aboutsummaryrefslogtreecommitdiff
path: root/arch/s390/crypto/aes_s390.c
blob: 58f46734465ffad0f7dcb8412799b747c923ffd2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
/*
 * Cryptographic API.
 *
 * s390 implementation of the AES Cipher Algorithm.
 *
 * s390 Version:
 *   Copyright IBM Corp. 2005,2007
 *   Author(s): Jan Glauber (jang@de.ibm.com)
 *		Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback
 *
 * Derived from "crypto/aes_generic.c"
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#define KMSG_COMPONENT "aes_s390"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <crypto/aes.h>
#include <crypto/algapi.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include "crypt_s390.h"

#define AES_KEYLEN_128		1
#define AES_KEYLEN_192		2
#define AES_KEYLEN_256		4

static char keylen_flag = 0;

struct s390_aes_ctx {
	u8 iv[AES_BLOCK_SIZE];
	u8 key[AES_MAX_KEY_SIZE];
	long enc;
	long dec;
	int key_len;
	union {
		struct crypto_blkcipher *blk;
		struct crypto_cipher *cip;
	} fallback;
};

/*
 * Check if the key_len is supported by the HW.
 * Returns 0 if it is, a positive number if it is not and software fallback is
 * required or a negative number in case the key size is not valid
 */
static int need_fallback(unsigned int key_len)
{
	switch (key_len) {
	case 16:
		if (!(keylen_flag & AES_KEYLEN_128))
			return 1;
		break;
	case 24:
		if (!(keylen_flag & AES_KEYLEN_192))
			return 1;
		break;
	case 32:
		if (!(keylen_flag & AES_KEYLEN_256))
			return 1;
		break;
	default:
		return -1;
		break;
	}
	return 0;
}

static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key,
		unsigned int key_len)
{
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
	int ret;

	sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
	sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags &
			CRYPTO_TFM_REQ_MASK);

	ret = crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len);
	if (ret) {
		tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
		tfm->crt_flags |= (sctx->fallback.cip->base.crt_flags &
				CRYPTO_TFM_RES_MASK);
	}
	return ret;
}

static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
		       unsigned int key_len)
{
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
	u32 *flags = &tfm->crt_flags;
	int ret;

	ret = need_fallback(key_len);
	if (ret < 0) {
		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
		return -EINVAL;
	}

	sctx->key_len = key_len;
	if (!ret) {
		memcpy(sctx->key, in_key, key_len);
		return 0;
	}

	return setkey_fallback_cip(tfm, in_key, key_len);
}

static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
	const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);

	if (unlikely(need_fallback(sctx->key_len))) {
		crypto_cipher_encrypt_one(sctx->fallback.cip, out, in);
		return;
	}

	switch (sctx->key_len) {
	case 16:
		crypt_s390_km(KM_AES_128_ENCRYPT, &sctx->key, out, in,
			      AES_BLOCK_SIZE);
		break;
	case 24:
		crypt_s390_km(KM_AES_192_ENCRYPT, &sctx->key, out, in,
			      AES_BLOCK_SIZE);
		break;
	case 32:
		crypt_s390_km(KM_AES_256_ENCRYPT, &sctx->key, out, in,
			      AES_BLOCK_SIZE);
		break;
	}
}

static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
	const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);

	if (unlikely(need_fallback(sctx->key_len))) {
		crypto_cipher_decrypt_one(sctx->fallback.cip, out, in);
		return;
	}

	switch (sctx->key_len) {
	case 16:
		crypt_s390_km(KM_AES_128_DECRYPT, &sctx->key, out, in,
			      AES_BLOCK_SIZE);
		break;
	case 24:
		crypt_s390_km(KM_AES_192_DECRYPT, &sctx->key, out, in,
			      AES_BLOCK_SIZE);
		break;
	case 32:
		crypt_s390_km(KM_AES_256_DECRYPT, &sctx->key, out, in,
			      AES_BLOCK_SIZE);
		break;
	}
}

static int fallback_init_cip(struct crypto_tfm *tfm)
{
	const char *name = tfm->__crt_alg->cra_name;
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);

	sctx->fallback.cip = crypto_alloc_cipher(name, 0,
			CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);

	if (IS_ERR(sctx->fallback.cip)) {
		pr_err("Allocating AES fallback algorithm %s failed\n",
		       name);
		return PTR_ERR(sctx->fallback.cip);
	}

	return 0;
}

static void fallback_exit_cip(struct crypto_tfm *tfm)
{
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);

	crypto_free_cipher(sctx->fallback.cip);
	sctx->fallback.cip = NULL;
}

static struct crypto_alg aes_alg = {
	.cra_name		=	"aes",
	.cra_driver_name	=	"aes-s390",
	.cra_priority		=	CRYPT_S390_PRIORITY,
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER |
					CRYPTO_ALG_NEED_FALLBACK,
	.cra_blocksize		=	AES_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct s390_aes_ctx),
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(aes_alg.cra_list),
	.cra_init               =       fallback_init_cip,
	.cra_exit               =       fallback_exit_cip,
	.cra_u			=	{
		.cipher = {
			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
			.cia_setkey		=	aes_set_key,
			.cia_encrypt		=	aes_encrypt,
			.cia_decrypt		=	aes_decrypt,
		}
	}
};

static int setkey_fallback_blk(struct crypto_tfm *tfm, const u8 *key,
		unsigned int len)
{
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
	unsigned int ret;

	sctx->fallback.blk->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
	sctx->fallback.blk->base.crt_flags |= (tfm->crt_flags &
			CRYPTO_TFM_REQ_MASK);

	ret = crypto_blkcipher_setkey(sctx->fallback.blk, key, len);
	if (ret) {
		tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
		tfm->crt_flags |= (sctx->fallback.blk->base.crt_flags &
				CRYPTO_TFM_RES_MASK);
	}
	return ret;
}

static int fallback_blk_dec(struct blkcipher_desc *desc,
		struct scatterlist *dst, struct scatterlist *src,
		unsigned int nbytes)
{
	unsigned int ret;
	struct crypto_blkcipher *tfm;
	struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);

	tfm = desc->tfm;
	desc->tfm = sctx->fallback.blk;

	ret = crypto_blkcipher_decrypt_iv(desc, dst, src, nbytes);

	desc->tfm = tfm;
	return ret;
}

static int fallback_blk_enc(struct blkcipher_desc *desc,
		struct scatterlist *dst, struct scatterlist *src,
		unsigned int nbytes)
{
	unsigned int ret;
	struct crypto_blkcipher *tfm;
	struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);

	tfm = desc->tfm;
	desc->tfm = sctx->fallback.blk;

	ret = crypto_blkcipher_encrypt_iv(desc, dst, src, nbytes);

	desc->tfm = tfm;
	return ret;
}

static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
			   unsigned int key_len)
{
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
	int ret;

	ret = need_fallback(key_len);
	if (ret > 0) {
		sctx->key_len = key_len;
		return setkey_fallback_blk(tfm, in_key, key_len);
	}

	switch (key_len) {
	case 16:
		sctx->enc = KM_AES_128_ENCRYPT;
		sctx->dec = KM_AES_128_DECRYPT;
		break;
	case 24:
		sctx->enc = KM_AES_192_ENCRYPT;
		sctx->dec = KM_AES_192_DECRYPT;
		break;
	case 32:
		sctx->enc = KM_AES_256_ENCRYPT;
		sctx->dec = KM_AES_256_DECRYPT;
		break;
	}

	return aes_set_key(tfm, in_key, key_len);
}

static int ecb_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
			 struct blkcipher_walk *walk)
{
	int ret = blkcipher_walk_virt(desc, walk);
	unsigned int nbytes;

	while ((nbytes = walk->nbytes)) {
		/* only use complete blocks */
		unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
		u8 *out = walk->dst.virt.addr;
		u8 *in = walk->src.virt.addr;

		ret = crypt_s390_km(func, param, out, in, n);
		BUG_ON((ret < 0) || (ret != n));

		nbytes &= AES_BLOCK_SIZE - 1;
		ret = blkcipher_walk_done(desc, walk, nbytes);
	}

	return ret;
}

static int ecb_aes_encrypt(struct blkcipher_desc *desc,
			   struct scatterlist *dst, struct scatterlist *src,
			   unsigned int nbytes)
{
	struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;

	if (unlikely(need_fallback(sctx->key_len)))
		return fallback_blk_enc(desc, dst, src, nbytes);

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return ecb_aes_crypt(desc, sctx->enc, sctx->key, &walk);
}

static int ecb_aes_decrypt(struct blkcipher_desc *desc,
			   struct scatterlist *dst, struct scatterlist *src,
			   unsigned int nbytes)
{
	struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;

	if (unlikely(need_fallback(sctx->key_len)))
		return fallback_blk_dec(desc, dst, src, nbytes);

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return ecb_aes_crypt(desc, sctx->dec, sctx->key, &walk);
}

static int fallback_init_blk(struct crypto_tfm *tfm)
{
	const char *name = tfm->__crt_alg->cra_name;
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);

	sctx->fallback.blk = crypto_alloc_blkcipher(name, 0,
			CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);

	if (IS_ERR(sctx->fallback.blk)) {
		pr_err("Allocating AES fallback algorithm %s failed\n",
		       name);
		return PTR_ERR(sctx->fallback.blk);
	}

	return 0;
}

static void fallback_exit_blk(struct crypto_tfm *tfm)
{
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);

	crypto_free_blkcipher(sctx->fallback.blk);
	sctx->fallback.blk = NULL;
}

static struct crypto_alg ecb_aes_alg = {
	.cra_name		=	"ecb(aes)",
	.cra_driver_name	=	"ecb-aes-s390",
	.cra_priority		=	CRYPT_S390_COMPOSITE_PRIORITY,
	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER |
					CRYPTO_ALG_NEED_FALLBACK,
	.cra_blocksize		=	AES_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct s390_aes_ctx),
	.cra_type		=	&crypto_blkcipher_type,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(ecb_aes_alg.cra_list),
	.cra_init		=	fallback_init_blk,
	.cra_exit		=	fallback_exit_blk,
	.cra_u			=	{
		.blkcipher = {
			.min_keysize		=	AES_MIN_KEY_SIZE,
			.max_keysize		=	AES_MAX_KEY_SIZE,
			.setkey			=	ecb_aes_set_key,
			.encrypt		=	ecb_aes_encrypt,
			.decrypt		=	ecb_aes_decrypt,
		}
	}
};

static int cbc_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
			   unsigned int key_len)
{
	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
	int ret;

	ret = need_fallback(key_len);
	if (ret > 0) {
		sctx->key_len = key_len;
		return setkey_fallback_blk(tfm, in_key, key_len);
	}

	switch (key_len) {
	case 16:
		sctx->enc = KMC_AES_128_ENCRYPT;
		sctx->dec = KMC_AES_128_DECRYPT;
		break;
	case 24:
		sctx->enc = KMC_AES_192_ENCRYPT;
		sctx->dec = KMC_AES_192_DECRYPT;
		break;
	case 32:
		sctx->enc = KMC_AES_256_ENCRYPT;
		sctx->dec = KMC_AES_256_DECRYPT;
		break;
	}

	return aes_set_key(tfm, in_key, key_len);
}

static int cbc_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
			 struct blkcipher_walk *walk)
{
	int ret = blkcipher_walk_virt(desc, walk);
	unsigned int nbytes = walk->nbytes;

	if (!nbytes)
		goto out;

	memcpy(param, walk->iv, AES_BLOCK_SIZE);
	do {
		/* only use complete blocks */
		unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
		u8 *out = walk->dst.virt.addr;
		u8 *in = walk->src.virt.addr;

		ret = crypt_s390_kmc(func, param, out, in, n);
		BUG_ON((ret < 0) || (ret != n));

		nbytes &= AES_BLOCK_SIZE - 1;
		ret = blkcipher_walk_done(desc, walk, nbytes);
	} while ((nbytes = walk->nbytes));
	memcpy(walk->iv, param, AES_BLOCK_SIZE);

out:
	return ret;
}

static int cbc_aes_encrypt(struct blkcipher_desc *desc,
			   struct scatterlist *dst, struct scatterlist *src,
			   unsigned int nbytes)
{
	struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;

	if (unlikely(need_fallback(sctx->key_len)))
		return fallback_blk_enc(desc, dst, src, nbytes);

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return cbc_aes_crypt(desc, sctx->enc, sctx->iv, &walk);
}

static int cbc_aes_decrypt(struct blkcipher_desc *desc,
			   struct scatterlist *dst, struct scatterlist *src,
			   unsigned int nbytes)
{
	struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk walk;

	if (unlikely(need_fallback(sctx->key_len)))
		return fallback_blk_dec(desc, dst, src, nbytes);

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return cbc_aes_crypt(desc, sctx->dec, sctx->iv, &walk);
}

static struct crypto_alg cbc_aes_alg = {
	.cra_name		=	"cbc(aes)",
	.cra_driver_name	=	"cbc-aes-s390",
	.cra_priority		=	CRYPT_S390_COMPOSITE_PRIORITY,
	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER |
					CRYPTO_ALG_NEED_FALLBACK,
	.cra_blocksize		=	AES_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct s390_aes_ctx),
	.cra_type		=	&crypto_blkcipher_type,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(cbc_aes_alg.cra_list),
	.cra_init		=	fallback_init_blk,
	.cra_exit		=	fallback_exit_blk,
	.cra_u			=	{
		.blkcipher = {
			.min_keysize		=	AES_MIN_KEY_SIZE,
			.max_keysize		=	AES_MAX_KEY_SIZE,
			.ivsize			=	AES_BLOCK_SIZE,
			.setkey			=	cbc_aes_set_key,
			.encrypt		=	cbc_aes_encrypt,
			.decrypt		=	cbc_aes_decrypt,
		}
	}
};

static int __init aes_s390_init(void)
{
	int ret;

	if (crypt_s390_func_available(KM_AES_128_ENCRYPT))
		keylen_flag |= AES_KEYLEN_128;
	if (crypt_s390_func_available(KM_AES_192_ENCRYPT))
		keylen_flag |= AES_KEYLEN_192;
	if (crypt_s390_func_available(KM_AES_256_ENCRYPT))
		keylen_flag |= AES_KEYLEN_256;

	if (!keylen_flag)
		return -EOPNOTSUPP;

	/* z9 109 and z9 BC/EC only support 128 bit key length */
	if (keylen_flag == AES_KEYLEN_128)
		pr_info("AES hardware acceleration is only available for"
			" 128-bit keys\n");

	ret = crypto_register_alg(&aes_alg);
	if (ret)
		goto aes_err;

	ret = crypto_register_alg(&ecb_aes_alg);
	if (ret)
		goto ecb_aes_err;

	ret = crypto_register_alg(&cbc_aes_alg);
	if (ret)
		goto cbc_aes_err;

out:
	return ret;

cbc_aes_err:
	crypto_unregister_alg(&ecb_aes_alg);
ecb_aes_err:
	crypto_unregister_alg(&aes_alg);
aes_err:
	goto out;
}

static void __exit aes_s390_fini(void)
{
	crypto_unregister_alg(&cbc_aes_alg);
	crypto_unregister_alg(&ecb_aes_alg);
	crypto_unregister_alg(&aes_alg);
}

module_init(aes_s390_init);
module_exit(aes_s390_fini);

MODULE_ALIAS("aes-all");

MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
MODULE_LICENSE("GPL");