ssl/d1_both.c

   1 /* ssl/d1_both.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <limits.h>
 117 #include <string.h>
 118 #include <stdio.h>
 119 #include "ssl_locl.h"
 120 #include <openssl/buffer.h>
 121 #include <openssl/rand.h>
 122 #include <openssl/objects.h>
 123 #include <openssl/evp.h>
 124 #include <openssl/x509.h>
 125
 126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 127
 128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
 129                         if ((end) - (start) <= 8) { \
 130                                 long ii; \
 131                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 132                         } else { \
 133                                 long ii; \
 134                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 135                                 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
 136                                 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 137                         } }
 138
 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 140                         long ii; \
 141                         OPENSSL_assert((msg_len) > 0); \
 142                         is_complete = 1; \
 143                         if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 144                         if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
 145                                 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 146
 147 #if 0
 148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 149                         long ii; \
 150                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 151                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 152                         printf("\n"); }
 153 #endif
 154
 155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 156 static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 157
 158 /* XDTLS:  figure out the right values */
 159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 160
 161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 163         unsigned long frag_len);
 164 static unsigned char *dtls1_write_message_header(SSL *s,
 165         unsigned char *p);
 166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 167         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 168         unsigned long frag_len);
 169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 170         long max, int *ok);
 171
 172 static hm_fragment *
 173 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 174         {
 175         hm_fragment *frag = NULL;
 176         unsigned char *buf = NULL;
 177         unsigned char *bitmask = NULL;
 178
 179         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 180         if ( frag == NULL)
 181                 return NULL;
 182
 183         if (frag_len)
 184                 {
 185                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 186                 if ( buf == NULL)
 187                         {
 188                         OPENSSL_free(frag);
 189                         return NULL;
 190                         }
 191                 }
 192
 193         /* zero length fragment gets zero frag->fragment */
 194         frag->fragment = buf;
 195
 196         /* Initialize reassembly bitmask if necessary */
 197         if (reassembly)
 198                 {
 199                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 200                 if (bitmask == NULL)
 201                         {
 202                         if (buf != NULL) OPENSSL_free(buf);
 203                         OPENSSL_free(frag);
 204                         return NULL;
 205                         }
 206                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 207                 }
 208
 209         frag->reassembly = bitmask;
 210
 211         return frag;
 212         }
 213
 214 static void
 215 dtls1_hm_fragment_free(hm_fragment *frag)
 216         {
 217
 218         if (frag->msg_header.is_ccs)
 219                 {
 220                 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
 221                 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
 222                 }
 223         if (frag->fragment) OPENSSL_free(frag->fragment);
 224         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 225         OPENSSL_free(frag);
 226         }
 227
 228 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 229 int dtls1_do_write(SSL *s, int type)
 230         {
 231         int ret;
 232         int curr_mtu;
 233         unsigned int len, frag_off, mac_size, blocksize;
 234
 235         /* AHA!  Figure out the MTU, and stick to the right size */
 236         if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 237                 {
 238                 s->d1->mtu =
 239                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 240
 241                 /* I've seen the kernel return bogus numbers when it doesn't know
 242                  * (initial write), so just make sure we have a reasonable number */
 243                 if (s->d1->mtu < dtls1_min_mtu())
 244                         {
 245                         s->d1->mtu = 0;
 246                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 247                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 248                                 s->d1->mtu, NULL);
 249                         }
 250                 }
 251 #if 0
 252         mtu = s->d1->mtu;
 253
 254         fprintf(stderr, "using MTU = %d\n", mtu);
 255
 256         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 257
 258         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 259
 260         if ( curr_mtu > 0)
 261                 mtu = curr_mtu;
 262         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 263                 return ret;
 264
 265         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 266                 {
 267                 ret = BIO_flush(SSL_get_wbio(s));
 268                 if ( ret <= 0)
 269                         return ret;
 270                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 271                 }
 272 #endif
 273
 274         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu());  /* should have something reasonable now */
 275
 276         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 277                 OPENSSL_assert(s->init_num ==
 278                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 279
 280         if (s->write_hash)
 281                 {
 282                 if (s->enc_write_ctx && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE)
 283                         mac_size = 0;
 284                 else
 285                         mac_size = EVP_MD_CTX_size(s->write_hash);
 286                 }
 287         else
 288                 mac_size = 0;
 289
 290         if (s->enc_write_ctx &&
 291                 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
 292                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 293         else
 294                 blocksize = 0;
 295
 296         frag_off = 0;
 297         while( s->init_num)
 298                 {
 299                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 300                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 301
 302                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 303                         {
 304                         /* grr.. we could get an error if MTU picked was wrong */
 305                         ret = BIO_flush(SSL_get_wbio(s));
 306                         if ( ret <= 0)
 307                                 return ret;
 308                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 309                                 mac_size - blocksize;
 310                         }
 311
 312                 if ( s->init_num > curr_mtu)
 313                         len = curr_mtu;
 314                 else
 315                         len = s->init_num;
 316
 317
 318                 /* XDTLS: this function is too long.  split out the CCS part */
 319                 if ( type == SSL3_RT_HANDSHAKE)
 320                         {
 321                         if ( s->init_off != 0)
 322                                 {
 323                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 324                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 325                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 326
 327                                 if ( s->init_num > curr_mtu)
 328                                         len = curr_mtu;
 329                                 else
 330                                         len = s->init_num;
 331                                 }
 332
 333                         dtls1_fix_message_header(s, frag_off,
 334                                 len - DTLS1_HM_HEADER_LENGTH);
 335
 336                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 337
 338                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 339                         }
 340
 341                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 342                         len);
 343                 if (ret < 0)
 344                         {
 345                         /* might need to update MTU here, but we don't know
 346                          * which previous packet caused the failure -- so can't
 347                          * really retransmit anything.  continue as if everything
 348                          * is fine and wait for an alert to handle the
 349                          * retransmit
 350                          */
 351                         if ( BIO_ctrl(SSL_get_wbio(s),
 352                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 353                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 354                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 355                         else
 356                                 return(-1);
 357                         }
 358                 else
 359                         {
 360
 361                         /* bad if this assert fails, only part of the handshake
 362                          * message got sent.  but why would this happen? */
 363                         OPENSSL_assert(len == (unsigned int)ret);
 364
 365                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 366                                 {
 367                                 /* should not be done for 'Hello Request's, but in that case
 368                                  * we'll ignore the result anyway */
 369                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 370                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 371                                 int xlen;
 372
 373                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
 374                                         {
 375                                         /* reconstruct message header is if it
 376                                          * is being sent in single fragment */
 377                                         *p++ = msg_hdr->type;
 378                                         l2n3(msg_hdr->msg_len,p);
 379                                         s2n (msg_hdr->seq,p);
 380                                         l2n3(0,p);
 381                                         l2n3(msg_hdr->msg_len,p);
 382                                         p  -= DTLS1_HM_HEADER_LENGTH;
 383                                         xlen = ret;
 384                                         }
 385                                 else
 386                                         {
 387                                         p  += DTLS1_HM_HEADER_LENGTH;
 388                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 389                                         }
 390
 391                                 ssl3_finish_mac(s, p, xlen);
 392                                 }
 393
 394                         if (ret == s->init_num)
 395                                 {
 396                                 if (s->msg_callback)
 397                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 398                                                 (size_t)(s->init_off + s->init_num), s,
 399                                                 s->msg_callback_arg);
 400
 401                                 s->init_off = 0;  /* done writing this message */
 402                                 s->init_num = 0;
 403
 404                                 return(1);
 405                                 }
 406                         s->init_off+=ret;
 407                         s->init_num-=ret;
 408                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 409                         }
 410                 }
 411         return(0);
 412         }
 413
 414
 415 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 416  * maximum acceptable body length 'max'.
 417  * Read an entire handshake message.  Handshake messages arrive in
 418  * fragments.
 419  */
 420 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 421         {
 422         int i, al;
 423         struct hm_header_st *msg_hdr;
 424         unsigned char *p;
 425         unsigned long msg_len;
 426
 427         /* s3->tmp is used to store messages that are unexpected, caused
 428          * by the absence of an optional handshake message */
 429         if (s->s3->tmp.reuse_message)
 430                 {
 431                 s->s3->tmp.reuse_message=0;
 432                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 433                         {
 434                         al=SSL_AD_UNEXPECTED_MESSAGE;
 435                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 436                         goto f_err;
 437                         }
 438                 *ok=1;
 439                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 440                 s->init_num = (int)s->s3->tmp.message_size;
 441                 return s->init_num;
 442                 }
 443
 444         msg_hdr = &s->d1->r_msg_hdr;
 445         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 446
 447 again:
 448         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 449         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 450                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 451                 goto again;
 452         else if ( i <= 0 && !*ok)
 453                 return i;
 454
 455         p = (unsigned char *)s->init_buf->data;
 456         msg_len = msg_hdr->msg_len;
 457
 458         /* reconstruct message header */
 459         *(p++) = msg_hdr->type;
 460         l2n3(msg_len,p);
 461         s2n (msg_hdr->seq,p);
 462         l2n3(0,p);
 463         l2n3(msg_len,p);
 464         if (s->version != DTLS1_BAD_VER) {
 465                 p       -= DTLS1_HM_HEADER_LENGTH;
 466                 msg_len += DTLS1_HM_HEADER_LENGTH;
 467         }
 468
 469         ssl3_finish_mac(s, p, msg_len);
 470         if (s->msg_callback)
 471                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 472                         p, msg_len,
 473                         s, s->msg_callback_arg);
 474
 475         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 476
 477         /* Don't change sequence numbers while listening */
 478         if (!s->d1->listen)
 479                 s->d1->handshake_read_seq++;
 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,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         unsigned char seq64be[8];
 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         memset(seq64be,0,sizeof(seq64be));
 621         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 622         seq64be[7] = (unsigned char) msg_hdr->seq;
 623         item = pqueue_find(s->d1->buffered_messages, seq64be);
 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, (long)msg_hdr->frag_off,
 662                             (long)(msg_hdr->frag_off + frag_len));
 663
 664         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)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                 memset(seq64be,0,sizeof(seq64be));
 676                 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
 677                 seq64be[7] = (unsigned char)(msg_hdr->seq);
 678
 679                 item = pitem_new(seq64be, frag);
 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         unsigned char seq64be[8];
 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         memset(seq64be,0,sizeof(seq64be));
 713         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 714         seq64be[7] = (unsigned char) msg_hdr->seq;
 715         item = pqueue_find(s->d1->buffered_messages, seq64be);
 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                 memset(seq64be,0,sizeof(seq64be));
 764                 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
 765                 seq64be[7] = (unsigned char)(msg_hdr->seq);
 766
 767                 item = pitem_new(seq64be, frag);
 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         /* Handshake fails if message header is incomplete */
 809         if (i != DTLS1_HM_HEADER_LENGTH)
 810                 {
 811                 al=SSL_AD_UNEXPECTED_MESSAGE;
 812                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 813                 goto f_err;
 814                 }
 815
 816         /* parse the message fragment header */
 817         dtls1_get_message_header(wire, &msg_hdr);
 818
 819         /*
 820          * if this is a future (or stale) message it gets buffered
 821          * (or dropped)--no further processing at this time
 822          * While listening, we accept seq 1 (ClientHello with cookie)
 823          * although we're still expecting seq 0 (ClientHello)
 824          */
 825         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 826                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 827
 828         len = msg_hdr.msg_len;
 829         frag_off = msg_hdr.frag_off;
 830         frag_len = msg_hdr.frag_len;
 831
 832         if (frag_len && frag_len < len)
 833                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 834
 835         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 836                 wire[0] == SSL3_MT_HELLO_REQUEST)
 837                 {
 838                 /* The server may always send 'Hello Request' messages --
 839                  * we are doing a handshake anyway now, so ignore them
 840                  * if their format is correct. Does not count for
 841                  * 'Finished' MAC. */
 842                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 843                         {
 844                         if (s->msg_callback)
 845                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 846                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 847                                         s->msg_callback_arg);
 848
 849                         s->init_num = 0;
 850                         return dtls1_get_message_fragment(s, st1, stn,
 851                                 max, ok);
 852                         }
 853                 else /* Incorrectly formated Hello request */
 854                         {
 855                         al=SSL_AD_UNEXPECTED_MESSAGE;
 856                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 857                         goto f_err;
 858                         }
 859                 }
 860
 861         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 862                 goto f_err;
 863
 864         /* XDTLS:  ressurect this when restart is in place */
 865         s->state=stn;
 866
 867         if ( frag_len > 0)
 868                 {
 869                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 870
 871                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 872                         &p[frag_off],frag_len,0);
 873                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 874                 if (i <= 0)
 875                         {
 876                         s->rwstate=SSL_READING;
 877                         *ok = 0;
 878                         return i;
 879                         }
 880                 }
 881         else
 882                 i = 0;
 883
 884         /* XDTLS:  an incorrectly formatted fragment should cause the
 885          * handshake to fail */
 886         if (i != (int)frag_len)
 887                 {
 888                 al=SSL3_AD_ILLEGAL_PARAMETER;
 889                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 890                 goto f_err;
 891                 }
 892
 893         *ok = 1;
 894
 895         /* Note that s->init_num is *not* used as current offset in
 896          * s->init_buf->data, but as a counter summing up fragments'
 897          * lengths: as soon as they sum up to handshake packet
 898          * length, we assume we have got all the fragments. */
 899         s->init_num = frag_len;
 900         return frag_len;
 901
 902 f_err:
 903         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 904         s->init_num = 0;
 905
 906         *ok=0;
 907         return(-1);
 908         }
 909
 910 /* for these 2 messages, we need to
 911  * ssl->enc_read_ctx                    re-init
 912  * ssl->s3->read_sequence               zero
 913  * ssl->s3->read_mac_secret             re-init
 914  * ssl->session->read_sym_enc           assign
 915  * ssl->session->read_compression       assign
 916  * ssl->session->read_hash              assign
 917  */
 918 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 919         {
 920         unsigned char *p;
 921
 922         if (s->state == a)
 923                 {
 924                 p=(unsigned char *)s->init_buf->data;
 925                 *p++=SSL3_MT_CCS;
 926                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 927                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 928
 929                 if (s->version == DTLS1_BAD_VER) {
 930                         s->d1->next_handshake_write_seq++;
 931                         s2n(s->d1->handshake_write_seq,p);
 932                         s->init_num+=2;
 933                 }
 934
 935                 s->init_off=0;
 936
 937                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 938                         s->d1->handshake_write_seq, 0, 0);
 939
 940                 /* buffer the message to handle re-xmits */
 941                 dtls1_buffer_message(s, 1);
 942
 943                 s->state=b;
 944                 }
 945
 946         /* SSL3_ST_CW_CHANGE_B */
 947         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 948         }
 949
 950 int dtls1_read_failed(SSL *s, int code)
 951         {
 952         if ( code > 0)
 953                 {
 954                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
 955                 return 1;
 956                 }
 957
 958         if (!dtls1_is_timer_expired(s))
 959                 {
 960                 /* not a timeout, none of our business,
 961                    let higher layers handle this.  in fact it's probably an error */
 962                 return code;
 963                 }
 964
 965 #ifndef OPENSSL_NO_HEARTBEATS
 966         if (!SSL_in_init(s) && !s->tlsext_hb_pending)  /* done, no need to send a retransmit */
 967 #else
 968         if (!SSL_in_init(s))  /* done, no need to send a retransmit */
 969 #endif
 970                 {
 971                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
 972                 return code;
 973                 }
 974
 975 #if 0 /* for now, each alert contains only one record number */
 976         item = pqueue_peek(state->rcvd_records);
 977         if ( item )
 978                 {
 979                 /* send an alert immediately for all the missing records */
 980                 }
 981         else
 982 #endif
 983
 984 #if 0  /* no more alert sending, just retransmit the last set of messages */
 985         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
 986                 ssl3_send_alert(s,SSL3_AL_WARNING,
 987                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 988 #endif
 989
 990         return dtls1_handle_timeout(s);
 991         }
 992
 993 int
 994 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
 995         {
 996         /* The index of the retransmission queue actually is the message sequence number,
 997          * since the queue only contains messages of a single handshake. However, the
 998          * ChangeCipherSpec has no message sequence number and so using only the sequence
 999          * will result in the CCS and Finished having the same index. To prevent this,
1000          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1001          * This does not only differ CSS and Finished, it also maintains the order of the
1002          * index (important for priority queues) and fits in the unsigned short variable.
1003          */
1004         return seq * 2 - is_ccs;
1005         }
1006
1007 int
1008 dtls1_retransmit_buffered_messages(SSL *s)
1009         {
1010         pqueue sent = s->d1->sent_messages;
1011         piterator iter;
1012         pitem *item;
1013         hm_fragment *frag;
1014         int found = 0;
1015
1016         iter = pqueue_iterator(sent);
1017
1018         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1019                 {
1020                 frag = (hm_fragment *)item->data;
1021                         if ( dtls1_retransmit_message(s,
1022                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1023                                 0, &found) <= 0 && found)
1024                         {
1025                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1026                         return -1;
1027                         }
1028                 }
1029
1030         return 1;
1031         }
1032
1033 int
1034 dtls1_buffer_message(SSL *s, int is_ccs)
1035         {
1036         pitem *item;
1037         hm_fragment *frag;
1038         unsigned char seq64be[8];
1039
1040         /* this function is called immediately after a message has
1041          * been serialized */
1042         OPENSSL_assert(s->init_off == 0);
1043
1044         frag = dtls1_hm_fragment_new(s->init_num, 0);
1045
1046         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1047
1048         if ( is_ccs)
1049                 {
1050                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1051                                DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1052                 }
1053         else
1054                 {
1055                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1056                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1057                 }
1058
1059         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1060         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1061         frag->msg_header.type = s->d1->w_msg_hdr.type;
1062         frag->msg_header.frag_off = 0;
1063         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1064         frag->msg_header.is_ccs = is_ccs;
1065
1066         /* save current state*/
1067         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1068         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1069         frag->msg_header.saved_retransmit_state.compress = s->compress;
1070         frag->msg_header.saved_retransmit_state.session = s->session;
1071         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1072
1073         memset(seq64be,0,sizeof(seq64be));
1074         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1075                                                                                                                   frag->msg_header.is_ccs)>>8);
1076         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1077                                                                                                                   frag->msg_header.is_ccs));
1078
1079         item = pitem_new(seq64be, frag);
1080         if ( item == NULL)
1081                 {
1082                 dtls1_hm_fragment_free(frag);
1083                 return 0;
1084                 }
1085
1086 #if 0
1087         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1088         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1089         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1090 #endif
1091
1092         pqueue_insert(s->d1->sent_messages, item);
1093         return 1;
1094         }
1095
1096 int
1097 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1098         int *found)
1099         {
1100         int ret;
1101         /* XDTLS: for now assuming that read/writes are blocking */
1102         pitem *item;
1103         hm_fragment *frag ;
1104         unsigned long header_length;
1105         unsigned char seq64be[8];
1106         struct dtls1_retransmit_state saved_state;
1107         unsigned char save_write_sequence[8];
1108
1109         /*
1110           OPENSSL_assert(s->init_num == 0);
1111           OPENSSL_assert(s->init_off == 0);
1112          */
1113
1114         /* XDTLS:  the requested message ought to be found, otherwise error */
1115         memset(seq64be,0,sizeof(seq64be));
1116         seq64be[6] = (unsigned char)(seq>>8);
1117         seq64be[7] = (unsigned char)seq;
1118
1119         item = pqueue_find(s->d1->sent_messages, seq64be);
1120         if ( item == NULL)
1121                 {
1122                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1123                 *found = 0;
1124                 return 0;
1125                 }
1126
1127         *found = 1;
1128         frag = (hm_fragment *)item->data;
1129
1130         if ( frag->msg_header.is_ccs)
1131                 header_length = DTLS1_CCS_HEADER_LENGTH;
1132         else
1133                 header_length = DTLS1_HM_HEADER_LENGTH;
1134
1135         memcpy(s->init_buf->data, frag->fragment,
1136                 frag->msg_header.msg_len + header_length);
1137                 s->init_num = frag->msg_header.msg_len + header_length;
1138
1139         dtls1_set_message_header_int(s, frag->msg_header.type,
1140                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1141                 frag->msg_header.frag_len);
1142
1143         /* save current state */
1144         saved_state.enc_write_ctx = s->enc_write_ctx;
1145         saved_state.write_hash = s->write_hash;
1146         saved_state.compress = s->compress;
1147         saved_state.session = s->session;
1148         saved_state.epoch = s->d1->w_epoch;
1149         saved_state.epoch = s->d1->w_epoch;
1150
1151         s->d1->retransmitting = 1;
1152
1153         /* restore state in which the message was originally sent */
1154         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1155         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1156         s->compress = frag->msg_header.saved_retransmit_state.compress;
1157         s->session = frag->msg_header.saved_retransmit_state.session;
1158         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1159
1160         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1161         {
1162                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1163                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1164         }
1165
1166         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1167                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1168
1169         /* restore current state */
1170         s->enc_write_ctx = saved_state.enc_write_ctx;
1171         s->write_hash = saved_state.write_hash;
1172         s->compress = saved_state.compress;
1173         s->session = saved_state.session;
1174         s->d1->w_epoch = saved_state.epoch;
1175
1176         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1177         {
1178                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1179                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1180         }
1181
1182         s->d1->retransmitting = 0;
1183
1184         (void)BIO_flush(SSL_get_wbio(s));
1185         return ret;
1186         }
1187
1188 /* call this function when the buffered messages are no longer needed */
1189 void
1190 dtls1_clear_record_buffer(SSL *s)
1191         {
1192         pitem *item;
1193
1194         for(item = pqueue_pop(s->d1->sent_messages);
1195                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1196                 {
1197                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1198                 pitem_free(item);
1199                 }
1200         }
1201
1202
1203 unsigned char *
1204 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1205                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1206         {
1207         /* Don't change sequence numbers while listening */
1208         if (frag_off == 0 && !s->d1->listen)
1209                 {
1210                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1211                 s->d1->next_handshake_write_seq++;
1212                 }
1213
1214         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1215                 frag_off, frag_len);
1216
1217         return p += DTLS1_HM_HEADER_LENGTH;
1218         }
1219
1220
1221 /* don't actually do the writing, wait till the MTU has been retrieved */
1222 static void
1223 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1224                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1225                             unsigned long frag_len)
1226         {
1227         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1228
1229         msg_hdr->type = mt;
1230         msg_hdr->msg_len = len;
1231         msg_hdr->seq = seq_num;
1232         msg_hdr->frag_off = frag_off;
1233         msg_hdr->frag_len = frag_len;
1234         }
1235
1236 static void
1237 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1238                         unsigned long frag_len)
1239         {
1240         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1241
1242         msg_hdr->frag_off = frag_off;
1243         msg_hdr->frag_len = frag_len;
1244         }
1245
1246 static unsigned char *
1247 dtls1_write_message_header(SSL *s, unsigned char *p)
1248         {
1249         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1250
1251         *p++ = msg_hdr->type;
1252         l2n3(msg_hdr->msg_len, p);
1253
1254         s2n(msg_hdr->seq, p);
1255         l2n3(msg_hdr->frag_off, p);
1256         l2n3(msg_hdr->frag_len, p);
1257
1258         return p;
1259         }
1260
1261 unsigned int
1262 dtls1_min_mtu(void)
1263         {
1264         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1265                 sizeof(g_probable_mtu[0])) - 1]);
1266         }
1267
1268 static unsigned int
1269 dtls1_guess_mtu(unsigned int curr_mtu)
1270         {
1271         unsigned int i;
1272
1273         if ( curr_mtu == 0 )
1274                 return g_probable_mtu[0] ;
1275
1276         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1277                 if ( curr_mtu > g_probable_mtu[i])
1278                         return g_probable_mtu[i];
1279
1280         return curr_mtu;
1281         }
1282
1283 void
1284 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1285         {
1286         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1287         msg_hdr->type = *(data++);
1288         n2l3(data, msg_hdr->msg_len);
1289
1290         n2s(data, msg_hdr->seq);
1291         n2l3(data, msg_hdr->frag_off);
1292         n2l3(data, msg_hdr->frag_len);
1293         }
1294
1295 void
1296 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1297         {
1298         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1299
1300         ccs_hdr->type = *(data++);
1301         }
1302
1303 int dtls1_shutdown(SSL *s)
1304         {
1305         int ret;
1306 #ifndef OPENSSL_NO_SCTP
1307         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1308             !(s->shutdown & SSL_SENT_SHUTDOWN))
1309                 {
1310                 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1311                 if (ret < 0) return -1;
1312
1313                 if (ret == 0)
1314                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1315                 }
1316 #endif
1317         ret = ssl3_shutdown(s);
1318 #ifndef OPENSSL_NO_SCTP
1319         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1320 #endif
1321         return ret;
1322         }
1323
1324 #ifndef OPENSSL_NO_HEARTBEATS
1325 int
1326 dtls1_process_heartbeat(SSL *s)
1327         {
1328         unsigned char *p = &s->s3->rrec.data[0], *pl;
1329         unsigned short hbtype;
1330         unsigned int payload;
1331         unsigned int padding = 16; /* Use minimum padding */
1332
1333         /* Read type and payload length first */
1334         hbtype = *p++;
1335         n2s(p, payload);
1336         pl = p;
1337
1338         if (s->msg_callback)
1339                 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1340                         &s->s3->rrec.data[0], s->s3->rrec.length,
1341                         s, s->msg_callback_arg);
1342
1343         if (hbtype == TLS1_HB_REQUEST)
1344                 {
1345                 unsigned char *buffer, *bp;
1346                 int r;
1347
1348                 /* Allocate memory for the response, size is 1 byte
1349                  * message type, plus 2 bytes payload length, plus
1350                  * payload, plus padding
1351                  */
1352                 buffer = OPENSSL_malloc(1 + 2 + payload + padding);
1353                 bp = buffer;
1354
1355                 /* Enter response type, length and copy payload */
1356                 *bp++ = TLS1_HB_RESPONSE;
1357                 s2n(payload, bp);
1358                 memcpy(bp, pl, payload);
1359                 bp += payload;
1360                 /* Random padding */
1361                 RAND_pseudo_bytes(bp, padding);
1362
1363                 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);
1364
1365                 if (r >= 0 && s->msg_callback)
1366                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1367                                 buffer, 3 + payload + padding,
1368                                 s, s->msg_callback_arg);
1369
1370                 OPENSSL_free(buffer);
1371
1372                 if (r < 0)
1373                         return r;
1374                 }
1375         else if (hbtype == TLS1_HB_RESPONSE)
1376                 {
1377                 unsigned int seq;
1378
1379                 /* We only send sequence numbers (2 bytes unsigned int),
1380                  * and 16 random bytes, so we just try to read the
1381                  * sequence number */
1382                 n2s(pl, seq);
1383
1384                 if (payload == 18 && seq == s->tlsext_hb_seq)
1385                         {
1386                         dtls1_stop_timer(s);
1387                         s->tlsext_hb_seq++;
1388                         s->tlsext_hb_pending = 0;
1389                         }
1390                 }
1391
1392         return 0;
1393         }
1394
1395 int
1396 dtls1_heartbeat(SSL *s)
1397         {
1398         unsigned char *buf, *p;
1399         int ret;
1400         unsigned int payload = 18; /* Sequence number + random bytes */
1401         unsigned int padding = 16; /* Use minimum padding */
1402
1403         /* Only send if peer supports and accepts HB requests... */
1404         if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1405             s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1406                 {
1407                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1408                 return -1;
1409                 }
1410
1411         /* ...and there is none in flight yet... */
1412         if (s->tlsext_hb_pending)
1413                 {
1414                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1415                 return -1;
1416                 }
1417
1418         /* ...and no handshake in progress. */
1419         if (SSL_in_init(s) || s->in_handshake)
1420                 {
1421                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1422                 return -1;
1423                 }
1424
1425         /* Check if padding is too long, payload and padding
1426          * must not exceed 2^14 - 3 = 16381 bytes in total.
1427          */
1428         OPENSSL_assert(payload + padding <= 16381);
1429
1430         /* Create HeartBeat message, we just use a sequence number
1431          * as payload to distuingish different messages and add
1432          * some random stuff.
1433          *  - Message Type, 1 byte
1434          *  - Payload Length, 2 bytes (unsigned int)
1435          *  - Payload, the sequence number (2 bytes uint)
1436          *  - Payload, random bytes (16 bytes uint)
1437          *  - Padding
1438          */
1439         buf = OPENSSL_malloc(1 + 2 + payload + padding);
1440         p = buf;
1441         /* Message Type */
1442         *p++ = TLS1_HB_REQUEST;
1443         /* Payload length (18 bytes here) */
1444         s2n(payload, p);
1445         /* Sequence number */
1446         s2n(s->tlsext_hb_seq, p);
1447         /* 16 random bytes */
1448         RAND_pseudo_bytes(p, 16);
1449         p += 16;
1450         /* Random padding */
1451         RAND_pseudo_bytes(p, padding);
1452
1453         ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1454         if (ret >= 0)
1455                 {
1456                 if (s->msg_callback)
1457                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1458                                 buf, 3 + payload + padding,
1459                                 s, s->msg_callback_arg);
1460
1461                 dtls1_start_timer(s);
1462                 s->tlsext_hb_pending = 1;
1463                 }
1464
1465         OPENSSL_free(buf);
1466
1467         return ret;
1468         }
1469 #endif