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         int curr_mtu;
 263         int retry = 1;
 264         unsigned int len, frag_off, mac_size, blocksize;
 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         while( s->init_num)
 293                 {
 294                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 295                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 296
 297                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 298                         {
 299                         /* grr.. we could get an error if MTU picked was wrong */
 300                         ret = BIO_flush(SSL_get_wbio(s));
 301                         if ( ret <= 0)
 302                                 return ret;
 303                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 304                                 mac_size - blocksize;
 305                         }
 306
 307                 if ( s->init_num > curr_mtu)
 308                         len = curr_mtu;
 309                 else
 310                         len = s->init_num;
 311
 312
 313                 /* XDTLS: this function is too long.  split out the CCS part */
 314                 if ( type == SSL3_RT_HANDSHAKE)
 315                         {
 316                         if ( s->init_off != 0)
 317                                 {
 318                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 319                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 320                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 321
 322                                 if ( s->init_num > curr_mtu)
 323                                         len = curr_mtu;
 324                                 else
 325                                         len = s->init_num;
 326                                 }
 327
 328                         if ( len < DTLS1_HM_HEADER_LENGTH )
 329                                 {
 330                                 /*
 331                                  * len is so small that we really can't do anything sensible
 332                                  * so fail
 333                                  */
 334                                 return -1;
 335                                 }
 336                         dtls1_fix_message_header(s, frag_off,
 337                                 len - DTLS1_HM_HEADER_LENGTH);
 338
 339                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 340                         }
 341
 342                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 343                         len);
 344                 if (ret < 0)
 345                         {
 346                         /* might need to update MTU here, but we don't know
 347                          * which previous packet caused the failure -- so can't
 348                          * really retransmit anything.  continue as if everything
 349                          * is fine and wait for an alert to handle the
 350                          * retransmit
 351                          */
 352                         if ( retry && BIO_ctrl(SSL_get_wbio(s),
 353                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 354                                 {
 355                                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 356                                         {
 357                                         if(!dtls1_query_mtu(s))
 358                                                 return -1;
 359                                         /* Have one more go */
 360                                         retry = 0;
 361                                         }
 362                                 else
 363                                         return -1;
 364                                 }
 365                         else
 366                                 {
 367                                 return(-1);
 368                                 }
 369                         }
 370                 else
 371                         {
 372
 373                         /* bad if this assert fails, only part of the handshake
 374                          * message got sent.  but why would this happen? */
 375                         OPENSSL_assert(len == (unsigned int)ret);
 376
 377                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 378                                 {
 379                                 /* should not be done for 'Hello Request's, but in that case
 380                                  * we'll ignore the result anyway */
 381                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 382                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 383                                 int xlen;
 384
 385                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
 386                                         {
 387                                         /* reconstruct message header is if it
 388                                          * is being sent in single fragment */
 389                                         *p++ = msg_hdr->type;
 390                                         l2n3(msg_hdr->msg_len,p);
 391                                         s2n (msg_hdr->seq,p);
 392                                         l2n3(0,p);
 393                                         l2n3(msg_hdr->msg_len,p);
 394                                         p  -= DTLS1_HM_HEADER_LENGTH;
 395                                         xlen = ret;
 396                                         }
 397                                 else
 398                                         {
 399                                         p  += DTLS1_HM_HEADER_LENGTH;
 400                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 401                                         }
 402
 403                                 ssl3_finish_mac(s, p, xlen);
 404                                 }
 405
 406                         if (ret == s->init_num)
 407                                 {
 408                                 if (s->msg_callback)
 409                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 410                                                 (size_t)(s->init_off + s->init_num), s,
 411                                                 s->msg_callback_arg);
 412
 413                                 s->init_off = 0;  /* done writing this message */
 414                                 s->init_num = 0;
 415
 416                                 return(1);
 417                                 }
 418                         s->init_off+=ret;
 419                         s->init_num-=ret;
 420                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 421                         }
 422                 }
 423         return(0);
 424         }
 425
 426
 427 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 428  * maximum acceptable body length 'max'.
 429  * Read an entire handshake message.  Handshake messages arrive in
 430  * fragments.
 431  */
 432 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 433         {
 434         int i, al;
 435         struct hm_header_st *msg_hdr;
 436         unsigned char *p;
 437         unsigned long msg_len;
 438
 439         /* s3->tmp is used to store messages that are unexpected, caused
 440          * by the absence of an optional handshake message */
 441         if (s->s3->tmp.reuse_message)
 442                 {
 443                 s->s3->tmp.reuse_message=0;
 444                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 445                         {
 446                         al=SSL_AD_UNEXPECTED_MESSAGE;
 447                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 448                         goto f_err;
 449                         }
 450                 *ok=1;
 451                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 452                 s->init_num = (int)s->s3->tmp.message_size;
 453                 return s->init_num;
 454                 }
 455
 456         msg_hdr = &s->d1->r_msg_hdr;
 457         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 458
 459 again:
 460         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 461         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 462                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 463                 goto again;
 464         else if ( i <= 0 && !*ok)
 465                 return i;
 466
 467         p = (unsigned char *)s->init_buf->data;
 468         msg_len = msg_hdr->msg_len;
 469
 470         /* reconstruct message header */
 471         *(p++) = msg_hdr->type;
 472         l2n3(msg_len,p);
 473         s2n (msg_hdr->seq,p);
 474         l2n3(0,p);
 475         l2n3(msg_len,p);
 476         if (s->version != DTLS1_BAD_VER) {
 477                 p       -= DTLS1_HM_HEADER_LENGTH;
 478                 msg_len += DTLS1_HM_HEADER_LENGTH;
 479         }
 480
 481         ssl3_finish_mac(s, p, msg_len);
 482         if (s->msg_callback)
 483                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 484                         p, msg_len,
 485                         s, s->msg_callback_arg);
 486
 487         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 488
 489         /* Don't change sequence numbers while listening */
 490         if (!s->d1->listen)
 491                 s->d1->handshake_read_seq++;
 492
 493         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 494         return s->init_num;
 495
 496 f_err:
 497         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 498         *ok = 0;
 499         return -1;
 500         }
 501
 502
 503 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 504         {
 505         size_t frag_off,frag_len,msg_len;
 506
 507         msg_len  = msg_hdr->msg_len;
 508         frag_off = msg_hdr->frag_off;
 509         frag_len = msg_hdr->frag_len;
 510
 511         /* sanity checking */
 512         if ( (frag_off+frag_len) > msg_len)
 513                 {
 514                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 515                 return SSL_AD_ILLEGAL_PARAMETER;
 516                 }
 517
 518         if ( (frag_off+frag_len) > (unsigned long)max)
 519                 {
 520                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 521                 return SSL_AD_ILLEGAL_PARAMETER;
 522                 }
 523
 524         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 525                 {
 526                 /* msg_len is limited to 2^24, but is effectively checked
 527                  * against max above */
 528                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
 529                         {
 530                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 531                         return SSL_AD_INTERNAL_ERROR;
 532                         }
 533
 534                 s->s3->tmp.message_size  = msg_len;
 535                 s->d1->r_msg_hdr.msg_len = msg_len;
 536                 s->s3->tmp.message_type  = msg_hdr->type;
 537                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 538                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 539                 }
 540         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 541                 {
 542                 /* They must be playing with us! BTW, failure to enforce
 543                  * upper limit would open possibility for buffer overrun. */
 544                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 545                 return SSL_AD_ILLEGAL_PARAMETER;
 546                 }
 547
 548         return 0; /* no error */
 549         }
 550
 551
 552 static int
 553 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 554         {
 555         /* (0) check whether the desired fragment is available
 556          * if so:
 557          * (1) copy over the fragment to s->init_buf->data[]
 558          * (2) update s->init_num
 559          */
 560         pitem *item;
 561         hm_fragment *frag;
 562         int al;
 563
 564         *ok = 0;
 565         item = pqueue_peek(s->d1->buffered_messages);
 566         if ( item == NULL)
 567                 return 0;
 568
 569         frag = (hm_fragment *)item->data;
 570
 571         /* Don't return if reassembly still in progress */
 572         if (frag->reassembly != NULL)
 573                 return 0;
 574
 575         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 576                 {
 577                 unsigned long frag_len = frag->msg_header.frag_len;
 578                 pqueue_pop(s->d1->buffered_messages);
 579
 580                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 581
 582                 if (al==0) /* no alert */
 583                         {
 584                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 585                         memcpy(&p[frag->msg_header.frag_off],
 586                                 frag->fragment,frag->msg_header.frag_len);
 587                         }
 588
 589                 dtls1_hm_fragment_free(frag);
 590                 pitem_free(item);
 591
 592                 if (al==0)
 593                         {
 594                         *ok = 1;
 595                         return frag_len;
 596                         }
 597
 598                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 599                 s->init_num = 0;
 600                 *ok = 0;
 601                 return -1;
 602                 }
 603         else
 604                 return 0;
 605         }
 606
 607 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 608  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 609  * be greater if the maximum certificate list size requires it. */
 610 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 611         {
 612         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 613         if (max_len < (unsigned long)s->max_cert_list)
 614                 return s->max_cert_list;
 615         return max_len;
 616         }
 617
 618 static int
 619 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 620         {
 621         hm_fragment *frag = NULL;
 622         pitem *item = NULL;
 623         int i = -1, is_complete;
 624         unsigned char seq64be[8];
 625         unsigned long frag_len = msg_hdr->frag_len;
 626
 627         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 628             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 629                 goto err;
 630
 631         if (frag_len == 0)
 632                 return DTLS1_HM_FRAGMENT_RETRY;
 633
 634         /* Try to find item in queue */
 635         memset(seq64be,0,sizeof(seq64be));
 636         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 637         seq64be[7] = (unsigned char) msg_hdr->seq;
 638         item = pqueue_find(s->d1->buffered_messages, seq64be);
 639
 640         if (item == NULL)
 641                 {
 642                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 643                 if ( frag == NULL)
 644                         goto err;
 645                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 646                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 647                 frag->msg_header.frag_off = 0;
 648                 }
 649         else
 650                 {
 651                 frag = (hm_fragment*) item->data;
 652                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 653                         {
 654                         item = NULL;
 655                         frag = NULL;
 656                         goto err;
 657                         }
 658                 }
 659
 660
 661         /* If message is already reassembled, this must be a
 662          * retransmit and can be dropped. In this case item != NULL and so frag
 663          * does not need to be freed.
 664          */
 665         if (frag->reassembly == NULL)
 666                 {
 667                 unsigned char devnull [256];
 668
 669                 while (frag_len)
 670                         {
 671                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 672                                 devnull,
 673                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 674                         if (i<=0) goto err;
 675                         frag_len -= i;
 676                         }
 677                 return DTLS1_HM_FRAGMENT_RETRY;
 678                 }
 679
 680         /* read the body of the fragment (header has already been read */
 681         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 682                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 683         if ((unsigned long)i!=frag_len)
 684                 i=-1;
 685         if (i<=0)
 686                 goto err;
 687
 688         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 689                             (long)(msg_hdr->frag_off + frag_len));
 690
 691         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 692                                    is_complete);
 693
 694         if (is_complete)
 695                 {
 696                 OPENSSL_free(frag->reassembly);
 697                 frag->reassembly = NULL;
 698                 }
 699
 700         if (item == NULL)
 701                 {
 702                 item = pitem_new(seq64be, frag);
 703                 if (item == NULL)
 704                         {
 705                         i = -1;
 706                         goto err;
 707                         }
 708
 709                 item = pqueue_insert(s->d1->buffered_messages, item);
 710                 /* pqueue_insert fails iff a duplicate item is inserted.
 711                  * However, |item| cannot be a duplicate. If it were,
 712                  * |pqueue_find|, above, would have returned it and control
 713                  * would never have reached this branch. */
 714                 OPENSSL_assert(item != NULL);
 715                 }
 716
 717         return DTLS1_HM_FRAGMENT_RETRY;
 718
 719 err:
 720         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 721         *ok = 0;
 722         return i;
 723         }
 724
 725
 726 static int
 727 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 728 {
 729         int i=-1;
 730         hm_fragment *frag = NULL;
 731         pitem *item = NULL;
 732         unsigned char seq64be[8];
 733         unsigned long frag_len = msg_hdr->frag_len;
 734
 735         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 736                 goto err;
 737
 738         /* Try to find item in queue, to prevent duplicate entries */
 739         memset(seq64be,0,sizeof(seq64be));
 740         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 741         seq64be[7] = (unsigned char) msg_hdr->seq;
 742         item = pqueue_find(s->d1->buffered_messages, seq64be);
 743
 744         /* If we already have an entry and this one is a fragment,
 745          * don't discard it and rather try to reassemble it.
 746          */
 747         if (item != NULL && frag_len != msg_hdr->msg_len)
 748                 item = NULL;
 749
 750         /* Discard the message if sequence number was already there, is
 751          * too far in the future, already in the queue or if we received
 752          * a FINISHED before the SERVER_HELLO, which then must be a stale
 753          * retransmit.
 754          */
 755         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 756                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 757                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 758                 {
 759                 unsigned char devnull [256];
 760
 761                 while (frag_len)
 762                         {
 763                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 764                                 devnull,
 765                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 766                         if (i<=0) goto err;
 767                         frag_len -= i;
 768                         }
 769                 }
 770         else
 771                 {
 772                 if (frag_len != msg_hdr->msg_len)
 773                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 774
 775                 if (frag_len > dtls1_max_handshake_message_len(s))
 776                         goto err;
 777
 778                 frag = dtls1_hm_fragment_new(frag_len, 0);
 779                 if ( frag == NULL)
 780                         goto err;
 781
 782                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 783
 784                 if (frag_len)
 785                         {
 786                         /* read the body of the fragment (header has already been read */
 787                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 788                                 frag->fragment,frag_len,0);
 789                         if ((unsigned long)i!=frag_len)
 790                                 i = -1;
 791                         if (i<=0)
 792                                 goto err;
 793                         }
 794
 795                 item = pitem_new(seq64be, frag);
 796                 if ( item == NULL)
 797                         goto err;
 798
 799                 item = pqueue_insert(s->d1->buffered_messages, item);
 800                 /* pqueue_insert fails iff a duplicate item is inserted.
 801                  * However, |item| cannot be a duplicate. If it were,
 802                  * |pqueue_find|, above, would have returned it. Then, either
 803                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 804                  * to NULL and it will have been processed with
 805                  * |dtls1_reassemble_fragment|, above, or the record will have
 806                  * been discarded. */
 807                 OPENSSL_assert(item != NULL);
 808                 }
 809
 810         return DTLS1_HM_FRAGMENT_RETRY;
 811
 812 err:
 813         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 814         *ok = 0;
 815         return i;
 816         }
 817
 818
 819 static long
 820 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 821         {
 822         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 823         unsigned long len, frag_off, frag_len;
 824         int i,al;
 825         struct hm_header_st msg_hdr;
 826
 827         redo:
 828         /* see if we have the required fragment already */
 829         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 830                 {
 831                 if (*ok)        s->init_num = frag_len;
 832                 return frag_len;
 833                 }
 834
 835         /* read handshake message header */
 836         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 837                 DTLS1_HM_HEADER_LENGTH, 0);
 838         if (i <= 0)     /* nbio, or an error */
 839                 {
 840                 s->rwstate=SSL_READING;
 841                 *ok = 0;
 842                 return i;
 843                 }
 844         /* Handshake fails if message header is incomplete */
 845         if (i != DTLS1_HM_HEADER_LENGTH)
 846                 {
 847                 al=SSL_AD_UNEXPECTED_MESSAGE;
 848                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 849                 goto f_err;
 850                 }
 851
 852         /* parse the message fragment header */
 853         dtls1_get_message_header(wire, &msg_hdr);
 854
 855         /*
 856          * if this is a future (or stale) message it gets buffered
 857          * (or dropped)--no further processing at this time
 858          * While listening, we accept seq 1 (ClientHello with cookie)
 859          * although we're still expecting seq 0 (ClientHello)
 860          */
 861         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 862                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 863
 864         len = msg_hdr.msg_len;
 865         frag_off = msg_hdr.frag_off;
 866         frag_len = msg_hdr.frag_len;
 867
 868         if (frag_len && frag_len < len)
 869                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 870
 871         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 872                 wire[0] == SSL3_MT_HELLO_REQUEST)
 873                 {
 874                 /* The server may always send 'Hello Request' messages --
 875                  * we are doing a handshake anyway now, so ignore them
 876                  * if their format is correct. Does not count for
 877                  * 'Finished' MAC. */
 878                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 879                         {
 880                         if (s->msg_callback)
 881                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 882                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 883                                         s->msg_callback_arg);
 884
 885                         s->init_num = 0;
 886                         goto redo;
 887                         }
 888                 else /* Incorrectly formated Hello request */
 889                         {
 890                         al=SSL_AD_UNEXPECTED_MESSAGE;
 891                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 892                         goto f_err;
 893                         }
 894                 }
 895
 896         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 897                 goto f_err;
 898
 899         /* XDTLS:  ressurect this when restart is in place */
 900         s->state=stn;
 901
 902         if ( frag_len > 0)
 903                 {
 904                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 905
 906                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 907                         &p[frag_off],frag_len,0);
 908                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 909                 if (i <= 0)
 910                         {
 911                         s->rwstate=SSL_READING;
 912                         *ok = 0;
 913                         return i;
 914                         }
 915                 }
 916         else
 917                 i = 0;
 918
 919         /* XDTLS:  an incorrectly formatted fragment should cause the
 920          * handshake to fail */
 921         if (i != (int)frag_len)
 922                 {
 923                 al=SSL3_AD_ILLEGAL_PARAMETER;
 924                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 925                 goto f_err;
 926                 }
 927
 928         *ok = 1;
 929
 930         /* Note that s->init_num is *not* used as current offset in
 931          * s->init_buf->data, but as a counter summing up fragments'
 932          * lengths: as soon as they sum up to handshake packet
 933          * length, we assume we have got all the fragments. */
 934         s->init_num = frag_len;
 935         return frag_len;
 936
 937 f_err:
 938         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 939         s->init_num = 0;
 940
 941         *ok=0;
 942         return(-1);
 943         }
 944
 945 /* for these 2 messages, we need to
 946  * ssl->enc_read_ctx                    re-init
 947  * ssl->s3->read_sequence               zero
 948  * ssl->s3->read_mac_secret             re-init
 949  * ssl->session->read_sym_enc           assign
 950  * ssl->session->read_compression       assign
 951  * ssl->session->read_hash              assign
 952  */
 953 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 954         {
 955         unsigned char *p;
 956
 957         if (s->state == a)
 958                 {
 959                 p=(unsigned char *)s->init_buf->data;
 960                 *p++=SSL3_MT_CCS;
 961                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 962                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 963
 964                 if (s->version == DTLS1_BAD_VER) {
 965                         s->d1->next_handshake_write_seq++;
 966                         s2n(s->d1->handshake_write_seq,p);
 967                         s->init_num+=2;
 968                 }
 969
 970                 s->init_off=0;
 971
 972                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 973                         s->d1->handshake_write_seq, 0, 0);
 974
 975                 /* buffer the message to handle re-xmits */
 976                 dtls1_buffer_message(s, 1);
 977
 978                 s->state=b;
 979                 }
 980
 981         /* SSL3_ST_CW_CHANGE_B */
 982         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 983         }
 984
 985 int dtls1_read_failed(SSL *s, int code)
 986         {
 987         if ( code > 0)
 988                 {
 989                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
 990                 return 1;
 991                 }
 992
 993         if (!dtls1_is_timer_expired(s))
 994                 {
 995                 /* not a timeout, none of our business,
 996                    let higher layers handle this.  in fact it's probably an error */
 997                 return code;
 998                 }
 999
1000 #ifndef OPENSSL_NO_HEARTBEATS
1001         if (!SSL_in_init(s) && !s->tlsext_hb_pending)  /* done, no need to send a retransmit */
1002 #else
1003         if (!SSL_in_init(s))  /* done, no need to send a retransmit */
1004 #endif
1005                 {
1006                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1007                 return code;
1008                 }
1009
1010 #if 0 /* for now, each alert contains only one record number */
1011         item = pqueue_peek(state->rcvd_records);
1012         if ( item )
1013                 {
1014                 /* send an alert immediately for all the missing records */
1015                 }
1016         else
1017 #endif
1018
1019 #if 0  /* no more alert sending, just retransmit the last set of messages */
1020         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1021                 ssl3_send_alert(s,SSL3_AL_WARNING,
1022                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1023 #endif
1024
1025         return dtls1_handle_timeout(s);
1026         }
1027
1028 int
1029 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1030         {
1031         /* The index of the retransmission queue actually is the message sequence number,
1032          * since the queue only contains messages of a single handshake. However, the
1033          * ChangeCipherSpec has no message sequence number and so using only the sequence
1034          * will result in the CCS and Finished having the same index. To prevent this,
1035          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1036          * This does not only differ CSS and Finished, it also maintains the order of the
1037          * index (important for priority queues) and fits in the unsigned short variable.
1038          */
1039         return seq * 2 - is_ccs;
1040         }
1041
1042 int
1043 dtls1_retransmit_buffered_messages(SSL *s)
1044         {
1045         pqueue sent = s->d1->sent_messages;
1046         piterator iter;
1047         pitem *item;
1048         hm_fragment *frag;
1049         int found = 0;
1050
1051         iter = pqueue_iterator(sent);
1052
1053         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1054                 {
1055                 frag = (hm_fragment *)item->data;
1056                         if ( dtls1_retransmit_message(s,
1057                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1058                                 0, &found) <= 0 && found)
1059                         {
1060                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1061                         return -1;
1062                         }
1063                 }
1064
1065         return 1;
1066         }
1067
1068 int
1069 dtls1_buffer_message(SSL *s, int is_ccs)
1070         {
1071         pitem *item;
1072         hm_fragment *frag;
1073         unsigned char seq64be[8];
1074
1075         /* this function is called immediately after a message has
1076          * been serialized */
1077         OPENSSL_assert(s->init_off == 0);
1078
1079         frag = dtls1_hm_fragment_new(s->init_num, 0);
1080         if (!frag)
1081                 return 0;
1082
1083         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1084
1085         if ( is_ccs)
1086                 {
1087                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1088                                DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1089                 }
1090         else
1091                 {
1092                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1093                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1094                 }
1095
1096         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1097         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1098         frag->msg_header.type = s->d1->w_msg_hdr.type;
1099         frag->msg_header.frag_off = 0;
1100         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1101         frag->msg_header.is_ccs = is_ccs;
1102
1103         /* save current state*/
1104         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1105         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1106         frag->msg_header.saved_retransmit_state.compress = s->compress;
1107         frag->msg_header.saved_retransmit_state.session = s->session;
1108         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1109
1110         memset(seq64be,0,sizeof(seq64be));
1111         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1112                                                                                                                   frag->msg_header.is_ccs)>>8);
1113         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1114                                                                                                                   frag->msg_header.is_ccs));
1115
1116         item = pitem_new(seq64be, frag);
1117         if ( item == NULL)
1118                 {
1119                 dtls1_hm_fragment_free(frag);
1120                 return 0;
1121                 }
1122
1123 #if 0
1124         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1125         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1126         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1127 #endif
1128
1129         pqueue_insert(s->d1->sent_messages, item);
1130         return 1;
1131         }
1132
1133 int
1134 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1135         int *found)
1136         {
1137         int ret;
1138         /* XDTLS: for now assuming that read/writes are blocking */
1139         pitem *item;
1140         hm_fragment *frag ;
1141         unsigned long header_length;
1142         unsigned char seq64be[8];
1143         struct dtls1_retransmit_state saved_state;
1144         unsigned char save_write_sequence[8];
1145
1146         /*
1147           OPENSSL_assert(s->init_num == 0);
1148           OPENSSL_assert(s->init_off == 0);
1149          */
1150
1151         /* XDTLS:  the requested message ought to be found, otherwise error */
1152         memset(seq64be,0,sizeof(seq64be));
1153         seq64be[6] = (unsigned char)(seq>>8);
1154         seq64be[7] = (unsigned char)seq;
1155
1156         item = pqueue_find(s->d1->sent_messages, seq64be);
1157         if ( item == NULL)
1158                 {
1159                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1160                 *found = 0;
1161                 return 0;
1162                 }
1163
1164         *found = 1;
1165         frag = (hm_fragment *)item->data;
1166
1167         if ( frag->msg_header.is_ccs)
1168                 header_length = DTLS1_CCS_HEADER_LENGTH;
1169         else
1170                 header_length = DTLS1_HM_HEADER_LENGTH;
1171
1172         memcpy(s->init_buf->data, frag->fragment,
1173                 frag->msg_header.msg_len + header_length);
1174                 s->init_num = frag->msg_header.msg_len + header_length;
1175
1176         dtls1_set_message_header_int(s, frag->msg_header.type,
1177                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1178                 frag->msg_header.frag_len);
1179
1180         /* save current state */
1181         saved_state.enc_write_ctx = s->enc_write_ctx;
1182         saved_state.write_hash = s->write_hash;
1183         saved_state.compress = s->compress;
1184         saved_state.session = s->session;
1185         saved_state.epoch = s->d1->w_epoch;
1186         saved_state.epoch = s->d1->w_epoch;
1187
1188         s->d1->retransmitting = 1;
1189
1190         /* restore state in which the message was originally sent */
1191         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1192         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1193         s->compress = frag->msg_header.saved_retransmit_state.compress;
1194         s->session = frag->msg_header.saved_retransmit_state.session;
1195         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1196
1197         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1198         {
1199                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1200                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1201         }
1202
1203         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1204                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1205
1206         /* restore current state */
1207         s->enc_write_ctx = saved_state.enc_write_ctx;
1208         s->write_hash = saved_state.write_hash;
1209         s->compress = saved_state.compress;
1210         s->session = saved_state.session;
1211         s->d1->w_epoch = saved_state.epoch;
1212
1213         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1214         {
1215                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1216                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1217         }
1218
1219         s->d1->retransmitting = 0;
1220
1221         (void)BIO_flush(SSL_get_wbio(s));
1222         return ret;
1223         }
1224
1225 /* call this function when the buffered messages are no longer needed */
1226 void
1227 dtls1_clear_record_buffer(SSL *s)
1228         {
1229         pitem *item;
1230
1231         for(item = pqueue_pop(s->d1->sent_messages);
1232                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1233                 {
1234                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1235                 pitem_free(item);
1236                 }
1237         }
1238
1239
1240 unsigned char *
1241 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1242                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1243         {
1244         /* Don't change sequence numbers while listening */
1245         if (frag_off == 0 && !s->d1->listen)
1246                 {
1247                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1248                 s->d1->next_handshake_write_seq++;
1249                 }
1250
1251         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1252                 frag_off, frag_len);
1253
1254         return p += DTLS1_HM_HEADER_LENGTH;
1255         }
1256
1257
1258 /* don't actually do the writing, wait till the MTU has been retrieved */
1259 static void
1260 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1261                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1262                             unsigned long frag_len)
1263         {
1264         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1265
1266         msg_hdr->type = mt;
1267         msg_hdr->msg_len = len;
1268         msg_hdr->seq = seq_num;
1269         msg_hdr->frag_off = frag_off;
1270         msg_hdr->frag_len = frag_len;
1271         }
1272
1273 static void
1274 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1275                         unsigned long frag_len)
1276         {
1277         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1278
1279         msg_hdr->frag_off = frag_off;
1280         msg_hdr->frag_len = frag_len;
1281         }
1282
1283 static unsigned char *
1284 dtls1_write_message_header(SSL *s, unsigned char *p)
1285         {
1286         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1287
1288         *p++ = msg_hdr->type;
1289         l2n3(msg_hdr->msg_len, p);
1290
1291         s2n(msg_hdr->seq, p);
1292         l2n3(msg_hdr->frag_off, p);
1293         l2n3(msg_hdr->frag_len, p);
1294
1295         return p;
1296         }
1297
1298 unsigned int
1299 dtls1_link_min_mtu(void)
1300         {
1301         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1302                 sizeof(g_probable_mtu[0])) - 1]);
1303         }
1304
1305 unsigned int
1306 dtls1_min_mtu(SSL *s)
1307         {
1308         return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1309         }
1310
1311
1312 void
1313 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1314         {
1315         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1316         msg_hdr->type = *(data++);
1317         n2l3(data, msg_hdr->msg_len);
1318
1319         n2s(data, msg_hdr->seq);
1320         n2l3(data, msg_hdr->frag_off);
1321         n2l3(data, msg_hdr->frag_len);
1322         }
1323
1324 void
1325 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1326         {
1327         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1328
1329         ccs_hdr->type = *(data++);
1330         }
1331
1332 int dtls1_shutdown(SSL *s)
1333         {
1334         int ret;
1335 #ifndef OPENSSL_NO_SCTP
1336         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1337             !(s->shutdown & SSL_SENT_SHUTDOWN))
1338                 {
1339                 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1340                 if (ret < 0) return -1;
1341
1342                 if (ret == 0)
1343                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1344                 }
1345 #endif
1346         ret = ssl3_shutdown(s);
1347 #ifndef OPENSSL_NO_SCTP
1348         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1349 #endif
1350         return ret;
1351         }
1352
1353 #ifndef OPENSSL_NO_HEARTBEATS
1354 int
1355 dtls1_process_heartbeat(SSL *s)
1356         {
1357         unsigned char *p = &s->s3->rrec.data[0], *pl;
1358         unsigned short hbtype;
1359         unsigned int payload;
1360         unsigned int padding = 16; /* Use minimum padding */
1361
1362         if (s->msg_callback)
1363                 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1364                         &s->s3->rrec.data[0], s->s3->rrec.length,
1365                         s, s->msg_callback_arg);
1366
1367         /* Read type and payload length first */
1368         if (1 + 2 + 16 > s->s3->rrec.length)
1369                 return 0; /* silently discard */
1370         if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
1371                 return 0; /* silently discard per RFC 6520 sec. 4 */
1372
1373         hbtype = *p++;
1374         n2s(p, payload);
1375         if (1 + 2 + payload + 16 > s->s3->rrec.length)
1376                 return 0; /* silently discard per RFC 6520 sec. 4 */
1377         pl = p;
1378
1379         if (hbtype == TLS1_HB_REQUEST)
1380                 {
1381                 unsigned char *buffer, *bp;
1382                 unsigned int write_length = 1 /* heartbeat type */ +
1383                                             2 /* heartbeat length */ +
1384                                             payload + padding;
1385                 int r;
1386
1387                 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1388                         return 0;
1389
1390                 /* Allocate memory for the response, size is 1 byte
1391                  * message type, plus 2 bytes payload length, plus
1392                  * payload, plus padding
1393                  */
1394                 buffer = OPENSSL_malloc(write_length);
1395                 bp = buffer;
1396
1397                 /* Enter response type, length and copy payload */
1398                 *bp++ = TLS1_HB_RESPONSE;
1399                 s2n(payload, bp);
1400                 memcpy(bp, pl, payload);
1401                 bp += payload;
1402                 /* Random padding */
1403                 RAND_pseudo_bytes(bp, padding);
1404
1405                 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1406
1407                 if (r >= 0 && s->msg_callback)
1408                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1409                                 buffer, write_length,
1410                                 s, s->msg_callback_arg);
1411
1412                 OPENSSL_free(buffer);
1413
1414                 if (r < 0)
1415                         return r;
1416                 }
1417         else if (hbtype == TLS1_HB_RESPONSE)
1418                 {
1419                 unsigned int seq;
1420
1421                 /* We only send sequence numbers (2 bytes unsigned int),
1422                  * and 16 random bytes, so we just try to read the
1423                  * sequence number */
1424                 n2s(pl, seq);
1425
1426                 if (payload == 18 && seq == s->tlsext_hb_seq)
1427                         {
1428                         dtls1_stop_timer(s);
1429                         s->tlsext_hb_seq++;
1430                         s->tlsext_hb_pending = 0;
1431                         }
1432                 }
1433
1434         return 0;
1435         }
1436
1437 int
1438 dtls1_heartbeat(SSL *s)
1439         {
1440         unsigned char *buf, *p;
1441         int ret;
1442         unsigned int payload = 18; /* Sequence number + random bytes */
1443         unsigned int padding = 16; /* Use minimum padding */
1444
1445         /* Only send if peer supports and accepts HB requests... */
1446         if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1447             s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1448                 {
1449                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1450                 return -1;
1451                 }
1452
1453         /* ...and there is none in flight yet... */
1454         if (s->tlsext_hb_pending)
1455                 {
1456                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1457                 return -1;
1458                 }
1459
1460         /* ...and no handshake in progress. */
1461         if (SSL_in_init(s) || s->in_handshake)
1462                 {
1463                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1464                 return -1;
1465                 }
1466
1467         /* Check if padding is too long, payload and padding
1468          * must not exceed 2^14 - 3 = 16381 bytes in total.
1469          */
1470         OPENSSL_assert(payload + padding <= 16381);
1471
1472         /* Create HeartBeat message, we just use a sequence number
1473          * as payload to distuingish different messages and add
1474          * some random stuff.
1475          *  - Message Type, 1 byte
1476          *  - Payload Length, 2 bytes (unsigned int)
1477          *  - Payload, the sequence number (2 bytes uint)
1478          *  - Payload, random bytes (16 bytes uint)
1479          *  - Padding
1480          */
1481         buf = OPENSSL_malloc(1 + 2 + payload + padding);
1482         p = buf;
1483         /* Message Type */
1484         *p++ = TLS1_HB_REQUEST;
1485         /* Payload length (18 bytes here) */
1486         s2n(payload, p);
1487         /* Sequence number */
1488         s2n(s->tlsext_hb_seq, p);
1489         /* 16 random bytes */
1490         RAND_pseudo_bytes(p, 16);
1491         p += 16;
1492         /* Random padding */
1493         RAND_pseudo_bytes(p, padding);
1494
1495         ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1496         if (ret >= 0)
1497                 {
1498                 if (s->msg_callback)
1499                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1500                                 buf, 3 + payload + padding,
1501                                 s, s->msg_callback_arg);
1502
1503                 dtls1_start_timer(s);
1504                 s->tlsext_hb_pending = 1;
1505                 }
1506
1507         OPENSSL_free(buf);
1508
1509         return ret;
1510         }
1511 #endif