ssl/d1_both.c

   1 /* ssl/d1_both.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <limits.h>
 117 #include <string.h>
 118 #include <stdio.h>
 119 #include "ssl_locl.h"
 120 #include <openssl/buffer.h>
 121 #include <openssl/rand.h>
 122 #include <openssl/objects.h>
 123 #include <openssl/evp.h>
 124 #include <openssl/x509.h>
 125
 126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 127
 128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
 129                         if ((end) - (start) <= 8) { \
 130                                 long ii; \
 131                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 132                         } else { \
 133                                 long ii; \
 134                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 135                                 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
 136                                 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 137                         } }
 138
 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 140                         long ii; \
 141                         OPENSSL_assert((msg_len) > 0); \
 142                         is_complete = 1; \
 143                         if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 144                         if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
 145                                 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 146
 147 #if 0
 148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 149                         long ii; \
 150                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 151                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 152                         printf("\n"); }
 153 #endif
 154
 155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 156 static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 157
 158 /* XDTLS:  figure out the right values */
 159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 160
 161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 163         unsigned long frag_len);
 164 static unsigned char *dtls1_write_message_header(SSL *s,
 165         unsigned char *p);
 166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 167         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 168         unsigned long frag_len);
 169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 170         long max, int *ok);
 171
 172 static hm_fragment *
 173 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 174         {
 175         hm_fragment *frag = NULL;
 176         unsigned char *buf = NULL;
 177         unsigned char *bitmask = NULL;
 178
 179         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 180         if ( frag == NULL)
 181                 return NULL;
 182
 183         if (frag_len)
 184                 {
 185                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 186                 if ( buf == NULL)
 187                         {
 188                         OPENSSL_free(frag);
 189                         return NULL;
 190                         }
 191                 }
 192
 193         /* zero length fragment gets zero frag->fragment */
 194         frag->fragment = buf;
 195
 196         /* Initialize reassembly bitmask if necessary */
 197         if (reassembly)
 198                 {
 199                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 200                 if (bitmask == NULL)
 201                         {
 202                         if (buf != NULL) OPENSSL_free(buf);
 203                         OPENSSL_free(frag);
 204                         return NULL;
 205                         }
 206                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 207                 }
 208
 209         frag->reassembly = bitmask;
 210
 211         return frag;
 212         }
 213
 214 static void
 215 dtls1_hm_fragment_free(hm_fragment *frag)
 216         {
 217         if (frag->fragment) OPENSSL_free(frag->fragment);
 218         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 219         OPENSSL_free(frag);
 220         }
 221
 222 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 223 int dtls1_do_write(SSL *s, int type)
 224         {
 225         int ret;
 226         int curr_mtu;
 227         unsigned int len, frag_off, mac_size, blocksize;
 228
 229         /* AHA!  Figure out the MTU, and stick to the right size */
 230         if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 231                 {
 232                 s->d1->mtu =
 233                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 234
 235                 /* I've seen the kernel return bogus numbers when it doesn't know
 236                  * (initial write), so just make sure we have a reasonable number */
 237                 if (s->d1->mtu < dtls1_min_mtu())
 238                         {
 239                         s->d1->mtu = 0;
 240                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 241                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 242                                 s->d1->mtu, NULL);
 243                         }
 244                 }
 245 #if 0
 246         mtu = s->d1->mtu;
 247
 248         fprintf(stderr, "using MTU = %d\n", mtu);
 249
 250         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 251
 252         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 253
 254         if ( curr_mtu > 0)
 255                 mtu = curr_mtu;
 256         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 257                 return ret;
 258
 259         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 260                 {
 261                 ret = BIO_flush(SSL_get_wbio(s));
 262                 if ( ret <= 0)
 263                         return ret;
 264                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 265                 }
 266 #endif
 267
 268         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu());  /* should have something reasonable now */
 269
 270         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 271                 OPENSSL_assert(s->init_num ==
 272                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 273
 274         if (s->write_hash)
 275                 mac_size = EVP_MD_size(s->write_hash);
 276         else
 277                 mac_size = 0;
 278
 279         if (s->enc_write_ctx &&
 280                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
 281                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 282         else
 283                 blocksize = 0;
 284
 285         frag_off = 0;
 286         while( s->init_num)
 287                 {
 288                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 289                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 290
 291                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 292                         {
 293                         /* grr.. we could get an error if MTU picked was wrong */
 294                         ret = BIO_flush(SSL_get_wbio(s));
 295                         if ( ret <= 0)
 296                                 return ret;
 297                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 298                                 mac_size - blocksize;
 299                         }
 300
 301                 if ( s->init_num > curr_mtu)
 302                         len = curr_mtu;
 303                 else
 304                         len = s->init_num;
 305
 306
 307                 /* XDTLS: this function is too long.  split out the CCS part */
 308                 if ( type == SSL3_RT_HANDSHAKE)
 309                         {
 310                         if ( s->init_off != 0)
 311                                 {
 312                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 313                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 314                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 315
 316                                 if ( s->init_num > curr_mtu)
 317                                         len = curr_mtu;
 318                                 else
 319                                         len = s->init_num;
 320                                 }
 321
 322                         dtls1_fix_message_header(s, frag_off,
 323                                 len - DTLS1_HM_HEADER_LENGTH);
 324
 325                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 326
 327                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 328                         }
 329
 330                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 331                         len);
 332                 if (ret < 0)
 333                         {
 334                         /* might need to update MTU here, but we don't know
 335                          * which previous packet caused the failure -- so can't
 336                          * really retransmit anything.  continue as if everything
 337                          * is fine and wait for an alert to handle the
 338                          * retransmit
 339                          */
 340                         if ( BIO_ctrl(SSL_get_wbio(s),
 341                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 342                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 343                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 344                         else
 345                                 return(-1);
 346                         }
 347                 else
 348                         {
 349
 350                         /* bad if this assert fails, only part of the handshake
 351                          * message got sent.  but why would this happen? */
 352                         OPENSSL_assert(len == (unsigned int)ret);
 353
 354                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 355                                 {
 356                                 /* should not be done for 'Hello Request's, but in that case
 357                                  * we'll ignore the result anyway */
 358                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 359                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 360                                 int xlen;
 361
 362                                 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER)
 363                                         {
 364                                         /* reconstruct message header is if it
 365                                          * is being sent in single fragment */
 366                                         *p++ = msg_hdr->type;
 367                                         l2n3(msg_hdr->msg_len,p);
 368                                         s2n (msg_hdr->seq,p);
 369                                         l2n3(0,p);
 370                                         l2n3(msg_hdr->msg_len,p);
 371                                         p  -= DTLS1_HM_HEADER_LENGTH;
 372                                         xlen = ret;
 373                                         }
 374                                 else
 375                                         {
 376                                         p  += DTLS1_HM_HEADER_LENGTH;
 377                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 378                                         }
 379
 380                                 ssl3_finish_mac(s, p, xlen);
 381                                 }
 382
 383                         if (ret == s->init_num)
 384                                 {
 385                                 if (s->msg_callback)
 386                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 387                                                 (size_t)(s->init_off + s->init_num), s,
 388                                                 s->msg_callback_arg);
 389
 390                                 s->init_off = 0;  /* done writing this message */
 391                                 s->init_num = 0;
 392
 393                                 return(1);
 394                                 }
 395                         s->init_off+=ret;
 396                         s->init_num-=ret;
 397                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 398                         }
 399                 }
 400         return(0);
 401         }
 402
 403
 404 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 405  * maximum acceptable body length 'max'.
 406  * Read an entire handshake message.  Handshake messages arrive in
 407  * fragments.
 408  */
 409 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 410         {
 411         int i, al;
 412         struct hm_header_st *msg_hdr;
 413         unsigned char *p;
 414         unsigned long msg_len;
 415
 416         /* s3->tmp is used to store messages that are unexpected, caused
 417          * by the absence of an optional handshake message */
 418         if (s->s3->tmp.reuse_message)
 419                 {
 420                 s->s3->tmp.reuse_message=0;
 421                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 422                         {
 423                         al=SSL_AD_UNEXPECTED_MESSAGE;
 424                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 425                         goto f_err;
 426                         }
 427                 *ok=1;
 428                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 429                 s->init_num = (int)s->s3->tmp.message_size;
 430                 return s->init_num;
 431                 }
 432
 433         msg_hdr = &s->d1->r_msg_hdr;
 434         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 435
 436 again:
 437         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 438         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 439                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 440                 goto again;
 441         else if ( i <= 0 && !*ok)
 442                 return i;
 443
 444         p = (unsigned char *)s->init_buf->data;
 445         msg_len = msg_hdr->msg_len;
 446
 447         /* reconstruct message header */
 448         *(p++) = msg_hdr->type;
 449         l2n3(msg_len,p);
 450         s2n (msg_hdr->seq,p);
 451         l2n3(0,p);
 452         l2n3(msg_len,p);
 453         if (s->version != DTLS1_BAD_VER) {
 454                 p       -= DTLS1_HM_HEADER_LENGTH;
 455                 msg_len += DTLS1_HM_HEADER_LENGTH;
 456         }
 457
 458         ssl3_finish_mac(s, p, msg_len);
 459         if (s->msg_callback)
 460                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 461                         p, msg_len,
 462                         s, s->msg_callback_arg);
 463
 464         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 465
 466         /* Don't change sequence numbers while listening */
 467         if (!s->d1->listen)
 468                 s->d1->handshake_read_seq++;
 469
 470         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 471         return s->init_num;
 472
 473 f_err:
 474         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 475         *ok = 0;
 476         return -1;
 477         }
 478
 479
 480 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 481         {
 482         size_t frag_off,frag_len,msg_len;
 483
 484         msg_len  = msg_hdr->msg_len;
 485         frag_off = msg_hdr->frag_off;
 486         frag_len = msg_hdr->frag_len;
 487
 488         /* sanity checking */
 489         if ( (frag_off+frag_len) > msg_len)
 490                 {
 491                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 492                 return SSL_AD_ILLEGAL_PARAMETER;
 493                 }
 494
 495         if ( (frag_off+frag_len) > (unsigned long)max)
 496                 {
 497                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 498                 return SSL_AD_ILLEGAL_PARAMETER;
 499                 }
 500
 501         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 502                 {
 503                 /* msg_len is limited to 2^24, but is effectively checked
 504                  * against max above */
 505                 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
 506                         {
 507                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 508                         return SSL_AD_INTERNAL_ERROR;
 509                         }
 510
 511                 s->s3->tmp.message_size  = msg_len;
 512                 s->d1->r_msg_hdr.msg_len = msg_len;
 513                 s->s3->tmp.message_type  = msg_hdr->type;
 514                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 515                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 516                 }
 517         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 518                 {
 519                 /* They must be playing with us! BTW, failure to enforce
 520                  * upper limit would open possibility for buffer overrun. */
 521                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 522                 return SSL_AD_ILLEGAL_PARAMETER;
 523                 }
 524
 525         return 0; /* no error */
 526         }
 527
 528
 529 static int
 530 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 531         {
 532         /* (0) check whether the desired fragment is available
 533          * if so:
 534          * (1) copy over the fragment to s->init_buf->data[]
 535          * (2) update s->init_num
 536          */
 537         pitem *item;
 538         hm_fragment *frag;
 539         int al;
 540
 541         *ok = 0;
 542         item = pqueue_peek(s->d1->buffered_messages);
 543         if ( item == NULL)
 544                 return 0;
 545
 546         frag = (hm_fragment *)item->data;
 547
 548         /* Don't return if reassembly still in progress */
 549         if (frag->reassembly != NULL)
 550                 return 0;
 551
 552         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 553                 {
 554                 unsigned long frag_len = frag->msg_header.frag_len;
 555                 pqueue_pop(s->d1->buffered_messages);
 556
 557                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 558
 559                 if (al==0) /* no alert */
 560                         {
 561                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 562                         memcpy(&p[frag->msg_header.frag_off],
 563                                 frag->fragment,frag->msg_header.frag_len);
 564                         }
 565
 566                 dtls1_hm_fragment_free(frag);
 567                 pitem_free(item);
 568
 569                 if (al==0)
 570                         {
 571                         *ok = 1;
 572                         return frag_len;
 573                         }
 574
 575                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 576                 s->init_num = 0;
 577                 *ok = 0;
 578                 return -1;
 579                 }
 580         else
 581                 return 0;
 582         }
 583
 584 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 585  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 586  * be greater if the maximum certificate list size requires it. */
 587 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 588         {
 589         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 590         if (max_len < (unsigned long)s->max_cert_list)
 591                 return s->max_cert_list;
 592         return max_len;
 593         }
 594
 595 static int
 596 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 597         {
 598         hm_fragment *frag = NULL;
 599         pitem *item = NULL;
 600         int i = -1, is_complete;
 601         PQ_64BIT seq64;
 602         unsigned long frag_len = msg_hdr->frag_len;
 603
 604         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 605             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 606                 goto err;
 607
 608         if (frag_len == 0)
 609                 return DTLS1_HM_FRAGMENT_RETRY;
 610
 611         /* Try to find item in queue */
 612         pq_64bit_init(&seq64);
 613         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 614         item = pqueue_find(s->d1->buffered_messages, seq64);
 615         pq_64bit_free(&seq64);
 616
 617         if (item == NULL)
 618                 {
 619                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 620                 if ( frag == NULL)
 621                         goto err;
 622                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 623                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 624                 frag->msg_header.frag_off = 0;
 625                 }
 626         else
 627                 {
 628                 frag = (hm_fragment*) item->data;
 629                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 630                         {
 631                         item = NULL;
 632                         frag = NULL;
 633                         goto err;
 634                         }
 635                 }
 636
 637
 638         /* If message is already reassembled, this must be a
 639          * retransmit and can be dropped. In this case item != NULL and so frag
 640          * does not need to be freed.
 641          */
 642         if (frag->reassembly == NULL)
 643                 {
 644                 unsigned char devnull [256];
 645
 646                 while (frag_len)
 647                         {
 648                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 649                                 devnull,
 650                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 651                         if (i<=0) goto err;
 652                         frag_len -= i;
 653                         }
 654                 return DTLS1_HM_FRAGMENT_RETRY;
 655                 }
 656
 657         /* read the body of the fragment (header has already been read */
 658         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 659                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 660         if ((unsigned long)i!=frag_len)
 661                 i=-1;
 662         if (i<=0)
 663                 goto err;
 664
 665         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 666                             (long)(msg_hdr->frag_off + frag_len));
 667
 668         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 669                                    is_complete);
 670
 671         if (is_complete)
 672                 {
 673                 OPENSSL_free(frag->reassembly);
 674                 frag->reassembly = NULL;
 675                 }
 676
 677         if (item == NULL)
 678                 {
 679                 pq_64bit_init(&seq64);
 680                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 681                 item = pitem_new(seq64, frag);
 682                 pq_64bit_free(&seq64);
 683
 684                 if (item == NULL)
 685                         {
 686                         i = -1;
 687                         goto err;
 688                         }
 689
 690                 item = pqueue_insert(s->d1->buffered_messages, item);
 691                 /* pqueue_insert fails iff a duplicate item is inserted.
 692                  * However, |item| cannot be a duplicate. If it were,
 693                  * |pqueue_find|, above, would have returned it and control
 694                  * would never have reached this branch. */
 695                 OPENSSL_assert(item != NULL);
 696                 }
 697
 698         return DTLS1_HM_FRAGMENT_RETRY;
 699
 700 err:
 701         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 702         *ok = 0;
 703         return i;
 704         }
 705
 706
 707 static int
 708 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 709 {
 710         int i=-1;
 711         hm_fragment *frag = NULL;
 712         pitem *item = NULL;
 713         PQ_64BIT seq64;
 714         unsigned long frag_len = msg_hdr->frag_len;
 715
 716         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 717                 goto err;
 718
 719         /* Try to find item in queue, to prevent duplicate entries */
 720         pq_64bit_init(&seq64);
 721         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 722         item = pqueue_find(s->d1->buffered_messages, seq64);
 723         pq_64bit_free(&seq64);
 724
 725         /* If we already have an entry and this one is a fragment,
 726          * don't discard it and rather try to reassemble it.
 727          */
 728         if (item != NULL && frag_len != msg_hdr->msg_len)
 729                 item = NULL;
 730
 731         /* Discard the message if sequence number was already there, is
 732          * too far in the future, already in the queue or if we received
 733          * a FINISHED before the SERVER_HELLO, which then must be a stale
 734          * retransmit.
 735          */
 736         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 737                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 738                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 739                 {
 740                 unsigned char devnull [256];
 741
 742                 while (frag_len)
 743                         {
 744                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 745                                 devnull,
 746                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 747                         if (i<=0) goto err;
 748                         frag_len -= i;
 749                         }
 750                 }
 751         else
 752                 {
 753                 if (frag_len != msg_hdr->msg_len)
 754                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 755
 756                 if (frag_len > dtls1_max_handshake_message_len(s))
 757                         goto err;
 758
 759                 frag = dtls1_hm_fragment_new(frag_len, 0);
 760                 if ( frag == NULL)
 761                         goto err;
 762
 763                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 764
 765                 if (frag_len)
 766                         {
 767                         /* read the body of the fragment (header has already been read) */
 768                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 769                                 frag->fragment,frag_len,0);
 770                         if ((unsigned long)i!=frag_len)
 771                                 i = -1;
 772                         if (i<=0)
 773                                 goto err;
 774                         }
 775
 776                 pq_64bit_init(&seq64);
 777                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 778
 779                 item = pitem_new(seq64, frag);
 780                 pq_64bit_free(&seq64);
 781                 if ( item == NULL)
 782                         goto err;
 783
 784                 item = pqueue_insert(s->d1->buffered_messages, item);
 785                 /* pqueue_insert fails iff a duplicate item is inserted.
 786                  * However, |item| cannot be a duplicate. If it were,
 787                  * |pqueue_find|, above, would have returned it. Then, either
 788                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 789                  * to NULL and it will have been processed with
 790                  * |dtls1_reassemble_fragment|, above, or the record will have
 791                  * been discarded. */
 792                 OPENSSL_assert(item != NULL);
 793                 }
 794
 795         return DTLS1_HM_FRAGMENT_RETRY;
 796
 797 err:
 798         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 799         *ok = 0;
 800         return i;
 801         }
 802
 803
 804 static long
 805 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 806         {
 807         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 808         unsigned long len, frag_off, frag_len;
 809         int i,al;
 810         struct hm_header_st msg_hdr;
 811
 812         redo:
 813         /* see if we have the required fragment already */
 814         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 815                 {
 816                 if (*ok)        s->init_num = frag_len;
 817                 return frag_len;
 818                 }
 819
 820         /* read handshake message header */
 821         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 822                 DTLS1_HM_HEADER_LENGTH, 0);
 823         if (i <= 0)     /* nbio, or an error */
 824                 {
 825                 s->rwstate=SSL_READING;
 826                 *ok = 0;
 827                 return i;
 828                 }
 829         /* Handshake fails if message header is incomplete */
 830         if (i != DTLS1_HM_HEADER_LENGTH)
 831                 {
 832                 al=SSL_AD_UNEXPECTED_MESSAGE;
 833                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 834                 goto f_err;
 835                 }
 836
 837         /* parse the message fragment header */
 838         dtls1_get_message_header(wire, &msg_hdr);
 839
 840         /*
 841          * if this is a future (or stale) message it gets buffered
 842          * (or dropped)--no further processing at this time
 843          * While listening, we accept seq 1 (ClientHello with cookie)
 844          * although we're still expecting seq 0 (ClientHello)
 845          */
 846         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 847                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 848
 849         len = msg_hdr.msg_len;
 850         frag_off = msg_hdr.frag_off;
 851         frag_len = msg_hdr.frag_len;
 852
 853         if (frag_len && frag_len < len)
 854                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 855
 856         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 857                 wire[0] == SSL3_MT_HELLO_REQUEST)
 858                 {
 859                 /* The server may always send 'Hello Request' messages --
 860                  * we are doing a handshake anyway now, so ignore them
 861                  * if their format is correct. Does not count for
 862                  * 'Finished' MAC. */
 863                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 864                         {
 865                         if (s->msg_callback)
 866                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 867                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 868                                         s->msg_callback_arg);
 869
 870                         s->init_num = 0;
 871                         goto redo;
 872                         }
 873                 else /* Incorrectly formated Hello request */
 874                         {
 875                         al=SSL_AD_UNEXPECTED_MESSAGE;
 876                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 877                         goto f_err;
 878                         }
 879                 }
 880
 881         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 882                 goto f_err;
 883
 884         /* XDTLS:  ressurect this when restart is in place */
 885         s->state=stn;
 886
 887         if ( frag_len > 0)
 888                 {
 889                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 890
 891                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 892                         &p[frag_off],frag_len,0);
 893                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 894                 if (i <= 0)
 895                         {
 896                         s->rwstate=SSL_READING;
 897                         *ok = 0;
 898                         return i;
 899                         }
 900                 }
 901         else
 902                 i = 0;
 903
 904         /* XDTLS:  an incorrectly formatted fragment should cause the
 905          * handshake to fail */
 906         if (i != (int)frag_len)
 907                 {
 908                 al=SSL3_AD_ILLEGAL_PARAMETER;
 909                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 910                 goto f_err;
 911                 }
 912
 913         *ok = 1;
 914
 915         /* Note that s->init_num is *not* used as current offset in
 916          * s->init_buf->data, but as a counter summing up fragments'
 917          * lengths: as soon as they sum up to handshake packet
 918          * length, we assume we have got all the fragments. */
 919         s->init_num = frag_len;
 920         return frag_len;
 921
 922 f_err:
 923         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 924         s->init_num = 0;
 925
 926         *ok=0;
 927         return(-1);
 928         }
 929
 930 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 931         {
 932         unsigned char *p,*d;
 933         int i;
 934         unsigned long l;
 935
 936         if (s->state == a)
 937                 {
 938                 d=(unsigned char *)s->init_buf->data;
 939                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 940
 941                 i=s->method->ssl3_enc->final_finish_mac(s,
 942                         &(s->s3->finish_dgst1),
 943                         &(s->s3->finish_dgst2),
 944                         sender,slen,s->s3->tmp.finish_md);
 945                 s->s3->tmp.finish_md_len = i;
 946                 memcpy(p, s->s3->tmp.finish_md, i);
 947                 p+=i;
 948                 l=i;
 949
 950         /* Copy the finished so we can use it for
 951          * renegotiation checks
 952          */
 953         if(s->type == SSL_ST_CONNECT)
 954                 {
 955                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 956                 memcpy(s->s3->previous_client_finished,
 957                        s->s3->tmp.finish_md, i);
 958                 s->s3->previous_client_finished_len=i;
 959                 }
 960         else
 961                 {
 962                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 963                 memcpy(s->s3->previous_server_finished,
 964                        s->s3->tmp.finish_md, i);
 965                 s->s3->previous_server_finished_len=i;
 966                 }
 967
 968 #ifdef OPENSSL_SYS_WIN16
 969                 /* MSVC 1.5 does not clear the top bytes of the word unless
 970                  * I do this.
 971                  */
 972                 l&=0xffff;
 973 #endif
 974
 975                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 976                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 977                 s->init_off=0;
 978
 979                 /* buffer the message to handle re-xmits */
 980                 dtls1_buffer_message(s, 0);
 981
 982                 s->state=b;
 983                 }
 984
 985         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 986         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 987         }
 988
 989 /* for these 2 messages, we need to
 990  * ssl->enc_read_ctx                    re-init
 991  * ssl->s3->read_sequence               zero
 992  * ssl->s3->read_mac_secret             re-init
 993  * ssl->session->read_sym_enc           assign
 994  * ssl->session->read_compression       assign
 995  * ssl->session->read_hash              assign
 996  */
 997 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 998         {
 999         unsigned char *p;
1000
1001         if (s->state == a)
1002                 {
1003                 p=(unsigned char *)s->init_buf->data;
1004                 *p++=SSL3_MT_CCS;
1005                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1006                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
1007
1008                 if (s->client_version == DTLS1_BAD_VER)
1009                         {
1010                         s->d1->next_handshake_write_seq++;
1011                         s2n(s->d1->handshake_write_seq,p);
1012                         s->init_num+=2;
1013                         }
1014
1015                 s->init_off=0;
1016
1017                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1018                         s->d1->handshake_write_seq, 0, 0);
1019
1020                 /* buffer the message to handle re-xmits */
1021                 dtls1_buffer_message(s, 1);
1022
1023                 s->state=b;
1024                 }
1025
1026         /* SSL3_ST_CW_CHANGE_B */
1027         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1028         }
1029
1030 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1031         {
1032                 int n;
1033                 unsigned char *p;
1034
1035                 n=i2d_X509(x,NULL);
1036                 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1037                         {
1038                         SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1039                         return 0;
1040                         }
1041                 p=(unsigned char *)&(buf->data[*l]);
1042                 l2n3(n,p);
1043                 i2d_X509(x,&p);
1044                 *l+=n+3;
1045
1046                 return 1;
1047         }
1048 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1049         {
1050         unsigned char *p;
1051         int i;
1052         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1053         BUF_MEM *buf;
1054
1055         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1056         buf=s->init_buf;
1057         if (!BUF_MEM_grow_clean(buf,10))
1058                 {
1059                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1060                 return(0);
1061                 }
1062         if (x != NULL)
1063                 {
1064                 X509_STORE_CTX xs_ctx;
1065
1066                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1067                         {
1068                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1069                         return(0);
1070                         }
1071
1072                 X509_verify_cert(&xs_ctx);
1073                 /* Don't leave errors in the queue */
1074                 ERR_clear_error();
1075                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1076                         {
1077                         x = sk_X509_value(xs_ctx.chain, i);
1078
1079                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1080                                 {
1081                                 X509_STORE_CTX_cleanup(&xs_ctx);
1082                                 return 0;
1083                                 }
1084                         }
1085                 X509_STORE_CTX_cleanup(&xs_ctx);
1086                 }
1087         /* Thawte special :-) */
1088         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1089                 {
1090                 x=sk_X509_value(s->ctx->extra_certs,i);
1091                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1092                         return 0;
1093                 }
1094
1095         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1096
1097         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1098         l2n3(l,p);
1099         l+=3;
1100         p=(unsigned char *)&(buf->data[0]);
1101         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1102
1103         l+=DTLS1_HM_HEADER_LENGTH;
1104         return(l);
1105         }
1106
1107 int dtls1_read_failed(SSL *s, int code)
1108         {
1109         if ( code > 0)
1110                 {
1111                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1112                 return 1;
1113                 }
1114
1115         if (!dtls1_is_timer_expired(s))
1116                 {
1117                 /* not a timeout, none of our business,
1118                    let higher layers handle this.  in fact it's probably an error */
1119                 return code;
1120                 }
1121
1122         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1123                 {
1124                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1125                 return code;
1126                 }
1127
1128 #if 0 /* for now, each alert contains only one record number */
1129         item = pqueue_peek(state->rcvd_records);
1130         if ( item )
1131                 {
1132                 /* send an alert immediately for all the missing records */
1133                 }
1134         else
1135 #endif
1136
1137 #if 0  /* no more alert sending, just retransmit the last set of messages */
1138         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1139                 ssl3_send_alert(s,SSL3_AL_WARNING,
1140                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1141 #endif
1142
1143         return dtls1_handle_timeout(s);
1144         }
1145
1146 int
1147 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1148         {
1149         /* The index of the retransmission queue actually is the message sequence number,
1150          * since the queue only contains messages of a single handshake. However, the
1151          * ChangeCipherSpec has no message sequence number and so using only the sequence
1152          * will result in the CCS and Finished having the same index. To prevent this,
1153          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1154          * This does not only differ CSS and Finished, it also maintains the order of the
1155          * index (important for priority queues) and fits in the unsigned short variable.
1156          */
1157         return seq * 2 - is_ccs;
1158         }
1159
1160 int
1161 dtls1_retransmit_buffered_messages(SSL *s)
1162         {
1163         pqueue sent = s->d1->sent_messages;
1164         piterator iter;
1165         pitem *item;
1166         hm_fragment *frag;
1167         int found = 0;
1168
1169         iter = pqueue_iterator(sent);
1170
1171         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1172                 {
1173                 frag = (hm_fragment *)item->data;
1174                         if ( dtls1_retransmit_message(s,
1175                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1176                                 0, &found) <= 0 && found)
1177                         {
1178                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1179                         return -1;
1180                         }
1181                 }
1182
1183         return 1;
1184         }
1185
1186 int
1187 dtls1_buffer_message(SSL *s, int is_ccs)
1188         {
1189         pitem *item;
1190         hm_fragment *frag;
1191         PQ_64BIT seq64;
1192
1193         /* this function is called immediately after a message has
1194          * been serialized */
1195         OPENSSL_assert(s->init_off == 0);
1196
1197         frag = dtls1_hm_fragment_new(s->init_num, 0);
1198         if (!frag)
1199                 return 0;
1200
1201         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1202
1203         if ( is_ccs)
1204                 {
1205                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1206                         DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
1207                 }
1208         else
1209                 {
1210                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1211                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1212                 }
1213
1214         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1215         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1216         frag->msg_header.type = s->d1->w_msg_hdr.type;
1217         frag->msg_header.frag_off = 0;
1218         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1219         frag->msg_header.is_ccs = is_ccs;
1220
1221         /* save current state*/
1222         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1223         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1224         frag->msg_header.saved_retransmit_state.compress = s->compress;
1225         frag->msg_header.saved_retransmit_state.session = s->session;
1226         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1227
1228         pq_64bit_init(&seq64);
1229
1230         pq_64bit_assign_word(&seq64,
1231                                                  dtls1_get_queue_priority(frag->msg_header.seq,
1232                                                                                                   frag->msg_header.is_ccs));
1233
1234         item = pitem_new(seq64, frag);
1235         pq_64bit_free(&seq64);
1236         if ( item == NULL)
1237                 {
1238                 dtls1_hm_fragment_free(frag);
1239                 return 0;
1240                 }
1241
1242 #if 0
1243         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1244         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1245         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1246 #endif
1247
1248         pqueue_insert(s->d1->sent_messages, item);
1249         return 1;
1250         }
1251
1252 int
1253 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1254         int *found)
1255         {
1256         int ret;
1257         /* XDTLS: for now assuming that read/writes are blocking */
1258         pitem *item;
1259         hm_fragment *frag ;
1260         unsigned long header_length;
1261         PQ_64BIT seq64;
1262         struct dtls1_retransmit_state saved_state;
1263         unsigned char save_write_sequence[8];
1264
1265         /*
1266           OPENSSL_assert(s->init_num == 0);
1267           OPENSSL_assert(s->init_off == 0);
1268          */
1269
1270         /* XDTLS:  the requested message ought to be found, otherwise error */
1271         pq_64bit_init(&seq64);
1272         pq_64bit_assign_word(&seq64, seq);
1273
1274         item = pqueue_find(s->d1->sent_messages, seq64);
1275         pq_64bit_free(&seq64);
1276         if ( item == NULL)
1277                 {
1278                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1279                 *found = 0;
1280                 return 0;
1281                 }
1282
1283         *found = 1;
1284         frag = (hm_fragment *)item->data;
1285
1286         if ( frag->msg_header.is_ccs)
1287                 header_length = DTLS1_CCS_HEADER_LENGTH;
1288         else
1289                 header_length = DTLS1_HM_HEADER_LENGTH;
1290
1291         memcpy(s->init_buf->data, frag->fragment,
1292                 frag->msg_header.msg_len + header_length);
1293                 s->init_num = frag->msg_header.msg_len + header_length;
1294
1295         dtls1_set_message_header_int(s, frag->msg_header.type,
1296                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1297                 frag->msg_header.frag_len);
1298
1299         /* save current state */
1300         saved_state.enc_write_ctx = s->enc_write_ctx;
1301         saved_state.write_hash = s->write_hash;
1302         saved_state.compress = s->compress;
1303         saved_state.session = s->session;
1304         saved_state.epoch = s->d1->w_epoch;
1305         saved_state.epoch = s->d1->w_epoch;
1306
1307         s->d1->retransmitting = 1;
1308
1309         /* restore state in which the message was originally sent */
1310         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1311         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1312         s->compress = frag->msg_header.saved_retransmit_state.compress;
1313         s->session = frag->msg_header.saved_retransmit_state.session;
1314         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1315
1316         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1317         {
1318                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1319                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1320         }
1321
1322         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1323                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1324
1325         /* restore current state */
1326         s->enc_write_ctx = saved_state.enc_write_ctx;
1327         s->write_hash = saved_state.write_hash;
1328         s->compress = saved_state.compress;
1329         s->session = saved_state.session;
1330         s->d1->w_epoch = saved_state.epoch;
1331
1332         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1333         {
1334                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1335                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1336         }
1337
1338         s->d1->retransmitting = 0;
1339
1340         (void)BIO_flush(SSL_get_wbio(s));
1341         return ret;
1342         }
1343
1344 /* call this function when the buffered messages are no longer needed */
1345 void
1346 dtls1_clear_record_buffer(SSL *s)
1347         {
1348         pitem *item;
1349
1350         for(item = pqueue_pop(s->d1->sent_messages);
1351                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1352                 {
1353                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1354                 pitem_free(item);
1355                 }
1356         }
1357
1358
1359 unsigned char *
1360 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1361                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1362         {
1363         /* Don't change sequence numbers while listening */
1364         if (frag_off == 0 && !s->d1->listen)
1365                 {
1366                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1367                 s->d1->next_handshake_write_seq++;
1368                 }
1369
1370         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1371                 frag_off, frag_len);
1372
1373         return p += DTLS1_HM_HEADER_LENGTH;
1374         }
1375
1376
1377 /* don't actually do the writing, wait till the MTU has been retrieved */
1378 static void
1379 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1380                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1381                             unsigned long frag_len)
1382         {
1383         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1384
1385         msg_hdr->type = mt;
1386         msg_hdr->msg_len = len;
1387         msg_hdr->seq = seq_num;
1388         msg_hdr->frag_off = frag_off;
1389         msg_hdr->frag_len = frag_len;
1390         }
1391
1392 static void
1393 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1394                         unsigned long frag_len)
1395         {
1396         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1397
1398         msg_hdr->frag_off = frag_off;
1399         msg_hdr->frag_len = frag_len;
1400         }
1401
1402 static unsigned char *
1403 dtls1_write_message_header(SSL *s, unsigned char *p)
1404         {
1405         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1406
1407         *p++ = msg_hdr->type;
1408         l2n3(msg_hdr->msg_len, p);
1409
1410         s2n(msg_hdr->seq, p);
1411         l2n3(msg_hdr->frag_off, p);
1412         l2n3(msg_hdr->frag_len, p);
1413
1414         return p;
1415         }
1416
1417 unsigned int
1418 dtls1_min_mtu(void)
1419         {
1420         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1421                 sizeof(g_probable_mtu[0])) - 1]);
1422         }
1423
1424 static unsigned int
1425 dtls1_guess_mtu(unsigned int curr_mtu)
1426         {
1427         size_t i;
1428
1429         if ( curr_mtu == 0 )
1430                 return g_probable_mtu[0] ;
1431
1432         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1433                 if ( curr_mtu > g_probable_mtu[i])
1434                         return g_probable_mtu[i];
1435
1436         return curr_mtu;
1437         }
1438
1439 void
1440 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1441         {
1442         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1443         msg_hdr->type = *(data++);
1444         n2l3(data, msg_hdr->msg_len);
1445
1446         n2s(data, msg_hdr->seq);
1447         n2l3(data, msg_hdr->frag_off);
1448         n2l3(data, msg_hdr->frag_len);
1449         }
1450
1451 void
1452 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1453         {
1454         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1455
1456         ccs_hdr->type = *(data++);
1457         }