crypto/openssl/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_min_mtu(void);
 162 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 163 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 164         unsigned long frag_len);
 165 static unsigned char *dtls1_write_message_header(SSL *s,
 166         unsigned char *p);
 167 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 168         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 169         unsigned long frag_len);
 170 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 171         long max, int *ok);
 172
 173 static hm_fragment *
 174 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 175         {
 176         hm_fragment *frag = NULL;
 177         unsigned char *buf = NULL;
 178         unsigned char *bitmask = NULL;
 179
 180         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 181         if ( frag == NULL)
 182                 return NULL;
 183
 184         if (frag_len)
 185                 {
 186                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 187                 if ( buf == NULL)
 188                         {
 189                         OPENSSL_free(frag);
 190                         return NULL;
 191                         }
 192                 }
 193
 194         /* zero length fragment gets zero frag->fragment */
 195         frag->fragment = buf;
 196
 197         /* Initialize reassembly bitmask if necessary */
 198         if (reassembly)
 199                 {
 200                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 201                 if (bitmask == NULL)
 202                         {
 203                         if (buf != NULL) OPENSSL_free(buf);
 204                         OPENSSL_free(frag);
 205                         return NULL;
 206                         }
 207                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 208                 }
 209
 210         frag->reassembly = bitmask;
 211
 212         return frag;
 213         }
 214
 215 static void
 216 dtls1_hm_fragment_free(hm_fragment *frag)
 217         {
 218         if (frag->fragment) OPENSSL_free(frag->fragment);
 219         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 220         OPENSSL_free(frag);
 221         }
 222
 223 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 224 int dtls1_do_write(SSL *s, int type)
 225         {
 226         int ret;
 227         int curr_mtu;
 228         unsigned int len, frag_off, mac_size, blocksize;
 229
 230         /* AHA!  Figure out the MTU, and stick to the right size */
 231         if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 232                 {
 233                 s->d1->mtu =
 234                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 235
 236                 /* I've seen the kernel return bogus numbers when it doesn't know
 237                  * (initial write), so just make sure we have a reasonable number */
 238                 if ( s->d1->mtu < dtls1_min_mtu())
 239                         {
 240                         s->d1->mtu = 0;
 241                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 242                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 243                                 s->d1->mtu, NULL);
 244                         }
 245                 }
 246 #if 0
 247         mtu = s->d1->mtu;
 248
 249         fprintf(stderr, "using MTU = %d\n", mtu);
 250
 251         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 252
 253         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 254
 255         if ( curr_mtu > 0)
 256                 mtu = curr_mtu;
 257         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 258                 return ret;
 259
 260         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 261                 {
 262                 ret = BIO_flush(SSL_get_wbio(s));
 263                 if ( ret <= 0)
 264                         return ret;
 265                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 266                 }
 267
 268         OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
 269
 270 #endif
 271
 272         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 273                 OPENSSL_assert(s->init_num ==
 274                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 275
 276         if (s->write_hash)
 277                 mac_size = EVP_MD_CTX_size(s->write_hash);
 278         else
 279                 mac_size = 0;
 280
 281         if (s->enc_write_ctx &&
 282                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
 283                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 284         else
 285                 blocksize = 0;
 286
 287         frag_off = 0;
 288         while( s->init_num)
 289                 {
 290                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 291                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 292
 293                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 294                         {
 295                         /* grr.. we could get an error if MTU picked was wrong */
 296                         ret = BIO_flush(SSL_get_wbio(s));
 297                         if ( ret <= 0)
 298                                 return ret;
 299                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 300                                 mac_size - blocksize;
 301                         }
 302
 303                 if ( s->init_num > curr_mtu)
 304                         len = curr_mtu;
 305                 else
 306                         len = s->init_num;
 307
 308
 309                 /* XDTLS: this function is too long.  split out the CCS part */
 310                 if ( type == SSL3_RT_HANDSHAKE)
 311                         {
 312                         if ( s->init_off != 0)
 313                                 {
 314                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 315                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 316                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 317
 318                                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
 319                                 if ( len <= DTLS1_HM_HEADER_LENGTH)
 320                                         len += DTLS1_HM_HEADER_LENGTH;
 321                                 }
 322
 323                         dtls1_fix_message_header(s, frag_off,
 324                                 len - DTLS1_HM_HEADER_LENGTH);
 325
 326                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 327
 328                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 329                         }
 330
 331                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 332                         len);
 333                 if (ret < 0)
 334                         {
 335                         /* might need to update MTU here, but we don't know
 336                          * which previous packet caused the failure -- so can't
 337                          * really retransmit anything.  continue as if everything
 338                          * is fine and wait for an alert to handle the
 339                          * retransmit
 340                          */
 341                         if ( BIO_ctrl(SSL_get_wbio(s),
 342                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 343                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 344                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 345                         else
 346                                 return(-1);
 347                         }
 348                 else
 349                         {
 350
 351                         /* bad if this assert fails, only part of the handshake
 352                          * message got sent.  but why would this happen? */
 353                         OPENSSL_assert(len == (unsigned int)ret);
 354
 355                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 356                                 {
 357                                 /* should not be done for 'Hello Request's, but in that case
 358                                  * we'll ignore the result anyway */
 359                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 360                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 361                                 int xlen;
 362
 363                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
 364                                         {
 365                                         /* reconstruct message header is if it
 366                                          * is being sent in single fragment */
 367                                         *p++ = msg_hdr->type;
 368                                         l2n3(msg_hdr->msg_len,p);
 369                                         s2n (msg_hdr->seq,p);
 370                                         l2n3(0,p);
 371                                         l2n3(msg_hdr->msg_len,p);
 372                                         p  -= DTLS1_HM_HEADER_LENGTH;
 373                                         xlen = ret;
 374                                         }
 375                                 else
 376                                         {
 377                                         p  += DTLS1_HM_HEADER_LENGTH;
 378                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 379                                         }
 380
 381                                 ssl3_finish_mac(s, p, xlen);
 382                                 }
 383
 384                         if (ret == s->init_num)
 385                                 {
 386                                 if (s->msg_callback)
 387                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 388                                                 (size_t)(s->init_off + s->init_num), s,
 389                                                 s->msg_callback_arg);
 390
 391                                 s->init_off = 0;  /* done writing this message */
 392                                 s->init_num = 0;
 393
 394                                 return(1);
 395                                 }
 396                         s->init_off+=ret;
 397                         s->init_num-=ret;
 398                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 399                         }
 400                 }
 401         return(0);
 402         }
 403
 404
 405 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 406  * maximum acceptable body length 'max'.
 407  * Read an entire handshake message.  Handshake messages arrive in
 408  * fragments.
 409  */
 410 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 411         {
 412         int i, al;
 413         struct hm_header_st *msg_hdr;
 414         unsigned char *p;
 415         unsigned long msg_len;
 416
 417         /* s3->tmp is used to store messages that are unexpected, caused
 418          * by the absence of an optional handshake message */
 419         if (s->s3->tmp.reuse_message)
 420                 {
 421                 s->s3->tmp.reuse_message=0;
 422                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 423                         {
 424                         al=SSL_AD_UNEXPECTED_MESSAGE;
 425                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 426                         goto f_err;
 427                         }
 428                 *ok=1;
 429                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 430                 s->init_num = (int)s->s3->tmp.message_size;
 431                 return s->init_num;
 432                 }
 433
 434         msg_hdr = &s->d1->r_msg_hdr;
 435         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 436
 437 again:
 438         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 439         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 440                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 441                 goto again;
 442         else if ( i <= 0 && !*ok)
 443                 return i;
 444
 445         p = (unsigned char *)s->init_buf->data;
 446         msg_len = msg_hdr->msg_len;
 447
 448         /* reconstruct message header */
 449         *(p++) = msg_hdr->type;
 450         l2n3(msg_len,p);
 451         s2n (msg_hdr->seq,p);
 452         l2n3(0,p);
 453         l2n3(msg_len,p);
 454         if (s->version != DTLS1_BAD_VER) {
 455                 p       -= DTLS1_HM_HEADER_LENGTH;
 456                 msg_len += DTLS1_HM_HEADER_LENGTH;
 457         }
 458
 459         ssl3_finish_mac(s, p, msg_len);
 460         if (s->msg_callback)
 461                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 462                         p, msg_len,
 463                         s, s->msg_callback_arg);
 464
 465         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 466
 467         /* Don't change sequence numbers while listening */
 468         if (!s->d1->listen)
 469                 s->d1->handshake_read_seq++;
 470
 471         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 472         return s->init_num;
 473
 474 f_err:
 475         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 476         *ok = 0;
 477         return -1;
 478         }
 479
 480
 481 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 482         {
 483         size_t frag_off,frag_len,msg_len;
 484
 485         msg_len  = msg_hdr->msg_len;
 486         frag_off = msg_hdr->frag_off;
 487         frag_len = msg_hdr->frag_len;
 488
 489         /* sanity checking */
 490         if ( (frag_off+frag_len) > msg_len)
 491                 {
 492                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 493                 return SSL_AD_ILLEGAL_PARAMETER;
 494                 }
 495
 496         if ( (frag_off+frag_len) > (unsigned long)max)
 497                 {
 498                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 499                 return SSL_AD_ILLEGAL_PARAMETER;
 500                 }
 501
 502         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 503                 {
 504                 /* msg_len is limited to 2^24, but is effectively checked
 505                  * against max above */
 506                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
 507                         {
 508                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 509                         return SSL_AD_INTERNAL_ERROR;
 510                         }
 511
 512                 s->s3->tmp.message_size  = msg_len;
 513                 s->d1->r_msg_hdr.msg_len = msg_len;
 514                 s->s3->tmp.message_type  = msg_hdr->type;
 515                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 516                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 517                 }
 518         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 519                 {
 520                 /* They must be playing with us! BTW, failure to enforce
 521                  * upper limit would open possibility for buffer overrun. */
 522                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 523                 return SSL_AD_ILLEGAL_PARAMETER;
 524                 }
 525
 526         return 0; /* no error */
 527         }
 528
 529
 530 static int
 531 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 532         {
 533         /* (0) check whether the desired fragment is available
 534          * if so:
 535          * (1) copy over the fragment to s->init_buf->data[]
 536          * (2) update s->init_num
 537          */
 538         pitem *item;
 539         hm_fragment *frag;
 540         int al;
 541
 542         *ok = 0;
 543         item = pqueue_peek(s->d1->buffered_messages);
 544         if ( item == NULL)
 545                 return 0;
 546
 547         frag = (hm_fragment *)item->data;
 548
 549         /* Don't return if reassembly still in progress */
 550         if (frag->reassembly != NULL)
 551                 return 0;
 552
 553         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 554                 {
 555                 unsigned long frag_len = frag->msg_header.frag_len;
 556                 pqueue_pop(s->d1->buffered_messages);
 557
 558                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 559
 560                 if (al==0) /* no alert */
 561                         {
 562                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 563                         memcpy(&p[frag->msg_header.frag_off],
 564                                 frag->fragment,frag->msg_header.frag_len);
 565                         }
 566
 567                 dtls1_hm_fragment_free(frag);
 568                 pitem_free(item);
 569
 570                 if (al==0)
 571                         {
 572                         *ok = 1;
 573                         return frag_len;
 574                         }
 575
 576                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 577                 s->init_num = 0;
 578                 *ok = 0;
 579                 return -1;
 580                 }
 581         else
 582                 return 0;
 583         }
 584
 585
 586 static int
 587 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 588         {
 589         hm_fragment *frag = NULL;
 590         pitem *item = NULL;
 591         int i = -1, is_complete;
 592         unsigned char seq64be[8];
 593         unsigned long frag_len = msg_hdr->frag_len, max_len;
 594
 595         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 596                 goto err;
 597
 598         /* Determine maximum allowed message size. Depends on (user set)
 599          * maximum certificate length, but 16k is minimum.
 600          */
 601         if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
 602                 max_len = s->max_cert_list;
 603         else
 604                 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 605
 606         if ((msg_hdr->frag_off+frag_len) > max_len)
 607                 goto err;
 608
 609         /* Try to find item in queue */
 610         memset(seq64be,0,sizeof(seq64be));
 611         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 612         seq64be[7] = (unsigned char) msg_hdr->seq;
 613         item = pqueue_find(s->d1->buffered_messages, seq64be);
 614
 615         if (item == NULL)
 616                 {
 617                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 618                 if ( frag == NULL)
 619                         goto err;
 620                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 621                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 622                 frag->msg_header.frag_off = 0;
 623                 }
 624         else
 625                 frag = (hm_fragment*) item->data;
 626
 627         /* If message is already reassembled, this must be a
 628          * retransmit and can be dropped.
 629          */
 630         if (frag->reassembly == NULL)
 631                 {
 632                 unsigned char devnull [256];
 633
 634                 while (frag_len)
 635                         {
 636                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 637                                 devnull,
 638                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 639                         if (i<=0) goto err;
 640                         frag_len -= i;
 641                         }
 642                 return DTLS1_HM_FRAGMENT_RETRY;
 643                 }
 644
 645         /* read the body of the fragment (header has already been read */
 646         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 647                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 648         if (i<=0 || (unsigned long)i!=frag_len)
 649                 goto err;
 650
 651         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 652                             (long)(msg_hdr->frag_off + frag_len));
 653
 654         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 655                                    is_complete);
 656
 657         if (is_complete)
 658                 {
 659                 OPENSSL_free(frag->reassembly);
 660                 frag->reassembly = NULL;
 661                 }
 662
 663         if (item == NULL)
 664                 {
 665                 memset(seq64be,0,sizeof(seq64be));
 666                 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
 667                 seq64be[7] = (unsigned char)(msg_hdr->seq);
 668
 669                 item = pitem_new(seq64be, frag);
 670                 if (item == NULL)
 671                         {
 672                         goto err;
 673                         i = -1;
 674                         }
 675
 676                 pqueue_insert(s->d1->buffered_messages, item);
 677                 }
 678
 679         return DTLS1_HM_FRAGMENT_RETRY;
 680
 681 err:
 682         if (frag != NULL) dtls1_hm_fragment_free(frag);
 683         if (item != NULL) OPENSSL_free(item);
 684         *ok = 0;
 685         return i;
 686         }
 687
 688
 689 static int
 690 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 691 {
 692         int i=-1;
 693         hm_fragment *frag = NULL;
 694         pitem *item = NULL;
 695         unsigned char seq64be[8];
 696         unsigned long frag_len = msg_hdr->frag_len;
 697
 698         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 699                 goto err;
 700
 701         /* Try to find item in queue, to prevent duplicate entries */
 702         memset(seq64be,0,sizeof(seq64be));
 703         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 704         seq64be[7] = (unsigned char) msg_hdr->seq;
 705         item = pqueue_find(s->d1->buffered_messages, seq64be);
 706
 707         /* If we already have an entry and this one is a fragment,
 708          * don't discard it and rather try to reassemble it.
 709          */
 710         if (item != NULL && frag_len < msg_hdr->msg_len)
 711                 item = NULL;
 712
 713         /* Discard the message if sequence number was already there, is
 714          * too far in the future, already in the queue or if we received
 715          * a FINISHED before the SERVER_HELLO, which then must be a stale
 716          * retransmit.
 717          */
 718         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 719                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 720                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 721                 {
 722                 unsigned char devnull [256];
 723
 724                 while (frag_len)
 725                         {
 726                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 727                                 devnull,
 728                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 729                         if (i<=0) goto err;
 730                         frag_len -= i;
 731                         }
 732                 }
 733         else
 734                 {
 735                 if (frag_len && frag_len < msg_hdr->msg_len)
 736                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 737
 738                 frag = dtls1_hm_fragment_new(frag_len, 0);
 739                 if ( frag == NULL)
 740                         goto err;
 741
 742                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 743
 744                 if (frag_len)
 745                         {
 746                         /* read the body of the fragment (header has already been read */
 747                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 748                                 frag->fragment,frag_len,0);
 749                         if (i<=0 || (unsigned long)i!=frag_len)
 750                                 goto err;
 751                         }
 752
 753                 memset(seq64be,0,sizeof(seq64be));
 754                 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
 755                 seq64be[7] = (unsigned char)(msg_hdr->seq);
 756
 757                 item = pitem_new(seq64be, frag);
 758                 if ( item == NULL)
 759                         goto err;
 760
 761                 pqueue_insert(s->d1->buffered_messages, item);
 762                 }
 763
 764         return DTLS1_HM_FRAGMENT_RETRY;
 765
 766 err:
 767         if ( frag != NULL) dtls1_hm_fragment_free(frag);
 768         if ( item != NULL) OPENSSL_free(item);
 769         *ok = 0;
 770         return i;
 771         }
 772
 773
 774 static long
 775 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 776         {
 777         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 778         unsigned long len, frag_off, frag_len;
 779         int i,al;
 780         struct hm_header_st msg_hdr;
 781
 782         /* see if we have the required fragment already */
 783         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 784                 {
 785                 if (*ok)        s->init_num = frag_len;
 786                 return frag_len;
 787                 }
 788
 789         /* read handshake message header */
 790         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 791                 DTLS1_HM_HEADER_LENGTH, 0);
 792         if (i <= 0)     /* nbio, or an error */
 793                 {
 794                 s->rwstate=SSL_READING;
 795                 *ok = 0;
 796                 return i;
 797                 }
 798         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
 799
 800         /* parse the message fragment header */
 801         dtls1_get_message_header(wire, &msg_hdr);
 802
 803         /*
 804          * if this is a future (or stale) message it gets buffered
 805          * (or dropped)--no further processing at this time
 806          * While listening, we accept seq 1 (ClientHello with cookie)
 807          * although we're still expecting seq 0 (ClientHello)
 808          */
 809         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 810                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 811
 812         len = msg_hdr.msg_len;
 813         frag_off = msg_hdr.frag_off;
 814         frag_len = msg_hdr.frag_len;
 815
 816         if (frag_len && frag_len < len)
 817                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 818
 819         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 820                 wire[0] == SSL3_MT_HELLO_REQUEST)
 821                 {
 822                 /* The server may always send 'Hello Request' messages --
 823                  * we are doing a handshake anyway now, so ignore them
 824                  * if their format is correct. Does not count for
 825                  * 'Finished' MAC. */
 826                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 827                         {
 828                         if (s->msg_callback)
 829                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 830                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 831                                         s->msg_callback_arg);
 832
 833                         s->init_num = 0;
 834                         return dtls1_get_message_fragment(s, st1, stn,
 835                                 max, ok);
 836                         }
 837                 else /* Incorrectly formated Hello request */
 838                         {
 839                         al=SSL_AD_UNEXPECTED_MESSAGE;
 840                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 841                         goto f_err;
 842                         }
 843                 }
 844
 845         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 846                 goto f_err;
 847
 848         /* XDTLS:  ressurect this when restart is in place */
 849         s->state=stn;
 850
 851         if ( frag_len > 0)
 852                 {
 853                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 854
 855                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 856                         &p[frag_off],frag_len,0);
 857                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 858                 if (i <= 0)
 859                         {
 860                         s->rwstate=SSL_READING;
 861                         *ok = 0;
 862                         return i;
 863                         }
 864                 }
 865         else
 866                 i = 0;
 867
 868         /* XDTLS:  an incorrectly formatted fragment should cause the
 869          * handshake to fail */
 870         OPENSSL_assert(i == (int)frag_len);
 871
 872         *ok = 1;
 873
 874         /* Note that s->init_num is *not* used as current offset in
 875          * s->init_buf->data, but as a counter summing up fragments'
 876          * lengths: as soon as they sum up to handshake packet
 877          * length, we assume we have got all the fragments. */
 878         s->init_num = frag_len;
 879         return frag_len;
 880
 881 f_err:
 882         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 883         s->init_num = 0;
 884
 885         *ok=0;
 886         return(-1);
 887         }
 888
 889 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 890         {
 891         unsigned char *p,*d;
 892         int i;
 893         unsigned long l;
 894
 895         if (s->state == a)
 896                 {
 897                 d=(unsigned char *)s->init_buf->data;
 898                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 899
 900                 i=s->method->ssl3_enc->final_finish_mac(s,
 901                         sender,slen,s->s3->tmp.finish_md);
 902                 s->s3->tmp.finish_md_len = i;
 903                 memcpy(p, s->s3->tmp.finish_md, i);
 904                 p+=i;
 905                 l=i;
 906
 907         /* Copy the finished so we can use it for
 908          * renegotiation checks
 909          */
 910         if(s->type == SSL_ST_CONNECT)
 911                 {
 912                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 913                 memcpy(s->s3->previous_client_finished,
 914                        s->s3->tmp.finish_md, i);
 915                 s->s3->previous_client_finished_len=i;
 916                 }
 917         else
 918                 {
 919                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 920                 memcpy(s->s3->previous_server_finished,
 921                        s->s3->tmp.finish_md, i);
 922                 s->s3->previous_server_finished_len=i;
 923                 }
 924
 925 #ifdef OPENSSL_SYS_WIN16
 926                 /* MSVC 1.5 does not clear the top bytes of the word unless
 927                  * I do this.
 928                  */
 929                 l&=0xffff;
 930 #endif
 931
 932                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 933                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 934                 s->init_off=0;
 935
 936                 /* buffer the message to handle re-xmits */
 937                 dtls1_buffer_message(s, 0);
 938
 939                 s->state=b;
 940                 }
 941
 942         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 943         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 944         }
 945
 946 /* for these 2 messages, we need to
 947  * ssl->enc_read_ctx                    re-init
 948  * ssl->s3->read_sequence               zero
 949  * ssl->s3->read_mac_secret             re-init
 950  * ssl->session->read_sym_enc           assign
 951  * ssl->session->read_compression       assign
 952  * ssl->session->read_hash              assign
 953  */
 954 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 955         {
 956         unsigned char *p;
 957
 958         if (s->state == a)
 959                 {
 960                 p=(unsigned char *)s->init_buf->data;
 961                 *p++=SSL3_MT_CCS;
 962                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 963                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 964
 965                 if (s->version == DTLS1_BAD_VER) {
 966                         s->d1->next_handshake_write_seq++;
 967                         s2n(s->d1->handshake_write_seq,p);
 968                         s->init_num+=2;
 969                 }
 970
 971                 s->init_off=0;
 972
 973                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 974                         s->d1->handshake_write_seq, 0, 0);
 975
 976                 /* buffer the message to handle re-xmits */
 977                 dtls1_buffer_message(s, 1);
 978
 979                 s->state=b;
 980                 }
 981
 982         /* SSL3_ST_CW_CHANGE_B */
 983         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 984         }
 985
 986 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
 987         {
 988         int n;
 989         unsigned char *p;
 990
 991         n=i2d_X509(x,NULL);
 992         if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
 993                 {
 994                 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
 995                 return 0;
 996                 }
 997         p=(unsigned char *)&(buf->data[*l]);
 998         l2n3(n,p);
 999         i2d_X509(x,&p);
1000         *l+=n+3;
1001
1002         return 1;
1003         }
1004 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1005         {
1006         unsigned char *p;
1007         int i;
1008         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1009         BUF_MEM *buf;
1010
1011         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1012         buf=s->init_buf;
1013         if (!BUF_MEM_grow_clean(buf,10))
1014                 {
1015                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1016                 return(0);
1017                 }
1018         if (x != NULL)
1019                 {
1020                 X509_STORE_CTX xs_ctx;
1021
1022                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1023                         {
1024                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1025                         return(0);
1026                         }
1027
1028                 X509_verify_cert(&xs_ctx);
1029                 /* Don't leave errors in the queue */
1030                 ERR_clear_error();
1031                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1032                         {
1033                         x = sk_X509_value(xs_ctx.chain, i);
1034
1035                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1036                                 {
1037                                 X509_STORE_CTX_cleanup(&xs_ctx);
1038                                 return 0;
1039                                 }
1040                         }
1041                 X509_STORE_CTX_cleanup(&xs_ctx);
1042                 }
1043         /* Thawte special :-) */
1044         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1045                 {
1046                 x=sk_X509_value(s->ctx->extra_certs,i);
1047                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1048                         return 0;
1049                 }
1050
1051         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1052
1053         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1054         l2n3(l,p);
1055         l+=3;
1056         p=(unsigned char *)&(buf->data[0]);
1057         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1058
1059         l+=DTLS1_HM_HEADER_LENGTH;
1060         return(l);
1061         }
1062
1063 int dtls1_read_failed(SSL *s, int code)
1064         {
1065         if ( code > 0)
1066                 {
1067                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1068                 return 1;
1069                 }
1070
1071         if (!dtls1_is_timer_expired(s))
1072                 {
1073                 /* not a timeout, none of our business,
1074                    let higher layers handle this.  in fact it's probably an error */
1075                 return code;
1076                 }
1077
1078         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1079                 {
1080                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1081                 return code;
1082                 }
1083
1084 #if 0 /* for now, each alert contains only one record number */
1085         item = pqueue_peek(state->rcvd_records);
1086         if ( item )
1087                 {
1088                 /* send an alert immediately for all the missing records */
1089                 }
1090         else
1091 #endif
1092
1093 #if 0  /* no more alert sending, just retransmit the last set of messages */
1094         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1095                 ssl3_send_alert(s,SSL3_AL_WARNING,
1096                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1097 #endif
1098
1099         return dtls1_handle_timeout(s);
1100         }
1101
1102 int
1103 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1104         {
1105         /* The index of the retransmission queue actually is the message sequence number,
1106          * since the queue only contains messages of a single handshake. However, the
1107          * ChangeCipherSpec has no message sequence number and so using only the sequence
1108          * will result in the CCS and Finished having the same index. To prevent this,
1109          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1110          * This does not only differ CSS and Finished, it also maintains the order of the
1111          * index (important for priority queues) and fits in the unsigned short variable.
1112          */
1113         return seq * 2 - is_ccs;
1114         }
1115
1116 int
1117 dtls1_retransmit_buffered_messages(SSL *s)
1118         {
1119         pqueue sent = s->d1->sent_messages;
1120         piterator iter;
1121         pitem *item;
1122         hm_fragment *frag;
1123         int found = 0;
1124
1125         iter = pqueue_iterator(sent);
1126
1127         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1128                 {
1129                 frag = (hm_fragment *)item->data;
1130                         if ( dtls1_retransmit_message(s,
1131                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1132                                 0, &found) <= 0 && found)
1133                         {
1134                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1135                         return -1;
1136                         }
1137                 }
1138
1139         return 1;
1140         }
1141
1142 int
1143 dtls1_buffer_message(SSL *s, int is_ccs)
1144         {
1145         pitem *item;
1146         hm_fragment *frag;
1147         unsigned char seq64be[8];
1148
1149         /* this function is called immediately after a message has
1150          * been serialized */
1151         OPENSSL_assert(s->init_off == 0);
1152
1153         frag = dtls1_hm_fragment_new(s->init_num, 0);
1154
1155         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1156
1157         if ( is_ccs)
1158                 {
1159                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1160                                ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1161                 }
1162         else
1163                 {
1164                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1165                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1166                 }
1167
1168         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1169         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1170         frag->msg_header.type = s->d1->w_msg_hdr.type;
1171         frag->msg_header.frag_off = 0;
1172         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1173         frag->msg_header.is_ccs = is_ccs;
1174
1175         /* save current state*/
1176         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1177         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1178         frag->msg_header.saved_retransmit_state.compress = s->compress;
1179         frag->msg_header.saved_retransmit_state.session = s->session;
1180         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1181
1182         memset(seq64be,0,sizeof(seq64be));
1183         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1184                                                                                                                   frag->msg_header.is_ccs)>>8);
1185         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1186                                                                                                                   frag->msg_header.is_ccs));
1187
1188         item = pitem_new(seq64be, frag);
1189         if ( item == NULL)
1190                 {
1191                 dtls1_hm_fragment_free(frag);
1192                 return 0;
1193                 }
1194
1195 #if 0
1196         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1197         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1198         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1199 #endif
1200
1201         pqueue_insert(s->d1->sent_messages, item);
1202         return 1;
1203         }
1204
1205 int
1206 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1207         int *found)
1208         {
1209         int ret;
1210         /* XDTLS: for now assuming that read/writes are blocking */
1211         pitem *item;
1212         hm_fragment *frag ;
1213         unsigned long header_length;
1214         unsigned char seq64be[8];
1215         struct dtls1_retransmit_state saved_state;
1216         unsigned char save_write_sequence[8];
1217
1218         /*
1219           OPENSSL_assert(s->init_num == 0);
1220           OPENSSL_assert(s->init_off == 0);
1221          */
1222
1223         /* XDTLS:  the requested message ought to be found, otherwise error */
1224         memset(seq64be,0,sizeof(seq64be));
1225         seq64be[6] = (unsigned char)(seq>>8);
1226         seq64be[7] = (unsigned char)seq;
1227
1228         item = pqueue_find(s->d1->sent_messages, seq64be);
1229         if ( item == NULL)
1230                 {
1231                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1232                 *found = 0;
1233                 return 0;
1234                 }
1235
1236         *found = 1;
1237         frag = (hm_fragment *)item->data;
1238
1239         if ( frag->msg_header.is_ccs)
1240                 header_length = DTLS1_CCS_HEADER_LENGTH;
1241         else
1242                 header_length = DTLS1_HM_HEADER_LENGTH;
1243
1244         memcpy(s->init_buf->data, frag->fragment,
1245                 frag->msg_header.msg_len + header_length);
1246                 s->init_num = frag->msg_header.msg_len + header_length;
1247
1248         dtls1_set_message_header_int(s, frag->msg_header.type,
1249                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1250                 frag->msg_header.frag_len);
1251
1252         /* save current state */
1253         saved_state.enc_write_ctx = s->enc_write_ctx;
1254         saved_state.write_hash = s->write_hash;
1255         saved_state.compress = s->compress;
1256         saved_state.session = s->session;
1257         saved_state.epoch = s->d1->w_epoch;
1258         saved_state.epoch = s->d1->w_epoch;
1259
1260         s->d1->retransmitting = 1;
1261
1262         /* restore state in which the message was originally sent */
1263         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1264         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1265         s->compress = frag->msg_header.saved_retransmit_state.compress;
1266         s->session = frag->msg_header.saved_retransmit_state.session;
1267         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1268
1269         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1270         {
1271                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1272                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1273         }
1274
1275         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1276                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1277
1278         /* restore current state */
1279         s->enc_write_ctx = saved_state.enc_write_ctx;
1280         s->write_hash = saved_state.write_hash;
1281         s->compress = saved_state.compress;
1282         s->session = saved_state.session;
1283         s->d1->w_epoch = saved_state.epoch;
1284
1285         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1286         {
1287                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1288                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1289         }
1290
1291         s->d1->retransmitting = 0;
1292
1293         (void)BIO_flush(SSL_get_wbio(s));
1294         return ret;
1295         }
1296
1297 /* call this function when the buffered messages are no longer needed */
1298 void
1299 dtls1_clear_record_buffer(SSL *s)
1300         {
1301         pitem *item;
1302
1303         for(item = pqueue_pop(s->d1->sent_messages);
1304                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1305                 {
1306                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1307                 pitem_free(item);
1308                 }
1309         }
1310
1311
1312 unsigned char *
1313 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1314                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1315         {
1316         /* Don't change sequence numbers while listening */
1317         if (frag_off == 0 && !s->d1->listen)
1318                 {
1319                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1320                 s->d1->next_handshake_write_seq++;
1321                 }
1322
1323         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1324                 frag_off, frag_len);
1325
1326         return p += DTLS1_HM_HEADER_LENGTH;
1327         }
1328
1329
1330 /* don't actually do the writing, wait till the MTU has been retrieved */
1331 static void
1332 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1333                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1334                             unsigned long frag_len)
1335         {
1336         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1337
1338         msg_hdr->type = mt;
1339         msg_hdr->msg_len = len;
1340         msg_hdr->seq = seq_num;
1341         msg_hdr->frag_off = frag_off;
1342         msg_hdr->frag_len = frag_len;
1343         }
1344
1345 static void
1346 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1347                         unsigned long frag_len)
1348         {
1349         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1350
1351         msg_hdr->frag_off = frag_off;
1352         msg_hdr->frag_len = frag_len;
1353         }
1354
1355 static unsigned char *
1356 dtls1_write_message_header(SSL *s, unsigned char *p)
1357         {
1358         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1359
1360         *p++ = msg_hdr->type;
1361         l2n3(msg_hdr->msg_len, p);
1362
1363         s2n(msg_hdr->seq, p);
1364         l2n3(msg_hdr->frag_off, p);
1365         l2n3(msg_hdr->frag_len, p);
1366
1367         return p;
1368         }
1369
1370 static unsigned int
1371 dtls1_min_mtu(void)
1372         {
1373         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1374                 sizeof(g_probable_mtu[0])) - 1]);
1375         }
1376
1377 static unsigned int
1378 dtls1_guess_mtu(unsigned int curr_mtu)
1379         {
1380         unsigned int i;
1381
1382         if ( curr_mtu == 0 )
1383                 return g_probable_mtu[0] ;
1384
1385         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1386                 if ( curr_mtu > g_probable_mtu[i])
1387                         return g_probable_mtu[i];
1388
1389         return curr_mtu;
1390         }
1391
1392 void
1393 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1394         {
1395         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1396         msg_hdr->type = *(data++);
1397         n2l3(data, msg_hdr->msg_len);
1398
1399         n2s(data, msg_hdr->seq);
1400         n2l3(data, msg_hdr->frag_off);
1401         n2l3(data, msg_hdr->frag_len);
1402         }
1403
1404 void
1405 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1406         {
1407         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1408
1409         ccs_hdr->type = *(data++);
1410         }