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         PQ_64BIT seq64;
 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     pq_64bit_init(&seq64);
 457     pq_64bit_assign_word(&seq64, msg_hdr->seq);
 458
 459     item = pitem_new(seq64, frag);
 460     if ( item == NULL)
 461         goto err;
 462
 463     pq_64bit_free(&seq64);
 464
 465     pqueue_insert(s->d1->buffered_messages, item);
 466     return 1;
 467
 468 err:
 469     if ( frag != NULL) dtls1_hm_fragment_free(frag);
 470     if ( item != NULL) OPENSSL_free(item);
 471     return 0;
 472 }
 473
 474
 475 static void
 476 dtls1_process_handshake_fragment(SSL *s, int frag_len)
 477     {
 478     unsigned char *p;
 479
 480     p = (unsigned char *)s->init_buf->data;
 481
 482         ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len);
 483     }
 484
 485
 486 static int
 487 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok)
 488     {
 489     int i;
 490     unsigned char *p;
 491
 492     /* make sure there's enough room to read this fragment */
 493     if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf,
 494              (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num))
 495         {
 496         SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB);
 497         goto err;
 498         }
 499
 500     p = (unsigned char *)s->init_buf->data;
 501
 502     /* read the body of the fragment (header has already been read */
 503     if ( msg_hdr->frag_len > 0)
 504                 {
 505                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 506             &p[s->init_num],
 507             msg_hdr->frag_len,0);
 508                 if (i <= 0)
 509                         {
 510                         *ok = 0;
 511                         return i;
 512                         }
 513                 }
 514
 515     if ( msg_hdr->seq > s->d1->handshake_read_seq)
 516         dtls1_buffer_handshake_fragment(s, msg_hdr);
 517     else
 518         OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq);
 519
 520     return DTLS1_HM_FRAGMENT_RETRY;
 521 err:
 522     *ok = 0;
 523     return -1;
 524     }
 525
 526
 527 static long
 528 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 529         {
 530         unsigned char *p;
 531         unsigned long l, frag_off, frag_len;
 532         int i,al;
 533         struct hm_header_st msg_hdr;
 534     unsigned long overlap;
 535
 536     /* see if we have the required fragment already */
 537     if (dtls1_retrieve_buffered_fragment(s, &l))
 538     {
 539         /* compute MAC, remove fragment headers */
 540         dtls1_process_handshake_fragment(s, l);
 541         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 542         s->state = stn;
 543         return 1;
 544     }
 545
 546     /* get a handshake fragment from the record layer */
 547         p = (unsigned char *)s->init_buf->data;
 548
 549     /* read handshake message header */
 550         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
 551                 DTLS1_HM_HEADER_LENGTH, 0);
 552         if (i <= 0)     /* nbio, or an error */
 553                 {
 554                 s->rwstate=SSL_READING;
 555                 *ok = 0;
 556                 return i;
 557                 }
 558
 559         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
 560
 561         p += s->init_num;
 562     /* parse the message fragment header */
 563
 564     dtls1_get_message_header(p, &msg_hdr);
 565
 566     /*
 567      * if this is a future (or stale) message it gets buffered
 568      * (or dropped)--no further processing at this time
 569      */
 570     if ( msg_hdr.seq != s->d1->handshake_read_seq)
 571         return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 572
 573     l = msg_hdr.msg_len;
 574     frag_off = msg_hdr.frag_off;
 575         frag_len = msg_hdr.frag_len;
 576
 577     /* sanity checking */
 578     if ( frag_off + frag_len > l)
 579         {
 580         al=SSL_AD_ILLEGAL_PARAMETER;
 581         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 582         goto f_err;
 583         }
 584
 585         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 586         p[0] == SSL3_MT_HELLO_REQUEST)
 587         {
 588         /* The server may always send 'Hello Request' messages --
 589          * we are doing a handshake anyway now, so ignore them
 590          * if their format is correct. Does not count for
 591          * 'Finished' MAC. */
 592         if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
 593             {
 594             if (s->msg_callback)
 595                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 596                     p, DTLS1_HM_HEADER_LENGTH, s,
 597                     s->msg_callback_arg);
 598
 599             s->init_num = 0;
 600             return dtls1_get_message_fragment(s, st1, stn,
 601                 max, ok);
 602             }
 603         else /* Incorrectly formated Hello request */
 604             {
 605             al=SSL_AD_UNEXPECTED_MESSAGE;
 606             SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 607             goto f_err;
 608             }
 609         }
 610
 611     /* XDTLS: do a sanity check on the fragment */
 612
 613     s->init_num += i;
 614
 615         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 616                 {
 617                 /* BUF_MEM_grow takes an 'int' parameter */
 618                 if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH))
 619                         {
 620                         al=SSL_AD_ILLEGAL_PARAMETER;
 621                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 622                         goto f_err;
 623                         }
 624                 if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
 625                         + DTLS1_HM_HEADER_LENGTH))
 626                         {
 627                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
 628                         goto err;
 629                         }
 630         /* Only do this test when we're reading the expected message.
 631          * Stale messages will be dropped and future messages will be buffered */
 632         if ( l > (unsigned long)max)
 633                         {
 634                         al=SSL_AD_ILLEGAL_PARAMETER;
 635                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 636                         goto f_err;
 637                         }
 638
 639                 s->s3->tmp.message_size=l;
 640                 }
 641
 642     if ( frag_len > (unsigned long)max)
 643         {
 644         al=SSL_AD_ILLEGAL_PARAMETER;
 645         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 646         goto f_err;
 647         }
 648     if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
 649         {
 650         al=SSL_AD_ILLEGAL_PARAMETER;
 651         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 652         goto f_err;
 653         }
 654
 655     if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len
 656              + DTLS1_HM_HEADER_LENGTH + s->init_num))
 657         {
 658         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
 659         goto err;
 660         }
 661
 662         if ( s->d1->r_msg_hdr.frag_off == 0)
 663                 {
 664                 s->s3->tmp.message_type = msg_hdr.type;
 665                 s->d1->r_msg_hdr.type = msg_hdr.type;
 666                 s->d1->r_msg_hdr.msg_len = l;
 667                 /* s->d1->r_msg_hdr.seq = seq_num; */
 668                 }
 669
 670         /* XDTLS:  ressurect this when restart is in place */
 671         s->state=stn;
 672
 673         /* next state (stn) */
 674         p = (unsigned char *)s->init_buf->data;
 675
 676         if ( frag_len > 0)
 677                 {
 678                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 679             &p[s->init_num],
 680             frag_len,0);
 681         /* XDTLS:  fix this--message fragments cannot span multiple packets */
 682                 if (i <= 0)
 683                         {
 684                         s->rwstate=SSL_READING;
 685                         *ok = 0;
 686                         return i;
 687                         }
 688                 }
 689         else
 690                 i = 0;
 691
 692     /* XDTLS:  an incorrectly formatted fragment should cause the
 693      * handshake to fail */
 694         OPENSSL_assert(i == (int)frag_len);
 695
 696 #if 0
 697     /* Successfully read a fragment.
 698      * It may be (1) out of order, or
 699      *           (2) it's a repeat, in which case we dump it
 700      *           (3) the one we are expecting next (maybe with overlap)
 701      * If it is next one, it may overlap with previously read bytes
 702      */
 703
 704     /* case (1): buffer the future fragment
 705      * (we can treat fragments from a future message the same
 706      * as future fragments from the message being currently read, since
 707      * they are sematically simply out of order.
 708      */
 709     if ( msg_hdr.seq > s->d1->handshake_read_seq ||
 710         frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
 711     {
 712         dtls1_buffer_handshake_fragment(s, &msg_hdr);
 713         return DTLS1_HM_FRAGMENT_RETRY;
 714     }
 715
 716     /* case (2):  drop the entire fragment, and try again */
 717     if ( msg_hdr.seq < s->d1->handshake_read_seq ||
 718         frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
 719         {
 720         s->init_num -= DTLS1_HM_HEADER_LENGTH;
 721         return DTLS1_HM_FRAGMENT_RETRY;
 722         }
 723 #endif
 724
 725     /* case (3): received a immediately useful fragment.  Determine the
 726      * possible overlap and copy the fragment.
 727      */
 728     overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
 729
 730     /* retain the header for the first fragment */
 731     if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
 732         {
 733         memmove(&(s->init_buf->data[s->init_num]),
 734             &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
 735             frag_len - overlap);
 736
 737         s->init_num += frag_len - overlap;
 738         }
 739     else
 740         s->init_num += frag_len;
 741
 742     dtls1_process_handshake_fragment(s, frag_len - overlap);
 743
 744         if (s->msg_callback)
 745                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
 746                         (size_t)s->init_num, s,
 747                         s->msg_callback_arg);
 748         *ok=1;
 749
 750         return s->init_num;
 751
 752 f_err:
 753         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 754     s->init_num = 0;
 755 err:
 756         *ok=0;
 757         return(-1);
 758         }
 759
 760 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 761         {
 762         unsigned char *p,*d;
 763         int i;
 764         unsigned long l;
 765
 766         if (s->state == a)
 767                 {
 768                 d=(unsigned char *)s->init_buf->data;
 769                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 770
 771                 i=s->method->ssl3_enc->final_finish_mac(s,
 772                         &(s->s3->finish_dgst1),
 773                         &(s->s3->finish_dgst2),
 774                         sender,slen,s->s3->tmp.finish_md);
 775                 s->s3->tmp.finish_md_len = i;
 776                 memcpy(p, s->s3->tmp.finish_md, i);
 777                 p+=i;
 778                 l=i;
 779
 780 #ifdef OPENSSL_SYS_WIN16
 781                 /* MSVC 1.5 does not clear the top bytes of the word unless
 782                  * I do this.
 783                  */
 784                 l&=0xffff;
 785 #endif
 786
 787                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 788                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 789                 s->init_off=0;
 790
 791                 /* buffer the message to handle re-xmits */
 792                 dtls1_buffer_message(s, 0);
 793
 794                 s->state=b;
 795                 }
 796
 797         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 798         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 799         }
 800
 801 /* for these 2 messages, we need to
 802  * ssl->enc_read_ctx                    re-init
 803  * ssl->s3->read_sequence               zero
 804  * ssl->s3->read_mac_secret             re-init
 805  * ssl->session->read_sym_enc           assign
 806  * ssl->session->read_compression       assign
 807  * ssl->session->read_hash              assign
 808  */
 809 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 810         {
 811         unsigned char *p;
 812
 813         if (s->state == a)
 814                 {
 815                 p=(unsigned char *)s->init_buf->data;
 816                 *p++=SSL3_MT_CCS;
 817                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 818                 s->d1->next_handshake_write_seq++;
 819                 s2n(s->d1->handshake_write_seq,p);
 820
 821                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 822                 s->init_off=0;
 823
 824                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 825                         s->d1->handshake_write_seq, 0, 0);
 826
 827                 /* buffer the message to handle re-xmits */
 828                 dtls1_buffer_message(s, 1);
 829
 830                 s->state=b;
 831                 }
 832
 833         /* SSL3_ST_CW_CHANGE_B */
 834         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 835         }
 836
 837 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
 838         {
 839         unsigned char *p;
 840         int n,i;
 841         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
 842         BUF_MEM *buf;
 843         X509_STORE_CTX xs_ctx;
 844         X509_OBJECT obj;
 845
 846         /* TLSv1 sends a chain with nothing in it, instead of an alert */
 847         buf=s->init_buf;
 848         if (!BUF_MEM_grow_clean(buf,10))
 849                 {
 850                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 851                 return(0);
 852                 }
 853         if (x != NULL)
 854                 {
 855                 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
 856                         {
 857                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
 858                         return(0);
 859                         }
 860
 861                 for (;;)
 862                         {
 863                         n=i2d_X509(x,NULL);
 864                         if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
 865                                 {
 866                                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 867                                 return(0);
 868                                 }
 869                         p=(unsigned char *)&(buf->data[l]);
 870                         l2n3(n,p);
 871                         i2d_X509(x,&p);
 872                         l+=n+3;
 873                         if (X509_NAME_cmp(X509_get_subject_name(x),
 874                                 X509_get_issuer_name(x)) == 0) break;
 875
 876                         i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
 877                                 X509_get_issuer_name(x),&obj);
 878                         if (i <= 0) break;
 879                         x=obj.data.x509;
 880                         /* Count is one too high since the X509_STORE_get uped the
 881                          * ref count */
 882                         X509_free(x);
 883                         }
 884
 885                 X509_STORE_CTX_cleanup(&xs_ctx);
 886                 }
 887
 888         /* Thawte special :-) */
 889         if (s->ctx->extra_certs != NULL)
 890         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
 891                 {
 892                 x=sk_X509_value(s->ctx->extra_certs,i);
 893                 n=i2d_X509(x,NULL);
 894                 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
 895                         {
 896                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 897                         return(0);
 898                         }
 899                 p=(unsigned char *)&(buf->data[l]);
 900                 l2n3(n,p);
 901                 i2d_X509(x,&p);
 902                 l+=n+3;
 903                 }
 904
 905         l-= (3 + DTLS1_HM_HEADER_LENGTH);
 906
 907         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
 908         l2n3(l,p);
 909         l+=3;
 910         p=(unsigned char *)&(buf->data[0]);
 911         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
 912
 913         l+=DTLS1_HM_HEADER_LENGTH;
 914         return(l);
 915         }
 916
 917 int dtls1_read_failed(SSL *s, int code)
 918     {
 919     DTLS1_STATE *state;
 920     BIO *bio;
 921     int send_alert = 0;
 922
 923     if ( code > 0)
 924         {
 925         fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
 926         return 1;
 927         }
 928
 929     bio = SSL_get_rbio(s);
 930     if ( ! BIO_dgram_recv_timedout(bio))
 931         {
 932         /* not a timeout, none of our business,
 933            let higher layers handle this.  in fact it's probably an error */
 934         return code;
 935         }
 936
 937     if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
 938         {
 939         BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
 940         return code;
 941         }
 942
 943     state = s->d1;
 944     state->timeout.num_alerts++;
 945     if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 946         {
 947         /* fail the connection, enough alerts have been sent */
 948         SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
 949         return 0;
 950         }
 951
 952     state->timeout.read_timeouts++;
 953     if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 954         {
 955         send_alert = 1;
 956         state->timeout.read_timeouts = 1;
 957         }
 958
 959
 960 #if 0 /* for now, each alert contains only one record number */
 961     item = pqueue_peek(state->rcvd_records);
 962     if ( item )
 963         {
 964         /* send an alert immediately for all the missing records */
 965         }
 966     else
 967 #endif
 968
 969 #if 0  /* no more alert sending, just retransmit the last set of messages */
 970         if ( send_alert)
 971             ssl3_send_alert(s,SSL3_AL_WARNING,
 972                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 973 #endif
 974
 975     return dtls1_retransmit_buffered_messages(s) ;
 976     }
 977
 978
 979 static int
 980 dtls1_retransmit_buffered_messages(SSL *s)
 981     {
 982     pqueue sent = s->d1->sent_messages;
 983     piterator iter;
 984     pitem *item;
 985     hm_fragment *frag;
 986     int found = 0;
 987
 988     iter = pqueue_iterator(sent);
 989
 990     for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
 991         {
 992         frag = (hm_fragment *)item->data;
 993         if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
 994             found)
 995             {
 996             fprintf(stderr, "dtls1_retransmit_message() failed\n");
 997             return -1;
 998             }
 999         }
1000
1001     return 1;
1002     }
1003
1004 #if 0
1005 static dtls1_message_buffer *
1006 dtls1_message_buffer_new(unsigned int len)
1007     {
1008     dtls1_message_buffer *msg_buf;
1009
1010     msg_buf = (dtls1_message_buffer *)
1011         OPENSSL_malloc(sizeof(dtls1_message_buffer));
1012     if ( msg_buf == NULL)
1013         return NULL;
1014
1015     memset(msg_buf, 0x00, sizeof(dtls1_message_buffer));
1016
1017     msg_buf->data = (unsigned char *) OPENSSL_malloc(len);
1018     if ( msg_buf->data == NULL)
1019         {
1020         OPENSSL_free(msg_buf);
1021         return NULL;
1022         }
1023
1024     memset(msg_buf->data, 0x00, len);
1025     return msg_buf;
1026     }
1027 #endif
1028
1029 #if 0
1030 static void
1031 dtls1_message_buffer_free(dtls1_message_buffer *msg_buf)
1032     {
1033     if (msg_buf != NULL)
1034         {
1035         OPENSSL_free(msg_buf->data);
1036         OPENSSL_free(msg_buf);
1037         }
1038     }
1039 #endif
1040
1041 int
1042 dtls1_buffer_message(SSL *s, int is_ccs)
1043     {
1044     pitem *item;
1045     hm_fragment *frag;
1046         PQ_64BIT seq64;
1047
1048     /* this function is called immediately after a message has
1049      * been serialized */
1050     OPENSSL_assert(s->init_off == 0);
1051
1052     frag = dtls1_hm_fragment_new(s->init_num);
1053
1054     memcpy(frag->fragment, s->init_buf->data, s->init_num);
1055
1056     if ( is_ccs)
1057         {
1058         OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1059             DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1060         }
1061     else
1062         {
1063         OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1064             DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1065         }
1066
1067     frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1068     frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1069     frag->msg_header.type = s->d1->w_msg_hdr.type;
1070     frag->msg_header.frag_off = 0;
1071     frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1072     frag->msg_header.is_ccs = is_ccs;
1073
1074     pq_64bit_init(&seq64);
1075     pq_64bit_assign_word(&seq64, frag->msg_header.seq);
1076
1077     item = pitem_new(seq64, frag);
1078     pq_64bit_free(&seq64);
1079     if ( item == NULL)
1080         {
1081         dtls1_hm_fragment_free(frag);
1082         return 0;
1083         }
1084
1085 #if 0
1086     fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1087     fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1088     fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1089 #endif
1090
1091     pqueue_insert(s->d1->sent_messages, item);
1092     return 1;
1093     }
1094
1095 int
1096 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1097     int *found)
1098     {
1099     int ret;
1100     /* XDTLS: for now assuming that read/writes are blocking */
1101     pitem *item;
1102     hm_fragment *frag ;
1103     unsigned long header_length;
1104         PQ_64BIT seq64;
1105
1106     /*
1107       OPENSSL_assert(s->init_num == 0);
1108       OPENSSL_assert(s->init_off == 0);
1109      */
1110
1111     /* XDTLS:  the requested message ought to be found, otherwise error */
1112     pq_64bit_init(&seq64);
1113     pq_64bit_assign_word(&seq64, seq);
1114
1115     item = pqueue_find(s->d1->sent_messages, seq64);
1116     pq_64bit_free(&seq64);
1117     if ( item == NULL)
1118         {
1119         fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1120         *found = 0;
1121         return 0;
1122         }
1123
1124     *found = 1;
1125     frag = (hm_fragment *)item->data;
1126
1127     if ( frag->msg_header.is_ccs)
1128         header_length = DTLS1_CCS_HEADER_LENGTH;
1129     else
1130         header_length = DTLS1_HM_HEADER_LENGTH;
1131
1132     memcpy(s->init_buf->data, frag->fragment,
1133         frag->msg_header.msg_len + header_length);
1134         s->init_num = frag->msg_header.msg_len + header_length;
1135
1136     dtls1_set_message_header_int(s, frag->msg_header.type,
1137         frag->msg_header.msg_len, frag->msg_header.seq, 0,
1138         frag->msg_header.frag_len);
1139
1140     s->d1->retransmitting = 1;
1141     ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1142         SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1143     s->d1->retransmitting = 0;
1144
1145     (void)BIO_flush(SSL_get_wbio(s));
1146     return ret;
1147     }
1148
1149 /* call this function when the buffered messages are no longer needed */
1150 void
1151 dtls1_clear_record_buffer(SSL *s)
1152     {
1153     pitem *item;
1154
1155     for(item = pqueue_pop(s->d1->sent_messages);
1156         item != NULL; item = pqueue_pop(s->d1->sent_messages))
1157         {
1158         dtls1_hm_fragment_free((hm_fragment *)item->data);
1159         pitem_free(item);
1160         }
1161     }
1162
1163
1164 unsigned char *
1165 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1166     unsigned long len, unsigned long frag_off, unsigned long frag_len)
1167     {
1168     if ( frag_off == 0)
1169         {
1170         s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1171         s->d1->next_handshake_write_seq++;
1172         }
1173
1174     dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1175         frag_off, frag_len);
1176
1177     return p += DTLS1_HM_HEADER_LENGTH;
1178     }
1179
1180
1181 /* don't actually do the writing, wait till the MTU has been retrieved */
1182 static void
1183 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1184     unsigned long len, unsigned short seq_num, unsigned long frag_off,
1185     unsigned long frag_len)
1186     {
1187     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1188
1189     msg_hdr->type = mt;
1190     msg_hdr->msg_len = len;
1191     msg_hdr->seq = seq_num;
1192     msg_hdr->frag_off = frag_off;
1193     msg_hdr->frag_len = frag_len;
1194 }
1195
1196 static void
1197 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1198         unsigned long frag_len)
1199     {
1200     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1201
1202     msg_hdr->frag_off = frag_off;
1203     msg_hdr->frag_len = frag_len;
1204     }
1205
1206 static unsigned char *
1207 dtls1_write_message_header(SSL *s, unsigned char *p)
1208     {
1209     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1210
1211     *p++ = msg_hdr->type;
1212     l2n3(msg_hdr->msg_len, p);
1213
1214     s2n(msg_hdr->seq, p);
1215     l2n3(msg_hdr->frag_off, p);
1216     l2n3(msg_hdr->frag_len, p);
1217
1218     return p;
1219     }
1220
1221 static unsigned int
1222 dtls1_min_mtu(void)
1223     {
1224     return
1225         g_probable_mtu[(sizeof(g_probable_mtu) /
1226            sizeof(g_probable_mtu[0])) - 1];
1227     }
1228
1229 static unsigned int
1230 dtls1_guess_mtu(unsigned int curr_mtu)
1231         {
1232         size_t i;
1233
1234         if ( curr_mtu == 0 )
1235                 return g_probable_mtu[0] ;
1236
1237         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1238                 if ( curr_mtu > g_probable_mtu[i])
1239                         return g_probable_mtu[i];
1240
1241         return curr_mtu;
1242         }
1243
1244 void
1245 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1246     {
1247     memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1248     msg_hdr->type = *(data++);
1249     n2l3(data, msg_hdr->msg_len);
1250
1251     n2s(data, msg_hdr->seq);
1252     n2l3(data, msg_hdr->frag_off);
1253     n2l3(data, msg_hdr->frag_len);
1254     }
1255
1256 void
1257 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1258     {
1259     memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1260
1261     ccs_hdr->type = *(data++);
1262     n2s(data, ccs_hdr->seq);
1263 }