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 */ 128 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 129 130 static unsigned int dtls1_min_mtu(void); 131 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 132 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 133 unsigned long frag_len); 134 static unsigned char *dtls1_write_message_header(SSL *s, 135 unsigned char *p); 136 static 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); 139 static int dtls1_retransmit_buffered_messages(SSL *s); 140 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 141 long max, int *ok); 142 static void dtls1_process_handshake_fragment(SSL *s, int frag_len); 143 144 static hm_fragment * 145 dtls1_hm_fragment_new(unsigned long frag_len) 146 { 147 hm_fragment *frag = NULL; 148 unsigned char *buf = NULL; 149 150 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 151 if ( frag == NULL) 152 return NULL; 153 154 buf = (unsigned char *)OPENSSL_malloc(frag_len 155 + DTLS1_HM_HEADER_LENGTH); 156 if ( buf == NULL) 157 { 158 OPENSSL_free(frag); 159 return NULL; 160 } 161 162 frag->fragment = buf; 163 164 return frag; 165 } 166 167 static void 168 dtls1_hm_fragment_free(hm_fragment *frag) 169 { 170 OPENSSL_free(frag->fragment); 171 OPENSSL_free(frag); 172 } 173 174 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 175 int dtls1_do_write(SSL *s, int type) 176 { 177 int ret; 178 int curr_mtu; 179 unsigned int len, frag_off; 180 181 /* AHA! Figure out the MTU, and stick to the right size */ 182 if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 183 { 184 s->d1->mtu = 185 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 186 187 /* I've seen the kernel return bogus numbers when it doesn't know 188 * (initial write), so just make sure we have a reasonable number */ 189 if ( s->d1->mtu < dtls1_min_mtu()) 190 { 191 s->d1->mtu = 0; 192 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 193 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 194 s->d1->mtu, NULL); 195 } 196 } 197 #if 0 198 mtu = s->d1->mtu; 199 200 fprintf(stderr, "using MTU = %d\n", mtu); 201 202 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 203 204 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 205 206 if ( curr_mtu > 0) 207 mtu = curr_mtu; 208 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0) 209 return ret; 210 211 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) 212 { 213 ret = BIO_flush(SSL_get_wbio(s)); 214 if ( ret <= 0) 215 return ret; 216 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 217 } 218 219 OPENSSL_assert(mtu > 0); /* should have something reasonable now */ 220 221 #endif 222 223 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 224 OPENSSL_assert(s->init_num == 225 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 226 227 frag_off = 0; 228 while( s->init_num) 229 { 230 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 231 DTLS1_RT_HEADER_LENGTH; 232 233 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH) 234 { 235 /* grr.. we could get an error if MTU picked was wrong */ 236 ret = BIO_flush(SSL_get_wbio(s)); 237 if ( ret <= 0) 238 return ret; 239 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH; 240 } 241 242 if ( s->init_num > curr_mtu) 243 len = curr_mtu; 244 else 245 len = s->init_num; 246 247 248 /* XDTLS: this function is too long. split out the CCS part */ 249 if ( type == SSL3_RT_HANDSHAKE) 250 { 251 if ( s->init_off != 0) 252 { 253 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 254 s->init_off -= DTLS1_HM_HEADER_LENGTH; 255 s->init_num += DTLS1_HM_HEADER_LENGTH; 256 257 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */ 258 if ( len <= DTLS1_HM_HEADER_LENGTH) 259 len += DTLS1_HM_HEADER_LENGTH; 260 } 261 262 dtls1_fix_message_header(s, frag_off, 263 len - DTLS1_HM_HEADER_LENGTH); 264 265 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 266 267 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 268 } 269 270 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 271 len); 272 if (ret < 0) 273 { 274 /* might need to update MTU here, but we don't know 275 * which previous packet caused the failure -- so can't 276 * really retransmit anything. continue as if everything 277 * is fine and wait for an alert to handle the 278 * retransmit 279 */ 280 if ( BIO_ctrl(SSL_get_wbio(s), 281 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL)) 282 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 283 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 284 else 285 return(-1); 286 } 287 else 288 { 289 290 /* bad if this assert fails, only part of the handshake 291 * message got sent. but why would this happen? */ 292 OPENSSL_assert(len == (unsigned int)ret); 293 294 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 295 /* should not be done for 'Hello Request's, but in that case 296 * we'll ignore the result anyway */ 297 ssl3_finish_mac(s, 298 (unsigned char *)&s->init_buf->data[s->init_off + 299 DTLS1_HM_HEADER_LENGTH], ret - DTLS1_HM_HEADER_LENGTH); 300 301 if (ret == s->init_num) 302 { 303 if (s->msg_callback) 304 s->msg_callback(1, s->version, type, s->init_buf->data, 305 (size_t)(s->init_off + s->init_num), s, 306 s->msg_callback_arg); 307 308 s->init_off = 0; /* done writing this message */ 309 s->init_num = 0; 310 311 return(1); 312 } 313 s->init_off+=ret; 314 s->init_num-=ret; 315 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 316 } 317 } 318 return(0); 319 } 320 321 322 /* Obtain handshake message of message type 'mt' (any if mt == -1), 323 * maximum acceptable body length 'max'. 324 * Read an entire handshake message. Handshake messages arrive in 325 * fragments. 326 */ 327 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 328 { 329 int i, al; 330 331 /* s3->tmp is used to store messages that are unexpected, caused 332 * by the absence of an optional handshake message */ 333 if (s->s3->tmp.reuse_message) 334 { 335 s->s3->tmp.reuse_message=0; 336 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 337 { 338 al=SSL_AD_UNEXPECTED_MESSAGE; 339 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 340 goto f_err; 341 } 342 *ok=1; 343 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 344 s->init_num = (int)s->s3->tmp.message_size; 345 return s->init_num; 346 } 347 348 do 349 { 350 if ( s->d1->r_msg_hdr.frag_off == 0) 351 { 352 /* s->d1->r_message_header.msg_len = 0; */ 353 memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st)); 354 } 355 356 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 357 if ( i == DTLS1_HM_BAD_FRAGMENT || 358 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 359 continue; 360 else if ( i <= 0 && !*ok) 361 return i; 362 363 if (s->d1->r_msg_hdr.msg_len == (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH) 364 { 365 memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st)); 366 367 s->d1->handshake_read_seq++; 368 /* we just read a handshake message from the other side: 369 * this means that we don't need to retransmit of the 370 * buffered messages. 371 * XDTLS: may be able clear out this 372 * buffer a little sooner (i.e if an out-of-order 373 * handshake message/record is received at the record 374 * layer. 375 * XDTLS: exception is that the server needs to 376 * know that change cipher spec and finished messages 377 * have been received by the client before clearing this 378 * buffer. this can simply be done by waiting for the 379 * first data segment, but is there a better way? */ 380 dtls1_clear_record_buffer(s); 381 382 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 383 return s->init_num - DTLS1_HM_HEADER_LENGTH; 384 } 385 else 386 s->d1->r_msg_hdr.frag_off = i; 387 } while(1) ; 388 389 f_err: 390 ssl3_send_alert(s,SSL3_AL_FATAL,al); 391 *ok = 0; 392 return -1; 393 } 394 395 396 static int 397 dtls1_retrieve_buffered_fragment(SSL *s, unsigned long *copied) 398 { 399 /* (0) check whether the desired fragment is available 400 * if so: 401 * (1) copy over the fragment to s->init_buf->data[] 402 * (2) update s->init_num 403 */ 404 pitem *item; 405 hm_fragment *frag; 406 unsigned long overlap; 407 unsigned char *p; 408 409 item = pqueue_peek(s->d1->buffered_messages); 410 if ( item == NULL) 411 return 0; 412 413 frag = (hm_fragment *)item->data; 414 415 if ( s->d1->handshake_read_seq == frag->msg_header.seq && 416 frag->msg_header.frag_off <= (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH) 417 { 418 pqueue_pop(s->d1->buffered_messages); 419 overlap = s->init_num - DTLS1_HM_HEADER_LENGTH 420 - frag->msg_header.frag_off; 421 422 p = frag->fragment; 423 424 memcpy(&s->init_buf->data[s->init_num], 425 p + DTLS1_HM_HEADER_LENGTH + overlap, 426 frag->msg_header.frag_len - overlap); 427 428 OPENSSL_free(frag->fragment); 429 OPENSSL_free(frag); 430 pitem_free(item); 431 432 *copied = frag->msg_header.frag_len - overlap; 433 return *copied; 434 } 435 else 436 return 0; 437 } 438 439 440 static int 441 dtls1_buffer_handshake_fragment(SSL *s, struct hm_header_st* msg_hdr) 442 { 443 hm_fragment *frag = NULL; 444 pitem *item = NULL; 445 PQ_64BIT seq64; 446 447 frag = dtls1_hm_fragment_new(msg_hdr->frag_len); 448 if ( frag == NULL) 449 goto err; 450 451 memcpy(frag->fragment, &(s->init_buf->data[s->init_num]), 452 msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH); 453 454 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 455 456 pq_64bit_init(&seq64); 457 pq_64bit_assign_word(&seq64, msg_hdr->seq); 458 459 item = pitem_new(seq64, frag); 460 if ( item == NULL) 461 goto err; 462 463 pq_64bit_free(&seq64); 464 465 pqueue_insert(s->d1->buffered_messages, item); 466 return 1; 467 468 err: 469 if ( frag != NULL) dtls1_hm_fragment_free(frag); 470 if ( item != NULL) OPENSSL_free(item); 471 return 0; 472 } 473 474 475 static void 476 dtls1_process_handshake_fragment(SSL *s, int frag_len) 477 { 478 unsigned char *p; 479 480 p = (unsigned char *)s->init_buf->data; 481 482 ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len); 483 } 484 485 486 static int 487 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok) 488 { 489 int i; 490 unsigned char *p; 491 492 /* make sure there's enough room to read this fragment */ 493 if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf, 494 (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num)) 495 { 496 SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB); 497 goto err; 498 } 499 500 p = (unsigned char *)s->init_buf->data; 501 502 /* read the body of the fragment (header has already been read */ 503 if ( msg_hdr->frag_len > 0) 504 { 505 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 506 &p[s->init_num], 507 msg_hdr->frag_len,0); 508 if (i <= 0) 509 { 510 *ok = 0; 511 return i; 512 } 513 } 514 515 if ( msg_hdr->seq > s->d1->handshake_read_seq) 516 dtls1_buffer_handshake_fragment(s, msg_hdr); 517 else 518 OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq); 519 520 return DTLS1_HM_FRAGMENT_RETRY; 521 err: 522 *ok = 0; 523 return -1; 524 } 525 526 527 static long 528 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 529 { 530 unsigned char *p; 531 unsigned long l, frag_off, frag_len; 532 int i,al; 533 struct hm_header_st msg_hdr; 534 unsigned long overlap; 535 536 /* see if we have the required fragment already */ 537 if (dtls1_retrieve_buffered_fragment(s, &l)) 538 { 539 /* compute MAC, remove fragment headers */ 540 dtls1_process_handshake_fragment(s, l); 541 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 542 s->state = stn; 543 return 1; 544 } 545 546 /* get a handshake fragment from the record layer */ 547 p = (unsigned char *)s->init_buf->data; 548 549 /* read handshake message header */ 550 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num], 551 DTLS1_HM_HEADER_LENGTH, 0); 552 if (i <= 0) /* nbio, or an error */ 553 { 554 s->rwstate=SSL_READING; 555 *ok = 0; 556 return i; 557 } 558 559 OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH); 560 561 p += s->init_num; 562 /* parse the message fragment header */ 563 564 dtls1_get_message_header(p, &msg_hdr); 565 566 /* 567 * if this is a future (or stale) message it gets buffered 568 * (or dropped)--no further processing at this time 569 */ 570 if ( msg_hdr.seq != s->d1->handshake_read_seq) 571 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 572 573 l = msg_hdr.msg_len; 574 frag_off = msg_hdr.frag_off; 575 frag_len = msg_hdr.frag_len; 576 577 /* sanity checking */ 578 if ( frag_off + frag_len > l) 579 { 580 al=SSL_AD_ILLEGAL_PARAMETER; 581 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 582 goto f_err; 583 } 584 585 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 586 p[0] == SSL3_MT_HELLO_REQUEST) 587 { 588 /* The server may always send 'Hello Request' messages -- 589 * we are doing a handshake anyway now, so ignore them 590 * if their format is correct. Does not count for 591 * 'Finished' MAC. */ 592 if (p[1] == 0 && p[2] == 0 &&p[3] == 0) 593 { 594 if (s->msg_callback) 595 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 596 p, DTLS1_HM_HEADER_LENGTH, s, 597 s->msg_callback_arg); 598 599 s->init_num = 0; 600 return dtls1_get_message_fragment(s, st1, stn, 601 max, ok); 602 } 603 else /* Incorrectly formated Hello request */ 604 { 605 al=SSL_AD_UNEXPECTED_MESSAGE; 606 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 607 goto f_err; 608 } 609 } 610 611 /* XDTLS: do a sanity check on the fragment */ 612 613 s->init_num += i; 614 615 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 616 { 617 /* BUF_MEM_grow takes an 'int' parameter */ 618 if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH)) 619 { 620 al=SSL_AD_ILLEGAL_PARAMETER; 621 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 622 goto f_err; 623 } 624 if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l 625 + DTLS1_HM_HEADER_LENGTH)) 626 { 627 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB); 628 goto err; 629 } 630 /* Only do this test when we're reading the expected message. 631 * Stale messages will be dropped and future messages will be buffered */ 632 if ( l > (unsigned long)max) 633 { 634 al=SSL_AD_ILLEGAL_PARAMETER; 635 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 636 goto f_err; 637 } 638 639 s->s3->tmp.message_size=l; 640 } 641 642 if ( frag_len > (unsigned long)max) 643 { 644 al=SSL_AD_ILLEGAL_PARAMETER; 645 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 646 goto f_err; 647 } 648 if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH)) 649 { 650 al=SSL_AD_ILLEGAL_PARAMETER; 651 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 652 goto f_err; 653 } 654 655 if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len 656 + DTLS1_HM_HEADER_LENGTH + s->init_num)) 657 { 658 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB); 659 goto err; 660 } 661 662 if ( s->d1->r_msg_hdr.frag_off == 0) 663 { 664 s->s3->tmp.message_type = msg_hdr.type; 665 s->d1->r_msg_hdr.type = msg_hdr.type; 666 s->d1->r_msg_hdr.msg_len = l; 667 /* s->d1->r_msg_hdr.seq = seq_num; */ 668 } 669 670 /* XDTLS: ressurect this when restart is in place */ 671 s->state=stn; 672 673 /* next state (stn) */ 674 p = (unsigned char *)s->init_buf->data; 675 676 if ( frag_len > 0) 677 { 678 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 679 &p[s->init_num], 680 frag_len,0); 681 /* XDTLS: fix this--message fragments cannot span multiple packets */ 682 if (i <= 0) 683 { 684 s->rwstate=SSL_READING; 685 *ok = 0; 686 return i; 687 } 688 } 689 else 690 i = 0; 691 692 /* XDTLS: an incorrectly formatted fragment should cause the 693 * handshake to fail */ 694 OPENSSL_assert(i == (int)frag_len); 695 696 #if 0 697 /* Successfully read a fragment. 698 * It may be (1) out of order, or 699 * (2) it's a repeat, in which case we dump it 700 * (3) the one we are expecting next (maybe with overlap) 701 * If it is next one, it may overlap with previously read bytes 702 */ 703 704 /* case (1): buffer the future fragment 705 * (we can treat fragments from a future message the same 706 * as future fragments from the message being currently read, since 707 * they are sematically simply out of order. 708 */ 709 if ( msg_hdr.seq > s->d1->handshake_read_seq || 710 frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH) 711 { 712 dtls1_buffer_handshake_fragment(s, &msg_hdr); 713 return DTLS1_HM_FRAGMENT_RETRY; 714 } 715 716 /* case (2): drop the entire fragment, and try again */ 717 if ( msg_hdr.seq < s->d1->handshake_read_seq || 718 frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH) 719 { 720 s->init_num -= DTLS1_HM_HEADER_LENGTH; 721 return DTLS1_HM_FRAGMENT_RETRY; 722 } 723 #endif 724 725 /* case (3): received a immediately useful fragment. Determine the 726 * possible overlap and copy the fragment. 727 */ 728 overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off; 729 730 /* retain the header for the first fragment */ 731 if ( s->init_num > DTLS1_HM_HEADER_LENGTH) 732 { 733 memmove(&(s->init_buf->data[s->init_num]), 734 &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]), 735 frag_len - overlap); 736 737 s->init_num += frag_len - overlap; 738 } 739 else 740 s->init_num += frag_len; 741 742 dtls1_process_handshake_fragment(s, frag_len - overlap); 743 744 if (s->msg_callback) 745 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data, 746 (size_t)s->init_num, s, 747 s->msg_callback_arg); 748 *ok=1; 749 750 return s->init_num; 751 752 f_err: 753 ssl3_send_alert(s,SSL3_AL_FATAL,al); 754 s->init_num = 0; 755 err: 756 *ok=0; 757 return(-1); 758 } 759 760 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 761 { 762 unsigned char *p,*d; 763 int i; 764 unsigned long l; 765 766 if (s->state == a) 767 { 768 d=(unsigned char *)s->init_buf->data; 769 p= &(d[DTLS1_HM_HEADER_LENGTH]); 770 771 i=s->method->ssl3_enc->final_finish_mac(s, 772 &(s->s3->finish_dgst1), 773 &(s->s3->finish_dgst2), 774 sender,slen,s->s3->tmp.finish_md); 775 s->s3->tmp.finish_md_len = i; 776 memcpy(p, s->s3->tmp.finish_md, i); 777 p+=i; 778 l=i; 779 780 #ifdef OPENSSL_SYS_WIN16 781 /* MSVC 1.5 does not clear the top bytes of the word unless 782 * I do this. 783 */ 784 l&=0xffff; 785 #endif 786 787 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 788 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 789 s->init_off=0; 790 791 /* buffer the message to handle re-xmits */ 792 dtls1_buffer_message(s, 0); 793 794 s->state=b; 795 } 796 797 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 798 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 799 } 800 801 /* for these 2 messages, we need to 802 * ssl->enc_read_ctx re-init 803 * ssl->s3->read_sequence zero 804 * ssl->s3->read_mac_secret re-init 805 * ssl->session->read_sym_enc assign 806 * ssl->session->read_compression assign 807 * ssl->session->read_hash assign 808 */ 809 int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 810 { 811 unsigned char *p; 812 813 if (s->state == a) 814 { 815 p=(unsigned char *)s->init_buf->data; 816 *p++=SSL3_MT_CCS; 817 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 818 s->d1->next_handshake_write_seq++; 819 s2n(s->d1->handshake_write_seq,p); 820 821 s->init_num=DTLS1_CCS_HEADER_LENGTH; 822 s->init_off=0; 823 824 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 825 s->d1->handshake_write_seq, 0, 0); 826 827 /* buffer the message to handle re-xmits */ 828 dtls1_buffer_message(s, 1); 829 830 s->state=b; 831 } 832 833 /* SSL3_ST_CW_CHANGE_B */ 834 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 835 } 836 837 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 838 { 839 unsigned char *p; 840 int n,i; 841 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 842 BUF_MEM *buf; 843 X509_STORE_CTX xs_ctx; 844 X509_OBJECT obj; 845 846 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 847 buf=s->init_buf; 848 if (!BUF_MEM_grow_clean(buf,10)) 849 { 850 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 851 return(0); 852 } 853 if (x != NULL) 854 { 855 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL)) 856 { 857 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 858 return(0); 859 } 860 861 for (;;) 862 { 863 n=i2d_X509(x,NULL); 864 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3))) 865 { 866 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 867 return(0); 868 } 869 p=(unsigned char *)&(buf->data[l]); 870 l2n3(n,p); 871 i2d_X509(x,&p); 872 l+=n+3; 873 if (X509_NAME_cmp(X509_get_subject_name(x), 874 X509_get_issuer_name(x)) == 0) break; 875 876 i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509, 877 X509_get_issuer_name(x),&obj); 878 if (i <= 0) break; 879 x=obj.data.x509; 880 /* Count is one too high since the X509_STORE_get uped the 881 * ref count */ 882 X509_free(x); 883 } 884 885 X509_STORE_CTX_cleanup(&xs_ctx); 886 } 887 888 /* Thawte special :-) */ 889 if (s->ctx->extra_certs != NULL) 890 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 891 { 892 x=sk_X509_value(s->ctx->extra_certs,i); 893 n=i2d_X509(x,NULL); 894 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3))) 895 { 896 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 897 return(0); 898 } 899 p=(unsigned char *)&(buf->data[l]); 900 l2n3(n,p); 901 i2d_X509(x,&p); 902 l+=n+3; 903 } 904 905 l-= (3 + DTLS1_HM_HEADER_LENGTH); 906 907 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 908 l2n3(l,p); 909 l+=3; 910 p=(unsigned char *)&(buf->data[0]); 911 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 912 913 l+=DTLS1_HM_HEADER_LENGTH; 914 return(l); 915 } 916 917 int dtls1_read_failed(SSL *s, int code) 918 { 919 DTLS1_STATE *state; 920 BIO *bio; 921 int send_alert = 0; 922 923 if ( code > 0) 924 { 925 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 926 return 1; 927 } 928 929 bio = SSL_get_rbio(s); 930 if ( ! BIO_dgram_recv_timedout(bio)) 931 { 932 /* not a timeout, none of our business, 933 let higher layers handle this. in fact it's probably an error */ 934 return code; 935 } 936 937 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */ 938 { 939 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 940 return code; 941 } 942 943 state = s->d1; 944 state->timeout.num_alerts++; 945 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) 946 { 947 /* fail the connection, enough alerts have been sent */ 948 SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED); 949 return 0; 950 } 951 952 state->timeout.read_timeouts++; 953 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) 954 { 955 send_alert = 1; 956 state->timeout.read_timeouts = 1; 957 } 958 959 960 #if 0 /* for now, each alert contains only one record number */ 961 item = pqueue_peek(state->rcvd_records); 962 if ( item ) 963 { 964 /* send an alert immediately for all the missing records */ 965 } 966 else 967 #endif 968 969 #if 0 /* no more alert sending, just retransmit the last set of messages */ 970 if ( send_alert) 971 ssl3_send_alert(s,SSL3_AL_WARNING, 972 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 973 #endif 974 975 return dtls1_retransmit_buffered_messages(s) ; 976 } 977 978 979 static int 980 dtls1_retransmit_buffered_messages(SSL *s) 981 { 982 pqueue sent = s->d1->sent_messages; 983 piterator iter; 984 pitem *item; 985 hm_fragment *frag; 986 int found = 0; 987 988 iter = pqueue_iterator(sent); 989 990 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 991 { 992 frag = (hm_fragment *)item->data; 993 if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 && 994 found) 995 { 996 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 997 return -1; 998 } 999 } 1000 1001 return 1; 1002 } 1003 1004 #if 0 1005 static dtls1_message_buffer * 1006 dtls1_message_buffer_new(unsigned int len) 1007 { 1008 dtls1_message_buffer *msg_buf; 1009 1010 msg_buf = (dtls1_message_buffer *) 1011 OPENSSL_malloc(sizeof(dtls1_message_buffer)); 1012 if ( msg_buf == NULL) 1013 return NULL; 1014 1015 memset(msg_buf, 0x00, sizeof(dtls1_message_buffer)); 1016 1017 msg_buf->data = (unsigned char *) OPENSSL_malloc(len); 1018 if ( msg_buf->data == NULL) 1019 { 1020 OPENSSL_free(msg_buf); 1021 return NULL; 1022 } 1023 1024 memset(msg_buf->data, 0x00, len); 1025 return msg_buf; 1026 } 1027 #endif 1028 1029 #if 0 1030 static void 1031 dtls1_message_buffer_free(dtls1_message_buffer *msg_buf) 1032 { 1033 if (msg_buf != NULL) 1034 { 1035 OPENSSL_free(msg_buf->data); 1036 OPENSSL_free(msg_buf); 1037 } 1038 } 1039 #endif 1040 1041 int 1042 dtls1_buffer_message(SSL *s, int is_ccs) 1043 { 1044 pitem *item; 1045 hm_fragment *frag; 1046 PQ_64BIT seq64; 1047 1048 /* this function is called immediately after a message has 1049 * been serialized */ 1050 OPENSSL_assert(s->init_off == 0); 1051 1052 frag = dtls1_hm_fragment_new(s->init_num); 1053 1054 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1055 1056 if ( is_ccs) 1057 { 1058 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1059 DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num); 1060 } 1061 else 1062 { 1063 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1064 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1065 } 1066 1067 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1068 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1069 frag->msg_header.type = s->d1->w_msg_hdr.type; 1070 frag->msg_header.frag_off = 0; 1071 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1072 frag->msg_header.is_ccs = is_ccs; 1073 1074 pq_64bit_init(&seq64); 1075 pq_64bit_assign_word(&seq64, frag->msg_header.seq); 1076 1077 item = pitem_new(seq64, frag); 1078 pq_64bit_free(&seq64); 1079 if ( item == NULL) 1080 { 1081 dtls1_hm_fragment_free(frag); 1082 return 0; 1083 } 1084 1085 #if 0 1086 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1087 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1088 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1089 #endif 1090 1091 pqueue_insert(s->d1->sent_messages, item); 1092 return 1; 1093 } 1094 1095 int 1096 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1097 int *found) 1098 { 1099 int ret; 1100 /* XDTLS: for now assuming that read/writes are blocking */ 1101 pitem *item; 1102 hm_fragment *frag ; 1103 unsigned long header_length; 1104 PQ_64BIT seq64; 1105 1106 /* 1107 OPENSSL_assert(s->init_num == 0); 1108 OPENSSL_assert(s->init_off == 0); 1109 */ 1110 1111 /* XDTLS: the requested message ought to be found, otherwise error */ 1112 pq_64bit_init(&seq64); 1113 pq_64bit_assign_word(&seq64, seq); 1114 1115 item = pqueue_find(s->d1->sent_messages, seq64); 1116 pq_64bit_free(&seq64); 1117 if ( item == NULL) 1118 { 1119 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1120 *found = 0; 1121 return 0; 1122 } 1123 1124 *found = 1; 1125 frag = (hm_fragment *)item->data; 1126 1127 if ( frag->msg_header.is_ccs) 1128 header_length = DTLS1_CCS_HEADER_LENGTH; 1129 else 1130 header_length = DTLS1_HM_HEADER_LENGTH; 1131 1132 memcpy(s->init_buf->data, frag->fragment, 1133 frag->msg_header.msg_len + header_length); 1134 s->init_num = frag->msg_header.msg_len + header_length; 1135 1136 dtls1_set_message_header_int(s, frag->msg_header.type, 1137 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1138 frag->msg_header.frag_len); 1139 1140 s->d1->retransmitting = 1; 1141 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1142 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1143 s->d1->retransmitting = 0; 1144 1145 BIO_flush(SSL_get_wbio(s)); 1146 return ret; 1147 } 1148 1149 /* call this function when the buffered messages are no longer needed */ 1150 void 1151 dtls1_clear_record_buffer(SSL *s) 1152 { 1153 pitem *item; 1154 1155 for(item = pqueue_pop(s->d1->sent_messages); 1156 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1157 { 1158 dtls1_hm_fragment_free((hm_fragment *)item->data); 1159 pitem_free(item); 1160 } 1161 } 1162 1163 1164 unsigned char * 1165 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1166 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1167 { 1168 if ( frag_off == 0) 1169 { 1170 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1171 s->d1->next_handshake_write_seq++; 1172 } 1173 1174 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1175 frag_off, frag_len); 1176 1177 return p += DTLS1_HM_HEADER_LENGTH; 1178 } 1179 1180 1181 /* don't actually do the writing, wait till the MTU has been retrieved */ 1182 static void 1183 dtls1_set_message_header_int(SSL *s, unsigned char mt, 1184 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1185 unsigned long frag_len) 1186 { 1187 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1188 1189 msg_hdr->type = mt; 1190 msg_hdr->msg_len = len; 1191 msg_hdr->seq = seq_num; 1192 msg_hdr->frag_off = frag_off; 1193 msg_hdr->frag_len = frag_len; 1194 } 1195 1196 static void 1197 dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1198 unsigned long frag_len) 1199 { 1200 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1201 1202 msg_hdr->frag_off = frag_off; 1203 msg_hdr->frag_len = frag_len; 1204 } 1205 1206 static unsigned char * 1207 dtls1_write_message_header(SSL *s, unsigned char *p) 1208 { 1209 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1210 1211 *p++ = msg_hdr->type; 1212 l2n3(msg_hdr->msg_len, p); 1213 1214 s2n(msg_hdr->seq, p); 1215 l2n3(msg_hdr->frag_off, p); 1216 l2n3(msg_hdr->frag_len, p); 1217 1218 return p; 1219 } 1220 1221 static unsigned int 1222 dtls1_min_mtu(void) 1223 { 1224 return 1225 g_probable_mtu[(sizeof(g_probable_mtu) / 1226 sizeof(g_probable_mtu[0])) - 1]; 1227 } 1228 1229 static unsigned int 1230 dtls1_guess_mtu(unsigned int curr_mtu) 1231 { 1232 size_t i; 1233 1234 if ( curr_mtu == 0 ) 1235 return g_probable_mtu[0] ; 1236 1237 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1238 if ( curr_mtu > g_probable_mtu[i]) 1239 return g_probable_mtu[i]; 1240 1241 return curr_mtu; 1242 } 1243 1244 void 1245 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1246 { 1247 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1248 msg_hdr->type = *(data++); 1249 n2l3(data, msg_hdr->msg_len); 1250 1251 n2s(data, msg_hdr->seq); 1252 n2l3(data, msg_hdr->frag_off); 1253 n2l3(data, msg_hdr->frag_len); 1254 } 1255 1256 void 1257 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1258 { 1259 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1260 1261 ccs_hdr->type = *(data++); 1262 n2s(data, ccs_hdr->seq); 1263 } 1264