4 * AES Cipher Algorithm.
6 * Based on Brian Gladman's code.
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).
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.
19 * ---------------------------------------------------------------------------
20 * Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
21 * All rights reserved.
25 * The free distribution and use of this software in both source and binary
26 * form is allowed (with or without changes) provided that:
28 * 1. distributions of this source code include the above copyright
29 * notice, this list of conditions and the following disclaimer;
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;
35 * 3. the copyright holder's name is not used to endorse products
36 * built using this software without specific written permission.
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.
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 * ---------------------------------------------------------------------------
50 /* Some changes from the Gladman version:
51 s/RIJNDAEL(e_key)/E_KEY/g
52 s/RIJNDAEL(d_key)/D_KEY/g
55 #include <crypto/aes.h>
56 #include <linux/module.h>
57 #include <linux/init.h>
58 #include <linux/types.h>
59 #include <linux/errno.h>
60 #include <linux/crypto.h>
61 #include <asm/byteorder.h>
64 * #define byte(x, nr) ((unsigned char)((x) >> (nr*8)))
67 byte(const u32 x, const unsigned n)
77 #define E_KEY (&ctx->buf[0])
78 #define D_KEY (&ctx->buf[60])
80 static u8 pow_tab[256] __initdata;
81 static u8 log_tab[256] __initdata;
82 static u8 sbx_tab[256] __initdata;
83 static u8 isb_tab[256] __initdata;
84 static u32 rco_tab[10];
85 static u32 ft_tab[4][256];
86 static u32 it_tab[4][256];
88 static u32 fl_tab[4][256];
89 static u32 il_tab[4][256];
91 static inline u8 __init
94 u8 aa = log_tab[a], cc = aa + log_tab[b];
96 return pow_tab[cc + (cc < aa ? 1 : 0)];
99 #define ff_mult(a,b) (a && b ? f_mult(a, b) : 0)
101 #define f_rn(bo, bi, n, k) \
102 bo[n] = ft_tab[0][byte(bi[n],0)] ^ \
103 ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
104 ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
105 ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
107 #define i_rn(bo, bi, n, k) \
108 bo[n] = it_tab[0][byte(bi[n],0)] ^ \
109 it_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
110 it_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
111 it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
114 ( fl_tab[0][byte(x, 0)] ^ \
115 fl_tab[1][byte(x, 1)] ^ \
116 fl_tab[2][byte(x, 2)] ^ \
117 fl_tab[3][byte(x, 3)] )
119 #define f_rl(bo, bi, n, k) \
120 bo[n] = fl_tab[0][byte(bi[n],0)] ^ \
121 fl_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
122 fl_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
123 fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
125 #define i_rl(bo, bi, n, k) \
126 bo[n] = il_tab[0][byte(bi[n],0)] ^ \
127 il_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
128 il_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
129 il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
137 /* log and power tables for GF(2**8) finite field with
138 0x011b as modular polynomial - the simplest primitive
139 root is 0x03, used here to generate the tables */
141 for (i = 0, p = 1; i < 256; ++i) {
145 p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0);
150 for (i = 0, p = 1; i < 10; ++i) {
153 p = (p << 1) ^ (p & 0x80 ? 0x01b : 0);
156 for (i = 0; i < 256; ++i) {
157 p = (i ? pow_tab[255 - log_tab[i]] : 0);
158 q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2));
159 p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2));
164 for (i = 0; i < 256; ++i) {
169 fl_tab[1][i] = rol32(t, 8);
170 fl_tab[2][i] = rol32(t, 16);
171 fl_tab[3][i] = rol32(t, 24);
173 t = ((u32) ff_mult (2, p)) |
175 ((u32) p << 16) | ((u32) ff_mult (3, p) << 24);
178 ft_tab[1][i] = rol32(t, 8);
179 ft_tab[2][i] = rol32(t, 16);
180 ft_tab[3][i] = rol32(t, 24);
186 il_tab[1][i] = rol32(t, 8);
187 il_tab[2][i] = rol32(t, 16);
188 il_tab[3][i] = rol32(t, 24);
190 t = ((u32) ff_mult (14, p)) |
191 ((u32) ff_mult (9, p) << 8) |
192 ((u32) ff_mult (13, p) << 16) |
193 ((u32) ff_mult (11, p) << 24);
196 it_tab[1][i] = rol32(t, 8);
197 it_tab[2][i] = rol32(t, 16);
198 it_tab[3][i] = rol32(t, 24);
202 #define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
204 #define imix_col(y,x) \
210 (y) ^= ror32(u ^ t, 8) ^ \
214 /* initialise the key schedule from the user supplied key */
217 { t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \
218 t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \
219 t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \
220 t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \
221 t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \
225 { t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \
226 t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \
227 t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \
228 t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \
229 t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \
230 t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \
231 t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \
235 { t = ror32(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \
236 t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \
237 t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \
238 t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \
239 t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \
240 t = E_KEY[8 * i + 4] ^ ls_box(t); \
241 E_KEY[8 * i + 12] = t; \
242 t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \
243 t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \
244 t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \
247 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
248 unsigned int key_len)
250 struct aes_ctx *ctx = crypto_tfm_ctx(tfm);
251 const __le32 *key = (const __le32 *)in_key;
252 u32 *flags = &tfm->crt_flags;
256 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
260 ctx->key_length = key_len;
262 E_KEY[0] = le32_to_cpu(key[0]);
263 E_KEY[1] = le32_to_cpu(key[1]);
264 E_KEY[2] = le32_to_cpu(key[2]);
265 E_KEY[3] = le32_to_cpu(key[3]);
270 for (i = 0; i < 10; ++i)
275 E_KEY[4] = le32_to_cpu(key[4]);
276 t = E_KEY[5] = le32_to_cpu(key[5]);
277 for (i = 0; i < 8; ++i)
282 E_KEY[4] = le32_to_cpu(key[4]);
283 E_KEY[5] = le32_to_cpu(key[5]);
284 E_KEY[6] = le32_to_cpu(key[6]);
285 t = E_KEY[7] = le32_to_cpu(key[7]);
286 for (i = 0; i < 7; ++i)
296 for (i = 4; i < key_len + 24; ++i) {
297 imix_col (D_KEY[i], E_KEY[i]);
303 /* encrypt a block of text */
305 #define f_nround(bo, bi, k) \
306 f_rn(bo, bi, 0, k); \
307 f_rn(bo, bi, 1, k); \
308 f_rn(bo, bi, 2, k); \
309 f_rn(bo, bi, 3, k); \
312 #define f_lround(bo, bi, k) \
313 f_rl(bo, bi, 0, k); \
314 f_rl(bo, bi, 1, k); \
315 f_rl(bo, bi, 2, k); \
318 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
320 const struct aes_ctx *ctx = crypto_tfm_ctx(tfm);
321 const __le32 *src = (const __le32 *)in;
322 __le32 *dst = (__le32 *)out;
324 const u32 *kp = E_KEY + 4;
326 b0[0] = le32_to_cpu(src[0]) ^ E_KEY[0];
327 b0[1] = le32_to_cpu(src[1]) ^ E_KEY[1];
328 b0[2] = le32_to_cpu(src[2]) ^ E_KEY[2];
329 b0[3] = le32_to_cpu(src[3]) ^ E_KEY[3];
331 if (ctx->key_length > 24) {
332 f_nround (b1, b0, kp);
333 f_nround (b0, b1, kp);
336 if (ctx->key_length > 16) {
337 f_nround (b1, b0, kp);
338 f_nround (b0, b1, kp);
341 f_nround (b1, b0, kp);
342 f_nround (b0, b1, kp);
343 f_nround (b1, b0, kp);
344 f_nround (b0, b1, kp);
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_lround (b0, b1, kp);
352 dst[0] = cpu_to_le32(b0[0]);
353 dst[1] = cpu_to_le32(b0[1]);
354 dst[2] = cpu_to_le32(b0[2]);
355 dst[3] = cpu_to_le32(b0[3]);
358 /* decrypt a block of text */
360 #define i_nround(bo, bi, k) \
361 i_rn(bo, bi, 0, k); \
362 i_rn(bo, bi, 1, k); \
363 i_rn(bo, bi, 2, k); \
364 i_rn(bo, bi, 3, k); \
367 #define i_lround(bo, bi, k) \
368 i_rl(bo, bi, 0, k); \
369 i_rl(bo, bi, 1, k); \
370 i_rl(bo, bi, 2, k); \
373 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
375 const struct aes_ctx *ctx = crypto_tfm_ctx(tfm);
376 const __le32 *src = (const __le32 *)in;
377 __le32 *dst = (__le32 *)out;
379 const int key_len = ctx->key_length;
380 const u32 *kp = D_KEY + key_len + 20;
382 b0[0] = le32_to_cpu(src[0]) ^ E_KEY[key_len + 24];
383 b0[1] = le32_to_cpu(src[1]) ^ E_KEY[key_len + 25];
384 b0[2] = le32_to_cpu(src[2]) ^ E_KEY[key_len + 26];
385 b0[3] = le32_to_cpu(src[3]) ^ E_KEY[key_len + 27];
388 i_nround (b1, b0, kp);
389 i_nround (b0, b1, kp);
393 i_nround (b1, b0, kp);
394 i_nround (b0, b1, kp);
397 i_nround (b1, b0, kp);
398 i_nround (b0, b1, kp);
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_lround (b0, b1, kp);
408 dst[0] = cpu_to_le32(b0[0]);
409 dst[1] = cpu_to_le32(b0[1]);
410 dst[2] = cpu_to_le32(b0[2]);
411 dst[3] = cpu_to_le32(b0[3]);
415 static struct crypto_alg aes_alg = {
417 .cra_driver_name = "aes-generic",
419 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
420 .cra_blocksize = AES_BLOCK_SIZE,
421 .cra_ctxsize = sizeof(struct aes_ctx),
423 .cra_module = THIS_MODULE,
424 .cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
427 .cia_min_keysize = AES_MIN_KEY_SIZE,
428 .cia_max_keysize = AES_MAX_KEY_SIZE,
429 .cia_setkey = aes_set_key,
430 .cia_encrypt = aes_encrypt,
431 .cia_decrypt = aes_decrypt
436 static int __init aes_init(void)
439 return crypto_register_alg(&aes_alg);
442 static void __exit aes_fini(void)
444 crypto_unregister_alg(&aes_alg);
447 module_init(aes_init);
448 module_exit(aes_fini);
450 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
451 MODULE_LICENSE("Dual BSD/GPL");