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[CRYPTO] padlock: Update private header file
[deliverable/linux.git] / drivers / crypto / padlock-aes.c
1 /*
2 * Cryptographic API.
3 *
4 * Support for VIA PadLock hardware crypto engine.
5 *
6 * Copyright (c) 2004 Michal Ludvig <michal@logix.cz>
7 *
8 * Key expansion routine taken from crypto/aes.c
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * ---------------------------------------------------------------------------
16 * Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
17 * All rights reserved.
18 *
19 * LICENSE TERMS
20 *
21 * The free distribution and use of this software in both source and binary
22 * form is allowed (with or without changes) provided that:
23 *
24 * 1. distributions of this source code include the above copyright
25 * notice, this list of conditions and the following disclaimer;
26 *
27 * 2. distributions in binary form include the above copyright
28 * notice, this list of conditions and the following disclaimer
29 * in the documentation and/or other associated materials;
30 *
31 * 3. the copyright holder's name is not used to endorse products
32 * built using this software without specific written permission.
33 *
34 * ALTERNATIVELY, provided that this notice is retained in full, this product
35 * may be distributed under the terms of the GNU General Public License (GPL),
36 * in which case the provisions of the GPL apply INSTEAD OF those given above.
37 *
38 * DISCLAIMER
39 *
40 * This software is provided 'as is' with no explicit or implied warranties
41 * in respect of its properties, including, but not limited to, correctness
42 * and/or fitness for purpose.
43 * ---------------------------------------------------------------------------
44 */
45
46 #include <linux/module.h>
47 #include <linux/init.h>
48 #include <linux/types.h>
49 #include <linux/errno.h>
50 #include <linux/crypto.h>
51 #include <linux/interrupt.h>
52 #include <linux/kernel.h>
53 #include <asm/byteorder.h>
54 #include "padlock.h"
55
56 #define AES_MIN_KEY_SIZE 16 /* in uint8_t units */
57 #define AES_MAX_KEY_SIZE 32 /* ditto */
58 #define AES_BLOCK_SIZE 16 /* ditto */
59 #define AES_EXTENDED_KEY_SIZE 64 /* in uint32_t units */
60 #define AES_EXTENDED_KEY_SIZE_B (AES_EXTENDED_KEY_SIZE * sizeof(uint32_t))
61
62 /* Control word. */
63 struct cword {
64 unsigned int __attribute__ ((__packed__))
65 rounds:4,
66 algo:3,
67 keygen:1,
68 interm:1,
69 encdec:1,
70 ksize:2;
71 } __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
72
73 /* Whenever making any changes to the following
74 * structure *make sure* you keep E, d_data
75 * and cword aligned on 16 Bytes boundaries!!! */
76 struct aes_ctx {
77 struct {
78 struct cword encrypt;
79 struct cword decrypt;
80 } cword;
81 u32 *D;
82 int key_length;
83 u32 E[AES_EXTENDED_KEY_SIZE]
84 __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
85 u32 d_data[AES_EXTENDED_KEY_SIZE]
86 __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
87 };
88
89 /* ====== Key management routines ====== */
90
91 static inline uint32_t
92 generic_rotr32 (const uint32_t x, const unsigned bits)
93 {
94 const unsigned n = bits % 32;
95 return (x >> n) | (x << (32 - n));
96 }
97
98 static inline uint32_t
99 generic_rotl32 (const uint32_t x, const unsigned bits)
100 {
101 const unsigned n = bits % 32;
102 return (x << n) | (x >> (32 - n));
103 }
104
105 #define rotl generic_rotl32
106 #define rotr generic_rotr32
107
108 /*
109 * #define byte(x, nr) ((unsigned char)((x) >> (nr*8)))
110 */
111 static inline uint8_t
112 byte(const uint32_t x, const unsigned n)
113 {
114 return x >> (n << 3);
115 }
116
117 #define E_KEY ctx->E
118 #define D_KEY ctx->D
119
120 static uint8_t pow_tab[256];
121 static uint8_t log_tab[256];
122 static uint8_t sbx_tab[256];
123 static uint8_t isb_tab[256];
124 static uint32_t rco_tab[10];
125 static uint32_t ft_tab[4][256];
126 static uint32_t it_tab[4][256];
127
128 static uint32_t fl_tab[4][256];
129 static uint32_t il_tab[4][256];
130
131 static inline uint8_t
132 f_mult (uint8_t a, uint8_t b)
133 {
134 uint8_t aa = log_tab[a], cc = aa + log_tab[b];
135
136 return pow_tab[cc + (cc < aa ? 1 : 0)];
137 }
138
139 #define ff_mult(a,b) (a && b ? f_mult(a, b) : 0)
140
141 #define f_rn(bo, bi, n, k) \
142 bo[n] = ft_tab[0][byte(bi[n],0)] ^ \
143 ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
144 ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
145 ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
146
147 #define i_rn(bo, bi, n, k) \
148 bo[n] = it_tab[0][byte(bi[n],0)] ^ \
149 it_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
150 it_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
151 it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
152
153 #define ls_box(x) \
154 ( fl_tab[0][byte(x, 0)] ^ \
155 fl_tab[1][byte(x, 1)] ^ \
156 fl_tab[2][byte(x, 2)] ^ \
157 fl_tab[3][byte(x, 3)] )
158
159 #define f_rl(bo, bi, n, k) \
160 bo[n] = fl_tab[0][byte(bi[n],0)] ^ \
161 fl_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
162 fl_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
163 fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
164
165 #define i_rl(bo, bi, n, k) \
166 bo[n] = il_tab[0][byte(bi[n],0)] ^ \
167 il_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
168 il_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
169 il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
170
171 static void
172 gen_tabs (void)
173 {
174 uint32_t i, t;
175 uint8_t p, q;
176
177 /* log and power tables for GF(2**8) finite field with
178 0x011b as modular polynomial - the simplest prmitive
179 root is 0x03, used here to generate the tables */
180
181 for (i = 0, p = 1; i < 256; ++i) {
182 pow_tab[i] = (uint8_t) p;
183 log_tab[p] = (uint8_t) i;
184
185 p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0);
186 }
187
188 log_tab[1] = 0;
189
190 for (i = 0, p = 1; i < 10; ++i) {
191 rco_tab[i] = p;
192
193 p = (p << 1) ^ (p & 0x80 ? 0x01b : 0);
194 }
195
196 for (i = 0; i < 256; ++i) {
197 p = (i ? pow_tab[255 - log_tab[i]] : 0);
198 q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2));
199 p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2));
200 sbx_tab[i] = p;
201 isb_tab[p] = (uint8_t) i;
202 }
203
204 for (i = 0; i < 256; ++i) {
205 p = sbx_tab[i];
206
207 t = p;
208 fl_tab[0][i] = t;
209 fl_tab[1][i] = rotl (t, 8);
210 fl_tab[2][i] = rotl (t, 16);
211 fl_tab[3][i] = rotl (t, 24);
212
213 t = ((uint32_t) ff_mult (2, p)) |
214 ((uint32_t) p << 8) |
215 ((uint32_t) p << 16) | ((uint32_t) ff_mult (3, p) << 24);
216
217 ft_tab[0][i] = t;
218 ft_tab[1][i] = rotl (t, 8);
219 ft_tab[2][i] = rotl (t, 16);
220 ft_tab[3][i] = rotl (t, 24);
221
222 p = isb_tab[i];
223
224 t = p;
225 il_tab[0][i] = t;
226 il_tab[1][i] = rotl (t, 8);
227 il_tab[2][i] = rotl (t, 16);
228 il_tab[3][i] = rotl (t, 24);
229
230 t = ((uint32_t) ff_mult (14, p)) |
231 ((uint32_t) ff_mult (9, p) << 8) |
232 ((uint32_t) ff_mult (13, p) << 16) |
233 ((uint32_t) ff_mult (11, p) << 24);
234
235 it_tab[0][i] = t;
236 it_tab[1][i] = rotl (t, 8);
237 it_tab[2][i] = rotl (t, 16);
238 it_tab[3][i] = rotl (t, 24);
239 }
240 }
241
242 #define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
243
244 #define imix_col(y,x) \
245 u = star_x(x); \
246 v = star_x(u); \
247 w = star_x(v); \
248 t = w ^ (x); \
249 (y) = u ^ v ^ w; \
250 (y) ^= rotr(u ^ t, 8) ^ \
251 rotr(v ^ t, 16) ^ \
252 rotr(t,24)
253
254 /* initialise the key schedule from the user supplied key */
255
256 #define loop4(i) \
257 { t = rotr(t, 8); t = ls_box(t) ^ rco_tab[i]; \
258 t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \
259 t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \
260 t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \
261 t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \
262 }
263
264 #define loop6(i) \
265 { t = rotr(t, 8); t = ls_box(t) ^ rco_tab[i]; \
266 t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \
267 t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \
268 t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \
269 t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \
270 t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \
271 t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \
272 }
273
274 #define loop8(i) \
275 { t = rotr(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \
276 t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \
277 t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \
278 t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \
279 t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \
280 t = E_KEY[8 * i + 4] ^ ls_box(t); \
281 E_KEY[8 * i + 12] = t; \
282 t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \
283 t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \
284 t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \
285 }
286
287 /* Tells whether the ACE is capable to generate
288 the extended key for a given key_len. */
289 static inline int
290 aes_hw_extkey_available(uint8_t key_len)
291 {
292 /* TODO: We should check the actual CPU model/stepping
293 as it's possible that the capability will be
294 added in the next CPU revisions. */
295 if (key_len == 16)
296 return 1;
297 return 0;
298 }
299
300 static inline struct aes_ctx *aes_ctx(struct crypto_tfm *tfm)
301 {
302 unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
303 unsigned long align = PADLOCK_ALIGNMENT;
304
305 if (align <= crypto_tfm_ctx_alignment())
306 align = 1;
307 return (struct aes_ctx *)ALIGN(addr, align);
308 }
309
310 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
311 unsigned int key_len, u32 *flags)
312 {
313 struct aes_ctx *ctx = aes_ctx(tfm);
314 const __le32 *key = (const __le32 *)in_key;
315 uint32_t i, t, u, v, w;
316 uint32_t P[AES_EXTENDED_KEY_SIZE];
317 uint32_t rounds;
318
319 if (key_len != 16 && key_len != 24 && key_len != 32) {
320 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
321 return -EINVAL;
322 }
323
324 ctx->key_length = key_len;
325
326 /*
327 * If the hardware is capable of generating the extended key
328 * itself we must supply the plain key for both encryption
329 * and decryption.
330 */
331 ctx->D = ctx->E;
332
333 E_KEY[0] = le32_to_cpu(key[0]);
334 E_KEY[1] = le32_to_cpu(key[1]);
335 E_KEY[2] = le32_to_cpu(key[2]);
336 E_KEY[3] = le32_to_cpu(key[3]);
337
338 /* Prepare control words. */
339 memset(&ctx->cword, 0, sizeof(ctx->cword));
340
341 ctx->cword.decrypt.encdec = 1;
342 ctx->cword.encrypt.rounds = 10 + (key_len - 16) / 4;
343 ctx->cword.decrypt.rounds = ctx->cword.encrypt.rounds;
344 ctx->cword.encrypt.ksize = (key_len - 16) / 8;
345 ctx->cword.decrypt.ksize = ctx->cword.encrypt.ksize;
346
347 /* Don't generate extended keys if the hardware can do it. */
348 if (aes_hw_extkey_available(key_len))
349 return 0;
350
351 ctx->D = ctx->d_data;
352 ctx->cword.encrypt.keygen = 1;
353 ctx->cword.decrypt.keygen = 1;
354
355 switch (key_len) {
356 case 16:
357 t = E_KEY[3];
358 for (i = 0; i < 10; ++i)
359 loop4 (i);
360 break;
361
362 case 24:
363 E_KEY[4] = le32_to_cpu(key[4]);
364 t = E_KEY[5] = le32_to_cpu(key[5]);
365 for (i = 0; i < 8; ++i)
366 loop6 (i);
367 break;
368
369 case 32:
370 E_KEY[4] = le32_to_cpu(key[4]);
371 E_KEY[5] = le32_to_cpu(key[5]);
372 E_KEY[6] = le32_to_cpu(key[6]);
373 t = E_KEY[7] = le32_to_cpu(key[7]);
374 for (i = 0; i < 7; ++i)
375 loop8 (i);
376 break;
377 }
378
379 D_KEY[0] = E_KEY[0];
380 D_KEY[1] = E_KEY[1];
381 D_KEY[2] = E_KEY[2];
382 D_KEY[3] = E_KEY[3];
383
384 for (i = 4; i < key_len + 24; ++i) {
385 imix_col (D_KEY[i], E_KEY[i]);
386 }
387
388 /* PadLock needs a different format of the decryption key. */
389 rounds = 10 + (key_len - 16) / 4;
390
391 for (i = 0; i < rounds; i++) {
392 P[((i + 1) * 4) + 0] = D_KEY[((rounds - i - 1) * 4) + 0];
393 P[((i + 1) * 4) + 1] = D_KEY[((rounds - i - 1) * 4) + 1];
394 P[((i + 1) * 4) + 2] = D_KEY[((rounds - i - 1) * 4) + 2];
395 P[((i + 1) * 4) + 3] = D_KEY[((rounds - i - 1) * 4) + 3];
396 }
397
398 P[0] = E_KEY[(rounds * 4) + 0];
399 P[1] = E_KEY[(rounds * 4) + 1];
400 P[2] = E_KEY[(rounds * 4) + 2];
401 P[3] = E_KEY[(rounds * 4) + 3];
402
403 memcpy(D_KEY, P, AES_EXTENDED_KEY_SIZE_B);
404
405 return 0;
406 }
407
408 /* ====== Encryption/decryption routines ====== */
409
410 /* These are the real call to PadLock. */
411 static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
412 void *control_word, u32 count)
413 {
414 asm volatile ("pushfl; popfl"); /* enforce key reload. */
415 asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
416 : "+S"(input), "+D"(output)
417 : "d"(control_word), "b"(key), "c"(count));
418 }
419
420 static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key,
421 u8 *iv, void *control_word, u32 count)
422 {
423 /* Enforce key reload. */
424 asm volatile ("pushfl; popfl");
425 /* rep xcryptcbc */
426 asm volatile (".byte 0xf3,0x0f,0xa7,0xd0"
427 : "+S" (input), "+D" (output), "+a" (iv)
428 : "d" (control_word), "b" (key), "c" (count));
429 return iv;
430 }
431
432 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
433 {
434 struct aes_ctx *ctx = aes_ctx(tfm);
435 padlock_xcrypt_ecb(in, out, ctx->E, &ctx->cword.encrypt, 1);
436 }
437
438 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
439 {
440 struct aes_ctx *ctx = aes_ctx(tfm);
441 padlock_xcrypt_ecb(in, out, ctx->D, &ctx->cword.decrypt, 1);
442 }
443
444 static unsigned int aes_encrypt_ecb(const struct cipher_desc *desc, u8 *out,
445 const u8 *in, unsigned int nbytes)
446 {
447 struct aes_ctx *ctx = aes_ctx(desc->tfm);
448 padlock_xcrypt_ecb(in, out, ctx->E, &ctx->cword.encrypt,
449 nbytes / AES_BLOCK_SIZE);
450 return nbytes & ~(AES_BLOCK_SIZE - 1);
451 }
452
453 static unsigned int aes_decrypt_ecb(const struct cipher_desc *desc, u8 *out,
454 const u8 *in, unsigned int nbytes)
455 {
456 struct aes_ctx *ctx = aes_ctx(desc->tfm);
457 padlock_xcrypt_ecb(in, out, ctx->D, &ctx->cword.decrypt,
458 nbytes / AES_BLOCK_SIZE);
459 return nbytes & ~(AES_BLOCK_SIZE - 1);
460 }
461
462 static unsigned int aes_encrypt_cbc(const struct cipher_desc *desc, u8 *out,
463 const u8 *in, unsigned int nbytes)
464 {
465 struct aes_ctx *ctx = aes_ctx(desc->tfm);
466 u8 *iv;
467
468 iv = padlock_xcrypt_cbc(in, out, ctx->E, desc->info,
469 &ctx->cword.encrypt, nbytes / AES_BLOCK_SIZE);
470 memcpy(desc->info, iv, AES_BLOCK_SIZE);
471
472 return nbytes & ~(AES_BLOCK_SIZE - 1);
473 }
474
475 static unsigned int aes_decrypt_cbc(const struct cipher_desc *desc, u8 *out,
476 const u8 *in, unsigned int nbytes)
477 {
478 struct aes_ctx *ctx = aes_ctx(desc->tfm);
479 padlock_xcrypt_cbc(in, out, ctx->D, desc->info, &ctx->cword.decrypt,
480 nbytes / AES_BLOCK_SIZE);
481 return nbytes & ~(AES_BLOCK_SIZE - 1);
482 }
483
484 static struct crypto_alg aes_alg = {
485 .cra_name = "aes",
486 .cra_driver_name = "aes-padlock",
487 .cra_priority = PADLOCK_CRA_PRIORITY,
488 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
489 .cra_blocksize = AES_BLOCK_SIZE,
490 .cra_ctxsize = sizeof(struct aes_ctx),
491 .cra_alignmask = PADLOCK_ALIGNMENT - 1,
492 .cra_module = THIS_MODULE,
493 .cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
494 .cra_u = {
495 .cipher = {
496 .cia_min_keysize = AES_MIN_KEY_SIZE,
497 .cia_max_keysize = AES_MAX_KEY_SIZE,
498 .cia_setkey = aes_set_key,
499 .cia_encrypt = aes_encrypt,
500 .cia_decrypt = aes_decrypt,
501 .cia_encrypt_ecb = aes_encrypt_ecb,
502 .cia_decrypt_ecb = aes_decrypt_ecb,
503 .cia_encrypt_cbc = aes_encrypt_cbc,
504 .cia_decrypt_cbc = aes_decrypt_cbc,
505 }
506 }
507 };
508
509 static int __init padlock_init(void)
510 {
511 int ret;
512
513 if (!cpu_has_xcrypt) {
514 printk(KERN_ERR PFX "VIA PadLock not detected.\n");
515 return -ENODEV;
516 }
517
518 if (!cpu_has_xcrypt_enabled) {
519 printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
520 return -ENODEV;
521 }
522
523 gen_tabs();
524 if ((ret = crypto_register_alg(&aes_alg))) {
525 printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n");
526 return ret;
527 }
528
529 printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");
530
531 return ret;
532 }
533
534 static void __exit padlock_fini(void)
535 {
536 crypto_unregister_alg(&aes_alg);
537 }
538
539 module_init(padlock_init);
540 module_exit(padlock_fini);
541
542 MODULE_DESCRIPTION("VIA PadLock AES algorithm support");
543 MODULE_LICENSE("GPL");
544 MODULE_AUTHOR("Michal Ludvig");
545
546 MODULE_ALIAS("aes-padlock");
547
548 /* This module used to be called padlock. */
549 MODULE_ALIAS("padlock");
Linux kernel - Deliverables
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