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> 123 124 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 125 int len, int peek); 126 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 127 PQ_64BIT *seq_num); 128 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 129 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 130 unsigned int *is_next_epoch); 131 #if 0 132 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 133 unsigned short *priority, unsigned long *offset); 134 #endif 135 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 136 PQ_64BIT priority); 137 static int dtls1_process_record(SSL *s); 138 #if PQ_64BIT_IS_INTEGER 139 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num); 140 #endif 141 static void dtls1_clear_timeouts(SSL *s); 142 143 /* copy buffered record into SSL structure */ 144 static int 145 dtls1_copy_record(SSL *s, pitem *item) 146 { 147 DTLS1_RECORD_DATA *rdata; 148 149 rdata = (DTLS1_RECORD_DATA *)item->data; 150 151 if (s->s3->rbuf.buf != NULL) 152 OPENSSL_free(s->s3->rbuf.buf); 153 154 s->packet = rdata->packet; 155 s->packet_length = rdata->packet_length; 156 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 157 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 158 159 return(1); 160 } 161 162 163 static int 164 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority) 165 { 166 DTLS1_RECORD_DATA *rdata; 167 pitem *item; 168 169 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 170 item = pitem_new(priority, rdata); 171 if (rdata == NULL || item == NULL) 172 { 173 if (rdata != NULL) OPENSSL_free(rdata); 174 if (item != NULL) pitem_free(item); 175 176 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 177 return(0); 178 } 179 180 rdata->packet = s->packet; 181 rdata->packet_length = s->packet_length; 182 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 183 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 184 185 item->data = rdata; 186 187 /* insert should not fail, since duplicates are dropped */ 188 if (pqueue_insert(queue->q, item) == NULL) 189 { 190 OPENSSL_free(rdata); 191 pitem_free(item); 192 return(0); 193 } 194 195 s->packet = NULL; 196 s->packet_length = 0; 197 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 198 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 199 200 ssl3_setup_buffers(s); 201 202 return(1); 203 } 204 205 206 static int 207 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 208 { 209 pitem *item; 210 211 item = pqueue_pop(queue->q); 212 if (item) 213 { 214 dtls1_copy_record(s, item); 215 216 OPENSSL_free(item->data); 217 pitem_free(item); 218 219 return(1); 220 } 221 222 return(0); 223 } 224 225 226 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 227 * yet */ 228 #define dtls1_get_unprocessed_record(s) \ 229 dtls1_retrieve_buffered_record((s), \ 230 &((s)->d1->unprocessed_rcds)) 231 232 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 233 #define dtls1_get_processed_record(s) \ 234 dtls1_retrieve_buffered_record((s), \ 235 &((s)->d1->processed_rcds)) 236 237 static int 238 dtls1_process_buffered_records(SSL *s) 239 { 240 pitem *item; 241 242 item = pqueue_peek(s->d1->unprocessed_rcds.q); 243 if (item) 244 { 245 DTLS1_RECORD_DATA *rdata; 246 rdata = (DTLS1_RECORD_DATA *)item->data; 247 248 /* Check if epoch is current. */ 249 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 250 return(1); /* Nothing to do. */ 251 252 /* Process all the records. */ 253 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 254 { 255 dtls1_get_unprocessed_record(s); 256 if ( ! dtls1_process_record(s)) 257 return(0); 258 dtls1_buffer_record(s, &(s->d1->processed_rcds), 259 s->s3->rrec.seq_num); 260 } 261 } 262 263 /* sync epoch numbers once all the unprocessed records 264 * have been processed */ 265 s->d1->processed_rcds.epoch = s->d1->r_epoch; 266 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 267 268 return(1); 269 } 270 271 272 #if 0 273 274 static int 275 dtls1_get_buffered_record(SSL *s) 276 { 277 pitem *item; 278 PQ_64BIT priority = 279 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 280 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 281 282 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 283 nothing buffered */ 284 return 0; 285 286 287 item = pqueue_peek(s->d1->rcvd_records); 288 if (item && item->priority == priority) 289 { 290 /* Check if we've received the record of interest. It must be 291 * a handshake record, since data records as passed up without 292 * buffering */ 293 DTLS1_RECORD_DATA *rdata; 294 item = pqueue_pop(s->d1->rcvd_records); 295 rdata = (DTLS1_RECORD_DATA *)item->data; 296 297 if (s->s3->rbuf.buf != NULL) 298 OPENSSL_free(s->s3->rbuf.buf); 299 300 s->packet = rdata->packet; 301 s->packet_length = rdata->packet_length; 302 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 303 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 304 305 OPENSSL_free(item->data); 306 pitem_free(item); 307 308 /* s->d1->next_expected_seq_num++; */ 309 return(1); 310 } 311 312 return 0; 313 } 314 315 #endif 316 317 static int 318 dtls1_process_record(SSL *s) 319 { 320 int i,al; 321 int clear=0; 322 int enc_err; 323 SSL_SESSION *sess; 324 SSL3_RECORD *rr; 325 unsigned int mac_size; 326 unsigned char md[EVP_MAX_MD_SIZE]; 327 328 329 rr= &(s->s3->rrec); 330 sess = s->session; 331 332 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 333 * and we have that many bytes in s->packet 334 */ 335 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 336 337 /* ok, we can now read from 's->packet' data into 'rr' 338 * rr->input points at rr->length bytes, which 339 * need to be copied into rr->data by either 340 * the decryption or by the decompression 341 * When the data is 'copied' into the rr->data buffer, 342 * rr->input will be pointed at the new buffer */ 343 344 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 345 * rr->length bytes of encrypted compressed stuff. */ 346 347 /* check is not needed I believe */ 348 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 349 { 350 al=SSL_AD_RECORD_OVERFLOW; 351 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 352 goto f_err; 353 } 354 355 /* decrypt in place in 'rr->input' */ 356 rr->data=rr->input; 357 358 enc_err = s->method->ssl3_enc->enc(s,0); 359 if (enc_err <= 0) 360 { 361 if (enc_err == 0) 362 /* SSLerr() and ssl3_send_alert() have been called */ 363 goto err; 364 365 /* otherwise enc_err == -1 */ 366 goto decryption_failed_or_bad_record_mac; 367 } 368 369 #ifdef TLS_DEBUG 370 printf("dec %d\n",rr->length); 371 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 372 printf("\n"); 373 #endif 374 375 /* r->length is now the compressed data plus mac */ 376 if ( (sess == NULL) || 377 (s->enc_read_ctx == NULL) || 378 (s->read_hash == NULL)) 379 clear=1; 380 381 if (!clear) 382 { 383 mac_size=EVP_MD_size(s->read_hash); 384 385 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 386 { 387 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ 388 al=SSL_AD_RECORD_OVERFLOW; 389 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); 390 goto f_err; 391 #else 392 goto decryption_failed_or_bad_record_mac; 393 #endif 394 } 395 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ 396 if (rr->length < mac_size) 397 { 398 #if 0 /* OK only for stream ciphers */ 399 al=SSL_AD_DECODE_ERROR; 400 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT); 401 goto f_err; 402 #else 403 goto decryption_failed_or_bad_record_mac; 404 #endif 405 } 406 rr->length-=mac_size; 407 i=s->method->ssl3_enc->mac(s,md,0); 408 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0) 409 { 410 goto decryption_failed_or_bad_record_mac; 411 } 412 } 413 414 /* r->length is now just compressed */ 415 if (s->expand != NULL) 416 { 417 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 418 { 419 al=SSL_AD_RECORD_OVERFLOW; 420 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 421 goto f_err; 422 } 423 if (!ssl3_do_uncompress(s)) 424 { 425 al=SSL_AD_DECOMPRESSION_FAILURE; 426 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 427 goto f_err; 428 } 429 } 430 431 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 432 { 433 al=SSL_AD_RECORD_OVERFLOW; 434 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 435 goto f_err; 436 } 437 438 rr->off=0; 439 /* So at this point the following is true 440 * ssl->s3->rrec.type is the type of record 441 * ssl->s3->rrec.length == number of bytes in record 442 * ssl->s3->rrec.off == offset to first valid byte 443 * ssl->s3->rrec.data == where to take bytes from, increment 444 * after use :-). 445 */ 446 447 /* we have pulled in a full packet so zero things */ 448 s->packet_length=0; 449 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 450 return(1); 451 452 decryption_failed_or_bad_record_mac: 453 /* Separate 'decryption_failed' alert was introduced with TLS 1.0, 454 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption 455 * failure is directly visible from the ciphertext anyway, 456 * we should not reveal which kind of error occured -- this 457 * might become visible to an attacker (e.g. via logfile) */ 458 al=SSL_AD_BAD_RECORD_MAC; 459 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 460 f_err: 461 ssl3_send_alert(s,SSL3_AL_FATAL,al); 462 err: 463 return(0); 464 } 465 466 467 /* Call this to get a new input record. 468 * It will return <= 0 if more data is needed, normally due to an error 469 * or non-blocking IO. 470 * When it finishes, one packet has been decoded and can be found in 471 * ssl->s3->rrec.type - is the type of record 472 * ssl->s3->rrec.data, - data 473 * ssl->s3->rrec.length, - number of bytes 474 */ 475 /* used only by dtls1_read_bytes */ 476 int dtls1_get_record(SSL *s) 477 { 478 int ssl_major,ssl_minor,al; 479 int i,n; 480 SSL3_RECORD *rr; 481 SSL_SESSION *sess; 482 unsigned char *p; 483 short version; 484 DTLS1_BITMAP *bitmap; 485 unsigned int is_next_epoch; 486 487 rr= &(s->s3->rrec); 488 sess=s->session; 489 490 /* The epoch may have changed. If so, process all the 491 * pending records. This is a non-blocking operation. */ 492 if ( ! dtls1_process_buffered_records(s)) 493 return 0; 494 495 /* if we're renegotiating, then there may be buffered records */ 496 if (dtls1_get_processed_record(s)) 497 return 1; 498 499 /* get something from the wire */ 500 again: 501 /* check if we have the header */ 502 if ( (s->rstate != SSL_ST_READ_BODY) || 503 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 504 { 505 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 506 /* read timeout is handled by dtls1_read_bytes */ 507 if (n <= 0) return(n); /* error or non-blocking */ 508 509 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH); 510 511 s->rstate=SSL_ST_READ_BODY; 512 513 p=s->packet; 514 515 /* Pull apart the header into the DTLS1_RECORD */ 516 rr->type= *(p++); 517 ssl_major= *(p++); 518 ssl_minor= *(p++); 519 version=(ssl_major<<8)|ssl_minor; 520 521 /* sequence number is 64 bits, with top 2 bytes = epoch */ 522 n2s(p,rr->epoch); 523 524 memcpy(&(s->s3->read_sequence[2]), p, 6); 525 p+=6; 526 527 n2s(p,rr->length); 528 529 /* Lets check version */ 530 if (s->first_packet) 531 { 532 s->first_packet=0; 533 } 534 else 535 { 536 if (version != s->version) 537 { 538 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER); 539 /* Send back error using their 540 * version number :-) */ 541 s->version=version; 542 al=SSL_AD_PROTOCOL_VERSION; 543 goto f_err; 544 } 545 } 546 547 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00)) 548 { 549 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER); 550 goto err; 551 } 552 553 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 554 { 555 al=SSL_AD_RECORD_OVERFLOW; 556 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG); 557 goto f_err; 558 } 559 560 /* now s->rstate == SSL_ST_READ_BODY */ 561 } 562 563 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 564 565 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 566 { 567 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 568 i=rr->length; 569 n=ssl3_read_n(s,i,i,1); 570 if (n <= 0) return(n); /* error or non-blocking io */ 571 572 /* this packet contained a partial record, dump it */ 573 if ( n != i) 574 { 575 s->packet_length = 0; 576 goto again; 577 } 578 579 /* now n == rr->length, 580 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 581 } 582 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 583 584 /* match epochs. NULL means the packet is dropped on the floor */ 585 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 586 if ( bitmap == NULL) 587 { 588 s->packet_length = 0; /* dump this record */ 589 goto again; /* get another record */ 590 } 591 592 /* check whether this is a repeat, or aged record */ 593 if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num))) 594 { 595 s->packet_length=0; /* dump this record */ 596 goto again; /* get another record */ 597 } 598 599 /* just read a 0 length packet */ 600 if (rr->length == 0) goto again; 601 602 /* If this record is from the next epoch (either HM or ALERT), buffer it 603 * since it cannot be processed at this time. 604 * Records from the next epoch are marked as received even though they are 605 * not processed, so as to prevent any potential resource DoS attack */ 606 if (is_next_epoch) 607 { 608 dtls1_record_bitmap_update(s, bitmap); 609 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 610 s->packet_length = 0; 611 goto again; 612 } 613 614 if ( ! dtls1_process_record(s)) 615 return(0); 616 617 dtls1_clear_timeouts(s); /* done waiting */ 618 return(1); 619 620 f_err: 621 ssl3_send_alert(s,SSL3_AL_FATAL,al); 622 err: 623 return(0); 624 } 625 626 /* Return up to 'len' payload bytes received in 'type' records. 627 * 'type' is one of the following: 628 * 629 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 630 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 631 * - 0 (during a shutdown, no data has to be returned) 632 * 633 * If we don't have stored data to work from, read a SSL/TLS record first 634 * (possibly multiple records if we still don't have anything to return). 635 * 636 * This function must handle any surprises the peer may have for us, such as 637 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 638 * a surprise, but handled as if it were), or renegotiation requests. 639 * Also if record payloads contain fragments too small to process, we store 640 * them until there is enough for the respective protocol (the record protocol 641 * may use arbitrary fragmentation and even interleaving): 642 * Change cipher spec protocol 643 * just 1 byte needed, no need for keeping anything stored 644 * Alert protocol 645 * 2 bytes needed (AlertLevel, AlertDescription) 646 * Handshake protocol 647 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 648 * to detect unexpected Client Hello and Hello Request messages 649 * here, anything else is handled by higher layers 650 * Application data protocol 651 * none of our business 652 */ 653 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 654 { 655 int al,i,j,ret; 656 unsigned int n; 657 SSL3_RECORD *rr; 658 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 659 660 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 661 if (!ssl3_setup_buffers(s)) 662 return(-1); 663 664 /* XXX: check what the second '&& type' is about */ 665 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 666 (type != SSL3_RT_HANDSHAKE) && type) || 667 (peek && (type != SSL3_RT_APPLICATION_DATA))) 668 { 669 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 670 return -1; 671 } 672 673 /* check whether there's a handshake message (client hello?) waiting */ 674 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 675 return ret; 676 677 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 678 679 if (!s->in_handshake && SSL_in_init(s)) 680 { 681 /* type == SSL3_RT_APPLICATION_DATA */ 682 i=s->handshake_func(s); 683 if (i < 0) return(i); 684 if (i == 0) 685 { 686 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 687 return(-1); 688 } 689 } 690 691 start: 692 s->rwstate=SSL_NOTHING; 693 694 /* s->s3->rrec.type - is the type of record 695 * s->s3->rrec.data, - data 696 * s->s3->rrec.off, - offset into 'data' for next read 697 * s->s3->rrec.length, - number of bytes. */ 698 rr = &(s->s3->rrec); 699 700 /* get new packet if necessary */ 701 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 702 { 703 ret=dtls1_get_record(s); 704 if (ret <= 0) 705 { 706 ret = dtls1_read_failed(s, ret); 707 /* anything other than a timeout is an error */ 708 if (ret <= 0) 709 return(ret); 710 else 711 goto start; 712 } 713 } 714 715 /* we now have a packet which can be read and processed */ 716 717 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 718 * reset by ssl3_get_finished */ 719 && (rr->type != SSL3_RT_HANDSHAKE)) 720 { 721 al=SSL_AD_UNEXPECTED_MESSAGE; 722 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 723 goto err; 724 } 725 726 /* If the other end has shut down, throw anything we read away 727 * (even in 'peek' mode) */ 728 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 729 { 730 rr->length=0; 731 s->rwstate=SSL_NOTHING; 732 return(0); 733 } 734 735 736 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 737 { 738 /* make sure that we are not getting application data when we 739 * are doing a handshake for the first time */ 740 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 741 (s->enc_read_ctx == NULL)) 742 { 743 al=SSL_AD_UNEXPECTED_MESSAGE; 744 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 745 goto f_err; 746 } 747 748 if (len <= 0) return(len); 749 750 if ((unsigned int)len > rr->length) 751 n = rr->length; 752 else 753 n = (unsigned int)len; 754 755 memcpy(buf,&(rr->data[rr->off]),n); 756 if (!peek) 757 { 758 rr->length-=n; 759 rr->off+=n; 760 if (rr->length == 0) 761 { 762 s->rstate=SSL_ST_READ_HEADER; 763 rr->off=0; 764 } 765 } 766 return(n); 767 } 768 769 770 /* If we get here, then type != rr->type; if we have a handshake 771 * message, then it was unexpected (Hello Request or Client Hello). */ 772 773 /* In case of record types for which we have 'fragment' storage, 774 * fill that so that we can process the data at a fixed place. 775 */ 776 { 777 unsigned int k, dest_maxlen = 0; 778 unsigned char *dest = NULL; 779 unsigned int *dest_len = NULL; 780 781 if (rr->type == SSL3_RT_HANDSHAKE) 782 { 783 dest_maxlen = sizeof s->d1->handshake_fragment; 784 dest = s->d1->handshake_fragment; 785 dest_len = &s->d1->handshake_fragment_len; 786 } 787 else if (rr->type == SSL3_RT_ALERT) 788 { 789 dest_maxlen = sizeof(s->d1->alert_fragment); 790 dest = s->d1->alert_fragment; 791 dest_len = &s->d1->alert_fragment_len; 792 } 793 else /* else it's a CCS message */ 794 OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC); 795 796 797 if (dest_maxlen > 0) 798 { 799 /* XDTLS: In a pathalogical case, the Client Hello 800 * may be fragmented--don't always expect dest_maxlen bytes */ 801 if ( rr->length < dest_maxlen) 802 { 803 s->rstate=SSL_ST_READ_HEADER; 804 rr->length = 0; 805 goto start; 806 } 807 808 /* now move 'n' bytes: */ 809 for ( k = 0; k < dest_maxlen; k++) 810 { 811 dest[k] = rr->data[rr->off++]; 812 rr->length--; 813 } 814 *dest_len = dest_maxlen; 815 } 816 } 817 818 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 819 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 820 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 821 822 /* If we are a client, check for an incoming 'Hello Request': */ 823 if ((!s->server) && 824 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 825 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 826 (s->session != NULL) && (s->session->cipher != NULL)) 827 { 828 s->d1->handshake_fragment_len = 0; 829 830 if ((s->d1->handshake_fragment[1] != 0) || 831 (s->d1->handshake_fragment[2] != 0) || 832 (s->d1->handshake_fragment[3] != 0)) 833 { 834 al=SSL_AD_DECODE_ERROR; 835 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 836 goto err; 837 } 838 839 /* no need to check sequence number on HELLO REQUEST messages */ 840 841 if (s->msg_callback) 842 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 843 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 844 845 if (SSL_is_init_finished(s) && 846 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 847 !s->s3->renegotiate) 848 { 849 ssl3_renegotiate(s); 850 if (ssl3_renegotiate_check(s)) 851 { 852 i=s->handshake_func(s); 853 if (i < 0) return(i); 854 if (i == 0) 855 { 856 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 857 return(-1); 858 } 859 860 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 861 { 862 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 863 { 864 BIO *bio; 865 /* In the case where we try to read application data, 866 * but we trigger an SSL handshake, we return -1 with 867 * the retry option set. Otherwise renegotiation may 868 * cause nasty problems in the blocking world */ 869 s->rwstate=SSL_READING; 870 bio=SSL_get_rbio(s); 871 BIO_clear_retry_flags(bio); 872 BIO_set_retry_read(bio); 873 return(-1); 874 } 875 } 876 } 877 } 878 /* we either finished a handshake or ignored the request, 879 * now try again to obtain the (application) data we were asked for */ 880 goto start; 881 } 882 883 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 884 { 885 int alert_level = s->d1->alert_fragment[0]; 886 int alert_descr = s->d1->alert_fragment[1]; 887 888 s->d1->alert_fragment_len = 0; 889 890 if (s->msg_callback) 891 s->msg_callback(0, s->version, SSL3_RT_ALERT, 892 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 893 894 if (s->info_callback != NULL) 895 cb=s->info_callback; 896 else if (s->ctx->info_callback != NULL) 897 cb=s->ctx->info_callback; 898 899 if (cb != NULL) 900 { 901 j = (alert_level << 8) | alert_descr; 902 cb(s, SSL_CB_READ_ALERT, j); 903 } 904 905 if (alert_level == 1) /* warning */ 906 { 907 s->s3->warn_alert = alert_descr; 908 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 909 { 910 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 911 return(0); 912 } 913 #if 0 914 /* XXX: this is a possible improvement in the future */ 915 /* now check if it's a missing record */ 916 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 917 { 918 unsigned short seq; 919 unsigned int frag_off; 920 unsigned char *p = &(s->d1->alert_fragment[2]); 921 922 n2s(p, seq); 923 n2l3(p, frag_off); 924 925 dtls1_retransmit_message(s, seq, frag_off, &found); 926 if ( ! found && SSL_in_init(s)) 927 { 928 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 929 /* requested a message not yet sent, 930 send an alert ourselves */ 931 ssl3_send_alert(s,SSL3_AL_WARNING, 932 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 933 } 934 } 935 #endif 936 } 937 else if (alert_level == 2) /* fatal */ 938 { 939 char tmp[16]; 940 941 s->rwstate=SSL_NOTHING; 942 s->s3->fatal_alert = alert_descr; 943 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 944 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 945 ERR_add_error_data(2,"SSL alert number ",tmp); 946 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 947 SSL_CTX_remove_session(s->ctx,s->session); 948 return(0); 949 } 950 else 951 { 952 al=SSL_AD_ILLEGAL_PARAMETER; 953 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 954 goto f_err; 955 } 956 957 goto start; 958 } 959 960 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 961 { 962 s->rwstate=SSL_NOTHING; 963 rr->length=0; 964 return(0); 965 } 966 967 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 968 { 969 struct ccs_header_st ccs_hdr; 970 971 dtls1_get_ccs_header(rr->data, &ccs_hdr); 972 973 if ( ccs_hdr.seq == s->d1->handshake_read_seq) 974 { 975 /* 'Change Cipher Spec' is just a single byte, so we know 976 * exactly what the record payload has to look like */ 977 /* XDTLS: check that epoch is consistent */ 978 if ( (rr->length != DTLS1_CCS_HEADER_LENGTH) || 979 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 980 { 981 i=SSL_AD_ILLEGAL_PARAMETER; 982 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 983 goto err; 984 } 985 986 rr->length=0; 987 988 if (s->msg_callback) 989 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 990 rr->data, 1, s, s->msg_callback_arg); 991 992 s->s3->change_cipher_spec=1; 993 if (!ssl3_do_change_cipher_spec(s)) 994 goto err; 995 996 /* do this whenever CCS is processed */ 997 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 998 999 /* handshake read seq is reset upon handshake completion */ 1000 s->d1->handshake_read_seq++; 1001 1002 goto start; 1003 } 1004 else 1005 { 1006 rr->length = 0; 1007 goto start; 1008 } 1009 } 1010 1011 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1012 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1013 !s->in_handshake) 1014 { 1015 struct hm_header_st msg_hdr; 1016 1017 /* this may just be a stale retransmit */ 1018 dtls1_get_message_header(rr->data, &msg_hdr); 1019 if( rr->epoch != s->d1->r_epoch) 1020 { 1021 rr->length = 0; 1022 goto start; 1023 } 1024 1025 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1026 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1027 { 1028 #if 0 /* worked only because C operator preferences are not as expected (and 1029 * because this is not really needed for clients except for detecting 1030 * protocol violations): */ 1031 s->state=SSL_ST_BEFORE|(s->server) 1032 ?SSL_ST_ACCEPT 1033 :SSL_ST_CONNECT; 1034 #else 1035 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1036 #endif 1037 s->new_session=1; 1038 } 1039 i=s->handshake_func(s); 1040 if (i < 0) return(i); 1041 if (i == 0) 1042 { 1043 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1044 return(-1); 1045 } 1046 1047 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1048 { 1049 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1050 { 1051 BIO *bio; 1052 /* In the case where we try to read application data, 1053 * but we trigger an SSL handshake, we return -1 with 1054 * the retry option set. Otherwise renegotiation may 1055 * cause nasty problems in the blocking world */ 1056 s->rwstate=SSL_READING; 1057 bio=SSL_get_rbio(s); 1058 BIO_clear_retry_flags(bio); 1059 BIO_set_retry_read(bio); 1060 return(-1); 1061 } 1062 } 1063 goto start; 1064 } 1065 1066 switch (rr->type) 1067 { 1068 default: 1069 #ifndef OPENSSL_NO_TLS 1070 /* TLS just ignores unknown message types */ 1071 if (s->version == TLS1_VERSION) 1072 { 1073 rr->length = 0; 1074 goto start; 1075 } 1076 #endif 1077 al=SSL_AD_UNEXPECTED_MESSAGE; 1078 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1079 goto f_err; 1080 case SSL3_RT_CHANGE_CIPHER_SPEC: 1081 case SSL3_RT_ALERT: 1082 case SSL3_RT_HANDSHAKE: 1083 /* we already handled all of these, with the possible exception 1084 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1085 * should not happen when type != rr->type */ 1086 al=SSL_AD_UNEXPECTED_MESSAGE; 1087 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1088 goto f_err; 1089 case SSL3_RT_APPLICATION_DATA: 1090 /* At this point, we were expecting handshake data, 1091 * but have application data. If the library was 1092 * running inside ssl3_read() (i.e. in_read_app_data 1093 * is set) and it makes sense to read application data 1094 * at this point (session renegotiation not yet started), 1095 * we will indulge it. 1096 */ 1097 if (s->s3->in_read_app_data && 1098 (s->s3->total_renegotiations != 0) && 1099 (( 1100 (s->state & SSL_ST_CONNECT) && 1101 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1102 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1103 ) || ( 1104 (s->state & SSL_ST_ACCEPT) && 1105 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1106 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1107 ) 1108 )) 1109 { 1110 s->s3->in_read_app_data=2; 1111 return(-1); 1112 } 1113 else 1114 { 1115 al=SSL_AD_UNEXPECTED_MESSAGE; 1116 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1117 goto f_err; 1118 } 1119 } 1120 /* not reached */ 1121 1122 f_err: 1123 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1124 err: 1125 return(-1); 1126 } 1127 1128 int 1129 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1130 { 1131 unsigned int n,tot; 1132 int i; 1133 1134 if (SSL_in_init(s) && !s->in_handshake) 1135 { 1136 i=s->handshake_func(s); 1137 if (i < 0) return(i); 1138 if (i == 0) 1139 { 1140 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1141 return -1; 1142 } 1143 } 1144 1145 tot = s->s3->wnum; 1146 n = len - tot; 1147 1148 while( n) 1149 { 1150 /* dtls1_write_bytes sends one record at a time, sized according to 1151 * the currently known MTU */ 1152 i = dtls1_write_bytes(s, type, buf_, len); 1153 if (i <= 0) return i; 1154 1155 if ((i == (int)n) || 1156 (type == SSL3_RT_APPLICATION_DATA && 1157 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) 1158 { 1159 /* next chunk of data should get another prepended empty fragment 1160 * in ciphersuites with known-IV weakness: */ 1161 s->s3->empty_fragment_done = 0; 1162 return tot+i; 1163 } 1164 1165 tot += i; 1166 n-=i; 1167 } 1168 1169 return tot; 1170 } 1171 1172 1173 /* this only happens when a client hello is received and a handshake 1174 * is started. */ 1175 static int 1176 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1177 int len, int peek) 1178 { 1179 1180 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1181 /* (partially) satisfy request from storage */ 1182 { 1183 unsigned char *src = s->d1->handshake_fragment; 1184 unsigned char *dst = buf; 1185 unsigned int k,n; 1186 1187 /* peek == 0 */ 1188 n = 0; 1189 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1190 { 1191 *dst++ = *src++; 1192 len--; s->d1->handshake_fragment_len--; 1193 n++; 1194 } 1195 /* move any remaining fragment bytes: */ 1196 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1197 s->d1->handshake_fragment[k] = *src++; 1198 return n; 1199 } 1200 1201 return 0; 1202 } 1203 1204 1205 1206 1207 /* Call this to write data in records of type 'type' 1208 * It will return <= 0 if not all data has been sent or non-blocking IO. 1209 */ 1210 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len) 1211 { 1212 const unsigned char *buf=buf_; 1213 unsigned int tot,n,nw; 1214 int i; 1215 unsigned int mtu; 1216 1217 s->rwstate=SSL_NOTHING; 1218 tot=s->s3->wnum; 1219 1220 n=(len-tot); 1221 1222 /* handshake layer figures out MTU for itself, but data records 1223 * are also sent through this interface, so need to figure out MTU */ 1224 #if 0 1225 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL); 1226 mtu += DTLS1_HM_HEADER_LENGTH; /* HM already inserted */ 1227 #endif 1228 mtu = s->d1->mtu; 1229 1230 if (mtu > SSL3_RT_MAX_PLAIN_LENGTH) 1231 mtu = SSL3_RT_MAX_PLAIN_LENGTH; 1232 1233 if (n > mtu) 1234 nw=mtu; 1235 else 1236 nw=n; 1237 1238 i=do_dtls1_write(s, type, &(buf[tot]), nw, 0); 1239 if (i <= 0) 1240 { 1241 s->s3->wnum=tot; 1242 return i; 1243 } 1244 1245 if ( (int)s->s3->wnum + i == len) 1246 s->s3->wnum = 0; 1247 else 1248 s->s3->wnum += i; 1249 1250 return tot + i; 1251 } 1252 1253 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1254 { 1255 unsigned char *p,*pseq; 1256 int i,mac_size,clear=0; 1257 int prefix_len = 0; 1258 SSL3_RECORD *wr; 1259 SSL3_BUFFER *wb; 1260 SSL_SESSION *sess; 1261 int bs; 1262 1263 /* first check if there is a SSL3_BUFFER still being written 1264 * out. This will happen with non blocking IO */ 1265 if (s->s3->wbuf.left != 0) 1266 { 1267 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1268 return(ssl3_write_pending(s,type,buf,len)); 1269 } 1270 1271 /* If we have an alert to send, lets send it */ 1272 if (s->s3->alert_dispatch) 1273 { 1274 i=s->method->ssl_dispatch_alert(s); 1275 if (i <= 0) 1276 return(i); 1277 /* if it went, fall through and send more stuff */ 1278 } 1279 1280 if (len == 0 && !create_empty_fragment) 1281 return 0; 1282 1283 wr= &(s->s3->wrec); 1284 wb= &(s->s3->wbuf); 1285 sess=s->session; 1286 1287 if ( (sess == NULL) || 1288 (s->enc_write_ctx == NULL) || 1289 (s->write_hash == NULL)) 1290 clear=1; 1291 1292 if (clear) 1293 mac_size=0; 1294 else 1295 mac_size=EVP_MD_size(s->write_hash); 1296 1297 /* DTLS implements explicit IV, so no need for empty fragments */ 1298 #if 0 1299 /* 'create_empty_fragment' is true only when this function calls itself */ 1300 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1301 && SSL_version(s) != DTLS1_VERSION) 1302 { 1303 /* countermeasure against known-IV weakness in CBC ciphersuites 1304 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1305 */ 1306 1307 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1308 { 1309 /* recursive function call with 'create_empty_fragment' set; 1310 * this prepares and buffers the data for an empty fragment 1311 * (these 'prefix_len' bytes are sent out later 1312 * together with the actual payload) */ 1313 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1314 if (prefix_len <= 0) 1315 goto err; 1316 1317 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1318 { 1319 /* insufficient space */ 1320 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1321 goto err; 1322 } 1323 } 1324 1325 s->s3->empty_fragment_done = 1; 1326 } 1327 #endif 1328 1329 p = wb->buf + prefix_len; 1330 1331 /* write the header */ 1332 1333 *(p++)=type&0xff; 1334 wr->type=type; 1335 1336 *(p++)=(s->version>>8); 1337 *(p++)=s->version&0xff; 1338 1339 /* field where we are to write out packet epoch, seq num and len */ 1340 pseq=p; 1341 p+=10; 1342 1343 /* lets setup the record stuff. */ 1344 1345 /* Make space for the explicit IV in case of CBC. 1346 * (this is a bit of a boundary violation, but what the heck). 1347 */ 1348 if ( s->enc_write_ctx && 1349 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1350 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1351 else 1352 bs = 0; 1353 1354 wr->data=p + bs; /* make room for IV in case of CBC */ 1355 wr->length=(int)len; 1356 wr->input=(unsigned char *)buf; 1357 1358 /* we now 'read' from wr->input, wr->length bytes into 1359 * wr->data */ 1360 1361 /* first we compress */ 1362 if (s->compress != NULL) 1363 { 1364 if (!ssl3_do_compress(s)) 1365 { 1366 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1367 goto err; 1368 } 1369 } 1370 else 1371 { 1372 memcpy(wr->data,wr->input,wr->length); 1373 wr->input=wr->data; 1374 } 1375 1376 /* we should still have the output to wr->data and the input 1377 * from wr->input. Length should be wr->length. 1378 * wr->data still points in the wb->buf */ 1379 1380 if (mac_size != 0) 1381 { 1382 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1); 1383 wr->length+=mac_size; 1384 } 1385 1386 /* this is true regardless of mac size */ 1387 wr->input=p; 1388 wr->data=p; 1389 1390 1391 /* ssl3_enc can only have an error on read */ 1392 wr->length += bs; /* bs != 0 in case of CBC. The enc fn provides 1393 * the randomness */ 1394 s->method->ssl3_enc->enc(s,1); 1395 1396 /* record length after mac and block padding */ 1397 /* if (type == SSL3_RT_APPLICATION_DATA || 1398 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1399 1400 /* there's only one epoch between handshake and app data */ 1401 1402 s2n(s->d1->w_epoch, pseq); 1403 1404 /* XDTLS: ?? */ 1405 /* else 1406 s2n(s->d1->handshake_epoch, pseq); */ 1407 1408 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1409 pseq+=6; 1410 s2n(wr->length,pseq); 1411 1412 /* we should now have 1413 * wr->data pointing to the encrypted data, which is 1414 * wr->length long */ 1415 wr->type=type; /* not needed but helps for debugging */ 1416 wr->length+=DTLS1_RT_HEADER_LENGTH; 1417 1418 #if 0 /* this is now done at the message layer */ 1419 /* buffer the record, making it easy to handle retransmits */ 1420 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1421 dtls1_buffer_record(s, wr->data, wr->length, 1422 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1423 #endif 1424 1425 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1426 1427 if (create_empty_fragment) 1428 { 1429 /* we are in a recursive call; 1430 * just return the length, don't write out anything here 1431 */ 1432 return wr->length; 1433 } 1434 1435 /* now let's set up wb */ 1436 wb->left = prefix_len + wr->length; 1437 wb->offset = 0; 1438 1439 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1440 s->s3->wpend_tot=len; 1441 s->s3->wpend_buf=buf; 1442 s->s3->wpend_type=type; 1443 s->s3->wpend_ret=len; 1444 1445 /* we now just need to write the buffer */ 1446 return ssl3_write_pending(s,type,buf,len); 1447 err: 1448 return -1; 1449 } 1450 1451 1452 1453 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 1454 PQ_64BIT *seq_num) 1455 { 1456 #if PQ_64BIT_IS_INTEGER 1457 PQ_64BIT mask = 0x0000000000000001L; 1458 #endif 1459 PQ_64BIT rcd_num, tmp; 1460 1461 pq_64bit_init(&rcd_num); 1462 pq_64bit_init(&tmp); 1463 1464 /* this is the sequence number for the record just read */ 1465 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1466 1467 1468 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1469 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) 1470 { 1471 pq_64bit_assign(seq_num, &rcd_num); 1472 pq_64bit_free(&rcd_num); 1473 pq_64bit_free(&tmp); 1474 return 1; /* this record is new */ 1475 } 1476 1477 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1478 1479 if ( pq_64bit_get_word(&tmp) > bitmap->length) 1480 { 1481 pq_64bit_free(&rcd_num); 1482 pq_64bit_free(&tmp); 1483 return 0; /* stale, outside the window */ 1484 } 1485 1486 #if PQ_64BIT_IS_BIGNUM 1487 { 1488 int offset; 1489 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1490 pq_64bit_sub_word(&tmp, 1); 1491 offset = pq_64bit_get_word(&tmp); 1492 if ( pq_64bit_is_bit_set(&(bitmap->map), offset)) 1493 { 1494 pq_64bit_free(&rcd_num); 1495 pq_64bit_free(&tmp); 1496 return 0; 1497 } 1498 } 1499 #else 1500 mask <<= (bitmap->max_seq_num - rcd_num - 1); 1501 if (bitmap->map & mask) 1502 return 0; /* record previously received */ 1503 #endif 1504 1505 pq_64bit_assign(seq_num, &rcd_num); 1506 pq_64bit_free(&rcd_num); 1507 pq_64bit_free(&tmp); 1508 return 1; 1509 } 1510 1511 1512 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1513 { 1514 unsigned int shift; 1515 PQ_64BIT rcd_num; 1516 PQ_64BIT tmp; 1517 PQ_64BIT_CTX *ctx; 1518 1519 pq_64bit_init(&rcd_num); 1520 pq_64bit_init(&tmp); 1521 1522 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1523 1524 /* unfortunate code complexity due to 64-bit manipulation support 1525 * on 32-bit machines */ 1526 if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1527 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) 1528 { 1529 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num)); 1530 pq_64bit_add_word(&tmp, 1); 1531 1532 shift = (unsigned int)pq_64bit_get_word(&tmp); 1533 1534 pq_64bit_lshift(&(tmp), &(bitmap->map), shift); 1535 pq_64bit_assign(&(bitmap->map), &tmp); 1536 1537 pq_64bit_set_bit(&(bitmap->map), 0); 1538 pq_64bit_add_word(&rcd_num, 1); 1539 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num); 1540 1541 pq_64bit_assign_word(&tmp, 1); 1542 pq_64bit_lshift(&tmp, &tmp, bitmap->length); 1543 ctx = pq_64bit_ctx_new(&ctx); 1544 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx); 1545 pq_64bit_ctx_free(ctx); 1546 } 1547 else 1548 { 1549 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1550 pq_64bit_sub_word(&tmp, 1); 1551 shift = (unsigned int)pq_64bit_get_word(&tmp); 1552 1553 pq_64bit_set_bit(&(bitmap->map), shift); 1554 } 1555 1556 pq_64bit_free(&rcd_num); 1557 pq_64bit_free(&tmp); 1558 } 1559 1560 1561 int dtls1_dispatch_alert(SSL *s) 1562 { 1563 int i,j; 1564 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1565 unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */ 1566 unsigned char *ptr = &buf[0]; 1567 1568 s->s3->alert_dispatch=0; 1569 1570 memset(buf, 0x00, sizeof(buf)); 1571 *ptr++ = s->s3->send_alert[0]; 1572 *ptr++ = s->s3->send_alert[1]; 1573 1574 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1575 { 1576 s2n(s->d1->handshake_read_seq, ptr); 1577 #if 0 1578 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1579 1580 else 1581 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1582 #endif 1583 1584 #if 0 1585 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); 1586 #endif 1587 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1588 } 1589 1590 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1591 if (i <= 0) 1592 { 1593 s->s3->alert_dispatch=1; 1594 /* fprintf( stderr, "not done with alert\n" ); */ 1595 } 1596 else 1597 { 1598 if ( s->s3->send_alert[0] == SSL3_AL_FATAL || 1599 s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1600 (void)BIO_flush(s->wbio); 1601 1602 if (s->msg_callback) 1603 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1604 2, s, s->msg_callback_arg); 1605 1606 if (s->info_callback != NULL) 1607 cb=s->info_callback; 1608 else if (s->ctx->info_callback != NULL) 1609 cb=s->ctx->info_callback; 1610 1611 if (cb != NULL) 1612 { 1613 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1614 cb(s,SSL_CB_WRITE_ALERT,j); 1615 } 1616 } 1617 return(i); 1618 } 1619 1620 1621 static DTLS1_BITMAP * 1622 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1623 { 1624 1625 *is_next_epoch = 0; 1626 1627 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1628 if (rr->epoch == s->d1->r_epoch) 1629 return &s->d1->bitmap; 1630 1631 /* Only HM and ALERT messages can be from the next epoch */ 1632 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1633 (rr->type == SSL3_RT_HANDSHAKE || 1634 rr->type == SSL3_RT_ALERT)) 1635 { 1636 *is_next_epoch = 1; 1637 return &s->d1->next_bitmap; 1638 } 1639 1640 return NULL; 1641 } 1642 1643 #if 0 1644 static int 1645 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1646 unsigned long *offset) 1647 { 1648 1649 /* alerts are passed up immediately */ 1650 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1651 rr->type == SSL3_RT_ALERT) 1652 return 0; 1653 1654 /* Only need to buffer if a handshake is underway. 1655 * (this implies that Hello Request and Client Hello are passed up 1656 * immediately) */ 1657 if ( SSL_in_init(s)) 1658 { 1659 unsigned char *data = rr->data; 1660 /* need to extract the HM/CCS sequence number here */ 1661 if ( rr->type == SSL3_RT_HANDSHAKE || 1662 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1663 { 1664 unsigned short seq_num; 1665 struct hm_header_st msg_hdr; 1666 struct ccs_header_st ccs_hdr; 1667 1668 if ( rr->type == SSL3_RT_HANDSHAKE) 1669 { 1670 dtls1_get_message_header(data, &msg_hdr); 1671 seq_num = msg_hdr.seq; 1672 *offset = msg_hdr.frag_off; 1673 } 1674 else 1675 { 1676 dtls1_get_ccs_header(data, &ccs_hdr); 1677 seq_num = ccs_hdr.seq; 1678 *offset = 0; 1679 } 1680 1681 /* this is either a record we're waiting for, or a 1682 * retransmit of something we happened to previously 1683 * receive (higher layers will drop the repeat silently */ 1684 if ( seq_num < s->d1->handshake_read_seq) 1685 return 0; 1686 if (rr->type == SSL3_RT_HANDSHAKE && 1687 seq_num == s->d1->handshake_read_seq && 1688 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1689 return 0; 1690 else if ( seq_num == s->d1->handshake_read_seq && 1691 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1692 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1693 return 0; 1694 else 1695 { 1696 *priority = seq_num; 1697 return 1; 1698 } 1699 } 1700 else /* unknown record type */ 1701 return 0; 1702 } 1703 1704 return 0; 1705 } 1706 #endif 1707 1708 void 1709 dtls1_reset_seq_numbers(SSL *s, int rw) 1710 { 1711 unsigned char *seq; 1712 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1713 1714 if ( rw & SSL3_CC_READ) 1715 { 1716 seq = s->s3->read_sequence; 1717 s->d1->r_epoch++; 1718 1719 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map)); 1720 s->d1->bitmap.length = s->d1->next_bitmap.length; 1721 pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 1722 &(s->d1->next_bitmap.max_seq_num)); 1723 1724 pq_64bit_free(&(s->d1->next_bitmap.map)); 1725 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num)); 1726 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1727 pq_64bit_init(&(s->d1->next_bitmap.map)); 1728 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num)); 1729 } 1730 else 1731 { 1732 seq = s->s3->write_sequence; 1733 s->d1->w_epoch++; 1734 } 1735 1736 memset(seq, 0x00, seq_bytes); 1737 } 1738 1739 #if PQ_64BIT_IS_INTEGER 1740 static PQ_64BIT 1741 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num) 1742 { 1743 PQ_64BIT _num; 1744 1745 _num = (((PQ_64BIT)bytes[0]) << 56) | 1746 (((PQ_64BIT)bytes[1]) << 48) | 1747 (((PQ_64BIT)bytes[2]) << 40) | 1748 (((PQ_64BIT)bytes[3]) << 32) | 1749 (((PQ_64BIT)bytes[4]) << 24) | 1750 (((PQ_64BIT)bytes[5]) << 16) | 1751 (((PQ_64BIT)bytes[6]) << 8) | 1752 (((PQ_64BIT)bytes[7]) ); 1753 1754 *num = _num ; 1755 return _num; 1756 } 1757 #endif 1758 1759 1760 static void 1761 dtls1_clear_timeouts(SSL *s) 1762 { 1763 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st)); 1764 } 1765