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 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 126 int len, int peek); 127 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 128 PQ_64BIT *seq_num); 129 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 130 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 131 unsigned int *is_next_epoch); 132 #if 0 133 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 134 unsigned short *priority, unsigned long *offset); 135 #endif 136 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 137 PQ_64BIT *priority); 138 static int dtls1_process_record(SSL *s); 139 #if PQ_64BIT_IS_INTEGER 140 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num); 141 #endif 142 static void dtls1_clear_timeouts(SSL *s); 143 144 /* copy buffered record into SSL structure */ 145 static int 146 dtls1_copy_record(SSL *s, pitem *item) 147 { 148 DTLS1_RECORD_DATA *rdata; 149 150 rdata = (DTLS1_RECORD_DATA *)item->data; 151 152 if (s->s3->rbuf.buf != NULL) 153 OPENSSL_free(s->s3->rbuf.buf); 154 155 s->packet = rdata->packet; 156 s->packet_length = rdata->packet_length; 157 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 158 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 159 160 return(1); 161 } 162 163 164 static int 165 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT *priority) 166 { 167 DTLS1_RECORD_DATA *rdata; 168 pitem *item; 169 170 /* Limit the size of the queue to prevent DOS attacks */ 171 if (pqueue_size(queue->q) >= 100) 172 return 0; 173 174 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 175 item = pitem_new(*priority, rdata); 176 if (rdata == NULL || item == NULL) 177 { 178 if (rdata != NULL) OPENSSL_free(rdata); 179 if (item != NULL) pitem_free(item); 180 181 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 182 return(0); 183 } 184 185 rdata->packet = s->packet; 186 rdata->packet_length = s->packet_length; 187 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 188 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 189 190 item->data = rdata; 191 192 /* insert should not fail, since duplicates are dropped */ 193 if (pqueue_insert(queue->q, item) == NULL) 194 { 195 OPENSSL_free(rdata); 196 pitem_free(item); 197 return(0); 198 } 199 200 s->packet = NULL; 201 s->packet_length = 0; 202 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 203 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 204 205 if (!ssl3_setup_buffers(s)) 206 { 207 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 208 OPENSSL_free(rdata); 209 pitem_free(item); 210 return(0); 211 } 212 213 return(1); 214 } 215 216 217 static int 218 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 219 { 220 pitem *item; 221 222 item = pqueue_pop(queue->q); 223 if (item) 224 { 225 dtls1_copy_record(s, item); 226 227 OPENSSL_free(item->data); 228 pitem_free(item); 229 230 return(1); 231 } 232 233 return(0); 234 } 235 236 237 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 238 * yet */ 239 #define dtls1_get_unprocessed_record(s) \ 240 dtls1_retrieve_buffered_record((s), \ 241 &((s)->d1->unprocessed_rcds)) 242 243 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 244 #define dtls1_get_processed_record(s) \ 245 dtls1_retrieve_buffered_record((s), \ 246 &((s)->d1->processed_rcds)) 247 248 static int 249 dtls1_process_buffered_records(SSL *s) 250 { 251 pitem *item; 252 253 item = pqueue_peek(s->d1->unprocessed_rcds.q); 254 if (item) 255 { 256 DTLS1_RECORD_DATA *rdata; 257 rdata = (DTLS1_RECORD_DATA *)item->data; 258 259 /* Check if epoch is current. */ 260 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 261 return(1); /* Nothing to do. */ 262 263 /* Process all the records. */ 264 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 265 { 266 dtls1_get_unprocessed_record(s); 267 if ( ! dtls1_process_record(s)) 268 return(0); 269 dtls1_buffer_record(s, &(s->d1->processed_rcds), 270 &s->s3->rrec.seq_num); 271 } 272 } 273 274 /* sync epoch numbers once all the unprocessed records 275 * have been processed */ 276 s->d1->processed_rcds.epoch = s->d1->r_epoch; 277 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 278 279 return(1); 280 } 281 282 283 #if 0 284 285 static int 286 dtls1_get_buffered_record(SSL *s) 287 { 288 pitem *item; 289 PQ_64BIT priority = 290 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 291 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 292 293 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 294 nothing buffered */ 295 return 0; 296 297 298 item = pqueue_peek(s->d1->rcvd_records); 299 if (item && item->priority == priority) 300 { 301 /* Check if we've received the record of interest. It must be 302 * a handshake record, since data records as passed up without 303 * buffering */ 304 DTLS1_RECORD_DATA *rdata; 305 item = pqueue_pop(s->d1->rcvd_records); 306 rdata = (DTLS1_RECORD_DATA *)item->data; 307 308 if (s->s3->rbuf.buf != NULL) 309 OPENSSL_free(s->s3->rbuf.buf); 310 311 s->packet = rdata->packet; 312 s->packet_length = rdata->packet_length; 313 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 314 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 315 316 OPENSSL_free(item->data); 317 pitem_free(item); 318 319 /* s->d1->next_expected_seq_num++; */ 320 return(1); 321 } 322 323 return 0; 324 } 325 326 #endif 327 328 static int 329 dtls1_process_record(SSL *s) 330 { 331 int i,al; 332 int clear=0; 333 int enc_err; 334 SSL_SESSION *sess; 335 SSL3_RECORD *rr; 336 unsigned int mac_size; 337 unsigned char md[EVP_MAX_MD_SIZE]; 338 339 340 rr= &(s->s3->rrec); 341 sess = s->session; 342 343 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 344 * and we have that many bytes in s->packet 345 */ 346 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 347 348 /* ok, we can now read from 's->packet' data into 'rr' 349 * rr->input points at rr->length bytes, which 350 * need to be copied into rr->data by either 351 * the decryption or by the decompression 352 * When the data is 'copied' into the rr->data buffer, 353 * rr->input will be pointed at the new buffer */ 354 355 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 356 * rr->length bytes of encrypted compressed stuff. */ 357 358 /* check is not needed I believe */ 359 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 360 { 361 al=SSL_AD_RECORD_OVERFLOW; 362 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 363 goto f_err; 364 } 365 366 /* decrypt in place in 'rr->input' */ 367 rr->data=rr->input; 368 369 enc_err = s->method->ssl3_enc->enc(s,0); 370 if (enc_err <= 0) 371 { 372 if (enc_err == 0) 373 /* SSLerr() and ssl3_send_alert() have been called */ 374 goto err; 375 376 /* otherwise enc_err == -1 */ 377 goto decryption_failed_or_bad_record_mac; 378 } 379 380 #ifdef TLS_DEBUG 381 printf("dec %d\n",rr->length); 382 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 383 printf("\n"); 384 #endif 385 386 /* r->length is now the compressed data plus mac */ 387 if ( (sess == NULL) || 388 (s->enc_read_ctx == NULL) || 389 (s->read_hash == NULL)) 390 clear=1; 391 392 if (!clear) 393 { 394 mac_size=EVP_MD_size(s->read_hash); 395 396 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 397 { 398 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ 399 al=SSL_AD_RECORD_OVERFLOW; 400 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); 401 goto f_err; 402 #else 403 goto decryption_failed_or_bad_record_mac; 404 #endif 405 } 406 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ 407 if (rr->length < mac_size) 408 { 409 #if 0 /* OK only for stream ciphers */ 410 al=SSL_AD_DECODE_ERROR; 411 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT); 412 goto f_err; 413 #else 414 goto decryption_failed_or_bad_record_mac; 415 #endif 416 } 417 rr->length-=mac_size; 418 i=s->method->ssl3_enc->mac(s,md,0); 419 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0) 420 { 421 goto decryption_failed_or_bad_record_mac; 422 } 423 } 424 425 /* r->length is now just compressed */ 426 if (s->expand != NULL) 427 { 428 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 429 { 430 al=SSL_AD_RECORD_OVERFLOW; 431 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 432 goto f_err; 433 } 434 if (!ssl3_do_uncompress(s)) 435 { 436 al=SSL_AD_DECOMPRESSION_FAILURE; 437 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 438 goto f_err; 439 } 440 } 441 442 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 443 { 444 al=SSL_AD_RECORD_OVERFLOW; 445 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 446 goto f_err; 447 } 448 449 rr->off=0; 450 /* So at this point the following is true 451 * ssl->s3->rrec.type is the type of record 452 * ssl->s3->rrec.length == number of bytes in record 453 * ssl->s3->rrec.off == offset to first valid byte 454 * ssl->s3->rrec.data == where to take bytes from, increment 455 * after use :-). 456 */ 457 458 /* we have pulled in a full packet so zero things */ 459 s->packet_length=0; 460 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 461 return(1); 462 463 decryption_failed_or_bad_record_mac: 464 /* Separate 'decryption_failed' alert was introduced with TLS 1.0, 465 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption 466 * failure is directly visible from the ciphertext anyway, 467 * we should not reveal which kind of error occured -- this 468 * might become visible to an attacker (e.g. via logfile) */ 469 al=SSL_AD_BAD_RECORD_MAC; 470 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 471 f_err: 472 ssl3_send_alert(s,SSL3_AL_FATAL,al); 473 err: 474 return(0); 475 } 476 477 478 /* Call this to get a new input record. 479 * It will return <= 0 if more data is needed, normally due to an error 480 * or non-blocking IO. 481 * When it finishes, one packet has been decoded and can be found in 482 * ssl->s3->rrec.type - is the type of record 483 * ssl->s3->rrec.data, - data 484 * ssl->s3->rrec.length, - number of bytes 485 */ 486 /* used only by dtls1_read_bytes */ 487 int dtls1_get_record(SSL *s) 488 { 489 int ssl_major,ssl_minor; 490 int i,n; 491 SSL3_RECORD *rr; 492 SSL_SESSION *sess; 493 unsigned char *p = NULL; 494 unsigned short version; 495 DTLS1_BITMAP *bitmap; 496 unsigned int is_next_epoch; 497 498 rr= &(s->s3->rrec); 499 sess=s->session; 500 501 /* The epoch may have changed. If so, process all the 502 * pending records. This is a non-blocking operation. */ 503 if ( ! dtls1_process_buffered_records(s)) 504 return 0; 505 506 /* if we're renegotiating, then there may be buffered records */ 507 if (dtls1_get_processed_record(s)) 508 return 1; 509 510 /* get something from the wire */ 511 again: 512 /* check if we have the header */ 513 if ( (s->rstate != SSL_ST_READ_BODY) || 514 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 515 { 516 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 517 /* read timeout is handled by dtls1_read_bytes */ 518 if (n <= 0) return(n); /* error or non-blocking */ 519 520 /* this packet contained a partial record, dump it */ 521 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 522 { 523 s->packet_length = 0; 524 goto again; 525 } 526 527 s->rstate=SSL_ST_READ_BODY; 528 529 p=s->packet; 530 531 /* Pull apart the header into the DTLS1_RECORD */ 532 rr->type= *(p++); 533 ssl_major= *(p++); 534 ssl_minor= *(p++); 535 version=(ssl_major<<8)|ssl_minor; 536 537 /* sequence number is 64 bits, with top 2 bytes = epoch */ 538 n2s(p,rr->epoch); 539 540 memcpy(&(s->s3->read_sequence[2]), p, 6); 541 p+=6; 542 543 n2s(p,rr->length); 544 545 /* Lets check version */ 546 if (!s->first_packet) 547 { 548 if (version != s->version && version != DTLS1_BAD_VER) 549 { 550 /* unexpected version, silently discard */ 551 rr->length = 0; 552 s->packet_length = 0; 553 goto again; 554 } 555 } 556 557 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) && 558 (version & 0xff00) != (DTLS1_BAD_VER & 0xff00)) 559 { 560 /* wrong version, silently discard record */ 561 rr->length = 0; 562 s->packet_length = 0; 563 goto again; 564 } 565 566 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 567 { 568 /* record too long, silently discard it */ 569 rr->length = 0; 570 s->packet_length = 0; 571 goto again; 572 } 573 574 /* If we receive a valid record larger than the current buffer size, 575 * allocate some memory for it. 576 */ 577 if (rr->length > s->s3->rbuf.len - DTLS1_RT_HEADER_LENGTH) 578 { 579 unsigned char *pp; 580 unsigned int newlen = rr->length + DTLS1_RT_HEADER_LENGTH; 581 if ((pp=OPENSSL_realloc(s->s3->rbuf.buf, newlen))==NULL) 582 { 583 SSLerr(SSL_F_DTLS1_GET_RECORD,ERR_R_MALLOC_FAILURE); 584 return(-1); 585 } 586 p = pp + (p - s->s3->rbuf.buf); 587 s->s3->rbuf.buf=pp; 588 s->s3->rbuf.len=newlen; 589 s->packet= &(s->s3->rbuf.buf[0]); 590 } 591 592 s->client_version = version; 593 /* now s->rstate == SSL_ST_READ_BODY */ 594 } 595 596 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 597 598 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 599 { 600 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 601 i=rr->length; 602 n=ssl3_read_n(s,i,i,1); 603 if (n <= 0) return(n); /* error or non-blocking io */ 604 605 /* this packet contained a partial record, dump it */ 606 if ( n != i) 607 { 608 rr->length = 0; 609 s->packet_length = 0; 610 goto again; 611 } 612 613 /* now n == rr->length, 614 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 615 } 616 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 617 618 /* match epochs. NULL means the packet is dropped on the floor */ 619 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 620 if ( bitmap == NULL) 621 { 622 rr->length = 0; 623 s->packet_length = 0; /* dump this record */ 624 goto again; /* get another record */ 625 } 626 627 /* Check whether this is a repeat, or aged record. 628 * Don't check if we're listening and this message is 629 * a ClientHello. They can look as if they're replayed, 630 * since they arrive from different connections and 631 * would be dropped unnecessarily. 632 */ 633 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 634 *p == SSL3_MT_CLIENT_HELLO) && 635 ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num))) 636 { 637 rr->length = 0; 638 s->packet_length=0; /* dump this record */ 639 goto again; /* get another record */ 640 } 641 642 /* just read a 0 length packet */ 643 if (rr->length == 0) goto again; 644 645 /* If this record is from the next epoch (either HM or ALERT), buffer it 646 * since it cannot be processed at this time. 647 * Records from the next epoch are marked as received even though they are 648 * not processed, so as to prevent any potential resource DoS attack */ 649 if (is_next_epoch) 650 { 651 dtls1_record_bitmap_update(s, bitmap); 652 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), &rr->seq_num); 653 rr->length = 0; 654 s->packet_length = 0; 655 goto again; 656 } 657 658 if ( ! dtls1_process_record(s)) 659 return(0); 660 661 dtls1_clear_timeouts(s); /* done waiting */ 662 return(1); 663 664 } 665 666 /* Return up to 'len' payload bytes received in 'type' records. 667 * 'type' is one of the following: 668 * 669 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 670 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 671 * - 0 (during a shutdown, no data has to be returned) 672 * 673 * If we don't have stored data to work from, read a SSL/TLS record first 674 * (possibly multiple records if we still don't have anything to return). 675 * 676 * This function must handle any surprises the peer may have for us, such as 677 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 678 * a surprise, but handled as if it were), or renegotiation requests. 679 * Also if record payloads contain fragments too small to process, we store 680 * them until there is enough for the respective protocol (the record protocol 681 * may use arbitrary fragmentation and even interleaving): 682 * Change cipher spec protocol 683 * just 1 byte needed, no need for keeping anything stored 684 * Alert protocol 685 * 2 bytes needed (AlertLevel, AlertDescription) 686 * Handshake protocol 687 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 688 * to detect unexpected Client Hello and Hello Request messages 689 * here, anything else is handled by higher layers 690 * Application data protocol 691 * none of our business 692 */ 693 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 694 { 695 int al,i,j,ret; 696 unsigned int n; 697 SSL3_RECORD *rr; 698 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 699 700 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 701 if (!ssl3_setup_buffers(s)) 702 return(-1); 703 704 /* XXX: check what the second '&& type' is about */ 705 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 706 (type != SSL3_RT_HANDSHAKE) && type) || 707 (peek && (type != SSL3_RT_APPLICATION_DATA))) 708 { 709 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 710 return -1; 711 } 712 713 /* check whether there's a handshake message (client hello?) waiting */ 714 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 715 return ret; 716 717 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 718 719 if (!s->in_handshake && SSL_in_init(s)) 720 { 721 /* type == SSL3_RT_APPLICATION_DATA */ 722 i=s->handshake_func(s); 723 if (i < 0) return(i); 724 if (i == 0) 725 { 726 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 727 return(-1); 728 } 729 } 730 731 start: 732 s->rwstate=SSL_NOTHING; 733 734 /* s->s3->rrec.type - is the type of record 735 * s->s3->rrec.data, - data 736 * s->s3->rrec.off, - offset into 'data' for next read 737 * s->s3->rrec.length, - number of bytes. */ 738 rr = &(s->s3->rrec); 739 740 /* We are not handshaking and have no data yet, 741 * so process data buffered during the last handshake 742 * in advance, if any. 743 */ 744 if (s->state == SSL_ST_OK && rr->length == 0) 745 { 746 pitem *item; 747 item = pqueue_pop(s->d1->buffered_app_data.q); 748 if (item) 749 { 750 dtls1_copy_record(s, item); 751 752 OPENSSL_free(item->data); 753 pitem_free(item); 754 } 755 } 756 757 /* Check for timeout */ 758 if (dtls1_handle_timeout(s) > 0) 759 goto start; 760 761 /* get new packet if necessary */ 762 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 763 { 764 ret=dtls1_get_record(s); 765 if (ret <= 0) 766 { 767 ret = dtls1_read_failed(s, ret); 768 /* anything other than a timeout is an error */ 769 if (ret <= 0) 770 return(ret); 771 else 772 goto start; 773 } 774 } 775 776 /* we now have a packet which can be read and processed */ 777 778 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 779 * reset by ssl3_get_finished */ 780 && (rr->type != SSL3_RT_HANDSHAKE)) 781 { 782 /* We now have application data between CCS and Finished. 783 * Most likely the packets were reordered on their way, so 784 * buffer the application data for later processing rather 785 * than dropping the connection. 786 */ 787 dtls1_buffer_record(s, &(s->d1->buffered_app_data), 0); 788 rr->length = 0; 789 goto start; 790 } 791 792 /* If the other end has shut down, throw anything we read away 793 * (even in 'peek' mode) */ 794 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 795 { 796 rr->length=0; 797 s->rwstate=SSL_NOTHING; 798 return(0); 799 } 800 801 802 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 803 { 804 /* make sure that we are not getting application data when we 805 * are doing a handshake for the first time */ 806 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 807 (s->enc_read_ctx == NULL)) 808 { 809 al=SSL_AD_UNEXPECTED_MESSAGE; 810 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 811 goto f_err; 812 } 813 814 if (len <= 0) return(len); 815 816 if ((unsigned int)len > rr->length) 817 n = rr->length; 818 else 819 n = (unsigned int)len; 820 821 memcpy(buf,&(rr->data[rr->off]),n); 822 if (!peek) 823 { 824 rr->length-=n; 825 rr->off+=n; 826 if (rr->length == 0) 827 { 828 s->rstate=SSL_ST_READ_HEADER; 829 rr->off=0; 830 } 831 } 832 return(n); 833 } 834 835 836 /* If we get here, then type != rr->type; if we have a handshake 837 * message, then it was unexpected (Hello Request or Client Hello). */ 838 839 /* In case of record types for which we have 'fragment' storage, 840 * fill that so that we can process the data at a fixed place. 841 */ 842 { 843 unsigned int k, dest_maxlen = 0; 844 unsigned char *dest = NULL; 845 unsigned int *dest_len = NULL; 846 847 if (rr->type == SSL3_RT_HANDSHAKE) 848 { 849 dest_maxlen = sizeof s->d1->handshake_fragment; 850 dest = s->d1->handshake_fragment; 851 dest_len = &s->d1->handshake_fragment_len; 852 } 853 else if (rr->type == SSL3_RT_ALERT) 854 { 855 dest_maxlen = sizeof(s->d1->alert_fragment); 856 dest = s->d1->alert_fragment; 857 dest_len = &s->d1->alert_fragment_len; 858 } 859 /* else it's a CCS message, or application data or wrong */ 860 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 861 { 862 /* Application data while renegotiating 863 * is allowed. Try again reading. 864 */ 865 if (rr->type == SSL3_RT_APPLICATION_DATA) 866 { 867 BIO *bio; 868 s->s3->in_read_app_data=2; 869 bio=SSL_get_rbio(s); 870 s->rwstate=SSL_READING; 871 BIO_clear_retry_flags(bio); 872 BIO_set_retry_read(bio); 873 return(-1); 874 } 875 876 /* Not certain if this is the right error handling */ 877 al=SSL_AD_UNEXPECTED_MESSAGE; 878 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 879 goto f_err; 880 } 881 882 if (dest_maxlen > 0) 883 { 884 /* XDTLS: In a pathalogical case, the Client Hello 885 * may be fragmented--don't always expect dest_maxlen bytes */ 886 if ( rr->length < dest_maxlen) 887 { 888 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 889 /* 890 * for normal alerts rr->length is 2, while 891 * dest_maxlen is 7 if we were to handle this 892 * non-existing alert... 893 */ 894 FIX ME 895 #endif 896 s->rstate=SSL_ST_READ_HEADER; 897 rr->length = 0; 898 goto start; 899 } 900 901 /* now move 'n' bytes: */ 902 for ( k = 0; k < dest_maxlen; k++) 903 { 904 dest[k] = rr->data[rr->off++]; 905 rr->length--; 906 } 907 *dest_len = dest_maxlen; 908 } 909 } 910 911 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 912 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 913 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 914 915 /* If we are a client, check for an incoming 'Hello Request': */ 916 if ((!s->server) && 917 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 918 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 919 (s->session != NULL) && (s->session->cipher != NULL)) 920 { 921 s->d1->handshake_fragment_len = 0; 922 923 if ((s->d1->handshake_fragment[1] != 0) || 924 (s->d1->handshake_fragment[2] != 0) || 925 (s->d1->handshake_fragment[3] != 0)) 926 { 927 al=SSL_AD_DECODE_ERROR; 928 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 929 goto err; 930 } 931 932 /* no need to check sequence number on HELLO REQUEST messages */ 933 934 if (s->msg_callback) 935 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 936 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 937 938 if (SSL_is_init_finished(s) && 939 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 940 !s->s3->renegotiate) 941 { 942 ssl3_renegotiate(s); 943 if (ssl3_renegotiate_check(s)) 944 { 945 i=s->handshake_func(s); 946 if (i < 0) return(i); 947 if (i == 0) 948 { 949 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 950 return(-1); 951 } 952 953 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 954 { 955 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 956 { 957 BIO *bio; 958 /* In the case where we try to read application data, 959 * but we trigger an SSL handshake, we return -1 with 960 * the retry option set. Otherwise renegotiation may 961 * cause nasty problems in the blocking world */ 962 s->rwstate=SSL_READING; 963 bio=SSL_get_rbio(s); 964 BIO_clear_retry_flags(bio); 965 BIO_set_retry_read(bio); 966 return(-1); 967 } 968 } 969 } 970 } 971 /* we either finished a handshake or ignored the request, 972 * now try again to obtain the (application) data we were asked for */ 973 goto start; 974 } 975 976 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 977 { 978 int alert_level = s->d1->alert_fragment[0]; 979 int alert_descr = s->d1->alert_fragment[1]; 980 981 s->d1->alert_fragment_len = 0; 982 983 if (s->msg_callback) 984 s->msg_callback(0, s->version, SSL3_RT_ALERT, 985 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 986 987 if (s->info_callback != NULL) 988 cb=s->info_callback; 989 else if (s->ctx->info_callback != NULL) 990 cb=s->ctx->info_callback; 991 992 if (cb != NULL) 993 { 994 j = (alert_level << 8) | alert_descr; 995 cb(s, SSL_CB_READ_ALERT, j); 996 } 997 998 if (alert_level == 1) /* warning */ 999 { 1000 s->s3->warn_alert = alert_descr; 1001 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1002 { 1003 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1004 return(0); 1005 } 1006 #if 0 1007 /* XXX: this is a possible improvement in the future */ 1008 /* now check if it's a missing record */ 1009 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1010 { 1011 unsigned short seq; 1012 unsigned int frag_off; 1013 unsigned char *p = &(s->d1->alert_fragment[2]); 1014 1015 n2s(p, seq); 1016 n2l3(p, frag_off); 1017 1018 dtls1_retransmit_message(s, 1019 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1020 frag_off, &found); 1021 if ( ! found && SSL_in_init(s)) 1022 { 1023 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1024 /* requested a message not yet sent, 1025 send an alert ourselves */ 1026 ssl3_send_alert(s,SSL3_AL_WARNING, 1027 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1028 } 1029 } 1030 #endif 1031 } 1032 else if (alert_level == 2) /* fatal */ 1033 { 1034 char tmp[16]; 1035 1036 s->rwstate=SSL_NOTHING; 1037 s->s3->fatal_alert = alert_descr; 1038 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1039 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1040 ERR_add_error_data(2,"SSL alert number ",tmp); 1041 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1042 SSL_CTX_remove_session(s->ctx,s->session); 1043 return(0); 1044 } 1045 else 1046 { 1047 al=SSL_AD_ILLEGAL_PARAMETER; 1048 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1049 goto f_err; 1050 } 1051 1052 goto start; 1053 } 1054 1055 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1056 { 1057 s->rwstate=SSL_NOTHING; 1058 rr->length=0; 1059 return(0); 1060 } 1061 1062 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1063 { 1064 struct ccs_header_st ccs_hdr; 1065 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1066 1067 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1068 1069 /* 'Change Cipher Spec' is just a single byte, so we know 1070 * exactly what the record payload has to look like */ 1071 /* XDTLS: check that epoch is consistent */ 1072 if (s->client_version == DTLS1_BAD_VER || s->version == DTLS1_BAD_VER) 1073 ccs_hdr_len = 3; 1074 1075 if ((rr->length != ccs_hdr_len) || (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1076 { 1077 i=SSL_AD_ILLEGAL_PARAMETER; 1078 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1079 goto err; 1080 } 1081 1082 rr->length=0; 1083 1084 if (s->msg_callback) 1085 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1086 rr->data, 1, s, s->msg_callback_arg); 1087 1088 /* We can't process a CCS now, because previous handshake 1089 * messages are still missing, so just drop it. 1090 */ 1091 if (!s->d1->change_cipher_spec_ok) 1092 { 1093 goto start; 1094 } 1095 1096 s->d1->change_cipher_spec_ok = 0; 1097 1098 s->s3->change_cipher_spec=1; 1099 if (!ssl3_do_change_cipher_spec(s)) 1100 goto err; 1101 1102 /* do this whenever CCS is processed */ 1103 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1104 1105 if (s->client_version == DTLS1_BAD_VER) 1106 s->d1->handshake_read_seq++; 1107 1108 goto start; 1109 } 1110 1111 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1112 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1113 !s->in_handshake) 1114 { 1115 struct hm_header_st msg_hdr; 1116 1117 /* this may just be a stale retransmit */ 1118 dtls1_get_message_header(rr->data, &msg_hdr); 1119 if( rr->epoch != s->d1->r_epoch) 1120 { 1121 rr->length = 0; 1122 goto start; 1123 } 1124 1125 /* If we are server, we may have a repeated FINISHED of the 1126 * client here, then retransmit our CCS and FINISHED. 1127 */ 1128 if (msg_hdr.type == SSL3_MT_FINISHED) 1129 { 1130 dtls1_retransmit_buffered_messages(s); 1131 rr->length = 0; 1132 goto start; 1133 } 1134 1135 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1136 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1137 { 1138 #if 0 /* worked only because C operator preferences are not as expected (and 1139 * because this is not really needed for clients except for detecting 1140 * protocol violations): */ 1141 s->state=SSL_ST_BEFORE|(s->server) 1142 ?SSL_ST_ACCEPT 1143 :SSL_ST_CONNECT; 1144 #else 1145 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1146 #endif 1147 s->new_session=1; 1148 } 1149 i=s->handshake_func(s); 1150 if (i < 0) return(i); 1151 if (i == 0) 1152 { 1153 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1154 return(-1); 1155 } 1156 1157 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1158 { 1159 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1160 { 1161 BIO *bio; 1162 /* In the case where we try to read application data, 1163 * but we trigger an SSL handshake, we return -1 with 1164 * the retry option set. Otherwise renegotiation may 1165 * cause nasty problems in the blocking world */ 1166 s->rwstate=SSL_READING; 1167 bio=SSL_get_rbio(s); 1168 BIO_clear_retry_flags(bio); 1169 BIO_set_retry_read(bio); 1170 return(-1); 1171 } 1172 } 1173 goto start; 1174 } 1175 1176 switch (rr->type) 1177 { 1178 default: 1179 #ifndef OPENSSL_NO_TLS 1180 /* TLS just ignores unknown message types */ 1181 if (s->version == TLS1_VERSION) 1182 { 1183 rr->length = 0; 1184 goto start; 1185 } 1186 #endif 1187 al=SSL_AD_UNEXPECTED_MESSAGE; 1188 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1189 goto f_err; 1190 case SSL3_RT_CHANGE_CIPHER_SPEC: 1191 case SSL3_RT_ALERT: 1192 case SSL3_RT_HANDSHAKE: 1193 /* we already handled all of these, with the possible exception 1194 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1195 * should not happen when type != rr->type */ 1196 al=SSL_AD_UNEXPECTED_MESSAGE; 1197 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1198 goto f_err; 1199 case SSL3_RT_APPLICATION_DATA: 1200 /* At this point, we were expecting handshake data, 1201 * but have application data. If the library was 1202 * running inside ssl3_read() (i.e. in_read_app_data 1203 * is set) and it makes sense to read application data 1204 * at this point (session renegotiation not yet started), 1205 * we will indulge it. 1206 */ 1207 if (s->s3->in_read_app_data && 1208 (s->s3->total_renegotiations != 0) && 1209 (( 1210 (s->state & SSL_ST_CONNECT) && 1211 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1212 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1213 ) || ( 1214 (s->state & SSL_ST_ACCEPT) && 1215 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1216 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1217 ) 1218 )) 1219 { 1220 s->s3->in_read_app_data=2; 1221 return(-1); 1222 } 1223 else 1224 { 1225 al=SSL_AD_UNEXPECTED_MESSAGE; 1226 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1227 goto f_err; 1228 } 1229 } 1230 /* not reached */ 1231 1232 f_err: 1233 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1234 err: 1235 return(-1); 1236 } 1237 1238 int 1239 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1240 { 1241 int i; 1242 1243 if (SSL_in_init(s) && !s->in_handshake) 1244 { 1245 i=s->handshake_func(s); 1246 if (i < 0) return(i); 1247 if (i == 0) 1248 { 1249 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1250 return -1; 1251 } 1252 } 1253 1254 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1255 { 1256 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1257 return -1; 1258 } 1259 1260 i = dtls1_write_bytes(s, type, buf_, len); 1261 return i; 1262 } 1263 1264 1265 /* this only happens when a client hello is received and a handshake 1266 * is started. */ 1267 static int 1268 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1269 int len, int peek) 1270 { 1271 1272 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1273 /* (partially) satisfy request from storage */ 1274 { 1275 unsigned char *src = s->d1->handshake_fragment; 1276 unsigned char *dst = buf; 1277 unsigned int k,n; 1278 1279 /* peek == 0 */ 1280 n = 0; 1281 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1282 { 1283 *dst++ = *src++; 1284 len--; s->d1->handshake_fragment_len--; 1285 n++; 1286 } 1287 /* move any remaining fragment bytes: */ 1288 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1289 s->d1->handshake_fragment[k] = *src++; 1290 return n; 1291 } 1292 1293 return 0; 1294 } 1295 1296 1297 1298 1299 /* Call this to write data in records of type 'type' 1300 * It will return <= 0 if not all data has been sent or non-blocking IO. 1301 */ 1302 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1303 { 1304 int i; 1305 1306 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1307 s->rwstate=SSL_NOTHING; 1308 i=do_dtls1_write(s, type, buf, len, 0); 1309 return i; 1310 } 1311 1312 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1313 { 1314 unsigned char *p,*pseq; 1315 int i,mac_size,clear=0; 1316 int prefix_len = 0; 1317 SSL3_RECORD *wr; 1318 SSL3_BUFFER *wb; 1319 SSL_SESSION *sess; 1320 int bs; 1321 unsigned int len_with_overhead = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD; 1322 1323 /* first check if there is a SSL3_BUFFER still being written 1324 * out. This will happen with non blocking IO */ 1325 if (s->s3->wbuf.left != 0) 1326 { 1327 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1328 return(ssl3_write_pending(s,type,buf,len)); 1329 } 1330 1331 if (s->s3->wbuf.len < len_with_overhead) 1332 { 1333 if ((p=OPENSSL_realloc(s->s3->wbuf.buf, len_with_overhead)) == NULL) { 1334 SSLerr(SSL_F_DO_DTLS1_WRITE,ERR_R_MALLOC_FAILURE); 1335 goto err; 1336 } 1337 s->s3->wbuf.buf = p; 1338 s->s3->wbuf.len = len_with_overhead; 1339 } 1340 1341 /* If we have an alert to send, lets send it */ 1342 if (s->s3->alert_dispatch) 1343 { 1344 i=s->method->ssl_dispatch_alert(s); 1345 if (i <= 0) 1346 return(i); 1347 /* if it went, fall through and send more stuff */ 1348 } 1349 1350 if (len == 0 && !create_empty_fragment) 1351 return 0; 1352 1353 wr= &(s->s3->wrec); 1354 wb= &(s->s3->wbuf); 1355 sess=s->session; 1356 1357 if ( (sess == NULL) || 1358 (s->enc_write_ctx == NULL) || 1359 (s->write_hash == NULL)) 1360 clear=1; 1361 1362 if (clear) 1363 mac_size=0; 1364 else 1365 mac_size=EVP_MD_size(s->write_hash); 1366 1367 /* DTLS implements explicit IV, so no need for empty fragments */ 1368 #if 0 1369 /* 'create_empty_fragment' is true only when this function calls itself */ 1370 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1371 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1372 { 1373 /* countermeasure against known-IV weakness in CBC ciphersuites 1374 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1375 */ 1376 1377 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1378 { 1379 /* recursive function call with 'create_empty_fragment' set; 1380 * this prepares and buffers the data for an empty fragment 1381 * (these 'prefix_len' bytes are sent out later 1382 * together with the actual payload) */ 1383 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1384 if (prefix_len <= 0) 1385 goto err; 1386 1387 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1388 { 1389 /* insufficient space */ 1390 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1391 goto err; 1392 } 1393 } 1394 1395 s->s3->empty_fragment_done = 1; 1396 } 1397 #endif 1398 1399 p = wb->buf + prefix_len; 1400 1401 /* write the header */ 1402 1403 *(p++)=type&0xff; 1404 wr->type=type; 1405 1406 if (s->client_version == DTLS1_BAD_VER) 1407 *(p++) = DTLS1_BAD_VER>>8, 1408 *(p++) = DTLS1_BAD_VER&0xff; 1409 else 1410 *(p++)=(s->version>>8), 1411 *(p++)=s->version&0xff; 1412 1413 /* field where we are to write out packet epoch, seq num and len */ 1414 pseq=p; 1415 p+=10; 1416 1417 /* lets setup the record stuff. */ 1418 1419 /* Make space for the explicit IV in case of CBC. 1420 * (this is a bit of a boundary violation, but what the heck). 1421 */ 1422 if ( s->enc_write_ctx && 1423 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1424 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1425 else 1426 bs = 0; 1427 1428 wr->data=p + bs; /* make room for IV in case of CBC */ 1429 wr->length=(int)len; 1430 wr->input=(unsigned char *)buf; 1431 1432 /* we now 'read' from wr->input, wr->length bytes into 1433 * wr->data */ 1434 1435 /* first we compress */ 1436 if (s->compress != NULL) 1437 { 1438 if (!ssl3_do_compress(s)) 1439 { 1440 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1441 goto err; 1442 } 1443 } 1444 else 1445 { 1446 memcpy(wr->data,wr->input,wr->length); 1447 wr->input=wr->data; 1448 } 1449 1450 /* we should still have the output to wr->data and the input 1451 * from wr->input. Length should be wr->length. 1452 * wr->data still points in the wb->buf */ 1453 1454 if (mac_size != 0) 1455 { 1456 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1); 1457 wr->length+=mac_size; 1458 } 1459 1460 /* this is true regardless of mac size */ 1461 wr->input=p; 1462 wr->data=p; 1463 1464 1465 /* ssl3_enc can only have an error on read */ 1466 if (bs) /* bs != 0 in case of CBC */ 1467 { 1468 RAND_pseudo_bytes(p,bs); 1469 /* master IV and last CBC residue stand for 1470 * the rest of randomness */ 1471 wr->length += bs; 1472 } 1473 1474 s->method->ssl3_enc->enc(s,1); 1475 1476 /* record length after mac and block padding */ 1477 /* if (type == SSL3_RT_APPLICATION_DATA || 1478 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1479 1480 /* there's only one epoch between handshake and app data */ 1481 1482 s2n(s->d1->w_epoch, pseq); 1483 1484 /* XDTLS: ?? */ 1485 /* else 1486 s2n(s->d1->handshake_epoch, pseq); */ 1487 1488 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1489 pseq+=6; 1490 s2n(wr->length,pseq); 1491 1492 /* we should now have 1493 * wr->data pointing to the encrypted data, which is 1494 * wr->length long */ 1495 wr->type=type; /* not needed but helps for debugging */ 1496 wr->length+=DTLS1_RT_HEADER_LENGTH; 1497 1498 #if 0 /* this is now done at the message layer */ 1499 /* buffer the record, making it easy to handle retransmits */ 1500 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1501 dtls1_buffer_record(s, wr->data, wr->length, 1502 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1503 #endif 1504 1505 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1506 1507 if (create_empty_fragment) 1508 { 1509 /* we are in a recursive call; 1510 * just return the length, don't write out anything here 1511 */ 1512 return wr->length; 1513 } 1514 1515 /* now let's set up wb */ 1516 wb->left = prefix_len + wr->length; 1517 wb->offset = 0; 1518 1519 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1520 s->s3->wpend_tot=len; 1521 s->s3->wpend_buf=buf; 1522 s->s3->wpend_type=type; 1523 s->s3->wpend_ret=len; 1524 1525 /* we now just need to write the buffer */ 1526 return ssl3_write_pending(s,type,buf,len); 1527 err: 1528 return -1; 1529 } 1530 1531 1532 1533 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 1534 PQ_64BIT *seq_num) 1535 { 1536 #if PQ_64BIT_IS_INTEGER 1537 PQ_64BIT mask = 0x0000000000000001L; 1538 #endif 1539 PQ_64BIT rcd_num, tmp; 1540 1541 pq_64bit_init(&rcd_num); 1542 pq_64bit_init(&tmp); 1543 1544 /* this is the sequence number for the record just read */ 1545 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1546 1547 1548 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1549 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) 1550 { 1551 pq_64bit_assign(seq_num, &rcd_num); 1552 pq_64bit_free(&rcd_num); 1553 pq_64bit_free(&tmp); 1554 return 1; /* this record is new */ 1555 } 1556 1557 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1558 1559 if ( pq_64bit_get_word(&tmp) > bitmap->length) 1560 { 1561 pq_64bit_free(&rcd_num); 1562 pq_64bit_free(&tmp); 1563 return 0; /* stale, outside the window */ 1564 } 1565 1566 #if PQ_64BIT_IS_BIGNUM 1567 { 1568 int offset; 1569 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1570 pq_64bit_sub_word(&tmp, 1); 1571 offset = pq_64bit_get_word(&tmp); 1572 if ( pq_64bit_is_bit_set(&(bitmap->map), offset)) 1573 { 1574 pq_64bit_free(&rcd_num); 1575 pq_64bit_free(&tmp); 1576 return 0; 1577 } 1578 } 1579 #else 1580 mask <<= (bitmap->max_seq_num - rcd_num - 1); 1581 if (bitmap->map & mask) 1582 return 0; /* record previously received */ 1583 #endif 1584 1585 pq_64bit_assign(seq_num, &rcd_num); 1586 pq_64bit_free(&rcd_num); 1587 pq_64bit_free(&tmp); 1588 return 1; 1589 } 1590 1591 1592 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1593 { 1594 unsigned int shift; 1595 PQ_64BIT rcd_num; 1596 PQ_64BIT tmp; 1597 PQ_64BIT_CTX *ctx; 1598 1599 pq_64bit_init(&rcd_num); 1600 pq_64bit_init(&tmp); 1601 1602 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1603 1604 /* unfortunate code complexity due to 64-bit manipulation support 1605 * on 32-bit machines */ 1606 if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1607 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) 1608 { 1609 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num)); 1610 pq_64bit_add_word(&tmp, 1); 1611 1612 shift = (unsigned int)pq_64bit_get_word(&tmp); 1613 1614 pq_64bit_lshift(&(tmp), &(bitmap->map), shift); 1615 pq_64bit_assign(&(bitmap->map), &tmp); 1616 1617 pq_64bit_set_bit(&(bitmap->map), 0); 1618 pq_64bit_add_word(&rcd_num, 1); 1619 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num); 1620 1621 pq_64bit_assign_word(&tmp, 1); 1622 pq_64bit_lshift(&tmp, &tmp, bitmap->length); 1623 ctx = pq_64bit_ctx_new(&ctx); 1624 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx); 1625 pq_64bit_ctx_free(ctx); 1626 } 1627 else 1628 { 1629 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1630 pq_64bit_sub_word(&tmp, 1); 1631 shift = (unsigned int)pq_64bit_get_word(&tmp); 1632 1633 pq_64bit_set_bit(&(bitmap->map), shift); 1634 } 1635 1636 pq_64bit_free(&rcd_num); 1637 pq_64bit_free(&tmp); 1638 } 1639 1640 1641 int dtls1_dispatch_alert(SSL *s) 1642 { 1643 int i,j; 1644 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1645 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1646 unsigned char *ptr = &buf[0]; 1647 1648 s->s3->alert_dispatch=0; 1649 1650 memset(buf, 0x00, sizeof(buf)); 1651 *ptr++ = s->s3->send_alert[0]; 1652 *ptr++ = s->s3->send_alert[1]; 1653 1654 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1655 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1656 { 1657 s2n(s->d1->handshake_read_seq, ptr); 1658 #if 0 1659 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1660 1661 else 1662 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1663 #endif 1664 1665 #if 0 1666 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); 1667 #endif 1668 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1669 } 1670 #endif 1671 1672 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1673 if (i <= 0) 1674 { 1675 s->s3->alert_dispatch=1; 1676 /* fprintf( stderr, "not done with alert\n" ); */ 1677 } 1678 else 1679 { 1680 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1681 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1682 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1683 #endif 1684 ) 1685 (void)BIO_flush(s->wbio); 1686 1687 if (s->msg_callback) 1688 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1689 2, s, s->msg_callback_arg); 1690 1691 if (s->info_callback != NULL) 1692 cb=s->info_callback; 1693 else if (s->ctx->info_callback != NULL) 1694 cb=s->ctx->info_callback; 1695 1696 if (cb != NULL) 1697 { 1698 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1699 cb(s,SSL_CB_WRITE_ALERT,j); 1700 } 1701 } 1702 return(i); 1703 } 1704 1705 1706 static DTLS1_BITMAP * 1707 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1708 { 1709 1710 *is_next_epoch = 0; 1711 1712 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1713 if (rr->epoch == s->d1->r_epoch) 1714 return &s->d1->bitmap; 1715 1716 /* Only HM and ALERT messages can be from the next epoch */ 1717 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1718 (rr->type == SSL3_RT_HANDSHAKE || 1719 rr->type == SSL3_RT_ALERT)) 1720 { 1721 *is_next_epoch = 1; 1722 return &s->d1->next_bitmap; 1723 } 1724 1725 return NULL; 1726 } 1727 1728 #if 0 1729 static int 1730 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1731 unsigned long *offset) 1732 { 1733 1734 /* alerts are passed up immediately */ 1735 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1736 rr->type == SSL3_RT_ALERT) 1737 return 0; 1738 1739 /* Only need to buffer if a handshake is underway. 1740 * (this implies that Hello Request and Client Hello are passed up 1741 * immediately) */ 1742 if ( SSL_in_init(s)) 1743 { 1744 unsigned char *data = rr->data; 1745 /* need to extract the HM/CCS sequence number here */ 1746 if ( rr->type == SSL3_RT_HANDSHAKE || 1747 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1748 { 1749 unsigned short seq_num; 1750 struct hm_header_st msg_hdr; 1751 struct ccs_header_st ccs_hdr; 1752 1753 if ( rr->type == SSL3_RT_HANDSHAKE) 1754 { 1755 dtls1_get_message_header(data, &msg_hdr); 1756 seq_num = msg_hdr.seq; 1757 *offset = msg_hdr.frag_off; 1758 } 1759 else 1760 { 1761 dtls1_get_ccs_header(data, &ccs_hdr); 1762 seq_num = ccs_hdr.seq; 1763 *offset = 0; 1764 } 1765 1766 /* this is either a record we're waiting for, or a 1767 * retransmit of something we happened to previously 1768 * receive (higher layers will drop the repeat silently */ 1769 if ( seq_num < s->d1->handshake_read_seq) 1770 return 0; 1771 if (rr->type == SSL3_RT_HANDSHAKE && 1772 seq_num == s->d1->handshake_read_seq && 1773 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1774 return 0; 1775 else if ( seq_num == s->d1->handshake_read_seq && 1776 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1777 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1778 return 0; 1779 else 1780 { 1781 *priority = seq_num; 1782 return 1; 1783 } 1784 } 1785 else /* unknown record type */ 1786 return 0; 1787 } 1788 1789 return 0; 1790 } 1791 #endif 1792 1793 void 1794 dtls1_reset_seq_numbers(SSL *s, int rw) 1795 { 1796 unsigned char *seq; 1797 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1798 1799 if ( rw & SSL3_CC_READ) 1800 { 1801 seq = s->s3->read_sequence; 1802 s->d1->r_epoch++; 1803 1804 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map)); 1805 s->d1->bitmap.length = s->d1->next_bitmap.length; 1806 pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 1807 &(s->d1->next_bitmap.max_seq_num)); 1808 1809 pq_64bit_free(&(s->d1->next_bitmap.map)); 1810 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num)); 1811 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1812 pq_64bit_init(&(s->d1->next_bitmap.map)); 1813 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num)); 1814 } 1815 else 1816 { 1817 seq = s->s3->write_sequence; 1818 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1819 s->d1->w_epoch++; 1820 } 1821 1822 memset(seq, 0x00, seq_bytes); 1823 } 1824 1825 #if PQ_64BIT_IS_INTEGER 1826 static PQ_64BIT 1827 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num) 1828 { 1829 PQ_64BIT _num; 1830 1831 _num = (((PQ_64BIT)bytes[0]) << 56) | 1832 (((PQ_64BIT)bytes[1]) << 48) | 1833 (((PQ_64BIT)bytes[2]) << 40) | 1834 (((PQ_64BIT)bytes[3]) << 32) | 1835 (((PQ_64BIT)bytes[4]) << 24) | 1836 (((PQ_64BIT)bytes[5]) << 16) | 1837 (((PQ_64BIT)bytes[6]) << 8) | 1838 (((PQ_64BIT)bytes[7]) ); 1839 1840 *num = _num ; 1841 return _num; 1842 } 1843 #endif 1844 1845 1846 static void 1847 dtls1_clear_timeouts(SSL *s) 1848 { 1849 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st)); 1850 } 1851
