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