Line data    Source code

       1             : /* ====================================================================
       2             :  * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
       3             :  *
       4             :  * Redistribution and use in source and binary forms, with or without
       5             :  * modification, are permitted provided that the following conditions
       6             :  * are met:
       7             :  *
       8             :  * 1. Redistributions of source code must retain the above copyright
       9             :  *    notice, this list of conditions and the following disclaimer.
      10             :  *
      11             :  * 2. Redistributions in binary form must reproduce the above copyright
      12             :  *    notice, this list of conditions and the following disclaimer in
      13             :  *    the documentation and/or other materials provided with the
      14             :  *    distribution.
      15             :  *
      16             :  * 3. All advertising materials mentioning features or use of this
      17             :  *    software must display the following acknowledgment:
      18             :  *    "This product includes software developed by the OpenSSL Project
      19             :  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
      20             :  *
      21             :  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
      22             :  *    endorse or promote products derived from this software without
      23             :  *    prior written permission. For written permission, please contact
      24             :  *    openssl-core@openssl.org.
      25             :  *
      26             :  * 5. Products derived from this software may not be called "OpenSSL"
      27             :  *    nor may "OpenSSL" appear in their names without prior written
      28             :  *    permission of the OpenSSL Project.
      29             :  *
      30             :  * 6. Redistributions of any form whatsoever must retain the following
      31             :  *    acknowledgment:
      32             :  *    "This product includes software developed by the OpenSSL Project
      33             :  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
      34             :  *
      35             :  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
      36             :  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      37             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
      38             :  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
      39             :  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      40             :  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
      41             :  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
      42             :  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      43             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
      44             :  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
      45             :  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
      46             :  * OF THE POSSIBILITY OF SUCH DAMAGE.
      47             :  * ====================================================================
      48             :  *
      49             :  */
      50             : 
      51             : #include <openssl/crypto.h>
      52             : #include "modes_lcl.h"
      53             : #include <string.h>
      54             : 
      55             : #ifndef MODES_DEBUG
      56             : # ifndef NDEBUG
      57             : #  define NDEBUG
      58             : # endif
      59             : #endif
      60             : #include <assert.h>
      61             : 
      62             : /*
      63             :  * The input and output encrypted as though 128bit ofb mode is being used.
      64             :  * The extra state information to record how much of the 128bit block we have
      65             :  * used is contained in *num;
      66             :  */
      67           0 : void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out,
      68             :                            size_t len, const void *key,
      69             :                            unsigned char ivec[16], int *num, block128_f block)
      70             : {
      71             :     unsigned int n;
      72             :     size_t l = 0;
      73             : 
      74             :     assert(in && out && key && ivec && num);
      75             : 
      76           0 :     n = *num;
      77             : 
      78             : #if !defined(OPENSSL_SMALL_FOOTPRINT)
      79             :     if (16 % sizeof(size_t) == 0) { /* always true actually */
      80             :         do {
      81           0 :             while (n && len) {
      82           0 :                 *(out++) = *(in++) ^ ivec[n];
      83           0 :                 --len;
      84           0 :                 n = (n + 1) % 16;
      85             :             }
      86             : # if defined(STRICT_ALIGNMENT)
      87             :             if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) !=
      88             :                 0)
      89             :                 break;
      90             : # endif
      91           0 :             while (len >= 16) {
      92           0 :                 (*block) (ivec, ivec, key);
      93           0 :                 for (; n < 16; n += sizeof(size_t))
      94           0 :                     *(size_t *)(out + n) =
      95           0 :                         *(size_t *)(in + n) ^ *(size_t *)(ivec + n);
      96           0 :                 len -= 16;
      97           0 :                 out += 16;
      98           0 :                 in += 16;
      99             :                 n = 0;
     100             :             }
     101           0 :             if (len) {
     102           0 :                 (*block) (ivec, ivec, key);
     103           0 :                 while (len--) {
     104           0 :                     out[n] = in[n] ^ ivec[n];
     105           0 :                     ++n;
     106             :                 }
     107             :             }
     108           0 :             *num = n;
     109           0 :             return;
     110             :         } while (0);
     111             :     }
     112             :     /* the rest would be commonly eliminated by x86* compiler */
     113             : #endif
     114             :     while (l < len) {
     115             :         if (n == 0) {
     116             :             (*block) (ivec, ivec, key);
     117             :         }
     118             :         out[l] = in[l] ^ ivec[n];
     119             :         ++l;
     120             :         n = (n + 1) % 16;
     121             :     }
     122             : 
     123             :     *num = n;
     124             : }