crypto/openssl/ssl/d1_both.c

   1 /* ssl/d1_both.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <limits.h>
 117 #include <string.h>
 118 #include <stdio.h>
 119 #include "ssl_locl.h"
 120 #include <openssl/buffer.h>
 121 #include <openssl/rand.h>
 122 #include <openssl/objects.h>
 123 #include <openssl/evp.h>
 124 #include <openssl/x509.h>
 125
 126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 127
 128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
 129                         if ((end) - (start) <= 8) { \
 130                                 long ii; \
 131                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 132                         } else { \
 133                                 long ii; \
 134                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 135                                 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
 136                                 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 137                         } }
 138
 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 140                         long ii; \
 141                         OPENSSL_assert((msg_len) > 0); \
 142                         is_complete = 1; \
 143                         if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 144                         if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
 145                                 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 146
 147 #if 0
 148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 149                         long ii; \
 150                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 151                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 152                         printf("\n"); }
 153 #endif
 154
 155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 156 static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 157
 158 /* XDTLS:  figure out the right values */
 159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 160
 161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 163         unsigned long frag_len);
 164 static unsigned char *dtls1_write_message_header(SSL *s,
 165         unsigned char *p);
 166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 167         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 168         unsigned long frag_len);
 169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 170         long max, int *ok);
 171
 172 static hm_fragment *
 173 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 174         {
 175         hm_fragment *frag = NULL;
 176         unsigned char *buf = NULL;
 177         unsigned char *bitmask = NULL;
 178
 179         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 180         if ( frag == NULL)
 181                 return NULL;
 182
 183         if (frag_len)
 184                 {
 185                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 186                 if ( buf == NULL)
 187                         {
 188                         OPENSSL_free(frag);
 189                         return NULL;
 190                         }
 191                 }
 192
 193         /* zero length fragment gets zero frag->fragment */
 194         frag->fragment = buf;
 195
 196         /* Initialize reassembly bitmask if necessary */
 197         if (reassembly)
 198                 {
 199                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 200                 if (bitmask == NULL)
 201                         {
 202                         if (buf != NULL) OPENSSL_free(buf);
 203                         OPENSSL_free(frag);
 204                         return NULL;
 205                         }
 206                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 207                 }
 208
 209         frag->reassembly = bitmask;
 210
 211         return frag;
 212         }
 213
 214 static void
 215 dtls1_hm_fragment_free(hm_fragment *frag)
 216         {
 217         if (frag->fragment) OPENSSL_free(frag->fragment);
 218         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 219         OPENSSL_free(frag);
 220         }
 221
 222 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 223 int dtls1_do_write(SSL *s, int type)
 224         {
 225         int ret;
 226         int curr_mtu;
 227         unsigned int len, frag_off, mac_size, blocksize;
 228
 229         /* AHA!  Figure out the MTU, and stick to the right size */
 230         if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 231                 {
 232                 s->d1->mtu =
 233                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 234
 235                 /* I've seen the kernel return bogus numbers when it doesn't know
 236                  * (initial write), so just make sure we have a reasonable number */
 237                 if (s->d1->mtu < dtls1_min_mtu())
 238                         {
 239                         s->d1->mtu = 0;
 240                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 241                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 242                                 s->d1->mtu, NULL);
 243                         }
 244                 }
 245 #if 0
 246         mtu = s->d1->mtu;
 247
 248         fprintf(stderr, "using MTU = %d\n", mtu);
 249
 250         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 251
 252         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 253
 254         if ( curr_mtu > 0)
 255                 mtu = curr_mtu;
 256         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 257                 return ret;
 258
 259         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 260                 {
 261                 ret = BIO_flush(SSL_get_wbio(s));
 262                 if ( ret <= 0)
 263                         return ret;
 264                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 265                 }
 266 #endif
 267
 268         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu());  /* should have something reasonable now */
 269
 270         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 271                 OPENSSL_assert(s->init_num ==
 272                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 273
 274         if (s->write_hash)
 275                 mac_size = EVP_MD_size(s->write_hash);
 276         else
 277                 mac_size = 0;
 278
 279         if (s->enc_write_ctx &&
 280                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
 281                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 282         else
 283                 blocksize = 0;
 284
 285         frag_off = 0;
 286         while( s->init_num)
 287                 {
 288                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 289                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 290
 291                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 292                         {
 293                         /* grr.. we could get an error if MTU picked was wrong */
 294                         ret = BIO_flush(SSL_get_wbio(s));
 295                         if ( ret <= 0)
 296                                 return ret;
 297                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 298                                 mac_size - blocksize;
 299                         }
 300
 301                 if ( s->init_num > curr_mtu)
 302                         len = curr_mtu;
 303                 else
 304                         len = s->init_num;
 305
 306
 307                 /* XDTLS: this function is too long.  split out the CCS part */
 308                 if ( type == SSL3_RT_HANDSHAKE)
 309                         {
 310                         if ( s->init_off != 0)
 311                                 {
 312                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 313                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 314                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 315
 316                                 if ( s->init_num > curr_mtu)
 317                                         len = curr_mtu;
 318                                 else
 319                                         len = s->init_num;
 320                                 }
 321
 322                         dtls1_fix_message_header(s, frag_off,
 323                                 len - DTLS1_HM_HEADER_LENGTH);
 324
 325                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 326
 327                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 328                         }
 329
 330                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 331                         len);
 332                 if (ret < 0)
 333                         {
 334                         /* might need to update MTU here, but we don't know
 335                          * which previous packet caused the failure -- so can't
 336                          * really retransmit anything.  continue as if everything
 337                          * is fine and wait for an alert to handle the
 338                          * retransmit
 339                          */
 340                         if ( BIO_ctrl(SSL_get_wbio(s),
 341                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 342                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 343                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 344                         else
 345                                 return(-1);
 346                         }
 347                 else
 348                         {
 349
 350                         /* bad if this assert fails, only part of the handshake
 351                          * message got sent.  but why would this happen? */
 352                         OPENSSL_assert(len == (unsigned int)ret);
 353
 354                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 355                                 {
 356                                 /* should not be done for 'Hello Request's, but in that case
 357                                  * we'll ignore the result anyway */
 358                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 359                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 360                                 int xlen;
 361
 362                                 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER)
 363                                         {
 364                                         /* reconstruct message header is if it
 365                                          * is being sent in single fragment */
 366                                         *p++ = msg_hdr->type;
 367                                         l2n3(msg_hdr->msg_len,p);
 368                                         s2n (msg_hdr->seq,p);
 369                                         l2n3(0,p);
 370                                         l2n3(msg_hdr->msg_len,p);
 371                                         p  -= DTLS1_HM_HEADER_LENGTH;
 372                                         xlen = ret;
 373                                         }
 374                                 else
 375                                         {
 376                                         p  += DTLS1_HM_HEADER_LENGTH;
 377                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 378                                         }
 379
 380                                 ssl3_finish_mac(s, p, xlen);
 381                                 }
 382
 383                         if (ret == s->init_num)
 384                                 {
 385                                 if (s->msg_callback)
 386                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 387                                                 (size_t)(s->init_off + s->init_num), s,
 388                                                 s->msg_callback_arg);
 389
 390                                 s->init_off = 0;  /* done writing this message */
 391                                 s->init_num = 0;
 392
 393                                 return(1);
 394                                 }
 395                         s->init_off+=ret;
 396                         s->init_num-=ret;
 397                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 398                         }
 399                 }
 400         return(0);
 401         }
 402
 403
 404 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 405  * maximum acceptable body length 'max'.
 406  * Read an entire handshake message.  Handshake messages arrive in
 407  * fragments.
 408  */
 409 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 410         {
 411         int i, al;
 412         struct hm_header_st *msg_hdr;
 413         unsigned char *p;
 414         unsigned long msg_len;
 415
 416         /* s3->tmp is used to store messages that are unexpected, caused
 417          * by the absence of an optional handshake message */
 418         if (s->s3->tmp.reuse_message)
 419                 {
 420                 s->s3->tmp.reuse_message=0;
 421                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 422                         {
 423                         al=SSL_AD_UNEXPECTED_MESSAGE;
 424                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 425                         goto f_err;
 426                         }
 427                 *ok=1;
 428                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 429                 s->init_num = (int)s->s3->tmp.message_size;
 430                 return s->init_num;
 431                 }
 432
 433         msg_hdr = &s->d1->r_msg_hdr;
 434         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 435
 436 again:
 437         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 438         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 439                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 440                 goto again;
 441         else if ( i <= 0 && !*ok)
 442                 return i;
 443
 444         p = (unsigned char *)s->init_buf->data;
 445         msg_len = msg_hdr->msg_len;
 446
 447         /* reconstruct message header */
 448         *(p++) = msg_hdr->type;
 449         l2n3(msg_len,p);
 450         s2n (msg_hdr->seq,p);
 451         l2n3(0,p);
 452         l2n3(msg_len,p);
 453         if (s->version != DTLS1_BAD_VER) {
 454                 p       -= DTLS1_HM_HEADER_LENGTH;
 455                 msg_len += DTLS1_HM_HEADER_LENGTH;
 456         }
 457
 458         ssl3_finish_mac(s, p, msg_len);
 459         if (s->msg_callback)
 460                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 461                         p, msg_len,
 462                         s, s->msg_callback_arg);
 463
 464         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 465
 466         /* Don't change sequence numbers while listening */
 467         if (!s->d1->listen)
 468                 s->d1->handshake_read_seq++;
 469
 470         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 471         return s->init_num;
 472
 473 f_err:
 474         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 475         *ok = 0;
 476         return -1;
 477         }
 478
 479
 480 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 481         {
 482         size_t frag_off,frag_len,msg_len;
 483
 484         msg_len  = msg_hdr->msg_len;
 485         frag_off = msg_hdr->frag_off;
 486         frag_len = msg_hdr->frag_len;
 487
 488         /* sanity checking */
 489         if ( (frag_off+frag_len) > msg_len)
 490                 {
 491                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 492                 return SSL_AD_ILLEGAL_PARAMETER;
 493                 }
 494
 495         if ( (frag_off+frag_len) > (unsigned long)max)
 496                 {
 497                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 498                 return SSL_AD_ILLEGAL_PARAMETER;
 499                 }
 500
 501         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 502                 {
 503                 /* msg_len is limited to 2^24, but is effectively checked
 504                  * against max above */
 505                 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
 506                         {
 507                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 508                         return SSL_AD_INTERNAL_ERROR;
 509                         }
 510
 511                 s->s3->tmp.message_size  = msg_len;
 512                 s->d1->r_msg_hdr.msg_len = msg_len;
 513                 s->s3->tmp.message_type  = msg_hdr->type;
 514                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 515                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 516                 }
 517         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 518                 {
 519                 /* They must be playing with us! BTW, failure to enforce
 520                  * upper limit would open possibility for buffer overrun. */
 521                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 522                 return SSL_AD_ILLEGAL_PARAMETER;
 523                 }
 524
 525         return 0; /* no error */
 526         }
 527
 528
 529 static int
 530 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 531         {
 532         /* (0) check whether the desired fragment is available
 533          * if so:
 534          * (1) copy over the fragment to s->init_buf->data[]
 535          * (2) update s->init_num
 536          */
 537         pitem *item;
 538         hm_fragment *frag;
 539         int al;
 540
 541         *ok = 0;
 542         item = pqueue_peek(s->d1->buffered_messages);
 543         if ( item == NULL)
 544                 return 0;
 545
 546         frag = (hm_fragment *)item->data;
 547
 548         /* Don't return if reassembly still in progress */
 549         if (frag->reassembly != NULL)
 550                 return 0;
 551
 552         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 553                 {
 554                 unsigned long frag_len = frag->msg_header.frag_len;
 555                 pqueue_pop(s->d1->buffered_messages);
 556
 557                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 558
 559                 if (al==0) /* no alert */
 560                         {
 561                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 562                         memcpy(&p[frag->msg_header.frag_off],
 563                                 frag->fragment,frag->msg_header.frag_len);
 564                         }
 565
 566                 dtls1_hm_fragment_free(frag);
 567                 pitem_free(item);
 568
 569                 if (al==0)
 570                         {
 571                         *ok = 1;
 572                         return frag_len;
 573                         }
 574
 575                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 576                 s->init_num = 0;
 577                 *ok = 0;
 578                 return -1;
 579                 }
 580         else
 581                 return 0;
 582         }
 583
 584
 585 static int
 586 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 587         {
 588         hm_fragment *frag = NULL;
 589         pitem *item = NULL;
 590         int i = -1, is_complete;
 591         PQ_64BIT seq64;
 592         unsigned long frag_len = msg_hdr->frag_len, max_len;
 593
 594         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 595                 goto err;
 596
 597         /* Determine maximum allowed message size. Depends on (user set)
 598          * maximum certificate length, but 16k is minimum.
 599          */
 600         if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
 601                 max_len = s->max_cert_list;
 602         else
 603                 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 604
 605         if ((msg_hdr->frag_off+frag_len) > max_len)
 606                 goto err;
 607
 608         /* Try to find item in queue */
 609         pq_64bit_init(&seq64);
 610         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 611         item = pqueue_find(s->d1->buffered_messages, seq64);
 612         pq_64bit_free(&seq64);
 613
 614         if (item == NULL)
 615                 {
 616                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 617                 if ( frag == NULL)
 618                         goto err;
 619                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 620                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 621                 frag->msg_header.frag_off = 0;
 622                 }
 623         else
 624                 {
 625                 frag = (hm_fragment*) item->data;
 626                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 627                         {
 628                         item = NULL;
 629                         frag = NULL;
 630                         goto err;
 631                         }
 632                 }
 633
 634
 635         /* If message is already reassembled, this must be a
 636          * retransmit and can be dropped.
 637          */
 638         if (frag->reassembly == NULL)
 639                 {
 640                 unsigned char devnull [256];
 641
 642                 while (frag_len)
 643                         {
 644                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 645                                 devnull,
 646                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 647                         if (i<=0) goto err;
 648                         frag_len -= i;
 649                         }
 650                 return DTLS1_HM_FRAGMENT_RETRY;
 651                 }
 652
 653         /* read the body of the fragment (header has already been read */
 654         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 655                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 656         if (i<=0 || (unsigned long)i!=frag_len)
 657                 goto err;
 658
 659         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 660                             (long)(msg_hdr->frag_off + frag_len));
 661
 662         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 663                                    is_complete);
 664
 665         if (is_complete)
 666                 {
 667                 OPENSSL_free(frag->reassembly);
 668                 frag->reassembly = NULL;
 669                 }
 670
 671         if (item == NULL)
 672                 {
 673                 pq_64bit_init(&seq64);
 674                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 675                 item = pitem_new(seq64, frag);
 676                 pq_64bit_free(&seq64);
 677
 678                 if (item == NULL)
 679                         {
 680                         i = -1;
 681                         goto err;
 682                         }
 683
 684                 pqueue_insert(s->d1->buffered_messages, item);
 685                 }
 686
 687         return DTLS1_HM_FRAGMENT_RETRY;
 688
 689 err:
 690         if (frag != NULL) dtls1_hm_fragment_free(frag);
 691         if (item != NULL) OPENSSL_free(item);
 692         *ok = 0;
 693         return i;
 694         }
 695
 696
 697 static int
 698 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 699 {
 700         int i=-1;
 701         hm_fragment *frag = NULL;
 702         pitem *item = NULL;
 703         PQ_64BIT seq64;
 704         unsigned long frag_len = msg_hdr->frag_len;
 705
 706         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 707                 goto err;
 708
 709         /* Try to find item in queue, to prevent duplicate entries */
 710         pq_64bit_init(&seq64);
 711         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 712         item = pqueue_find(s->d1->buffered_messages, seq64);
 713         pq_64bit_free(&seq64);
 714
 715         /* If we already have an entry and this one is a fragment,
 716          * don't discard it and rather try to reassemble it.
 717          */
 718         if (item != NULL && frag_len < msg_hdr->msg_len)
 719                 item = NULL;
 720
 721         /* Discard the message if sequence number was already there, is
 722          * too far in the future, already in the queue or if we received
 723          * a FINISHED before the SERVER_HELLO, which then must be a stale
 724          * retransmit.
 725          */
 726         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 727                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 728                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 729                 {
 730                 unsigned char devnull [256];
 731
 732                 while (frag_len)
 733                         {
 734                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 735                                 devnull,
 736                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 737                         if (i<=0) goto err;
 738                         frag_len -= i;
 739                         }
 740                 }
 741         else
 742                 {
 743                 if (frag_len && frag_len < msg_hdr->msg_len)
 744                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 745
 746                 frag = dtls1_hm_fragment_new(frag_len, 0);
 747                 if ( frag == NULL)
 748                         goto err;
 749
 750                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 751
 752                 if (frag_len)
 753                         {
 754                         /* read the body of the fragment (header has already been read) */
 755                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 756                                 frag->fragment,frag_len,0);
 757                         if (i<=0 || (unsigned long)i!=frag_len)
 758                                 goto err;
 759                         }
 760
 761                 pq_64bit_init(&seq64);
 762                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 763
 764                 item = pitem_new(seq64, frag);
 765                 pq_64bit_free(&seq64);
 766                 if ( item == NULL)
 767                         goto err;
 768
 769                 pqueue_insert(s->d1->buffered_messages, item);
 770                 }
 771
 772         return DTLS1_HM_FRAGMENT_RETRY;
 773
 774 err:
 775         if ( frag != NULL) dtls1_hm_fragment_free(frag);
 776         if ( item != NULL) OPENSSL_free(item);
 777         *ok = 0;
 778         return i;
 779         }
 780
 781
 782 static long
 783 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 784         {
 785         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 786         unsigned long len, frag_off, frag_len;
 787         int i,al;
 788         struct hm_header_st msg_hdr;
 789
 790         redo:
 791         /* see if we have the required fragment already */
 792         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 793                 {
 794                 if (*ok)        s->init_num = frag_len;
 795                 return frag_len;
 796                 }
 797
 798         /* read handshake message header */
 799         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 800                 DTLS1_HM_HEADER_LENGTH, 0);
 801         if (i <= 0)     /* nbio, or an error */
 802                 {
 803                 s->rwstate=SSL_READING;
 804                 *ok = 0;
 805                 return i;
 806                 }
 807         /* Handshake fails if message header is incomplete */
 808         if (i != DTLS1_HM_HEADER_LENGTH)
 809                 {
 810                 al=SSL_AD_UNEXPECTED_MESSAGE;
 811                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 812                 goto f_err;
 813                 }
 814
 815         /* parse the message fragment header */
 816         dtls1_get_message_header(wire, &msg_hdr);
 817
 818         /*
 819          * if this is a future (or stale) message it gets buffered
 820          * (or dropped)--no further processing at this time
 821          * While listening, we accept seq 1 (ClientHello with cookie)
 822          * although we're still expecting seq 0 (ClientHello)
 823          */
 824         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 825                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 826
 827         len = msg_hdr.msg_len;
 828         frag_off = msg_hdr.frag_off;
 829         frag_len = msg_hdr.frag_len;
 830
 831         if (frag_len && frag_len < len)
 832                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 833
 834         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 835                 wire[0] == SSL3_MT_HELLO_REQUEST)
 836                 {
 837                 /* The server may always send 'Hello Request' messages --
 838                  * we are doing a handshake anyway now, so ignore them
 839                  * if their format is correct. Does not count for
 840                  * 'Finished' MAC. */
 841                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 842                         {
 843                         if (s->msg_callback)
 844                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 845                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 846                                         s->msg_callback_arg);
 847
 848                         s->init_num = 0;
 849                         goto redo;
 850                         }
 851                 else /* Incorrectly formated Hello request */
 852                         {
 853                         al=SSL_AD_UNEXPECTED_MESSAGE;
 854                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 855                         goto f_err;
 856                         }
 857                 }
 858
 859         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 860                 goto f_err;
 861
 862         /* XDTLS:  ressurect this when restart is in place */
 863         s->state=stn;
 864
 865         if ( frag_len > 0)
 866                 {
 867                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 868
 869                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 870                         &p[frag_off],frag_len,0);
 871                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 872                 if (i <= 0)
 873                         {
 874                         s->rwstate=SSL_READING;
 875                         *ok = 0;
 876                         return i;
 877                         }
 878                 }
 879         else
 880                 i = 0;
 881
 882         /* XDTLS:  an incorrectly formatted fragment should cause the
 883          * handshake to fail */
 884         if (i != (int)frag_len)
 885                 {
 886                 al=SSL3_AD_ILLEGAL_PARAMETER;
 887                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 888                 goto f_err;
 889                 }
 890
 891         *ok = 1;
 892
 893         /* Note that s->init_num is *not* used as current offset in
 894          * s->init_buf->data, but as a counter summing up fragments'
 895          * lengths: as soon as they sum up to handshake packet
 896          * length, we assume we have got all the fragments. */
 897         s->init_num = frag_len;
 898         return frag_len;
 899
 900 f_err:
 901         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 902         s->init_num = 0;
 903
 904         *ok=0;
 905         return(-1);
 906         }
 907
 908 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 909         {
 910         unsigned char *p,*d;
 911         int i;
 912         unsigned long l;
 913
 914         if (s->state == a)
 915                 {
 916                 d=(unsigned char *)s->init_buf->data;
 917                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 918
 919                 i=s->method->ssl3_enc->final_finish_mac(s,
 920                         &(s->s3->finish_dgst1),
 921                         &(s->s3->finish_dgst2),
 922                         sender,slen,s->s3->tmp.finish_md);
 923                 s->s3->tmp.finish_md_len = i;
 924                 memcpy(p, s->s3->tmp.finish_md, i);
 925                 p+=i;
 926                 l=i;
 927
 928         /* Copy the finished so we can use it for
 929          * renegotiation checks
 930          */
 931         if(s->type == SSL_ST_CONNECT)
 932                 {
 933                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 934                 memcpy(s->s3->previous_client_finished,
 935                        s->s3->tmp.finish_md, i);
 936                 s->s3->previous_client_finished_len=i;
 937                 }
 938         else
 939                 {
 940                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 941                 memcpy(s->s3->previous_server_finished,
 942                        s->s3->tmp.finish_md, i);
 943                 s->s3->previous_server_finished_len=i;
 944                 }
 945
 946 #ifdef OPENSSL_SYS_WIN16
 947                 /* MSVC 1.5 does not clear the top bytes of the word unless
 948                  * I do this.
 949                  */
 950                 l&=0xffff;
 951 #endif
 952
 953                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 954                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 955                 s->init_off=0;
 956
 957                 /* buffer the message to handle re-xmits */
 958                 dtls1_buffer_message(s, 0);
 959
 960                 s->state=b;
 961                 }
 962
 963         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 964         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 965         }
 966
 967 /* for these 2 messages, we need to
 968  * ssl->enc_read_ctx                    re-init
 969  * ssl->s3->read_sequence               zero
 970  * ssl->s3->read_mac_secret             re-init
 971  * ssl->session->read_sym_enc           assign
 972  * ssl->session->read_compression       assign
 973  * ssl->session->read_hash              assign
 974  */
 975 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 976         {
 977         unsigned char *p;
 978
 979         if (s->state == a)
 980                 {
 981                 p=(unsigned char *)s->init_buf->data;
 982                 *p++=SSL3_MT_CCS;
 983                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 984                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 985
 986                 if (s->client_version == DTLS1_BAD_VER)
 987                         {
 988                         s->d1->next_handshake_write_seq++;
 989                         s2n(s->d1->handshake_write_seq,p);
 990                         s->init_num+=2;
 991                         }
 992
 993                 s->init_off=0;
 994
 995                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 996                         s->d1->handshake_write_seq, 0, 0);
 997
 998                 /* buffer the message to handle re-xmits */
 999                 dtls1_buffer_message(s, 1);
1000
1001                 s->state=b;
1002                 }
1003
1004         /* SSL3_ST_CW_CHANGE_B */
1005         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1006         }
1007
1008 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1009         {
1010                 int n;
1011                 unsigned char *p;
1012
1013                 n=i2d_X509(x,NULL);
1014                 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1015                         {
1016                         SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1017                         return 0;
1018                         }
1019                 p=(unsigned char *)&(buf->data[*l]);
1020                 l2n3(n,p);
1021                 i2d_X509(x,&p);
1022                 *l+=n+3;
1023
1024                 return 1;
1025         }
1026 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1027         {
1028         unsigned char *p;
1029         int i;
1030         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1031         BUF_MEM *buf;
1032
1033         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1034         buf=s->init_buf;
1035         if (!BUF_MEM_grow_clean(buf,10))
1036                 {
1037                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1038                 return(0);
1039                 }
1040         if (x != NULL)
1041                 {
1042                 X509_STORE_CTX xs_ctx;
1043
1044                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1045                         {
1046                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1047                         return(0);
1048                         }
1049
1050                 X509_verify_cert(&xs_ctx);
1051                 /* Don't leave errors in the queue */
1052                 ERR_clear_error();
1053                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1054                         {
1055                         x = sk_X509_value(xs_ctx.chain, i);
1056
1057                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1058                                 {
1059                                 X509_STORE_CTX_cleanup(&xs_ctx);
1060                                 return 0;
1061                                 }
1062                         }
1063                 X509_STORE_CTX_cleanup(&xs_ctx);
1064                 }
1065         /* Thawte special :-) */
1066         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1067                 {
1068                 x=sk_X509_value(s->ctx->extra_certs,i);
1069                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1070                         return 0;
1071                 }
1072
1073         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1074
1075         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1076         l2n3(l,p);
1077         l+=3;
1078         p=(unsigned char *)&(buf->data[0]);
1079         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1080
1081         l+=DTLS1_HM_HEADER_LENGTH;
1082         return(l);
1083         }
1084
1085 int dtls1_read_failed(SSL *s, int code)
1086         {
1087         if ( code > 0)
1088                 {
1089                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1090                 return 1;
1091                 }
1092
1093         if (!dtls1_is_timer_expired(s))
1094                 {
1095                 /* not a timeout, none of our business,
1096                    let higher layers handle this.  in fact it's probably an error */
1097                 return code;
1098                 }
1099
1100         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1101                 {
1102                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1103                 return code;
1104                 }
1105
1106 #if 0 /* for now, each alert contains only one record number */
1107         item = pqueue_peek(state->rcvd_records);
1108         if ( item )
1109                 {
1110                 /* send an alert immediately for all the missing records */
1111                 }
1112         else
1113 #endif
1114
1115 #if 0  /* no more alert sending, just retransmit the last set of messages */
1116         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1117                 ssl3_send_alert(s,SSL3_AL_WARNING,
1118                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1119 #endif
1120
1121         return dtls1_handle_timeout(s);
1122         }
1123
1124 int
1125 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1126         {
1127         /* The index of the retransmission queue actually is the message sequence number,
1128          * since the queue only contains messages of a single handshake. However, the
1129          * ChangeCipherSpec has no message sequence number and so using only the sequence
1130          * will result in the CCS and Finished having the same index. To prevent this,
1131          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1132          * This does not only differ CSS and Finished, it also maintains the order of the
1133          * index (important for priority queues) and fits in the unsigned short variable.
1134          */
1135         return seq * 2 - is_ccs;
1136         }
1137
1138 int
1139 dtls1_retransmit_buffered_messages(SSL *s)
1140         {
1141         pqueue sent = s->d1->sent_messages;
1142         piterator iter;
1143         pitem *item;
1144         hm_fragment *frag;
1145         int found = 0;
1146
1147         iter = pqueue_iterator(sent);
1148
1149         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1150                 {
1151                 frag = (hm_fragment *)item->data;
1152                         if ( dtls1_retransmit_message(s,
1153                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1154                                 0, &found) <= 0 && found)
1155                         {
1156                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1157                         return -1;
1158                         }
1159                 }
1160
1161         return 1;
1162         }
1163
1164 int
1165 dtls1_buffer_message(SSL *s, int is_ccs)
1166         {
1167         pitem *item;
1168         hm_fragment *frag;
1169         PQ_64BIT seq64;
1170
1171         /* this function is called immediately after a message has
1172          * been serialized */
1173         OPENSSL_assert(s->init_off == 0);
1174
1175         frag = dtls1_hm_fragment_new(s->init_num, 0);
1176
1177         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1178
1179         if ( is_ccs)
1180                 {
1181                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1182                         DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
1183                 }
1184         else
1185                 {
1186                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1187                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1188                 }
1189
1190         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1191         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1192         frag->msg_header.type = s->d1->w_msg_hdr.type;
1193         frag->msg_header.frag_off = 0;
1194         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1195         frag->msg_header.is_ccs = is_ccs;
1196
1197         /* save current state*/
1198         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1199         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1200         frag->msg_header.saved_retransmit_state.compress = s->compress;
1201         frag->msg_header.saved_retransmit_state.session = s->session;
1202         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1203
1204         pq_64bit_init(&seq64);
1205
1206         pq_64bit_assign_word(&seq64,
1207                                                  dtls1_get_queue_priority(frag->msg_header.seq,
1208                                                                                                   frag->msg_header.is_ccs));
1209
1210         item = pitem_new(seq64, frag);
1211         pq_64bit_free(&seq64);
1212         if ( item == NULL)
1213                 {
1214                 dtls1_hm_fragment_free(frag);
1215                 return 0;
1216                 }
1217
1218 #if 0
1219         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1220         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1221         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1222 #endif
1223
1224         pqueue_insert(s->d1->sent_messages, item);
1225         return 1;
1226         }
1227
1228 int
1229 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1230         int *found)
1231         {
1232         int ret;
1233         /* XDTLS: for now assuming that read/writes are blocking */
1234         pitem *item;
1235         hm_fragment *frag ;
1236         unsigned long header_length;
1237         PQ_64BIT seq64;
1238         struct dtls1_retransmit_state saved_state;
1239         unsigned char save_write_sequence[8];
1240
1241         /*
1242           OPENSSL_assert(s->init_num == 0);
1243           OPENSSL_assert(s->init_off == 0);
1244          */
1245
1246         /* XDTLS:  the requested message ought to be found, otherwise error */
1247         pq_64bit_init(&seq64);
1248         pq_64bit_assign_word(&seq64, seq);
1249
1250         item = pqueue_find(s->d1->sent_messages, seq64);
1251         pq_64bit_free(&seq64);
1252         if ( item == NULL)
1253                 {
1254                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1255                 *found = 0;
1256                 return 0;
1257                 }
1258
1259         *found = 1;
1260         frag = (hm_fragment *)item->data;
1261
1262         if ( frag->msg_header.is_ccs)
1263                 header_length = DTLS1_CCS_HEADER_LENGTH;
1264         else
1265                 header_length = DTLS1_HM_HEADER_LENGTH;
1266
1267         memcpy(s->init_buf->data, frag->fragment,
1268                 frag->msg_header.msg_len + header_length);
1269                 s->init_num = frag->msg_header.msg_len + header_length;
1270
1271         dtls1_set_message_header_int(s, frag->msg_header.type,
1272                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1273                 frag->msg_header.frag_len);
1274
1275         /* save current state */
1276         saved_state.enc_write_ctx = s->enc_write_ctx;
1277         saved_state.write_hash = s->write_hash;
1278         saved_state.compress = s->compress;
1279         saved_state.session = s->session;
1280         saved_state.epoch = s->d1->w_epoch;
1281         saved_state.epoch = s->d1->w_epoch;
1282
1283         s->d1->retransmitting = 1;
1284
1285         /* restore state in which the message was originally sent */
1286         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1287         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1288         s->compress = frag->msg_header.saved_retransmit_state.compress;
1289         s->session = frag->msg_header.saved_retransmit_state.session;
1290         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1291
1292         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1293         {
1294                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1295                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1296         }
1297
1298         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1299                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1300
1301         /* restore current state */
1302         s->enc_write_ctx = saved_state.enc_write_ctx;
1303         s->write_hash = saved_state.write_hash;
1304         s->compress = saved_state.compress;
1305         s->session = saved_state.session;
1306         s->d1->w_epoch = saved_state.epoch;
1307
1308         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1309         {
1310                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1311                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1312         }
1313
1314         s->d1->retransmitting = 0;
1315
1316         (void)BIO_flush(SSL_get_wbio(s));
1317         return ret;
1318         }
1319
1320 /* call this function when the buffered messages are no longer needed */
1321 void
1322 dtls1_clear_record_buffer(SSL *s)
1323         {
1324         pitem *item;
1325
1326         for(item = pqueue_pop(s->d1->sent_messages);
1327                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1328                 {
1329                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1330                 pitem_free(item);
1331                 }
1332         }
1333
1334
1335 unsigned char *
1336 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1337                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1338         {
1339         /* Don't change sequence numbers while listening */
1340         if (frag_off == 0 && !s->d1->listen)
1341                 {
1342                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1343                 s->d1->next_handshake_write_seq++;
1344                 }
1345
1346         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1347                 frag_off, frag_len);
1348
1349         return p += DTLS1_HM_HEADER_LENGTH;
1350         }
1351
1352
1353 /* don't actually do the writing, wait till the MTU has been retrieved */
1354 static void
1355 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1356                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1357                             unsigned long frag_len)
1358         {
1359         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1360
1361         msg_hdr->type = mt;
1362         msg_hdr->msg_len = len;
1363         msg_hdr->seq = seq_num;
1364         msg_hdr->frag_off = frag_off;
1365         msg_hdr->frag_len = frag_len;
1366         }
1367
1368 static void
1369 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1370                         unsigned long frag_len)
1371         {
1372         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1373
1374         msg_hdr->frag_off = frag_off;
1375         msg_hdr->frag_len = frag_len;
1376         }
1377
1378 static unsigned char *
1379 dtls1_write_message_header(SSL *s, unsigned char *p)
1380         {
1381         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1382
1383         *p++ = msg_hdr->type;
1384         l2n3(msg_hdr->msg_len, p);
1385
1386         s2n(msg_hdr->seq, p);
1387         l2n3(msg_hdr->frag_off, p);
1388         l2n3(msg_hdr->frag_len, p);
1389
1390         return p;
1391         }
1392
1393 unsigned int
1394 dtls1_min_mtu(void)
1395         {
1396         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1397                 sizeof(g_probable_mtu[0])) - 1]);
1398         }
1399
1400 static unsigned int
1401 dtls1_guess_mtu(unsigned int curr_mtu)
1402         {
1403         size_t i;
1404
1405         if ( curr_mtu == 0 )
1406                 return g_probable_mtu[0] ;
1407
1408         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1409                 if ( curr_mtu > g_probable_mtu[i])
1410                         return g_probable_mtu[i];
1411
1412         return curr_mtu;
1413         }
1414
1415 void
1416 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1417         {
1418         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1419         msg_hdr->type = *(data++);
1420         n2l3(data, msg_hdr->msg_len);
1421
1422         n2s(data, msg_hdr->seq);
1423         n2l3(data, msg_hdr->frag_off);
1424         n2l3(data, msg_hdr->frag_len);
1425         }
1426
1427 void
1428 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1429         {
1430         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1431
1432         ccs_hdr->type = *(data++);
1433         }