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