aes256-set-decrypt-key.c

/* aes256-set-decrypt-key.c
 *
 * Key setup for the aes/rijndael block cipher.
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2013, 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.
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>

#include "aes-internal.h"
#include "macros.h"

void
aes256_invert_key (struct aes256_ctx *dst, const struct aes256_ctx *src)
{
  _aes_invert (_AES256_ROUNDS, dst->keys, src->keys); 
}

void
aes256_set_decrypt_key(struct aes256_ctx *ctx, const uint8_t *key)
{
  aes256_set_encrypt_key (ctx, key);
  aes256_invert_key (ctx, ctx);
}