src/third_party/boringssl/src/ssl/d1_both.c

   1 /*
   2  * DTLS implementation written by Nagendra Modadugu
   3  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    openssl-core@openssl.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  59  * All rights reserved.
  60  *
  61  * This package is an SSL implementation written
  62  * by Eric Young (eay@cryptsoft.com).
  63  * The implementation was written so as to conform with Netscapes SSL.
  64  *
  65  * This library is free for commercial and non-commercial use as long as
  66  * the following conditions are aheared to.  The following conditions
  67  * apply to all code found in this distribution, be it the RC4, RSA,
  68  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  69  * included with this distribution is covered by the same copyright terms
  70  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  71  *
  72  * Copyright remains Eric Young's, and as such any Copyright notices in
  73  * the code are not to be removed.
  74  * If this package is used in a product, Eric Young should be given attribution
  75  * as the author of the parts of the library used.
  76  * This can be in the form of a textual message at program startup or
  77  * in documentation (online or textual) provided with the package.
  78  *
  79  * Redistribution and use in source and binary forms, with or without
  80  * modification, are permitted provided that the following conditions
  81  * are met:
  82  * 1. Redistributions of source code must retain the copyright
  83  *    notice, this list of conditions and the following disclaimer.
  84  * 2. Redistributions in binary form must reproduce the above copyright
  85  *    notice, this list of conditions and the following disclaimer in the
  86  *    documentation and/or other materials provided with the distribution.
  87  * 3. All advertising materials mentioning features or use of this software
  88  *    must display the following acknowledgement:
  89  *    "This product includes cryptographic software written by
  90  *     Eric Young (eay@cryptsoft.com)"
  91  *    The word 'cryptographic' can be left out if the rouines from the library
  92  *    being used are not cryptographic related :-).
  93  * 4. If you include any Windows specific code (or a derivative thereof) from
  94  *    the apps directory (application code) you must include an acknowledgement:
  95  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  96  *
  97  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  98  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  99  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 100  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 101  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 102  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 103  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 104  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 105  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 106  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 107  * SUCH DAMAGE.
 108  *
 109  * The licence and distribution terms for any publically available version or
 110  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 111  * copied and put under another distribution licence
 112  * [including the GNU Public Licence.] */
 113
 114 #include <assert.h>
 115 #include <limits.h>
 116 #include <stdio.h>
 117 #include <string.h>
 118
 119 #include <openssl/buf.h>
 120 #include <openssl/err.h>
 121 #include <openssl/evp.h>
 122 #include <openssl/mem.h>
 123 #include <openssl/obj.h>
 124 #include <openssl/rand.h>
 125 #include <openssl/x509.h>
 126
 127 #include "ssl_locl.h"
 128
 129 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 130
 131 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
 132                         if ((end) - (start) <= 8) { \
 133                                 long ii; \
 134                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 135                         } else { \
 136                                 long ii; \
 137                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 138                                 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
 139                                 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 140                         } }
 141
 142 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 143                         long ii; \
 144                         assert((msg_len) > 0); \
 145                         is_complete = 1; \
 146                         if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 147                         if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
 148                                 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 149
 150 #if 0
 151 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 152                         long ii; \
 153                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 154                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 155                         printf("\n"); }
 156 #endif
 157
 158 static const uint8_t bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 159 static const uint8_t bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 160
 161 /* XDTLS:  figure out the right values */
 162 static const unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 163
 164 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 165 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 166         unsigned long frag_len);
 167 static unsigned char *dtls1_write_message_header(SSL *s,
 168         unsigned char *p);
 169 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 170         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 171         unsigned long frag_len);
 172 static long dtls1_get_message_fragment(SSL *s, int stn,
 173         long max, int *ok);
 174
 175 static hm_fragment *
 176 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 177         {
 178         hm_fragment *frag = NULL;
 179         unsigned char *buf = NULL;
 180         unsigned char *bitmask = NULL;
 181
 182         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 183         if ( frag == NULL)
 184                 return NULL;
 185
 186         if (frag_len)
 187                 {
 188                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 189                 if ( buf == NULL)
 190                         {
 191                         OPENSSL_free(frag);
 192                         return NULL;
 193                         }
 194                 }
 195
 196         /* zero length fragment gets zero frag->fragment */
 197         frag->fragment = buf;
 198
 199         /* Initialize reassembly bitmask if necessary */
 200         if (reassembly)
 201                 {
 202                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 203                 if (bitmask == NULL)
 204                         {
 205                         if (buf != NULL) OPENSSL_free(buf);
 206                         OPENSSL_free(frag);
 207                         return NULL;
 208                         }
 209                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 210                 }
 211
 212         frag->reassembly = bitmask;
 213
 214         return frag;
 215         }
 216
 217 static void
 218 dtls1_hm_fragment_free(hm_fragment *frag)
 219         {
 220
 221         if (frag->msg_header.is_ccs)
 222                 {
 223                 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
 224                 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
 225                 }
 226         if (frag->fragment) OPENSSL_free(frag->fragment);
 227         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 228         OPENSSL_free(frag);
 229         }
 230
 231 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 232 int dtls1_do_write(SSL *s, int type, enum should_add_to_finished_hash should_add_to_finished_hash)
 233         {
 234         int ret;
 235         int curr_mtu;
 236         unsigned int len, frag_off, mac_size, blocksize;
 237
 238         /* AHA!  Figure out the MTU, and stick to the right size */
 239         if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 240                 {
 241                 s->d1->mtu =
 242                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 243
 244                 /* I've seen the kernel return bogus numbers when it doesn't know
 245                  * (initial write), so just make sure we have a reasonable number */
 246                 if (s->d1->mtu < dtls1_min_mtu())
 247                         {
 248                         s->d1->mtu = 0;
 249                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 250                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 251                                 s->d1->mtu, NULL);
 252                         }
 253                 }
 254 #if 0
 255         mtu = s->d1->mtu;
 256
 257         fprintf(stderr, "using MTU = %d\n", mtu);
 258
 259         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 260
 261         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 262
 263         if ( curr_mtu > 0)
 264                 mtu = curr_mtu;
 265         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 266                 return ret;
 267
 268         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 269                 {
 270                 ret = BIO_flush(SSL_get_wbio(s));
 271                 if ( ret <= 0)
 272                         return ret;
 273                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 274                 }
 275 #endif
 276
 277         assert(s->d1->mtu >= dtls1_min_mtu());  /* should have something reasonable now */
 278
 279         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 280                 assert(s->init_num ==
 281                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 282
 283         if (s->write_hash)
 284                 {
 285                 if (s->enc_write_ctx && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE)
 286                         mac_size = 0;
 287                 else
 288                         mac_size = EVP_MD_CTX_size(s->write_hash);
 289                 }
 290         else
 291                 mac_size = 0;
 292
 293         if (s->enc_write_ctx &&
 294                 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
 295                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 296         else
 297                 blocksize = 0;
 298
 299         frag_off = 0;
 300         while( s->init_num)
 301                 {
 302                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 303                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 304
 305                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 306                         {
 307                         /* grr.. we could get an error if MTU picked was wrong */
 308                         ret = BIO_flush(SSL_get_wbio(s));
 309                         if ( ret <= 0)
 310                                 return ret;
 311                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 312                                 mac_size - blocksize;
 313                         }
 314
 315                 if ( s->init_num > curr_mtu)
 316                         len = curr_mtu;
 317                 else
 318                         len = s->init_num;
 319
 320
 321                 /* XDTLS: this function is too long.  split out the CCS part */
 322                 if ( type == SSL3_RT_HANDSHAKE)
 323                         {
 324                         if ( s->init_off != 0)
 325                                 {
 326                                 assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 327                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 328                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 329
 330                                 if ( s->init_num > curr_mtu)
 331                                         len = curr_mtu;
 332                                 else
 333                                         len = s->init_num;
 334                                 }
 335
 336                         dtls1_fix_message_header(s, frag_off,
 337                                 len - DTLS1_HM_HEADER_LENGTH);
 338
 339                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 340
 341                         assert(len >= DTLS1_HM_HEADER_LENGTH);
 342                         }
 343
 344                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 345                         len);
 346                 if (ret < 0)
 347                         {
 348                         /* might need to update MTU here, but we don't know
 349                          * which previous packet caused the failure -- so can't
 350                          * really retransmit anything.  continue as if everything
 351                          * is fine and wait for an alert to handle the
 352                          * retransmit
 353                          */
 354                         if ( BIO_ctrl(SSL_get_wbio(s),
 355                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 356                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 357                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 358                         else
 359                                 return(-1);
 360                         }
 361                 else
 362                         {
 363
 364                         /* bad if this assert fails, only part of the handshake
 365                          * message got sent.  but why would this happen? */
 366                         assert(len == (unsigned int)ret);
 367
 368                         if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting &&
 369                             should_add_to_finished_hash == add_to_finished_hash)
 370                                 {
 371                                 /* should not be done for 'Hello Request's, but in that case
 372                                  * we'll ignore the result anyway */
 373                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 374                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 375                                 int xlen;
 376
 377                                 if (frag_off == 0)
 378                                         {
 379                                         /* reconstruct message header is if it
 380                                          * is being sent in single fragment */
 381                                         *p++ = msg_hdr->type;
 382                                         l2n3(msg_hdr->msg_len,p);
 383                                         s2n (msg_hdr->seq,p);
 384                                         l2n3(0,p);
 385                                         l2n3(msg_hdr->msg_len,p);
 386                                         p  -= DTLS1_HM_HEADER_LENGTH;
 387                                         xlen = ret;
 388                                         }
 389                                 else
 390                                         {
 391                                         p  += DTLS1_HM_HEADER_LENGTH;
 392                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 393                                         }
 394
 395                                 ssl3_finish_mac(s, p, xlen);
 396                                 }
 397
 398                         if (ret == s->init_num)
 399                                 {
 400                                 if (s->msg_callback)
 401                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 402                                                 (size_t)(s->init_off + s->init_num), s,
 403                                                 s->msg_callback_arg);
 404
 405                                 s->init_off = 0;  /* done writing this message */
 406                                 s->init_num = 0;
 407
 408                                 return(1);
 409                                 }
 410                         s->init_off+=ret;
 411                         s->init_num-=ret;
 412                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 413                         }
 414                 }
 415         return(0);
 416         }
 417
 418
 419 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 420  * maximum acceptable body length 'max'.
 421  * Read an entire handshake message.  Handshake messages arrive in
 422  * fragments.
 423  */
 424 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int hash_message, int *ok)
 425         {
 426         int i, al;
 427         struct hm_header_st *msg_hdr;
 428         unsigned char *p;
 429         unsigned long msg_len;
 430
 431         /* s3->tmp is used to store messages that are unexpected, caused
 432          * by the absence of an optional handshake message */
 433         if (s->s3->tmp.reuse_message)
 434                 {
 435                 /* A SSL_GET_MESSAGE_DONT_HASH_MESSAGE call cannot be combined
 436                  * with reuse_message; the SSL_GET_MESSAGE_DONT_HASH_MESSAGE
 437                  * would have to have been applied to the previous call. */
 438                 assert(hash_message != SSL_GET_MESSAGE_DONT_HASH_MESSAGE);
 439                 s->s3->tmp.reuse_message=0;
 440                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 441                         {
 442                         al=SSL_AD_UNEXPECTED_MESSAGE;
 443                         OPENSSL_PUT_ERROR(SSL, dtls1_get_message, SSL_R_UNEXPECTED_MESSAGE);
 444                         goto f_err;
 445                         }
 446                 *ok=1;
 447                 s->init_msg = (uint8_t*)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 448                 s->init_num = (int)s->s3->tmp.message_size;
 449                 return s->init_num;
 450                 }
 451
 452         msg_hdr = &s->d1->r_msg_hdr;
 453         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 454
 455 again:
 456         i = dtls1_get_message_fragment(s, stn, max, ok);
 457         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 458                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 459                 goto again;
 460         else if ( i <= 0 && !*ok)
 461                 return i;
 462
 463         p = (unsigned char *)s->init_buf->data;
 464         msg_len = msg_hdr->msg_len;
 465
 466         /* reconstruct message header */
 467         *(p++) = msg_hdr->type;
 468         l2n3(msg_len,p);
 469         s2n (msg_hdr->seq,p);
 470         l2n3(0,p);
 471         l2n3(msg_len,p);
 472         p       -= DTLS1_HM_HEADER_LENGTH;
 473         msg_len += DTLS1_HM_HEADER_LENGTH;
 474
 475         s->init_msg = (uint8_t*)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 476
 477         if (hash_message != SSL_GET_MESSAGE_DONT_HASH_MESSAGE)
 478                 ssl3_hash_current_message(s);
 479         if (s->msg_callback)
 480                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 481                         p, msg_len,
 482                         s, s->msg_callback_arg);
 483
 484         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 485
 486         /* Don't change sequence numbers while listening */
 487         if (!s->d1->listen)
 488                 s->d1->handshake_read_seq++;
 489
 490         return s->init_num;
 491
 492 f_err:
 493         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 494         *ok = 0;
 495         return -1;
 496         }
 497
 498
 499 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 500         {
 501         size_t frag_off,frag_len,msg_len;
 502
 503         msg_len  = msg_hdr->msg_len;
 504         frag_off = msg_hdr->frag_off;
 505         frag_len = msg_hdr->frag_len;
 506
 507         /* sanity checking */
 508         if ( (frag_off+frag_len) > msg_len)
 509                 {
 510                 OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment, SSL_R_EXCESSIVE_MESSAGE_SIZE);
 511                 return SSL_AD_ILLEGAL_PARAMETER;
 512                 }
 513
 514         if ( (frag_off+frag_len) > (unsigned long)max)
 515                 {
 516                 OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment, SSL_R_EXCESSIVE_MESSAGE_SIZE);
 517                 return SSL_AD_ILLEGAL_PARAMETER;
 518                 }
 519
 520         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 521                 {
 522                 /* msg_len is limited to 2^24, but is effectively checked
 523                  * against max above */
 524                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
 525                         {
 526                         OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment, ERR_R_BUF_LIB);
 527                         return SSL_AD_INTERNAL_ERROR;
 528                         }
 529
 530                 s->s3->tmp.message_size  = msg_len;
 531                 s->d1->r_msg_hdr.msg_len = msg_len;
 532                 s->s3->tmp.message_type  = msg_hdr->type;
 533                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 534                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 535                 }
 536         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 537                 {
 538                 /* They must be playing with us! BTW, failure to enforce
 539                  * upper limit would open possibility for buffer overrun. */
 540                 OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment, SSL_R_EXCESSIVE_MESSAGE_SIZE);
 541                 return SSL_AD_ILLEGAL_PARAMETER;
 542                 }
 543
 544         return 0; /* no error */
 545         }
 546
 547
 548 static int
 549 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 550         {
 551         /* (0) check whether the desired fragment is available
 552          * if so:
 553          * (1) copy over the fragment to s->init_buf->data[]
 554          * (2) update s->init_num
 555          */
 556         pitem *item;
 557         hm_fragment *frag;
 558         int al;
 559
 560         *ok = 0;
 561         item = pqueue_peek(s->d1->buffered_messages);
 562         if ( item == NULL)
 563                 return 0;
 564
 565         frag = (hm_fragment *)item->data;
 566
 567         /* Don't return if reassembly still in progress */
 568         if (frag->reassembly != NULL)
 569                 return 0;
 570
 571         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 572                 {
 573                 unsigned long frag_len = frag->msg_header.frag_len;
 574                 pqueue_pop(s->d1->buffered_messages);
 575
 576                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 577
 578                 if (al==0) /* no alert */
 579                         {
 580                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 581                         memcpy(&p[frag->msg_header.frag_off],
 582                                 frag->fragment,frag->msg_header.frag_len);
 583                         }
 584
 585                 dtls1_hm_fragment_free(frag);
 586                 pitem_free(item);
 587
 588                 if (al==0)
 589                         {
 590                         *ok = 1;
 591                         return frag_len;
 592                         }
 593
 594                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 595                 s->init_num = 0;
 596                 *ok = 0;
 597                 return -1;
 598                 }
 599         else
 600                 return 0;
 601         }
 602
 603 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 604  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 605  * be greater if the maximum certificate list size requires it. */
 606 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 607         {
 608         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 609         if (max_len < (unsigned long)s->max_cert_list)
 610                 return s->max_cert_list;
 611         return max_len;
 612         }
 613
 614 static int
 615 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 616         {
 617         hm_fragment *frag = NULL;
 618         pitem *item = NULL;
 619         int i = -1, is_complete;
 620         unsigned char seq64be[8];
 621         unsigned long frag_len = msg_hdr->frag_len;
 622
 623         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 624             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 625                 goto err;
 626
 627         if (frag_len == 0)
 628                 return DTLS1_HM_FRAGMENT_RETRY;
 629
 630         /* Try to find item in queue */
 631         memset(seq64be,0,sizeof(seq64be));
 632         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 633         seq64be[7] = (unsigned char) msg_hdr->seq;
 634         item = pqueue_find(s->d1->buffered_messages, seq64be);
 635
 636         if (item == NULL)
 637                 {
 638                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 639                 if ( frag == NULL)
 640                         goto err;
 641                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 642                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 643                 frag->msg_header.frag_off = 0;
 644                 }
 645         else
 646                 {
 647                 frag = (hm_fragment*) item->data;
 648                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 649                         {
 650                         item = NULL;
 651                         frag = NULL;
 652                         goto err;
 653                         }
 654                 }
 655
 656         /* If message is already reassembled, this must be a
 657          * retransmit and can be dropped. In this case item != NULL and so frag
 658          * does not need to be freed. */
 659         if (frag->reassembly == NULL)
 660                 {
 661                 unsigned char devnull [256];
 662
 663                 assert(item != NULL);
 664                 while (frag_len)
 665                         {
 666                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 667                                 devnull,
 668                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 669                         if (i<=0) goto err;
 670                         frag_len -= i;
 671                         }
 672                 return DTLS1_HM_FRAGMENT_RETRY;
 673                 }
 674
 675         /* read the body of the fragment (header has already been read */
 676         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 677                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 678         if ((unsigned long)i!=frag_len)
 679                 i=-1;
 680         if (i<=0)
 681                 goto err;
 682
 683         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 684                             (long)(msg_hdr->frag_off + frag_len));
 685
 686         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 687                                    is_complete);
 688
 689         if (is_complete)
 690                 {
 691                 OPENSSL_free(frag->reassembly);
 692                 frag->reassembly = NULL;
 693                 }
 694
 695         if (item == NULL)
 696                 {
 697                 item = pitem_new(seq64be, frag);
 698                 if (item == NULL)
 699                         {
 700                         i = -1;
 701                         goto err;
 702                         }
 703
 704                 item = pqueue_insert(s->d1->buffered_messages, item);
 705                 /* pqueue_insert fails iff a duplicate item is inserted.
 706                  * However, |item| cannot be a duplicate. If it were,
 707                  * |pqueue_find|, above, would have returned it and control
 708                  * would never have reached this branch. */
 709                 assert(item != NULL);
 710                 }
 711
 712         return DTLS1_HM_FRAGMENT_RETRY;
 713
 714 err:
 715         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 716         *ok = 0;
 717         return i;
 718         }
 719
 720
 721 static int
 722 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 723 {
 724         int i=-1;
 725         hm_fragment *frag = NULL;
 726         pitem *item = NULL;
 727         unsigned char seq64be[8];
 728         unsigned long frag_len = msg_hdr->frag_len;
 729
 730         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 731                 goto err;
 732
 733         /* Try to find item in queue, to prevent duplicate entries */
 734         memset(seq64be,0,sizeof(seq64be));
 735         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 736         seq64be[7] = (unsigned char) msg_hdr->seq;
 737         item = pqueue_find(s->d1->buffered_messages, seq64be);
 738
 739         /* If we already have an entry and this one is a fragment,
 740          * don't discard it and rather try to reassemble it.
 741          */
 742         if (item != NULL && frag_len != msg_hdr->msg_len)
 743                 item = NULL;
 744
 745         /* Discard the message if sequence number was already there, is
 746          * too far in the future, already in the queue or if we received
 747          * a FINISHED before the SERVER_HELLO, which then must be a stale
 748          * retransmit.
 749          */
 750         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 751                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 752                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 753                 {
 754                 unsigned char devnull [256];
 755
 756                 while (frag_len)
 757                         {
 758                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 759                                 devnull,
 760                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 761                         if (i<=0) goto err;
 762                         frag_len -= i;
 763                         }
 764                 }
 765         else
 766                 {
 767                 if (frag_len != msg_hdr->msg_len)
 768                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 769
 770                 if (frag_len > dtls1_max_handshake_message_len(s))
 771                         goto err;
 772
 773                 frag = dtls1_hm_fragment_new(frag_len, 0);
 774                 if ( frag == NULL)
 775                         goto err;
 776
 777                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 778
 779                 if (frag_len)
 780                         {
 781                         /* read the body of the fragment (header has already been read */
 782                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 783                                 frag->fragment,frag_len,0);
 784                         if ((unsigned long)i!=frag_len)
 785                                 i = -1;
 786                         if (i<=0)
 787                                 goto err;
 788                         }
 789
 790                 item = pitem_new(seq64be, frag);
 791                 if ( item == NULL)
 792                         goto err;
 793
 794                 item = pqueue_insert(s->d1->buffered_messages, item);
 795                 /* pqueue_insert fails iff a duplicate item is inserted.
 796                  * However, |item| cannot be a duplicate. If it were,
 797                  * |pqueue_find|, above, would have returned it. Then, either
 798                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 799                  * to NULL and it will have been processed with
 800                  * |dtls1_reassemble_fragment|, above, or the record will have
 801                  * been discarded. */
 802                 assert(item != NULL);
 803                 }
 804
 805         return DTLS1_HM_FRAGMENT_RETRY;
 806
 807 err:
 808         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 809         *ok = 0;
 810         return i;
 811         }
 812
 813
 814 static long
 815 dtls1_get_message_fragment(SSL *s, int stn, long max, int *ok)
 816         {
 817         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 818         unsigned long len, frag_off, frag_len;
 819         int i,al;
 820         struct hm_header_st msg_hdr;
 821
 822         redo:
 823         /* see if we have the required fragment already */
 824         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 825                 {
 826                 if (*ok)        s->init_num = frag_len;
 827                 return frag_len;
 828                 }
 829
 830         /* read handshake message header */
 831         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 832                 DTLS1_HM_HEADER_LENGTH, 0);
 833         if (i <= 0)     /* nbio, or an error */
 834                 {
 835                 s->rwstate=SSL_READING;
 836                 *ok = 0;
 837                 return i;
 838                 }
 839         /* Handshake fails if message header is incomplete */
 840         if (i != DTLS1_HM_HEADER_LENGTH)
 841                 {
 842                 al=SSL_AD_UNEXPECTED_MESSAGE;
 843                 OPENSSL_PUT_ERROR(SSL, dtls1_get_message_fragment, SSL_R_UNEXPECTED_MESSAGE);
 844                 goto f_err;
 845                 }
 846
 847         /* parse the message fragment header */
 848         dtls1_get_message_header(wire, &msg_hdr);
 849
 850         /*
 851          * if this is a future (or stale) message it gets buffered
 852          * (or dropped)--no further processing at this time
 853          * While listening, we accept seq 1 (ClientHello with cookie)
 854          * although we're still expecting seq 0 (ClientHello)
 855          */
 856         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 857                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 858
 859         len = msg_hdr.msg_len;
 860         frag_off = msg_hdr.frag_off;
 861         frag_len = msg_hdr.frag_len;
 862
 863         if (frag_len && frag_len < len)
 864                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 865
 866         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 867                 wire[0] == SSL3_MT_HELLO_REQUEST)
 868                 {
 869                 /* The server may always send 'Hello Request' messages --
 870                  * we are doing a handshake anyway now, so ignore them
 871                  * if their format is correct. Does not count for
 872                  * 'Finished' MAC. */
 873                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 874                         {
 875                         if (s->msg_callback)
 876                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 877                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 878                                         s->msg_callback_arg);
 879
 880                         s->init_num = 0;
 881                         goto redo;
 882                         }
 883                 else /* Incorrectly formated Hello request */
 884                         {
 885                         al=SSL_AD_UNEXPECTED_MESSAGE;
 886                         OPENSSL_PUT_ERROR(SSL, dtls1_get_message_fragment, SSL_R_UNEXPECTED_MESSAGE);
 887                         goto f_err;
 888                         }
 889                 }
 890
 891         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 892                 goto f_err;
 893
 894         /* XDTLS:  ressurect this when restart is in place */
 895         s->state=stn;
 896
 897         if ( frag_len > 0)
 898                 {
 899                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 900
 901                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 902                         &p[frag_off],frag_len,0);
 903                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 904                 if (i <= 0)
 905                         {
 906                         s->rwstate=SSL_READING;
 907                         *ok = 0;
 908                         return i;
 909                         }
 910                 }
 911         else
 912                 i = 0;
 913
 914         /* XDTLS:  an incorrectly formatted fragment should cause the
 915          * handshake to fail */
 916         if (i != (int)frag_len)
 917                 {
 918                 al=SSL3_AD_ILLEGAL_PARAMETER;
 919                 OPENSSL_PUT_ERROR(SSL, dtls1_get_message_fragment, SSL3_AD_ILLEGAL_PARAMETER);
 920                 goto f_err;
 921                 }
 922
 923         *ok = 1;
 924
 925         /* Note that s->init_num is *not* used as current offset in
 926          * s->init_buf->data, but as a counter summing up fragments'
 927          * lengths: as soon as they sum up to handshake packet
 928          * length, we assume we have got all the fragments. */
 929         s->init_num = frag_len;
 930         return frag_len;
 931
 932 f_err:
 933         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 934         s->init_num = 0;
 935
 936         *ok=0;
 937         return(-1);
 938         }
 939
 940 /* for these 2 messages, we need to
 941  * ssl->enc_read_ctx                    re-init
 942  * ssl->s3->read_sequence               zero
 943  * ssl->s3->read_mac_secret             re-init
 944  * ssl->session->read_sym_enc           assign
 945  * ssl->session->read_compression       assign
 946  * ssl->session->read_hash              assign
 947  */
 948 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 949         {
 950         unsigned char *p;
 951
 952         if (s->state == a)
 953                 {
 954                 p=(unsigned char *)s->init_buf->data;
 955                 *p++=SSL3_MT_CCS;
 956                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 957                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 958
 959                 s->init_off=0;
 960
 961                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 962                         s->d1->handshake_write_seq, 0, 0);
 963
 964                 /* buffer the message to handle re-xmits */
 965                 dtls1_buffer_message(s, 1);
 966
 967                 s->state=b;
 968                 }
 969
 970         /* SSL3_ST_CW_CHANGE_B */
 971         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC, dont_add_to_finished_hash));
 972         }
 973
 974 int dtls1_read_failed(SSL *s, int code)
 975         {
 976         if ( code > 0)
 977                 {
 978                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
 979                 return 1;
 980                 }
 981
 982         if (!dtls1_is_timer_expired(s))
 983                 {
 984                 /* not a timeout, none of our business,
 985                    let higher layers handle this.  in fact it's probably an error */
 986                 return code;
 987                 }
 988
 989         if (!SSL_in_init(s))  /* done, no need to send a retransmit */
 990                 {
 991                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
 992                 return code;
 993                 }
 994
 995         return dtls1_handle_timeout(s);
 996         }
 997
 998 int
 999 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1000         {
1001         /* The index of the retransmission queue actually is the message sequence number,
1002          * since the queue only contains messages of a single handshake. However, the
1003          * ChangeCipherSpec has no message sequence number and so using only the sequence
1004          * will result in the CCS and Finished having the same index. To prevent this,
1005          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1006          * This does not only differ CSS and Finished, it also maintains the order of the
1007          * index (important for priority queues) and fits in the unsigned short variable.
1008          */
1009         return seq * 2 - is_ccs;
1010         }
1011
1012 int
1013 dtls1_retransmit_buffered_messages(SSL *s)
1014         {
1015         pqueue sent = s->d1->sent_messages;
1016         piterator iter;
1017         pitem *item;
1018         hm_fragment *frag;
1019         int found = 0;
1020
1021         iter = pqueue_iterator(sent);
1022
1023         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1024                 {
1025                 frag = (hm_fragment *)item->data;
1026                         if ( dtls1_retransmit_message(s,
1027                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1028                                 0, &found) <= 0 && found)
1029                         {
1030                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1031                         return -1;
1032                         }
1033                 }
1034
1035         return 1;
1036         }
1037
1038 int
1039 dtls1_buffer_message(SSL *s, int is_ccs)
1040         {
1041         pitem *item;
1042         hm_fragment *frag;
1043         unsigned char seq64be[8];
1044
1045         /* this function is called immediately after a message has
1046          * been serialized */
1047         assert(s->init_off == 0);
1048
1049         frag = dtls1_hm_fragment_new(s->init_num, 0);
1050         if (!frag)
1051                 return 0;
1052
1053         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1054
1055         if ( is_ccs)
1056                 {
1057                 assert(s->d1->w_msg_hdr.msg_len +
1058                                DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1059                 }
1060         else
1061                 {
1062                 assert(s->d1->w_msg_hdr.msg_len +
1063                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1064                 }
1065
1066         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1067         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1068         frag->msg_header.type = s->d1->w_msg_hdr.type;
1069         frag->msg_header.frag_off = 0;
1070         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1071         frag->msg_header.is_ccs = is_ccs;
1072
1073         /* save current state*/
1074         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1075         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1076         frag->msg_header.saved_retransmit_state.session = s->session;
1077         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1078
1079         memset(seq64be,0,sizeof(seq64be));
1080         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1081                                                                                                                   frag->msg_header.is_ccs)>>8);
1082         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1083                                                                                                                   frag->msg_header.is_ccs));
1084
1085         item = pitem_new(seq64be, frag);
1086         if ( item == NULL)
1087                 {
1088                 dtls1_hm_fragment_free(frag);
1089                 return 0;
1090                 }
1091
1092 #if 0
1093         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1094         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1095         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1096 #endif
1097
1098         pqueue_insert(s->d1->sent_messages, item);
1099         return 1;
1100         }
1101
1102 int
1103 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1104         int *found)
1105         {
1106         int ret;
1107         /* XDTLS: for now assuming that read/writes are blocking */
1108         pitem *item;
1109         hm_fragment *frag ;
1110         unsigned long header_length;
1111         unsigned char seq64be[8];
1112         struct dtls1_retransmit_state saved_state;
1113         unsigned char save_write_sequence[8];
1114
1115         /*
1116           assert(s->init_num == 0);
1117           assert(s->init_off == 0);
1118          */
1119
1120         /* XDTLS:  the requested message ought to be found, otherwise error */
1121         memset(seq64be,0,sizeof(seq64be));
1122         seq64be[6] = (unsigned char)(seq>>8);
1123         seq64be[7] = (unsigned char)seq;
1124
1125         item = pqueue_find(s->d1->sent_messages, seq64be);
1126         if ( item == NULL)
1127                 {
1128                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1129                 *found = 0;
1130                 return 0;
1131                 }
1132
1133         *found = 1;
1134         frag = (hm_fragment *)item->data;
1135
1136         if ( frag->msg_header.is_ccs)
1137                 header_length = DTLS1_CCS_HEADER_LENGTH;
1138         else
1139                 header_length = DTLS1_HM_HEADER_LENGTH;
1140
1141         memcpy(s->init_buf->data, frag->fragment,
1142                 frag->msg_header.msg_len + header_length);
1143                 s->init_num = frag->msg_header.msg_len + header_length;
1144
1145         dtls1_set_message_header_int(s, frag->msg_header.type,
1146                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1147                 frag->msg_header.frag_len);
1148
1149         /* save current state */
1150         saved_state.enc_write_ctx = s->enc_write_ctx;
1151         saved_state.write_hash = s->write_hash;
1152         saved_state.session = s->session;
1153         saved_state.epoch = s->d1->w_epoch;
1154
1155         s->d1->retransmitting = 1;
1156
1157         /* restore state in which the message was originally sent */
1158         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1159         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1160         s->session = frag->msg_header.saved_retransmit_state.session;
1161         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1162
1163         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1164         {
1165                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1166                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1167         }
1168
1169         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1170                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE, add_to_finished_hash);
1171
1172         /* restore current state */
1173         s->enc_write_ctx = saved_state.enc_write_ctx;
1174         s->write_hash = saved_state.write_hash;
1175         s->session = saved_state.session;
1176         s->d1->w_epoch = saved_state.epoch;
1177
1178         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1179         {
1180                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1181                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1182         }
1183
1184         s->d1->retransmitting = 0;
1185
1186         (void)BIO_flush(SSL_get_wbio(s));
1187         return ret;
1188         }
1189
1190 /* call this function when the buffered messages are no longer needed */
1191 void
1192 dtls1_clear_record_buffer(SSL *s)
1193         {
1194         pitem *item;
1195
1196         for(item = pqueue_pop(s->d1->sent_messages);
1197                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1198                 {
1199                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1200                 pitem_free(item);
1201                 }
1202         }
1203
1204
1205 unsigned char *
1206 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1207                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1208         {
1209         /* Don't change sequence numbers while listening */
1210         if (frag_off == 0 && !s->d1->listen)
1211                 {
1212                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1213                 s->d1->next_handshake_write_seq++;
1214                 }
1215
1216         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1217                 frag_off, frag_len);
1218
1219         return p += DTLS1_HM_HEADER_LENGTH;
1220         }
1221
1222
1223 /* don't actually do the writing, wait till the MTU has been retrieved */
1224 static void
1225 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1226                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1227                             unsigned long frag_len)
1228         {
1229         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1230
1231         msg_hdr->type = mt;
1232         msg_hdr->msg_len = len;
1233         msg_hdr->seq = seq_num;
1234         msg_hdr->frag_off = frag_off;
1235         msg_hdr->frag_len = frag_len;
1236         }
1237
1238 static void
1239 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1240                         unsigned long frag_len)
1241         {
1242         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1243
1244         msg_hdr->frag_off = frag_off;
1245         msg_hdr->frag_len = frag_len;
1246         }
1247
1248 static unsigned char *
1249 dtls1_write_message_header(SSL *s, unsigned char *p)
1250         {
1251         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1252
1253         *p++ = msg_hdr->type;
1254         l2n3(msg_hdr->msg_len, p);
1255
1256         s2n(msg_hdr->seq, p);
1257         l2n3(msg_hdr->frag_off, p);
1258         l2n3(msg_hdr->frag_len, p);
1259
1260         return p;
1261         }
1262
1263 unsigned int
1264 dtls1_min_mtu(void)
1265         {
1266         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1267                 sizeof(g_probable_mtu[0])) - 1]);
1268         }
1269
1270 static unsigned int
1271 dtls1_guess_mtu(unsigned int curr_mtu)
1272         {
1273         unsigned int i;
1274
1275         if ( curr_mtu == 0 )
1276                 return g_probable_mtu[0] ;
1277
1278         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1279                 if ( curr_mtu > g_probable_mtu[i])
1280                         return g_probable_mtu[i];
1281
1282         return curr_mtu;
1283         }
1284
1285 void
1286 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1287         {
1288         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1289         msg_hdr->type = *(data++);
1290         n2l3(data, msg_hdr->msg_len);
1291
1292         n2s(data, msg_hdr->seq);
1293         n2l3(data, msg_hdr->frag_off);
1294         n2l3(data, msg_hdr->frag_len);
1295         }
1296
1297 void
1298 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1299         {
1300         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1301
1302         ccs_hdr->type = *(data++);
1303         }
1304
1305 int dtls1_shutdown(SSL *s)
1306         {
1307         int ret;
1308         ret = ssl3_shutdown(s);
1309         return ret;
1310         }