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
_key_to_kb(struct key_blob * kb,const u8 * key,unsigned int keylen)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
_free_kb_keybuf(struct key_blob * kb)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
__paes_keyblob2pkey(struct key_blob * kb,struct pkey_protkey * pk)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
__paes_convert_key(struct s390_paes_ctx * ctx)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
ecb_paes_init(struct crypto_skcipher * tfm)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
ecb_paes_exit(struct crypto_skcipher * tfm)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
__ecb_paes_set_key(struct s390_paes_ctx * ctx)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
ecb_paes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)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
ecb_paes_crypt(struct skcipher_request * req,unsigned long modifier)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, ¶m,
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
ecb_paes_encrypt(struct skcipher_request * req)249 static int ecb_paes_encrypt(struct skcipher_request *req)
250 {
251 return ecb_paes_crypt(req, 0);
252 }
253
ecb_paes_decrypt(struct skcipher_request * req)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
cbc_paes_init(struct crypto_skcipher * tfm)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
cbc_paes_exit(struct crypto_skcipher * tfm)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
__cbc_paes_set_key(struct s390_paes_ctx * ctx)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
cbc_paes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)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
cbc_paes_crypt(struct skcipher_request * req,unsigned long modifier)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, ¶m,
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
cbc_paes_encrypt(struct skcipher_request * req)368 static int cbc_paes_encrypt(struct skcipher_request *req)
369 {
370 return cbc_paes_crypt(req, 0);
371 }
372
cbc_paes_decrypt(struct skcipher_request * req)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
xts_paes_init(struct crypto_skcipher * tfm)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
xts_paes_exit(struct crypto_skcipher * tfm)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
__xts_paes_convert_key(struct s390_pxts_ctx * ctx)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
__xts_paes_set_key(struct s390_pxts_ctx * ctx)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
xts_paes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int xts_key_len)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
xts_paes_crypt(struct skcipher_request * req,unsigned long modifier)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
xts_paes_encrypt(struct skcipher_request * req)548 static int xts_paes_encrypt(struct skcipher_request *req)
549 {
550 return xts_paes_crypt(req, 0);
551 }
552
xts_paes_decrypt(struct skcipher_request * req)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
ctr_paes_init(struct crypto_skcipher * tfm)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
ctr_paes_exit(struct crypto_skcipher * tfm)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
__ctr_paes_set_key(struct s390_paes_ctx * ctx)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
ctr_paes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)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
__ctrblk_init(u8 * ctrptr,u8 * iv,unsigned int nbytes)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
ctr_paes_crypt(struct skcipher_request * req)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, ¶m, 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 memset(buf, 0, AES_BLOCK_SIZE);
697 memcpy(buf, walk.src.virt.addr, nbytes);
698 while (1) {
699 if (cpacf_kmctr(ctx->fc, ¶m, buf,
700 buf, AES_BLOCK_SIZE,
701 walk.iv) == AES_BLOCK_SIZE)
702 break;
703 if (__paes_convert_key(ctx))
704 return skcipher_walk_done(&walk, -EIO);
705 spin_lock_bh(&ctx->pk_lock);
706 memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
707 spin_unlock_bh(&ctx->pk_lock);
708 }
709 memcpy(walk.dst.virt.addr, buf, nbytes);
710 crypto_inc(walk.iv, AES_BLOCK_SIZE);
711 ret = skcipher_walk_done(&walk, nbytes);
712 }
713
714 return ret;
715 }
716
717 static struct skcipher_alg ctr_paes_alg = {
718 .base.cra_name = "ctr(paes)",
719 .base.cra_driver_name = "ctr-paes-s390",
720 .base.cra_priority = 402, /* ecb-paes-s390 + 1 */
721 .base.cra_blocksize = 1,
722 .base.cra_ctxsize = sizeof(struct s390_paes_ctx),
723 .base.cra_module = THIS_MODULE,
724 .base.cra_list = LIST_HEAD_INIT(ctr_paes_alg.base.cra_list),
725 .init = ctr_paes_init,
726 .exit = ctr_paes_exit,
727 .min_keysize = PAES_MIN_KEYSIZE,
728 .max_keysize = PAES_MAX_KEYSIZE,
729 .ivsize = AES_BLOCK_SIZE,
730 .setkey = ctr_paes_set_key,
731 .encrypt = ctr_paes_crypt,
732 .decrypt = ctr_paes_crypt,
733 .chunksize = AES_BLOCK_SIZE,
734 };
735
__crypto_unregister_skcipher(struct skcipher_alg * alg)736 static inline void __crypto_unregister_skcipher(struct skcipher_alg *alg)
737 {
738 if (!list_empty(&alg->base.cra_list))
739 crypto_unregister_skcipher(alg);
740 }
741
paes_s390_fini(void)742 static void paes_s390_fini(void)
743 {
744 __crypto_unregister_skcipher(&ctr_paes_alg);
745 __crypto_unregister_skcipher(&xts_paes_alg);
746 __crypto_unregister_skcipher(&cbc_paes_alg);
747 __crypto_unregister_skcipher(&ecb_paes_alg);
748 if (ctrblk)
749 free_page((unsigned long) ctrblk);
750 }
751
paes_s390_init(void)752 static int __init paes_s390_init(void)
753 {
754 int ret;
755
756 /* Query available functions for KM, KMC and KMCTR */
757 cpacf_query(CPACF_KM, &km_functions);
758 cpacf_query(CPACF_KMC, &kmc_functions);
759 cpacf_query(CPACF_KMCTR, &kmctr_functions);
760
761 if (cpacf_test_func(&km_functions, CPACF_KM_PAES_128) ||
762 cpacf_test_func(&km_functions, CPACF_KM_PAES_192) ||
763 cpacf_test_func(&km_functions, CPACF_KM_PAES_256)) {
764 ret = crypto_register_skcipher(&ecb_paes_alg);
765 if (ret)
766 goto out_err;
767 }
768
769 if (cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
770 cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
771 cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256)) {
772 ret = crypto_register_skcipher(&cbc_paes_alg);
773 if (ret)
774 goto out_err;
775 }
776
777 if (cpacf_test_func(&km_functions, CPACF_KM_PXTS_128) ||
778 cpacf_test_func(&km_functions, CPACF_KM_PXTS_256)) {
779 ret = crypto_register_skcipher(&xts_paes_alg);
780 if (ret)
781 goto out_err;
782 }
783
784 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_128) ||
785 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_192) ||
786 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_256)) {
787 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
788 if (!ctrblk) {
789 ret = -ENOMEM;
790 goto out_err;
791 }
792 ret = crypto_register_skcipher(&ctr_paes_alg);
793 if (ret)
794 goto out_err;
795 }
796
797 return 0;
798 out_err:
799 paes_s390_fini();
800 return ret;
801 }
802
803 module_init(paes_s390_init);
804 module_exit(paes_s390_fini);
805
806 MODULE_ALIAS_CRYPTO("paes");
807
808 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm with protected keys");
809 MODULE_LICENSE("GPL");
810