ssl/d1_pkt.c

   1 /* ssl/d1_pkt.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 <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182
 183 /* copy buffered record into SSL structure */
 184 static int
 185 dtls1_copy_record(SSL *s, pitem *item)
 186     {
 187     DTLS1_RECORD_DATA *rdata;
 188
 189     rdata = (DTLS1_RECORD_DATA *)item->data;
 190
 191     if (s->s3->rbuf.buf != NULL)
 192         OPENSSL_free(s->s3->rbuf.buf);
 193
 194     s->packet = rdata->packet;
 195     s->packet_length = rdata->packet_length;
 196     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 197     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 198
 199         /* Set proper sequence number for mac calculation */
 200         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 201
 202     return(1);
 203     }
 204
 205
 206 static int
 207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 208         {
 209         DTLS1_RECORD_DATA *rdata;
 210         pitem *item;
 211
 212         /* Limit the size of the queue to prevent DOS attacks */
 213         if (pqueue_size(queue->q) >= 100)
 214                 return 0;
 215
 216         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 217         item = pitem_new(priority, rdata);
 218         if (rdata == NULL || item == NULL)
 219                 {
 220                 if (rdata != NULL) OPENSSL_free(rdata);
 221                 if (item != NULL) pitem_free(item);
 222
 223                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 224                 return(0);
 225                 }
 226
 227         rdata->packet = s->packet;
 228         rdata->packet_length = s->packet_length;
 229         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 230         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 231
 232         item->data = rdata;
 233
 234 #ifndef OPENSSL_NO_SCTP
 235         /* Store bio_dgram_sctp_rcvinfo struct */
 236         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 237             (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
 238                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 239         }
 240 #endif
 241
 242         /* insert should not fail, since duplicates are dropped */
 243         if (pqueue_insert(queue->q, item) == NULL)
 244                 {
 245                 OPENSSL_free(rdata);
 246                 pitem_free(item);
 247                 return(0);
 248                 }
 249
 250         s->packet = NULL;
 251         s->packet_length = 0;
 252         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 253         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 254
 255         if (!ssl3_setup_buffers(s))
 256                 {
 257                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 258                 OPENSSL_free(rdata);
 259                 pitem_free(item);
 260                 return(0);
 261                 }
 262
 263         return(1);
 264         }
 265
 266
 267 static int
 268 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 269     {
 270     pitem *item;
 271
 272     item = pqueue_pop(queue->q);
 273     if (item)
 274         {
 275         dtls1_copy_record(s, item);
 276
 277         OPENSSL_free(item->data);
 278                 pitem_free(item);
 279
 280         return(1);
 281         }
 282
 283     return(0);
 284     }
 285
 286
 287 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 288  * yet */
 289 #define dtls1_get_unprocessed_record(s) \
 290                    dtls1_retrieve_buffered_record((s), \
 291                    &((s)->d1->unprocessed_rcds))
 292
 293 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 294 #define dtls1_get_processed_record(s) \
 295                    dtls1_retrieve_buffered_record((s), \
 296                    &((s)->d1->processed_rcds))
 297
 298 static int
 299 dtls1_process_buffered_records(SSL *s)
 300     {
 301     pitem *item;
 302
 303     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 304     if (item)
 305         {
 306         /* Check if epoch is current. */
 307         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 308             return(1);  /* Nothing to do. */
 309
 310         /* Process all the records. */
 311         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 312             {
 313             dtls1_get_unprocessed_record(s);
 314             if ( ! dtls1_process_record(s))
 315                 return(0);
 316             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 317                 s->s3->rrec.seq_num);
 318             }
 319         }
 320
 321     /* sync epoch numbers once all the unprocessed records
 322      * have been processed */
 323     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 324     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 325
 326     return(1);
 327     }
 328
 329
 330 #if 0
 331
 332 static int
 333 dtls1_get_buffered_record(SSL *s)
 334         {
 335         pitem *item;
 336         PQ_64BIT priority =
 337                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 338                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 339
 340         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 341                                                            nothing buffered */
 342                 return 0;
 343
 344
 345         item = pqueue_peek(s->d1->rcvd_records);
 346         if (item && item->priority == priority)
 347                 {
 348                 /* Check if we've received the record of interest.  It must be
 349                  * a handshake record, since data records as passed up without
 350                  * buffering */
 351                 DTLS1_RECORD_DATA *rdata;
 352                 item = pqueue_pop(s->d1->rcvd_records);
 353                 rdata = (DTLS1_RECORD_DATA *)item->data;
 354
 355                 if (s->s3->rbuf.buf != NULL)
 356                         OPENSSL_free(s->s3->rbuf.buf);
 357
 358                 s->packet = rdata->packet;
 359                 s->packet_length = rdata->packet_length;
 360                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 361                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 362
 363                 OPENSSL_free(item->data);
 364                 pitem_free(item);
 365
 366                 /* s->d1->next_expected_seq_num++; */
 367                 return(1);
 368                 }
 369
 370         return 0;
 371         }
 372
 373 #endif
 374
 375 static int
 376 dtls1_process_record(SSL *s)
 377 {
 378         int i,al;
 379         int clear=0;
 380         int enc_err;
 381         SSL_SESSION *sess;
 382         SSL3_RECORD *rr;
 383         unsigned int mac_size;
 384         unsigned char md[EVP_MAX_MD_SIZE];
 385         int decryption_failed_or_bad_record_mac = 0;
 386         unsigned char *mac = NULL;
 387
 388
 389         rr= &(s->s3->rrec);
 390         sess = s->session;
 391
 392         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 393          * and we have that many bytes in s->packet
 394          */
 395         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 396
 397         /* ok, we can now read from 's->packet' data into 'rr'
 398          * rr->input points at rr->length bytes, which
 399          * need to be copied into rr->data by either
 400          * the decryption or by the decompression
 401          * When the data is 'copied' into the rr->data buffer,
 402          * rr->input will be pointed at the new buffer */
 403
 404         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 405          * rr->length bytes of encrypted compressed stuff. */
 406
 407         /* check is not needed I believe */
 408         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 409                 {
 410                 al=SSL_AD_RECORD_OVERFLOW;
 411                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 412                 goto f_err;
 413                 }
 414
 415         /* decrypt in place in 'rr->input' */
 416         rr->data=rr->input;
 417
 418         enc_err = s->method->ssl3_enc->enc(s,0);
 419         if (enc_err <= 0)
 420                 {
 421                 /* To minimize information leaked via timing, we will always
 422                  * perform all computations before discarding the message.
 423                  */
 424                 decryption_failed_or_bad_record_mac = 1;
 425                 }
 426
 427 #ifdef TLS_DEBUG
 428 printf("dec %d\n",rr->length);
 429 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 430 printf("\n");
 431 #endif
 432
 433         /* r->length is now the compressed data plus mac */
 434         if (    (sess == NULL) ||
 435                 (s->enc_read_ctx == NULL) ||
 436                 (s->read_hash == NULL))
 437                 clear=1;
 438
 439         if (!clear)
 440                 {
 441                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 442                 int t;
 443                 t=EVP_MD_CTX_size(s->read_hash);
 444                 OPENSSL_assert(t >= 0);
 445                 mac_size=t;
 446
 447                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 448                         {
 449 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 450                         al=SSL_AD_RECORD_OVERFLOW;
 451                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 452                         goto f_err;
 453 #else
 454                         decryption_failed_or_bad_record_mac = 1;
 455 #endif
 456                         }
 457                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 458                 if (rr->length >= mac_size)
 459                         {
 460                         rr->length -= mac_size;
 461                         mac = &rr->data[rr->length];
 462                         }
 463                 else
 464                         rr->length = 0;
 465                 i=s->method->ssl3_enc->mac(s,md,0);
 466                 if (i < 0 || mac == NULL || memcmp(md, mac, mac_size) != 0)
 467                         {
 468                         decryption_failed_or_bad_record_mac = 1;
 469                         }
 470                 }
 471
 472         if (decryption_failed_or_bad_record_mac)
 473                 {
 474                 /* decryption failed, silently discard message */
 475                 rr->length = 0;
 476                 s->packet_length = 0;
 477                 goto err;
 478                 }
 479
 480         /* r->length is now just compressed */
 481         if (s->expand != NULL)
 482                 {
 483                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 484                         {
 485                         al=SSL_AD_RECORD_OVERFLOW;
 486                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 487                         goto f_err;
 488                         }
 489                 if (!ssl3_do_uncompress(s))
 490                         {
 491                         al=SSL_AD_DECOMPRESSION_FAILURE;
 492                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 493                         goto f_err;
 494                         }
 495                 }
 496
 497         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 498                 {
 499                 al=SSL_AD_RECORD_OVERFLOW;
 500                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 501                 goto f_err;
 502                 }
 503
 504         rr->off=0;
 505         /* So at this point the following is true
 506          * ssl->s3->rrec.type   is the type of record
 507          * ssl->s3->rrec.length == number of bytes in record
 508          * ssl->s3->rrec.off    == offset to first valid byte
 509          * ssl->s3->rrec.data   == where to take bytes from, increment
 510          *                         after use :-).
 511          */
 512
 513         /* we have pulled in a full packet so zero things */
 514         s->packet_length=0;
 515         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 516         return(1);
 517
 518 f_err:
 519         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 520 err:
 521         return(0);
 522 }
 523
 524
 525 /* Call this to get a new input record.
 526  * It will return <= 0 if more data is needed, normally due to an error
 527  * or non-blocking IO.
 528  * When it finishes, one packet has been decoded and can be found in
 529  * ssl->s3->rrec.type    - is the type of record
 530  * ssl->s3->rrec.data,   - data
 531  * ssl->s3->rrec.length, - number of bytes
 532  */
 533 /* used only by dtls1_read_bytes */
 534 int dtls1_get_record(SSL *s)
 535         {
 536         int ssl_major,ssl_minor;
 537         int i,n;
 538         SSL3_RECORD *rr;
 539         unsigned char *p = NULL;
 540         unsigned short version;
 541         DTLS1_BITMAP *bitmap;
 542         unsigned int is_next_epoch;
 543
 544         rr= &(s->s3->rrec);
 545
 546         /* The epoch may have changed.  If so, process all the
 547          * pending records.  This is a non-blocking operation. */
 548         dtls1_process_buffered_records(s);
 549
 550         /* if we're renegotiating, then there may be buffered records */
 551         if (dtls1_get_processed_record(s))
 552                 return 1;
 553
 554         /* get something from the wire */
 555 again:
 556         /* check if we have the header */
 557         if (    (s->rstate != SSL_ST_READ_BODY) ||
 558                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 559                 {
 560                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 561                 /* read timeout is handled by dtls1_read_bytes */
 562                 if (n <= 0) return(n); /* error or non-blocking */
 563
 564                 /* this packet contained a partial record, dump it */
 565                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 566                         {
 567                         s->packet_length = 0;
 568                         goto again;
 569                         }
 570
 571                 s->rstate=SSL_ST_READ_BODY;
 572
 573                 p=s->packet;
 574
 575                 /* Pull apart the header into the DTLS1_RECORD */
 576                 rr->type= *(p++);
 577                 ssl_major= *(p++);
 578                 ssl_minor= *(p++);
 579                 version=(ssl_major<<8)|ssl_minor;
 580
 581                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 582                 n2s(p,rr->epoch);
 583
 584                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 585                 p+=6;
 586
 587                 n2s(p,rr->length);
 588
 589                 /* Lets check version */
 590                 if (!s->first_packet)
 591                         {
 592                         if (version != s->version)
 593                                 {
 594                                 /* unexpected version, silently discard */
 595                                 rr->length = 0;
 596                                 s->packet_length = 0;
 597                                 goto again;
 598                                 }
 599                         }
 600
 601                 if ((version & 0xff00) != (s->version & 0xff00))
 602                         {
 603                         /* wrong version, silently discard record */
 604                         rr->length = 0;
 605                         s->packet_length = 0;
 606                         goto again;
 607                         }
 608
 609                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 610                         {
 611                         /* record too long, silently discard it */
 612                         rr->length = 0;
 613                         s->packet_length = 0;
 614                         goto again;
 615                         }
 616
 617                 /* now s->rstate == SSL_ST_READ_BODY */
 618                 }
 619
 620         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 621
 622         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 623                 {
 624                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 625                 i=rr->length;
 626                 n=ssl3_read_n(s,i,i,1);
 627                 if (n <= 0) return(n); /* error or non-blocking io */
 628
 629                 /* this packet contained a partial record, dump it */
 630                 if ( n != i)
 631                         {
 632                         rr->length = 0;
 633                         s->packet_length = 0;
 634                         goto again;
 635                         }
 636
 637                 /* now n == rr->length,
 638                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 639                 }
 640         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 641
 642         /* match epochs.  NULL means the packet is dropped on the floor */
 643         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 644         if ( bitmap == NULL)
 645                 {
 646                 rr->length = 0;
 647                 s->packet_length = 0;  /* dump this record */
 648                 goto again;   /* get another record */
 649                 }
 650
 651 #ifndef OPENSSL_NO_SCTP
 652         /* Only do replay check if no SCTP bio */
 653         if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
 654                 {
 655 #endif
 656                 /* Check whether this is a repeat, or aged record.
 657                  * Don't check if we're listening and this message is
 658                  * a ClientHello. They can look as if they're replayed,
 659                  * since they arrive from different connections and
 660                  * would be dropped unnecessarily.
 661                  */
 662                 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 663                     *p == SSL3_MT_CLIENT_HELLO) &&
 664                     !dtls1_record_replay_check(s, bitmap))
 665                         {
 666                         rr->length = 0;
 667                         s->packet_length=0; /* dump this record */
 668                         goto again;     /* get another record */
 669                         }
 670 #ifndef OPENSSL_NO_SCTP
 671                 }
 672 #endif
 673
 674         /* just read a 0 length packet */
 675         if (rr->length == 0) goto again;
 676
 677         /* If this record is from the next epoch (either HM or ALERT),
 678          * and a handshake is currently in progress, buffer it since it
 679          * cannot be processed at this time. However, do not buffer
 680          * anything while listening.
 681          */
 682         if (is_next_epoch)
 683                 {
 684                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 685                         {
 686                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 687                         }
 688                 rr->length = 0;
 689                 s->packet_length = 0;
 690                 goto again;
 691                 }
 692
 693         if (!dtls1_process_record(s))
 694                 {
 695                 rr->length = 0;
 696                 s->packet_length = 0;  /* dump this record */
 697                 goto again;   /* get another record */
 698                 }
 699
 700         return(1);
 701
 702         }
 703
 704 /* Return up to 'len' payload bytes received in 'type' records.
 705  * 'type' is one of the following:
 706  *
 707  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 708  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 709  *   -  0 (during a shutdown, no data has to be returned)
 710  *
 711  * If we don't have stored data to work from, read a SSL/TLS record first
 712  * (possibly multiple records if we still don't have anything to return).
 713  *
 714  * This function must handle any surprises the peer may have for us, such as
 715  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 716  * a surprise, but handled as if it were), or renegotiation requests.
 717  * Also if record payloads contain fragments too small to process, we store
 718  * them until there is enough for the respective protocol (the record protocol
 719  * may use arbitrary fragmentation and even interleaving):
 720  *     Change cipher spec protocol
 721  *             just 1 byte needed, no need for keeping anything stored
 722  *     Alert protocol
 723  *             2 bytes needed (AlertLevel, AlertDescription)
 724  *     Handshake protocol
 725  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 726  *             to detect unexpected Client Hello and Hello Request messages
 727  *             here, anything else is handled by higher layers
 728  *     Application data protocol
 729  *             none of our business
 730  */
 731 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 732         {
 733         int al,i,j,ret;
 734         unsigned int n;
 735         SSL3_RECORD *rr;
 736         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 737
 738         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 739                 if (!ssl3_setup_buffers(s))
 740                         return(-1);
 741
 742     /* XXX: check what the second '&& type' is about */
 743         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 744                 (type != SSL3_RT_HANDSHAKE) && type) ||
 745             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 746                 {
 747                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 748                 return -1;
 749                 }
 750
 751         /* check whether there's a handshake message (client hello?) waiting */
 752         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 753                 return ret;
 754
 755         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 756
 757 #ifndef OPENSSL_NO_SCTP
 758         /* Continue handshake if it had to be interrupted to read
 759          * app data with SCTP.
 760          */
 761         if ((!s->in_handshake && SSL_in_init(s)) ||
 762             (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 763              (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
 764              s->s3->in_read_app_data != 2))
 765 #else
 766         if (!s->in_handshake && SSL_in_init(s))
 767 #endif
 768                 {
 769                 /* type == SSL3_RT_APPLICATION_DATA */
 770                 i=s->handshake_func(s);
 771                 if (i < 0) return(i);
 772                 if (i == 0)
 773                         {
 774                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 775                         return(-1);
 776                         }
 777                 }
 778
 779 start:
 780         s->rwstate=SSL_NOTHING;
 781
 782         /* s->s3->rrec.type         - is the type of record
 783          * s->s3->rrec.data,    - data
 784          * s->s3->rrec.off,     - offset into 'data' for next read
 785          * s->s3->rrec.length,  - number of bytes. */
 786         rr = &(s->s3->rrec);
 787
 788         /* We are not handshaking and have no data yet,
 789          * so process data buffered during the last handshake
 790          * in advance, if any.
 791          */
 792         if (s->state == SSL_ST_OK && rr->length == 0)
 793                 {
 794                 pitem *item;
 795                 item = pqueue_pop(s->d1->buffered_app_data.q);
 796                 if (item)
 797                         {
 798 #ifndef OPENSSL_NO_SCTP
 799                         /* Restore bio_dgram_sctp_rcvinfo struct */
 800                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
 801                                 {
 802                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
 803                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 804                                 }
 805 #endif
 806
 807                         dtls1_copy_record(s, item);
 808
 809                         OPENSSL_free(item->data);
 810                         pitem_free(item);
 811                         }
 812                 }
 813
 814         /* Check for timeout */
 815         if (dtls1_handle_timeout(s) > 0)
 816                 goto start;
 817
 818         /* get new packet if necessary */
 819         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 820                 {
 821                 ret=dtls1_get_record(s);
 822                 if (ret <= 0)
 823                         {
 824                         ret = dtls1_read_failed(s, ret);
 825                         /* anything other than a timeout is an error */
 826                         if (ret <= 0)
 827                                 return(ret);
 828                         else
 829                                 goto start;
 830                         }
 831                 }
 832
 833         /* we now have a packet which can be read and processed */
 834
 835         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 836                                        * reset by ssl3_get_finished */
 837                 && (rr->type != SSL3_RT_HANDSHAKE))
 838                 {
 839                 /* We now have application data between CCS and Finished.
 840                  * Most likely the packets were reordered on their way, so
 841                  * buffer the application data for later processing rather
 842                  * than dropping the connection.
 843                  */
 844                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 845                 rr->length = 0;
 846                 goto start;
 847                 }
 848
 849         /* If the other end has shut down, throw anything we read away
 850          * (even in 'peek' mode) */
 851         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 852                 {
 853                 rr->length=0;
 854                 s->rwstate=SSL_NOTHING;
 855                 return(0);
 856                 }
 857
 858
 859         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 860                 {
 861                 /* make sure that we are not getting application data when we
 862                  * are doing a handshake for the first time */
 863                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 864                         (s->enc_read_ctx == NULL))
 865                         {
 866                         al=SSL_AD_UNEXPECTED_MESSAGE;
 867                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 868                         goto f_err;
 869                         }
 870
 871                 if (len <= 0) return(len);
 872
 873                 if ((unsigned int)len > rr->length)
 874                         n = rr->length;
 875                 else
 876                         n = (unsigned int)len;
 877
 878                 memcpy(buf,&(rr->data[rr->off]),n);
 879                 if (!peek)
 880                         {
 881                         rr->length-=n;
 882                         rr->off+=n;
 883                         if (rr->length == 0)
 884                                 {
 885                                 s->rstate=SSL_ST_READ_HEADER;
 886                                 rr->off=0;
 887                                 }
 888                         }
 889
 890 #ifndef OPENSSL_NO_SCTP
 891                         /* We were about to renegotiate but had to read
 892                          * belated application data first, so retry.
 893                          */
 894                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 895                             rr->type == SSL3_RT_APPLICATION_DATA &&
 896                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
 897                                 {
 898                                 s->rwstate=SSL_READING;
 899                                 BIO_clear_retry_flags(SSL_get_rbio(s));
 900                                 BIO_set_retry_read(SSL_get_rbio(s));
 901                                 }
 902
 903                         /* We might had to delay a close_notify alert because
 904                          * of reordered app data. If there was an alert and there
 905                          * is no message to read anymore, finally set shutdown.
 906                          */
 907                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 908                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
 909                                 {
 910                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 911                                 return(0);
 912                                 }
 913 #endif
 914                 return(n);
 915                 }
 916
 917
 918         /* If we get here, then type != rr->type; if we have a handshake
 919          * message, then it was unexpected (Hello Request or Client Hello). */
 920
 921         /* In case of record types for which we have 'fragment' storage,
 922          * fill that so that we can process the data at a fixed place.
 923          */
 924                 {
 925                 unsigned int k, dest_maxlen = 0;
 926                 unsigned char *dest = NULL;
 927                 unsigned int *dest_len = NULL;
 928
 929                 if (rr->type == SSL3_RT_HANDSHAKE)
 930                         {
 931                         dest_maxlen = sizeof s->d1->handshake_fragment;
 932                         dest = s->d1->handshake_fragment;
 933                         dest_len = &s->d1->handshake_fragment_len;
 934                         }
 935                 else if (rr->type == SSL3_RT_ALERT)
 936                         {
 937                         dest_maxlen = sizeof(s->d1->alert_fragment);
 938                         dest = s->d1->alert_fragment;
 939                         dest_len = &s->d1->alert_fragment_len;
 940                         }
 941 #ifndef OPENSSL_NO_HEARTBEATS
 942                 else if (rr->type == TLS1_RT_HEARTBEAT)
 943                         {
 944                         dtls1_process_heartbeat(s);
 945
 946                         /* Exit and notify application to read again */
 947                         rr->length = 0;
 948                         s->rwstate=SSL_READING;
 949                         BIO_clear_retry_flags(SSL_get_rbio(s));
 950                         BIO_set_retry_read(SSL_get_rbio(s));
 951                         return(-1);
 952                         }
 953 #endif
 954                 /* else it's a CCS message, or application data or wrong */
 955                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 956                         {
 957                         /* Application data while renegotiating
 958                          * is allowed. Try again reading.
 959                          */
 960                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 961                                 {
 962                                 BIO *bio;
 963                                 s->s3->in_read_app_data=2;
 964                                 bio=SSL_get_rbio(s);
 965                                 s->rwstate=SSL_READING;
 966                                 BIO_clear_retry_flags(bio);
 967                                 BIO_set_retry_read(bio);
 968                                 return(-1);
 969                                 }
 970
 971                         /* Not certain if this is the right error handling */
 972                         al=SSL_AD_UNEXPECTED_MESSAGE;
 973                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 974                         goto f_err;
 975                         }
 976
 977                 if (dest_maxlen > 0)
 978                         {
 979             /* XDTLS:  In a pathalogical case, the Client Hello
 980              *  may be fragmented--don't always expect dest_maxlen bytes */
 981                         if ( rr->length < dest_maxlen)
 982                                 {
 983 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 984                                 /*
 985                                  * for normal alerts rr->length is 2, while
 986                                  * dest_maxlen is 7 if we were to handle this
 987                                  * non-existing alert...
 988                                  */
 989                                 FIX ME
 990 #endif
 991                                 s->rstate=SSL_ST_READ_HEADER;
 992                                 rr->length = 0;
 993                                 goto start;
 994                                 }
 995
 996                         /* now move 'n' bytes: */
 997                         for ( k = 0; k < dest_maxlen; k++)
 998                                 {
 999                                 dest[k] = rr->data[rr->off++];
1000                                 rr->length--;
1001                                 }
1002                         *dest_len = dest_maxlen;
1003                         }
1004                 }
1005
1006         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1007          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1008          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1009
1010         /* If we are a client, check for an incoming 'Hello Request': */
1011         if ((!s->server) &&
1012                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1013                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1014                 (s->session != NULL) && (s->session->cipher != NULL))
1015                 {
1016                 s->d1->handshake_fragment_len = 0;
1017
1018                 if ((s->d1->handshake_fragment[1] != 0) ||
1019                         (s->d1->handshake_fragment[2] != 0) ||
1020                         (s->d1->handshake_fragment[3] != 0))
1021                         {
1022                         al=SSL_AD_DECODE_ERROR;
1023                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1024                         goto err;
1025                         }
1026
1027                 /* no need to check sequence number on HELLO REQUEST messages */
1028
1029                 if (s->msg_callback)
1030                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1031                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1032
1033                 if (SSL_is_init_finished(s) &&
1034                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1035                         !s->s3->renegotiate)
1036                         {
1037                         s->new_session = 1;
1038                         ssl3_renegotiate(s);
1039                         if (ssl3_renegotiate_check(s))
1040                                 {
1041                                 i=s->handshake_func(s);
1042                                 if (i < 0) return(i);
1043                                 if (i == 0)
1044                                         {
1045                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1046                                         return(-1);
1047                                         }
1048
1049                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1050                                         {
1051                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1052                                                 {
1053                                                 BIO *bio;
1054                                                 /* In the case where we try to read application data,
1055                                                  * but we trigger an SSL handshake, we return -1 with
1056                                                  * the retry option set.  Otherwise renegotiation may
1057                                                  * cause nasty problems in the blocking world */
1058                                                 s->rwstate=SSL_READING;
1059                                                 bio=SSL_get_rbio(s);
1060                                                 BIO_clear_retry_flags(bio);
1061                                                 BIO_set_retry_read(bio);
1062                                                 return(-1);
1063                                                 }
1064                                         }
1065                                 }
1066                         }
1067                 /* we either finished a handshake or ignored the request,
1068                  * now try again to obtain the (application) data we were asked for */
1069                 goto start;
1070                 }
1071
1072         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1073                 {
1074                 int alert_level = s->d1->alert_fragment[0];
1075                 int alert_descr = s->d1->alert_fragment[1];
1076
1077                 s->d1->alert_fragment_len = 0;
1078
1079                 if (s->msg_callback)
1080                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1081                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1082
1083                 if (s->info_callback != NULL)
1084                         cb=s->info_callback;
1085                 else if (s->ctx->info_callback != NULL)
1086                         cb=s->ctx->info_callback;
1087
1088                 if (cb != NULL)
1089                         {
1090                         j = (alert_level << 8) | alert_descr;
1091                         cb(s, SSL_CB_READ_ALERT, j);
1092                         }
1093
1094                 if (alert_level == 1) /* warning */
1095                         {
1096                         s->s3->warn_alert = alert_descr;
1097                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1098                                 {
1099 #ifndef OPENSSL_NO_SCTP
1100                                 /* With SCTP and streams the socket may deliver app data
1101                                  * after a close_notify alert. We have to check this
1102                                  * first so that nothing gets discarded.
1103                                  */
1104                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1105                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1106                                         {
1107                                         s->d1->shutdown_received = 1;
1108                                         s->rwstate=SSL_READING;
1109                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1110                                         BIO_set_retry_read(SSL_get_rbio(s));
1111                                         return -1;
1112                                         }
1113 #endif
1114                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1115                                 return(0);
1116                                 }
1117 #if 0
1118             /* XXX: this is a possible improvement in the future */
1119                         /* now check if it's a missing record */
1120                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1121                                 {
1122                                 unsigned short seq;
1123                                 unsigned int frag_off;
1124                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1125
1126                                 n2s(p, seq);
1127                                 n2l3(p, frag_off);
1128
1129                                 dtls1_retransmit_message(s,
1130                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1131                                                                                  frag_off, &found);
1132                                 if ( ! found  && SSL_in_init(s))
1133                                         {
1134                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1135                                         /* requested a message not yet sent,
1136                                            send an alert ourselves */
1137                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1138                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1139                                         }
1140                                 }
1141 #endif
1142                         }
1143                 else if (alert_level == 2) /* fatal */
1144                         {
1145                         char tmp[16];
1146
1147                         s->rwstate=SSL_NOTHING;
1148                         s->s3->fatal_alert = alert_descr;
1149                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1150                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1151                         ERR_add_error_data(2,"SSL alert number ",tmp);
1152                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1153                         SSL_CTX_remove_session(s->ctx,s->session);
1154                         return(0);
1155                         }
1156                 else
1157                         {
1158                         al=SSL_AD_ILLEGAL_PARAMETER;
1159                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1160                         goto f_err;
1161                         }
1162
1163                 goto start;
1164                 }
1165
1166         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1167                 {
1168                 s->rwstate=SSL_NOTHING;
1169                 rr->length=0;
1170                 return(0);
1171                 }
1172
1173         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1174                 {
1175                 struct ccs_header_st ccs_hdr;
1176                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1177
1178                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1179
1180                 if (s->version == DTLS1_BAD_VER)
1181                         ccs_hdr_len = 3;
1182
1183                 /* 'Change Cipher Spec' is just a single byte, so we know
1184                  * exactly what the record payload has to look like */
1185                 /* XDTLS: check that epoch is consistent */
1186                 if (    (rr->length != ccs_hdr_len) ||
1187                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1188                         {
1189                         i=SSL_AD_ILLEGAL_PARAMETER;
1190                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1191                         goto err;
1192                         }
1193
1194                 rr->length=0;
1195
1196                 if (s->msg_callback)
1197                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1198                                 rr->data, 1, s, s->msg_callback_arg);
1199
1200                 /* We can't process a CCS now, because previous handshake
1201                  * messages are still missing, so just drop it.
1202                  */
1203                 if (!s->d1->change_cipher_spec_ok)
1204                         {
1205                         goto start;
1206                         }
1207
1208                 s->d1->change_cipher_spec_ok = 0;
1209
1210                 s->s3->change_cipher_spec=1;
1211                 if (!ssl3_do_change_cipher_spec(s))
1212                         goto err;
1213
1214                 /* do this whenever CCS is processed */
1215                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1216
1217                 if (s->version == DTLS1_BAD_VER)
1218                         s->d1->handshake_read_seq++;
1219
1220 #ifndef OPENSSL_NO_SCTP
1221                 /* Remember that a CCS has been received,
1222                  * so that an old key of SCTP-Auth can be
1223                  * deleted when a CCS is sent. Will be ignored
1224                  * if no SCTP is used
1225                  */
1226                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1227 #endif
1228
1229                 goto start;
1230                 }
1231
1232         /* Unexpected handshake message (Client Hello, or protocol violation) */
1233         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1234                 !s->in_handshake)
1235                 {
1236                 struct hm_header_st msg_hdr;
1237
1238                 /* this may just be a stale retransmit */
1239                 dtls1_get_message_header(rr->data, &msg_hdr);
1240                 if( rr->epoch != s->d1->r_epoch)
1241                         {
1242                         rr->length = 0;
1243                         goto start;
1244                         }
1245
1246                 /* If we are server, we may have a repeated FINISHED of the
1247                  * client here, then retransmit our CCS and FINISHED.
1248                  */
1249                 if (msg_hdr.type == SSL3_MT_FINISHED)
1250                         {
1251                         if (dtls1_check_timeout_num(s) < 0)
1252                                 return -1;
1253
1254                         dtls1_retransmit_buffered_messages(s);
1255                         rr->length = 0;
1256                         goto start;
1257                         }
1258
1259                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1260                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1261                         {
1262 #if 0 /* worked only because C operator preferences are not as expected (and
1263        * because this is not really needed for clients except for detecting
1264        * protocol violations): */
1265                         s->state=SSL_ST_BEFORE|(s->server)
1266                                 ?SSL_ST_ACCEPT
1267                                 :SSL_ST_CONNECT;
1268 #else
1269                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1270 #endif
1271                         s->renegotiate=1;
1272                         s->new_session=1;
1273                         }
1274                 i=s->handshake_func(s);
1275                 if (i < 0) return(i);
1276                 if (i == 0)
1277                         {
1278                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1279                         return(-1);
1280                         }
1281
1282                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1283                         {
1284                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1285                                 {
1286                                 BIO *bio;
1287                                 /* In the case where we try to read application data,
1288                                  * but we trigger an SSL handshake, we return -1 with
1289                                  * the retry option set.  Otherwise renegotiation may
1290                                  * cause nasty problems in the blocking world */
1291                                 s->rwstate=SSL_READING;
1292                                 bio=SSL_get_rbio(s);
1293                                 BIO_clear_retry_flags(bio);
1294                                 BIO_set_retry_read(bio);
1295                                 return(-1);
1296                                 }
1297                         }
1298                 goto start;
1299                 }
1300
1301         switch (rr->type)
1302                 {
1303         default:
1304 #ifndef OPENSSL_NO_TLS
1305                 /* TLS just ignores unknown message types */
1306                 if (s->version == TLS1_VERSION)
1307                         {
1308                         rr->length = 0;
1309                         goto start;
1310                         }
1311 #endif
1312                 al=SSL_AD_UNEXPECTED_MESSAGE;
1313                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1314                 goto f_err;
1315         case SSL3_RT_CHANGE_CIPHER_SPEC:
1316         case SSL3_RT_ALERT:
1317         case SSL3_RT_HANDSHAKE:
1318                 /* we already handled all of these, with the possible exception
1319                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1320                  * should not happen when type != rr->type */
1321                 al=SSL_AD_UNEXPECTED_MESSAGE;
1322                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1323                 goto f_err;
1324         case SSL3_RT_APPLICATION_DATA:
1325                 /* At this point, we were expecting handshake data,
1326                  * but have application data.  If the library was
1327                  * running inside ssl3_read() (i.e. in_read_app_data
1328                  * is set) and it makes sense to read application data
1329                  * at this point (session renegotiation not yet started),
1330                  * we will indulge it.
1331                  */
1332                 if (s->s3->in_read_app_data &&
1333                         (s->s3->total_renegotiations != 0) &&
1334                         ((
1335                                 (s->state & SSL_ST_CONNECT) &&
1336                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1337                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1338                                 ) || (
1339                                         (s->state & SSL_ST_ACCEPT) &&
1340                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1341                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1342                                         )
1343                                 ))
1344                         {
1345                         s->s3->in_read_app_data=2;
1346                         return(-1);
1347                         }
1348                 else
1349                         {
1350                         al=SSL_AD_UNEXPECTED_MESSAGE;
1351                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1352                         goto f_err;
1353                         }
1354                 }
1355         /* not reached */
1356
1357 f_err:
1358         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1359 err:
1360         return(-1);
1361         }
1362
1363 int
1364 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1365         {
1366         int i;
1367
1368 #ifndef OPENSSL_NO_SCTP
1369                 /* Check if we have to continue an interrupted handshake
1370                  * for reading belated app data with SCTP.
1371                  */
1372                 if ((SSL_in_init(s) && !s->in_handshake) ||
1373                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1374                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1375 #else
1376                 if (SSL_in_init(s) && !s->in_handshake)
1377 #endif
1378                 {
1379                 i=s->handshake_func(s);
1380                 if (i < 0) return(i);
1381                 if (i == 0)
1382                         {
1383                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1384                         return -1;
1385                         }
1386                 }
1387
1388         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1389                 {
1390                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1391                         return -1;
1392                 }
1393
1394         i = dtls1_write_bytes(s, type, buf_, len);
1395         return i;
1396         }
1397
1398
1399         /* this only happens when a client hello is received and a handshake
1400          * is started. */
1401 static int
1402 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1403         int len, int peek)
1404         {
1405
1406         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1407                 /* (partially) satisfy request from storage */
1408                 {
1409                 unsigned char *src = s->d1->handshake_fragment;
1410                 unsigned char *dst = buf;
1411                 unsigned int k,n;
1412
1413                 /* peek == 0 */
1414                 n = 0;
1415                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1416                         {
1417                         *dst++ = *src++;
1418                         len--; s->d1->handshake_fragment_len--;
1419                         n++;
1420                         }
1421                 /* move any remaining fragment bytes: */
1422                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1423                         s->d1->handshake_fragment[k] = *src++;
1424                 return n;
1425                 }
1426
1427         return 0;
1428         }
1429
1430
1431
1432
1433 /* Call this to write data in records of type 'type'
1434  * It will return <= 0 if not all data has been sent or non-blocking IO.
1435  */
1436 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1437         {
1438         int i;
1439
1440         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1441         s->rwstate=SSL_NOTHING;
1442         i=do_dtls1_write(s, type, buf, len, 0);
1443         return i;
1444         }
1445
1446 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1447         {
1448         unsigned char *p,*pseq;
1449         int i,mac_size,clear=0;
1450         int prefix_len = 0;
1451         SSL3_RECORD *wr;
1452         SSL3_BUFFER *wb;
1453         SSL_SESSION *sess;
1454         int bs;
1455
1456         /* first check if there is a SSL3_BUFFER still being written
1457          * out.  This will happen with non blocking IO */
1458         if (s->s3->wbuf.left != 0)
1459                 {
1460                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1461                 return(ssl3_write_pending(s,type,buf,len));
1462                 }
1463
1464         /* If we have an alert to send, lets send it */
1465         if (s->s3->alert_dispatch)
1466                 {
1467                 i=s->method->ssl_dispatch_alert(s);
1468                 if (i <= 0)
1469                         return(i);
1470                 /* if it went, fall through and send more stuff */
1471                 }
1472
1473         if (len == 0 && !create_empty_fragment)
1474                 return 0;
1475
1476         wr= &(s->s3->wrec);
1477         wb= &(s->s3->wbuf);
1478         sess=s->session;
1479
1480         if (    (sess == NULL) ||
1481                 (s->enc_write_ctx == NULL) ||
1482                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1483                 clear=1;
1484
1485         if (clear)
1486                 mac_size=0;
1487         else
1488                 {
1489                 mac_size=EVP_MD_CTX_size(s->write_hash);
1490                 if (mac_size < 0)
1491                         goto err;
1492                 }
1493
1494         /* DTLS implements explicit IV, so no need for empty fragments */
1495 #if 0
1496         /* 'create_empty_fragment' is true only when this function calls itself */
1497         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1498             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1499                 {
1500                 /* countermeasure against known-IV weakness in CBC ciphersuites
1501                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1502                  */
1503
1504                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1505                         {
1506                         /* recursive function call with 'create_empty_fragment' set;
1507                          * this prepares and buffers the data for an empty fragment
1508                          * (these 'prefix_len' bytes are sent out later
1509                          * together with the actual payload) */
1510                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1511                         if (prefix_len <= 0)
1512                                 goto err;
1513
1514                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1515                                 {
1516                                 /* insufficient space */
1517                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1518                                 goto err;
1519                                 }
1520                         }
1521
1522                 s->s3->empty_fragment_done = 1;
1523                 }
1524 #endif
1525         p = wb->buf + prefix_len;
1526
1527         /* write the header */
1528
1529         *(p++)=type&0xff;
1530         wr->type=type;
1531
1532         *(p++)=(s->version>>8);
1533         *(p++)=s->version&0xff;
1534
1535         /* field where we are to write out packet epoch, seq num and len */
1536         pseq=p;
1537         p+=10;
1538
1539         /* lets setup the record stuff. */
1540
1541         /* Make space for the explicit IV in case of CBC.
1542          * (this is a bit of a boundary violation, but what the heck).
1543          */
1544         if ( s->enc_write_ctx &&
1545                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1546                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1547         else
1548                 bs = 0;
1549
1550         wr->data=p + bs;  /* make room for IV in case of CBC */
1551         wr->length=(int)len;
1552         wr->input=(unsigned char *)buf;
1553
1554         /* we now 'read' from wr->input, wr->length bytes into
1555          * wr->data */
1556
1557         /* first we compress */
1558         if (s->compress != NULL)
1559                 {
1560                 if (!ssl3_do_compress(s))
1561                         {
1562                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1563                         goto err;
1564                         }
1565                 }
1566         else
1567                 {
1568                 memcpy(wr->data,wr->input,wr->length);
1569                 wr->input=wr->data;
1570                 }
1571
1572         /* we should still have the output to wr->data and the input
1573          * from wr->input.  Length should be wr->length.
1574          * wr->data still points in the wb->buf */
1575
1576         if (mac_size != 0)
1577                 {
1578                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1579                         goto err;
1580                 wr->length+=mac_size;
1581                 }
1582
1583         /* this is true regardless of mac size */
1584         wr->input=p;
1585         wr->data=p;
1586
1587
1588         /* ssl3_enc can only have an error on read */
1589         if (bs) /* bs != 0 in case of CBC */
1590                 {
1591                 RAND_pseudo_bytes(p,bs);
1592                 /* master IV and last CBC residue stand for
1593                  * the rest of randomness */
1594                 wr->length += bs;
1595                 }
1596
1597         s->method->ssl3_enc->enc(s,1);
1598
1599         /* record length after mac and block padding */
1600 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1601         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1602
1603         /* there's only one epoch between handshake and app data */
1604
1605         s2n(s->d1->w_epoch, pseq);
1606
1607         /* XDTLS: ?? */
1608 /*      else
1609         s2n(s->d1->handshake_epoch, pseq); */
1610
1611         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1612         pseq+=6;
1613         s2n(wr->length,pseq);
1614
1615         /* we should now have
1616          * wr->data pointing to the encrypted data, which is
1617          * wr->length long */
1618         wr->type=type; /* not needed but helps for debugging */
1619         wr->length+=DTLS1_RT_HEADER_LENGTH;
1620
1621 #if 0  /* this is now done at the message layer */
1622         /* buffer the record, making it easy to handle retransmits */
1623         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1624                 dtls1_buffer_record(s, wr->data, wr->length,
1625                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1626 #endif
1627
1628         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1629
1630         if (create_empty_fragment)
1631                 {
1632                 /* we are in a recursive call;
1633                  * just return the length, don't write out anything here
1634                  */
1635                 return wr->length;
1636                 }
1637
1638         /* now let's set up wb */
1639         wb->left = prefix_len + wr->length;
1640         wb->offset = 0;
1641
1642         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1643         s->s3->wpend_tot=len;
1644         s->s3->wpend_buf=buf;
1645         s->s3->wpend_type=type;
1646         s->s3->wpend_ret=len;
1647
1648         /* we now just need to write the buffer */
1649         return ssl3_write_pending(s,type,buf,len);
1650 err:
1651         return -1;
1652         }
1653
1654
1655
1656 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1657         {
1658         int cmp;
1659         unsigned int shift;
1660         const unsigned char *seq = s->s3->read_sequence;
1661
1662         cmp = satsub64be(seq,bitmap->max_seq_num);
1663         if (cmp > 0)
1664                 {
1665                 memcpy (s->s3->rrec.seq_num,seq,8);
1666                 return 1; /* this record in new */
1667                 }
1668         shift = -cmp;
1669         if (shift >= sizeof(bitmap->map)*8)
1670                 return 0; /* stale, outside the window */
1671         else if (bitmap->map & (1UL<<shift))
1672                 return 0; /* record previously received */
1673
1674         memcpy (s->s3->rrec.seq_num,seq,8);
1675         return 1;
1676         }
1677
1678
1679 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1680         {
1681         int cmp;
1682         unsigned int shift;
1683         const unsigned char *seq = s->s3->read_sequence;
1684
1685         cmp = satsub64be(seq,bitmap->max_seq_num);
1686         if (cmp > 0)
1687                 {
1688                 shift = cmp;
1689                 if (shift < sizeof(bitmap->map)*8)
1690                         bitmap->map <<= shift, bitmap->map |= 1UL;
1691                 else
1692                         bitmap->map = 1UL;
1693                 memcpy(bitmap->max_seq_num,seq,8);
1694                 }
1695         else    {
1696                 shift = -cmp;
1697                 if (shift < sizeof(bitmap->map)*8)
1698                         bitmap->map |= 1UL<<shift;
1699                 }
1700         }
1701
1702
1703 int dtls1_dispatch_alert(SSL *s)
1704         {
1705         int i,j;
1706         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1707         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1708         unsigned char *ptr = &buf[0];
1709
1710         s->s3->alert_dispatch=0;
1711
1712         memset(buf, 0x00, sizeof(buf));
1713         *ptr++ = s->s3->send_alert[0];
1714         *ptr++ = s->s3->send_alert[1];
1715
1716 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1717         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1718                 {
1719                 s2n(s->d1->handshake_read_seq, ptr);
1720 #if 0
1721                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1722
1723                 else
1724                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1725 #endif
1726
1727 #if 0
1728                 fprintf(stderr, "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",s->d1->handshake_read_seq,s->d1->r_msg_hdr.seq);
1729 #endif
1730                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1731                 }
1732 #endif
1733
1734         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1735         if (i <= 0)
1736                 {
1737                 s->s3->alert_dispatch=1;
1738                 /* fprintf( stderr, "not done with alert\n" ); */
1739                 }
1740         else
1741                 {
1742                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1743 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1744                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1745 #endif
1746                     )
1747                         (void)BIO_flush(s->wbio);
1748
1749                 if (s->msg_callback)
1750                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1751                                 2, s, s->msg_callback_arg);
1752
1753                 if (s->info_callback != NULL)
1754                         cb=s->info_callback;
1755                 else if (s->ctx->info_callback != NULL)
1756                         cb=s->ctx->info_callback;
1757
1758                 if (cb != NULL)
1759                         {
1760                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1761                         cb(s,SSL_CB_WRITE_ALERT,j);
1762                         }
1763                 }
1764         return(i);
1765         }
1766
1767
1768 static DTLS1_BITMAP *
1769 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1770     {
1771
1772     *is_next_epoch = 0;
1773
1774     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1775     if (rr->epoch == s->d1->r_epoch)
1776         return &s->d1->bitmap;
1777
1778     /* Only HM and ALERT messages can be from the next epoch */
1779     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1780         (rr->type == SSL3_RT_HANDSHAKE ||
1781             rr->type == SSL3_RT_ALERT))
1782         {
1783         *is_next_epoch = 1;
1784         return &s->d1->next_bitmap;
1785         }
1786
1787     return NULL;
1788     }
1789
1790 #if 0
1791 static int
1792 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1793         unsigned long *offset)
1794         {
1795
1796         /* alerts are passed up immediately */
1797         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1798                 rr->type == SSL3_RT_ALERT)
1799                 return 0;
1800
1801         /* Only need to buffer if a handshake is underway.
1802          * (this implies that Hello Request and Client Hello are passed up
1803          * immediately) */
1804         if ( SSL_in_init(s))
1805                 {
1806                 unsigned char *data = rr->data;
1807                 /* need to extract the HM/CCS sequence number here */
1808                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1809                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1810                         {
1811                         unsigned short seq_num;
1812                         struct hm_header_st msg_hdr;
1813                         struct ccs_header_st ccs_hdr;
1814
1815                         if ( rr->type == SSL3_RT_HANDSHAKE)
1816                                 {
1817                                 dtls1_get_message_header(data, &msg_hdr);
1818                                 seq_num = msg_hdr.seq;
1819                                 *offset = msg_hdr.frag_off;
1820                                 }
1821                         else
1822                                 {
1823                                 dtls1_get_ccs_header(data, &ccs_hdr);
1824                                 seq_num = ccs_hdr.seq;
1825                                 *offset = 0;
1826                                 }
1827
1828                         /* this is either a record we're waiting for, or a
1829                          * retransmit of something we happened to previously
1830                          * receive (higher layers will drop the repeat silently */
1831                         if ( seq_num < s->d1->handshake_read_seq)
1832                                 return 0;
1833                         if (rr->type == SSL3_RT_HANDSHAKE &&
1834                                 seq_num == s->d1->handshake_read_seq &&
1835                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1836                                 return 0;
1837                         else if ( seq_num == s->d1->handshake_read_seq &&
1838                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1839                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1840                                 return 0;
1841                         else
1842                                 {
1843                                 *priority = seq_num;
1844                                 return 1;
1845                                 }
1846                         }
1847                 else /* unknown record type */
1848                         return 0;
1849                 }
1850
1851         return 0;
1852         }
1853 #endif
1854
1855 void
1856 dtls1_reset_seq_numbers(SSL *s, int rw)
1857         {
1858         unsigned char *seq;
1859         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1860
1861         if ( rw & SSL3_CC_READ)
1862                 {
1863                 seq = s->s3->read_sequence;
1864                 s->d1->r_epoch++;
1865                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1866                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1867                 }
1868         else
1869                 {
1870                 seq = s->s3->write_sequence;
1871                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1872                 s->d1->w_epoch++;
1873                 }
1874
1875         memset(seq, 0x00, seq_bytes);
1876         }