xref: /linux/arch/s390/crypto/paes_s390.c (revision 0340dc4c82590d8735c58cf904a8aa1173273ab5)
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 MAXEP11AESKEYBLOBSIZE
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 	return pkey_keyblob2pkey(kb->key, kb->keylen,
129 				 pk->protkey, &pk->len, &pk->type);
130 }
131 
132 static inline int __paes_convert_key(struct s390_paes_ctx *ctx)
133 {
134 	int ret;
135 	struct pkey_protkey pkey;
136 
137 	pkey.len = sizeof(pkey.protkey);
138 	ret = __paes_keyblob2pkey(&ctx->kb, &pkey);
139 	if (ret)
140 		return ret;
141 
142 	spin_lock_bh(&ctx->pk_lock);
143 	memcpy(&ctx->pk, &pkey, sizeof(pkey));
144 	spin_unlock_bh(&ctx->pk_lock);
145 
146 	return 0;
147 }
148 
149 static int ecb_paes_init(struct crypto_skcipher *tfm)
150 {
151 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
152 
153 	ctx->kb.key = NULL;
154 	spin_lock_init(&ctx->pk_lock);
155 
156 	return 0;
157 }
158 
159 static void ecb_paes_exit(struct crypto_skcipher *tfm)
160 {
161 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
162 
163 	_free_kb_keybuf(&ctx->kb);
164 }
165 
166 static inline int __ecb_paes_set_key(struct s390_paes_ctx *ctx)
167 {
168 	int rc;
169 	unsigned long fc;
170 
171 	rc = __paes_convert_key(ctx);
172 	if (rc)
173 		return rc;
174 
175 	/* Pick the correct function code based on the protected key type */
176 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PAES_128 :
177 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KM_PAES_192 :
178 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KM_PAES_256 : 0;
179 
180 	/* Check if the function code is available */
181 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
182 
183 	return ctx->fc ? 0 : -EINVAL;
184 }
185 
186 static int ecb_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
187 			    unsigned int key_len)
188 {
189 	int rc;
190 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
191 
192 	_free_kb_keybuf(&ctx->kb);
193 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
194 	if (rc)
195 		return rc;
196 
197 	return __ecb_paes_set_key(ctx);
198 }
199 
200 static int ecb_paes_crypt(struct skcipher_request *req, unsigned long modifier)
201 {
202 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
203 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
204 	struct skcipher_walk walk;
205 	unsigned int nbytes, n, k;
206 	int ret;
207 	struct {
208 		u8 key[MAXPROTKEYSIZE];
209 	} param;
210 
211 	ret = skcipher_walk_virt(&walk, req, false);
212 	if (ret)
213 		return ret;
214 
215 	spin_lock_bh(&ctx->pk_lock);
216 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
217 	spin_unlock_bh(&ctx->pk_lock);
218 
219 	while ((nbytes = walk.nbytes) != 0) {
220 		/* only use complete blocks */
221 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
222 		k = cpacf_km(ctx->fc | modifier, &param,
223 			     walk.dst.virt.addr, walk.src.virt.addr, n);
224 		if (k)
225 			ret = skcipher_walk_done(&walk, nbytes - k);
226 		if (k < n) {
227 			if (__paes_convert_key(ctx))
228 				return skcipher_walk_done(&walk, -EIO);
229 			spin_lock_bh(&ctx->pk_lock);
230 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
231 			spin_unlock_bh(&ctx->pk_lock);
232 		}
233 	}
234 	return ret;
235 }
236 
237 static int ecb_paes_encrypt(struct skcipher_request *req)
238 {
239 	return ecb_paes_crypt(req, 0);
240 }
241 
242 static int ecb_paes_decrypt(struct skcipher_request *req)
243 {
244 	return ecb_paes_crypt(req, CPACF_DECRYPT);
245 }
246 
247 static struct skcipher_alg ecb_paes_alg = {
248 	.base.cra_name		=	"ecb(paes)",
249 	.base.cra_driver_name	=	"ecb-paes-s390",
250 	.base.cra_priority	=	401,	/* combo: aes + ecb + 1 */
251 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
252 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
253 	.base.cra_module	=	THIS_MODULE,
254 	.base.cra_list		=	LIST_HEAD_INIT(ecb_paes_alg.base.cra_list),
255 	.init			=	ecb_paes_init,
256 	.exit			=	ecb_paes_exit,
257 	.min_keysize		=	PAES_MIN_KEYSIZE,
258 	.max_keysize		=	PAES_MAX_KEYSIZE,
259 	.setkey			=	ecb_paes_set_key,
260 	.encrypt		=	ecb_paes_encrypt,
261 	.decrypt		=	ecb_paes_decrypt,
262 };
263 
264 static int cbc_paes_init(struct crypto_skcipher *tfm)
265 {
266 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
267 
268 	ctx->kb.key = NULL;
269 	spin_lock_init(&ctx->pk_lock);
270 
271 	return 0;
272 }
273 
274 static void cbc_paes_exit(struct crypto_skcipher *tfm)
275 {
276 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
277 
278 	_free_kb_keybuf(&ctx->kb);
279 }
280 
281 static inline int __cbc_paes_set_key(struct s390_paes_ctx *ctx)
282 {
283 	int rc;
284 	unsigned long fc;
285 
286 	rc = __paes_convert_key(ctx);
287 	if (rc)
288 		return rc;
289 
290 	/* Pick the correct function code based on the protected key type */
291 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMC_PAES_128 :
292 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMC_PAES_192 :
293 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KMC_PAES_256 : 0;
294 
295 	/* Check if the function code is available */
296 	ctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
297 
298 	return ctx->fc ? 0 : -EINVAL;
299 }
300 
301 static int cbc_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
302 			    unsigned int key_len)
303 {
304 	int rc;
305 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
306 
307 	_free_kb_keybuf(&ctx->kb);
308 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
309 	if (rc)
310 		return rc;
311 
312 	return __cbc_paes_set_key(ctx);
313 }
314 
315 static int cbc_paes_crypt(struct skcipher_request *req, unsigned long modifier)
316 {
317 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
318 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
319 	struct skcipher_walk walk;
320 	unsigned int nbytes, n, k;
321 	int ret;
322 	struct {
323 		u8 iv[AES_BLOCK_SIZE];
324 		u8 key[MAXPROTKEYSIZE];
325 	} param;
326 
327 	ret = skcipher_walk_virt(&walk, req, false);
328 	if (ret)
329 		return ret;
330 
331 	memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
332 	spin_lock_bh(&ctx->pk_lock);
333 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
334 	spin_unlock_bh(&ctx->pk_lock);
335 
336 	while ((nbytes = walk.nbytes) != 0) {
337 		/* only use complete blocks */
338 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
339 		k = cpacf_kmc(ctx->fc | modifier, &param,
340 			      walk.dst.virt.addr, walk.src.virt.addr, n);
341 		if (k) {
342 			memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
343 			ret = skcipher_walk_done(&walk, nbytes - k);
344 		}
345 		if (k < n) {
346 			if (__paes_convert_key(ctx))
347 				return skcipher_walk_done(&walk, -EIO);
348 			spin_lock_bh(&ctx->pk_lock);
349 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
350 			spin_unlock_bh(&ctx->pk_lock);
351 		}
352 	}
353 	return ret;
354 }
355 
356 static int cbc_paes_encrypt(struct skcipher_request *req)
357 {
358 	return cbc_paes_crypt(req, 0);
359 }
360 
361 static int cbc_paes_decrypt(struct skcipher_request *req)
362 {
363 	return cbc_paes_crypt(req, CPACF_DECRYPT);
364 }
365 
366 static struct skcipher_alg cbc_paes_alg = {
367 	.base.cra_name		=	"cbc(paes)",
368 	.base.cra_driver_name	=	"cbc-paes-s390",
369 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
370 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
371 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
372 	.base.cra_module	=	THIS_MODULE,
373 	.base.cra_list		=	LIST_HEAD_INIT(cbc_paes_alg.base.cra_list),
374 	.init			=	cbc_paes_init,
375 	.exit			=	cbc_paes_exit,
376 	.min_keysize		=	PAES_MIN_KEYSIZE,
377 	.max_keysize		=	PAES_MAX_KEYSIZE,
378 	.ivsize			=	AES_BLOCK_SIZE,
379 	.setkey			=	cbc_paes_set_key,
380 	.encrypt		=	cbc_paes_encrypt,
381 	.decrypt		=	cbc_paes_decrypt,
382 };
383 
384 static int xts_paes_init(struct crypto_skcipher *tfm)
385 {
386 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
387 
388 	ctx->kb[0].key = NULL;
389 	ctx->kb[1].key = NULL;
390 	spin_lock_init(&ctx->pk_lock);
391 
392 	return 0;
393 }
394 
395 static void xts_paes_exit(struct crypto_skcipher *tfm)
396 {
397 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
398 
399 	_free_kb_keybuf(&ctx->kb[0]);
400 	_free_kb_keybuf(&ctx->kb[1]);
401 }
402 
403 static inline int __xts_paes_convert_key(struct s390_pxts_ctx *ctx)
404 {
405 	struct pkey_protkey pkey0, pkey1;
406 
407 	pkey0.len = sizeof(pkey0.protkey);
408 	pkey1.len = sizeof(pkey1.protkey);
409 
410 	if (__paes_keyblob2pkey(&ctx->kb[0], &pkey0) ||
411 	    __paes_keyblob2pkey(&ctx->kb[1], &pkey1))
412 		return -EINVAL;
413 
414 	spin_lock_bh(&ctx->pk_lock);
415 	memcpy(&ctx->pk[0], &pkey0, sizeof(pkey0));
416 	memcpy(&ctx->pk[1], &pkey1, sizeof(pkey1));
417 	spin_unlock_bh(&ctx->pk_lock);
418 
419 	return 0;
420 }
421 
422 static inline int __xts_paes_set_key(struct s390_pxts_ctx *ctx)
423 {
424 	unsigned long fc;
425 
426 	if (__xts_paes_convert_key(ctx))
427 		return -EINVAL;
428 
429 	if (ctx->pk[0].type != ctx->pk[1].type)
430 		return -EINVAL;
431 
432 	/* Pick the correct function code based on the protected key type */
433 	fc = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PXTS_128 :
434 		(ctx->pk[0].type == PKEY_KEYTYPE_AES_256) ?
435 		CPACF_KM_PXTS_256 : 0;
436 
437 	/* Check if the function code is available */
438 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
439 
440 	return ctx->fc ? 0 : -EINVAL;
441 }
442 
443 static int xts_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
444 			    unsigned int xts_key_len)
445 {
446 	int rc;
447 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
448 	u8 ckey[2 * AES_MAX_KEY_SIZE];
449 	unsigned int ckey_len, key_len;
450 
451 	if (xts_key_len % 2)
452 		return -EINVAL;
453 
454 	key_len = xts_key_len / 2;
455 
456 	_free_kb_keybuf(&ctx->kb[0]);
457 	_free_kb_keybuf(&ctx->kb[1]);
458 	rc = _key_to_kb(&ctx->kb[0], in_key, key_len);
459 	if (rc)
460 		return rc;
461 	rc = _key_to_kb(&ctx->kb[1], in_key + key_len, key_len);
462 	if (rc)
463 		return rc;
464 
465 	rc = __xts_paes_set_key(ctx);
466 	if (rc)
467 		return rc;
468 
469 	/*
470 	 * xts_verify_key verifies the key length is not odd and makes
471 	 * sure that the two keys are not the same. This can be done
472 	 * on the two protected keys as well
473 	 */
474 	ckey_len = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ?
475 		AES_KEYSIZE_128 : AES_KEYSIZE_256;
476 	memcpy(ckey, ctx->pk[0].protkey, ckey_len);
477 	memcpy(ckey + ckey_len, ctx->pk[1].protkey, ckey_len);
478 	return xts_verify_key(tfm, ckey, 2*ckey_len);
479 }
480 
481 static int xts_paes_crypt(struct skcipher_request *req, unsigned long modifier)
482 {
483 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
484 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
485 	struct skcipher_walk walk;
486 	unsigned int keylen, offset, nbytes, n, k;
487 	int ret;
488 	struct {
489 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
490 		u8 tweak[16];
491 		u8 block[16];
492 		u8 bit[16];
493 		u8 xts[16];
494 	} pcc_param;
495 	struct {
496 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
497 		u8 init[16];
498 	} xts_param;
499 
500 	ret = skcipher_walk_virt(&walk, req, false);
501 	if (ret)
502 		return ret;
503 
504 	keylen = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 48 : 64;
505 	offset = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 16 : 0;
506 
507 	memset(&pcc_param, 0, sizeof(pcc_param));
508 	memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
509 	spin_lock_bh(&ctx->pk_lock);
510 	memcpy(pcc_param.key + offset, ctx->pk[1].protkey, keylen);
511 	memcpy(xts_param.key + offset, ctx->pk[0].protkey, keylen);
512 	spin_unlock_bh(&ctx->pk_lock);
513 	cpacf_pcc(ctx->fc, pcc_param.key + offset);
514 	memcpy(xts_param.init, pcc_param.xts, 16);
515 
516 	while ((nbytes = walk.nbytes) != 0) {
517 		/* only use complete blocks */
518 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
519 		k = cpacf_km(ctx->fc | modifier, xts_param.key + offset,
520 			     walk.dst.virt.addr, walk.src.virt.addr, n);
521 		if (k)
522 			ret = skcipher_walk_done(&walk, nbytes - k);
523 		if (k < n) {
524 			if (__xts_paes_convert_key(ctx))
525 				return skcipher_walk_done(&walk, -EIO);
526 			spin_lock_bh(&ctx->pk_lock);
527 			memcpy(xts_param.key + offset,
528 			       ctx->pk[0].protkey, keylen);
529 			spin_unlock_bh(&ctx->pk_lock);
530 		}
531 	}
532 
533 	return ret;
534 }
535 
536 static int xts_paes_encrypt(struct skcipher_request *req)
537 {
538 	return xts_paes_crypt(req, 0);
539 }
540 
541 static int xts_paes_decrypt(struct skcipher_request *req)
542 {
543 	return xts_paes_crypt(req, CPACF_DECRYPT);
544 }
545 
546 static struct skcipher_alg xts_paes_alg = {
547 	.base.cra_name		=	"xts(paes)",
548 	.base.cra_driver_name	=	"xts-paes-s390",
549 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
550 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
551 	.base.cra_ctxsize	=	sizeof(struct s390_pxts_ctx),
552 	.base.cra_module	=	THIS_MODULE,
553 	.base.cra_list		=	LIST_HEAD_INIT(xts_paes_alg.base.cra_list),
554 	.init			=	xts_paes_init,
555 	.exit			=	xts_paes_exit,
556 	.min_keysize		=	2 * PAES_MIN_KEYSIZE,
557 	.max_keysize		=	2 * PAES_MAX_KEYSIZE,
558 	.ivsize			=	AES_BLOCK_SIZE,
559 	.setkey			=	xts_paes_set_key,
560 	.encrypt		=	xts_paes_encrypt,
561 	.decrypt		=	xts_paes_decrypt,
562 };
563 
564 static int ctr_paes_init(struct crypto_skcipher *tfm)
565 {
566 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
567 
568 	ctx->kb.key = NULL;
569 	spin_lock_init(&ctx->pk_lock);
570 
571 	return 0;
572 }
573 
574 static void ctr_paes_exit(struct crypto_skcipher *tfm)
575 {
576 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
577 
578 	_free_kb_keybuf(&ctx->kb);
579 }
580 
581 static inline int __ctr_paes_set_key(struct s390_paes_ctx *ctx)
582 {
583 	int rc;
584 	unsigned long fc;
585 
586 	rc = __paes_convert_key(ctx);
587 	if (rc)
588 		return rc;
589 
590 	/* Pick the correct function code based on the protected key type */
591 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMCTR_PAES_128 :
592 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMCTR_PAES_192 :
593 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ?
594 		CPACF_KMCTR_PAES_256 : 0;
595 
596 	/* Check if the function code is available */
597 	ctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
598 
599 	return ctx->fc ? 0 : -EINVAL;
600 }
601 
602 static int ctr_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
603 			    unsigned int key_len)
604 {
605 	int rc;
606 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
607 
608 	_free_kb_keybuf(&ctx->kb);
609 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
610 	if (rc)
611 		return rc;
612 
613 	return __ctr_paes_set_key(ctx);
614 }
615 
616 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
617 {
618 	unsigned int i, n;
619 
620 	/* only use complete blocks, max. PAGE_SIZE */
621 	memcpy(ctrptr, iv, AES_BLOCK_SIZE);
622 	n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
623 	for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
624 		memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
625 		crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
626 		ctrptr += AES_BLOCK_SIZE;
627 	}
628 	return n;
629 }
630 
631 static int ctr_paes_crypt(struct skcipher_request *req)
632 {
633 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
634 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
635 	u8 buf[AES_BLOCK_SIZE], *ctrptr;
636 	struct skcipher_walk walk;
637 	unsigned int nbytes, n, k;
638 	int ret, locked;
639 	struct {
640 		u8 key[MAXPROTKEYSIZE];
641 	} param;
642 
643 	ret = skcipher_walk_virt(&walk, req, false);
644 	if (ret)
645 		return ret;
646 
647 	spin_lock_bh(&ctx->pk_lock);
648 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
649 	spin_unlock_bh(&ctx->pk_lock);
650 
651 	locked = mutex_trylock(&ctrblk_lock);
652 
653 	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
654 		n = AES_BLOCK_SIZE;
655 		if (nbytes >= 2*AES_BLOCK_SIZE && locked)
656 			n = __ctrblk_init(ctrblk, walk.iv, nbytes);
657 		ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
658 		k = cpacf_kmctr(ctx->fc, &param, walk.dst.virt.addr,
659 				walk.src.virt.addr, n, ctrptr);
660 		if (k) {
661 			if (ctrptr == ctrblk)
662 				memcpy(walk.iv, ctrptr + k - AES_BLOCK_SIZE,
663 				       AES_BLOCK_SIZE);
664 			crypto_inc(walk.iv, AES_BLOCK_SIZE);
665 			ret = skcipher_walk_done(&walk, nbytes - k);
666 		}
667 		if (k < n) {
668 			if (__paes_convert_key(ctx)) {
669 				if (locked)
670 					mutex_unlock(&ctrblk_lock);
671 				return skcipher_walk_done(&walk, -EIO);
672 			}
673 			spin_lock_bh(&ctx->pk_lock);
674 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
675 			spin_unlock_bh(&ctx->pk_lock);
676 		}
677 	}
678 	if (locked)
679 		mutex_unlock(&ctrblk_lock);
680 	/*
681 	 * final block may be < AES_BLOCK_SIZE, copy only nbytes
682 	 */
683 	if (nbytes) {
684 		memset(buf, 0, AES_BLOCK_SIZE);
685 		memcpy(buf, walk.src.virt.addr, nbytes);
686 		while (1) {
687 			if (cpacf_kmctr(ctx->fc, &param, buf,
688 					buf, AES_BLOCK_SIZE,
689 					walk.iv) == AES_BLOCK_SIZE)
690 				break;
691 			if (__paes_convert_key(ctx))
692 				return skcipher_walk_done(&walk, -EIO);
693 			spin_lock_bh(&ctx->pk_lock);
694 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
695 			spin_unlock_bh(&ctx->pk_lock);
696 		}
697 		memcpy(walk.dst.virt.addr, buf, nbytes);
698 		crypto_inc(walk.iv, AES_BLOCK_SIZE);
699 		ret = skcipher_walk_done(&walk, nbytes);
700 	}
701 
702 	return ret;
703 }
704 
705 static struct skcipher_alg ctr_paes_alg = {
706 	.base.cra_name		=	"ctr(paes)",
707 	.base.cra_driver_name	=	"ctr-paes-s390",
708 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
709 	.base.cra_blocksize	=	1,
710 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
711 	.base.cra_module	=	THIS_MODULE,
712 	.base.cra_list		=	LIST_HEAD_INIT(ctr_paes_alg.base.cra_list),
713 	.init			=	ctr_paes_init,
714 	.exit			=	ctr_paes_exit,
715 	.min_keysize		=	PAES_MIN_KEYSIZE,
716 	.max_keysize		=	PAES_MAX_KEYSIZE,
717 	.ivsize			=	AES_BLOCK_SIZE,
718 	.setkey			=	ctr_paes_set_key,
719 	.encrypt		=	ctr_paes_crypt,
720 	.decrypt		=	ctr_paes_crypt,
721 	.chunksize		=	AES_BLOCK_SIZE,
722 };
723 
724 static inline void __crypto_unregister_skcipher(struct skcipher_alg *alg)
725 {
726 	if (!list_empty(&alg->base.cra_list))
727 		crypto_unregister_skcipher(alg);
728 }
729 
730 static void paes_s390_fini(void)
731 {
732 	__crypto_unregister_skcipher(&ctr_paes_alg);
733 	__crypto_unregister_skcipher(&xts_paes_alg);
734 	__crypto_unregister_skcipher(&cbc_paes_alg);
735 	__crypto_unregister_skcipher(&ecb_paes_alg);
736 	if (ctrblk)
737 		free_page((unsigned long) ctrblk);
738 }
739 
740 static int __init paes_s390_init(void)
741 {
742 	int ret;
743 
744 	/* Query available functions for KM, KMC and KMCTR */
745 	cpacf_query(CPACF_KM, &km_functions);
746 	cpacf_query(CPACF_KMC, &kmc_functions);
747 	cpacf_query(CPACF_KMCTR, &kmctr_functions);
748 
749 	if (cpacf_test_func(&km_functions, CPACF_KM_PAES_128) ||
750 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_192) ||
751 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_256)) {
752 		ret = crypto_register_skcipher(&ecb_paes_alg);
753 		if (ret)
754 			goto out_err;
755 	}
756 
757 	if (cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
758 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
759 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256)) {
760 		ret = crypto_register_skcipher(&cbc_paes_alg);
761 		if (ret)
762 			goto out_err;
763 	}
764 
765 	if (cpacf_test_func(&km_functions, CPACF_KM_PXTS_128) ||
766 	    cpacf_test_func(&km_functions, CPACF_KM_PXTS_256)) {
767 		ret = crypto_register_skcipher(&xts_paes_alg);
768 		if (ret)
769 			goto out_err;
770 	}
771 
772 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_128) ||
773 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_192) ||
774 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_256)) {
775 		ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
776 		if (!ctrblk) {
777 			ret = -ENOMEM;
778 			goto out_err;
779 		}
780 		ret = crypto_register_skcipher(&ctr_paes_alg);
781 		if (ret)
782 			goto out_err;
783 	}
784 
785 	return 0;
786 out_err:
787 	paes_s390_fini();
788 	return ret;
789 }
790 
791 module_init(paes_s390_init);
792 module_exit(paes_s390_fini);
793 
794 MODULE_ALIAS_CRYPTO("paes");
795 
796 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm with protected keys");
797 MODULE_LICENSE("GPL");
798