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