mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 18:11:56 +00:00
fb4f10ed50
The XTEA implementation was incorrect due to a misinterpretation of operator precedence. Because of the wide-spread nature of this error, the erroneous implementation will be kept, albeit under the new name of XETA. Signed-off-by: Aaron Grothe <ajgrothe@yahoo.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
322 lines
6.5 KiB
C
322 lines
6.5 KiB
C
/*
|
|
* Cryptographic API.
|
|
*
|
|
* TEA, XTEA, and XETA crypto alogrithms
|
|
*
|
|
* The TEA and Xtended TEA algorithms were developed by David Wheeler
|
|
* and Roger Needham at the Computer Laboratory of Cambridge University.
|
|
*
|
|
* Due to the order of evaluation in XTEA many people have incorrectly
|
|
* implemented it. XETA (XTEA in the wrong order), exists for
|
|
* compatibility with these implementations.
|
|
*
|
|
* Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
|
|
*
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <asm/scatterlist.h>
|
|
#include <linux/crypto.h>
|
|
|
|
#define TEA_KEY_SIZE 16
|
|
#define TEA_BLOCK_SIZE 8
|
|
#define TEA_ROUNDS 32
|
|
#define TEA_DELTA 0x9e3779b9
|
|
|
|
#define XTEA_KEY_SIZE 16
|
|
#define XTEA_BLOCK_SIZE 8
|
|
#define XTEA_ROUNDS 32
|
|
#define XTEA_DELTA 0x9e3779b9
|
|
|
|
#define u32_in(x) le32_to_cpu(*(const __le32 *)(x))
|
|
#define u32_out(to, from) (*(__le32 *)(to) = cpu_to_le32(from))
|
|
|
|
struct tea_ctx {
|
|
u32 KEY[4];
|
|
};
|
|
|
|
struct xtea_ctx {
|
|
u32 KEY[4];
|
|
};
|
|
|
|
static int tea_setkey(void *ctx_arg, const u8 *in_key,
|
|
unsigned int key_len, u32 *flags)
|
|
{
|
|
|
|
struct tea_ctx *ctx = ctx_arg;
|
|
|
|
if (key_len != 16)
|
|
{
|
|
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
|
|
return -EINVAL;
|
|
}
|
|
|
|
ctx->KEY[0] = u32_in (in_key);
|
|
ctx->KEY[1] = u32_in (in_key + 4);
|
|
ctx->KEY[2] = u32_in (in_key + 8);
|
|
ctx->KEY[3] = u32_in (in_key + 12);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
static void tea_encrypt(void *ctx_arg, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, n, sum = 0;
|
|
u32 k0, k1, k2, k3;
|
|
|
|
struct tea_ctx *ctx = ctx_arg;
|
|
|
|
y = u32_in (src);
|
|
z = u32_in (src + 4);
|
|
|
|
k0 = ctx->KEY[0];
|
|
k1 = ctx->KEY[1];
|
|
k2 = ctx->KEY[2];
|
|
k3 = ctx->KEY[3];
|
|
|
|
n = TEA_ROUNDS;
|
|
|
|
while (n-- > 0) {
|
|
sum += TEA_DELTA;
|
|
y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
|
|
z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
|
|
}
|
|
|
|
u32_out (dst, y);
|
|
u32_out (dst + 4, z);
|
|
}
|
|
|
|
static void tea_decrypt(void *ctx_arg, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, n, sum;
|
|
u32 k0, k1, k2, k3;
|
|
|
|
struct tea_ctx *ctx = ctx_arg;
|
|
|
|
y = u32_in (src);
|
|
z = u32_in (src + 4);
|
|
|
|
k0 = ctx->KEY[0];
|
|
k1 = ctx->KEY[1];
|
|
k2 = ctx->KEY[2];
|
|
k3 = ctx->KEY[3];
|
|
|
|
sum = TEA_DELTA << 5;
|
|
|
|
n = TEA_ROUNDS;
|
|
|
|
while (n-- > 0) {
|
|
z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
|
|
y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
|
|
sum -= TEA_DELTA;
|
|
}
|
|
|
|
u32_out (dst, y);
|
|
u32_out (dst + 4, z);
|
|
|
|
}
|
|
|
|
static int xtea_setkey(void *ctx_arg, const u8 *in_key,
|
|
unsigned int key_len, u32 *flags)
|
|
{
|
|
|
|
struct xtea_ctx *ctx = ctx_arg;
|
|
|
|
if (key_len != 16)
|
|
{
|
|
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
|
|
return -EINVAL;
|
|
}
|
|
|
|
ctx->KEY[0] = u32_in (in_key);
|
|
ctx->KEY[1] = u32_in (in_key + 4);
|
|
ctx->KEY[2] = u32_in (in_key + 8);
|
|
ctx->KEY[3] = u32_in (in_key + 12);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
static void xtea_encrypt(void *ctx_arg, u8 *dst, const u8 *src)
|
|
{
|
|
|
|
u32 y, z, sum = 0;
|
|
u32 limit = XTEA_DELTA * XTEA_ROUNDS;
|
|
|
|
struct xtea_ctx *ctx = ctx_arg;
|
|
|
|
y = u32_in (src);
|
|
z = u32_in (src + 4);
|
|
|
|
while (sum != limit) {
|
|
y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]);
|
|
sum += XTEA_DELTA;
|
|
z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]);
|
|
}
|
|
|
|
u32_out (dst, y);
|
|
u32_out (dst + 4, z);
|
|
|
|
}
|
|
|
|
static void xtea_decrypt(void *ctx_arg, u8 *dst, const u8 *src)
|
|
{
|
|
|
|
u32 y, z, sum;
|
|
struct tea_ctx *ctx = ctx_arg;
|
|
|
|
y = u32_in (src);
|
|
z = u32_in (src + 4);
|
|
|
|
sum = XTEA_DELTA * XTEA_ROUNDS;
|
|
|
|
while (sum) {
|
|
z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]);
|
|
sum -= XTEA_DELTA;
|
|
y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]);
|
|
}
|
|
|
|
u32_out (dst, y);
|
|
u32_out (dst + 4, z);
|
|
|
|
}
|
|
|
|
|
|
static void xeta_encrypt(void *ctx_arg, u8 *dst, const u8 *src)
|
|
{
|
|
|
|
u32 y, z, sum = 0;
|
|
u32 limit = XTEA_DELTA * XTEA_ROUNDS;
|
|
|
|
struct xtea_ctx *ctx = ctx_arg;
|
|
|
|
y = u32_in (src);
|
|
z = u32_in (src + 4);
|
|
|
|
while (sum != limit) {
|
|
y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3];
|
|
sum += XTEA_DELTA;
|
|
z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3];
|
|
}
|
|
|
|
u32_out (dst, y);
|
|
u32_out (dst + 4, z);
|
|
|
|
}
|
|
|
|
static void xeta_decrypt(void *ctx_arg, u8 *dst, const u8 *src)
|
|
{
|
|
|
|
u32 y, z, sum;
|
|
struct tea_ctx *ctx = ctx_arg;
|
|
|
|
y = u32_in (src);
|
|
z = u32_in (src + 4);
|
|
|
|
sum = XTEA_DELTA * XTEA_ROUNDS;
|
|
|
|
while (sum) {
|
|
z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3];
|
|
sum -= XTEA_DELTA;
|
|
y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3];
|
|
}
|
|
|
|
u32_out (dst, y);
|
|
u32_out (dst + 4, z);
|
|
|
|
}
|
|
|
|
static struct crypto_alg tea_alg = {
|
|
.cra_name = "tea",
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = TEA_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof (struct tea_ctx),
|
|
.cra_module = THIS_MODULE,
|
|
.cra_list = LIST_HEAD_INIT(tea_alg.cra_list),
|
|
.cra_u = { .cipher = {
|
|
.cia_min_keysize = TEA_KEY_SIZE,
|
|
.cia_max_keysize = TEA_KEY_SIZE,
|
|
.cia_setkey = tea_setkey,
|
|
.cia_encrypt = tea_encrypt,
|
|
.cia_decrypt = tea_decrypt } }
|
|
};
|
|
|
|
static struct crypto_alg xtea_alg = {
|
|
.cra_name = "xtea",
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = XTEA_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof (struct xtea_ctx),
|
|
.cra_module = THIS_MODULE,
|
|
.cra_list = LIST_HEAD_INIT(xtea_alg.cra_list),
|
|
.cra_u = { .cipher = {
|
|
.cia_min_keysize = XTEA_KEY_SIZE,
|
|
.cia_max_keysize = XTEA_KEY_SIZE,
|
|
.cia_setkey = xtea_setkey,
|
|
.cia_encrypt = xtea_encrypt,
|
|
.cia_decrypt = xtea_decrypt } }
|
|
};
|
|
|
|
static struct crypto_alg xeta_alg = {
|
|
.cra_name = "xeta",
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = XTEA_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof (struct xtea_ctx),
|
|
.cra_module = THIS_MODULE,
|
|
.cra_list = LIST_HEAD_INIT(xtea_alg.cra_list),
|
|
.cra_u = { .cipher = {
|
|
.cia_min_keysize = XTEA_KEY_SIZE,
|
|
.cia_max_keysize = XTEA_KEY_SIZE,
|
|
.cia_setkey = xtea_setkey,
|
|
.cia_encrypt = xeta_encrypt,
|
|
.cia_decrypt = xeta_decrypt } }
|
|
};
|
|
|
|
static int __init init(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
ret = crypto_register_alg(&tea_alg);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = crypto_register_alg(&xtea_alg);
|
|
if (ret < 0) {
|
|
crypto_unregister_alg(&tea_alg);
|
|
goto out;
|
|
}
|
|
|
|
ret = crypto_register_alg(&xeta_alg);
|
|
if (ret < 0) {
|
|
crypto_unregister_alg(&tea_alg);
|
|
crypto_unregister_alg(&xtea_alg);
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit fini(void)
|
|
{
|
|
crypto_unregister_alg(&tea_alg);
|
|
crypto_unregister_alg(&xtea_alg);
|
|
crypto_unregister_alg(&xeta_alg);
|
|
}
|
|
|
|
MODULE_ALIAS("xtea");
|
|
MODULE_ALIAS("xeta");
|
|
|
|
module_init(init);
|
|
module_exit(fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");
|