Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/crypto/aes.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 11618 byte(s)
Tag kernel26-2.6.12-alx-r9
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 | * |
14 | * This program is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * --------------------------------------------------------------------------- |
20 | * Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK. |
21 | * All rights reserved. |
22 | * |
23 | * LICENSE TERMS |
24 | * |
25 | * The free distribution and use of this software in both source and binary |
26 | * form is allowed (with or without changes) provided that: |
27 | * |
28 | * 1. distributions of this source code include the above copyright |
29 | * notice, this list of conditions and the following disclaimer; |
30 | * |
31 | * 2. distributions in binary form include the above copyright |
32 | * notice, this list of conditions and the following disclaimer |
33 | * in the documentation and/or other associated materials; |
34 | * |
35 | * 3. the copyright holder's name is not used to endorse products |
36 | * built using this software without specific written permission. |
37 | * |
38 | * ALTERNATIVELY, provided that this notice is retained in full, this product |
39 | * may be distributed under the terms of the GNU General Public License (GPL), |
40 | * in which case the provisions of the GPL apply INSTEAD OF those given above. |
41 | * |
42 | * DISCLAIMER |
43 | * |
44 | * This software is provided 'as is' with no explicit or implied warranties |
45 | * in respect of its properties, including, but not limited to, correctness |
46 | * and/or fitness for purpose. |
47 | * --------------------------------------------------------------------------- |
48 | */ |
49 | |
50 | /* Some changes from the Gladman version: |
51 | s/RIJNDAEL(e_key)/E_KEY/g |
52 | s/RIJNDAEL(d_key)/D_KEY/g |
53 | */ |
54 | |
55 | #include <linux/module.h> |
56 | #include <linux/init.h> |
57 | #include <linux/types.h> |
58 | #include <linux/errno.h> |
59 | #include <linux/crypto.h> |
60 | #include <asm/byteorder.h> |
61 | |
62 | #define AES_MIN_KEY_SIZE 16 |
63 | #define AES_MAX_KEY_SIZE 32 |
64 | |
65 | #define AES_BLOCK_SIZE 16 |
66 | |
67 | /* |
68 | * #define byte(x, nr) ((unsigned char)((x) >> (nr*8))) |
69 | */ |
70 | inline static u8 |
71 | byte(const u32 x, const unsigned n) |
72 | { |
73 | return x >> (n << 3); |
74 | } |
75 | |
76 | #define u32_in(x) le32_to_cpu(*(const u32 *)(x)) |
77 | #define u32_out(to, from) (*(u32 *)(to) = cpu_to_le32(from)) |
78 | |
79 | struct aes_ctx { |
80 | int key_length; |
81 | u32 E[60]; |
82 | u32 D[60]; |
83 | }; |
84 | |
85 | #define E_KEY ctx->E |
86 | #define D_KEY ctx->D |
87 | |
88 | static u8 pow_tab[256] __initdata; |
89 | static u8 log_tab[256] __initdata; |
90 | static u8 sbx_tab[256] __initdata; |
91 | static u8 isb_tab[256] __initdata; |
92 | static u32 rco_tab[10]; |
93 | static u32 ft_tab[4][256]; |
94 | static u32 it_tab[4][256]; |
95 | |
96 | static u32 fl_tab[4][256]; |
97 | static u32 il_tab[4][256]; |
98 | |
99 | static inline u8 __init |
100 | f_mult (u8 a, u8 b) |
101 | { |
102 | u8 aa = log_tab[a], cc = aa + log_tab[b]; |
103 | |
104 | return pow_tab[cc + (cc < aa ? 1 : 0)]; |
105 | } |
106 | |
107 | #define ff_mult(a,b) (a && b ? f_mult(a, b) : 0) |
108 | |
109 | #define f_rn(bo, bi, n, k) \ |
110 | bo[n] = ft_tab[0][byte(bi[n],0)] ^ \ |
111 | ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ \ |
112 | ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
113 | ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n) |
114 | |
115 | #define i_rn(bo, bi, n, k) \ |
116 | bo[n] = it_tab[0][byte(bi[n],0)] ^ \ |
117 | it_tab[1][byte(bi[(n + 3) & 3],1)] ^ \ |
118 | it_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
119 | it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n) |
120 | |
121 | #define ls_box(x) \ |
122 | ( fl_tab[0][byte(x, 0)] ^ \ |
123 | fl_tab[1][byte(x, 1)] ^ \ |
124 | fl_tab[2][byte(x, 2)] ^ \ |
125 | fl_tab[3][byte(x, 3)] ) |
126 | |
127 | #define f_rl(bo, bi, n, k) \ |
128 | bo[n] = fl_tab[0][byte(bi[n],0)] ^ \ |
129 | fl_tab[1][byte(bi[(n + 1) & 3],1)] ^ \ |
130 | fl_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
131 | fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n) |
132 | |
133 | #define i_rl(bo, bi, n, k) \ |
134 | bo[n] = il_tab[0][byte(bi[n],0)] ^ \ |
135 | il_tab[1][byte(bi[(n + 3) & 3],1)] ^ \ |
136 | il_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
137 | il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n) |
138 | |
139 | static void __init |
140 | gen_tabs (void) |
141 | { |
142 | u32 i, t; |
143 | u8 p, q; |
144 | |
145 | /* log and power tables for GF(2**8) finite field with |
146 | 0x011b as modular polynomial - the simplest primitive |
147 | root is 0x03, used here to generate the tables */ |
148 | |
149 | for (i = 0, p = 1; i < 256; ++i) { |
150 | pow_tab[i] = (u8) p; |
151 | log_tab[p] = (u8) i; |
152 | |
153 | p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0); |
154 | } |
155 | |
156 | log_tab[1] = 0; |
157 | |
158 | for (i = 0, p = 1; i < 10; ++i) { |
159 | rco_tab[i] = p; |
160 | |
161 | p = (p << 1) ^ (p & 0x80 ? 0x01b : 0); |
162 | } |
163 | |
164 | for (i = 0; i < 256; ++i) { |
165 | p = (i ? pow_tab[255 - log_tab[i]] : 0); |
166 | q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2)); |
167 | p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2)); |
168 | sbx_tab[i] = p; |
169 | isb_tab[p] = (u8) i; |
170 | } |
171 | |
172 | for (i = 0; i < 256; ++i) { |
173 | p = sbx_tab[i]; |
174 | |
175 | t = p; |
176 | fl_tab[0][i] = t; |
177 | fl_tab[1][i] = rol32(t, 8); |
178 | fl_tab[2][i] = rol32(t, 16); |
179 | fl_tab[3][i] = rol32(t, 24); |
180 | |
181 | t = ((u32) ff_mult (2, p)) | |
182 | ((u32) p << 8) | |
183 | ((u32) p << 16) | ((u32) ff_mult (3, p) << 24); |
184 | |
185 | ft_tab[0][i] = t; |
186 | ft_tab[1][i] = rol32(t, 8); |
187 | ft_tab[2][i] = rol32(t, 16); |
188 | ft_tab[3][i] = rol32(t, 24); |
189 | |
190 | p = isb_tab[i]; |
191 | |
192 | t = p; |
193 | il_tab[0][i] = t; |
194 | il_tab[1][i] = rol32(t, 8); |
195 | il_tab[2][i] = rol32(t, 16); |
196 | il_tab[3][i] = rol32(t, 24); |
197 | |
198 | t = ((u32) ff_mult (14, p)) | |
199 | ((u32) ff_mult (9, p) << 8) | |
200 | ((u32) ff_mult (13, p) << 16) | |
201 | ((u32) ff_mult (11, p) << 24); |
202 | |
203 | it_tab[0][i] = t; |
204 | it_tab[1][i] = rol32(t, 8); |
205 | it_tab[2][i] = rol32(t, 16); |
206 | it_tab[3][i] = rol32(t, 24); |
207 | } |
208 | } |
209 | |
210 | #define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b) |
211 | |
212 | #define imix_col(y,x) \ |
213 | u = star_x(x); \ |
214 | v = star_x(u); \ |
215 | w = star_x(v); \ |
216 | t = w ^ (x); \ |
217 | (y) = u ^ v ^ w; \ |
218 | (y) ^= ror32(u ^ t, 8) ^ \ |
219 | ror32(v ^ t, 16) ^ \ |
220 | ror32(t,24) |
221 | |
222 | /* initialise the key schedule from the user supplied key */ |
223 | |
224 | #define loop4(i) \ |
225 | { t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \ |
226 | t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \ |
227 | t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \ |
228 | t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \ |
229 | t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \ |
230 | } |
231 | |
232 | #define loop6(i) \ |
233 | { t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \ |
234 | t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \ |
235 | t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \ |
236 | t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \ |
237 | t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \ |
238 | t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \ |
239 | t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \ |
240 | } |
241 | |
242 | #define loop8(i) \ |
243 | { t = ror32(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \ |
244 | t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \ |
245 | t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \ |
246 | t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \ |
247 | t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \ |
248 | t = E_KEY[8 * i + 4] ^ ls_box(t); \ |
249 | E_KEY[8 * i + 12] = t; \ |
250 | t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \ |
251 | t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \ |
252 | t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \ |
253 | } |
254 | |
255 | static int |
256 | aes_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) |
257 | { |
258 | struct aes_ctx *ctx = ctx_arg; |
259 | u32 i, t, u, v, w; |
260 | |
261 | if (key_len != 16 && key_len != 24 && key_len != 32) { |
262 | *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; |
263 | return -EINVAL; |
264 | } |
265 | |
266 | ctx->key_length = key_len; |
267 | |
268 | E_KEY[0] = u32_in (in_key); |
269 | E_KEY[1] = u32_in (in_key + 4); |
270 | E_KEY[2] = u32_in (in_key + 8); |
271 | E_KEY[3] = u32_in (in_key + 12); |
272 | |
273 | switch (key_len) { |
274 | case 16: |
275 | t = E_KEY[3]; |
276 | for (i = 0; i < 10; ++i) |
277 | loop4 (i); |
278 | break; |
279 | |
280 | case 24: |
281 | E_KEY[4] = u32_in (in_key + 16); |
282 | t = E_KEY[5] = u32_in (in_key + 20); |
283 | for (i = 0; i < 8; ++i) |
284 | loop6 (i); |
285 | break; |
286 | |
287 | case 32: |
288 | E_KEY[4] = u32_in (in_key + 16); |
289 | E_KEY[5] = u32_in (in_key + 20); |
290 | E_KEY[6] = u32_in (in_key + 24); |
291 | t = E_KEY[7] = u32_in (in_key + 28); |
292 | for (i = 0; i < 7; ++i) |
293 | loop8 (i); |
294 | break; |
295 | } |
296 | |
297 | D_KEY[0] = E_KEY[0]; |
298 | D_KEY[1] = E_KEY[1]; |
299 | D_KEY[2] = E_KEY[2]; |
300 | D_KEY[3] = E_KEY[3]; |
301 | |
302 | for (i = 4; i < key_len + 24; ++i) { |
303 | imix_col (D_KEY[i], E_KEY[i]); |
304 | } |
305 | |
306 | return 0; |
307 | } |
308 | |
309 | /* encrypt a block of text */ |
310 | |
311 | #define f_nround(bo, bi, k) \ |
312 | f_rn(bo, bi, 0, k); \ |
313 | f_rn(bo, bi, 1, k); \ |
314 | f_rn(bo, bi, 2, k); \ |
315 | f_rn(bo, bi, 3, k); \ |
316 | k += 4 |
317 | |
318 | #define f_lround(bo, bi, k) \ |
319 | f_rl(bo, bi, 0, k); \ |
320 | f_rl(bo, bi, 1, k); \ |
321 | f_rl(bo, bi, 2, k); \ |
322 | f_rl(bo, bi, 3, k) |
323 | |
324 | static void aes_encrypt(void *ctx_arg, u8 *out, const u8 *in) |
325 | { |
326 | const struct aes_ctx *ctx = ctx_arg; |
327 | u32 b0[4], b1[4]; |
328 | const u32 *kp = E_KEY + 4; |
329 | |
330 | b0[0] = u32_in (in) ^ E_KEY[0]; |
331 | b0[1] = u32_in (in + 4) ^ E_KEY[1]; |
332 | b0[2] = u32_in (in + 8) ^ E_KEY[2]; |
333 | b0[3] = u32_in (in + 12) ^ E_KEY[3]; |
334 | |
335 | if (ctx->key_length > 24) { |
336 | f_nround (b1, b0, kp); |
337 | f_nround (b0, b1, kp); |
338 | } |
339 | |
340 | if (ctx->key_length > 16) { |
341 | f_nround (b1, b0, kp); |
342 | f_nround (b0, b1, kp); |
343 | } |
344 | |
345 | f_nround (b1, b0, kp); |
346 | f_nround (b0, b1, kp); |
347 | f_nround (b1, b0, kp); |
348 | f_nround (b0, b1, kp); |
349 | f_nround (b1, b0, kp); |
350 | f_nround (b0, b1, kp); |
351 | f_nround (b1, b0, kp); |
352 | f_nround (b0, b1, kp); |
353 | f_nround (b1, b0, kp); |
354 | f_lround (b0, b1, kp); |
355 | |
356 | u32_out (out, b0[0]); |
357 | u32_out (out + 4, b0[1]); |
358 | u32_out (out + 8, b0[2]); |
359 | u32_out (out + 12, b0[3]); |
360 | } |
361 | |
362 | /* decrypt a block of text */ |
363 | |
364 | #define i_nround(bo, bi, k) \ |
365 | i_rn(bo, bi, 0, k); \ |
366 | i_rn(bo, bi, 1, k); \ |
367 | i_rn(bo, bi, 2, k); \ |
368 | i_rn(bo, bi, 3, k); \ |
369 | k -= 4 |
370 | |
371 | #define i_lround(bo, bi, k) \ |
372 | i_rl(bo, bi, 0, k); \ |
373 | i_rl(bo, bi, 1, k); \ |
374 | i_rl(bo, bi, 2, k); \ |
375 | i_rl(bo, bi, 3, k) |
376 | |
377 | static void aes_decrypt(void *ctx_arg, u8 *out, const u8 *in) |
378 | { |
379 | const struct aes_ctx *ctx = ctx_arg; |
380 | u32 b0[4], b1[4]; |
381 | const int key_len = ctx->key_length; |
382 | const u32 *kp = D_KEY + key_len + 20; |
383 | |
384 | b0[0] = u32_in (in) ^ E_KEY[key_len + 24]; |
385 | b0[1] = u32_in (in + 4) ^ E_KEY[key_len + 25]; |
386 | b0[2] = u32_in (in + 8) ^ E_KEY[key_len + 26]; |
387 | b0[3] = u32_in (in + 12) ^ E_KEY[key_len + 27]; |
388 | |
389 | if (key_len > 24) { |
390 | i_nround (b1, b0, kp); |
391 | i_nround (b0, b1, kp); |
392 | } |
393 | |
394 | if (key_len > 16) { |
395 | i_nround (b1, b0, kp); |
396 | i_nround (b0, b1, kp); |
397 | } |
398 | |
399 | i_nround (b1, b0, kp); |
400 | i_nround (b0, b1, kp); |
401 | i_nround (b1, b0, kp); |
402 | i_nround (b0, b1, kp); |
403 | i_nround (b1, b0, kp); |
404 | i_nround (b0, b1, kp); |
405 | i_nround (b1, b0, kp); |
406 | i_nround (b0, b1, kp); |
407 | i_nround (b1, b0, kp); |
408 | i_lround (b0, b1, kp); |
409 | |
410 | u32_out (out, b0[0]); |
411 | u32_out (out + 4, b0[1]); |
412 | u32_out (out + 8, b0[2]); |
413 | u32_out (out + 12, b0[3]); |
414 | } |
415 | |
416 | |
417 | static struct crypto_alg aes_alg = { |
418 | .cra_name = "aes", |
419 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
420 | .cra_blocksize = AES_BLOCK_SIZE, |
421 | .cra_ctxsize = sizeof(struct aes_ctx), |
422 | .cra_module = THIS_MODULE, |
423 | .cra_list = LIST_HEAD_INIT(aes_alg.cra_list), |
424 | .cra_u = { |
425 | .cipher = { |
426 | .cia_min_keysize = AES_MIN_KEY_SIZE, |
427 | .cia_max_keysize = AES_MAX_KEY_SIZE, |
428 | .cia_setkey = aes_set_key, |
429 | .cia_encrypt = aes_encrypt, |
430 | .cia_decrypt = aes_decrypt |
431 | } |
432 | } |
433 | }; |
434 | |
435 | static int __init aes_init(void) |
436 | { |
437 | gen_tabs(); |
438 | return crypto_register_alg(&aes_alg); |
439 | } |
440 | |
441 | static void __exit aes_fini(void) |
442 | { |
443 | crypto_unregister_alg(&aes_alg); |
444 | } |
445 | |
446 | module_init(aes_init); |
447 | module_exit(aes_fini); |
448 | |
449 | MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); |
450 | MODULE_LICENSE("Dual BSD/GPL"); |
451 |