linux/crypto/tea.c
Herbert Xu 14386d4713 crypto: Prepare to move crypto_tfm_ctx
The helper crypto_tfm_ctx is only used by the Crypto API algorithm
code and should really be in algapi.h.  However, for historical
reasons many files relied on it to be in crypto.h.  This patch
changes those files to use algapi.h instead in prepartion for a
move.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-12-02 18:12:40 +08:00

279 lines
6.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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
*/
#include <crypto/algapi.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/byteorder.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_driver_name = "tea-generic",
.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_driver_name = "xtea-generic",
.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_driver_name = "xeta-generic",
.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");
subsys_initcall(tea_mod_init);
module_exit(tea_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");