 /* get another record */ 627 } 628 629 return (1); 630 631 } 632 633 /* Return up to 'len' payload bytes received in 'type' records. 634 * 'type' is one of the following: 635 * 636 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 637 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 638 * - 0 (during a shutdown, no data has to be returned) 639 * 640 * If we don't have stored data to work from, read a SSL/TLS record first 641 * (possibly multiple records if we still don't have anything to return). 642 * 643 * This function must handle any surprises the peer may have for us, such as 644 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 645 * a surprise, but handled as if it were), or renegotiation requests. 646 * Also if record payloads contain fragments too small to process, we store 647 * them until there is enough for the respective protocol (the record protocol 648 * may use arbitrary fragmentation and even interleaving): 649 * Change cipher spec protocol 650 * just 1 byte needed, no need for keeping anything stored 651 * Alert protocol 652 * 2 bytes needed (AlertLevel, AlertDescription) 653 * Handshake protocol 654 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 655 * to detect unexpected Client Hello and Hello Request messages 656 * here, anything else is handled by higher layers 657 * Application data protocol 658 * none of our business 659 */ 660 int 661 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 662 { 663 int al, i, j, ret; 664 unsigned int n; 665 SSL3_RECORD *rr; 666 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 667 668 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 669 if (!ssl3_setup_buffers(s)) 670 return (-1); 671 672 if ((type && 673 type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || 674 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 675 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 676 return -1; 677 } 678 679 /* check whether there's a handshake message (client hello?) waiting */ 680 if ((ret = have_handshake_fragment(s, type, buf, len, peek))) 681 return ret; 682 683 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 684 685 #ifndef OPENSSL_NO_SCTP 686 /* Continue handshake if it had to be interrupted to read 687 * app data with SCTP. 688 */ 689 if ((!s->in_handshake && SSL_in_init(s)) || 690 (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 691 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || 692 s->state == DTLS1_SCTP_ST_CR_READ_SOCK) && 693 s->s3->in_read_app_data != 2)) 694 #else 695 if (!s->in_handshake && SSL_in_init(s)) 696 #endif 697 { 698 /* type == SSL3_RT_APPLICATION_DATA */ 699 i = s->handshake_func(s); 700 if (i < 0) 701 return (i); 702 if (i == 0) { 703 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 704 return (-1); 705 } 706 } 707 708 start: 709 s->rwstate = SSL_NOTHING; 710 711 /* s->s3->rrec.type - is the type of record 712 * s->s3->rrec.data, - data 713 * s->s3->rrec.off, - offset into 'data' for next read 714 * s->s3->rrec.length, - number of bytes. */ 715 rr = &(s->s3->rrec); 716 717 /* We are not handshaking and have no data yet, 718 * so process data buffered during the last handshake 719 * in advance, if any. 720 */ 721 if (s->state == SSL_ST_OK && rr->length == 0) { 722 pitem *item; 723 item = pqueue_pop(s->d1->buffered_app_data.q); 724 if (item) { 725 #ifndef OPENSSL_NO_SCTP 726 /* Restore bio_dgram_sctp_rcvinfo struct */ 727 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) { 728 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data; 729 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 730 } 731 #endif 732 733 dtls1_copy_record(s, item); 734 735 free(item->data); 736 pitem_free(item); 737 } 738 } 739 740 /* Check for timeout */ 741 if (dtls1_handle_timeout(s) > 0) 742 goto start; 743 744 /* get new packet if necessary */ 745 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) { 746 ret = dtls1_get_record(s); 747 if (ret <= 0) { 748 ret = dtls1_read_failed(s, ret); 749 /* anything other than a timeout is an error */ 750 if (ret <= 0) 751 return (ret); 752 else 753 goto start; 754 } 755 } 756 757 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) { 758 rr->length = 0; 759 goto start; 760 } 761 762 /* we now have a packet which can be read and processed */ 763 764 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 765 * reset by ssl3_get_finished */ 766 && (rr->type != SSL3_RT_HANDSHAKE)) { 767 /* We now have application data between CCS and Finished. 768 * Most likely the packets were reordered on their way, so 769 * buffer the application data for later processing rather 770 * than dropping the connection. 771 */ 772 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num); 773 rr->length = 0; 774 goto start; 775 } 776 777 /* If the other end has shut down, throw anything we read away 778 * (even in 'peek' mode) */ 779 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 780 rr->length = 0; 781 s->rwstate = SSL_NOTHING; 782 return (0); 783 } 784 785 786 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 787 { 788 /* make sure that we are not getting application data when we 789 * are doing a handshake for the first time */ 790 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 791 (s->enc_read_ctx == NULL)) { 792 al = SSL_AD_UNEXPECTED_MESSAGE; 793 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE); 794 goto f_err; 795 } 796 797 if (len <= 0) 798 return (len); 799 800 if ((unsigned int)len > rr->length) 801 n = rr->length; 802 else 803 n = (unsigned int)len; 804 805 memcpy(buf, &(rr->data[rr->off]), n); 806 if (!peek) { 807 rr->length -= n; 808 rr->off += n; 809 if (rr->length == 0) { 810 s->rstate = SSL_ST_READ_HEADER; 811 rr->off = 0; 812 } 813 } 814 815 #ifndef OPENSSL_NO_SCTP 816 /* We were about to renegotiate but had to read 817 * belated application data first, so retry. 818 */ 819 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 820 rr->type == SSL3_RT_APPLICATION_DATA && 821 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || 822 s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) { 823 s->rwstate = SSL_READING; 824 BIO_clear_retry_flags(SSL_get_rbio(s)); 825 BIO_set_retry_read(SSL_get_rbio(s)); 826 } 827 828 /* We might had to delay a close_notify alert because 829 * of reordered app data. If there was an alert and there 830 * is no message to read anymore, finally set shutdown. 831 */ 832 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 833 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 834 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 835 return (0); 836 } 837 #endif 838 return (n); 839 } 840 841 842 /* If we get here, then type != rr->type; if we have a handshake 843 * message, then it was unexpected (Hello Request or Client Hello). */ 844 845 /* In case of record types for which we have 'fragment' storage, 846 * fill that so that we can process the data at a fixed place. 847 */ 848 { 849 unsigned int k, dest_maxlen = 0; 850 unsigned char *dest = NULL; 851 unsigned int *dest_len = NULL; 852 853 if (rr->type == SSL3_RT_HANDSHAKE) { 854 dest_maxlen = sizeof s->d1->handshake_fragment; 855 dest = s->d1->handshake_fragment; 856 dest_len = &s->d1->handshake_fragment_len; 857 } else if (rr->type == SSL3_RT_ALERT) { 858 dest_maxlen = sizeof(s->d1->alert_fragment); 859 dest = s->d1->alert_fragment; 860 dest_len = &s->d1->alert_fragment_len; 861 } 862 /* else it's a CCS message, or application data or wrong */ 863 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) { 864 /* Application data while renegotiating 865 * is allowed. Try again reading. 866 */ 867 if (rr->type == SSL3_RT_APPLICATION_DATA) { 868 BIO *bio; 869 s->s3->in_read_app_data = 2; 870 bio = SSL_get_rbio(s); 871 s->rwstate = SSL_READING; 872 BIO_clear_retry_flags(bio); 873 BIO_set_retry_read(bio); 874 return (-1); 875 } 876 877 /* Not certain if this is the right error handling */ 878 al = SSL_AD_UNEXPECTED_MESSAGE; 879 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 880 goto f_err; 881 } 882 883 if (dest_maxlen > 0) { 884 /* XDTLS: In a pathalogical case, the Client Hello 885 * may be fragmented--don't always expect dest_maxlen bytes */ 886 if (rr->length < dest_maxlen) { 887 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 888 /* 889 * for normal alerts rr->length is 2, while 890 * dest_maxlen is 7 if we were to handle this 891 * non-existing alert... 892 */ 893 FIX ME 894 #endif 895 s->rstate = SSL_ST_READ_HEADER; 896 rr->length = 0; 897 goto start; 898 } 899 900 /* now move 'n' bytes: */ 901 for ( k = 0; k < dest_maxlen; k++) { 902 dest[k] = rr->data[rr->off++]; 903 rr->length--; 904 } 905 *dest_len = dest_maxlen; 906 } 907 } 908 909 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 910 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 911 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 912 913 /* If we are a client, check for an incoming 'Hello Request': */ 914 if ((!s->server) && 915 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 916 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 917 (s->session != NULL) && (s->session->cipher != NULL)) { 918 s->d1->handshake_fragment_len = 0; 919 920 if ((s->d1->handshake_fragment[1] != 0) || 921 (s->d1->handshake_fragment[2] != 0) || 922 (s->d1->handshake_fragment[3] != 0)) { 923 al = SSL_AD_DECODE_ERROR; 924 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST); 925 goto err; 926 } 927 928 /* no need to check sequence number on HELLO REQUEST messages */ 929 930 if (s->msg_callback) 931 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 932 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 933 934 if (SSL_is_init_finished(s) && 935 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 936 !s->s3->renegotiate) { 937 s->d1->handshake_read_seq++; 938 s->new_session = 1; 939 ssl3_renegotiate(s); 940 if (ssl3_renegotiate_check(s)) { 941 i = s->handshake_func(s); 942 if (i < 0) 943 return (i); 944 if (i == 0) { 945 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 946 return (-1); 947 } 948 949 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 950 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 951 { 952 BIO *bio; 953 /* In the case where we try to read application data, 954 * but we trigger an SSL handshake, we return -1 with 955 * the retry option set. Otherwise renegotiation may 956 * cause nasty problems in the blocking world */ 957 s->rwstate = SSL_READING; 958 bio = SSL_get_rbio(s); 959 BIO_clear_retry_flags(bio); 960 BIO_set_retry_read(bio); 961 return (-1); 962 } 963 } 964 } 965 } 966 /* we either finished a handshake or ignored the request, 967 * now try again to obtain the (application) data we were asked for */ 968 goto start; 969 } 970 971 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) { 972 int alert_level = s->d1->alert_fragment[0]; 973 int alert_descr = s->d1->alert_fragment[1]; 974 975 s->d1->alert_fragment_len = 0; 976 977 if (s->msg_callback) 978 s->msg_callback(0, s->version, SSL3_RT_ALERT, 979 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 980 981 if (s->info_callback != NULL) 982 cb = s->info_callback; 983 else if (s->ctx->info_callback != NULL) 984 cb = s->ctx->info_callback; 985 986 if (cb != NULL) { 987 j = (alert_level << 8) | alert_descr; 988 cb(s, SSL_CB_READ_ALERT, j); 989 } 990 991 if (alert_level == 1) /* warning */ 992 { 993 s->s3->warn_alert = alert_descr; 994 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 995 #ifndef OPENSSL_NO_SCTP 996 /* With SCTP and streams the socket may deliver app data 997 * after a close_notify alert. We have to check this 998 * first so that nothing gets discarded. 999 */ 1000 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1001 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) { 1002 s->d1->shutdown_received = 1; 1003 s->rwstate = SSL_READING; 1004 BIO_clear_retry_flags(SSL_get_rbio(s)); 1005 BIO_set_retry_read(SSL_get_rbio(s)); 1006 return -1; 1007 } 1008 #endif 1009 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1010 return (0); 1011 } 1012 } else if (alert_level == 2) /* fatal */ 1013 { 1014 s->rwstate = SSL_NOTHING; 1015 s->s3->fatal_alert = alert_descr; 1016 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1017 ERR_asprintf_error_data("SSL alert number %d", 1018 alert_descr); 1019 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1020 SSL_CTX_remove_session(s->ctx, s->session); 1021 return (0); 1022 } else { 1023 al = SSL_AD_ILLEGAL_PARAMETER; 1024 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE); 1025 goto f_err; 1026 } 1027 1028 goto start; 1029 } 1030 1031 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1032 { 1033 s->rwstate = SSL_NOTHING; 1034 rr->length = 0; 1035 return (0); 1036 } 1037 1038 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1039 struct ccs_header_st ccs_hdr; 1040 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1041 1042 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1043 1044 if (s->version == DTLS1_BAD_VER) 1045 ccs_hdr_len = 3; 1046 1047 /* 'Change Cipher Spec' is just a single byte, so we know 1048 * exactly what the record payload has to look like */ 1049 /* XDTLS: check that epoch is consistent */ 1050 if ((rr->length != ccs_hdr_len) || 1051 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { 1052 i = SSL_AD_ILLEGAL_PARAMETER; 1053 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1054 goto err; 1055 } 1056 1057 rr->length = 0; 1058 1059 if (s->msg_callback) 1060 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1061 rr->data, 1, s, s->msg_callback_arg); 1062 1063 /* We can't process a CCS now, because previous handshake 1064 * messages are still missing, so just drop it. 1065 */ 1066 if (!s->d1->change_cipher_spec_ok) { 1067 goto start; 1068 } 1069 1070 s->d1->change_cipher_spec_ok = 0; 1071 1072 s->s3->change_cipher_spec = 1; 1073 if (!ssl3_do_change_cipher_spec(s)) 1074 goto err; 1075 1076 /* do this whenever CCS is processed */ 1077 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1078 1079 if (s->version == DTLS1_BAD_VER) 1080 s->d1->handshake_read_seq++; 1081 1082 #ifndef OPENSSL_NO_SCTP 1083 /* Remember that a CCS has been received, 1084 * so that an old key of SCTP-Auth can be 1085 * deleted when a CCS is sent. Will be ignored 1086 * if no SCTP is used 1087 */ 1088 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1089 #endif 1090 1091 goto start; 1092 } 1093 1094 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1095 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1096 !s->in_handshake) { 1097 struct hm_header_st msg_hdr; 1098 1099 /* this may just be a stale retransmit */ 1100 dtls1_get_message_header(rr->data, &msg_hdr); 1101 if (rr->epoch != s->d1->r_epoch) { 1102 rr->length = 0; 1103 goto start; 1104 } 1105 1106 /* If we are server, we may have a repeated FINISHED of the 1107 * client here, then retransmit our CCS and FINISHED. 1108 */ 1109 if (msg_hdr.type == SSL3_MT_FINISHED) { 1110 if (dtls1_check_timeout_num(s) < 0) 1111 return -1; 1112 1113 dtls1_retransmit_buffered_messages(s); 1114 rr->length = 0; 1115 goto start; 1116 } 1117 1118 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1119 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1120 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1121 s->renegotiate = 1; 1122 s->new_session = 1; 1123 } 1124 i = s->handshake_func(s); 1125 if (i < 0) 1126 return (i); 1127 if (i == 0) { 1128 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1129 return (-1); 1130 } 1131 1132 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1133 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1134 { 1135 BIO *bio; 1136 /* In the case where we try to read application data, 1137 * but we trigger an SSL handshake, we return -1 with 1138 * the retry option set. Otherwise renegotiation may 1139 * cause nasty problems in the blocking world */ 1140 s->rwstate = SSL_READING; 1141 bio = SSL_get_rbio(s); 1142 BIO_clear_retry_flags(bio); 1143 BIO_set_retry_read(bio); 1144 return (-1); 1145 } 1146 } 1147 goto start; 1148 } 1149 1150 switch (rr->type) { 1151 default: 1152 /* TLS just ignores unknown message types */ 1153 if (s->version == TLS1_VERSION) { 1154 rr->length = 0; 1155 goto start; 1156 } 1157 al = SSL_AD_UNEXPECTED_MESSAGE; 1158 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1159 goto f_err; 1160 case SSL3_RT_CHANGE_CIPHER_SPEC: 1161 case SSL3_RT_ALERT: 1162 case SSL3_RT_HANDSHAKE: 1163 /* we already handled all of these, with the possible exception 1164 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1165 * should not happen when type != rr->type */ 1166 al = SSL_AD_UNEXPECTED_MESSAGE; 1167 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 1168 goto f_err; 1169 case SSL3_RT_APPLICATION_DATA: 1170 /* At this point, we were expecting handshake data, 1171 * but have application data. If the library was 1172 * running inside ssl3_read() (i.e. in_read_app_data 1173 * is set) and it makes sense to read application data 1174 * at this point (session renegotiation not yet started), 1175 * we will indulge it. 1176 */ 1177 if (s->s3->in_read_app_data && 1178 (s->s3->total_renegotiations != 0) && 1179 (((s->state & SSL_ST_CONNECT) && 1180 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1181 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 1182 (s->state & SSL_ST_ACCEPT) && 1183 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1184 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1185 s->s3->in_read_app_data = 2; 1186 return (-1); 1187 } else { 1188 al = SSL_AD_UNEXPECTED_MESSAGE; 1189 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1190 goto f_err; 1191 } 1192 } 1193 /* not reached */ 1194 1195 f_err: 1196 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1197 err: 1198 return (-1); 1199 } 1200 1201 int 1202 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1203 { 1204 int i; 1205 1206 #ifndef OPENSSL_NO_SCTP 1207 /* Check if we have to continue an interrupted handshake 1208 * for reading belated app data with SCTP. 1209 */ 1210 if ((SSL_in_init(s) && !s->in_handshake) || 1211 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1212 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || 1213 s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1214 #else 1215 if (SSL_in_init(s) && !s->in_handshake) 1216 #endif 1217 { 1218 i = s->handshake_func(s); 1219 if (i < 0) 1220 return (i); 1221 if (i == 0) { 1222 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1223 return -1; 1224 } 1225 } 1226 1227 if (len > SSL3_RT_MAX_PLAIN_LENGTH) { 1228 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG); 1229 return -1; 1230 } 1231 1232 i = dtls1_write_bytes(s, type, buf_, len); 1233 return i; 1234 } 1235 1236 1237 /* this only happens when a client hello is received and a handshake 1238 * is started. */ 1239 static int 1240 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1241 int len, int peek) 1242 { 1243 1244 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1245 /* (partially) satisfy request from storage */ 1246 { 1247 unsigned char *src = s->d1->handshake_fragment; 1248 unsigned char *dst = buf; 1249 unsigned int k, n; 1250 1251 /* peek == 0 */ 1252 n = 0; 1253 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) { 1254 *dst++ = *src++; 1255 len--; 1256 s->d1->handshake_fragment_len--; 1257 n++; 1258 } 1259 /* move any remaining fragment bytes: */ 1260 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1261 s->d1->handshake_fragment[k] = *src++; 1262 return n; 1263 } 1264 1265 return 0; 1266 } 1267 1268 1269 /* Call this to write data in records of type 'type' 1270 * It will return <= 0 if not all data has been sent or non-blocking IO. 1271 */ 1272 int 1273 dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1274 { 1275 int i; 1276 1277 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1278 s->rwstate = SSL_NOTHING; 1279 i = do_dtls1_write(s, type, buf, len); 1280 return i; 1281 } 1282 1283 int 1284 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 1285 { 1286 unsigned char *p, *pseq; 1287 int i, mac_size, clear = 0; 1288 int prefix_len = 0; 1289 SSL3_RECORD *wr; 1290 SSL3_BUFFER *wb; 1291 SSL_SESSION *sess; 1292 int bs; 1293 1294 /* first check if there is a SSL3_BUFFER still being written 1295 * out. This will happen with non blocking IO */ 1296 if (s->s3->wbuf.left != 0) { 1297 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1298 return (ssl3_write_pending(s, type, buf, len)); 1299 } 1300 1301 /* If we have an alert to send, lets send it */ 1302 if (s->s3->alert_dispatch) { 1303 i = s->method->ssl_dispatch_alert(s); 1304 if (i <= 0) 1305 return (i); 1306 /* if it went, fall through and send more stuff */ 1307 } 1308 1309 if (len == 0) 1310 return 0; 1311 1312 wr = &(s->s3->wrec); 1313 wb = &(s->s3->wbuf); 1314 sess = s->session; 1315 1316 if ((sess == NULL) || (s->enc_write_ctx == NULL) || 1317 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1318 clear = 1; 1319 1320 if (clear) 1321 mac_size = 0; 1322 else { 1323 mac_size = EVP_MD_CTX_size(s->write_hash); 1324 if (mac_size < 0) 1325 goto err; 1326 } 1327 1328 /* DTLS implements explicit IV, so no need for empty fragments. */ 1329 1330 p = wb->buf + prefix_len; 1331 1332 /* write the header */ 1333 1334 *(p++) = type&0xff; 1335 wr->type = type; 1336 1337 *(p++) = (s->version >> 8); 1338 *(p++) = s->version&0xff; 1339 1340 /* field where we are to write out packet epoch, seq num and len */ 1341 pseq = p; 1342 1343 p += 10; 1344 1345 /* lets setup the record stuff. */ 1346 1347 /* Make space for the explicit IV in case of CBC. 1348 * (this is a bit of a boundary violation, but what the heck). 1349 */ 1350 if (s->enc_write_ctx && 1351 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1352 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1353 else 1354 bs = 0; 1355 1356 wr->data = p + bs; 1357 /* make room for IV in case of CBC */ 1358 wr->length = (int)len; 1359 wr->input = (unsigned char *)buf; 1360 1361 /* we now 'read' from wr->input, wr->length bytes into 1362 * wr->data */ 1363 1364 memcpy(wr->data, wr->input, wr->length); 1365 wr->input = wr->data; 1366 1367 /* we should still have the output to wr->data and the input 1368 * from wr->input. Length should be wr->length. 1369 * wr->data still points in the wb->buf */ 1370 1371 if (mac_size != 0) { 1372 if (s->method->ssl3_enc->mac(s, &(p[wr->length + bs]), 1) < 0) 1373 goto err; 1374 wr->length += mac_size; 1375 } 1376 1377 /* this is true regardless of mac size */ 1378 wr->input = p; 1379 wr->data = p; 1380 1381 1382 /* ssl3_enc can only have an error on read */ 1383 if (bs) /* bs != 0 in case of CBC */ 1384 { 1385 arc4random_buf(p, bs); 1386 /* master IV and last CBC residue stand for 1387 * the rest of randomness */ 1388 wr->length += bs; 1389 } 1390 1391 s->method->ssl3_enc->enc(s, 1); 1392 1393 /* record length after mac and block padding */ 1394 /* if (type == SSL3_RT_APPLICATION_DATA || 1395 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1396 1397 /* there's only one epoch between handshake and app data */ 1398 1399 s2n(s->d1->w_epoch, pseq); 1400 1401 /* XDTLS: ?? */ 1402 /* else 1403 s2n(s->d1->handshake_epoch, pseq); 1404 */ 1405 1406 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1407 pseq += 6; 1408 s2n(wr->length, pseq); 1409 1410 /* we should now have 1411 * wr->data pointing to the encrypted data, which is 1412 * wr->length long */ 1413 wr->type=type; /* not needed but helps for debugging */ 1414 wr->length += DTLS1_RT_HEADER_LENGTH; 1415 1416 ssl3_record_sequence_increment(s->s3->write_sequence); 1417 1418 /* now let's set up wb */ 1419 wb->left = prefix_len + wr->length; 1420 wb->offset = 0; 1421 1422 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1423 s->s3->wpend_tot = len; 1424 s->s3->wpend_buf = buf; 1425 s->s3->wpend_type = type; 1426 s->s3->wpend_ret = len; 1427 1428 /* we now just need to write the buffer */ 1429 return ssl3_write_pending(s, type, buf, len); 1430 err: 1431 return -1; 1432 } 1433 1434 1435 1436 static int 1437 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1438 { 1439 int cmp; 1440 unsigned int shift; 1441 const unsigned char *seq = s->s3->read_sequence; 1442 1443 cmp = satsub64be(seq, bitmap->max_seq_num); 1444 if (cmp > 0) { 1445 memcpy (s->s3->rrec.seq_num, seq, 8); 1446 return 1; /* this record in new */ 1447 } 1448 shift = -cmp; 1449 if (shift >= sizeof(bitmap->map)*8) 1450 return 0; /* stale, outside the window */ 1451 else if (bitmap->map & (1UL << shift)) 1452 return 0; /* record previously received */ 1453 1454 memcpy(s->s3->rrec.seq_num, seq, 8); 1455 return 1; 1456 } 1457 1458 1459 static void 1460 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1461 { 1462 int cmp; 1463 unsigned int shift; 1464 const unsigned char *seq = s->s3->read_sequence; 1465 1466 cmp = satsub64be(seq, bitmap->max_seq_num); 1467 if (cmp > 0) { 1468 shift = cmp; 1469 if (shift < sizeof(bitmap->map)*8) 1470 bitmap->map <<= shift, bitmap->map |= 1UL; 1471 else 1472 bitmap->map = 1UL; 1473 memcpy(bitmap->max_seq_num, seq, 8); 1474 } else { 1475 shift = -cmp; 1476 if (shift < sizeof(bitmap->map) * 8) 1477 bitmap->map |= 1UL << shift; 1478 } 1479 } 1480 1481 1482 int 1483 dtls1_dispatch_alert(SSL *s) 1484 { 1485 int i, j; 1486 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1487 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1488 unsigned char *ptr = &buf[0]; 1489 1490 s->s3->alert_dispatch = 0; 1491 1492 memset(buf, 0x00, sizeof(buf)); 1493 *ptr++ = s->s3->send_alert[0]; 1494 *ptr++ = s->s3->send_alert[1]; 1495 1496 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1497 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) { 1498 s2n(s->d1->handshake_read_seq, ptr); 1499 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1500 } 1501 #endif 1502 1503 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf)); 1504 if (i <= 0) { 1505 s->s3->alert_dispatch = 1; 1506 /* fprintf( stderr, "not done with alert\n" ); */ 1507 } else { 1508 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1509 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1510 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1511 #endif 1512 ) 1513 (void)BIO_flush(s->wbio); 1514 1515 if (s->msg_callback) 1516 s->msg_callback(1, s->version, SSL3_RT_ALERT, 1517 s->s3->send_alert, 2, s, s->msg_callback_arg); 1518 1519 if (s->info_callback != NULL) 1520 cb = s->info_callback; 1521 else if (s->ctx->info_callback != NULL) 1522 cb = s->ctx->info_callback; 1523 1524 if (cb != NULL) { 1525 j = (s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1526 cb(s, SSL_CB_WRITE_ALERT, j); 1527 } 1528 } 1529 return (i); 1530 } 1531 1532 1533 static DTLS1_BITMAP * 1534 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1535 { 1536 1537 *is_next_epoch = 0; 1538 1539 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1540 if (rr->epoch == s->d1->r_epoch) 1541 return &s->d1->bitmap; 1542 1543 /* Only HM and ALERT messages can be from the next epoch */ 1544 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1545 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { 1546 *is_next_epoch = 1; 1547 return &s->d1->next_bitmap; 1548 } 1549 1550 return NULL; 1551 } 1552 1553 void 1554 dtls1_reset_seq_numbers(SSL *s, int rw) 1555 { 1556 unsigned char *seq; 1557 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1558 1559 if (rw & SSL3_CC_READ) { 1560 seq = s->s3->read_sequence; 1561 s->d1->r_epoch++; 1562 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1563 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1564 } else { 1565 seq = s->s3->write_sequence; 1566 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1567 s->d1->w_epoch++; 1568 } 1569 1570 memset(seq, 0x00, seq_bytes); 1571 } 1572