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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Sebastian Siewior89e12652007-10-17 23:18:57 +080050#include <crypto/aes.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <linux/module.h>
52#include <linux/init.h>
53#include <linux/types.h>
54#include <linux/errno.h>
55#include <linux/crypto.h>
56#include <asm/byteorder.h>
57
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +080058static inline u8 byte(const u32 x, const unsigned n)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
60 return x >> (n << 3);
61}
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063static u8 pow_tab[256] __initdata;
64static u8 log_tab[256] __initdata;
65static u8 sbx_tab[256] __initdata;
66static u8 isb_tab[256] __initdata;
67static u32 rco_tab[10];
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Sebastian Siewior96e82e42007-11-08 21:20:30 +080069u32 crypto_ft_tab[4][256];
70u32 crypto_fl_tab[4][256];
71u32 crypto_it_tab[4][256];
72u32 crypto_il_tab[4][256];
73
74EXPORT_SYMBOL_GPL(crypto_ft_tab);
75EXPORT_SYMBOL_GPL(crypto_fl_tab);
76EXPORT_SYMBOL_GPL(crypto_it_tab);
77EXPORT_SYMBOL_GPL(crypto_il_tab);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +080079static inline u8 __init f_mult(u8 a, u8 b)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
81 u8 aa = log_tab[a], cc = aa + log_tab[b];
82
83 return pow_tab[cc + (cc < aa ? 1 : 0)];
84}
85
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +080086#define ff_mult(a, b) (a && b ? f_mult(a, b) : 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +080088static void __init gen_tabs(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
90 u32 i, t;
91 u8 p, q;
92
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +080093 /*
94 * log and power tables for GF(2**8) finite field with
95 * 0x011b as modular polynomial - the simplest primitive
96 * root is 0x03, used here to generate the tables
97 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 for (i = 0, p = 1; i < 256; ++i) {
100 pow_tab[i] = (u8) p;
101 log_tab[p] = (u8) i;
102
103 p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0);
104 }
105
106 log_tab[1] = 0;
107
108 for (i = 0, p = 1; i < 10; ++i) {
109 rco_tab[i] = p;
110
111 p = (p << 1) ^ (p & 0x80 ? 0x01b : 0);
112 }
113
114 for (i = 0; i < 256; ++i) {
115 p = (i ? pow_tab[255 - log_tab[i]] : 0);
116 q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2));
117 p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2));
118 sbx_tab[i] = p;
119 isb_tab[p] = (u8) i;
120 }
121
122 for (i = 0; i < 256; ++i) {
123 p = sbx_tab[i];
124
125 t = p;
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800126 crypto_fl_tab[0][i] = t;
127 crypto_fl_tab[1][i] = rol32(t, 8);
128 crypto_fl_tab[2][i] = rol32(t, 16);
129 crypto_fl_tab[3][i] = rol32(t, 24);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800131 t = ((u32) ff_mult(2, p)) |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 ((u32) p << 8) |
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800133 ((u32) p << 16) | ((u32) ff_mult(3, p) << 24);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800135 crypto_ft_tab[0][i] = t;
136 crypto_ft_tab[1][i] = rol32(t, 8);
137 crypto_ft_tab[2][i] = rol32(t, 16);
138 crypto_ft_tab[3][i] = rol32(t, 24);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140 p = isb_tab[i];
141
142 t = p;
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800143 crypto_il_tab[0][i] = t;
144 crypto_il_tab[1][i] = rol32(t, 8);
145 crypto_il_tab[2][i] = rol32(t, 16);
146 crypto_il_tab[3][i] = rol32(t, 24);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800148 t = ((u32) ff_mult(14, p)) |
149 ((u32) ff_mult(9, p) << 8) |
150 ((u32) ff_mult(13, p) << 16) |
151 ((u32) ff_mult(11, p) << 24);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800153 crypto_it_tab[0][i] = t;
154 crypto_it_tab[1][i] = rol32(t, 8);
155 crypto_it_tab[2][i] = rol32(t, 16);
156 crypto_it_tab[3][i] = rol32(t, 24);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 }
158}
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160/* initialise the key schedule from the user supplied key */
161
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800162#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800164#define imix_col(y,x) do { \
165 u = star_x(x); \
166 v = star_x(u); \
167 w = star_x(v); \
168 t = w ^ (x); \
169 (y) = u ^ v ^ w; \
170 (y) ^= ror32(u ^ t, 8) ^ \
171 ror32(v ^ t, 16) ^ \
172 ror32(t, 24); \
173} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800175#define ls_box(x) \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800176 crypto_fl_tab[0][byte(x, 0)] ^ \
177 crypto_fl_tab[1][byte(x, 1)] ^ \
178 crypto_fl_tab[2][byte(x, 2)] ^ \
179 crypto_fl_tab[3][byte(x, 3)]
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800180
181#define loop4(i) do { \
182 t = ror32(t, 8); \
183 t = ls_box(t) ^ rco_tab[i]; \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800184 t ^= ctx->key_enc[4 * i]; \
185 ctx->key_enc[4 * i + 4] = t; \
186 t ^= ctx->key_enc[4 * i + 1]; \
187 ctx->key_enc[4 * i + 5] = t; \
188 t ^= ctx->key_enc[4 * i + 2]; \
189 ctx->key_enc[4 * i + 6] = t; \
190 t ^= ctx->key_enc[4 * i + 3]; \
191 ctx->key_enc[4 * i + 7] = t; \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800192} while (0)
193
194#define loop6(i) do { \
195 t = ror32(t, 8); \
196 t = ls_box(t) ^ rco_tab[i]; \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800197 t ^= ctx->key_enc[6 * i]; \
198 ctx->key_enc[6 * i + 6] = t; \
199 t ^= ctx->key_enc[6 * i + 1]; \
200 ctx->key_enc[6 * i + 7] = t; \
201 t ^= ctx->key_enc[6 * i + 2]; \
202 ctx->key_enc[6 * i + 8] = t; \
203 t ^= ctx->key_enc[6 * i + 3]; \
204 ctx->key_enc[6 * i + 9] = t; \
205 t ^= ctx->key_enc[6 * i + 4]; \
206 ctx->key_enc[6 * i + 10] = t; \
207 t ^= ctx->key_enc[6 * i + 5]; \
208 ctx->key_enc[6 * i + 11] = t; \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800209} while (0)
210
211#define loop8(i) do { \
212 t = ror32(t, 8); \
213 t = ls_box(t) ^ rco_tab[i]; \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800214 t ^= ctx->key_enc[8 * i]; \
215 ctx->key_enc[8 * i + 8] = t; \
216 t ^= ctx->key_enc[8 * i + 1]; \
217 ctx->key_enc[8 * i + 9] = t; \
218 t ^= ctx->key_enc[8 * i + 2]; \
219 ctx->key_enc[8 * i + 10] = t; \
220 t ^= ctx->key_enc[8 * i + 3]; \
221 ctx->key_enc[8 * i + 11] = t; \
222 t = ctx->key_enc[8 * i + 4] ^ ls_box(t); \
223 ctx->key_enc[8 * i + 12] = t; \
224 t ^= ctx->key_enc[8 * i + 5]; \
225 ctx->key_enc[8 * i + 13] = t; \
226 t ^= ctx->key_enc[8 * i + 6]; \
227 ctx->key_enc[8 * i + 14] = t; \
228 t ^= ctx->key_enc[8 * i + 7]; \
229 ctx->key_enc[8 * i + 15] = t; \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800230} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
Sebastian Siewior54276632008-04-01 20:58:51 +0800232/**
233 * crypto_aes_expand_key - Expands the AES key as described in FIPS-197
234 * @ctx: The location where the computed key will be stored.
235 * @in_key: The supplied key.
236 * @key_len: The length of the supplied key.
237 *
238 * Returns 0 on success. The function fails only if an invalid key size (or
239 * pointer) is supplied.
240 * The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes
241 * key schedule plus a 16 bytes key which is used before the first round).
242 * The decryption key is prepared for the "Equivalent Inverse Cipher" as
243 * described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is
244 * for the initial combination, the second slot for the first round and so on.
245 */
246int crypto_aes_expand_key(struct crypto_aes_ctx *ctx, const u8 *in_key,
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800247 unsigned int key_len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248{
Herbert Xu06ace7a2005-10-30 21:25:15 +1100249 const __le32 *key = (const __le32 *)in_key;
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800250 u32 i, t, u, v, w, j;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
Sebastian Siewior54276632008-04-01 20:58:51 +0800252 if (key_len != AES_KEYSIZE_128 && key_len != AES_KEYSIZE_192 &&
253 key_len != AES_KEYSIZE_256)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 ctx->key_length = key_len;
257
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800258 ctx->key_dec[key_len + 24] = ctx->key_enc[0] = le32_to_cpu(key[0]);
259 ctx->key_dec[key_len + 25] = ctx->key_enc[1] = le32_to_cpu(key[1]);
260 ctx->key_dec[key_len + 26] = ctx->key_enc[2] = le32_to_cpu(key[2]);
261 ctx->key_dec[key_len + 27] = ctx->key_enc[3] = le32_to_cpu(key[3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 switch (key_len) {
Sebastian Siewior54276632008-04-01 20:58:51 +0800264 case AES_KEYSIZE_128:
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800265 t = ctx->key_enc[3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 for (i = 0; i < 10; ++i)
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800267 loop4(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 break;
269
Sebastian Siewior54276632008-04-01 20:58:51 +0800270 case AES_KEYSIZE_192:
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800271 ctx->key_enc[4] = le32_to_cpu(key[4]);
272 t = ctx->key_enc[5] = le32_to_cpu(key[5]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 for (i = 0; i < 8; ++i)
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800274 loop6(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 break;
276
Sebastian Siewior54276632008-04-01 20:58:51 +0800277 case AES_KEYSIZE_256:
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800278 ctx->key_enc[4] = le32_to_cpu(key[4]);
279 ctx->key_enc[5] = le32_to_cpu(key[5]);
280 ctx->key_enc[6] = le32_to_cpu(key[6]);
281 t = ctx->key_enc[7] = le32_to_cpu(key[7]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 for (i = 0; i < 7; ++i)
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800283 loop8(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 break;
285 }
286
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800287 ctx->key_dec[0] = ctx->key_enc[key_len + 24];
288 ctx->key_dec[1] = ctx->key_enc[key_len + 25];
289 ctx->key_dec[2] = ctx->key_enc[key_len + 26];
290 ctx->key_dec[3] = ctx->key_enc[key_len + 27];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292 for (i = 4; i < key_len + 24; ++i) {
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800293 j = key_len + 24 - (i & ~3) + (i & 3);
294 imix_col(ctx->key_dec[j], ctx->key_enc[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 return 0;
297}
Sebastian Siewior54276632008-04-01 20:58:51 +0800298EXPORT_SYMBOL_GPL(crypto_aes_expand_key);
299
300/**
301 * crypto_aes_set_key - Set the AES key.
302 * @tfm: The %crypto_tfm that is used in the context.
303 * @in_key: The input key.
304 * @key_len: The size of the key.
305 *
306 * Returns 0 on success, on failure the %CRYPTO_TFM_RES_BAD_KEY_LEN flag in tfm
307 * is set. The function uses crypto_aes_expand_key() to expand the key.
308 * &crypto_aes_ctx _must_ be the private data embedded in @tfm which is
309 * retrieved with crypto_tfm_ctx().
310 */
311int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
312 unsigned int key_len)
313{
314 struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
315 u32 *flags = &tfm->crt_flags;
316 int ret;
317
318 ret = crypto_aes_expand_key(ctx, in_key, key_len);
319 if (!ret)
320 return 0;
321
322 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
323 return -EINVAL;
324}
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800325EXPORT_SYMBOL_GPL(crypto_aes_set_key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326
327/* encrypt a block of text */
328
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800329#define f_rn(bo, bi, n, k) do { \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800330 bo[n] = crypto_ft_tab[0][byte(bi[n], 0)] ^ \
331 crypto_ft_tab[1][byte(bi[(n + 1) & 3], 1)] ^ \
332 crypto_ft_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
333 crypto_ft_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n); \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800334} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800336#define f_nround(bo, bi, k) do {\
337 f_rn(bo, bi, 0, k); \
338 f_rn(bo, bi, 1, k); \
339 f_rn(bo, bi, 2, k); \
340 f_rn(bo, bi, 3, k); \
341 k += 4; \
342} while (0)
343
344#define f_rl(bo, bi, n, k) do { \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800345 bo[n] = crypto_fl_tab[0][byte(bi[n], 0)] ^ \
346 crypto_fl_tab[1][byte(bi[(n + 1) & 3], 1)] ^ \
347 crypto_fl_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
348 crypto_fl_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n); \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800349} while (0)
350
351#define f_lround(bo, bi, k) do {\
352 f_rl(bo, bi, 0, k); \
353 f_rl(bo, bi, 1, k); \
354 f_rl(bo, bi, 2, k); \
355 f_rl(bo, bi, 3, k); \
356} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
Herbert Xu6c2bb982006-05-16 22:09:29 +1000358static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359{
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800360 const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +1100361 const __le32 *src = (const __le32 *)in;
362 __le32 *dst = (__le32 *)out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 u32 b0[4], b1[4];
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800364 const u32 *kp = ctx->key_enc + 4;
365 const int key_len = ctx->key_length;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800367 b0[0] = le32_to_cpu(src[0]) ^ ctx->key_enc[0];
368 b0[1] = le32_to_cpu(src[1]) ^ ctx->key_enc[1];
369 b0[2] = le32_to_cpu(src[2]) ^ ctx->key_enc[2];
370 b0[3] = le32_to_cpu(src[3]) ^ ctx->key_enc[3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800372 if (key_len > 24) {
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800373 f_nround(b1, b0, kp);
374 f_nround(b0, b1, kp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 }
376
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800377 if (key_len > 16) {
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800378 f_nround(b1, b0, kp);
379 f_nround(b0, b1, kp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 }
381
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800382 f_nround(b1, b0, kp);
383 f_nround(b0, b1, kp);
384 f_nround(b1, b0, kp);
385 f_nround(b0, b1, kp);
386 f_nround(b1, b0, kp);
387 f_nround(b0, b1, kp);
388 f_nround(b1, b0, kp);
389 f_nround(b0, b1, kp);
390 f_nround(b1, b0, kp);
391 f_lround(b0, b1, kp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
Herbert Xu06ace7a2005-10-30 21:25:15 +1100393 dst[0] = cpu_to_le32(b0[0]);
394 dst[1] = cpu_to_le32(b0[1]);
395 dst[2] = cpu_to_le32(b0[2]);
396 dst[3] = cpu_to_le32(b0[3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397}
398
399/* decrypt a block of text */
400
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800401#define i_rn(bo, bi, n, k) do { \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800402 bo[n] = crypto_it_tab[0][byte(bi[n], 0)] ^ \
403 crypto_it_tab[1][byte(bi[(n + 3) & 3], 1)] ^ \
404 crypto_it_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
405 crypto_it_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n); \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800406} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800408#define i_nround(bo, bi, k) do {\
409 i_rn(bo, bi, 0, k); \
410 i_rn(bo, bi, 1, k); \
411 i_rn(bo, bi, 2, k); \
412 i_rn(bo, bi, 3, k); \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800413 k += 4; \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800414} while (0)
415
416#define i_rl(bo, bi, n, k) do { \
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800417 bo[n] = crypto_il_tab[0][byte(bi[n], 0)] ^ \
418 crypto_il_tab[1][byte(bi[(n + 3) & 3], 1)] ^ \
419 crypto_il_tab[2][byte(bi[(n + 2) & 3], 2)] ^ \
420 crypto_il_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n); \
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800421} while (0)
422
423#define i_lround(bo, bi, k) do {\
424 i_rl(bo, bi, 0, k); \
425 i_rl(bo, bi, 1, k); \
426 i_rl(bo, bi, 2, k); \
427 i_rl(bo, bi, 3, k); \
428} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
Herbert Xu6c2bb982006-05-16 22:09:29 +1000430static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431{
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800432 const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
Herbert Xu06ace7a2005-10-30 21:25:15 +1100433 const __le32 *src = (const __le32 *)in;
434 __le32 *dst = (__le32 *)out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 u32 b0[4], b1[4];
436 const int key_len = ctx->key_length;
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800437 const u32 *kp = ctx->key_dec + 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800439 b0[0] = le32_to_cpu(src[0]) ^ ctx->key_dec[0];
440 b0[1] = le32_to_cpu(src[1]) ^ ctx->key_dec[1];
441 b0[2] = le32_to_cpu(src[2]) ^ ctx->key_dec[2];
442 b0[3] = le32_to_cpu(src[3]) ^ ctx->key_dec[3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443
444 if (key_len > 24) {
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800445 i_nround(b1, b0, kp);
446 i_nround(b0, b1, kp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 }
448
449 if (key_len > 16) {
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800450 i_nround(b1, b0, kp);
451 i_nround(b0, b1, kp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 }
453
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800454 i_nround(b1, b0, kp);
455 i_nround(b0, b1, kp);
456 i_nround(b1, b0, kp);
457 i_nround(b0, b1, kp);
458 i_nround(b1, b0, kp);
459 i_nround(b0, b1, kp);
460 i_nround(b1, b0, kp);
461 i_nround(b0, b1, kp);
462 i_nround(b1, b0, kp);
463 i_lround(b0, b1, kp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464
Herbert Xu06ace7a2005-10-30 21:25:15 +1100465 dst[0] = cpu_to_le32(b0[0]);
466 dst[1] = cpu_to_le32(b0[1]);
467 dst[2] = cpu_to_le32(b0[2]);
468 dst[3] = cpu_to_le32(b0[3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469}
470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471static struct crypto_alg aes_alg = {
472 .cra_name = "aes",
Herbert Xuc8a19c92005-11-05 18:06:26 +1100473 .cra_driver_name = "aes-generic",
474 .cra_priority = 100,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
476 .cra_blocksize = AES_BLOCK_SIZE,
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800477 .cra_ctxsize = sizeof(struct crypto_aes_ctx),
Herbert Xua429d262006-01-07 16:38:15 +1100478 .cra_alignmask = 3,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 .cra_module = THIS_MODULE,
480 .cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
481 .cra_u = {
482 .cipher = {
483 .cia_min_keysize = AES_MIN_KEY_SIZE,
484 .cia_max_keysize = AES_MAX_KEY_SIZE,
Sebastian Siewior96e82e42007-11-08 21:20:30 +0800485 .cia_setkey = crypto_aes_set_key,
Sebastian Siewiorbe5fb272007-11-08 20:39:26 +0800486 .cia_encrypt = aes_encrypt,
487 .cia_decrypt = aes_decrypt
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 }
489 }
490};
491
492static int __init aes_init(void)
493{
494 gen_tabs();
495 return crypto_register_alg(&aes_alg);
496}
497
498static void __exit aes_fini(void)
499{
500 crypto_unregister_alg(&aes_alg);
501}
502
503module_init(aes_init);
504module_exit(aes_fini);
505
506MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
507MODULE_LICENSE("Dual BSD/GPL");
Sebastian Siewiorf8246af2007-10-05 16:52:01 +0800508MODULE_ALIAS("aes");