release/src/router/openssl/crypto/modes/ofb128.c

   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 /* The input and output encrypted as though 128bit ofb mode is being
  63  * used.  The extra state information to record how much of the
  64  * 128bit block we have used is contained in *num;
  65  */
  66 void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out,
  67                         size_t len, const void *key,
  68                         unsigned char ivec[16], int *num,
  69                         block128_f block)
  70 {
  71         unsigned int n;
  72         size_t l=0;
  73
  74         assert(in && out && key && ivec && num);
  75
  76         n = *num;
  77
  78 #if !defined(OPENSSL_SMALL_FOOTPRINT)
  79         if (16%sizeof(size_t) == 0) do { /* always true actually */
  80                 while (n && len) {
  81                         *(out++) = *(in++) ^ ivec[n];
  82                         --len;
  83                         n = (n+1) % 16;
  84                 }
  85 #if defined(STRICT_ALIGNMENT)
  86                 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
  87                         break;
  88 #endif
  89                 while (len>=16) {
  90                         (*block)(ivec, ivec, key);
  91                         for (; n<16; n+=sizeof(size_t))
  92                                 *(size_t*)(out+n) =
  93                                 *(size_t*)(in+n) ^ *(size_t*)(ivec+n);
  94                         len -= 16;
  95                         out += 16;
  96                         in  += 16;
  97                         n = 0;
  98                 }
  99                 if (len) {
 100                         (*block)(ivec, ivec, key);
 101                         while (len--) {
 102                                 out[n] = in[n] ^ ivec[n];
 103                                 ++n;
 104                         }
 105                 }
 106                 *num = n;
 107                 return;
 108         } while(0);
 109         /* the rest would be commonly eliminated by x86* compiler */
 110 #endif
 111         while (l<len) {
 112                 if (n==0) {
 113                         (*block)(ivec, ivec, key);
 114                 }
 115                 out[l] = in[l] ^ ivec[n];
 116                 ++l;
 117                 n = (n+1) % 16;
 118         }
 119
 120         *num=n;
 121 }