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