xref: /openbmc/linux/arch/s390/crypto/paes_s390.c (revision d6e2d652)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Cryptographic API.
4  *
5  * s390 implementation of the AES Cipher Algorithm with protected keys.
6  *
7  * s390 Version:
8  *   Copyright IBM Corp. 2017, 2023
9  *   Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
10  *		Harald Freudenberger <freude@de.ibm.com>
11  */
12 
13 #define KMSG_COMPONENT "paes_s390"
14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15 
16 #include <crypto/aes.h>
17 #include <crypto/algapi.h>
18 #include <linux/bug.h>
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/cpufeature.h>
22 #include <linux/init.h>
23 #include <linux/mutex.h>
24 #include <linux/spinlock.h>
25 #include <linux/delay.h>
26 #include <crypto/internal/skcipher.h>
27 #include <crypto/xts.h>
28 #include <asm/cpacf.h>
29 #include <asm/pkey.h>
30 
31 /*
32  * Key blobs smaller/bigger than these defines are rejected
33  * by the common code even before the individual setkey function
34  * is called. As paes can handle different kinds of key blobs
35  * and padding is also possible, the limits need to be generous.
36  */
37 #define PAES_MIN_KEYSIZE 16
38 #define PAES_MAX_KEYSIZE 320
39 
40 static u8 *ctrblk;
41 static DEFINE_MUTEX(ctrblk_lock);
42 
43 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
44 
45 struct key_blob {
46 	/*
47 	 * Small keys will be stored in the keybuf. Larger keys are
48 	 * stored in extra allocated memory. In both cases does
49 	 * key point to the memory where the key is stored.
50 	 * The code distinguishes by checking keylen against
51 	 * sizeof(keybuf). See the two following helper functions.
52 	 */
53 	u8 *key;
54 	u8 keybuf[128];
55 	unsigned int keylen;
56 };
57 
58 static inline int _key_to_kb(struct key_blob *kb,
59 			     const u8 *key,
60 			     unsigned int keylen)
61 {
62 	struct clearkey_header {
63 		u8  type;
64 		u8  res0[3];
65 		u8  version;
66 		u8  res1[3];
67 		u32 keytype;
68 		u32 len;
69 	} __packed * h;
70 
71 	switch (keylen) {
72 	case 16:
73 	case 24:
74 	case 32:
75 		/* clear key value, prepare pkey clear key token in keybuf */
76 		memset(kb->keybuf, 0, sizeof(kb->keybuf));
77 		h = (struct clearkey_header *) kb->keybuf;
78 		h->version = 0x02; /* TOKVER_CLEAR_KEY */
79 		h->keytype = (keylen - 8) >> 3;
80 		h->len = keylen;
81 		memcpy(kb->keybuf + sizeof(*h), key, keylen);
82 		kb->keylen = sizeof(*h) + keylen;
83 		kb->key = kb->keybuf;
84 		break;
85 	default:
86 		/* other key material, let pkey handle this */
87 		if (keylen <= sizeof(kb->keybuf))
88 			kb->key = kb->keybuf;
89 		else {
90 			kb->key = kmalloc(keylen, GFP_KERNEL);
91 			if (!kb->key)
92 				return -ENOMEM;
93 		}
94 		memcpy(kb->key, key, keylen);
95 		kb->keylen = keylen;
96 		break;
97 	}
98 
99 	return 0;
100 }
101 
102 static inline void _free_kb_keybuf(struct key_blob *kb)
103 {
104 	if (kb->key && kb->key != kb->keybuf
105 	    && kb->keylen > sizeof(kb->keybuf)) {
106 		kfree_sensitive(kb->key);
107 		kb->key = NULL;
108 	}
109 }
110 
111 struct s390_paes_ctx {
112 	struct key_blob kb;
113 	struct pkey_protkey pk;
114 	spinlock_t pk_lock;
115 	unsigned long fc;
116 };
117 
118 struct s390_pxts_ctx {
119 	struct key_blob kb[2];
120 	struct pkey_protkey pk[2];
121 	spinlock_t pk_lock;
122 	unsigned long fc;
123 };
124 
125 static inline int __paes_keyblob2pkey(struct key_blob *kb,
126 				     struct pkey_protkey *pk)
127 {
128 	int i, ret;
129 
130 	/* try three times in case of failure */
131 	for (i = 0; i < 3; i++) {
132 		if (i > 0 && ret == -EAGAIN && in_task())
133 			if (msleep_interruptible(1000))
134 				return -EINTR;
135 		ret = pkey_keyblob2pkey(kb->key, kb->keylen,
136 					pk->protkey, &pk->len, &pk->type);
137 		if (ret == 0)
138 			break;
139 	}
140 
141 	return ret;
142 }
143 
144 static inline int __paes_convert_key(struct s390_paes_ctx *ctx)
145 {
146 	int ret;
147 	struct pkey_protkey pkey;
148 
149 	pkey.len = sizeof(pkey.protkey);
150 	ret = __paes_keyblob2pkey(&ctx->kb, &pkey);
151 	if (ret)
152 		return ret;
153 
154 	spin_lock_bh(&ctx->pk_lock);
155 	memcpy(&ctx->pk, &pkey, sizeof(pkey));
156 	spin_unlock_bh(&ctx->pk_lock);
157 
158 	return 0;
159 }
160 
161 static int ecb_paes_init(struct crypto_skcipher *tfm)
162 {
163 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
164 
165 	ctx->kb.key = NULL;
166 	spin_lock_init(&ctx->pk_lock);
167 
168 	return 0;
169 }
170 
171 static void ecb_paes_exit(struct crypto_skcipher *tfm)
172 {
173 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
174 
175 	_free_kb_keybuf(&ctx->kb);
176 }
177 
178 static inline int __ecb_paes_set_key(struct s390_paes_ctx *ctx)
179 {
180 	int rc;
181 	unsigned long fc;
182 
183 	rc = __paes_convert_key(ctx);
184 	if (rc)
185 		return rc;
186 
187 	/* Pick the correct function code based on the protected key type */
188 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PAES_128 :
189 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KM_PAES_192 :
190 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KM_PAES_256 : 0;
191 
192 	/* Check if the function code is available */
193 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
194 
195 	return ctx->fc ? 0 : -EINVAL;
196 }
197 
198 static int ecb_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
199 			    unsigned int key_len)
200 {
201 	int rc;
202 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
203 
204 	_free_kb_keybuf(&ctx->kb);
205 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
206 	if (rc)
207 		return rc;
208 
209 	return __ecb_paes_set_key(ctx);
210 }
211 
212 static int ecb_paes_crypt(struct skcipher_request *req, unsigned long modifier)
213 {
214 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
215 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
216 	struct skcipher_walk walk;
217 	unsigned int nbytes, n, k;
218 	int ret;
219 	struct {
220 		u8 key[MAXPROTKEYSIZE];
221 	} param;
222 
223 	ret = skcipher_walk_virt(&walk, req, false);
224 	if (ret)
225 		return ret;
226 
227 	spin_lock_bh(&ctx->pk_lock);
228 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
229 	spin_unlock_bh(&ctx->pk_lock);
230 
231 	while ((nbytes = walk.nbytes) != 0) {
232 		/* only use complete blocks */
233 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
234 		k = cpacf_km(ctx->fc | modifier, &param,
235 			     walk.dst.virt.addr, walk.src.virt.addr, n);
236 		if (k)
237 			ret = skcipher_walk_done(&walk, nbytes - k);
238 		if (k < n) {
239 			if (__paes_convert_key(ctx))
240 				return skcipher_walk_done(&walk, -EIO);
241 			spin_lock_bh(&ctx->pk_lock);
242 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
243 			spin_unlock_bh(&ctx->pk_lock);
244 		}
245 	}
246 	return ret;
247 }
248 
249 static int ecb_paes_encrypt(struct skcipher_request *req)
250 {
251 	return ecb_paes_crypt(req, 0);
252 }
253 
254 static int ecb_paes_decrypt(struct skcipher_request *req)
255 {
256 	return ecb_paes_crypt(req, CPACF_DECRYPT);
257 }
258 
259 static struct skcipher_alg ecb_paes_alg = {
260 	.base.cra_name		=	"ecb(paes)",
261 	.base.cra_driver_name	=	"ecb-paes-s390",
262 	.base.cra_priority	=	401,	/* combo: aes + ecb + 1 */
263 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
264 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
265 	.base.cra_module	=	THIS_MODULE,
266 	.base.cra_list		=	LIST_HEAD_INIT(ecb_paes_alg.base.cra_list),
267 	.init			=	ecb_paes_init,
268 	.exit			=	ecb_paes_exit,
269 	.min_keysize		=	PAES_MIN_KEYSIZE,
270 	.max_keysize		=	PAES_MAX_KEYSIZE,
271 	.setkey			=	ecb_paes_set_key,
272 	.encrypt		=	ecb_paes_encrypt,
273 	.decrypt		=	ecb_paes_decrypt,
274 };
275 
276 static int cbc_paes_init(struct crypto_skcipher *tfm)
277 {
278 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
279 
280 	ctx->kb.key = NULL;
281 	spin_lock_init(&ctx->pk_lock);
282 
283 	return 0;
284 }
285 
286 static void cbc_paes_exit(struct crypto_skcipher *tfm)
287 {
288 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
289 
290 	_free_kb_keybuf(&ctx->kb);
291 }
292 
293 static inline int __cbc_paes_set_key(struct s390_paes_ctx *ctx)
294 {
295 	int rc;
296 	unsigned long fc;
297 
298 	rc = __paes_convert_key(ctx);
299 	if (rc)
300 		return rc;
301 
302 	/* Pick the correct function code based on the protected key type */
303 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMC_PAES_128 :
304 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMC_PAES_192 :
305 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KMC_PAES_256 : 0;
306 
307 	/* Check if the function code is available */
308 	ctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
309 
310 	return ctx->fc ? 0 : -EINVAL;
311 }
312 
313 static int cbc_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
314 			    unsigned int key_len)
315 {
316 	int rc;
317 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
318 
319 	_free_kb_keybuf(&ctx->kb);
320 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
321 	if (rc)
322 		return rc;
323 
324 	return __cbc_paes_set_key(ctx);
325 }
326 
327 static int cbc_paes_crypt(struct skcipher_request *req, unsigned long modifier)
328 {
329 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
330 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
331 	struct skcipher_walk walk;
332 	unsigned int nbytes, n, k;
333 	int ret;
334 	struct {
335 		u8 iv[AES_BLOCK_SIZE];
336 		u8 key[MAXPROTKEYSIZE];
337 	} param;
338 
339 	ret = skcipher_walk_virt(&walk, req, false);
340 	if (ret)
341 		return ret;
342 
343 	memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
344 	spin_lock_bh(&ctx->pk_lock);
345 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
346 	spin_unlock_bh(&ctx->pk_lock);
347 
348 	while ((nbytes = walk.nbytes) != 0) {
349 		/* only use complete blocks */
350 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
351 		k = cpacf_kmc(ctx->fc | modifier, &param,
352 			      walk.dst.virt.addr, walk.src.virt.addr, n);
353 		if (k) {
354 			memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
355 			ret = skcipher_walk_done(&walk, nbytes - k);
356 		}
357 		if (k < n) {
358 			if (__paes_convert_key(ctx))
359 				return skcipher_walk_done(&walk, -EIO);
360 			spin_lock_bh(&ctx->pk_lock);
361 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
362 			spin_unlock_bh(&ctx->pk_lock);
363 		}
364 	}
365 	return ret;
366 }
367 
368 static int cbc_paes_encrypt(struct skcipher_request *req)
369 {
370 	return cbc_paes_crypt(req, 0);
371 }
372 
373 static int cbc_paes_decrypt(struct skcipher_request *req)
374 {
375 	return cbc_paes_crypt(req, CPACF_DECRYPT);
376 }
377 
378 static struct skcipher_alg cbc_paes_alg = {
379 	.base.cra_name		=	"cbc(paes)",
380 	.base.cra_driver_name	=	"cbc-paes-s390",
381 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
382 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
383 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
384 	.base.cra_module	=	THIS_MODULE,
385 	.base.cra_list		=	LIST_HEAD_INIT(cbc_paes_alg.base.cra_list),
386 	.init			=	cbc_paes_init,
387 	.exit			=	cbc_paes_exit,
388 	.min_keysize		=	PAES_MIN_KEYSIZE,
389 	.max_keysize		=	PAES_MAX_KEYSIZE,
390 	.ivsize			=	AES_BLOCK_SIZE,
391 	.setkey			=	cbc_paes_set_key,
392 	.encrypt		=	cbc_paes_encrypt,
393 	.decrypt		=	cbc_paes_decrypt,
394 };
395 
396 static int xts_paes_init(struct crypto_skcipher *tfm)
397 {
398 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
399 
400 	ctx->kb[0].key = NULL;
401 	ctx->kb[1].key = NULL;
402 	spin_lock_init(&ctx->pk_lock);
403 
404 	return 0;
405 }
406 
407 static void xts_paes_exit(struct crypto_skcipher *tfm)
408 {
409 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
410 
411 	_free_kb_keybuf(&ctx->kb[0]);
412 	_free_kb_keybuf(&ctx->kb[1]);
413 }
414 
415 static inline int __xts_paes_convert_key(struct s390_pxts_ctx *ctx)
416 {
417 	struct pkey_protkey pkey0, pkey1;
418 
419 	pkey0.len = sizeof(pkey0.protkey);
420 	pkey1.len = sizeof(pkey1.protkey);
421 
422 	if (__paes_keyblob2pkey(&ctx->kb[0], &pkey0) ||
423 	    __paes_keyblob2pkey(&ctx->kb[1], &pkey1))
424 		return -EINVAL;
425 
426 	spin_lock_bh(&ctx->pk_lock);
427 	memcpy(&ctx->pk[0], &pkey0, sizeof(pkey0));
428 	memcpy(&ctx->pk[1], &pkey1, sizeof(pkey1));
429 	spin_unlock_bh(&ctx->pk_lock);
430 
431 	return 0;
432 }
433 
434 static inline int __xts_paes_set_key(struct s390_pxts_ctx *ctx)
435 {
436 	unsigned long fc;
437 
438 	if (__xts_paes_convert_key(ctx))
439 		return -EINVAL;
440 
441 	if (ctx->pk[0].type != ctx->pk[1].type)
442 		return -EINVAL;
443 
444 	/* Pick the correct function code based on the protected key type */
445 	fc = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PXTS_128 :
446 		(ctx->pk[0].type == PKEY_KEYTYPE_AES_256) ?
447 		CPACF_KM_PXTS_256 : 0;
448 
449 	/* Check if the function code is available */
450 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
451 
452 	return ctx->fc ? 0 : -EINVAL;
453 }
454 
455 static int xts_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
456 			    unsigned int xts_key_len)
457 {
458 	int rc;
459 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
460 	u8 ckey[2 * AES_MAX_KEY_SIZE];
461 	unsigned int ckey_len, key_len;
462 
463 	if (xts_key_len % 2)
464 		return -EINVAL;
465 
466 	key_len = xts_key_len / 2;
467 
468 	_free_kb_keybuf(&ctx->kb[0]);
469 	_free_kb_keybuf(&ctx->kb[1]);
470 	rc = _key_to_kb(&ctx->kb[0], in_key, key_len);
471 	if (rc)
472 		return rc;
473 	rc = _key_to_kb(&ctx->kb[1], in_key + key_len, key_len);
474 	if (rc)
475 		return rc;
476 
477 	rc = __xts_paes_set_key(ctx);
478 	if (rc)
479 		return rc;
480 
481 	/*
482 	 * xts_verify_key verifies the key length is not odd and makes
483 	 * sure that the two keys are not the same. This can be done
484 	 * on the two protected keys as well
485 	 */
486 	ckey_len = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ?
487 		AES_KEYSIZE_128 : AES_KEYSIZE_256;
488 	memcpy(ckey, ctx->pk[0].protkey, ckey_len);
489 	memcpy(ckey + ckey_len, ctx->pk[1].protkey, ckey_len);
490 	return xts_verify_key(tfm, ckey, 2*ckey_len);
491 }
492 
493 static int xts_paes_crypt(struct skcipher_request *req, unsigned long modifier)
494 {
495 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
496 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
497 	struct skcipher_walk walk;
498 	unsigned int keylen, offset, nbytes, n, k;
499 	int ret;
500 	struct {
501 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
502 		u8 tweak[16];
503 		u8 block[16];
504 		u8 bit[16];
505 		u8 xts[16];
506 	} pcc_param;
507 	struct {
508 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
509 		u8 init[16];
510 	} xts_param;
511 
512 	ret = skcipher_walk_virt(&walk, req, false);
513 	if (ret)
514 		return ret;
515 
516 	keylen = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 48 : 64;
517 	offset = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 16 : 0;
518 
519 	memset(&pcc_param, 0, sizeof(pcc_param));
520 	memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
521 	spin_lock_bh(&ctx->pk_lock);
522 	memcpy(pcc_param.key + offset, ctx->pk[1].protkey, keylen);
523 	memcpy(xts_param.key + offset, ctx->pk[0].protkey, keylen);
524 	spin_unlock_bh(&ctx->pk_lock);
525 	cpacf_pcc(ctx->fc, pcc_param.key + offset);
526 	memcpy(xts_param.init, pcc_param.xts, 16);
527 
528 	while ((nbytes = walk.nbytes) != 0) {
529 		/* only use complete blocks */
530 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
531 		k = cpacf_km(ctx->fc | modifier, xts_param.key + offset,
532 			     walk.dst.virt.addr, walk.src.virt.addr, n);
533 		if (k)
534 			ret = skcipher_walk_done(&walk, nbytes - k);
535 		if (k < n) {
536 			if (__xts_paes_convert_key(ctx))
537 				return skcipher_walk_done(&walk, -EIO);
538 			spin_lock_bh(&ctx->pk_lock);
539 			memcpy(xts_param.key + offset,
540 			       ctx->pk[0].protkey, keylen);
541 			spin_unlock_bh(&ctx->pk_lock);
542 		}
543 	}
544 
545 	return ret;
546 }
547 
548 static int xts_paes_encrypt(struct skcipher_request *req)
549 {
550 	return xts_paes_crypt(req, 0);
551 }
552 
553 static int xts_paes_decrypt(struct skcipher_request *req)
554 {
555 	return xts_paes_crypt(req, CPACF_DECRYPT);
556 }
557 
558 static struct skcipher_alg xts_paes_alg = {
559 	.base.cra_name		=	"xts(paes)",
560 	.base.cra_driver_name	=	"xts-paes-s390",
561 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
562 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
563 	.base.cra_ctxsize	=	sizeof(struct s390_pxts_ctx),
564 	.base.cra_module	=	THIS_MODULE,
565 	.base.cra_list		=	LIST_HEAD_INIT(xts_paes_alg.base.cra_list),
566 	.init			=	xts_paes_init,
567 	.exit			=	xts_paes_exit,
568 	.min_keysize		=	2 * PAES_MIN_KEYSIZE,
569 	.max_keysize		=	2 * PAES_MAX_KEYSIZE,
570 	.ivsize			=	AES_BLOCK_SIZE,
571 	.setkey			=	xts_paes_set_key,
572 	.encrypt		=	xts_paes_encrypt,
573 	.decrypt		=	xts_paes_decrypt,
574 };
575 
576 static int ctr_paes_init(struct crypto_skcipher *tfm)
577 {
578 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
579 
580 	ctx->kb.key = NULL;
581 	spin_lock_init(&ctx->pk_lock);
582 
583 	return 0;
584 }
585 
586 static void ctr_paes_exit(struct crypto_skcipher *tfm)
587 {
588 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
589 
590 	_free_kb_keybuf(&ctx->kb);
591 }
592 
593 static inline int __ctr_paes_set_key(struct s390_paes_ctx *ctx)
594 {
595 	int rc;
596 	unsigned long fc;
597 
598 	rc = __paes_convert_key(ctx);
599 	if (rc)
600 		return rc;
601 
602 	/* Pick the correct function code based on the protected key type */
603 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMCTR_PAES_128 :
604 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMCTR_PAES_192 :
605 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ?
606 		CPACF_KMCTR_PAES_256 : 0;
607 
608 	/* Check if the function code is available */
609 	ctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
610 
611 	return ctx->fc ? 0 : -EINVAL;
612 }
613 
614 static int ctr_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
615 			    unsigned int key_len)
616 {
617 	int rc;
618 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
619 
620 	_free_kb_keybuf(&ctx->kb);
621 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
622 	if (rc)
623 		return rc;
624 
625 	return __ctr_paes_set_key(ctx);
626 }
627 
628 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
629 {
630 	unsigned int i, n;
631 
632 	/* only use complete blocks, max. PAGE_SIZE */
633 	memcpy(ctrptr, iv, AES_BLOCK_SIZE);
634 	n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
635 	for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
636 		memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
637 		crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
638 		ctrptr += AES_BLOCK_SIZE;
639 	}
640 	return n;
641 }
642 
643 static int ctr_paes_crypt(struct skcipher_request *req)
644 {
645 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
646 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
647 	u8 buf[AES_BLOCK_SIZE], *ctrptr;
648 	struct skcipher_walk walk;
649 	unsigned int nbytes, n, k;
650 	int ret, locked;
651 	struct {
652 		u8 key[MAXPROTKEYSIZE];
653 	} param;
654 
655 	ret = skcipher_walk_virt(&walk, req, false);
656 	if (ret)
657 		return ret;
658 
659 	spin_lock_bh(&ctx->pk_lock);
660 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
661 	spin_unlock_bh(&ctx->pk_lock);
662 
663 	locked = mutex_trylock(&ctrblk_lock);
664 
665 	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
666 		n = AES_BLOCK_SIZE;
667 		if (nbytes >= 2*AES_BLOCK_SIZE && locked)
668 			n = __ctrblk_init(ctrblk, walk.iv, nbytes);
669 		ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
670 		k = cpacf_kmctr(ctx->fc, &param, walk.dst.virt.addr,
671 				walk.src.virt.addr, n, ctrptr);
672 		if (k) {
673 			if (ctrptr == ctrblk)
674 				memcpy(walk.iv, ctrptr + k - AES_BLOCK_SIZE,
675 				       AES_BLOCK_SIZE);
676 			crypto_inc(walk.iv, AES_BLOCK_SIZE);
677 			ret = skcipher_walk_done(&walk, nbytes - k);
678 		}
679 		if (k < n) {
680 			if (__paes_convert_key(ctx)) {
681 				if (locked)
682 					mutex_unlock(&ctrblk_lock);
683 				return skcipher_walk_done(&walk, -EIO);
684 			}
685 			spin_lock_bh(&ctx->pk_lock);
686 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
687 			spin_unlock_bh(&ctx->pk_lock);
688 		}
689 	}
690 	if (locked)
691 		mutex_unlock(&ctrblk_lock);
692 	/*
693 	 * final block may be < AES_BLOCK_SIZE, copy only nbytes
694 	 */
695 	if (nbytes) {
696 		while (1) {
697 			if (cpacf_kmctr(ctx->fc, &param, buf,
698 					walk.src.virt.addr, AES_BLOCK_SIZE,
699 					walk.iv) == AES_BLOCK_SIZE)
700 				break;
701 			if (__paes_convert_key(ctx))
702 				return skcipher_walk_done(&walk, -EIO);
703 			spin_lock_bh(&ctx->pk_lock);
704 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
705 			spin_unlock_bh(&ctx->pk_lock);
706 		}
707 		memcpy(walk.dst.virt.addr, buf, nbytes);
708 		crypto_inc(walk.iv, AES_BLOCK_SIZE);
709 		ret = skcipher_walk_done(&walk, nbytes);
710 	}
711 
712 	return ret;
713 }
714 
715 static struct skcipher_alg ctr_paes_alg = {
716 	.base.cra_name		=	"ctr(paes)",
717 	.base.cra_driver_name	=	"ctr-paes-s390",
718 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
719 	.base.cra_blocksize	=	1,
720 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
721 	.base.cra_module	=	THIS_MODULE,
722 	.base.cra_list		=	LIST_HEAD_INIT(ctr_paes_alg.base.cra_list),
723 	.init			=	ctr_paes_init,
724 	.exit			=	ctr_paes_exit,
725 	.min_keysize		=	PAES_MIN_KEYSIZE,
726 	.max_keysize		=	PAES_MAX_KEYSIZE,
727 	.ivsize			=	AES_BLOCK_SIZE,
728 	.setkey			=	ctr_paes_set_key,
729 	.encrypt		=	ctr_paes_crypt,
730 	.decrypt		=	ctr_paes_crypt,
731 	.chunksize		=	AES_BLOCK_SIZE,
732 };
733 
734 static inline void __crypto_unregister_skcipher(struct skcipher_alg *alg)
735 {
736 	if (!list_empty(&alg->base.cra_list))
737 		crypto_unregister_skcipher(alg);
738 }
739 
740 static void paes_s390_fini(void)
741 {
742 	__crypto_unregister_skcipher(&ctr_paes_alg);
743 	__crypto_unregister_skcipher(&xts_paes_alg);
744 	__crypto_unregister_skcipher(&cbc_paes_alg);
745 	__crypto_unregister_skcipher(&ecb_paes_alg);
746 	if (ctrblk)
747 		free_page((unsigned long) ctrblk);
748 }
749 
750 static int __init paes_s390_init(void)
751 {
752 	int ret;
753 
754 	/* Query available functions for KM, KMC and KMCTR */
755 	cpacf_query(CPACF_KM, &km_functions);
756 	cpacf_query(CPACF_KMC, &kmc_functions);
757 	cpacf_query(CPACF_KMCTR, &kmctr_functions);
758 
759 	if (cpacf_test_func(&km_functions, CPACF_KM_PAES_128) ||
760 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_192) ||
761 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_256)) {
762 		ret = crypto_register_skcipher(&ecb_paes_alg);
763 		if (ret)
764 			goto out_err;
765 	}
766 
767 	if (cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
768 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
769 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256)) {
770 		ret = crypto_register_skcipher(&cbc_paes_alg);
771 		if (ret)
772 			goto out_err;
773 	}
774 
775 	if (cpacf_test_func(&km_functions, CPACF_KM_PXTS_128) ||
776 	    cpacf_test_func(&km_functions, CPACF_KM_PXTS_256)) {
777 		ret = crypto_register_skcipher(&xts_paes_alg);
778 		if (ret)
779 			goto out_err;
780 	}
781 
782 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_128) ||
783 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_192) ||
784 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_256)) {
785 		ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
786 		if (!ctrblk) {
787 			ret = -ENOMEM;
788 			goto out_err;
789 		}
790 		ret = crypto_register_skcipher(&ctr_paes_alg);
791 		if (ret)
792 			goto out_err;
793 	}
794 
795 	return 0;
796 out_err:
797 	paes_s390_fini();
798 	return ret;
799 }
800 
801 module_init(paes_s390_init);
802 module_exit(paes_s390_fini);
803 
804 MODULE_ALIAS_CRYPTO("paes");
805 
806 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm with protected keys");
807 MODULE_LICENSE("GPL");
808