d1_pkt.c revision 656d9c7f52f88b3a3daccafa7655dec086c4756e
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 125static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 126 int len, int peek); 127static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 128 PQ_64BIT *seq_num); 129static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 130static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 131 unsigned int *is_next_epoch); 132#if 0 133static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 134 unsigned short *priority, unsigned long *offset); 135#endif 136static int dtls1_buffer_record(SSL *s, record_pqueue *q, 137 PQ_64BIT priority); 138static int dtls1_process_record(SSL *s); 139#if PQ_64BIT_IS_INTEGER 140static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num); 141#endif 142static void dtls1_clear_timeouts(SSL *s); 143 144/* copy buffered record into SSL structure */ 145static int 146dtls1_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 164static int 165dtls1_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 213static int 214dtls1_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 244static int 245dtls1_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 281static int 282dtls1_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 324static int 325dtls1_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 377printf("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'); } 379printf("\n"); 380#endif 381 382 /* r->length is now the compressed data plus mac */ 383if ( (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 459decryption_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); 467f_err: 468 ssl3_send_alert(s,SSL3_AL_FATAL,al); 469err: 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 */ 483int 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 */ 507again: 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 s->packet_length=0; /* dump this record */ 601 goto again; /* get another record */ 602 } 603 604 /* just read a 0 length packet */ 605 if (rr->length == 0) goto again; 606 607 /* If this record is from the next epoch (either HM or ALERT), buffer it 608 * since it cannot be processed at this time. 609 * Records from the next epoch are marked as received even though they are 610 * not processed, so as to prevent any potential resource DoS attack */ 611 if (is_next_epoch) 612 { 613 dtls1_record_bitmap_update(s, bitmap); 614 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 615 s->packet_length = 0; 616 goto again; 617 } 618 619 if ( ! dtls1_process_record(s)) 620 return(0); 621 622 dtls1_clear_timeouts(s); /* done waiting */ 623 return(1); 624 625f_err: 626 ssl3_send_alert(s,SSL3_AL_FATAL,al); 627err: 628 return(0); 629 } 630 631/* Return up to 'len' payload bytes received in 'type' records. 632 * 'type' is one of the following: 633 * 634 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 635 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 636 * - 0 (during a shutdown, no data has to be returned) 637 * 638 * If we don't have stored data to work from, read a SSL/TLS record first 639 * (possibly multiple records if we still don't have anything to return). 640 * 641 * This function must handle any surprises the peer may have for us, such as 642 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 643 * a surprise, but handled as if it were), or renegotiation requests. 644 * Also if record payloads contain fragments too small to process, we store 645 * them until there is enough for the respective protocol (the record protocol 646 * may use arbitrary fragmentation and even interleaving): 647 * Change cipher spec protocol 648 * just 1 byte needed, no need for keeping anything stored 649 * Alert protocol 650 * 2 bytes needed (AlertLevel, AlertDescription) 651 * Handshake protocol 652 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 653 * to detect unexpected Client Hello and Hello Request messages 654 * here, anything else is handled by higher layers 655 * Application data protocol 656 * none of our business 657 */ 658int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 659 { 660 int al,i,j,ret; 661 unsigned int n; 662 SSL3_RECORD *rr; 663 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 664 665 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 666 if (!ssl3_setup_buffers(s)) 667 return(-1); 668 669 /* XXX: check what the second '&& type' is about */ 670 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 671 (type != SSL3_RT_HANDSHAKE) && type) || 672 (peek && (type != SSL3_RT_APPLICATION_DATA))) 673 { 674 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 675 return -1; 676 } 677 678 /* check whether there's a handshake message (client hello?) waiting */ 679 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 680 return ret; 681 682 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 683 684 if (!s->in_handshake && SSL_in_init(s)) 685 { 686 /* type == SSL3_RT_APPLICATION_DATA */ 687 i=s->handshake_func(s); 688 if (i < 0) return(i); 689 if (i == 0) 690 { 691 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 692 return(-1); 693 } 694 } 695 696start: 697 s->rwstate=SSL_NOTHING; 698 699 /* s->s3->rrec.type - is the type of record 700 * s->s3->rrec.data, - data 701 * s->s3->rrec.off, - offset into 'data' for next read 702 * s->s3->rrec.length, - number of bytes. */ 703 rr = &(s->s3->rrec); 704 705 /* get new packet if necessary */ 706 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 707 { 708 ret=dtls1_get_record(s); 709 if (ret <= 0) 710 { 711 ret = dtls1_read_failed(s, ret); 712 /* anything other than a timeout is an error */ 713 if (ret <= 0) 714 return(ret); 715 else 716 goto start; 717 } 718 } 719 720 /* we now have a packet which can be read and processed */ 721 722 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 723 * reset by ssl3_get_finished */ 724 && (rr->type != SSL3_RT_HANDSHAKE)) 725 { 726 al=SSL_AD_UNEXPECTED_MESSAGE; 727 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 728 goto err; 729 } 730 731 /* If the other end has shut down, throw anything we read away 732 * (even in 'peek' mode) */ 733 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 734 { 735 rr->length=0; 736 s->rwstate=SSL_NOTHING; 737 return(0); 738 } 739 740 741 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 742 { 743 /* make sure that we are not getting application data when we 744 * are doing a handshake for the first time */ 745 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 746 (s->enc_read_ctx == NULL)) 747 { 748 al=SSL_AD_UNEXPECTED_MESSAGE; 749 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 750 goto f_err; 751 } 752 753 if (len <= 0) return(len); 754 755 if ((unsigned int)len > rr->length) 756 n = rr->length; 757 else 758 n = (unsigned int)len; 759 760 memcpy(buf,&(rr->data[rr->off]),n); 761 if (!peek) 762 { 763 rr->length-=n; 764 rr->off+=n; 765 if (rr->length == 0) 766 { 767 s->rstate=SSL_ST_READ_HEADER; 768 rr->off=0; 769 } 770 } 771 return(n); 772 } 773 774 775 /* If we get here, then type != rr->type; if we have a handshake 776 * message, then it was unexpected (Hello Request or Client Hello). */ 777 778 /* In case of record types for which we have 'fragment' storage, 779 * fill that so that we can process the data at a fixed place. 780 */ 781 { 782 unsigned int k, dest_maxlen = 0; 783 unsigned char *dest = NULL; 784 unsigned int *dest_len = NULL; 785 786 if (rr->type == SSL3_RT_HANDSHAKE) 787 { 788 dest_maxlen = sizeof s->d1->handshake_fragment; 789 dest = s->d1->handshake_fragment; 790 dest_len = &s->d1->handshake_fragment_len; 791 } 792 else if (rr->type == SSL3_RT_ALERT) 793 { 794 dest_maxlen = sizeof(s->d1->alert_fragment); 795 dest = s->d1->alert_fragment; 796 dest_len = &s->d1->alert_fragment_len; 797 } 798 /* else it's a CCS message, or it's wrong */ 799 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 800 { 801 /* Not certain if this is the right error handling */ 802 al=SSL_AD_UNEXPECTED_MESSAGE; 803 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 804 goto f_err; 805 } 806 807 808 if (dest_maxlen > 0) 809 { 810 /* XDTLS: In a pathalogical case, the Client Hello 811 * may be fragmented--don't always expect dest_maxlen bytes */ 812 if ( rr->length < dest_maxlen) 813 { 814 s->rstate=SSL_ST_READ_HEADER; 815 rr->length = 0; 816 goto start; 817 } 818 819 /* now move 'n' bytes: */ 820 for ( k = 0; k < dest_maxlen; k++) 821 { 822 dest[k] = rr->data[rr->off++]; 823 rr->length--; 824 } 825 *dest_len = dest_maxlen; 826 } 827 } 828 829 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 830 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 831 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 832 833 /* If we are a client, check for an incoming 'Hello Request': */ 834 if ((!s->server) && 835 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 836 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 837 (s->session != NULL) && (s->session->cipher != NULL)) 838 { 839 s->d1->handshake_fragment_len = 0; 840 841 if ((s->d1->handshake_fragment[1] != 0) || 842 (s->d1->handshake_fragment[2] != 0) || 843 (s->d1->handshake_fragment[3] != 0)) 844 { 845 al=SSL_AD_DECODE_ERROR; 846 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 847 goto err; 848 } 849 850 /* no need to check sequence number on HELLO REQUEST messages */ 851 852 if (s->msg_callback) 853 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 854 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 855 856 if (SSL_is_init_finished(s) && 857 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 858 !s->s3->renegotiate) 859 { 860 ssl3_renegotiate(s); 861 if (ssl3_renegotiate_check(s)) 862 { 863 i=s->handshake_func(s); 864 if (i < 0) return(i); 865 if (i == 0) 866 { 867 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 868 return(-1); 869 } 870 871 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 872 { 873 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 874 { 875 BIO *bio; 876 /* In the case where we try to read application data, 877 * but we trigger an SSL handshake, we return -1 with 878 * the retry option set. Otherwise renegotiation may 879 * cause nasty problems in the blocking world */ 880 s->rwstate=SSL_READING; 881 bio=SSL_get_rbio(s); 882 BIO_clear_retry_flags(bio); 883 BIO_set_retry_read(bio); 884 return(-1); 885 } 886 } 887 } 888 } 889 /* we either finished a handshake or ignored the request, 890 * now try again to obtain the (application) data we were asked for */ 891 goto start; 892 } 893 894 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 895 { 896 int alert_level = s->d1->alert_fragment[0]; 897 int alert_descr = s->d1->alert_fragment[1]; 898 899 s->d1->alert_fragment_len = 0; 900 901 if (s->msg_callback) 902 s->msg_callback(0, s->version, SSL3_RT_ALERT, 903 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 904 905 if (s->info_callback != NULL) 906 cb=s->info_callback; 907 else if (s->ctx->info_callback != NULL) 908 cb=s->ctx->info_callback; 909 910 if (cb != NULL) 911 { 912 j = (alert_level << 8) | alert_descr; 913 cb(s, SSL_CB_READ_ALERT, j); 914 } 915 916 if (alert_level == 1) /* warning */ 917 { 918 s->s3->warn_alert = alert_descr; 919 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 920 { 921 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 922 return(0); 923 } 924#if 0 925 /* XXX: this is a possible improvement in the future */ 926 /* now check if it's a missing record */ 927 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 928 { 929 unsigned short seq; 930 unsigned int frag_off; 931 unsigned char *p = &(s->d1->alert_fragment[2]); 932 933 n2s(p, seq); 934 n2l3(p, frag_off); 935 936 dtls1_retransmit_message(s, seq, frag_off, &found); 937 if ( ! found && SSL_in_init(s)) 938 { 939 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 940 /* requested a message not yet sent, 941 send an alert ourselves */ 942 ssl3_send_alert(s,SSL3_AL_WARNING, 943 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 944 } 945 } 946#endif 947 } 948 else if (alert_level == 2) /* fatal */ 949 { 950 char tmp[16]; 951 952 s->rwstate=SSL_NOTHING; 953 s->s3->fatal_alert = alert_descr; 954 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 955 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 956 ERR_add_error_data(2,"SSL alert number ",tmp); 957 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 958 SSL_CTX_remove_session(s->ctx,s->session); 959 return(0); 960 } 961 else 962 { 963 al=SSL_AD_ILLEGAL_PARAMETER; 964 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 965 goto f_err; 966 } 967 968 goto start; 969 } 970 971 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 972 { 973 s->rwstate=SSL_NOTHING; 974 rr->length=0; 975 return(0); 976 } 977 978 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 979 { 980 struct ccs_header_st ccs_hdr; 981 982 dtls1_get_ccs_header(rr->data, &ccs_hdr); 983 984 /* 'Change Cipher Spec' is just a single byte, so we know 985 * exactly what the record payload has to look like */ 986 /* XDTLS: check that epoch is consistent */ 987 if ( (s->client_version == DTLS1_BAD_VER && rr->length != 3) || 988 (s->client_version != DTLS1_BAD_VER && rr->length != DTLS1_CCS_HEADER_LENGTH) || 989 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 990 { 991 i=SSL_AD_ILLEGAL_PARAMETER; 992 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 993 goto err; 994 } 995 996 rr->length=0; 997 998 if (s->msg_callback) 999 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1000 rr->data, 1, s, s->msg_callback_arg); 1001 1002 s->s3->change_cipher_spec=1; 1003 if (!ssl3_do_change_cipher_spec(s)) 1004 goto err; 1005 1006 /* do this whenever CCS is processed */ 1007 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1008 1009 if (s->client_version == DTLS1_BAD_VER) 1010 s->d1->handshake_read_seq++; 1011 1012 goto start; 1013 } 1014 1015 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1016 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1017 !s->in_handshake) 1018 { 1019 struct hm_header_st msg_hdr; 1020 1021 /* this may just be a stale retransmit */ 1022 dtls1_get_message_header(rr->data, &msg_hdr); 1023 if( rr->epoch != s->d1->r_epoch) 1024 { 1025 rr->length = 0; 1026 goto start; 1027 } 1028 1029 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1030 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1031 { 1032#if 0 /* worked only because C operator preferences are not as expected (and 1033 * because this is not really needed for clients except for detecting 1034 * protocol violations): */ 1035 s->state=SSL_ST_BEFORE|(s->server) 1036 ?SSL_ST_ACCEPT 1037 :SSL_ST_CONNECT; 1038#else 1039 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1040#endif 1041 s->new_session=1; 1042 } 1043 i=s->handshake_func(s); 1044 if (i < 0) return(i); 1045 if (i == 0) 1046 { 1047 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1048 return(-1); 1049 } 1050 1051 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1052 { 1053 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1054 { 1055 BIO *bio; 1056 /* In the case where we try to read application data, 1057 * but we trigger an SSL handshake, we return -1 with 1058 * the retry option set. Otherwise renegotiation may 1059 * cause nasty problems in the blocking world */ 1060 s->rwstate=SSL_READING; 1061 bio=SSL_get_rbio(s); 1062 BIO_clear_retry_flags(bio); 1063 BIO_set_retry_read(bio); 1064 return(-1); 1065 } 1066 } 1067 goto start; 1068 } 1069 1070 switch (rr->type) 1071 { 1072 default: 1073#ifndef OPENSSL_NO_TLS 1074 /* TLS just ignores unknown message types */ 1075 if (s->version == TLS1_VERSION) 1076 { 1077 rr->length = 0; 1078 goto start; 1079 } 1080#endif 1081 al=SSL_AD_UNEXPECTED_MESSAGE; 1082 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1083 goto f_err; 1084 case SSL3_RT_CHANGE_CIPHER_SPEC: 1085 case SSL3_RT_ALERT: 1086 case SSL3_RT_HANDSHAKE: 1087 /* we already handled all of these, with the possible exception 1088 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1089 * should not happen when type != rr->type */ 1090 al=SSL_AD_UNEXPECTED_MESSAGE; 1091 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1092 goto f_err; 1093 case SSL3_RT_APPLICATION_DATA: 1094 /* At this point, we were expecting handshake data, 1095 * but have application data. If the library was 1096 * running inside ssl3_read() (i.e. in_read_app_data 1097 * is set) and it makes sense to read application data 1098 * at this point (session renegotiation not yet started), 1099 * we will indulge it. 1100 */ 1101 if (s->s3->in_read_app_data && 1102 (s->s3->total_renegotiations != 0) && 1103 (( 1104 (s->state & SSL_ST_CONNECT) && 1105 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1106 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1107 ) || ( 1108 (s->state & SSL_ST_ACCEPT) && 1109 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1110 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1111 ) 1112 )) 1113 { 1114 s->s3->in_read_app_data=2; 1115 return(-1); 1116 } 1117 else 1118 { 1119 al=SSL_AD_UNEXPECTED_MESSAGE; 1120 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1121 goto f_err; 1122 } 1123 } 1124 /* not reached */ 1125 1126f_err: 1127 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1128err: 1129 return(-1); 1130 } 1131 1132int 1133dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1134 { 1135 unsigned int n,tot; 1136 int i; 1137 1138 if (SSL_in_init(s) && !s->in_handshake) 1139 { 1140 i=s->handshake_func(s); 1141 if (i < 0) return(i); 1142 if (i == 0) 1143 { 1144 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1145 return -1; 1146 } 1147 } 1148 1149 tot = s->s3->wnum; 1150 n = len - tot; 1151 1152 while( n) 1153 { 1154 /* dtls1_write_bytes sends one record at a time, sized according to 1155 * the currently known MTU */ 1156 i = dtls1_write_bytes(s, type, buf_, len); 1157 if (i <= 0) return i; 1158 1159 if ((i == (int)n) || 1160 (type == SSL3_RT_APPLICATION_DATA && 1161 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) 1162 { 1163 /* next chunk of data should get another prepended empty fragment 1164 * in ciphersuites with known-IV weakness: */ 1165 s->s3->empty_fragment_done = 0; 1166 return tot+i; 1167 } 1168 1169 tot += i; 1170 n-=i; 1171 } 1172 1173 return tot; 1174 } 1175 1176 1177 /* this only happens when a client hello is received and a handshake 1178 * is started. */ 1179static int 1180have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1181 int len, int peek) 1182 { 1183 1184 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1185 /* (partially) satisfy request from storage */ 1186 { 1187 unsigned char *src = s->d1->handshake_fragment; 1188 unsigned char *dst = buf; 1189 unsigned int k,n; 1190 1191 /* peek == 0 */ 1192 n = 0; 1193 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1194 { 1195 *dst++ = *src++; 1196 len--; s->d1->handshake_fragment_len--; 1197 n++; 1198 } 1199 /* move any remaining fragment bytes: */ 1200 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1201 s->d1->handshake_fragment[k] = *src++; 1202 return n; 1203 } 1204 1205 return 0; 1206 } 1207 1208 1209 1210 1211/* Call this to write data in records of type 'type' 1212 * It will return <= 0 if not all data has been sent or non-blocking IO. 1213 */ 1214int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len) 1215 { 1216 const unsigned char *buf=buf_; 1217 unsigned int tot,n,nw; 1218 int i; 1219 unsigned int mtu; 1220 1221 s->rwstate=SSL_NOTHING; 1222 tot=s->s3->wnum; 1223 1224 n=(len-tot); 1225 1226 /* handshake layer figures out MTU for itself, but data records 1227 * are also sent through this interface, so need to figure out MTU */ 1228#if 0 1229 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL); 1230 mtu += DTLS1_HM_HEADER_LENGTH; /* HM already inserted */ 1231#endif 1232 mtu = s->d1->mtu; 1233 1234 if (mtu > SSL3_RT_MAX_PLAIN_LENGTH) 1235 mtu = SSL3_RT_MAX_PLAIN_LENGTH; 1236 1237 if (n > mtu) 1238 nw=mtu; 1239 else 1240 nw=n; 1241 1242 i=do_dtls1_write(s, type, &(buf[tot]), nw, 0); 1243 if (i <= 0) 1244 { 1245 s->s3->wnum=tot; 1246 return i; 1247 } 1248 1249 if ( (int)s->s3->wnum + i == len) 1250 s->s3->wnum = 0; 1251 else 1252 s->s3->wnum += i; 1253 1254 return tot + i; 1255 } 1256 1257int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1258 { 1259 unsigned char *p,*pseq; 1260 int i,mac_size,clear=0; 1261 int prefix_len = 0; 1262 SSL3_RECORD *wr; 1263 SSL3_BUFFER *wb; 1264 SSL_SESSION *sess; 1265 int bs; 1266 1267 /* first check if there is a SSL3_BUFFER still being written 1268 * out. This will happen with non blocking IO */ 1269 if (s->s3->wbuf.left != 0) 1270 { 1271 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1272 return(ssl3_write_pending(s,type,buf,len)); 1273 } 1274 1275 /* If we have an alert to send, lets send it */ 1276 if (s->s3->alert_dispatch) 1277 { 1278 i=s->method->ssl_dispatch_alert(s); 1279 if (i <= 0) 1280 return(i); 1281 /* if it went, fall through and send more stuff */ 1282 } 1283 1284 if (len == 0 && !create_empty_fragment) 1285 return 0; 1286 1287 wr= &(s->s3->wrec); 1288 wb= &(s->s3->wbuf); 1289 sess=s->session; 1290 1291 if ( (sess == NULL) || 1292 (s->enc_write_ctx == NULL) || 1293 (s->write_hash == NULL)) 1294 clear=1; 1295 1296 if (clear) 1297 mac_size=0; 1298 else 1299 mac_size=EVP_MD_size(s->write_hash); 1300 1301 /* DTLS implements explicit IV, so no need for empty fragments */ 1302#if 0 1303 /* 'create_empty_fragment' is true only when this function calls itself */ 1304 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1305 && SSL_version(s) != DTLS1_VERSION) 1306 { 1307 /* countermeasure against known-IV weakness in CBC ciphersuites 1308 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1309 */ 1310 1311 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1312 { 1313 /* recursive function call with 'create_empty_fragment' set; 1314 * this prepares and buffers the data for an empty fragment 1315 * (these 'prefix_len' bytes are sent out later 1316 * together with the actual payload) */ 1317 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1318 if (prefix_len <= 0) 1319 goto err; 1320 1321 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1322 { 1323 /* insufficient space */ 1324 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1325 goto err; 1326 } 1327 } 1328 1329 s->s3->empty_fragment_done = 1; 1330 } 1331#endif 1332 1333 p = wb->buf + prefix_len; 1334 1335 /* write the header */ 1336 1337 *(p++)=type&0xff; 1338 wr->type=type; 1339 1340 if (s->client_version == DTLS1_BAD_VER) 1341 *(p++) = DTLS1_BAD_VER>>8, 1342 *(p++) = DTLS1_BAD_VER&0xff; 1343 else 1344 *(p++)=(s->version>>8), 1345 *(p++)=s->version&0xff; 1346 1347 /* field where we are to write out packet epoch, seq num and len */ 1348 pseq=p; 1349 p+=10; 1350 1351 /* lets setup the record stuff. */ 1352 1353 /* Make space for the explicit IV in case of CBC. 1354 * (this is a bit of a boundary violation, but what the heck). 1355 */ 1356 if ( s->enc_write_ctx && 1357 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1358 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1359 else 1360 bs = 0; 1361 1362 wr->data=p + bs; /* make room for IV in case of CBC */ 1363 wr->length=(int)len; 1364 wr->input=(unsigned char *)buf; 1365 1366 /* we now 'read' from wr->input, wr->length bytes into 1367 * wr->data */ 1368 1369 /* first we compress */ 1370 if (s->compress != NULL) 1371 { 1372 if (!ssl3_do_compress(s)) 1373 { 1374 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1375 goto err; 1376 } 1377 } 1378 else 1379 { 1380 memcpy(wr->data,wr->input,wr->length); 1381 wr->input=wr->data; 1382 } 1383 1384 /* we should still have the output to wr->data and the input 1385 * from wr->input. Length should be wr->length. 1386 * wr->data still points in the wb->buf */ 1387 1388 if (mac_size != 0) 1389 { 1390 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1); 1391 wr->length+=mac_size; 1392 } 1393 1394 /* this is true regardless of mac size */ 1395 wr->input=p; 1396 wr->data=p; 1397 1398 1399 /* ssl3_enc can only have an error on read */ 1400 if (bs) /* bs != 0 in case of CBC */ 1401 { 1402 RAND_pseudo_bytes(p,bs); 1403 /* master IV and last CBC residue stand for 1404 * the rest of randomness */ 1405 wr->length += bs; 1406 } 1407 1408 s->method->ssl3_enc->enc(s,1); 1409 1410 /* record length after mac and block padding */ 1411/* if (type == SSL3_RT_APPLICATION_DATA || 1412 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1413 1414 /* there's only one epoch between handshake and app data */ 1415 1416 s2n(s->d1->w_epoch, pseq); 1417 1418 /* XDTLS: ?? */ 1419/* else 1420 s2n(s->d1->handshake_epoch, pseq); */ 1421 1422 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1423 pseq+=6; 1424 s2n(wr->length,pseq); 1425 1426 /* we should now have 1427 * wr->data pointing to the encrypted data, which is 1428 * wr->length long */ 1429 wr->type=type; /* not needed but helps for debugging */ 1430 wr->length+=DTLS1_RT_HEADER_LENGTH; 1431 1432#if 0 /* this is now done at the message layer */ 1433 /* buffer the record, making it easy to handle retransmits */ 1434 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1435 dtls1_buffer_record(s, wr->data, wr->length, 1436 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1437#endif 1438 1439 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1440 1441 if (create_empty_fragment) 1442 { 1443 /* we are in a recursive call; 1444 * just return the length, don't write out anything here 1445 */ 1446 return wr->length; 1447 } 1448 1449 /* now let's set up wb */ 1450 wb->left = prefix_len + wr->length; 1451 wb->offset = 0; 1452 1453 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1454 s->s3->wpend_tot=len; 1455 s->s3->wpend_buf=buf; 1456 s->s3->wpend_type=type; 1457 s->s3->wpend_ret=len; 1458 1459 /* we now just need to write the buffer */ 1460 return ssl3_write_pending(s,type,buf,len); 1461err: 1462 return -1; 1463 } 1464 1465 1466 1467static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, 1468 PQ_64BIT *seq_num) 1469 { 1470#if PQ_64BIT_IS_INTEGER 1471 PQ_64BIT mask = 0x0000000000000001L; 1472#endif 1473 PQ_64BIT rcd_num, tmp; 1474 1475 pq_64bit_init(&rcd_num); 1476 pq_64bit_init(&tmp); 1477 1478 /* this is the sequence number for the record just read */ 1479 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1480 1481 1482 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1483 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) 1484 { 1485 pq_64bit_assign(seq_num, &rcd_num); 1486 pq_64bit_free(&rcd_num); 1487 pq_64bit_free(&tmp); 1488 return 1; /* this record is new */ 1489 } 1490 1491 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1492 1493 if ( pq_64bit_get_word(&tmp) > bitmap->length) 1494 { 1495 pq_64bit_free(&rcd_num); 1496 pq_64bit_free(&tmp); 1497 return 0; /* stale, outside the window */ 1498 } 1499 1500#if PQ_64BIT_IS_BIGNUM 1501 { 1502 int offset; 1503 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1504 pq_64bit_sub_word(&tmp, 1); 1505 offset = pq_64bit_get_word(&tmp); 1506 if ( pq_64bit_is_bit_set(&(bitmap->map), offset)) 1507 { 1508 pq_64bit_free(&rcd_num); 1509 pq_64bit_free(&tmp); 1510 return 0; 1511 } 1512 } 1513#else 1514 mask <<= (bitmap->max_seq_num - rcd_num - 1); 1515 if (bitmap->map & mask) 1516 return 0; /* record previously received */ 1517#endif 1518 1519 pq_64bit_assign(seq_num, &rcd_num); 1520 pq_64bit_free(&rcd_num); 1521 pq_64bit_free(&tmp); 1522 return 1; 1523 } 1524 1525 1526static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1527 { 1528 unsigned int shift; 1529 PQ_64BIT rcd_num; 1530 PQ_64BIT tmp; 1531 PQ_64BIT_CTX *ctx; 1532 1533 pq_64bit_init(&rcd_num); 1534 pq_64bit_init(&tmp); 1535 1536 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8); 1537 1538 /* unfortunate code complexity due to 64-bit manipulation support 1539 * on 32-bit machines */ 1540 if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) || 1541 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num))) 1542 { 1543 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num)); 1544 pq_64bit_add_word(&tmp, 1); 1545 1546 shift = (unsigned int)pq_64bit_get_word(&tmp); 1547 1548 pq_64bit_lshift(&(tmp), &(bitmap->map), shift); 1549 pq_64bit_assign(&(bitmap->map), &tmp); 1550 1551 pq_64bit_set_bit(&(bitmap->map), 0); 1552 pq_64bit_add_word(&rcd_num, 1); 1553 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num); 1554 1555 pq_64bit_assign_word(&tmp, 1); 1556 pq_64bit_lshift(&tmp, &tmp, bitmap->length); 1557 ctx = pq_64bit_ctx_new(&ctx); 1558 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx); 1559 pq_64bit_ctx_free(ctx); 1560 } 1561 else 1562 { 1563 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num); 1564 pq_64bit_sub_word(&tmp, 1); 1565 shift = (unsigned int)pq_64bit_get_word(&tmp); 1566 1567 pq_64bit_set_bit(&(bitmap->map), shift); 1568 } 1569 1570 pq_64bit_free(&rcd_num); 1571 pq_64bit_free(&tmp); 1572 } 1573 1574 1575int dtls1_dispatch_alert(SSL *s) 1576 { 1577 int i,j; 1578 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1579 unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */ 1580 unsigned char *ptr = &buf[0]; 1581 1582 s->s3->alert_dispatch=0; 1583 1584 memset(buf, 0x00, sizeof(buf)); 1585 *ptr++ = s->s3->send_alert[0]; 1586 *ptr++ = s->s3->send_alert[1]; 1587 1588 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1589 { 1590 s2n(s->d1->handshake_read_seq, ptr); 1591#if 0 1592 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1593 1594 else 1595 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1596#endif 1597 1598#if 0 1599 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); 1600#endif 1601 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1602 } 1603 1604 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1605 if (i <= 0) 1606 { 1607 s->s3->alert_dispatch=1; 1608 /* fprintf( stderr, "not done with alert\n" ); */ 1609 } 1610 else 1611 { 1612 if ( s->s3->send_alert[0] == SSL3_AL_FATAL || 1613 s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1614 (void)BIO_flush(s->wbio); 1615 1616 if (s->msg_callback) 1617 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1618 2, s, s->msg_callback_arg); 1619 1620 if (s->info_callback != NULL) 1621 cb=s->info_callback; 1622 else if (s->ctx->info_callback != NULL) 1623 cb=s->ctx->info_callback; 1624 1625 if (cb != NULL) 1626 { 1627 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1628 cb(s,SSL_CB_WRITE_ALERT,j); 1629 } 1630 } 1631 return(i); 1632 } 1633 1634 1635static DTLS1_BITMAP * 1636dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1637 { 1638 1639 *is_next_epoch = 0; 1640 1641 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1642 if (rr->epoch == s->d1->r_epoch) 1643 return &s->d1->bitmap; 1644 1645 /* Only HM and ALERT messages can be from the next epoch */ 1646 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1647 (rr->type == SSL3_RT_HANDSHAKE || 1648 rr->type == SSL3_RT_ALERT)) 1649 { 1650 *is_next_epoch = 1; 1651 return &s->d1->next_bitmap; 1652 } 1653 1654 return NULL; 1655 } 1656 1657#if 0 1658static int 1659dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1660 unsigned long *offset) 1661 { 1662 1663 /* alerts are passed up immediately */ 1664 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1665 rr->type == SSL3_RT_ALERT) 1666 return 0; 1667 1668 /* Only need to buffer if a handshake is underway. 1669 * (this implies that Hello Request and Client Hello are passed up 1670 * immediately) */ 1671 if ( SSL_in_init(s)) 1672 { 1673 unsigned char *data = rr->data; 1674 /* need to extract the HM/CCS sequence number here */ 1675 if ( rr->type == SSL3_RT_HANDSHAKE || 1676 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1677 { 1678 unsigned short seq_num; 1679 struct hm_header_st msg_hdr; 1680 struct ccs_header_st ccs_hdr; 1681 1682 if ( rr->type == SSL3_RT_HANDSHAKE) 1683 { 1684 dtls1_get_message_header(data, &msg_hdr); 1685 seq_num = msg_hdr.seq; 1686 *offset = msg_hdr.frag_off; 1687 } 1688 else 1689 { 1690 dtls1_get_ccs_header(data, &ccs_hdr); 1691 seq_num = ccs_hdr.seq; 1692 *offset = 0; 1693 } 1694 1695 /* this is either a record we're waiting for, or a 1696 * retransmit of something we happened to previously 1697 * receive (higher layers will drop the repeat silently */ 1698 if ( seq_num < s->d1->handshake_read_seq) 1699 return 0; 1700 if (rr->type == SSL3_RT_HANDSHAKE && 1701 seq_num == s->d1->handshake_read_seq && 1702 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1703 return 0; 1704 else if ( seq_num == s->d1->handshake_read_seq && 1705 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1706 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1707 return 0; 1708 else 1709 { 1710 *priority = seq_num; 1711 return 1; 1712 } 1713 } 1714 else /* unknown record type */ 1715 return 0; 1716 } 1717 1718 return 0; 1719 } 1720#endif 1721 1722void 1723dtls1_reset_seq_numbers(SSL *s, int rw) 1724 { 1725 unsigned char *seq; 1726 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1727 1728 if ( rw & SSL3_CC_READ) 1729 { 1730 seq = s->s3->read_sequence; 1731 s->d1->r_epoch++; 1732 1733 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map)); 1734 s->d1->bitmap.length = s->d1->next_bitmap.length; 1735 pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 1736 &(s->d1->next_bitmap.max_seq_num)); 1737 1738 pq_64bit_free(&(s->d1->next_bitmap.map)); 1739 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num)); 1740 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1741 pq_64bit_init(&(s->d1->next_bitmap.map)); 1742 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num)); 1743 } 1744 else 1745 { 1746 seq = s->s3->write_sequence; 1747 s->d1->w_epoch++; 1748 } 1749 1750 memset(seq, 0x00, seq_bytes); 1751 } 1752 1753#if PQ_64BIT_IS_INTEGER 1754static PQ_64BIT 1755bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num) 1756 { 1757 PQ_64BIT _num; 1758 1759 _num = (((PQ_64BIT)bytes[0]) << 56) | 1760 (((PQ_64BIT)bytes[1]) << 48) | 1761 (((PQ_64BIT)bytes[2]) << 40) | 1762 (((PQ_64BIT)bytes[3]) << 32) | 1763 (((PQ_64BIT)bytes[4]) << 24) | 1764 (((PQ_64BIT)bytes[5]) << 16) | 1765 (((PQ_64BIT)bytes[6]) << 8) | 1766 (((PQ_64BIT)bytes[7]) ); 1767 1768 *num = _num ; 1769 return _num; 1770 } 1771#endif 1772 1773 1774static void 1775dtls1_clear_timeouts(SSL *s) 1776 { 1777 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st)); 1778 } 1779