kernel-ark/arch/x86_64/crypto/aes.c
Herbert Xu c8a19c91b5 [CRYPTO] Allow AES C/ASM implementations to coexist
As the Crypto API now allows multiple implementations to be registered
for the same algorithm, we no longer have to play tricks with Kconfig
to select the right AES implementation.

This patch sets the driver name and priority for all the AES
implementations and removes the Kconfig conditions on the C implementation
for AES.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2006-01-09 14:15:39 -08:00

327 lines
8.2 KiB
C

/*
* Cryptographic API.
*
* AES Cipher Algorithm.
*
* Based on Brian Gladman's code.
*
* Linux developers:
* Alexander Kjeldaas <astor@fast.no>
* Herbert Valerio Riedel <hvr@hvrlab.org>
* Kyle McMartin <kyle@debian.org>
* Adam J. Richter <adam@yggdrasil.com> (conversion to 2.5 API).
* Andreas Steinmetz <ast@domdv.de> (adapted to x86_64 assembler)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of 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.
*
* ---------------------------------------------------------------------------
* Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
* All rights reserved.
*
* LICENSE TERMS
*
* The free distribution and use of this software in both source and binary
* form is allowed (with or without changes) provided that:
*
* 1. distributions of this source code include the above copyright
* notice, this list of conditions and the following disclaimer;
*
* 2. distributions in binary form include the above copyright
* notice, this list of conditions and the following disclaimer
* in the documentation and/or other associated materials;
*
* 3. the copyright holder's name is not used to endorse products
* built using this software without specific written permission.
*
* ALTERNATIVELY, provided that this notice is retained in full, this product
* may be distributed under the terms of the GNU General Public License (GPL),
* in which case the provisions of the GPL apply INSTEAD OF those given above.
*
* DISCLAIMER
*
* This software is provided 'as is' with no explicit or implied warranties
* in respect of its properties, including, but not limited to, correctness
* and/or fitness for purpose.
* ---------------------------------------------------------------------------
*/
/* Some changes from the Gladman version:
s/RIJNDAEL(e_key)/E_KEY/g
s/RIJNDAEL(d_key)/D_KEY/g
*/
#include <asm/byteorder.h>
#include <linux/bitops.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#define AES_MIN_KEY_SIZE 16
#define AES_MAX_KEY_SIZE 32
#define AES_BLOCK_SIZE 16
/*
* #define byte(x, nr) ((unsigned char)((x) >> (nr*8)))
*/
static inline u8 byte(const u32 x, const unsigned n)
{
return x >> (n << 3);
}
struct aes_ctx
{
u32 key_length;
u32 E[60];
u32 D[60];
};
#define E_KEY ctx->E
#define D_KEY ctx->D
static u8 pow_tab[256] __initdata;
static u8 log_tab[256] __initdata;
static u8 sbx_tab[256] __initdata;
static u8 isb_tab[256] __initdata;
static u32 rco_tab[10];
u32 aes_ft_tab[4][256];
u32 aes_it_tab[4][256];
u32 aes_fl_tab[4][256];
u32 aes_il_tab[4][256];
static inline u8 f_mult(u8 a, u8 b)
{
u8 aa = log_tab[a], cc = aa + log_tab[b];
return pow_tab[cc + (cc < aa ? 1 : 0)];
}
#define ff_mult(a, b) (a && b ? f_mult(a, b) : 0)
#define ls_box(x) \
(aes_fl_tab[0][byte(x, 0)] ^ \
aes_fl_tab[1][byte(x, 1)] ^ \
aes_fl_tab[2][byte(x, 2)] ^ \
aes_fl_tab[3][byte(x, 3)])
static void __init gen_tabs(void)
{
u32 i, t;
u8 p, q;
/* log and power tables for GF(2**8) finite field with
0x011b as modular polynomial - the simplest primitive
root is 0x03, used here to generate the tables */
for (i = 0, p = 1; i < 256; ++i) {
pow_tab[i] = (u8)p;
log_tab[p] = (u8)i;
p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0);
}
log_tab[1] = 0;
for (i = 0, p = 1; i < 10; ++i) {
rco_tab[i] = p;
p = (p << 1) ^ (p & 0x80 ? 0x01b : 0);
}
for (i = 0; i < 256; ++i) {
p = (i ? pow_tab[255 - log_tab[i]] : 0);
q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2));
p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2));
sbx_tab[i] = p;
isb_tab[p] = (u8)i;
}
for (i = 0; i < 256; ++i) {
p = sbx_tab[i];
t = p;
aes_fl_tab[0][i] = t;
aes_fl_tab[1][i] = rol32(t, 8);
aes_fl_tab[2][i] = rol32(t, 16);
aes_fl_tab[3][i] = rol32(t, 24);
t = ((u32)ff_mult(2, p)) |
((u32)p << 8) |
((u32)p << 16) | ((u32)ff_mult(3, p) << 24);
aes_ft_tab[0][i] = t;
aes_ft_tab[1][i] = rol32(t, 8);
aes_ft_tab[2][i] = rol32(t, 16);
aes_ft_tab[3][i] = rol32(t, 24);
p = isb_tab[i];
t = p;
aes_il_tab[0][i] = t;
aes_il_tab[1][i] = rol32(t, 8);
aes_il_tab[2][i] = rol32(t, 16);
aes_il_tab[3][i] = rol32(t, 24);
t = ((u32)ff_mult(14, p)) |
((u32)ff_mult(9, p) << 8) |
((u32)ff_mult(13, p) << 16) |
((u32)ff_mult(11, p) << 24);
aes_it_tab[0][i] = t;
aes_it_tab[1][i] = rol32(t, 8);
aes_it_tab[2][i] = rol32(t, 16);
aes_it_tab[3][i] = rol32(t, 24);
}
}
#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
#define imix_col(y, x) \
u = star_x(x); \
v = star_x(u); \
w = star_x(v); \
t = w ^ (x); \
(y) = u ^ v ^ w; \
(y) ^= ror32(u ^ t, 8) ^ \
ror32(v ^ t, 16) ^ \
ror32(t, 24)
/* initialise the key schedule from the user supplied key */
#define loop4(i) \
{ \
t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \
t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \
t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \
t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \
t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \
}
#define loop6(i) \
{ \
t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \
t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \
t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \
t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \
t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \
t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \
t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \
}
#define loop8(i) \
{ \
t = ror32(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \
t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \
t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \
t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \
t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \
t = E_KEY[8 * i + 4] ^ ls_box(t); \
E_KEY[8 * i + 12] = t; \
t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \
t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \
t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \
}
static int aes_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len,
u32 *flags)
{
struct aes_ctx *ctx = ctx_arg;
const __le32 *key = (const __le32 *)in_key;
u32 i, j, t, u, v, w;
if (key_len != 16 && key_len != 24 && key_len != 32) {
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
ctx->key_length = key_len;
D_KEY[key_len + 24] = E_KEY[0] = le32_to_cpu(key[0]);
D_KEY[key_len + 25] = E_KEY[1] = le32_to_cpu(key[1]);
D_KEY[key_len + 26] = E_KEY[2] = le32_to_cpu(key[2]);
D_KEY[key_len + 27] = E_KEY[3] = le32_to_cpu(key[3]);
switch (key_len) {
case 16:
t = E_KEY[3];
for (i = 0; i < 10; ++i)
loop4(i);
break;
case 24:
E_KEY[4] = le32_to_cpu(key[4]);
t = E_KEY[5] = le32_to_cpu(key[5]);
for (i = 0; i < 8; ++i)
loop6 (i);
break;
case 32:
E_KEY[4] = le32_to_cpu(key[4]);
E_KEY[5] = le32_to_cpu(key[5]);
E_KEY[6] = le32_to_cpu(key[6]);
t = E_KEY[7] = le32_to_cpu(key[7]);
for (i = 0; i < 7; ++i)
loop8(i);
break;
}
D_KEY[0] = E_KEY[key_len + 24];
D_KEY[1] = E_KEY[key_len + 25];
D_KEY[2] = E_KEY[key_len + 26];
D_KEY[3] = E_KEY[key_len + 27];
for (i = 4; i < key_len + 24; ++i) {
j = key_len + 24 - (i & ~3) + (i & 3);
imix_col(D_KEY[j], E_KEY[i]);
}
return 0;
}
extern void aes_encrypt(void *ctx_arg, u8 *out, const u8 *in);
extern void aes_decrypt(void *ctx_arg, u8 *out, const u8 *in);
static struct crypto_alg aes_alg = {
.cra_name = "aes",
.cra_driver_name = "aes-x86_64",
.cra_priority = 200,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct aes_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
.cra_u = {
.cipher = {
.cia_min_keysize = AES_MIN_KEY_SIZE,
.cia_max_keysize = AES_MAX_KEY_SIZE,
.cia_setkey = aes_set_key,
.cia_encrypt = aes_encrypt,
.cia_decrypt = aes_decrypt
}
}
};
static int __init aes_init(void)
{
gen_tabs();
return crypto_register_alg(&aes_alg);
}
static void __exit aes_fini(void)
{
crypto_unregister_alg(&aes_alg);
}
module_init(aes_init);
module_exit(aes_fini);
MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
MODULE_LICENSE("GPL");
MODULE_ALIAS("aes");