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, orig_len;
 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
 414         enc_err = s->method->ssl3_enc->enc(s,0);
 415         /* enc_err is:
 416          *    0: (in non-constant time) if the record is publically invalid.
 417          *    1: if the padding is valid
 418          *    -1: if the padding is invalid */
 419         if (enc_err == 0)
 420                 {
 421                 /* For DTLS we simply ignore bad packets. */
 422                 rr->length = 0;
 423                 s->packet_length = 0;
 424                 goto err;
 425                 }
 426
 427 #ifdef TLS_DEBUG
 428 printf("dec %d\n",rr->length);
 429 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 430 printf("\n");
 431 #endif
 432
 433         /* r->length is now the compressed data plus mac */
 434         if ((sess != NULL) &&
 435             (s->enc_read_ctx != NULL) &&
 436             (EVP_MD_CTX_md(s->read_hash) != NULL))
 437                 {
 438                 /* s->read_hash != NULL => mac_size != -1 */
 439                 unsigned char *mac = NULL;
 440                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 441                 mac_size=EVP_MD_CTX_size(s->read_hash);
 442                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 443
 444                 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
 445                 orig_len = rr->length+((unsigned int)rr->type>>8);
 446
 447                 /* orig_len is the length of the record before any padding was
 448                  * removed. This is public information, as is the MAC in use,
 449                  * therefore we can safely process the record in a different
 450                  * amount of time if it's too short to possibly contain a MAC.
 451                  */
 452                 if (orig_len < mac_size ||
 453                     /* CBC records must have a padding length byte too. */
 454                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 455                      orig_len < mac_size+1))
 456                         {
 457                         al=SSL_AD_DECODE_ERROR;
 458                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 459                         goto f_err;
 460                         }
 461
 462                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 463                         {
 464                         /* We update the length so that the TLS header bytes
 465                          * can be constructed correctly but we need to extract
 466                          * the MAC in constant time from within the record,
 467                          * without leaking the contents of the padding bytes.
 468                          * */
 469                         mac = mac_tmp;
 470                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
 471                         rr->length -= mac_size;
 472                         }
 473                 else
 474                         {
 475                         /* In this case there's no padding, so |orig_len|
 476                          * equals |rec->length| and we checked that there's
 477                          * enough bytes for |mac_size| above. */
 478                         rr->length -= mac_size;
 479                         mac = &rr->data[rr->length];
 480                         }
 481
 482                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 483                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 484                         enc_err = -1;
 485                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 486                         enc_err = -1;
 487                 }
 488
 489         if (enc_err < 0)
 490                 {
 491                 /* decryption failed, silently discard message */
 492                 rr->length = 0;
 493                 s->packet_length = 0;
 494                 goto err;
 495                 }
 496
 497         /* r->length is now just compressed */
 498         if (s->expand != NULL)
 499                 {
 500                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 501                         {
 502                         al=SSL_AD_RECORD_OVERFLOW;
 503                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 504                         goto f_err;
 505                         }
 506                 if (!ssl3_do_uncompress(s))
 507                         {
 508                         al=SSL_AD_DECOMPRESSION_FAILURE;
 509                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 510                         goto f_err;
 511                         }
 512                 }
 513
 514         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 515                 {
 516                 al=SSL_AD_RECORD_OVERFLOW;
 517                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 518                 goto f_err;
 519                 }
 520
 521         rr->off=0;
 522         /* So at this point the following is true
 523          * ssl->s3->rrec.type   is the type of record
 524          * ssl->s3->rrec.length == number of bytes in record
 525          * ssl->s3->rrec.off    == offset to first valid byte
 526          * ssl->s3->rrec.data   == where to take bytes from, increment
 527          *                         after use :-).
 528          */
 529
 530         /* we have pulled in a full packet so zero things */
 531         s->packet_length=0;
 532         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 533         return(1);
 534
 535 f_err:
 536         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 537 err:
 538         return(0);
 539 }
 540
 541
 542 /* Call this to get a new input record.
 543  * It will return <= 0 if more data is needed, normally due to an error
 544  * or non-blocking IO.
 545  * When it finishes, one packet has been decoded and can be found in
 546  * ssl->s3->rrec.type    - is the type of record
 547  * ssl->s3->rrec.data,   - data
 548  * ssl->s3->rrec.length, - number of bytes
 549  */
 550 /* used only by dtls1_read_bytes */
 551 int dtls1_get_record(SSL *s)
 552         {
 553         int ssl_major,ssl_minor;
 554         int i,n;
 555         SSL3_RECORD *rr;
 556         unsigned char *p = NULL;
 557         unsigned short version;
 558         DTLS1_BITMAP *bitmap;
 559         unsigned int is_next_epoch;
 560
 561         rr= &(s->s3->rrec);
 562
 563         /* The epoch may have changed.  If so, process all the
 564          * pending records.  This is a non-blocking operation. */
 565         dtls1_process_buffered_records(s);
 566
 567         /* if we're renegotiating, then there may be buffered records */
 568         if (dtls1_get_processed_record(s))
 569                 return 1;
 570
 571         /* get something from the wire */
 572 again:
 573         /* check if we have the header */
 574         if (    (s->rstate != SSL_ST_READ_BODY) ||
 575                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 576                 {
 577                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 578                 /* read timeout is handled by dtls1_read_bytes */
 579                 if (n <= 0) return(n); /* error or non-blocking */
 580
 581                 /* this packet contained a partial record, dump it */
 582                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 583                         {
 584                         s->packet_length = 0;
 585                         goto again;
 586                         }
 587
 588                 s->rstate=SSL_ST_READ_BODY;
 589
 590                 p=s->packet;
 591
 592                 /* Pull apart the header into the DTLS1_RECORD */
 593                 rr->type= *(p++);
 594                 ssl_major= *(p++);
 595                 ssl_minor= *(p++);
 596                 version=(ssl_major<<8)|ssl_minor;
 597
 598                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 599                 n2s(p,rr->epoch);
 600
 601                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 602                 p+=6;
 603
 604                 n2s(p,rr->length);
 605
 606                 /* Lets check version */
 607                 if (!s->first_packet)
 608                         {
 609                         if (version != s->version)
 610                                 {
 611                                 /* unexpected version, silently discard */
 612                                 rr->length = 0;
 613                                 s->packet_length = 0;
 614                                 goto again;
 615                                 }
 616                         }
 617
 618                 if ((version & 0xff00) != (s->version & 0xff00))
 619                         {
 620                         /* wrong version, silently discard record */
 621                         rr->length = 0;
 622                         s->packet_length = 0;
 623                         goto again;
 624                         }
 625
 626                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 627                         {
 628                         /* record too long, silently discard it */
 629                         rr->length = 0;
 630                         s->packet_length = 0;
 631                         goto again;
 632                         }
 633
 634                 /* now s->rstate == SSL_ST_READ_BODY */
 635                 }
 636
 637         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 638
 639         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 640                 {
 641                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 642                 i=rr->length;
 643                 n=ssl3_read_n(s,i,i,1);
 644                 if (n <= 0) return(n); /* error or non-blocking io */
 645
 646                 /* this packet contained a partial record, dump it */
 647                 if ( n != i)
 648                         {
 649                         rr->length = 0;
 650                         s->packet_length = 0;
 651                         goto again;
 652                         }
 653
 654                 /* now n == rr->length,
 655                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 656                 }
 657         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 658
 659         /* match epochs.  NULL means the packet is dropped on the floor */
 660         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 661         if ( bitmap == NULL)
 662                 {
 663                 rr->length = 0;
 664                 s->packet_length = 0;  /* dump this record */
 665                 goto again;   /* get another record */
 666                 }
 667
 668 #ifndef OPENSSL_NO_SCTP
 669         /* Only do replay check if no SCTP bio */
 670         if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
 671                 {
 672 #endif
 673                 /* Check whether this is a repeat, or aged record.
 674                  * Don't check if we're listening and this message is
 675                  * a ClientHello. They can look as if they're replayed,
 676                  * since they arrive from different connections and
 677                  * would be dropped unnecessarily.
 678                  */
 679                 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 680                     *p == SSL3_MT_CLIENT_HELLO) &&
 681                     !dtls1_record_replay_check(s, bitmap))
 682                         {
 683                         rr->length = 0;
 684                         s->packet_length=0; /* dump this record */
 685                         goto again;     /* get another record */
 686                         }
 687 #ifndef OPENSSL_NO_SCTP
 688                 }
 689 #endif
 690
 691         /* just read a 0 length packet */
 692         if (rr->length == 0) goto again;
 693
 694         /* If this record is from the next epoch (either HM or ALERT),
 695          * and a handshake is currently in progress, buffer it since it
 696          * cannot be processed at this time. However, do not buffer
 697          * anything while listening.
 698          */
 699         if (is_next_epoch)
 700                 {
 701                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 702                         {
 703                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 704                         }
 705                 rr->length = 0;
 706                 s->packet_length = 0;
 707                 goto again;
 708                 }
 709
 710         if (!dtls1_process_record(s))
 711                 {
 712                 rr->length = 0;
 713                 s->packet_length = 0;  /* dump this record */
 714                 goto again;   /* get another record */
 715                 }
 716
 717         return(1);
 718
 719         }
 720
 721 /* Return up to 'len' payload bytes received in 'type' records.
 722  * 'type' is one of the following:
 723  *
 724  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 725  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 726  *   -  0 (during a shutdown, no data has to be returned)
 727  *
 728  * If we don't have stored data to work from, read a SSL/TLS record first
 729  * (possibly multiple records if we still don't have anything to return).
 730  *
 731  * This function must handle any surprises the peer may have for us, such as
 732  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 733  * a surprise, but handled as if it were), or renegotiation requests.
 734  * Also if record payloads contain fragments too small to process, we store
 735  * them until there is enough for the respective protocol (the record protocol
 736  * may use arbitrary fragmentation and even interleaving):
 737  *     Change cipher spec protocol
 738  *             just 1 byte needed, no need for keeping anything stored
 739  *     Alert protocol
 740  *             2 bytes needed (AlertLevel, AlertDescription)
 741  *     Handshake protocol
 742  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 743  *             to detect unexpected Client Hello and Hello Request messages
 744  *             here, anything else is handled by higher layers
 745  *     Application data protocol
 746  *             none of our business
 747  */
 748 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 749         {
 750         int al,i,j,ret;
 751         unsigned int n;
 752         SSL3_RECORD *rr;
 753         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 754
 755         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 756                 if (!ssl3_setup_buffers(s))
 757                         return(-1);
 758
 759     /* XXX: check what the second '&& type' is about */
 760         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 761                 (type != SSL3_RT_HANDSHAKE) && type) ||
 762             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 763                 {
 764                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 765                 return -1;
 766                 }
 767
 768         /* check whether there's a handshake message (client hello?) waiting */
 769         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 770                 return ret;
 771
 772         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 773
 774 #ifndef OPENSSL_NO_SCTP
 775         /* Continue handshake if it had to be interrupted to read
 776          * app data with SCTP.
 777          */
 778         if ((!s->in_handshake && SSL_in_init(s)) ||
 779             (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 780              (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
 781              s->s3->in_read_app_data != 2))
 782 #else
 783         if (!s->in_handshake && SSL_in_init(s))
 784 #endif
 785                 {
 786                 /* type == SSL3_RT_APPLICATION_DATA */
 787                 i=s->handshake_func(s);
 788                 if (i < 0) return(i);
 789                 if (i == 0)
 790                         {
 791                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 792                         return(-1);
 793                         }
 794                 }
 795
 796 start:
 797         s->rwstate=SSL_NOTHING;
 798
 799         /* s->s3->rrec.type         - is the type of record
 800          * s->s3->rrec.data,    - data
 801          * s->s3->rrec.off,     - offset into 'data' for next read
 802          * s->s3->rrec.length,  - number of bytes. */
 803         rr = &(s->s3->rrec);
 804
 805         /* We are not handshaking and have no data yet,
 806          * so process data buffered during the last handshake
 807          * in advance, if any.
 808          */
 809         if (s->state == SSL_ST_OK && rr->length == 0)
 810                 {
 811                 pitem *item;
 812                 item = pqueue_pop(s->d1->buffered_app_data.q);
 813                 if (item)
 814                         {
 815 #ifndef OPENSSL_NO_SCTP
 816                         /* Restore bio_dgram_sctp_rcvinfo struct */
 817                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
 818                                 {
 819                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
 820                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 821                                 }
 822 #endif
 823
 824                         dtls1_copy_record(s, item);
 825
 826                         OPENSSL_free(item->data);
 827                         pitem_free(item);
 828                         }
 829                 }
 830
 831         /* Check for timeout */
 832         if (dtls1_handle_timeout(s) > 0)
 833                 goto start;
 834
 835         /* get new packet if necessary */
 836         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 837                 {
 838                 ret=dtls1_get_record(s);
 839                 if (ret <= 0)
 840                         {
 841                         ret = dtls1_read_failed(s, ret);
 842                         /* anything other than a timeout is an error */
 843                         if (ret <= 0)
 844                                 return(ret);
 845                         else
 846                                 goto start;
 847                         }
 848                 }
 849
 850         if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
 851                 {
 852                 rr->length = 0;
 853                 goto start;
 854                 }
 855
 856         /* we now have a packet which can be read and processed */
 857
 858         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 859                                        * reset by ssl3_get_finished */
 860                 && (rr->type != SSL3_RT_HANDSHAKE))
 861                 {
 862                 /* We now have application data between CCS and Finished.
 863                  * Most likely the packets were reordered on their way, so
 864                  * buffer the application data for later processing rather
 865                  * than dropping the connection.
 866                  */
 867                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 868                 rr->length = 0;
 869                 goto start;
 870                 }
 871
 872         /* If the other end has shut down, throw anything we read away
 873          * (even in 'peek' mode) */
 874         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 875                 {
 876                 rr->length=0;
 877                 s->rwstate=SSL_NOTHING;
 878                 return(0);
 879                 }
 880
 881
 882         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 883                 {
 884                 /* make sure that we are not getting application data when we
 885                  * are doing a handshake for the first time */
 886                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 887                         (s->enc_read_ctx == NULL))
 888                         {
 889                         al=SSL_AD_UNEXPECTED_MESSAGE;
 890                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 891                         goto f_err;
 892                         }
 893
 894                 if (len <= 0) return(len);
 895
 896                 if ((unsigned int)len > rr->length)
 897                         n = rr->length;
 898                 else
 899                         n = (unsigned int)len;
 900
 901                 memcpy(buf,&(rr->data[rr->off]),n);
 902                 if (!peek)
 903                         {
 904                         rr->length-=n;
 905                         rr->off+=n;
 906                         if (rr->length == 0)
 907                                 {
 908                                 s->rstate=SSL_ST_READ_HEADER;
 909                                 rr->off=0;
 910                                 }
 911                         }
 912
 913 #ifndef OPENSSL_NO_SCTP
 914                         /* We were about to renegotiate but had to read
 915                          * belated application data first, so retry.
 916                          */
 917                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 918                             rr->type == SSL3_RT_APPLICATION_DATA &&
 919                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
 920                                 {
 921                                 s->rwstate=SSL_READING;
 922                                 BIO_clear_retry_flags(SSL_get_rbio(s));
 923                                 BIO_set_retry_read(SSL_get_rbio(s));
 924                                 }
 925
 926                         /* We might had to delay a close_notify alert because
 927                          * of reordered app data. If there was an alert and there
 928                          * is no message to read anymore, finally set shutdown.
 929                          */
 930                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 931                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
 932                                 {
 933                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 934                                 return(0);
 935                                 }
 936 #endif
 937                 return(n);
 938                 }
 939
 940
 941         /* If we get here, then type != rr->type; if we have a handshake
 942          * message, then it was unexpected (Hello Request or Client Hello). */
 943
 944         /* In case of record types for which we have 'fragment' storage,
 945          * fill that so that we can process the data at a fixed place.
 946          */
 947                 {
 948                 unsigned int k, dest_maxlen = 0;
 949                 unsigned char *dest = NULL;
 950                 unsigned int *dest_len = NULL;
 951
 952                 if (rr->type == SSL3_RT_HANDSHAKE)
 953                         {
 954                         dest_maxlen = sizeof s->d1->handshake_fragment;
 955                         dest = s->d1->handshake_fragment;
 956                         dest_len = &s->d1->handshake_fragment_len;
 957                         }
 958                 else if (rr->type == SSL3_RT_ALERT)
 959                         {
 960                         dest_maxlen = sizeof(s->d1->alert_fragment);
 961                         dest = s->d1->alert_fragment;
 962                         dest_len = &s->d1->alert_fragment_len;
 963                         }
 964 #ifndef OPENSSL_NO_HEARTBEATS
 965                 else if (rr->type == TLS1_RT_HEARTBEAT)
 966                         {
 967                         dtls1_process_heartbeat(s);
 968
 969                         /* Exit and notify application to read again */
 970                         rr->length = 0;
 971                         s->rwstate=SSL_READING;
 972                         BIO_clear_retry_flags(SSL_get_rbio(s));
 973                         BIO_set_retry_read(SSL_get_rbio(s));
 974                         return(-1);
 975                         }
 976 #endif
 977                 /* else it's a CCS message, or application data or wrong */
 978                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 979                         {
 980                         /* Application data while renegotiating
 981                          * is allowed. Try again reading.
 982                          */
 983                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 984                                 {
 985                                 BIO *bio;
 986                                 s->s3->in_read_app_data=2;
 987                                 bio=SSL_get_rbio(s);
 988                                 s->rwstate=SSL_READING;
 989                                 BIO_clear_retry_flags(bio);
 990                                 BIO_set_retry_read(bio);
 991                                 return(-1);
 992                                 }
 993
 994                         /* Not certain if this is the right error handling */
 995                         al=SSL_AD_UNEXPECTED_MESSAGE;
 996                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 997                         goto f_err;
 998                         }
 999
1000                 if (dest_maxlen > 0)
1001                         {
1002             /* XDTLS:  In a pathalogical case, the Client Hello
1003              *  may be fragmented--don't always expect dest_maxlen bytes */
1004                         if ( rr->length < dest_maxlen)
1005                                 {
1006 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1007                                 /*
1008                                  * for normal alerts rr->length is 2, while
1009                                  * dest_maxlen is 7 if we were to handle this
1010                                  * non-existing alert...
1011                                  */
1012                                 FIX ME
1013 #endif
1014                                 s->rstate=SSL_ST_READ_HEADER;
1015                                 rr->length = 0;
1016                                 goto start;
1017                                 }
1018
1019                         /* now move 'n' bytes: */
1020                         for ( k = 0; k < dest_maxlen; k++)
1021                                 {
1022                                 dest[k] = rr->data[rr->off++];
1023                                 rr->length--;
1024                                 }
1025                         *dest_len = dest_maxlen;
1026                         }
1027                 }
1028
1029         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1030          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1031          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1032
1033         /* If we are a client, check for an incoming 'Hello Request': */
1034         if ((!s->server) &&
1035                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1036                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1037                 (s->session != NULL) && (s->session->cipher != NULL))
1038                 {
1039                 s->d1->handshake_fragment_len = 0;
1040
1041                 if ((s->d1->handshake_fragment[1] != 0) ||
1042                         (s->d1->handshake_fragment[2] != 0) ||
1043                         (s->d1->handshake_fragment[3] != 0))
1044                         {
1045                         al=SSL_AD_DECODE_ERROR;
1046                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1047                         goto err;
1048                         }
1049
1050                 /* no need to check sequence number on HELLO REQUEST messages */
1051
1052                 if (s->msg_callback)
1053                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1054                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1055
1056                 if (SSL_is_init_finished(s) &&
1057                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1058                         !s->s3->renegotiate)
1059                         {
1060                         s->new_session = 1;
1061                         ssl3_renegotiate(s);
1062                         if (ssl3_renegotiate_check(s))
1063                                 {
1064                                 i=s->handshake_func(s);
1065                                 if (i < 0) return(i);
1066                                 if (i == 0)
1067                                         {
1068                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1069                                         return(-1);
1070                                         }
1071
1072                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1073                                         {
1074                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1075                                                 {
1076                                                 BIO *bio;
1077                                                 /* In the case where we try to read application data,
1078                                                  * but we trigger an SSL handshake, we return -1 with
1079                                                  * the retry option set.  Otherwise renegotiation may
1080                                                  * cause nasty problems in the blocking world */
1081                                                 s->rwstate=SSL_READING;
1082                                                 bio=SSL_get_rbio(s);
1083                                                 BIO_clear_retry_flags(bio);
1084                                                 BIO_set_retry_read(bio);
1085                                                 return(-1);
1086                                                 }
1087                                         }
1088                                 }
1089                         }
1090                 /* we either finished a handshake or ignored the request,
1091                  * now try again to obtain the (application) data we were asked for */
1092                 goto start;
1093                 }
1094
1095         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1096                 {
1097                 int alert_level = s->d1->alert_fragment[0];
1098                 int alert_descr = s->d1->alert_fragment[1];
1099
1100                 s->d1->alert_fragment_len = 0;
1101
1102                 if (s->msg_callback)
1103                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1104                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1105
1106                 if (s->info_callback != NULL)
1107                         cb=s->info_callback;
1108                 else if (s->ctx->info_callback != NULL)
1109                         cb=s->ctx->info_callback;
1110
1111                 if (cb != NULL)
1112                         {
1113                         j = (alert_level << 8) | alert_descr;
1114                         cb(s, SSL_CB_READ_ALERT, j);
1115                         }
1116
1117                 if (alert_level == 1) /* warning */
1118                         {
1119                         s->s3->warn_alert = alert_descr;
1120                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1121                                 {
1122 #ifndef OPENSSL_NO_SCTP
1123                                 /* With SCTP and streams the socket may deliver app data
1124                                  * after a close_notify alert. We have to check this
1125                                  * first so that nothing gets discarded.
1126                                  */
1127                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1128                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1129                                         {
1130                                         s->d1->shutdown_received = 1;
1131                                         s->rwstate=SSL_READING;
1132                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1133                                         BIO_set_retry_read(SSL_get_rbio(s));
1134                                         return -1;
1135                                         }
1136 #endif
1137                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1138                                 return(0);
1139                                 }
1140 #if 0
1141             /* XXX: this is a possible improvement in the future */
1142                         /* now check if it's a missing record */
1143                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1144                                 {
1145                                 unsigned short seq;
1146                                 unsigned int frag_off;
1147                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1148
1149                                 n2s(p, seq);
1150                                 n2l3(p, frag_off);
1151
1152                                 dtls1_retransmit_message(s,
1153                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1154                                                                                  frag_off, &found);
1155                                 if ( ! found  && SSL_in_init(s))
1156                                         {
1157                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1158                                         /* requested a message not yet sent,
1159                                            send an alert ourselves */
1160                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1161                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1162                                         }
1163                                 }
1164 #endif
1165                         }
1166                 else if (alert_level == 2) /* fatal */
1167                         {
1168                         char tmp[16];
1169
1170                         s->rwstate=SSL_NOTHING;
1171                         s->s3->fatal_alert = alert_descr;
1172                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1173                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1174                         ERR_add_error_data(2,"SSL alert number ",tmp);
1175                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1176                         SSL_CTX_remove_session(s->ctx,s->session);
1177                         return(0);
1178                         }
1179                 else
1180                         {
1181                         al=SSL_AD_ILLEGAL_PARAMETER;
1182                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1183                         goto f_err;
1184                         }
1185
1186                 goto start;
1187                 }
1188
1189         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1190                 {
1191                 s->rwstate=SSL_NOTHING;
1192                 rr->length=0;
1193                 return(0);
1194                 }
1195
1196         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1197                 {
1198                 struct ccs_header_st ccs_hdr;
1199                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1200
1201                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1202
1203                 if (s->version == DTLS1_BAD_VER)
1204                         ccs_hdr_len = 3;
1205
1206                 /* 'Change Cipher Spec' is just a single byte, so we know
1207                  * exactly what the record payload has to look like */
1208                 /* XDTLS: check that epoch is consistent */
1209                 if (    (rr->length != ccs_hdr_len) ||
1210                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1211                         {
1212                         i=SSL_AD_ILLEGAL_PARAMETER;
1213                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1214                         goto err;
1215                         }
1216
1217                 rr->length=0;
1218
1219                 if (s->msg_callback)
1220                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1221                                 rr->data, 1, s, s->msg_callback_arg);
1222
1223                 /* We can't process a CCS now, because previous handshake
1224                  * messages are still missing, so just drop it.
1225                  */
1226                 if (!s->d1->change_cipher_spec_ok)
1227                         {
1228                         goto start;
1229                         }
1230
1231                 s->d1->change_cipher_spec_ok = 0;
1232
1233                 s->s3->change_cipher_spec=1;
1234                 if (!ssl3_do_change_cipher_spec(s))
1235                         goto err;
1236
1237                 /* do this whenever CCS is processed */
1238                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1239
1240                 if (s->version == DTLS1_BAD_VER)
1241                         s->d1->handshake_read_seq++;
1242
1243 #ifndef OPENSSL_NO_SCTP
1244                 /* Remember that a CCS has been received,
1245                  * so that an old key of SCTP-Auth can be
1246                  * deleted when a CCS is sent. Will be ignored
1247                  * if no SCTP is used
1248                  */
1249                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1250 #endif
1251
1252                 goto start;
1253                 }
1254
1255         /* Unexpected handshake message (Client Hello, or protocol violation) */
1256         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1257                 !s->in_handshake)
1258                 {
1259                 struct hm_header_st msg_hdr;
1260
1261                 /* this may just be a stale retransmit */
1262                 dtls1_get_message_header(rr->data, &msg_hdr);
1263                 if( rr->epoch != s->d1->r_epoch)
1264                         {
1265                         rr->length = 0;
1266                         goto start;
1267                         }
1268
1269                 /* If we are server, we may have a repeated FINISHED of the
1270                  * client here, then retransmit our CCS and FINISHED.
1271                  */
1272                 if (msg_hdr.type == SSL3_MT_FINISHED)
1273                         {
1274                         if (dtls1_check_timeout_num(s) < 0)
1275                                 return -1;
1276
1277                         dtls1_retransmit_buffered_messages(s);
1278                         rr->length = 0;
1279                         goto start;
1280                         }
1281
1282                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1283                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1284                         {
1285 #if 0 /* worked only because C operator preferences are not as expected (and
1286        * because this is not really needed for clients except for detecting
1287        * protocol violations): */
1288                         s->state=SSL_ST_BEFORE|(s->server)
1289                                 ?SSL_ST_ACCEPT
1290                                 :SSL_ST_CONNECT;
1291 #else
1292                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1293 #endif
1294                         s->renegotiate=1;
1295                         s->new_session=1;
1296                         }
1297                 i=s->handshake_func(s);
1298                 if (i < 0) return(i);
1299                 if (i == 0)
1300                         {
1301                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1302                         return(-1);
1303                         }
1304
1305                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1306                         {
1307                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1308                                 {
1309                                 BIO *bio;
1310                                 /* In the case where we try to read application data,
1311                                  * but we trigger an SSL handshake, we return -1 with
1312                                  * the retry option set.  Otherwise renegotiation may
1313                                  * cause nasty problems in the blocking world */
1314                                 s->rwstate=SSL_READING;
1315                                 bio=SSL_get_rbio(s);
1316                                 BIO_clear_retry_flags(bio);
1317                                 BIO_set_retry_read(bio);
1318                                 return(-1);
1319                                 }
1320                         }
1321                 goto start;
1322                 }
1323
1324         switch (rr->type)
1325                 {
1326         default:
1327 #ifndef OPENSSL_NO_TLS
1328                 /* TLS just ignores unknown message types */
1329                 if (s->version == TLS1_VERSION)
1330                         {
1331                         rr->length = 0;
1332                         goto start;
1333                         }
1334 #endif
1335                 al=SSL_AD_UNEXPECTED_MESSAGE;
1336                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1337                 goto f_err;
1338         case SSL3_RT_CHANGE_CIPHER_SPEC:
1339         case SSL3_RT_ALERT:
1340         case SSL3_RT_HANDSHAKE:
1341                 /* we already handled all of these, with the possible exception
1342                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1343                  * should not happen when type != rr->type */
1344                 al=SSL_AD_UNEXPECTED_MESSAGE;
1345                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1346                 goto f_err;
1347         case SSL3_RT_APPLICATION_DATA:
1348                 /* At this point, we were expecting handshake data,
1349                  * but have application data.  If the library was
1350                  * running inside ssl3_read() (i.e. in_read_app_data
1351                  * is set) and it makes sense to read application data
1352                  * at this point (session renegotiation not yet started),
1353                  * we will indulge it.
1354                  */
1355                 if (s->s3->in_read_app_data &&
1356                         (s->s3->total_renegotiations != 0) &&
1357                         ((
1358                                 (s->state & SSL_ST_CONNECT) &&
1359                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1360                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1361                                 ) || (
1362                                         (s->state & SSL_ST_ACCEPT) &&
1363                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1364                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1365                                         )
1366                                 ))
1367                         {
1368                         s->s3->in_read_app_data=2;
1369                         return(-1);
1370                         }
1371                 else
1372                         {
1373                         al=SSL_AD_UNEXPECTED_MESSAGE;
1374                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1375                         goto f_err;
1376                         }
1377                 }
1378         /* not reached */
1379
1380 f_err:
1381         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1382 err:
1383         return(-1);
1384         }
1385
1386 int
1387 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1388         {
1389         int i;
1390
1391 #ifndef OPENSSL_NO_SCTP
1392                 /* Check if we have to continue an interrupted handshake
1393                  * for reading belated app data with SCTP.
1394                  */
1395                 if ((SSL_in_init(s) && !s->in_handshake) ||
1396                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1397                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1398 #else
1399                 if (SSL_in_init(s) && !s->in_handshake)
1400 #endif
1401                 {
1402                 i=s->handshake_func(s);
1403                 if (i < 0) return(i);
1404                 if (i == 0)
1405                         {
1406                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1407                         return -1;
1408                         }
1409                 }
1410
1411         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1412                 {
1413                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1414                         return -1;
1415                 }
1416
1417         i = dtls1_write_bytes(s, type, buf_, len);
1418         return i;
1419         }
1420
1421
1422         /* this only happens when a client hello is received and a handshake
1423          * is started. */
1424 static int
1425 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1426         int len, int peek)
1427         {
1428
1429         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1430                 /* (partially) satisfy request from storage */
1431                 {
1432                 unsigned char *src = s->d1->handshake_fragment;
1433                 unsigned char *dst = buf;
1434                 unsigned int k,n;
1435
1436                 /* peek == 0 */
1437                 n = 0;
1438                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1439                         {
1440                         *dst++ = *src++;
1441                         len--; s->d1->handshake_fragment_len--;
1442                         n++;
1443                         }
1444                 /* move any remaining fragment bytes: */
1445                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1446                         s->d1->handshake_fragment[k] = *src++;
1447                 return n;
1448                 }
1449
1450         return 0;
1451         }
1452
1453
1454
1455
1456 /* Call this to write data in records of type 'type'
1457  * It will return <= 0 if not all data has been sent or non-blocking IO.
1458  */
1459 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1460         {
1461         int i;
1462
1463         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1464         s->rwstate=SSL_NOTHING;
1465         i=do_dtls1_write(s, type, buf, len, 0);
1466         return i;
1467         }
1468
1469 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1470         {
1471         unsigned char *p,*pseq;
1472         int i,mac_size,clear=0;
1473         int prefix_len = 0;
1474         SSL3_RECORD *wr;
1475         SSL3_BUFFER *wb;
1476         SSL_SESSION *sess;
1477         int bs;
1478
1479         /* first check if there is a SSL3_BUFFER still being written
1480          * out.  This will happen with non blocking IO */
1481         if (s->s3->wbuf.left != 0)
1482                 {
1483                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1484                 return(ssl3_write_pending(s,type,buf,len));
1485                 }
1486
1487         /* If we have an alert to send, lets send it */
1488         if (s->s3->alert_dispatch)
1489                 {
1490                 i=s->method->ssl_dispatch_alert(s);
1491                 if (i <= 0)
1492                         return(i);
1493                 /* if it went, fall through and send more stuff */
1494                 }
1495
1496         if (len == 0 && !create_empty_fragment)
1497                 return 0;
1498
1499         wr= &(s->s3->wrec);
1500         wb= &(s->s3->wbuf);
1501         sess=s->session;
1502
1503         if (    (sess == NULL) ||
1504                 (s->enc_write_ctx == NULL) ||
1505                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1506                 clear=1;
1507
1508         if (clear)
1509                 mac_size=0;
1510         else
1511                 {
1512                 mac_size=EVP_MD_CTX_size(s->write_hash);
1513                 if (mac_size < 0)
1514                         goto err;
1515                 }
1516
1517         /* DTLS implements explicit IV, so no need for empty fragments */
1518 #if 0
1519         /* 'create_empty_fragment' is true only when this function calls itself */
1520         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1521             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1522                 {
1523                 /* countermeasure against known-IV weakness in CBC ciphersuites
1524                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1525                  */
1526
1527                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1528                         {
1529                         /* recursive function call with 'create_empty_fragment' set;
1530                          * this prepares and buffers the data for an empty fragment
1531                          * (these 'prefix_len' bytes are sent out later
1532                          * together with the actual payload) */
1533                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1534                         if (prefix_len <= 0)
1535                                 goto err;
1536
1537                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1538                                 {
1539                                 /* insufficient space */
1540                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1541                                 goto err;
1542                                 }
1543                         }
1544
1545                 s->s3->empty_fragment_done = 1;
1546                 }
1547 #endif
1548         p = wb->buf + prefix_len;
1549
1550         /* write the header */
1551
1552         *(p++)=type&0xff;
1553         wr->type=type;
1554
1555         *(p++)=(s->version>>8);
1556         *(p++)=s->version&0xff;
1557
1558         /* field where we are to write out packet epoch, seq num and len */
1559         pseq=p;
1560         p+=10;
1561
1562         /* lets setup the record stuff. */
1563
1564         /* Make space for the explicit IV in case of CBC.
1565          * (this is a bit of a boundary violation, but what the heck).
1566          */
1567         if ( s->enc_write_ctx &&
1568                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1569                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1570         else
1571                 bs = 0;
1572
1573         wr->data=p + bs;  /* make room for IV in case of CBC */
1574         wr->length=(int)len;
1575         wr->input=(unsigned char *)buf;
1576
1577         /* we now 'read' from wr->input, wr->length bytes into
1578          * wr->data */
1579
1580         /* first we compress */
1581         if (s->compress != NULL)
1582                 {
1583                 if (!ssl3_do_compress(s))
1584                         {
1585                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1586                         goto err;
1587                         }
1588                 }
1589         else
1590                 {
1591                 memcpy(wr->data,wr->input,wr->length);
1592                 wr->input=wr->data;
1593                 }
1594
1595         /* we should still have the output to wr->data and the input
1596          * from wr->input.  Length should be wr->length.
1597          * wr->data still points in the wb->buf */
1598
1599         if (mac_size != 0)
1600                 {
1601                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1602                         goto err;
1603                 wr->length+=mac_size;
1604                 }
1605
1606         /* this is true regardless of mac size */
1607         wr->input=p;
1608         wr->data=p;
1609
1610
1611         /* ssl3_enc can only have an error on read */
1612         if (bs) /* bs != 0 in case of CBC */
1613                 {
1614                 RAND_pseudo_bytes(p,bs);
1615                 /* master IV and last CBC residue stand for
1616                  * the rest of randomness */
1617                 wr->length += bs;
1618                 }
1619
1620         s->method->ssl3_enc->enc(s,1);
1621
1622         /* record length after mac and block padding */
1623 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1624         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1625
1626         /* there's only one epoch between handshake and app data */
1627
1628         s2n(s->d1->w_epoch, pseq);
1629
1630         /* XDTLS: ?? */
1631 /*      else
1632         s2n(s->d1->handshake_epoch, pseq); */
1633
1634         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1635         pseq+=6;
1636         s2n(wr->length,pseq);
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         }