ssl/d1_pkt.c

   1 /* ssl/d1_pkt.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182
 183 /* copy buffered record into SSL structure */
 184 static int
 185 dtls1_copy_record(SSL *s, pitem *item)
 186     {
 187     DTLS1_RECORD_DATA *rdata;
 188
 189     rdata = (DTLS1_RECORD_DATA *)item->data;
 190
 191     if (s->s3->rbuf.buf != NULL)
 192         OPENSSL_free(s->s3->rbuf.buf);
 193
 194     s->packet = rdata->packet;
 195     s->packet_length = rdata->packet_length;
 196     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 197     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 198
 199         /* Set proper sequence number for mac calculation */
 200         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 201
 202     return(1);
 203     }
 204
 205
 206 static int
 207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 208         {
 209         DTLS1_RECORD_DATA *rdata;
 210         pitem *item;
 211
 212         /* Limit the size of the queue to prevent DOS attacks */
 213         if (pqueue_size(queue->q) >= 100)
 214                 return 0;
 215
 216         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 217         item = pitem_new(priority, rdata);
 218         if (rdata == NULL || item == NULL)
 219                 {
 220                 if (rdata != NULL) OPENSSL_free(rdata);
 221                 if (item != NULL) pitem_free(item);
 222
 223                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 224                 return(0);
 225                 }
 226
 227         rdata->packet = s->packet;
 228         rdata->packet_length = s->packet_length;
 229         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 230         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 231
 232         item->data = rdata;
 233
 234 #ifndef OPENSSL_NO_SCTP
 235         /* Store bio_dgram_sctp_rcvinfo struct */
 236         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 237             (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
 238                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 239         }
 240 #endif
 241
 242         /* insert should not fail, since duplicates are dropped */
 243         if (pqueue_insert(queue->q, item) == NULL)
 244                 {
 245                 OPENSSL_free(rdata);
 246                 pitem_free(item);
 247                 return(0);
 248                 }
 249
 250         s->packet = NULL;
 251         s->packet_length = 0;
 252         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 253         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 254
 255         if (!ssl3_setup_buffers(s))
 256                 {
 257                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 258                 OPENSSL_free(rdata);
 259                 pitem_free(item);
 260                 return(0);
 261                 }
 262
 263         return(1);
 264         }
 265
 266
 267 static int
 268 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 269     {
 270     pitem *item;
 271
 272     item = pqueue_pop(queue->q);
 273     if (item)
 274         {
 275         dtls1_copy_record(s, item);
 276
 277         OPENSSL_free(item->data);
 278                 pitem_free(item);
 279
 280         return(1);
 281         }
 282
 283     return(0);
 284     }
 285
 286
 287 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 288  * yet */
 289 #define dtls1_get_unprocessed_record(s) \
 290                    dtls1_retrieve_buffered_record((s), \
 291                    &((s)->d1->unprocessed_rcds))
 292
 293 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 294 #define dtls1_get_processed_record(s) \
 295                    dtls1_retrieve_buffered_record((s), \
 296                    &((s)->d1->processed_rcds))
 297
 298 static int
 299 dtls1_process_buffered_records(SSL *s)
 300     {
 301     pitem *item;
 302
 303     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 304     if (item)
 305         {
 306         /* Check if epoch is current. */
 307         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 308             return(1);  /* Nothing to do. */
 309
 310         /* Process all the records. */
 311         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 312             {
 313             dtls1_get_unprocessed_record(s);
 314             if ( ! dtls1_process_record(s))
 315                 return(0);
 316             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 317                 s->s3->rrec.seq_num);
 318             }
 319         }
 320
 321     /* sync epoch numbers once all the unprocessed records
 322      * have been processed */
 323     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 324     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 325
 326     return(1);
 327     }
 328
 329
 330 #if 0
 331
 332 static int
 333 dtls1_get_buffered_record(SSL *s)
 334         {
 335         pitem *item;
 336         PQ_64BIT priority =
 337                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 338                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 339
 340         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 341                                                            nothing buffered */
 342                 return 0;
 343
 344
 345         item = pqueue_peek(s->d1->rcvd_records);
 346         if (item && item->priority == priority)
 347                 {
 348                 /* Check if we've received the record of interest.  It must be
 349                  * a handshake record, since data records as passed up without
 350                  * buffering */
 351                 DTLS1_RECORD_DATA *rdata;
 352                 item = pqueue_pop(s->d1->rcvd_records);
 353                 rdata = (DTLS1_RECORD_DATA *)item->data;
 354
 355                 if (s->s3->rbuf.buf != NULL)
 356                         OPENSSL_free(s->s3->rbuf.buf);
 357
 358                 s->packet = rdata->packet;
 359                 s->packet_length = rdata->packet_length;
 360                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 361                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 362
 363                 OPENSSL_free(item->data);
 364                 pitem_free(item);
 365
 366                 /* s->d1->next_expected_seq_num++; */
 367                 return(1);
 368                 }
 369
 370         return 0;
 371         }
 372
 373 #endif
 374
 375 static int
 376 dtls1_process_record(SSL *s)
 377 {
 378         int i,al;
 379         int enc_err;
 380         SSL_SESSION *sess;
 381         SSL3_RECORD *rr;
 382         unsigned int mac_size;
 383         unsigned char md[EVP_MAX_MD_SIZE];
 384
 385         rr= &(s->s3->rrec);
 386         sess = s->session;
 387
 388         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 389          * and we have that many bytes in s->packet
 390          */
 391         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 392
 393         /* ok, we can now read from 's->packet' data into 'rr'
 394          * rr->input points at rr->length bytes, which
 395          * need to be copied into rr->data by either
 396          * the decryption or by the decompression
 397          * When the data is 'copied' into the rr->data buffer,
 398          * rr->input will be pointed at the new buffer */
 399
 400         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 401          * rr->length bytes of encrypted compressed stuff. */
 402
 403         /* check is not needed I believe */
 404         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 405                 {
 406                 al=SSL_AD_RECORD_OVERFLOW;
 407                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 408                 goto f_err;
 409                 }
 410
 411         /* decrypt in place in 'rr->input' */
 412         rr->data=rr->input;
 413         rr->orig_len=rr->length;
 414
 415         enc_err = s->method->ssl3_enc->enc(s,0);
 416         /* enc_err is:
 417          *    0: (in non-constant time) if the record is publically invalid.
 418          *    1: if the padding is valid
 419          *    -1: if the padding is invalid */
 420         if (enc_err == 0)
 421                 {
 422                 /* For DTLS we simply ignore bad packets. */
 423                 rr->length = 0;
 424                 s->packet_length = 0;
 425                 goto err;
 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             (EVP_MD_CTX_md(s->read_hash) != NULL))
 438                 {
 439                 /* s->read_hash != NULL => mac_size != -1 */
 440                 unsigned char *mac = NULL;
 441                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 442                 mac_size=EVP_MD_CTX_size(s->read_hash);
 443                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 444
 445                 /* orig_len is the length of the record before any padding was
 446                  * removed. This is public information, as is the MAC in use,
 447                  * therefore we can safely process the record in a different
 448                  * amount of time if it's too short to possibly contain a MAC.
 449                  */
 450                 if (rr->orig_len < mac_size ||
 451                     /* CBC records must have a padding length byte too. */
 452                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 453                      rr->orig_len < mac_size+1))
 454                         {
 455                         al=SSL_AD_DECODE_ERROR;
 456                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 457                         goto f_err;
 458                         }
 459
 460                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 461                         {
 462                         /* We update the length so that the TLS header bytes
 463                          * can be constructed correctly but we need to extract
 464                          * the MAC in constant time from within the record,
 465                          * without leaking the contents of the padding bytes.
 466                          * */
 467                         mac = mac_tmp;
 468                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
 469                         rr->length -= mac_size;
 470                         }
 471                 else
 472                         {
 473                         /* In this case there's no padding, so |rec->orig_len|
 474                          * equals |rec->length| and we checked that there's
 475                          * enough bytes for |mac_size| above. */
 476                         rr->length -= mac_size;
 477                         mac = &rr->data[rr->length];
 478                         }
 479
 480                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 481                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 482                         enc_err = -1;
 483                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 484                         enc_err = -1;
 485                 }
 486
 487         if (enc_err < 0)
 488                 {
 489                 /* decryption failed, silently discard message */
 490                 rr->length = 0;
 491                 s->packet_length = 0;
 492                 goto err;
 493                 }
 494
 495         /* r->length is now just compressed */
 496         if (s->expand != NULL)
 497                 {
 498                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 499                         {
 500                         al=SSL_AD_RECORD_OVERFLOW;
 501                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 502                         goto f_err;
 503                         }
 504                 if (!ssl3_do_uncompress(s))
 505                         {
 506                         al=SSL_AD_DECOMPRESSION_FAILURE;
 507                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 508                         goto f_err;
 509                         }
 510                 }
 511
 512         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 513                 {
 514                 al=SSL_AD_RECORD_OVERFLOW;
 515                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 516                 goto f_err;
 517                 }
 518
 519         rr->off=0;
 520         /* So at this point the following is true
 521          * ssl->s3->rrec.type   is the type of record
 522          * ssl->s3->rrec.length == number of bytes in record
 523          * ssl->s3->rrec.off    == offset to first valid byte
 524          * ssl->s3->rrec.data   == where to take bytes from, increment
 525          *                         after use :-).
 526          */
 527
 528         /* we have pulled in a full packet so zero things */
 529         s->packet_length=0;
 530         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 531         return(1);
 532
 533 f_err:
 534         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 535 err:
 536         return(0);
 537 }
 538
 539
 540 /* Call this to get a new input record.
 541  * It will return <= 0 if more data is needed, normally due to an error
 542  * or non-blocking IO.
 543  * When it finishes, one packet has been decoded and can be found in
 544  * ssl->s3->rrec.type    - is the type of record
 545  * ssl->s3->rrec.data,   - data
 546  * ssl->s3->rrec.length, - number of bytes
 547  */
 548 /* used only by dtls1_read_bytes */
 549 int dtls1_get_record(SSL *s)
 550         {
 551         int ssl_major,ssl_minor;
 552         int i,n;
 553         SSL3_RECORD *rr;
 554         unsigned char *p = NULL;
 555         unsigned short version;
 556         DTLS1_BITMAP *bitmap;
 557         unsigned int is_next_epoch;
 558
 559         rr= &(s->s3->rrec);
 560
 561         /* The epoch may have changed.  If so, process all the
 562          * pending records.  This is a non-blocking operation. */
 563         dtls1_process_buffered_records(s);
 564
 565         /* if we're renegotiating, then there may be buffered records */
 566         if (dtls1_get_processed_record(s))
 567                 return 1;
 568
 569         /* get something from the wire */
 570 again:
 571         /* check if we have the header */
 572         if (    (s->rstate != SSL_ST_READ_BODY) ||
 573                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 574                 {
 575                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 576                 /* read timeout is handled by dtls1_read_bytes */
 577                 if (n <= 0) return(n); /* error or non-blocking */
 578
 579                 /* this packet contained a partial record, dump it */
 580                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 581                         {
 582                         s->packet_length = 0;
 583                         goto again;
 584                         }
 585
 586                 s->rstate=SSL_ST_READ_BODY;
 587
 588                 p=s->packet;
 589
 590                 if (s->msg_callback)
 591                         s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
 592
 593                 /* Pull apart the header into the DTLS1_RECORD */
 594                 rr->type= *(p++);
 595                 ssl_major= *(p++);
 596                 ssl_minor= *(p++);
 597                 version=(ssl_major<<8)|ssl_minor;
 598
 599                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 600                 n2s(p,rr->epoch);
 601
 602                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 603                 p+=6;
 604
 605                 n2s(p,rr->length);
 606
 607                 /* Lets check version */
 608                 if (!s->first_packet)
 609                         {
 610                         if (version != s->version)
 611                                 {
 612                                 /* unexpected version, silently discard */
 613                                 rr->length = 0;
 614                                 s->packet_length = 0;
 615                                 goto again;
 616                                 }
 617                         }
 618
 619                 if ((version & 0xff00) != (s->version & 0xff00))
 620                         {
 621                         /* wrong version, silently discard record */
 622                         rr->length = 0;
 623                         s->packet_length = 0;
 624                         goto again;
 625                         }
 626
 627                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 628                         {
 629                         /* record too long, silently discard it */
 630                         rr->length = 0;
 631                         s->packet_length = 0;
 632                         goto again;
 633                         }
 634
 635                 /* now s->rstate == SSL_ST_READ_BODY */
 636                 }
 637
 638         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 639
 640         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 641                 {
 642                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 643                 i=rr->length;
 644                 n=ssl3_read_n(s,i,i,1);
 645                 if (n <= 0) return(n); /* error or non-blocking io */
 646
 647                 /* this packet contained a partial record, dump it */
 648                 if ( n != i)
 649                         {
 650                         rr->length = 0;
 651                         s->packet_length = 0;
 652                         goto again;
 653                         }
 654
 655                 /* now n == rr->length,
 656                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 657                 }
 658         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 659
 660         /* match epochs.  NULL means the packet is dropped on the floor */
 661         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 662         if ( bitmap == NULL)
 663                 {
 664                 rr->length = 0;
 665                 s->packet_length = 0;  /* dump this record */
 666                 goto again;   /* get another record */
 667                 }
 668
 669 #ifndef OPENSSL_NO_SCTP
 670         /* Only do replay check if no SCTP bio */
 671         if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
 672                 {
 673 #endif
 674                 /* Check whether this is a repeat, or aged record.
 675                  * Don't check if we're listening and this message is
 676                  * a ClientHello. They can look as if they're replayed,
 677                  * since they arrive from different connections and
 678                  * would be dropped unnecessarily.
 679                  */
 680                 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 681                     *p == SSL3_MT_CLIENT_HELLO) &&
 682                     !dtls1_record_replay_check(s, bitmap))
 683                         {
 684                         rr->length = 0;
 685                         s->packet_length=0; /* dump this record */
 686                         goto again;     /* get another record */
 687                         }
 688 #ifndef OPENSSL_NO_SCTP
 689                 }
 690 #endif
 691
 692         /* just read a 0 length packet */
 693         if (rr->length == 0) goto again;
 694
 695         /* If this record is from the next epoch (either HM or ALERT),
 696          * and a handshake is currently in progress, buffer it since it
 697          * cannot be processed at this time. However, do not buffer
 698          * anything while listening.
 699          */
 700         if (is_next_epoch)
 701                 {
 702                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 703                         {
 704                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 705                         }
 706                 rr->length = 0;
 707                 s->packet_length = 0;
 708                 goto again;
 709                 }
 710
 711         if (!dtls1_process_record(s))
 712                 {
 713                 rr->length = 0;
 714                 s->packet_length = 0;  /* dump this record */
 715                 goto again;   /* get another record */
 716                 }
 717
 718         return(1);
 719
 720         }
 721
 722 /* Return up to 'len' payload bytes received in 'type' records.
 723  * 'type' is one of the following:
 724  *
 725  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 726  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 727  *   -  0 (during a shutdown, no data has to be returned)
 728  *
 729  * If we don't have stored data to work from, read a SSL/TLS record first
 730  * (possibly multiple records if we still don't have anything to return).
 731  *
 732  * This function must handle any surprises the peer may have for us, such as
 733  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 734  * a surprise, but handled as if it were), or renegotiation requests.
 735  * Also if record payloads contain fragments too small to process, we store
 736  * them until there is enough for the respective protocol (the record protocol
 737  * may use arbitrary fragmentation and even interleaving):
 738  *     Change cipher spec protocol
 739  *             just 1 byte needed, no need for keeping anything stored
 740  *     Alert protocol
 741  *             2 bytes needed (AlertLevel, AlertDescription)
 742  *     Handshake protocol
 743  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 744  *             to detect unexpected Client Hello and Hello Request messages
 745  *             here, anything else is handled by higher layers
 746  *     Application data protocol
 747  *             none of our business
 748  */
 749 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 750         {
 751         int al,i,j,ret;
 752         unsigned int n;
 753         SSL3_RECORD *rr;
 754         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 755
 756         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 757                 if (!ssl3_setup_buffers(s))
 758                         return(-1);
 759
 760     /* XXX: check what the second '&& type' is about */
 761         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 762                 (type != SSL3_RT_HANDSHAKE) && type) ||
 763             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 764                 {
 765                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 766                 return -1;
 767                 }
 768
 769         /* check whether there's a handshake message (client hello?) waiting */
 770         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 771                 return ret;
 772
 773         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 774
 775 #ifndef OPENSSL_NO_SCTP
 776         /* Continue handshake if it had to be interrupted to read
 777          * app data with SCTP.
 778          */
 779         if ((!s->in_handshake && SSL_in_init(s)) ||
 780             (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 781              (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
 782              s->s3->in_read_app_data != 2))
 783 #else
 784         if (!s->in_handshake && SSL_in_init(s))
 785 #endif
 786                 {
 787                 /* type == SSL3_RT_APPLICATION_DATA */
 788                 i=s->handshake_func(s);
 789                 if (i < 0) return(i);
 790                 if (i == 0)
 791                         {
 792                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 793                         return(-1);
 794                         }
 795                 }
 796
 797 start:
 798         s->rwstate=SSL_NOTHING;
 799
 800         /* s->s3->rrec.type         - is the type of record
 801          * s->s3->rrec.data,    - data
 802          * s->s3->rrec.off,     - offset into 'data' for next read
 803          * s->s3->rrec.length,  - number of bytes. */
 804         rr = &(s->s3->rrec);
 805
 806         /* We are not handshaking and have no data yet,
 807          * so process data buffered during the last handshake
 808          * in advance, if any.
 809          */
 810         if (s->state == SSL_ST_OK && rr->length == 0)
 811                 {
 812                 pitem *item;
 813                 item = pqueue_pop(s->d1->buffered_app_data.q);
 814                 if (item)
 815                         {
 816 #ifndef OPENSSL_NO_SCTP
 817                         /* Restore bio_dgram_sctp_rcvinfo struct */
 818                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
 819                                 {
 820                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
 821                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 822                                 }
 823 #endif
 824
 825                         dtls1_copy_record(s, item);
 826
 827                         OPENSSL_free(item->data);
 828                         pitem_free(item);
 829                         }
 830                 }
 831
 832         /* Check for timeout */
 833         if (dtls1_handle_timeout(s) > 0)
 834                 goto start;
 835
 836         /* get new packet if necessary */
 837         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 838                 {
 839                 ret=dtls1_get_record(s);
 840                 if (ret <= 0)
 841                         {
 842                         ret = dtls1_read_failed(s, ret);
 843                         /* anything other than a timeout is an error */
 844                         if (ret <= 0)
 845                                 return(ret);
 846                         else
 847                                 goto start;
 848                         }
 849                 }
 850
 851         /* we now have a packet which can be read and processed */
 852
 853         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 854                                        * reset by ssl3_get_finished */
 855                 && (rr->type != SSL3_RT_HANDSHAKE))
 856                 {
 857                 /* We now have application data between CCS and Finished.
 858                  * Most likely the packets were reordered on their way, so
 859                  * buffer the application data for later processing rather
 860                  * than dropping the connection.
 861                  */
 862                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 863                 rr->length = 0;
 864                 goto start;
 865                 }
 866
 867         /* If the other end has shut down, throw anything we read away
 868          * (even in 'peek' mode) */
 869         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 870                 {
 871                 rr->length=0;
 872                 s->rwstate=SSL_NOTHING;
 873                 return(0);
 874                 }
 875
 876
 877         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 878                 {
 879                 /* make sure that we are not getting application data when we
 880                  * are doing a handshake for the first time */
 881                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 882                         (s->enc_read_ctx == NULL))
 883                         {
 884                         al=SSL_AD_UNEXPECTED_MESSAGE;
 885                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 886                         goto f_err;
 887                         }
 888
 889                 if (len <= 0) return(len);
 890
 891                 if ((unsigned int)len > rr->length)
 892                         n = rr->length;
 893                 else
 894                         n = (unsigned int)len;
 895
 896                 memcpy(buf,&(rr->data[rr->off]),n);
 897                 if (!peek)
 898                         {
 899                         rr->length-=n;
 900                         rr->off+=n;
 901                         if (rr->length == 0)
 902                                 {
 903                                 s->rstate=SSL_ST_READ_HEADER;
 904                                 rr->off=0;
 905                                 }
 906                         }
 907
 908 #ifndef OPENSSL_NO_SCTP
 909                         /* We were about to renegotiate but had to read
 910                          * belated application data first, so retry.
 911                          */
 912                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 913                             rr->type == SSL3_RT_APPLICATION_DATA &&
 914                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
 915                                 {
 916                                 s->rwstate=SSL_READING;
 917                                 BIO_clear_retry_flags(SSL_get_rbio(s));
 918                                 BIO_set_retry_read(SSL_get_rbio(s));
 919                                 }
 920
 921                         /* We might had to delay a close_notify alert because
 922                          * of reordered app data. If there was an alert and there
 923                          * is no message to read anymore, finally set shutdown.
 924                          */
 925                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 926                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
 927                                 {
 928                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 929                                 return(0);
 930                                 }
 931 #endif
 932                 return(n);
 933                 }
 934
 935
 936         /* If we get here, then type != rr->type; if we have a handshake
 937          * message, then it was unexpected (Hello Request or Client Hello). */
 938
 939         /* In case of record types for which we have 'fragment' storage,
 940          * fill that so that we can process the data at a fixed place.
 941          */
 942                 {
 943                 unsigned int k, dest_maxlen = 0;
 944                 unsigned char *dest = NULL;
 945                 unsigned int *dest_len = NULL;
 946
 947                 if (rr->type == SSL3_RT_HANDSHAKE)
 948                         {
 949                         dest_maxlen = sizeof s->d1->handshake_fragment;
 950                         dest = s->d1->handshake_fragment;
 951                         dest_len = &s->d1->handshake_fragment_len;
 952                         }
 953                 else if (rr->type == SSL3_RT_ALERT)
 954                         {
 955                         dest_maxlen = sizeof(s->d1->alert_fragment);
 956                         dest = s->d1->alert_fragment;
 957                         dest_len = &s->d1->alert_fragment_len;
 958                         }
 959 #ifndef OPENSSL_NO_HEARTBEATS
 960                 else if (rr->type == TLS1_RT_HEARTBEAT)
 961                         {
 962                         dtls1_process_heartbeat(s);
 963
 964                         /* Exit and notify application to read again */
 965                         rr->length = 0;
 966                         s->rwstate=SSL_READING;
 967                         BIO_clear_retry_flags(SSL_get_rbio(s));
 968                         BIO_set_retry_read(SSL_get_rbio(s));
 969                         return(-1);
 970                         }
 971 #endif
 972                 /* else it's a CCS message, or application data or wrong */
 973                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 974                         {
 975                         /* Application data while renegotiating
 976                          * is allowed. Try again reading.
 977                          */
 978                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 979                                 {
 980                                 BIO *bio;
 981                                 s->s3->in_read_app_data=2;
 982                                 bio=SSL_get_rbio(s);
 983                                 s->rwstate=SSL_READING;
 984                                 BIO_clear_retry_flags(bio);
 985                                 BIO_set_retry_read(bio);
 986                                 return(-1);
 987                                 }
 988
 989                         /* Not certain if this is the right error handling */
 990                         al=SSL_AD_UNEXPECTED_MESSAGE;
 991                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 992                         goto f_err;
 993                         }
 994
 995                 if (dest_maxlen > 0)
 996                         {
 997             /* XDTLS:  In a pathalogical case, the Client Hello
 998              *  may be fragmented--don't always expect dest_maxlen bytes */
 999                         if ( rr->length < dest_maxlen)
1000                                 {
1001 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1002                                 /*
1003                                  * for normal alerts rr->length is 2, while
1004                                  * dest_maxlen is 7 if we were to handle this
1005                                  * non-existing alert...
1006                                  */
1007                                 FIX ME
1008 #endif
1009                                 s->rstate=SSL_ST_READ_HEADER;
1010                                 rr->length = 0;
1011                                 goto start;
1012                                 }
1013
1014                         /* now move 'n' bytes: */
1015                         for ( k = 0; k < dest_maxlen; k++)
1016                                 {
1017                                 dest[k] = rr->data[rr->off++];
1018                                 rr->length--;
1019                                 }
1020                         *dest_len = dest_maxlen;
1021                         }
1022                 }
1023
1024         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1025          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1026          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1027
1028         /* If we are a client, check for an incoming 'Hello Request': */
1029         if ((!s->server) &&
1030                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1031                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1032                 (s->session != NULL) && (s->session->cipher != NULL))
1033                 {
1034                 s->d1->handshake_fragment_len = 0;
1035
1036                 if ((s->d1->handshake_fragment[1] != 0) ||
1037                         (s->d1->handshake_fragment[2] != 0) ||
1038                         (s->d1->handshake_fragment[3] != 0))
1039                         {
1040                         al=SSL_AD_DECODE_ERROR;
1041                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1042                         goto err;
1043                         }
1044
1045                 /* no need to check sequence number on HELLO REQUEST messages */
1046
1047                 if (s->msg_callback)
1048                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1049                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1050
1051                 if (SSL_is_init_finished(s) &&
1052                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1053                         !s->s3->renegotiate)
1054                         {
1055                         s->new_session = 1;
1056                         ssl3_renegotiate(s);
1057                         if (ssl3_renegotiate_check(s))
1058                                 {
1059                                 i=s->handshake_func(s);
1060                                 if (i < 0) return(i);
1061                                 if (i == 0)
1062                                         {
1063                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1064                                         return(-1);
1065                                         }
1066
1067                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1068                                         {
1069                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1070                                                 {
1071                                                 BIO *bio;
1072                                                 /* In the case where we try to read application data,
1073                                                  * but we trigger an SSL handshake, we return -1 with
1074                                                  * the retry option set.  Otherwise renegotiation may
1075                                                  * cause nasty problems in the blocking world */
1076                                                 s->rwstate=SSL_READING;
1077                                                 bio=SSL_get_rbio(s);
1078                                                 BIO_clear_retry_flags(bio);
1079                                                 BIO_set_retry_read(bio);
1080                                                 return(-1);
1081                                                 }
1082                                         }
1083                                 }
1084                         }
1085                 /* we either finished a handshake or ignored the request,
1086                  * now try again to obtain the (application) data we were asked for */
1087                 goto start;
1088                 }
1089
1090         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1091                 {
1092                 int alert_level = s->d1->alert_fragment[0];
1093                 int alert_descr = s->d1->alert_fragment[1];
1094
1095                 s->d1->alert_fragment_len = 0;
1096
1097                 if (s->msg_callback)
1098                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1099                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1100
1101                 if (s->info_callback != NULL)
1102                         cb=s->info_callback;
1103                 else if (s->ctx->info_callback != NULL)
1104                         cb=s->ctx->info_callback;
1105
1106                 if (cb != NULL)
1107                         {
1108                         j = (alert_level << 8) | alert_descr;
1109                         cb(s, SSL_CB_READ_ALERT, j);
1110                         }
1111
1112                 if (alert_level == 1) /* warning */
1113                         {
1114                         s->s3->warn_alert = alert_descr;
1115                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1116                                 {
1117 #ifndef OPENSSL_NO_SCTP
1118                                 /* With SCTP and streams the socket may deliver app data
1119                                  * after a close_notify alert. We have to check this
1120                                  * first so that nothing gets discarded.
1121                                  */
1122                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1123                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1124                                         {
1125                                         s->d1->shutdown_received = 1;
1126                                         s->rwstate=SSL_READING;
1127                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1128                                         BIO_set_retry_read(SSL_get_rbio(s));
1129                                         return -1;
1130                                         }
1131 #endif
1132                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1133                                 return(0);
1134                                 }
1135 #if 0
1136             /* XXX: this is a possible improvement in the future */
1137                         /* now check if it's a missing record */
1138                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1139                                 {
1140                                 unsigned short seq;
1141                                 unsigned int frag_off;
1142                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1143
1144                                 n2s(p, seq);
1145                                 n2l3(p, frag_off);
1146
1147                                 dtls1_retransmit_message(s,
1148                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1149                                                                                  frag_off, &found);
1150                                 if ( ! found  && SSL_in_init(s))
1151                                         {
1152                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1153                                         /* requested a message not yet sent,
1154                                            send an alert ourselves */
1155                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1156                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1157                                         }
1158                                 }
1159 #endif
1160                         }
1161                 else if (alert_level == 2) /* fatal */
1162                         {
1163                         char tmp[16];
1164
1165                         s->rwstate=SSL_NOTHING;
1166                         s->s3->fatal_alert = alert_descr;
1167                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1168                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1169                         ERR_add_error_data(2,"SSL alert number ",tmp);
1170                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1171                         SSL_CTX_remove_session(s->ctx,s->session);
1172                         return(0);
1173                         }
1174                 else
1175                         {
1176                         al=SSL_AD_ILLEGAL_PARAMETER;
1177                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1178                         goto f_err;
1179                         }
1180
1181                 goto start;
1182                 }
1183
1184         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1185                 {
1186                 s->rwstate=SSL_NOTHING;
1187                 rr->length=0;
1188                 return(0);
1189                 }
1190
1191         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1192                 {
1193                 struct ccs_header_st ccs_hdr;
1194                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1195
1196                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1197
1198                 if (s->version == DTLS1_BAD_VER)
1199                         ccs_hdr_len = 3;
1200
1201                 /* 'Change Cipher Spec' is just a single byte, so we know
1202                  * exactly what the record payload has to look like */
1203                 /* XDTLS: check that epoch is consistent */
1204                 if (    (rr->length != ccs_hdr_len) ||
1205                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1206                         {
1207                         i=SSL_AD_ILLEGAL_PARAMETER;
1208                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1209                         goto err;
1210                         }
1211
1212                 rr->length=0;
1213
1214                 if (s->msg_callback)
1215                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1216                                 rr->data, 1, s, s->msg_callback_arg);
1217
1218                 /* We can't process a CCS now, because previous handshake
1219                  * messages are still missing, so just drop it.
1220                  */
1221                 if (!s->d1->change_cipher_spec_ok)
1222                         {
1223                         goto start;
1224                         }
1225
1226                 s->d1->change_cipher_spec_ok = 0;
1227
1228                 s->s3->change_cipher_spec=1;
1229                 if (!ssl3_do_change_cipher_spec(s))
1230                         goto err;
1231
1232                 /* do this whenever CCS is processed */
1233                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1234
1235                 if (s->version == DTLS1_BAD_VER)
1236                         s->d1->handshake_read_seq++;
1237
1238 #ifndef OPENSSL_NO_SCTP
1239                 /* Remember that a CCS has been received,
1240                  * so that an old key of SCTP-Auth can be
1241                  * deleted when a CCS is sent. Will be ignored
1242                  * if no SCTP is used
1243                  */
1244                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1245 #endif
1246
1247                 goto start;
1248                 }
1249
1250         /* Unexpected handshake message (Client Hello, or protocol violation) */
1251         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1252                 !s->in_handshake)
1253                 {
1254                 struct hm_header_st msg_hdr;
1255
1256                 /* this may just be a stale retransmit */
1257                 dtls1_get_message_header(rr->data, &msg_hdr);
1258                 if( rr->epoch != s->d1->r_epoch)
1259                         {
1260                         rr->length = 0;
1261                         goto start;
1262                         }
1263
1264                 /* If we are server, we may have a repeated FINISHED of the
1265                  * client here, then retransmit our CCS and FINISHED.
1266                  */
1267                 if (msg_hdr.type == SSL3_MT_FINISHED)
1268                         {
1269                         if (dtls1_check_timeout_num(s) < 0)
1270                                 return -1;
1271
1272                         dtls1_retransmit_buffered_messages(s);
1273                         rr->length = 0;
1274                         goto start;
1275                         }
1276
1277                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1278                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1279                         {
1280 #if 0 /* worked only because C operator preferences are not as expected (and
1281        * because this is not really needed for clients except for detecting
1282        * protocol violations): */
1283                         s->state=SSL_ST_BEFORE|(s->server)
1284                                 ?SSL_ST_ACCEPT
1285                                 :SSL_ST_CONNECT;
1286 #else
1287                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1288 #endif
1289                         s->renegotiate=1;
1290                         s->new_session=1;
1291                         }
1292                 i=s->handshake_func(s);
1293                 if (i < 0) return(i);
1294                 if (i == 0)
1295                         {
1296                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1297                         return(-1);
1298                         }
1299
1300                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1301                         {
1302                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1303                                 {
1304                                 BIO *bio;
1305                                 /* In the case where we try to read application data,
1306                                  * but we trigger an SSL handshake, we return -1 with
1307                                  * the retry option set.  Otherwise renegotiation may
1308                                  * cause nasty problems in the blocking world */
1309                                 s->rwstate=SSL_READING;
1310                                 bio=SSL_get_rbio(s);
1311                                 BIO_clear_retry_flags(bio);
1312                                 BIO_set_retry_read(bio);
1313                                 return(-1);
1314                                 }
1315                         }
1316                 goto start;
1317                 }
1318
1319         switch (rr->type)
1320                 {
1321         default:
1322 #ifndef OPENSSL_NO_TLS
1323                 /* TLS just ignores unknown message types */
1324                 if (s->version == TLS1_VERSION)
1325                         {
1326                         rr->length = 0;
1327                         goto start;
1328                         }
1329 #endif
1330                 al=SSL_AD_UNEXPECTED_MESSAGE;
1331                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1332                 goto f_err;
1333         case SSL3_RT_CHANGE_CIPHER_SPEC:
1334         case SSL3_RT_ALERT:
1335         case SSL3_RT_HANDSHAKE:
1336                 /* we already handled all of these, with the possible exception
1337                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1338                  * should not happen when type != rr->type */
1339                 al=SSL_AD_UNEXPECTED_MESSAGE;
1340                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1341                 goto f_err;
1342         case SSL3_RT_APPLICATION_DATA:
1343                 /* At this point, we were expecting handshake data,
1344                  * but have application data.  If the library was
1345                  * running inside ssl3_read() (i.e. in_read_app_data
1346                  * is set) and it makes sense to read application data
1347                  * at this point (session renegotiation not yet started),
1348                  * we will indulge it.
1349                  */
1350                 if (s->s3->in_read_app_data &&
1351                         (s->s3->total_renegotiations != 0) &&
1352                         ((
1353                                 (s->state & SSL_ST_CONNECT) &&
1354                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1355                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1356                                 ) || (
1357                                         (s->state & SSL_ST_ACCEPT) &&
1358                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1359                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1360                                         )
1361                                 ))
1362                         {
1363                         s->s3->in_read_app_data=2;
1364                         return(-1);
1365                         }
1366                 else
1367                         {
1368                         al=SSL_AD_UNEXPECTED_MESSAGE;
1369                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1370                         goto f_err;
1371                         }
1372                 }
1373         /* not reached */
1374
1375 f_err:
1376         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1377 err:
1378         return(-1);
1379         }
1380
1381 int
1382 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1383         {
1384         int i;
1385
1386 #ifndef OPENSSL_NO_SCTP
1387                 /* Check if we have to continue an interrupted handshake
1388                  * for reading belated app data with SCTP.
1389                  */
1390                 if ((SSL_in_init(s) && !s->in_handshake) ||
1391                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1392                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1393 #else
1394                 if (SSL_in_init(s) && !s->in_handshake)
1395 #endif
1396                 {
1397                 i=s->handshake_func(s);
1398                 if (i < 0) return(i);
1399                 if (i == 0)
1400                         {
1401                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1402                         return -1;
1403                         }
1404                 }
1405
1406         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1407                 {
1408                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1409                         return -1;
1410                 }
1411
1412         i = dtls1_write_bytes(s, type, buf_, len);
1413         return i;
1414         }
1415
1416
1417         /* this only happens when a client hello is received and a handshake
1418          * is started. */
1419 static int
1420 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1421         int len, int peek)
1422         {
1423
1424         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1425                 /* (partially) satisfy request from storage */
1426                 {
1427                 unsigned char *src = s->d1->handshake_fragment;
1428                 unsigned char *dst = buf;
1429                 unsigned int k,n;
1430
1431                 /* peek == 0 */
1432                 n = 0;
1433                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1434                         {
1435                         *dst++ = *src++;
1436                         len--; s->d1->handshake_fragment_len--;
1437                         n++;
1438                         }
1439                 /* move any remaining fragment bytes: */
1440                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1441                         s->d1->handshake_fragment[k] = *src++;
1442                 return n;
1443                 }
1444
1445         return 0;
1446         }
1447
1448
1449
1450
1451 /* Call this to write data in records of type 'type'
1452  * It will return <= 0 if not all data has been sent or non-blocking IO.
1453  */
1454 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1455         {
1456         int i;
1457
1458         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1459         s->rwstate=SSL_NOTHING;
1460         i=do_dtls1_write(s, type, buf, len, 0);
1461         return i;
1462         }
1463
1464 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1465         {
1466         unsigned char *p,*pseq;
1467         int i,mac_size,clear=0;
1468         int prefix_len = 0;
1469         int eivlen;
1470         SSL3_RECORD *wr;
1471         SSL3_BUFFER *wb;
1472         SSL_SESSION *sess;
1473
1474         /* first check if there is a SSL3_BUFFER still being written
1475          * out.  This will happen with non blocking IO */
1476         if (s->s3->wbuf.left != 0)
1477                 {
1478                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1479                 return(ssl3_write_pending(s,type,buf,len));
1480                 }
1481
1482         /* If we have an alert to send, lets send it */
1483         if (s->s3->alert_dispatch)
1484                 {
1485                 i=s->method->ssl_dispatch_alert(s);
1486                 if (i <= 0)
1487                         return(i);
1488                 /* if it went, fall through and send more stuff */
1489                 }
1490
1491         if (len == 0 && !create_empty_fragment)
1492                 return 0;
1493
1494         wr= &(s->s3->wrec);
1495         wb= &(s->s3->wbuf);
1496         sess=s->session;
1497
1498         if (    (sess == NULL) ||
1499                 (s->enc_write_ctx == NULL) ||
1500                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1501                 clear=1;
1502
1503         if (clear)
1504                 mac_size=0;
1505         else
1506                 {
1507                 mac_size=EVP_MD_CTX_size(s->write_hash);
1508                 if (mac_size < 0)
1509                         goto err;
1510                 }
1511
1512         /* DTLS implements explicit IV, so no need for empty fragments */
1513 #if 0
1514         /* 'create_empty_fragment' is true only when this function calls itself */
1515         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1516             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1517                 {
1518                 /* countermeasure against known-IV weakness in CBC ciphersuites
1519                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1520                  */
1521
1522                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1523                         {
1524                         /* recursive function call with 'create_empty_fragment' set;
1525                          * this prepares and buffers the data for an empty fragment
1526                          * (these 'prefix_len' bytes are sent out later
1527                          * together with the actual payload) */
1528                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1529                         if (prefix_len <= 0)
1530                                 goto err;
1531
1532                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1533                                 {
1534                                 /* insufficient space */
1535                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1536                                 goto err;
1537                                 }
1538                         }
1539
1540                 s->s3->empty_fragment_done = 1;
1541                 }
1542 #endif
1543         p = wb->buf + prefix_len;
1544
1545         /* write the header */
1546
1547         *(p++)=type&0xff;
1548         wr->type=type;
1549
1550         *(p++)=(s->version>>8);
1551         *(p++)=s->version&0xff;
1552
1553         /* field where we are to write out packet epoch, seq num and len */
1554         pseq=p;
1555         p+=10;
1556
1557         /* Explicit IV length, block ciphers appropriate version flag */
1558         if (s->enc_write_ctx)
1559                 {
1560                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1561                 if (mode == EVP_CIPH_CBC_MODE)
1562                         {
1563                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1564                         if (eivlen <= 1)
1565                                 eivlen = 0;
1566                         }
1567                 /* Need explicit part of IV for GCM mode */
1568                 else if (mode == EVP_CIPH_GCM_MODE)
1569                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1570                 else
1571                         eivlen = 0;
1572                 }
1573         else
1574                 eivlen = 0;
1575
1576         /* lets setup the record stuff. */
1577         wr->data=p + eivlen;  /* make room for IV in case of CBC */
1578         wr->length=(int)len;
1579         wr->input=(unsigned char *)buf;
1580
1581         /* we now 'read' from wr->input, wr->length bytes into
1582          * wr->data */
1583
1584         /* first we compress */
1585         if (s->compress != NULL)
1586                 {
1587                 if (!ssl3_do_compress(s))
1588                         {
1589                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1590                         goto err;
1591                         }
1592                 }
1593         else
1594                 {
1595                 memcpy(wr->data,wr->input,wr->length);
1596                 wr->input=wr->data;
1597                 }
1598
1599         /* we should still have the output to wr->data and the input
1600          * from wr->input.  Length should be wr->length.
1601          * wr->data still points in the wb->buf */
1602
1603         if (mac_size != 0)
1604                 {
1605                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
1606                         goto err;
1607                 wr->length+=mac_size;
1608                 }
1609
1610         /* this is true regardless of mac size */
1611         wr->input=p;
1612         wr->data=p;
1613
1614         if (eivlen)
1615                 wr->length += eivlen;
1616
1617         s->method->ssl3_enc->enc(s,1);
1618
1619         /* record length after mac and block padding */
1620 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1621         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1622
1623         /* there's only one epoch between handshake and app data */
1624
1625         s2n(s->d1->w_epoch, pseq);
1626
1627         /* XDTLS: ?? */
1628 /*      else
1629         s2n(s->d1->handshake_epoch, pseq); */
1630
1631         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1632         pseq+=6;
1633         s2n(wr->length,pseq);
1634
1635         if (s->msg_callback)
1636                 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1637
1638         /* we should now have
1639          * wr->data pointing to the encrypted data, which is
1640          * wr->length long */
1641         wr->type=type; /* not needed but helps for debugging */
1642         wr->length+=DTLS1_RT_HEADER_LENGTH;
1643
1644 #if 0  /* this is now done at the message layer */
1645         /* buffer the record, making it easy to handle retransmits */
1646         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1647                 dtls1_buffer_record(s, wr->data, wr->length,
1648                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1649 #endif
1650
1651         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1652
1653         if (create_empty_fragment)
1654                 {
1655                 /* we are in a recursive call;
1656                  * just return the length, don't write out anything here
1657                  */
1658                 return wr->length;
1659                 }
1660
1661         /* now let's set up wb */
1662         wb->left = prefix_len + wr->length;
1663         wb->offset = 0;
1664
1665         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1666         s->s3->wpend_tot=len;
1667         s->s3->wpend_buf=buf;
1668         s->s3->wpend_type=type;
1669         s->s3->wpend_ret=len;
1670
1671         /* we now just need to write the buffer */
1672         return ssl3_write_pending(s,type,buf,len);
1673 err:
1674         return -1;
1675         }
1676
1677
1678
1679 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1680         {
1681         int cmp;
1682         unsigned int shift;
1683         const unsigned char *seq = s->s3->read_sequence;
1684
1685         cmp = satsub64be(seq,bitmap->max_seq_num);
1686         if (cmp > 0)
1687                 {
1688                 memcpy (s->s3->rrec.seq_num,seq,8);
1689                 return 1; /* this record in new */
1690                 }
1691         shift = -cmp;
1692         if (shift >= sizeof(bitmap->map)*8)
1693                 return 0; /* stale, outside the window */
1694         else if (bitmap->map & (1UL<<shift))
1695                 return 0; /* record previously received */
1696
1697         memcpy (s->s3->rrec.seq_num,seq,8);
1698         return 1;
1699         }
1700
1701
1702 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1703         {
1704         int cmp;
1705         unsigned int shift;
1706         const unsigned char *seq = s->s3->read_sequence;
1707
1708         cmp = satsub64be(seq,bitmap->max_seq_num);
1709         if (cmp > 0)
1710                 {
1711                 shift = cmp;
1712                 if (shift < sizeof(bitmap->map)*8)
1713                         bitmap->map <<= shift, bitmap->map |= 1UL;
1714                 else
1715                         bitmap->map = 1UL;
1716                 memcpy(bitmap->max_seq_num,seq,8);
1717                 }
1718         else    {
1719                 shift = -cmp;
1720                 if (shift < sizeof(bitmap->map)*8)
1721                         bitmap->map |= 1UL<<shift;
1722                 }
1723         }
1724
1725
1726 int dtls1_dispatch_alert(SSL *s)
1727         {
1728         int i,j;
1729         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1730         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1731         unsigned char *ptr = &buf[0];
1732
1733         s->s3->alert_dispatch=0;
1734
1735         memset(buf, 0x00, sizeof(buf));
1736         *ptr++ = s->s3->send_alert[0];
1737         *ptr++ = s->s3->send_alert[1];
1738
1739 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1740         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1741                 {
1742                 s2n(s->d1->handshake_read_seq, ptr);
1743 #if 0
1744                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1745
1746                 else
1747                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1748 #endif
1749
1750 #if 0
1751                 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);
1752 #endif
1753                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1754                 }
1755 #endif
1756
1757         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1758         if (i <= 0)
1759                 {
1760                 s->s3->alert_dispatch=1;
1761                 /* fprintf( stderr, "not done with alert\n" ); */
1762                 }
1763         else
1764                 {
1765                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1766 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1767                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1768 #endif
1769                     )
1770                         (void)BIO_flush(s->wbio);
1771
1772                 if (s->msg_callback)
1773                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1774                                 2, s, s->msg_callback_arg);
1775
1776                 if (s->info_callback != NULL)
1777                         cb=s->info_callback;
1778                 else if (s->ctx->info_callback != NULL)
1779                         cb=s->ctx->info_callback;
1780
1781                 if (cb != NULL)
1782                         {
1783                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1784                         cb(s,SSL_CB_WRITE_ALERT,j);
1785                         }
1786                 }
1787         return(i);
1788         }
1789
1790
1791 static DTLS1_BITMAP *
1792 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1793     {
1794
1795     *is_next_epoch = 0;
1796
1797     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1798     if (rr->epoch == s->d1->r_epoch)
1799         return &s->d1->bitmap;
1800
1801     /* Only HM and ALERT messages can be from the next epoch */
1802     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1803         (rr->type == SSL3_RT_HANDSHAKE ||
1804             rr->type == SSL3_RT_ALERT))
1805         {
1806         *is_next_epoch = 1;
1807         return &s->d1->next_bitmap;
1808         }
1809
1810     return NULL;
1811     }
1812
1813 #if 0
1814 static int
1815 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1816         unsigned long *offset)
1817         {
1818
1819         /* alerts are passed up immediately */
1820         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1821                 rr->type == SSL3_RT_ALERT)
1822                 return 0;
1823
1824         /* Only need to buffer if a handshake is underway.
1825          * (this implies that Hello Request and Client Hello are passed up
1826          * immediately) */
1827         if ( SSL_in_init(s))
1828                 {
1829                 unsigned char *data = rr->data;
1830                 /* need to extract the HM/CCS sequence number here */
1831                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1832                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1833                         {
1834                         unsigned short seq_num;
1835                         struct hm_header_st msg_hdr;
1836                         struct ccs_header_st ccs_hdr;
1837
1838                         if ( rr->type == SSL3_RT_HANDSHAKE)
1839                                 {
1840                                 dtls1_get_message_header(data, &msg_hdr);
1841                                 seq_num = msg_hdr.seq;
1842                                 *offset = msg_hdr.frag_off;
1843                                 }
1844                         else
1845                                 {
1846                                 dtls1_get_ccs_header(data, &ccs_hdr);
1847                                 seq_num = ccs_hdr.seq;
1848                                 *offset = 0;
1849                                 }
1850
1851                         /* this is either a record we're waiting for, or a
1852                          * retransmit of something we happened to previously
1853                          * receive (higher layers will drop the repeat silently */
1854                         if ( seq_num < s->d1->handshake_read_seq)
1855                                 return 0;
1856                         if (rr->type == SSL3_RT_HANDSHAKE &&
1857                                 seq_num == s->d1->handshake_read_seq &&
1858                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1859                                 return 0;
1860                         else if ( seq_num == s->d1->handshake_read_seq &&
1861                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1862                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1863                                 return 0;
1864                         else
1865                                 {
1866                                 *priority = seq_num;
1867                                 return 1;
1868                                 }
1869                         }
1870                 else /* unknown record type */
1871                         return 0;
1872                 }
1873
1874         return 0;
1875         }
1876 #endif
1877
1878 void
1879 dtls1_reset_seq_numbers(SSL *s, int rw)
1880         {
1881         unsigned char *seq;
1882         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1883
1884         if ( rw & SSL3_CC_READ)
1885                 {
1886                 seq = s->s3->read_sequence;
1887                 s->d1->r_epoch++;
1888                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1889                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1890                 }
1891         else
1892                 {
1893                 seq = s->s3->write_sequence;
1894                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1895                 s->d1->w_epoch++;
1896                 }
1897
1898         memset(seq, 0x00, seq_bytes);
1899         }