[GitHub/mt8127/android_kernel_alcatel_ttab.git] / crypto / tea.c

/* 
 * Cryptographic API.
 *
 * TEA and Xtended TEA Algorithms
 *
 * The TEA and Xtended TEA algorithms were developed by David Wheeler 
 * and Roger Needham at the Computer Laboratory of Cambridge University.
 *
 * 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/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 __le32 *)(x))
#define u32_out(to, from) (*(__le32 *)(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 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 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;
	}

out:	
	return ret;
}

static void __exit fini(void)
{
	crypto_unregister_alg(&tea_alg);
	crypto_unregister_alg(&xtea_alg);
}

MODULE_ALIAS("xtea");

module_init(init);
module_exit(fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TEA & XTEA Cryptographic Algorithms");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Cryptographic API.
	3	*
	4	* TEA and Xtended TEA Algorithms
	5	*
	6	* The TEA and Xtended TEA algorithms were developed by David Wheeler
	7	* and Roger Needham at the Computer Laboratory of Cambridge University.
	8	*
	9	* Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License as published by
	13	* the Free Software Foundation; either version 2 of the License, or
	14	* (at your option) any later version.
	15	*
	16	*/
	17
	18	#include <linux/init.h>
	19	#include <linux/module.h>
	20	#include <linux/mm.h>
	21	#include <asm/scatterlist.h>
	22	#include <linux/crypto.h>
	23
	24	#define TEA_KEY_SIZE 16
	25	#define TEA_BLOCK_SIZE 8
	26	#define TEA_ROUNDS 32
	27	#define TEA_DELTA 0x9e3779b9
	28
	29	#define XTEA_KEY_SIZE 16
	30	#define XTEA_BLOCK_SIZE 8
	31	#define XTEA_ROUNDS 32
	32	#define XTEA_DELTA 0x9e3779b9
	33
	34	#define u32_in(x) le32_to_cpu((const __le32 )(x))
	35	#define u32_out(to, from) ((__le32 )(to) = cpu_to_le32(from))
	36
	37	struct tea_ctx {
	38	u32 KEY[4];
	39	};
	40
	41	struct xtea_ctx {
	42	u32 KEY[4];
	43	};
	44
	45	static int tea_setkey(void ctx_arg, const u8 in_key,
	46	unsigned int key_len, u32 *flags)
	47	{
	48
	49	struct tea_ctx *ctx = ctx_arg;
	50
	51	if (key_len != 16)
	52	{
	53	*flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	54	return -EINVAL;
	55	}
	56
	57	ctx->KEY[0] = u32_in (in_key);
	58	ctx->KEY[1] = u32_in (in_key + 4);
	59	ctx->KEY[2] = u32_in (in_key + 8);
	60	ctx->KEY[3] = u32_in (in_key + 12);
	61
	62	return 0;
	63
	64	}
65
66	static void tea_encrypt(void ctx_arg, u8 dst, const u8 *src)
67	{
68	u32 y, z, n, sum = 0;
69	u32 k0, k1, k2, k3;
70
71	struct tea_ctx *ctx = ctx_arg;
72
73	y = u32_in (src);
74	z = u32_in (src + 4);
75
76	k0 = ctx->KEY[0];
77	k1 = ctx->KEY[1];
78	k2 = ctx->KEY[2];
79	k3 = ctx->KEY[3];
80
81	n = TEA_ROUNDS;
82
83	while (n-- > 0) {
84	sum += TEA_DELTA;
85	y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
86	z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
87	}
88
89	u32_out (dst, y);
90	u32_out (dst + 4, z);
91	}
92
93	static void tea_decrypt(void ctx_arg, u8 dst, const u8 *src)
94	{
95	u32 y, z, n, sum;
96	u32 k0, k1, k2, k3;
97
98	struct tea_ctx *ctx = ctx_arg;
99
100	y = u32_in (src);
101	z = u32_in (src + 4);
102
103	k0 = ctx->KEY[0];
104	k1 = ctx->KEY[1];
105	k2 = ctx->KEY[2];
106	k3 = ctx->KEY[3];
107
108	sum = TEA_DELTA << 5;
109
110	n = TEA_ROUNDS;
111
112	while (n-- > 0) {
113	z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
114	y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
115	sum -= TEA_DELTA;
116	}
117
118	u32_out (dst, y);
119	u32_out (dst + 4, z);
120
121	}
122
123	static int xtea_setkey(void ctx_arg, const u8 in_key,
124	unsigned int key_len, u32 *flags)
125	{
126
127	struct xtea_ctx *ctx = ctx_arg;
128
129	if (key_len != 16)
130	{
131	*flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
132	return -EINVAL;
133	}
134
135	ctx->KEY[0] = u32_in (in_key);
136	ctx->KEY[1] = u32_in (in_key + 4);
137	ctx->KEY[2] = u32_in (in_key + 8);
138	ctx->KEY[3] = u32_in (in_key + 12);
139
140	return 0;
141
142	}
143
144	static void xtea_encrypt(void ctx_arg, u8 dst, const u8 *src)
145	{
146
147	u32 y, z, sum = 0;
148	u32 limit = XTEA_DELTA * XTEA_ROUNDS;
149
150	struct xtea_ctx *ctx = ctx_arg;
151
152	y = u32_in (src);
153	z = u32_in (src + 4);
154
155	while (sum != limit) {
156	y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3];
157	sum += XTEA_DELTA;
158	z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3];
159	}
160
161	u32_out (dst, y);
162	u32_out (dst + 4, z);
163
164	}
165
166	static void xtea_decrypt(void ctx_arg, u8 dst, const u8 *src)
167	{
168
169	u32 y, z, sum;
170	struct tea_ctx *ctx = ctx_arg;
171
172	y = u32_in (src);
173	z = u32_in (src + 4);
174
175	sum = XTEA_DELTA * XTEA_ROUNDS;
176
177	while (sum) {
178	z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3];
179	sum -= XTEA_DELTA;
180	y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3];
181	}
182
183	u32_out (dst, y);
184	u32_out (dst + 4, z);
185
186	}
187
188	static struct crypto_alg tea_alg = {
189	.cra_name = "tea",
190	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
191	.cra_blocksize = TEA_BLOCK_SIZE,
192	.cra_ctxsize = sizeof (struct tea_ctx),
193	.cra_module = THIS_MODULE,
194	.cra_list = LIST_HEAD_INIT(tea_alg.cra_list),
195	.cra_u = { .cipher = {
196	.cia_min_keysize = TEA_KEY_SIZE,
197	.cia_max_keysize = TEA_KEY_SIZE,
198	.cia_setkey = tea_setkey,
199	.cia_encrypt = tea_encrypt,
200	.cia_decrypt = tea_decrypt } }
201	};
202
203	static struct crypto_alg xtea_alg = {
204	.cra_name = "xtea",
205	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
206	.cra_blocksize = XTEA_BLOCK_SIZE,
207	.cra_ctxsize = sizeof (struct xtea_ctx),
208	.cra_module = THIS_MODULE,
209	.cra_list = LIST_HEAD_INIT(xtea_alg.cra_list),
210	.cra_u = { .cipher = {
211	.cia_min_keysize = XTEA_KEY_SIZE,
212	.cia_max_keysize = XTEA_KEY_SIZE,
213	.cia_setkey = xtea_setkey,
214	.cia_encrypt = xtea_encrypt,
215	.cia_decrypt = xtea_decrypt } }
216	};
217
218	static int __init init(void)
219	{
220	int ret = 0;
221
222	ret = crypto_register_alg(&tea_alg);
223	if (ret < 0)
224	goto out;
225
226	ret = crypto_register_alg(&xtea_alg);
227	if (ret < 0) {
228	crypto_unregister_alg(&tea_alg);
229	goto out;
230	}
231
232	out:
233	return ret;
234	}
235
236	static void __exit fini(void)
237	{
238	crypto_unregister_alg(&tea_alg);
239	crypto_unregister_alg(&xtea_alg);
240	}
241
242	MODULE_ALIAS("xtea");
243
244	module_init(init);
245	module_exit(fini);
246
247	MODULE_LICENSE("GPL");
248	MODULE_DESCRIPTION("TEA & XTEA Cryptographic Algorithms");