1 /* ssl/d1_pkt.c */ 2 /* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6 /* ==================================================================== 7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core@openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116 #include <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 void dtls1_clear_timeouts(SSL *s); 183 184 /* copy buffered record into SSL structure */ 185 static int 186 dtls1_copy_record(SSL *s, pitem *item) 187 { 188 DTLS1_RECORD_DATA *rdata; 189 190 rdata = (DTLS1_RECORD_DATA *)item->data; 191 192 if (s->s3->rbuf.buf != NULL) 193 OPENSSL_free(s->s3->rbuf.buf); 194 195 s->packet = rdata->packet; 196 s->packet_length = rdata->packet_length; 197 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 198 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 199 200 /* Set proper sequence number for mac calculation */ 201 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 202 203 return(1); 204 } 205 206 207 static int 208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 209 { 210 DTLS1_RECORD_DATA *rdata; 211 pitem *item; 212 213 /* Limit the size of the queue to prevent DOS attacks */ 214 if (pqueue_size(queue->q) >= 100) 215 return 0; 216 217 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 218 item = pitem_new(priority, rdata); 219 if (rdata == NULL || item == NULL) 220 { 221 if (rdata != NULL) OPENSSL_free(rdata); 222 if (item != NULL) pitem_free(item); 223 224 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 225 return(0); 226 } 227 228 rdata->packet = s->packet; 229 rdata->packet_length = s->packet_length; 230 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 231 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 232 233 item->data = rdata; 234 235 /* insert should not fail, since duplicates are dropped */ 236 if (pqueue_insert(queue->q, item) == NULL) 237 { 238 OPENSSL_free(rdata); 239 pitem_free(item); 240 return(0); 241 } 242 243 s->packet = NULL; 244 s->packet_length = 0; 245 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 246 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 247 248 if (!ssl3_setup_buffers(s)) 249 { 250 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 251 OPENSSL_free(rdata); 252 pitem_free(item); 253 return(0); 254 } 255 256 return(1); 257 } 258 259 260 static int 261 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 262 { 263 pitem *item; 264 265 item = pqueue_pop(queue->q); 266 if (item) 267 { 268 dtls1_copy_record(s, item); 269 270 OPENSSL_free(item->data); 271 pitem_free(item); 272 273 return(1); 274 } 275 276 return(0); 277 } 278 279 280 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 281 * yet */ 282 #define dtls1_get_unprocessed_record(s) \ 283 dtls1_retrieve_buffered_record((s), \ 284 &((s)->d1->unprocessed_rcds)) 285 286 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 287 #define dtls1_get_processed_record(s) \ 288 dtls1_retrieve_buffered_record((s), \ 289 &((s)->d1->processed_rcds)) 290 291 static int 292 dtls1_process_buffered_records(SSL *s) 293 { 294 pitem *item; 295 296 item = pqueue_peek(s->d1->unprocessed_rcds.q); 297 if (item) 298 { 299 /* Check if epoch is current. */ 300 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 301 return(1); /* Nothing to do. */ 302 303 /* Process all the records. */ 304 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 305 { 306 dtls1_get_unprocessed_record(s); 307 if ( ! dtls1_process_record(s)) 308 return(0); 309 dtls1_buffer_record(s, &(s->d1->processed_rcds), 310 s->s3->rrec.seq_num); 311 } 312 } 313 314 /* sync epoch numbers once all the unprocessed records 315 * have been processed */ 316 s->d1->processed_rcds.epoch = s->d1->r_epoch; 317 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 318 319 return(1); 320 } 321 322 323 #if 0 324 325 static int 326 dtls1_get_buffered_record(SSL *s) 327 { 328 pitem *item; 329 PQ_64BIT priority = 330 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 331 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 332 333 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 334 nothing buffered */ 335 return 0; 336 337 338 item = pqueue_peek(s->d1->rcvd_records); 339 if (item && item->priority == priority) 340 { 341 /* Check if we've received the record of interest. It must be 342 * a handshake record, since data records as passed up without 343 * buffering */ 344 DTLS1_RECORD_DATA *rdata; 345 item = pqueue_pop(s->d1->rcvd_records); 346 rdata = (DTLS1_RECORD_DATA *)item->data; 347 348 if (s->s3->rbuf.buf != NULL) 349 OPENSSL_free(s->s3->rbuf.buf); 350 351 s->packet = rdata->packet; 352 s->packet_length = rdata->packet_length; 353 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 354 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 355 356 OPENSSL_free(item->data); 357 pitem_free(item); 358 359 /* s->d1->next_expected_seq_num++; */ 360 return(1); 361 } 362 363 return 0; 364 } 365 366 #endif 367 368 static int 369 dtls1_process_record(SSL *s) 370 { 371 int i,al; 372 int clear=0; 373 int enc_err; 374 SSL_SESSION *sess; 375 SSL3_RECORD *rr; 376 unsigned int mac_size; 377 unsigned char md[EVP_MAX_MD_SIZE]; 378 int decryption_failed_or_bad_record_mac = 0; 379 380 381 rr= &(s->s3->rrec); 382 sess = s->session; 383 384 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 385 * and we have that many bytes in s->packet 386 */ 387 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 388 389 /* ok, we can now read from 's->packet' data into 'rr' 390 * rr->input points at rr->length bytes, which 391 * need to be copied into rr->data by either 392 * the decryption or by the decompression 393 * When the data is 'copied' into the rr->data buffer, 394 * rr->input will be pointed at the new buffer */ 395 396 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 397 * rr->length bytes of encrypted compressed stuff. */ 398 399 /* check is not needed I believe */ 400 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 401 { 402 al=SSL_AD_RECORD_OVERFLOW; 403 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 404 goto f_err; 405 } 406 407 /* decrypt in place in 'rr->input' */ 408 rr->data=rr->input; 409 410 enc_err = s->method->ssl3_enc->enc(s,0); 411 if (enc_err <= 0) 412 { 413 /* To minimize information leaked via timing, we will always 414 * perform all computations before discarding the message. 415 */ 416 decryption_failed_or_bad_record_mac = 1; 417 } 418 419 #ifdef TLS_DEBUG 420 printf("dec %d\n",rr->length); 421 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 422 printf("\n"); 423 #endif 424 425 /* r->length is now the compressed data plus mac */ 426 if ( (sess == NULL) || 427 (s->enc_read_ctx == NULL) || 428 (s->read_hash == NULL)) 429 clear=1; 430 431 if (!clear) 432 { 433 /* !clear => s->read_hash != NULL => mac_size != -1 */ 434 int t; 435 t=EVP_MD_CTX_size(s->read_hash); 436 OPENSSL_assert(t >= 0); 437 mac_size=t; 438 439 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 440 { 441 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ 442 al=SSL_AD_RECORD_OVERFLOW; 443 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); 444 goto f_err; 445 #else 446 decryption_failed_or_bad_record_mac = 1; 447 #endif 448 } 449 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ 450 if (rr->length < mac_size) 451 { 452 #if 0 /* OK only for stream ciphers */ 453 al=SSL_AD_DECODE_ERROR; 454 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT); 455 goto f_err; 456 #else 457 decryption_failed_or_bad_record_mac = 1; 458 #endif 459 } 460 rr->length-=mac_size; 461 i=s->method->ssl3_enc->mac(s,md,0); 462 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0) 463 { 464 decryption_failed_or_bad_record_mac = 1; 465 } 466 } 467 468 if (decryption_failed_or_bad_record_mac) 469 { 470 /* decryption failed, silently discard message */ 471 rr->length = 0; 472 s->packet_length = 0; 473 goto err; 474 } 475 476 /* r->length is now just compressed */ 477 if (s->expand != NULL) 478 { 479 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 480 { 481 al=SSL_AD_RECORD_OVERFLOW; 482 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 483 goto f_err; 484 } 485 if (!ssl3_do_uncompress(s)) 486 { 487 al=SSL_AD_DECOMPRESSION_FAILURE; 488 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 489 goto f_err; 490 } 491 } 492 493 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 494 { 495 al=SSL_AD_RECORD_OVERFLOW; 496 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 497 goto f_err; 498 } 499 500 rr->off=0; 501 /* So at this point the following is true 502 * ssl->s3->rrec.type is the type of record 503 * ssl->s3->rrec.length == number of bytes in record 504 * ssl->s3->rrec.off == offset to first valid byte 505 * ssl->s3->rrec.data == where to take bytes from, increment 506 * after use :-). 507 */ 508 509 /* we have pulled in a full packet so zero things */ 510 s->packet_length=0; 511 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 512 return(1); 513 514 f_err: 515 ssl3_send_alert(s,SSL3_AL_FATAL,al); 516 err: 517 return(0); 518 } 519 520 521 /* Call this to get a new input record. 522 * It will return <= 0 if more data is needed, normally due to an error 523 * or non-blocking IO. 524 * When it finishes, one packet has been decoded and can be found in 525 * ssl->s3->rrec.type - is the type of record 526 * ssl->s3->rrec.data, - data 527 * ssl->s3->rrec.length, - number of bytes 528 */ 529 /* used only by dtls1_read_bytes */ 530 int dtls1_get_record(SSL *s) 531 { 532 int ssl_major,ssl_minor; 533 int i,n; 534 SSL3_RECORD *rr; 535 unsigned char *p = NULL; 536 unsigned short version; 537 DTLS1_BITMAP *bitmap; 538 unsigned int is_next_epoch; 539 540 rr= &(s->s3->rrec); 541 542 /* The epoch may have changed. If so, process all the 543 * pending records. This is a non-blocking operation. */ 544 dtls1_process_buffered_records(s); 545 546 /* if we're renegotiating, then there may be buffered records */ 547 if (dtls1_get_processed_record(s)) 548 return 1; 549 550 /* get something from the wire */ 551 again: 552 /* check if we have the header */ 553 if ( (s->rstate != SSL_ST_READ_BODY) || 554 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 555 { 556 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 557 /* read timeout is handled by dtls1_read_bytes */ 558 if (n <= 0) return(n); /* error or non-blocking */ 559 560 /* this packet contained a partial record, dump it */ 561 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 562 { 563 s->packet_length = 0; 564 goto again; 565 } 566 567 s->rstate=SSL_ST_READ_BODY; 568 569 p=s->packet; 570 571 /* Pull apart the header into the DTLS1_RECORD */ 572 rr->type= *(p++); 573 ssl_major= *(p++); 574 ssl_minor= *(p++); 575 version=(ssl_major<<8)|ssl_minor; 576 577 /* sequence number is 64 bits, with top 2 bytes = epoch */ 578 n2s(p,rr->epoch); 579 580 memcpy(&(s->s3->read_sequence[2]), p, 6); 581 p+=6; 582 583 n2s(p,rr->length); 584 585 /* Lets check version */ 586 if (!s->first_packet) 587 { 588 if (version != s->version) 589 { 590 /* unexpected version, silently discard */ 591 rr->length = 0; 592 s->packet_length = 0; 593 goto again; 594 } 595 } 596 597 if ((version & 0xff00) != (s->version & 0xff00)) 598 { 599 /* wrong version, silently discard record */ 600 rr->length = 0; 601 s->packet_length = 0; 602 goto again; 603 } 604 605 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 606 { 607 /* record too long, silently discard it */ 608 rr->length = 0; 609 s->packet_length = 0; 610 goto again; 611 } 612 613 /* now s->rstate == SSL_ST_READ_BODY */ 614 } 615 616 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 617 618 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 619 { 620 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 621 i=rr->length; 622 n=ssl3_read_n(s,i,i,1); 623 if (n <= 0) return(n); /* error or non-blocking io */ 624 625 /* this packet contained a partial record, dump it */ 626 if ( n != i) 627 { 628 rr->length = 0; 629 s->packet_length = 0; 630 goto again; 631 } 632 633 /* now n == rr->length, 634 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 635 } 636 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 637 638 /* match epochs. NULL means the packet is dropped on the floor */ 639 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 640 if ( bitmap == NULL) 641 { 642 rr->length = 0; 643 s->packet_length = 0; /* dump this record */ 644 goto again; /* get another record */ 645 } 646 647 /* Check whether this is a repeat, or aged record. 648 * Don't check if we're listening and this message is 649 * a ClientHello. They can look as if they're replayed, 650 * since they arrive from different connections and 651 * would be dropped unnecessarily. 652 */ 653 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 654 *p == SSL3_MT_CLIENT_HELLO) && 655 !dtls1_record_replay_check(s, bitmap)) 656 { 657 rr->length = 0; 658 s->packet_length=0; /* dump this record */ 659 goto again; /* get another record */ 660 } 661 662 /* just read a 0 length packet */ 663 if (rr->length == 0) goto again; 664 665 /* If this record is from the next epoch (either HM or ALERT), 666 * and a handshake is currently in progress, buffer it since it 667 * cannot be processed at this time. However, do not buffer 668 * anything while listening. 669 */ 670 if (is_next_epoch) 671 { 672 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) 673 { 674 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 675 } 676 rr->length = 0; 677 s->packet_length = 0; 678 goto again; 679 } 680 681 if (!dtls1_process_record(s)) 682 { 683 rr->length = 0; 684 s->packet_length = 0; /* dump this record */ 685 goto again; /* get another record */ 686 } 687 688 dtls1_clear_timeouts(s); /* done waiting */ 689 return(1); 690 691 } 692 693 /* Return up to 'len' payload bytes received in 'type' records. 694 * 'type' is one of the following: 695 * 696 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 697 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 698 * - 0 (during a shutdown, no data has to be returned) 699 * 700 * If we don't have stored data to work from, read a SSL/TLS record first 701 * (possibly multiple records if we still don't have anything to return). 702 * 703 * This function must handle any surprises the peer may have for us, such as 704 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 705 * a surprise, but handled as if it were), or renegotiation requests. 706 * Also if record payloads contain fragments too small to process, we store 707 * them until there is enough for the respective protocol (the record protocol 708 * may use arbitrary fragmentation and even interleaving): 709 * Change cipher spec protocol 710 * just 1 byte needed, no need for keeping anything stored 711 * Alert protocol 712 * 2 bytes needed (AlertLevel, AlertDescription) 713 * Handshake protocol 714 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 715 * to detect unexpected Client Hello and Hello Request messages 716 * here, anything else is handled by higher layers 717 * Application data protocol 718 * none of our business 719 */ 720 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 721 { 722 int al,i,j,ret; 723 unsigned int n; 724 SSL3_RECORD *rr; 725 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 726 727 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 728 if (!ssl3_setup_buffers(s)) 729 return(-1); 730 731 /* XXX: check what the second '&& type' is about */ 732 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 733 (type != SSL3_RT_HANDSHAKE) && type) || 734 (peek && (type != SSL3_RT_APPLICATION_DATA))) 735 { 736 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 737 return -1; 738 } 739 740 /* check whether there's a handshake message (client hello?) waiting */ 741 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 742 return ret; 743 744 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 745 746 if (!s->in_handshake && SSL_in_init(s)) 747 { 748 /* type == SSL3_RT_APPLICATION_DATA */ 749 i=s->handshake_func(s); 750 if (i < 0) return(i); 751 if (i == 0) 752 { 753 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 754 return(-1); 755 } 756 } 757 758 start: 759 s->rwstate=SSL_NOTHING; 760 761 /* s->s3->rrec.type - is the type of record 762 * s->s3->rrec.data, - data 763 * s->s3->rrec.off, - offset into 'data' for next read 764 * s->s3->rrec.length, - number of bytes. */ 765 rr = &(s->s3->rrec); 766 767 /* We are not handshaking and have no data yet, 768 * so process data buffered during the last handshake 769 * in advance, if any. 770 */ 771 if (s->state == SSL_ST_OK && rr->length == 0) 772 { 773 pitem *item; 774 item = pqueue_pop(s->d1->buffered_app_data.q); 775 if (item) 776 { 777 dtls1_copy_record(s, item); 778 779 OPENSSL_free(item->data); 780 pitem_free(item); 781 } 782 } 783 784 /* Check for timeout */ 785 if (dtls1_handle_timeout(s) > 0) 786 goto start; 787 788 /* get new packet if necessary */ 789 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 790 { 791 ret=dtls1_get_record(s); 792 if (ret <= 0) 793 { 794 ret = dtls1_read_failed(s, ret); 795 /* anything other than a timeout is an error */ 796 if (ret <= 0) 797 return(ret); 798 else 799 goto start; 800 } 801 } 802 803 /* we now have a packet which can be read and processed */ 804 805 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 806 * reset by ssl3_get_finished */ 807 && (rr->type != SSL3_RT_HANDSHAKE)) 808 { 809 /* We now have application data between CCS and Finished. 810 * Most likely the packets were reordered on their way, so 811 * buffer the application data for later processing rather 812 * than dropping the connection. 813 */ 814 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num); 815 rr->length = 0; 816 goto start; 817 } 818 819 /* If the other end has shut down, throw anything we read away 820 * (even in 'peek' mode) */ 821 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 822 { 823 rr->length=0; 824 s->rwstate=SSL_NOTHING; 825 return(0); 826 } 827 828 829 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 830 { 831 /* make sure that we are not getting application data when we 832 * are doing a handshake for the first time */ 833 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 834 (s->enc_read_ctx == NULL)) 835 { 836 al=SSL_AD_UNEXPECTED_MESSAGE; 837 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 838 goto f_err; 839 } 840 841 if (len <= 0) return(len); 842 843 if ((unsigned int)len > rr->length) 844 n = rr->length; 845 else 846 n = (unsigned int)len; 847 848 memcpy(buf,&(rr->data[rr->off]),n); 849 if (!peek) 850 { 851 rr->length-=n; 852 rr->off+=n; 853 if (rr->length == 0) 854 { 855 s->rstate=SSL_ST_READ_HEADER; 856 rr->off=0; 857 } 858 } 859 return(n); 860 } 861 862 863 /* If we get here, then type != rr->type; if we have a handshake 864 * message, then it was unexpected (Hello Request or Client Hello). */ 865 866 /* In case of record types for which we have 'fragment' storage, 867 * fill that so that we can process the data at a fixed place. 868 */ 869 { 870 unsigned int k, dest_maxlen = 0; 871 unsigned char *dest = NULL; 872 unsigned int *dest_len = NULL; 873 874 if (rr->type == SSL3_RT_HANDSHAKE) 875 { 876 dest_maxlen = sizeof s->d1->handshake_fragment; 877 dest = s->d1->handshake_fragment; 878 dest_len = &s->d1->handshake_fragment_len; 879 } 880 else if (rr->type == SSL3_RT_ALERT) 881 { 882 dest_maxlen = sizeof(s->d1->alert_fragment); 883 dest = s->d1->alert_fragment; 884 dest_len = &s->d1->alert_fragment_len; 885 } 886 /* else it's a CCS message, or application data or wrong */ 887 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 888 { 889 /* Application data while renegotiating 890 * is allowed. Try again reading. 891 */ 892 if (rr->type == SSL3_RT_APPLICATION_DATA) 893 { 894 BIO *bio; 895 s->s3->in_read_app_data=2; 896 bio=SSL_get_rbio(s); 897 s->rwstate=SSL_READING; 898 BIO_clear_retry_flags(bio); 899 BIO_set_retry_read(bio); 900 return(-1); 901 } 902 903 /* Not certain if this is the right error handling */ 904 al=SSL_AD_UNEXPECTED_MESSAGE; 905 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 906 goto f_err; 907 } 908 909 if (dest_maxlen > 0) 910 { 911 /* XDTLS: In a pathalogical case, the Client Hello 912 * may be fragmented--don't always expect dest_maxlen bytes */ 913 if ( rr->length < dest_maxlen) 914 { 915 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 916 /* 917 * for normal alerts rr->length is 2, while 918 * dest_maxlen is 7 if we were to handle this 919 * non-existing alert... 920 */ 921 FIX ME 922 #endif 923 s->rstate=SSL_ST_READ_HEADER; 924 rr->length = 0; 925 goto start; 926 } 927 928 /* now move 'n' bytes: */ 929 for ( k = 0; k < dest_maxlen; k++) 930 { 931 dest[k] = rr->data[rr->off++]; 932 rr->length--; 933 } 934 *dest_len = dest_maxlen; 935 } 936 } 937 938 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 939 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 940 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 941 942 /* If we are a client, check for an incoming 'Hello Request': */ 943 if ((!s->server) && 944 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 945 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 946 (s->session != NULL) && (s->session->cipher != NULL)) 947 { 948 s->d1->handshake_fragment_len = 0; 949 950 if ((s->d1->handshake_fragment[1] != 0) || 951 (s->d1->handshake_fragment[2] != 0) || 952 (s->d1->handshake_fragment[3] != 0)) 953 { 954 al=SSL_AD_DECODE_ERROR; 955 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 956 goto err; 957 } 958 959 /* no need to check sequence number on HELLO REQUEST messages */ 960 961 if (s->msg_callback) 962 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 963 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 964 965 if (SSL_is_init_finished(s) && 966 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 967 !s->s3->renegotiate) 968 { 969 ssl3_renegotiate(s); 970 if (ssl3_renegotiate_check(s)) 971 { 972 i=s->handshake_func(s); 973 if (i < 0) return(i); 974 if (i == 0) 975 { 976 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 977 return(-1); 978 } 979 980 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 981 { 982 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 983 { 984 BIO *bio; 985 /* In the case where we try to read application data, 986 * but we trigger an SSL handshake, we return -1 with 987 * the retry option set. Otherwise renegotiation may 988 * cause nasty problems in the blocking world */ 989 s->rwstate=SSL_READING; 990 bio=SSL_get_rbio(s); 991 BIO_clear_retry_flags(bio); 992 BIO_set_retry_read(bio); 993 return(-1); 994 } 995 } 996 } 997 } 998 /* we either finished a handshake or ignored the request, 999 * now try again to obtain the (application) data we were asked for */ 1000 goto start; 1001 } 1002 1003 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1004 { 1005 int alert_level = s->d1->alert_fragment[0]; 1006 int alert_descr = s->d1->alert_fragment[1]; 1007 1008 s->d1->alert_fragment_len = 0; 1009 1010 if (s->msg_callback) 1011 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1012 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1013 1014 if (s->info_callback != NULL) 1015 cb=s->info_callback; 1016 else if (s->ctx->info_callback != NULL) 1017 cb=s->ctx->info_callback; 1018 1019 if (cb != NULL) 1020 { 1021 j = (alert_level << 8) | alert_descr; 1022 cb(s, SSL_CB_READ_ALERT, j); 1023 } 1024 1025 if (alert_level == 1) /* warning */ 1026 { 1027 s->s3->warn_alert = alert_descr; 1028 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1029 { 1030 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1031 return(0); 1032 } 1033 #if 0 1034 /* XXX: this is a possible improvement in the future */ 1035 /* now check if it's a missing record */ 1036 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1037 { 1038 unsigned short seq; 1039 unsigned int frag_off; 1040 unsigned char *p = &(s->d1->alert_fragment[2]); 1041 1042 n2s(p, seq); 1043 n2l3(p, frag_off); 1044 1045 dtls1_retransmit_message(s, 1046 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1047 frag_off, &found); 1048 if ( ! found && SSL_in_init(s)) 1049 { 1050 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1051 /* requested a message not yet sent, 1052 send an alert ourselves */ 1053 ssl3_send_alert(s,SSL3_AL_WARNING, 1054 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1055 } 1056 } 1057 #endif 1058 } 1059 else if (alert_level == 2) /* fatal */ 1060 { 1061 char tmp[16]; 1062 1063 s->rwstate=SSL_NOTHING; 1064 s->s3->fatal_alert = alert_descr; 1065 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1066 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1067 ERR_add_error_data(2,"SSL alert number ",tmp); 1068 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1069 SSL_CTX_remove_session(s->ctx,s->session); 1070 return(0); 1071 } 1072 else 1073 { 1074 al=SSL_AD_ILLEGAL_PARAMETER; 1075 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1076 goto f_err; 1077 } 1078 1079 goto start; 1080 } 1081 1082 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1083 { 1084 s->rwstate=SSL_NOTHING; 1085 rr->length=0; 1086 return(0); 1087 } 1088 1089 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1090 { 1091 struct ccs_header_st ccs_hdr; 1092 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1093 1094 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1095 1096 if (s->version == DTLS1_BAD_VER) 1097 ccs_hdr_len = 3; 1098 1099 /* 'Change Cipher Spec' is just a single byte, so we know 1100 * exactly what the record payload has to look like */ 1101 /* XDTLS: check that epoch is consistent */ 1102 if ( (rr->length != ccs_hdr_len) || 1103 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1104 { 1105 i=SSL_AD_ILLEGAL_PARAMETER; 1106 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1107 goto err; 1108 } 1109 1110 rr->length=0; 1111 1112 if (s->msg_callback) 1113 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1114 rr->data, 1, s, s->msg_callback_arg); 1115 1116 /* We can't process a CCS now, because previous handshake 1117 * messages are still missing, so just drop it. 1118 */ 1119 if (!s->d1->change_cipher_spec_ok) 1120 { 1121 goto start; 1122 } 1123 1124 s->d1->change_cipher_spec_ok = 0; 1125 1126 s->s3->change_cipher_spec=1; 1127 if (!ssl3_do_change_cipher_spec(s)) 1128 goto err; 1129 1130 /* do this whenever CCS is processed */ 1131 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1132 1133 if (s->version == DTLS1_BAD_VER) 1134 s->d1->handshake_read_seq++; 1135 1136 goto start; 1137 } 1138 1139 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1140 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1141 !s->in_handshake) 1142 { 1143 struct hm_header_st msg_hdr; 1144 1145 /* this may just be a stale retransmit */ 1146 dtls1_get_message_header(rr->data, &msg_hdr); 1147 if( rr->epoch != s->d1->r_epoch) 1148 { 1149 rr->length = 0; 1150 goto start; 1151 } 1152 1153 /* If we are server, we may have a repeated FINISHED of the 1154 * client here, then retransmit our CCS and FINISHED. 1155 */ 1156 if (msg_hdr.type == SSL3_MT_FINISHED) 1157 { 1158 dtls1_retransmit_buffered_messages(s); 1159 rr->length = 0; 1160 goto start; 1161 } 1162 1163 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1164 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1165 { 1166 #if 0 /* worked only because C operator preferences are not as expected (and 1167 * because this is not really needed for clients except for detecting 1168 * protocol violations): */ 1169 s->state=SSL_ST_BEFORE|(s->server) 1170 ?SSL_ST_ACCEPT 1171 :SSL_ST_CONNECT; 1172 #else 1173 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1174 #endif 1175 s->new_session=1; 1176 } 1177 i=s->handshake_func(s); 1178 if (i < 0) return(i); 1179 if (i == 0) 1180 { 1181 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1182 return(-1); 1183 } 1184 1185 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1186 { 1187 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1188 { 1189 BIO *bio; 1190 /* In the case where we try to read application data, 1191 * but we trigger an SSL handshake, we return -1 with 1192 * the retry option set. Otherwise renegotiation may 1193 * cause nasty problems in the blocking world */ 1194 s->rwstate=SSL_READING; 1195 bio=SSL_get_rbio(s); 1196 BIO_clear_retry_flags(bio); 1197 BIO_set_retry_read(bio); 1198 return(-1); 1199 } 1200 } 1201 goto start; 1202 } 1203 1204 switch (rr->type) 1205 { 1206 default: 1207 #ifndef OPENSSL_NO_TLS 1208 /* TLS just ignores unknown message types */ 1209 if (s->version == TLS1_VERSION) 1210 { 1211 rr->length = 0; 1212 goto start; 1213 } 1214 #endif 1215 al=SSL_AD_UNEXPECTED_MESSAGE; 1216 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1217 goto f_err; 1218 case SSL3_RT_CHANGE_CIPHER_SPEC: 1219 case SSL3_RT_ALERT: 1220 case SSL3_RT_HANDSHAKE: 1221 /* we already handled all of these, with the possible exception 1222 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1223 * should not happen when type != rr->type */ 1224 al=SSL_AD_UNEXPECTED_MESSAGE; 1225 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1226 goto f_err; 1227 case SSL3_RT_APPLICATION_DATA: 1228 /* At this point, we were expecting handshake data, 1229 * but have application data. If the library was 1230 * running inside ssl3_read() (i.e. in_read_app_data 1231 * is set) and it makes sense to read application data 1232 * at this point (session renegotiation not yet started), 1233 * we will indulge it. 1234 */ 1235 if (s->s3->in_read_app_data && 1236 (s->s3->total_renegotiations != 0) && 1237 (( 1238 (s->state & SSL_ST_CONNECT) && 1239 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1240 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1241 ) || ( 1242 (s->state & SSL_ST_ACCEPT) && 1243 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1244 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1245 ) 1246 )) 1247 { 1248 s->s3->in_read_app_data=2; 1249 return(-1); 1250 } 1251 else 1252 { 1253 al=SSL_AD_UNEXPECTED_MESSAGE; 1254 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1255 goto f_err; 1256 } 1257 } 1258 /* not reached */ 1259 1260 f_err: 1261 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1262 err: 1263 return(-1); 1264 } 1265 1266 int 1267 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1268 { 1269 int i; 1270 1271 if (SSL_in_init(s) && !s->in_handshake) 1272 { 1273 i=s->handshake_func(s); 1274 if (i < 0) return(i); 1275 if (i == 0) 1276 { 1277 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1278 return -1; 1279 } 1280 } 1281 1282 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1283 { 1284 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1285 return -1; 1286 } 1287 1288 i = dtls1_write_bytes(s, type, buf_, len); 1289 return i; 1290 } 1291 1292 1293 /* this only happens when a client hello is received and a handshake 1294 * is started. */ 1295 static int 1296 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1297 int len, int peek) 1298 { 1299 1300 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1301 /* (partially) satisfy request from storage */ 1302 { 1303 unsigned char *src = s->d1->handshake_fragment; 1304 unsigned char *dst = buf; 1305 unsigned int k,n; 1306 1307 /* peek == 0 */ 1308 n = 0; 1309 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1310 { 1311 *dst++ = *src++; 1312 len--; s->d1->handshake_fragment_len--; 1313 n++; 1314 } 1315 /* move any remaining fragment bytes: */ 1316 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1317 s->d1->handshake_fragment[k] = *src++; 1318 return n; 1319 } 1320 1321 return 0; 1322 } 1323 1324 1325 1326 1327 /* Call this to write data in records of type 'type' 1328 * It will return <= 0 if not all data has been sent or non-blocking IO. 1329 */ 1330 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1331 { 1332 int i; 1333 1334 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1335 s->rwstate=SSL_NOTHING; 1336 i=do_dtls1_write(s, type, buf, len, 0); 1337 return i; 1338 } 1339 1340 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1341 { 1342 unsigned char *p,*pseq; 1343 int i,mac_size,clear=0; 1344 int prefix_len = 0; 1345 SSL3_RECORD *wr; 1346 SSL3_BUFFER *wb; 1347 SSL_SESSION *sess; 1348 int bs; 1349 1350 /* first check if there is a SSL3_BUFFER still being written 1351 * out. This will happen with non blocking IO */ 1352 if (s->s3->wbuf.left != 0) 1353 { 1354 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1355 return(ssl3_write_pending(s,type,buf,len)); 1356 } 1357 1358 /* If we have an alert to send, lets send it */ 1359 if (s->s3->alert_dispatch) 1360 { 1361 i=s->method->ssl_dispatch_alert(s); 1362 if (i <= 0) 1363 return(i); 1364 /* if it went, fall through and send more stuff */ 1365 } 1366 1367 if (len == 0 && !create_empty_fragment) 1368 return 0; 1369 1370 wr= &(s->s3->wrec); 1371 wb= &(s->s3->wbuf); 1372 sess=s->session; 1373 1374 if ( (sess == NULL) || 1375 (s->enc_write_ctx == NULL) || 1376 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1377 clear=1; 1378 1379 if (clear) 1380 mac_size=0; 1381 else 1382 { 1383 mac_size=EVP_MD_CTX_size(s->write_hash); 1384 if (mac_size < 0) 1385 goto err; 1386 } 1387 1388 /* DTLS implements explicit IV, so no need for empty fragments */ 1389 #if 0 1390 /* 'create_empty_fragment' is true only when this function calls itself */ 1391 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1392 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1393 { 1394 /* countermeasure against known-IV weakness in CBC ciphersuites 1395 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1396 */ 1397 1398 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1399 { 1400 /* recursive function call with 'create_empty_fragment' set; 1401 * this prepares and buffers the data for an empty fragment 1402 * (these 'prefix_len' bytes are sent out later 1403 * together with the actual payload) */ 1404 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1405 if (prefix_len <= 0) 1406 goto err; 1407 1408 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1409 { 1410 /* insufficient space */ 1411 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1412 goto err; 1413 } 1414 } 1415 1416 s->s3->empty_fragment_done = 1; 1417 } 1418 #endif 1419 p = wb->buf + prefix_len; 1420 1421 /* write the header */ 1422 1423 *(p++)=type&0xff; 1424 wr->type=type; 1425 1426 *(p++)=(s->version>>8); 1427 *(p++)=s->version&0xff; 1428 1429 /* field where we are to write out packet epoch, seq num and len */ 1430 pseq=p; 1431 p+=10; 1432 1433 /* lets setup the record stuff. */ 1434 1435 /* Make space for the explicit IV in case of CBC. 1436 * (this is a bit of a boundary violation, but what the heck). 1437 */ 1438 if ( s->enc_write_ctx && 1439 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1440 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1441 else 1442 bs = 0; 1443 1444 wr->data=p + bs; /* make room for IV in case of CBC */ 1445 wr->length=(int)len; 1446 wr->input=(unsigned char *)buf; 1447 1448 /* we now 'read' from wr->input, wr->length bytes into 1449 * wr->data */ 1450 1451 /* first we compress */ 1452 if (s->compress != NULL) 1453 { 1454 if (!ssl3_do_compress(s)) 1455 { 1456 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1457 goto err; 1458 } 1459 } 1460 else 1461 { 1462 memcpy(wr->data,wr->input,wr->length); 1463 wr->input=wr->data; 1464 } 1465 1466 /* we should still have the output to wr->data and the input 1467 * from wr->input. Length should be wr->length. 1468 * wr->data still points in the wb->buf */ 1469 1470 if (mac_size != 0) 1471 { 1472 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0) 1473 goto err; 1474 wr->length+=mac_size; 1475 } 1476 1477 /* this is true regardless of mac size */ 1478 wr->input=p; 1479 wr->data=p; 1480 1481 1482 /* ssl3_enc can only have an error on read */ 1483 if (bs) /* bs != 0 in case of CBC */ 1484 { 1485 RAND_pseudo_bytes(p,bs); 1486 /* master IV and last CBC residue stand for 1487 * the rest of randomness */ 1488 wr->length += bs; 1489 } 1490 1491 s->method->ssl3_enc->enc(s,1); 1492 1493 /* record length after mac and block padding */ 1494 /* if (type == SSL3_RT_APPLICATION_DATA || 1495 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1496 1497 /* there's only one epoch between handshake and app data */ 1498 1499 s2n(s->d1->w_epoch, pseq); 1500 1501 /* XDTLS: ?? */ 1502 /* else 1503 s2n(s->d1->handshake_epoch, pseq); */ 1504 1505 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1506 pseq+=6; 1507 s2n(wr->length,pseq); 1508 1509 /* we should now have 1510 * wr->data pointing to the encrypted data, which is 1511 * wr->length long */ 1512 wr->type=type; /* not needed but helps for debugging */ 1513 wr->length+=DTLS1_RT_HEADER_LENGTH; 1514 1515 #if 0 /* this is now done at the message layer */ 1516 /* buffer the record, making it easy to handle retransmits */ 1517 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1518 dtls1_buffer_record(s, wr->data, wr->length, 1519 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1520 #endif 1521 1522 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1523 1524 if (create_empty_fragment) 1525 { 1526 /* we are in a recursive call; 1527 * just return the length, don't write out anything here 1528 */ 1529 return wr->length; 1530 } 1531 1532 /* now let's set up wb */ 1533 wb->left = prefix_len + wr->length; 1534 wb->offset = 0; 1535 1536 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1537 s->s3->wpend_tot=len; 1538 s->s3->wpend_buf=buf; 1539 s->s3->wpend_type=type; 1540 s->s3->wpend_ret=len; 1541 1542 /* we now just need to write the buffer */ 1543 return ssl3_write_pending(s,type,buf,len); 1544 err: 1545 return -1; 1546 } 1547 1548 1549 1550 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1551 { 1552 int cmp; 1553 unsigned int shift; 1554 const unsigned char *seq = s->s3->read_sequence; 1555 1556 cmp = satsub64be(seq,bitmap->max_seq_num); 1557 if (cmp > 0) 1558 { 1559 memcpy (s->s3->rrec.seq_num,seq,8); 1560 return 1; /* this record in new */ 1561 } 1562 shift = -cmp; 1563 if (shift >= sizeof(bitmap->map)*8) 1564 return 0; /* stale, outside the window */ 1565 else if (bitmap->map & (1UL<<shift)) 1566 return 0; /* record previously received */ 1567 1568 memcpy (s->s3->rrec.seq_num,seq,8); 1569 return 1; 1570 } 1571 1572 1573 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1574 { 1575 int cmp; 1576 unsigned int shift; 1577 const unsigned char *seq = s->s3->read_sequence; 1578 1579 cmp = satsub64be(seq,bitmap->max_seq_num); 1580 if (cmp > 0) 1581 { 1582 shift = cmp; 1583 if (shift < sizeof(bitmap->map)*8) 1584 bitmap->map <<= shift, bitmap->map |= 1UL; 1585 else 1586 bitmap->map = 1UL; 1587 memcpy(bitmap->max_seq_num,seq,8); 1588 } 1589 else { 1590 shift = -cmp; 1591 if (shift < sizeof(bitmap->map)*8) 1592 bitmap->map |= 1UL<<shift; 1593 } 1594 } 1595 1596 1597 int dtls1_dispatch_alert(SSL *s) 1598 { 1599 int i,j; 1600 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1601 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1602 unsigned char *ptr = &buf[0]; 1603 1604 s->s3->alert_dispatch=0; 1605 1606 memset(buf, 0x00, sizeof(buf)); 1607 *ptr++ = s->s3->send_alert[0]; 1608 *ptr++ = s->s3->send_alert[1]; 1609 1610 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1611 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1612 { 1613 s2n(s->d1->handshake_read_seq, ptr); 1614 #if 0 1615 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1616 1617 else 1618 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1619 #endif 1620 1621 #if 0 1622 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); 1623 #endif 1624 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1625 } 1626 #endif 1627 1628 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1629 if (i <= 0) 1630 { 1631 s->s3->alert_dispatch=1; 1632 /* fprintf( stderr, "not done with alert\n" ); */ 1633 } 1634 else 1635 { 1636 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1637 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1638 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1639 #endif 1640 ) 1641 (void)BIO_flush(s->wbio); 1642 1643 if (s->msg_callback) 1644 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1645 2, s, s->msg_callback_arg); 1646 1647 if (s->info_callback != NULL) 1648 cb=s->info_callback; 1649 else if (s->ctx->info_callback != NULL) 1650 cb=s->ctx->info_callback; 1651 1652 if (cb != NULL) 1653 { 1654 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1655 cb(s,SSL_CB_WRITE_ALERT,j); 1656 } 1657 } 1658 return(i); 1659 } 1660 1661 1662 static DTLS1_BITMAP * 1663 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1664 { 1665 1666 *is_next_epoch = 0; 1667 1668 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1669 if (rr->epoch == s->d1->r_epoch) 1670 return &s->d1->bitmap; 1671 1672 /* Only HM and ALERT messages can be from the next epoch */ 1673 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1674 (rr->type == SSL3_RT_HANDSHAKE || 1675 rr->type == SSL3_RT_ALERT)) 1676 { 1677 *is_next_epoch = 1; 1678 return &s->d1->next_bitmap; 1679 } 1680 1681 return NULL; 1682 } 1683 1684 #if 0 1685 static int 1686 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1687 unsigned long *offset) 1688 { 1689 1690 /* alerts are passed up immediately */ 1691 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1692 rr->type == SSL3_RT_ALERT) 1693 return 0; 1694 1695 /* Only need to buffer if a handshake is underway. 1696 * (this implies that Hello Request and Client Hello are passed up 1697 * immediately) */ 1698 if ( SSL_in_init(s)) 1699 { 1700 unsigned char *data = rr->data; 1701 /* need to extract the HM/CCS sequence number here */ 1702 if ( rr->type == SSL3_RT_HANDSHAKE || 1703 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1704 { 1705 unsigned short seq_num; 1706 struct hm_header_st msg_hdr; 1707 struct ccs_header_st ccs_hdr; 1708 1709 if ( rr->type == SSL3_RT_HANDSHAKE) 1710 { 1711 dtls1_get_message_header(data, &msg_hdr); 1712 seq_num = msg_hdr.seq; 1713 *offset = msg_hdr.frag_off; 1714 } 1715 else 1716 { 1717 dtls1_get_ccs_header(data, &ccs_hdr); 1718 seq_num = ccs_hdr.seq; 1719 *offset = 0; 1720 } 1721 1722 /* this is either a record we're waiting for, or a 1723 * retransmit of something we happened to previously 1724 * receive (higher layers will drop the repeat silently */ 1725 if ( seq_num < s->d1->handshake_read_seq) 1726 return 0; 1727 if (rr->type == SSL3_RT_HANDSHAKE && 1728 seq_num == s->d1->handshake_read_seq && 1729 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1730 return 0; 1731 else if ( seq_num == s->d1->handshake_read_seq && 1732 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1733 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1734 return 0; 1735 else 1736 { 1737 *priority = seq_num; 1738 return 1; 1739 } 1740 } 1741 else /* unknown record type */ 1742 return 0; 1743 } 1744 1745 return 0; 1746 } 1747 #endif 1748 1749 void 1750 dtls1_reset_seq_numbers(SSL *s, int rw) 1751 { 1752 unsigned char *seq; 1753 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1754 1755 if ( rw & SSL3_CC_READ) 1756 { 1757 seq = s->s3->read_sequence; 1758 s->d1->r_epoch++; 1759 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1760 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1761 } 1762 else 1763 { 1764 seq = s->s3->write_sequence; 1765 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1766 s->d1->w_epoch++; 1767 } 1768 1769 memset(seq, 0x00, seq_bytes); 1770 } 1771 1772 1773 static void 1774 dtls1_clear_timeouts(SSL *s) 1775 { 1776 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st)); 1777 } 1778