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         unsigned int len, frag_off, mac_size, blocksize;
 264
 265         if(!dtls1_query_mtu(s))
 266                 return -1;
 267 #if 0
 268         mtu = s->d1->mtu;
 269
 270         fprintf(stderr, "using MTU = %d\n", mtu);
 271
 272         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 273
 274         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 275
 276         if ( curr_mtu > 0)
 277                 mtu = curr_mtu;
 278         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 279                 return ret;
 280
 281         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 282                 {
 283                 ret = BIO_flush(SSL_get_wbio(s));
 284                 if ( ret <= 0)
 285                         return ret;
 286                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 287                 }
 288 #endif
 289
 290         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s));  /* should have something reasonable now */
 291
 292         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 293                 OPENSSL_assert(s->init_num ==
 294                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 295
 296         if (s->write_hash)
 297                 {
 298                 if (s->enc_write_ctx && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE)
 299                         mac_size = 0;
 300                 else
 301                         mac_size = EVP_MD_CTX_size(s->write_hash);
 302                 }
 303         else
 304                 mac_size = 0;
 305
 306         if (s->enc_write_ctx &&
 307                 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
 308                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 309         else
 310                 blocksize = 0;
 311
 312         frag_off = 0;
 313         while( s->init_num)
 314                 {
 315                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 316                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 317
 318                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 319                         {
 320                         /* grr.. we could get an error if MTU picked was wrong */
 321                         ret = BIO_flush(SSL_get_wbio(s));
 322                         if ( ret <= 0)
 323                                 return ret;
 324                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 325                                 mac_size - blocksize;
 326                         }
 327
 328                 if ( s->init_num > curr_mtu)
 329                         len = curr_mtu;
 330                 else
 331                         len = s->init_num;
 332
 333
 334                 /* XDTLS: this function is too long.  split out the CCS part */
 335                 if ( type == SSL3_RT_HANDSHAKE)
 336                         {
 337                         if ( s->init_off != 0)
 338                                 {
 339                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 340                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 341                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 342
 343                                 if ( s->init_num > curr_mtu)
 344                                         len = curr_mtu;
 345                                 else
 346                                         len = s->init_num;
 347                                 }
 348
 349                         if ( len < DTLS1_HM_HEADER_LENGTH )
 350                                 {
 351                                 /*
 352                                  * len is so small that we really can't do anything sensible
 353                                  * so fail
 354                                  */
 355                                 return -1;
 356                                 }
 357                         dtls1_fix_message_header(s, frag_off,
 358                                 len - DTLS1_HM_HEADER_LENGTH);
 359
 360                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 361                         }
 362
 363                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 364                         len);
 365                 if (ret < 0)
 366                         {
 367                         /* might need to update MTU here, but we don't know
 368                          * which previous packet caused the failure -- so can't
 369                          * really retransmit anything.  continue as if everything
 370                          * is fine and wait for an alert to handle the
 371                          * retransmit
 372                          */
 373                         if ( BIO_ctrl(SSL_get_wbio(s),
 374                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 375                                 {
 376                                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 377                                         {
 378                                         if(!dtls1_query_mtu(s))
 379                                                 return -1;
 380                                         }
 381                                 else
 382                                         return -1;
 383                                 }
 384                         else
 385                                 {
 386                                 return(-1);
 387                                 }
 388                         }
 389                 else
 390                         {
 391
 392                         /* bad if this assert fails, only part of the handshake
 393                          * message got sent.  but why would this happen? */
 394                         OPENSSL_assert(len == (unsigned int)ret);
 395
 396                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 397                                 {
 398                                 /* should not be done for 'Hello Request's, but in that case
 399                                  * we'll ignore the result anyway */
 400                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 401                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 402                                 int xlen;
 403
 404                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
 405                                         {
 406                                         /* reconstruct message header is if it
 407                                          * is being sent in single fragment */
 408                                         *p++ = msg_hdr->type;
 409                                         l2n3(msg_hdr->msg_len,p);
 410                                         s2n (msg_hdr->seq,p);
 411                                         l2n3(0,p);
 412                                         l2n3(msg_hdr->msg_len,p);
 413                                         p  -= DTLS1_HM_HEADER_LENGTH;
 414                                         xlen = ret;
 415                                         }
 416                                 else
 417                                         {
 418                                         p  += DTLS1_HM_HEADER_LENGTH;
 419                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 420                                         }
 421
 422                                 ssl3_finish_mac(s, p, xlen);
 423                                 }
 424
 425                         if (ret == s->init_num)
 426                                 {
 427                                 if (s->msg_callback)
 428                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 429                                                 (size_t)(s->init_off + s->init_num), s,
 430                                                 s->msg_callback_arg);
 431
 432                                 s->init_off = 0;  /* done writing this message */
 433                                 s->init_num = 0;
 434
 435                                 return(1);
 436                                 }
 437                         s->init_off+=ret;
 438                         s->init_num-=ret;
 439                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 440                         }
 441                 }
 442         return(0);
 443         }
 444
 445
 446 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 447  * maximum acceptable body length 'max'.
 448  * Read an entire handshake message.  Handshake messages arrive in
 449  * fragments.
 450  */
 451 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 452         {
 453         int i, al;
 454         struct hm_header_st *msg_hdr;
 455         unsigned char *p;
 456         unsigned long msg_len;
 457
 458         /* s3->tmp is used to store messages that are unexpected, caused
 459          * by the absence of an optional handshake message */
 460         if (s->s3->tmp.reuse_message)
 461                 {
 462                 s->s3->tmp.reuse_message=0;
 463                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 464                         {
 465                         al=SSL_AD_UNEXPECTED_MESSAGE;
 466                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 467                         goto f_err;
 468                         }
 469                 *ok=1;
 470                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 471                 s->init_num = (int)s->s3->tmp.message_size;
 472                 return s->init_num;
 473                 }
 474
 475         msg_hdr = &s->d1->r_msg_hdr;
 476         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 477
 478 again:
 479         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 480         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 481                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 482                 goto again;
 483         else if ( i <= 0 && !*ok)
 484                 return i;
 485
 486         p = (unsigned char *)s->init_buf->data;
 487         msg_len = msg_hdr->msg_len;
 488
 489         /* reconstruct message header */
 490         *(p++) = msg_hdr->type;
 491         l2n3(msg_len,p);
 492         s2n (msg_hdr->seq,p);
 493         l2n3(0,p);
 494         l2n3(msg_len,p);
 495         if (s->version != DTLS1_BAD_VER) {
 496                 p       -= DTLS1_HM_HEADER_LENGTH;
 497                 msg_len += DTLS1_HM_HEADER_LENGTH;
 498         }
 499
 500         ssl3_finish_mac(s, p, msg_len);
 501         if (s->msg_callback)
 502                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 503                         p, msg_len,
 504                         s, s->msg_callback_arg);
 505
 506         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 507
 508         /* Don't change sequence numbers while listening */
 509         if (!s->d1->listen)
 510                 s->d1->handshake_read_seq++;
 511
 512         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 513         return s->init_num;
 514
 515 f_err:
 516         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 517         *ok = 0;
 518         return -1;
 519         }
 520
 521
 522 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 523         {
 524         size_t frag_off,frag_len,msg_len;
 525
 526         msg_len  = msg_hdr->msg_len;
 527         frag_off = msg_hdr->frag_off;
 528         frag_len = msg_hdr->frag_len;
 529
 530         /* sanity checking */
 531         if ( (frag_off+frag_len) > msg_len)
 532                 {
 533                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 534                 return SSL_AD_ILLEGAL_PARAMETER;
 535                 }
 536
 537         if ( (frag_off+frag_len) > (unsigned long)max)
 538                 {
 539                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 540                 return SSL_AD_ILLEGAL_PARAMETER;
 541                 }
 542
 543         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 544                 {
 545                 /* msg_len is limited to 2^24, but is effectively checked
 546                  * against max above */
 547                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
 548                         {
 549                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 550                         return SSL_AD_INTERNAL_ERROR;
 551                         }
 552
 553                 s->s3->tmp.message_size  = msg_len;
 554                 s->d1->r_msg_hdr.msg_len = msg_len;
 555                 s->s3->tmp.message_type  = msg_hdr->type;
 556                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 557                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 558                 }
 559         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 560                 {
 561                 /* They must be playing with us! BTW, failure to enforce
 562                  * upper limit would open possibility for buffer overrun. */
 563                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 564                 return SSL_AD_ILLEGAL_PARAMETER;
 565                 }
 566
 567         return 0; /* no error */
 568         }
 569
 570
 571 static int
 572 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 573         {
 574         /* (0) check whether the desired fragment is available
 575          * if so:
 576          * (1) copy over the fragment to s->init_buf->data[]
 577          * (2) update s->init_num
 578          */
 579         pitem *item;
 580         hm_fragment *frag;
 581         int al;
 582
 583         *ok = 0;
 584         item = pqueue_peek(s->d1->buffered_messages);
 585         if ( item == NULL)
 586                 return 0;
 587
 588         frag = (hm_fragment *)item->data;
 589
 590         /* Don't return if reassembly still in progress */
 591         if (frag->reassembly != NULL)
 592                 return 0;
 593
 594         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 595                 {
 596                 unsigned long frag_len = frag->msg_header.frag_len;
 597                 pqueue_pop(s->d1->buffered_messages);
 598
 599                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 600
 601                 if (al==0) /* no alert */
 602                         {
 603                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 604                         memcpy(&p[frag->msg_header.frag_off],
 605                                 frag->fragment,frag->msg_header.frag_len);
 606                         }
 607
 608                 dtls1_hm_fragment_free(frag);
 609                 pitem_free(item);
 610
 611                 if (al==0)
 612                         {
 613                         *ok = 1;
 614                         return frag_len;
 615                         }
 616
 617                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 618                 s->init_num = 0;
 619                 *ok = 0;
 620                 return -1;
 621                 }
 622         else
 623                 return 0;
 624         }
 625
 626 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 627  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 628  * be greater if the maximum certificate list size requires it. */
 629 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 630         {
 631         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 632         if (max_len < (unsigned long)s->max_cert_list)
 633                 return s->max_cert_list;
 634         return max_len;
 635         }
 636
 637 static int
 638 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 639         {
 640         hm_fragment *frag = NULL;
 641         pitem *item = NULL;
 642         int i = -1, is_complete;
 643         unsigned char seq64be[8];
 644         unsigned long frag_len = msg_hdr->frag_len;
 645
 646         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 647             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 648                 goto err;
 649
 650         if (frag_len == 0)
 651                 return DTLS1_HM_FRAGMENT_RETRY;
 652
 653         /* Try to find item in queue */
 654         memset(seq64be,0,sizeof(seq64be));
 655         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 656         seq64be[7] = (unsigned char) msg_hdr->seq;
 657         item = pqueue_find(s->d1->buffered_messages, seq64be);
 658
 659         if (item == NULL)
 660                 {
 661                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 662                 if ( frag == NULL)
 663                         goto err;
 664                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 665                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 666                 frag->msg_header.frag_off = 0;
 667                 }
 668         else
 669                 {
 670                 frag = (hm_fragment*) item->data;
 671                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 672                         {
 673                         item = NULL;
 674                         frag = NULL;
 675                         goto err;
 676                         }
 677                 }
 678
 679
 680         /* If message is already reassembled, this must be a
 681          * retransmit and can be dropped. In this case item != NULL and so frag
 682          * does not need to be freed.
 683          */
 684         if (frag->reassembly == NULL)
 685                 {
 686                 unsigned char devnull [256];
 687
 688                 while (frag_len)
 689                         {
 690                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 691                                 devnull,
 692                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 693                         if (i<=0) goto err;
 694                         frag_len -= i;
 695                         }
 696                 return DTLS1_HM_FRAGMENT_RETRY;
 697                 }
 698
 699         /* read the body of the fragment (header has already been read */
 700         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 701                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 702         if ((unsigned long)i!=frag_len)
 703                 i=-1;
 704         if (i<=0)
 705                 goto err;
 706
 707         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 708                             (long)(msg_hdr->frag_off + frag_len));
 709
 710         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 711                                    is_complete);
 712
 713         if (is_complete)
 714                 {
 715                 OPENSSL_free(frag->reassembly);
 716                 frag->reassembly = NULL;
 717                 }
 718
 719         if (item == NULL)
 720                 {
 721                 item = pitem_new(seq64be, frag);
 722                 if (item == NULL)
 723                         {
 724                         i = -1;
 725                         goto err;
 726                         }
 727
 728                 item = pqueue_insert(s->d1->buffered_messages, item);
 729                 /* pqueue_insert fails iff a duplicate item is inserted.
 730                  * However, |item| cannot be a duplicate. If it were,
 731                  * |pqueue_find|, above, would have returned it and control
 732                  * would never have reached this branch. */
 733                 OPENSSL_assert(item != NULL);
 734                 }
 735
 736         return DTLS1_HM_FRAGMENT_RETRY;
 737
 738 err:
 739         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 740         *ok = 0;
 741         return i;
 742         }
 743
 744
 745 static int
 746 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 747 {
 748         int i=-1;
 749         hm_fragment *frag = NULL;
 750         pitem *item = NULL;
 751         unsigned char seq64be[8];
 752         unsigned long frag_len = msg_hdr->frag_len;
 753
 754         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 755                 goto err;
 756
 757         /* Try to find item in queue, to prevent duplicate entries */
 758         memset(seq64be,0,sizeof(seq64be));
 759         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 760         seq64be[7] = (unsigned char) msg_hdr->seq;
 761         item = pqueue_find(s->d1->buffered_messages, seq64be);
 762
 763         /* If we already have an entry and this one is a fragment,
 764          * don't discard it and rather try to reassemble it.
 765          */
 766         if (item != NULL && frag_len != msg_hdr->msg_len)
 767                 item = NULL;
 768
 769         /* Discard the message if sequence number was already there, is
 770          * too far in the future, already in the queue or if we received
 771          * a FINISHED before the SERVER_HELLO, which then must be a stale
 772          * retransmit.
 773          */
 774         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 775                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 776                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 777                 {
 778                 unsigned char devnull [256];
 779
 780                 while (frag_len)
 781                         {
 782                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 783                                 devnull,
 784                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 785                         if (i<=0) goto err;
 786                         frag_len -= i;
 787                         }
 788                 }
 789         else
 790                 {
 791                 if (frag_len != msg_hdr->msg_len)
 792                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 793
 794                 if (frag_len > dtls1_max_handshake_message_len(s))
 795                         goto err;
 796
 797                 frag = dtls1_hm_fragment_new(frag_len, 0);
 798                 if ( frag == NULL)
 799                         goto err;
 800
 801                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 802
 803                 if (frag_len)
 804                         {
 805                         /* read the body of the fragment (header has already been read */
 806                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 807                                 frag->fragment,frag_len,0);
 808                         if ((unsigned long)i!=frag_len)
 809                                 i = -1;
 810                         if (i<=0)
 811                                 goto err;
 812                         }
 813
 814                 item = pitem_new(seq64be, frag);
 815                 if ( item == NULL)
 816                         goto err;
 817
 818                 item = pqueue_insert(s->d1->buffered_messages, item);
 819                 /* pqueue_insert fails iff a duplicate item is inserted.
 820                  * However, |item| cannot be a duplicate. If it were,
 821                  * |pqueue_find|, above, would have returned it. Then, either
 822                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 823                  * to NULL and it will have been processed with
 824                  * |dtls1_reassemble_fragment|, above, or the record will have
 825                  * been discarded. */
 826                 OPENSSL_assert(item != NULL);
 827                 }
 828
 829         return DTLS1_HM_FRAGMENT_RETRY;
 830
 831 err:
 832         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 833         *ok = 0;
 834         return i;
 835         }
 836
 837
 838 static long
 839 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 840         {
 841         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 842         unsigned long len, frag_off, frag_len;
 843         int i,al;
 844         struct hm_header_st msg_hdr;
 845
 846         redo:
 847         /* see if we have the required fragment already */
 848         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 849                 {
 850                 if (*ok)        s->init_num = frag_len;
 851                 return frag_len;
 852                 }
 853
 854         /* read handshake message header */
 855         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 856                 DTLS1_HM_HEADER_LENGTH, 0);
 857         if (i <= 0)     /* nbio, or an error */
 858                 {
 859                 s->rwstate=SSL_READING;
 860                 *ok = 0;
 861                 return i;
 862                 }
 863         /* Handshake fails if message header is incomplete */
 864         if (i != DTLS1_HM_HEADER_LENGTH)
 865                 {
 866                 al=SSL_AD_UNEXPECTED_MESSAGE;
 867                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 868                 goto f_err;
 869                 }
 870
 871         /* parse the message fragment header */
 872         dtls1_get_message_header(wire, &msg_hdr);
 873
 874         /*
 875          * if this is a future (or stale) message it gets buffered
 876          * (or dropped)--no further processing at this time
 877          * While listening, we accept seq 1 (ClientHello with cookie)
 878          * although we're still expecting seq 0 (ClientHello)
 879          */
 880         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 881                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 882
 883         len = msg_hdr.msg_len;
 884         frag_off = msg_hdr.frag_off;
 885         frag_len = msg_hdr.frag_len;
 886
 887         if (frag_len && frag_len < len)
 888                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 889
 890         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 891                 wire[0] == SSL3_MT_HELLO_REQUEST)
 892                 {
 893                 /* The server may always send 'Hello Request' messages --
 894                  * we are doing a handshake anyway now, so ignore them
 895                  * if their format is correct. Does not count for
 896                  * 'Finished' MAC. */
 897                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 898                         {
 899                         if (s->msg_callback)
 900                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 901                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 902                                         s->msg_callback_arg);
 903
 904                         s->init_num = 0;
 905                         goto redo;
 906                         }
 907                 else /* Incorrectly formated Hello request */
 908                         {
 909                         al=SSL_AD_UNEXPECTED_MESSAGE;
 910                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 911                         goto f_err;
 912                         }
 913                 }
 914
 915         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 916                 goto f_err;
 917
 918         /* XDTLS:  ressurect this when restart is in place */
 919         s->state=stn;
 920
 921         if ( frag_len > 0)
 922                 {
 923                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 924
 925                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 926                         &p[frag_off],frag_len,0);
 927                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 928                 if (i <= 0)
 929                         {
 930                         s->rwstate=SSL_READING;
 931                         *ok = 0;
 932                         return i;
 933                         }
 934                 }
 935         else
 936                 i = 0;
 937
 938         /* XDTLS:  an incorrectly formatted fragment should cause the
 939          * handshake to fail */
 940         if (i != (int)frag_len)
 941                 {
 942                 al=SSL3_AD_ILLEGAL_PARAMETER;
 943                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 944                 goto f_err;
 945                 }
 946
 947         *ok = 1;
 948
 949         /* Note that s->init_num is *not* used as current offset in
 950          * s->init_buf->data, but as a counter summing up fragments'
 951          * lengths: as soon as they sum up to handshake packet
 952          * length, we assume we have got all the fragments. */
 953         s->init_num = frag_len;
 954         return frag_len;
 955
 956 f_err:
 957         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 958         s->init_num = 0;
 959
 960         *ok=0;
 961         return(-1);
 962         }
 963
 964 /* for these 2 messages, we need to
 965  * ssl->enc_read_ctx                    re-init
 966  * ssl->s3->read_sequence               zero
 967  * ssl->s3->read_mac_secret             re-init
 968  * ssl->session->read_sym_enc           assign
 969  * ssl->session->read_compression       assign
 970  * ssl->session->read_hash              assign
 971  */
 972 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 973         {
 974         unsigned char *p;
 975
 976         if (s->state == a)
 977                 {
 978                 p=(unsigned char *)s->init_buf->data;
 979                 *p++=SSL3_MT_CCS;
 980                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 981                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 982
 983                 if (s->version == DTLS1_BAD_VER) {
 984                         s->d1->next_handshake_write_seq++;
 985                         s2n(s->d1->handshake_write_seq,p);
 986                         s->init_num+=2;
 987                 }
 988
 989                 s->init_off=0;
 990
 991                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 992                         s->d1->handshake_write_seq, 0, 0);
 993
 994                 /* buffer the message to handle re-xmits */
 995                 dtls1_buffer_message(s, 1);
 996
 997                 s->state=b;
 998                 }
 999
1000         /* SSL3_ST_CW_CHANGE_B */
1001         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1002         }
1003
1004 int dtls1_read_failed(SSL *s, int code)
1005         {
1006         if ( code > 0)
1007                 {
1008                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1009                 return 1;
1010                 }
1011
1012         if (!dtls1_is_timer_expired(s))
1013                 {
1014                 /* not a timeout, none of our business,
1015                    let higher layers handle this.  in fact it's probably an error */
1016                 return code;
1017                 }
1018
1019 #ifndef OPENSSL_NO_HEARTBEATS
1020         if (!SSL_in_init(s) && !s->tlsext_hb_pending)  /* done, no need to send a retransmit */
1021 #else
1022         if (!SSL_in_init(s))  /* done, no need to send a retransmit */
1023 #endif
1024                 {
1025                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1026                 return code;
1027                 }
1028
1029 #if 0 /* for now, each alert contains only one record number */
1030         item = pqueue_peek(state->rcvd_records);
1031         if ( item )
1032                 {
1033                 /* send an alert immediately for all the missing records */
1034                 }
1035         else
1036 #endif
1037
1038 #if 0  /* no more alert sending, just retransmit the last set of messages */
1039         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1040                 ssl3_send_alert(s,SSL3_AL_WARNING,
1041                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1042 #endif
1043
1044         return dtls1_handle_timeout(s);
1045         }
1046
1047 int
1048 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1049         {
1050         /* The index of the retransmission queue actually is the message sequence number,
1051          * since the queue only contains messages of a single handshake. However, the
1052          * ChangeCipherSpec has no message sequence number and so using only the sequence
1053          * will result in the CCS and Finished having the same index. To prevent this,
1054          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1055          * This does not only differ CSS and Finished, it also maintains the order of the
1056          * index (important for priority queues) and fits in the unsigned short variable.
1057          */
1058         return seq * 2 - is_ccs;
1059         }
1060
1061 int
1062 dtls1_retransmit_buffered_messages(SSL *s)
1063         {
1064         pqueue sent = s->d1->sent_messages;
1065         piterator iter;
1066         pitem *item;
1067         hm_fragment *frag;
1068         int found = 0;
1069
1070         iter = pqueue_iterator(sent);
1071
1072         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1073                 {
1074                 frag = (hm_fragment *)item->data;
1075                         if ( dtls1_retransmit_message(s,
1076                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1077                                 0, &found) <= 0 && found)
1078                         {
1079                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1080                         return -1;
1081                         }
1082                 }
1083
1084         return 1;
1085         }
1086
1087 int
1088 dtls1_buffer_message(SSL *s, int is_ccs)
1089         {
1090         pitem *item;
1091         hm_fragment *frag;
1092         unsigned char seq64be[8];
1093
1094         /* this function is called immediately after a message has
1095          * been serialized */
1096         OPENSSL_assert(s->init_off == 0);
1097
1098         frag = dtls1_hm_fragment_new(s->init_num, 0);
1099         if (!frag)
1100                 return 0;
1101
1102         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1103
1104         if ( is_ccs)
1105                 {
1106                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1107                                DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1108                 }
1109         else
1110                 {
1111                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1112                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1113                 }
1114
1115         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1116         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1117         frag->msg_header.type = s->d1->w_msg_hdr.type;
1118         frag->msg_header.frag_off = 0;
1119         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1120         frag->msg_header.is_ccs = is_ccs;
1121
1122         /* save current state*/
1123         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1124         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1125         frag->msg_header.saved_retransmit_state.compress = s->compress;
1126         frag->msg_header.saved_retransmit_state.session = s->session;
1127         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1128
1129         memset(seq64be,0,sizeof(seq64be));
1130         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1131                                                                                                                   frag->msg_header.is_ccs)>>8);
1132         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1133                                                                                                                   frag->msg_header.is_ccs));
1134
1135         item = pitem_new(seq64be, frag);
1136         if ( item == NULL)
1137                 {
1138                 dtls1_hm_fragment_free(frag);
1139                 return 0;
1140                 }
1141
1142 #if 0
1143         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1144         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1145         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1146 #endif
1147
1148         pqueue_insert(s->d1->sent_messages, item);
1149         return 1;
1150         }
1151
1152 int
1153 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1154         int *found)
1155         {
1156         int ret;
1157         /* XDTLS: for now assuming that read/writes are blocking */
1158         pitem *item;
1159         hm_fragment *frag ;
1160         unsigned long header_length;
1161         unsigned char seq64be[8];
1162         struct dtls1_retransmit_state saved_state;
1163         unsigned char save_write_sequence[8];
1164
1165         /*
1166           OPENSSL_assert(s->init_num == 0);
1167           OPENSSL_assert(s->init_off == 0);
1168          */
1169
1170         /* XDTLS:  the requested message ought to be found, otherwise error */
1171         memset(seq64be,0,sizeof(seq64be));
1172         seq64be[6] = (unsigned char)(seq>>8);
1173         seq64be[7] = (unsigned char)seq;
1174
1175         item = pqueue_find(s->d1->sent_messages, seq64be);
1176         if ( item == NULL)
1177                 {
1178                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1179                 *found = 0;
1180                 return 0;
1181                 }
1182
1183         *found = 1;
1184         frag = (hm_fragment *)item->data;
1185
1186         if ( frag->msg_header.is_ccs)
1187                 header_length = DTLS1_CCS_HEADER_LENGTH;
1188         else
1189                 header_length = DTLS1_HM_HEADER_LENGTH;
1190
1191         memcpy(s->init_buf->data, frag->fragment,
1192                 frag->msg_header.msg_len + header_length);
1193                 s->init_num = frag->msg_header.msg_len + header_length;
1194
1195         dtls1_set_message_header_int(s, frag->msg_header.type,
1196                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1197                 frag->msg_header.frag_len);
1198
1199         /* save current state */
1200         saved_state.enc_write_ctx = s->enc_write_ctx;
1201         saved_state.write_hash = s->write_hash;
1202         saved_state.compress = s->compress;
1203         saved_state.session = s->session;
1204         saved_state.epoch = s->d1->w_epoch;
1205         saved_state.epoch = s->d1->w_epoch;
1206
1207         s->d1->retransmitting = 1;
1208
1209         /* restore state in which the message was originally sent */
1210         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1211         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1212         s->compress = frag->msg_header.saved_retransmit_state.compress;
1213         s->session = frag->msg_header.saved_retransmit_state.session;
1214         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1215
1216         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1217         {
1218                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1219                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1220         }
1221
1222         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1223                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1224
1225         /* restore current state */
1226         s->enc_write_ctx = saved_state.enc_write_ctx;
1227         s->write_hash = saved_state.write_hash;
1228         s->compress = saved_state.compress;
1229         s->session = saved_state.session;
1230         s->d1->w_epoch = saved_state.epoch;
1231
1232         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1233         {
1234                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1235                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1236         }
1237
1238         s->d1->retransmitting = 0;
1239
1240         (void)BIO_flush(SSL_get_wbio(s));
1241         return ret;
1242         }
1243
1244 /* call this function when the buffered messages are no longer needed */
1245 void
1246 dtls1_clear_record_buffer(SSL *s)
1247         {
1248         pitem *item;
1249
1250         for(item = pqueue_pop(s->d1->sent_messages);
1251                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1252                 {
1253                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1254                 pitem_free(item);
1255                 }
1256         }
1257
1258
1259 unsigned char *
1260 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1261                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1262         {
1263         /* Don't change sequence numbers while listening */
1264         if (frag_off == 0 && !s->d1->listen)
1265                 {
1266                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1267                 s->d1->next_handshake_write_seq++;
1268                 }
1269
1270         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1271                 frag_off, frag_len);
1272
1273         return p += DTLS1_HM_HEADER_LENGTH;
1274         }
1275
1276
1277 /* don't actually do the writing, wait till the MTU has been retrieved */
1278 static void
1279 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1280                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1281                             unsigned long frag_len)
1282         {
1283         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1284
1285         msg_hdr->type = mt;
1286         msg_hdr->msg_len = len;
1287         msg_hdr->seq = seq_num;
1288         msg_hdr->frag_off = frag_off;
1289         msg_hdr->frag_len = frag_len;
1290         }
1291
1292 static void
1293 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1294                         unsigned long frag_len)
1295         {
1296         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1297
1298         msg_hdr->frag_off = frag_off;
1299         msg_hdr->frag_len = frag_len;
1300         }
1301
1302 static unsigned char *
1303 dtls1_write_message_header(SSL *s, unsigned char *p)
1304         {
1305         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1306
1307         *p++ = msg_hdr->type;
1308         l2n3(msg_hdr->msg_len, p);
1309
1310         s2n(msg_hdr->seq, p);
1311         l2n3(msg_hdr->frag_off, p);
1312         l2n3(msg_hdr->frag_len, p);
1313
1314         return p;
1315         }
1316
1317 unsigned int
1318 dtls1_link_min_mtu(void)
1319         {
1320         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1321                 sizeof(g_probable_mtu[0])) - 1]);
1322         }
1323
1324 unsigned int
1325 dtls1_min_mtu(SSL *s)
1326         {
1327         return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1328         }
1329
1330
1331 void
1332 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1333         {
1334         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1335         msg_hdr->type = *(data++);
1336         n2l3(data, msg_hdr->msg_len);
1337
1338         n2s(data, msg_hdr->seq);
1339         n2l3(data, msg_hdr->frag_off);
1340         n2l3(data, msg_hdr->frag_len);
1341         }
1342
1343 void
1344 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1345         {
1346         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1347
1348         ccs_hdr->type = *(data++);
1349         }
1350
1351 int dtls1_shutdown(SSL *s)
1352         {
1353         int ret;
1354 #ifndef OPENSSL_NO_SCTP
1355         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1356             !(s->shutdown & SSL_SENT_SHUTDOWN))
1357                 {
1358                 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1359                 if (ret < 0) return -1;
1360
1361                 if (ret == 0)
1362                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1363                 }
1364 #endif
1365         ret = ssl3_shutdown(s);
1366 #ifndef OPENSSL_NO_SCTP
1367         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1368 #endif
1369         return ret;
1370         }
1371
1372 #ifndef OPENSSL_NO_HEARTBEATS
1373 int
1374 dtls1_process_heartbeat(SSL *s)
1375         {
1376         unsigned char *p = &s->s3->rrec.data[0], *pl;
1377         unsigned short hbtype;
1378         unsigned int payload;
1379         unsigned int padding = 16; /* Use minimum padding */
1380
1381         if (s->msg_callback)
1382                 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1383                         &s->s3->rrec.data[0], s->s3->rrec.length,
1384                         s, s->msg_callback_arg);
1385
1386         /* Read type and payload length first */
1387         if (1 + 2 + 16 > s->s3->rrec.length)
1388                 return 0; /* silently discard */
1389         if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
1390                 return 0; /* silently discard per RFC 6520 sec. 4 */
1391
1392         hbtype = *p++;
1393         n2s(p, payload);
1394         if (1 + 2 + payload + 16 > s->s3->rrec.length)
1395                 return 0; /* silently discard per RFC 6520 sec. 4 */
1396         pl = p;
1397
1398         if (hbtype == TLS1_HB_REQUEST)
1399                 {
1400                 unsigned char *buffer, *bp;
1401                 unsigned int write_length = 1 /* heartbeat type */ +
1402                                             2 /* heartbeat length */ +
1403                                             payload + padding;
1404                 int r;
1405
1406                 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1407                         return 0;
1408
1409                 /* Allocate memory for the response, size is 1 byte
1410                  * message type, plus 2 bytes payload length, plus
1411                  * payload, plus padding
1412                  */
1413                 buffer = OPENSSL_malloc(write_length);
1414                 bp = buffer;
1415
1416                 /* Enter response type, length and copy payload */
1417                 *bp++ = TLS1_HB_RESPONSE;
1418                 s2n(payload, bp);
1419                 memcpy(bp, pl, payload);
1420                 bp += payload;
1421                 /* Random padding */
1422                 RAND_pseudo_bytes(bp, padding);
1423
1424                 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1425
1426                 if (r >= 0 && s->msg_callback)
1427                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1428                                 buffer, write_length,
1429                                 s, s->msg_callback_arg);
1430
1431                 OPENSSL_free(buffer);
1432
1433                 if (r < 0)
1434                         return r;
1435                 }
1436         else if (hbtype == TLS1_HB_RESPONSE)
1437                 {
1438                 unsigned int seq;
1439
1440                 /* We only send sequence numbers (2 bytes unsigned int),
1441                  * and 16 random bytes, so we just try to read the
1442                  * sequence number */
1443                 n2s(pl, seq);
1444
1445                 if (payload == 18 && seq == s->tlsext_hb_seq)
1446                         {
1447                         dtls1_stop_timer(s);
1448                         s->tlsext_hb_seq++;
1449                         s->tlsext_hb_pending = 0;
1450                         }
1451                 }
1452
1453         return 0;
1454         }
1455
1456 int
1457 dtls1_heartbeat(SSL *s)
1458         {
1459         unsigned char *buf, *p;
1460         int ret;
1461         unsigned int payload = 18; /* Sequence number + random bytes */
1462         unsigned int padding = 16; /* Use minimum padding */
1463
1464         /* Only send if peer supports and accepts HB requests... */
1465         if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1466             s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1467                 {
1468                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1469                 return -1;
1470                 }
1471
1472         /* ...and there is none in flight yet... */
1473         if (s->tlsext_hb_pending)
1474                 {
1475                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1476                 return -1;
1477                 }
1478
1479         /* ...and no handshake in progress. */
1480         if (SSL_in_init(s) || s->in_handshake)
1481                 {
1482                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1483                 return -1;
1484                 }
1485
1486         /* Check if padding is too long, payload and padding
1487          * must not exceed 2^14 - 3 = 16381 bytes in total.
1488          */
1489         OPENSSL_assert(payload + padding <= 16381);
1490
1491         /* Create HeartBeat message, we just use a sequence number
1492          * as payload to distuingish different messages and add
1493          * some random stuff.
1494          *  - Message Type, 1 byte
1495          *  - Payload Length, 2 bytes (unsigned int)
1496          *  - Payload, the sequence number (2 bytes uint)
1497          *  - Payload, random bytes (16 bytes uint)
1498          *  - Padding
1499          */
1500         buf = OPENSSL_malloc(1 + 2 + payload + padding);
1501         p = buf;
1502         /* Message Type */
1503         *p++ = TLS1_HB_REQUEST;
1504         /* Payload length (18 bytes here) */
1505         s2n(payload, p);
1506         /* Sequence number */
1507         s2n(s->tlsext_hb_seq, p);
1508         /* 16 random bytes */
1509         RAND_pseudo_bytes(p, 16);
1510         p += 16;
1511         /* Random padding */
1512         RAND_pseudo_bytes(p, padding);
1513
1514         ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1515         if (ret >= 0)
1516                 {
1517                 if (s->msg_callback)
1518                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1519                                 buf, 3 + payload + padding,
1520                                 s, s->msg_callback_arg);
1521
1522                 dtls1_start_timer(s);
1523                 s->tlsext_hb_pending = 1;
1524                 }
1525
1526         OPENSSL_free(buf);
1527
1528         return ret;
1529         }
1530 #endif