1 // SPDX-License-Identifier: GPL-2.0-or-later 1
2 /*
3 * Cryptographic API.
4 *
5 * TEA, XTEA, and XETA crypto alogrithms
6 *
7 * The TEA and Xtended TEA algorithms were dev
8 * and Roger Needham at the Computer Laborator
9 *
10 * Due to the order of evaluation in XTEA many
11 * implemented it. XETA (XTEA in the wrong or
12 * compatibility with these implementations.
13 *
14 * Copyright (c) 2004 Aaron Grothe ajgrothe@ya
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,
43 unsigned int key_len)
44 {
45 struct tea_ctx *ctx = crypto_tfm_ctx(t
46 const __le32 *key = (const __le32 *)in
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
58 {
59 u32 y, z, n, sum = 0;
60 u32 k0, k1, k2, k3;
61 struct tea_ctx *ctx = crypto_tfm_ctx(t
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 + su
78 z += ((y << 4) + k2) ^ (y + su
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
86 {
87 u32 y, z, n, sum;
88 u32 k0, k1, k2, k3;
89 struct tea_ctx *ctx = crypto_tfm_ctx(t
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 + su
107 y -= ((z << 4) + k0) ^ (z + su
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,
116 unsigned int key_len)
117 {
118 struct xtea_ctx *ctx = crypto_tfm_ctx(
119 const __le32 *key = (const __le32 *)in
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 *tf
131 {
132 u32 y, z, sum = 0;
133 u32 limit = XTEA_DELTA * XTEA_ROUNDS;
134 struct xtea_ctx *ctx = crypto_tfm_ctx(
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) ^
143 sum += XTEA_DELTA;
144 z += ((y << 4 ^ y >> 5) + y) ^
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 *tf
152 {
153 u32 y, z, sum;
154 struct tea_ctx *ctx = crypto_tfm_ctx(t
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) ^
165 sum -= XTEA_DELTA;
166 y -= ((z << 4 ^ z >> 5) + z) ^
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 *tf
175 {
176 u32 y, z, sum = 0;
177 u32 limit = XTEA_DELTA * XTEA_ROUNDS;
178 struct xtea_ctx *ctx = crypto_tfm_ctx(
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 ^
187 sum += XTEA_DELTA;
188 z += (y << 4 ^ y >> 5) + (y ^
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 *tf
196 {
197 u32 y, z, sum;
198 struct tea_ctx *ctx = crypto_tfm_ctx(t
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 ^
209 sum -= XTEA_DELTA;
210 y -= (z << 4 ^ z >> 5) + (z ^
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-g
220 .cra_flags = CRYPTO
221 .cra_blocksize = TEA_BL
222 .cra_ctxsize = sizeof
223 .cra_alignmask = 3,
224 .cra_module = THIS_M
225 .cra_u = { .cip
226 .cia_min_keysize = TEA_KE
227 .cia_max_keysize = TEA_KE
228 .cia_setkey = tea_se
229 .cia_encrypt = tea_en
230 .cia_decrypt = tea_de
231 }, {
232 .cra_name = "xtea"
233 .cra_driver_name = "xtea-
234 .cra_flags = CRYPTO
235 .cra_blocksize = XTEA_B
236 .cra_ctxsize = sizeof
237 .cra_alignmask = 3,
238 .cra_module = THIS_M
239 .cra_u = { .cip
240 .cia_min_keysize = XTEA_K
241 .cia_max_keysize = XTEA_K
242 .cia_setkey = xtea_s
243 .cia_encrypt = xtea_e
244 .cia_decrypt = xtea_d
245 }, {
246 .cra_name = "xeta"
247 .cra_driver_name = "xeta-
248 .cra_flags = CRYPTO
249 .cra_blocksize = XTEA_B
250 .cra_ctxsize = sizeof
251 .cra_alignmask = 3,
252 .cra_module = THIS_M
253 .cra_u = { .cip
254 .cia_min_keysize = XTEA_K
255 .cia_max_keysize = XTEA_K
256 .cia_setkey = xtea_s
257 .cia_encrypt = xeta_e
258 .cia_decrypt = xeta_d
259 } };
260
261 static int __init tea_mod_init(void)
262 {
263 return crypto_register_algs(tea_algs,
264 }
265
266 static void __exit tea_mod_fini(void)
267 {
268 crypto_unregister_algs(tea_algs, ARRAY
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 Cryptogra
280
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