1 /* ssl/d1_pkt.c */ 2 /* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra (at) cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6 /* ==================================================================== 7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core (at) openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay (at) cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh (at) cryptsoft.com). 57 * 58 */ 59 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay (at) cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay (at) cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116 #include <stdio.h> 117 #include <errno.h> 118 #define USE_SOCKETS 119 #include "ssl_locl.h" 120 #include <openssl/evp.h> 121 #include <openssl/buffer.h> 122 #include <openssl/pqueue.h> 123 #include <openssl/rand.h> 124 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */ 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2) 127 { int ret,sat,brw,i; 128 129 if (sizeof(long) == 8) do 130 { const union { long one; char little; } is_endian = {1}; 131 long l; 132 133 if (is_endian.little) break; 134 /* not reached on little-endians */ 135 /* following test is redundant, because input is 136 * always aligned, but I take no chances... */ 137 if (((size_t)v1|(size_t)v2)&0x7) break; 138 139 l = *((long *)v1); 140 l -= *((long *)v2); 141 if (l>128) return 128; 142 else if (l<-128) return -128; 143 else return (int)l; 144 } while (0); 145 146 ret = (int)v1[7]-(int)v2[7]; 147 sat = 0; 148 brw = ret>>8; /* brw is either 0 or -1 */ 149 if (ret & 0x80) 150 { for (i=6;i>=0;i--) 151 { brw += (int)v1[i]-(int)v2[i]; 152 sat |= ~brw; 153 brw >>= 8; 154 } 155 } 156 else 157 { for (i=6;i>=0;i--) 158 { brw += (int)v1[i]-(int)v2[i]; 159 sat |= brw; 160 brw >>= 8; 161 } 162 } 163 brw <<= 8; /* brw is either 0 or -256 */ 164 165 if (sat&0xff) return brw | 0x80; 166 else return brw + (ret&0xFF); 167 } 168 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 170 int len, int peek); 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 174 unsigned int *is_next_epoch); 175 #if 0 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, 177 unsigned short *priority, unsigned long *offset); 178 #endif 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q, 180 unsigned char *priority); 181 static int dtls1_process_record(SSL *s); 182 static void dtls1_clear_timeouts(SSL *s); 183 184 /* copy buffered record into SSL structure */ 185 static int 186 dtls1_copy_record(SSL *s, pitem *item) 187 { 188 DTLS1_RECORD_DATA *rdata; 189 190 rdata = (DTLS1_RECORD_DATA *)item->data; 191 192 if (s->s3->rbuf.buf != NULL) 193 OPENSSL_free(s->s3->rbuf.buf); 194 195 s->packet = rdata->packet; 196 s->packet_length = rdata->packet_length; 197 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 198 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 199 200 /* Set proper sequence number for mac calculation */ 201 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6); 202 203 return(1); 204 } 205 206 207 static int 208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 209 { 210 DTLS1_RECORD_DATA *rdata; 211 pitem *item; 212 213 /* Limit the size of the queue to prevent DOS attacks */ 214 if (pqueue_size(queue->q) >= 100) 215 return 0; 216 217 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA)); 218 item = pitem_new(priority, rdata); 219 if (rdata == NULL || item == NULL) 220 { 221 if (rdata != NULL) OPENSSL_free(rdata); 222 if (item != NULL) pitem_free(item); 223 224 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 225 return(0); 226 } 227 228 rdata->packet = s->packet; 229 rdata->packet_length = s->packet_length; 230 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER)); 231 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD)); 232 233 item->data = rdata; 234 235 /* insert should not fail, since duplicates are dropped */ 236 if (pqueue_insert(queue->q, item) == NULL) 237 { 238 OPENSSL_free(rdata); 239 pitem_free(item); 240 return(0); 241 } 242 243 s->packet = NULL; 244 s->packet_length = 0; 245 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER)); 246 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD)); 247 248 if (!ssl3_setup_buffers(s)) 249 { 250 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR); 251 OPENSSL_free(rdata); 252 pitem_free(item); 253 return(0); 254 } 255 256 return(1); 257 } 258 259 260 static int 261 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 262 { 263 pitem *item; 264 265 item = pqueue_pop(queue->q); 266 if (item) 267 { 268 dtls1_copy_record(s, item); 269 270 OPENSSL_free(item->data); 271 pitem_free(item); 272 273 return(1); 274 } 275 276 return(0); 277 } 278 279 280 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 281 * yet */ 282 #define dtls1_get_unprocessed_record(s) \ 283 dtls1_retrieve_buffered_record((s), \ 284 &((s)->d1->unprocessed_rcds)) 285 286 /* retrieve a buffered record that belongs to the current epoch, ie, processed */ 287 #define dtls1_get_processed_record(s) \ 288 dtls1_retrieve_buffered_record((s), \ 289 &((s)->d1->processed_rcds)) 290 291 static int 292 dtls1_process_buffered_records(SSL *s) 293 { 294 pitem *item; 295 296 item = pqueue_peek(s->d1->unprocessed_rcds.q); 297 if (item) 298 { 299 DTLS1_RECORD_DATA *rdata; 300 rdata = (DTLS1_RECORD_DATA *)item->data; 301 302 /* Check if epoch is current. */ 303 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch) 304 return(1); /* Nothing to do. */ 305 306 /* Process all the records. */ 307 while (pqueue_peek(s->d1->unprocessed_rcds.q)) 308 { 309 dtls1_get_unprocessed_record(s); 310 if ( ! dtls1_process_record(s)) 311 return(0); 312 dtls1_buffer_record(s, &(s->d1->processed_rcds), 313 s->s3->rrec.seq_num); 314 } 315 } 316 317 /* sync epoch numbers once all the unprocessed records 318 * have been processed */ 319 s->d1->processed_rcds.epoch = s->d1->r_epoch; 320 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1; 321 322 return(1); 323 } 324 325 326 #if 0 327 328 static int 329 dtls1_get_buffered_record(SSL *s) 330 { 331 pitem *item; 332 PQ_64BIT priority = 333 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 334 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off); 335 336 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating, 337 nothing buffered */ 338 return 0; 339 340 341 item = pqueue_peek(s->d1->rcvd_records); 342 if (item && item->priority == priority) 343 { 344 /* Check if we've received the record of interest. It must be 345 * a handshake record, since data records as passed up without 346 * buffering */ 347 DTLS1_RECORD_DATA *rdata; 348 item = pqueue_pop(s->d1->rcvd_records); 349 rdata = (DTLS1_RECORD_DATA *)item->data; 350 351 if (s->s3->rbuf.buf != NULL) 352 OPENSSL_free(s->s3->rbuf.buf); 353 354 s->packet = rdata->packet; 355 s->packet_length = rdata->packet_length; 356 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER)); 357 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD)); 358 359 OPENSSL_free(item->data); 360 pitem_free(item); 361 362 /* s->d1->next_expected_seq_num++; */ 363 return(1); 364 } 365 366 return 0; 367 } 368 369 #endif 370 371 static int 372 dtls1_process_record(SSL *s) 373 { 374 int i,al; 375 int clear=0; 376 int enc_err; 377 SSL_SESSION *sess; 378 SSL3_RECORD *rr; 379 unsigned int mac_size; 380 unsigned char md[EVP_MAX_MD_SIZE]; 381 382 383 rr= &(s->s3->rrec); 384 sess = s->session; 385 386 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 387 * and we have that many bytes in s->packet 388 */ 389 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]); 390 391 /* ok, we can now read from 's->packet' data into 'rr' 392 * rr->input points at rr->length bytes, which 393 * need to be copied into rr->data by either 394 * the decryption or by the decompression 395 * When the data is 'copied' into the rr->data buffer, 396 * rr->input will be pointed at the new buffer */ 397 398 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 399 * rr->length bytes of encrypted compressed stuff. */ 400 401 /* check is not needed I believe */ 402 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 403 { 404 al=SSL_AD_RECORD_OVERFLOW; 405 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 406 goto f_err; 407 } 408 409 /* decrypt in place in 'rr->input' */ 410 rr->data=rr->input; 411 412 enc_err = s->method->ssl3_enc->enc(s,0); 413 if (enc_err <= 0) 414 { 415 if (enc_err == 0) 416 /* SSLerr() and ssl3_send_alert() have been called */ 417 goto err; 418 419 /* otherwise enc_err == -1 */ 420 goto err; 421 } 422 423 #ifdef TLS_DEBUG 424 printf("dec %d\n",rr->length); 425 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } 426 printf("\n"); 427 #endif 428 429 /* r->length is now the compressed data plus mac */ 430 if ( (sess == NULL) || 431 (s->enc_read_ctx == NULL) || 432 (s->read_hash == NULL)) 433 clear=1; 434 435 if (!clear) 436 { 437 /* !clear => s->read_hash != NULL => mac_size != -1 */ 438 int t; 439 t=EVP_MD_CTX_size(s->read_hash); 440 OPENSSL_assert(t >= 0); 441 mac_size=t; 442 443 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) 444 { 445 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ 446 al=SSL_AD_RECORD_OVERFLOW; 447 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); 448 goto f_err; 449 #else 450 goto err; 451 #endif 452 } 453 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ 454 if (rr->length < mac_size) 455 { 456 #if 0 /* OK only for stream ciphers */ 457 al=SSL_AD_DECODE_ERROR; 458 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT); 459 goto f_err; 460 #else 461 goto err; 462 #endif 463 } 464 rr->length-=mac_size; 465 i=s->method->ssl3_enc->mac(s,md,0); 466 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0) 467 { 468 goto err; 469 } 470 } 471 472 /* r->length is now just compressed */ 473 if (s->expand != NULL) 474 { 475 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) 476 { 477 al=SSL_AD_RECORD_OVERFLOW; 478 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); 479 goto f_err; 480 } 481 if (!ssl3_do_uncompress(s)) 482 { 483 al=SSL_AD_DECOMPRESSION_FAILURE; 484 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION); 485 goto f_err; 486 } 487 } 488 489 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) 490 { 491 al=SSL_AD_RECORD_OVERFLOW; 492 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); 493 goto f_err; 494 } 495 496 rr->off=0; 497 /* So at this point the following is true 498 * ssl->s3->rrec.type is the type of record 499 * ssl->s3->rrec.length == number of bytes in record 500 * ssl->s3->rrec.off == offset to first valid byte 501 * ssl->s3->rrec.data == where to take bytes from, increment 502 * after use :-). 503 */ 504 505 /* we have pulled in a full packet so zero things */ 506 s->packet_length=0; 507 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */ 508 return(1); 509 510 f_err: 511 ssl3_send_alert(s,SSL3_AL_FATAL,al); 512 err: 513 return(0); 514 } 515 516 517 /* Call this to get a new input record. 518 * It will return <= 0 if more data is needed, normally due to an error 519 * or non-blocking IO. 520 * When it finishes, one packet has been decoded and can be found in 521 * ssl->s3->rrec.type - is the type of record 522 * ssl->s3->rrec.data, - data 523 * ssl->s3->rrec.length, - number of bytes 524 */ 525 /* used only by dtls1_read_bytes */ 526 int dtls1_get_record(SSL *s) 527 { 528 int ssl_major,ssl_minor; 529 int i,n; 530 SSL3_RECORD *rr; 531 SSL_SESSION *sess; 532 unsigned char *p = NULL; 533 unsigned short version; 534 DTLS1_BITMAP *bitmap; 535 unsigned int is_next_epoch; 536 537 rr= &(s->s3->rrec); 538 sess=s->session; 539 540 /* The epoch may have changed. If so, process all the 541 * pending records. This is a non-blocking operation. */ 542 dtls1_process_buffered_records(s); 543 544 /* if we're renegotiating, then there may be buffered records */ 545 if (dtls1_get_processed_record(s)) 546 return 1; 547 548 /* get something from the wire */ 549 again: 550 /* check if we have the header */ 551 if ( (s->rstate != SSL_ST_READ_BODY) || 552 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 553 { 554 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 555 /* read timeout is handled by dtls1_read_bytes */ 556 if (n <= 0) return(n); /* error or non-blocking */ 557 558 /* this packet contained a partial record, dump it */ 559 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) 560 { 561 s->packet_length = 0; 562 goto again; 563 } 564 565 s->rstate=SSL_ST_READ_BODY; 566 567 p=s->packet; 568 569 /* Pull apart the header into the DTLS1_RECORD */ 570 rr->type= *(p++); 571 ssl_major= *(p++); 572 ssl_minor= *(p++); 573 version=(ssl_major<<8)|ssl_minor; 574 575 /* sequence number is 64 bits, with top 2 bytes = epoch */ 576 n2s(p,rr->epoch); 577 578 memcpy(&(s->s3->read_sequence[2]), p, 6); 579 p+=6; 580 581 n2s(p,rr->length); 582 583 /* Lets check version */ 584 if (!s->first_packet) 585 { 586 if (version != s->version) 587 { 588 /* unexpected version, silently discard */ 589 rr->length = 0; 590 s->packet_length = 0; 591 goto again; 592 } 593 } 594 595 if ((version & 0xff00) != (s->version & 0xff00)) 596 { 597 /* wrong version, silently discard record */ 598 rr->length = 0; 599 s->packet_length = 0; 600 goto again; 601 } 602 603 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) 604 { 605 /* record too long, silently discard it */ 606 rr->length = 0; 607 s->packet_length = 0; 608 goto again; 609 } 610 611 /* If we receive a valid record larger than the current buffer size, 612 * allocate some memory for it. 613 */ 614 if (rr->length > s->s3->rbuf.len - DTLS1_RT_HEADER_LENGTH) 615 { 616 unsigned char *pp; 617 unsigned int newlen = rr->length + DTLS1_RT_HEADER_LENGTH; 618 if ((pp=OPENSSL_realloc(s->s3->rbuf.buf, newlen))==NULL) 619 { 620 SSLerr(SSL_F_DTLS1_GET_RECORD,ERR_R_MALLOC_FAILURE); 621 return(-1); 622 } 623 p = pp + (p - s->s3->rbuf.buf); 624 s->s3->rbuf.buf=pp; 625 s->s3->rbuf.len=newlen; 626 s->packet= &(s->s3->rbuf.buf[0]); 627 } 628 629 /* now s->rstate == SSL_ST_READ_BODY */ 630 } 631 632 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 633 634 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH) 635 { 636 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ 637 i=rr->length; 638 n=ssl3_read_n(s,i,i,1); 639 if (n <= 0) return(n); /* error or non-blocking io */ 640 641 /* this packet contained a partial record, dump it */ 642 if ( n != i) 643 { 644 rr->length = 0; 645 s->packet_length = 0; 646 goto again; 647 } 648 649 /* now n == rr->length, 650 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ 651 } 652 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */ 653 654 /* match epochs. NULL means the packet is dropped on the floor */ 655 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 656 if ( bitmap == NULL) 657 { 658 rr->length = 0; 659 s->packet_length = 0; /* dump this record */ 660 goto again; /* get another record */ 661 } 662 663 /* Check whether this is a repeat, or aged record. 664 * Don't check if we're listening and this message is 665 * a ClientHello. They can look as if they're replayed, 666 * since they arrive from different connections and 667 * would be dropped unnecessarily. 668 */ 669 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && 670 *p == SSL3_MT_CLIENT_HELLO) && 671 !dtls1_record_replay_check(s, bitmap)) 672 { 673 rr->length = 0; 674 s->packet_length=0; /* dump this record */ 675 goto again; /* get another record */ 676 } 677 678 /* just read a 0 length packet */ 679 if (rr->length == 0) goto again; 680 681 /* If this record is from the next epoch (either HM or ALERT), 682 * and a handshake is currently in progress, buffer it since it 683 * cannot be processed at this time. */ 684 if (is_next_epoch) 685 { 686 if (SSL_in_init(s) || s->in_handshake) 687 { 688 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); 689 } 690 rr->length = 0; 691 s->packet_length = 0; 692 goto again; 693 } 694 695 if (!dtls1_process_record(s)) 696 { 697 rr->length = 0; 698 s->packet_length = 0; /* dump this record */ 699 goto again; /* get another record */ 700 } 701 702 dtls1_clear_timeouts(s); /* done waiting */ 703 return(1); 704 705 } 706 707 /* Return up to 'len' payload bytes received in 'type' records. 708 * 'type' is one of the following: 709 * 710 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 711 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 712 * - 0 (during a shutdown, no data has to be returned) 713 * 714 * If we don't have stored data to work from, read a SSL/TLS record first 715 * (possibly multiple records if we still don't have anything to return). 716 * 717 * This function must handle any surprises the peer may have for us, such as 718 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 719 * a surprise, but handled as if it were), or renegotiation requests. 720 * Also if record payloads contain fragments too small to process, we store 721 * them until there is enough for the respective protocol (the record protocol 722 * may use arbitrary fragmentation and even interleaving): 723 * Change cipher spec protocol 724 * just 1 byte needed, no need for keeping anything stored 725 * Alert protocol 726 * 2 bytes needed (AlertLevel, AlertDescription) 727 * Handshake protocol 728 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 729 * to detect unexpected Client Hello and Hello Request messages 730 * here, anything else is handled by higher layers 731 * Application data protocol 732 * none of our business 733 */ 734 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 735 { 736 int al,i,j,ret; 737 unsigned int n; 738 SSL3_RECORD *rr; 739 void (*cb)(const SSL *ssl,int type2,int val)=NULL; 740 741 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 742 if (!ssl3_setup_buffers(s)) 743 return(-1); 744 745 /* XXX: check what the second '&& type' is about */ 746 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 747 (type != SSL3_RT_HANDSHAKE) && type) || 748 (peek && (type != SSL3_RT_APPLICATION_DATA))) 749 { 750 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR); 751 return -1; 752 } 753 754 /* check whether there's a handshake message (client hello?) waiting */ 755 if ( (ret = have_handshake_fragment(s, type, buf, len, peek))) 756 return ret; 757 758 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ 759 760 if (!s->in_handshake && SSL_in_init(s)) 761 { 762 /* type == SSL3_RT_APPLICATION_DATA */ 763 i=s->handshake_func(s); 764 if (i < 0) return(i); 765 if (i == 0) 766 { 767 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 768 return(-1); 769 } 770 } 771 772 start: 773 s->rwstate=SSL_NOTHING; 774 775 /* s->s3->rrec.type - is the type of record 776 * s->s3->rrec.data, - data 777 * s->s3->rrec.off, - offset into 'data' for next read 778 * s->s3->rrec.length, - number of bytes. */ 779 rr = &(s->s3->rrec); 780 781 /* We are not handshaking and have no data yet, 782 * so process data buffered during the last handshake 783 * in advance, if any. 784 */ 785 if (s->state == SSL_ST_OK && rr->length == 0) 786 { 787 pitem *item; 788 item = pqueue_pop(s->d1->buffered_app_data.q); 789 if (item) 790 { 791 dtls1_copy_record(s, item); 792 793 OPENSSL_free(item->data); 794 pitem_free(item); 795 } 796 } 797 798 /* Check for timeout */ 799 if (dtls1_handle_timeout(s) > 0) 800 goto start; 801 802 /* get new packet if necessary */ 803 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) 804 { 805 ret=dtls1_get_record(s); 806 if (ret <= 0) 807 { 808 ret = dtls1_read_failed(s, ret); 809 /* anything other than a timeout is an error */ 810 if (ret <= 0) 811 return(ret); 812 else 813 goto start; 814 } 815 } 816 817 /* we now have a packet which can be read and processed */ 818 819 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 820 * reset by ssl3_get_finished */ 821 && (rr->type != SSL3_RT_HANDSHAKE)) 822 { 823 /* We now have application data between CCS and Finished. 824 * Most likely the packets were reordered on their way, so 825 * buffer the application data for later processing rather 826 * than dropping the connection. 827 */ 828 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num); 829 rr->length = 0; 830 goto start; 831 } 832 833 /* If the other end has shut down, throw anything we read away 834 * (even in 'peek' mode) */ 835 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) 836 { 837 rr->length=0; 838 s->rwstate=SSL_NOTHING; 839 return(0); 840 } 841 842 843 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 844 { 845 /* make sure that we are not getting application data when we 846 * are doing a handshake for the first time */ 847 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 848 (s->enc_read_ctx == NULL)) 849 { 850 al=SSL_AD_UNEXPECTED_MESSAGE; 851 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE); 852 goto f_err; 853 } 854 855 if (len <= 0) return(len); 856 857 if ((unsigned int)len > rr->length) 858 n = rr->length; 859 else 860 n = (unsigned int)len; 861 862 memcpy(buf,&(rr->data[rr->off]),n); 863 if (!peek) 864 { 865 rr->length-=n; 866 rr->off+=n; 867 if (rr->length == 0) 868 { 869 s->rstate=SSL_ST_READ_HEADER; 870 rr->off=0; 871 } 872 } 873 return(n); 874 } 875 876 877 /* If we get here, then type != rr->type; if we have a handshake 878 * message, then it was unexpected (Hello Request or Client Hello). */ 879 880 /* In case of record types for which we have 'fragment' storage, 881 * fill that so that we can process the data at a fixed place. 882 */ 883 { 884 unsigned int k, dest_maxlen = 0; 885 unsigned char *dest = NULL; 886 unsigned int *dest_len = NULL; 887 888 if (rr->type == SSL3_RT_HANDSHAKE) 889 { 890 dest_maxlen = sizeof s->d1->handshake_fragment; 891 dest = s->d1->handshake_fragment; 892 dest_len = &s->d1->handshake_fragment_len; 893 } 894 else if (rr->type == SSL3_RT_ALERT) 895 { 896 dest_maxlen = sizeof(s->d1->alert_fragment); 897 dest = s->d1->alert_fragment; 898 dest_len = &s->d1->alert_fragment_len; 899 } 900 /* else it's a CCS message, or application data or wrong */ 901 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) 902 { 903 /* Application data while renegotiating 904 * is allowed. Try again reading. 905 */ 906 if (rr->type == SSL3_RT_APPLICATION_DATA) 907 { 908 BIO *bio; 909 s->s3->in_read_app_data=2; 910 bio=SSL_get_rbio(s); 911 s->rwstate=SSL_READING; 912 BIO_clear_retry_flags(bio); 913 BIO_set_retry_read(bio); 914 return(-1); 915 } 916 917 /* Not certain if this is the right error handling */ 918 al=SSL_AD_UNEXPECTED_MESSAGE; 919 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 920 goto f_err; 921 } 922 923 if (dest_maxlen > 0) 924 { 925 /* XDTLS: In a pathalogical case, the Client Hello 926 * may be fragmented--don't always expect dest_maxlen bytes */ 927 if ( rr->length < dest_maxlen) 928 { 929 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 930 /* 931 * for normal alerts rr->length is 2, while 932 * dest_maxlen is 7 if we were to handle this 933 * non-existing alert... 934 */ 935 FIX ME 936 #endif 937 s->rstate=SSL_ST_READ_HEADER; 938 rr->length = 0; 939 goto start; 940 } 941 942 /* now move 'n' bytes: */ 943 for ( k = 0; k < dest_maxlen; k++) 944 { 945 dest[k] = rr->data[rr->off++]; 946 rr->length--; 947 } 948 *dest_len = dest_maxlen; 949 } 950 } 951 952 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE; 953 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT. 954 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 955 956 /* If we are a client, check for an incoming 'Hello Request': */ 957 if ((!s->server) && 958 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 959 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 960 (s->session != NULL) && (s->session->cipher != NULL)) 961 { 962 s->d1->handshake_fragment_len = 0; 963 964 if ((s->d1->handshake_fragment[1] != 0) || 965 (s->d1->handshake_fragment[2] != 0) || 966 (s->d1->handshake_fragment[3] != 0)) 967 { 968 al=SSL_AD_DECODE_ERROR; 969 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST); 970 goto err; 971 } 972 973 /* no need to check sequence number on HELLO REQUEST messages */ 974 975 if (s->msg_callback) 976 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 977 s->d1->handshake_fragment, 4, s, s->msg_callback_arg); 978 979 if (SSL_is_init_finished(s) && 980 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 981 !s->s3->renegotiate) 982 { 983 ssl3_renegotiate(s); 984 if (ssl3_renegotiate_check(s)) 985 { 986 i=s->handshake_func(s); 987 if (i < 0) return(i); 988 if (i == 0) 989 { 990 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 991 return(-1); 992 } 993 994 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 995 { 996 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 997 { 998 BIO *bio; 999 /* In the case where we try to read application data, 1000 * but we trigger an SSL handshake, we return -1 with 1001 * the retry option set. Otherwise renegotiation may 1002 * cause nasty problems in the blocking world */ 1003 s->rwstate=SSL_READING; 1004 bio=SSL_get_rbio(s); 1005 BIO_clear_retry_flags(bio); 1006 BIO_set_retry_read(bio); 1007 return(-1); 1008 } 1009 } 1010 } 1011 } 1012 /* we either finished a handshake or ignored the request, 1013 * now try again to obtain the (application) data we were asked for */ 1014 goto start; 1015 } 1016 1017 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) 1018 { 1019 int alert_level = s->d1->alert_fragment[0]; 1020 int alert_descr = s->d1->alert_fragment[1]; 1021 1022 s->d1->alert_fragment_len = 0; 1023 1024 if (s->msg_callback) 1025 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1026 s->d1->alert_fragment, 2, s, s->msg_callback_arg); 1027 1028 if (s->info_callback != NULL) 1029 cb=s->info_callback; 1030 else if (s->ctx->info_callback != NULL) 1031 cb=s->ctx->info_callback; 1032 1033 if (cb != NULL) 1034 { 1035 j = (alert_level << 8) | alert_descr; 1036 cb(s, SSL_CB_READ_ALERT, j); 1037 } 1038 1039 if (alert_level == 1) /* warning */ 1040 { 1041 s->s3->warn_alert = alert_descr; 1042 if (alert_descr == SSL_AD_CLOSE_NOTIFY) 1043 { 1044 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1045 return(0); 1046 } 1047 #if 0 1048 /* XXX: this is a possible improvement in the future */ 1049 /* now check if it's a missing record */ 1050 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1051 { 1052 unsigned short seq; 1053 unsigned int frag_off; 1054 unsigned char *p = &(s->d1->alert_fragment[2]); 1055 1056 n2s(p, seq); 1057 n2l3(p, frag_off); 1058 1059 dtls1_retransmit_message(s, 1060 dtls1_get_queue_priority(frag->msg_header.seq, 0), 1061 frag_off, &found); 1062 if ( ! found && SSL_in_init(s)) 1063 { 1064 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */ 1065 /* requested a message not yet sent, 1066 send an alert ourselves */ 1067 ssl3_send_alert(s,SSL3_AL_WARNING, 1068 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1069 } 1070 } 1071 #endif 1072 } 1073 else if (alert_level == 2) /* fatal */ 1074 { 1075 char tmp[16]; 1076 1077 s->rwstate=SSL_NOTHING; 1078 s->s3->fatal_alert = alert_descr; 1079 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1080 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr); 1081 ERR_add_error_data(2,"SSL alert number ",tmp); 1082 s->shutdown|=SSL_RECEIVED_SHUTDOWN; 1083 SSL_CTX_remove_session(s->ctx,s->session); 1084 return(0); 1085 } 1086 else 1087 { 1088 al=SSL_AD_ILLEGAL_PARAMETER; 1089 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE); 1090 goto f_err; 1091 } 1092 1093 goto start; 1094 } 1095 1096 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */ 1097 { 1098 s->rwstate=SSL_NOTHING; 1099 rr->length=0; 1100 return(0); 1101 } 1102 1103 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1104 { 1105 struct ccs_header_st ccs_hdr; 1106 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; 1107 1108 dtls1_get_ccs_header(rr->data, &ccs_hdr); 1109 1110 if (s->version == DTLS1_BAD_VER) 1111 ccs_hdr_len = 3; 1112 1113 /* 'Change Cipher Spec' is just a single byte, so we know 1114 * exactly what the record payload has to look like */ 1115 /* XDTLS: check that epoch is consistent */ 1116 if ( (rr->length != ccs_hdr_len) || 1117 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) 1118 { 1119 i=SSL_AD_ILLEGAL_PARAMETER; 1120 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC); 1121 goto err; 1122 } 1123 1124 rr->length=0; 1125 1126 if (s->msg_callback) 1127 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1128 rr->data, 1, s, s->msg_callback_arg); 1129 1130 /* We can't process a CCS now, because previous handshake 1131 * messages are still missing, so just drop it. 1132 */ 1133 if (!s->d1->change_cipher_spec_ok) 1134 { 1135 goto start; 1136 } 1137 1138 s->d1->change_cipher_spec_ok = 0; 1139 1140 s->s3->change_cipher_spec=1; 1141 if (!ssl3_do_change_cipher_spec(s)) 1142 goto err; 1143 1144 /* do this whenever CCS is processed */ 1145 dtls1_reset_seq_numbers(s, SSL3_CC_READ); 1146 1147 if (s->version == DTLS1_BAD_VER) 1148 s->d1->handshake_read_seq++; 1149 1150 goto start; 1151 } 1152 1153 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1154 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 1155 !s->in_handshake) 1156 { 1157 struct hm_header_st msg_hdr; 1158 1159 /* this may just be a stale retransmit */ 1160 dtls1_get_message_header(rr->data, &msg_hdr); 1161 if( rr->epoch != s->d1->r_epoch) 1162 { 1163 rr->length = 0; 1164 goto start; 1165 } 1166 1167 /* If we are server, we may have a repeated FINISHED of the 1168 * client here, then retransmit our CCS and FINISHED. 1169 */ 1170 if (msg_hdr.type == SSL3_MT_FINISHED) 1171 { 1172 dtls1_retransmit_buffered_messages(s); 1173 rr->length = 0; 1174 goto start; 1175 } 1176 1177 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) && 1178 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) 1179 { 1180 #if 0 /* worked only because C operator preferences are not as expected (and 1181 * because this is not really needed for clients except for detecting 1182 * protocol violations): */ 1183 s->state=SSL_ST_BEFORE|(s->server) 1184 ?SSL_ST_ACCEPT 1185 :SSL_ST_CONNECT; 1186 #else 1187 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1188 #endif 1189 s->new_session=1; 1190 } 1191 i=s->handshake_func(s); 1192 if (i < 0) return(i); 1193 if (i == 0) 1194 { 1195 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1196 return(-1); 1197 } 1198 1199 if (!(s->mode & SSL_MODE_AUTO_RETRY)) 1200 { 1201 if (s->s3->rbuf.left == 0) /* no read-ahead left? */ 1202 { 1203 BIO *bio; 1204 /* In the case where we try to read application data, 1205 * but we trigger an SSL handshake, we return -1 with 1206 * the retry option set. Otherwise renegotiation may 1207 * cause nasty problems in the blocking world */ 1208 s->rwstate=SSL_READING; 1209 bio=SSL_get_rbio(s); 1210 BIO_clear_retry_flags(bio); 1211 BIO_set_retry_read(bio); 1212 return(-1); 1213 } 1214 } 1215 goto start; 1216 } 1217 1218 switch (rr->type) 1219 { 1220 default: 1221 #ifndef OPENSSL_NO_TLS 1222 /* TLS just ignores unknown message types */ 1223 if (s->version == TLS1_VERSION) 1224 { 1225 rr->length = 0; 1226 goto start; 1227 } 1228 #endif 1229 al=SSL_AD_UNEXPECTED_MESSAGE; 1230 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1231 goto f_err; 1232 case SSL3_RT_CHANGE_CIPHER_SPEC: 1233 case SSL3_RT_ALERT: 1234 case SSL3_RT_HANDSHAKE: 1235 /* we already handled all of these, with the possible exception 1236 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that 1237 * should not happen when type != rr->type */ 1238 al=SSL_AD_UNEXPECTED_MESSAGE; 1239 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR); 1240 goto f_err; 1241 case SSL3_RT_APPLICATION_DATA: 1242 /* At this point, we were expecting handshake data, 1243 * but have application data. If the library was 1244 * running inside ssl3_read() (i.e. in_read_app_data 1245 * is set) and it makes sense to read application data 1246 * at this point (session renegotiation not yet started), 1247 * we will indulge it. 1248 */ 1249 if (s->s3->in_read_app_data && 1250 (s->s3->total_renegotiations != 0) && 1251 (( 1252 (s->state & SSL_ST_CONNECT) && 1253 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1254 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1255 ) || ( 1256 (s->state & SSL_ST_ACCEPT) && 1257 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1258 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1259 ) 1260 )) 1261 { 1262 s->s3->in_read_app_data=2; 1263 return(-1); 1264 } 1265 else 1266 { 1267 al=SSL_AD_UNEXPECTED_MESSAGE; 1268 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD); 1269 goto f_err; 1270 } 1271 } 1272 /* not reached */ 1273 1274 f_err: 1275 ssl3_send_alert(s,SSL3_AL_FATAL,al); 1276 err: 1277 return(-1); 1278 } 1279 1280 int 1281 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) 1282 { 1283 int i; 1284 1285 if (SSL_in_init(s) && !s->in_handshake) 1286 { 1287 i=s->handshake_func(s); 1288 if (i < 0) return(i); 1289 if (i == 0) 1290 { 1291 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); 1292 return -1; 1293 } 1294 } 1295 1296 if (len > SSL3_RT_MAX_PLAIN_LENGTH) 1297 { 1298 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); 1299 return -1; 1300 } 1301 1302 i = dtls1_write_bytes(s, type, buf_, len); 1303 return i; 1304 } 1305 1306 1307 /* this only happens when a client hello is received and a handshake 1308 * is started. */ 1309 static int 1310 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 1311 int len, int peek) 1312 { 1313 1314 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0)) 1315 /* (partially) satisfy request from storage */ 1316 { 1317 unsigned char *src = s->d1->handshake_fragment; 1318 unsigned char *dst = buf; 1319 unsigned int k,n; 1320 1321 /* peek == 0 */ 1322 n = 0; 1323 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) 1324 { 1325 *dst++ = *src++; 1326 len--; s->d1->handshake_fragment_len--; 1327 n++; 1328 } 1329 /* move any remaining fragment bytes: */ 1330 for (k = 0; k < s->d1->handshake_fragment_len; k++) 1331 s->d1->handshake_fragment[k] = *src++; 1332 return n; 1333 } 1334 1335 return 0; 1336 } 1337 1338 1339 1340 1341 /* Call this to write data in records of type 'type' 1342 * It will return <= 0 if not all data has been sent or non-blocking IO. 1343 */ 1344 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len) 1345 { 1346 int i; 1347 1348 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); 1349 s->rwstate=SSL_NOTHING; 1350 i=do_dtls1_write(s, type, buf, len, 0); 1351 return i; 1352 } 1353 1354 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment) 1355 { 1356 unsigned char *p,*pseq; 1357 int i,mac_size,clear=0; 1358 int prefix_len = 0; 1359 SSL3_RECORD *wr; 1360 SSL3_BUFFER *wb; 1361 SSL_SESSION *sess; 1362 int bs; 1363 unsigned int len_with_overhead = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD; 1364 1365 /* first check if there is a SSL3_BUFFER still being written 1366 * out. This will happen with non blocking IO */ 1367 if (s->s3->wbuf.left != 0) 1368 { 1369 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ 1370 return(ssl3_write_pending(s,type,buf,len)); 1371 } 1372 1373 if (s->s3->wbuf.len < len_with_overhead) 1374 { 1375 if ((p=OPENSSL_realloc(s->s3->wbuf.buf, len_with_overhead)) == NULL) { 1376 SSLerr(SSL_F_DO_DTLS1_WRITE,ERR_R_MALLOC_FAILURE); 1377 goto err; 1378 } 1379 s->s3->wbuf.buf = p; 1380 s->s3->wbuf.len = len_with_overhead; 1381 } 1382 1383 /* If we have an alert to send, lets send it */ 1384 if (s->s3->alert_dispatch) 1385 { 1386 i=s->method->ssl_dispatch_alert(s); 1387 if (i <= 0) 1388 return(i); 1389 /* if it went, fall through and send more stuff */ 1390 } 1391 1392 if (len == 0 && !create_empty_fragment) 1393 return 0; 1394 1395 wr= &(s->s3->wrec); 1396 wb= &(s->s3->wbuf); 1397 sess=s->session; 1398 1399 if ( (sess == NULL) || 1400 (s->enc_write_ctx == NULL) || 1401 (EVP_MD_CTX_md(s->write_hash) == NULL)) 1402 clear=1; 1403 1404 if (clear) 1405 mac_size=0; 1406 else 1407 { 1408 mac_size=EVP_MD_CTX_size(s->write_hash); 1409 if (mac_size < 0) 1410 goto err; 1411 } 1412 1413 /* DTLS implements explicit IV, so no need for empty fragments */ 1414 #if 0 1415 /* 'create_empty_fragment' is true only when this function calls itself */ 1416 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done 1417 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) 1418 { 1419 /* countermeasure against known-IV weakness in CBC ciphersuites 1420 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 1421 */ 1422 1423 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) 1424 { 1425 /* recursive function call with 'create_empty_fragment' set; 1426 * this prepares and buffers the data for an empty fragment 1427 * (these 'prefix_len' bytes are sent out later 1428 * together with the actual payload) */ 1429 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1); 1430 if (prefix_len <= 0) 1431 goto err; 1432 1433 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) 1434 { 1435 /* insufficient space */ 1436 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR); 1437 goto err; 1438 } 1439 } 1440 1441 s->s3->empty_fragment_done = 1; 1442 } 1443 #endif 1444 p = wb->buf + prefix_len; 1445 1446 /* write the header */ 1447 1448 *(p++)=type&0xff; 1449 wr->type=type; 1450 1451 *(p++)=(s->version>>8); 1452 *(p++)=s->version&0xff; 1453 1454 /* field where we are to write out packet epoch, seq num and len */ 1455 pseq=p; 1456 p+=10; 1457 1458 /* lets setup the record stuff. */ 1459 1460 /* Make space for the explicit IV in case of CBC. 1461 * (this is a bit of a boundary violation, but what the heck). 1462 */ 1463 if ( s->enc_write_ctx && 1464 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE)) 1465 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 1466 else 1467 bs = 0; 1468 1469 wr->data=p + bs; /* make room for IV in case of CBC */ 1470 wr->length=(int)len; 1471 wr->input=(unsigned char *)buf; 1472 1473 /* we now 'read' from wr->input, wr->length bytes into 1474 * wr->data */ 1475 1476 /* first we compress */ 1477 if (s->compress != NULL) 1478 { 1479 if (!ssl3_do_compress(s)) 1480 { 1481 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE); 1482 goto err; 1483 } 1484 } 1485 else 1486 { 1487 memcpy(wr->data,wr->input,wr->length); 1488 wr->input=wr->data; 1489 } 1490 1491 /* we should still have the output to wr->data and the input 1492 * from wr->input. Length should be wr->length. 1493 * wr->data still points in the wb->buf */ 1494 1495 if (mac_size != 0) 1496 { 1497 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0) 1498 goto err; 1499 wr->length+=mac_size; 1500 } 1501 1502 /* this is true regardless of mac size */ 1503 wr->input=p; 1504 wr->data=p; 1505 1506 1507 /* ssl3_enc can only have an error on read */ 1508 if (bs) /* bs != 0 in case of CBC */ 1509 { 1510 RAND_pseudo_bytes(p,bs); 1511 /* master IV and last CBC residue stand for 1512 * the rest of randomness */ 1513 wr->length += bs; 1514 } 1515 1516 s->method->ssl3_enc->enc(s,1); 1517 1518 /* record length after mac and block padding */ 1519 /* if (type == SSL3_RT_APPLICATION_DATA || 1520 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */ 1521 1522 /* there's only one epoch between handshake and app data */ 1523 1524 s2n(s->d1->w_epoch, pseq); 1525 1526 /* XDTLS: ?? */ 1527 /* else 1528 s2n(s->d1->handshake_epoch, pseq); */ 1529 1530 memcpy(pseq, &(s->s3->write_sequence[2]), 6); 1531 pseq+=6; 1532 s2n(wr->length,pseq); 1533 1534 /* we should now have 1535 * wr->data pointing to the encrypted data, which is 1536 * wr->length long */ 1537 wr->type=type; /* not needed but helps for debugging */ 1538 wr->length+=DTLS1_RT_HEADER_LENGTH; 1539 1540 #if 0 /* this is now done at the message layer */ 1541 /* buffer the record, making it easy to handle retransmits */ 1542 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC) 1543 dtls1_buffer_record(s, wr->data, wr->length, 1544 *((PQ_64BIT *)&(s->s3->write_sequence[0]))); 1545 #endif 1546 1547 ssl3_record_sequence_update(&(s->s3->write_sequence[0])); 1548 1549 if (create_empty_fragment) 1550 { 1551 /* we are in a recursive call; 1552 * just return the length, don't write out anything here 1553 */ 1554 return wr->length; 1555 } 1556 1557 /* now let's set up wb */ 1558 wb->left = prefix_len + wr->length; 1559 wb->offset = 0; 1560 1561 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ 1562 s->s3->wpend_tot=len; 1563 s->s3->wpend_buf=buf; 1564 s->s3->wpend_type=type; 1565 s->s3->wpend_ret=len; 1566 1567 /* we now just need to write the buffer */ 1568 return ssl3_write_pending(s,type,buf,len); 1569 err: 1570 return -1; 1571 } 1572 1573 1574 1575 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) 1576 { 1577 int cmp; 1578 unsigned int shift; 1579 const unsigned char *seq = s->s3->read_sequence; 1580 1581 cmp = satsub64be(seq,bitmap->max_seq_num); 1582 if (cmp > 0) 1583 { 1584 memcpy (s->s3->rrec.seq_num,seq,8); 1585 return 1; /* this record in new */ 1586 } 1587 shift = -cmp; 1588 if (shift >= sizeof(bitmap->map)*8) 1589 return 0; /* stale, outside the window */ 1590 else if (bitmap->map & (1UL<<shift)) 1591 return 0; /* record previously received */ 1592 1593 memcpy (s->s3->rrec.seq_num,seq,8); 1594 return 1; 1595 } 1596 1597 1598 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) 1599 { 1600 int cmp; 1601 unsigned int shift; 1602 const unsigned char *seq = s->s3->read_sequence; 1603 1604 cmp = satsub64be(seq,bitmap->max_seq_num); 1605 if (cmp > 0) 1606 { 1607 shift = cmp; 1608 if (shift < sizeof(bitmap->map)*8) 1609 bitmap->map <<= shift, bitmap->map |= 1UL; 1610 else 1611 bitmap->map = 1UL; 1612 memcpy(bitmap->max_seq_num,seq,8); 1613 } 1614 else { 1615 shift = -cmp; 1616 if (shift < sizeof(bitmap->map)*8) 1617 bitmap->map |= 1UL<<shift; 1618 } 1619 } 1620 1621 1622 int dtls1_dispatch_alert(SSL *s) 1623 { 1624 int i,j; 1625 void (*cb)(const SSL *ssl,int type,int val)=NULL; 1626 unsigned char buf[DTLS1_AL_HEADER_LENGTH]; 1627 unsigned char *ptr = &buf[0]; 1628 1629 s->s3->alert_dispatch=0; 1630 1631 memset(buf, 0x00, sizeof(buf)); 1632 *ptr++ = s->s3->send_alert[0]; 1633 *ptr++ = s->s3->send_alert[1]; 1634 1635 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1636 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) 1637 { 1638 s2n(s->d1->handshake_read_seq, ptr); 1639 #if 0 1640 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */ 1641 1642 else 1643 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */ 1644 #endif 1645 1646 #if 0 1647 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); 1648 #endif 1649 l2n3(s->d1->r_msg_hdr.frag_off, ptr); 1650 } 1651 #endif 1652 1653 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0); 1654 if (i <= 0) 1655 { 1656 s->s3->alert_dispatch=1; 1657 /* fprintf( stderr, "not done with alert\n" ); */ 1658 } 1659 else 1660 { 1661 if (s->s3->send_alert[0] == SSL3_AL_FATAL 1662 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1663 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 1664 #endif 1665 ) 1666 (void)BIO_flush(s->wbio); 1667 1668 if (s->msg_callback) 1669 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1670 2, s, s->msg_callback_arg); 1671 1672 if (s->info_callback != NULL) 1673 cb=s->info_callback; 1674 else if (s->ctx->info_callback != NULL) 1675 cb=s->ctx->info_callback; 1676 1677 if (cb != NULL) 1678 { 1679 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1]; 1680 cb(s,SSL_CB_WRITE_ALERT,j); 1681 } 1682 } 1683 return(i); 1684 } 1685 1686 1687 static DTLS1_BITMAP * 1688 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch) 1689 { 1690 1691 *is_next_epoch = 0; 1692 1693 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1694 if (rr->epoch == s->d1->r_epoch) 1695 return &s->d1->bitmap; 1696 1697 /* Only HM and ALERT messages can be from the next epoch */ 1698 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) && 1699 (rr->type == SSL3_RT_HANDSHAKE || 1700 rr->type == SSL3_RT_ALERT)) 1701 { 1702 *is_next_epoch = 1; 1703 return &s->d1->next_bitmap; 1704 } 1705 1706 return NULL; 1707 } 1708 1709 #if 0 1710 static int 1711 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority, 1712 unsigned long *offset) 1713 { 1714 1715 /* alerts are passed up immediately */ 1716 if ( rr->type == SSL3_RT_APPLICATION_DATA || 1717 rr->type == SSL3_RT_ALERT) 1718 return 0; 1719 1720 /* Only need to buffer if a handshake is underway. 1721 * (this implies that Hello Request and Client Hello are passed up 1722 * immediately) */ 1723 if ( SSL_in_init(s)) 1724 { 1725 unsigned char *data = rr->data; 1726 /* need to extract the HM/CCS sequence number here */ 1727 if ( rr->type == SSL3_RT_HANDSHAKE || 1728 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) 1729 { 1730 unsigned short seq_num; 1731 struct hm_header_st msg_hdr; 1732 struct ccs_header_st ccs_hdr; 1733 1734 if ( rr->type == SSL3_RT_HANDSHAKE) 1735 { 1736 dtls1_get_message_header(data, &msg_hdr); 1737 seq_num = msg_hdr.seq; 1738 *offset = msg_hdr.frag_off; 1739 } 1740 else 1741 { 1742 dtls1_get_ccs_header(data, &ccs_hdr); 1743 seq_num = ccs_hdr.seq; 1744 *offset = 0; 1745 } 1746 1747 /* this is either a record we're waiting for, or a 1748 * retransmit of something we happened to previously 1749 * receive (higher layers will drop the repeat silently */ 1750 if ( seq_num < s->d1->handshake_read_seq) 1751 return 0; 1752 if (rr->type == SSL3_RT_HANDSHAKE && 1753 seq_num == s->d1->handshake_read_seq && 1754 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off) 1755 return 0; 1756 else if ( seq_num == s->d1->handshake_read_seq && 1757 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC || 1758 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off)) 1759 return 0; 1760 else 1761 { 1762 *priority = seq_num; 1763 return 1; 1764 } 1765 } 1766 else /* unknown record type */ 1767 return 0; 1768 } 1769 1770 return 0; 1771 } 1772 #endif 1773 1774 void 1775 dtls1_reset_seq_numbers(SSL *s, int rw) 1776 { 1777 unsigned char *seq; 1778 unsigned int seq_bytes = sizeof(s->s3->read_sequence); 1779 1780 if ( rw & SSL3_CC_READ) 1781 { 1782 seq = s->s3->read_sequence; 1783 s->d1->r_epoch++; 1784 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); 1785 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP)); 1786 } 1787 else 1788 { 1789 seq = s->s3->write_sequence; 1790 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); 1791 s->d1->w_epoch++; 1792 } 1793 1794 memset(seq, 0x00, seq_bytes); 1795 } 1796 1797 1798 static void 1799 dtls1_clear_timeouts(SSL *s) 1800 { 1801 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st)); 1802 } 1803
