ssl/d1_both.c

   1 /* ssl/d1_both.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <limits.h>
 117 #include <string.h>
 118 #include <stdio.h>
 119 #include "ssl_locl.h"
 120 #include <openssl/buffer.h>
 121 #include <openssl/rand.h>
 122 #include <openssl/objects.h>
 123 #include <openssl/evp.h>
 124 #include <openssl/x509.h>
 125
 126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 127
 128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
 129                         if ((end) - (start) <= 8) { \
 130                                 long ii; \
 131                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 132                         } else { \
 133                                 long ii; \
 134                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 135                                 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
 136                                 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 137                         } }
 138
 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 140                         long ii; \
 141                         OPENSSL_assert((msg_len) > 0); \
 142                         is_complete = 1; \
 143                         if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 144                         if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
 145                                 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 146
 147 #if 0
 148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 149                         long ii; \
 150                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 151                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 152                         printf("\n"); }
 153 #endif
 154
 155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 156 static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 157
 158 /* XDTLS:  figure out the right values */
 159 static const unsigned int g_probable_mtu[] = {1500, 512, 256};
 160
 161 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 162         unsigned long frag_len);
 163 static unsigned char *dtls1_write_message_header(SSL *s,
 164         unsigned char *p);
 165 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 166         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 167         unsigned long frag_len);
 168 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 169         long max, int *ok);
 170
 171 static hm_fragment *
 172 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 173         {
 174         hm_fragment *frag = NULL;
 175         unsigned char *buf = NULL;
 176         unsigned char *bitmask = NULL;
 177
 178         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 179         if ( frag == NULL)
 180                 return NULL;
 181
 182         if (frag_len)
 183                 {
 184                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 185                 if ( buf == NULL)
 186                         {
 187                         OPENSSL_free(frag);
 188                         return NULL;
 189                         }
 190                 }
 191
 192         /* zero length fragment gets zero frag->fragment */
 193         frag->fragment = buf;
 194
 195         /* Initialize reassembly bitmask if necessary */
 196         if (reassembly)
 197                 {
 198                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 199                 if (bitmask == NULL)
 200                         {
 201                         if (buf != NULL) OPENSSL_free(buf);
 202                         OPENSSL_free(frag);
 203                         return NULL;
 204                         }
 205                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 206                 }
 207
 208         frag->reassembly = bitmask;
 209
 210         return frag;
 211         }
 212
 213 void dtls1_hm_fragment_free(hm_fragment *frag)
 214         {
 215
 216         if (frag->msg_header.is_ccs)
 217                 {
 218                 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
 219                 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
 220                 }
 221         if (frag->fragment) OPENSSL_free(frag->fragment);
 222         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 223         OPENSSL_free(frag);
 224         }
 225
 226 static int dtls1_query_mtu(SSL *s)
 227 {
 228         if(s->d1->link_mtu)
 229                 {
 230                 s->d1->mtu = s->d1->link_mtu-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
 231                 s->d1->link_mtu = 0;
 232                 }
 233
 234         /* AHA!  Figure out the MTU, and stick to the right size */
 235         if (s->d1->mtu < dtls1_min_mtu(s))
 236                 {
 237                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 238                         {
 239                         s->d1->mtu =
 240                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 241
 242                         /* I've seen the kernel return bogus numbers when it doesn't know
 243                          * (initial write), so just make sure we have a reasonable number */
 244                         if (s->d1->mtu < dtls1_min_mtu(s))
 245                                 {
 246                                 /* Set to min mtu */
 247                                 s->d1->mtu = dtls1_min_mtu(s);
 248                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 249                                         s->d1->mtu, NULL);
 250                                 }
 251                         }
 252                 else
 253                         return 0;
 254                 }
 255         return 1;
 256 }
 257
 258 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 259 int dtls1_do_write(SSL *s, int type)
 260         {
 261         int ret;
 262         unsigned int curr_mtu;
 263         int retry = 1;
 264         unsigned int len, frag_off, mac_size, blocksize, used_len;
 265
 266         if(!dtls1_query_mtu(s))
 267                 return -1;
 268
 269         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s));  /* should have something reasonable now */
 270
 271         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 272                 OPENSSL_assert(s->init_num ==
 273                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 274
 275         if (s->write_hash)
 276                 {
 277                 if (s->enc_write_ctx && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE)
 278                         mac_size = 0;
 279                 else
 280                         mac_size = EVP_MD_CTX_size(s->write_hash);
 281                 }
 282         else
 283                 mac_size = 0;
 284
 285         if (s->enc_write_ctx &&
 286                 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
 287                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 288         else
 289                 blocksize = 0;
 290
 291         frag_off = 0;
 292         /* s->init_num shouldn't ever be < 0...but just in case */
 293         while(s->init_num > 0)
 294                 {
 295                 used_len = BIO_wpending(SSL_get_wbio(s)) +  DTLS1_RT_HEADER_LENGTH
 296                         + mac_size + blocksize;
 297                 if(s->d1->mtu > used_len)
 298                         curr_mtu = s->d1->mtu - used_len;
 299                 else
 300                         curr_mtu = 0;
 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                         used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
 309                         if(s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH)
 310                                 {
 311                                 curr_mtu = s->d1->mtu - used_len;
 312                                 }
 313                         else
 314                                 {
 315                                 /* Shouldn't happen */
 316                                 return -1;
 317                                 }
 318                         }
 319
 320                 /* We just checked that s->init_num > 0 so this cast should be safe */
 321                 if (((unsigned int)s->init_num) > curr_mtu)
 322                         len = curr_mtu;
 323                 else
 324                         len = s->init_num;
 325
 326                 /* Shouldn't ever happen */
 327                 if(len > INT_MAX)
 328                         len = INT_MAX;
 329
 330                 /* XDTLS: this function is too long.  split out the CCS part */
 331                 if ( type == SSL3_RT_HANDSHAKE)
 332                         {
 333                         if ( s->init_off != 0)
 334                                 {
 335                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 336                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 337                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 338
 339                                 /* We just checked that s->init_num > 0 so this cast should be safe */
 340                                 if (((unsigned int)s->init_num) > curr_mtu)
 341                                         len = curr_mtu;
 342                                 else
 343                                         len = s->init_num;
 344                                 }
 345
 346                         /* Shouldn't ever happen */
 347                         if(len > INT_MAX)
 348                                 len = INT_MAX;
 349
 350                         if ( len < DTLS1_HM_HEADER_LENGTH )
 351                                 {
 352                                 /*
 353                                  * len is so small that we really can't do anything sensible
 354                                  * so fail
 355                                  */
 356                                 return -1;
 357                                 }
 358                         dtls1_fix_message_header(s, frag_off,
 359                                 len - DTLS1_HM_HEADER_LENGTH);
 360
 361                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 362                         }
 363
 364                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 365                         len);
 366                 if (ret < 0)
 367                         {
 368                         /* might need to update MTU here, but we don't know
 369                          * which previous packet caused the failure -- so can't
 370                          * really retransmit anything.  continue as if everything
 371                          * is fine and wait for an alert to handle the
 372                          * retransmit
 373                          */
 374                         if ( retry && BIO_ctrl(SSL_get_wbio(s),
 375                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 376                                 {
 377                                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 378                                         {
 379                                         if(!dtls1_query_mtu(s))
 380                                                 return -1;
 381                                         /* Have one more go */
 382                                         retry = 0;
 383                                         }
 384                                 else
 385                                         return -1;
 386                                 }
 387                         else
 388                                 {
 389                                 return(-1);
 390                                 }
 391                         }
 392                 else
 393                         {
 394
 395                         /* bad if this assert fails, only part of the handshake
 396                          * message got sent.  but why would this happen? */
 397                         OPENSSL_assert(len == (unsigned int)ret);
 398
 399                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 400                                 {
 401                                 /* should not be done for 'Hello Request's, but in that case
 402                                  * we'll ignore the result anyway */
 403                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 404                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 405                                 int xlen;
 406
 407                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
 408                                         {
 409                                         /* reconstruct message header is if it
 410                                          * is being sent in single fragment */
 411                                         *p++ = msg_hdr->type;
 412                                         l2n3(msg_hdr->msg_len,p);
 413                                         s2n (msg_hdr->seq,p);
 414                                         l2n3(0,p);
 415                                         l2n3(msg_hdr->msg_len,p);
 416                                         p  -= DTLS1_HM_HEADER_LENGTH;
 417                                         xlen = ret;
 418                                         }
 419                                 else
 420                                         {
 421                                         p  += DTLS1_HM_HEADER_LENGTH;
 422                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 423                                         }
 424
 425                                 ssl3_finish_mac(s, p, xlen);
 426                                 }
 427
 428                         if (ret == s->init_num)
 429                                 {
 430                                 if (s->msg_callback)
 431                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 432                                                 (size_t)(s->init_off + s->init_num), s,
 433                                                 s->msg_callback_arg);
 434
 435                                 s->init_off = 0;  /* done writing this message */
 436                                 s->init_num = 0;
 437
 438                                 return(1);
 439                                 }
 440                         s->init_off+=ret;
 441                         s->init_num-=ret;
 442                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 443                         }
 444                 }
 445         return(0);
 446         }
 447
 448
 449 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 450  * maximum acceptable body length 'max'.
 451  * Read an entire handshake message.  Handshake messages arrive in
 452  * fragments.
 453  */
 454 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 455         {
 456         int i, al;
 457         struct hm_header_st *msg_hdr;
 458         unsigned char *p;
 459         unsigned long msg_len;
 460
 461         /* s3->tmp is used to store messages that are unexpected, caused
 462          * by the absence of an optional handshake message */
 463         if (s->s3->tmp.reuse_message)
 464                 {
 465                 s->s3->tmp.reuse_message=0;
 466                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 467                         {
 468                         al=SSL_AD_UNEXPECTED_MESSAGE;
 469                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 470                         goto f_err;
 471                         }
 472                 *ok=1;
 473                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 474                 s->init_num = (int)s->s3->tmp.message_size;
 475                 return s->init_num;
 476                 }
 477
 478         msg_hdr = &s->d1->r_msg_hdr;
 479         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 480
 481 again:
 482         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 483         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 484                 i == DTLS1_HM_FRAGMENT_RETRY)
 485                 {
 486                 /* bad fragment received */
 487                 goto again;
 488                 }
 489         else if ( i <= 0 && !*ok)
 490                 {
 491                 return i;
 492                 }
 493
 494         p = (unsigned char *)s->init_buf->data;
 495         msg_len = msg_hdr->msg_len;
 496
 497         /* reconstruct message header */
 498         *(p++) = msg_hdr->type;
 499         l2n3(msg_len,p);
 500         s2n (msg_hdr->seq,p);
 501         l2n3(0,p);
 502         l2n3(msg_len,p);
 503         if (s->version != DTLS1_BAD_VER) {
 504                 p       -= DTLS1_HM_HEADER_LENGTH;
 505                 msg_len += DTLS1_HM_HEADER_LENGTH;
 506         }
 507
 508         ssl3_finish_mac(s, p, msg_len);
 509         if (s->msg_callback)
 510                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 511                         p, msg_len,
 512                         s, s->msg_callback_arg);
 513
 514         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 515
 516         /* Don't change sequence numbers while listening */
 517         if (!s->d1->listen)
 518                 s->d1->handshake_read_seq++;
 519
 520         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 521         return s->init_num;
 522
 523 f_err:
 524         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 525         *ok = 0;
 526         return -1;
 527         }
 528
 529
 530 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 531         {
 532         size_t frag_off,frag_len,msg_len;
 533
 534         msg_len  = msg_hdr->msg_len;
 535         frag_off = msg_hdr->frag_off;
 536         frag_len = msg_hdr->frag_len;
 537
 538         /* sanity checking */
 539         if ( (frag_off+frag_len) > msg_len)
 540                 {
 541                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 542                 return SSL_AD_ILLEGAL_PARAMETER;
 543                 }
 544
 545         if ( (frag_off+frag_len) > (unsigned long)max)
 546                 {
 547                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 548                 return SSL_AD_ILLEGAL_PARAMETER;
 549                 }
 550
 551         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 552                 {
 553                 /* msg_len is limited to 2^24, but is effectively checked
 554                  * against max above */
 555                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
 556                         {
 557                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 558                         return SSL_AD_INTERNAL_ERROR;
 559                         }
 560
 561                 s->s3->tmp.message_size  = msg_len;
 562                 s->d1->r_msg_hdr.msg_len = msg_len;
 563                 s->s3->tmp.message_type  = msg_hdr->type;
 564                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 565                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 566                 }
 567         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 568                 {
 569                 /* They must be playing with us! BTW, failure to enforce
 570                  * upper limit would open possibility for buffer overrun. */
 571                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 572                 return SSL_AD_ILLEGAL_PARAMETER;
 573                 }
 574
 575         return 0; /* no error */
 576         }
 577
 578
 579 static int
 580 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 581         {
 582         /*-
 583          * (0) check whether the desired fragment is available
 584          * if so:
 585          * (1) copy over the fragment to s->init_buf->data[]
 586          * (2) update s->init_num
 587          */
 588         pitem *item;
 589         hm_fragment *frag;
 590         int al;
 591
 592         *ok = 0;
 593         item = pqueue_peek(s->d1->buffered_messages);
 594         if ( item == NULL)
 595                 return 0;
 596
 597         frag = (hm_fragment *)item->data;
 598
 599         /* Don't return if reassembly still in progress */
 600         if (frag->reassembly != NULL)
 601                 return 0;
 602
 603         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 604                 {
 605                 unsigned long frag_len = frag->msg_header.frag_len;
 606                 pqueue_pop(s->d1->buffered_messages);
 607
 608                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 609
 610                 if (al==0) /* no alert */
 611                         {
 612                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 613                         memcpy(&p[frag->msg_header.frag_off],
 614                                 frag->fragment,frag->msg_header.frag_len);
 615                         }
 616
 617                 dtls1_hm_fragment_free(frag);
 618                 pitem_free(item);
 619
 620                 if (al==0)
 621                         {
 622                         *ok = 1;
 623                         return frag_len;
 624                         }
 625
 626                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 627                 s->init_num = 0;
 628                 *ok = 0;
 629                 return -1;
 630                 }
 631         else
 632                 return 0;
 633         }
 634
 635 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 636  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 637  * be greater if the maximum certificate list size requires it. */
 638 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 639         {
 640         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 641         if (max_len < (unsigned long)s->max_cert_list)
 642                 return s->max_cert_list;
 643         return max_len;
 644         }
 645
 646 static int
 647 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 648         {
 649         hm_fragment *frag = NULL;
 650         pitem *item = NULL;
 651         int i = -1, is_complete;
 652         unsigned char seq64be[8];
 653         unsigned long frag_len = msg_hdr->frag_len;
 654
 655         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 656             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 657                 goto err;
 658
 659         if (frag_len == 0)
 660                 return DTLS1_HM_FRAGMENT_RETRY;
 661
 662         /* Try to find item in queue */
 663         memset(seq64be,0,sizeof(seq64be));
 664         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 665         seq64be[7] = (unsigned char) msg_hdr->seq;
 666         item = pqueue_find(s->d1->buffered_messages, seq64be);
 667
 668         if (item == NULL)
 669                 {
 670                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 671                 if ( frag == NULL)
 672                         goto err;
 673                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 674                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 675                 frag->msg_header.frag_off = 0;
 676                 }
 677         else
 678                 {
 679                 frag = (hm_fragment*) item->data;
 680                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 681                         {
 682                         item = NULL;
 683                         frag = NULL;
 684                         goto err;
 685                         }
 686                 }
 687
 688
 689         /* If message is already reassembled, this must be a
 690          * retransmit and can be dropped. In this case item != NULL and so frag
 691          * does not need to be freed.
 692          */
 693         if (frag->reassembly == NULL)
 694                 {
 695                 unsigned char devnull [256];
 696
 697                 while (frag_len)
 698                         {
 699                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 700                                 devnull,
 701                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 702                         if (i<=0) goto err;
 703                         frag_len -= i;
 704                         }
 705                 return DTLS1_HM_FRAGMENT_RETRY;
 706                 }
 707
 708         /* read the body of the fragment (header has already been read */
 709         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 710                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 711         if ((unsigned long)i!=frag_len)
 712                 i=-1;
 713         if (i<=0)
 714                 goto err;
 715
 716         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 717                             (long)(msg_hdr->frag_off + frag_len));
 718
 719         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 720                                    is_complete);
 721
 722         if (is_complete)
 723                 {
 724                 OPENSSL_free(frag->reassembly);
 725                 frag->reassembly = NULL;
 726                 }
 727
 728         if (item == NULL)
 729                 {
 730                 item = pitem_new(seq64be, frag);
 731                 if (item == NULL)
 732                         {
 733                         i = -1;
 734                         goto err;
 735                         }
 736
 737                 item = pqueue_insert(s->d1->buffered_messages, item);
 738                 /* pqueue_insert fails iff a duplicate item is inserted.
 739                  * However, |item| cannot be a duplicate. If it were,
 740                  * |pqueue_find|, above, would have returned it and control
 741                  * would never have reached this branch. */
 742                 OPENSSL_assert(item != NULL);
 743                 }
 744
 745         return DTLS1_HM_FRAGMENT_RETRY;
 746
 747 err:
 748         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 749         *ok = 0;
 750         return i;
 751         }
 752
 753
 754 static int
 755 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 756 {
 757         int i=-1;
 758         hm_fragment *frag = NULL;
 759         pitem *item = NULL;
 760         unsigned char seq64be[8];
 761         unsigned long frag_len = msg_hdr->frag_len;
 762
 763         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 764                 goto err;
 765
 766         /* Try to find item in queue, to prevent duplicate entries */
 767         memset(seq64be,0,sizeof(seq64be));
 768         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 769         seq64be[7] = (unsigned char) msg_hdr->seq;
 770         item = pqueue_find(s->d1->buffered_messages, seq64be);
 771
 772         /* If we already have an entry and this one is a fragment,
 773          * don't discard it and rather try to reassemble it.
 774          */
 775         if (item != NULL && frag_len != msg_hdr->msg_len)
 776                 item = NULL;
 777
 778         /* Discard the message if sequence number was already there, is
 779          * too far in the future, already in the queue or if we received
 780          * a FINISHED before the SERVER_HELLO, which then must be a stale
 781          * retransmit.
 782          */
 783         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 784                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 785                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 786                 {
 787                 unsigned char devnull [256];
 788
 789                 while (frag_len)
 790                         {
 791                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 792                                 devnull,
 793                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 794                         if (i<=0) goto err;
 795                         frag_len -= i;
 796                         }
 797                 }
 798         else
 799                 {
 800                 if (frag_len != msg_hdr->msg_len)
 801                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 802
 803                 if (frag_len > dtls1_max_handshake_message_len(s))
 804                         goto err;
 805
 806                 frag = dtls1_hm_fragment_new(frag_len, 0);
 807                 if ( frag == NULL)
 808                         goto err;
 809
 810                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 811
 812                 if (frag_len)
 813                         {
 814                         /* read the body of the fragment (header has already been read */
 815                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 816                                 frag->fragment,frag_len,0);
 817                         if ((unsigned long)i!=frag_len)
 818                                 i = -1;
 819                         if (i<=0)
 820                                 goto err;
 821                         }
 822
 823                 item = pitem_new(seq64be, frag);
 824                 if ( item == NULL)
 825                         goto err;
 826
 827                 item = pqueue_insert(s->d1->buffered_messages, item);
 828                 /* pqueue_insert fails iff a duplicate item is inserted.
 829                  * However, |item| cannot be a duplicate. If it were,
 830                  * |pqueue_find|, above, would have returned it. Then, either
 831                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 832                  * to NULL and it will have been processed with
 833                  * |dtls1_reassemble_fragment|, above, or the record will have
 834                  * been discarded. */
 835                 OPENSSL_assert(item != NULL);
 836                 }
 837
 838         return DTLS1_HM_FRAGMENT_RETRY;
 839
 840 err:
 841         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 842         *ok = 0;
 843         return i;
 844         }
 845
 846
 847 static long
 848 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 849         {
 850         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 851         unsigned long len, frag_off, frag_len;
 852         int i,al;
 853         struct hm_header_st msg_hdr;
 854
 855         redo:
 856         /* see if we have the required fragment already */
 857         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 858                 {
 859                 if (*ok)        s->init_num = frag_len;
 860                 return frag_len;
 861                 }
 862
 863         /* read handshake message header */
 864         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 865                 DTLS1_HM_HEADER_LENGTH, 0);
 866         if (i <= 0)     /* nbio, or an error */
 867                 {
 868                 s->rwstate=SSL_READING;
 869                 *ok = 0;
 870                 return i;
 871                 }
 872         /* Handshake fails if message header is incomplete */
 873         if (i != DTLS1_HM_HEADER_LENGTH)
 874                 {
 875                 al=SSL_AD_UNEXPECTED_MESSAGE;
 876                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 877                 goto f_err;
 878                 }
 879
 880         /* parse the message fragment header */
 881         dtls1_get_message_header(wire, &msg_hdr);
 882
 883         /*
 884          * if this is a future (or stale) message it gets buffered
 885          * (or dropped)--no further processing at this time
 886          * While listening, we accept seq 1 (ClientHello with cookie)
 887          * although we're still expecting seq 0 (ClientHello)
 888          */
 889         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 890                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 891
 892         len = msg_hdr.msg_len;
 893         frag_off = msg_hdr.frag_off;
 894         frag_len = msg_hdr.frag_len;
 895
 896         if (frag_len && frag_len < len)
 897                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 898
 899         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 900                 wire[0] == SSL3_MT_HELLO_REQUEST)
 901                 {
 902                 /* The server may always send 'Hello Request' messages --
 903                  * we are doing a handshake anyway now, so ignore them
 904                  * if their format is correct. Does not count for
 905                  * 'Finished' MAC. */
 906                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 907                         {
 908                         if (s->msg_callback)
 909                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 910                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 911                                         s->msg_callback_arg);
 912
 913                         s->init_num = 0;
 914                         goto redo;
 915                         }
 916                 else /* Incorrectly formated Hello request */
 917                         {
 918                         al=SSL_AD_UNEXPECTED_MESSAGE;
 919                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 920                         goto f_err;
 921                         }
 922                 }
 923
 924         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 925                 goto f_err;
 926
 927         /* XDTLS:  ressurect this when restart is in place */
 928         s->state=stn;
 929
 930         if ( frag_len > 0)
 931                 {
 932                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 933
 934                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 935                         &p[frag_off],frag_len,0);
 936                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 937                 if (i <= 0)
 938                         {
 939                         s->rwstate=SSL_READING;
 940                         *ok = 0;
 941                         return i;
 942                         }
 943                 }
 944         else
 945                 i = 0;
 946
 947         /* XDTLS:  an incorrectly formatted fragment should cause the
 948          * handshake to fail */
 949         if (i != (int)frag_len)
 950                 {
 951                 al=SSL3_AD_ILLEGAL_PARAMETER;
 952                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 953                 goto f_err;
 954                 }
 955
 956         *ok = 1;
 957
 958         /* Note that s->init_num is *not* used as current offset in
 959          * s->init_buf->data, but as a counter summing up fragments'
 960          * lengths: as soon as they sum up to handshake packet
 961          * length, we assume we have got all the fragments. */
 962         s->init_num = frag_len;
 963         return frag_len;
 964
 965 f_err:
 966         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 967         s->init_num = 0;
 968
 969         *ok=0;
 970         return(-1);
 971         }
 972
 973 /*-
 974  * for these 2 messages, we need to
 975  * ssl->enc_read_ctx                    re-init
 976  * ssl->s3->read_sequence               zero
 977  * ssl->s3->read_mac_secret             re-init
 978  * ssl->session->read_sym_enc           assign
 979  * ssl->session->read_compression       assign
 980  * ssl->session->read_hash              assign
 981  */
 982 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 983         {
 984         unsigned char *p;
 985
 986         if (s->state == a)
 987                 {
 988                 p=(unsigned char *)s->init_buf->data;
 989                 *p++=SSL3_MT_CCS;
 990                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 991                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 992
 993                 if (s->version == DTLS1_BAD_VER) {
 994                         s->d1->next_handshake_write_seq++;
 995                         s2n(s->d1->handshake_write_seq,p);
 996                         s->init_num+=2;
 997                 }
 998
 999                 s->init_off=0;
1000
1001                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1002                         s->d1->handshake_write_seq, 0, 0);
1003
1004                 /* buffer the message to handle re-xmits */
1005                 dtls1_buffer_message(s, 1);
1006
1007                 s->state=b;
1008                 }
1009
1010         /* SSL3_ST_CW_CHANGE_B */
1011         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1012         }
1013
1014 int dtls1_read_failed(SSL *s, int code)
1015         {
1016         if ( code > 0)
1017                 {
1018                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1019                 return 1;
1020                 }
1021
1022         if (!dtls1_is_timer_expired(s))
1023                 {
1024                 /* not a timeout, none of our business,
1025                    let higher layers handle this.  in fact it's probably an error */
1026                 return code;
1027                 }
1028
1029 #ifndef OPENSSL_NO_HEARTBEATS
1030         /* done, no need to send a retransmit */
1031         if (!SSL_in_init(s) && !s->tlsext_hb_pending)
1032 #else
1033         /* done, no need to send a retransmit */
1034         if (!SSL_in_init(s))
1035 #endif
1036                 {
1037                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1038                 return code;
1039                 }
1040
1041 #if 0 /* for now, each alert contains only one record number */
1042         item = pqueue_peek(state->rcvd_records);
1043         if ( item )
1044                 {
1045                 /* send an alert immediately for all the missing records */
1046                 }
1047         else
1048 #endif
1049
1050 #if 0  /* no more alert sending, just retransmit the last set of messages */
1051         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1052                 ssl3_send_alert(s,SSL3_AL_WARNING,
1053                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1054 #endif
1055
1056         return dtls1_handle_timeout(s);
1057         }
1058
1059 int
1060 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1061         {
1062         /* The index of the retransmission queue actually is the message sequence number,
1063          * since the queue only contains messages of a single handshake. However, the
1064          * ChangeCipherSpec has no message sequence number and so using only the sequence
1065          * will result in the CCS and Finished having the same index. To prevent this,
1066          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1067          * This does not only differ CSS and Finished, it also maintains the order of the
1068          * index (important for priority queues) and fits in the unsigned short variable.
1069          */
1070         return seq * 2 - is_ccs;
1071         }
1072
1073 int
1074 dtls1_retransmit_buffered_messages(SSL *s)
1075         {
1076         pqueue sent = s->d1->sent_messages;
1077         piterator iter;
1078         pitem *item;
1079         hm_fragment *frag;
1080         int found = 0;
1081
1082         iter = pqueue_iterator(sent);
1083
1084         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1085                 {
1086                 frag = (hm_fragment *)item->data;
1087                         if ( dtls1_retransmit_message(s,
1088                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1089                                 0, &found) <= 0 && found)
1090                         {
1091                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1092                         return -1;
1093                         }
1094                 }
1095
1096         return 1;
1097         }
1098
1099 int
1100 dtls1_buffer_message(SSL *s, int is_ccs)
1101         {
1102         pitem *item;
1103         hm_fragment *frag;
1104         unsigned char seq64be[8];
1105
1106         /* this function is called immediately after a message has
1107          * been serialized */
1108         OPENSSL_assert(s->init_off == 0);
1109
1110         frag = dtls1_hm_fragment_new(s->init_num, 0);
1111         if (!frag)
1112                 return 0;
1113
1114         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1115
1116         if ( is_ccs)
1117                 {
1118                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1119                                DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1120                 }
1121         else
1122                 {
1123                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1124                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1125                 }
1126
1127         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1128         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1129         frag->msg_header.type = s->d1->w_msg_hdr.type;
1130         frag->msg_header.frag_off = 0;
1131         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1132         frag->msg_header.is_ccs = is_ccs;
1133
1134         /* save current state*/
1135         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1136         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1137         frag->msg_header.saved_retransmit_state.compress = s->compress;
1138         frag->msg_header.saved_retransmit_state.session = s->session;
1139         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1140
1141         memset(seq64be,0,sizeof(seq64be));
1142         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1143                                                                                                                   frag->msg_header.is_ccs)>>8);
1144         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1145                                                                                                                   frag->msg_header.is_ccs));
1146
1147         item = pitem_new(seq64be, frag);
1148         if ( item == NULL)
1149                 {
1150                 dtls1_hm_fragment_free(frag);
1151                 return 0;
1152                 }
1153
1154 #if 0
1155         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1156         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1157         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1158 #endif
1159
1160         pqueue_insert(s->d1->sent_messages, item);
1161         return 1;
1162         }
1163
1164 int
1165 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1166         int *found)
1167         {
1168         int ret;
1169         /* XDTLS: for now assuming that read/writes are blocking */
1170         pitem *item;
1171         hm_fragment *frag ;
1172         unsigned long header_length;
1173         unsigned char seq64be[8];
1174         struct dtls1_retransmit_state saved_state;
1175         unsigned char save_write_sequence[8];
1176
1177         /*-
1178           OPENSSL_assert(s->init_num == 0);
1179           OPENSSL_assert(s->init_off == 0);
1180          */
1181
1182         /* XDTLS:  the requested message ought to be found, otherwise error */
1183         memset(seq64be,0,sizeof(seq64be));
1184         seq64be[6] = (unsigned char)(seq>>8);
1185         seq64be[7] = (unsigned char)seq;
1186
1187         item = pqueue_find(s->d1->sent_messages, seq64be);
1188         if ( item == NULL)
1189                 {
1190                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1191                 *found = 0;
1192                 return 0;
1193                 }
1194
1195         *found = 1;
1196         frag = (hm_fragment *)item->data;
1197
1198         if ( frag->msg_header.is_ccs)
1199                 header_length = DTLS1_CCS_HEADER_LENGTH;
1200         else
1201                 header_length = DTLS1_HM_HEADER_LENGTH;
1202
1203         memcpy(s->init_buf->data, frag->fragment,
1204                 frag->msg_header.msg_len + header_length);
1205                 s->init_num = frag->msg_header.msg_len + header_length;
1206
1207         dtls1_set_message_header_int(s, frag->msg_header.type,
1208                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1209                 frag->msg_header.frag_len);
1210
1211         /* save current state */
1212         saved_state.enc_write_ctx = s->enc_write_ctx;
1213         saved_state.write_hash = s->write_hash;
1214         saved_state.compress = s->compress;
1215         saved_state.session = s->session;
1216         saved_state.epoch = s->d1->w_epoch;
1217         saved_state.epoch = s->d1->w_epoch;
1218
1219         s->d1->retransmitting = 1;
1220
1221         /* restore state in which the message was originally sent */
1222         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1223         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1224         s->compress = frag->msg_header.saved_retransmit_state.compress;
1225         s->session = frag->msg_header.saved_retransmit_state.session;
1226         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1227
1228         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1229         {
1230                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1231                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1232         }
1233
1234         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1235                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1236
1237         /* restore current state */
1238         s->enc_write_ctx = saved_state.enc_write_ctx;
1239         s->write_hash = saved_state.write_hash;
1240         s->compress = saved_state.compress;
1241         s->session = saved_state.session;
1242         s->d1->w_epoch = saved_state.epoch;
1243
1244         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1245         {
1246                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1247                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1248         }
1249
1250         s->d1->retransmitting = 0;
1251
1252         (void)BIO_flush(SSL_get_wbio(s));
1253         return ret;
1254         }
1255
1256 /* call this function when the buffered messages are no longer needed */
1257 void
1258 dtls1_clear_record_buffer(SSL *s)
1259         {
1260         pitem *item;
1261
1262         for(item = pqueue_pop(s->d1->sent_messages);
1263                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1264                 {
1265                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1266                 pitem_free(item);
1267                 }
1268         }
1269
1270
1271 unsigned char *
1272 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1273                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1274         {
1275         /* Don't change sequence numbers while listening */
1276         if (frag_off == 0 && !s->d1->listen)
1277                 {
1278                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1279                 s->d1->next_handshake_write_seq++;
1280                 }
1281
1282         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1283                 frag_off, frag_len);
1284
1285         return p += DTLS1_HM_HEADER_LENGTH;
1286         }
1287
1288
1289 /* don't actually do the writing, wait till the MTU has been retrieved */
1290 static void
1291 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1292                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1293                             unsigned long frag_len)
1294         {
1295         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1296
1297         msg_hdr->type = mt;
1298         msg_hdr->msg_len = len;
1299         msg_hdr->seq = seq_num;
1300         msg_hdr->frag_off = frag_off;
1301         msg_hdr->frag_len = frag_len;
1302         }
1303
1304 static void
1305 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1306                         unsigned long frag_len)
1307         {
1308         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1309
1310         msg_hdr->frag_off = frag_off;
1311         msg_hdr->frag_len = frag_len;
1312         }
1313
1314 static unsigned char *
1315 dtls1_write_message_header(SSL *s, unsigned char *p)
1316         {
1317         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1318
1319         *p++ = msg_hdr->type;
1320         l2n3(msg_hdr->msg_len, p);
1321
1322         s2n(msg_hdr->seq, p);
1323         l2n3(msg_hdr->frag_off, p);
1324         l2n3(msg_hdr->frag_len, p);
1325
1326         return p;
1327         }
1328
1329 unsigned int
1330 dtls1_link_min_mtu(void)
1331         {
1332         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1333                 sizeof(g_probable_mtu[0])) - 1]);
1334         }
1335
1336 unsigned int
1337 dtls1_min_mtu(SSL *s)
1338         {
1339         return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1340         }
1341
1342
1343 void
1344 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1345         {
1346         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1347         msg_hdr->type = *(data++);
1348         n2l3(data, msg_hdr->msg_len);
1349
1350         n2s(data, msg_hdr->seq);
1351         n2l3(data, msg_hdr->frag_off);
1352         n2l3(data, msg_hdr->frag_len);
1353         }
1354
1355 void
1356 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1357         {
1358         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1359
1360         ccs_hdr->type = *(data++);
1361         }
1362
1363 int dtls1_shutdown(SSL *s)
1364         {
1365         int ret;
1366 #ifndef OPENSSL_NO_SCTP
1367         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1368             !(s->shutdown & SSL_SENT_SHUTDOWN))
1369                 {
1370                 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1371                 if (ret < 0) return -1;
1372
1373                 if (ret == 0)
1374                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1375                 }
1376 #endif
1377         ret = ssl3_shutdown(s);
1378 #ifndef OPENSSL_NO_SCTP
1379         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1380 #endif
1381         return ret;
1382         }
1383
1384 #ifndef OPENSSL_NO_HEARTBEATS
1385 int
1386 dtls1_process_heartbeat(SSL *s)
1387         {
1388         unsigned char *p = &s->s3->rrec.data[0], *pl;
1389         unsigned short hbtype;
1390         unsigned int payload;
1391         unsigned int padding = 16; /* Use minimum padding */
1392
1393         if (s->msg_callback)
1394                 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1395                         &s->s3->rrec.data[0], s->s3->rrec.length,
1396                         s, s->msg_callback_arg);
1397
1398         /* Read type and payload length first */
1399         if (1 + 2 + 16 > s->s3->rrec.length)
1400                 return 0; /* silently discard */
1401         if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
1402                 return 0; /* silently discard per RFC 6520 sec. 4 */
1403
1404         hbtype = *p++;
1405         n2s(p, payload);
1406         if (1 + 2 + payload + 16 > s->s3->rrec.length)
1407                 return 0; /* silently discard per RFC 6520 sec. 4 */
1408         pl = p;
1409
1410         if (hbtype == TLS1_HB_REQUEST)
1411                 {
1412                 unsigned char *buffer, *bp;
1413                 unsigned int write_length = 1 /* heartbeat type */ +
1414                                             2 /* heartbeat length */ +
1415                                             payload + padding;
1416                 int r;
1417
1418                 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1419                         return 0;
1420
1421                 /* Allocate memory for the response, size is 1 byte
1422                  * message type, plus 2 bytes payload length, plus
1423                  * payload, plus padding
1424                  */
1425                 buffer = OPENSSL_malloc(write_length);
1426                 if (buffer == NULL)
1427                         return -1;
1428                 bp = buffer;
1429
1430                 /* Enter response type, length and copy payload */
1431                 *bp++ = TLS1_HB_RESPONSE;
1432                 s2n(payload, bp);
1433                 memcpy(bp, pl, payload);
1434                 bp += payload;
1435                 /* Random padding */
1436                 RAND_pseudo_bytes(bp, padding);
1437
1438                 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1439
1440                 if (r >= 0 && s->msg_callback)
1441                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1442                                 buffer, write_length,
1443                                 s, s->msg_callback_arg);
1444
1445                 OPENSSL_free(buffer);
1446
1447                 if (r < 0)
1448                         return r;
1449                 }
1450         else if (hbtype == TLS1_HB_RESPONSE)
1451                 {
1452                 unsigned int seq;
1453
1454                 /* We only send sequence numbers (2 bytes unsigned int),
1455                  * and 16 random bytes, so we just try to read the
1456                  * sequence number */
1457                 n2s(pl, seq);
1458
1459                 if (payload == 18 && seq == s->tlsext_hb_seq)
1460                         {
1461                         dtls1_stop_timer(s);
1462                         s->tlsext_hb_seq++;
1463                         s->tlsext_hb_pending = 0;
1464                         }
1465                 }
1466
1467         return 0;
1468         }
1469
1470 int
1471 dtls1_heartbeat(SSL *s)
1472         {
1473         unsigned char *buf, *p;
1474         int ret;
1475         unsigned int payload = 18; /* Sequence number + random bytes */
1476         unsigned int padding = 16; /* Use minimum padding */
1477
1478         /* Only send if peer supports and accepts HB requests... */
1479         if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1480             s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1481                 {
1482                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1483                 return -1;
1484                 }
1485
1486         /* ...and there is none in flight yet... */
1487         if (s->tlsext_hb_pending)
1488                 {
1489                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1490                 return -1;
1491                 }
1492
1493         /* ...and no handshake in progress. */
1494         if (SSL_in_init(s) || s->in_handshake)
1495                 {
1496                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1497                 return -1;
1498                 }
1499
1500         /* Check if padding is too long, payload and padding
1501          * must not exceed 2^14 - 3 = 16381 bytes in total.
1502          */
1503         OPENSSL_assert(payload + padding <= 16381);
1504
1505         /*-
1506          * Create HeartBeat message, we just use a sequence number
1507          * as payload to distuingish different messages and add
1508          * some random stuff.
1509          *  - Message Type, 1 byte
1510          *  - Payload Length, 2 bytes (unsigned int)
1511          *  - Payload, the sequence number (2 bytes uint)
1512          *  - Payload, random bytes (16 bytes uint)
1513          *  - Padding
1514          */
1515         buf = OPENSSL_malloc(1 + 2 + payload + padding);
1516         if (buf == NULL)
1517                 {
1518                 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_MALLOC_FAILURE);
1519                 return -1;
1520                 }
1521         p = buf;
1522         /* Message Type */
1523         *p++ = TLS1_HB_REQUEST;
1524         /* Payload length (18 bytes here) */
1525         s2n(payload, p);
1526         /* Sequence number */
1527         s2n(s->tlsext_hb_seq, p);
1528         /* 16 random bytes */
1529         RAND_pseudo_bytes(p, 16);
1530         p += 16;
1531         /* Random padding */
1532         RAND_pseudo_bytes(p, padding);
1533
1534         ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1535         if (ret >= 0)
1536                 {
1537                 if (s->msg_callback)
1538                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1539                                 buf, 3 + payload + padding,
1540                                 s, s->msg_callback_arg);
1541
1542                 dtls1_start_timer(s);
1543                 s->tlsext_hb_pending = 1;
1544                 }
1545
1546         OPENSSL_free(buf);
1547
1548         return ret;
1549         }
1550 #endif