You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
325 lines
8.2 KiB
325 lines
8.2 KiB
/*
|
|
* 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);
|
|
}
|
|
|
|
#define u32_in(x) le32_to_cpu(*(const __le32 *)(x))
|
|
|
|
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;
|
|
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] = u32_in(in_key);
|
|
D_KEY[key_len + 25] = E_KEY[1] = u32_in(in_key + 4);
|
|
D_KEY[key_len + 26] = E_KEY[2] = u32_in(in_key + 8);
|
|
D_KEY[key_len + 27] = E_KEY[3] = u32_in(in_key + 12);
|
|
|
|
switch (key_len) {
|
|
case 16:
|
|
t = E_KEY[3];
|
|
for (i = 0; i < 10; ++i)
|
|
loop4(i);
|
|
break;
|
|
|
|
case 24:
|
|
E_KEY[4] = u32_in(in_key + 16);
|
|
t = E_KEY[5] = u32_in(in_key + 20);
|
|
for (i = 0; i < 8; ++i)
|
|
loop6 (i);
|
|
break;
|
|
|
|
case 32:
|
|
E_KEY[4] = u32_in(in_key + 16);
|
|
E_KEY[5] = u32_in(in_key + 20);
|
|
E_KEY[6] = u32_in(in_key + 24);
|
|
t = E_KEY[7] = u32_in(in_key + 28);
|
|
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_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");
|
|
|