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                                 unsigned long ii; \
 131                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 132                         } else { \
 133                                 unsigned long ii; \
 134                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 135                                 for (ii = (((start) >> 3) + 1); ii < ((end) >> 3); ii++) bitmask[ii] = 0xff; \
 136                                 bitmask[((end) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 137                         } }
 138
 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 140                         unsigned long ii; \
 141                         is_complete = 1; \
 142                         if (bitmask[((msg_len) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 143                         if (is_complete) for (ii = 0; ii < ((msg_len) >> 3); ii++) \
 144                         if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 145
 146 #if 0
 147 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 148                         int ii; \
 149                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 150                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 151                         printf("\n"); }
 152 #endif
 153
 154 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 155 static unsigned char bitmask_end_values[]   = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 156
 157 /* XDTLS:  figure out the right values */
 158 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 159
 160 static unsigned int dtls1_min_mtu(void);
 161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 163         unsigned long frag_len);
 164 static unsigned char *dtls1_write_message_header(SSL *s,
 165         unsigned char *p);
 166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 167         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 168         unsigned long frag_len);
 169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 170         long max, int *ok);
 171
 172 static hm_fragment *
 173 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 174         {
 175         hm_fragment *frag = NULL;
 176         unsigned char *buf = NULL;
 177         unsigned char *bitmask = NULL;
 178
 179         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 180         if ( frag == NULL)
 181                 return NULL;
 182
 183         if (frag_len)
 184                 {
 185                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 186                 if ( buf == NULL)
 187                         {
 188                         OPENSSL_free(frag);
 189                         return NULL;
 190                         }
 191                 }
 192
 193         /* zero length fragment gets zero frag->fragment */
 194         frag->fragment = buf;
 195
 196         /* Initialize reassembly bitmask if necessary */
 197         if (reassembly)
 198                 {
 199                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 200                 if (bitmask == NULL)
 201                         {
 202                         if (buf != NULL) OPENSSL_free(buf);
 203                         OPENSSL_free(frag);
 204                         return NULL;
 205                         }
 206                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 207                 }
 208
 209         frag->reassembly = bitmask;
 210
 211         return frag;
 212         }
 213
 214 static void
 215 dtls1_hm_fragment_free(hm_fragment *frag)
 216         {
 217         if (frag->fragment) OPENSSL_free(frag->fragment);
 218         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 219         OPENSSL_free(frag);
 220         }
 221
 222 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 223 int dtls1_do_write(SSL *s, int type)
 224         {
 225         int ret;
 226         int curr_mtu;
 227         unsigned int len, frag_off, mac_size, blocksize;
 228
 229         /* AHA!  Figure out the MTU, and stick to the right size */
 230         if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 231                 {
 232                 s->d1->mtu =
 233                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 234
 235                 /* I've seen the kernel return bogus numbers when it doesn't know
 236                  * (initial write), so just make sure we have a reasonable number */
 237                 if ( s->d1->mtu < dtls1_min_mtu())
 238                         {
 239                         s->d1->mtu = 0;
 240                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 241                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 242                                 s->d1->mtu, NULL);
 243                         }
 244                 }
 245 #if 0
 246         mtu = s->d1->mtu;
 247
 248         fprintf(stderr, "using MTU = %d\n", mtu);
 249
 250         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 251
 252         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 253
 254         if ( curr_mtu > 0)
 255                 mtu = curr_mtu;
 256         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 257                 return ret;
 258
 259         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 260                 {
 261                 ret = BIO_flush(SSL_get_wbio(s));
 262                 if ( ret <= 0)
 263                         return ret;
 264                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 265                 }
 266
 267         OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
 268
 269 #endif
 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_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                                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
 318                                 if ( len <= DTLS1_HM_HEADER_LENGTH)
 319                                         len += DTLS1_HM_HEADER_LENGTH;
 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         s->d1->handshake_read_seq++;
 467         /* we just read a handshake message from the other side:
 468          * this means that we don't need to retransmit of the
 469          * buffered messages.
 470          * XDTLS: may be able clear out this
 471          * buffer a little sooner (i.e if an out-of-order
 472          * handshake message/record is received at the record
 473          * layer.
 474          * XDTLS: exception is that the server needs to
 475          * know that change cipher spec and finished messages
 476          * have been received by the client before clearing this
 477          * buffer.  this can simply be done by waiting for the
 478          * first data  segment, but is there a better way?  */
 479         dtls1_clear_record_buffer(s);
 480
 481         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 482         return s->init_num;
 483
 484 f_err:
 485         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 486         *ok = 0;
 487         return -1;
 488         }
 489
 490
 491 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 492         {
 493         size_t frag_off,frag_len,msg_len;
 494
 495         msg_len  = msg_hdr->msg_len;
 496         frag_off = msg_hdr->frag_off;
 497         frag_len = msg_hdr->frag_len;
 498
 499         /* sanity checking */
 500         if ( (frag_off+frag_len) > msg_len)
 501                 {
 502                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 503                 return SSL_AD_ILLEGAL_PARAMETER;
 504                 }
 505
 506         if ( (frag_off+frag_len) > (unsigned long)max)
 507                 {
 508                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 509                 return SSL_AD_ILLEGAL_PARAMETER;
 510                 }
 511
 512         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 513                 {
 514                 /* msg_len is limited to 2^24, but is effectively checked
 515                  * against max above */
 516                 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
 517                         {
 518                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 519                         return SSL_AD_INTERNAL_ERROR;
 520                         }
 521
 522                 s->s3->tmp.message_size  = msg_len;
 523                 s->d1->r_msg_hdr.msg_len = msg_len;
 524                 s->s3->tmp.message_type  = msg_hdr->type;
 525                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 526                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 527                 }
 528         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 529                 {
 530                 /* They must be playing with us! BTW, failure to enforce
 531                  * upper limit would open possibility for buffer overrun. */
 532                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 533                 return SSL_AD_ILLEGAL_PARAMETER;
 534                 }
 535
 536         return 0; /* no error */
 537         }
 538
 539
 540 static int
 541 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 542         {
 543         /* (0) check whether the desired fragment is available
 544          * if so:
 545          * (1) copy over the fragment to s->init_buf->data[]
 546          * (2) update s->init_num
 547          */
 548         pitem *item;
 549         hm_fragment *frag;
 550         int al;
 551
 552         *ok = 0;
 553         item = pqueue_peek(s->d1->buffered_messages);
 554         if ( item == NULL)
 555                 return 0;
 556
 557         frag = (hm_fragment *)item->data;
 558
 559         /* Don't return if reassembly still in progress */
 560         if (frag->reassembly != NULL)
 561                 return 0;
 562
 563         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 564                 {
 565                 unsigned long frag_len = frag->msg_header.frag_len;
 566                 pqueue_pop(s->d1->buffered_messages);
 567
 568                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 569
 570                 if (al==0) /* no alert */
 571                         {
 572                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 573                         memcpy(&p[frag->msg_header.frag_off],
 574                                 frag->fragment,frag->msg_header.frag_len);
 575                         }
 576
 577                 dtls1_hm_fragment_free(frag);
 578                 pitem_free(item);
 579
 580                 if (al==0)
 581                         {
 582                         *ok = 1;
 583                         return frag_len;
 584                         }
 585
 586                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 587                 s->init_num = 0;
 588                 *ok = 0;
 589                 return -1;
 590                 }
 591         else
 592                 return 0;
 593         }
 594
 595
 596 static int
 597 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 598         {
 599         hm_fragment *frag = NULL;
 600         pitem *item = NULL;
 601         int i = -1, is_complete;
 602         PQ_64BIT seq64;
 603         unsigned long frag_len = msg_hdr->frag_len, max_len;
 604
 605         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 606                 goto err;
 607
 608         /* Determine maximum allowed message size. Depends on (user set)
 609          * maximum certificate length, but 16k is minimum.
 610          */
 611         if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
 612                 max_len = s->max_cert_list;
 613         else
 614                 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 615
 616         if ((msg_hdr->frag_off+frag_len) > max_len)
 617                 goto err;
 618
 619         /* Try to find item in queue */
 620         pq_64bit_init(&seq64);
 621         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 622         item = pqueue_find(s->d1->buffered_messages, seq64);
 623         pq_64bit_free(&seq64);
 624
 625         if (item == NULL)
 626                 {
 627                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 628                 if ( frag == NULL)
 629                         goto err;
 630                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 631                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 632                 frag->msg_header.frag_off = 0;
 633                 }
 634         else
 635                 frag = (hm_fragment*) item->data;
 636
 637         /* If message is already reassembled, this must be a
 638          * retransmit and can be dropped.
 639          */
 640         if (frag->reassembly == NULL)
 641                 {
 642                 unsigned char devnull [256];
 643
 644                 while (frag_len)
 645                         {
 646                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 647                                 devnull,
 648                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 649                         if (i<=0) goto err;
 650                         frag_len -= i;
 651                         }
 652                 return DTLS1_HM_FRAGMENT_RETRY;
 653                 }
 654
 655         /* read the body of the fragment (header has already been read */
 656         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 657                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 658         if (i<=0 || (unsigned long)i!=frag_len)
 659                 goto err;
 660
 661         RSMBLY_BITMASK_MARK(frag->reassembly, msg_hdr->frag_off,
 662                             msg_hdr->frag_off + frag_len);
 663
 664         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, msg_hdr->msg_len,
 665                                    is_complete)
 666
 667         if (is_complete)
 668                 {
 669                 OPENSSL_free(frag->reassembly);
 670                 frag->reassembly = NULL;
 671                 }
 672
 673         if (item == NULL)
 674                 {
 675                 pq_64bit_init(&seq64);
 676                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 677                 item = pitem_new(seq64, frag);
 678                 pq_64bit_free(&seq64);
 679
 680                 if (item == NULL)
 681                         {
 682                         goto err;
 683                         i = -1;
 684                         }
 685
 686                 pqueue_insert(s->d1->buffered_messages, item);
 687                 }
 688
 689         return DTLS1_HM_FRAGMENT_RETRY;
 690
 691 err:
 692         if (frag != NULL) dtls1_hm_fragment_free(frag);
 693         if (item != NULL) OPENSSL_free(item);
 694         *ok = 0;
 695         return i;
 696         }
 697
 698
 699 static int
 700 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 701 {
 702         int i=-1;
 703         hm_fragment *frag = NULL;
 704         pitem *item = NULL;
 705         PQ_64BIT seq64;
 706         unsigned long frag_len = msg_hdr->frag_len;
 707
 708         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 709                 goto err;
 710
 711         /* Try to find item in queue, to prevent duplicate entries */
 712         pq_64bit_init(&seq64);
 713         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 714         item = pqueue_find(s->d1->buffered_messages, seq64);
 715         pq_64bit_free(&seq64);
 716
 717         /* If we already have an entry and this one is a fragment,
 718          * don't discard it and rather try to reassemble it.
 719          */
 720         if (item != NULL && frag_len < msg_hdr->msg_len)
 721                 item = NULL;
 722
 723         /* Discard the message if sequence number was already there, is
 724          * too far in the future, already in the queue or if we received
 725          * a FINISHED before the SERVER_HELLO, which then must be a stale
 726          * retransmit.
 727          */
 728         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 729                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 730                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 731                 {
 732                 unsigned char devnull [256];
 733
 734                 while (frag_len)
 735                         {
 736                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 737                                 devnull,
 738                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 739                         if (i<=0) goto err;
 740                         frag_len -= i;
 741                         }
 742                 }
 743         else
 744                 {
 745                 if (frag_len && frag_len < msg_hdr->msg_len)
 746                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 747
 748                 frag = dtls1_hm_fragment_new(frag_len, 0);
 749                 if ( frag == NULL)
 750                         goto err;
 751
 752                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 753
 754                 if (frag_len)
 755                         {
 756                         /* read the body of the fragment (header has already been read) */
 757                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 758                                 frag->fragment,frag_len,0);
 759                         if (i<=0 || (unsigned long)i!=frag_len)
 760                                 goto err;
 761                         }
 762
 763                 pq_64bit_init(&seq64);
 764                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 765
 766                 item = pitem_new(seq64, frag);
 767                 pq_64bit_free(&seq64);
 768                 if ( item == NULL)
 769                         goto err;
 770
 771                 pqueue_insert(s->d1->buffered_messages, item);
 772                 }
 773
 774         return DTLS1_HM_FRAGMENT_RETRY;
 775
 776 err:
 777         if ( frag != NULL) dtls1_hm_fragment_free(frag);
 778         if ( item != NULL) OPENSSL_free(item);
 779         *ok = 0;
 780         return i;
 781         }
 782
 783
 784 static long
 785 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 786         {
 787         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 788         unsigned long len, frag_off, frag_len;
 789         int i,al;
 790         struct hm_header_st msg_hdr;
 791
 792         /* see if we have the required fragment already */
 793         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 794                 {
 795                 if (*ok)        s->init_num = frag_len;
 796                 return frag_len;
 797                 }
 798
 799         /* read handshake message header */
 800         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 801                 DTLS1_HM_HEADER_LENGTH, 0);
 802         if (i <= 0)     /* nbio, or an error */
 803                 {
 804                 s->rwstate=SSL_READING;
 805                 *ok = 0;
 806                 return i;
 807                 }
 808         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
 809
 810         /* parse the message fragment header */
 811         dtls1_get_message_header(wire, &msg_hdr);
 812
 813         /*
 814          * if this is a future (or stale) message it gets buffered
 815          * (or dropped)--no further processing at this time
 816          */
 817         if ( msg_hdr.seq != s->d1->handshake_read_seq)
 818                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 819
 820         len = msg_hdr.msg_len;
 821         frag_off = msg_hdr.frag_off;
 822         frag_len = msg_hdr.frag_len;
 823
 824         if (frag_len && frag_len < len)
 825                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 826
 827         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 828                 wire[0] == SSL3_MT_HELLO_REQUEST)
 829                 {
 830                 /* The server may always send 'Hello Request' messages --
 831                  * we are doing a handshake anyway now, so ignore them
 832                  * if their format is correct. Does not count for
 833                  * 'Finished' MAC. */
 834                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 835                         {
 836                         if (s->msg_callback)
 837                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 838                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 839                                         s->msg_callback_arg);
 840
 841                         s->init_num = 0;
 842                         return dtls1_get_message_fragment(s, st1, stn,
 843                                 max, ok);
 844                         }
 845                 else /* Incorrectly formated Hello request */
 846                         {
 847                         al=SSL_AD_UNEXPECTED_MESSAGE;
 848                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 849                         goto f_err;
 850                         }
 851                 }
 852
 853         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 854                 goto f_err;
 855
 856         /* XDTLS:  ressurect this when restart is in place */
 857         s->state=stn;
 858
 859         if ( frag_len > 0)
 860                 {
 861                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 862
 863                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 864                         &p[frag_off],frag_len,0);
 865                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 866                 if (i <= 0)
 867                         {
 868                         s->rwstate=SSL_READING;
 869                         *ok = 0;
 870                         return i;
 871                         }
 872                 }
 873         else
 874                 i = 0;
 875
 876         /* XDTLS:  an incorrectly formatted fragment should cause the
 877          * handshake to fail */
 878         OPENSSL_assert(i == (int)frag_len);
 879
 880         *ok = 1;
 881
 882         /* Note that s->init_num is *not* used as current offset in
 883          * s->init_buf->data, but as a counter summing up fragments'
 884          * lengths: as soon as they sum up to handshake packet
 885          * length, we assume we have got all the fragments. */
 886         s->init_num = frag_len;
 887         return frag_len;
 888
 889 f_err:
 890         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 891         s->init_num = 0;
 892
 893         *ok=0;
 894         return(-1);
 895         }
 896
 897 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 898         {
 899         unsigned char *p,*d;
 900         int i;
 901         unsigned long l;
 902
 903         if (s->state == a)
 904                 {
 905                 d=(unsigned char *)s->init_buf->data;
 906                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 907
 908                 i=s->method->ssl3_enc->final_finish_mac(s,
 909                         &(s->s3->finish_dgst1),
 910                         &(s->s3->finish_dgst2),
 911                         sender,slen,s->s3->tmp.finish_md);
 912                 s->s3->tmp.finish_md_len = i;
 913                 memcpy(p, s->s3->tmp.finish_md, i);
 914                 p+=i;
 915                 l=i;
 916
 917         /* Copy the finished so we can use it for
 918          * renegotiation checks
 919          */
 920         if(s->type == SSL_ST_CONNECT)
 921                 {
 922                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 923                 memcpy(s->s3->previous_client_finished,
 924                        s->s3->tmp.finish_md, i);
 925                 s->s3->previous_client_finished_len=i;
 926                 }
 927         else
 928                 {
 929                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 930                 memcpy(s->s3->previous_server_finished,
 931                        s->s3->tmp.finish_md, i);
 932                 s->s3->previous_server_finished_len=i;
 933                 }
 934
 935 #ifdef OPENSSL_SYS_WIN16
 936                 /* MSVC 1.5 does not clear the top bytes of the word unless
 937                  * I do this.
 938                  */
 939                 l&=0xffff;
 940 #endif
 941
 942                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 943                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 944                 s->init_off=0;
 945
 946                 /* buffer the message to handle re-xmits */
 947                 dtls1_buffer_message(s, 0);
 948
 949                 s->state=b;
 950                 }
 951
 952         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 953         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 954         }
 955
 956 /* for these 2 messages, we need to
 957  * ssl->enc_read_ctx                    re-init
 958  * ssl->s3->read_sequence               zero
 959  * ssl->s3->read_mac_secret             re-init
 960  * ssl->session->read_sym_enc           assign
 961  * ssl->session->read_compression       assign
 962  * ssl->session->read_hash              assign
 963  */
 964 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 965         {
 966         unsigned char *p;
 967
 968         if (s->state == a)
 969                 {
 970                 p=(unsigned char *)s->init_buf->data;
 971                 *p++=SSL3_MT_CCS;
 972                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 973                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 974
 975                 if (s->client_version == DTLS1_BAD_VER)
 976                         {
 977                         s->d1->next_handshake_write_seq++;
 978                         s2n(s->d1->handshake_write_seq,p);
 979                         s->init_num+=2;
 980                         }
 981
 982                 s->init_off=0;
 983
 984                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 985                         s->d1->handshake_write_seq, 0, 0);
 986
 987                 /* buffer the message to handle re-xmits */
 988                 dtls1_buffer_message(s, 1);
 989
 990                 s->state=b;
 991                 }
 992
 993         /* SSL3_ST_CW_CHANGE_B */
 994         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 995         }
 996
 997 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
 998         {
 999                 int n;
1000                 unsigned char *p;
1001
1002                 n=i2d_X509(x,NULL);
1003                 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1004                         {
1005                         SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1006                         return 0;
1007                         }
1008                 p=(unsigned char *)&(buf->data[*l]);
1009                 l2n3(n,p);
1010                 i2d_X509(x,&p);
1011                 *l+=n+3;
1012
1013                 return 1;
1014         }
1015 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1016         {
1017         unsigned char *p;
1018         int i;
1019         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1020         BUF_MEM *buf;
1021
1022         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1023         buf=s->init_buf;
1024         if (!BUF_MEM_grow_clean(buf,10))
1025                 {
1026                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1027                 return(0);
1028                 }
1029         if (x != NULL)
1030                 {
1031                 X509_STORE_CTX xs_ctx;
1032
1033                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1034                         {
1035                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1036                         return(0);
1037                         }
1038
1039                 X509_verify_cert(&xs_ctx);
1040                 /* Don't leave errors in the queue */
1041                 ERR_clear_error();
1042                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1043                         {
1044                         x = sk_X509_value(xs_ctx.chain, i);
1045
1046                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1047                                 {
1048                                 X509_STORE_CTX_cleanup(&xs_ctx);
1049                                 return 0;
1050                                 }
1051                         }
1052                 X509_STORE_CTX_cleanup(&xs_ctx);
1053                 }
1054         /* Thawte special :-) */
1055         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1056                 {
1057                 x=sk_X509_value(s->ctx->extra_certs,i);
1058                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1059                         return 0;
1060                 }
1061
1062         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1063
1064         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1065         l2n3(l,p);
1066         l+=3;
1067         p=(unsigned char *)&(buf->data[0]);
1068         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1069
1070         l+=DTLS1_HM_HEADER_LENGTH;
1071         return(l);
1072         }
1073
1074 int dtls1_read_failed(SSL *s, int code)
1075         {
1076         if ( code > 0)
1077                 {
1078                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1079                 return 1;
1080                 }
1081
1082         if (!dtls1_is_timer_expired(s))
1083                 {
1084                 /* not a timeout, none of our business,
1085                    let higher layers handle this.  in fact it's probably an error */
1086                 return code;
1087                 }
1088
1089         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1090                 {
1091                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1092                 return code;
1093                 }
1094
1095 #if 0 /* for now, each alert contains only one record number */
1096         item = pqueue_peek(state->rcvd_records);
1097         if ( item )
1098                 {
1099                 /* send an alert immediately for all the missing records */
1100                 }
1101         else
1102 #endif
1103
1104 #if 0  /* no more alert sending, just retransmit the last set of messages */
1105         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1106                 ssl3_send_alert(s,SSL3_AL_WARNING,
1107                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1108 #endif
1109
1110         return dtls1_handle_timeout(s);
1111         }
1112
1113 int
1114 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1115         {
1116         /* The index of the retransmission queue actually is the message sequence number,
1117          * since the queue only contains messages of a single handshake. However, the
1118          * ChangeCipherSpec has no message sequence number and so using only the sequence
1119          * will result in the CCS and Finished having the same index. To prevent this,
1120          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1121          * This does not only differ CSS and Finished, it also maintains the order of the
1122          * index (important for priority queues) and fits in the unsigned short variable.
1123          */
1124         return seq * 2 - is_ccs;
1125         }
1126
1127 int
1128 dtls1_retransmit_buffered_messages(SSL *s)
1129         {
1130         pqueue sent = s->d1->sent_messages;
1131         piterator iter;
1132         pitem *item;
1133         hm_fragment *frag;
1134         int found = 0;
1135
1136         iter = pqueue_iterator(sent);
1137
1138         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1139                 {
1140                 frag = (hm_fragment *)item->data;
1141                         if ( dtls1_retransmit_message(s,
1142                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1143                                 0, &found) <= 0 && found)
1144                         {
1145                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1146                         return -1;
1147                         }
1148                 }
1149
1150         return 1;
1151         }
1152
1153 int
1154 dtls1_buffer_message(SSL *s, int is_ccs)
1155         {
1156         pitem *item;
1157         hm_fragment *frag;
1158         PQ_64BIT seq64;
1159
1160         /* this function is called immediately after a message has
1161          * been serialized */
1162         OPENSSL_assert(s->init_off == 0);
1163
1164         frag = dtls1_hm_fragment_new(s->init_num, 0);
1165
1166         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1167
1168         if ( is_ccs)
1169                 {
1170                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1171                         DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
1172                 }
1173         else
1174                 {
1175                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1176                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1177                 }
1178
1179         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1180         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1181         frag->msg_header.type = s->d1->w_msg_hdr.type;
1182         frag->msg_header.frag_off = 0;
1183         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1184         frag->msg_header.is_ccs = is_ccs;
1185
1186         /* save current state*/
1187         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1188         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1189         frag->msg_header.saved_retransmit_state.compress = s->compress;
1190         frag->msg_header.saved_retransmit_state.session = s->session;
1191         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1192
1193         pq_64bit_init(&seq64);
1194
1195         pq_64bit_assign_word(&seq64,
1196                                                  dtls1_get_queue_priority(frag->msg_header.seq,
1197                                                                                                   frag->msg_header.is_ccs));
1198
1199         item = pitem_new(seq64, frag);
1200         pq_64bit_free(&seq64);
1201         if ( item == NULL)
1202                 {
1203                 dtls1_hm_fragment_free(frag);
1204                 return 0;
1205                 }
1206
1207 #if 0
1208         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1209         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1210         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1211 #endif
1212
1213         pqueue_insert(s->d1->sent_messages, item);
1214         return 1;
1215         }
1216
1217 int
1218 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1219         int *found)
1220         {
1221         int ret;
1222         /* XDTLS: for now assuming that read/writes are blocking */
1223         pitem *item;
1224         hm_fragment *frag ;
1225         unsigned long header_length;
1226         PQ_64BIT seq64;
1227         struct dtls1_retransmit_state saved_state;
1228         unsigned char save_write_sequence[8];
1229
1230         /*
1231           OPENSSL_assert(s->init_num == 0);
1232           OPENSSL_assert(s->init_off == 0);
1233          */
1234
1235         /* XDTLS:  the requested message ought to be found, otherwise error */
1236         pq_64bit_init(&seq64);
1237         pq_64bit_assign_word(&seq64, seq);
1238
1239         item = pqueue_find(s->d1->sent_messages, seq64);
1240         pq_64bit_free(&seq64);
1241         if ( item == NULL)
1242                 {
1243                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1244                 *found = 0;
1245                 return 0;
1246                 }
1247
1248         *found = 1;
1249         frag = (hm_fragment *)item->data;
1250
1251         if ( frag->msg_header.is_ccs)
1252                 header_length = DTLS1_CCS_HEADER_LENGTH;
1253         else
1254                 header_length = DTLS1_HM_HEADER_LENGTH;
1255
1256         memcpy(s->init_buf->data, frag->fragment,
1257                 frag->msg_header.msg_len + header_length);
1258                 s->init_num = frag->msg_header.msg_len + header_length;
1259
1260         dtls1_set_message_header_int(s, frag->msg_header.type,
1261                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1262                 frag->msg_header.frag_len);
1263
1264         /* save current state */
1265         saved_state.enc_write_ctx = s->enc_write_ctx;
1266         saved_state.write_hash = s->write_hash;
1267         saved_state.compress = s->compress;
1268         saved_state.session = s->session;
1269         saved_state.epoch = s->d1->w_epoch;
1270         saved_state.epoch = s->d1->w_epoch;
1271
1272         s->d1->retransmitting = 1;
1273
1274         /* restore state in which the message was originally sent */
1275         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1276         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1277         s->compress = frag->msg_header.saved_retransmit_state.compress;
1278         s->session = frag->msg_header.saved_retransmit_state.session;
1279         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1280
1281         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1282         {
1283                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1284                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1285         }
1286
1287         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1288                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1289
1290         /* restore current state */
1291         s->enc_write_ctx = saved_state.enc_write_ctx;
1292         s->write_hash = saved_state.write_hash;
1293         s->compress = saved_state.compress;
1294         s->session = saved_state.session;
1295         s->d1->w_epoch = saved_state.epoch;
1296
1297         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1298         {
1299                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1300                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1301         }
1302
1303         s->d1->retransmitting = 0;
1304
1305         (void)BIO_flush(SSL_get_wbio(s));
1306         return ret;
1307         }
1308
1309 /* call this function when the buffered messages are no longer needed */
1310 void
1311 dtls1_clear_record_buffer(SSL *s)
1312         {
1313         pitem *item;
1314
1315         for(item = pqueue_pop(s->d1->sent_messages);
1316                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1317                 {
1318                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1319                 pitem_free(item);
1320                 }
1321         }
1322
1323
1324 unsigned char *
1325 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1326                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1327         {
1328         if ( frag_off == 0)
1329                 {
1330                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1331                 s->d1->next_handshake_write_seq++;
1332                 }
1333
1334         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1335                 frag_off, frag_len);
1336
1337         return p += DTLS1_HM_HEADER_LENGTH;
1338         }
1339
1340
1341 /* don't actually do the writing, wait till the MTU has been retrieved */
1342 static void
1343 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1344                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1345                             unsigned long frag_len)
1346         {
1347         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1348
1349         msg_hdr->type = mt;
1350         msg_hdr->msg_len = len;
1351         msg_hdr->seq = seq_num;
1352         msg_hdr->frag_off = frag_off;
1353         msg_hdr->frag_len = frag_len;
1354         }
1355
1356 static void
1357 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1358                         unsigned long frag_len)
1359         {
1360         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1361
1362         msg_hdr->frag_off = frag_off;
1363         msg_hdr->frag_len = frag_len;
1364         }
1365
1366 static unsigned char *
1367 dtls1_write_message_header(SSL *s, unsigned char *p)
1368         {
1369         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1370
1371         *p++ = msg_hdr->type;
1372         l2n3(msg_hdr->msg_len, p);
1373
1374         s2n(msg_hdr->seq, p);
1375         l2n3(msg_hdr->frag_off, p);
1376         l2n3(msg_hdr->frag_len, p);
1377
1378         return p;
1379         }
1380
1381 static unsigned int
1382 dtls1_min_mtu(void)
1383         {
1384         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1385                 sizeof(g_probable_mtu[0])) - 1]);
1386         }
1387
1388 static unsigned int
1389 dtls1_guess_mtu(unsigned int curr_mtu)
1390         {
1391         size_t i;
1392
1393         if ( curr_mtu == 0 )
1394                 return g_probable_mtu[0] ;
1395
1396         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1397                 if ( curr_mtu > g_probable_mtu[i])
1398                         return g_probable_mtu[i];
1399
1400         return curr_mtu;
1401         }
1402
1403 void
1404 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1405         {
1406         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1407         msg_hdr->type = *(data++);
1408         n2l3(data, msg_hdr->msg_len);
1409
1410         n2s(data, msg_hdr->seq);
1411         n2l3(data, msg_hdr->frag_off);
1412         n2l3(data, msg_hdr->frag_len);
1413         }
1414
1415 void
1416 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1417         {
1418         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1419
1420         ccs_hdr->type = *(data++);
1421         }