d1_both.c revision 172767
1/* ssl/d1_both.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 <limits.h> 117#include <string.h> 118#include <stdio.h> 119#include "ssl_locl.h" 120#include <openssl/buffer.h> 121#include <openssl/rand.h> 122#include <openssl/objects.h> 123#include <openssl/evp.h> 124#include <openssl/x509.h> 125 126 127/* XDTLS: figure out the right values */ 128static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 129 130static unsigned int dtls1_min_mtu(void); 131static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 132static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 133 unsigned long frag_len); 134static unsigned char *dtls1_write_message_header(SSL *s, 135 unsigned char *p); 136static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 137 unsigned long len, unsigned short seq_num, unsigned long frag_off, 138 unsigned long frag_len); 139static int dtls1_retransmit_buffered_messages(SSL *s); 140static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 141 long max, int *ok); 142 143static hm_fragment * 144dtls1_hm_fragment_new(unsigned long frag_len) 145 { 146 hm_fragment *frag = NULL; 147 unsigned char *buf = NULL; 148 149 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 150 if ( frag == NULL) 151 return NULL; 152 153 if (frag_len) 154 { 155 buf = (unsigned char *)OPENSSL_malloc(frag_len); 156 if ( buf == NULL) 157 { 158 OPENSSL_free(frag); 159 return NULL; 160 } 161 } 162 163 /* zero length fragment gets zero frag->fragment */ 164 frag->fragment = buf; 165 166 return frag; 167 } 168 169static void 170dtls1_hm_fragment_free(hm_fragment *frag) 171 { 172 if (frag->fragment) OPENSSL_free(frag->fragment); 173 OPENSSL_free(frag); 174 } 175 176/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 177int dtls1_do_write(SSL *s, int type) 178 { 179 int ret; 180 int curr_mtu; 181 unsigned int len, frag_off; 182 183 /* AHA! Figure out the MTU, and stick to the right size */ 184 if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 185 { 186 s->d1->mtu = 187 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 188 189 /* I've seen the kernel return bogus numbers when it doesn't know 190 * (initial write), so just make sure we have a reasonable number */ 191 if ( s->d1->mtu < dtls1_min_mtu()) 192 { 193 s->d1->mtu = 0; 194 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 195 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 196 s->d1->mtu, NULL); 197 } 198 } 199#if 0 200 mtu = s->d1->mtu; 201 202 fprintf(stderr, "using MTU = %d\n", mtu); 203 204 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 205 206 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 207 208 if ( curr_mtu > 0) 209 mtu = curr_mtu; 210 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0) 211 return ret; 212 213 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) 214 { 215 ret = BIO_flush(SSL_get_wbio(s)); 216 if ( ret <= 0) 217 return ret; 218 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 219 } 220 221 OPENSSL_assert(mtu > 0); /* should have something reasonable now */ 222 223#endif 224 225 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 226 OPENSSL_assert(s->init_num == 227 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 228 229 frag_off = 0; 230 while( s->init_num) 231 { 232 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 233 DTLS1_RT_HEADER_LENGTH; 234 235 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH) 236 { 237 /* grr.. we could get an error if MTU picked was wrong */ 238 ret = BIO_flush(SSL_get_wbio(s)); 239 if ( ret <= 0) 240 return ret; 241 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH; 242 } 243 244 if ( s->init_num > curr_mtu) 245 len = curr_mtu; 246 else 247 len = s->init_num; 248 249 250 /* XDTLS: this function is too long. split out the CCS part */ 251 if ( type == SSL3_RT_HANDSHAKE) 252 { 253 if ( s->init_off != 0) 254 { 255 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 256 s->init_off -= DTLS1_HM_HEADER_LENGTH; 257 s->init_num += DTLS1_HM_HEADER_LENGTH; 258 259 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */ 260 if ( len <= DTLS1_HM_HEADER_LENGTH) 261 len += DTLS1_HM_HEADER_LENGTH; 262 } 263 264 dtls1_fix_message_header(s, frag_off, 265 len - DTLS1_HM_HEADER_LENGTH); 266 267 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 268 269 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 270 } 271 272 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 273 len); 274 if (ret < 0) 275 { 276 /* might need to update MTU here, but we don't know 277 * which previous packet caused the failure -- so can't 278 * really retransmit anything. continue as if everything 279 * is fine and wait for an alert to handle the 280 * retransmit 281 */ 282 if ( BIO_ctrl(SSL_get_wbio(s), 283 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL)) 284 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 285 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 286 else 287 return(-1); 288 } 289 else 290 { 291 292 /* bad if this assert fails, only part of the handshake 293 * message got sent. but why would this happen? */ 294 OPENSSL_assert(len == (unsigned int)ret); 295 296 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 297 { 298 /* should not be done for 'Hello Request's, but in that case 299 * we'll ignore the result anyway */ 300 unsigned char *p = &s->init_buf->data[s->init_off]; 301 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 302 int len; 303 304 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER) 305 { 306 /* reconstruct message header is if it 307 * is being sent in single fragment */ 308 *p++ = msg_hdr->type; 309 l2n3(msg_hdr->msg_len,p); 310 s2n (msg_hdr->seq,p); 311 l2n3(0,p); 312 l2n3(msg_hdr->msg_len,p); 313 p -= DTLS1_HM_HEADER_LENGTH; 314 len = ret; 315 } 316 else 317 { 318 p += DTLS1_HM_HEADER_LENGTH; 319 len = ret - DTLS1_HM_HEADER_LENGTH; 320 } 321 322 ssl3_finish_mac(s, p, len); 323 } 324 325 if (ret == s->init_num) 326 { 327 if (s->msg_callback) 328 s->msg_callback(1, s->version, type, s->init_buf->data, 329 (size_t)(s->init_off + s->init_num), s, 330 s->msg_callback_arg); 331 332 s->init_off = 0; /* done writing this message */ 333 s->init_num = 0; 334 335 return(1); 336 } 337 s->init_off+=ret; 338 s->init_num-=ret; 339 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 340 } 341 } 342 return(0); 343 } 344 345 346/* Obtain handshake message of message type 'mt' (any if mt == -1), 347 * maximum acceptable body length 'max'. 348 * Read an entire handshake message. Handshake messages arrive in 349 * fragments. 350 */ 351long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 352 { 353 int i, al; 354 struct hm_header_st *msg_hdr; 355 356 /* s3->tmp is used to store messages that are unexpected, caused 357 * by the absence of an optional handshake message */ 358 if (s->s3->tmp.reuse_message) 359 { 360 s->s3->tmp.reuse_message=0; 361 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 362 { 363 al=SSL_AD_UNEXPECTED_MESSAGE; 364 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 365 goto f_err; 366 } 367 *ok=1; 368 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 369 s->init_num = (int)s->s3->tmp.message_size; 370 return s->init_num; 371 } 372 373 msg_hdr = &s->d1->r_msg_hdr; 374 do 375 { 376 if ( msg_hdr->frag_off == 0) 377 { 378 /* s->d1->r_message_header.msg_len = 0; */ 379 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 380 } 381 382 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 383 if ( i == DTLS1_HM_BAD_FRAGMENT || 384 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 385 continue; 386 else if ( i <= 0 && !*ok) 387 return i; 388 389 /* Note that s->init_sum is used as a counter summing 390 * up fragments' lengths: as soon as they sum up to 391 * handshake packet length, we assume we have got all 392 * the fragments. Overlapping fragments would cause 393 * premature termination, so we don't expect overlaps. 394 * Well, handling overlaps would require something more 395 * drastic. Indeed, as it is now there is no way to 396 * tell if out-of-order fragment from the middle was 397 * the last. '>=' is the best/least we can do to control 398 * the potential damage caused by malformed overlaps. */ 399 if ((unsigned int)s->init_num >= msg_hdr->msg_len) 400 { 401 unsigned char *p = s->init_buf->data; 402 unsigned long msg_len = msg_hdr->msg_len; 403 404 /* reconstruct message header as if it was 405 * sent in single fragment */ 406 *(p++) = msg_hdr->type; 407 l2n3(msg_len,p); 408 s2n (msg_hdr->seq,p); 409 l2n3(0,p); 410 l2n3(msg_len,p); 411 if (s->client_version != DTLS1_BAD_VER) 412 p -= DTLS1_HM_HEADER_LENGTH, 413 msg_len += DTLS1_HM_HEADER_LENGTH; 414 415 ssl3_finish_mac(s, p, msg_len); 416 if (s->msg_callback) 417 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 418 p, msg_len, 419 s, s->msg_callback_arg); 420 421 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 422 423 s->d1->handshake_read_seq++; 424 /* we just read a handshake message from the other side: 425 * this means that we don't need to retransmit of the 426 * buffered messages. 427 * XDTLS: may be able clear out this 428 * buffer a little sooner (i.e if an out-of-order 429 * handshake message/record is received at the record 430 * layer. 431 * XDTLS: exception is that the server needs to 432 * know that change cipher spec and finished messages 433 * have been received by the client before clearing this 434 * buffer. this can simply be done by waiting for the 435 * first data segment, but is there a better way? */ 436 dtls1_clear_record_buffer(s); 437 438 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 439 return s->init_num; 440 } 441 else 442 msg_hdr->frag_off = i; 443 } while(1) ; 444 445f_err: 446 ssl3_send_alert(s,SSL3_AL_FATAL,al); 447 *ok = 0; 448 return -1; 449 } 450 451 452static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 453 { 454 size_t frag_off,frag_len,msg_len; 455 456 msg_len = msg_hdr->msg_len; 457 frag_off = msg_hdr->frag_off; 458 frag_len = msg_hdr->frag_len; 459 460 /* sanity checking */ 461 if ( (frag_off+frag_len) > msg_len) 462 { 463 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 464 return SSL_AD_ILLEGAL_PARAMETER; 465 } 466 467 if ( (frag_off+frag_len) > (unsigned long)max) 468 { 469 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 470 return SSL_AD_ILLEGAL_PARAMETER; 471 } 472 473 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 474 { 475 /* msg_len is limited to 2^24, but is effectively checked 476 * against max above */ 477 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH)) 478 { 479 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 480 return SSL_AD_INTERNAL_ERROR; 481 } 482 483 s->s3->tmp.message_size = msg_len; 484 s->d1->r_msg_hdr.msg_len = msg_len; 485 s->s3->tmp.message_type = msg_hdr->type; 486 s->d1->r_msg_hdr.type = msg_hdr->type; 487 s->d1->r_msg_hdr.seq = msg_hdr->seq; 488 } 489 else if (msg_len != s->d1->r_msg_hdr.msg_len) 490 { 491 /* They must be playing with us! BTW, failure to enforce 492 * upper limit would open possibility for buffer overrun. */ 493 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 494 return SSL_AD_ILLEGAL_PARAMETER; 495 } 496 497 return 0; /* no error */ 498 } 499 500 501static int 502dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 503 { 504 /* (0) check whether the desired fragment is available 505 * if so: 506 * (1) copy over the fragment to s->init_buf->data[] 507 * (2) update s->init_num 508 */ 509 pitem *item; 510 hm_fragment *frag; 511 int al; 512 513 *ok = 0; 514 item = pqueue_peek(s->d1->buffered_messages); 515 if ( item == NULL) 516 return 0; 517 518 frag = (hm_fragment *)item->data; 519 520 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 521 { 522 pqueue_pop(s->d1->buffered_messages); 523 524 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 525 526 if (al==0) /* no alert */ 527 { 528 unsigned char *p = s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 529 memcpy(&p[frag->msg_header.frag_off], 530 frag->fragment,frag->msg_header.frag_len); 531 } 532 533 dtls1_hm_fragment_free(frag); 534 pitem_free(item); 535 536 if (al==0) 537 { 538 *ok = 1; 539 return frag->msg_header.frag_len; 540 } 541 542 ssl3_send_alert(s,SSL3_AL_FATAL,al); 543 s->init_num = 0; 544 *ok = 0; 545 return -1; 546 } 547 else 548 return 0; 549 } 550 551 552static int 553dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok) 554{ 555 int i=-1; 556 hm_fragment *frag = NULL; 557 pitem *item = NULL; 558 PQ_64BIT seq64; 559 unsigned long frag_len = msg_hdr->frag_len; 560 561 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 562 goto err; 563 564 if (msg_hdr->seq <= s->d1->handshake_read_seq) 565 { 566 unsigned char devnull [256]; 567 568 while (frag_len) 569 { 570 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 571 devnull, 572 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 573 if (i<=0) goto err; 574 frag_len -= i; 575 } 576 } 577 578 frag = dtls1_hm_fragment_new(frag_len); 579 if ( frag == NULL) 580 goto err; 581 582 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 583 584 if (frag_len) 585 { 586 /* read the body of the fragment (header has already been read */ 587 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 588 frag->fragment,frag_len,0); 589 if (i<=0 || (unsigned long)i!=frag_len) 590 goto err; 591 } 592 593 pq_64bit_init(&seq64); 594 pq_64bit_assign_word(&seq64, msg_hdr->seq); 595 596 item = pitem_new(seq64, frag); 597 pq_64bit_free(&seq64); 598 if ( item == NULL) 599 goto err; 600 601 pqueue_insert(s->d1->buffered_messages, item); 602 return DTLS1_HM_FRAGMENT_RETRY; 603 604err: 605 if ( frag != NULL) dtls1_hm_fragment_free(frag); 606 if ( item != NULL) OPENSSL_free(item); 607 *ok = 0; 608 return i; 609 } 610 611 612static long 613dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 614 { 615 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 616 unsigned long l, frag_off, frag_len; 617 int i,al; 618 struct hm_header_st msg_hdr; 619 620 /* see if we have the required fragment already */ 621 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 622 { 623 if (*ok) s->init_num += frag_len; 624 return frag_len; 625 } 626 627 /* read handshake message header */ 628 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 629 DTLS1_HM_HEADER_LENGTH, 0); 630 if (i <= 0) /* nbio, or an error */ 631 { 632 s->rwstate=SSL_READING; 633 *ok = 0; 634 return i; 635 } 636 OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH); 637 638 /* parse the message fragment header */ 639 dtls1_get_message_header(wire, &msg_hdr); 640 641 /* 642 * if this is a future (or stale) message it gets buffered 643 * (or dropped)--no further processing at this time 644 */ 645 if ( msg_hdr.seq != s->d1->handshake_read_seq) 646 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 647 648 l = msg_hdr.msg_len; 649 frag_off = msg_hdr.frag_off; 650 frag_len = msg_hdr.frag_len; 651 652 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 653 wire[0] == SSL3_MT_HELLO_REQUEST) 654 { 655 /* The server may always send 'Hello Request' messages -- 656 * we are doing a handshake anyway now, so ignore them 657 * if their format is correct. Does not count for 658 * 'Finished' MAC. */ 659 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 660 { 661 if (s->msg_callback) 662 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 663 wire, DTLS1_HM_HEADER_LENGTH, s, 664 s->msg_callback_arg); 665 666 s->init_num = 0; 667 return dtls1_get_message_fragment(s, st1, stn, 668 max, ok); 669 } 670 else /* Incorrectly formated Hello request */ 671 { 672 al=SSL_AD_UNEXPECTED_MESSAGE; 673 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 674 goto f_err; 675 } 676 } 677 678 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 679 goto f_err; 680 681 /* XDTLS: ressurect this when restart is in place */ 682 s->state=stn; 683 684 if ( frag_len > 0) 685 { 686 unsigned char *p=s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 687 688 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 689 &p[frag_off],frag_len,0); 690 /* XDTLS: fix this--message fragments cannot span multiple packets */ 691 if (i <= 0) 692 { 693 s->rwstate=SSL_READING; 694 *ok = 0; 695 return i; 696 } 697 } 698 else 699 i = 0; 700 701 /* XDTLS: an incorrectly formatted fragment should cause the 702 * handshake to fail */ 703 OPENSSL_assert(i == (int)frag_len); 704 705 *ok = 1; 706 707 /* Note that s->init_num is *not* used as current offset in 708 * s->init_buf->data, but as a counter summing up fragments' 709 * lengths: as soon as they sum up to handshake packet 710 * length, we assume we have got all the fragments. */ 711 s->init_num += frag_len; 712 return frag_len; 713 714f_err: 715 ssl3_send_alert(s,SSL3_AL_FATAL,al); 716 s->init_num = 0; 717 718 *ok=0; 719 return(-1); 720 } 721 722int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 723 { 724 unsigned char *p,*d; 725 int i; 726 unsigned long l; 727 728 if (s->state == a) 729 { 730 d=(unsigned char *)s->init_buf->data; 731 p= &(d[DTLS1_HM_HEADER_LENGTH]); 732 733 i=s->method->ssl3_enc->final_finish_mac(s, 734 &(s->s3->finish_dgst1), 735 &(s->s3->finish_dgst2), 736 sender,slen,s->s3->tmp.finish_md); 737 s->s3->tmp.finish_md_len = i; 738 memcpy(p, s->s3->tmp.finish_md, i); 739 p+=i; 740 l=i; 741 742#ifdef OPENSSL_SYS_WIN16 743 /* MSVC 1.5 does not clear the top bytes of the word unless 744 * I do this. 745 */ 746 l&=0xffff; 747#endif 748 749 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 750 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 751 s->init_off=0; 752 753 /* buffer the message to handle re-xmits */ 754 dtls1_buffer_message(s, 0); 755 756 s->state=b; 757 } 758 759 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 760 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 761 } 762 763/* for these 2 messages, we need to 764 * ssl->enc_read_ctx re-init 765 * ssl->s3->read_sequence zero 766 * ssl->s3->read_mac_secret re-init 767 * ssl->session->read_sym_enc assign 768 * ssl->session->read_compression assign 769 * ssl->session->read_hash assign 770 */ 771int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 772 { 773 unsigned char *p; 774 775 if (s->state == a) 776 { 777 p=(unsigned char *)s->init_buf->data; 778 *p++=SSL3_MT_CCS; 779 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 780 s->d1->next_handshake_write_seq++; 781 s->init_num=DTLS1_CCS_HEADER_LENGTH; 782 783 if (s->client_version == DTLS1_BAD_VER) 784 { 785 s2n(s->d1->handshake_write_seq,p); 786 s->init_num+=2; 787 } 788 789 s->init_off=0; 790 791 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 792 s->d1->handshake_write_seq, 0, 0); 793 794 /* buffer the message to handle re-xmits */ 795 dtls1_buffer_message(s, 1); 796 797 s->state=b; 798 } 799 800 /* SSL3_ST_CW_CHANGE_B */ 801 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 802 } 803 804unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 805 { 806 unsigned char *p; 807 int n,i; 808 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 809 BUF_MEM *buf; 810 X509_STORE_CTX xs_ctx; 811 X509_OBJECT obj; 812 813 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 814 buf=s->init_buf; 815 if (!BUF_MEM_grow_clean(buf,10)) 816 { 817 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 818 return(0); 819 } 820 if (x != NULL) 821 { 822 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL)) 823 { 824 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 825 return(0); 826 } 827 828 for (;;) 829 { 830 n=i2d_X509(x,NULL); 831 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3))) 832 { 833 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 834 return(0); 835 } 836 p=(unsigned char *)&(buf->data[l]); 837 l2n3(n,p); 838 i2d_X509(x,&p); 839 l+=n+3; 840 if (X509_NAME_cmp(X509_get_subject_name(x), 841 X509_get_issuer_name(x)) == 0) break; 842 843 i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509, 844 X509_get_issuer_name(x),&obj); 845 if (i <= 0) break; 846 x=obj.data.x509; 847 /* Count is one too high since the X509_STORE_get uped the 848 * ref count */ 849 X509_free(x); 850 } 851 852 X509_STORE_CTX_cleanup(&xs_ctx); 853 } 854 855 /* Thawte special :-) */ 856 if (s->ctx->extra_certs != NULL) 857 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 858 { 859 x=sk_X509_value(s->ctx->extra_certs,i); 860 n=i2d_X509(x,NULL); 861 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3))) 862 { 863 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 864 return(0); 865 } 866 p=(unsigned char *)&(buf->data[l]); 867 l2n3(n,p); 868 i2d_X509(x,&p); 869 l+=n+3; 870 } 871 872 l-= (3 + DTLS1_HM_HEADER_LENGTH); 873 874 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 875 l2n3(l,p); 876 l+=3; 877 p=(unsigned char *)&(buf->data[0]); 878 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 879 880 l+=DTLS1_HM_HEADER_LENGTH; 881 return(l); 882 } 883 884int dtls1_read_failed(SSL *s, int code) 885 { 886 DTLS1_STATE *state; 887 BIO *bio; 888 int send_alert = 0; 889 890 if ( code > 0) 891 { 892 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 893 return 1; 894 } 895 896 bio = SSL_get_rbio(s); 897 if ( ! BIO_dgram_recv_timedout(bio)) 898 { 899 /* not a timeout, none of our business, 900 let higher layers handle this. in fact it's probably an error */ 901 return code; 902 } 903 904 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */ 905 { 906 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 907 return code; 908 } 909 910 state = s->d1; 911 state->timeout.num_alerts++; 912 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 913 { 914 /* fail the connection, enough alerts have been sent */ 915 SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED); 916 return 0; 917 } 918 919 state->timeout.read_timeouts++; 920 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 921 { 922 send_alert = 1; 923 state->timeout.read_timeouts = 1; 924 } 925 926 927#if 0 /* for now, each alert contains only one record number */ 928 item = pqueue_peek(state->rcvd_records); 929 if ( item ) 930 { 931 /* send an alert immediately for all the missing records */ 932 } 933 else 934#endif 935 936#if 0 /* no more alert sending, just retransmit the last set of messages */ 937 if ( send_alert) 938 ssl3_send_alert(s,SSL3_AL_WARNING, 939 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 940#endif 941 942 return dtls1_retransmit_buffered_messages(s) ; 943 } 944 945 946static int 947dtls1_retransmit_buffered_messages(SSL *s) 948 { 949 pqueue sent = s->d1->sent_messages; 950 piterator iter; 951 pitem *item; 952 hm_fragment *frag; 953 int found = 0; 954 955 iter = pqueue_iterator(sent); 956 957 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 958 { 959 frag = (hm_fragment *)item->data; 960 if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 && 961 found) 962 { 963 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 964 return -1; 965 } 966 } 967 968 return 1; 969 } 970 971int 972dtls1_buffer_message(SSL *s, int is_ccs) 973 { 974 pitem *item; 975 hm_fragment *frag; 976 PQ_64BIT seq64; 977 978 /* this function is called immediately after a message has 979 * been serialized */ 980 OPENSSL_assert(s->init_off == 0); 981 982 frag = dtls1_hm_fragment_new(s->init_num); 983 984 memcpy(frag->fragment, s->init_buf->data, s->init_num); 985 986 if ( is_ccs) 987 { 988 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 989 DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num); 990 } 991 else 992 { 993 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 994 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 995 } 996 997 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 998 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 999 frag->msg_header.type = s->d1->w_msg_hdr.type; 1000 frag->msg_header.frag_off = 0; 1001 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1002 frag->msg_header.is_ccs = is_ccs; 1003 1004 pq_64bit_init(&seq64); 1005 pq_64bit_assign_word(&seq64, frag->msg_header.seq); 1006 1007 item = pitem_new(seq64, frag); 1008 pq_64bit_free(&seq64); 1009 if ( item == NULL) 1010 { 1011 dtls1_hm_fragment_free(frag); 1012 return 0; 1013 } 1014 1015#if 0 1016 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1017 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1018 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1019#endif 1020 1021 pqueue_insert(s->d1->sent_messages, item); 1022 return 1; 1023 } 1024 1025int 1026dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1027 int *found) 1028 { 1029 int ret; 1030 /* XDTLS: for now assuming that read/writes are blocking */ 1031 pitem *item; 1032 hm_fragment *frag ; 1033 unsigned long header_length; 1034 PQ_64BIT seq64; 1035 1036 /* 1037 OPENSSL_assert(s->init_num == 0); 1038 OPENSSL_assert(s->init_off == 0); 1039 */ 1040 1041 /* XDTLS: the requested message ought to be found, otherwise error */ 1042 pq_64bit_init(&seq64); 1043 pq_64bit_assign_word(&seq64, seq); 1044 1045 item = pqueue_find(s->d1->sent_messages, seq64); 1046 pq_64bit_free(&seq64); 1047 if ( item == NULL) 1048 { 1049 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1050 *found = 0; 1051 return 0; 1052 } 1053 1054 *found = 1; 1055 frag = (hm_fragment *)item->data; 1056 1057 if ( frag->msg_header.is_ccs) 1058 header_length = DTLS1_CCS_HEADER_LENGTH; 1059 else 1060 header_length = DTLS1_HM_HEADER_LENGTH; 1061 1062 memcpy(s->init_buf->data, frag->fragment, 1063 frag->msg_header.msg_len + header_length); 1064 s->init_num = frag->msg_header.msg_len + header_length; 1065 1066 dtls1_set_message_header_int(s, frag->msg_header.type, 1067 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1068 frag->msg_header.frag_len); 1069 1070 s->d1->retransmitting = 1; 1071 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1072 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1073 s->d1->retransmitting = 0; 1074 1075 (void)BIO_flush(SSL_get_wbio(s)); 1076 return ret; 1077 } 1078 1079/* call this function when the buffered messages are no longer needed */ 1080void 1081dtls1_clear_record_buffer(SSL *s) 1082 { 1083 pitem *item; 1084 1085 for(item = pqueue_pop(s->d1->sent_messages); 1086 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1087 { 1088 dtls1_hm_fragment_free((hm_fragment *)item->data); 1089 pitem_free(item); 1090 } 1091 } 1092 1093 1094unsigned char * 1095dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1096 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1097 { 1098 if ( frag_off == 0) 1099 { 1100 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1101 s->d1->next_handshake_write_seq++; 1102 } 1103 1104 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1105 frag_off, frag_len); 1106 1107 return p += DTLS1_HM_HEADER_LENGTH; 1108 } 1109 1110 1111/* don't actually do the writing, wait till the MTU has been retrieved */ 1112static void 1113dtls1_set_message_header_int(SSL *s, unsigned char mt, 1114 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1115 unsigned long frag_len) 1116 { 1117 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1118 1119 msg_hdr->type = mt; 1120 msg_hdr->msg_len = len; 1121 msg_hdr->seq = seq_num; 1122 msg_hdr->frag_off = frag_off; 1123 msg_hdr->frag_len = frag_len; 1124 } 1125 1126static void 1127dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1128 unsigned long frag_len) 1129 { 1130 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1131 1132 msg_hdr->frag_off = frag_off; 1133 msg_hdr->frag_len = frag_len; 1134 } 1135 1136static unsigned char * 1137dtls1_write_message_header(SSL *s, unsigned char *p) 1138 { 1139 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1140 1141 *p++ = msg_hdr->type; 1142 l2n3(msg_hdr->msg_len, p); 1143 1144 s2n(msg_hdr->seq, p); 1145 l2n3(msg_hdr->frag_off, p); 1146 l2n3(msg_hdr->frag_len, p); 1147 1148 return p; 1149 } 1150 1151static unsigned int 1152dtls1_min_mtu(void) 1153 { 1154 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1155 sizeof(g_probable_mtu[0])) - 1]); 1156 } 1157 1158static unsigned int 1159dtls1_guess_mtu(unsigned int curr_mtu) 1160 { 1161 size_t i; 1162 1163 if ( curr_mtu == 0 ) 1164 return g_probable_mtu[0] ; 1165 1166 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1167 if ( curr_mtu > g_probable_mtu[i]) 1168 return g_probable_mtu[i]; 1169 1170 return curr_mtu; 1171 } 1172 1173void 1174dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1175 { 1176 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1177 msg_hdr->type = *(data++); 1178 n2l3(data, msg_hdr->msg_len); 1179 1180 n2s(data, msg_hdr->seq); 1181 n2l3(data, msg_hdr->frag_off); 1182 n2l3(data, msg_hdr->frag_len); 1183 } 1184 1185void 1186dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1187 { 1188 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1189 1190 ccs_hdr->type = *(data++); 1191 } 1192