1 /* ssl/d1_pkt.c */ 2 /* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra (at) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh (at) cryptsoft.com). 57 * 58 */ 59 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116 #include <stdio.h> 117 #include <errno.h> 118 #define USE_SOCKETS 119 #include "ssl_locl.h" 120 #include <openssl/evp.h> 121 #include <openssl/buffer.h> 122 #include <openssl/pqueue.h> 123 #include <openssl/rand.h> 124 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2) 127 { int ret,sat,brw,i; 128 129 if (sizeof(long) == 8) do 130 { const union { long one; char little; } is_endian = {1}; 131 long l; 132 133 if (is_endian.little) break; 134 /* not reached on little-endians */ 135 /* following test is redundant, because input is 136 * always aligned, but I take no chances... */ 137 if (((size_t)v1|(size_t)v2)&0x7) break; 138 139 l = *((long *)v1); 140 l -= *((long *)v2); 141 if (l>128) return 128; 142 else if (l<-128) return -128; 143 else return (int)l; 144 } while (0); 145 146 ret = (int)v1[7]-(int)v2[7]; 147 sat = 0; 148 brw = ret>>8; /* brw is either 0 or -1 */ 149 if (ret & 0x80) 150 { for (i=6;i>=0;i--) 151 { brw += (int)v1[i]-(int)v2[i]; 152 sat |= ~brw; 153 brw >>= 8; 154 } 155 } 156 else 157 { for (i=6;i>=0;i--) 158 { brw += (int)v1[i]-(int)v2[i]; 159 sat |= brw; 160 brw >>= 8; 161 } 162 } 163 brw <<= 8; /* brw is either 0 or -256 */ 164 165 if (sat&0xff) return brw | 0x80; 166 else return brw + (ret&0xFF); 167 } 168 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 170 int len, int peek); 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 174 unsigned int *is_next_epoch); 175 #if 0 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 177 unsigned short *priority, unsigned long *offset); 178 #endif 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 180 unsigned char *priority); 181 static int dtls1_process_record(SSL *s); 182 183 /* copy buffered record into SSL structure */ 184 static int 185 dtls1_copy_record(SSL *s, pitem *item) 186 { 187 DTLS1_RECORD_DATA *rdata; 188 189 rdata = (DTLS1_RECORD_DATA *)item->data; 190 191 if (s->s3->rbuf.buf != NULL) 192 OPENSSL_free(s->s3->rbuf.buf); 193 194 s->packet = rdata->packet; 195 s->packet_length = rdata->packet_length; 196 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 197 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 198 199 /* Set proper sequence number for mac calculation */ 200 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 201 202 return(1); 203 } 204 205 206 static int 207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 208 { 209 DTLS1_RECORD_DATA *rdata; 210 pitem *item; 211 212 /* Limit the size of the queue to prevent DOS attacks */ 213 if (pqueue_size(queue->q) >= 100) 214 return 0; 215 216 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 217 item = pitem_new(priority, rdata); 218 if (rdata == NULL || item == NULL) 219 { 220 if (rdata != NULL) OPENSSL_free(rdata); 221 if (item != NULL) pitem_free(item); 222 223 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 224 return(0); 225 } 226 227 rdata->packet = s->packet; 228 rdata->packet_length = s->packet_length; 229 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 230 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 231 232 item->data = rdata; 233 234 #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 /* insert should not fail, since duplicates are dropped */ 243 if (pqueue_insert(queue->q, item) == NULL) 244 { 245 OPENSSL_free(rdata); 246 pitem_free(item); 247 return(0); 248 } 249 250 s->packet = NULL; 251 s->packet_length = 0; 252 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 253 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 254 255 if (!ssl3_setup_buffers(s)) 256 { 257 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 258 OPENSSL_free(rdata); 259 pitem_free(item); 260 return(0); 261 } 262 263 return(1); 264 } 265 266 267 static int 268 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 269 { 270 pitem *item; 271 272 item = pqueue_pop(queue->q); 273 if (item) 274 { 275 dtls1_copy_record(s, item); 276 277 OPENSSL_free(item->data); 278 pitem_free(item); 279 280 return(1); 281 } 282 283 return(0); 284 } 285 286 287 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 288 * yet */ 289 #define dtls1_get_unprocessed_record(s) \ 290 dtls1_retrieve_buffered_record((s), \ 291 &((s)->d1->unprocessed_rcds)) 292 293 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 294 #define dtls1_get_processed_record(s) \ 295 dtls1_retrieve_buffered_record((s), \ 296 &((s)->d1->processed_rcds)) 297 298 static int 299 dtls1_process_buffered_records(SSL *s) 300 { 301 pitem *item; 302 303 item = pqueue_peek(s->d1->unprocessed_rcds.q); 304 if (item) 305 { 306 /* Check if epoch is current. */ 307 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 308 return(1); /* Nothing to do. */ 309 310 /* Process all the records. */ 311 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 312 { 313 dtls1_get_unprocessed_record(s); 314 if ( ! dtls1_process_record(s)) 315 return(0); 316 dtls1_buffer_record(s, &(s->d1->processed_rcds), 317 s->s3->rrec.seq_num); 318 } 319 } 320 321 /* sync epoch numbers once all the unprocessed records 322 * have been processed */ 323 s->d1->processed_rcds.epoch = s->d1->r_epoch; 324 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 325 326 return(1); 327 } 328 329 330 #if 0 331 332 static int 333 dtls1_get_buffered_record(SSL *s) 334 { 335 pitem *item; 336 PQ_64BIT priority = 337 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 338 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 339 340 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 341 nothing buffered */ 342 return 0; 343 344 345 item = pqueue_peek(s->d1->rcvd_records); 346 if (item && item->priority == priority) 347 { 348 /* Check if we've received the record of interest. It must be 349 * a handshake record, since data records as passed up without 350 * buffering */ 351 DTLS1_RECORD_DATA *rdata; 352 item = pqueue_pop(s->d1->rcvd_records); 353 rdata = (DTLS1_RECORD_DATA *)item->data; 354 355 if (s->s3->rbuf.buf != NULL) 356 OPENSSL_free(s->s3->rbuf.buf); 357 358 s->packet = rdata->packet; 359 s->packet_length = rdata->packet_length; 360 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 361 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 362 363 OPENSSL_free(item->data); 364 pitem_free(item); 365 366 /* s->d1->next_expected_seq_num++; */ 367 return(1); 368 } 369 370 return 0; 371 } 372 373 #endif 374 375 static int 376 dtls1_process_record(SSL *s) 377 { 378 int i,al; 379 int enc_err; 380 SSL_SESSION *sess; 381 SSL3_RECORD *rr; 382 unsigned int mac_size, orig_len; 383 unsigned char md[EVP_MAX_MD_SIZE]; 384 385 rr= &(s->s3->rrec); 386 sess = s->session; 387 388 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 389 * and we have that many bytes in s->packet 390 */ 391 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 392 393 /* ok, we can now read from 's->packet' data into 'rr' 394 * rr->input points at rr->length bytes, which 395 * need to be copied into rr->data by either 396 * the decryption or by the decompression 397 * When the data is 'copied' into the rr->data buffer, 398 * rr->input will be pointed at the new buffer */ 399 400 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 401 * rr->length bytes of encrypted compressed stuff. */ 402 403 /* check is not needed I believe */ 404 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 405 { 406 al=SSL_AD_RECORD_OVERFLOW; 407 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 408 goto f_err; 409 } 410 411 /* decrypt in place in 'rr->input' */ 412 rr->data=rr->input; 413 414 enc_err = s->method->ssl3_enc->enc(s,0); 415 /* enc_err is: 416 * 0: (in non-constant time) if the record is publically invalid. 417 * 1: if the padding is valid 418 * -1: if the padding is invalid */ 419 if (enc_err == 0) 420 { 421 /* For DTLS we simply ignore bad packets. */ 422 rr->length = 0; 423 s->packet_length = 0; 424 goto err; 425 } 426 427 #ifdef TLS_DEBUG 428 printf("dec %d\n",rr->length); 429 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 430 printf("\n"); 431 #endif 432 433 /* r->length is now the compressed data plus mac */ 434 if ((sess != NULL) && 435 (s->enc_read_ctx != NULL) && 436 (EVP_MD_CTX_md(s->read_hash) != NULL)) 437 { 438 /* s->read_hash != NULL => mac_size != -1 */ 439 unsigned char *mac = NULL; 440 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 441 mac_size=EVP_MD_CTX_size(s->read_hash); 442 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 443 444 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 445 orig_len = rr->length+((unsigned int)rr->type>>8); 446 447 /* orig_len is the length of the record before any padding was 448 * removed. This is public information, as is the MAC in use, 449 * therefore we can safely process the record in a different 450 * amount of time if it's too short to possibly contain a MAC. 451 */ 452 if (orig_len < mac_size || 453 /* CBC records must have a padding length byte too. */ 454 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 455 orig_len < mac_size+1)) 456 { 457 al=SSL_AD_DECODE_ERROR; 458 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT); 459 goto f_err; 460 } 461 462 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) 463 { 464 /* We update the length so that the TLS header bytes 465 * can be constructed correctly but we need to extract 466 * the MAC in constant time from within the record, 467 * without leaking the contents of the padding bytes. 468 * */ 469 mac = mac_tmp; 470 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 471 rr->length -= mac_size; 472 } 473 else 474 { 475 /* In this case there's no padding, so |orig_len| 476 * equals |rec->length| and we checked that there's 477 * enough bytes for |mac_size| above. */ 478 rr->length -= mac_size; 479 mac = &rr->data[rr->length]; 480 } 481 482 i=s->method->ssl3_enc->mac(s,md,0 /* not send */); 483 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 484 enc_err = -1; 485 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 486 enc_err = -1; 487 } 488 489 if (enc_err < 0) 490 { 491 /* decryption failed, silently discard message */ 492 rr->length = 0; 493 s->packet_length = 0; 494 goto err; 495 } 496 497 /* r->length is now just compressed */ 498 if (s->expand != NULL) 499 { 500 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 501 { 502 al=SSL_AD_RECORD_OVERFLOW; 503 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 504 goto f_err; 505 } 506 if (!ssl3_do_uncompress(s)) 507 { 508 al=SSL_AD_DECOMPRESSION_FAILURE; 509 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 510 goto f_err; 511 } 512 } 513 514 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 515 { 516 al=SSL_AD_RECORD_OVERFLOW; 517 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 518 goto f_err; 519 } 520 521 rr->off=0; 522 /* So at this point the following is true 523 * ssl->s3->rrec.type is the type of record 524 * ssl->s3->rrec.length == number of bytes in record 525 * ssl->s3->rrec.off == offset to first valid byte 526 * ssl->s3->rrec.data == where to take bytes from, increment 527 * after use :-). 528 */ 529 530 /* we have pulled in a full packet so zero things */ 531 s->packet_length=0; 532 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 533 return(1); 534 535 f_err: 536 ssl3_send_alert(s,SSL3_AL_FATAL,al); 537 err: 538 return(0); 539 } 540 541 542 /* Call this to get a new input record. 543 * It will return <= 0 if more data is needed, normally due to an error 544 * or non-blocking IO. 545 * When it finishes, one packet has been decoded and can be found in 546 * ssl->s3->rrec.type - is the type of record 547 * ssl->s3->rrec.data, - data 548 * ssl->s3->rrec.length, - number of bytes 549 */ 550 /* used only by dtls1_read_bytes */ 551 int dtls1_get_record(SSL *s) 552 { 553 int ssl_major,ssl_minor; 554 int i,n; 555 SSL3_RECORD *rr; 556 unsigned char *p = NULL; 557 unsigned short version; 558 DTLS1_BITMAP *bitmap; 559 unsigned int is_next_epoch; 560 561 rr= &(s->s3->rrec); 562 563 /* The epoch may have changed. If so, process all the 564 * pending records. This is a non-blocking operation. */ 565 dtls1_process_buffered_records(s); 566 567 /* if we're renegotiating, then there may be buffered records */ 568 if (dtls1_get_processed_record(s)) 569 return 1; 570 571 /* get something from the wire */ 572 again: 573 /* check if we have the header */ 574 if ( (s->rstate != SSL_ST_READ_BODY) || 575 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 576 { 577 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 578 /* read timeout is handled by dtls1_read_bytes */ 579 if (n <= 0) return(n); /* error or non-blocking */ 580 581 /* this packet contained a partial record, dump it */ 582 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 583 { 584 s->packet_length = 0; 585 goto again; 586 } 587 588 s->rstate=SSL_ST_READ_BODY; 589 590 p=s->packet; 591 592 /* Pull apart the header into the DTLS1_RECORD */ 593 rr->type= *(p++); 594 ssl_major= *(p++); 595 ssl_minor= *(p++); 596 version=(ssl_major<<8)|ssl_minor; 597 598 /* sequence number is 64 bits, with top 2 bytes = epoch */ 599 n2s(p,rr->epoch); 600 601 memcpy(&(s->s3->read_sequence[2]), p, 6); 602 p+=6; 603 604 n2s(p,rr->length); 605 606 /* Lets check version */ 607 if (!s->first_packet) 608 { 609 if (version != s->version) 610 { 611 /* unexpected version, silently discard */ 612 rr->length = 0; 613 s->packet_length = 0; 614 goto again; 615 } 616 } 617 618 if ((version & 0xff00) != (s->version & 0xff00)) 619 { 620 /* wrong version, silently discard record */ 621 rr->length = 0; 622 s->packet_length = 0; 623 goto again; 624 } 625 626 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 627 { 628 /* record too long, silently discard it */ 629 rr->length = 0; 630 s->packet_length = 0; 631 goto again; 632 } 633 634 /* now s->rstate == SSL_ST_READ_BODY */ 635 } 636 637 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 638 639 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 640 { 641 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 642 i=rr->length; 643 n=ssl3_read_n(s,i,i,1); 644 if (n <= 0) return(n); /* error or non-blocking io */ 645 646 /* this packet contained a partial record, dump it */ 647 if ( n != i) 648 { 649 rr->length = 0; 650 s->packet_length = 0; 651 goto again; 652 } 653 654 /* now n == rr->length, 655 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 656 } 657 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 658 659 /* match epochs. NULL means the packet is dropped on the floor */ 660 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 661 if ( bitmap == NULL) 662 { 663 rr->length = 0; 664 s->packet_length = 0; /* dump this record */ 665 goto again; /* get another record */ 666 } 667 668 #ifndef OPENSSL_NO_SCTP 669 /* Only do replay check if no SCTP bio */ 670 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) 671 { 672 #endif 673 /* Check whether this is a repeat, or aged record. 674 * Don't check if we're listening and this message is 675 * a ClientHello. They can look as if they're replayed, 676 * since they arrive from different connections and 677 * would be dropped unnecessarily. 678 */ 679 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 680 *p == SSL3_MT_CLIENT_HELLO) && 681 !dtls1_record_replay_check(s, bitmap)) 682 { 683 rr->length = 0; 684 s->packet_length=0; /* dump this record */ 685 goto again; /* get another record */ 686 } 687 #ifndef OPENSSL_NO_SCTP 688 } 689 #endif 690 691 /* just read a 0 length packet */ 692 if (rr->length == 0) goto again; 693 694 /* If this record is from the next epoch (either HM or ALERT), 695 * and a handshake is currently in progress, buffer it since it 696 * cannot be processed at this time. However, do not buffer 697 * anything while listening. 698 */ 699 if (is_next_epoch) 700 { 701 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) 702 { 703 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 704 } 705 rr->length = 0; 706 s->packet_length = 0; 707 goto again; 708 } 709 710 if (!dtls1_process_record(s)) 711 { 712 rr->length = 0; 713 s->packet_length = 0; /* dump this record */ 714 goto again; /* get another record */ 715 } 716 717 return(1); 718 719 } 720 721 /* Return up to 'len' payload bytes received in 'type' records. 722 * 'type' is one of the following: 723 * 724 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 725 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 726 * - 0 (during a shutdown, no data has to be returned) 727 * 728 * If we don't have stored data to work from, read a SSL/TLS record first 729 * (possibly multiple records if we still don't have anything to return). 730 * 731 * This function must handle any surprises the peer may have for us, such as 732 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 733 * a surprise, but handled as if it were), or renegotiation requests. 734 * Also if record payloads contain fragments too small to process, we store 735 * them until there is enough for the respective protocol (the record protocol 736 * may use arbitrary fragmentation and even interleaving): 737 * Change cipher spec protocol 738 * just 1 byte needed, no need for keeping anything stored 739 * Alert protocol 740 * 2 bytes needed (AlertLevel, AlertDescription) 741 * Handshake protocol 742 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 743 * to detect unexpected Client Hello and Hello Request messages 744 * here, anything else is handled by higher layers 745 * Application data protocol 746 * none of our business 747 */ 748 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 749 { 750 int al,i,j,ret; 751 unsigned int n; 752 SSL3_RECORD *rr; 753 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 754 755 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 756 if (!ssl3_setup_buffers(s)) 757 return(-1); 758 759 /* XXX: check what the second '&& type' is about */ 760 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 761 (type != SSL3_RT_HANDSHAKE) && type) || 762 (peek && (type != SSL3_RT_APPLICATION_DATA))) 763 { 764 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 765 return -1; 766 } 767 768 /* check whether there's a handshake message (client hello?) waiting */ 769 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 770 return ret; 771 772 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 773 774 #ifndef OPENSSL_NO_SCTP 775 /* Continue handshake if it had to be interrupted to read 776 * app data with SCTP. 777 */ 778 if ((!s->in_handshake && SSL_in_init(s)) || 779 (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 780 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) && 781 s->s3->in_read_app_data != 2)) 782 #else 783 if (!s->in_handshake && SSL_in_init(s)) 784 #endif 785 { 786 /* type == SSL3_RT_APPLICATION_DATA */ 787 i=s->handshake_func(s); 788 if (i < 0) return(i); 789 if (i == 0) 790 { 791 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 792 return(-1); 793 } 794 } 795 796 start: 797 s->rwstate=SSL_NOTHING; 798 799 /* s->s3->rrec.type - is the type of record 800 * s->s3->rrec.data, - data 801 * s->s3->rrec.off, - offset into 'data' for next read 802 * s->s3->rrec.length, - number of bytes. */ 803 rr = &(s->s3->rrec); 804 805 /* We are not handshaking and have no data yet, 806 * so process data buffered during the last handshake 807 * in advance, if any. 808 */ 809 if (s->state == SSL_ST_OK && rr->length == 0) 810 { 811 pitem *item; 812 item = pqueue_pop(s->d1->buffered_app_data.q); 813 if (item) 814 { 815 #ifndef OPENSSL_NO_SCTP 816 /* Restore bio_dgram_sctp_rcvinfo struct */ 817 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) 818 { 819 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data; 820 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 821 } 822 #endif 823 824 dtls1_copy_record(s, item); 825 826 OPENSSL_free(item->data); 827 pitem_free(item); 828 } 829 } 830 831 /* Check for timeout */ 832 if (dtls1_handle_timeout(s) > 0) 833 goto start; 834 835 /* get new packet if necessary */ 836 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 837 { 838 ret=dtls1_get_record(s); 839 if (ret <= 0) 840 { 841 ret = dtls1_read_failed(s, ret); 842 /* anything other than a timeout is an error */ 843 if (ret <= 0) 844 return(ret); 845 else 846 goto start; 847 } 848 } 849 850 /* we now have a packet which can be read and processed */ 851 852 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 853 * reset by ssl3_get_finished */ 854 && (rr->type != SSL3_RT_HANDSHAKE)) 855 { 856 /* We now have application data between CCS and Finished. 857 * Most likely the packets were reordered on their way, so 858 * buffer the application data for later processing rather 859 * than dropping the connection. 860 */ 861 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num); 862 rr->length = 0; 863 goto start; 864 } 865 866 /* If the other end has shut down, throw anything we read away 867 * (even in 'peek' mode) */ 868 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 869 { 870 rr->length=0; 871 s->rwstate=SSL_NOTHING; 872 return(0); 873 } 874 875 876 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 877 { 878 /* make sure that we are not getting application data when we 879 * are doing a handshake for the first time */ 880 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 881 (s->enc_read_ctx == NULL)) 882 { 883 al=SSL_AD_UNEXPECTED_MESSAGE; 884 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 885 goto f_err; 886 } 887 888 if (len <= 0) return(len); 889 890 if ((unsigned int)len > rr->length) 891 n = rr->length; 892 else 893 n = (unsigned int)len; 894 895 memcpy(buf,&(rr->data[rr->off]),n); 896 if (!peek) 897 { 898 rr->length-=n; 899 rr->off+=n; 900 if (rr->length == 0) 901 { 902 s->rstate=SSL_ST_READ_HEADER; 903 rr->off=0; 904 } 905 } 906 907 #ifndef OPENSSL_NO_SCTP 908 /* We were about to renegotiate but had to read 909 * belated application data first, so retry. 910 */ 911 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 912 rr->type == SSL3_RT_APPLICATION_DATA && 913 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) 914 { 915 s->rwstate=SSL_READING; 916 BIO_clear_retry_flags(SSL_get_rbio(s)); 917 BIO_set_retry_read(SSL_get_rbio(s)); 918 } 919 920 /* We might had to delay a close_notify alert because 921 * of reordered app data. If there was an alert and there 922 * is no message to read anymore, finally set shutdown. 923 */ 924 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 925 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 926 { 927 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 928 return(0); 929 } 930 #endif 931 return(n); 932 } 933 934 935 /* If we get here, then type != rr->type; if we have a handshake 936 * message, then it was unexpected (Hello Request or Client Hello). */ 937 938 /* In case of record types for which we have 'fragment' storage, 939 * fill that so that we can process the data at a fixed place. 940 */ 941 { 942 unsigned int k, dest_maxlen = 0; 943 unsigned char *dest = NULL; 944 unsigned int *dest_len = NULL; 945 946 if (rr->type == SSL3_RT_HANDSHAKE) 947 { 948 dest_maxlen = sizeof s->d1->handshake_fragment; 949 dest = s->d1->handshake_fragment; 950 dest_len = &s->d1->handshake_fragment_len; 951 } 952 else if (rr->type == SSL3_RT_ALERT) 953 { 954 dest_maxlen = sizeof(s->d1->alert_fragment); 955 dest = s->d1->alert_fragment; 956 dest_len = &s->d1->alert_fragment_len; 957 } 958 #ifndef OPENSSL_NO_HEARTBEATS 959 else if (rr->type == TLS1_RT_HEARTBEAT) 960 { 961 dtls1_process_heartbeat(s); 962 963 /* Exit and notify application to read again */ 964 rr->length = 0; 965 s->rwstate=SSL_READING; 966 BIO_clear_retry_flags(SSL_get_rbio(s)); 967 BIO_set_retry_read(SSL_get_rbio(s)); 968 return(-1); 969 } 970 #endif 971 /* else it's a CCS message, or application data or wrong */ 972 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 973 { 974 /* Application data while renegotiating 975 * is allowed. Try again reading. 976 */ 977 if (rr->type == SSL3_RT_APPLICATION_DATA) 978 { 979 BIO *bio; 980 s->s3->in_read_app_data=2; 981 bio=SSL_get_rbio(s); 982 s->rwstate=SSL_READING; 983 BIO_clear_retry_flags(bio); 984 BIO_set_retry_read(bio); 985 return(-1); 986 } 987 988 /* Not certain if this is the right error handling */ 989 al=SSL_AD_UNEXPECTED_MESSAGE; 990 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 991 goto f_err; 992 } 993 994 if (dest_maxlen > 0) 995 { 996 /* XDTLS: In a pathalogical case, the Client Hello 997 * may be fragmented--don't always expect dest_maxlen bytes */ 998 if ( rr->length < dest_maxlen) 999 { 1000 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1001 /* 1002 * for normal alerts rr->length is 2, while 1003 * dest_maxlen is 7 if we were to handle this 1004 * non-existing alert... 1005 */ 1006 FIX ME 1007 #endif 1008 s->rstate=SSL_ST_READ_HEADER; 1009 rr->length = 0; 1010 goto start; 1011 } 1012 1013 /* now move 'n' bytes: */ 1014 for ( k = 0; k < dest_maxlen; k++) 1015 { 1016 dest[k] = rr->data[rr->off++]; 1017 rr->length--; 1018 } 1019 *dest_len = dest_maxlen; 1020 } 1021 } 1022 1023 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 1024 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 1025 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 1026 1027 /* If we are a client, check for an incoming 'Hello Request': */ 1028 if ((!s->server) && 1029 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1030 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1031 (s->session != NULL) && (s->session->cipher != NULL)) 1032 { 1033 s->d1->handshake_fragment_len = 0; 1034 1035 if ((s->d1->handshake_fragment[1] != 0) || 1036 (s->d1->handshake_fragment[2] != 0) || 1037 (s->d1->handshake_fragment[3] != 0)) 1038 { 1039 al=SSL_AD_DECODE_ERROR; 1040 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 1041 goto err; 1042 } 1043 1044 /* no need to check sequence number on HELLO REQUEST messages */ 1045 1046 if (s->msg_callback) 1047 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1048 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 1049 1050 if (SSL_is_init_finished(s) && 1051 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1052 !s->s3->renegotiate) 1053 { 1054 s->new_session = 1; 1055 ssl3_renegotiate(s); 1056 if (ssl3_renegotiate_check(s)) 1057 { 1058 i=s->handshake_func(s); 1059 if (i < 0) return(i); 1060 if (i == 0) 1061 { 1062 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1063 return(-1); 1064 } 1065 1066 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1067 { 1068 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1069 { 1070 BIO *bio; 1071 /* In the case where we try to read application data, 1072 * but we trigger an SSL handshake, we return -1 with 1073 * the retry option set. Otherwise renegotiation may 1074 * cause nasty problems in the blocking world */ 1075 s->rwstate=SSL_READING; 1076 bio=SSL_get_rbio(s); 1077 BIO_clear_retry_flags(bio); 1078 BIO_set_retry_read(bio); 1079 return(-1); 1080 } 1081 } 1082 } 1083 } 1084 /* we either finished a handshake or ignored the request, 1085 * now try again to obtain the (application) data we were asked for */ 1086 goto start; 1087 } 1088 1089 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1090 { 1091 int alert_level = s->d1->alert_fragment[0]; 1092 int alert_descr = s->d1->alert_fragment[1]; 1093 1094 s->d1->alert_fragment_len = 0; 1095 1096 if (s->msg_callback) 1097 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1098 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1099 1100 if (s->info_callback != NULL) 1101 cb=s->info_callback; 1102 else if (s->ctx->info_callback != NULL) 1103 cb=s->ctx->info_callback; 1104 1105 if (cb != NULL) 1106 { 1107 j = (alert_level << 8) | alert_descr; 1108 cb(s, SSL_CB_READ_ALERT, j); 1109 } 1110 1111 if (alert_level == 1) /* warning */ 1112 { 1113 s->s3->warn_alert = alert_descr; 1114 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1115 { 1116 #ifndef OPENSSL_NO_SCTP 1117 /* With SCTP and streams the socket may deliver app data 1118 * after a close_notify alert. We have to check this 1119 * first so that nothing gets discarded. 1120 */ 1121 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1122 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 1123 { 1124 s->d1->shutdown_received = 1; 1125 s->rwstate=SSL_READING; 1126 BIO_clear_retry_flags(SSL_get_rbio(s)); 1127 BIO_set_retry_read(SSL_get_rbio(s)); 1128 return -1; 1129 } 1130 #endif 1131 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1132 return(0); 1133 } 1134 #if 0 1135 /* XXX: this is a possible improvement in the future */ 1136 /* now check if it's a missing record */ 1137 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1138 { 1139 unsigned short seq; 1140 unsigned int frag_off; 1141 unsigned char *p = &(s->d1->alert_fragment[2]); 1142 1143 n2s(p, seq); 1144 n2l3(p, frag_off); 1145 1146 dtls1_retransmit_message(s, 1147 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1148 frag_off, &found); 1149 if ( ! found && SSL_in_init(s)) 1150 { 1151 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1152 /* requested a message not yet sent, 1153 send an alert ourselves */ 1154 ssl3_send_alert(s,SSL3_AL_WARNING, 1155 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1156 } 1157 } 1158 #endif 1159 } 1160 else if (alert_level == 2) /* fatal */ 1161 { 1162 char tmp[16]; 1163 1164 s->rwstate=SSL_NOTHING; 1165 s->s3->fatal_alert = alert_descr; 1166 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1167 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1168 ERR_add_error_data(2,"SSL alert number ",tmp); 1169 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1170 SSL_CTX_remove_session(s->ctx,s->session); 1171 return(0); 1172 } 1173 else 1174 { 1175 al=SSL_AD_ILLEGAL_PARAMETER; 1176 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1177 goto f_err; 1178 } 1179 1180 goto start; 1181 } 1182 1183 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1184 { 1185 s->rwstate=SSL_NOTHING; 1186 rr->length=0; 1187 return(0); 1188 } 1189 1190 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1191 { 1192 struct ccs_header_st ccs_hdr; 1193 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1194 1195 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1196 1197 if (s->version == DTLS1_BAD_VER) 1198 ccs_hdr_len = 3; 1199 1200 /* 'Change Cipher Spec' is just a single byte, so we know 1201 * exactly what the record payload has to look like */ 1202 /* XDTLS: check that epoch is consistent */ 1203 if ( (rr->length != ccs_hdr_len) || 1204 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1205 { 1206 i=SSL_AD_ILLEGAL_PARAMETER; 1207 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1208 goto err; 1209 } 1210 1211 rr->length=0; 1212 1213 if (s->msg_callback) 1214 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1215 rr->data, 1, s, s->msg_callback_arg); 1216 1217 /* We can't process a CCS now, because previous handshake 1218 * messages are still missing, so just drop it. 1219 */ 1220 if (!s->d1->change_cipher_spec_ok) 1221 { 1222 goto start; 1223 } 1224 1225 s->d1->change_cipher_spec_ok = 0; 1226 1227 s->s3->change_cipher_spec=1; 1228 if (!ssl3_do_change_cipher_spec(s)) 1229 goto err; 1230 1231 /* do this whenever CCS is processed */ 1232 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1233 1234 if (s->version == DTLS1_BAD_VER) 1235 s->d1->handshake_read_seq++; 1236 1237 #ifndef OPENSSL_NO_SCTP 1238 /* Remember that a CCS has been received, 1239 * so that an old key of SCTP-Auth can be 1240 * deleted when a CCS is sent. Will be ignored 1241 * if no SCTP is used 1242 */ 1243 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1244 #endif 1245 1246 goto start; 1247 } 1248 1249 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1250 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1251 !s->in_handshake) 1252 { 1253 struct hm_header_st msg_hdr; 1254 1255 /* this may just be a stale retransmit */ 1256 dtls1_get_message_header(rr->data, &msg_hdr); 1257 if( rr->epoch != s->d1->r_epoch) 1258 { 1259 rr->length = 0; 1260 goto start; 1261 } 1262 1263 /* If we are server, we may have a repeated FINISHED of the 1264 * client here, then retransmit our CCS and FINISHED. 1265 */ 1266 if (msg_hdr.type == SSL3_MT_FINISHED) 1267 { 1268 if (dtls1_check_timeout_num(s) < 0) 1269 return -1; 1270 1271 dtls1_retransmit_buffered_messages(s); 1272 rr->length = 0; 1273 goto start; 1274 } 1275 1276 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1277 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1278 { 1279 #if 0 /* worked only because C operator preferences are not as expected (and 1280 * because this is not really needed for clients except for detecting 1281 * protocol violations): */ 1282 s->state=SSL_ST_BEFORE|(s->server) 1283 ?SSL_ST_ACCEPT 1284 :SSL_ST_CONNECT; 1285 #else 1286 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1287 #endif 1288 s->renegotiate=1; 1289 s->new_session=1; 1290 } 1291 i=s->handshake_func(s); 1292 if (i < 0) return(i); 1293 if (i == 0) 1294 { 1295 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1296 return(-1); 1297 } 1298 1299 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1300 { 1301 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1302 { 1303 BIO *bio; 1304 /* In the case where we try to read application data, 1305 * but we trigger an SSL handshake, we return -1 with 1306 * the retry option set. Otherwise renegotiation may 1307 * cause nasty problems in the blocking world */ 1308 s->rwstate=SSL_READING; 1309 bio=SSL_get_rbio(s); 1310 BIO_clear_retry_flags(bio); 1311 BIO_set_retry_read(bio); 1312 return(-1); 1313 } 1314 } 1315 goto start; 1316 } 1317 1318 switch (rr->type) 1319 { 1320 default: 1321 #ifndef OPENSSL_NO_TLS 1322 /* TLS just ignores unknown message types */ 1323 if (s->version == TLS1_VERSION) 1324 { 1325 rr->length = 0; 1326 goto start; 1327 } 1328 #endif 1329 al=SSL_AD_UNEXPECTED_MESSAGE; 1330 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1331 goto f_err; 1332 case SSL3_RT_CHANGE_CIPHER_SPEC: 1333 case SSL3_RT_ALERT: 1334 case SSL3_RT_HANDSHAKE: 1335 /* we already handled all of these, with the possible exception 1336 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1337 * should not happen when type != rr->type */ 1338 al=SSL_AD_UNEXPECTED_MESSAGE; 1339 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1340 goto f_err; 1341 case SSL3_RT_APPLICATION_DATA: 1342 /* At this point, we were expecting handshake data, 1343 * but have application data. If the library was 1344 * running inside ssl3_read() (i.e. in_read_app_data 1345 * is set) and it makes sense to read application data 1346 * at this point (session renegotiation not yet started), 1347 * we will indulge it. 1348 */ 1349 if (s->s3->in_read_app_data && 1350 (s->s3->total_renegotiations != 0) && 1351 (( 1352 (s->state & SSL_ST_CONNECT) && 1353 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1354 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1355 ) || ( 1356 (s->state & SSL_ST_ACCEPT) && 1357 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1358 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1359 ) 1360 )) 1361 { 1362 s->s3->in_read_app_data=2; 1363 return(-1); 1364 } 1365 else 1366 { 1367 al=SSL_AD_UNEXPECTED_MESSAGE; 1368 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1369 goto f_err; 1370 } 1371 } 1372 /* not reached */ 1373 1374 f_err: 1375 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1376 err: 1377 return(-1); 1378 } 1379 1380 int 1381 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1382 { 1383 int i; 1384 1385 #ifndef OPENSSL_NO_SCTP 1386 /* Check if we have to continue an interrupted handshake 1387 * for reading belated app data with SCTP. 1388 */ 1389 if ((SSL_in_init(s) && !s->in_handshake) || 1390 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1391 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1392 #else 1393 if (SSL_in_init(s) && !s->in_handshake) 1394 #endif 1395 { 1396 i=s->handshake_func(s); 1397 if (i < 0) return(i); 1398 if (i == 0) 1399 { 1400 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1401 return -1; 1402 } 1403 } 1404 1405 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1406 { 1407 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1408 return -1; 1409 } 1410 1411 i = dtls1_write_bytes(s, type, buf_, len); 1412 return i; 1413 } 1414 1415 1416 /* this only happens when a client hello is received and a handshake 1417 * is started. */ 1418 static int 1419 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1420 int len, int peek) 1421 { 1422 1423 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1424 /* (partially) satisfy request from storage */ 1425 { 1426 unsigned char *src = s->d1->handshake_fragment; 1427 unsigned char *dst = buf; 1428 unsigned int k,n; 1429 1430 /* peek == 0 */ 1431 n = 0; 1432 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1433 { 1434 *dst++ = *src++; 1435 len--; s->d1->handshake_fragment_len--; 1436 n++; 1437 } 1438 /* move any remaining fragment bytes: */ 1439 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1440 s->d1->handshake_fragment[k] = *src++; 1441 return n; 1442 } 1443 1444 return 0; 1445 } 1446 1447 1448 1449 1450 /* Call this to write data in records of type 'type' 1451 * It will return <= 0 if not all data has been sent or non-blocking IO. 1452 */ 1453 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1454 { 1455 int i; 1456 1457 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1458 s->rwstate=SSL_NOTHING; 1459 i=do_dtls1_write(s, type, buf, len, 0); 1460 return i; 1461 } 1462 1463 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1464 { 1465 unsigned char *p,*pseq; 1466 int i,mac_size,clear=0; 1467 int prefix_len = 0; 1468 SSL3_RECORD *wr; 1469 SSL3_BUFFER *wb; 1470 SSL_SESSION *sess; 1471 int bs; 1472 1473 /* first check if there is a SSL3_BUFFER still being written 1474 * out. This will happen with non blocking IO */ 1475 if (s->s3->wbuf.left != 0) 1476 { 1477 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1478 return(ssl3_write_pending(s,type,buf,len)); 1479 } 1480 1481 /* If we have an alert to send, lets send it */ 1482 if (s->s3->alert_dispatch) 1483 { 1484 i=s->method->ssl_dispatch_alert(s); 1485 if (i <= 0) 1486 return(i); 1487 /* if it went, fall through and send more stuff */ 1488 } 1489 1490 if (len == 0 && !create_empty_fragment) 1491 return 0; 1492 1493 wr= &(s->s3->wrec); 1494 wb= &(s->s3->wbuf); 1495 sess=s->session; 1496 1497 if ( (sess == NULL) || 1498 (s->enc_write_ctx == NULL) || 1499 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1500 clear=1; 1501 1502 if (clear) 1503 mac_size=0; 1504 else 1505 { 1506 mac_size=EVP_MD_CTX_size(s->write_hash); 1507 if (mac_size < 0) 1508 goto err; 1509 } 1510 1511 /* DTLS implements explicit IV, so no need for empty fragments */ 1512 #if 0 1513 /* 'create_empty_fragment' is true only when this function calls itself */ 1514 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1515 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1516 { 1517 /* countermeasure against known-IV weakness in CBC ciphersuites 1518 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1519 */ 1520 1521 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1522 { 1523 /* recursive function call with 'create_empty_fragment' set; 1524 * this prepares and buffers the data for an empty fragment 1525 * (these 'prefix_len' bytes are sent out later 1526 * together with the actual payload) */ 1527 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1528 if (prefix_len <= 0) 1529 goto err; 1530 1531 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1532 { 1533 /* insufficient space */ 1534 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1535 goto err; 1536 } 1537 } 1538 1539 s->s3->empty_fragment_done = 1; 1540 } 1541 #endif 1542 p = wb->buf + prefix_len; 1543 1544 /* write the header */ 1545 1546 *(p++)=type&0xff; 1547 wr->type=type; 1548 1549 *(p++)=(s->version>>8); 1550 *(p++)=s->version&0xff; 1551 1552 /* field where we are to write out packet epoch, seq num and len */ 1553 pseq=p; 1554 p+=10; 1555 1556 /* lets setup the record stuff. */ 1557 1558 /* Make space for the explicit IV in case of CBC. 1559 * (this is a bit of a boundary violation, but what the heck). 1560 */ 1561 if ( s->enc_write_ctx && 1562 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1563 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1564 else 1565 bs = 0; 1566 1567 wr->data=p + bs; /* make room for IV in case of CBC */ 1568 wr->length=(int)len; 1569 wr->input=(unsigned char *)buf; 1570 1571 /* we now 'read' from wr->input, wr->length bytes into 1572 * wr->data */ 1573 1574 /* first we compress */ 1575 if (s->compress != NULL) 1576 { 1577 if (!ssl3_do_compress(s)) 1578 { 1579 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1580 goto err; 1581 } 1582 } 1583 else 1584 { 1585 memcpy(wr->data,wr->input,wr->length); 1586 wr->input=wr->data; 1587 } 1588 1589 /* we should still have the output to wr->data and the input 1590 * from wr->input. Length should be wr->length. 1591 * wr->data still points in the wb->buf */ 1592 1593 if (mac_size != 0) 1594 { 1595 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0) 1596 goto err; 1597 wr->length+=mac_size; 1598 } 1599 1600 /* this is true regardless of mac size */ 1601 wr->input=p; 1602 wr->data=p; 1603 1604 1605 /* ssl3_enc can only have an error on read */ 1606 if (bs) /* bs != 0 in case of CBC */ 1607 { 1608 RAND_pseudo_bytes(p,bs); 1609 /* master IV and last CBC residue stand for 1610 * the rest of randomness */ 1611 wr->length += bs; 1612 } 1613 1614 s->method->ssl3_enc->enc(s,1); 1615 1616 /* record length after mac and block padding */ 1617 /* if (type == SSL3_RT_APPLICATION_DATA || 1618 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1619 1620 /* there's only one epoch between handshake and app data */ 1621 1622 s2n(s->d1->w_epoch, pseq); 1623 1624 /* XDTLS: ?? */ 1625 /* else 1626 s2n(s->d1->handshake_epoch, pseq); */ 1627 1628 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1629 pseq+=6; 1630 s2n(wr->length,pseq); 1631 1632 /* we should now have 1633 * wr->data pointing to the encrypted data, which is 1634 * wr->length long */ 1635 wr->type=type; /* not needed but helps for debugging */ 1636 wr->length+=DTLS1_RT_HEADER_LENGTH; 1637 1638 #if 0 /* this is now done at the message layer */ 1639 /* buffer the record, making it easy to handle retransmits */ 1640 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1641 dtls1_buffer_record(s, wr->data, wr->length, 1642 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1643 #endif 1644 1645 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1646 1647 if (create_empty_fragment) 1648 { 1649 /* we are in a recursive call; 1650 * just return the length, don't write out anything here 1651 */ 1652 return wr->length; 1653 } 1654 1655 /* now let's set up wb */ 1656 wb->left = prefix_len + wr->length; 1657 wb->offset = 0; 1658 1659 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1660 s->s3->wpend_tot=len; 1661 s->s3->wpend_buf=buf; 1662 s->s3->wpend_type=type; 1663 s->s3->wpend_ret=len; 1664 1665 /* we now just need to write the buffer */ 1666 return ssl3_write_pending(s,type,buf,len); 1667 err: 1668 return -1; 1669 } 1670 1671 1672 1673 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1674 { 1675 int cmp; 1676 unsigned int shift; 1677 const unsigned char *seq = s->s3->read_sequence; 1678 1679 cmp = satsub64be(seq,bitmap->max_seq_num); 1680 if (cmp > 0) 1681 { 1682 memcpy (s->s3->rrec.seq_num,seq,8); 1683 return 1; /* this record in new */ 1684 } 1685 shift = -cmp; 1686 if (shift >= sizeof(bitmap->map)*8) 1687 return 0; /* stale, outside the window */ 1688 else if (bitmap->map & (1UL<<shift)) 1689 return 0; /* record previously received */ 1690 1691 memcpy (s->s3->rrec.seq_num,seq,8); 1692 return 1; 1693 } 1694 1695 1696 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1697 { 1698 int cmp; 1699 unsigned int shift; 1700 const unsigned char *seq = s->s3->read_sequence; 1701 1702 cmp = satsub64be(seq,bitmap->max_seq_num); 1703 if (cmp > 0) 1704 { 1705 shift = cmp; 1706 if (shift < sizeof(bitmap->map)*8) 1707 bitmap->map <<= shift, bitmap->map |= 1UL; 1708 else 1709 bitmap->map = 1UL; 1710 memcpy(bitmap->max_seq_num,seq,8); 1711 } 1712 else { 1713 shift = -cmp; 1714 if (shift < sizeof(bitmap->map)*8) 1715 bitmap->map |= 1UL<<shift; 1716 } 1717 } 1718 1719 1720 int dtls1_dispatch_alert(SSL *s) 1721 { 1722 int i,j; 1723 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1724 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1725 unsigned char *ptr = &buf[0]; 1726 1727 s->s3->alert_dispatch=0; 1728 1729 memset(buf, 0x00, sizeof(buf)); 1730 *ptr++ = s->s3->send_alert[0]; 1731 *ptr++ = s->s3->send_alert[1]; 1732 1733 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1734 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1735 { 1736 s2n(s->d1->handshake_read_seq, ptr); 1737 #if 0 1738 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1739 1740 else 1741 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1742 #endif 1743 1744 #if 0 1745 fprintf(stderr, "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",s->d1->handshake_read_seq,s->d1->r_msg_hdr.seq); 1746 #endif 1747 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1748 } 1749 #endif 1750 1751 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1752 if (i <= 0) 1753 { 1754 s->s3->alert_dispatch=1; 1755 /* fprintf( stderr, "not done with alert\n" ); */ 1756 } 1757 else 1758 { 1759 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1760 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1761 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1762 #endif 1763 ) 1764 (void)BIO_flush(s->wbio); 1765 1766 if (s->msg_callback) 1767 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1768 2, s, s->msg_callback_arg); 1769 1770 if (s->info_callback != NULL) 1771 cb=s->info_callback; 1772 else if (s->ctx->info_callback != NULL) 1773 cb=s->ctx->info_callback; 1774 1775 if (cb != NULL) 1776 { 1777 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1778 cb(s,SSL_CB_WRITE_ALERT,j); 1779 } 1780 } 1781 return(i); 1782 } 1783 1784 1785 static DTLS1_BITMAP * 1786 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1787 { 1788 1789 *is_next_epoch = 0; 1790 1791 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1792 if (rr->epoch == s->d1->r_epoch) 1793 return &s->d1->bitmap; 1794 1795 /* Only HM and ALERT messages can be from the next epoch */ 1796 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1797 (rr->type == SSL3_RT_HANDSHAKE || 1798 rr->type == SSL3_RT_ALERT)) 1799 { 1800 *is_next_epoch = 1; 1801 return &s->d1->next_bitmap; 1802 } 1803 1804 return NULL; 1805 } 1806 1807 #if 0 1808 static int 1809 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1810 unsigned long *offset) 1811 { 1812 1813 /* alerts are passed up immediately */ 1814 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1815 rr->type == SSL3_RT_ALERT) 1816 return 0; 1817 1818 /* Only need to buffer if a handshake is underway. 1819 * (this implies that Hello Request and Client Hello are passed up 1820 * immediately) */ 1821 if ( SSL_in_init(s)) 1822 { 1823 unsigned char *data = rr->data; 1824 /* need to extract the HM/CCS sequence number here */ 1825 if ( rr->type == SSL3_RT_HANDSHAKE || 1826 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1827 { 1828 unsigned short seq_num; 1829 struct hm_header_st msg_hdr; 1830 struct ccs_header_st ccs_hdr; 1831 1832 if ( rr->type == SSL3_RT_HANDSHAKE) 1833 { 1834 dtls1_get_message_header(data, &msg_hdr); 1835 seq_num = msg_hdr.seq; 1836 *offset = msg_hdr.frag_off; 1837 } 1838 else 1839 { 1840 dtls1_get_ccs_header(data, &ccs_hdr); 1841 seq_num = ccs_hdr.seq; 1842 *offset = 0; 1843 } 1844 1845 /* this is either a record we're waiting for, or a 1846 * retransmit of something we happened to previously 1847 * receive (higher layers will drop the repeat silently */ 1848 if ( seq_num < s->d1->handshake_read_seq) 1849 return 0; 1850 if (rr->type == SSL3_RT_HANDSHAKE && 1851 seq_num == s->d1->handshake_read_seq && 1852 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1853 return 0; 1854 else if ( seq_num == s->d1->handshake_read_seq && 1855 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1856 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1857 return 0; 1858 else 1859 { 1860 *priority = seq_num; 1861 return 1; 1862 } 1863 } 1864 else /* unknown record type */ 1865 return 0; 1866 } 1867 1868 return 0; 1869 } 1870 #endif 1871 1872 void 1873 dtls1_reset_seq_numbers(SSL *s, int rw) 1874 { 1875 unsigned char *seq; 1876 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1877 1878 if ( rw & SSL3_CC_READ) 1879 { 1880 seq = s->s3->read_sequence; 1881 s->d1->r_epoch++; 1882 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1883 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1884 } 1885 else 1886 { 1887 seq = s->s3->write_sequence; 1888 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1889 s->d1->w_epoch++; 1890 } 1891 1892 memset(seq, 0x00, seq_bytes); 1893 } 1894
