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 ( ! (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                                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
 317                                 if ( len <= DTLS1_HM_HEADER_LENGTH)
 318                                         len += DTLS1_HM_HEADER_LENGTH;
 319                                 }
 320
 321                         dtls1_fix_message_header(s, frag_off,
 322                                 len - DTLS1_HM_HEADER_LENGTH);
 323
 324                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 325
 326                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 327                         }
 328
 329                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 330                         len);
 331                 if (ret < 0)
 332                         {
 333                         /* might need to update MTU here, but we don't know
 334                          * which previous packet caused the failure -- so can't
 335                          * really retransmit anything.  continue as if everything
 336                          * is fine and wait for an alert to handle the
 337                          * retransmit
 338                          */
 339                         if ( BIO_ctrl(SSL_get_wbio(s),
 340                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 341                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 342                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 343                         else
 344                                 return(-1);
 345                         }
 346                 else
 347                         {
 348
 349                         /* bad if this assert fails, only part of the handshake
 350                          * message got sent.  but why would this happen? */
 351                         OPENSSL_assert(len == (unsigned int)ret);
 352
 353                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 354                                 {
 355                                 /* should not be done for 'Hello Request's, but in that case
 356                                  * we'll ignore the result anyway */
 357                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 358                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 359                                 int xlen;
 360
 361                                 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER)
 362                                         {
 363                                         /* reconstruct message header is if it
 364                                          * is being sent in single fragment */
 365                                         *p++ = msg_hdr->type;
 366                                         l2n3(msg_hdr->msg_len,p);
 367                                         s2n (msg_hdr->seq,p);
 368                                         l2n3(0,p);
 369                                         l2n3(msg_hdr->msg_len,p);
 370                                         p  -= DTLS1_HM_HEADER_LENGTH;
 371                                         xlen = ret;
 372                                         }
 373                                 else
 374                                         {
 375                                         p  += DTLS1_HM_HEADER_LENGTH;
 376                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 377                                         }
 378
 379                                 ssl3_finish_mac(s, p, xlen);
 380                                 }
 381
 382                         if (ret == s->init_num)
 383                                 {
 384                                 if (s->msg_callback)
 385                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 386                                                 (size_t)(s->init_off + s->init_num), s,
 387                                                 s->msg_callback_arg);
 388
 389                                 s->init_off = 0;  /* done writing this message */
 390                                 s->init_num = 0;
 391
 392                                 return(1);
 393                                 }
 394                         s->init_off+=ret;
 395                         s->init_num-=ret;
 396                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 397                         }
 398                 }
 399         return(0);
 400         }
 401
 402
 403 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 404  * maximum acceptable body length 'max'.
 405  * Read an entire handshake message.  Handshake messages arrive in
 406  * fragments.
 407  */
 408 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 409         {
 410         int i, al;
 411         struct hm_header_st *msg_hdr;
 412         unsigned char *p;
 413         unsigned long msg_len;
 414
 415         /* s3->tmp is used to store messages that are unexpected, caused
 416          * by the absence of an optional handshake message */
 417         if (s->s3->tmp.reuse_message)
 418                 {
 419                 s->s3->tmp.reuse_message=0;
 420                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 421                         {
 422                         al=SSL_AD_UNEXPECTED_MESSAGE;
 423                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 424                         goto f_err;
 425                         }
 426                 *ok=1;
 427                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 428                 s->init_num = (int)s->s3->tmp.message_size;
 429                 return s->init_num;
 430                 }
 431
 432         msg_hdr = &s->d1->r_msg_hdr;
 433         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 434
 435 again:
 436         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 437         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 438                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 439                 goto again;
 440         else if ( i <= 0 && !*ok)
 441                 return i;
 442
 443         p = (unsigned char *)s->init_buf->data;
 444         msg_len = msg_hdr->msg_len;
 445
 446         /* reconstruct message header */
 447         *(p++) = msg_hdr->type;
 448         l2n3(msg_len,p);
 449         s2n (msg_hdr->seq,p);
 450         l2n3(0,p);
 451         l2n3(msg_len,p);
 452         if (s->version != DTLS1_BAD_VER) {
 453                 p       -= DTLS1_HM_HEADER_LENGTH;
 454                 msg_len += DTLS1_HM_HEADER_LENGTH;
 455         }
 456
 457         ssl3_finish_mac(s, p, msg_len);
 458         if (s->msg_callback)
 459                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 460                         p, msg_len,
 461                         s, s->msg_callback_arg);
 462
 463         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 464
 465         /* Don't change sequence numbers while listening */
 466         if (!s->d1->listen)
 467                 s->d1->handshake_read_seq++;
 468
 469         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 470         return s->init_num;
 471
 472 f_err:
 473         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 474         *ok = 0;
 475         return -1;
 476         }
 477
 478
 479 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 480         {
 481         size_t frag_off,frag_len,msg_len;
 482
 483         msg_len  = msg_hdr->msg_len;
 484         frag_off = msg_hdr->frag_off;
 485         frag_len = msg_hdr->frag_len;
 486
 487         /* sanity checking */
 488         if ( (frag_off+frag_len) > msg_len)
 489                 {
 490                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 491                 return SSL_AD_ILLEGAL_PARAMETER;
 492                 }
 493
 494         if ( (frag_off+frag_len) > (unsigned long)max)
 495                 {
 496                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 497                 return SSL_AD_ILLEGAL_PARAMETER;
 498                 }
 499
 500         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 501                 {
 502                 /* msg_len is limited to 2^24, but is effectively checked
 503                  * against max above */
 504                 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
 505                         {
 506                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 507                         return SSL_AD_INTERNAL_ERROR;
 508                         }
 509
 510                 s->s3->tmp.message_size  = msg_len;
 511                 s->d1->r_msg_hdr.msg_len = msg_len;
 512                 s->s3->tmp.message_type  = msg_hdr->type;
 513                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 514                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 515                 }
 516         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 517                 {
 518                 /* They must be playing with us! BTW, failure to enforce
 519                  * upper limit would open possibility for buffer overrun. */
 520                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 521                 return SSL_AD_ILLEGAL_PARAMETER;
 522                 }
 523
 524         return 0; /* no error */
 525         }
 526
 527
 528 static int
 529 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 530         {
 531         /* (0) check whether the desired fragment is available
 532          * if so:
 533          * (1) copy over the fragment to s->init_buf->data[]
 534          * (2) update s->init_num
 535          */
 536         pitem *item;
 537         hm_fragment *frag;
 538         int al;
 539
 540         *ok = 0;
 541         item = pqueue_peek(s->d1->buffered_messages);
 542         if ( item == NULL)
 543                 return 0;
 544
 545         frag = (hm_fragment *)item->data;
 546
 547         /* Don't return if reassembly still in progress */
 548         if (frag->reassembly != NULL)
 549                 return 0;
 550
 551         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 552                 {
 553                 unsigned long frag_len = frag->msg_header.frag_len;
 554                 pqueue_pop(s->d1->buffered_messages);
 555
 556                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 557
 558                 if (al==0) /* no alert */
 559                         {
 560                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 561                         memcpy(&p[frag->msg_header.frag_off],
 562                                 frag->fragment,frag->msg_header.frag_len);
 563                         }
 564
 565                 dtls1_hm_fragment_free(frag);
 566                 pitem_free(item);
 567
 568                 if (al==0)
 569                         {
 570                         *ok = 1;
 571                         return frag_len;
 572                         }
 573
 574                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 575                 s->init_num = 0;
 576                 *ok = 0;
 577                 return -1;
 578                 }
 579         else
 580                 return 0;
 581         }
 582
 583
 584 static int
 585 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 586         {
 587         hm_fragment *frag = NULL;
 588         pitem *item = NULL;
 589         int i = -1, is_complete;
 590         PQ_64BIT seq64;
 591         unsigned long frag_len = msg_hdr->frag_len, max_len;
 592
 593         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 594                 goto err;
 595
 596         /* Determine maximum allowed message size. Depends on (user set)
 597          * maximum certificate length, but 16k is minimum.
 598          */
 599         if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
 600                 max_len = s->max_cert_list;
 601         else
 602                 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 603
 604         if ((msg_hdr->frag_off+frag_len) > max_len)
 605                 goto err;
 606
 607         /* Try to find item in queue */
 608         pq_64bit_init(&seq64);
 609         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 610         item = pqueue_find(s->d1->buffered_messages, seq64);
 611         pq_64bit_free(&seq64);
 612
 613         if (item == NULL)
 614                 {
 615                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 616                 if ( frag == NULL)
 617                         goto err;
 618                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 619                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 620                 frag->msg_header.frag_off = 0;
 621                 }
 622         else
 623                 frag = (hm_fragment*) item->data;
 624
 625         /* If message is already reassembled, this must be a
 626          * retransmit and can be dropped.
 627          */
 628         if (frag->reassembly == NULL)
 629                 {
 630                 unsigned char devnull [256];
 631
 632                 while (frag_len)
 633                         {
 634                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 635                                 devnull,
 636                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 637                         if (i<=0) goto err;
 638                         frag_len -= i;
 639                         }
 640                 return DTLS1_HM_FRAGMENT_RETRY;
 641                 }
 642
 643         /* read the body of the fragment (header has already been read */
 644         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 645                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 646         if (i<=0 || (unsigned long)i!=frag_len)
 647                 goto err;
 648
 649         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 650                             (long)(msg_hdr->frag_off + frag_len));
 651
 652         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 653                                    is_complete);
 654
 655         if (is_complete)
 656                 {
 657                 OPENSSL_free(frag->reassembly);
 658                 frag->reassembly = NULL;
 659                 }
 660
 661         if (item == NULL)
 662                 {
 663                 pq_64bit_init(&seq64);
 664                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 665                 item = pitem_new(seq64, frag);
 666                 pq_64bit_free(&seq64);
 667
 668                 if (item == NULL)
 669                         {
 670                         goto err;
 671                         i = -1;
 672                         }
 673
 674                 pqueue_insert(s->d1->buffered_messages, item);
 675                 }
 676
 677         return DTLS1_HM_FRAGMENT_RETRY;
 678
 679 err:
 680         if (frag != NULL) dtls1_hm_fragment_free(frag);
 681         if (item != NULL) OPENSSL_free(item);
 682         *ok = 0;
 683         return i;
 684         }
 685
 686
 687 static int
 688 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 689 {
 690         int i=-1;
 691         hm_fragment *frag = NULL;
 692         pitem *item = NULL;
 693         PQ_64BIT seq64;
 694         unsigned long frag_len = msg_hdr->frag_len;
 695
 696         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 697                 goto err;
 698
 699         /* Try to find item in queue, to prevent duplicate entries */
 700         pq_64bit_init(&seq64);
 701         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 702         item = pqueue_find(s->d1->buffered_messages, seq64);
 703         pq_64bit_free(&seq64);
 704
 705         /* If we already have an entry and this one is a fragment,
 706          * don't discard it and rather try to reassemble it.
 707          */
 708         if (item != NULL && frag_len < msg_hdr->msg_len)
 709                 item = NULL;
 710
 711         /* Discard the message if sequence number was already there, is
 712          * too far in the future, already in the queue or if we received
 713          * a FINISHED before the SERVER_HELLO, which then must be a stale
 714          * retransmit.
 715          */
 716         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 717                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 718                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 719                 {
 720                 unsigned char devnull [256];
 721
 722                 while (frag_len)
 723                         {
 724                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 725                                 devnull,
 726                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 727                         if (i<=0) goto err;
 728                         frag_len -= i;
 729                         }
 730                 }
 731         else
 732                 {
 733                 if (frag_len && frag_len < msg_hdr->msg_len)
 734                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 735
 736                 frag = dtls1_hm_fragment_new(frag_len, 0);
 737                 if ( frag == NULL)
 738                         goto err;
 739
 740                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 741
 742                 if (frag_len)
 743                         {
 744                         /* read the body of the fragment (header has already been read) */
 745                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 746                                 frag->fragment,frag_len,0);
 747                         if (i<=0 || (unsigned long)i!=frag_len)
 748                                 goto err;
 749                         }
 750
 751                 pq_64bit_init(&seq64);
 752                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 753
 754                 item = pitem_new(seq64, frag);
 755                 pq_64bit_free(&seq64);
 756                 if ( item == NULL)
 757                         goto err;
 758
 759                 pqueue_insert(s->d1->buffered_messages, item);
 760                 }
 761
 762         return DTLS1_HM_FRAGMENT_RETRY;
 763
 764 err:
 765         if ( frag != NULL) dtls1_hm_fragment_free(frag);
 766         if ( item != NULL) OPENSSL_free(item);
 767         *ok = 0;
 768         return i;
 769         }
 770
 771
 772 static long
 773 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 774         {
 775         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 776         unsigned long len, frag_off, frag_len;
 777         int i,al;
 778         struct hm_header_st msg_hdr;
 779
 780         /* see if we have the required fragment already */
 781         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 782                 {
 783                 if (*ok)        s->init_num = frag_len;
 784                 return frag_len;
 785                 }
 786
 787         /* read handshake message header */
 788         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 789                 DTLS1_HM_HEADER_LENGTH, 0);
 790         if (i <= 0)     /* nbio, or an error */
 791                 {
 792                 s->rwstate=SSL_READING;
 793                 *ok = 0;
 794                 return i;
 795                 }
 796         /* Handshake fails if message header is incomplete */
 797         if (i != DTLS1_HM_HEADER_LENGTH)
 798                 {
 799                 al=SSL_AD_UNEXPECTED_MESSAGE;
 800                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 801                 goto f_err;
 802                 }
 803
 804         /* parse the message fragment header */
 805         dtls1_get_message_header(wire, &msg_hdr);
 806
 807         /*
 808          * if this is a future (or stale) message it gets buffered
 809          * (or dropped)--no further processing at this time
 810          * While listening, we accept seq 1 (ClientHello with cookie)
 811          * although we're still expecting seq 0 (ClientHello)
 812          */
 813         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 814                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 815
 816         len = msg_hdr.msg_len;
 817         frag_off = msg_hdr.frag_off;
 818         frag_len = msg_hdr.frag_len;
 819
 820         if (frag_len && frag_len < len)
 821                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 822
 823         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 824                 wire[0] == SSL3_MT_HELLO_REQUEST)
 825                 {
 826                 /* The server may always send 'Hello Request' messages --
 827                  * we are doing a handshake anyway now, so ignore them
 828                  * if their format is correct. Does not count for
 829                  * 'Finished' MAC. */
 830                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 831                         {
 832                         if (s->msg_callback)
 833                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 834                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 835                                         s->msg_callback_arg);
 836
 837                         s->init_num = 0;
 838                         return dtls1_get_message_fragment(s, st1, stn,
 839                                 max, ok);
 840                         }
 841                 else /* Incorrectly formated Hello request */
 842                         {
 843                         al=SSL_AD_UNEXPECTED_MESSAGE;
 844                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 845                         goto f_err;
 846                         }
 847                 }
 848
 849         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 850                 goto f_err;
 851
 852         /* XDTLS:  ressurect this when restart is in place */
 853         s->state=stn;
 854
 855         if ( frag_len > 0)
 856                 {
 857                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 858
 859                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 860                         &p[frag_off],frag_len,0);
 861                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 862                 if (i <= 0)
 863                         {
 864                         s->rwstate=SSL_READING;
 865                         *ok = 0;
 866                         return i;
 867                         }
 868                 }
 869         else
 870                 i = 0;
 871
 872         /* XDTLS:  an incorrectly formatted fragment should cause the
 873          * handshake to fail */
 874         if (i != (int)frag_len)
 875                 {
 876                 al=SSL3_AD_ILLEGAL_PARAMETER;
 877                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 878                 goto f_err;
 879                 }
 880
 881         *ok = 1;
 882
 883         /* Note that s->init_num is *not* used as current offset in
 884          * s->init_buf->data, but as a counter summing up fragments'
 885          * lengths: as soon as they sum up to handshake packet
 886          * length, we assume we have got all the fragments. */
 887         s->init_num = frag_len;
 888         return frag_len;
 889
 890 f_err:
 891         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 892         s->init_num = 0;
 893
 894         *ok=0;
 895         return(-1);
 896         }
 897
 898 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 899         {
 900         unsigned char *p,*d;
 901         int i;
 902         unsigned long l;
 903
 904         if (s->state == a)
 905                 {
 906                 d=(unsigned char *)s->init_buf->data;
 907                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 908
 909                 i=s->method->ssl3_enc->final_finish_mac(s,
 910                         &(s->s3->finish_dgst1),
 911                         &(s->s3->finish_dgst2),
 912                         sender,slen,s->s3->tmp.finish_md);
 913                 s->s3->tmp.finish_md_len = i;
 914                 memcpy(p, s->s3->tmp.finish_md, i);
 915                 p+=i;
 916                 l=i;
 917
 918         /* Copy the finished so we can use it for
 919          * renegotiation checks
 920          */
 921         if(s->type == SSL_ST_CONNECT)
 922                 {
 923                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 924                 memcpy(s->s3->previous_client_finished,
 925                        s->s3->tmp.finish_md, i);
 926                 s->s3->previous_client_finished_len=i;
 927                 }
 928         else
 929                 {
 930                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 931                 memcpy(s->s3->previous_server_finished,
 932                        s->s3->tmp.finish_md, i);
 933                 s->s3->previous_server_finished_len=i;
 934                 }
 935
 936 #ifdef OPENSSL_SYS_WIN16
 937                 /* MSVC 1.5 does not clear the top bytes of the word unless
 938                  * I do this.
 939                  */
 940                 l&=0xffff;
 941 #endif
 942
 943                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 944                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 945                 s->init_off=0;
 946
 947                 /* buffer the message to handle re-xmits */
 948                 dtls1_buffer_message(s, 0);
 949
 950                 s->state=b;
 951                 }
 952
 953         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 954         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 955         }
 956
 957 /* for these 2 messages, we need to
 958  * ssl->enc_read_ctx                    re-init
 959  * ssl->s3->read_sequence               zero
 960  * ssl->s3->read_mac_secret             re-init
 961  * ssl->session->read_sym_enc           assign
 962  * ssl->session->read_compression       assign
 963  * ssl->session->read_hash              assign
 964  */
 965 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 966         {
 967         unsigned char *p;
 968
 969         if (s->state == a)
 970                 {
 971                 p=(unsigned char *)s->init_buf->data;
 972                 *p++=SSL3_MT_CCS;
 973                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 974                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 975
 976                 if (s->client_version == DTLS1_BAD_VER)
 977                         {
 978                         s->d1->next_handshake_write_seq++;
 979                         s2n(s->d1->handshake_write_seq,p);
 980                         s->init_num+=2;
 981                         }
 982
 983                 s->init_off=0;
 984
 985                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 986                         s->d1->handshake_write_seq, 0, 0);
 987
 988                 /* buffer the message to handle re-xmits */
 989                 dtls1_buffer_message(s, 1);
 990
 991                 s->state=b;
 992                 }
 993
 994         /* SSL3_ST_CW_CHANGE_B */
 995         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 996         }
 997
 998 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
 999         {
1000                 int n;
1001                 unsigned char *p;
1002
1003                 n=i2d_X509(x,NULL);
1004                 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1005                         {
1006                         SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1007                         return 0;
1008                         }
1009                 p=(unsigned char *)&(buf->data[*l]);
1010                 l2n3(n,p);
1011                 i2d_X509(x,&p);
1012                 *l+=n+3;
1013
1014                 return 1;
1015         }
1016 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1017         {
1018         unsigned char *p;
1019         int i;
1020         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1021         BUF_MEM *buf;
1022
1023         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1024         buf=s->init_buf;
1025         if (!BUF_MEM_grow_clean(buf,10))
1026                 {
1027                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1028                 return(0);
1029                 }
1030         if (x != NULL)
1031                 {
1032                 X509_STORE_CTX xs_ctx;
1033
1034                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1035                         {
1036                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1037                         return(0);
1038                         }
1039
1040                 X509_verify_cert(&xs_ctx);
1041                 /* Don't leave errors in the queue */
1042                 ERR_clear_error();
1043                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1044                         {
1045                         x = sk_X509_value(xs_ctx.chain, i);
1046
1047                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1048                                 {
1049                                 X509_STORE_CTX_cleanup(&xs_ctx);
1050                                 return 0;
1051                                 }
1052                         }
1053                 X509_STORE_CTX_cleanup(&xs_ctx);
1054                 }
1055         /* Thawte special :-) */
1056         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1057                 {
1058                 x=sk_X509_value(s->ctx->extra_certs,i);
1059                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1060                         return 0;
1061                 }
1062
1063         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1064
1065         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1066         l2n3(l,p);
1067         l+=3;
1068         p=(unsigned char *)&(buf->data[0]);
1069         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1070
1071         l+=DTLS1_HM_HEADER_LENGTH;
1072         return(l);
1073         }
1074
1075 int dtls1_read_failed(SSL *s, int code)
1076         {
1077         if ( code > 0)
1078                 {
1079                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1080                 return 1;
1081                 }
1082
1083         if (!dtls1_is_timer_expired(s))
1084                 {
1085                 /* not a timeout, none of our business,
1086                    let higher layers handle this.  in fact it's probably an error */
1087                 return code;
1088                 }
1089
1090         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1091                 {
1092                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1093                 return code;
1094                 }
1095
1096 #if 0 /* for now, each alert contains only one record number */
1097         item = pqueue_peek(state->rcvd_records);
1098         if ( item )
1099                 {
1100                 /* send an alert immediately for all the missing records */
1101                 }
1102         else
1103 #endif
1104
1105 #if 0  /* no more alert sending, just retransmit the last set of messages */
1106         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1107                 ssl3_send_alert(s,SSL3_AL_WARNING,
1108                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1109 #endif
1110
1111         return dtls1_handle_timeout(s);
1112         }
1113
1114 int
1115 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1116         {
1117         /* The index of the retransmission queue actually is the message sequence number,
1118          * since the queue only contains messages of a single handshake. However, the
1119          * ChangeCipherSpec has no message sequence number and so using only the sequence
1120          * will result in the CCS and Finished having the same index. To prevent this,
1121          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1122          * This does not only differ CSS and Finished, it also maintains the order of the
1123          * index (important for priority queues) and fits in the unsigned short variable.
1124          */
1125         return seq * 2 - is_ccs;
1126         }
1127
1128 int
1129 dtls1_retransmit_buffered_messages(SSL *s)
1130         {
1131         pqueue sent = s->d1->sent_messages;
1132         piterator iter;
1133         pitem *item;
1134         hm_fragment *frag;
1135         int found = 0;
1136
1137         iter = pqueue_iterator(sent);
1138
1139         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1140                 {
1141                 frag = (hm_fragment *)item->data;
1142                         if ( dtls1_retransmit_message(s,
1143                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1144                                 0, &found) <= 0 && found)
1145                         {
1146                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1147                         return -1;
1148                         }
1149                 }
1150
1151         return 1;
1152         }
1153
1154 int
1155 dtls1_buffer_message(SSL *s, int is_ccs)
1156         {
1157         pitem *item;
1158         hm_fragment *frag;
1159         PQ_64BIT seq64;
1160
1161         /* this function is called immediately after a message has
1162          * been serialized */
1163         OPENSSL_assert(s->init_off == 0);
1164
1165         frag = dtls1_hm_fragment_new(s->init_num, 0);
1166
1167         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1168
1169         if ( is_ccs)
1170                 {
1171                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1172                         DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
1173                 }
1174         else
1175                 {
1176                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1177                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1178                 }
1179
1180         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1181         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1182         frag->msg_header.type = s->d1->w_msg_hdr.type;
1183         frag->msg_header.frag_off = 0;
1184         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1185         frag->msg_header.is_ccs = is_ccs;
1186
1187         /* save current state*/
1188         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1189         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1190         frag->msg_header.saved_retransmit_state.compress = s->compress;
1191         frag->msg_header.saved_retransmit_state.session = s->session;
1192         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1193
1194         pq_64bit_init(&seq64);
1195
1196         pq_64bit_assign_word(&seq64,
1197                                                  dtls1_get_queue_priority(frag->msg_header.seq,
1198                                                                                                   frag->msg_header.is_ccs));
1199
1200         item = pitem_new(seq64, frag);
1201         pq_64bit_free(&seq64);
1202         if ( item == NULL)
1203                 {
1204                 dtls1_hm_fragment_free(frag);
1205                 return 0;
1206                 }
1207
1208 #if 0
1209         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1210         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1211         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1212 #endif
1213
1214         pqueue_insert(s->d1->sent_messages, item);
1215         return 1;
1216         }
1217
1218 int
1219 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1220         int *found)
1221         {
1222         int ret;
1223         /* XDTLS: for now assuming that read/writes are blocking */
1224         pitem *item;
1225         hm_fragment *frag ;
1226         unsigned long header_length;
1227         PQ_64BIT seq64;
1228         struct dtls1_retransmit_state saved_state;
1229         unsigned char save_write_sequence[8];
1230
1231         /*
1232           OPENSSL_assert(s->init_num == 0);
1233           OPENSSL_assert(s->init_off == 0);
1234          */
1235
1236         /* XDTLS:  the requested message ought to be found, otherwise error */
1237         pq_64bit_init(&seq64);
1238         pq_64bit_assign_word(&seq64, seq);
1239
1240         item = pqueue_find(s->d1->sent_messages, seq64);
1241         pq_64bit_free(&seq64);
1242         if ( item == NULL)
1243                 {
1244                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1245                 *found = 0;
1246                 return 0;
1247                 }
1248
1249         *found = 1;
1250         frag = (hm_fragment *)item->data;
1251
1252         if ( frag->msg_header.is_ccs)
1253                 header_length = DTLS1_CCS_HEADER_LENGTH;
1254         else
1255                 header_length = DTLS1_HM_HEADER_LENGTH;
1256
1257         memcpy(s->init_buf->data, frag->fragment,
1258                 frag->msg_header.msg_len + header_length);
1259                 s->init_num = frag->msg_header.msg_len + header_length;
1260
1261         dtls1_set_message_header_int(s, frag->msg_header.type,
1262                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1263                 frag->msg_header.frag_len);
1264
1265         /* save current state */
1266         saved_state.enc_write_ctx = s->enc_write_ctx;
1267         saved_state.write_hash = s->write_hash;
1268         saved_state.compress = s->compress;
1269         saved_state.session = s->session;
1270         saved_state.epoch = s->d1->w_epoch;
1271         saved_state.epoch = s->d1->w_epoch;
1272
1273         s->d1->retransmitting = 1;
1274
1275         /* restore state in which the message was originally sent */
1276         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1277         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1278         s->compress = frag->msg_header.saved_retransmit_state.compress;
1279         s->session = frag->msg_header.saved_retransmit_state.session;
1280         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1281
1282         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1283         {
1284                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1285                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1286         }
1287
1288         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1289                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1290
1291         /* restore current state */
1292         s->enc_write_ctx = saved_state.enc_write_ctx;
1293         s->write_hash = saved_state.write_hash;
1294         s->compress = saved_state.compress;
1295         s->session = saved_state.session;
1296         s->d1->w_epoch = saved_state.epoch;
1297
1298         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1299         {
1300                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1301                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1302         }
1303
1304         s->d1->retransmitting = 0;
1305
1306         (void)BIO_flush(SSL_get_wbio(s));
1307         return ret;
1308         }
1309
1310 /* call this function when the buffered messages are no longer needed */
1311 void
1312 dtls1_clear_record_buffer(SSL *s)
1313         {
1314         pitem *item;
1315
1316         for(item = pqueue_pop(s->d1->sent_messages);
1317                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1318                 {
1319                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1320                 pitem_free(item);
1321                 }
1322         }
1323
1324
1325 unsigned char *
1326 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1327                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1328         {
1329         /* Don't change sequence numbers while listening */
1330         if (frag_off == 0 && !s->d1->listen)
1331                 {
1332                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1333                 s->d1->next_handshake_write_seq++;
1334                 }
1335
1336         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1337                 frag_off, frag_len);
1338
1339         return p += DTLS1_HM_HEADER_LENGTH;
1340         }
1341
1342
1343 /* don't actually do the writing, wait till the MTU has been retrieved */
1344 static void
1345 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1346                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1347                             unsigned long frag_len)
1348         {
1349         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1350
1351         msg_hdr->type = mt;
1352         msg_hdr->msg_len = len;
1353         msg_hdr->seq = seq_num;
1354         msg_hdr->frag_off = frag_off;
1355         msg_hdr->frag_len = frag_len;
1356         }
1357
1358 static void
1359 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1360                         unsigned long frag_len)
1361         {
1362         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1363
1364         msg_hdr->frag_off = frag_off;
1365         msg_hdr->frag_len = frag_len;
1366         }
1367
1368 static unsigned char *
1369 dtls1_write_message_header(SSL *s, unsigned char *p)
1370         {
1371         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1372
1373         *p++ = msg_hdr->type;
1374         l2n3(msg_hdr->msg_len, p);
1375
1376         s2n(msg_hdr->seq, p);
1377         l2n3(msg_hdr->frag_off, p);
1378         l2n3(msg_hdr->frag_len, p);
1379
1380         return p;
1381         }
1382
1383 unsigned int
1384 dtls1_min_mtu(void)
1385         {
1386         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1387                 sizeof(g_probable_mtu[0])) - 1]);
1388         }
1389
1390 static unsigned int
1391 dtls1_guess_mtu(unsigned int curr_mtu)
1392         {
1393         size_t i;
1394
1395         if ( curr_mtu == 0 )
1396                 return g_probable_mtu[0] ;
1397
1398         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1399                 if ( curr_mtu > g_probable_mtu[i])
1400                         return g_probable_mtu[i];
1401
1402         return curr_mtu;
1403         }
1404
1405 void
1406 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1407         {
1408         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1409         msg_hdr->type = *(data++);
1410         n2l3(data, msg_hdr->msg_len);
1411
1412         n2s(data, msg_hdr->seq);
1413         n2l3(data, msg_hdr->frag_off);
1414         n2l3(data, msg_hdr->frag_len);
1415         }
1416
1417 void
1418 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1419         {
1420         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1421
1422         ccs_hdr->type = *(data++);
1423         }