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 static int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 183 unsigned int len); 184 185 /* copy buffered record into SSL structure */ 186 static int 187 dtls1_copy_record(SSL *s, pitem *item) 188 { 189 DTLS1_RECORD_DATA *rdata; 190 191 rdata = (DTLS1_RECORD_DATA *)item->data; 192 193 if (s->s3->rbuf.buf != NULL) 194 OPENSSL_free(s->s3->rbuf.buf); 195 196 s->packet = rdata->packet; 197 s->packet_length = rdata->packet_length; 198 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 199 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 200 201 /* Set proper sequence number for mac calculation */ 202 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 203 204 return(1); 205 } 206 207 208 static int 209 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 210 { 211 DTLS1_RECORD_DATA *rdata; 212 pitem *item; 213 214 /* Limit the size of the queue to prevent DOS attacks */ 215 if (pqueue_size(queue->q) >= 100) 216 return 0; 217 218 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 219 item = pitem_new(priority, rdata); 220 if (rdata == NULL || item == NULL) 221 { 222 if (rdata != NULL) OPENSSL_free(rdata); 223 if (item != NULL) pitem_free(item); 224 225 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 226 return(0); 227 } 228 229 rdata->packet = s->packet; 230 rdata->packet_length = s->packet_length; 231 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 232 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 233 234 item->data = rdata; 235 236 #ifndef OPENSSL_NO_SCTP 237 /* Store bio_dgram_sctp_rcvinfo struct */ 238 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 239 (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) { 240 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 241 } 242 #endif 243 244 s->packet = NULL; 245 s->packet_length = 0; 246 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 247 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 248 249 if (!ssl3_setup_buffers(s)) 250 { 251 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 252 OPENSSL_free(rdata); 253 pitem_free(item); 254 return(0); 255 } 256 257 /* insert should not fail, since duplicates are dropped */ 258 if (pqueue_insert(queue->q, item) == NULL) 259 { 260 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 261 OPENSSL_free(rdata); 262 pitem_free(item); 263 return(0); 264 } 265 266 return(1); 267 } 268 269 270 static int 271 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 272 { 273 pitem *item; 274 275 item = pqueue_pop(queue->q); 276 if (item) 277 { 278 dtls1_copy_record(s, item); 279 280 OPENSSL_free(item->data); 281 pitem_free(item); 282 283 return(1); 284 } 285 286 return(0); 287 } 288 289 290 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 291 * yet */ 292 #define dtls1_get_unprocessed_record(s) \ 293 dtls1_retrieve_buffered_record((s), \ 294 &((s)->d1->unprocessed_rcds)) 295 296 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 297 #define dtls1_get_processed_record(s) \ 298 dtls1_retrieve_buffered_record((s), \ 299 &((s)->d1->processed_rcds)) 300 301 static int 302 dtls1_process_buffered_records(SSL *s) 303 { 304 pitem *item; 305 306 item = pqueue_peek(s->d1->unprocessed_rcds.q); 307 if (item) 308 { 309 /* Check if epoch is current. */ 310 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 311 return(1); /* Nothing to do. */ 312 313 /* Process all the records. */ 314 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 315 { 316 dtls1_get_unprocessed_record(s); 317 if ( ! dtls1_process_record(s)) 318 return(0); 319 dtls1_buffer_record(s, &(s->d1->processed_rcds), 320 s->s3->rrec.seq_num); 321 } 322 } 323 324 /* sync epoch numbers once all the unprocessed records 325 * have been processed */ 326 s->d1->processed_rcds.epoch = s->d1->r_epoch; 327 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 328 329 return(1); 330 } 331 332 333 #if 0 334 335 static int 336 dtls1_get_buffered_record(SSL *s) 337 { 338 pitem *item; 339 PQ_64BIT priority = 340 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 341 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 342 343 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 344 nothing buffered */ 345 return 0; 346 347 348 item = pqueue_peek(s->d1->rcvd_records); 349 if (item && item->priority == priority) 350 { 351 /* Check if we've received the record of interest. It must be 352 * a handshake record, since data records as passed up without 353 * buffering */ 354 DTLS1_RECORD_DATA *rdata; 355 item = pqueue_pop(s->d1->rcvd_records); 356 rdata = (DTLS1_RECORD_DATA *)item->data; 357 358 if (s->s3->rbuf.buf != NULL) 359 OPENSSL_free(s->s3->rbuf.buf); 360 361 s->packet = rdata->packet; 362 s->packet_length = rdata->packet_length; 363 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 364 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 365 366 OPENSSL_free(item->data); 367 pitem_free(item); 368 369 /* s->d1->next_expected_seq_num++; */ 370 return(1); 371 } 372 373 return 0; 374 } 375 376 #endif 377 378 static int 379 dtls1_process_record(SSL *s) 380 { 381 int i,al; 382 int enc_err; 383 SSL_SESSION *sess; 384 SSL3_RECORD *rr; 385 unsigned int mac_size, orig_len; 386 unsigned char md[EVP_MAX_MD_SIZE]; 387 388 rr= &(s->s3->rrec); 389 sess = s->session; 390 391 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 392 * and we have that many bytes in s->packet 393 */ 394 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 395 396 /* ok, we can now read from 's->packet' data into 'rr' 397 * rr->input points at rr->length bytes, which 398 * need to be copied into rr->data by either 399 * the decryption or by the decompression 400 * When the data is 'copied' into the rr->data buffer, 401 * rr->input will be pointed at the new buffer */ 402 403 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 404 * rr->length bytes of encrypted compressed stuff. */ 405 406 /* check is not needed I believe */ 407 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 408 { 409 al=SSL_AD_RECORD_OVERFLOW; 410 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 411 goto f_err; 412 } 413 414 /* decrypt in place in 'rr->input' */ 415 rr->data=rr->input; 416 417 enc_err = s->method->ssl3_enc->enc(s,0); 418 /* enc_err is: 419 * 0: (in non-constant time) if the record is publically invalid. 420 * 1: if the padding is valid 421 * -1: if the padding is invalid */ 422 if (enc_err == 0) 423 { 424 /* For DTLS we simply ignore bad packets. */ 425 rr->length = 0; 426 s->packet_length = 0; 427 goto err; 428 } 429 430 #ifdef TLS_DEBUG 431 printf("dec %d\n",rr->length); 432 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 433 printf("\n"); 434 #endif 435 436 /* r->length is now the compressed data plus mac */ 437 if ((sess != NULL) && 438 (s->enc_read_ctx != NULL) && 439 (EVP_MD_CTX_md(s->read_hash) != NULL)) 440 { 441 /* s->read_hash != NULL => mac_size != -1 */ 442 unsigned char *mac = NULL; 443 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 444 mac_size=EVP_MD_CTX_size(s->read_hash); 445 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 446 447 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 448 orig_len = rr->length+((unsigned int)rr->type>>8); 449 450 /* orig_len is the length of the record before any padding was 451 * removed. This is public information, as is the MAC in use, 452 * therefore we can safely process the record in a different 453 * amount of time if it's too short to possibly contain a MAC. 454 */ 455 if (orig_len < mac_size || 456 /* CBC records must have a padding length byte too. */ 457 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 458 orig_len < mac_size+1)) 459 { 460 al=SSL_AD_DECODE_ERROR; 461 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT); 462 goto f_err; 463 } 464 465 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) 466 { 467 /* We update the length so that the TLS header bytes 468 * can be constructed correctly but we need to extract 469 * the MAC in constant time from within the record, 470 * without leaking the contents of the padding bytes. 471 * */ 472 mac = mac_tmp; 473 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 474 rr->length -= mac_size; 475 } 476 else 477 { 478 /* In this case there's no padding, so |orig_len| 479 * equals |rec->length| and we checked that there's 480 * enough bytes for |mac_size| above. */ 481 rr->length -= mac_size; 482 mac = &rr->data[rr->length]; 483 } 484 485 i=s->method->ssl3_enc->mac(s,md,0 /* not send */); 486 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 487 enc_err = -1; 488 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 489 enc_err = -1; 490 } 491 492 if (enc_err < 0) 493 { 494 /* decryption failed, silently discard message */ 495 rr->length = 0; 496 s->packet_length = 0; 497 goto err; 498 } 499 500 /* r->length is now just compressed */ 501 if (s->expand != NULL) 502 { 503 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 504 { 505 al=SSL_AD_RECORD_OVERFLOW; 506 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 507 goto f_err; 508 } 509 if (!ssl3_do_uncompress(s)) 510 { 511 al=SSL_AD_DECOMPRESSION_FAILURE; 512 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 513 goto f_err; 514 } 515 } 516 517 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 518 { 519 al=SSL_AD_RECORD_OVERFLOW; 520 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 521 goto f_err; 522 } 523 524 rr->off=0; 525 /* So at this point the following is true 526 * ssl->s3->rrec.type is the type of record 527 * ssl->s3->rrec.length == number of bytes in record 528 * ssl->s3->rrec.off == offset to first valid byte 529 * ssl->s3->rrec.data == where to take bytes from, increment 530 * after use :-). 531 */ 532 533 /* we have pulled in a full packet so zero things */ 534 s->packet_length=0; 535 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 536 return(1); 537 538 f_err: 539 ssl3_send_alert(s,SSL3_AL_FATAL,al); 540 err: 541 return(0); 542 } 543 544 545 /* Call this to get a new input record. 546 * It will return <= 0 if more data is needed, normally due to an error 547 * or non-blocking IO. 548 * When it finishes, one packet has been decoded and can be found in 549 * ssl->s3->rrec.type - is the type of record 550 * ssl->s3->rrec.data, - data 551 * ssl->s3->rrec.length, - number of bytes 552 */ 553 /* used only by dtls1_read_bytes */ 554 int dtls1_get_record(SSL *s) 555 { 556 int ssl_major,ssl_minor; 557 int i,n; 558 SSL3_RECORD *rr; 559 unsigned char *p = NULL; 560 unsigned short version; 561 DTLS1_BITMAP *bitmap; 562 unsigned int is_next_epoch; 563 564 rr= &(s->s3->rrec); 565 566 /* The epoch may have changed. If so, process all the 567 * pending records. This is a non-blocking operation. */ 568 dtls1_process_buffered_records(s); 569 570 /* if we're renegotiating, then there may be buffered records */ 571 if (dtls1_get_processed_record(s)) 572 return 1; 573 574 /* get something from the wire */ 575 again: 576 /* check if we have the header */ 577 if ( (s->rstate != SSL_ST_READ_BODY) || 578 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 579 { 580 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 581 /* read timeout is handled by dtls1_read_bytes */ 582 if (n <= 0) return(n); /* error or non-blocking */ 583 584 /* this packet contained a partial record, dump it */ 585 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 586 { 587 s->packet_length = 0; 588 goto again; 589 } 590 591 s->rstate=SSL_ST_READ_BODY; 592 593 p=s->packet; 594 595 /* Pull apart the header into the DTLS1_RECORD */ 596 rr->type= *(p++); 597 ssl_major= *(p++); 598 ssl_minor= *(p++); 599 version=(ssl_major<<8)|ssl_minor; 600 601 /* sequence number is 64 bits, with top 2 bytes = epoch */ 602 n2s(p,rr->epoch); 603 604 memcpy(&(s->s3->read_sequence[2]), p, 6); 605 p+=6; 606 607 n2s(p,rr->length); 608 609 /* Lets check version */ 610 if (!s->first_packet) 611 { 612 if (version != s->version) 613 { 614 /* unexpected version, silently discard */ 615 rr->length = 0; 616 s->packet_length = 0; 617 goto again; 618 } 619 } 620 621 if ((version & 0xff00) != (s->version & 0xff00)) 622 { 623 /* wrong version, silently discard record */ 624 rr->length = 0; 625 s->packet_length = 0; 626 goto again; 627 } 628 629 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 630 { 631 /* record too long, silently discard it */ 632 rr->length = 0; 633 s->packet_length = 0; 634 goto again; 635 } 636 637 /* now s->rstate == SSL_ST_READ_BODY */ 638 } 639 640 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 641 642 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 643 { 644 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 645 i=rr->length; 646 n=ssl3_read_n(s,i,i,1); 647 if (n <= 0) return(n); /* error or non-blocking io */ 648 649 /* this packet contained a partial record, dump it */ 650 if ( n != i) 651 { 652 rr->length = 0; 653 s->packet_length = 0; 654 goto again; 655 } 656 657 /* now n == rr->length, 658 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 659 } 660 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 661 662 /* match epochs. NULL means the packet is dropped on the floor */ 663 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 664 if ( bitmap == NULL) 665 { 666 rr->length = 0; 667 s->packet_length = 0; /* dump this record */ 668 goto again; /* get another record */ 669 } 670 671 #ifndef OPENSSL_NO_SCTP 672 /* Only do replay check if no SCTP bio */ 673 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) 674 { 675 #endif 676 /* Check whether this is a repeat, or aged record. 677 * Don't check if we're listening and this message is 678 * a ClientHello. They can look as if they're replayed, 679 * since they arrive from different connections and 680 * would be dropped unnecessarily. 681 */ 682 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 683 *p == SSL3_MT_CLIENT_HELLO) && 684 !dtls1_record_replay_check(s, bitmap)) 685 { 686 rr->length = 0; 687 s->packet_length=0; /* dump this record */ 688 goto again; /* get another record */ 689 } 690 #ifndef OPENSSL_NO_SCTP 691 } 692 #endif 693 694 /* just read a 0 length packet */ 695 if (rr->length == 0) goto again; 696 697 /* If this record is from the next epoch (either HM or ALERT), 698 * and a handshake is currently in progress, buffer it since it 699 * cannot be processed at this time. However, do not buffer 700 * anything while listening. 701 */ 702 if (is_next_epoch) 703 { 704 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) 705 { 706 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 707 } 708 rr->length = 0; 709 s->packet_length = 0; 710 goto again; 711 } 712 713 if (!dtls1_process_record(s)) 714 { 715 rr->length = 0; 716 s->packet_length = 0; /* dump this record */ 717 goto again; /* get another record */ 718 } 719 720 return(1); 721 722 } 723 724 /* Return up to 'len' payload bytes received in 'type' records. 725 * 'type' is one of the following: 726 * 727 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 728 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 729 * - 0 (during a shutdown, no data has to be returned) 730 * 731 * If we don't have stored data to work from, read a SSL/TLS record first 732 * (possibly multiple records if we still don't have anything to return). 733 * 734 * This function must handle any surprises the peer may have for us, such as 735 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 736 * a surprise, but handled as if it were), or renegotiation requests. 737 * Also if record payloads contain fragments too small to process, we store 738 * them until there is enough for the respective protocol (the record protocol 739 * may use arbitrary fragmentation and even interleaving): 740 * Change cipher spec protocol 741 * just 1 byte needed, no need for keeping anything stored 742 * Alert protocol 743 * 2 bytes needed (AlertLevel, AlertDescription) 744 * Handshake protocol 745 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 746 * to detect unexpected Client Hello and Hello Request messages 747 * here, anything else is handled by higher layers 748 * Application data protocol 749 * none of our business 750 */ 751 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 752 { 753 int al,i,j,ret; 754 unsigned int n; 755 SSL3_RECORD *rr; 756 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 757 758 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 759 if (!ssl3_setup_buffers(s)) 760 return(-1); 761 762 /* XXX: check what the second '&& type' is about */ 763 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 764 (type != SSL3_RT_HANDSHAKE) && type) || 765 (peek && (type != SSL3_RT_APPLICATION_DATA))) 766 { 767 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 768 return -1; 769 } 770 771 /* check whether there's a handshake message (client hello?) waiting */ 772 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 773 return ret; 774 775 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 776 777 #ifndef OPENSSL_NO_SCTP 778 /* Continue handshake if it had to be interrupted to read 779 * app data with SCTP. 780 */ 781 if ((!s->in_handshake && SSL_in_init(s)) || 782 (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 783 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) && 784 s->s3->in_read_app_data != 2)) 785 #else 786 if (!s->in_handshake && SSL_in_init(s)) 787 #endif 788 { 789 /* type == SSL3_RT_APPLICATION_DATA */ 790 i=s->handshake_func(s); 791 if (i < 0) return(i); 792 if (i == 0) 793 { 794 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 795 return(-1); 796 } 797 } 798 799 start: 800 s->rwstate=SSL_NOTHING; 801 802 /* s->s3->rrec.type - is the type of record 803 * s->s3->rrec.data, - data 804 * s->s3->rrec.off, - offset into 'data' for next read 805 * s->s3->rrec.length, - number of bytes. */ 806 rr = &(s->s3->rrec); 807 808 /* We are not handshaking and have no data yet, 809 * so process data buffered during the last handshake 810 * in advance, if any. 811 */ 812 if (s->state == SSL_ST_OK && rr->length == 0) 813 { 814 pitem *item; 815 item = pqueue_pop(s->d1->buffered_app_data.q); 816 if (item) 817 { 818 #ifndef OPENSSL_NO_SCTP 819 /* Restore bio_dgram_sctp_rcvinfo struct */ 820 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) 821 { 822 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data; 823 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo); 824 } 825 #endif 826 827 dtls1_copy_record(s, item); 828 829 OPENSSL_free(item->data); 830 pitem_free(item); 831 } 832 } 833 834 /* Check for timeout */ 835 if (dtls1_handle_timeout(s) > 0) 836 goto start; 837 838 /* get new packet if necessary */ 839 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 840 { 841 ret=dtls1_get_record(s); 842 if (ret <= 0) 843 { 844 ret = dtls1_read_failed(s, ret); 845 /* anything other than a timeout is an error */ 846 if (ret <= 0) 847 return(ret); 848 else 849 goto start; 850 } 851 } 852 853 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) 854 { 855 rr->length = 0; 856 goto start; 857 } 858 859 /* we now have a packet which can be read and processed */ 860 861 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 862 * reset by ssl3_get_finished */ 863 && (rr->type != SSL3_RT_HANDSHAKE)) 864 { 865 /* We now have application data between CCS and Finished. 866 * Most likely the packets were reordered on their way, so 867 * buffer the application data for later processing rather 868 * than dropping the connection. 869 */ 870 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num); 871 rr->length = 0; 872 goto start; 873 } 874 875 /* If the other end has shut down, throw anything we read away 876 * (even in 'peek' mode) */ 877 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 878 { 879 rr->length=0; 880 s->rwstate=SSL_NOTHING; 881 return(0); 882 } 883 884 885 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 886 { 887 /* make sure that we are not getting application data when we 888 * are doing a handshake for the first time */ 889 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 890 (s->enc_read_ctx == NULL)) 891 { 892 al=SSL_AD_UNEXPECTED_MESSAGE; 893 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 894 goto f_err; 895 } 896 897 if (len <= 0) return(len); 898 899 if ((unsigned int)len > rr->length) 900 n = rr->length; 901 else 902 n = (unsigned int)len; 903 904 memcpy(buf,&(rr->data[rr->off]),n); 905 if (!peek) 906 { 907 rr->length-=n; 908 rr->off+=n; 909 if (rr->length == 0) 910 { 911 s->rstate=SSL_ST_READ_HEADER; 912 rr->off=0; 913 } 914 } 915 916 #ifndef OPENSSL_NO_SCTP 917 /* We were about to renegotiate but had to read 918 * belated application data first, so retry. 919 */ 920 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 921 rr->type == SSL3_RT_APPLICATION_DATA && 922 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) 923 { 924 s->rwstate=SSL_READING; 925 BIO_clear_retry_flags(SSL_get_rbio(s)); 926 BIO_set_retry_read(SSL_get_rbio(s)); 927 } 928 929 /* We might had to delay a close_notify alert because 930 * of reordered app data. If there was an alert and there 931 * is no message to read anymore, finally set shutdown. 932 */ 933 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 934 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 935 { 936 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 937 return(0); 938 } 939 #endif 940 return(n); 941 } 942 943 944 /* If we get here, then type != rr->type; if we have a handshake 945 * message, then it was unexpected (Hello Request or Client Hello). */ 946 947 /* In case of record types for which we have 'fragment' storage, 948 * fill that so that we can process the data at a fixed place. 949 */ 950 { 951 unsigned int k, dest_maxlen = 0; 952 unsigned char *dest = NULL; 953 unsigned int *dest_len = NULL; 954 955 if (rr->type == SSL3_RT_HANDSHAKE) 956 { 957 dest_maxlen = sizeof s->d1->handshake_fragment; 958 dest = s->d1->handshake_fragment; 959 dest_len = &s->d1->handshake_fragment_len; 960 } 961 else if (rr->type == SSL3_RT_ALERT) 962 { 963 dest_maxlen = sizeof(s->d1->alert_fragment); 964 dest = s->d1->alert_fragment; 965 dest_len = &s->d1->alert_fragment_len; 966 } 967 #ifndef OPENSSL_NO_HEARTBEATS 968 else if (rr->type == TLS1_RT_HEARTBEAT) 969 { 970 dtls1_process_heartbeat(s); 971 972 /* Exit and notify application to read again */ 973 rr->length = 0; 974 s->rwstate=SSL_READING; 975 BIO_clear_retry_flags(SSL_get_rbio(s)); 976 BIO_set_retry_read(SSL_get_rbio(s)); 977 return(-1); 978 } 979 #endif 980 /* else it's a CCS message, or application data or wrong */ 981 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 982 { 983 /* Application data while renegotiating 984 * is allowed. Try again reading. 985 */ 986 if (rr->type == SSL3_RT_APPLICATION_DATA) 987 { 988 BIO *bio; 989 s->s3->in_read_app_data=2; 990 bio=SSL_get_rbio(s); 991 s->rwstate=SSL_READING; 992 BIO_clear_retry_flags(bio); 993 BIO_set_retry_read(bio); 994 return(-1); 995 } 996 997 /* Not certain if this is the right error handling */ 998 al=SSL_AD_UNEXPECTED_MESSAGE; 999 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1000 goto f_err; 1001 } 1002 1003 if (dest_maxlen > 0) 1004 { 1005 /* XDTLS: In a pathalogical case, the Client Hello 1006 * may be fragmented--don't always expect dest_maxlen bytes */ 1007 if ( rr->length < dest_maxlen) 1008 { 1009 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1010 /* 1011 * for normal alerts rr->length is 2, while 1012 * dest_maxlen is 7 if we were to handle this 1013 * non-existing alert... 1014 */ 1015 FIX ME 1016 #endif 1017 s->rstate=SSL_ST_READ_HEADER; 1018 rr->length = 0; 1019 goto start; 1020 } 1021 1022 /* now move 'n' bytes: */ 1023 for ( k = 0; k < dest_maxlen; k++) 1024 { 1025 dest[k] = rr->data[rr->off++]; 1026 rr->length--; 1027 } 1028 *dest_len = dest_maxlen; 1029 } 1030 } 1031 1032 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 1033 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 1034 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 1035 1036 /* If we are a client, check for an incoming 'Hello Request': */ 1037 if ((!s->server) && 1038 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1039 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1040 (s->session != NULL) && (s->session->cipher != NULL)) 1041 { 1042 s->d1->handshake_fragment_len = 0; 1043 1044 if ((s->d1->handshake_fragment[1] != 0) || 1045 (s->d1->handshake_fragment[2] != 0) || 1046 (s->d1->handshake_fragment[3] != 0)) 1047 { 1048 al=SSL_AD_DECODE_ERROR; 1049 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 1050 goto err; 1051 } 1052 1053 /* no need to check sequence number on HELLO REQUEST messages */ 1054 1055 if (s->msg_callback) 1056 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1057 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 1058 1059 if (SSL_is_init_finished(s) && 1060 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1061 !s->s3->renegotiate) 1062 { 1063 s->d1->handshake_read_seq++; 1064 s->new_session = 1; 1065 ssl3_renegotiate(s); 1066 if (ssl3_renegotiate_check(s)) 1067 { 1068 i=s->handshake_func(s); 1069 if (i < 0) return(i); 1070 if (i == 0) 1071 { 1072 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1073 return(-1); 1074 } 1075 1076 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1077 { 1078 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1079 { 1080 BIO *bio; 1081 /* In the case where we try to read application data, 1082 * but we trigger an SSL handshake, we return -1 with 1083 * the retry option set. Otherwise renegotiation may 1084 * cause nasty problems in the blocking world */ 1085 s->rwstate=SSL_READING; 1086 bio=SSL_get_rbio(s); 1087 BIO_clear_retry_flags(bio); 1088 BIO_set_retry_read(bio); 1089 return(-1); 1090 } 1091 } 1092 } 1093 } 1094 /* we either finished a handshake or ignored the request, 1095 * now try again to obtain the (application) data we were asked for */ 1096 goto start; 1097 } 1098 1099 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1100 { 1101 int alert_level = s->d1->alert_fragment[0]; 1102 int alert_descr = s->d1->alert_fragment[1]; 1103 1104 s->d1->alert_fragment_len = 0; 1105 1106 if (s->msg_callback) 1107 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1108 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1109 1110 if (s->info_callback != NULL) 1111 cb=s->info_callback; 1112 else if (s->ctx->info_callback != NULL) 1113 cb=s->ctx->info_callback; 1114 1115 if (cb != NULL) 1116 { 1117 j = (alert_level << 8) | alert_descr; 1118 cb(s, SSL_CB_READ_ALERT, j); 1119 } 1120 1121 if (alert_level == 1) /* warning */ 1122 { 1123 s->s3->warn_alert = alert_descr; 1124 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1125 { 1126 #ifndef OPENSSL_NO_SCTP 1127 /* With SCTP and streams the socket may deliver app data 1128 * after a close_notify alert. We have to check this 1129 * first so that nothing gets discarded. 1130 */ 1131 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 1132 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) 1133 { 1134 s->d1->shutdown_received = 1; 1135 s->rwstate=SSL_READING; 1136 BIO_clear_retry_flags(SSL_get_rbio(s)); 1137 BIO_set_retry_read(SSL_get_rbio(s)); 1138 return -1; 1139 } 1140 #endif 1141 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1142 return(0); 1143 } 1144 #if 0 1145 /* XXX: this is a possible improvement in the future */ 1146 /* now check if it's a missing record */ 1147 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1148 { 1149 unsigned short seq; 1150 unsigned int frag_off; 1151 unsigned char *p = &(s->d1->alert_fragment[2]); 1152 1153 n2s(p, seq); 1154 n2l3(p, frag_off); 1155 1156 dtls1_retransmit_message(s, 1157 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1158 frag_off, &found); 1159 if ( ! found && SSL_in_init(s)) 1160 { 1161 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1162 /* requested a message not yet sent, 1163 send an alert ourselves */ 1164 ssl3_send_alert(s,SSL3_AL_WARNING, 1165 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1166 } 1167 } 1168 #endif 1169 } 1170 else if (alert_level == 2) /* fatal */ 1171 { 1172 char tmp[16]; 1173 1174 s->rwstate=SSL_NOTHING; 1175 s->s3->fatal_alert = alert_descr; 1176 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1177 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1178 ERR_add_error_data(2,"SSL alert number ",tmp); 1179 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1180 SSL_CTX_remove_session(s->ctx,s->session); 1181 return(0); 1182 } 1183 else 1184 { 1185 al=SSL_AD_ILLEGAL_PARAMETER; 1186 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1187 goto f_err; 1188 } 1189 1190 goto start; 1191 } 1192 1193 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1194 { 1195 s->rwstate=SSL_NOTHING; 1196 rr->length=0; 1197 return(0); 1198 } 1199 1200 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1201 { 1202 struct ccs_header_st ccs_hdr; 1203 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1204 1205 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1206 1207 if (s->version == DTLS1_BAD_VER) 1208 ccs_hdr_len = 3; 1209 1210 /* 'Change Cipher Spec' is just a single byte, so we know 1211 * exactly what the record payload has to look like */ 1212 /* XDTLS: check that epoch is consistent */ 1213 if ( (rr->length != ccs_hdr_len) || 1214 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1215 { 1216 i=SSL_AD_ILLEGAL_PARAMETER; 1217 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1218 goto err; 1219 } 1220 1221 rr->length=0; 1222 1223 if (s->msg_callback) 1224 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1225 rr->data, 1, s, s->msg_callback_arg); 1226 1227 /* We can't process a CCS now, because previous handshake 1228 * messages are still missing, so just drop it. 1229 */ 1230 if (!s->d1->change_cipher_spec_ok) 1231 { 1232 goto start; 1233 } 1234 1235 s->d1->change_cipher_spec_ok = 0; 1236 1237 s->s3->change_cipher_spec=1; 1238 if (!ssl3_do_change_cipher_spec(s)) 1239 goto err; 1240 1241 /* do this whenever CCS is processed */ 1242 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1243 1244 if (s->version == DTLS1_BAD_VER) 1245 s->d1->handshake_read_seq++; 1246 1247 #ifndef OPENSSL_NO_SCTP 1248 /* Remember that a CCS has been received, 1249 * so that an old key of SCTP-Auth can be 1250 * deleted when a CCS is sent. Will be ignored 1251 * if no SCTP is used 1252 */ 1253 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); 1254 #endif 1255 1256 goto start; 1257 } 1258 1259 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1260 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1261 !s->in_handshake) 1262 { 1263 struct hm_header_st msg_hdr; 1264 1265 /* this may just be a stale retransmit */ 1266 dtls1_get_message_header(rr->data, &msg_hdr); 1267 if( rr->epoch != s->d1->r_epoch) 1268 { 1269 rr->length = 0; 1270 goto start; 1271 } 1272 1273 /* If we are server, we may have a repeated FINISHED of the 1274 * client here, then retransmit our CCS and FINISHED. 1275 */ 1276 if (msg_hdr.type == SSL3_MT_FINISHED) 1277 { 1278 if (dtls1_check_timeout_num(s) < 0) 1279 return -1; 1280 1281 dtls1_retransmit_buffered_messages(s); 1282 rr->length = 0; 1283 goto start; 1284 } 1285 1286 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1287 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1288 { 1289 #if 0 /* worked only because C operator preferences are not as expected (and 1290 * because this is not really needed for clients except for detecting 1291 * protocol violations): */ 1292 s->state=SSL_ST_BEFORE|(s->server) 1293 ?SSL_ST_ACCEPT 1294 :SSL_ST_CONNECT; 1295 #else 1296 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1297 #endif 1298 s->renegotiate=1; 1299 s->new_session=1; 1300 } 1301 i=s->handshake_func(s); 1302 if (i < 0) return(i); 1303 if (i == 0) 1304 { 1305 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1306 return(-1); 1307 } 1308 1309 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1310 { 1311 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1312 { 1313 BIO *bio; 1314 /* In the case where we try to read application data, 1315 * but we trigger an SSL handshake, we return -1 with 1316 * the retry option set. Otherwise renegotiation may 1317 * cause nasty problems in the blocking world */ 1318 s->rwstate=SSL_READING; 1319 bio=SSL_get_rbio(s); 1320 BIO_clear_retry_flags(bio); 1321 BIO_set_retry_read(bio); 1322 return(-1); 1323 } 1324 } 1325 goto start; 1326 } 1327 1328 switch (rr->type) 1329 { 1330 default: 1331 #ifndef OPENSSL_NO_TLS 1332 /* TLS just ignores unknown message types */ 1333 if (s->version == TLS1_VERSION) 1334 { 1335 rr->length = 0; 1336 goto start; 1337 } 1338 #endif 1339 al=SSL_AD_UNEXPECTED_MESSAGE; 1340 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1341 goto f_err; 1342 case SSL3_RT_CHANGE_CIPHER_SPEC: 1343 case SSL3_RT_ALERT: 1344 case SSL3_RT_HANDSHAKE: 1345 /* we already handled all of these, with the possible exception 1346 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1347 * should not happen when type != rr->type */ 1348 al=SSL_AD_UNEXPECTED_MESSAGE; 1349 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1350 goto f_err; 1351 case SSL3_RT_APPLICATION_DATA: 1352 /* At this point, we were expecting handshake data, 1353 * but have application data. If the library was 1354 * running inside ssl3_read() (i.e. in_read_app_data 1355 * is set) and it makes sense to read application data 1356 * at this point (session renegotiation not yet started), 1357 * we will indulge it. 1358 */ 1359 if (s->s3->in_read_app_data && 1360 (s->s3->total_renegotiations != 0) && 1361 (( 1362 (s->state & SSL_ST_CONNECT) && 1363 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1364 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1365 ) || ( 1366 (s->state & SSL_ST_ACCEPT) && 1367 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1368 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1369 ) 1370 )) 1371 { 1372 s->s3->in_read_app_data=2; 1373 return(-1); 1374 } 1375 else 1376 { 1377 al=SSL_AD_UNEXPECTED_MESSAGE; 1378 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1379 goto f_err; 1380 } 1381 } 1382 /* not reached */ 1383 1384 f_err: 1385 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1386 err: 1387 return(-1); 1388 } 1389 1390 int 1391 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1392 { 1393 int i; 1394 1395 #ifndef OPENSSL_NO_SCTP 1396 /* Check if we have to continue an interrupted handshake 1397 * for reading belated app data with SCTP. 1398 */ 1399 if ((SSL_in_init(s) && !s->in_handshake) || 1400 (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1401 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))) 1402 #else 1403 if (SSL_in_init(s) && !s->in_handshake) 1404 #endif 1405 { 1406 i=s->handshake_func(s); 1407 if (i < 0) return(i); 1408 if (i == 0) 1409 { 1410 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1411 return -1; 1412 } 1413 } 1414 1415 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1416 { 1417 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1418 return -1; 1419 } 1420 1421 i = dtls1_write_bytes(s, type, buf_, len); 1422 return i; 1423 } 1424 1425 1426 /* this only happens when a client hello is received and a handshake 1427 * is started. */ 1428 static int 1429 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1430 int len, int peek) 1431 { 1432 1433 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1434 /* (partially) satisfy request from storage */ 1435 { 1436 unsigned char *src = s->d1->handshake_fragment; 1437 unsigned char *dst = buf; 1438 unsigned int k,n; 1439 1440 /* peek == 0 */ 1441 n = 0; 1442 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1443 { 1444 *dst++ = *src++; 1445 len--; s->d1->handshake_fragment_len--; 1446 n++; 1447 } 1448 /* move any remaining fragment bytes: */ 1449 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1450 s->d1->handshake_fragment[k] = *src++; 1451 return n; 1452 } 1453 1454 return 0; 1455 } 1456 1457 1458 1459 1460 /* Call this to write data in records of type 'type' 1461 * It will return <= 0 if not all data has been sent or non-blocking IO. 1462 */ 1463 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1464 { 1465 int i; 1466 1467 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1468 s->rwstate=SSL_NOTHING; 1469 i=do_dtls1_write(s, type, buf, len); 1470 return i; 1471 } 1472 1473 static int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 1474 unsigned int len) 1475 { 1476 unsigned char *p,*pseq; 1477 int i,mac_size,clear=0; 1478 int prefix_len = 0; 1479 SSL3_RECORD *wr; 1480 SSL3_BUFFER *wb; 1481 SSL_SESSION *sess; 1482 int bs; 1483 1484 /* first check if there is a SSL3_BUFFER still being written 1485 * out. This will happen with non blocking IO */ 1486 if (s->s3->wbuf.left != 0) 1487 { 1488 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1489 return(ssl3_write_pending(s,type,buf,len)); 1490 } 1491 1492 /* If we have an alert to send, lets send it */ 1493 if (s->s3->alert_dispatch) 1494 { 1495 i=s->method->ssl_dispatch_alert(s); 1496 if (i <= 0) 1497 return(i); 1498 /* if it went, fall through and send more stuff */ 1499 } 1500 1501 if (len == 0) 1502 return 0; 1503 1504 wr= &(s->s3->wrec); 1505 wb= &(s->s3->wbuf); 1506 sess=s->session; 1507 1508 if ( (sess == NULL) || 1509 (s->enc_write_ctx == NULL) || 1510 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1511 clear=1; 1512 1513 if (clear) 1514 mac_size=0; 1515 else 1516 { 1517 mac_size=EVP_MD_CTX_size(s->write_hash); 1518 if (mac_size < 0) 1519 goto err; 1520 } 1521 1522 p = wb->buf + prefix_len; 1523 1524 /* write the header */ 1525 1526 *(p++)=type&0xff; 1527 wr->type=type; 1528 1529 *(p++)=(s->version>>8); 1530 *(p++)=s->version&0xff; 1531 1532 /* field where we are to write out packet epoch, seq num and len */ 1533 pseq=p; 1534 p+=10; 1535 1536 /* lets setup the record stuff. */ 1537 1538 /* Make space for the explicit IV in case of CBC. 1539 * (this is a bit of a boundary violation, but what the heck). 1540 */ 1541 if ( s->enc_write_ctx && 1542 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1543 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1544 else 1545 bs = 0; 1546 1547 wr->data=p + bs; /* make room for IV in case of CBC */ 1548 wr->length=(int)len; 1549 wr->input=(unsigned char *)buf; 1550 1551 /* we now 'read' from wr->input, wr->length bytes into 1552 * wr->data */ 1553 1554 /* first we compress */ 1555 if (s->compress != NULL) 1556 { 1557 if (!ssl3_do_compress(s)) 1558 { 1559 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1560 goto err; 1561 } 1562 } 1563 else 1564 { 1565 memcpy(wr->data,wr->input,wr->length); 1566 wr->input=wr->data; 1567 } 1568 1569 /* we should still have the output to wr->data and the input 1570 * from wr->input. Length should be wr->length. 1571 * wr->data still points in the wb->buf */ 1572 1573 if (mac_size != 0) 1574 { 1575 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0) 1576 goto err; 1577 wr->length+=mac_size; 1578 } 1579 1580 /* this is true regardless of mac size */ 1581 wr->input=p; 1582 wr->data=p; 1583 1584 1585 /* ssl3_enc can only have an error on read */ 1586 if (bs) /* bs != 0 in case of CBC */ 1587 { 1588 RAND_pseudo_bytes(p,bs); 1589 /* master IV and last CBC residue stand for 1590 * the rest of randomness */ 1591 wr->length += bs; 1592 } 1593 1594 s->method->ssl3_enc->enc(s,1); 1595 1596 /* record length after mac and block padding */ 1597 /* if (type == SSL3_RT_APPLICATION_DATA || 1598 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1599 1600 /* there's only one epoch between handshake and app data */ 1601 1602 s2n(s->d1->w_epoch, pseq); 1603 1604 /* XDTLS: ?? */ 1605 /* else 1606 s2n(s->d1->handshake_epoch, pseq); */ 1607 1608 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1609 pseq+=6; 1610 s2n(wr->length,pseq); 1611 1612 /* we should now have 1613 * wr->data pointing to the encrypted data, which is 1614 * wr->length long */ 1615 wr->type=type; /* not needed but helps for debugging */ 1616 wr->length+=DTLS1_RT_HEADER_LENGTH; 1617 1618 #if 0 /* this is now done at the message layer */ 1619 /* buffer the record, making it easy to handle retransmits */ 1620 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1621 dtls1_buffer_record(s, wr->data, wr->length, 1622 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1623 #endif 1624 1625 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1626 1627 /* now let's set up wb */ 1628 wb->left = prefix_len + wr->length; 1629 wb->offset = 0; 1630 1631 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1632 s->s3->wpend_tot=len; 1633 s->s3->wpend_buf=buf; 1634 s->s3->wpend_type=type; 1635 s->s3->wpend_ret=len; 1636 1637 /* we now just need to write the buffer */ 1638 return ssl3_write_pending(s,type,buf,len); 1639 err: 1640 return -1; 1641 } 1642 1643 1644 1645 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1646 { 1647 int cmp; 1648 unsigned int shift; 1649 const unsigned char *seq = s->s3->read_sequence; 1650 1651 cmp = satsub64be(seq,bitmap->max_seq_num); 1652 if (cmp > 0) 1653 { 1654 memcpy (s->s3->rrec.seq_num,seq,8); 1655 return 1; /* this record in new */ 1656 } 1657 shift = -cmp; 1658 if (shift >= sizeof(bitmap->map)*8) 1659 return 0; /* stale, outside the window */ 1660 else if (bitmap->map & (1UL<<shift)) 1661 return 0; /* record previously received */ 1662 1663 memcpy (s->s3->rrec.seq_num,seq,8); 1664 return 1; 1665 } 1666 1667 1668 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1669 { 1670 int cmp; 1671 unsigned int shift; 1672 const unsigned char *seq = s->s3->read_sequence; 1673 1674 cmp = satsub64be(seq,bitmap->max_seq_num); 1675 if (cmp > 0) 1676 { 1677 shift = cmp; 1678 if (shift < sizeof(bitmap->map)*8) 1679 bitmap->map <<= shift, bitmap->map |= 1UL; 1680 else 1681 bitmap->map = 1UL; 1682 memcpy(bitmap->max_seq_num,seq,8); 1683 } 1684 else { 1685 shift = -cmp; 1686 if (shift < sizeof(bitmap->map)*8) 1687 bitmap->map |= 1UL<<shift; 1688 } 1689 } 1690 1691 1692 int dtls1_dispatch_alert(SSL *s) 1693 { 1694 int i,j; 1695 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1696 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1697 unsigned char *ptr = &buf[0]; 1698 1699 s->s3->alert_dispatch=0; 1700 1701 memset(buf, 0x00, sizeof(buf)); 1702 *ptr++ = s->s3->send_alert[0]; 1703 *ptr++ = s->s3->send_alert[1]; 1704 1705 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1706 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1707 { 1708 s2n(s->d1->handshake_read_seq, ptr); 1709 #if 0 1710 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1711 1712 else 1713 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1714 #endif 1715 1716 #if 0 1717 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); 1718 #endif 1719 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1720 } 1721 #endif 1722 1723 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf)); 1724 if (i <= 0) 1725 { 1726 s->s3->alert_dispatch=1; 1727 /* fprintf( stderr, "not done with alert\n" ); */ 1728 } 1729 else 1730 { 1731 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1732 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1733 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1734 #endif 1735 ) 1736 (void)BIO_flush(s->wbio); 1737 1738 if (s->msg_callback) 1739 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1740 2, s, s->msg_callback_arg); 1741 1742 if (s->info_callback != NULL) 1743 cb=s->info_callback; 1744 else if (s->ctx->info_callback != NULL) 1745 cb=s->ctx->info_callback; 1746 1747 if (cb != NULL) 1748 { 1749 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1750 cb(s,SSL_CB_WRITE_ALERT,j); 1751 } 1752 } 1753 return(i); 1754 } 1755 1756 1757 static DTLS1_BITMAP * 1758 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1759 { 1760 1761 *is_next_epoch = 0; 1762 1763 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1764 if (rr->epoch == s->d1->r_epoch) 1765 return &s->d1->bitmap; 1766 1767 /* Only HM and ALERT messages can be from the next epoch */ 1768 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1769 (rr->type == SSL3_RT_HANDSHAKE || 1770 rr->type == SSL3_RT_ALERT)) 1771 { 1772 *is_next_epoch = 1; 1773 return &s->d1->next_bitmap; 1774 } 1775 1776 return NULL; 1777 } 1778 1779 #if 0 1780 static int 1781 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1782 unsigned long *offset) 1783 { 1784 1785 /* alerts are passed up immediately */ 1786 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1787 rr->type == SSL3_RT_ALERT) 1788 return 0; 1789 1790 /* Only need to buffer if a handshake is underway. 1791 * (this implies that Hello Request and Client Hello are passed up 1792 * immediately) */ 1793 if ( SSL_in_init(s)) 1794 { 1795 unsigned char *data = rr->data; 1796 /* need to extract the HM/CCS sequence number here */ 1797 if ( rr->type == SSL3_RT_HANDSHAKE || 1798 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1799 { 1800 unsigned short seq_num; 1801 struct hm_header_st msg_hdr; 1802 struct ccs_header_st ccs_hdr; 1803 1804 if ( rr->type == SSL3_RT_HANDSHAKE) 1805 { 1806 dtls1_get_message_header(data, &msg_hdr); 1807 seq_num = msg_hdr.seq; 1808 *offset = msg_hdr.frag_off; 1809 } 1810 else 1811 { 1812 dtls1_get_ccs_header(data, &ccs_hdr); 1813 seq_num = ccs_hdr.seq; 1814 *offset = 0; 1815 } 1816 1817 /* this is either a record we're waiting for, or a 1818 * retransmit of something we happened to previously 1819 * receive (higher layers will drop the repeat silently */ 1820 if ( seq_num < s->d1->handshake_read_seq) 1821 return 0; 1822 if (rr->type == SSL3_RT_HANDSHAKE && 1823 seq_num == s->d1->handshake_read_seq && 1824 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1825 return 0; 1826 else if ( seq_num == s->d1->handshake_read_seq && 1827 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1828 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1829 return 0; 1830 else 1831 { 1832 *priority = seq_num; 1833 return 1; 1834 } 1835 } 1836 else /* unknown record type */ 1837 return 0; 1838 } 1839 1840 return 0; 1841 } 1842 #endif 1843 1844 void 1845 dtls1_reset_seq_numbers(SSL *s, int rw) 1846 { 1847 unsigned char *seq; 1848 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1849 1850 if ( rw & SSL3_CC_READ) 1851 { 1852 seq = s->s3->read_sequence; 1853 s->d1->r_epoch++; 1854 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1855 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1856 } 1857 else 1858 { 1859 seq = s->s3->write_sequence; 1860 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1861 s->d1->w_epoch++; 1862 } 1863 1864 memset(seq, 0x00, seq_bytes); 1865 } 1866
