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 static void dtls1_clear_timeouts(SSL *s);
 183
 184 /* copy buffered record into SSL structure */
 185 static int
 186 dtls1_copy_record(SSL *s, pitem *item)
 187     {
 188     DTLS1_RECORD_DATA *rdata;
 189
 190     rdata = (DTLS1_RECORD_DATA *)item->data;
 191
 192     if (s->s3->rbuf.buf != NULL)
 193         OPENSSL_free(s->s3->rbuf.buf);
 194
 195     s->packet = rdata->packet;
 196     s->packet_length = rdata->packet_length;
 197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 199
 200         /* Set proper sequence number for mac calculation */
 201         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 202
 203     return(1);
 204     }
 205
 206
 207 static int
 208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 209         {
 210         DTLS1_RECORD_DATA *rdata;
 211         pitem *item;
 212
 213         /* Limit the size of the queue to prevent DOS attacks */
 214         if (pqueue_size(queue->q) >= 100)
 215                 return 0;
 216
 217         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 218         item = pitem_new(priority, rdata);
 219         if (rdata == NULL || item == NULL)
 220                 {
 221                 if (rdata != NULL) OPENSSL_free(rdata);
 222                 if (item != NULL) pitem_free(item);
 223
 224                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 225                 return(0);
 226                 }
 227
 228         rdata->packet = s->packet;
 229         rdata->packet_length = s->packet_length;
 230         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 231         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 232
 233         item->data = rdata;
 234
 235 #ifndef OPENSSL_NO_SCTP
 236         /* Store bio_dgram_sctp_rcvinfo struct */
 237         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 238             (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
 239                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 240         }
 241 #endif
 242
 243         /* insert should not fail, since duplicates are dropped */
 244         if (pqueue_insert(queue->q, item) == NULL)
 245                 {
 246                 OPENSSL_free(rdata);
 247                 pitem_free(item);
 248                 return(0);
 249                 }
 250
 251         s->packet = NULL;
 252         s->packet_length = 0;
 253         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 254         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 255
 256         if (!ssl3_setup_buffers(s))
 257                 {
 258                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 259                 OPENSSL_free(rdata);
 260                 pitem_free(item);
 261                 return(0);
 262                 }
 263
 264         return(1);
 265         }
 266
 267
 268 static int
 269 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 270     {
 271     pitem *item;
 272
 273     item = pqueue_pop(queue->q);
 274     if (item)
 275         {
 276         dtls1_copy_record(s, item);
 277
 278         OPENSSL_free(item->data);
 279                 pitem_free(item);
 280
 281         return(1);
 282         }
 283
 284     return(0);
 285     }
 286
 287
 288 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 289  * yet */
 290 #define dtls1_get_unprocessed_record(s) \
 291                    dtls1_retrieve_buffered_record((s), \
 292                    &((s)->d1->unprocessed_rcds))
 293
 294 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 295 #define dtls1_get_processed_record(s) \
 296                    dtls1_retrieve_buffered_record((s), \
 297                    &((s)->d1->processed_rcds))
 298
 299 static int
 300 dtls1_process_buffered_records(SSL *s)
 301     {
 302     pitem *item;
 303
 304     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 305     if (item)
 306         {
 307         /* Check if epoch is current. */
 308         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 309             return(1);  /* Nothing to do. */
 310
 311         /* Process all the records. */
 312         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 313             {
 314             dtls1_get_unprocessed_record(s);
 315             if ( ! dtls1_process_record(s))
 316                 return(0);
 317             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 318                 s->s3->rrec.seq_num);
 319             }
 320         }
 321
 322     /* sync epoch numbers once all the unprocessed records
 323      * have been processed */
 324     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 325     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 326
 327     return(1);
 328     }
 329
 330
 331 #if 0
 332
 333 static int
 334 dtls1_get_buffered_record(SSL *s)
 335         {
 336         pitem *item;
 337         PQ_64BIT priority =
 338                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 339                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 340
 341         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 342                                                            nothing buffered */
 343                 return 0;
 344
 345
 346         item = pqueue_peek(s->d1->rcvd_records);
 347         if (item && item->priority == priority)
 348                 {
 349                 /* Check if we've received the record of interest.  It must be
 350                  * a handshake record, since data records as passed up without
 351                  * buffering */
 352                 DTLS1_RECORD_DATA *rdata;
 353                 item = pqueue_pop(s->d1->rcvd_records);
 354                 rdata = (DTLS1_RECORD_DATA *)item->data;
 355
 356                 if (s->s3->rbuf.buf != NULL)
 357                         OPENSSL_free(s->s3->rbuf.buf);
 358
 359                 s->packet = rdata->packet;
 360                 s->packet_length = rdata->packet_length;
 361                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 362                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 363
 364                 OPENSSL_free(item->data);
 365                 pitem_free(item);
 366
 367                 /* s->d1->next_expected_seq_num++; */
 368                 return(1);
 369                 }
 370
 371         return 0;
 372         }
 373
 374 #endif
 375
 376 static int
 377 dtls1_process_record(SSL *s)
 378 {
 379         int i,al;
 380         int clear=0;
 381         int enc_err;
 382         SSL_SESSION *sess;
 383         SSL3_RECORD *rr;
 384         unsigned int mac_size;
 385         unsigned char md[EVP_MAX_MD_SIZE];
 386         int decryption_failed_or_bad_record_mac = 0;
 387         unsigned char *mac = NULL;
 388
 389
 390         rr= &(s->s3->rrec);
 391         sess = s->session;
 392
 393         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 394          * and we have that many bytes in s->packet
 395          */
 396         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 397
 398         /* ok, we can now read from 's->packet' data into 'rr'
 399          * rr->input points at rr->length bytes, which
 400          * need to be copied into rr->data by either
 401          * the decryption or by the decompression
 402          * When the data is 'copied' into the rr->data buffer,
 403          * rr->input will be pointed at the new buffer */
 404
 405         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 406          * rr->length bytes of encrypted compressed stuff. */
 407
 408         /* check is not needed I believe */
 409         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 410                 {
 411                 al=SSL_AD_RECORD_OVERFLOW;
 412                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 413                 goto f_err;
 414                 }
 415
 416         /* decrypt in place in 'rr->input' */
 417         rr->data=rr->input;
 418
 419         enc_err = s->method->ssl3_enc->enc(s,0);
 420         if (enc_err <= 0)
 421                 {
 422                 /* To minimize information leaked via timing, we will always
 423                  * perform all computations before discarding the message.
 424                  */
 425                 decryption_failed_or_bad_record_mac = 1;
 426                 }
 427
 428 #ifdef TLS_DEBUG
 429 printf("dec %d\n",rr->length);
 430 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 431 printf("\n");
 432 #endif
 433
 434         /* r->length is now the compressed data plus mac */
 435         if (    (sess == NULL) ||
 436                 (s->enc_read_ctx == NULL) ||
 437                 (s->read_hash == NULL))
 438                 clear=1;
 439
 440         if (!clear)
 441                 {
 442                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 443                 int t;
 444                 t=EVP_MD_CTX_size(s->read_hash);
 445                 OPENSSL_assert(t >= 0);
 446                 mac_size=t;
 447
 448                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 449                         {
 450 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 451                         al=SSL_AD_RECORD_OVERFLOW;
 452                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 453                         goto f_err;
 454 #else
 455                         decryption_failed_or_bad_record_mac = 1;
 456 #endif
 457                         }
 458                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 459                 if (rr->length >= mac_size)
 460                         {
 461                         rr->length -= mac_size;
 462                         mac = &rr->data[rr->length];
 463                         }
 464                 else
 465                         rr->length = 0;
 466                 i=s->method->ssl3_enc->mac(s,md,0);
 467                 if (i < 0 || mac == NULL || memcmp(md, mac, mac_size) != 0)
 468                         {
 469                         decryption_failed_or_bad_record_mac = 1;
 470                         }
 471                 }
 472
 473         if (decryption_failed_or_bad_record_mac)
 474                 {
 475                 /* decryption failed, silently discard message */
 476                 rr->length = 0;
 477                 s->packet_length = 0;
 478                 goto err;
 479                 }
 480
 481         /* r->length is now just compressed */
 482         if (s->expand != NULL)
 483                 {
 484                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 485                         {
 486                         al=SSL_AD_RECORD_OVERFLOW;
 487                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 488                         goto f_err;
 489                         }
 490                 if (!ssl3_do_uncompress(s))
 491                         {
 492                         al=SSL_AD_DECOMPRESSION_FAILURE;
 493                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 494                         goto f_err;
 495                         }
 496                 }
 497
 498         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 499                 {
 500                 al=SSL_AD_RECORD_OVERFLOW;
 501                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 502                 goto f_err;
 503                 }
 504
 505         rr->off=0;
 506         /* So at this point the following is true
 507          * ssl->s3->rrec.type   is the type of record
 508          * ssl->s3->rrec.length == number of bytes in record
 509          * ssl->s3->rrec.off    == offset to first valid byte
 510          * ssl->s3->rrec.data   == where to take bytes from, increment
 511          *                         after use :-).
 512          */
 513
 514         /* we have pulled in a full packet so zero things */
 515         s->packet_length=0;
 516         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 517         return(1);
 518
 519 f_err:
 520         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 521 err:
 522         return(0);
 523 }
 524
 525
 526 /* Call this to get a new input record.
 527  * It will return <= 0 if more data is needed, normally due to an error
 528  * or non-blocking IO.
 529  * When it finishes, one packet has been decoded and can be found in
 530  * ssl->s3->rrec.type    - is the type of record
 531  * ssl->s3->rrec.data,   - data
 532  * ssl->s3->rrec.length, - number of bytes
 533  */
 534 /* used only by dtls1_read_bytes */
 535 int dtls1_get_record(SSL *s)
 536         {
 537         int ssl_major,ssl_minor;
 538         int i,n;
 539         SSL3_RECORD *rr;
 540         unsigned char *p = NULL;
 541         unsigned short version;
 542         DTLS1_BITMAP *bitmap;
 543         unsigned int is_next_epoch;
 544
 545         rr= &(s->s3->rrec);
 546
 547         /* The epoch may have changed.  If so, process all the
 548          * pending records.  This is a non-blocking operation. */
 549         dtls1_process_buffered_records(s);
 550
 551         /* if we're renegotiating, then there may be buffered records */
 552         if (dtls1_get_processed_record(s))
 553                 return 1;
 554
 555         /* get something from the wire */
 556 again:
 557         /* check if we have the header */
 558         if (    (s->rstate != SSL_ST_READ_BODY) ||
 559                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 560                 {
 561                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 562                 /* read timeout is handled by dtls1_read_bytes */
 563                 if (n <= 0) return(n); /* error or non-blocking */
 564
 565                 /* this packet contained a partial record, dump it */
 566                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 567                         {
 568                         s->packet_length = 0;
 569                         goto again;
 570                         }
 571
 572                 s->rstate=SSL_ST_READ_BODY;
 573
 574                 p=s->packet;
 575
 576                 /* Pull apart the header into the DTLS1_RECORD */
 577                 rr->type= *(p++);
 578                 ssl_major= *(p++);
 579                 ssl_minor= *(p++);
 580                 version=(ssl_major<<8)|ssl_minor;
 581
 582                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 583                 n2s(p,rr->epoch);
 584
 585                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 586                 p+=6;
 587
 588                 n2s(p,rr->length);
 589
 590                 /* Lets check version */
 591                 if (!s->first_packet)
 592                         {
 593                         if (version != s->version)
 594                                 {
 595                                 /* unexpected version, silently discard */
 596                                 rr->length = 0;
 597                                 s->packet_length = 0;
 598                                 goto again;
 599                                 }
 600                         }
 601
 602                 if ((version & 0xff00) != (s->version & 0xff00))
 603                         {
 604                         /* wrong version, silently discard record */
 605                         rr->length = 0;
 606                         s->packet_length = 0;
 607                         goto again;
 608                         }
 609
 610                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 611                         {
 612                         /* record too long, silently discard it */
 613                         rr->length = 0;
 614                         s->packet_length = 0;
 615                         goto again;
 616                         }
 617
 618                 /* now s->rstate == SSL_ST_READ_BODY */
 619                 }
 620
 621         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 622
 623         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 624                 {
 625                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 626                 i=rr->length;
 627                 n=ssl3_read_n(s,i,i,1);
 628                 if (n <= 0) return(n); /* error or non-blocking io */
 629
 630                 /* this packet contained a partial record, dump it */
 631                 if ( n != i)
 632                         {
 633                         rr->length = 0;
 634                         s->packet_length = 0;
 635                         goto again;
 636                         }
 637
 638                 /* now n == rr->length,
 639                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 640                 }
 641         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 642
 643         /* match epochs.  NULL means the packet is dropped on the floor */
 644         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 645         if ( bitmap == NULL)
 646                 {
 647                 rr->length = 0;
 648                 s->packet_length = 0;  /* dump this record */
 649                 goto again;   /* get another record */
 650                 }
 651
 652 #ifndef OPENSSL_NO_SCTP
 653         /* Only do replay check if no SCTP bio */
 654         if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
 655                 {
 656 #endif
 657                 /* Check whether this is a repeat, or aged record.
 658                  * Don't check if we're listening and this message is
 659                  * a ClientHello. They can look as if they're replayed,
 660                  * since they arrive from different connections and
 661                  * would be dropped unnecessarily.
 662                  */
 663                 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 664                     *p == SSL3_MT_CLIENT_HELLO) &&
 665                     !dtls1_record_replay_check(s, bitmap))
 666                         {
 667                         rr->length = 0;
 668                         s->packet_length=0; /* dump this record */
 669                         goto again;     /* get another record */
 670                         }
 671 #ifndef OPENSSL_NO_SCTP
 672                 }
 673 #endif
 674
 675         /* just read a 0 length packet */
 676         if (rr->length == 0) goto again;
 677
 678         /* If this record is from the next epoch (either HM or ALERT),
 679          * and a handshake is currently in progress, buffer it since it
 680          * cannot be processed at this time. However, do not buffer
 681          * anything while listening.
 682          */
 683         if (is_next_epoch)
 684                 {
 685                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 686                         {
 687                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 688                         }
 689                 rr->length = 0;
 690                 s->packet_length = 0;
 691                 goto again;
 692                 }
 693
 694         if (!dtls1_process_record(s))
 695                 {
 696                 rr->length = 0;
 697                 s->packet_length = 0;  /* dump this record */
 698                 goto again;   /* get another record */
 699                 }
 700
 701         dtls1_clear_timeouts(s);  /* done waiting */
 702         return(1);
 703
 704         }
 705
 706 /* Return up to 'len' payload bytes received in 'type' records.
 707  * 'type' is one of the following:
 708  *
 709  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 710  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 711  *   -  0 (during a shutdown, no data has to be returned)
 712  *
 713  * If we don't have stored data to work from, read a SSL/TLS record first
 714  * (possibly multiple records if we still don't have anything to return).
 715  *
 716  * This function must handle any surprises the peer may have for us, such as
 717  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 718  * a surprise, but handled as if it were), or renegotiation requests.
 719  * Also if record payloads contain fragments too small to process, we store
 720  * them until there is enough for the respective protocol (the record protocol
 721  * may use arbitrary fragmentation and even interleaving):
 722  *     Change cipher spec protocol
 723  *             just 1 byte needed, no need for keeping anything stored
 724  *     Alert protocol
 725  *             2 bytes needed (AlertLevel, AlertDescription)
 726  *     Handshake protocol
 727  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 728  *             to detect unexpected Client Hello and Hello Request messages
 729  *             here, anything else is handled by higher layers
 730  *     Application data protocol
 731  *             none of our business
 732  */
 733 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 734         {
 735         int al,i,j,ret;
 736         unsigned int n;
 737         SSL3_RECORD *rr;
 738         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 739
 740         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 741                 if (!ssl3_setup_buffers(s))
 742                         return(-1);
 743
 744     /* XXX: check what the second '&& type' is about */
 745         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 746                 (type != SSL3_RT_HANDSHAKE) && type) ||
 747             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 748                 {
 749                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 750                 return -1;
 751                 }
 752
 753         /* check whether there's a handshake message (client hello?) waiting */
 754         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 755                 return ret;
 756
 757         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 758
 759 #ifndef OPENSSL_NO_SCTP
 760         /* Continue handshake if it had to be interrupted to read
 761          * app data with SCTP.
 762          */
 763         if ((!s->in_handshake && SSL_in_init(s)) ||
 764             (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 765              (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
 766              s->s3->in_read_app_data != 2))
 767 #else
 768         if (!s->in_handshake && SSL_in_init(s))
 769 #endif
 770                 {
 771                 /* type == SSL3_RT_APPLICATION_DATA */
 772                 i=s->handshake_func(s);
 773                 if (i < 0) return(i);
 774                 if (i == 0)
 775                         {
 776                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 777                         return(-1);
 778                         }
 779                 }
 780
 781 start:
 782         s->rwstate=SSL_NOTHING;
 783
 784         /* s->s3->rrec.type         - is the type of record
 785          * s->s3->rrec.data,    - data
 786          * s->s3->rrec.off,     - offset into 'data' for next read
 787          * s->s3->rrec.length,  - number of bytes. */
 788         rr = &(s->s3->rrec);
 789
 790         /* We are not handshaking and have no data yet,
 791          * so process data buffered during the last handshake
 792          * in advance, if any.
 793          */
 794         if (s->state == SSL_ST_OK && rr->length == 0)
 795                 {
 796                 pitem *item;
 797                 item = pqueue_pop(s->d1->buffered_app_data.q);
 798                 if (item)
 799                         {
 800 #ifndef OPENSSL_NO_SCTP
 801                         /* Restore bio_dgram_sctp_rcvinfo struct */
 802                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
 803                                 {
 804                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
 805                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 806                                 }
 807 #endif
 808
 809                         dtls1_copy_record(s, item);
 810
 811                         OPENSSL_free(item->data);
 812                         pitem_free(item);
 813                         }
 814                 }
 815
 816         /* Check for timeout */
 817         if (dtls1_handle_timeout(s) > 0)
 818                 goto start;
 819
 820         /* get new packet if necessary */
 821         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 822                 {
 823                 ret=dtls1_get_record(s);
 824                 if (ret <= 0)
 825                         {
 826                         ret = dtls1_read_failed(s, ret);
 827                         /* anything other than a timeout is an error */
 828                         if (ret <= 0)
 829                                 return(ret);
 830                         else
 831                                 goto start;
 832                         }
 833                 }
 834
 835         /* we now have a packet which can be read and processed */
 836
 837         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 838                                        * reset by ssl3_get_finished */
 839                 && (rr->type != SSL3_RT_HANDSHAKE))
 840                 {
 841                 /* We now have application data between CCS and Finished.
 842                  * Most likely the packets were reordered on their way, so
 843                  * buffer the application data for later processing rather
 844                  * than dropping the connection.
 845                  */
 846                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 847                 rr->length = 0;
 848                 goto start;
 849                 }
 850
 851         /* If the other end has shut down, throw anything we read away
 852          * (even in 'peek' mode) */
 853         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 854                 {
 855                 rr->length=0;
 856                 s->rwstate=SSL_NOTHING;
 857                 return(0);
 858                 }
 859
 860
 861         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 862                 {
 863                 /* make sure that we are not getting application data when we
 864                  * are doing a handshake for the first time */
 865                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 866                         (s->enc_read_ctx == NULL))
 867                         {
 868                         al=SSL_AD_UNEXPECTED_MESSAGE;
 869                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 870                         goto f_err;
 871                         }
 872
 873                 if (len <= 0) return(len);
 874
 875                 if ((unsigned int)len > rr->length)
 876                         n = rr->length;
 877                 else
 878                         n = (unsigned int)len;
 879
 880                 memcpy(buf,&(rr->data[rr->off]),n);
 881                 if (!peek)
 882                         {
 883                         rr->length-=n;
 884                         rr->off+=n;
 885                         if (rr->length == 0)
 886                                 {
 887                                 s->rstate=SSL_ST_READ_HEADER;
 888                                 rr->off=0;
 889                                 }
 890                         }
 891
 892 #ifndef OPENSSL_NO_SCTP
 893                         /* We were about to renegotiate but had to read
 894                          * belated application data first, so retry.
 895                          */
 896                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 897                             rr->type == SSL3_RT_APPLICATION_DATA &&
 898                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
 899                                 {
 900                                 s->rwstate=SSL_READING;
 901                                 BIO_clear_retry_flags(SSL_get_rbio(s));
 902                                 BIO_set_retry_read(SSL_get_rbio(s));
 903                                 }
 904
 905                         /* We might had to delay a close_notify alert because
 906                          * of reordered app data. If there was an alert and there
 907                          * is no message to read anymore, finally set shutdown.
 908                          */
 909                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 910                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
 911                                 {
 912                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 913                                 return(0);
 914                                 }
 915 #endif
 916                 return(n);
 917                 }
 918
 919
 920         /* If we get here, then type != rr->type; if we have a handshake
 921          * message, then it was unexpected (Hello Request or Client Hello). */
 922
 923         /* In case of record types for which we have 'fragment' storage,
 924          * fill that so that we can process the data at a fixed place.
 925          */
 926                 {
 927                 unsigned int k, dest_maxlen = 0;
 928                 unsigned char *dest = NULL;
 929                 unsigned int *dest_len = NULL;
 930
 931                 if (rr->type == SSL3_RT_HANDSHAKE)
 932                         {
 933                         dest_maxlen = sizeof s->d1->handshake_fragment;
 934                         dest = s->d1->handshake_fragment;
 935                         dest_len = &s->d1->handshake_fragment_len;
 936                         }
 937                 else if (rr->type == SSL3_RT_ALERT)
 938                         {
 939                         dest_maxlen = sizeof(s->d1->alert_fragment);
 940                         dest = s->d1->alert_fragment;
 941                         dest_len = &s->d1->alert_fragment_len;
 942                         }
 943 #ifndef OPENSSL_NO_HEARTBEATS
 944                 else if (rr->type == TLS1_RT_HEARTBEAT)
 945                         {
 946                         dtls1_process_heartbeat(s);
 947
 948                         /* Exit and notify application to read again */
 949                         rr->length = 0;
 950                         s->rwstate=SSL_READING;
 951                         BIO_clear_retry_flags(SSL_get_rbio(s));
 952                         BIO_set_retry_read(SSL_get_rbio(s));
 953                         return(-1);
 954                         }
 955 #endif
 956                 /* else it's a CCS message, or application data or wrong */
 957                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 958                         {
 959                         /* Application data while renegotiating
 960                          * is allowed. Try again reading.
 961                          */
 962                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 963                                 {
 964                                 BIO *bio;
 965                                 s->s3->in_read_app_data=2;
 966                                 bio=SSL_get_rbio(s);
 967                                 s->rwstate=SSL_READING;
 968                                 BIO_clear_retry_flags(bio);
 969                                 BIO_set_retry_read(bio);
 970                                 return(-1);
 971                                 }
 972
 973                         /* Not certain if this is the right error handling */
 974                         al=SSL_AD_UNEXPECTED_MESSAGE;
 975                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 976                         goto f_err;
 977                         }
 978
 979                 if (dest_maxlen > 0)
 980                         {
 981             /* XDTLS:  In a pathalogical case, the Client Hello
 982              *  may be fragmented--don't always expect dest_maxlen bytes */
 983                         if ( rr->length < dest_maxlen)
 984                                 {
 985 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 986                                 /*
 987                                  * for normal alerts rr->length is 2, while
 988                                  * dest_maxlen is 7 if we were to handle this
 989                                  * non-existing alert...
 990                                  */
 991                                 FIX ME
 992 #endif
 993                                 s->rstate=SSL_ST_READ_HEADER;
 994                                 rr->length = 0;
 995                                 goto start;
 996                                 }
 997
 998                         /* now move 'n' bytes: */
 999                         for ( k = 0; k < dest_maxlen; k++)
1000                                 {
1001                                 dest[k] = rr->data[rr->off++];
1002                                 rr->length--;
1003                                 }
1004                         *dest_len = dest_maxlen;
1005                         }
1006                 }
1007
1008         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1009          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1010          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1011
1012         /* If we are a client, check for an incoming 'Hello Request': */
1013         if ((!s->server) &&
1014                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1015                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1016                 (s->session != NULL) && (s->session->cipher != NULL))
1017                 {
1018                 s->d1->handshake_fragment_len = 0;
1019
1020                 if ((s->d1->handshake_fragment[1] != 0) ||
1021                         (s->d1->handshake_fragment[2] != 0) ||
1022                         (s->d1->handshake_fragment[3] != 0))
1023                         {
1024                         al=SSL_AD_DECODE_ERROR;
1025                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1026                         goto err;
1027                         }
1028
1029                 /* no need to check sequence number on HELLO REQUEST messages */
1030
1031                 if (s->msg_callback)
1032                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1033                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1034
1035                 if (SSL_is_init_finished(s) &&
1036                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1037                         !s->s3->renegotiate)
1038                         {
1039                         s->new_session = 1;
1040                         ssl3_renegotiate(s);
1041                         if (ssl3_renegotiate_check(s))
1042                                 {
1043                                 i=s->handshake_func(s);
1044                                 if (i < 0) return(i);
1045                                 if (i == 0)
1046                                         {
1047                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1048                                         return(-1);
1049                                         }
1050
1051                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1052                                         {
1053                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1054                                                 {
1055                                                 BIO *bio;
1056                                                 /* In the case where we try to read application data,
1057                                                  * but we trigger an SSL handshake, we return -1 with
1058                                                  * the retry option set.  Otherwise renegotiation may
1059                                                  * cause nasty problems in the blocking world */
1060                                                 s->rwstate=SSL_READING;
1061                                                 bio=SSL_get_rbio(s);
1062                                                 BIO_clear_retry_flags(bio);
1063                                                 BIO_set_retry_read(bio);
1064                                                 return(-1);
1065                                                 }
1066                                         }
1067                                 }
1068                         }
1069                 /* we either finished a handshake or ignored the request,
1070                  * now try again to obtain the (application) data we were asked for */
1071                 goto start;
1072                 }
1073
1074         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1075                 {
1076                 int alert_level = s->d1->alert_fragment[0];
1077                 int alert_descr = s->d1->alert_fragment[1];
1078
1079                 s->d1->alert_fragment_len = 0;
1080
1081                 if (s->msg_callback)
1082                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1083                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1084
1085                 if (s->info_callback != NULL)
1086                         cb=s->info_callback;
1087                 else if (s->ctx->info_callback != NULL)
1088                         cb=s->ctx->info_callback;
1089
1090                 if (cb != NULL)
1091                         {
1092                         j = (alert_level << 8) | alert_descr;
1093                         cb(s, SSL_CB_READ_ALERT, j);
1094                         }
1095
1096                 if (alert_level == 1) /* warning */
1097                         {
1098                         s->s3->warn_alert = alert_descr;
1099                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1100                                 {
1101 #ifndef OPENSSL_NO_SCTP
1102                                 /* With SCTP and streams the socket may deliver app data
1103                                  * after a close_notify alert. We have to check this
1104                                  * first so that nothing gets discarded.
1105                                  */
1106                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1107                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1108                                         {
1109                                         s->d1->shutdown_received = 1;
1110                                         s->rwstate=SSL_READING;
1111                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1112                                         BIO_set_retry_read(SSL_get_rbio(s));
1113                                         return -1;
1114                                         }
1115 #endif
1116                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1117                                 return(0);
1118                                 }
1119 #if 0
1120             /* XXX: this is a possible improvement in the future */
1121                         /* now check if it's a missing record */
1122                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1123                                 {
1124                                 unsigned short seq;
1125                                 unsigned int frag_off;
1126                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1127
1128                                 n2s(p, seq);
1129                                 n2l3(p, frag_off);
1130
1131                                 dtls1_retransmit_message(s,
1132                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1133                                                                                  frag_off, &found);
1134                                 if ( ! found  && SSL_in_init(s))
1135                                         {
1136                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1137                                         /* requested a message not yet sent,
1138                                            send an alert ourselves */
1139                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1140                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1141                                         }
1142                                 }
1143 #endif
1144                         }
1145                 else if (alert_level == 2) /* fatal */
1146                         {
1147                         char tmp[16];
1148
1149                         s->rwstate=SSL_NOTHING;
1150                         s->s3->fatal_alert = alert_descr;
1151                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1152                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1153                         ERR_add_error_data(2,"SSL alert number ",tmp);
1154                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1155                         SSL_CTX_remove_session(s->ctx,s->session);
1156                         return(0);
1157                         }
1158                 else
1159                         {
1160                         al=SSL_AD_ILLEGAL_PARAMETER;
1161                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1162                         goto f_err;
1163                         }
1164
1165                 goto start;
1166                 }
1167
1168         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1169                 {
1170                 s->rwstate=SSL_NOTHING;
1171                 rr->length=0;
1172                 return(0);
1173                 }
1174
1175         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1176                 {
1177                 struct ccs_header_st ccs_hdr;
1178                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1179
1180                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1181
1182                 if (s->version == DTLS1_BAD_VER)
1183                         ccs_hdr_len = 3;
1184
1185                 /* 'Change Cipher Spec' is just a single byte, so we know
1186                  * exactly what the record payload has to look like */
1187                 /* XDTLS: check that epoch is consistent */
1188                 if (    (rr->length != ccs_hdr_len) ||
1189                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1190                         {
1191                         i=SSL_AD_ILLEGAL_PARAMETER;
1192                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1193                         goto err;
1194                         }
1195
1196                 rr->length=0;
1197
1198                 if (s->msg_callback)
1199                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1200                                 rr->data, 1, s, s->msg_callback_arg);
1201
1202                 /* We can't process a CCS now, because previous handshake
1203                  * messages are still missing, so just drop it.
1204                  */
1205                 if (!s->d1->change_cipher_spec_ok)
1206                         {
1207                         goto start;
1208                         }
1209
1210                 s->d1->change_cipher_spec_ok = 0;
1211
1212                 s->s3->change_cipher_spec=1;
1213                 if (!ssl3_do_change_cipher_spec(s))
1214                         goto err;
1215
1216                 /* do this whenever CCS is processed */
1217                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1218
1219                 if (s->version == DTLS1_BAD_VER)
1220                         s->d1->handshake_read_seq++;
1221
1222 #ifndef OPENSSL_NO_SCTP
1223                 /* Remember that a CCS has been received,
1224                  * so that an old key of SCTP-Auth can be
1225                  * deleted when a CCS is sent. Will be ignored
1226                  * if no SCTP is used
1227                  */
1228                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1229 #endif
1230
1231                 goto start;
1232                 }
1233
1234         /* Unexpected handshake message (Client Hello, or protocol violation) */
1235         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1236                 !s->in_handshake)
1237                 {
1238                 struct hm_header_st msg_hdr;
1239
1240                 /* this may just be a stale retransmit */
1241                 dtls1_get_message_header(rr->data, &msg_hdr);
1242                 if( rr->epoch != s->d1->r_epoch)
1243                         {
1244                         rr->length = 0;
1245                         goto start;
1246                         }
1247
1248                 /* If we are server, we may have a repeated FINISHED of the
1249                  * client here, then retransmit our CCS and FINISHED.
1250                  */
1251                 if (msg_hdr.type == SSL3_MT_FINISHED)
1252                         {
1253                         dtls1_retransmit_buffered_messages(s);
1254                         rr->length = 0;
1255                         goto start;
1256                         }
1257
1258                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1259                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1260                         {
1261 #if 0 /* worked only because C operator preferences are not as expected (and
1262        * because this is not really needed for clients except for detecting
1263        * protocol violations): */
1264                         s->state=SSL_ST_BEFORE|(s->server)
1265                                 ?SSL_ST_ACCEPT
1266                                 :SSL_ST_CONNECT;
1267 #else
1268                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1269 #endif
1270                         s->renegotiate=1;
1271                         s->new_session=1;
1272                         }
1273                 i=s->handshake_func(s);
1274                 if (i < 0) return(i);
1275                 if (i == 0)
1276                         {
1277                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1278                         return(-1);
1279                         }
1280
1281                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1282                         {
1283                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1284                                 {
1285                                 BIO *bio;
1286                                 /* In the case where we try to read application data,
1287                                  * but we trigger an SSL handshake, we return -1 with
1288                                  * the retry option set.  Otherwise renegotiation may
1289                                  * cause nasty problems in the blocking world */
1290                                 s->rwstate=SSL_READING;
1291                                 bio=SSL_get_rbio(s);
1292                                 BIO_clear_retry_flags(bio);
1293                                 BIO_set_retry_read(bio);
1294                                 return(-1);
1295                                 }
1296                         }
1297                 goto start;
1298                 }
1299
1300         switch (rr->type)
1301                 {
1302         default:
1303 #ifndef OPENSSL_NO_TLS
1304                 /* TLS just ignores unknown message types */
1305                 if (s->version == TLS1_VERSION)
1306                         {
1307                         rr->length = 0;
1308                         goto start;
1309                         }
1310 #endif
1311                 al=SSL_AD_UNEXPECTED_MESSAGE;
1312                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1313                 goto f_err;
1314         case SSL3_RT_CHANGE_CIPHER_SPEC:
1315         case SSL3_RT_ALERT:
1316         case SSL3_RT_HANDSHAKE:
1317                 /* we already handled all of these, with the possible exception
1318                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1319                  * should not happen when type != rr->type */
1320                 al=SSL_AD_UNEXPECTED_MESSAGE;
1321                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1322                 goto f_err;
1323         case SSL3_RT_APPLICATION_DATA:
1324                 /* At this point, we were expecting handshake data,
1325                  * but have application data.  If the library was
1326                  * running inside ssl3_read() (i.e. in_read_app_data
1327                  * is set) and it makes sense to read application data
1328                  * at this point (session renegotiation not yet started),
1329                  * we will indulge it.
1330                  */
1331                 if (s->s3->in_read_app_data &&
1332                         (s->s3->total_renegotiations != 0) &&
1333                         ((
1334                                 (s->state & SSL_ST_CONNECT) &&
1335                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1336                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1337                                 ) || (
1338                                         (s->state & SSL_ST_ACCEPT) &&
1339                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1340                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1341                                         )
1342                                 ))
1343                         {
1344                         s->s3->in_read_app_data=2;
1345                         return(-1);
1346                         }
1347                 else
1348                         {
1349                         al=SSL_AD_UNEXPECTED_MESSAGE;
1350                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1351                         goto f_err;
1352                         }
1353                 }
1354         /* not reached */
1355
1356 f_err:
1357         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1358 err:
1359         return(-1);
1360         }
1361
1362 int
1363 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1364         {
1365         int i;
1366
1367 #ifndef OPENSSL_NO_SCTP
1368                 /* Check if we have to continue an interrupted handshake
1369                  * for reading belated app data with SCTP.
1370                  */
1371                 if ((SSL_in_init(s) && !s->in_handshake) ||
1372                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1373                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1374 #else
1375                 if (SSL_in_init(s) && !s->in_handshake)
1376 #endif
1377                 {
1378                 i=s->handshake_func(s);
1379                 if (i < 0) return(i);
1380                 if (i == 0)
1381                         {
1382                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1383                         return -1;
1384                         }
1385                 }
1386
1387         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1388                 {
1389                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1390                         return -1;
1391                 }
1392
1393         i = dtls1_write_bytes(s, type, buf_, len);
1394         return i;
1395         }
1396
1397
1398         /* this only happens when a client hello is received and a handshake
1399          * is started. */
1400 static int
1401 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1402         int len, int peek)
1403         {
1404
1405         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1406                 /* (partially) satisfy request from storage */
1407                 {
1408                 unsigned char *src = s->d1->handshake_fragment;
1409                 unsigned char *dst = buf;
1410                 unsigned int k,n;
1411
1412                 /* peek == 0 */
1413                 n = 0;
1414                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1415                         {
1416                         *dst++ = *src++;
1417                         len--; s->d1->handshake_fragment_len--;
1418                         n++;
1419                         }
1420                 /* move any remaining fragment bytes: */
1421                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1422                         s->d1->handshake_fragment[k] = *src++;
1423                 return n;
1424                 }
1425
1426         return 0;
1427         }
1428
1429
1430
1431
1432 /* Call this to write data in records of type 'type'
1433  * It will return <= 0 if not all data has been sent or non-blocking IO.
1434  */
1435 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1436         {
1437         int i;
1438
1439         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1440         s->rwstate=SSL_NOTHING;
1441         i=do_dtls1_write(s, type, buf, len, 0);
1442         return i;
1443         }
1444
1445 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1446         {
1447         unsigned char *p,*pseq;
1448         int i,mac_size,clear=0;
1449         int prefix_len = 0;
1450         SSL3_RECORD *wr;
1451         SSL3_BUFFER *wb;
1452         SSL_SESSION *sess;
1453         int bs;
1454
1455         /* first check if there is a SSL3_BUFFER still being written
1456          * out.  This will happen with non blocking IO */
1457         if (s->s3->wbuf.left != 0)
1458                 {
1459                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1460                 return(ssl3_write_pending(s,type,buf,len));
1461                 }
1462
1463         /* If we have an alert to send, lets send it */
1464         if (s->s3->alert_dispatch)
1465                 {
1466                 i=s->method->ssl_dispatch_alert(s);
1467                 if (i <= 0)
1468                         return(i);
1469                 /* if it went, fall through and send more stuff */
1470                 }
1471
1472         if (len == 0 && !create_empty_fragment)
1473                 return 0;
1474
1475         wr= &(s->s3->wrec);
1476         wb= &(s->s3->wbuf);
1477         sess=s->session;
1478
1479         if (    (sess == NULL) ||
1480                 (s->enc_write_ctx == NULL) ||
1481                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1482                 clear=1;
1483
1484         if (clear)
1485                 mac_size=0;
1486         else
1487                 {
1488                 mac_size=EVP_MD_CTX_size(s->write_hash);
1489                 if (mac_size < 0)
1490                         goto err;
1491                 }
1492
1493         /* DTLS implements explicit IV, so no need for empty fragments */
1494 #if 0
1495         /* 'create_empty_fragment' is true only when this function calls itself */
1496         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1497             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1498                 {
1499                 /* countermeasure against known-IV weakness in CBC ciphersuites
1500                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1501                  */
1502
1503                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1504                         {
1505                         /* recursive function call with 'create_empty_fragment' set;
1506                          * this prepares and buffers the data for an empty fragment
1507                          * (these 'prefix_len' bytes are sent out later
1508                          * together with the actual payload) */
1509                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1510                         if (prefix_len <= 0)
1511                                 goto err;
1512
1513                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1514                                 {
1515                                 /* insufficient space */
1516                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1517                                 goto err;
1518                                 }
1519                         }
1520
1521                 s->s3->empty_fragment_done = 1;
1522                 }
1523 #endif
1524         p = wb->buf + prefix_len;
1525
1526         /* write the header */
1527
1528         *(p++)=type&0xff;
1529         wr->type=type;
1530
1531         *(p++)=(s->version>>8);
1532         *(p++)=s->version&0xff;
1533
1534         /* field where we are to write out packet epoch, seq num and len */
1535         pseq=p;
1536         p+=10;
1537
1538         /* lets setup the record stuff. */
1539
1540         /* Make space for the explicit IV in case of CBC.
1541          * (this is a bit of a boundary violation, but what the heck).
1542          */
1543         if ( s->enc_write_ctx &&
1544                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1545                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1546         else
1547                 bs = 0;
1548
1549         wr->data=p + bs;  /* make room for IV in case of CBC */
1550         wr->length=(int)len;
1551         wr->input=(unsigned char *)buf;
1552
1553         /* we now 'read' from wr->input, wr->length bytes into
1554          * wr->data */
1555
1556         /* first we compress */
1557         if (s->compress != NULL)
1558                 {
1559                 if (!ssl3_do_compress(s))
1560                         {
1561                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1562                         goto err;
1563                         }
1564                 }
1565         else
1566                 {
1567                 memcpy(wr->data,wr->input,wr->length);
1568                 wr->input=wr->data;
1569                 }
1570
1571         /* we should still have the output to wr->data and the input
1572          * from wr->input.  Length should be wr->length.
1573          * wr->data still points in the wb->buf */
1574
1575         if (mac_size != 0)
1576                 {
1577                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1578                         goto err;
1579                 wr->length+=mac_size;
1580                 }
1581
1582         /* this is true regardless of mac size */
1583         wr->input=p;
1584         wr->data=p;
1585
1586
1587         /* ssl3_enc can only have an error on read */
1588         if (bs) /* bs != 0 in case of CBC */
1589                 {
1590                 RAND_pseudo_bytes(p,bs);
1591                 /* master IV and last CBC residue stand for
1592                  * the rest of randomness */
1593                 wr->length += bs;
1594                 }
1595
1596         s->method->ssl3_enc->enc(s,1);
1597
1598         /* record length after mac and block padding */
1599 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1600         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1601
1602         /* there's only one epoch between handshake and app data */
1603
1604         s2n(s->d1->w_epoch, pseq);
1605
1606         /* XDTLS: ?? */
1607 /*      else
1608         s2n(s->d1->handshake_epoch, pseq); */
1609
1610         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1611         pseq+=6;
1612         s2n(wr->length,pseq);
1613
1614         /* we should now have
1615          * wr->data pointing to the encrypted data, which is
1616          * wr->length long */
1617         wr->type=type; /* not needed but helps for debugging */
1618         wr->length+=DTLS1_RT_HEADER_LENGTH;
1619
1620 #if 0  /* this is now done at the message layer */
1621         /* buffer the record, making it easy to handle retransmits */
1622         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1623                 dtls1_buffer_record(s, wr->data, wr->length,
1624                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1625 #endif
1626
1627         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1628
1629         if (create_empty_fragment)
1630                 {
1631                 /* we are in a recursive call;
1632                  * just return the length, don't write out anything here
1633                  */
1634                 return wr->length;
1635                 }
1636
1637         /* now let's set up wb */
1638         wb->left = prefix_len + wr->length;
1639         wb->offset = 0;
1640
1641         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1642         s->s3->wpend_tot=len;
1643         s->s3->wpend_buf=buf;
1644         s->s3->wpend_type=type;
1645         s->s3->wpend_ret=len;
1646
1647         /* we now just need to write the buffer */
1648         return ssl3_write_pending(s,type,buf,len);
1649 err:
1650         return -1;
1651         }
1652
1653
1654
1655 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1656         {
1657         int cmp;
1658         unsigned int shift;
1659         const unsigned char *seq = s->s3->read_sequence;
1660
1661         cmp = satsub64be(seq,bitmap->max_seq_num);
1662         if (cmp > 0)
1663                 {
1664                 memcpy (s->s3->rrec.seq_num,seq,8);
1665                 return 1; /* this record in new */
1666                 }
1667         shift = -cmp;
1668         if (shift >= sizeof(bitmap->map)*8)
1669                 return 0; /* stale, outside the window */
1670         else if (bitmap->map & (1UL<<shift))
1671                 return 0; /* record previously received */
1672
1673         memcpy (s->s3->rrec.seq_num,seq,8);
1674         return 1;
1675         }
1676
1677
1678 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1679         {
1680         int cmp;
1681         unsigned int shift;
1682         const unsigned char *seq = s->s3->read_sequence;
1683
1684         cmp = satsub64be(seq,bitmap->max_seq_num);
1685         if (cmp > 0)
1686                 {
1687                 shift = cmp;
1688                 if (shift < sizeof(bitmap->map)*8)
1689                         bitmap->map <<= shift, bitmap->map |= 1UL;
1690                 else
1691                         bitmap->map = 1UL;
1692                 memcpy(bitmap->max_seq_num,seq,8);
1693                 }
1694         else    {
1695                 shift = -cmp;
1696                 if (shift < sizeof(bitmap->map)*8)
1697                         bitmap->map |= 1UL<<shift;
1698                 }
1699         }
1700
1701
1702 int dtls1_dispatch_alert(SSL *s)
1703         {
1704         int i,j;
1705         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1706         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1707         unsigned char *ptr = &buf[0];
1708
1709         s->s3->alert_dispatch=0;
1710
1711         memset(buf, 0x00, sizeof(buf));
1712         *ptr++ = s->s3->send_alert[0];
1713         *ptr++ = s->s3->send_alert[1];
1714
1715 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1716         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1717                 {
1718                 s2n(s->d1->handshake_read_seq, ptr);
1719 #if 0
1720                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1721
1722                 else
1723                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1724 #endif
1725
1726 #if 0
1727                 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);
1728 #endif
1729                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1730                 }
1731 #endif
1732
1733         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1734         if (i <= 0)
1735                 {
1736                 s->s3->alert_dispatch=1;
1737                 /* fprintf( stderr, "not done with alert\n" ); */
1738                 }
1739         else
1740                 {
1741                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1742 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1743                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1744 #endif
1745                     )
1746                         (void)BIO_flush(s->wbio);
1747
1748                 if (s->msg_callback)
1749                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1750                                 2, s, s->msg_callback_arg);
1751
1752                 if (s->info_callback != NULL)
1753                         cb=s->info_callback;
1754                 else if (s->ctx->info_callback != NULL)
1755                         cb=s->ctx->info_callback;
1756
1757                 if (cb != NULL)
1758                         {
1759                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1760                         cb(s,SSL_CB_WRITE_ALERT,j);
1761                         }
1762                 }
1763         return(i);
1764         }
1765
1766
1767 static DTLS1_BITMAP *
1768 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1769     {
1770
1771     *is_next_epoch = 0;
1772
1773     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1774     if (rr->epoch == s->d1->r_epoch)
1775         return &s->d1->bitmap;
1776
1777     /* Only HM and ALERT messages can be from the next epoch */
1778     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1779         (rr->type == SSL3_RT_HANDSHAKE ||
1780             rr->type == SSL3_RT_ALERT))
1781         {
1782         *is_next_epoch = 1;
1783         return &s->d1->next_bitmap;
1784         }
1785
1786     return NULL;
1787     }
1788
1789 #if 0
1790 static int
1791 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1792         unsigned long *offset)
1793         {
1794
1795         /* alerts are passed up immediately */
1796         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1797                 rr->type == SSL3_RT_ALERT)
1798                 return 0;
1799
1800         /* Only need to buffer if a handshake is underway.
1801          * (this implies that Hello Request and Client Hello are passed up
1802          * immediately) */
1803         if ( SSL_in_init(s))
1804                 {
1805                 unsigned char *data = rr->data;
1806                 /* need to extract the HM/CCS sequence number here */
1807                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1808                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1809                         {
1810                         unsigned short seq_num;
1811                         struct hm_header_st msg_hdr;
1812                         struct ccs_header_st ccs_hdr;
1813
1814                         if ( rr->type == SSL3_RT_HANDSHAKE)
1815                                 {
1816                                 dtls1_get_message_header(data, &msg_hdr);
1817                                 seq_num = msg_hdr.seq;
1818                                 *offset = msg_hdr.frag_off;
1819                                 }
1820                         else
1821                                 {
1822                                 dtls1_get_ccs_header(data, &ccs_hdr);
1823                                 seq_num = ccs_hdr.seq;
1824                                 *offset = 0;
1825                                 }
1826
1827                         /* this is either a record we're waiting for, or a
1828                          * retransmit of something we happened to previously
1829                          * receive (higher layers will drop the repeat silently */
1830                         if ( seq_num < s->d1->handshake_read_seq)
1831                                 return 0;
1832                         if (rr->type == SSL3_RT_HANDSHAKE &&
1833                                 seq_num == s->d1->handshake_read_seq &&
1834                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1835                                 return 0;
1836                         else if ( seq_num == s->d1->handshake_read_seq &&
1837                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1838                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1839                                 return 0;
1840                         else
1841                                 {
1842                                 *priority = seq_num;
1843                                 return 1;
1844                                 }
1845                         }
1846                 else /* unknown record type */
1847                         return 0;
1848                 }
1849
1850         return 0;
1851         }
1852 #endif
1853
1854 void
1855 dtls1_reset_seq_numbers(SSL *s, int rw)
1856         {
1857         unsigned char *seq;
1858         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1859
1860         if ( rw & SSL3_CC_READ)
1861                 {
1862                 seq = s->s3->read_sequence;
1863                 s->d1->r_epoch++;
1864                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1865                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1866                 }
1867         else
1868                 {
1869                 seq = s->s3->write_sequence;
1870                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1871                 s->d1->w_epoch++;
1872                 }
1873
1874         memset(seq, 0x00, seq_bytes);
1875         }
1876
1877
1878 static void
1879 dtls1_clear_timeouts(SSL *s)
1880         {
1881         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1882         }