1 /* ssl/d1_both.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 <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 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8) 127 128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \ 129 if ((end) - (start) <= 8) { \ 130 long ii; \ 131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \ 132 } else { \ 133 long ii; \ 134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \ 135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \ 136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \ 137 } } 138 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \ 140 long ii; \ 141 OPENSSL_assert((msg_len) > 0); \ 142 is_complete = 1; \ 143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \ 144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \ 145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } } 146 147 #if 0 148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \ 149 long ii; \ 150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \ 151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \ 152 printf("\n"); } 153 #endif 154 155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80}; 156 static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f}; 157 158 /* XDTLS: figure out the right values */ 159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28}; 160 161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu); 162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 163 unsigned long frag_len); 164 static unsigned char *dtls1_write_message_header(SSL *s, 165 unsigned char *p); 166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt, 167 unsigned long len, unsigned short seq_num, unsigned long frag_off, 168 unsigned long frag_len); 169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 170 long max, int *ok); 171 172 static hm_fragment * 173 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly) 174 { 175 hm_fragment *frag = NULL; 176 unsigned char *buf = NULL; 177 unsigned char *bitmask = NULL; 178 179 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); 180 if ( frag == NULL) 181 return NULL; 182 183 if (frag_len) 184 { 185 buf = (unsigned char *)OPENSSL_malloc(frag_len); 186 if ( buf == NULL) 187 { 188 OPENSSL_free(frag); 189 return NULL; 190 } 191 } 192 193 /* zero length fragment gets zero frag->fragment */ 194 frag->fragment = buf; 195 196 /* Initialize reassembly bitmask if necessary */ 197 if (reassembly) 198 { 199 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len)); 200 if (bitmask == NULL) 201 { 202 if (buf != NULL) OPENSSL_free(buf); 203 OPENSSL_free(frag); 204 return NULL; 205 } 206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len)); 207 } 208 209 frag->reassembly = bitmask; 210 211 return frag; 212 } 213 214 static void 215 dtls1_hm_fragment_free(hm_fragment *frag) 216 { 217 218 if (frag->msg_header.is_ccs) 219 { 220 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx); 221 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash); 222 } 223 if (frag->fragment) OPENSSL_free(frag->fragment); 224 if (frag->reassembly) OPENSSL_free(frag->reassembly); 225 OPENSSL_free(frag); 226 } 227 228 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ 229 int dtls1_do_write(SSL *s, int type) 230 { 231 int ret; 232 int curr_mtu; 233 unsigned int len, frag_off, mac_size, blocksize; 234 235 /* AHA! Figure out the MTU, and stick to the right size */ 236 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) 237 { 238 s->d1->mtu = 239 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 240 241 /* I've seen the kernel return bogus numbers when it doesn't know 242 * (initial write), so just make sure we have a reasonable number */ 243 if (s->d1->mtu < dtls1_min_mtu()) 244 { 245 s->d1->mtu = 0; 246 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu); 247 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 248 s->d1->mtu, NULL); 249 } 250 } 251 #if 0 252 mtu = s->d1->mtu; 253 254 fprintf(stderr, "using MTU = %d\n", mtu); 255 256 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 257 258 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s)); 259 260 if ( curr_mtu > 0) 261 mtu = curr_mtu; 262 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0) 263 return ret; 264 265 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu) 266 { 267 ret = BIO_flush(SSL_get_wbio(s)); 268 if ( ret <= 0) 269 return ret; 270 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH); 271 } 272 #endif 273 274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */ 275 276 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE) 277 OPENSSL_assert(s->init_num == 278 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); 279 280 if (s->write_hash) 281 mac_size = EVP_MD_CTX_size(s->write_hash); 282 else 283 mac_size = 0; 284 285 if (s->enc_write_ctx && 286 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) 287 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher); 288 else 289 blocksize = 0; 290 291 frag_off = 0; 292 while( s->init_num) 293 { 294 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 295 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; 296 297 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH) 298 { 299 /* grr.. we could get an error if MTU picked was wrong */ 300 ret = BIO_flush(SSL_get_wbio(s)); 301 if ( ret <= 0) 302 return ret; 303 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - 304 mac_size - blocksize; 305 } 306 307 if ( s->init_num > curr_mtu) 308 len = curr_mtu; 309 else 310 len = s->init_num; 311 312 313 /* XDTLS: this function is too long. split out the CCS part */ 314 if ( type == SSL3_RT_HANDSHAKE) 315 { 316 if ( s->init_off != 0) 317 { 318 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH); 319 s->init_off -= DTLS1_HM_HEADER_LENGTH; 320 s->init_num += DTLS1_HM_HEADER_LENGTH; 321 322 if ( s->init_num > curr_mtu) 323 len = curr_mtu; 324 else 325 len = s->init_num; 326 } 327 328 dtls1_fix_message_header(s, frag_off, 329 len - DTLS1_HM_HEADER_LENGTH); 330 331 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]); 332 333 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); 334 } 335 336 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off], 337 len); 338 if (ret < 0) 339 { 340 /* might need to update MTU here, but we don't know 341 * which previous packet caused the failure -- so can't 342 * really retransmit anything. continue as if everything 343 * is fine and wait for an alert to handle the 344 * retransmit 345 */ 346 if ( BIO_ctrl(SSL_get_wbio(s), 347 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 ) 348 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), 349 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL); 350 else 351 return(-1); 352 } 353 else 354 { 355 356 /* bad if this assert fails, only part of the handshake 357 * message got sent. but why would this happen? */ 358 OPENSSL_assert(len == (unsigned int)ret); 359 360 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting) 361 { 362 /* should not be done for 'Hello Request's, but in that case 363 * we'll ignore the result anyway */ 364 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off]; 365 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 366 int xlen; 367 368 if (frag_off == 0 && s->version != DTLS1_BAD_VER) 369 { 370 /* reconstruct message header is if it 371 * is being sent in single fragment */ 372 *p++ = msg_hdr->type; 373 l2n3(msg_hdr->msg_len,p); 374 s2n (msg_hdr->seq,p); 375 l2n3(0,p); 376 l2n3(msg_hdr->msg_len,p); 377 p -= DTLS1_HM_HEADER_LENGTH; 378 xlen = ret; 379 } 380 else 381 { 382 p += DTLS1_HM_HEADER_LENGTH; 383 xlen = ret - DTLS1_HM_HEADER_LENGTH; 384 } 385 386 ssl3_finish_mac(s, p, xlen); 387 } 388 389 if (ret == s->init_num) 390 { 391 if (s->msg_callback) 392 s->msg_callback(1, s->version, type, s->init_buf->data, 393 (size_t)(s->init_off + s->init_num), s, 394 s->msg_callback_arg); 395 396 s->init_off = 0; /* done writing this message */ 397 s->init_num = 0; 398 399 return(1); 400 } 401 s->init_off+=ret; 402 s->init_num-=ret; 403 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH); 404 } 405 } 406 return(0); 407 } 408 409 410 /* Obtain handshake message of message type 'mt' (any if mt == -1), 411 * maximum acceptable body length 'max'. 412 * Read an entire handshake message. Handshake messages arrive in 413 * fragments. 414 */ 415 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok) 416 { 417 int i, al; 418 struct hm_header_st *msg_hdr; 419 unsigned char *p; 420 unsigned long msg_len; 421 422 /* s3->tmp is used to store messages that are unexpected, caused 423 * by the absence of an optional handshake message */ 424 if (s->s3->tmp.reuse_message) 425 { 426 s->s3->tmp.reuse_message=0; 427 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) 428 { 429 al=SSL_AD_UNEXPECTED_MESSAGE; 430 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE); 431 goto f_err; 432 } 433 *ok=1; 434 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 435 s->init_num = (int)s->s3->tmp.message_size; 436 return s->init_num; 437 } 438 439 msg_hdr = &s->d1->r_msg_hdr; 440 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 441 442 again: 443 i = dtls1_get_message_fragment(s, st1, stn, max, ok); 444 if ( i == DTLS1_HM_BAD_FRAGMENT || 445 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */ 446 goto again; 447 else if ( i <= 0 && !*ok) 448 return i; 449 450 p = (unsigned char *)s->init_buf->data; 451 msg_len = msg_hdr->msg_len; 452 453 /* reconstruct message header */ 454 *(p++) = msg_hdr->type; 455 l2n3(msg_len,p); 456 s2n (msg_hdr->seq,p); 457 l2n3(0,p); 458 l2n3(msg_len,p); 459 if (s->version != DTLS1_BAD_VER) { 460 p -= DTLS1_HM_HEADER_LENGTH; 461 msg_len += DTLS1_HM_HEADER_LENGTH; 462 } 463 464 ssl3_finish_mac(s, p, msg_len); 465 if (s->msg_callback) 466 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 467 p, msg_len, 468 s, s->msg_callback_arg); 469 470 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 471 472 /* Don't change sequence numbers while listening */ 473 if (!s->d1->listen) 474 s->d1->handshake_read_seq++; 475 476 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH; 477 return s->init_num; 478 479 f_err: 480 ssl3_send_alert(s,SSL3_AL_FATAL,al); 481 *ok = 0; 482 return -1; 483 } 484 485 486 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max) 487 { 488 size_t frag_off,frag_len,msg_len; 489 490 msg_len = msg_hdr->msg_len; 491 frag_off = msg_hdr->frag_off; 492 frag_len = msg_hdr->frag_len; 493 494 /* sanity checking */ 495 if ( (frag_off+frag_len) > msg_len) 496 { 497 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 498 return SSL_AD_ILLEGAL_PARAMETER; 499 } 500 501 if ( (frag_off+frag_len) > (unsigned long)max) 502 { 503 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 504 return SSL_AD_ILLEGAL_PARAMETER; 505 } 506 507 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */ 508 { 509 /* msg_len is limited to 2^24, but is effectively checked 510 * against max above */ 511 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH)) 512 { 513 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB); 514 return SSL_AD_INTERNAL_ERROR; 515 } 516 517 s->s3->tmp.message_size = msg_len; 518 s->d1->r_msg_hdr.msg_len = msg_len; 519 s->s3->tmp.message_type = msg_hdr->type; 520 s->d1->r_msg_hdr.type = msg_hdr->type; 521 s->d1->r_msg_hdr.seq = msg_hdr->seq; 522 } 523 else if (msg_len != s->d1->r_msg_hdr.msg_len) 524 { 525 /* They must be playing with us! BTW, failure to enforce 526 * upper limit would open possibility for buffer overrun. */ 527 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE); 528 return SSL_AD_ILLEGAL_PARAMETER; 529 } 530 531 return 0; /* no error */ 532 } 533 534 535 static int 536 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) 537 { 538 /* (0) check whether the desired fragment is available 539 * if so: 540 * (1) copy over the fragment to s->init_buf->data[] 541 * (2) update s->init_num 542 */ 543 pitem *item; 544 hm_fragment *frag; 545 int al; 546 547 *ok = 0; 548 item = pqueue_peek(s->d1->buffered_messages); 549 if ( item == NULL) 550 return 0; 551 552 frag = (hm_fragment *)item->data; 553 554 /* Don't return if reassembly still in progress */ 555 if (frag->reassembly != NULL) 556 return 0; 557 558 if ( s->d1->handshake_read_seq == frag->msg_header.seq) 559 { 560 unsigned long frag_len = frag->msg_header.frag_len; 561 pqueue_pop(s->d1->buffered_messages); 562 563 al=dtls1_preprocess_fragment(s,&frag->msg_header,max); 564 565 if (al==0) /* no alert */ 566 { 567 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 568 memcpy(&p[frag->msg_header.frag_off], 569 frag->fragment,frag->msg_header.frag_len); 570 } 571 572 dtls1_hm_fragment_free(frag); 573 pitem_free(item); 574 575 if (al==0) 576 { 577 *ok = 1; 578 return frag_len; 579 } 580 581 ssl3_send_alert(s,SSL3_AL_FATAL,al); 582 s->init_num = 0; 583 *ok = 0; 584 return -1; 585 } 586 else 587 return 0; 588 } 589 590 /* dtls1_max_handshake_message_len returns the maximum number of bytes 591 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may 592 * be greater if the maximum certificate list size requires it. */ 593 static unsigned long dtls1_max_handshake_message_len(const SSL *s) 594 { 595 unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; 596 if (max_len < (unsigned long)s->max_cert_list) 597 return s->max_cert_list; 598 return max_len; 599 } 600 601 static int 602 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 603 { 604 hm_fragment *frag = NULL; 605 pitem *item = NULL; 606 int i = -1, is_complete; 607 unsigned char seq64be[8]; 608 unsigned long frag_len = msg_hdr->frag_len; 609 610 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len || 611 msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) 612 goto err; 613 614 if (frag_len == 0) 615 return DTLS1_HM_FRAGMENT_RETRY; 616 617 /* Try to find item in queue */ 618 memset(seq64be,0,sizeof(seq64be)); 619 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 620 seq64be[7] = (unsigned char) msg_hdr->seq; 621 item = pqueue_find(s->d1->buffered_messages, seq64be); 622 623 if (item == NULL) 624 { 625 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1); 626 if ( frag == NULL) 627 goto err; 628 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 629 frag->msg_header.frag_len = frag->msg_header.msg_len; 630 frag->msg_header.frag_off = 0; 631 } 632 else 633 { 634 frag = (hm_fragment*) item->data; 635 if (frag->msg_header.msg_len != msg_hdr->msg_len) 636 { 637 item = NULL; 638 frag = NULL; 639 goto err; 640 } 641 } 642 643 644 /* If message is already reassembled, this must be a 645 * retransmit and can be dropped. In this case item != NULL and so frag 646 * does not need to be freed. 647 */ 648 if (frag->reassembly == NULL) 649 { 650 unsigned char devnull [256]; 651 652 while (frag_len) 653 { 654 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 655 devnull, 656 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 657 if (i<=0) goto err; 658 frag_len -= i; 659 } 660 return DTLS1_HM_FRAGMENT_RETRY; 661 } 662 663 /* read the body of the fragment (header has already been read */ 664 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 665 frag->fragment + msg_hdr->frag_off,frag_len,0); 666 if ((unsigned long)i!=frag_len) 667 i=-1; 668 if (i<=0) 669 goto err; 670 671 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off, 672 (long)(msg_hdr->frag_off + frag_len)); 673 674 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len, 675 is_complete); 676 677 if (is_complete) 678 { 679 OPENSSL_free(frag->reassembly); 680 frag->reassembly = NULL; 681 } 682 683 if (item == NULL) 684 { 685 item = pitem_new(seq64be, frag); 686 if (item == NULL) 687 { 688 i = -1; 689 goto err; 690 } 691 692 item = pqueue_insert(s->d1->buffered_messages, item); 693 /* pqueue_insert fails iff a duplicate item is inserted. 694 * However, |item| cannot be a duplicate. If it were, 695 * |pqueue_find|, above, would have returned it and control 696 * would never have reached this branch. */ 697 OPENSSL_assert(item != NULL); 698 } 699 700 return DTLS1_HM_FRAGMENT_RETRY; 701 702 err: 703 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 704 *ok = 0; 705 return i; 706 } 707 708 709 static int 710 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok) 711 { 712 int i=-1; 713 hm_fragment *frag = NULL; 714 pitem *item = NULL; 715 unsigned char seq64be[8]; 716 unsigned long frag_len = msg_hdr->frag_len; 717 718 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) 719 goto err; 720 721 /* Try to find item in queue, to prevent duplicate entries */ 722 memset(seq64be,0,sizeof(seq64be)); 723 seq64be[6] = (unsigned char) (msg_hdr->seq>>8); 724 seq64be[7] = (unsigned char) msg_hdr->seq; 725 item = pqueue_find(s->d1->buffered_messages, seq64be); 726 727 /* If we already have an entry and this one is a fragment, 728 * don't discard it and rather try to reassemble it. 729 */ 730 if (item != NULL && frag_len != msg_hdr->msg_len) 731 item = NULL; 732 733 /* Discard the message if sequence number was already there, is 734 * too far in the future, already in the queue or if we received 735 * a FINISHED before the SERVER_HELLO, which then must be a stale 736 * retransmit. 737 */ 738 if (msg_hdr->seq <= s->d1->handshake_read_seq || 739 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || 740 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) 741 { 742 unsigned char devnull [256]; 743 744 while (frag_len) 745 { 746 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 747 devnull, 748 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0); 749 if (i<=0) goto err; 750 frag_len -= i; 751 } 752 } 753 else 754 { 755 if (frag_len != msg_hdr->msg_len) 756 return dtls1_reassemble_fragment(s, msg_hdr, ok); 757 758 if (frag_len > dtls1_max_handshake_message_len(s)) 759 goto err; 760 761 frag = dtls1_hm_fragment_new(frag_len, 0); 762 if ( frag == NULL) 763 goto err; 764 765 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr)); 766 767 if (frag_len) 768 { 769 /* read the body of the fragment (header has already been read */ 770 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 771 frag->fragment,frag_len,0); 772 if ((unsigned long)i!=frag_len) 773 i = -1; 774 if (i<=0) 775 goto err; 776 } 777 778 item = pitem_new(seq64be, frag); 779 if ( item == NULL) 780 goto err; 781 782 item = pqueue_insert(s->d1->buffered_messages, item); 783 /* pqueue_insert fails iff a duplicate item is inserted. 784 * However, |item| cannot be a duplicate. If it were, 785 * |pqueue_find|, above, would have returned it. Then, either 786 * |frag_len| != |msg_hdr->msg_len| in which case |item| is set 787 * to NULL and it will have been processed with 788 * |dtls1_reassemble_fragment|, above, or the record will have 789 * been discarded. */ 790 OPENSSL_assert(item != NULL); 791 } 792 793 return DTLS1_HM_FRAGMENT_RETRY; 794 795 err: 796 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag); 797 *ok = 0; 798 return i; 799 } 800 801 802 static long 803 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok) 804 { 805 unsigned char wire[DTLS1_HM_HEADER_LENGTH]; 806 unsigned long len, frag_off, frag_len; 807 int i,al; 808 struct hm_header_st msg_hdr; 809 810 redo: 811 /* see if we have the required fragment already */ 812 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok) 813 { 814 if (*ok) s->init_num = frag_len; 815 return frag_len; 816 } 817 818 /* read handshake message header */ 819 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire, 820 DTLS1_HM_HEADER_LENGTH, 0); 821 if (i <= 0) /* nbio, or an error */ 822 { 823 s->rwstate=SSL_READING; 824 *ok = 0; 825 return i; 826 } 827 /* Handshake fails if message header is incomplete */ 828 if (i != DTLS1_HM_HEADER_LENGTH) 829 { 830 al=SSL_AD_UNEXPECTED_MESSAGE; 831 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 832 goto f_err; 833 } 834 835 /* parse the message fragment header */ 836 dtls1_get_message_header(wire, &msg_hdr); 837 838 /* 839 * if this is a future (or stale) message it gets buffered 840 * (or dropped)--no further processing at this time 841 * While listening, we accept seq 1 (ClientHello with cookie) 842 * although we're still expecting seq 0 (ClientHello) 843 */ 844 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1)) 845 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok); 846 847 len = msg_hdr.msg_len; 848 frag_off = msg_hdr.frag_off; 849 frag_len = msg_hdr.frag_len; 850 851 if (frag_len && frag_len < len) 852 return dtls1_reassemble_fragment(s, &msg_hdr, ok); 853 854 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && 855 wire[0] == SSL3_MT_HELLO_REQUEST) 856 { 857 /* The server may always send 'Hello Request' messages -- 858 * we are doing a handshake anyway now, so ignore them 859 * if their format is correct. Does not count for 860 * 'Finished' MAC. */ 861 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) 862 { 863 if (s->msg_callback) 864 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 865 wire, DTLS1_HM_HEADER_LENGTH, s, 866 s->msg_callback_arg); 867 868 s->init_num = 0; 869 goto redo; 870 } 871 else /* Incorrectly formated Hello request */ 872 { 873 al=SSL_AD_UNEXPECTED_MESSAGE; 874 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE); 875 goto f_err; 876 } 877 } 878 879 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max))) 880 goto f_err; 881 882 /* XDTLS: ressurect this when restart is in place */ 883 s->state=stn; 884 885 if ( frag_len > 0) 886 { 887 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH; 888 889 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE, 890 &p[frag_off],frag_len,0); 891 /* XDTLS: fix this--message fragments cannot span multiple packets */ 892 if (i <= 0) 893 { 894 s->rwstate=SSL_READING; 895 *ok = 0; 896 return i; 897 } 898 } 899 else 900 i = 0; 901 902 /* XDTLS: an incorrectly formatted fragment should cause the 903 * handshake to fail */ 904 if (i != (int)frag_len) 905 { 906 al=SSL3_AD_ILLEGAL_PARAMETER; 907 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER); 908 goto f_err; 909 } 910 911 *ok = 1; 912 913 /* Note that s->init_num is *not* used as current offset in 914 * s->init_buf->data, but as a counter summing up fragments' 915 * lengths: as soon as they sum up to handshake packet 916 * length, we assume we have got all the fragments. */ 917 s->init_num = frag_len; 918 return frag_len; 919 920 f_err: 921 ssl3_send_alert(s,SSL3_AL_FATAL,al); 922 s->init_num = 0; 923 924 *ok=0; 925 return(-1); 926 } 927 928 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen) 929 { 930 unsigned char *p,*d; 931 int i; 932 unsigned long l; 933 934 if (s->state == a) 935 { 936 d=(unsigned char *)s->init_buf->data; 937 p= &(d[DTLS1_HM_HEADER_LENGTH]); 938 939 i=s->method->ssl3_enc->final_finish_mac(s, 940 sender,slen,s->s3->tmp.finish_md); 941 s->s3->tmp.finish_md_len = i; 942 memcpy(p, s->s3->tmp.finish_md, i); 943 p+=i; 944 l=i; 945 946 /* Copy the finished so we can use it for 947 * renegotiation checks 948 */ 949 if(s->type == SSL_ST_CONNECT) 950 { 951 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 952 memcpy(s->s3->previous_client_finished, 953 s->s3->tmp.finish_md, i); 954 s->s3->previous_client_finished_len=i; 955 } 956 else 957 { 958 OPENSSL_assert(i <= EVP_MAX_MD_SIZE); 959 memcpy(s->s3->previous_server_finished, 960 s->s3->tmp.finish_md, i); 961 s->s3->previous_server_finished_len=i; 962 } 963 964 #ifdef OPENSSL_SYS_WIN16 965 /* MSVC 1.5 does not clear the top bytes of the word unless 966 * I do this. 967 */ 968 l&=0xffff; 969 #endif 970 971 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l); 972 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH; 973 s->init_off=0; 974 975 /* buffer the message to handle re-xmits */ 976 dtls1_buffer_message(s, 0); 977 978 s->state=b; 979 } 980 981 /* SSL3_ST_SEND_xxxxxx_HELLO_B */ 982 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); 983 } 984 985 /* for these 2 messages, we need to 986 * ssl->enc_read_ctx re-init 987 * ssl->s3->read_sequence zero 988 * ssl->s3->read_mac_secret re-init 989 * ssl->session->read_sym_enc assign 990 * ssl->session->read_compression assign 991 * ssl->session->read_hash assign 992 */ 993 int dtls1_send_change_cipher_spec(SSL *s, int a, int b) 994 { 995 unsigned char *p; 996 997 if (s->state == a) 998 { 999 p=(unsigned char *)s->init_buf->data; 1000 *p++=SSL3_MT_CCS; 1001 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1002 s->init_num=DTLS1_CCS_HEADER_LENGTH; 1003 1004 if (s->version == DTLS1_BAD_VER) { 1005 s->d1->next_handshake_write_seq++; 1006 s2n(s->d1->handshake_write_seq,p); 1007 s->init_num+=2; 1008 } 1009 1010 s->init_off=0; 1011 1012 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 1013 s->d1->handshake_write_seq, 0, 0); 1014 1015 /* buffer the message to handle re-xmits */ 1016 dtls1_buffer_message(s, 1); 1017 1018 s->state=b; 1019 } 1020 1021 /* SSL3_ST_CW_CHANGE_B */ 1022 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC)); 1023 } 1024 1025 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x) 1026 { 1027 int n; 1028 unsigned char *p; 1029 1030 n=i2d_X509(x,NULL); 1031 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3))) 1032 { 1033 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB); 1034 return 0; 1035 } 1036 p=(unsigned char *)&(buf->data[*l]); 1037 l2n3(n,p); 1038 i2d_X509(x,&p); 1039 *l+=n+3; 1040 1041 return 1; 1042 } 1043 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x) 1044 { 1045 unsigned char *p; 1046 int i; 1047 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH; 1048 BUF_MEM *buf; 1049 1050 /* TLSv1 sends a chain with nothing in it, instead of an alert */ 1051 buf=s->init_buf; 1052 if (!BUF_MEM_grow_clean(buf,10)) 1053 { 1054 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB); 1055 return(0); 1056 } 1057 if (x != NULL) 1058 { 1059 X509_STORE_CTX xs_ctx; 1060 1061 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL)) 1062 { 1063 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB); 1064 return(0); 1065 } 1066 1067 X509_verify_cert(&xs_ctx); 1068 /* Don't leave errors in the queue */ 1069 ERR_clear_error(); 1070 for (i=0; i < sk_X509_num(xs_ctx.chain); i++) 1071 { 1072 x = sk_X509_value(xs_ctx.chain, i); 1073 1074 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1075 { 1076 X509_STORE_CTX_cleanup(&xs_ctx); 1077 return 0; 1078 } 1079 } 1080 X509_STORE_CTX_cleanup(&xs_ctx); 1081 } 1082 /* Thawte special :-) */ 1083 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++) 1084 { 1085 x=sk_X509_value(s->ctx->extra_certs,i); 1086 if (!dtls1_add_cert_to_buf(buf, &l, x)) 1087 return 0; 1088 } 1089 1090 l-= (3 + DTLS1_HM_HEADER_LENGTH); 1091 1092 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]); 1093 l2n3(l,p); 1094 l+=3; 1095 p=(unsigned char *)&(buf->data[0]); 1096 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l); 1097 1098 l+=DTLS1_HM_HEADER_LENGTH; 1099 return(l); 1100 } 1101 1102 int dtls1_read_failed(SSL *s, int code) 1103 { 1104 if ( code > 0) 1105 { 1106 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__); 1107 return 1; 1108 } 1109 1110 if (!dtls1_is_timer_expired(s)) 1111 { 1112 /* not a timeout, none of our business, 1113 let higher layers handle this. in fact it's probably an error */ 1114 return code; 1115 } 1116 1117 #ifndef OPENSSL_NO_HEARTBEATS 1118 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */ 1119 #else 1120 if (!SSL_in_init(s)) /* done, no need to send a retransmit */ 1121 #endif 1122 { 1123 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ); 1124 return code; 1125 } 1126 1127 #if 0 /* for now, each alert contains only one record number */ 1128 item = pqueue_peek(state->rcvd_records); 1129 if ( item ) 1130 { 1131 /* send an alert immediately for all the missing records */ 1132 } 1133 else 1134 #endif 1135 1136 #if 0 /* no more alert sending, just retransmit the last set of messages */ 1137 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT) 1138 ssl3_send_alert(s,SSL3_AL_WARNING, 1139 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE); 1140 #endif 1141 1142 return dtls1_handle_timeout(s); 1143 } 1144 1145 int 1146 dtls1_get_queue_priority(unsigned short seq, int is_ccs) 1147 { 1148 /* The index of the retransmission queue actually is the message sequence number, 1149 * since the queue only contains messages of a single handshake. However, the 1150 * ChangeCipherSpec has no message sequence number and so using only the sequence 1151 * will result in the CCS and Finished having the same index. To prevent this, 1152 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted. 1153 * This does not only differ CSS and Finished, it also maintains the order of the 1154 * index (important for priority queues) and fits in the unsigned short variable. 1155 */ 1156 return seq * 2 - is_ccs; 1157 } 1158 1159 int 1160 dtls1_retransmit_buffered_messages(SSL *s) 1161 { 1162 pqueue sent = s->d1->sent_messages; 1163 piterator iter; 1164 pitem *item; 1165 hm_fragment *frag; 1166 int found = 0; 1167 1168 iter = pqueue_iterator(sent); 1169 1170 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) 1171 { 1172 frag = (hm_fragment *)item->data; 1173 if ( dtls1_retransmit_message(s, 1174 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), 1175 0, &found) <= 0 && found) 1176 { 1177 fprintf(stderr, "dtls1_retransmit_message() failed\n"); 1178 return -1; 1179 } 1180 } 1181 1182 return 1; 1183 } 1184 1185 int 1186 dtls1_buffer_message(SSL *s, int is_ccs) 1187 { 1188 pitem *item; 1189 hm_fragment *frag; 1190 unsigned char seq64be[8]; 1191 1192 /* this function is called immediately after a message has 1193 * been serialized */ 1194 OPENSSL_assert(s->init_off == 0); 1195 1196 frag = dtls1_hm_fragment_new(s->init_num, 0); 1197 if (!frag) 1198 return 0; 1199 1200 memcpy(frag->fragment, s->init_buf->data, s->init_num); 1201 1202 if ( is_ccs) 1203 { 1204 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1205 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num); 1206 } 1207 else 1208 { 1209 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 1210 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num); 1211 } 1212 1213 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len; 1214 frag->msg_header.seq = s->d1->w_msg_hdr.seq; 1215 frag->msg_header.type = s->d1->w_msg_hdr.type; 1216 frag->msg_header.frag_off = 0; 1217 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len; 1218 frag->msg_header.is_ccs = is_ccs; 1219 1220 /* save current state*/ 1221 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx; 1222 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash; 1223 frag->msg_header.saved_retransmit_state.compress = s->compress; 1224 frag->msg_header.saved_retransmit_state.session = s->session; 1225 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch; 1226 1227 memset(seq64be,0,sizeof(seq64be)); 1228 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1229 frag->msg_header.is_ccs)>>8); 1230 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq, 1231 frag->msg_header.is_ccs)); 1232 1233 item = pitem_new(seq64be, frag); 1234 if ( item == NULL) 1235 { 1236 dtls1_hm_fragment_free(frag); 1237 return 0; 1238 } 1239 1240 #if 0 1241 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type); 1242 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len); 1243 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num); 1244 #endif 1245 1246 pqueue_insert(s->d1->sent_messages, item); 1247 return 1; 1248 } 1249 1250 int 1251 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off, 1252 int *found) 1253 { 1254 int ret; 1255 /* XDTLS: for now assuming that read/writes are blocking */ 1256 pitem *item; 1257 hm_fragment *frag ; 1258 unsigned long header_length; 1259 unsigned char seq64be[8]; 1260 struct dtls1_retransmit_state saved_state; 1261 unsigned char save_write_sequence[8]; 1262 1263 /* 1264 OPENSSL_assert(s->init_num == 0); 1265 OPENSSL_assert(s->init_off == 0); 1266 */ 1267 1268 /* XDTLS: the requested message ought to be found, otherwise error */ 1269 memset(seq64be,0,sizeof(seq64be)); 1270 seq64be[6] = (unsigned char)(seq>>8); 1271 seq64be[7] = (unsigned char)seq; 1272 1273 item = pqueue_find(s->d1->sent_messages, seq64be); 1274 if ( item == NULL) 1275 { 1276 fprintf(stderr, "retransmit: message %d non-existant\n", seq); 1277 *found = 0; 1278 return 0; 1279 } 1280 1281 *found = 1; 1282 frag = (hm_fragment *)item->data; 1283 1284 if ( frag->msg_header.is_ccs) 1285 header_length = DTLS1_CCS_HEADER_LENGTH; 1286 else 1287 header_length = DTLS1_HM_HEADER_LENGTH; 1288 1289 memcpy(s->init_buf->data, frag->fragment, 1290 frag->msg_header.msg_len + header_length); 1291 s->init_num = frag->msg_header.msg_len + header_length; 1292 1293 dtls1_set_message_header_int(s, frag->msg_header.type, 1294 frag->msg_header.msg_len, frag->msg_header.seq, 0, 1295 frag->msg_header.frag_len); 1296 1297 /* save current state */ 1298 saved_state.enc_write_ctx = s->enc_write_ctx; 1299 saved_state.write_hash = s->write_hash; 1300 saved_state.compress = s->compress; 1301 saved_state.session = s->session; 1302 saved_state.epoch = s->d1->w_epoch; 1303 saved_state.epoch = s->d1->w_epoch; 1304 1305 s->d1->retransmitting = 1; 1306 1307 /* restore state in which the message was originally sent */ 1308 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; 1309 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash; 1310 s->compress = frag->msg_header.saved_retransmit_state.compress; 1311 s->session = frag->msg_header.saved_retransmit_state.session; 1312 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch; 1313 1314 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1315 { 1316 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1317 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence)); 1318 } 1319 1320 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 1321 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); 1322 1323 /* restore current state */ 1324 s->enc_write_ctx = saved_state.enc_write_ctx; 1325 s->write_hash = saved_state.write_hash; 1326 s->compress = saved_state.compress; 1327 s->session = saved_state.session; 1328 s->d1->w_epoch = saved_state.epoch; 1329 1330 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) 1331 { 1332 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence)); 1333 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence)); 1334 } 1335 1336 s->d1->retransmitting = 0; 1337 1338 (void)BIO_flush(SSL_get_wbio(s)); 1339 return ret; 1340 } 1341 1342 /* call this function when the buffered messages are no longer needed */ 1343 void 1344 dtls1_clear_record_buffer(SSL *s) 1345 { 1346 pitem *item; 1347 1348 for(item = pqueue_pop(s->d1->sent_messages); 1349 item != NULL; item = pqueue_pop(s->d1->sent_messages)) 1350 { 1351 dtls1_hm_fragment_free((hm_fragment *)item->data); 1352 pitem_free(item); 1353 } 1354 } 1355 1356 1357 unsigned char * 1358 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt, 1359 unsigned long len, unsigned long frag_off, unsigned long frag_len) 1360 { 1361 /* Don't change sequence numbers while listening */ 1362 if (frag_off == 0 && !s->d1->listen) 1363 { 1364 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; 1365 s->d1->next_handshake_write_seq++; 1366 } 1367 1368 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq, 1369 frag_off, frag_len); 1370 1371 return p += DTLS1_HM_HEADER_LENGTH; 1372 } 1373 1374 1375 /* don't actually do the writing, wait till the MTU has been retrieved */ 1376 static void 1377 dtls1_set_message_header_int(SSL *s, unsigned char mt, 1378 unsigned long len, unsigned short seq_num, unsigned long frag_off, 1379 unsigned long frag_len) 1380 { 1381 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1382 1383 msg_hdr->type = mt; 1384 msg_hdr->msg_len = len; 1385 msg_hdr->seq = seq_num; 1386 msg_hdr->frag_off = frag_off; 1387 msg_hdr->frag_len = frag_len; 1388 } 1389 1390 static void 1391 dtls1_fix_message_header(SSL *s, unsigned long frag_off, 1392 unsigned long frag_len) 1393 { 1394 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1395 1396 msg_hdr->frag_off = frag_off; 1397 msg_hdr->frag_len = frag_len; 1398 } 1399 1400 static unsigned char * 1401 dtls1_write_message_header(SSL *s, unsigned char *p) 1402 { 1403 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; 1404 1405 *p++ = msg_hdr->type; 1406 l2n3(msg_hdr->msg_len, p); 1407 1408 s2n(msg_hdr->seq, p); 1409 l2n3(msg_hdr->frag_off, p); 1410 l2n3(msg_hdr->frag_len, p); 1411 1412 return p; 1413 } 1414 1415 unsigned int 1416 dtls1_min_mtu(void) 1417 { 1418 return (g_probable_mtu[(sizeof(g_probable_mtu) / 1419 sizeof(g_probable_mtu[0])) - 1]); 1420 } 1421 1422 static unsigned int 1423 dtls1_guess_mtu(unsigned int curr_mtu) 1424 { 1425 unsigned int i; 1426 1427 if ( curr_mtu == 0 ) 1428 return g_probable_mtu[0] ; 1429 1430 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++) 1431 if ( curr_mtu > g_probable_mtu[i]) 1432 return g_probable_mtu[i]; 1433 1434 return curr_mtu; 1435 } 1436 1437 void 1438 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) 1439 { 1440 memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); 1441 msg_hdr->type = *(data++); 1442 n2l3(data, msg_hdr->msg_len); 1443 1444 n2s(data, msg_hdr->seq); 1445 n2l3(data, msg_hdr->frag_off); 1446 n2l3(data, msg_hdr->frag_len); 1447 } 1448 1449 void 1450 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr) 1451 { 1452 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st)); 1453 1454 ccs_hdr->type = *(data++); 1455 } 1456 1457 int dtls1_shutdown(SSL *s) 1458 { 1459 int ret; 1460 #ifndef OPENSSL_NO_SCTP 1461 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) && 1462 !(s->shutdown & SSL_SENT_SHUTDOWN)) 1463 { 1464 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s)); 1465 if (ret < 0) return -1; 1466 1467 if (ret == 0) 1468 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL); 1469 } 1470 #endif 1471 ret = ssl3_shutdown(s); 1472 #ifndef OPENSSL_NO_SCTP 1473 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL); 1474 #endif 1475 return ret; 1476 } 1477 1478 #ifndef OPENSSL_NO_HEARTBEATS 1479 int 1480 dtls1_process_heartbeat(SSL *s) 1481 { 1482 unsigned char *p = &s->s3->rrec.data[0], *pl; 1483 unsigned short hbtype; 1484 unsigned int payload; 1485 unsigned int padding = 16; /* Use minimum padding */ 1486 1487 if (s->msg_callback) 1488 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, 1489 &s->s3->rrec.data[0], s->s3->rrec.length, 1490 s, s->msg_callback_arg); 1491 1492 /* Read type and payload length first */ 1493 if (1 + 2 + 16 > s->s3->rrec.length) 1494 return 0; /* silently discard */ 1495 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH) 1496 return 0; /* silently discard per RFC 6520 sec. 4 */ 1497 1498 hbtype = *p++; 1499 n2s(p, payload); 1500 if (1 + 2 + payload + 16 > s->s3->rrec.length) 1501 return 0; /* silently discard per RFC 6520 sec. 4 */ 1502 pl = p; 1503 1504 if (hbtype == TLS1_HB_REQUEST) 1505 { 1506 unsigned char *buffer, *bp; 1507 unsigned int write_length = 1 /* heartbeat type */ + 1508 2 /* heartbeat length */ + 1509 payload + padding; 1510 int r; 1511 1512 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) 1513 return 0; 1514 1515 /* Allocate memory for the response, size is 1 byte 1516 * message type, plus 2 bytes payload length, plus 1517 * payload, plus padding 1518 */ 1519 buffer = OPENSSL_malloc(write_length); 1520 bp = buffer; 1521 1522 /* Enter response type, length and copy payload */ 1523 *bp++ = TLS1_HB_RESPONSE; 1524 s2n(payload, bp); 1525 memcpy(bp, pl, payload); 1526 bp += payload; 1527 /* Random padding */ 1528 RAND_pseudo_bytes(bp, padding); 1529 1530 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); 1531 1532 if (r >= 0 && s->msg_callback) 1533 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1534 buffer, write_length, 1535 s, s->msg_callback_arg); 1536 1537 OPENSSL_free(buffer); 1538 1539 if (r < 0) 1540 return r; 1541 } 1542 else if (hbtype == TLS1_HB_RESPONSE) 1543 { 1544 unsigned int seq; 1545 1546 /* We only send sequence numbers (2 bytes unsigned int), 1547 * and 16 random bytes, so we just try to read the 1548 * sequence number */ 1549 n2s(pl, seq); 1550 1551 if (payload == 18 && seq == s->tlsext_hb_seq) 1552 { 1553 dtls1_stop_timer(s); 1554 s->tlsext_hb_seq++; 1555 s->tlsext_hb_pending = 0; 1556 } 1557 } 1558 1559 return 0; 1560 } 1561 1562 int 1563 dtls1_heartbeat(SSL *s) 1564 { 1565 unsigned char *buf, *p; 1566 int ret; 1567 unsigned int payload = 18; /* Sequence number + random bytes */ 1568 unsigned int padding = 16; /* Use minimum padding */ 1569 1570 /* Only send if peer supports and accepts HB requests... */ 1571 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) || 1572 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) 1573 { 1574 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT); 1575 return -1; 1576 } 1577 1578 /* ...and there is none in flight yet... */ 1579 if (s->tlsext_hb_pending) 1580 { 1581 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING); 1582 return -1; 1583 } 1584 1585 /* ...and no handshake in progress. */ 1586 if (SSL_in_init(s) || s->in_handshake) 1587 { 1588 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE); 1589 return -1; 1590 } 1591 1592 /* Check if padding is too long, payload and padding 1593 * must not exceed 2^14 - 3 = 16381 bytes in total. 1594 */ 1595 OPENSSL_assert(payload + padding <= 16381); 1596 1597 /* Create HeartBeat message, we just use a sequence number 1598 * as payload to distuingish different messages and add 1599 * some random stuff. 1600 * - Message Type, 1 byte 1601 * - Payload Length, 2 bytes (unsigned int) 1602 * - Payload, the sequence number (2 bytes uint) 1603 * - Payload, random bytes (16 bytes uint) 1604 * - Padding 1605 */ 1606 buf = OPENSSL_malloc(1 + 2 + payload + padding); 1607 p = buf; 1608 /* Message Type */ 1609 *p++ = TLS1_HB_REQUEST; 1610 /* Payload length (18 bytes here) */ 1611 s2n(payload, p); 1612 /* Sequence number */ 1613 s2n(s->tlsext_hb_seq, p); 1614 /* 16 random bytes */ 1615 RAND_pseudo_bytes(p, 16); 1616 p += 16; 1617 /* Random padding */ 1618 RAND_pseudo_bytes(p, padding); 1619 1620 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding); 1621 if (ret >= 0) 1622 { 1623 if (s->msg_callback) 1624 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, 1625 buf, 3 + payload + padding, 1626 s, s->msg_callback_arg); 1627 1628 dtls1_start_timer(s); 1629 s->tlsext_hb_pending = 1; 1630 } 1631 1632 OPENSSL_free(buf); 1633 1634 return ret; 1635 } 1636 #endif 1637
