crypto/openssl-0.9/crypto/camellia/cmll_ctr.c

   1 /* crypto/camellia/camellia_ctr.c -*- mode:C; c-file-style: "eay" -*- */
   2 /* ====================================================================
   3  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@openssl.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  */
  51
  52 #ifndef CAMELLIA_DEBUG
  53 # ifndef NDEBUG
  54 #  define NDEBUG
  55 # endif
  56 #endif
  57 #include <assert.h>
  58
  59 #include <openssl/camellia.h>
  60 #include "cmll_locl.h"
  61
  62 /* NOTE: the IV/counter CTR mode is big-endian.  The rest of the Camellia code
  63  * is endian-neutral. */
  64 /* increment counter (128-bit int) by 1 */
  65 static void Camellia_ctr128_inc(unsigned char *counter)
  66         {
  67         unsigned long c;
  68
  69         /* Grab bottom dword of counter and increment */
  70         c = GETU32(counter + 12);
  71         c++;    c &= 0xFFFFFFFF;
  72         PUTU32(counter + 12, c);
  73
  74         /* if no overflow, we're done */
  75         if (c)
  76                 return;
  77
  78         /* Grab 1st dword of counter and increment */
  79         c = GETU32(counter +  8);
  80         c++;    c &= 0xFFFFFFFF;
  81         PUTU32(counter +  8, c);
  82
  83         /* if no overflow, we're done */
  84         if (c)
  85                 return;
  86
  87         /* Grab 2nd dword of counter and increment */
  88         c = GETU32(counter +  4);
  89         c++;    c &= 0xFFFFFFFF;
  90         PUTU32(counter +  4, c);
  91
  92         /* if no overflow, we're done */
  93         if (c)
  94                 return;
  95
  96         /* Grab top dword of counter and increment */
  97         c = GETU32(counter +  0);
  98         c++;    c &= 0xFFFFFFFF;
  99         PUTU32(counter +  0, c);
 100         }
 101
 102 /* The input encrypted as though 128bit counter mode is being
 103  * used.  The extra state information to record how much of the
 104  * 128bit block we have used is contained in *num, and the
 105  * encrypted counter is kept in ecount_buf.  Both *num and
 106  * ecount_buf must be initialised with zeros before the first
 107  * call to Camellia_ctr128_encrypt().
 108  *
 109  * This algorithm assumes that the counter is in the x lower bits
 110  * of the IV (ivec), and that the application has full control over
 111  * overflow and the rest of the IV.  This implementation takes NO
 112  * responsability for checking that the counter doesn't overflow
 113  * into the rest of the IV when incremented.
 114  */
 115 void Camellia_ctr128_encrypt(const unsigned char *in, unsigned char *out,
 116         const unsigned long length, const CAMELLIA_KEY *key,
 117         unsigned char ivec[CAMELLIA_BLOCK_SIZE],
 118         unsigned char ecount_buf[CAMELLIA_BLOCK_SIZE],
 119         unsigned int *num)
 120         {
 121
 122         unsigned int n;
 123         unsigned long l=length;
 124
 125         assert(in && out && key && counter && num);
 126         assert(*num < CAMELLIA_BLOCK_SIZE);
 127
 128         n = *num;
 129
 130         while (l--)
 131                 {
 132                 if (n == 0)
 133                         {
 134                         Camellia_encrypt(ivec, ecount_buf, key);
 135                         Camellia_ctr128_inc(ivec);
 136                         }
 137                 *(out++) = *(in++) ^ ecount_buf[n];
 138                 n = (n+1) % CAMELLIA_BLOCK_SIZE;
 139                 }
 140
 141         *num=n;
 142         }
 143