xref: /openbmc/linux/arch/s390/crypto/paes_s390.c (revision 5c816641)
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. 2017,2020
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(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, pk);
136 		if (ret == 0)
137 			break;
138 	}
139 
140 	return ret;
141 }
142 
143 static inline int __paes_convert_key(struct s390_paes_ctx *ctx)
144 {
145 	int ret;
146 	struct pkey_protkey pkey;
147 
148 	ret = __paes_keyblob2pkey(&ctx->kb, &pkey);
149 	if (ret)
150 		return ret;
151 
152 	spin_lock_bh(&ctx->pk_lock);
153 	memcpy(&ctx->pk, &pkey, sizeof(pkey));
154 	spin_unlock_bh(&ctx->pk_lock);
155 
156 	return 0;
157 }
158 
159 static int ecb_paes_init(struct crypto_skcipher *tfm)
160 {
161 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
162 
163 	ctx->kb.key = NULL;
164 	spin_lock_init(&ctx->pk_lock);
165 
166 	return 0;
167 }
168 
169 static void ecb_paes_exit(struct crypto_skcipher *tfm)
170 {
171 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
172 
173 	_free_kb_keybuf(&ctx->kb);
174 }
175 
176 static inline int __ecb_paes_set_key(struct s390_paes_ctx *ctx)
177 {
178 	int rc;
179 	unsigned long fc;
180 
181 	rc = __paes_convert_key(ctx);
182 	if (rc)
183 		return rc;
184 
185 	/* Pick the correct function code based on the protected key type */
186 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PAES_128 :
187 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KM_PAES_192 :
188 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KM_PAES_256 : 0;
189 
190 	/* Check if the function code is available */
191 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
192 
193 	return ctx->fc ? 0 : -EINVAL;
194 }
195 
196 static int ecb_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
197 			    unsigned int key_len)
198 {
199 	int rc;
200 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
201 
202 	_free_kb_keybuf(&ctx->kb);
203 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
204 	if (rc)
205 		return rc;
206 
207 	return __ecb_paes_set_key(ctx);
208 }
209 
210 static int ecb_paes_crypt(struct skcipher_request *req, unsigned long modifier)
211 {
212 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
213 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
214 	struct skcipher_walk walk;
215 	unsigned int nbytes, n, k;
216 	int ret;
217 	struct {
218 		u8 key[MAXPROTKEYSIZE];
219 	} param;
220 
221 	ret = skcipher_walk_virt(&walk, req, false);
222 	if (ret)
223 		return ret;
224 
225 	spin_lock_bh(&ctx->pk_lock);
226 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
227 	spin_unlock_bh(&ctx->pk_lock);
228 
229 	while ((nbytes = walk.nbytes) != 0) {
230 		/* only use complete blocks */
231 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
232 		k = cpacf_km(ctx->fc | modifier, &param,
233 			     walk.dst.virt.addr, walk.src.virt.addr, n);
234 		if (k)
235 			ret = skcipher_walk_done(&walk, nbytes - k);
236 		if (k < n) {
237 			if (__paes_convert_key(ctx))
238 				return skcipher_walk_done(&walk, -EIO);
239 			spin_lock_bh(&ctx->pk_lock);
240 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
241 			spin_unlock_bh(&ctx->pk_lock);
242 		}
243 	}
244 	return ret;
245 }
246 
247 static int ecb_paes_encrypt(struct skcipher_request *req)
248 {
249 	return ecb_paes_crypt(req, 0);
250 }
251 
252 static int ecb_paes_decrypt(struct skcipher_request *req)
253 {
254 	return ecb_paes_crypt(req, CPACF_DECRYPT);
255 }
256 
257 static struct skcipher_alg ecb_paes_alg = {
258 	.base.cra_name		=	"ecb(paes)",
259 	.base.cra_driver_name	=	"ecb-paes-s390",
260 	.base.cra_priority	=	401,	/* combo: aes + ecb + 1 */
261 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
262 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
263 	.base.cra_module	=	THIS_MODULE,
264 	.base.cra_list		=	LIST_HEAD_INIT(ecb_paes_alg.base.cra_list),
265 	.init			=	ecb_paes_init,
266 	.exit			=	ecb_paes_exit,
267 	.min_keysize		=	PAES_MIN_KEYSIZE,
268 	.max_keysize		=	PAES_MAX_KEYSIZE,
269 	.setkey			=	ecb_paes_set_key,
270 	.encrypt		=	ecb_paes_encrypt,
271 	.decrypt		=	ecb_paes_decrypt,
272 };
273 
274 static int cbc_paes_init(struct crypto_skcipher *tfm)
275 {
276 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
277 
278 	ctx->kb.key = NULL;
279 	spin_lock_init(&ctx->pk_lock);
280 
281 	return 0;
282 }
283 
284 static void cbc_paes_exit(struct crypto_skcipher *tfm)
285 {
286 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
287 
288 	_free_kb_keybuf(&ctx->kb);
289 }
290 
291 static inline int __cbc_paes_set_key(struct s390_paes_ctx *ctx)
292 {
293 	int rc;
294 	unsigned long fc;
295 
296 	rc = __paes_convert_key(ctx);
297 	if (rc)
298 		return rc;
299 
300 	/* Pick the correct function code based on the protected key type */
301 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMC_PAES_128 :
302 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMC_PAES_192 :
303 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KMC_PAES_256 : 0;
304 
305 	/* Check if the function code is available */
306 	ctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
307 
308 	return ctx->fc ? 0 : -EINVAL;
309 }
310 
311 static int cbc_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
312 			    unsigned int key_len)
313 {
314 	int rc;
315 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
316 
317 	_free_kb_keybuf(&ctx->kb);
318 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
319 	if (rc)
320 		return rc;
321 
322 	return __cbc_paes_set_key(ctx);
323 }
324 
325 static int cbc_paes_crypt(struct skcipher_request *req, unsigned long modifier)
326 {
327 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
328 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
329 	struct skcipher_walk walk;
330 	unsigned int nbytes, n, k;
331 	int ret;
332 	struct {
333 		u8 iv[AES_BLOCK_SIZE];
334 		u8 key[MAXPROTKEYSIZE];
335 	} param;
336 
337 	ret = skcipher_walk_virt(&walk, req, false);
338 	if (ret)
339 		return ret;
340 
341 	memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
342 	spin_lock_bh(&ctx->pk_lock);
343 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
344 	spin_unlock_bh(&ctx->pk_lock);
345 
346 	while ((nbytes = walk.nbytes) != 0) {
347 		/* only use complete blocks */
348 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
349 		k = cpacf_kmc(ctx->fc | modifier, &param,
350 			      walk.dst.virt.addr, walk.src.virt.addr, n);
351 		if (k) {
352 			memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
353 			ret = skcipher_walk_done(&walk, nbytes - k);
354 		}
355 		if (k < n) {
356 			if (__paes_convert_key(ctx))
357 				return skcipher_walk_done(&walk, -EIO);
358 			spin_lock_bh(&ctx->pk_lock);
359 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
360 			spin_unlock_bh(&ctx->pk_lock);
361 		}
362 	}
363 	return ret;
364 }
365 
366 static int cbc_paes_encrypt(struct skcipher_request *req)
367 {
368 	return cbc_paes_crypt(req, 0);
369 }
370 
371 static int cbc_paes_decrypt(struct skcipher_request *req)
372 {
373 	return cbc_paes_crypt(req, CPACF_DECRYPT);
374 }
375 
376 static struct skcipher_alg cbc_paes_alg = {
377 	.base.cra_name		=	"cbc(paes)",
378 	.base.cra_driver_name	=	"cbc-paes-s390",
379 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
380 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
381 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
382 	.base.cra_module	=	THIS_MODULE,
383 	.base.cra_list		=	LIST_HEAD_INIT(cbc_paes_alg.base.cra_list),
384 	.init			=	cbc_paes_init,
385 	.exit			=	cbc_paes_exit,
386 	.min_keysize		=	PAES_MIN_KEYSIZE,
387 	.max_keysize		=	PAES_MAX_KEYSIZE,
388 	.ivsize			=	AES_BLOCK_SIZE,
389 	.setkey			=	cbc_paes_set_key,
390 	.encrypt		=	cbc_paes_encrypt,
391 	.decrypt		=	cbc_paes_decrypt,
392 };
393 
394 static int xts_paes_init(struct crypto_skcipher *tfm)
395 {
396 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
397 
398 	ctx->kb[0].key = NULL;
399 	ctx->kb[1].key = NULL;
400 	spin_lock_init(&ctx->pk_lock);
401 
402 	return 0;
403 }
404 
405 static void xts_paes_exit(struct crypto_skcipher *tfm)
406 {
407 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
408 
409 	_free_kb_keybuf(&ctx->kb[0]);
410 	_free_kb_keybuf(&ctx->kb[1]);
411 }
412 
413 static inline int __xts_paes_convert_key(struct s390_pxts_ctx *ctx)
414 {
415 	struct pkey_protkey pkey0, pkey1;
416 
417 	if (__paes_keyblob2pkey(&ctx->kb[0], &pkey0) ||
418 	    __paes_keyblob2pkey(&ctx->kb[1], &pkey1))
419 		return -EINVAL;
420 
421 	spin_lock_bh(&ctx->pk_lock);
422 	memcpy(&ctx->pk[0], &pkey0, sizeof(pkey0));
423 	memcpy(&ctx->pk[1], &pkey1, sizeof(pkey1));
424 	spin_unlock_bh(&ctx->pk_lock);
425 
426 	return 0;
427 }
428 
429 static inline int __xts_paes_set_key(struct s390_pxts_ctx *ctx)
430 {
431 	unsigned long fc;
432 
433 	if (__xts_paes_convert_key(ctx))
434 		return -EINVAL;
435 
436 	if (ctx->pk[0].type != ctx->pk[1].type)
437 		return -EINVAL;
438 
439 	/* Pick the correct function code based on the protected key type */
440 	fc = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PXTS_128 :
441 		(ctx->pk[0].type == PKEY_KEYTYPE_AES_256) ?
442 		CPACF_KM_PXTS_256 : 0;
443 
444 	/* Check if the function code is available */
445 	ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
446 
447 	return ctx->fc ? 0 : -EINVAL;
448 }
449 
450 static int xts_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
451 			    unsigned int xts_key_len)
452 {
453 	int rc;
454 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
455 	u8 ckey[2 * AES_MAX_KEY_SIZE];
456 	unsigned int ckey_len, key_len;
457 
458 	if (xts_key_len % 2)
459 		return -EINVAL;
460 
461 	key_len = xts_key_len / 2;
462 
463 	_free_kb_keybuf(&ctx->kb[0]);
464 	_free_kb_keybuf(&ctx->kb[1]);
465 	rc = _key_to_kb(&ctx->kb[0], in_key, key_len);
466 	if (rc)
467 		return rc;
468 	rc = _key_to_kb(&ctx->kb[1], in_key + key_len, key_len);
469 	if (rc)
470 		return rc;
471 
472 	rc = __xts_paes_set_key(ctx);
473 	if (rc)
474 		return rc;
475 
476 	/*
477 	 * xts_check_key verifies the key length is not odd and makes
478 	 * sure that the two keys are not the same. This can be done
479 	 * on the two protected keys as well
480 	 */
481 	ckey_len = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ?
482 		AES_KEYSIZE_128 : AES_KEYSIZE_256;
483 	memcpy(ckey, ctx->pk[0].protkey, ckey_len);
484 	memcpy(ckey + ckey_len, ctx->pk[1].protkey, ckey_len);
485 	return xts_verify_key(tfm, ckey, 2*ckey_len);
486 }
487 
488 static int xts_paes_crypt(struct skcipher_request *req, unsigned long modifier)
489 {
490 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
491 	struct s390_pxts_ctx *ctx = crypto_skcipher_ctx(tfm);
492 	struct skcipher_walk walk;
493 	unsigned int keylen, offset, nbytes, n, k;
494 	int ret;
495 	struct {
496 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
497 		u8 tweak[16];
498 		u8 block[16];
499 		u8 bit[16];
500 		u8 xts[16];
501 	} pcc_param;
502 	struct {
503 		u8 key[MAXPROTKEYSIZE];	/* key + verification pattern */
504 		u8 init[16];
505 	} xts_param;
506 
507 	ret = skcipher_walk_virt(&walk, req, false);
508 	if (ret)
509 		return ret;
510 
511 	keylen = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 48 : 64;
512 	offset = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 16 : 0;
513 
514 	memset(&pcc_param, 0, sizeof(pcc_param));
515 	memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
516 	spin_lock_bh(&ctx->pk_lock);
517 	memcpy(pcc_param.key + offset, ctx->pk[1].protkey, keylen);
518 	memcpy(xts_param.key + offset, ctx->pk[0].protkey, keylen);
519 	spin_unlock_bh(&ctx->pk_lock);
520 	cpacf_pcc(ctx->fc, pcc_param.key + offset);
521 	memcpy(xts_param.init, pcc_param.xts, 16);
522 
523 	while ((nbytes = walk.nbytes) != 0) {
524 		/* only use complete blocks */
525 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
526 		k = cpacf_km(ctx->fc | modifier, xts_param.key + offset,
527 			     walk.dst.virt.addr, walk.src.virt.addr, n);
528 		if (k)
529 			ret = skcipher_walk_done(&walk, nbytes - k);
530 		if (k < n) {
531 			if (__xts_paes_convert_key(ctx))
532 				return skcipher_walk_done(&walk, -EIO);
533 			spin_lock_bh(&ctx->pk_lock);
534 			memcpy(xts_param.key + offset,
535 			       ctx->pk[0].protkey, keylen);
536 			spin_unlock_bh(&ctx->pk_lock);
537 		}
538 	}
539 
540 	return ret;
541 }
542 
543 static int xts_paes_encrypt(struct skcipher_request *req)
544 {
545 	return xts_paes_crypt(req, 0);
546 }
547 
548 static int xts_paes_decrypt(struct skcipher_request *req)
549 {
550 	return xts_paes_crypt(req, CPACF_DECRYPT);
551 }
552 
553 static struct skcipher_alg xts_paes_alg = {
554 	.base.cra_name		=	"xts(paes)",
555 	.base.cra_driver_name	=	"xts-paes-s390",
556 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
557 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
558 	.base.cra_ctxsize	=	sizeof(struct s390_pxts_ctx),
559 	.base.cra_module	=	THIS_MODULE,
560 	.base.cra_list		=	LIST_HEAD_INIT(xts_paes_alg.base.cra_list),
561 	.init			=	xts_paes_init,
562 	.exit			=	xts_paes_exit,
563 	.min_keysize		=	2 * PAES_MIN_KEYSIZE,
564 	.max_keysize		=	2 * PAES_MAX_KEYSIZE,
565 	.ivsize			=	AES_BLOCK_SIZE,
566 	.setkey			=	xts_paes_set_key,
567 	.encrypt		=	xts_paes_encrypt,
568 	.decrypt		=	xts_paes_decrypt,
569 };
570 
571 static int ctr_paes_init(struct crypto_skcipher *tfm)
572 {
573 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
574 
575 	ctx->kb.key = NULL;
576 	spin_lock_init(&ctx->pk_lock);
577 
578 	return 0;
579 }
580 
581 static void ctr_paes_exit(struct crypto_skcipher *tfm)
582 {
583 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
584 
585 	_free_kb_keybuf(&ctx->kb);
586 }
587 
588 static inline int __ctr_paes_set_key(struct s390_paes_ctx *ctx)
589 {
590 	int rc;
591 	unsigned long fc;
592 
593 	rc = __paes_convert_key(ctx);
594 	if (rc)
595 		return rc;
596 
597 	/* Pick the correct function code based on the protected key type */
598 	fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMCTR_PAES_128 :
599 		(ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMCTR_PAES_192 :
600 		(ctx->pk.type == PKEY_KEYTYPE_AES_256) ?
601 		CPACF_KMCTR_PAES_256 : 0;
602 
603 	/* Check if the function code is available */
604 	ctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
605 
606 	return ctx->fc ? 0 : -EINVAL;
607 }
608 
609 static int ctr_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
610 			    unsigned int key_len)
611 {
612 	int rc;
613 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
614 
615 	_free_kb_keybuf(&ctx->kb);
616 	rc = _key_to_kb(&ctx->kb, in_key, key_len);
617 	if (rc)
618 		return rc;
619 
620 	return __ctr_paes_set_key(ctx);
621 }
622 
623 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
624 {
625 	unsigned int i, n;
626 
627 	/* only use complete blocks, max. PAGE_SIZE */
628 	memcpy(ctrptr, iv, AES_BLOCK_SIZE);
629 	n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
630 	for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
631 		memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
632 		crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
633 		ctrptr += AES_BLOCK_SIZE;
634 	}
635 	return n;
636 }
637 
638 static int ctr_paes_crypt(struct skcipher_request *req)
639 {
640 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
641 	struct s390_paes_ctx *ctx = crypto_skcipher_ctx(tfm);
642 	u8 buf[AES_BLOCK_SIZE], *ctrptr;
643 	struct skcipher_walk walk;
644 	unsigned int nbytes, n, k;
645 	int ret, locked;
646 	struct {
647 		u8 key[MAXPROTKEYSIZE];
648 	} param;
649 
650 	ret = skcipher_walk_virt(&walk, req, false);
651 	if (ret)
652 		return ret;
653 
654 	spin_lock_bh(&ctx->pk_lock);
655 	memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
656 	spin_unlock_bh(&ctx->pk_lock);
657 
658 	locked = mutex_trylock(&ctrblk_lock);
659 
660 	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
661 		n = AES_BLOCK_SIZE;
662 		if (nbytes >= 2*AES_BLOCK_SIZE && locked)
663 			n = __ctrblk_init(ctrblk, walk.iv, nbytes);
664 		ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
665 		k = cpacf_kmctr(ctx->fc, &param, walk.dst.virt.addr,
666 				walk.src.virt.addr, n, ctrptr);
667 		if (k) {
668 			if (ctrptr == ctrblk)
669 				memcpy(walk.iv, ctrptr + k - AES_BLOCK_SIZE,
670 				       AES_BLOCK_SIZE);
671 			crypto_inc(walk.iv, AES_BLOCK_SIZE);
672 			ret = skcipher_walk_done(&walk, nbytes - k);
673 		}
674 		if (k < n) {
675 			if (__paes_convert_key(ctx)) {
676 				if (locked)
677 					mutex_unlock(&ctrblk_lock);
678 				return skcipher_walk_done(&walk, -EIO);
679 			}
680 			spin_lock_bh(&ctx->pk_lock);
681 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
682 			spin_unlock_bh(&ctx->pk_lock);
683 		}
684 	}
685 	if (locked)
686 		mutex_unlock(&ctrblk_lock);
687 	/*
688 	 * final block may be < AES_BLOCK_SIZE, copy only nbytes
689 	 */
690 	if (nbytes) {
691 		while (1) {
692 			if (cpacf_kmctr(ctx->fc, &param, buf,
693 					walk.src.virt.addr, AES_BLOCK_SIZE,
694 					walk.iv) == AES_BLOCK_SIZE)
695 				break;
696 			if (__paes_convert_key(ctx))
697 				return skcipher_walk_done(&walk, -EIO);
698 			spin_lock_bh(&ctx->pk_lock);
699 			memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
700 			spin_unlock_bh(&ctx->pk_lock);
701 		}
702 		memcpy(walk.dst.virt.addr, buf, nbytes);
703 		crypto_inc(walk.iv, AES_BLOCK_SIZE);
704 		ret = skcipher_walk_done(&walk, nbytes);
705 	}
706 
707 	return ret;
708 }
709 
710 static struct skcipher_alg ctr_paes_alg = {
711 	.base.cra_name		=	"ctr(paes)",
712 	.base.cra_driver_name	=	"ctr-paes-s390",
713 	.base.cra_priority	=	402,	/* ecb-paes-s390 + 1 */
714 	.base.cra_blocksize	=	1,
715 	.base.cra_ctxsize	=	sizeof(struct s390_paes_ctx),
716 	.base.cra_module	=	THIS_MODULE,
717 	.base.cra_list		=	LIST_HEAD_INIT(ctr_paes_alg.base.cra_list),
718 	.init			=	ctr_paes_init,
719 	.exit			=	ctr_paes_exit,
720 	.min_keysize		=	PAES_MIN_KEYSIZE,
721 	.max_keysize		=	PAES_MAX_KEYSIZE,
722 	.ivsize			=	AES_BLOCK_SIZE,
723 	.setkey			=	ctr_paes_set_key,
724 	.encrypt		=	ctr_paes_crypt,
725 	.decrypt		=	ctr_paes_crypt,
726 	.chunksize		=	AES_BLOCK_SIZE,
727 };
728 
729 static inline void __crypto_unregister_skcipher(struct skcipher_alg *alg)
730 {
731 	if (!list_empty(&alg->base.cra_list))
732 		crypto_unregister_skcipher(alg);
733 }
734 
735 static void paes_s390_fini(void)
736 {
737 	__crypto_unregister_skcipher(&ctr_paes_alg);
738 	__crypto_unregister_skcipher(&xts_paes_alg);
739 	__crypto_unregister_skcipher(&cbc_paes_alg);
740 	__crypto_unregister_skcipher(&ecb_paes_alg);
741 	if (ctrblk)
742 		free_page((unsigned long) ctrblk);
743 }
744 
745 static int __init paes_s390_init(void)
746 {
747 	int ret;
748 
749 	/* Query available functions for KM, KMC and KMCTR */
750 	cpacf_query(CPACF_KM, &km_functions);
751 	cpacf_query(CPACF_KMC, &kmc_functions);
752 	cpacf_query(CPACF_KMCTR, &kmctr_functions);
753 
754 	if (cpacf_test_func(&km_functions, CPACF_KM_PAES_128) ||
755 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_192) ||
756 	    cpacf_test_func(&km_functions, CPACF_KM_PAES_256)) {
757 		ret = crypto_register_skcipher(&ecb_paes_alg);
758 		if (ret)
759 			goto out_err;
760 	}
761 
762 	if (cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
763 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
764 	    cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256)) {
765 		ret = crypto_register_skcipher(&cbc_paes_alg);
766 		if (ret)
767 			goto out_err;
768 	}
769 
770 	if (cpacf_test_func(&km_functions, CPACF_KM_PXTS_128) ||
771 	    cpacf_test_func(&km_functions, CPACF_KM_PXTS_256)) {
772 		ret = crypto_register_skcipher(&xts_paes_alg);
773 		if (ret)
774 			goto out_err;
775 	}
776 
777 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_128) ||
778 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_192) ||
779 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_256)) {
780 		ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
781 		if (!ctrblk) {
782 			ret = -ENOMEM;
783 			goto out_err;
784 		}
785 		ret = crypto_register_skcipher(&ctr_paes_alg);
786 		if (ret)
787 			goto out_err;
788 	}
789 
790 	return 0;
791 out_err:
792 	paes_s390_fini();
793 	return ret;
794 }
795 
796 module_init(paes_s390_init);
797 module_exit(paes_s390_fini);
798 
799 MODULE_ALIAS_CRYPTO("paes");
800 
801 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm with protected keys");
802 MODULE_LICENSE("GPL");
803