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 clear=0; 380 int enc_err; 381 SSL_SESSION *sess; 382 SSL3_RECORD *rr; 383 unsigned int mac_size; 384 unsigned char md[EVP_MAX_MD_SIZE]; 385 int decryption_failed_or_bad_record_mac = 0; 386 unsigned char *mac = NULL; 387 388 389 rr= &(s->s3->rrec); 390 sess = s->session; 391 392 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 393 * and we have that many bytes in s->packet 394 */ 395 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 396 397 /* ok, we can now read from 's->packet' data into 'rr' 398 * rr->input points at rr->length bytes, which 399 * need to be copied into rr->data by either 400 * the decryption or by the decompression 401 * When the data is 'copied' into the rr->data buffer, 402 * rr->input will be pointed at the new buffer */ 403 404 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 405 * rr->length bytes of encrypted compressed stuff. */ 406 407 /* check is not needed I believe */ 408 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 409 { 410 al=SSL_AD_RECORD_OVERFLOW; 411 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 412 goto f_err; 413 } 414 415 /* decrypt in place in 'rr->input' */ 416 rr->data=rr->input; 417 418 enc_err = s->method->ssl3_enc->enc(s,0); 419 if (enc_err <= 0) 420 { 421 /* To minimize information leaked via timing, we will always 422 * perform all computations before discarding the message. 423 */ 424 decryption_failed_or_bad_record_mac = 1; 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 (s->read_hash == NULL)) 437 clear=1; 438 439 if (!clear) 440 { 441 /* !clear => s->read_hash != NULL => mac_size != -1 */ 442 int t; 443 t=EVP_MD_CTX_size(s->read_hash); 444 OPENSSL_assert(t >= 0); 445 mac_size=t; 446 447 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 448 { 449 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ 450 al=SSL_AD_RECORD_OVERFLOW; 451 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); 452 goto f_err; 453 #else 454 decryption_failed_or_bad_record_mac = 1; 455 #endif 456 } 457 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ 458 if (rr->length >= mac_size) 459 { 460 rr->length -= mac_size; 461 mac = &rr->data[rr->length]; 462 } 463 else 464 rr->length = 0; 465 i=s->method->ssl3_enc->mac(s,md,0); 466 if (i < 0 || mac == NULL || memcmp(md, mac, mac_size) != 0) 467 { 468 decryption_failed_or_bad_record_mac = 1; 469 } 470 } 471 472 if (decryption_failed_or_bad_record_mac) 473 { 474 /* decryption failed, silently discard message */ 475 rr->length = 0; 476 s->packet_length = 0; 477 goto err; 478 } 479 480 /* r->length is now just compressed */ 481 if (s->expand != NULL) 482 { 483 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 484 { 485 al=SSL_AD_RECORD_OVERFLOW; 486 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 487 goto f_err; 488 } 489 if (!ssl3_do_uncompress(s)) 490 { 491 al=SSL_AD_DECOMPRESSION_FAILURE; 492 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 493 goto f_err; 494 } 495 } 496 497 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 498 { 499 al=SSL_AD_RECORD_OVERFLOW; 500 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 501 goto f_err; 502 } 503 504 rr->off=0; 505 /* So at this point the following is true 506 * ssl->s3->rrec.type is the type of record 507 * ssl->s3->rrec.length == number of bytes in record 508 * ssl->s3->rrec.off == offset to first valid byte 509 * ssl->s3->rrec.data == where to take bytes from, increment 510 * after use :-). 511 */ 512 513 /* we have pulled in a full packet so zero things */ 514 s->packet_length=0; 515 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 516 return(1); 517 518 f_err: 519 ssl3_send_alert(s,SSL3_AL_FATAL,al); 520 err: 521 return(0); 522 } 523 524 525 /* Call this to get a new input record. 526 * It will return <= 0 if more data is needed, normally due to an error 527 * or non-blocking IO. 528 * When it finishes, one packet has been decoded and can be found in 529 * ssl->s3->rrec.type - is the type of record 530 * ssl->s3->rrec.data, - data 531 * ssl->s3->rrec.length, - number of bytes 532 */ 533 /* used only by dtls1_read_bytes */ 534 int dtls1_get_record(SSL *s) 535 { 536 int ssl_major,ssl_minor; 537 int i,n; 538 SSL3_RECORD *rr; 539 unsigned char *p = NULL; 540 unsigned short version; 541 DTLS1_BITMAP *bitmap; 542 unsigned int is_next_epoch; 543 544 rr= &(s->s3->rrec); 545 546 /* The epoch may have changed. If so, process all the 547 * pending records. This is a non-blocking operation. */ 548 dtls1_process_buffered_records(s); 549 550 /* if we're renegotiating, then there may be buffered records */ 551 if (dtls1_get_processed_record(s)) 552 return 1; 553 554 /* get something from the wire */ 555 again: 556 /* check if we have the header */ 557 if ( (s->rstate != SSL_ST_READ_BODY) || 558 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 559 { 560 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 561 /* read timeout is handled by dtls1_read_bytes */ 562 if (n <= 0) return(n); /* error or non-blocking */ 563 564 /* this packet contained a partial record, dump it */ 565 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 566 { 567 s->packet_length = 0; 568 goto again; 569 } 570 571 s->rstate=SSL_ST_READ_BODY; 572 573 p=s->packet; 574 575 /* Pull apart the header into the DTLS1_RECORD */ 576 rr->type= *(p++); 577 ssl_major= *(p++); 578 ssl_minor= *(p++); 579 version=(ssl_major<<8)|ssl_minor; 580 581 /* sequence number is 64 bits, with top 2 bytes = epoch */ 582 n2s(p,rr->epoch); 583 584 memcpy(&(s->s3->read_sequence[2]), p, 6); 585 p+=6; 586 587 n2s(p,rr->length); 588 589 /* Lets check version */ 590 if (!s->first_packet) 591 { 592 if (version != s->version) 593 { 594 /* unexpected version, silently discard */ 595 rr->length = 0; 596 s->packet_length = 0; 597 goto again; 598 } 599 } 600 601 if ((version & 0xff00) != (s->version & 0xff00)) 602 { 603 /* wrong version, silently discard record */ 604 rr->length = 0; 605 s->packet_length = 0; 606 goto again; 607 } 608 609 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 610 { 611 /* record too long, silently discard it */ 612 rr->length = 0; 613 s->packet_length = 0; 614 goto again; 615 } 616 617 /* If we receive a valid record larger than the current buffer size, 618 * allocate some memory for it. 619 */ 620 if (rr->length > s->s3->rbuf.len - DTLS1_RT_HEADER_LENGTH) 621 { 622 unsigned char *pp; 623 unsigned int newlen = rr->length + DTLS1_RT_HEADER_LENGTH; 624 if ((pp=OPENSSL_realloc(s->s3->rbuf.buf, newlen))==NULL) 625 { 626 SSLerr(SSL_F_DTLS1_GET_RECORD,ERR_R_MALLOC_FAILURE); 627 return(-1); 628 } 629 p = pp + (p - s->s3->rbuf.buf); 630 s->s3->rbuf.buf=pp; 631 s->s3->rbuf.len=newlen; 632 s->packet= &(s->s3->rbuf.buf[0]); 633 } 634 635 /* now s->rstate == SSL_ST_READ_BODY */ 636 } 637 638 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 639 640 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 641 { 642 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 643 i=rr->length; 644 n=ssl3_read_n(s,i,i,1); 645 if (n <= 0) return(n); /* error or non-blocking io */ 646 647 /* this packet contained a partial record, dump it */ 648 if ( n != i) 649 { 650 rr->length = 0; 651 s->packet_length = 0; 652 goto again; 653 } 654 655 /* now n == rr->length, 656 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 657 } 658 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 659 660 /* match epochs. NULL means the packet is dropped on the floor */ 661 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 662 if ( bitmap == NULL) 663 { 664 rr->length = 0; 665 s->packet_length = 0; /* dump this record */ 666 goto again; /* get another record */ 667 } 668 669 #ifndef OPENSSL_NO_SCTP 670 /* Only do replay check if no SCTP bio */ 671 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) 672 { 673 #endif 674 /* Check whether this is a repeat, or aged record. 675 * Don't check if we're listening and this message is 676 * a ClientHello. They can look as if they're replayed, 677 * since they arrive from different connections and 678 * would be dropped unnecessarily. 679 */ 680 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 681 *p == SSL3_MT_CLIENT_HELLO) && 682 !dtls1_record_replay_check(s, bitmap)) 683 { 684 rr->length = 0; 685 s->packet_length=0; /* dump this record */ 686 goto again; /* get another record */ 687 } 688 #ifndef OPENSSL_NO_SCTP 689 } 690 #endif 691 692 /* just read a 0 length packet */ 693 if (rr->length == 0) goto again; 694 695 /* If this record is from the next epoch (either HM or ALERT), 696 * and a handshake is currently in progress, buffer it since it 697 * cannot be processed at this time. However, do not buffer 698 * anything while listening. 699 */ 700 if (is_next_epoch) 701 { 702 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) 703 { 704 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 705 } 706 rr->length = 0; 707 s->packet_length = 0; 708 goto again; 709 } 710 711 if (!dtls1_process_record(s)) 712 { 713 rr->length = 0; 714 s->packet_length = 0; /* dump this record */ 715 goto again; /* get another record */ 716 } 717 718 return(1); 719 720 } 721 722 /* Return up to 'len' payload bytes received in 'type' records. 723 * 'type' is one of the following: 724 * 725 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 726 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 727 * - 0 (during a shutdown, no data has to be returned) 728 * 729 * If we don't have stored data to work from, read a SSL/TLS record first 730 * (possibly multiple records if we still don't have anything to return). 731 * 732 * This function must handle any surprises the peer may have for us, such as 733 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 734 * a surprise, but handled as if it were), or renegotiation requests. 735 * Also if record payloads contain fragments too small to process, we store 736 * them until there is enough for the respective protocol (the record protocol 737 * may use arbitrary fragmentation and even interleaving): 738 * Change cipher spec protocol 739 * just 1 byte needed, no need for keeping anything stored 740 * Alert protocol 741 * 2 bytes needed (AlertLevel, AlertDescription) 742 * Handshake protocol 743 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 744 * to detect unexpected Client Hello and Hello Request messages 745 * here, anything else is handled by higher layers 746 * Application data protocol 747 * none of our business 748 */ 749 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 750 { 751 int al,i,j,ret; 752 unsigned int n; 753 SSL3_RECORD *rr; 754 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 755 756 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 757 if (!ssl3_setup_buffers(s)) 758 return(-1); 759 760 /* XXX: check what the second '&& type' is about */ 761 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 762 (type != SSL3_RT_HANDSHAKE) && type) || 763 (peek && (type != SSL3_RT_APPLICATION_DATA))) 764 { 765 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 766 return -1; 767 } 768 769 /* check whether there's a handshake message (client hello?) waiting */ 770 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 771 return ret; 772 773 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 774 775 #ifndef OPENSSL_NO_SCTP 776 /* Continue handshake if it had to be interrupted to read 777 * app data with SCTP. 778 */ 779 if ((!s->in_handshake && SSL_in_init(s)) || 780 (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 781 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) && 782 s->s3->in_read_app_data != 2)) 783 #else 784 if (!s->in_handshake && SSL_in_init(s)) 785 #endif 786 { 787 /* type == SSL3_RT_APPLICATION_DATA */ 788 i=s->handshake_func(s); 789 if (i < 0) return(i); 790 if (i == 0) 791 { 792 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 793 return(-1); 794 } 795 } 796 797 start: 798 s->rwstate=SSL_NOTHING; 799 800 /* s->s3->rrec.type - is the type of record 801 * s->s3->rrec.data, - data 802 * s->s3->rrec.off, - offset into 'data' for next read 803 * s->s3->rrec.length, - number of bytes. */ 804 rr = &(s->s3->rrec); 805 806 /* We are not handshaking and have no data yet, 807 * so process data buffered during the last handshake 808 * in advance, if any. 809 */ 810 if (s->state == SSL_ST_OK && rr->length == 0) 811 { 812 pitem *item; 813 item = pqueue_pop(s->d1->buffered_app_data.q); 814 if (item) 815 { 816 #ifndef OPENSSL_NO_SCTP 817 /* Restore bio_dgram_sctp_rcvinfo struct */ 818 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) 819 { 820 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data; 821 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 822 } 823 #endif 824 825 dtls1_copy_record(s, item); 826 827 OPENSSL_free(item->data); 828 pitem_free(item); 829 } 830 } 831 832 /* Check for timeout */ 833 if (dtls1_handle_timeout(s) > 0) 834 goto start; 835 836 /* get new packet if necessary */ 837 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 838 { 839 ret=dtls1_get_record(s); 840 if (ret <= 0) 841 { 842 ret = dtls1_read_failed(s, ret); 843 /* anything other than a timeout is an error */ 844 if (ret <= 0) 845 return(ret); 846 else 847 goto start; 848 } 849 } 850 851 /* we now have a packet which can be read and processed */ 852 853 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 854 * reset by ssl3_get_finished */ 855 && (rr->type != SSL3_RT_HANDSHAKE)) 856 { 857 /* We now have application data between CCS and Finished. 858 * Most likely the packets were reordered on their way, so 859 * buffer the application data for later processing rather 860 * than dropping the connection. 861 */ 862 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num); 863 rr->length = 0; 864 goto start; 865 } 866 867 /* If the other end has shut down, throw anything we read away 868 * (even in 'peek' mode) */ 869 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 870 { 871 rr->length=0; 872 s->rwstate=SSL_NOTHING; 873 return(0); 874 } 875 876 877 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 878 { 879 /* make sure that we are not getting application data when we 880 * are doing a handshake for the first time */ 881 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 882 (s->enc_read_ctx == NULL)) 883 { 884 al=SSL_AD_UNEXPECTED_MESSAGE; 885 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 886 goto f_err; 887 } 888 889 if (len <= 0) return(len); 890 891 if ((unsigned int)len > rr->length) 892 n = rr->length; 893 else 894 n = (unsigned int)len; 895 896 memcpy(buf,&(rr->data[rr->off]),n); 897 if (!peek) 898 { 899 rr->length-=n; 900 rr->off+=n; 901 if (rr->length == 0) 902 { 903 s->rstate=SSL_ST_READ_HEADER; 904 rr->off=0; 905 } 906 } 907 908 #ifndef OPENSSL_NO_SCTP 909 /* We were about to renegotiate but had to read 910 * belated application data first, so retry. 911 */ 912 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 913 rr->type == SSL3_RT_APPLICATION_DATA && 914 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) 915 { 916 s->rwstate=SSL_READING; 917 BIO_clear_retry_flags(SSL_get_rbio(s)); 918 BIO_set_retry_read(SSL_get_rbio(s)); 919 } 920 921 /* We might had to delay a close_notify alert because 922 * of reordered app data. If there was an alert and there 923 * is no message to read anymore, finally set shutdown. 924 */ 925 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 926 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 927 { 928 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 929 return(0); 930 } 931 #endif 932 return(n); 933 } 934 935 936 /* If we get here, then type != rr->type; if we have a handshake 937 * message, then it was unexpected (Hello Request or Client Hello). */ 938 939 /* In case of record types for which we have 'fragment' storage, 940 * fill that so that we can process the data at a fixed place. 941 */ 942 { 943 unsigned int k, dest_maxlen = 0; 944 unsigned char *dest = NULL; 945 unsigned int *dest_len = NULL; 946 947 if (rr->type == SSL3_RT_HANDSHAKE) 948 { 949 dest_maxlen = sizeof s->d1->handshake_fragment; 950 dest = s->d1->handshake_fragment; 951 dest_len = &s->d1->handshake_fragment_len; 952 } 953 else if (rr->type == SSL3_RT_ALERT) 954 { 955 dest_maxlen = sizeof(s->d1->alert_fragment); 956 dest = s->d1->alert_fragment; 957 dest_len = &s->d1->alert_fragment_len; 958 } 959 #ifndef OPENSSL_NO_HEARTBEATS 960 else if (rr->type == TLS1_RT_HEARTBEAT) 961 { 962 dtls1_process_heartbeat(s); 963 964 /* Exit and notify application to read again */ 965 rr->length = 0; 966 s->rwstate=SSL_READING; 967 BIO_clear_retry_flags(SSL_get_rbio(s)); 968 BIO_set_retry_read(SSL_get_rbio(s)); 969 return(-1); 970 } 971 #endif 972 /* else it's a CCS message, or application data or wrong */ 973 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 974 { 975 /* Application data while renegotiating 976 * is allowed. Try again reading. 977 */ 978 if (rr->type == SSL3_RT_APPLICATION_DATA) 979 { 980 BIO *bio; 981 s->s3->in_read_app_data=2; 982 bio=SSL_get_rbio(s); 983 s->rwstate=SSL_READING; 984 BIO_clear_retry_flags(bio); 985 BIO_set_retry_read(bio); 986 return(-1); 987 } 988 989 /* Not certain if this is the right error handling */ 990 al=SSL_AD_UNEXPECTED_MESSAGE; 991 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 992 goto f_err; 993 } 994 995 if (dest_maxlen > 0) 996 { 997 /* XDTLS: In a pathalogical case, the Client Hello 998 * may be fragmented--don't always expect dest_maxlen bytes */ 999 if ( rr->length < dest_maxlen) 1000 { 1001 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1002 /* 1003 * for normal alerts rr->length is 2, while 1004 * dest_maxlen is 7 if we were to handle this 1005 * non-existing alert... 1006 */ 1007 FIX ME 1008 #endif 1009 s->rstate=SSL_ST_READ_HEADER; 1010 rr->length = 0; 1011 goto start; 1012 } 1013 1014 /* now move 'n' bytes: */ 1015 for ( k = 0; k < dest_maxlen; k++) 1016 { 1017 dest[k] = rr->data[rr->off++]; 1018 rr->length--; 1019 } 1020 *dest_len = dest_maxlen; 1021 } 1022 } 1023 1024 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 1025 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 1026 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 1027 1028 /* If we are a client, check for an incoming 'Hello Request': */ 1029 if ((!s->server) && 1030 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1031 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1032 (s->session != NULL) && (s->session->cipher != NULL)) 1033 { 1034 s->d1->handshake_fragment_len = 0; 1035 1036 if ((s->d1->handshake_fragment[1] != 0) || 1037 (s->d1->handshake_fragment[2] != 0) || 1038 (s->d1->handshake_fragment[3] != 0)) 1039 { 1040 al=SSL_AD_DECODE_ERROR; 1041 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 1042 goto err; 1043 } 1044 1045 /* no need to check sequence number on HELLO REQUEST messages */ 1046 1047 if (s->msg_callback) 1048 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1049 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 1050 1051 if (SSL_is_init_finished(s) && 1052 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1053 !s->s3->renegotiate) 1054 { 1055 s->new_session = 1; 1056 ssl3_renegotiate(s); 1057 if (ssl3_renegotiate_check(s)) 1058 { 1059 i=s->handshake_func(s); 1060 if (i < 0) return(i); 1061 if (i == 0) 1062 { 1063 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1064 return(-1); 1065 } 1066 1067 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1068 { 1069 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1070 { 1071 BIO *bio; 1072 /* In the case where we try to read application data, 1073 * but we trigger an SSL handshake, we return -1 with 1074 * the retry option set. Otherwise renegotiation may 1075 * cause nasty problems in the blocking world */ 1076 s->rwstate=SSL_READING; 1077 bio=SSL_get_rbio(s); 1078 BIO_clear_retry_flags(bio); 1079 BIO_set_retry_read(bio); 1080 return(-1); 1081 } 1082 } 1083 } 1084 } 1085 /* we either finished a handshake or ignored the request, 1086 * now try again to obtain the (application) data we were asked for */ 1087 goto start; 1088 } 1089 1090 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1091 { 1092 int alert_level = s->d1->alert_fragment[0]; 1093 int alert_descr = s->d1->alert_fragment[1]; 1094 1095 s->d1->alert_fragment_len = 0; 1096 1097 if (s->msg_callback) 1098 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1099 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1100 1101 if (s->info_callback != NULL) 1102 cb=s->info_callback; 1103 else if (s->ctx->info_callback != NULL) 1104 cb=s->ctx->info_callback; 1105 1106 if (cb != NULL) 1107 { 1108 j = (alert_level << 8) | alert_descr; 1109 cb(s, SSL_CB_READ_ALERT, j); 1110 } 1111 1112 if (alert_level == 1) /* warning */ 1113 { 1114 s->s3->warn_alert = alert_descr; 1115 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1116 { 1117 #ifndef OPENSSL_NO_SCTP 1118 /* With SCTP and streams the socket may deliver app data 1119 * after a close_notify alert. We have to check this 1120 * first so that nothing gets discarded. 1121 */ 1122 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1123 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 1124 { 1125 s->d1->shutdown_received = 1; 1126 s->rwstate=SSL_READING; 1127 BIO_clear_retry_flags(SSL_get_rbio(s)); 1128 BIO_set_retry_read(SSL_get_rbio(s)); 1129 return -1; 1130 } 1131 #endif 1132 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1133 return(0); 1134 } 1135 #if 0 1136 /* XXX: this is a possible improvement in the future */ 1137 /* now check if it's a missing record */ 1138 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1139 { 1140 unsigned short seq; 1141 unsigned int frag_off; 1142 unsigned char *p = &(s->d1->alert_fragment[2]); 1143 1144 n2s(p, seq); 1145 n2l3(p, frag_off); 1146 1147 dtls1_retransmit_message(s, 1148 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1149 frag_off, &found); 1150 if ( ! found && SSL_in_init(s)) 1151 { 1152 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1153 /* requested a message not yet sent, 1154 send an alert ourselves */ 1155 ssl3_send_alert(s,SSL3_AL_WARNING, 1156 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1157 } 1158 } 1159 #endif 1160 } 1161 else if (alert_level == 2) /* fatal */ 1162 { 1163 char tmp[16]; 1164 1165 s->rwstate=SSL_NOTHING; 1166 s->s3->fatal_alert = alert_descr; 1167 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1168 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1169 ERR_add_error_data(2,"SSL alert number ",tmp); 1170 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1171 SSL_CTX_remove_session(s->ctx,s->session); 1172 return(0); 1173 } 1174 else 1175 { 1176 al=SSL_AD_ILLEGAL_PARAMETER; 1177 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1178 goto f_err; 1179 } 1180 1181 goto start; 1182 } 1183 1184 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1185 { 1186 s->rwstate=SSL_NOTHING; 1187 rr->length=0; 1188 return(0); 1189 } 1190 1191 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1192 { 1193 struct ccs_header_st ccs_hdr; 1194 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1195 1196 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1197 1198 if (s->version == DTLS1_BAD_VER) 1199 ccs_hdr_len = 3; 1200 1201 /* 'Change Cipher Spec' is just a single byte, so we know 1202 * exactly what the record payload has to look like */ 1203 /* XDTLS: check that epoch is consistent */ 1204 if ( (rr->length != ccs_hdr_len) || 1205 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1206 { 1207 i=SSL_AD_ILLEGAL_PARAMETER; 1208 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1209 goto err; 1210 } 1211 1212 rr->length=0; 1213 1214 if (s->msg_callback) 1215 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1216 rr->data, 1, s, s->msg_callback_arg); 1217 1218 /* We can't process a CCS now, because previous handshake 1219 * messages are still missing, so just drop it. 1220 */ 1221 if (!s->d1->change_cipher_spec_ok) 1222 { 1223 goto start; 1224 } 1225 1226 s->d1->change_cipher_spec_ok = 0; 1227 1228 s->s3->change_cipher_spec=1; 1229 if (!ssl3_do_change_cipher_spec(s)) 1230 goto err; 1231 1232 /* do this whenever CCS is processed */ 1233 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1234 1235 if (s->version == DTLS1_BAD_VER) 1236 s->d1->handshake_read_seq++; 1237 1238 #ifndef OPENSSL_NO_SCTP 1239 /* Remember that a CCS has been received, 1240 * so that an old key of SCTP-Auth can be 1241 * deleted when a CCS is sent. Will be ignored 1242 * if no SCTP is used 1243 */ 1244 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1245 #endif 1246 1247 goto start; 1248 } 1249 1250 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1251 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1252 !s->in_handshake) 1253 { 1254 struct hm_header_st msg_hdr; 1255 1256 /* this may just be a stale retransmit */ 1257 dtls1_get_message_header(rr->data, &msg_hdr); 1258 if( rr->epoch != s->d1->r_epoch) 1259 { 1260 rr->length = 0; 1261 goto start; 1262 } 1263 1264 /* If we are server, we may have a repeated FINISHED of the 1265 * client here, then retransmit our CCS and FINISHED. 1266 */ 1267 if (msg_hdr.type == SSL3_MT_FINISHED) 1268 { 1269 if (dtls1_check_timeout_num(s) < 0) 1270 return -1; 1271 1272 dtls1_retransmit_buffered_messages(s); 1273 rr->length = 0; 1274 goto start; 1275 } 1276 1277 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1278 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1279 { 1280 #if 0 /* worked only because C operator preferences are not as expected (and 1281 * because this is not really needed for clients except for detecting 1282 * protocol violations): */ 1283 s->state=SSL_ST_BEFORE|(s->server) 1284 ?SSL_ST_ACCEPT 1285 :SSL_ST_CONNECT; 1286 #else 1287 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1288 #endif 1289 s->renegotiate=1; 1290 s->new_session=1; 1291 } 1292 i=s->handshake_func(s); 1293 if (i < 0) return(i); 1294 if (i == 0) 1295 { 1296 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1297 return(-1); 1298 } 1299 1300 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1301 { 1302 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1303 { 1304 BIO *bio; 1305 /* In the case where we try to read application data, 1306 * but we trigger an SSL handshake, we return -1 with 1307 * the retry option set. Otherwise renegotiation may 1308 * cause nasty problems in the blocking world */ 1309 s->rwstate=SSL_READING; 1310 bio=SSL_get_rbio(s); 1311 BIO_clear_retry_flags(bio); 1312 BIO_set_retry_read(bio); 1313 return(-1); 1314 } 1315 } 1316 goto start; 1317 } 1318 1319 switch (rr->type) 1320 { 1321 default: 1322 #ifndef OPENSSL_NO_TLS 1323 /* TLS just ignores unknown message types */ 1324 if (s->version == TLS1_VERSION) 1325 { 1326 rr->length = 0; 1327 goto start; 1328 } 1329 #endif 1330 al=SSL_AD_UNEXPECTED_MESSAGE; 1331 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1332 goto f_err; 1333 case SSL3_RT_CHANGE_CIPHER_SPEC: 1334 case SSL3_RT_ALERT: 1335 case SSL3_RT_HANDSHAKE: 1336 /* we already handled all of these, with the possible exception 1337 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1338 * should not happen when type != rr->type */ 1339 al=SSL_AD_UNEXPECTED_MESSAGE; 1340 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1341 goto f_err; 1342 case SSL3_RT_APPLICATION_DATA: 1343 /* At this point, we were expecting handshake data, 1344 * but have application data. If the library was 1345 * running inside ssl3_read() (i.e. in_read_app_data 1346 * is set) and it makes sense to read application data 1347 * at this point (session renegotiation not yet started), 1348 * we will indulge it. 1349 */ 1350 if (s->s3->in_read_app_data && 1351 (s->s3->total_renegotiations != 0) && 1352 (( 1353 (s->state & SSL_ST_CONNECT) && 1354 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1355 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1356 ) || ( 1357 (s->state & SSL_ST_ACCEPT) && 1358 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1359 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1360 ) 1361 )) 1362 { 1363 s->s3->in_read_app_data=2; 1364 return(-1); 1365 } 1366 else 1367 { 1368 al=SSL_AD_UNEXPECTED_MESSAGE; 1369 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1370 goto f_err; 1371 } 1372 } 1373 /* not reached */ 1374 1375 f_err: 1376 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1377 err: 1378 return(-1); 1379 } 1380 1381 int 1382 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1383 { 1384 int i; 1385 1386 #ifndef OPENSSL_NO_SCTP 1387 /* Check if we have to continue an interrupted handshake 1388 * for reading belated app data with SCTP. 1389 */ 1390 if ((SSL_in_init(s) && !s->in_handshake) || 1391 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1392 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1393 #else 1394 if (SSL_in_init(s) && !s->in_handshake) 1395 #endif 1396 { 1397 i=s->handshake_func(s); 1398 if (i < 0) return(i); 1399 if (i == 0) 1400 { 1401 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1402 return -1; 1403 } 1404 } 1405 1406 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1407 { 1408 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1409 return -1; 1410 } 1411 1412 i = dtls1_write_bytes(s, type, buf_, len); 1413 return i; 1414 } 1415 1416 1417 /* this only happens when a client hello is received and a handshake 1418 * is started. */ 1419 static int 1420 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1421 int len, int peek) 1422 { 1423 1424 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1425 /* (partially) satisfy request from storage */ 1426 { 1427 unsigned char *src = s->d1->handshake_fragment; 1428 unsigned char *dst = buf; 1429 unsigned int k,n; 1430 1431 /* peek == 0 */ 1432 n = 0; 1433 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1434 { 1435 *dst++ = *src++; 1436 len--; s->d1->handshake_fragment_len--; 1437 n++; 1438 } 1439 /* move any remaining fragment bytes: */ 1440 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1441 s->d1->handshake_fragment[k] = *src++; 1442 return n; 1443 } 1444 1445 return 0; 1446 } 1447 1448 1449 1450 1451 /* Call this to write data in records of type 'type' 1452 * It will return <= 0 if not all data has been sent or non-blocking IO. 1453 */ 1454 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1455 { 1456 int i; 1457 1458 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1459 s->rwstate=SSL_NOTHING; 1460 i=do_dtls1_write(s, type, buf, len, 0); 1461 return i; 1462 } 1463 1464 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1465 { 1466 unsigned char *p,*pseq; 1467 int i,mac_size,clear=0; 1468 int prefix_len = 0; 1469 SSL3_RECORD *wr; 1470 SSL3_BUFFER *wb; 1471 SSL_SESSION *sess; 1472 int bs; 1473 unsigned int len_with_overhead = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD; 1474 1475 /* first check if there is a SSL3_BUFFER still being written 1476 * out. This will happen with non blocking IO */ 1477 if (s->s3->wbuf.left != 0) 1478 { 1479 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1480 return(ssl3_write_pending(s,type,buf,len)); 1481 } 1482 1483 if (s->s3->wbuf.len < len_with_overhead) 1484 { 1485 if ((p=OPENSSL_realloc(s->s3->wbuf.buf, len_with_overhead)) == NULL) { 1486 SSLerr(SSL_F_DO_DTLS1_WRITE,ERR_R_MALLOC_FAILURE); 1487 goto err; 1488 } 1489 s->s3->wbuf.buf = p; 1490 s->s3->wbuf.len = len_with_overhead; 1491 } 1492 1493 /* If we have an alert to send, lets send it */ 1494 if (s->s3->alert_dispatch) 1495 { 1496 i=s->method->ssl_dispatch_alert(s); 1497 if (i <= 0) 1498 return(i); 1499 /* if it went, fall through and send more stuff */ 1500 } 1501 1502 if (len == 0 && !create_empty_fragment) 1503 return 0; 1504 1505 wr= &(s->s3->wrec); 1506 wb= &(s->s3->wbuf); 1507 sess=s->session; 1508 1509 if ( (sess == NULL) || 1510 (s->enc_write_ctx == NULL) || 1511 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1512 clear=1; 1513 1514 if (clear) 1515 mac_size=0; 1516 else 1517 { 1518 mac_size=EVP_MD_CTX_size(s->write_hash); 1519 if (mac_size < 0) 1520 goto err; 1521 } 1522 1523 /* DTLS implements explicit IV, so no need for empty fragments */ 1524 #if 0 1525 /* 'create_empty_fragment' is true only when this function calls itself */ 1526 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1527 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1528 { 1529 /* countermeasure against known-IV weakness in CBC ciphersuites 1530 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1531 */ 1532 1533 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1534 { 1535 /* recursive function call with 'create_empty_fragment' set; 1536 * this prepares and buffers the data for an empty fragment 1537 * (these 'prefix_len' bytes are sent out later 1538 * together with the actual payload) */ 1539 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1540 if (prefix_len <= 0) 1541 goto err; 1542 1543 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1544 { 1545 /* insufficient space */ 1546 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1547 goto err; 1548 } 1549 } 1550 1551 s->s3->empty_fragment_done = 1; 1552 } 1553 #endif 1554 p = wb->buf + prefix_len; 1555 1556 /* write the header */ 1557 1558 *(p++)=type&0xff; 1559 wr->type=type; 1560 1561 *(p++)=(s->version>>8); 1562 *(p++)=s->version&0xff; 1563 1564 /* field where we are to write out packet epoch, seq num and len */ 1565 pseq=p; 1566 p+=10; 1567 1568 /* lets setup the record stuff. */ 1569 1570 /* Make space for the explicit IV in case of CBC. 1571 * (this is a bit of a boundary violation, but what the heck). 1572 */ 1573 if ( s->enc_write_ctx && 1574 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1575 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1576 else 1577 bs = 0; 1578 1579 wr->data=p + bs; /* make room for IV in case of CBC */ 1580 wr->length=(int)len; 1581 wr->input=(unsigned char *)buf; 1582 1583 /* we now 'read' from wr->input, wr->length bytes into 1584 * wr->data */ 1585 1586 /* first we compress */ 1587 if (s->compress != NULL) 1588 { 1589 if (!ssl3_do_compress(s)) 1590 { 1591 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1592 goto err; 1593 } 1594 } 1595 else 1596 { 1597 memcpy(wr->data,wr->input,wr->length); 1598 wr->input=wr->data; 1599 } 1600 1601 /* we should still have the output to wr->data and the input 1602 * from wr->input. Length should be wr->length. 1603 * wr->data still points in the wb->buf */ 1604 1605 if (mac_size != 0) 1606 { 1607 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0) 1608 goto err; 1609 wr->length+=mac_size; 1610 } 1611 1612 /* this is true regardless of mac size */ 1613 wr->input=p; 1614 wr->data=p; 1615 1616 1617 /* ssl3_enc can only have an error on read */ 1618 if (bs) /* bs != 0 in case of CBC */ 1619 { 1620 RAND_pseudo_bytes(p,bs); 1621 /* master IV and last CBC residue stand for 1622 * the rest of randomness */ 1623 wr->length += bs; 1624 } 1625 1626 s->method->ssl3_enc->enc(s,1); 1627 1628 /* record length after mac and block padding */ 1629 /* if (type == SSL3_RT_APPLICATION_DATA || 1630 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1631 1632 /* there's only one epoch between handshake and app data */ 1633 1634 s2n(s->d1->w_epoch, pseq); 1635 1636 /* XDTLS: ?? */ 1637 /* else 1638 s2n(s->d1->handshake_epoch, pseq); */ 1639 1640 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1641 pseq+=6; 1642 s2n(wr->length,pseq); 1643 1644 /* we should now have 1645 * wr->data pointing to the encrypted data, which is 1646 * wr->length long */ 1647 wr->type=type; /* not needed but helps for debugging */ 1648 wr->length+=DTLS1_RT_HEADER_LENGTH; 1649 1650 #if 0 /* this is now done at the message layer */ 1651 /* buffer the record, making it easy to handle retransmits */ 1652 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1653 dtls1_buffer_record(s, wr->data, wr->length, 1654 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1655 #endif 1656 1657 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1658 1659 if (create_empty_fragment) 1660 { 1661 /* we are in a recursive call; 1662 * just return the length, don't write out anything here 1663 */ 1664 return wr->length; 1665 } 1666 1667 /* now let's set up wb */ 1668 wb->left = prefix_len + wr->length; 1669 wb->offset = 0; 1670 1671 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1672 s->s3->wpend_tot=len; 1673 s->s3->wpend_buf=buf; 1674 s->s3->wpend_type=type; 1675 s->s3->wpend_ret=len; 1676 1677 /* we now just need to write the buffer */ 1678 return ssl3_write_pending(s,type,buf,len); 1679 err: 1680 return -1; 1681 } 1682 1683 1684 1685 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1686 { 1687 int cmp; 1688 unsigned int shift; 1689 const unsigned char *seq = s->s3->read_sequence; 1690 1691 cmp = satsub64be(seq,bitmap->max_seq_num); 1692 if (cmp > 0) 1693 { 1694 memcpy (s->s3->rrec.seq_num,seq,8); 1695 return 1; /* this record in new */ 1696 } 1697 shift = -cmp; 1698 if (shift >= sizeof(bitmap->map)*8) 1699 return 0; /* stale, outside the window */ 1700 else if (bitmap->map & (1UL<<shift)) 1701 return 0; /* record previously received */ 1702 1703 memcpy (s->s3->rrec.seq_num,seq,8); 1704 return 1; 1705 } 1706 1707 1708 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1709 { 1710 int cmp; 1711 unsigned int shift; 1712 const unsigned char *seq = s->s3->read_sequence; 1713 1714 cmp = satsub64be(seq,bitmap->max_seq_num); 1715 if (cmp > 0) 1716 { 1717 shift = cmp; 1718 if (shift < sizeof(bitmap->map)*8) 1719 bitmap->map <<= shift, bitmap->map |= 1UL; 1720 else 1721 bitmap->map = 1UL; 1722 memcpy(bitmap->max_seq_num,seq,8); 1723 } 1724 else { 1725 shift = -cmp; 1726 if (shift < sizeof(bitmap->map)*8) 1727 bitmap->map |= 1UL<<shift; 1728 } 1729 } 1730 1731 1732 int dtls1_dispatch_alert(SSL *s) 1733 { 1734 int i,j; 1735 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1736 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1737 unsigned char *ptr = &buf[0]; 1738 1739 s->s3->alert_dispatch=0; 1740 1741 memset(buf, 0x00, sizeof(buf)); 1742 *ptr++ = s->s3->send_alert[0]; 1743 *ptr++ = s->s3->send_alert[1]; 1744 1745 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1746 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1747 { 1748 s2n(s->d1->handshake_read_seq, ptr); 1749 #if 0 1750 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1751 1752 else 1753 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1754 #endif 1755 1756 #if 0 1757 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); 1758 #endif 1759 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1760 } 1761 #endif 1762 1763 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1764 if (i <= 0) 1765 { 1766 s->s3->alert_dispatch=1; 1767 /* fprintf( stderr, "not done with alert\n" ); */ 1768 } 1769 else 1770 { 1771 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1772 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1773 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1774 #endif 1775 ) 1776 (void)BIO_flush(s->wbio); 1777 1778 if (s->msg_callback) 1779 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1780 2, s, s->msg_callback_arg); 1781 1782 if (s->info_callback != NULL) 1783 cb=s->info_callback; 1784 else if (s->ctx->info_callback != NULL) 1785 cb=s->ctx->info_callback; 1786 1787 if (cb != NULL) 1788 { 1789 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1790 cb(s,SSL_CB_WRITE_ALERT,j); 1791 } 1792 } 1793 return(i); 1794 } 1795 1796 1797 static DTLS1_BITMAP * 1798 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1799 { 1800 1801 *is_next_epoch = 0; 1802 1803 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1804 if (rr->epoch == s->d1->r_epoch) 1805 return &s->d1->bitmap; 1806 1807 /* Only HM and ALERT messages can be from the next epoch */ 1808 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1809 (rr->type == SSL3_RT_HANDSHAKE || 1810 rr->type == SSL3_RT_ALERT)) 1811 { 1812 *is_next_epoch = 1; 1813 return &s->d1->next_bitmap; 1814 } 1815 1816 return NULL; 1817 } 1818 1819 #if 0 1820 static int 1821 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1822 unsigned long *offset) 1823 { 1824 1825 /* alerts are passed up immediately */ 1826 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1827 rr->type == SSL3_RT_ALERT) 1828 return 0; 1829 1830 /* Only need to buffer if a handshake is underway. 1831 * (this implies that Hello Request and Client Hello are passed up 1832 * immediately) */ 1833 if ( SSL_in_init(s)) 1834 { 1835 unsigned char *data = rr->data; 1836 /* need to extract the HM/CCS sequence number here */ 1837 if ( rr->type == SSL3_RT_HANDSHAKE || 1838 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1839 { 1840 unsigned short seq_num; 1841 struct hm_header_st msg_hdr; 1842 struct ccs_header_st ccs_hdr; 1843 1844 if ( rr->type == SSL3_RT_HANDSHAKE) 1845 { 1846 dtls1_get_message_header(data, &msg_hdr); 1847 seq_num = msg_hdr.seq; 1848 *offset = msg_hdr.frag_off; 1849 } 1850 else 1851 { 1852 dtls1_get_ccs_header(data, &ccs_hdr); 1853 seq_num = ccs_hdr.seq; 1854 *offset = 0; 1855 } 1856 1857 /* this is either a record we're waiting for, or a 1858 * retransmit of something we happened to previously 1859 * receive (higher layers will drop the repeat silently */ 1860 if ( seq_num < s->d1->handshake_read_seq) 1861 return 0; 1862 if (rr->type == SSL3_RT_HANDSHAKE && 1863 seq_num == s->d1->handshake_read_seq && 1864 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1865 return 0; 1866 else if ( seq_num == s->d1->handshake_read_seq && 1867 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1868 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1869 return 0; 1870 else 1871 { 1872 *priority = seq_num; 1873 return 1; 1874 } 1875 } 1876 else /* unknown record type */ 1877 return 0; 1878 } 1879 1880 return 0; 1881 } 1882 #endif 1883 1884 void 1885 dtls1_reset_seq_numbers(SSL *s, int rw) 1886 { 1887 unsigned char *seq; 1888 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1889 1890 if ( rw & SSL3_CC_READ) 1891 { 1892 seq = s->s3->read_sequence; 1893 s->d1->r_epoch++; 1894 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1895 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1896 } 1897 else 1898 { 1899 seq = s->s3->write_sequence; 1900 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1901 s->d1->w_epoch++; 1902 } 1903 1904 memset(seq, 0x00, seq_bytes); 1905 } 1906
