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
 127 /* XDTLS:  figure out the right values */
 128 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 129
 130 static unsigned int dtls1_min_mtu(void);
 131 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 132 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 133         unsigned long frag_len);
 134 static unsigned char *dtls1_write_message_header(SSL *s,
 135         unsigned char *p);
 136 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 137         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 138         unsigned long frag_len);
 139 static int dtls1_retransmit_buffered_messages(SSL *s);
 140 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 141         long max, int *ok);
 142 static void dtls1_process_handshake_fragment(SSL *s, int frag_len);
 143
 144 static hm_fragment *
 145 dtls1_hm_fragment_new(unsigned long frag_len)
 146         {
 147         hm_fragment *frag = NULL;
 148         unsigned char *buf = NULL;
 149
 150         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 151         if ( frag == NULL)
 152                 return NULL;
 153
 154         buf = (unsigned char *)OPENSSL_malloc(frag_len
 155                 + DTLS1_HM_HEADER_LENGTH);
 156         if ( buf == NULL)
 157                 {
 158                 OPENSSL_free(frag);
 159                 return NULL;
 160                 }
 161
 162         frag->fragment = buf;
 163
 164         return frag;
 165         }
 166
 167 static void
 168 dtls1_hm_fragment_free(hm_fragment *frag)
 169         {
 170         OPENSSL_free(frag->fragment);
 171         OPENSSL_free(frag);
 172         }
 173
 174 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 175 int dtls1_do_write(SSL *s, int type)
 176         {
 177         int ret;
 178         int curr_mtu;
 179         unsigned int len, frag_off;
 180
 181         /* AHA!  Figure out the MTU, and stick to the right size */
 182         if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 183                 {
 184                 s->d1->mtu =
 185                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 186
 187                 /* I've seen the kernel return bogus numbers when it doesn't know
 188                  * (initial write), so just make sure we have a reasonable number */
 189                 if ( s->d1->mtu < dtls1_min_mtu())
 190                         {
 191                         s->d1->mtu = 0;
 192                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 193                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 194                                 s->d1->mtu, NULL);
 195                         }
 196                 }
 197 #if 0
 198         mtu = s->d1->mtu;
 199
 200         fprintf(stderr, "using MTU = %d\n", mtu);
 201
 202         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 203
 204         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 205
 206         if ( curr_mtu > 0)
 207                 mtu = curr_mtu;
 208         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 209                 return ret;
 210
 211         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 212                 {
 213                 ret = BIO_flush(SSL_get_wbio(s));
 214                 if ( ret <= 0)
 215                         return ret;
 216                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 217                 }
 218
 219         OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
 220
 221 #endif
 222
 223         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 224                 OPENSSL_assert(s->init_num ==
 225                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 226
 227         frag_off = 0;
 228         while( s->init_num)
 229                 {
 230                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 231                         DTLS1_RT_HEADER_LENGTH;
 232
 233                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 234                         {
 235                         /* grr.. we could get an error if MTU picked was wrong */
 236                         ret = BIO_flush(SSL_get_wbio(s));
 237                         if ( ret <= 0)
 238                                 return ret;
 239                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;
 240                         }
 241
 242                 if ( s->init_num > curr_mtu)
 243                         len = curr_mtu;
 244                 else
 245                         len = s->init_num;
 246
 247
 248                 /* XDTLS: this function is too long.  split out the CCS part */
 249                 if ( type == SSL3_RT_HANDSHAKE)
 250                         {
 251                         if ( s->init_off != 0)
 252                                 {
 253                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 254                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 255                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 256
 257                                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
 258                                 if ( len <= DTLS1_HM_HEADER_LENGTH)
 259                                         len += DTLS1_HM_HEADER_LENGTH;
 260                                 }
 261
 262                         dtls1_fix_message_header(s, frag_off,
 263                                 len - DTLS1_HM_HEADER_LENGTH);
 264
 265                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 266
 267                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 268                         }
 269
 270                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 271                         len);
 272                 if (ret < 0)
 273                         {
 274                         /* might need to update MTU here, but we don't know
 275                          * which previous packet caused the failure -- so can't
 276                          * really retransmit anything.  continue as if everything
 277                          * is fine and wait for an alert to handle the
 278                          * retransmit
 279                          */
 280                         if ( BIO_ctrl(SSL_get_wbio(s),
 281                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
 282                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 283                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 284                         else
 285                                 return(-1);
 286                         }
 287                 else
 288                         {
 289
 290                         /* bad if this assert fails, only part of the handshake
 291                          * message got sent.  but why would this happen? */
 292                         OPENSSL_assert(len == (unsigned int)ret);
 293
 294                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 295                                 /* should not be done for 'Hello Request's, but in that case
 296                                  * we'll ignore the result anyway */
 297                                 ssl3_finish_mac(s,
 298                                         (unsigned char *)&s->init_buf->data[s->init_off +
 299                                                 DTLS1_HM_HEADER_LENGTH], ret - DTLS1_HM_HEADER_LENGTH);
 300
 301                         if (ret == s->init_num)
 302                                 {
 303                                 if (s->msg_callback)
 304                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 305                                                 (size_t)(s->init_off + s->init_num), s,
 306                                                 s->msg_callback_arg);
 307
 308                                 s->init_off = 0;  /* done writing this message */
 309                                 s->init_num = 0;
 310
 311                                 return(1);
 312                                 }
 313                         s->init_off+=ret;
 314                         s->init_num-=ret;
 315                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 316                         }
 317                 }
 318         return(0);
 319         }
 320
 321
 322 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 323  * maximum acceptable body length 'max'.
 324  * Read an entire handshake message.  Handshake messages arrive in
 325  * fragments.
 326  */
 327 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 328         {
 329         int i, al;
 330
 331         /* s3->tmp is used to store messages that are unexpected, caused
 332          * by the absence of an optional handshake message */
 333         if (s->s3->tmp.reuse_message)
 334                 {
 335                 s->s3->tmp.reuse_message=0;
 336                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 337                         {
 338                         al=SSL_AD_UNEXPECTED_MESSAGE;
 339                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 340                         goto f_err;
 341                         }
 342                 *ok=1;
 343                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 344                 s->init_num = (int)s->s3->tmp.message_size;
 345                 return s->init_num;
 346                 }
 347
 348         do
 349                 {
 350                 if ( s->d1->r_msg_hdr.frag_off == 0)
 351                         {
 352                         /* s->d1->r_message_header.msg_len = 0; */
 353                         memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
 354                         }
 355
 356                 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 357                 if ( i == DTLS1_HM_BAD_FRAGMENT ||
 358                         i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 359                         continue;
 360                 else if ( i <= 0 && !*ok)
 361                         return i;
 362
 363                 if (s->d1->r_msg_hdr.msg_len == (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
 364                         {
 365                         memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
 366
 367                         s->d1->handshake_read_seq++;
 368                         /* we just read a handshake message from the other side:
 369                          * this means that we don't need to retransmit of the
 370                          * buffered messages.
 371                          * XDTLS: may be able clear out this
 372                          * buffer a little sooner (i.e if an out-of-order
 373                          * handshake message/record is received at the record
 374                          * layer.
 375                          * XDTLS: exception is that the server needs to
 376                          * know that change cipher spec and finished messages
 377                          * have been received by the client before clearing this
 378                          * buffer.  this can simply be done by waiting for the
 379                          * first data  segment, but is there a better way?  */
 380                         dtls1_clear_record_buffer(s);
 381
 382                         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 383                         return s->init_num - DTLS1_HM_HEADER_LENGTH;
 384                         }
 385                 else
 386                         s->d1->r_msg_hdr.frag_off = i;
 387                 } while(1) ;
 388
 389 f_err:
 390         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 391         *ok = 0;
 392         return -1;
 393         }
 394
 395
 396 static int
 397 dtls1_retrieve_buffered_fragment(SSL *s, unsigned long *copied)
 398         {
 399         /* (0) check whether the desired fragment is available
 400          * if so:
 401          * (1) copy over the fragment to s->init_buf->data[]
 402          * (2) update s->init_num
 403          */
 404         pitem *item;
 405         hm_fragment *frag;
 406         unsigned long overlap;
 407         unsigned char *p;
 408
 409         item = pqueue_peek(s->d1->buffered_messages);
 410         if ( item == NULL)
 411                 return 0;
 412
 413         frag = (hm_fragment *)item->data;
 414
 415         if ( s->d1->handshake_read_seq == frag->msg_header.seq &&
 416                 frag->msg_header.frag_off <= (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
 417                 {
 418                 pqueue_pop(s->d1->buffered_messages);
 419                 overlap = s->init_num - DTLS1_HM_HEADER_LENGTH
 420                         - frag->msg_header.frag_off;
 421
 422                 p = frag->fragment;
 423
 424                 memcpy(&s->init_buf->data[s->init_num],
 425                         p + DTLS1_HM_HEADER_LENGTH + overlap,
 426                         frag->msg_header.frag_len - overlap);
 427
 428                 OPENSSL_free(frag->fragment);
 429                 OPENSSL_free(frag);
 430                 pitem_free(item);
 431
 432                 *copied = frag->msg_header.frag_len - overlap;
 433                 return *copied;
 434                 }
 435         else
 436                 return 0;
 437         }
 438
 439
 440 static int
 441 dtls1_buffer_handshake_fragment(SSL *s, struct hm_header_st* msg_hdr)
 442 {
 443         hm_fragment *frag = NULL;
 444         pitem *item = NULL;
 445         unsigned char seq64be[8];
 446
 447         frag = dtls1_hm_fragment_new(msg_hdr->frag_len);
 448         if ( frag == NULL)
 449                 goto err;
 450
 451         memcpy(frag->fragment, &(s->init_buf->data[s->init_num]),
 452                 msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH);
 453
 454         memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 455
 456         memset(seq64be,0,sizeof(seq64be));
 457         seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
 458         seq64be[7] = (unsigned char)(msg_hdr->seq);
 459
 460         item = pitem_new(seq64be, frag);
 461         if ( item == NULL)
 462                 goto err;
 463
 464         pqueue_insert(s->d1->buffered_messages, item);
 465         return 1;
 466
 467 err:
 468         if ( frag != NULL) dtls1_hm_fragment_free(frag);
 469         if ( item != NULL) OPENSSL_free(item);
 470         return 0;
 471 }
 472
 473
 474 static void
 475 dtls1_process_handshake_fragment(SSL *s, int frag_len)
 476         {
 477         unsigned char *p;
 478
 479         p = (unsigned char *)s->init_buf->data;
 480
 481         ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len);
 482         }
 483
 484
 485 static int
 486 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok)
 487         {
 488         int i;
 489         unsigned char *p;
 490
 491         /* make sure there's enough room to read this fragment */
 492         if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf,
 493                          (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num))
 494                 {
 495                 SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB);
 496                 goto err;
 497                 }
 498
 499         p = (unsigned char *)s->init_buf->data;
 500
 501         /* read the body of the fragment (header has already been read */
 502         if ( msg_hdr->frag_len > 0)
 503                 {
 504                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 505                         &p[s->init_num],
 506                         msg_hdr->frag_len,0);
 507                 if (i <= 0)
 508                         {
 509                         *ok = 0;
 510                         return i;
 511                         }
 512                 }
 513
 514         if ( msg_hdr->seq > s->d1->handshake_read_seq)
 515                 dtls1_buffer_handshake_fragment(s, msg_hdr);
 516         else
 517                 OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq);
 518
 519         return DTLS1_HM_FRAGMENT_RETRY;
 520 err:
 521         *ok = 0;
 522         return -1;
 523         }
 524
 525
 526 static long
 527 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 528         {
 529         unsigned char *p;
 530         unsigned long l, frag_off, frag_len;
 531         int i,al;
 532         struct hm_header_st msg_hdr;
 533         unsigned long overlap;
 534
 535         /* see if we have the required fragment already */
 536         if (dtls1_retrieve_buffered_fragment(s, &l))
 537         {
 538                 /* compute MAC, remove fragment headers */
 539                 dtls1_process_handshake_fragment(s, l);
 540                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 541                 s->state = stn;
 542                 return 1;
 543         }
 544
 545         /* get a handshake fragment from the record layer */
 546         p = (unsigned char *)s->init_buf->data;
 547
 548         /* read handshake message header */
 549         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
 550                 DTLS1_HM_HEADER_LENGTH, 0);
 551         if (i <= 0)     /* nbio, or an error */
 552                 {
 553                 s->rwstate=SSL_READING;
 554                 *ok = 0;
 555                 return i;
 556                 }
 557
 558         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
 559
 560         p += s->init_num;
 561         /* parse the message fragment header */
 562
 563         dtls1_get_message_header(p, &msg_hdr);
 564
 565         /*
 566          * if this is a future (or stale) message it gets buffered
 567          * (or dropped)--no further processing at this time
 568          */
 569         if ( msg_hdr.seq != s->d1->handshake_read_seq)
 570                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 571
 572         l = msg_hdr.msg_len;
 573         frag_off = msg_hdr.frag_off;
 574         frag_len = msg_hdr.frag_len;
 575
 576         /* sanity checking */
 577         if ( frag_off + frag_len > l)
 578                 {
 579                 al=SSL_AD_ILLEGAL_PARAMETER;
 580                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 581                 goto f_err;
 582                 }
 583
 584         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 585                 p[0] == SSL3_MT_HELLO_REQUEST)
 586                 {
 587                 /* The server may always send 'Hello Request' messages --
 588                  * we are doing a handshake anyway now, so ignore them
 589                  * if their format is correct. Does not count for
 590                  * 'Finished' MAC. */
 591                 if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
 592                         {
 593                         if (s->msg_callback)
 594                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 595                                         p, DTLS1_HM_HEADER_LENGTH, s,
 596                                         s->msg_callback_arg);
 597
 598                         s->init_num = 0;
 599                         return dtls1_get_message_fragment(s, st1, stn,
 600                                 max, ok);
 601                         }
 602                 else /* Incorrectly formated Hello request */
 603                         {
 604                         al=SSL_AD_UNEXPECTED_MESSAGE;
 605                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 606                         goto f_err;
 607                         }
 608                 }
 609
 610         /* XDTLS: do a sanity check on the fragment */
 611
 612         s->init_num += i;
 613
 614         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 615                 {
 616                 /* BUF_MEM_grow takes an 'int' parameter */
 617                 if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH))
 618                         {
 619                         al=SSL_AD_ILLEGAL_PARAMETER;
 620                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 621                         goto f_err;
 622                         }
 623                 if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
 624                         + DTLS1_HM_HEADER_LENGTH))
 625                         {
 626                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
 627                         goto err;
 628                         }
 629                 /* Only do this test when we're reading the expected message.
 630                  * Stale messages will be dropped and future messages will be buffered */
 631                 if ( l > (unsigned long)max)
 632                         {
 633                         al=SSL_AD_ILLEGAL_PARAMETER;
 634                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 635                         goto f_err;
 636                         }
 637
 638                 s->s3->tmp.message_size=l;
 639                 }
 640
 641         if ( frag_len > (unsigned long)max)
 642                 {
 643                 al=SSL_AD_ILLEGAL_PARAMETER;
 644                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 645                 goto f_err;
 646                 }
 647         if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
 648                 {
 649                 al=SSL_AD_ILLEGAL_PARAMETER;
 650                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 651                 goto f_err;
 652                 }
 653
 654         if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len
 655                          + DTLS1_HM_HEADER_LENGTH + s->init_num))
 656                 {
 657                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
 658                 goto err;
 659                 }
 660
 661         if ( s->d1->r_msg_hdr.frag_off == 0)
 662                 {
 663                 s->s3->tmp.message_type = msg_hdr.type;
 664                 s->d1->r_msg_hdr.type = msg_hdr.type;
 665                 s->d1->r_msg_hdr.msg_len = l;
 666                 /* s->d1->r_msg_hdr.seq = seq_num; */
 667                 }
 668
 669         /* XDTLS:  ressurect this when restart is in place */
 670         s->state=stn;
 671
 672         /* next state (stn) */
 673         p = (unsigned char *)s->init_buf->data;
 674
 675         if ( frag_len > 0)
 676                 {
 677                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 678                         &p[s->init_num],
 679                         frag_len,0);
 680                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 681                 if (i <= 0)
 682                         {
 683                         s->rwstate=SSL_READING;
 684                         *ok = 0;
 685                         return i;
 686                         }
 687                 }
 688         else
 689                 i = 0;
 690
 691         /* XDTLS:  an incorrectly formatted fragment should cause the
 692          * handshake to fail */
 693         OPENSSL_assert(i == (int)frag_len);
 694
 695 #if 0
 696         /* Successfully read a fragment.
 697          * It may be (1) out of order, or
 698          *                 (2) it's a repeat, in which case we dump it
 699          *                 (3) the one we are expecting next (maybe with overlap)
 700          * If it is next one, it may overlap with previously read bytes
 701          */
 702
 703         /* case (1): buffer the future fragment
 704          * (we can treat fragments from a future message the same
 705          * as future fragments from the message being currently read, since
 706          * they are sematically simply out of order.
 707          */
 708         if ( msg_hdr.seq > s->d1->handshake_read_seq ||
 709                 frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
 710         {
 711                 dtls1_buffer_handshake_fragment(s, &msg_hdr);
 712                 return DTLS1_HM_FRAGMENT_RETRY;
 713         }
 714
 715         /* case (2):  drop the entire fragment, and try again */
 716         if ( msg_hdr.seq < s->d1->handshake_read_seq ||
 717                 frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
 718                 {
 719                 s->init_num -= DTLS1_HM_HEADER_LENGTH;
 720                 return DTLS1_HM_FRAGMENT_RETRY;
 721                 }
 722 #endif
 723
 724         /* case (3): received a immediately useful fragment.  Determine the
 725          * possible overlap and copy the fragment.
 726          */
 727         overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
 728
 729         /* retain the header for the first fragment */
 730         if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
 731                 {
 732                 memmove(&(s->init_buf->data[s->init_num]),
 733                         &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
 734                         frag_len - overlap);
 735
 736                 s->init_num += frag_len - overlap;
 737                 }
 738         else
 739                 s->init_num += frag_len;
 740
 741         dtls1_process_handshake_fragment(s, frag_len - overlap);
 742
 743         if (s->msg_callback)
 744                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
 745                         (size_t)s->init_num, s,
 746                         s->msg_callback_arg);
 747         *ok=1;
 748
 749         return s->init_num;
 750
 751 f_err:
 752         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 753         s->init_num = 0;
 754 err:
 755         *ok=0;
 756         return(-1);
 757         }
 758
 759 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 760         {
 761         unsigned char *p,*d;
 762         int i;
 763         unsigned long l;
 764
 765         if (s->state == a)
 766                 {
 767                 d=(unsigned char *)s->init_buf->data;
 768                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 769
 770                 i=s->method->ssl3_enc->final_finish_mac(s,
 771                         sender,slen,s->s3->tmp.finish_md);
 772                 s->s3->tmp.finish_md_len = i;
 773                 memcpy(p, s->s3->tmp.finish_md, i);
 774                 p+=i;
 775                 l=i;
 776
 777 #ifdef OPENSSL_SYS_WIN16
 778                 /* MSVC 1.5 does not clear the top bytes of the word unless
 779                  * I do this.
 780                  */
 781                 l&=0xffff;
 782 #endif
 783
 784                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 785                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 786                 s->init_off=0;
 787
 788                 /* buffer the message to handle re-xmits */
 789                 dtls1_buffer_message(s, 0);
 790
 791                 s->state=b;
 792                 }
 793
 794         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 795         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 796         }
 797
 798 /* for these 2 messages, we need to
 799  * ssl->enc_read_ctx                    re-init
 800  * ssl->s3->read_sequence               zero
 801  * ssl->s3->read_mac_secret             re-init
 802  * ssl->session->read_sym_enc           assign
 803  * ssl->session->read_compression       assign
 804  * ssl->session->read_hash              assign
 805  */
 806 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 807         {
 808         unsigned char *p;
 809
 810         if (s->state == a)
 811                 {
 812                 p=(unsigned char *)s->init_buf->data;
 813                 *p++=SSL3_MT_CCS;
 814                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 815                 s->d1->next_handshake_write_seq++;
 816                 s2n(s->d1->handshake_write_seq,p);
 817
 818                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 819                 s->init_off=0;
 820
 821                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 822                         s->d1->handshake_write_seq, 0, 0);
 823
 824                 /* buffer the message to handle re-xmits */
 825                 dtls1_buffer_message(s, 1);
 826
 827                 s->state=b;
 828                 }
 829
 830         /* SSL3_ST_CW_CHANGE_B */
 831         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 832         }
 833
 834 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
 835         {
 836         unsigned char *p;
 837         int n,i;
 838         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
 839         BUF_MEM *buf;
 840         X509_STORE_CTX xs_ctx;
 841         X509_OBJECT obj;
 842
 843         /* TLSv1 sends a chain with nothing in it, instead of an alert */
 844         buf=s->init_buf;
 845         if (!BUF_MEM_grow_clean(buf,10))
 846                 {
 847                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 848                 return(0);
 849                 }
 850         if (x != NULL)
 851                 {
 852                 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
 853                         {
 854                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
 855                         return(0);
 856                         }
 857
 858                 for (;;)
 859                         {
 860                         n=i2d_X509(x,NULL);
 861                         if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
 862                                 {
 863                                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 864                                 return(0);
 865                                 }
 866                         p=(unsigned char *)&(buf->data[l]);
 867                         l2n3(n,p);
 868                         i2d_X509(x,&p);
 869                         l+=n+3;
 870                         if (X509_NAME_cmp(X509_get_subject_name(x),
 871                                 X509_get_issuer_name(x)) == 0) break;
 872
 873                         i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
 874                                 X509_get_issuer_name(x),&obj);
 875                         if (i <= 0) break;
 876                         x=obj.data.x509;
 877                         /* Count is one too high since the X509_STORE_get uped the
 878                          * ref count */
 879                         X509_free(x);
 880                         }
 881
 882                 X509_STORE_CTX_cleanup(&xs_ctx);
 883                 }
 884
 885         /* Thawte special :-) */
 886         if (s->ctx->extra_certs != NULL)
 887         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
 888                 {
 889                 x=sk_X509_value(s->ctx->extra_certs,i);
 890                 n=i2d_X509(x,NULL);
 891                 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
 892                         {
 893                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 894                         return(0);
 895                         }
 896                 p=(unsigned char *)&(buf->data[l]);
 897                 l2n3(n,p);
 898                 i2d_X509(x,&p);
 899                 l+=n+3;
 900                 }
 901
 902         l-= (3 + DTLS1_HM_HEADER_LENGTH);
 903
 904         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
 905         l2n3(l,p);
 906         l+=3;
 907         p=(unsigned char *)&(buf->data[0]);
 908         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
 909
 910         l+=DTLS1_HM_HEADER_LENGTH;
 911         return(l);
 912         }
 913
 914 int dtls1_read_failed(SSL *s, int code)
 915         {
 916         DTLS1_STATE *state;
 917         BIO *bio;
 918         int send_alert = 0;
 919
 920         if ( code > 0)
 921                 {
 922                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
 923                 return 1;
 924                 }
 925
 926         bio = SSL_get_rbio(s);
 927         if ( ! BIO_dgram_recv_timedout(bio))
 928                 {
 929                 /* not a timeout, none of our business,
 930                    let higher layers handle this.  in fact it's probably an error */
 931                 return code;
 932                 }
 933
 934         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
 935                 {
 936                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
 937                 return code;
 938                 }
 939
 940         state = s->d1;
 941         state->timeout.num_alerts++;
 942         if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 943                 {
 944                 /* fail the connection, enough alerts have been sent */
 945                 SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
 946                 return 0;
 947                 }
 948
 949         state->timeout.read_timeouts++;
 950         if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 951                 {
 952                 send_alert = 1;
 953                 state->timeout.read_timeouts = 1;
 954                 }
 955
 956
 957 #if 0 /* for now, each alert contains only one record number */
 958         item = pqueue_peek(state->rcvd_records);
 959         if ( item )
 960                 {
 961                 /* send an alert immediately for all the missing records */
 962                 }
 963         else
 964 #endif
 965
 966 #if 0  /* no more alert sending, just retransmit the last set of messages */
 967                 if ( send_alert)
 968                         ssl3_send_alert(s,SSL3_AL_WARNING,
 969                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 970 #endif
 971
 972         return dtls1_retransmit_buffered_messages(s) ;
 973         }
 974
 975
 976 static int
 977 dtls1_retransmit_buffered_messages(SSL *s)
 978         {
 979         pqueue sent = s->d1->sent_messages;
 980         piterator iter;
 981         pitem *item;
 982         hm_fragment *frag;
 983         int found = 0;
 984
 985         iter = pqueue_iterator(sent);
 986
 987         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
 988                 {
 989                 frag = (hm_fragment *)item->data;
 990                 if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
 991                         found)
 992                         {
 993                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
 994                         return -1;
 995                         }
 996                 }
 997
 998         return 1;
 999         }
1000
1001 #if 0
1002 static dtls1_message_buffer *
1003 dtls1_message_buffer_new(unsigned int len)
1004         {
1005         dtls1_message_buffer *msg_buf;
1006
1007         msg_buf = (dtls1_message_buffer *)
1008                 OPENSSL_malloc(sizeof(dtls1_message_buffer));
1009         if ( msg_buf == NULL)
1010                 return NULL;
1011
1012         memset(msg_buf, 0x00, sizeof(dtls1_message_buffer));
1013
1014         msg_buf->data = (unsigned char *) OPENSSL_malloc(len);
1015         if ( msg_buf->data == NULL)
1016                 {
1017                 OPENSSL_free(msg_buf);
1018                 return NULL;
1019                 }
1020
1021         memset(msg_buf->data, 0x00, len);
1022         return msg_buf;
1023         }
1024 #endif
1025
1026 #if 0
1027 static void
1028 dtls1_message_buffer_free(dtls1_message_buffer *msg_buf)
1029         {
1030         if (msg_buf != NULL)
1031                 {
1032                 OPENSSL_free(msg_buf->data);
1033                 OPENSSL_free(msg_buf);
1034                 }
1035         }
1036 #endif
1037
1038 int
1039 dtls1_buffer_message(SSL *s, int is_ccs)
1040         {
1041         pitem *item;
1042         hm_fragment *frag;
1043         unsigned char seq64be[8];
1044
1045         /* this function is called immediately after a message has
1046          * been serialized */
1047         OPENSSL_assert(s->init_off == 0);
1048
1049         frag = dtls1_hm_fragment_new(s->init_num);
1050
1051         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1052
1053         if ( is_ccs)
1054                 {
1055                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1056                         DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1057                 }
1058         else
1059                 {
1060                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1061                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1062                 }
1063
1064         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1065         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1066         frag->msg_header.type = s->d1->w_msg_hdr.type;
1067         frag->msg_header.frag_off = 0;
1068         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1069         frag->msg_header.is_ccs = is_ccs;
1070
1071         memset(seq64be,0,sizeof(seq64be));
1072         seq64be[6] = (unsigned char)(frag->msg_header.seq>>8);
1073         seq64be[7] = (unsigned char)(frag->msg_header.seq);
1074
1075         item = pitem_new(seq64be, frag);
1076         if ( item == NULL)
1077                 {
1078                 dtls1_hm_fragment_free(frag);
1079                 return 0;
1080                 }
1081
1082 #if 0
1083         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1084         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1085         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1086 #endif
1087
1088         pqueue_insert(s->d1->sent_messages, item);
1089         return 1;
1090         }
1091
1092 int
1093 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1094         int *found)
1095         {
1096         int ret;
1097         /* XDTLS: for now assuming that read/writes are blocking */
1098         pitem *item;
1099         hm_fragment *frag ;
1100         unsigned long header_length;
1101         unsigned char seq64be[8];
1102
1103         /*
1104           OPENSSL_assert(s->init_num == 0);
1105           OPENSSL_assert(s->init_off == 0);
1106          */
1107
1108         /* XDTLS:  the requested message ought to be found, otherwise error */
1109         memset(seq64be,0,sizeof(seq64be));
1110         seq64be[6] = (unsigned char)(seq>>8);
1111         seq64be[7] = (unsigned char)seq;
1112
1113         item = pqueue_find(s->d1->sent_messages, seq64be);
1114         if ( item == NULL)
1115                 {
1116                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1117                 *found = 0;
1118                 return 0;
1119                 }
1120
1121         *found = 1;
1122         frag = (hm_fragment *)item->data;
1123
1124         if ( frag->msg_header.is_ccs)
1125                 header_length = DTLS1_CCS_HEADER_LENGTH;
1126         else
1127                 header_length = DTLS1_HM_HEADER_LENGTH;
1128
1129         memcpy(s->init_buf->data, frag->fragment,
1130                 frag->msg_header.msg_len + header_length);
1131                 s->init_num = frag->msg_header.msg_len + header_length;
1132
1133         dtls1_set_message_header_int(s, frag->msg_header.type,
1134                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1135                 frag->msg_header.frag_len);
1136
1137         s->d1->retransmitting = 1;
1138         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1139                 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1140         s->d1->retransmitting = 0;
1141
1142         (void)BIO_flush(SSL_get_wbio(s));
1143         return ret;
1144         }
1145
1146 /* call this function when the buffered messages are no longer needed */
1147 void
1148 dtls1_clear_record_buffer(SSL *s)
1149         {
1150         pitem *item;
1151
1152         for(item = pqueue_pop(s->d1->sent_messages);
1153                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1154                 {
1155                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1156                 pitem_free(item);
1157                 }
1158         }
1159
1160
1161 unsigned char *
1162 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1163                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1164         {
1165         if ( frag_off == 0)
1166                 {
1167                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1168                 s->d1->next_handshake_write_seq++;
1169                 }
1170
1171         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1172                 frag_off, frag_len);
1173
1174         return p += DTLS1_HM_HEADER_LENGTH;
1175         }
1176
1177
1178 /* don't actually do the writing, wait till the MTU has been retrieved */
1179 static void
1180 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1181                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1182                             unsigned long frag_len)
1183         {
1184         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1185
1186         msg_hdr->type = mt;
1187         msg_hdr->msg_len = len;
1188         msg_hdr->seq = seq_num;
1189         msg_hdr->frag_off = frag_off;
1190         msg_hdr->frag_len = frag_len;
1191         }
1192
1193 static void
1194 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1195                         unsigned long frag_len)
1196         {
1197         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1198
1199         msg_hdr->frag_off = frag_off;
1200         msg_hdr->frag_len = frag_len;
1201         }
1202
1203 static unsigned char *
1204 dtls1_write_message_header(SSL *s, unsigned char *p)
1205         {
1206         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1207
1208         *p++ = msg_hdr->type;
1209         l2n3(msg_hdr->msg_len, p);
1210
1211         s2n(msg_hdr->seq, p);
1212         l2n3(msg_hdr->frag_off, p);
1213         l2n3(msg_hdr->frag_len, p);
1214
1215         return p;
1216         }
1217
1218 static unsigned int
1219 dtls1_min_mtu(void)
1220         {
1221         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1222                 sizeof(g_probable_mtu[0])) - 1]);
1223         }
1224
1225 static unsigned int
1226 dtls1_guess_mtu(unsigned int curr_mtu)
1227         {
1228         unsigned int i;
1229
1230         if ( curr_mtu == 0 )
1231                 return g_probable_mtu[0] ;
1232
1233         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1234                 if ( curr_mtu > g_probable_mtu[i])
1235                         return g_probable_mtu[i];
1236
1237         return curr_mtu;
1238         }
1239
1240 void
1241 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1242         {
1243         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1244         msg_hdr->type = *(data++);
1245         n2l3(data, msg_hdr->msg_len);
1246
1247         n2s(data, msg_hdr->seq);
1248         n2l3(data, msg_hdr->frag_off);
1249         n2l3(data, msg_hdr->frag_len);
1250         }
1251
1252 void
1253 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1254         {
1255         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1256
1257         ccs_hdr->type = *(data++);
1258         n2s(data, ccs_hdr->seq);
1259         }