282 lines
6.6 KiB
C
282 lines
6.6 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/byteorder.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/types.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
|
|
|
|
struct tea_ctx {
|
|
u32 KEY[4];
|
|
};
|
|
|
|
struct xtea_ctx {
|
|
u32 KEY[4];
|
|
};
|
|
|
|
static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
|
|
unsigned int key_len)
|
|
{
|
|
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *key = (const __le32 *)in_key;
|
|
|
|
ctx->KEY[0] = le32_to_cpu(key[0]);
|
|
ctx->KEY[1] = le32_to_cpu(key[1]);
|
|
ctx->KEY[2] = le32_to_cpu(key[2]);
|
|
ctx->KEY[3] = le32_to_cpu(key[3]);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, n, sum = 0;
|
|
u32 k0, k1, k2, k3;
|
|
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *in = (const __le32 *)src;
|
|
__le32 *out = (__le32 *)dst;
|
|
|
|
y = le32_to_cpu(in[0]);
|
|
z = le32_to_cpu(in[1]);
|
|
|
|
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);
|
|
}
|
|
|
|
out[0] = cpu_to_le32(y);
|
|
out[1] = cpu_to_le32(z);
|
|
}
|
|
|
|
static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, n, sum;
|
|
u32 k0, k1, k2, k3;
|
|
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *in = (const __le32 *)src;
|
|
__le32 *out = (__le32 *)dst;
|
|
|
|
y = le32_to_cpu(in[0]);
|
|
z = le32_to_cpu(in[1]);
|
|
|
|
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;
|
|
}
|
|
|
|
out[0] = cpu_to_le32(y);
|
|
out[1] = cpu_to_le32(z);
|
|
}
|
|
|
|
static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
|
|
unsigned int key_len)
|
|
{
|
|
struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *key = (const __le32 *)in_key;
|
|
|
|
ctx->KEY[0] = le32_to_cpu(key[0]);
|
|
ctx->KEY[1] = le32_to_cpu(key[1]);
|
|
ctx->KEY[2] = le32_to_cpu(key[2]);
|
|
ctx->KEY[3] = le32_to_cpu(key[3]);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, sum = 0;
|
|
u32 limit = XTEA_DELTA * XTEA_ROUNDS;
|
|
struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *in = (const __le32 *)src;
|
|
__le32 *out = (__le32 *)dst;
|
|
|
|
y = le32_to_cpu(in[0]);
|
|
z = le32_to_cpu(in[1]);
|
|
|
|
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]);
|
|
}
|
|
|
|
out[0] = cpu_to_le32(y);
|
|
out[1] = cpu_to_le32(z);
|
|
}
|
|
|
|
static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, sum;
|
|
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *in = (const __le32 *)src;
|
|
__le32 *out = (__le32 *)dst;
|
|
|
|
y = le32_to_cpu(in[0]);
|
|
z = le32_to_cpu(in[1]);
|
|
|
|
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]);
|
|
}
|
|
|
|
out[0] = cpu_to_le32(y);
|
|
out[1] = cpu_to_le32(z);
|
|
}
|
|
|
|
|
|
static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, sum = 0;
|
|
u32 limit = XTEA_DELTA * XTEA_ROUNDS;
|
|
struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *in = (const __le32 *)src;
|
|
__le32 *out = (__le32 *)dst;
|
|
|
|
y = le32_to_cpu(in[0]);
|
|
z = le32_to_cpu(in[1]);
|
|
|
|
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];
|
|
}
|
|
|
|
out[0] = cpu_to_le32(y);
|
|
out[1] = cpu_to_le32(z);
|
|
}
|
|
|
|
static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
|
|
{
|
|
u32 y, z, sum;
|
|
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
|
|
const __le32 *in = (const __le32 *)src;
|
|
__le32 *out = (__le32 *)dst;
|
|
|
|
y = le32_to_cpu(in[0]);
|
|
z = le32_to_cpu(in[1]);
|
|
|
|
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];
|
|
}
|
|
|
|
out[0] = cpu_to_le32(y);
|
|
out[1] = cpu_to_le32(z);
|
|
}
|
|
|
|
static struct crypto_alg tea_algs[3] = { {
|
|
.cra_name = "tea",
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = TEA_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof (struct tea_ctx),
|
|
.cra_alignmask = 3,
|
|
.cra_module = THIS_MODULE,
|
|
.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 } }
|
|
}, {
|
|
.cra_name = "xtea",
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = XTEA_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof (struct xtea_ctx),
|
|
.cra_alignmask = 3,
|
|
.cra_module = THIS_MODULE,
|
|
.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 } }
|
|
}, {
|
|
.cra_name = "xeta",
|
|
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
|
|
.cra_blocksize = XTEA_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof (struct xtea_ctx),
|
|
.cra_alignmask = 3,
|
|
.cra_module = THIS_MODULE,
|
|
.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 tea_mod_init(void)
|
|
{
|
|
return crypto_register_algs(tea_algs, ARRAY_SIZE(tea_algs));
|
|
}
|
|
|
|
static void __exit tea_mod_fini(void)
|
|
{
|
|
crypto_unregister_algs(tea_algs, ARRAY_SIZE(tea_algs));
|
|
}
|
|
|
|
MODULE_ALIAS_CRYPTO("tea");
|
|
MODULE_ALIAS_CRYPTO("xtea");
|
|
MODULE_ALIAS_CRYPTO("xeta");
|
|
|
|
module_init(tea_mod_init);
|
|
module_exit(tea_mod_fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");
|