1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Cryptographic API. |
4 | * |
5 | * TEA, XTEA, and XETA crypto alogrithms |
6 | * |
7 | * The TEA and Xtended TEA algorithms were developed by David Wheeler |
8 | * and Roger Needham at the Computer Laboratory of Cambridge University. |
9 | * |
10 | * Due to the order of evaluation in XTEA many people have incorrectly |
11 | * implemented it. XETA (XTEA in the wrong order), exists for |
12 | * compatibility with these implementations. |
13 | * |
14 | * Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com |
15 | */ |
16 | |
17 | #include <crypto/algapi.h> |
18 | #include <linux/init.h> |
19 | #include <linux/module.h> |
20 | #include <linux/mm.h> |
21 | #include <asm/byteorder.h> |
22 | #include <linux/types.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 | struct tea_ctx { |
35 | u32 KEY[4]; |
36 | }; |
37 | |
38 | struct xtea_ctx { |
39 | u32 KEY[4]; |
40 | }; |
41 | |
42 | static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key, |
43 | unsigned int key_len) |
44 | { |
45 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
46 | const __le32 *key = (const __le32 *)in_key; |
47 | |
48 | ctx->KEY[0] = le32_to_cpu(key[0]); |
49 | ctx->KEY[1] = le32_to_cpu(key[1]); |
50 | ctx->KEY[2] = le32_to_cpu(key[2]); |
51 | ctx->KEY[3] = le32_to_cpu(key[3]); |
52 | |
53 | return 0; |
54 | |
55 | } |
56 | |
57 | static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
58 | { |
59 | u32 y, z, n, sum = 0; |
60 | u32 k0, k1, k2, k3; |
61 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
62 | const __le32 *in = (const __le32 *)src; |
63 | __le32 *out = (__le32 *)dst; |
64 | |
65 | y = le32_to_cpu(in[0]); |
66 | z = le32_to_cpu(in[1]); |
67 | |
68 | k0 = ctx->KEY[0]; |
69 | k1 = ctx->KEY[1]; |
70 | k2 = ctx->KEY[2]; |
71 | k3 = ctx->KEY[3]; |
72 | |
73 | n = TEA_ROUNDS; |
74 | |
75 | while (n-- > 0) { |
76 | sum += TEA_DELTA; |
77 | y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1); |
78 | z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3); |
79 | } |
80 | |
81 | out[0] = cpu_to_le32(y); |
82 | out[1] = cpu_to_le32(z); |
83 | } |
84 | |
85 | static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
86 | { |
87 | u32 y, z, n, sum; |
88 | u32 k0, k1, k2, k3; |
89 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
90 | const __le32 *in = (const __le32 *)src; |
91 | __le32 *out = (__le32 *)dst; |
92 | |
93 | y = le32_to_cpu(in[0]); |
94 | z = le32_to_cpu(in[1]); |
95 | |
96 | k0 = ctx->KEY[0]; |
97 | k1 = ctx->KEY[1]; |
98 | k2 = ctx->KEY[2]; |
99 | k3 = ctx->KEY[3]; |
100 | |
101 | sum = TEA_DELTA << 5; |
102 | |
103 | n = TEA_ROUNDS; |
104 | |
105 | while (n-- > 0) { |
106 | z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3); |
107 | y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1); |
108 | sum -= TEA_DELTA; |
109 | } |
110 | |
111 | out[0] = cpu_to_le32(y); |
112 | out[1] = cpu_to_le32(z); |
113 | } |
114 | |
115 | static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key, |
116 | unsigned int key_len) |
117 | { |
118 | struct xtea_ctx *ctx = crypto_tfm_ctx(tfm); |
119 | const __le32 *key = (const __le32 *)in_key; |
120 | |
121 | ctx->KEY[0] = le32_to_cpu(key[0]); |
122 | ctx->KEY[1] = le32_to_cpu(key[1]); |
123 | ctx->KEY[2] = le32_to_cpu(key[2]); |
124 | ctx->KEY[3] = le32_to_cpu(key[3]); |
125 | |
126 | return 0; |
127 | |
128 | } |
129 | |
130 | static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
131 | { |
132 | u32 y, z, sum = 0; |
133 | u32 limit = XTEA_DELTA * XTEA_ROUNDS; |
134 | struct xtea_ctx *ctx = crypto_tfm_ctx(tfm); |
135 | const __le32 *in = (const __le32 *)src; |
136 | __le32 *out = (__le32 *)dst; |
137 | |
138 | y = le32_to_cpu(in[0]); |
139 | z = le32_to_cpu(in[1]); |
140 | |
141 | while (sum != limit) { |
142 | y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]); |
143 | sum += XTEA_DELTA; |
144 | z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]); |
145 | } |
146 | |
147 | out[0] = cpu_to_le32(y); |
148 | out[1] = cpu_to_le32(z); |
149 | } |
150 | |
151 | static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
152 | { |
153 | u32 y, z, sum; |
154 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
155 | const __le32 *in = (const __le32 *)src; |
156 | __le32 *out = (__le32 *)dst; |
157 | |
158 | y = le32_to_cpu(in[0]); |
159 | z = le32_to_cpu(in[1]); |
160 | |
161 | sum = XTEA_DELTA * XTEA_ROUNDS; |
162 | |
163 | while (sum) { |
164 | z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]); |
165 | sum -= XTEA_DELTA; |
166 | y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]); |
167 | } |
168 | |
169 | out[0] = cpu_to_le32(y); |
170 | out[1] = cpu_to_le32(z); |
171 | } |
172 | |
173 | |
174 | static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
175 | { |
176 | u32 y, z, sum = 0; |
177 | u32 limit = XTEA_DELTA * XTEA_ROUNDS; |
178 | struct xtea_ctx *ctx = crypto_tfm_ctx(tfm); |
179 | const __le32 *in = (const __le32 *)src; |
180 | __le32 *out = (__le32 *)dst; |
181 | |
182 | y = le32_to_cpu(in[0]); |
183 | z = le32_to_cpu(in[1]); |
184 | |
185 | while (sum != limit) { |
186 | y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3]; |
187 | sum += XTEA_DELTA; |
188 | z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3]; |
189 | } |
190 | |
191 | out[0] = cpu_to_le32(y); |
192 | out[1] = cpu_to_le32(z); |
193 | } |
194 | |
195 | static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
196 | { |
197 | u32 y, z, sum; |
198 | struct tea_ctx *ctx = crypto_tfm_ctx(tfm); |
199 | const __le32 *in = (const __le32 *)src; |
200 | __le32 *out = (__le32 *)dst; |
201 | |
202 | y = le32_to_cpu(in[0]); |
203 | z = le32_to_cpu(in[1]); |
204 | |
205 | sum = XTEA_DELTA * XTEA_ROUNDS; |
206 | |
207 | while (sum) { |
208 | z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3]; |
209 | sum -= XTEA_DELTA; |
210 | y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3]; |
211 | } |
212 | |
213 | out[0] = cpu_to_le32(y); |
214 | out[1] = cpu_to_le32(z); |
215 | } |
216 | |
217 | static struct crypto_alg tea_algs[3] = { { |
218 | .cra_name = "tea" , |
219 | .cra_driver_name = "tea-generic" , |
220 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
221 | .cra_blocksize = TEA_BLOCK_SIZE, |
222 | .cra_ctxsize = sizeof (struct tea_ctx), |
223 | .cra_alignmask = 3, |
224 | .cra_module = THIS_MODULE, |
225 | .cra_u = { .cipher = { |
226 | .cia_min_keysize = TEA_KEY_SIZE, |
227 | .cia_max_keysize = TEA_KEY_SIZE, |
228 | .cia_setkey = tea_setkey, |
229 | .cia_encrypt = tea_encrypt, |
230 | .cia_decrypt = tea_decrypt } } |
231 | }, { |
232 | .cra_name = "xtea" , |
233 | .cra_driver_name = "xtea-generic" , |
234 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
235 | .cra_blocksize = XTEA_BLOCK_SIZE, |
236 | .cra_ctxsize = sizeof (struct xtea_ctx), |
237 | .cra_alignmask = 3, |
238 | .cra_module = THIS_MODULE, |
239 | .cra_u = { .cipher = { |
240 | .cia_min_keysize = XTEA_KEY_SIZE, |
241 | .cia_max_keysize = XTEA_KEY_SIZE, |
242 | .cia_setkey = xtea_setkey, |
243 | .cia_encrypt = xtea_encrypt, |
244 | .cia_decrypt = xtea_decrypt } } |
245 | }, { |
246 | .cra_name = "xeta" , |
247 | .cra_driver_name = "xeta-generic" , |
248 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
249 | .cra_blocksize = XTEA_BLOCK_SIZE, |
250 | .cra_ctxsize = sizeof (struct xtea_ctx), |
251 | .cra_alignmask = 3, |
252 | .cra_module = THIS_MODULE, |
253 | .cra_u = { .cipher = { |
254 | .cia_min_keysize = XTEA_KEY_SIZE, |
255 | .cia_max_keysize = XTEA_KEY_SIZE, |
256 | .cia_setkey = xtea_setkey, |
257 | .cia_encrypt = xeta_encrypt, |
258 | .cia_decrypt = xeta_decrypt } } |
259 | } }; |
260 | |
261 | static int __init tea_mod_init(void) |
262 | { |
263 | return crypto_register_algs(algs: tea_algs, ARRAY_SIZE(tea_algs)); |
264 | } |
265 | |
266 | static void __exit tea_mod_fini(void) |
267 | { |
268 | crypto_unregister_algs(algs: tea_algs, ARRAY_SIZE(tea_algs)); |
269 | } |
270 | |
271 | MODULE_ALIAS_CRYPTO("tea" ); |
272 | MODULE_ALIAS_CRYPTO("xtea" ); |
273 | MODULE_ALIAS_CRYPTO("xeta" ); |
274 | |
275 | subsys_initcall(tea_mod_init); |
276 | module_exit(tea_mod_fini); |
277 | |
278 | MODULE_LICENSE("GPL" ); |
279 | MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms" ); |
280 | |