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