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/* aes-internal.h
*
* The aes/rijndael block cipher.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2001 Niels Möller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The nettle library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the nettle library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02111-1301, USA.
*/
#ifndef NETTLE_AES_INTERNAL_H_INCLUDED
#define NETTLE_AES_INTERNAL_H_INCLUDED
#include "aes.h"
/* Name mangling */
#define _aes_encrypt _nettle_aes_encrypt
#define _aes_decrypt _nettle_aes_decrypt
#define _aes_encrypt_table _nettle_aes_encrypt_table
/* Define to use only small tables. */
#ifndef AES_SMALL
# define AES_SMALL 0
#endif
#if AES_SMALL
# define AES_TABLE_SIZE 1
#else
# define AES_TABLE_SIZE 4
#endif
struct aes_table
{
uint8_t sbox[0x100];
uint32_t table[AES_TABLE_SIZE][0x100];
};
void
_aes_encrypt(const struct aes_ctx *ctx,
const struct aes_table *T,
unsigned length, uint8_t *dst,
const uint8_t *src);
void
_aes_decrypt(const struct aes_ctx *ctx,
const struct aes_table *T,
unsigned length, uint8_t *dst,
const uint8_t *src);
/* Macros */
/* Get the byte with index 0, 1, 2 and 3 */
#define B0(x) ((x) & 0xff)
#define B1(x) (((x) >> 8) & 0xff)
#define B2(x) (((x) >> 16) & 0xff)
#define B3(x) (((x) >> 24) & 0xff)
#define SUBBYTE(x, box) ((uint32_t)(box)[B0(x)] \
| ((uint32_t)(box)[B1(x)] << 8) \
| ((uint32_t)(box)[B2(x)] << 16) \
| ((uint32_t)(box)[B3(x)] << 24))
#define AES_ROUND(T, w0, w1, w2, w3, k) \
(( T->table[0][ B0(w0) ] \
^ T->table[1][ B1(w1) ] \
^ T->table[2][ B2(w2) ] \
^ T->table[3][ B3(w3) ]) ^ (k))
#define AES_FINAL_ROUND(T, w0, w1, w2, w3, k) \
(( (uint32_t) T->sbox[ B0(w0) ] \
| ((uint32_t) T->sbox[ B1(w1) ] << 8) \
| ((uint32_t) T->sbox[ B2(w2) ] << 16) \
| ((uint32_t) T->sbox[ B3(w3) ] << 24)) ^ (k))
/* Globally visible so that the same sbox table can be used by aes_set_encrypt_key */
extern const struct aes_table _aes_encrypt_table;
#define aes_sbox (_aes_encrypt_table.sbox)
#endif /* NETTLE_AES_INTERNAL_H_INCLUDED */
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