Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Cryptographic API. | |
3 | * | |
fb4f10ed | 4 | * TEA, XTEA, and XETA crypto alogrithms |
1da177e4 LT |
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 | * | |
fb4f10ed AG |
9 | * 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 | * | |
1da177e4 LT |
13 | * 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> | |
06ace7a9 | 25 | #include <asm/byteorder.h> |
1da177e4 LT |
26 | #include <asm/scatterlist.h> |
27 | #include <linux/crypto.h> | |
06ace7a9 | 28 | #include <linux/types.h> |
1da177e4 LT |
29 | |
30 | #define TEA_KEY_SIZE 16 | |
31 | #define TEA_BLOCK_SIZE 8 | |
32 | #define TEA_ROUNDS 32 | |
33 | #define TEA_DELTA 0x9e3779b9 | |
34 | ||
35 | #define XTEA_KEY_SIZE 16 | |
36 | #define XTEA_BLOCK_SIZE 8 | |
37 | #define XTEA_ROUNDS 32 | |
38 | #define XTEA_DELTA 0x9e3779b9 | |
39 | ||
1da177e4 LT |
40 | struct tea_ctx { |
41 | u32 KEY[4]; | |
42 | }; | |
43 | ||
44 | struct xtea_ctx { | |
45 | u32 KEY[4]; | |
46 | }; | |
47 | ||
6c2bb98b HX |
48 | static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key, |
49 | unsigned int key_len, u32 *flags) | |
50 | { | |
51 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); | |
06ace7a9 | 52 | const __le32 *key = (const __le32 *)in_key; |
1da177e4 LT |
53 | |
54 | if (key_len != 16) | |
55 | { | |
56 | *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; | |
57 | return -EINVAL; | |
58 | } | |
59 | ||
06ace7a9 HX |
60 | ctx->KEY[0] = le32_to_cpu(key[0]); |
61 | ctx->KEY[1] = le32_to_cpu(key[1]); | |
62 | ctx->KEY[2] = le32_to_cpu(key[2]); | |
63 | ctx->KEY[3] = le32_to_cpu(key[3]); | |
1da177e4 LT |
64 | |
65 | return 0; | |
66 | ||
67 | } | |
68 | ||
6c2bb98b HX |
69 | static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
70 | { | |
1da177e4 LT |
71 | u32 y, z, n, sum = 0; |
72 | u32 k0, k1, k2, k3; | |
6c2bb98b | 73 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
06ace7a9 HX |
74 | const __le32 *in = (const __le32 *)src; |
75 | __le32 *out = (__le32 *)dst; | |
1da177e4 | 76 | |
06ace7a9 HX |
77 | y = le32_to_cpu(in[0]); |
78 | z = le32_to_cpu(in[1]); | |
1da177e4 LT |
79 | |
80 | k0 = ctx->KEY[0]; | |
81 | k1 = ctx->KEY[1]; | |
82 | k2 = ctx->KEY[2]; | |
83 | k3 = ctx->KEY[3]; | |
84 | ||
85 | n = TEA_ROUNDS; | |
86 | ||
87 | while (n-- > 0) { | |
88 | sum += TEA_DELTA; | |
89 | y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1); | |
90 | z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3); | |
91 | } | |
92 | ||
06ace7a9 HX |
93 | out[0] = cpu_to_le32(y); |
94 | out[1] = cpu_to_le32(z); | |
1da177e4 LT |
95 | } |
96 | ||
6c2bb98b HX |
97 | static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
98 | { | |
1da177e4 LT |
99 | u32 y, z, n, sum; |
100 | u32 k0, k1, k2, k3; | |
6c2bb98b | 101 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
06ace7a9 HX |
102 | const __le32 *in = (const __le32 *)src; |
103 | __le32 *out = (__le32 *)dst; | |
1da177e4 | 104 | |
06ace7a9 HX |
105 | y = le32_to_cpu(in[0]); |
106 | z = le32_to_cpu(in[1]); | |
1da177e4 LT |
107 | |
108 | k0 = ctx->KEY[0]; | |
109 | k1 = ctx->KEY[1]; | |
110 | k2 = ctx->KEY[2]; | |
111 | k3 = ctx->KEY[3]; | |
112 | ||
113 | sum = TEA_DELTA << 5; | |
114 | ||
115 | n = TEA_ROUNDS; | |
116 | ||
117 | while (n-- > 0) { | |
118 | z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3); | |
119 | y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1); | |
120 | sum -= TEA_DELTA; | |
121 | } | |
122 | ||
06ace7a9 HX |
123 | out[0] = cpu_to_le32(y); |
124 | out[1] = cpu_to_le32(z); | |
1da177e4 LT |
125 | } |
126 | ||
6c2bb98b HX |
127 | static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key, |
128 | unsigned int key_len, u32 *flags) | |
129 | { | |
130 | struct xtea_ctx *ctx = crypto_tfm_ctx(tfm); | |
06ace7a9 | 131 | const __le32 *key = (const __le32 *)in_key; |
1da177e4 LT |
132 | |
133 | if (key_len != 16) | |
134 | { | |
135 | *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; | |
136 | return -EINVAL; | |
137 | } | |
138 | ||
06ace7a9 HX |
139 | ctx->KEY[0] = le32_to_cpu(key[0]); |
140 | ctx->KEY[1] = le32_to_cpu(key[1]); | |
141 | ctx->KEY[2] = le32_to_cpu(key[2]); | |
142 | ctx->KEY[3] = le32_to_cpu(key[3]); | |
1da177e4 LT |
143 | |
144 | return 0; | |
145 | ||
146 | } | |
147 | ||
6c2bb98b HX |
148 | static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
149 | { | |
1da177e4 LT |
150 | u32 y, z, sum = 0; |
151 | u32 limit = XTEA_DELTA * XTEA_ROUNDS; | |
6c2bb98b | 152 | struct xtea_ctx *ctx = crypto_tfm_ctx(tfm); |
06ace7a9 HX |
153 | const __le32 *in = (const __le32 *)src; |
154 | __le32 *out = (__le32 *)dst; | |
1da177e4 | 155 | |
06ace7a9 HX |
156 | y = le32_to_cpu(in[0]); |
157 | z = le32_to_cpu(in[1]); | |
1da177e4 LT |
158 | |
159 | while (sum != limit) { | |
fb4f10ed | 160 | y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]); |
1da177e4 | 161 | sum += XTEA_DELTA; |
fb4f10ed | 162 | z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]); |
1da177e4 LT |
163 | } |
164 | ||
06ace7a9 HX |
165 | out[0] = cpu_to_le32(y); |
166 | out[1] = cpu_to_le32(z); | |
1da177e4 LT |
167 | } |
168 | ||
6c2bb98b HX |
169 | static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
170 | { | |
1da177e4 | 171 | u32 y, z, sum; |
6c2bb98b | 172 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
06ace7a9 HX |
173 | const __le32 *in = (const __le32 *)src; |
174 | __le32 *out = (__le32 *)dst; | |
1da177e4 | 175 | |
06ace7a9 HX |
176 | y = le32_to_cpu(in[0]); |
177 | z = le32_to_cpu(in[1]); | |
1da177e4 LT |
178 | |
179 | sum = XTEA_DELTA * XTEA_ROUNDS; | |
180 | ||
fb4f10ed AG |
181 | while (sum) { |
182 | z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]); | |
183 | sum -= XTEA_DELTA; | |
184 | y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]); | |
185 | } | |
186 | ||
06ace7a9 HX |
187 | out[0] = cpu_to_le32(y); |
188 | out[1] = cpu_to_le32(z); | |
fb4f10ed AG |
189 | } |
190 | ||
191 | ||
6c2bb98b HX |
192 | static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
193 | { | |
fb4f10ed AG |
194 | u32 y, z, sum = 0; |
195 | u32 limit = XTEA_DELTA * XTEA_ROUNDS; | |
6c2bb98b | 196 | struct xtea_ctx *ctx = crypto_tfm_ctx(tfm); |
06ace7a9 HX |
197 | const __le32 *in = (const __le32 *)src; |
198 | __le32 *out = (__le32 *)dst; | |
fb4f10ed | 199 | |
06ace7a9 HX |
200 | y = le32_to_cpu(in[0]); |
201 | z = le32_to_cpu(in[1]); | |
fb4f10ed AG |
202 | |
203 | while (sum != limit) { | |
204 | y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3]; | |
205 | sum += XTEA_DELTA; | |
206 | z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3]; | |
207 | } | |
208 | ||
06ace7a9 HX |
209 | out[0] = cpu_to_le32(y); |
210 | out[1] = cpu_to_le32(z); | |
fb4f10ed AG |
211 | } |
212 | ||
6c2bb98b HX |
213 | static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
214 | { | |
fb4f10ed | 215 | u32 y, z, sum; |
6c2bb98b | 216 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
06ace7a9 HX |
217 | const __le32 *in = (const __le32 *)src; |
218 | __le32 *out = (__le32 *)dst; | |
fb4f10ed | 219 | |
06ace7a9 HX |
220 | y = le32_to_cpu(in[0]); |
221 | z = le32_to_cpu(in[1]); | |
fb4f10ed AG |
222 | |
223 | sum = XTEA_DELTA * XTEA_ROUNDS; | |
224 | ||
1da177e4 LT |
225 | while (sum) { |
226 | z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3]; | |
227 | sum -= XTEA_DELTA; | |
228 | y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3]; | |
229 | } | |
230 | ||
06ace7a9 HX |
231 | out[0] = cpu_to_le32(y); |
232 | out[1] = cpu_to_le32(z); | |
1da177e4 LT |
233 | } |
234 | ||
235 | static struct crypto_alg tea_alg = { | |
236 | .cra_name = "tea", | |
237 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, | |
238 | .cra_blocksize = TEA_BLOCK_SIZE, | |
239 | .cra_ctxsize = sizeof (struct tea_ctx), | |
a429d260 | 240 | .cra_alignmask = 3, |
1da177e4 LT |
241 | .cra_module = THIS_MODULE, |
242 | .cra_list = LIST_HEAD_INIT(tea_alg.cra_list), | |
243 | .cra_u = { .cipher = { | |
244 | .cia_min_keysize = TEA_KEY_SIZE, | |
245 | .cia_max_keysize = TEA_KEY_SIZE, | |
246 | .cia_setkey = tea_setkey, | |
247 | .cia_encrypt = tea_encrypt, | |
248 | .cia_decrypt = tea_decrypt } } | |
249 | }; | |
250 | ||
251 | static struct crypto_alg xtea_alg = { | |
252 | .cra_name = "xtea", | |
253 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, | |
254 | .cra_blocksize = XTEA_BLOCK_SIZE, | |
255 | .cra_ctxsize = sizeof (struct xtea_ctx), | |
a429d260 | 256 | .cra_alignmask = 3, |
1da177e4 LT |
257 | .cra_module = THIS_MODULE, |
258 | .cra_list = LIST_HEAD_INIT(xtea_alg.cra_list), | |
259 | .cra_u = { .cipher = { | |
260 | .cia_min_keysize = XTEA_KEY_SIZE, | |
261 | .cia_max_keysize = XTEA_KEY_SIZE, | |
262 | .cia_setkey = xtea_setkey, | |
263 | .cia_encrypt = xtea_encrypt, | |
264 | .cia_decrypt = xtea_decrypt } } | |
265 | }; | |
266 | ||
fb4f10ed AG |
267 | static struct crypto_alg xeta_alg = { |
268 | .cra_name = "xeta", | |
269 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, | |
270 | .cra_blocksize = XTEA_BLOCK_SIZE, | |
271 | .cra_ctxsize = sizeof (struct xtea_ctx), | |
a429d260 | 272 | .cra_alignmask = 3, |
fb4f10ed AG |
273 | .cra_module = THIS_MODULE, |
274 | .cra_list = LIST_HEAD_INIT(xtea_alg.cra_list), | |
275 | .cra_u = { .cipher = { | |
276 | .cia_min_keysize = XTEA_KEY_SIZE, | |
277 | .cia_max_keysize = XTEA_KEY_SIZE, | |
278 | .cia_setkey = xtea_setkey, | |
279 | .cia_encrypt = xeta_encrypt, | |
280 | .cia_decrypt = xeta_decrypt } } | |
281 | }; | |
282 | ||
1da177e4 LT |
283 | static int __init init(void) |
284 | { | |
285 | int ret = 0; | |
286 | ||
287 | ret = crypto_register_alg(&tea_alg); | |
288 | if (ret < 0) | |
289 | goto out; | |
290 | ||
291 | ret = crypto_register_alg(&xtea_alg); | |
292 | if (ret < 0) { | |
293 | crypto_unregister_alg(&tea_alg); | |
294 | goto out; | |
295 | } | |
296 | ||
fb4f10ed AG |
297 | ret = crypto_register_alg(&xeta_alg); |
298 | if (ret < 0) { | |
299 | crypto_unregister_alg(&tea_alg); | |
300 | crypto_unregister_alg(&xtea_alg); | |
301 | goto out; | |
302 | } | |
303 | ||
1da177e4 LT |
304 | out: |
305 | return ret; | |
306 | } | |
307 | ||
308 | static void __exit fini(void) | |
309 | { | |
310 | crypto_unregister_alg(&tea_alg); | |
311 | crypto_unregister_alg(&xtea_alg); | |
fb4f10ed | 312 | crypto_unregister_alg(&xeta_alg); |
1da177e4 LT |
313 | } |
314 | ||
315 | MODULE_ALIAS("xtea"); | |
fb4f10ed | 316 | MODULE_ALIAS("xeta"); |
1da177e4 LT |
317 | |
318 | module_init(init); | |
319 | module_exit(fini); | |
320 | ||
321 | MODULE_LICENSE("GPL"); | |
fb4f10ed | 322 | MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms"); |