Subversion Repositories test_project

/*

 * 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_alg = {

        .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_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_alignmask          =       3,

        .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_alignmask          =       3,

        .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");