/* camellia256-set-encrypt-key.c

   Key setup for the camellia block cipher.

   Copyright (C) 2006,2007 NTT

   (Nippon Telegraph and Telephone Corporation).

   Copyright (C) 2010, 2013 Niels Möller

   This file is part of GNU Nettle.

   GNU Nettle is free software: you can redistribute it and/or

   modify it under the terms of either:

     * the GNU Lesser General Public License as published by the Free

       Software Foundation; either version 3 of the License, or (at your

       option) any later version.

   or

     * the GNU General Public License as published by the Free

       Software Foundation; either version 2 of the License, or (at your

       option) any later version.

   or both in parallel, as here.

   GNU Nettle is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   General Public License for more details.

   You should have received copies of the GNU General Public License and

   the GNU Lesser General Public License along with this program.  If

   not, see http://www.gnu.org/licenses/.

*/

/*

 * Algorithm Specification 

 *  http://info.isl.ntt.co.jp/crypt/eng/camellia/specifications.html

 */

/* Based on camellia.c ver 1.2.0, see

   http://info.isl.ntt.co.jp/crypt/eng/camellia/dl/camellia-LGPL-1.2.0.tar.gz.

 */

#if HAVE_CONFIG_H

# include "config.h"

#endif

#include <assert.h>

#include <limits.h>

#include "camellia-internal.h"

#include "macros.h"

static void

_camellia256_set_encrypt_key (struct camellia256_ctx *ctx,

            uint64_t k0, uint64_t k1,

            uint64_t k2, uint64_t k3)

{

  uint64_t subkey[_CAMELLIA256_NKEYS + 2];

  uint64_t w;

  /* generate KL dependent subkeys */

  subkey[0] = k0; subkey[1] = k1;

  ROTL128(45, k0, k1);

  subkey[12] = k0; subkey[13] = k1;

  ROTL128(15, k0, k1);

  subkey[16] = k0; subkey[17] = k1;

  ROTL128(17, k0, k1);

  subkey[22] = k0; subkey[23] = k1;

  ROTL128(34, k0, k1);

  subkey[30] = k0; subkey[31] = k1;

  /* generate KR dependent subkeys */

  ROTL128(15, k2, k3);

  subkey[4] = k2; subkey[5] = k3;

  ROTL128(15, k2, k3);

  subkey[8] = k2; subkey[9] = k3;

  ROTL128(30, k2, k3);

  subkey[18] = k2; subkey[19] = k3;

  ROTL128(34, k2, k3);

  subkey[26] = k2; subkey[27] = k3;

  ROTL128(34, k2, k3);

  /* generate KA */

  /* The construction of KA is done as

     D1 = (KL ^ KR) >> 64

     D2 = (KL ^ KR) & MASK64

     W = F(D1, SIGMA1)

     D2 = D2 ^ W

     D1 = F(D2, SIGMA2) ^ (KR >> 64)

     D2 = F(D1, SIGMA3) ^ W ^ (KR & MASK64)

     D1 = D1 ^ F(W, SIGMA2)

     D2 = D2 ^ F(D1, SIGMA3)

     D1 = D1 ^ F(D2, SIGMA4)

  */

  k0 = subkey[0] ^ k2;

  k1 = subkey[1] ^ k3;

  CAMELLIA_F(k0, SIGMA1, w);

  k1 ^= w;

  CAMELLIA_F(k1, SIGMA2, k0);

  k0 ^= k2;

  CAMELLIA_F(k0, SIGMA3, k1);

  k1 ^= w ^ k3;

  CAMELLIA_F(k1, SIGMA4, w);

  k0 ^= w;

  /* generate KB */

  k2 ^= k0; k3 ^= k1;

  CAMELLIA_F(k2, SIGMA5, w);

  k3 ^= w;

  CAMELLIA_F(k3, SIGMA6, w);

  k2 ^= w;

  /* generate KA dependent subkeys */

  ROTL128(15, k0, k1);

  subkey[6] = k0; subkey[7] = k1;

  ROTL128(30, k0, k1);

  subkey[14] = k0; subkey[15] = k1;

  ROTL128(32, k0, k1);

  subkey[24] = k0; subkey[25] = k1;

  ROTL128(17, k0, k1);

  subkey[28] = k0; subkey[29] = k1;

  /* generate KB dependent subkeys */

  subkey[2] = k2; subkey[3] = k3;

  ROTL128(30, k2, k3);

  subkey[10] = k2; subkey[11] = k3;

  ROTL128(30, k2, k3);

  subkey[20] = k2; subkey[21] = k3;

  ROTL128(51, k2, k3);

  subkey[32] = k2; subkey[33] = k3;

  /* Common final processing */

  _nettle_camellia_absorb (_CAMELLIA256_NKEYS, ctx->keys, subkey);

}

void

camellia256_set_encrypt_key(struct camellia256_ctx *ctx,

          const uint8_t *key)

{

  uint64_t k0, k1, k2, k3;

  k0 = READ_UINT64(key);

  k1 = READ_UINT64(key +  8);

  k2 = READ_UINT64(key + 16);

  k3 = READ_UINT64(key + 24);

  _camellia256_set_encrypt_key (ctx, k0, k1, k2, k3);

}

void

camellia192_set_encrypt_key(struct camellia256_ctx *ctx,

          const uint8_t *key)

{

  uint64_t k0, k1, k2;

  k0 = READ_UINT64(key);

  k1 = READ_UINT64(key +  8);

  k2 = READ_UINT64(key + 16);

  _camellia256_set_encrypt_key (ctx, k0, k1, k2, ~k2);

}