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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Cryptographic API.
3 *
Aaron Grothefb4f10e2005-09-01 17:42:46 -07004 * TEA, XTEA, and XETA crypto alogrithms
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * The TEA and Xtended TEA algorithms were developed by David Wheeler
7 * and Roger Needham at the Computer Laboratory of Cambridge University.
8 *
Aaron Grothefb4f10e2005-09-01 17:42:46 -07009 * Due to the order of evaluation in XTEA many people have incorrectly
10 * implemented it. XETA (XTEA in the wrong order), exists for
11 * compatibility with these implementations.
12 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or
18 * (at your option) any later version.
19 *
20 */
21
22#include <linux/init.h>
23#include <linux/module.h>
24#include <linux/mm.h>
Herbert Xu06ace7a2005-10-30 21:25:15 +110025#include <asm/byteorder.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/crypto.h>
Herbert Xu06ace7a2005-10-30 21:25:15 +110027#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29#define TEA_KEY_SIZE 16
30#define TEA_BLOCK_SIZE 8
31#define TEA_ROUNDS 32
32#define TEA_DELTA 0x9e3779b9
33
34#define XTEA_KEY_SIZE 16
35#define XTEA_BLOCK_SIZE 8
36#define XTEA_ROUNDS 32
37#define XTEA_DELTA 0x9e3779b9
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039struct tea_ctx {
40 u32 KEY[4];
41};
42
43struct xtea_ctx {
44 u32 KEY[4];
45};
46
Herbert Xu6c2bb982006-05-16 22:09:29 +100047static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
Herbert Xu560c06a2006-08-13 14:16:39 +100048 unsigned int key_len)
Herbert Xu6c2bb982006-05-16 22:09:29 +100049{
50 struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +110051 const __le32 *key = (const __le32 *)in_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
Herbert Xu06ace7a2005-10-30 21:25:15 +110053 ctx->KEY[0] = le32_to_cpu(key[0]);
54 ctx->KEY[1] = le32_to_cpu(key[1]);
55 ctx->KEY[2] = le32_to_cpu(key[2]);
56 ctx->KEY[3] = le32_to_cpu(key[3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58 return 0;
59
60}
61
Herbert Xu6c2bb982006-05-16 22:09:29 +100062static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
63{
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 u32 y, z, n, sum = 0;
65 u32 k0, k1, k2, k3;
Herbert Xu6c2bb982006-05-16 22:09:29 +100066 struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +110067 const __le32 *in = (const __le32 *)src;
68 __le32 *out = (__le32 *)dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Herbert Xu06ace7a2005-10-30 21:25:15 +110070 y = le32_to_cpu(in[0]);
71 z = le32_to_cpu(in[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 k0 = ctx->KEY[0];
74 k1 = ctx->KEY[1];
75 k2 = ctx->KEY[2];
76 k3 = ctx->KEY[3];
77
78 n = TEA_ROUNDS;
79
80 while (n-- > 0) {
81 sum += TEA_DELTA;
82 y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
83 z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
84 }
85
Herbert Xu06ace7a2005-10-30 21:25:15 +110086 out[0] = cpu_to_le32(y);
87 out[1] = cpu_to_le32(z);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088}
89
Herbert Xu6c2bb982006-05-16 22:09:29 +100090static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
91{
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 u32 y, z, n, sum;
93 u32 k0, k1, k2, k3;
Herbert Xu6c2bb982006-05-16 22:09:29 +100094 struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +110095 const __le32 *in = (const __le32 *)src;
96 __le32 *out = (__le32 *)dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Herbert Xu06ace7a2005-10-30 21:25:15 +110098 y = le32_to_cpu(in[0]);
99 z = le32_to_cpu(in[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101 k0 = ctx->KEY[0];
102 k1 = ctx->KEY[1];
103 k2 = ctx->KEY[2];
104 k3 = ctx->KEY[3];
105
106 sum = TEA_DELTA << 5;
107
108 n = TEA_ROUNDS;
109
110 while (n-- > 0) {
111 z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
112 y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
113 sum -= TEA_DELTA;
114 }
115
Herbert Xu06ace7a2005-10-30 21:25:15 +1100116 out[0] = cpu_to_le32(y);
117 out[1] = cpu_to_le32(z);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118}
119
Herbert Xu6c2bb982006-05-16 22:09:29 +1000120static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
Herbert Xu560c06a2006-08-13 14:16:39 +1000121 unsigned int key_len)
Herbert Xu6c2bb982006-05-16 22:09:29 +1000122{
123 struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +1100124 const __le32 *key = (const __le32 *)in_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Herbert Xu06ace7a2005-10-30 21:25:15 +1100126 ctx->KEY[0] = le32_to_cpu(key[0]);
127 ctx->KEY[1] = le32_to_cpu(key[1]);
128 ctx->KEY[2] = le32_to_cpu(key[2]);
129 ctx->KEY[3] = le32_to_cpu(key[3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131 return 0;
132
133}
134
Herbert Xu6c2bb982006-05-16 22:09:29 +1000135static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
136{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 u32 y, z, sum = 0;
138 u32 limit = XTEA_DELTA * XTEA_ROUNDS;
Herbert Xu6c2bb982006-05-16 22:09:29 +1000139 struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +1100140 const __le32 *in = (const __le32 *)src;
141 __le32 *out = (__le32 *)dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Herbert Xu06ace7a2005-10-30 21:25:15 +1100143 y = le32_to_cpu(in[0]);
144 z = le32_to_cpu(in[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146 while (sum != limit) {
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700147 y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 sum += XTEA_DELTA;
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700149 z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 }
151
Herbert Xu06ace7a2005-10-30 21:25:15 +1100152 out[0] = cpu_to_le32(y);
153 out[1] = cpu_to_le32(z);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154}
155
Herbert Xu6c2bb982006-05-16 22:09:29 +1000156static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
157{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 u32 y, z, sum;
Herbert Xu6c2bb982006-05-16 22:09:29 +1000159 struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +1100160 const __le32 *in = (const __le32 *)src;
161 __le32 *out = (__le32 *)dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Herbert Xu06ace7a2005-10-30 21:25:15 +1100163 y = le32_to_cpu(in[0]);
164 z = le32_to_cpu(in[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 sum = XTEA_DELTA * XTEA_ROUNDS;
167
168 while (sum) {
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700169 z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]);
170 sum -= XTEA_DELTA;
171 y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]);
172 }
173
Herbert Xu06ace7a2005-10-30 21:25:15 +1100174 out[0] = cpu_to_le32(y);
175 out[1] = cpu_to_le32(z);
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700176}
177
178
Herbert Xu6c2bb982006-05-16 22:09:29 +1000179static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
180{
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700181 u32 y, z, sum = 0;
182 u32 limit = XTEA_DELTA * XTEA_ROUNDS;
Herbert Xu6c2bb982006-05-16 22:09:29 +1000183 struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +1100184 const __le32 *in = (const __le32 *)src;
185 __le32 *out = (__le32 *)dst;
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700186
Herbert Xu06ace7a2005-10-30 21:25:15 +1100187 y = le32_to_cpu(in[0]);
188 z = le32_to_cpu(in[1]);
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700189
190 while (sum != limit) {
191 y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3];
192 sum += XTEA_DELTA;
193 z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3];
194 }
195
Herbert Xu06ace7a2005-10-30 21:25:15 +1100196 out[0] = cpu_to_le32(y);
197 out[1] = cpu_to_le32(z);
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700198}
199
Herbert Xu6c2bb982006-05-16 22:09:29 +1000200static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
201{
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700202 u32 y, z, sum;
Herbert Xu6c2bb982006-05-16 22:09:29 +1000203 struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +1100204 const __le32 *in = (const __le32 *)src;
205 __le32 *out = (__le32 *)dst;
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700206
Herbert Xu06ace7a2005-10-30 21:25:15 +1100207 y = le32_to_cpu(in[0]);
208 z = le32_to_cpu(in[1]);
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700209
210 sum = XTEA_DELTA * XTEA_ROUNDS;
211
212 while (sum) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3];
214 sum -= XTEA_DELTA;
215 y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3];
216 }
217
Herbert Xu06ace7a2005-10-30 21:25:15 +1100218 out[0] = cpu_to_le32(y);
219 out[1] = cpu_to_le32(z);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220}
221
Jussi Kivilinna738206d32012-07-11 14:19:55 +0300222static struct crypto_alg tea_algs[3] = { {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 .cra_name = "tea",
224 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
225 .cra_blocksize = TEA_BLOCK_SIZE,
226 .cra_ctxsize = sizeof (struct tea_ctx),
Herbert Xua429d262006-01-07 16:38:15 +1100227 .cra_alignmask = 3,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 .cra_module = THIS_MODULE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 .cra_u = { .cipher = {
230 .cia_min_keysize = TEA_KEY_SIZE,
231 .cia_max_keysize = TEA_KEY_SIZE,
232 .cia_setkey = tea_setkey,
233 .cia_encrypt = tea_encrypt,
234 .cia_decrypt = tea_decrypt } }
Jussi Kivilinna738206d32012-07-11 14:19:55 +0300235}, {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 .cra_name = "xtea",
237 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
238 .cra_blocksize = XTEA_BLOCK_SIZE,
239 .cra_ctxsize = sizeof (struct xtea_ctx),
Herbert Xua429d262006-01-07 16:38:15 +1100240 .cra_alignmask = 3,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 .cra_module = THIS_MODULE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 .cra_u = { .cipher = {
243 .cia_min_keysize = XTEA_KEY_SIZE,
244 .cia_max_keysize = XTEA_KEY_SIZE,
245 .cia_setkey = xtea_setkey,
246 .cia_encrypt = xtea_encrypt,
247 .cia_decrypt = xtea_decrypt } }
Jussi Kivilinna738206d32012-07-11 14:19:55 +0300248}, {
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700249 .cra_name = "xeta",
250 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
251 .cra_blocksize = XTEA_BLOCK_SIZE,
252 .cra_ctxsize = sizeof (struct xtea_ctx),
Herbert Xua429d262006-01-07 16:38:15 +1100253 .cra_alignmask = 3,
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700254 .cra_module = THIS_MODULE,
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700255 .cra_u = { .cipher = {
256 .cia_min_keysize = XTEA_KEY_SIZE,
257 .cia_max_keysize = XTEA_KEY_SIZE,
258 .cia_setkey = xtea_setkey,
259 .cia_encrypt = xeta_encrypt,
260 .cia_decrypt = xeta_decrypt } }
Jussi Kivilinna738206d32012-07-11 14:19:55 +0300261} };
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700262
Kamalesh Babulal3af5b902008-04-05 21:00:57 +0800263static int __init tea_mod_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
Jussi Kivilinna738206d32012-07-11 14:19:55 +0300265 return crypto_register_algs(tea_algs, ARRAY_SIZE(tea_algs));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266}
267
Kamalesh Babulal3af5b902008-04-05 21:00:57 +0800268static void __exit tea_mod_fini(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269{
Jussi Kivilinna738206d32012-07-11 14:19:55 +0300270 crypto_unregister_algs(tea_algs, ARRAY_SIZE(tea_algs));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271}
272
273MODULE_ALIAS("xtea");
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700274MODULE_ALIAS("xeta");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
Kamalesh Babulal3af5b902008-04-05 21:00:57 +0800276module_init(tea_mod_init);
277module_exit(tea_mod_fini);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
279MODULE_LICENSE("GPL");
Aaron Grothefb4f10e2005-09-01 17:42:46 -0700280MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");