mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 01:51:53 +00:00
5427663f49
The key expansion routine could be get little more generic, become a kernel doc entry and then get exported. Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc> Tested-by: Stefan Hellermann <stefan@the2masters.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
509 lines
14 KiB
C
509 lines
14 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).
|
|
*
|
|
* 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.
|
|
* ---------------------------------------------------------------------------
|
|
*/
|
|
|
|
#include <crypto/aes.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/types.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/crypto.h>
|
|
#include <asm/byteorder.h>
|
|
|
|
static inline u8 byte(const u32 x, const unsigned n)
|
|
{
|
|
return x >> (n << 3);
|
|
}
|
|
|
|
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 crypto_ft_tab[4][256];
|
|
u32 crypto_fl_tab[4][256];
|
|
u32 crypto_it_tab[4][256];
|
|
u32 crypto_il_tab[4][256];
|
|
|
|
EXPORT_SYMBOL_GPL(crypto_ft_tab);
|
|
EXPORT_SYMBOL_GPL(crypto_fl_tab);
|
|
EXPORT_SYMBOL_GPL(crypto_it_tab);
|
|
EXPORT_SYMBOL_GPL(crypto_il_tab);
|
|
|
|
static inline u8 __init 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)
|
|
|
|
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;
|
|
crypto_fl_tab[0][i] = t;
|
|
crypto_fl_tab[1][i] = rol32(t, 8);
|
|
crypto_fl_tab[2][i] = rol32(t, 16);
|
|
crypto_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);
|
|
|
|
crypto_ft_tab[0][i] = t;
|
|
crypto_ft_tab[1][i] = rol32(t, 8);
|
|
crypto_ft_tab[2][i] = rol32(t, 16);
|
|
crypto_ft_tab[3][i] = rol32(t, 24);
|
|
|
|
p = isb_tab[i];
|
|
|
|
t = p;
|
|
crypto_il_tab[0][i] = t;
|
|
crypto_il_tab[1][i] = rol32(t, 8);
|
|
crypto_il_tab[2][i] = rol32(t, 16);
|
|
crypto_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);
|
|
|
|
crypto_it_tab[0][i] = t;
|
|
crypto_it_tab[1][i] = rol32(t, 8);
|
|
crypto_it_tab[2][i] = rol32(t, 16);
|
|
crypto_it_tab[3][i] = rol32(t, 24);
|
|
}
|
|
}
|
|
|
|
/* initialise the key schedule from the user supplied key */
|
|
|
|
#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
|
|
|
|
#define imix_col(y,x) do { \
|
|
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); \
|
|
} while (0)
|
|
|
|
#define ls_box(x) \
|
|
crypto_fl_tab[0][byte(x, 0)] ^ \
|
|
crypto_fl_tab[1][byte(x, 1)] ^ \
|
|
crypto_fl_tab[2][byte(x, 2)] ^ \
|
|
crypto_fl_tab[3][byte(x, 3)]
|
|
|
|
#define loop4(i) do { \
|
|
t = ror32(t, 8); \
|
|
t = ls_box(t) ^ rco_tab[i]; \
|
|
t ^= ctx->key_enc[4 * i]; \
|
|
ctx->key_enc[4 * i + 4] = t; \
|
|
t ^= ctx->key_enc[4 * i + 1]; \
|
|
ctx->key_enc[4 * i + 5] = t; \
|
|
t ^= ctx->key_enc[4 * i + 2]; \
|
|
ctx->key_enc[4 * i + 6] = t; \
|
|
t ^= ctx->key_enc[4 * i + 3]; \
|
|
ctx->key_enc[4 * i + 7] = t; \
|
|
} while (0)
|
|
|
|
#define loop6(i) do { \
|
|
t = ror32(t, 8); \
|
|
t = ls_box(t) ^ rco_tab[i]; \
|
|
t ^= ctx->key_enc[6 * i]; \
|
|
ctx->key_enc[6 * i + 6] = t; \
|
|
t ^= ctx->key_enc[6 * i + 1]; \
|
|
ctx->key_enc[6 * i + 7] = t; \
|
|
t ^= ctx->key_enc[6 * i + 2]; \
|
|
ctx->key_enc[6 * i + 8] = t; \
|
|
t ^= ctx->key_enc[6 * i + 3]; \
|
|
ctx->key_enc[6 * i + 9] = t; \
|
|
t ^= ctx->key_enc[6 * i + 4]; \
|
|
ctx->key_enc[6 * i + 10] = t; \
|
|
t ^= ctx->key_enc[6 * i + 5]; \
|
|
ctx->key_enc[6 * i + 11] = t; \
|
|
} while (0)
|
|
|
|
#define loop8(i) do { \
|
|
t = ror32(t, 8); \
|
|
t = ls_box(t) ^ rco_tab[i]; \
|
|
t ^= ctx->key_enc[8 * i]; \
|
|
ctx->key_enc[8 * i + 8] = t; \
|
|
t ^= ctx->key_enc[8 * i + 1]; \
|
|
ctx->key_enc[8 * i + 9] = t; \
|
|
t ^= ctx->key_enc[8 * i + 2]; \
|
|
ctx->key_enc[8 * i + 10] = t; \
|
|
t ^= ctx->key_enc[8 * i + 3]; \
|
|
ctx->key_enc[8 * i + 11] = t; \
|
|
t = ctx->key_enc[8 * i + 4] ^ ls_box(t); \
|
|
ctx->key_enc[8 * i + 12] = t; \
|
|
t ^= ctx->key_enc[8 * i + 5]; \
|
|
ctx->key_enc[8 * i + 13] = t; \
|
|
t ^= ctx->key_enc[8 * i + 6]; \
|
|
ctx->key_enc[8 * i + 14] = t; \
|
|
t ^= ctx->key_enc[8 * i + 7]; \
|
|
ctx->key_enc[8 * i + 15] = t; \
|
|
} while (0)
|
|
|
|
/**
|
|
* crypto_aes_expand_key - Expands the AES key as described in FIPS-197
|
|
* @ctx: The location where the computed key will be stored.
|
|
* @in_key: The supplied key.
|
|
* @key_len: The length of the supplied key.
|
|
*
|
|
* Returns 0 on success. The function fails only if an invalid key size (or
|
|
* pointer) is supplied.
|
|
* The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes
|
|
* key schedule plus a 16 bytes key which is used before the first round).
|
|
* The decryption key is prepared for the "Equivalent Inverse Cipher" as
|
|
* described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is
|
|
* for the initial combination, the second slot for the first round and so on.
|
|
*/
|
|
int crypto_aes_expand_key(struct crypto_aes_ctx *ctx, const u8 *in_key,
|
|
unsigned int key_len)
|
|
{
|
|
const __le32 *key = (const __le32 *)in_key;
|
|
u32 i, t, u, v, w, j;
|
|
|
|
if (key_len != AES_KEYSIZE_128 && key_len != AES_KEYSIZE_192 &&
|
|
key_len != AES_KEYSIZE_256)
|
|
return -EINVAL;
|
|
|
|
ctx->key_length = key_len;
|
|
|
|
ctx->key_dec[key_len + 24] = ctx->key_enc[0] = le32_to_cpu(key[0]);
|
|
ctx->key_dec[key_len + 25] = ctx->key_enc[1] = le32_to_cpu(key[1]);
|
|
ctx->key_dec[key_len + 26] = ctx->key_enc[2] = le32_to_cpu(key[2]);
|
|
ctx->key_dec[key_len + 27] = ctx->key_enc[3] = le32_to_cpu(key[3]);
|
|
|
|
switch (key_len) {
|
|
case AES_KEYSIZE_128:
|
|
t = ctx->key_enc[3];
|
|
for (i = 0; i < 10; ++i)
|
|
loop4(i);
|
|
break;
|
|
|
|
case AES_KEYSIZE_192:
|
|
ctx->key_enc[4] = le32_to_cpu(key[4]);
|
|
t = ctx->key_enc[5] = le32_to_cpu(key[5]);
|
|
for (i = 0; i < 8; ++i)
|
|
loop6(i);
|
|
break;
|
|
|
|
case AES_KEYSIZE_256:
|
|
ctx->key_enc[4] = le32_to_cpu(key[4]);
|
|
ctx->key_enc[5] = le32_to_cpu(key[5]);
|
|
ctx->key_enc[6] = le32_to_cpu(key[6]);
|
|
t = ctx->key_enc[7] = le32_to_cpu(key[7]);
|
|
for (i = 0; i < 7; ++i)
|
|
loop8(i);
|
|
break;
|
|
}
|
|
|
|
ctx->key_dec[0] = ctx->key_enc[key_len + 24];
|
|
ctx->key_dec[1] = ctx->key_enc[key_len + 25];
|
|
ctx->key_dec[2] = ctx->key_enc[key_len + 26];
|
|
ctx->key_dec[3] = ctx->key_enc[key_len + 27];
|
|
|
|
for (i = 4; i < key_len + 24; ++i) {
|
|
j = key_len + 24 - (i & ~3) + (i & 3);
|
|
imix_col(ctx->key_dec[j], ctx->key_enc[i]);
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_aes_expand_key);
|
|
|
|
/**
|
|
* crypto_aes_set_key - Set the AES key.
|
|
* @tfm: The %crypto_tfm that is used in the context.
|
|
* @in_key: The input key.
|
|
* @key_len: The size of the key.
|
|
*
|
|
* Returns 0 on success, on failure the %CRYPTO_TFM_RES_BAD_KEY_LEN flag in tfm
|
|
* is set. The function uses crypto_aes_expand_key() to expand the key.
|
|
* &crypto_aes_ctx _must_ be the private data embedded in @tfm which is
|
|
* retrieved with crypto_tfm_ctx().
|
|
*/
|
|
int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
|
|
unsigned int key_len)
|
|
{
|
|
struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
u32 *flags = &tfm->crt_flags;
|
|
int ret;
|
|
|
|
ret = crypto_aes_expand_key(ctx, in_key, key_len);
|
|
if (!ret)
|
|
return 0;
|
|
|
|
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_aes_set_key);
|
|
|
|
/* encrypt a block of text */
|
|
|
|
#define f_rn(bo, bi, n, k) do { \
|
|
bo[n] = crypto_ft_tab[0][byte(bi[n], 0)] ^ \
|
|
crypto_ft_tab[1][byte(bi[(n + 1) & 3], 1)] ^ \
|
|
crypto_ft_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
|
|
crypto_ft_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n); \
|
|
} while (0)
|
|
|
|
#define f_nround(bo, bi, k) do {\
|
|
f_rn(bo, bi, 0, k); \
|
|
f_rn(bo, bi, 1, k); \
|
|
f_rn(bo, bi, 2, k); \
|
|
f_rn(bo, bi, 3, k); \
|
|
k += 4; \
|
|
} while (0)
|
|
|
|
#define f_rl(bo, bi, n, k) do { \
|
|
bo[n] = crypto_fl_tab[0][byte(bi[n], 0)] ^ \
|
|
crypto_fl_tab[1][byte(bi[(n + 1) & 3], 1)] ^ \
|
|
crypto_fl_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
|
|
crypto_fl_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n); \
|
|
} while (0)
|
|
|
|
#define f_lround(bo, bi, k) do {\
|
|
f_rl(bo, bi, 0, k); \
|
|
f_rl(bo, bi, 1, k); \
|
|
f_rl(bo, bi, 2, k); \
|
|
f_rl(bo, bi, 3, k); \
|
|
} while (0)
|
|
|
|
static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
|
|
{
|
|
const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *src = (const __le32 *)in;
|
|
__le32 *dst = (__le32 *)out;
|
|
u32 b0[4], b1[4];
|
|
const u32 *kp = ctx->key_enc + 4;
|
|
const int key_len = ctx->key_length;
|
|
|
|
b0[0] = le32_to_cpu(src[0]) ^ ctx->key_enc[0];
|
|
b0[1] = le32_to_cpu(src[1]) ^ ctx->key_enc[1];
|
|
b0[2] = le32_to_cpu(src[2]) ^ ctx->key_enc[2];
|
|
b0[3] = le32_to_cpu(src[3]) ^ ctx->key_enc[3];
|
|
|
|
if (key_len > 24) {
|
|
f_nround(b1, b0, kp);
|
|
f_nround(b0, b1, kp);
|
|
}
|
|
|
|
if (key_len > 16) {
|
|
f_nround(b1, b0, kp);
|
|
f_nround(b0, b1, kp);
|
|
}
|
|
|
|
f_nround(b1, b0, kp);
|
|
f_nround(b0, b1, kp);
|
|
f_nround(b1, b0, kp);
|
|
f_nround(b0, b1, kp);
|
|
f_nround(b1, b0, kp);
|
|
f_nround(b0, b1, kp);
|
|
f_nround(b1, b0, kp);
|
|
f_nround(b0, b1, kp);
|
|
f_nround(b1, b0, kp);
|
|
f_lround(b0, b1, kp);
|
|
|
|
dst[0] = cpu_to_le32(b0[0]);
|
|
dst[1] = cpu_to_le32(b0[1]);
|
|
dst[2] = cpu_to_le32(b0[2]);
|
|
dst[3] = cpu_to_le32(b0[3]);
|
|
}
|
|
|
|
/* decrypt a block of text */
|
|
|
|
#define i_rn(bo, bi, n, k) do { \
|
|
bo[n] = crypto_it_tab[0][byte(bi[n], 0)] ^ \
|
|
crypto_it_tab[1][byte(bi[(n + 3) & 3], 1)] ^ \
|
|
crypto_it_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
|
|
crypto_it_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n); \
|
|
} while (0)
|
|
|
|
#define i_nround(bo, bi, k) do {\
|
|
i_rn(bo, bi, 0, k); \
|
|
i_rn(bo, bi, 1, k); \
|
|
i_rn(bo, bi, 2, k); \
|
|
i_rn(bo, bi, 3, k); \
|
|
k += 4; \
|
|
} while (0)
|
|
|
|
#define i_rl(bo, bi, n, k) do { \
|
|
bo[n] = crypto_il_tab[0][byte(bi[n], 0)] ^ \
|
|
crypto_il_tab[1][byte(bi[(n + 3) & 3], 1)] ^ \
|
|
crypto_il_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
|
|
crypto_il_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n); \
|
|
} while (0)
|
|
|
|
#define i_lround(bo, bi, k) do {\
|
|
i_rl(bo, bi, 0, k); \
|
|
i_rl(bo, bi, 1, k); \
|
|
i_rl(bo, bi, 2, k); \
|
|
i_rl(bo, bi, 3, k); \
|
|
} while (0)
|
|
|
|
static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
|
|
{
|
|
const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *src = (const __le32 *)in;
|
|
__le32 *dst = (__le32 *)out;
|
|
u32 b0[4], b1[4];
|
|
const int key_len = ctx->key_length;
|
|
const u32 *kp = ctx->key_dec + 4;
|
|
|
|
b0[0] = le32_to_cpu(src[0]) ^ ctx->key_dec[0];
|
|
b0[1] = le32_to_cpu(src[1]) ^ ctx->key_dec[1];
|
|
b0[2] = le32_to_cpu(src[2]) ^ ctx->key_dec[2];
|
|
b0[3] = le32_to_cpu(src[3]) ^ ctx->key_dec[3];
|
|
|
|
if (key_len > 24) {
|
|
i_nround(b1, b0, kp);
|
|
i_nround(b0, b1, kp);
|
|
}
|
|
|
|
if (key_len > 16) {
|
|
i_nround(b1, b0, kp);
|
|
i_nround(b0, b1, kp);
|
|
}
|
|
|
|
i_nround(b1, b0, kp);
|
|
i_nround(b0, b1, kp);
|
|
i_nround(b1, b0, kp);
|
|
i_nround(b0, b1, kp);
|
|
i_nround(b1, b0, kp);
|
|
i_nround(b0, b1, kp);
|
|
i_nround(b1, b0, kp);
|
|
i_nround(b0, b1, kp);
|
|
i_nround(b1, b0, kp);
|
|
i_lround(b0, b1, kp);
|
|
|
|
dst[0] = cpu_to_le32(b0[0]);
|
|
dst[1] = cpu_to_le32(b0[1]);
|
|
dst[2] = cpu_to_le32(b0[2]);
|
|
dst[3] = cpu_to_le32(b0[3]);
|
|
}
|
|
|
|
static struct crypto_alg aes_alg = {
|
|
.cra_name = "aes",
|
|
.cra_driver_name = "aes-generic",
|
|
.cra_priority = 100,
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = AES_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof(struct crypto_aes_ctx),
|
|
.cra_alignmask = 3,
|
|
.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 = crypto_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("Dual BSD/GPL");
|
|
MODULE_ALIAS("aes");
|