ssl/d1_both.c

   1 /* ssl/d1_both.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <limits.h>
 117 #include <string.h>
 118 #include <stdio.h>
 119 #include "ssl_locl.h"
 120 #include <openssl/buffer.h>
 121 #include <openssl/rand.h>
 122 #include <openssl/objects.h>
 123 #include <openssl/evp.h>
 124 #include <openssl/x509.h>
 125
 126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 127
 128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
 129                         if ((end) - (start) <= 8) { \
 130                                 long ii; \
 131                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 132                         } else { \
 133                                 long ii; \
 134                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 135                                 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
 136                                 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 137                         } }
 138
 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 140                         long ii; \
 141                         OPENSSL_assert((msg_len) > 0); \
 142                         is_complete = 1; \
 143                         if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 144                         if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
 145                                 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 146
 147 #if 0
 148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 149                         long ii; \
 150                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 151                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 152                         printf("\n"); }
 153 #endif
 154
 155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 156 static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 157
 158 /* XDTLS:  figure out the right values */
 159 static const unsigned int g_probable_mtu[] = {1500, 512, 256};
 160
 161 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 162         unsigned long frag_len);
 163 static unsigned char *dtls1_write_message_header(SSL *s,
 164         unsigned char *p);
 165 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 166         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 167         unsigned long frag_len);
 168 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 169         long max, int *ok);
 170
 171 static hm_fragment *
 172 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 173         {
 174         hm_fragment *frag = NULL;
 175         unsigned char *buf = NULL;
 176         unsigned char *bitmask = NULL;
 177
 178         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 179         if ( frag == NULL)
 180                 return NULL;
 181
 182         if (frag_len)
 183                 {
 184                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 185                 if ( buf == NULL)
 186                         {
 187                         OPENSSL_free(frag);
 188                         return NULL;
 189                         }
 190                 }
 191
 192         /* zero length fragment gets zero frag->fragment */
 193         frag->fragment = buf;
 194
 195         /* Initialize reassembly bitmask if necessary */
 196         if (reassembly)
 197                 {
 198                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 199                 if (bitmask == NULL)
 200                         {
 201                         if (buf != NULL) OPENSSL_free(buf);
 202                         OPENSSL_free(frag);
 203                         return NULL;
 204                         }
 205                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 206                 }
 207
 208         frag->reassembly = bitmask;
 209
 210         return frag;
 211         }
 212
 213 void dtls1_hm_fragment_free(hm_fragment *frag)
 214         {
 215
 216         if (frag->msg_header.is_ccs)
 217                 {
 218                 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
 219                 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
 220                 }
 221         if (frag->fragment) OPENSSL_free(frag->fragment);
 222         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 223         OPENSSL_free(frag);
 224         }
 225
 226 static int dtls1_query_mtu(SSL *s)
 227 {
 228         if(s->d1->link_mtu)
 229                 {
 230                 s->d1->mtu = s->d1->link_mtu-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
 231                 s->d1->link_mtu = 0;
 232                 }
 233
 234         /* AHA!  Figure out the MTU, and stick to the right size */
 235         if (s->d1->mtu < dtls1_min_mtu(s))
 236                 {
 237                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 238                         {
 239                         s->d1->mtu =
 240                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 241
 242                         /* I've seen the kernel return bogus numbers when it doesn't know
 243                          * (initial write), so just make sure we have a reasonable number */
 244                         if (s->d1->mtu < dtls1_min_mtu(s))
 245                                 {
 246                                 /* Set to min mtu */
 247                                 s->d1->mtu = dtls1_min_mtu(s);
 248                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 249                                         s->d1->mtu, NULL);
 250                                 }
 251                         }
 252                 else
 253                         return 0;
 254                 }
 255         return 1;
 256 }
 257
 258 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 259 int dtls1_do_write(SSL *s, int type)
 260         {
 261         int ret;
 262         int curr_mtu;
 263         int retry = 1;
 264         unsigned int len, frag_off, mac_size, blocksize;
 265
 266         if(!dtls1_query_mtu(s))
 267                 return -1;
 268
 269         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s));  /* should have something reasonable now */
 270
 271         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 272                 OPENSSL_assert(s->init_num ==
 273                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 274
 275         if (s->write_hash)
 276                 mac_size = EVP_MD_CTX_size(s->write_hash);
 277         else
 278                 mac_size = 0;
 279
 280         if (s->enc_write_ctx &&
 281                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
 282                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 283         else
 284                 blocksize = 0;
 285
 286         frag_off = 0;
 287         while( s->init_num)
 288                 {
 289                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 290                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 291
 292                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 293                         {
 294                         /* grr.. we could get an error if MTU picked was wrong */
 295                         ret = BIO_flush(SSL_get_wbio(s));
 296                         if ( ret <= 0)
 297                                 return ret;
 298                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 299                                 mac_size - blocksize;
 300                         }
 301
 302                 if ( s->init_num > curr_mtu)
 303                         len = curr_mtu;
 304                 else
 305                         len = s->init_num;
 306
 307
 308                 /* XDTLS: this function is too long.  split out the CCS part */
 309                 if ( type == SSL3_RT_HANDSHAKE)
 310                         {
 311                         if ( s->init_off != 0)
 312                                 {
 313                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 314                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 315                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 316
 317                                 if ( s->init_num > curr_mtu)
 318                                         len = curr_mtu;
 319                                 else
 320                                         len = s->init_num;
 321                                 }
 322
 323                         if ( len < DTLS1_HM_HEADER_LENGTH )
 324                                 {
 325                                 /*
 326                                  * len is so small that we really can't do anything sensible
 327                                  * so fail
 328                                  */
 329                                 return -1;
 330                                 }
 331                         dtls1_fix_message_header(s, frag_off,
 332                                 len - DTLS1_HM_HEADER_LENGTH);
 333
 334                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 335                         }
 336
 337                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 338                         len);
 339                 if (ret < 0)
 340                         {
 341                         /* might need to update MTU here, but we don't know
 342                          * which previous packet caused the failure -- so can't
 343                          * really retransmit anything.  continue as if everything
 344                          * is fine and wait for an alert to handle the
 345                          * retransmit
 346                          */
 347                         if ( retry && BIO_ctrl(SSL_get_wbio(s),
 348                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 349                                 {
 350                                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 351                                         {
 352                                         if(!dtls1_query_mtu(s))
 353                                                 return -1;
 354                                         /* Have one more go */
 355                                         retry = 0;
 356                                         }
 357                                 else
 358                                         return -1;
 359                                 }
 360                         else
 361                                 {
 362                                 return(-1);
 363                                 }
 364                         }
 365                 else
 366                         {
 367
 368                         /* bad if this assert fails, only part of the handshake
 369                          * message got sent.  but why would this happen? */
 370                         OPENSSL_assert(len == (unsigned int)ret);
 371
 372                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 373                                 {
 374                                 /* should not be done for 'Hello Request's, but in that case
 375                                  * we'll ignore the result anyway */
 376                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 377                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 378                                 int xlen;
 379
 380                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
 381                                         {
 382                                         /* reconstruct message header is if it
 383                                          * is being sent in single fragment */
 384                                         *p++ = msg_hdr->type;
 385                                         l2n3(msg_hdr->msg_len,p);
 386                                         s2n (msg_hdr->seq,p);
 387                                         l2n3(0,p);
 388                                         l2n3(msg_hdr->msg_len,p);
 389                                         p  -= DTLS1_HM_HEADER_LENGTH;
 390                                         xlen = ret;
 391                                         }
 392                                 else
 393                                         {
 394                                         p  += DTLS1_HM_HEADER_LENGTH;
 395                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 396                                         }
 397
 398                                 ssl3_finish_mac(s, p, xlen);
 399                                 }
 400
 401                         if (ret == s->init_num)
 402                                 {
 403                                 if (s->msg_callback)
 404                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 405                                                 (size_t)(s->init_off + s->init_num), s,
 406                                                 s->msg_callback_arg);
 407
 408                                 s->init_off = 0;  /* done writing this message */
 409                                 s->init_num = 0;
 410
 411                                 return(1);
 412                                 }
 413                         s->init_off+=ret;
 414                         s->init_num-=ret;
 415                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 416                         }
 417                 }
 418         return(0);
 419         }
 420
 421
 422 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 423  * maximum acceptable body length 'max'.
 424  * Read an entire handshake message.  Handshake messages arrive in
 425  * fragments.
 426  */
 427 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 428         {
 429         int i, al;
 430         struct hm_header_st *msg_hdr;
 431         unsigned char *p;
 432         unsigned long msg_len;
 433
 434         /* s3->tmp is used to store messages that are unexpected, caused
 435          * by the absence of an optional handshake message */
 436         if (s->s3->tmp.reuse_message)
 437                 {
 438                 s->s3->tmp.reuse_message=0;
 439                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 440                         {
 441                         al=SSL_AD_UNEXPECTED_MESSAGE;
 442                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 443                         goto f_err;
 444                         }
 445                 *ok=1;
 446                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 447                 s->init_num = (int)s->s3->tmp.message_size;
 448                 return s->init_num;
 449                 }
 450
 451         msg_hdr = &s->d1->r_msg_hdr;
 452         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 453
 454 again:
 455         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 456         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 457                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 458                 goto again;
 459         else if ( i <= 0 && !*ok)
 460                 return i;
 461
 462         p = (unsigned char *)s->init_buf->data;
 463         msg_len = msg_hdr->msg_len;
 464
 465         /* reconstruct message header */
 466         *(p++) = msg_hdr->type;
 467         l2n3(msg_len,p);
 468         s2n (msg_hdr->seq,p);
 469         l2n3(0,p);
 470         l2n3(msg_len,p);
 471         if (s->version != DTLS1_BAD_VER) {
 472                 p       -= DTLS1_HM_HEADER_LENGTH;
 473                 msg_len += DTLS1_HM_HEADER_LENGTH;
 474         }
 475
 476         ssl3_finish_mac(s, p, msg_len);
 477         if (s->msg_callback)
 478                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 479                         p, msg_len,
 480                         s, s->msg_callback_arg);
 481
 482         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 483
 484         /* Don't change sequence numbers while listening */
 485         if (!s->d1->listen)
 486                 s->d1->handshake_read_seq++;
 487
 488         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 489         return s->init_num;
 490
 491 f_err:
 492         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 493         *ok = 0;
 494         return -1;
 495         }
 496
 497
 498 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 499         {
 500         size_t frag_off,frag_len,msg_len;
 501
 502         msg_len  = msg_hdr->msg_len;
 503         frag_off = msg_hdr->frag_off;
 504         frag_len = msg_hdr->frag_len;
 505
 506         /* sanity checking */
 507         if ( (frag_off+frag_len) > msg_len)
 508                 {
 509                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 510                 return SSL_AD_ILLEGAL_PARAMETER;
 511                 }
 512
 513         if ( (frag_off+frag_len) > (unsigned long)max)
 514                 {
 515                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 516                 return SSL_AD_ILLEGAL_PARAMETER;
 517                 }
 518
 519         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 520                 {
 521                 /* msg_len is limited to 2^24, but is effectively checked
 522                  * against max above */
 523                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
 524                         {
 525                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 526                         return SSL_AD_INTERNAL_ERROR;
 527                         }
 528
 529                 s->s3->tmp.message_size  = msg_len;
 530                 s->d1->r_msg_hdr.msg_len = msg_len;
 531                 s->s3->tmp.message_type  = msg_hdr->type;
 532                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 533                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 534                 }
 535         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 536                 {
 537                 /* They must be playing with us! BTW, failure to enforce
 538                  * upper limit would open possibility for buffer overrun. */
 539                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 540                 return SSL_AD_ILLEGAL_PARAMETER;
 541                 }
 542
 543         return 0; /* no error */
 544         }
 545
 546
 547 static int
 548 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 549         {
 550         /* (0) check whether the desired fragment is available
 551          * if so:
 552          * (1) copy over the fragment to s->init_buf->data[]
 553          * (2) update s->init_num
 554          */
 555         pitem *item;
 556         hm_fragment *frag;
 557         int al;
 558
 559         *ok = 0;
 560         item = pqueue_peek(s->d1->buffered_messages);
 561         if ( item == NULL)
 562                 return 0;
 563
 564         frag = (hm_fragment *)item->data;
 565
 566         /* Don't return if reassembly still in progress */
 567         if (frag->reassembly != NULL)
 568                 return 0;
 569
 570         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 571                 {
 572                 unsigned long frag_len = frag->msg_header.frag_len;
 573                 pqueue_pop(s->d1->buffered_messages);
 574
 575                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 576
 577                 if (al==0) /* no alert */
 578                         {
 579                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 580                         memcpy(&p[frag->msg_header.frag_off],
 581                                 frag->fragment,frag->msg_header.frag_len);
 582                         }
 583
 584                 dtls1_hm_fragment_free(frag);
 585                 pitem_free(item);
 586
 587                 if (al==0)
 588                         {
 589                         *ok = 1;
 590                         return frag_len;
 591                         }
 592
 593                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 594                 s->init_num = 0;
 595                 *ok = 0;
 596                 return -1;
 597                 }
 598         else
 599                 return 0;
 600         }
 601
 602 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 603  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 604  * be greater if the maximum certificate list size requires it. */
 605 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 606         {
 607         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 608         if (max_len < (unsigned long)s->max_cert_list)
 609                 return s->max_cert_list;
 610         return max_len;
 611         }
 612
 613 static int
 614 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 615         {
 616         hm_fragment *frag = NULL;
 617         pitem *item = NULL;
 618         int i = -1, is_complete;
 619         unsigned char seq64be[8];
 620         unsigned long frag_len = msg_hdr->frag_len;
 621
 622         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 623             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 624                 goto err;
 625
 626         if (frag_len == 0)
 627                 return DTLS1_HM_FRAGMENT_RETRY;
 628
 629         /* Try to find item in queue */
 630         memset(seq64be,0,sizeof(seq64be));
 631         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 632         seq64be[7] = (unsigned char) msg_hdr->seq;
 633         item = pqueue_find(s->d1->buffered_messages, seq64be);
 634
 635         if (item == NULL)
 636                 {
 637                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 638                 if ( frag == NULL)
 639                         goto err;
 640                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 641                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 642                 frag->msg_header.frag_off = 0;
 643                 }
 644         else
 645                 {
 646                 frag = (hm_fragment*) item->data;
 647                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 648                         {
 649                         item = NULL;
 650                         frag = NULL;
 651                         goto err;
 652                         }
 653                 }
 654
 655
 656         /* If message is already reassembled, this must be a
 657          * retransmit and can be dropped. In this case item != NULL and so frag
 658          * does not need to be freed.
 659          */
 660         if (frag->reassembly == NULL)
 661                 {
 662                 unsigned char devnull [256];
 663
 664                 while (frag_len)
 665                         {
 666                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 667                                 devnull,
 668                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 669                         if (i<=0) goto err;
 670                         frag_len -= i;
 671                         }
 672                 return DTLS1_HM_FRAGMENT_RETRY;
 673                 }
 674
 675         /* read the body of the fragment (header has already been read */
 676         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 677                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 678         if ((unsigned long)i!=frag_len)
 679                 i=-1;
 680         if (i<=0)
 681                 goto err;
 682
 683         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 684                             (long)(msg_hdr->frag_off + frag_len));
 685
 686         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 687                                    is_complete);
 688
 689         if (is_complete)
 690                 {
 691                 OPENSSL_free(frag->reassembly);
 692                 frag->reassembly = NULL;
 693                 }
 694
 695         if (item == NULL)
 696                 {
 697                 item = pitem_new(seq64be, frag);
 698                 if (item == NULL)
 699                         {
 700                         i = -1;
 701                         goto err;
 702                         }
 703
 704                 item = pqueue_insert(s->d1->buffered_messages, item);
 705                 /* pqueue_insert fails iff a duplicate item is inserted.
 706                  * However, |item| cannot be a duplicate. If it were,
 707                  * |pqueue_find|, above, would have returned it and control
 708                  * would never have reached this branch. */
 709                 OPENSSL_assert(item != NULL);
 710                 }
 711
 712         return DTLS1_HM_FRAGMENT_RETRY;
 713
 714 err:
 715         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 716         *ok = 0;
 717         return i;
 718         }
 719
 720
 721 static int
 722 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 723 {
 724         int i=-1;
 725         hm_fragment *frag = NULL;
 726         pitem *item = NULL;
 727         unsigned char seq64be[8];
 728         unsigned long frag_len = msg_hdr->frag_len;
 729
 730         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 731                 goto err;
 732
 733         /* Try to find item in queue, to prevent duplicate entries */
 734         memset(seq64be,0,sizeof(seq64be));
 735         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 736         seq64be[7] = (unsigned char) msg_hdr->seq;
 737         item = pqueue_find(s->d1->buffered_messages, seq64be);
 738
 739         /* If we already have an entry and this one is a fragment,
 740          * don't discard it and rather try to reassemble it.
 741          */
 742         if (item != NULL && frag_len != msg_hdr->msg_len)
 743                 item = NULL;
 744
 745         /* Discard the message if sequence number was already there, is
 746          * too far in the future, already in the queue or if we received
 747          * a FINISHED before the SERVER_HELLO, which then must be a stale
 748          * retransmit.
 749          */
 750         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 751                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 752                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 753                 {
 754                 unsigned char devnull [256];
 755
 756                 while (frag_len)
 757                         {
 758                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 759                                 devnull,
 760                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 761                         if (i<=0) goto err;
 762                         frag_len -= i;
 763                         }
 764                 }
 765         else
 766                 {
 767                 if (frag_len != msg_hdr->msg_len)
 768                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 769
 770                 if (frag_len > dtls1_max_handshake_message_len(s))
 771                         goto err;
 772
 773                 frag = dtls1_hm_fragment_new(frag_len, 0);
 774                 if ( frag == NULL)
 775                         goto err;
 776
 777                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 778
 779                 if (frag_len)
 780                         {
 781                         /* read the body of the fragment (header has already been read */
 782                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 783                                 frag->fragment,frag_len,0);
 784                         if ((unsigned long)i!=frag_len)
 785                                 i = -1;
 786                         if (i<=0)
 787                                 goto err;
 788                         }
 789
 790                 item = pitem_new(seq64be, frag);
 791                 if ( item == NULL)
 792                         goto err;
 793
 794                 item = pqueue_insert(s->d1->buffered_messages, item);
 795                 /* pqueue_insert fails iff a duplicate item is inserted.
 796                  * However, |item| cannot be a duplicate. If it were,
 797                  * |pqueue_find|, above, would have returned it. Then, either
 798                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 799                  * to NULL and it will have been processed with
 800                  * |dtls1_reassemble_fragment|, above, or the record will have
 801                  * been discarded. */
 802                 OPENSSL_assert(item != NULL);
 803                 }
 804
 805         return DTLS1_HM_FRAGMENT_RETRY;
 806
 807 err:
 808         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 809         *ok = 0;
 810         return i;
 811         }
 812
 813
 814 static long
 815 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 816         {
 817         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 818         unsigned long len, frag_off, frag_len;
 819         int i,al;
 820         struct hm_header_st msg_hdr;
 821
 822         redo:
 823         /* see if we have the required fragment already */
 824         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 825                 {
 826                 if (*ok)        s->init_num = frag_len;
 827                 return frag_len;
 828                 }
 829
 830         /* read handshake message header */
 831         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 832                 DTLS1_HM_HEADER_LENGTH, 0);
 833         if (i <= 0)     /* nbio, or an error */
 834                 {
 835                 s->rwstate=SSL_READING;
 836                 *ok = 0;
 837                 return i;
 838                 }
 839         /* Handshake fails if message header is incomplete */
 840         if (i != DTLS1_HM_HEADER_LENGTH)
 841                 {
 842                 al=SSL_AD_UNEXPECTED_MESSAGE;
 843                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 844                 goto f_err;
 845                 }
 846
 847         /* parse the message fragment header */
 848         dtls1_get_message_header(wire, &msg_hdr);
 849
 850         /*
 851          * if this is a future (or stale) message it gets buffered
 852          * (or dropped)--no further processing at this time
 853          * While listening, we accept seq 1 (ClientHello with cookie)
 854          * although we're still expecting seq 0 (ClientHello)
 855          */
 856         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 857                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 858
 859         len = msg_hdr.msg_len;
 860         frag_off = msg_hdr.frag_off;
 861         frag_len = msg_hdr.frag_len;
 862
 863         if (frag_len && frag_len < len)
 864                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 865
 866         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 867                 wire[0] == SSL3_MT_HELLO_REQUEST)
 868                 {
 869                 /* The server may always send 'Hello Request' messages --
 870                  * we are doing a handshake anyway now, so ignore them
 871                  * if their format is correct. Does not count for
 872                  * 'Finished' MAC. */
 873                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 874                         {
 875                         if (s->msg_callback)
 876                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 877                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 878                                         s->msg_callback_arg);
 879
 880                         s->init_num = 0;
 881                         goto redo;
 882                         }
 883                 else /* Incorrectly formated Hello request */
 884                         {
 885                         al=SSL_AD_UNEXPECTED_MESSAGE;
 886                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 887                         goto f_err;
 888                         }
 889                 }
 890
 891         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 892                 goto f_err;
 893
 894         /* XDTLS:  ressurect this when restart is in place */
 895         s->state=stn;
 896
 897         if ( frag_len > 0)
 898                 {
 899                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 900
 901                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 902                         &p[frag_off],frag_len,0);
 903                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 904                 if (i <= 0)
 905                         {
 906                         s->rwstate=SSL_READING;
 907                         *ok = 0;
 908                         return i;
 909                         }
 910                 }
 911         else
 912                 i = 0;
 913
 914         /* XDTLS:  an incorrectly formatted fragment should cause the
 915          * handshake to fail */
 916         if (i != (int)frag_len)
 917                 {
 918                 al=SSL3_AD_ILLEGAL_PARAMETER;
 919                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 920                 goto f_err;
 921                 }
 922
 923         *ok = 1;
 924
 925         /* Note that s->init_num is *not* used as current offset in
 926          * s->init_buf->data, but as a counter summing up fragments'
 927          * lengths: as soon as they sum up to handshake packet
 928          * length, we assume we have got all the fragments. */
 929         s->init_num = frag_len;
 930         return frag_len;
 931
 932 f_err:
 933         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 934         s->init_num = 0;
 935
 936         *ok=0;
 937         return(-1);
 938         }
 939
 940 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 941         {
 942         unsigned char *p,*d;
 943         int i;
 944         unsigned long l;
 945
 946         if (s->state == a)
 947                 {
 948                 d=(unsigned char *)s->init_buf->data;
 949                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 950
 951                 i=s->method->ssl3_enc->final_finish_mac(s,
 952                         sender,slen,s->s3->tmp.finish_md);
 953                 s->s3->tmp.finish_md_len = i;
 954                 memcpy(p, s->s3->tmp.finish_md, i);
 955                 p+=i;
 956                 l=i;
 957
 958         /* Copy the finished so we can use it for
 959          * renegotiation checks
 960          */
 961         if(s->type == SSL_ST_CONNECT)
 962                 {
 963                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 964                 memcpy(s->s3->previous_client_finished,
 965                        s->s3->tmp.finish_md, i);
 966                 s->s3->previous_client_finished_len=i;
 967                 }
 968         else
 969                 {
 970                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 971                 memcpy(s->s3->previous_server_finished,
 972                        s->s3->tmp.finish_md, i);
 973                 s->s3->previous_server_finished_len=i;
 974                 }
 975
 976 #ifdef OPENSSL_SYS_WIN16
 977                 /* MSVC 1.5 does not clear the top bytes of the word unless
 978                  * I do this.
 979                  */
 980                 l&=0xffff;
 981 #endif
 982
 983                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 984                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 985                 s->init_off=0;
 986
 987                 /* buffer the message to handle re-xmits */
 988                 dtls1_buffer_message(s, 0);
 989
 990                 s->state=b;
 991                 }
 992
 993         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 994         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 995         }
 996
 997 /* for these 2 messages, we need to
 998  * ssl->enc_read_ctx                    re-init
 999  * ssl->s3->read_sequence               zero
1000  * ssl->s3->read_mac_secret             re-init
1001  * ssl->session->read_sym_enc           assign
1002  * ssl->session->read_compression       assign
1003  * ssl->session->read_hash              assign
1004  */
1005 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
1006         {
1007         unsigned char *p;
1008
1009         if (s->state == a)
1010                 {
1011                 p=(unsigned char *)s->init_buf->data;
1012                 *p++=SSL3_MT_CCS;
1013                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1014                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
1015
1016                 if (s->version == DTLS1_BAD_VER) {
1017                         s->d1->next_handshake_write_seq++;
1018                         s2n(s->d1->handshake_write_seq,p);
1019                         s->init_num+=2;
1020                 }
1021
1022                 s->init_off=0;
1023
1024                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1025                         s->d1->handshake_write_seq, 0, 0);
1026
1027                 /* buffer the message to handle re-xmits */
1028                 dtls1_buffer_message(s, 1);
1029
1030                 s->state=b;
1031                 }
1032
1033         /* SSL3_ST_CW_CHANGE_B */
1034         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1035         }
1036
1037 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1038         {
1039         int n;
1040         unsigned char *p;
1041
1042         n=i2d_X509(x,NULL);
1043         if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1044                 {
1045                 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1046                 return 0;
1047                 }
1048         p=(unsigned char *)&(buf->data[*l]);
1049         l2n3(n,p);
1050         i2d_X509(x,&p);
1051         *l+=n+3;
1052
1053         return 1;
1054         }
1055 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1056         {
1057         unsigned char *p;
1058         int i;
1059         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1060         BUF_MEM *buf;
1061
1062         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1063         buf=s->init_buf;
1064         if (!BUF_MEM_grow_clean(buf,10))
1065                 {
1066                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1067                 return(0);
1068                 }
1069         if (x != NULL)
1070                 {
1071                 X509_STORE_CTX xs_ctx;
1072
1073                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1074                         {
1075                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1076                         return(0);
1077                         }
1078
1079                 X509_verify_cert(&xs_ctx);
1080                 /* Don't leave errors in the queue */
1081                 ERR_clear_error();
1082                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1083                         {
1084                         x = sk_X509_value(xs_ctx.chain, i);
1085
1086                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1087                                 {
1088                                 X509_STORE_CTX_cleanup(&xs_ctx);
1089                                 return 0;
1090                                 }
1091                         }
1092                 X509_STORE_CTX_cleanup(&xs_ctx);
1093                 }
1094         /* Thawte special :-) */
1095         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1096                 {
1097                 x=sk_X509_value(s->ctx->extra_certs,i);
1098                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1099                         return 0;
1100                 }
1101
1102         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1103
1104         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1105         l2n3(l,p);
1106         l+=3;
1107         p=(unsigned char *)&(buf->data[0]);
1108         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1109
1110         l+=DTLS1_HM_HEADER_LENGTH;
1111         return(l);
1112         }
1113
1114 int dtls1_read_failed(SSL *s, int code)
1115         {
1116         if ( code > 0)
1117                 {
1118                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1119                 return 1;
1120                 }
1121
1122         if (!dtls1_is_timer_expired(s))
1123                 {
1124                 /* not a timeout, none of our business,
1125                    let higher layers handle this.  in fact it's probably an error */
1126                 return code;
1127                 }
1128
1129         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1130                 {
1131                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1132                 return code;
1133                 }
1134
1135 #if 0 /* for now, each alert contains only one record number */
1136         item = pqueue_peek(state->rcvd_records);
1137         if ( item )
1138                 {
1139                 /* send an alert immediately for all the missing records */
1140                 }
1141         else
1142 #endif
1143
1144 #if 0  /* no more alert sending, just retransmit the last set of messages */
1145         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1146                 ssl3_send_alert(s,SSL3_AL_WARNING,
1147                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1148 #endif
1149
1150         return dtls1_handle_timeout(s);
1151         }
1152
1153 int
1154 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1155         {
1156         /* The index of the retransmission queue actually is the message sequence number,
1157          * since the queue only contains messages of a single handshake. However, the
1158          * ChangeCipherSpec has no message sequence number and so using only the sequence
1159          * will result in the CCS and Finished having the same index. To prevent this,
1160          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1161          * This does not only differ CSS and Finished, it also maintains the order of the
1162          * index (important for priority queues) and fits in the unsigned short variable.
1163          */
1164         return seq * 2 - is_ccs;
1165         }
1166
1167 int
1168 dtls1_retransmit_buffered_messages(SSL *s)
1169         {
1170         pqueue sent = s->d1->sent_messages;
1171         piterator iter;
1172         pitem *item;
1173         hm_fragment *frag;
1174         int found = 0;
1175
1176         iter = pqueue_iterator(sent);
1177
1178         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1179                 {
1180                 frag = (hm_fragment *)item->data;
1181                         if ( dtls1_retransmit_message(s,
1182                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1183                                 0, &found) <= 0 && found)
1184                         {
1185                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1186                         return -1;
1187                         }
1188                 }
1189
1190         return 1;
1191         }
1192
1193 int
1194 dtls1_buffer_message(SSL *s, int is_ccs)
1195         {
1196         pitem *item;
1197         hm_fragment *frag;
1198         unsigned char seq64be[8];
1199
1200         /* this function is called immediately after a message has
1201          * been serialized */
1202         OPENSSL_assert(s->init_off == 0);
1203
1204         frag = dtls1_hm_fragment_new(s->init_num, 0);
1205         if (!frag)
1206                 return 0;
1207
1208         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1209
1210         if ( is_ccs)
1211                 {
1212                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1213                                ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1214                 }
1215         else
1216                 {
1217                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1218                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1219                 }
1220
1221         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1222         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1223         frag->msg_header.type = s->d1->w_msg_hdr.type;
1224         frag->msg_header.frag_off = 0;
1225         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1226         frag->msg_header.is_ccs = is_ccs;
1227
1228         /* save current state*/
1229         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1230         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1231         frag->msg_header.saved_retransmit_state.compress = s->compress;
1232         frag->msg_header.saved_retransmit_state.session = s->session;
1233         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1234
1235         memset(seq64be,0,sizeof(seq64be));
1236         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1237                                                                                                                   frag->msg_header.is_ccs)>>8);
1238         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1239                                                                                                                   frag->msg_header.is_ccs));
1240
1241         item = pitem_new(seq64be, frag);
1242         if ( item == NULL)
1243                 {
1244                 dtls1_hm_fragment_free(frag);
1245                 return 0;
1246                 }
1247
1248 #if 0
1249         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1250         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1251         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1252 #endif
1253
1254         pqueue_insert(s->d1->sent_messages, item);
1255         return 1;
1256         }
1257
1258 int
1259 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1260         int *found)
1261         {
1262         int ret;
1263         /* XDTLS: for now assuming that read/writes are blocking */
1264         pitem *item;
1265         hm_fragment *frag ;
1266         unsigned long header_length;
1267         unsigned char seq64be[8];
1268         struct dtls1_retransmit_state saved_state;
1269         unsigned char save_write_sequence[8];
1270
1271         /*
1272           OPENSSL_assert(s->init_num == 0);
1273           OPENSSL_assert(s->init_off == 0);
1274          */
1275
1276         /* XDTLS:  the requested message ought to be found, otherwise error */
1277         memset(seq64be,0,sizeof(seq64be));
1278         seq64be[6] = (unsigned char)(seq>>8);
1279         seq64be[7] = (unsigned char)seq;
1280
1281         item = pqueue_find(s->d1->sent_messages, seq64be);
1282         if ( item == NULL)
1283                 {
1284                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1285                 *found = 0;
1286                 return 0;
1287                 }
1288
1289         *found = 1;
1290         frag = (hm_fragment *)item->data;
1291
1292         if ( frag->msg_header.is_ccs)
1293                 header_length = DTLS1_CCS_HEADER_LENGTH;
1294         else
1295                 header_length = DTLS1_HM_HEADER_LENGTH;
1296
1297         memcpy(s->init_buf->data, frag->fragment,
1298                 frag->msg_header.msg_len + header_length);
1299                 s->init_num = frag->msg_header.msg_len + header_length;
1300
1301         dtls1_set_message_header_int(s, frag->msg_header.type,
1302                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1303                 frag->msg_header.frag_len);
1304
1305         /* save current state */
1306         saved_state.enc_write_ctx = s->enc_write_ctx;
1307         saved_state.write_hash = s->write_hash;
1308         saved_state.compress = s->compress;
1309         saved_state.session = s->session;
1310         saved_state.epoch = s->d1->w_epoch;
1311         saved_state.epoch = s->d1->w_epoch;
1312
1313         s->d1->retransmitting = 1;
1314
1315         /* restore state in which the message was originally sent */
1316         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1317         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1318         s->compress = frag->msg_header.saved_retransmit_state.compress;
1319         s->session = frag->msg_header.saved_retransmit_state.session;
1320         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1321
1322         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1323         {
1324                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1325                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1326         }
1327
1328         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1329                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1330
1331         /* restore current state */
1332         s->enc_write_ctx = saved_state.enc_write_ctx;
1333         s->write_hash = saved_state.write_hash;
1334         s->compress = saved_state.compress;
1335         s->session = saved_state.session;
1336         s->d1->w_epoch = saved_state.epoch;
1337
1338         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1339         {
1340                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1341                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1342         }
1343
1344         s->d1->retransmitting = 0;
1345
1346         (void)BIO_flush(SSL_get_wbio(s));
1347         return ret;
1348         }
1349
1350 /* call this function when the buffered messages are no longer needed */
1351 void
1352 dtls1_clear_record_buffer(SSL *s)
1353         {
1354         pitem *item;
1355
1356         for(item = pqueue_pop(s->d1->sent_messages);
1357                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1358                 {
1359                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1360                 pitem_free(item);
1361                 }
1362         }
1363
1364
1365 unsigned char *
1366 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1367                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1368         {
1369         /* Don't change sequence numbers while listening */
1370         if (frag_off == 0 && !s->d1->listen)
1371                 {
1372                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1373                 s->d1->next_handshake_write_seq++;
1374                 }
1375
1376         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1377                 frag_off, frag_len);
1378
1379         return p += DTLS1_HM_HEADER_LENGTH;
1380         }
1381
1382
1383 /* don't actually do the writing, wait till the MTU has been retrieved */
1384 static void
1385 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1386                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1387                             unsigned long frag_len)
1388         {
1389         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1390
1391         msg_hdr->type = mt;
1392         msg_hdr->msg_len = len;
1393         msg_hdr->seq = seq_num;
1394         msg_hdr->frag_off = frag_off;
1395         msg_hdr->frag_len = frag_len;
1396         }
1397
1398 static void
1399 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1400                         unsigned long frag_len)
1401         {
1402         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1403
1404         msg_hdr->frag_off = frag_off;
1405         msg_hdr->frag_len = frag_len;
1406         }
1407
1408 static unsigned char *
1409 dtls1_write_message_header(SSL *s, unsigned char *p)
1410         {
1411         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1412
1413         *p++ = msg_hdr->type;
1414         l2n3(msg_hdr->msg_len, p);
1415
1416         s2n(msg_hdr->seq, p);
1417         l2n3(msg_hdr->frag_off, p);
1418         l2n3(msg_hdr->frag_len, p);
1419
1420         return p;
1421         }
1422
1423 unsigned int
1424 dtls1_link_min_mtu(void)
1425         {
1426         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1427                 sizeof(g_probable_mtu[0])) - 1]);
1428         }
1429
1430 unsigned int
1431 dtls1_min_mtu(SSL *s)
1432         {
1433         return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1434         }
1435
1436
1437 void
1438 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1439         {
1440         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1441         msg_hdr->type = *(data++);
1442         n2l3(data, msg_hdr->msg_len);
1443
1444         n2s(data, msg_hdr->seq);
1445         n2l3(data, msg_hdr->frag_off);
1446         n2l3(data, msg_hdr->frag_len);
1447         }
1448
1449 void
1450 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1451         {
1452         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1453
1454         ccs_hdr->type = *(data++);
1455         }