| // 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 <linux/unaligned.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); |
| |
| ctx->KEY[0] = get_unaligned_le32(&in_key[0]); |
| ctx->KEY[1] = get_unaligned_le32(&in_key[4]); |
| ctx->KEY[2] = get_unaligned_le32(&in_key[8]); |
| ctx->KEY[3] = get_unaligned_le32(&in_key[12]); |
| |
| 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); |
| |
| y = get_unaligned_le32(&src[0]); |
| z = get_unaligned_le32(&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); |
| } |
| |
| put_unaligned_le32(y, &dst[0]); |
| put_unaligned_le32(z, &dst[4]); |
| } |
| |
| 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); |
| |
| y = get_unaligned_le32(&src[0]); |
| z = get_unaligned_le32(&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; |
| } |
| |
| put_unaligned_le32(y, &dst[0]); |
| put_unaligned_le32(z, &dst[4]); |
| } |
| |
| static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key, |
| unsigned int key_len) |
| { |
| struct xtea_ctx *ctx = crypto_tfm_ctx(tfm); |
| |
| ctx->KEY[0] = get_unaligned_le32(&in_key[0]); |
| ctx->KEY[1] = get_unaligned_le32(&in_key[4]); |
| ctx->KEY[2] = get_unaligned_le32(&in_key[8]); |
| ctx->KEY[3] = get_unaligned_le32(&in_key[12]); |
| |
| 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); |
| |
| y = get_unaligned_le32(&src[0]); |
| z = get_unaligned_le32(&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]); |
| } |
| |
| put_unaligned_le32(y, &dst[0]); |
| put_unaligned_le32(z, &dst[4]); |
| } |
| |
| 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); |
| |
| y = get_unaligned_le32(&src[0]); |
| z = get_unaligned_le32(&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]); |
| } |
| |
| put_unaligned_le32(y, &dst[0]); |
| put_unaligned_le32(z, &dst[4]); |
| } |
| |
| |
| 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); |
| |
| y = get_unaligned_le32(&src[0]); |
| z = get_unaligned_le32(&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]; |
| } |
| |
| put_unaligned_le32(y, &dst[0]); |
| put_unaligned_le32(z, &dst[4]); |
| } |
| |
| 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); |
| |
| y = get_unaligned_le32(&src[0]); |
| z = get_unaligned_le32(&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]; |
| } |
| |
| put_unaligned_le32(y, &dst[0]); |
| put_unaligned_le32(z, &dst[4]); |
| } |
| |
| 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_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_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_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"); |
