Hi allI want to use TEA encryption algorithm with OpenSSL.Is there any engine
to provide implementation of TEA algorithm ?gost engine is an example of
adding new cryptoalgorithms into OpenSSL but gost example is a bit complex.
Thanks in advance,
Siavash
TEA source code :
https://svn.exactcode.de/linux24-psionw/trunk/crypto/tea.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 ajgro...@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 u32 *)(x))
#define u32_out(to, from) (*(u32 *)(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_init(init);
module_exit(fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");
