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a2a892a2 AS |
1 | /* |
2 | * Cryptographic API. | |
3 | * | |
4 | * AES Cipher Algorithm. | |
5 | * | |
6 | * Based on Brian Gladman's code. | |
7 | * | |
8 | * Linux developers: | |
9 | * Alexander Kjeldaas <astor@fast.no> | |
10 | * Herbert Valerio Riedel <hvr@hvrlab.org> | |
11 | * Kyle McMartin <kyle@debian.org> | |
12 | * Adam J. Richter <adam@yggdrasil.com> (conversion to 2.5 API). | |
13 | * Andreas Steinmetz <ast@domdv.de> (adapted to x86_64 assembler) | |
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 | * Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK. | |
22 | * All rights reserved. | |
23 | * | |
24 | * LICENSE TERMS | |
25 | * | |
26 | * The free distribution and use of this software in both source and binary | |
27 | * form is allowed (with or without changes) provided that: | |
28 | * | |
29 | * 1. distributions of this source code include the above copyright | |
30 | * notice, this list of conditions and the following disclaimer; | |
31 | * | |
32 | * 2. distributions in binary form include the above copyright | |
33 | * notice, this list of conditions and the following disclaimer | |
34 | * in the documentation and/or other associated materials; | |
35 | * | |
36 | * 3. the copyright holder's name is not used to endorse products | |
37 | * built using this software without specific written permission. | |
38 | * | |
39 | * ALTERNATIVELY, provided that this notice is retained in full, this product | |
40 | * may be distributed under the terms of the GNU General Public License (GPL), | |
41 | * in which case the provisions of the GPL apply INSTEAD OF those given above. | |
42 | * | |
43 | * DISCLAIMER | |
44 | * | |
45 | * This software is provided 'as is' with no explicit or implied warranties | |
46 | * in respect of its properties, including, but not limited to, correctness | |
47 | * and/or fitness for purpose. | |
48 | * --------------------------------------------------------------------------- | |
49 | */ | |
50 | ||
51 | /* Some changes from the Gladman version: | |
52 | s/RIJNDAEL(e_key)/E_KEY/g | |
53 | s/RIJNDAEL(d_key)/D_KEY/g | |
54 | */ | |
55 | ||
56 | #include <asm/byteorder.h> | |
57 | #include <linux/bitops.h> | |
58 | #include <linux/crypto.h> | |
59 | #include <linux/errno.h> | |
60 | #include <linux/init.h> | |
61 | #include <linux/module.h> | |
62 | #include <linux/types.h> | |
63 | ||
64 | #define AES_MIN_KEY_SIZE 16 | |
65 | #define AES_MAX_KEY_SIZE 32 | |
66 | ||
67 | #define AES_BLOCK_SIZE 16 | |
68 | ||
69 | /* | |
70 | * #define byte(x, nr) ((unsigned char)((x) >> (nr*8))) | |
71 | */ | |
72 | static inline u8 byte(const u32 x, const unsigned n) | |
73 | { | |
74 | return x >> (n << 3); | |
75 | } | |
76 | ||
a2a892a2 AS |
77 | struct aes_ctx |
78 | { | |
79 | u32 key_length; | |
55e9dce3 | 80 | u32 buf[120]; |
a2a892a2 AS |
81 | }; |
82 | ||
55e9dce3 DM |
83 | #define E_KEY (&ctx->buf[0]) |
84 | #define D_KEY (&ctx->buf[60]) | |
a2a892a2 AS |
85 | |
86 | static u8 pow_tab[256] __initdata; | |
87 | static u8 log_tab[256] __initdata; | |
88 | static u8 sbx_tab[256] __initdata; | |
89 | static u8 isb_tab[256] __initdata; | |
90 | static u32 rco_tab[10]; | |
91 | u32 aes_ft_tab[4][256]; | |
92 | u32 aes_it_tab[4][256]; | |
93 | ||
94 | u32 aes_fl_tab[4][256]; | |
95 | u32 aes_il_tab[4][256]; | |
96 | ||
97 | static inline u8 f_mult(u8 a, u8 b) | |
98 | { | |
99 | u8 aa = log_tab[a], cc = aa + log_tab[b]; | |
100 | ||
101 | return pow_tab[cc + (cc < aa ? 1 : 0)]; | |
102 | } | |
103 | ||
104 | #define ff_mult(a, b) (a && b ? f_mult(a, b) : 0) | |
105 | ||
106 | #define ls_box(x) \ | |
107 | (aes_fl_tab[0][byte(x, 0)] ^ \ | |
108 | aes_fl_tab[1][byte(x, 1)] ^ \ | |
109 | aes_fl_tab[2][byte(x, 2)] ^ \ | |
110 | aes_fl_tab[3][byte(x, 3)]) | |
111 | ||
112 | static void __init gen_tabs(void) | |
113 | { | |
114 | u32 i, t; | |
115 | u8 p, q; | |
116 | ||
117 | /* log and power tables for GF(2**8) finite field with | |
118 | 0x011b as modular polynomial - the simplest primitive | |
119 | root is 0x03, used here to generate the tables */ | |
120 | ||
121 | for (i = 0, p = 1; i < 256; ++i) { | |
122 | pow_tab[i] = (u8)p; | |
123 | log_tab[p] = (u8)i; | |
124 | ||
125 | p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0); | |
126 | } | |
127 | ||
128 | log_tab[1] = 0; | |
129 | ||
130 | for (i = 0, p = 1; i < 10; ++i) { | |
131 | rco_tab[i] = p; | |
132 | ||
133 | p = (p << 1) ^ (p & 0x80 ? 0x01b : 0); | |
134 | } | |
135 | ||
136 | for (i = 0; i < 256; ++i) { | |
137 | p = (i ? pow_tab[255 - log_tab[i]] : 0); | |
138 | q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2)); | |
139 | p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2)); | |
140 | sbx_tab[i] = p; | |
141 | isb_tab[p] = (u8)i; | |
142 | } | |
143 | ||
144 | for (i = 0; i < 256; ++i) { | |
145 | p = sbx_tab[i]; | |
146 | ||
147 | t = p; | |
148 | aes_fl_tab[0][i] = t; | |
149 | aes_fl_tab[1][i] = rol32(t, 8); | |
150 | aes_fl_tab[2][i] = rol32(t, 16); | |
151 | aes_fl_tab[3][i] = rol32(t, 24); | |
152 | ||
153 | t = ((u32)ff_mult(2, p)) | | |
154 | ((u32)p << 8) | | |
155 | ((u32)p << 16) | ((u32)ff_mult(3, p) << 24); | |
156 | ||
157 | aes_ft_tab[0][i] = t; | |
158 | aes_ft_tab[1][i] = rol32(t, 8); | |
159 | aes_ft_tab[2][i] = rol32(t, 16); | |
160 | aes_ft_tab[3][i] = rol32(t, 24); | |
161 | ||
162 | p = isb_tab[i]; | |
163 | ||
164 | t = p; | |
165 | aes_il_tab[0][i] = t; | |
166 | aes_il_tab[1][i] = rol32(t, 8); | |
167 | aes_il_tab[2][i] = rol32(t, 16); | |
168 | aes_il_tab[3][i] = rol32(t, 24); | |
169 | ||
170 | t = ((u32)ff_mult(14, p)) | | |
171 | ((u32)ff_mult(9, p) << 8) | | |
172 | ((u32)ff_mult(13, p) << 16) | | |
173 | ((u32)ff_mult(11, p) << 24); | |
174 | ||
175 | aes_it_tab[0][i] = t; | |
176 | aes_it_tab[1][i] = rol32(t, 8); | |
177 | aes_it_tab[2][i] = rol32(t, 16); | |
178 | aes_it_tab[3][i] = rol32(t, 24); | |
179 | } | |
180 | } | |
181 | ||
182 | #define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b) | |
183 | ||
184 | #define imix_col(y, x) \ | |
185 | u = star_x(x); \ | |
186 | v = star_x(u); \ | |
187 | w = star_x(v); \ | |
188 | t = w ^ (x); \ | |
189 | (y) = u ^ v ^ w; \ | |
190 | (y) ^= ror32(u ^ t, 8) ^ \ | |
191 | ror32(v ^ t, 16) ^ \ | |
192 | ror32(t, 24) | |
193 | ||
194 | /* initialise the key schedule from the user supplied key */ | |
195 | ||
196 | #define loop4(i) \ | |
197 | { \ | |
198 | t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \ | |
199 | t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \ | |
200 | t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \ | |
201 | t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \ | |
202 | t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \ | |
203 | } | |
204 | ||
205 | #define loop6(i) \ | |
206 | { \ | |
207 | t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \ | |
208 | t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \ | |
209 | t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \ | |
210 | t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \ | |
211 | t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \ | |
212 | t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \ | |
213 | t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \ | |
214 | } | |
215 | ||
216 | #define loop8(i) \ | |
217 | { \ | |
218 | t = ror32(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \ | |
219 | t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \ | |
220 | t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \ | |
221 | t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \ | |
222 | t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \ | |
223 | t = E_KEY[8 * i + 4] ^ ls_box(t); \ | |
224 | E_KEY[8 * i + 12] = t; \ | |
225 | t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \ | |
226 | t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \ | |
227 | t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \ | |
228 | } | |
229 | ||
6c2bb98b HX |
230 | static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, |
231 | unsigned int key_len, u32 *flags) | |
a2a892a2 | 232 | { |
6c2bb98b | 233 | struct aes_ctx *ctx = crypto_tfm_ctx(tfm); |
06ace7a9 | 234 | const __le32 *key = (const __le32 *)in_key; |
a2a892a2 AS |
235 | u32 i, j, t, u, v, w; |
236 | ||
237 | if (key_len != 16 && key_len != 24 && key_len != 32) { | |
238 | *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; | |
239 | return -EINVAL; | |
240 | } | |
241 | ||
242 | ctx->key_length = key_len; | |
243 | ||
06ace7a9 HX |
244 | D_KEY[key_len + 24] = E_KEY[0] = le32_to_cpu(key[0]); |
245 | D_KEY[key_len + 25] = E_KEY[1] = le32_to_cpu(key[1]); | |
246 | D_KEY[key_len + 26] = E_KEY[2] = le32_to_cpu(key[2]); | |
247 | D_KEY[key_len + 27] = E_KEY[3] = le32_to_cpu(key[3]); | |
a2a892a2 AS |
248 | |
249 | switch (key_len) { | |
250 | case 16: | |
251 | t = E_KEY[3]; | |
252 | for (i = 0; i < 10; ++i) | |
253 | loop4(i); | |
254 | break; | |
255 | ||
256 | case 24: | |
06ace7a9 HX |
257 | E_KEY[4] = le32_to_cpu(key[4]); |
258 | t = E_KEY[5] = le32_to_cpu(key[5]); | |
a2a892a2 AS |
259 | for (i = 0; i < 8; ++i) |
260 | loop6 (i); | |
261 | break; | |
262 | ||
263 | case 32: | |
06ace7a9 HX |
264 | E_KEY[4] = le32_to_cpu(key[4]); |
265 | E_KEY[5] = le32_to_cpu(key[5]); | |
266 | E_KEY[6] = le32_to_cpu(key[6]); | |
267 | t = E_KEY[7] = le32_to_cpu(key[7]); | |
a2a892a2 AS |
268 | for (i = 0; i < 7; ++i) |
269 | loop8(i); | |
270 | break; | |
271 | } | |
272 | ||
273 | D_KEY[0] = E_KEY[key_len + 24]; | |
274 | D_KEY[1] = E_KEY[key_len + 25]; | |
275 | D_KEY[2] = E_KEY[key_len + 26]; | |
276 | D_KEY[3] = E_KEY[key_len + 27]; | |
277 | ||
278 | for (i = 4; i < key_len + 24; ++i) { | |
279 | j = key_len + 24 - (i & ~3) + (i & 3); | |
280 | imix_col(D_KEY[j], E_KEY[i]); | |
281 | } | |
282 | ||
283 | return 0; | |
284 | } | |
285 | ||
e90b1a2b HX |
286 | asmlinkage void aes_enc_blk(struct crypto_tfm *tfm, u8 *out, const u8 *in); |
287 | asmlinkage void aes_dec_blk(struct crypto_tfm *tfm, u8 *out, const u8 *in); | |
288 | ||
289 | static void aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) | |
290 | { | |
291 | aes_enc_blk(tfm, dst, src); | |
292 | } | |
293 | ||
294 | static void aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) | |
295 | { | |
296 | aes_dec_blk(tfm, dst, src); | |
297 | } | |
a2a892a2 AS |
298 | |
299 | static struct crypto_alg aes_alg = { | |
300 | .cra_name = "aes", | |
c8a19c91 HX |
301 | .cra_driver_name = "aes-x86_64", |
302 | .cra_priority = 200, | |
a2a892a2 AS |
303 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
304 | .cra_blocksize = AES_BLOCK_SIZE, | |
305 | .cra_ctxsize = sizeof(struct aes_ctx), | |
306 | .cra_module = THIS_MODULE, | |
307 | .cra_list = LIST_HEAD_INIT(aes_alg.cra_list), | |
308 | .cra_u = { | |
309 | .cipher = { | |
310 | .cia_min_keysize = AES_MIN_KEY_SIZE, | |
311 | .cia_max_keysize = AES_MAX_KEY_SIZE, | |
312 | .cia_setkey = aes_set_key, | |
313 | .cia_encrypt = aes_encrypt, | |
314 | .cia_decrypt = aes_decrypt | |
315 | } | |
316 | } | |
317 | }; | |
318 | ||
319 | static int __init aes_init(void) | |
320 | { | |
321 | gen_tabs(); | |
322 | return crypto_register_alg(&aes_alg); | |
323 | } | |
324 | ||
325 | static void __exit aes_fini(void) | |
326 | { | |
327 | crypto_unregister_alg(&aes_alg); | |
328 | } | |
329 | ||
330 | module_init(aes_init); | |
331 | module_exit(aes_fini); | |
332 | ||
333 | MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); | |
334 | MODULE_LICENSE("GPL"); | |
03c6b749 | 335 | MODULE_ALIAS("aes"); |