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