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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
67static inline
68u32 generic_rotr32 (const u32 x, const unsigned bits)
69{
70 const unsigned n = bits % 32;
71 return (x >> n) | (x << (32 - n));
72}
73
74static inline
75u32 generic_rotl32 (const u32 x, const unsigned bits)
76{
77 const unsigned n = bits % 32;
78 return (x << n) | (x >> (32 - n));
79}
80
81#define rotl generic_rotl32
82#define rotr generic_rotr32
83
84
85
86
87inline static u8
88byte(const u32 x, const unsigned n)
89{
90 return x >> (n << 3);
91}
92
93#define u32_in(x) le32_to_cpu(*(const u32 *)(x))
94#define u32_out(to, from) (*(u32 *)(to) = cpu_to_le32(from))
95
96struct aes_ctx {
97 int key_length;
98 u32 E[60];
99 u32 D[60];
100};
101
102#define E_KEY ctx->E
103#define D_KEY ctx->D
104
105static u8 pow_tab[256] __initdata;
106static u8 log_tab[256] __initdata;
107static u8 sbx_tab[256] __initdata;
108static u8 isb_tab[256] __initdata;
109static u32 rco_tab[10];
110static u32 ft_tab[4][256];
111static u32 it_tab[4][256];
112
113static u32 fl_tab[4][256];
114static u32 il_tab[4][256];
115
116static inline u8 __init
117f_mult (u8 a, u8 b)
118{
119 u8 aa = log_tab[a], cc = aa + log_tab[b];
120
121 return pow_tab[cc + (cc < aa ? 1 : 0)];
122}
123
124#define ff_mult(a,b) (a && b ? f_mult(a, b) : 0)
125
126#define f_rn(bo, bi, n, k) \
127 bo[n] = ft_tab[0][byte(bi[n],0)] ^ \
128 ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
129 ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
130 ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
131
132#define i_rn(bo, bi, n, k) \
133 bo[n] = it_tab[0][byte(bi[n],0)] ^ \
134 it_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
135 it_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
136 it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
137
138#define ls_box(x) \
139 ( fl_tab[0][byte(x, 0)] ^ \
140 fl_tab[1][byte(x, 1)] ^ \
141 fl_tab[2][byte(x, 2)] ^ \
142 fl_tab[3][byte(x, 3)] )
143
144#define f_rl(bo, bi, n, k) \
145 bo[n] = fl_tab[0][byte(bi[n],0)] ^ \
146 fl_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
147 fl_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
148 fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
149
150#define i_rl(bo, bi, n, k) \
151 bo[n] = il_tab[0][byte(bi[n],0)] ^ \
152 il_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
153 il_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
154 il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
155
156static void __init
157gen_tabs (void)
158{
159 u32 i, t;
160 u8 p, q;
161
162
163
164
165
166 for (i = 0, p = 1; i < 256; ++i) {
167 pow_tab[i] = (u8) p;
168 log_tab[p] = (u8) i;
169
170 p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0);
171 }
172
173 log_tab[1] = 0;
174
175 for (i = 0, p = 1; i < 10; ++i) {
176 rco_tab[i] = p;
177
178 p = (p << 1) ^ (p & 0x80 ? 0x01b : 0);
179 }
180
181 for (i = 0; i < 256; ++i) {
182 p = (i ? pow_tab[255 - log_tab[i]] : 0);
183 q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2));
184 p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2));
185 sbx_tab[i] = p;
186 isb_tab[p] = (u8) i;
187 }
188
189 for (i = 0; i < 256; ++i) {
190 p = sbx_tab[i];
191
192 t = p;
193 fl_tab[0][i] = t;
194 fl_tab[1][i] = rotl (t, 8);
195 fl_tab[2][i] = rotl (t, 16);
196 fl_tab[3][i] = rotl (t, 24);
197
198 t = ((u32) ff_mult (2, p)) |
199 ((u32) p << 8) |
200 ((u32) p << 16) | ((u32) ff_mult (3, p) << 24);
201
202 ft_tab[0][i] = t;
203 ft_tab[1][i] = rotl (t, 8);
204 ft_tab[2][i] = rotl (t, 16);
205 ft_tab[3][i] = rotl (t, 24);
206
207 p = isb_tab[i];
208
209 t = p;
210 il_tab[0][i] = t;
211 il_tab[1][i] = rotl (t, 8);
212 il_tab[2][i] = rotl (t, 16);
213 il_tab[3][i] = rotl (t, 24);
214
215 t = ((u32) ff_mult (14, p)) |
216 ((u32) ff_mult (9, p) << 8) |
217 ((u32) ff_mult (13, p) << 16) |
218 ((u32) ff_mult (11, p) << 24);
219
220 it_tab[0][i] = t;
221 it_tab[1][i] = rotl (t, 8);
222 it_tab[2][i] = rotl (t, 16);
223 it_tab[3][i] = rotl (t, 24);
224 }
225}
226
227#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
228
229#define imix_col(y,x) \
230 u = star_x(x); \
231 v = star_x(u); \
232 w = star_x(v); \
233 t = w ^ (x); \
234 (y) = u ^ v ^ w; \
235 (y) ^= rotr(u ^ t, 8) ^ \
236 rotr(v ^ t, 16) ^ \
237 rotr(t,24)
238
239
240
241#define loop4(i) \
242{ t = rotr(t, 8); t = ls_box(t) ^ rco_tab[i]; \
243 t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \
244 t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \
245 t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \
246 t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \
247}
248
249#define loop6(i) \
250{ t = rotr(t, 8); t = ls_box(t) ^ rco_tab[i]; \
251 t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \
252 t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \
253 t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \
254 t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \
255 t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \
256 t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \
257}
258
259#define loop8(i) \
260{ t = rotr(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \
261 t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \
262 t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \
263 t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \
264 t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \
265 t = E_KEY[8 * i + 4] ^ ls_box(t); \
266 E_KEY[8 * i + 12] = t; \
267 t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \
268 t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \
269 t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \
270}
271
272static int
273aes_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags)
274{
275 struct aes_ctx *ctx = ctx_arg;
276 u32 i, t, u, v, w;
277
278 if (key_len != 16 && key_len != 24 && key_len != 32) {
279 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
280 return -EINVAL;
281 }
282
283 ctx->key_length = key_len;
284
285 E_KEY[0] = u32_in (in_key);
286 E_KEY[1] = u32_in (in_key + 4);
287 E_KEY[2] = u32_in (in_key + 8);
288 E_KEY[3] = u32_in (in_key + 12);
289
290 switch (key_len) {
291 case 16:
292 t = E_KEY[3];
293 for (i = 0; i < 10; ++i)
294 loop4 (i);
295 break;
296
297 case 24:
298 E_KEY[4] = u32_in (in_key + 16);
299 t = E_KEY[5] = u32_in (in_key + 20);
300 for (i = 0; i < 8; ++i)
301 loop6 (i);
302 break;
303
304 case 32:
305 E_KEY[4] = u32_in (in_key + 16);
306 E_KEY[5] = u32_in (in_key + 20);
307 E_KEY[6] = u32_in (in_key + 24);
308 t = E_KEY[7] = u32_in (in_key + 28);
309 for (i = 0; i < 7; ++i)
310 loop8 (i);
311 break;
312 }
313
314 D_KEY[0] = E_KEY[0];
315 D_KEY[1] = E_KEY[1];
316 D_KEY[2] = E_KEY[2];
317 D_KEY[3] = E_KEY[3];
318
319 for (i = 4; i < key_len + 24; ++i) {
320 imix_col (D_KEY[i], E_KEY[i]);
321 }
322
323 return 0;
324}
325
326
327
328#define f_nround(bo, bi, k) \
329 f_rn(bo, bi, 0, k); \
330 f_rn(bo, bi, 1, k); \
331 f_rn(bo, bi, 2, k); \
332 f_rn(bo, bi, 3, k); \
333 k += 4
334
335#define f_lround(bo, bi, k) \
336 f_rl(bo, bi, 0, k); \
337 f_rl(bo, bi, 1, k); \
338 f_rl(bo, bi, 2, k); \
339 f_rl(bo, bi, 3, k)
340
341static void aes_encrypt(void *ctx_arg, u8 *out, const u8 *in)
342{
343 const struct aes_ctx *ctx = ctx_arg;
344 u32 b0[4], b1[4];
345 const u32 *kp = E_KEY + 4;
346
347 b0[0] = u32_in (in) ^ E_KEY[0];
348 b0[1] = u32_in (in + 4) ^ E_KEY[1];
349 b0[2] = u32_in (in + 8) ^ E_KEY[2];
350 b0[3] = u32_in (in + 12) ^ E_KEY[3];
351
352 if (ctx->key_length > 24) {
353 f_nround (b1, b0, kp);
354 f_nround (b0, b1, kp);
355 }
356
357 if (ctx->key_length > 16) {
358 f_nround (b1, b0, kp);
359 f_nround (b0, b1, kp);
360 }
361
362 f_nround (b1, b0, kp);
363 f_nround (b0, b1, kp);
364 f_nround (b1, b0, kp);
365 f_nround (b0, b1, kp);
366 f_nround (b1, b0, kp);
367 f_nround (b0, b1, kp);
368 f_nround (b1, b0, kp);
369 f_nround (b0, b1, kp);
370 f_nround (b1, b0, kp);
371 f_lround (b0, b1, kp);
372
373 u32_out (out, b0[0]);
374 u32_out (out + 4, b0[1]);
375 u32_out (out + 8, b0[2]);
376 u32_out (out + 12, b0[3]);
377}
378
379
380
381#define i_nround(bo, bi, k) \
382 i_rn(bo, bi, 0, k); \
383 i_rn(bo, bi, 1, k); \
384 i_rn(bo, bi, 2, k); \
385 i_rn(bo, bi, 3, k); \
386 k -= 4
387
388#define i_lround(bo, bi, k) \
389 i_rl(bo, bi, 0, k); \
390 i_rl(bo, bi, 1, k); \
391 i_rl(bo, bi, 2, k); \
392 i_rl(bo, bi, 3, k)
393
394static void aes_decrypt(void *ctx_arg, u8 *out, const u8 *in)
395{
396 const struct aes_ctx *ctx = ctx_arg;
397 u32 b0[4], b1[4];
398 const int key_len = ctx->key_length;
399 const u32 *kp = D_KEY + key_len + 20;
400
401 b0[0] = u32_in (in) ^ E_KEY[key_len + 24];
402 b0[1] = u32_in (in + 4) ^ E_KEY[key_len + 25];
403 b0[2] = u32_in (in + 8) ^ E_KEY[key_len + 26];
404 b0[3] = u32_in (in + 12) ^ E_KEY[key_len + 27];
405
406 if (key_len > 24) {
407 i_nround (b1, b0, kp);
408 i_nround (b0, b1, kp);
409 }
410
411 if (key_len > 16) {
412 i_nround (b1, b0, kp);
413 i_nround (b0, b1, kp);
414 }
415
416 i_nround (b1, b0, kp);
417 i_nround (b0, b1, kp);
418 i_nround (b1, b0, kp);
419 i_nround (b0, b1, kp);
420 i_nround (b1, b0, kp);
421 i_nround (b0, b1, kp);
422 i_nround (b1, b0, kp);
423 i_nround (b0, b1, kp);
424 i_nround (b1, b0, kp);
425 i_lround (b0, b1, kp);
426
427 u32_out (out, b0[0]);
428 u32_out (out + 4, b0[1]);
429 u32_out (out + 8, b0[2]);
430 u32_out (out + 12, b0[3]);
431}
432
433
434static struct crypto_alg aes_alg = {
435 .cra_name = "aes",
436 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
437 .cra_blocksize = AES_BLOCK_SIZE,
438 .cra_ctxsize = sizeof(struct aes_ctx),
439 .cra_module = THIS_MODULE,
440 .cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
441 .cra_u = {
442 .cipher = {
443 .cia_min_keysize = AES_MIN_KEY_SIZE,
444 .cia_max_keysize = AES_MAX_KEY_SIZE,
445 .cia_setkey = aes_set_key,
446 .cia_encrypt = aes_encrypt,
447 .cia_decrypt = aes_decrypt
448 }
449 }
450};
451
452static int __init aes_init(void)
453{
454 gen_tabs();
455 return crypto_register_alg(&aes_alg);
456}
457
458static void __exit aes_fini(void)
459{
460 crypto_unregister_alg(&aes_alg);
461}
462
463module_init(aes_init);
464module_exit(aes_fini);
465
466MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
467MODULE_LICENSE("Dual BSD/GPL");
468
469
