[email protected] (Niels Möller) writes:
> Camellia uses fewer subkeys for 128 bit keys than for 192 or 256 bit
> keys. So this is a bit similar to AES, and I think an analogous reorg
> would make sense.
I tried this out now. New header file below.
camellia192 and camellia256 are really the same, except for the key
schedule. Hence some #defines to make several camellia192 symbols
aliases to the corresponding camellia256 things. I don't quite like use
a define on the struct tag, but I hope that's ok. And maybe I should
substitute _CAMELLIA*_NKEYS for _CAMELLIA*_ROUNDS, since it's not
exactly a round count.
Comments appreciated.
Regards,
/Niels
/* camellia.h
*
* Copyright (C) 2006,2007
* NTT (Nippon Telegraph and Telephone Corporation).
*
* Copyright (C) 2010, 2013 Niels Möller
*
* This 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.
*
* This 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
USA
*/
#ifndef NETTLE_CAMELLIA_H_INCLUDED
#define NETTLE_CAMELLIA_H_INCLUDED
#include "nettle-types.h"
#ifdef __cplusplus
extern "C" {
#endif
/* Name mangling */
#define camellia128_set_encrypt_key nettle_camellia128_set_encrypt_key
#define camellia128_set_decrypt_key nettle_camellia_set_decrypt_key
#define camellia128_invert_key nettle_camellia128_invert_key
#define camellia128_crypt nettle_camellia128_crypt
#define camellia192_set_encrypt_key nettle_camellia192_set_encrypt_key
#define camellia192_set_decrypt_key nettle_camellia192_set_decrypt_key
#define camellia256_set_encrypt_key nettle_camellia256_set_encrypt_key
#define camellia256_set_decrypt_key nettle_camellia256_set_decrypt_key
#define camellia256_invert_key nettle_camellia256_invert_key
#define camellia256_crypt nettle_camellia256_crypt
#define CAMELLIA_BLOCK_SIZE 16
/* Valid key sizes are 128, 192 or 256 bits (16, 24 or 32 bytes) */
#define CAMELLIA128_KEY_SIZE 16
#define CAMELLIA192_KEY_SIZE 24
#define CAMELLIA256_KEY_SIZE 32
/* For 128-bit keys, there are 18 regular rounds, pre- and
post-whitening, and two FL and FLINV rounds, using a total of 26
subkeys, each of 64 bit. For 192- and 256-bit keys, there are 6
additional regular rounds and one additional FL and FLINV, using a
total of 34 subkeys. */
/* The clever combination of subkeys imply one of the pre- and
post-whitening keys is folded with the round keys, so that subkey
#1 and the last one (#25 or #33) is not used. The result is that we
have only 24 or 32 subkeys at the end of key setup. */
#define _CAMELLIA128_ROUNDS 24
#define _CAMELLIA256_ROUNDS 32
struct camellia128_ctx
{
uint64_t keys[_CAMELLIA128_ROUNDS];
};
void
camellia128_set_encrypt_key(struct camellia128_ctx *ctx,
const uint8_t *key);
void
camellia128_set_decrypt_key(struct camellia128_ctx *ctx,
const uint8_t *key);
void
camellia128_invert_key(struct camellia128_ctx *dst,
const struct camellia128_ctx *src);
void
camellia128_crypt(const struct camellia128_ctx *ctx,
size_t length, uint8_t *dst,
const uint8_t *src);
struct camellia256_ctx
{
uint64_t keys[_CAMELLIA256_ROUNDS];
};
void
camellia256_set_encrypt_key(struct camellia256_ctx *ctx,
const uint8_t *key);
void
camellia256_set_decrypt_key(struct camellia256_ctx *ctx,
const uint8_t *key);
void
camellia256_invert_key(struct camellia256_ctx *dst,
const struct camellia256_ctx *src);
void
camellia256_crypt(const struct camellia256_ctx *ctx,
size_t length, uint8_t *dst,
const uint8_t *src);
/* camellia192 is the same as camellia256, except for the key
schedule. */
/* Slightly ugly with a #define on a struct tag, since it might cause
surprises if also used as a name of a variable. */
#define camellia192_ctx camellia256_ctx
void
camellia192_set_encrypt_key(struct camellia256_ctx *ctx,
const uint8_t *key);
void
camellia192_set_decrypt_key(struct camellia256_ctx *ctx,
const uint8_t *key);
#define camellia192_invert_key camellia256_invert_key
#define camellia192_crypt camellia256_crypt
#ifdef __cplusplus
}
#endif
#endif /* NETTLE_CAMELLIA_H_INCLUDED */
--
Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26.
Internet email is subject to wholesale government surveillance.
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