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         s->packet = NULL;
 243         s->packet_length = 0;
 244         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 245         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 246
 247         if (!ssl3_setup_buffers(s))
 248                 {
 249                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 250                 if (rdata->rbuf.buf != NULL)
 251                         OPENSSL_free(rdata->rbuf.buf);
 252                 OPENSSL_free(rdata);
 253                 pitem_free(item);
 254                 return(-1);
 255                 }
 256
 257         /* insert should not fail, since duplicates are dropped */
 258         if (pqueue_insert(queue->q, item) == NULL)
 259                 {
 260                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 261                 if (rdata->rbuf.buf != NULL)
 262                         OPENSSL_free(rdata->rbuf.buf);
 263                 OPENSSL_free(rdata);
 264                 pitem_free(item);
 265                 return(-1);
 266                 }
 267
 268         return(1);
 269         }
 270
 271
 272 static int
 273 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 274     {
 275     pitem *item;
 276
 277     item = pqueue_pop(queue->q);
 278     if (item)
 279         {
 280         dtls1_copy_record(s, item);
 281
 282         OPENSSL_free(item->data);
 283                 pitem_free(item);
 284
 285         return(1);
 286         }
 287
 288     return(0);
 289     }
 290
 291
 292 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 293  * yet */
 294 #define dtls1_get_unprocessed_record(s) \
 295                    dtls1_retrieve_buffered_record((s), \
 296                    &((s)->d1->unprocessed_rcds))
 297
 298 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 299 #define dtls1_get_processed_record(s) \
 300                    dtls1_retrieve_buffered_record((s), \
 301                    &((s)->d1->processed_rcds))
 302
 303 static int
 304 dtls1_process_buffered_records(SSL *s)
 305     {
 306     pitem *item;
 307
 308     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 309     if (item)
 310         {
 311         /* Check if epoch is current. */
 312         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 313             return(1);  /* Nothing to do. */
 314
 315         /* Process all the records. */
 316         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 317             {
 318             dtls1_get_unprocessed_record(s);
 319             if ( ! dtls1_process_record(s))
 320                 return(0);
 321             if(dtls1_buffer_record(s, &(s->d1->processed_rcds),
 322                 s->s3->rrec.seq_num)<0)
 323                 return -1;
 324             }
 325         }
 326
 327     /* sync epoch numbers once all the unprocessed records
 328      * have been processed */
 329     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 330     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 331
 332     return(1);
 333     }
 334
 335
 336 #if 0
 337
 338 static int
 339 dtls1_get_buffered_record(SSL *s)
 340         {
 341         pitem *item;
 342         PQ_64BIT priority =
 343                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 344                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 345
 346     /* if we're not (re)negotiating, nothing buffered */
 347         if ( ! SSL_in_init(s))
 348                 return 0;
 349
 350
 351         item = pqueue_peek(s->d1->rcvd_records);
 352         if (item && item->priority == priority)
 353                 {
 354                 /* Check if we've received the record of interest.  It must be
 355                  * a handshake record, since data records as passed up without
 356                  * buffering */
 357                 DTLS1_RECORD_DATA *rdata;
 358                 item = pqueue_pop(s->d1->rcvd_records);
 359                 rdata = (DTLS1_RECORD_DATA *)item->data;
 360
 361                 if (s->s3->rbuf.buf != NULL)
 362                         OPENSSL_free(s->s3->rbuf.buf);
 363
 364                 s->packet = rdata->packet;
 365                 s->packet_length = rdata->packet_length;
 366                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 367                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 368
 369                 OPENSSL_free(item->data);
 370                 pitem_free(item);
 371
 372                 /* s->d1->next_expected_seq_num++; */
 373                 return(1);
 374                 }
 375
 376         return 0;
 377         }
 378
 379 #endif
 380
 381 static int
 382 dtls1_process_record(SSL *s)
 383 {
 384         int i,al;
 385         int enc_err;
 386         SSL_SESSION *sess;
 387         SSL3_RECORD *rr;
 388         unsigned int mac_size;
 389         unsigned char md[EVP_MAX_MD_SIZE];
 390
 391         rr= &(s->s3->rrec);
 392         sess = s->session;
 393
 394         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 395          * and we have that many bytes in s->packet
 396          */
 397         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 398
 399         /* ok, we can now read from 's->packet' data into 'rr'
 400          * rr->input points at rr->length bytes, which
 401          * need to be copied into rr->data by either
 402          * the decryption or by the decompression
 403          * When the data is 'copied' into the rr->data buffer,
 404          * rr->input will be pointed at the new buffer */
 405
 406         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 407          * rr->length bytes of encrypted compressed stuff. */
 408
 409         /* check is not needed I believe */
 410         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 411                 {
 412                 al=SSL_AD_RECORD_OVERFLOW;
 413                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 414                 goto f_err;
 415                 }
 416
 417         /* decrypt in place in 'rr->input' */
 418         rr->data=rr->input;
 419         rr->orig_len=rr->length;
 420
 421         enc_err = s->method->ssl3_enc->enc(s,0);
 422         /*-
 423          * enc_err is:
 424          *    0: (in non-constant time) if the record is publically invalid.
 425          *    1: if the padding is valid
 426          *   -1: if the padding is invalid
 427          */
 428         if (enc_err == 0)
 429                 {
 430                 /* For DTLS we simply ignore bad packets. */
 431                 rr->length = 0;
 432                 s->packet_length = 0;
 433                 goto err;
 434                 }
 435
 436 #ifdef TLS_DEBUG
 437 printf("dec %d\n",rr->length);
 438 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 439 printf("\n");
 440 #endif
 441
 442         /* r->length is now the compressed data plus mac */
 443         if ((sess != NULL) &&
 444             (s->enc_read_ctx != NULL) &&
 445             (EVP_MD_CTX_md(s->read_hash) != NULL))
 446                 {
 447                 /* s->read_hash != NULL => mac_size != -1 */
 448                 unsigned char *mac = NULL;
 449                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 450                 mac_size=EVP_MD_CTX_size(s->read_hash);
 451                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 452
 453                 /* orig_len is the length of the record before any padding was
 454                  * removed. This is public information, as is the MAC in use,
 455                  * therefore we can safely process the record in a different
 456                  * amount of time if it's too short to possibly contain a MAC.
 457                  */
 458                 if (rr->orig_len < mac_size ||
 459                     /* CBC records must have a padding length byte too. */
 460                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 461                      rr->orig_len < mac_size+1))
 462                         {
 463                         al=SSL_AD_DECODE_ERROR;
 464                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 465                         goto f_err;
 466                         }
 467
 468                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 469                         {
 470                         /* We update the length so that the TLS header bytes
 471                          * can be constructed correctly but we need to extract
 472                          * the MAC in constant time from within the record,
 473                          * without leaking the contents of the padding bytes.
 474                          * */
 475                         mac = mac_tmp;
 476                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
 477                         rr->length -= mac_size;
 478                         }
 479                 else
 480                         {
 481                         /* In this case there's no padding, so |rec->orig_len|
 482                          * equals |rec->length| and we checked that there's
 483                          * enough bytes for |mac_size| above. */
 484                         rr->length -= mac_size;
 485                         mac = &rr->data[rr->length];
 486                         }
 487
 488                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 489                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 490                         enc_err = -1;
 491                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 492                         enc_err = -1;
 493                 }
 494
 495         if (enc_err < 0)
 496                 {
 497                 /* decryption failed, silently discard message */
 498                 rr->length = 0;
 499                 s->packet_length = 0;
 500                 goto err;
 501                 }
 502
 503         /* r->length is now just compressed */
 504         if (s->expand != NULL)
 505                 {
 506                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 507                         {
 508                         al=SSL_AD_RECORD_OVERFLOW;
 509                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 510                         goto f_err;
 511                         }
 512                 if (!ssl3_do_uncompress(s))
 513                         {
 514                         al=SSL_AD_DECOMPRESSION_FAILURE;
 515                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 516                         goto f_err;
 517                         }
 518                 }
 519
 520         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 521                 {
 522                 al=SSL_AD_RECORD_OVERFLOW;
 523                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 524                 goto f_err;
 525                 }
 526
 527         rr->off=0;
 528         /*-
 529          * So at this point the following is true
 530          * ssl->s3->rrec.type   is the type of record
 531          * ssl->s3->rrec.length == number of bytes in record
 532          * ssl->s3->rrec.off    == offset to first valid byte
 533          * ssl->s3->rrec.data   == where to take bytes from, increment
 534          *                         after use :-).
 535          */
 536
 537         /* we have pulled in a full packet so zero things */
 538         s->packet_length=0;
 539         return(1);
 540
 541 f_err:
 542         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 543 err:
 544         return(0);
 545 }
 546
 547
 548 /*-
 549  * Call this to get a new input record.
 550  * It will return <= 0 if more data is needed, normally due to an error
 551  * or non-blocking IO.
 552  * When it finishes, one packet has been decoded and can be found in
 553  * ssl->s3->rrec.type    - is the type of record
 554  * ssl->s3->rrec.data,   - data
 555  * ssl->s3->rrec.length, - number of bytes
 556  */
 557 /* used only by dtls1_read_bytes */
 558 int dtls1_get_record(SSL *s)
 559         {
 560         int ssl_major,ssl_minor;
 561         int i,n;
 562         SSL3_RECORD *rr;
 563         unsigned char *p = NULL;
 564         unsigned short version;
 565         DTLS1_BITMAP *bitmap;
 566         unsigned int is_next_epoch;
 567
 568         rr= &(s->s3->rrec);
 569
 570         /* The epoch may have changed.  If so, process all the
 571          * pending records.  This is a non-blocking operation. */
 572         if(dtls1_process_buffered_records(s)<0)
 573                 return -1;
 574
 575         /* if we're renegotiating, then there may be buffered records */
 576         if (dtls1_get_processed_record(s))
 577                 return 1;
 578
 579         /* get something from the wire */
 580 again:
 581         /* check if we have the header */
 582         if (    (s->rstate != SSL_ST_READ_BODY) ||
 583                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 584                 {
 585                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 586                 /* read timeout is handled by dtls1_read_bytes */
 587                 if (n <= 0) return(n); /* error or non-blocking */
 588
 589                 /* this packet contained a partial record, dump it */
 590                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 591                         {
 592                         s->packet_length = 0;
 593                         goto again;
 594                         }
 595
 596                 s->rstate=SSL_ST_READ_BODY;
 597
 598                 p=s->packet;
 599
 600                 if (s->msg_callback)
 601                         s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
 602
 603                 /* Pull apart the header into the DTLS1_RECORD */
 604                 rr->type= *(p++);
 605                 ssl_major= *(p++);
 606                 ssl_minor= *(p++);
 607                 version=(ssl_major<<8)|ssl_minor;
 608
 609                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 610                 n2s(p,rr->epoch);
 611
 612                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 613                 p+=6;
 614
 615                 n2s(p,rr->length);
 616
 617                 /* Lets check version */
 618                 if (!s->first_packet)
 619                         {
 620                         if (version != s->version)
 621                                 {
 622                                 /* unexpected version, silently discard */
 623                                 rr->length = 0;
 624                                 s->packet_length = 0;
 625                                 goto again;
 626                                 }
 627                         }
 628
 629                 if ((version & 0xff00) != (s->version & 0xff00))
 630                         {
 631                         /* wrong version, silently discard record */
 632                         rr->length = 0;
 633                         s->packet_length = 0;
 634                         goto again;
 635                         }
 636
 637                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 638                         {
 639                         /* record too long, silently discard it */
 640                         rr->length = 0;
 641                         s->packet_length = 0;
 642                         goto again;
 643                         }
 644
 645                 /* now s->rstate == SSL_ST_READ_BODY */
 646                 }
 647
 648         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 649
 650         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 651                 {
 652                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 653                 i=rr->length;
 654                 n=ssl3_read_n(s,i,i,1);
 655                 /* this packet contained a partial record, dump it */
 656                 if ( n != i)
 657                         {
 658                         rr->length = 0;
 659                         s->packet_length = 0;
 660                         goto again;
 661                         }
 662
 663                 /* now n == rr->length,
 664                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 665                 }
 666         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 667
 668         /* match epochs.  NULL means the packet is dropped on the floor */
 669         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 670         if ( bitmap == NULL)
 671                 {
 672                 rr->length = 0;
 673                 s->packet_length = 0;  /* dump this record */
 674                 goto again;   /* get another record */
 675                 }
 676
 677 #ifndef OPENSSL_NO_SCTP
 678         /* Only do replay check if no SCTP bio */
 679         if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
 680                 {
 681 #endif
 682                 /* Check whether this is a repeat, or aged record.
 683                  * Don't check if we're listening and this message is
 684                  * a ClientHello. They can look as if they're replayed,
 685                  * since they arrive from different connections and
 686                  * would be dropped unnecessarily.
 687                  */
 688                 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 689                     s->packet_length > DTLS1_RT_HEADER_LENGTH &&
 690                     s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
 691                     !dtls1_record_replay_check(s, bitmap))
 692                         {
 693                         rr->length = 0;
 694                         s->packet_length=0; /* dump this record */
 695                         goto again;     /* get another record */
 696                         }
 697 #ifndef OPENSSL_NO_SCTP
 698                 }
 699 #endif
 700
 701         /* just read a 0 length packet */
 702         if (rr->length == 0) goto again;
 703
 704         /* If this record is from the next epoch (either HM or ALERT),
 705          * and a handshake is currently in progress, buffer it since it
 706          * cannot be processed at this time. However, do not buffer
 707          * anything while listening.
 708          */
 709         if (is_next_epoch)
 710                 {
 711                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 712                         {
 713                         if(dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num)<0)
 714                                 return -1;
 715                         dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 716                         }
 717                 rr->length = 0;
 718                 s->packet_length = 0;
 719                 goto again;
 720                 }
 721
 722         if (!dtls1_process_record(s))
 723                 {
 724                 rr->length = 0;
 725                 s->packet_length = 0;  /* dump this record */
 726                 goto again;   /* get another record */
 727                 }
 728         dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 729
 730         return(1);
 731
 732         }
 733
 734 /*-
 735  * Return up to 'len' payload bytes received in 'type' records.
 736  * 'type' is one of the following:
 737  *
 738  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 739  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 740  *   -  0 (during a shutdown, no data has to be returned)
 741  *
 742  * If we don't have stored data to work from, read a SSL/TLS record first
 743  * (possibly multiple records if we still don't have anything to return).
 744  *
 745  * This function must handle any surprises the peer may have for us, such as
 746  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 747  * a surprise, but handled as if it were), or renegotiation requests.
 748  * Also if record payloads contain fragments too small to process, we store
 749  * them until there is enough for the respective protocol (the record protocol
 750  * may use arbitrary fragmentation and even interleaving):
 751  *     Change cipher spec protocol
 752  *             just 1 byte needed, no need for keeping anything stored
 753  *     Alert protocol
 754  *             2 bytes needed (AlertLevel, AlertDescription)
 755  *     Handshake protocol
 756  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 757  *             to detect unexpected Client Hello and Hello Request messages
 758  *             here, anything else is handled by higher layers
 759  *     Application data protocol
 760  *             none of our business
 761  */
 762 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 763         {
 764         int al,i,j,ret;
 765         unsigned int n;
 766         SSL3_RECORD *rr;
 767         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 768
 769         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 770                 if (!ssl3_setup_buffers(s))
 771                         return(-1);
 772
 773         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 774                 (type != SSL3_RT_HANDSHAKE)) ||
 775             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 776                 {
 777                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 778                 return -1;
 779                 }
 780
 781         /* check whether there's a handshake message (client hello?) waiting */
 782         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 783                 return ret;
 784
 785         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 786
 787 #ifndef OPENSSL_NO_SCTP
 788         /* Continue handshake if it had to be interrupted to read
 789          * app data with SCTP.
 790          */
 791         if ((!s->in_handshake && SSL_in_init(s)) ||
 792             (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 793              (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
 794              s->s3->in_read_app_data != 2))
 795 #else
 796         if (!s->in_handshake && SSL_in_init(s))
 797 #endif
 798                 {
 799                 /* type == SSL3_RT_APPLICATION_DATA */
 800                 i=s->handshake_func(s);
 801                 if (i < 0) return(i);
 802                 if (i == 0)
 803                         {
 804                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 805                         return(-1);
 806                         }
 807                 }
 808
 809 start:
 810         s->rwstate=SSL_NOTHING;
 811
 812         /*-
 813          * s->s3->rrec.type         - is the type of record
 814          * s->s3->rrec.data,    - data
 815          * s->s3->rrec.off,     - offset into 'data' for next read
 816          * s->s3->rrec.length,  - number of bytes.
 817          */
 818         rr = &(s->s3->rrec);
 819
 820         /* We are not handshaking and have no data yet,
 821          * so process data buffered during the last handshake
 822          * in advance, if any.
 823          */
 824         if (s->state == SSL_ST_OK && rr->length == 0)
 825                 {
 826                 pitem *item;
 827                 item = pqueue_pop(s->d1->buffered_app_data.q);
 828                 if (item)
 829                         {
 830 #ifndef OPENSSL_NO_SCTP
 831                         /* Restore bio_dgram_sctp_rcvinfo struct */
 832                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
 833                                 {
 834                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
 835                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
 836                                 }
 837 #endif
 838
 839                         dtls1_copy_record(s, item);
 840
 841                         OPENSSL_free(item->data);
 842                         pitem_free(item);
 843                         }
 844                 }
 845
 846         /* Check for timeout */
 847         if (dtls1_handle_timeout(s) > 0)
 848                 goto start;
 849
 850         /* get new packet if necessary */
 851         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 852                 {
 853                 ret=dtls1_get_record(s);
 854                 if (ret <= 0)
 855                         {
 856                         ret = dtls1_read_failed(s, ret);
 857                         /* anything other than a timeout is an error */
 858                         if (ret <= 0)
 859                                 return(ret);
 860                         else
 861                                 goto start;
 862                         }
 863                 }
 864
 865         if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
 866                 {
 867                 rr->length = 0;
 868                 goto start;
 869                 }
 870
 871         /* we now have a packet which can be read and processed */
 872
 873         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 874                                        * reset by ssl3_get_finished */
 875                 && (rr->type != SSL3_RT_HANDSHAKE))
 876                 {
 877                 /* We now have application data between CCS and Finished.
 878                  * Most likely the packets were reordered on their way, so
 879                  * buffer the application data for later processing rather
 880                  * than dropping the connection.
 881                  */
 882                 if(dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num)<0)
 883                         {
 884                         SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 885                         return -1;
 886                         }
 887                 rr->length = 0;
 888                 goto start;
 889                 }
 890
 891         /* If the other end has shut down, throw anything we read away
 892          * (even in 'peek' mode) */
 893         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 894                 {
 895                 rr->length=0;
 896                 s->rwstate=SSL_NOTHING;
 897                 return(0);
 898                 }
 899
 900
 901         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 902                 {
 903                 /* make sure that we are not getting application data when we
 904                  * are doing a handshake for the first time */
 905                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 906                         (s->enc_read_ctx == NULL))
 907                         {
 908                         al=SSL_AD_UNEXPECTED_MESSAGE;
 909                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 910                         goto f_err;
 911                         }
 912
 913                 if (len <= 0) return(len);
 914
 915                 if ((unsigned int)len > rr->length)
 916                         n = rr->length;
 917                 else
 918                         n = (unsigned int)len;
 919
 920                 memcpy(buf,&(rr->data[rr->off]),n);
 921                 if (!peek)
 922                         {
 923                         rr->length-=n;
 924                         rr->off+=n;
 925                         if (rr->length == 0)
 926                                 {
 927                                 s->rstate=SSL_ST_READ_HEADER;
 928                                 rr->off=0;
 929                                 }
 930                         }
 931
 932 #ifndef OPENSSL_NO_SCTP
 933                         /* We were about to renegotiate but had to read
 934                          * belated application data first, so retry.
 935                          */
 936                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 937                             rr->type == SSL3_RT_APPLICATION_DATA &&
 938                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
 939                                 {
 940                                 s->rwstate=SSL_READING;
 941                                 BIO_clear_retry_flags(SSL_get_rbio(s));
 942                                 BIO_set_retry_read(SSL_get_rbio(s));
 943                                 }
 944
 945                         /* We might had to delay a close_notify alert because
 946                          * of reordered app data. If there was an alert and there
 947                          * is no message to read anymore, finally set shutdown.
 948                          */
 949                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
 950                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
 951                                 {
 952                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 953                                 return(0);
 954                                 }
 955 #endif
 956                 return(n);
 957                 }
 958
 959
 960         /* If we get here, then type != rr->type; if we have a handshake
 961          * message, then it was unexpected (Hello Request or Client Hello). */
 962
 963         /* In case of record types for which we have 'fragment' storage,
 964          * fill that so that we can process the data at a fixed place.
 965          */
 966                 {
 967                 unsigned int k, dest_maxlen = 0;
 968                 unsigned char *dest = NULL;
 969                 unsigned int *dest_len = NULL;
 970
 971                 if (rr->type == SSL3_RT_HANDSHAKE)
 972                         {
 973                         dest_maxlen = sizeof s->d1->handshake_fragment;
 974                         dest = s->d1->handshake_fragment;
 975                         dest_len = &s->d1->handshake_fragment_len;
 976                         }
 977                 else if (rr->type == SSL3_RT_ALERT)
 978                         {
 979                         dest_maxlen = sizeof(s->d1->alert_fragment);
 980                         dest = s->d1->alert_fragment;
 981                         dest_len = &s->d1->alert_fragment_len;
 982                         }
 983 #ifndef OPENSSL_NO_HEARTBEATS
 984                 else if (rr->type == TLS1_RT_HEARTBEAT)
 985                         {
 986                         dtls1_process_heartbeat(s);
 987
 988                         /* Exit and notify application to read again */
 989                         rr->length = 0;
 990                         s->rwstate=SSL_READING;
 991                         BIO_clear_retry_flags(SSL_get_rbio(s));
 992                         BIO_set_retry_read(SSL_get_rbio(s));
 993                         return(-1);
 994                         }
 995 #endif
 996                 /* else it's a CCS message, or application data or wrong */
 997                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 998                         {
 999                         /* Application data while renegotiating
1000                          * is allowed. Try again reading.
1001                          */
1002                         if (rr->type == SSL3_RT_APPLICATION_DATA)
1003                                 {
1004                                 BIO *bio;
1005                                 s->s3->in_read_app_data=2;
1006                                 bio=SSL_get_rbio(s);
1007                                 s->rwstate=SSL_READING;
1008                                 BIO_clear_retry_flags(bio);
1009                                 BIO_set_retry_read(bio);
1010                                 return(-1);
1011                                 }
1012
1013                         /* Not certain if this is the right error handling */
1014                         al=SSL_AD_UNEXPECTED_MESSAGE;
1015                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1016                         goto f_err;
1017                         }
1018
1019                 if (dest_maxlen > 0)
1020                         {
1021             /* XDTLS:  In a pathalogical case, the Client Hello
1022              *  may be fragmented--don't always expect dest_maxlen bytes */
1023                         if ( rr->length < dest_maxlen)
1024                                 {
1025 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1026                                 /*
1027                                  * for normal alerts rr->length is 2, while
1028                                  * dest_maxlen is 7 if we were to handle this
1029                                  * non-existing alert...
1030                                  */
1031                                 FIX ME
1032 #endif
1033                                 s->rstate=SSL_ST_READ_HEADER;
1034                                 rr->length = 0;
1035                                 goto start;
1036                                 }
1037
1038                         /* now move 'n' bytes: */
1039                         for ( k = 0; k < dest_maxlen; k++)
1040                                 {
1041                                 dest[k] = rr->data[rr->off++];
1042                                 rr->length--;
1043                                 }
1044                         *dest_len = dest_maxlen;
1045                         }
1046                 }
1047
1048         /*-
1049          * s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1050          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1051          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
1052          */
1053
1054         /* If we are a client, check for an incoming 'Hello Request': */
1055         if ((!s->server) &&
1056                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1057                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1058                 (s->session != NULL) && (s->session->cipher != NULL))
1059                 {
1060                 s->d1->handshake_fragment_len = 0;
1061
1062                 if ((s->d1->handshake_fragment[1] != 0) ||
1063                         (s->d1->handshake_fragment[2] != 0) ||
1064                         (s->d1->handshake_fragment[3] != 0))
1065                         {
1066                         al=SSL_AD_DECODE_ERROR;
1067                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1068                         goto err;
1069                         }
1070
1071                 /* no need to check sequence number on HELLO REQUEST messages */
1072
1073                 if (s->msg_callback)
1074                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1075                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1076
1077                 if (SSL_is_init_finished(s) &&
1078                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1079                         !s->s3->renegotiate)
1080                         {
1081                         s->d1->handshake_read_seq++;
1082                         s->new_session = 1;
1083                         ssl3_renegotiate(s);
1084                         if (ssl3_renegotiate_check(s))
1085                                 {
1086                                 i=s->handshake_func(s);
1087                                 if (i < 0) return(i);
1088                                 if (i == 0)
1089                                         {
1090                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1091                                         return(-1);
1092                                         }
1093
1094                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1095                                         {
1096                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1097                                                 {
1098                                                 BIO *bio;
1099                                                 /* In the case where we try to read application data,
1100                                                  * but we trigger an SSL handshake, we return -1 with
1101                                                  * the retry option set.  Otherwise renegotiation may
1102                                                  * cause nasty problems in the blocking world */
1103                                                 s->rwstate=SSL_READING;
1104                                                 bio=SSL_get_rbio(s);
1105                                                 BIO_clear_retry_flags(bio);
1106                                                 BIO_set_retry_read(bio);
1107                                                 return(-1);
1108                                                 }
1109                                         }
1110                                 }
1111                         }
1112                 /* we either finished a handshake or ignored the request,
1113                  * now try again to obtain the (application) data we were asked for */
1114                 goto start;
1115                 }
1116
1117         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1118                 {
1119                 int alert_level = s->d1->alert_fragment[0];
1120                 int alert_descr = s->d1->alert_fragment[1];
1121
1122                 s->d1->alert_fragment_len = 0;
1123
1124                 if (s->msg_callback)
1125                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1126                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1127
1128                 if (s->info_callback != NULL)
1129                         cb=s->info_callback;
1130                 else if (s->ctx->info_callback != NULL)
1131                         cb=s->ctx->info_callback;
1132
1133                 if (cb != NULL)
1134                         {
1135                         j = (alert_level << 8) | alert_descr;
1136                         cb(s, SSL_CB_READ_ALERT, j);
1137                         }
1138
1139                 if (alert_level == 1) /* warning */
1140                         {
1141                         s->s3->warn_alert = alert_descr;
1142                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1143                                 {
1144 #ifndef OPENSSL_NO_SCTP
1145                                 /* With SCTP and streams the socket may deliver app data
1146                                  * after a close_notify alert. We have to check this
1147                                  * first so that nothing gets discarded.
1148                                  */
1149                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1150                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1151                                         {
1152                                         s->d1->shutdown_received = 1;
1153                                         s->rwstate=SSL_READING;
1154                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1155                                         BIO_set_retry_read(SSL_get_rbio(s));
1156                                         return -1;
1157                                         }
1158 #endif
1159                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1160                                 return(0);
1161                                 }
1162 #if 0
1163             /* XXX: this is a possible improvement in the future */
1164                         /* now check if it's a missing record */
1165                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1166                                 {
1167                                 unsigned short seq;
1168                                 unsigned int frag_off;
1169                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1170
1171                                 n2s(p, seq);
1172                                 n2l3(p, frag_off);
1173
1174                                 dtls1_retransmit_message(s,
1175                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1176                                                                                  frag_off, &found);
1177                                 if ( ! found  && SSL_in_init(s))
1178                                         {
1179                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1180                                         /* requested a message not yet sent,
1181                                            send an alert ourselves */
1182                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1183                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1184                                         }
1185                                 }
1186 #endif
1187                         }
1188                 else if (alert_level == 2) /* fatal */
1189                         {
1190                         char tmp[16];
1191
1192                         s->rwstate=SSL_NOTHING;
1193                         s->s3->fatal_alert = alert_descr;
1194                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1195                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1196                         ERR_add_error_data(2,"SSL alert number ",tmp);
1197                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1198                         SSL_CTX_remove_session(s->ctx,s->session);
1199                         return(0);
1200                         }
1201                 else
1202                         {
1203                         al=SSL_AD_ILLEGAL_PARAMETER;
1204                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1205                         goto f_err;
1206                         }
1207
1208                 goto start;
1209                 }
1210
1211         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1212                 {
1213                 s->rwstate=SSL_NOTHING;
1214                 rr->length=0;
1215                 return(0);
1216                 }
1217
1218         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1219                 {
1220                 struct ccs_header_st ccs_hdr;
1221                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1222
1223                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1224
1225                 if (s->version == DTLS1_BAD_VER)
1226                         ccs_hdr_len = 3;
1227
1228                 /* 'Change Cipher Spec' is just a single byte, so we know
1229                  * exactly what the record payload has to look like */
1230                 /* XDTLS: check that epoch is consistent */
1231                 if (    (rr->length != ccs_hdr_len) ||
1232                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1233                         {
1234                         i=SSL_AD_ILLEGAL_PARAMETER;
1235                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1236                         goto err;
1237                         }
1238
1239                 rr->length=0;
1240
1241                 if (s->msg_callback)
1242                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1243                                 rr->data, 1, s, s->msg_callback_arg);
1244
1245                 /* We can't process a CCS now, because previous handshake
1246                  * messages are still missing, so just drop it.
1247                  */
1248                 if (!s->d1->change_cipher_spec_ok)
1249                         {
1250                         goto start;
1251                         }
1252
1253                 s->d1->change_cipher_spec_ok = 0;
1254
1255                 s->s3->change_cipher_spec=1;
1256                 if (!ssl3_do_change_cipher_spec(s))
1257                         goto err;
1258
1259                 /* do this whenever CCS is processed */
1260                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1261
1262                 if (s->version == DTLS1_BAD_VER)
1263                         s->d1->handshake_read_seq++;
1264
1265 #ifndef OPENSSL_NO_SCTP
1266                 /* Remember that a CCS has been received,
1267                  * so that an old key of SCTP-Auth can be
1268                  * deleted when a CCS is sent. Will be ignored
1269                  * if no SCTP is used
1270                  */
1271                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1272 #endif
1273
1274                 goto start;
1275                 }
1276
1277         /* Unexpected handshake message (Client Hello, or protocol violation) */
1278         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1279                 !s->in_handshake)
1280                 {
1281                 struct hm_header_st msg_hdr;
1282
1283                 /* this may just be a stale retransmit */
1284                 dtls1_get_message_header(rr->data, &msg_hdr);
1285                 if( rr->epoch != s->d1->r_epoch)
1286                         {
1287                         rr->length = 0;
1288                         goto start;
1289                         }
1290
1291                 /* If we are server, we may have a repeated FINISHED of the
1292                  * client here, then retransmit our CCS and FINISHED.
1293                  */
1294                 if (msg_hdr.type == SSL3_MT_FINISHED)
1295                         {
1296                         if (dtls1_check_timeout_num(s) < 0)
1297                                 return -1;
1298
1299                         dtls1_retransmit_buffered_messages(s);
1300                         rr->length = 0;
1301                         goto start;
1302                         }
1303
1304                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1305                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1306                         {
1307 #if 0 /* worked only because C operator preferences are not as expected (and
1308        * because this is not really needed for clients except for detecting
1309        * protocol violations): */
1310                         s->state=SSL_ST_BEFORE|(s->server)
1311                                 ?SSL_ST_ACCEPT
1312                                 :SSL_ST_CONNECT;
1313 #else
1314                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1315 #endif
1316                         s->renegotiate=1;
1317                         s->new_session=1;
1318                         }
1319                 i=s->handshake_func(s);
1320                 if (i < 0) return(i);
1321                 if (i == 0)
1322                         {
1323                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1324                         return(-1);
1325                         }
1326
1327                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1328                         {
1329                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1330                                 {
1331                                 BIO *bio;
1332                                 /* In the case where we try to read application data,
1333                                  * but we trigger an SSL handshake, we return -1 with
1334                                  * the retry option set.  Otherwise renegotiation may
1335                                  * cause nasty problems in the blocking world */
1336                                 s->rwstate=SSL_READING;
1337                                 bio=SSL_get_rbio(s);
1338                                 BIO_clear_retry_flags(bio);
1339                                 BIO_set_retry_read(bio);
1340                                 return(-1);
1341                                 }
1342                         }
1343                 goto start;
1344                 }
1345
1346         switch (rr->type)
1347                 {
1348         default:
1349 #ifndef OPENSSL_NO_TLS
1350                 /* TLS just ignores unknown message types */
1351                 if (s->version == TLS1_VERSION)
1352                         {
1353                         rr->length = 0;
1354                         goto start;
1355                         }
1356 #endif
1357                 al=SSL_AD_UNEXPECTED_MESSAGE;
1358                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1359                 goto f_err;
1360         case SSL3_RT_CHANGE_CIPHER_SPEC:
1361         case SSL3_RT_ALERT:
1362         case SSL3_RT_HANDSHAKE:
1363                 /* we already handled all of these, with the possible exception
1364                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1365                  * should not happen when type != rr->type */
1366                 al=SSL_AD_UNEXPECTED_MESSAGE;
1367                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1368                 goto f_err;
1369         case SSL3_RT_APPLICATION_DATA:
1370                 /* At this point, we were expecting handshake data,
1371                  * but have application data.  If the library was
1372                  * running inside ssl3_read() (i.e. in_read_app_data
1373                  * is set) and it makes sense to read application data
1374                  * at this point (session renegotiation not yet started),
1375                  * we will indulge it.
1376                  */
1377                 if (s->s3->in_read_app_data &&
1378                         (s->s3->total_renegotiations != 0) &&
1379                         ((
1380                                 (s->state & SSL_ST_CONNECT) &&
1381                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1382                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1383                                 ) || (
1384                                         (s->state & SSL_ST_ACCEPT) &&
1385                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1386                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1387                                         )
1388                                 ))
1389                         {
1390                         s->s3->in_read_app_data=2;
1391                         return(-1);
1392                         }
1393                 else
1394                         {
1395                         al=SSL_AD_UNEXPECTED_MESSAGE;
1396                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1397                         goto f_err;
1398                         }
1399                 }
1400         /* not reached */
1401
1402 f_err:
1403         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1404 err:
1405         return(-1);
1406         }
1407
1408 int
1409 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1410         {
1411         int i;
1412
1413 #ifndef OPENSSL_NO_SCTP
1414                 /* Check if we have to continue an interrupted handshake
1415                  * for reading belated app data with SCTP.
1416                  */
1417                 if ((SSL_in_init(s) && !s->in_handshake) ||
1418                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1419                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1420 #else
1421                 if (SSL_in_init(s) && !s->in_handshake)
1422 #endif
1423                 {
1424                 i=s->handshake_func(s);
1425                 if (i < 0) return(i);
1426                 if (i == 0)
1427                         {
1428                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1429                         return -1;
1430                         }
1431                 }
1432
1433         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1434                 {
1435                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1436                         return -1;
1437                 }
1438
1439         i = dtls1_write_bytes(s, type, buf_, len);
1440         return i;
1441         }
1442
1443
1444         /* this only happens when a client hello is received and a handshake
1445          * is started. */
1446 static int
1447 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1448         int len, int peek)
1449         {
1450
1451         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1452                 /* (partially) satisfy request from storage */
1453                 {
1454                 unsigned char *src = s->d1->handshake_fragment;
1455                 unsigned char *dst = buf;
1456                 unsigned int k,n;
1457
1458                 /* peek == 0 */
1459                 n = 0;
1460                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1461                         {
1462                         *dst++ = *src++;
1463                         len--; s->d1->handshake_fragment_len--;
1464                         n++;
1465                         }
1466                 /* move any remaining fragment bytes: */
1467                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1468                         s->d1->handshake_fragment[k] = *src++;
1469                 return n;
1470                 }
1471
1472         return 0;
1473         }
1474
1475
1476
1477
1478 /* Call this to write data in records of type 'type'
1479  * It will return <= 0 if not all data has been sent or non-blocking IO.
1480  */
1481 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1482         {
1483         int i;
1484
1485         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1486         s->rwstate=SSL_NOTHING;
1487         i=do_dtls1_write(s, type, buf, len, 0);
1488         return i;
1489         }
1490
1491 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1492         {
1493         unsigned char *p,*pseq;
1494         int i,mac_size,clear=0;
1495         int prefix_len = 0;
1496         int eivlen;
1497         SSL3_RECORD *wr;
1498         SSL3_BUFFER *wb;
1499         SSL_SESSION *sess;
1500
1501         /* first check if there is a SSL3_BUFFER still being written
1502          * out.  This will happen with non blocking IO */
1503         if (s->s3->wbuf.left != 0)
1504                 {
1505                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1506                 return(ssl3_write_pending(s,type,buf,len));
1507                 }
1508
1509         /* If we have an alert to send, lets send it */
1510         if (s->s3->alert_dispatch)
1511                 {
1512                 i=s->method->ssl_dispatch_alert(s);
1513                 if (i <= 0)
1514                         return(i);
1515                 /* if it went, fall through and send more stuff */
1516                 }
1517
1518         if (len == 0 && !create_empty_fragment)
1519                 return 0;
1520
1521         wr= &(s->s3->wrec);
1522         wb= &(s->s3->wbuf);
1523         sess=s->session;
1524
1525         if (    (sess == NULL) ||
1526                 (s->enc_write_ctx == NULL) ||
1527                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1528                 clear=1;
1529
1530         if (clear)
1531                 mac_size=0;
1532         else
1533                 {
1534                 mac_size=EVP_MD_CTX_size(s->write_hash);
1535                 if (mac_size < 0)
1536                         goto err;
1537                 }
1538
1539         /* DTLS implements explicit IV, so no need for empty fragments */
1540 #if 0
1541         /* 'create_empty_fragment' is true only when this function calls itself */
1542         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1543             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1544                 {
1545                 /* countermeasure against known-IV weakness in CBC ciphersuites
1546                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1547                  */
1548
1549                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1550                         {
1551                         /* recursive function call with 'create_empty_fragment' set;
1552                          * this prepares and buffers the data for an empty fragment
1553                          * (these 'prefix_len' bytes are sent out later
1554                          * together with the actual payload) */
1555                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1556                         if (prefix_len <= 0)
1557                                 goto err;
1558
1559                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1560                                 {
1561                                 /* insufficient space */
1562                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1563                                 goto err;
1564                                 }
1565                         }
1566
1567                 s->s3->empty_fragment_done = 1;
1568                 }
1569 #endif
1570         p = wb->buf + prefix_len;
1571
1572         /* write the header */
1573
1574         *(p++)=type&0xff;
1575         wr->type=type;
1576         /* Special case: for hello verify request, client version 1.0 and
1577          * we haven't decided which version to use yet send back using
1578          * version 1.0 header: otherwise some clients will ignore it.
1579          */
1580         if (s->method->version == DTLS_ANY_VERSION)
1581                 {
1582                 *(p++)=DTLS1_VERSION>>8;
1583                 *(p++)=DTLS1_VERSION&0xff;
1584                 }
1585         else
1586                 {
1587                 *(p++)=s->version>>8;
1588                 *(p++)=s->version&0xff;
1589                 }
1590
1591         /* field where we are to write out packet epoch, seq num and len */
1592         pseq=p;
1593         p+=10;
1594
1595         /* Explicit IV length, block ciphers appropriate version flag */
1596         if (s->enc_write_ctx)
1597                 {
1598                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1599                 if (mode == EVP_CIPH_CBC_MODE)
1600                         {
1601                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1602                         if (eivlen <= 1)
1603                                 eivlen = 0;
1604                         }
1605                 /* Need explicit part of IV for GCM mode */
1606                 else if (mode == EVP_CIPH_GCM_MODE)
1607                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1608                 else
1609                         eivlen = 0;
1610                 }
1611         else
1612                 eivlen = 0;
1613
1614         /* lets setup the record stuff. */
1615         wr->data=p + eivlen;  /* make room for IV in case of CBC */
1616         wr->length=(int)len;
1617         wr->input=(unsigned char *)buf;
1618
1619         /* we now 'read' from wr->input, wr->length bytes into
1620          * wr->data */
1621
1622         /* first we compress */
1623         if (s->compress != NULL)
1624                 {
1625                 if (!ssl3_do_compress(s))
1626                         {
1627                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1628                         goto err;
1629                         }
1630                 }
1631         else
1632                 {
1633                 memcpy(wr->data,wr->input,wr->length);
1634                 wr->input=wr->data;
1635                 }
1636
1637         /* we should still have the output to wr->data and the input
1638          * from wr->input.  Length should be wr->length.
1639          * wr->data still points in the wb->buf */
1640
1641         if (mac_size != 0)
1642                 {
1643                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
1644                         goto err;
1645                 wr->length+=mac_size;
1646                 }
1647
1648         /* this is true regardless of mac size */
1649         wr->input=p;
1650         wr->data=p;
1651
1652         if (eivlen)
1653                 wr->length += eivlen;
1654
1655         if(s->method->ssl3_enc->enc(s,1) < 1) goto err;
1656
1657         /* record length after mac and block padding */
1658 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1659         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1660
1661         /* there's only one epoch between handshake and app data */
1662
1663         s2n(s->d1->w_epoch, pseq);
1664
1665         /* XDTLS: ?? */
1666 /*      else
1667         s2n(s->d1->handshake_epoch, pseq); */
1668
1669         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1670         pseq+=6;
1671         s2n(wr->length,pseq);
1672
1673         if (s->msg_callback)
1674                 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1675
1676         /* we should now have
1677          * wr->data pointing to the encrypted data, which is
1678          * wr->length long */
1679         wr->type=type; /* not needed but helps for debugging */
1680         wr->length+=DTLS1_RT_HEADER_LENGTH;
1681
1682 #if 0  /* this is now done at the message layer */
1683         /* buffer the record, making it easy to handle retransmits */
1684         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1685                 dtls1_buffer_record(s, wr->data, wr->length,
1686                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1687 #endif
1688
1689         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1690
1691         if (create_empty_fragment)
1692                 {
1693                 /* we are in a recursive call;
1694                  * just return the length, don't write out anything here
1695                  */
1696                 return wr->length;
1697                 }
1698
1699         /* now let's set up wb */
1700         wb->left = prefix_len + wr->length;
1701         wb->offset = 0;
1702
1703         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1704         s->s3->wpend_tot=len;
1705         s->s3->wpend_buf=buf;
1706         s->s3->wpend_type=type;
1707         s->s3->wpend_ret=len;
1708
1709         /* we now just need to write the buffer */
1710         return ssl3_write_pending(s,type,buf,len);
1711 err:
1712         return -1;
1713         }
1714
1715
1716
1717 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1718         {
1719         int cmp;
1720         unsigned int shift;
1721         const unsigned char *seq = s->s3->read_sequence;
1722
1723         cmp = satsub64be(seq,bitmap->max_seq_num);
1724         if (cmp > 0)
1725                 {
1726                 memcpy (s->s3->rrec.seq_num,seq,8);
1727                 return 1; /* this record in new */
1728                 }
1729         shift = -cmp;
1730         if (shift >= sizeof(bitmap->map)*8)
1731                 return 0; /* stale, outside the window */
1732         else if (bitmap->map & (1UL<<shift))
1733                 return 0; /* record previously received */
1734
1735         memcpy (s->s3->rrec.seq_num,seq,8);
1736         return 1;
1737         }
1738
1739
1740 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1741         {
1742         int cmp;
1743         unsigned int shift;
1744         const unsigned char *seq = s->s3->read_sequence;
1745
1746         cmp = satsub64be(seq,bitmap->max_seq_num);
1747         if (cmp > 0)
1748                 {
1749                 shift = cmp;
1750                 if (shift < sizeof(bitmap->map)*8)
1751                         bitmap->map <<= shift, bitmap->map |= 1UL;
1752                 else
1753                         bitmap->map = 1UL;
1754                 memcpy(bitmap->max_seq_num,seq,8);
1755                 }
1756         else    {
1757                 shift = -cmp;
1758                 if (shift < sizeof(bitmap->map)*8)
1759                         bitmap->map |= 1UL<<shift;
1760                 }
1761         }
1762
1763
1764 int dtls1_dispatch_alert(SSL *s)
1765         {
1766         int i,j;
1767         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1768         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1769         unsigned char *ptr = &buf[0];
1770
1771         s->s3->alert_dispatch=0;
1772
1773         memset(buf, 0x00, sizeof(buf));
1774         *ptr++ = s->s3->send_alert[0];
1775         *ptr++ = s->s3->send_alert[1];
1776
1777 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1778         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1779                 {
1780                 s2n(s->d1->handshake_read_seq, ptr);
1781 #if 0
1782                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1783
1784                 else
1785                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1786 #endif
1787
1788 #if 0
1789                 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);
1790 #endif
1791                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1792                 }
1793 #endif
1794
1795         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1796         if (i <= 0)
1797                 {
1798                 s->s3->alert_dispatch=1;
1799                 /* fprintf( stderr, "not done with alert\n" ); */
1800                 }
1801         else
1802                 {
1803                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1804 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1805                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1806 #endif
1807                     )
1808                         (void)BIO_flush(s->wbio);
1809
1810                 if (s->msg_callback)
1811                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1812                                 2, s, s->msg_callback_arg);
1813
1814                 if (s->info_callback != NULL)
1815                         cb=s->info_callback;
1816                 else if (s->ctx->info_callback != NULL)
1817                         cb=s->ctx->info_callback;
1818
1819                 if (cb != NULL)
1820                         {
1821                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1822                         cb(s,SSL_CB_WRITE_ALERT,j);
1823                         }
1824                 }
1825         return(i);
1826         }
1827
1828
1829 static DTLS1_BITMAP *
1830 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1831     {
1832
1833     *is_next_epoch = 0;
1834
1835     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1836     if (rr->epoch == s->d1->r_epoch)
1837         return &s->d1->bitmap;
1838
1839     /* Only HM and ALERT messages can be from the next epoch */
1840     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1841         (rr->type == SSL3_RT_HANDSHAKE ||
1842             rr->type == SSL3_RT_ALERT))
1843         {
1844         *is_next_epoch = 1;
1845         return &s->d1->next_bitmap;
1846         }
1847
1848     return NULL;
1849     }
1850
1851 #if 0
1852 static int
1853 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1854         unsigned long *offset)
1855         {
1856
1857         /* alerts are passed up immediately */
1858         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1859                 rr->type == SSL3_RT_ALERT)
1860                 return 0;
1861
1862         /* Only need to buffer if a handshake is underway.
1863          * (this implies that Hello Request and Client Hello are passed up
1864          * immediately) */
1865         if ( SSL_in_init(s))
1866                 {
1867                 unsigned char *data = rr->data;
1868                 /* need to extract the HM/CCS sequence number here */
1869                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1870                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1871                         {
1872                         unsigned short seq_num;
1873                         struct hm_header_st msg_hdr;
1874                         struct ccs_header_st ccs_hdr;
1875
1876                         if ( rr->type == SSL3_RT_HANDSHAKE)
1877                                 {
1878                                 dtls1_get_message_header(data, &msg_hdr);
1879                                 seq_num = msg_hdr.seq;
1880                                 *offset = msg_hdr.frag_off;
1881                                 }
1882                         else
1883                                 {
1884                                 dtls1_get_ccs_header(data, &ccs_hdr);
1885                                 seq_num = ccs_hdr.seq;
1886                                 *offset = 0;
1887                                 }
1888
1889                         /* this is either a record we're waiting for, or a
1890                          * retransmit of something we happened to previously
1891                          * receive (higher layers will drop the repeat silently */
1892                         if ( seq_num < s->d1->handshake_read_seq)
1893                                 return 0;
1894                         if (rr->type == SSL3_RT_HANDSHAKE &&
1895                                 seq_num == s->d1->handshake_read_seq &&
1896                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1897                                 return 0;
1898                         else if ( seq_num == s->d1->handshake_read_seq &&
1899                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1900                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1901                                 return 0;
1902                         else
1903                                 {
1904                                 *priority = seq_num;
1905                                 return 1;
1906                                 }
1907                         }
1908                 else /* unknown record type */
1909                         return 0;
1910                 }
1911
1912         return 0;
1913         }
1914 #endif
1915
1916 void
1917 dtls1_reset_seq_numbers(SSL *s, int rw)
1918         {
1919         unsigned char *seq;
1920         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1921
1922         if ( rw & SSL3_CC_READ)
1923                 {
1924                 seq = s->s3->read_sequence;
1925                 s->d1->r_epoch++;
1926                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1927                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1928                 }
1929         else
1930                 {
1931                 seq = s->s3->write_sequence;
1932                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1933                 s->d1->w_epoch++;
1934                 }
1935
1936         memset(seq, 0x00, seq_bytes);
1937         }