1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Cryptographic API.
4 *
5 * s390 implementation of the AES Cipher Algorithm.
6 *
7 * s390 Version:
8 * Copyright IBM Corp. 2005, 2017
9 * Author(s): Jan Glauber (jang@de.ibm.com)
10 * Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback
11 * Patrick Steuer <patrick.steuer@de.ibm.com>
12 * Harald Freudenberger <freude@de.ibm.com>
13 *
14 * Derived from "crypto/aes_generic.c"
15 */
16
17#define pr_fmt(fmt) "aes_s390: " fmt
18
19#include <crypto/aes.h>
20#include <crypto/algapi.h>
21#include <crypto/ghash.h>
22#include <crypto/internal/aead.h>
23#include <crypto/internal/cipher.h>
24#include <crypto/internal/skcipher.h>
25#include <crypto/scatterwalk.h>
26#include <linux/err.h>
27#include <linux/module.h>
28#include <linux/cpufeature.h>
29#include <linux/init.h>
30#include <linux/mutex.h>
31#include <linux/fips.h>
32#include <linux/string.h>
33#include <crypto/xts.h>
34#include <asm/cpacf.h>
35
36static u8 *ctrblk;
37static DEFINE_MUTEX(ctrblk_lock);
38
39static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
40 kma_functions;
41
42struct s390_aes_ctx {
43 u8 key[AES_MAX_KEY_SIZE];
44 int key_len;
45 unsigned long fc;
46 union {
47 struct crypto_skcipher *skcipher;
48 struct crypto_cipher *cip;
49 } fallback;
50};
51
52struct s390_xts_ctx {
53 union {
54 u8 keys[64];
55 struct {
56 u8 key[32];
57 u8 pcc_key[32];
58 };
59 };
60 int key_len;
61 unsigned long fc;
62 struct crypto_skcipher *fallback;
63};
64
65struct gcm_sg_walk {
66 struct scatter_walk walk;
67 unsigned int walk_bytes;
68 unsigned int walk_bytes_remain;
69 u8 buf[AES_BLOCK_SIZE];
70 unsigned int buf_bytes;
71 u8 *ptr;
72 unsigned int nbytes;
73};
74
75static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key,
76 unsigned int key_len)
77{
78 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
79
80 sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
81 sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags &
82 CRYPTO_TFM_REQ_MASK);
83
84 return crypto_cipher_setkey(tfm: sctx->fallback.cip, key: in_key, keylen: key_len);
85}
86
87static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
88 unsigned int key_len)
89{
90 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
91 unsigned long fc;
92
93 /* Pick the correct function code based on the key length */
94 fc = (key_len == 16) ? CPACF_KM_AES_128 :
95 (key_len == 24) ? CPACF_KM_AES_192 :
96 (key_len == 32) ? CPACF_KM_AES_256 : 0;
97
98 /* Check if the function code is available */
99 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
100 if (!sctx->fc)
101 return setkey_fallback_cip(tfm, in_key, key_len);
102
103 sctx->key_len = key_len;
104 memcpy(sctx->key, in_key, key_len);
105 return 0;
106}
107
108static void crypto_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
109{
110 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
111
112 if (unlikely(!sctx->fc)) {
113 crypto_cipher_encrypt_one(tfm: sctx->fallback.cip, dst: out, src: in);
114 return;
115 }
116 cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE);
117}
118
119static void crypto_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
120{
121 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
122
123 if (unlikely(!sctx->fc)) {
124 crypto_cipher_decrypt_one(tfm: sctx->fallback.cip, dst: out, src: in);
125 return;
126 }
127 cpacf_km(sctx->fc | CPACF_DECRYPT,
128 &sctx->key, out, in, AES_BLOCK_SIZE);
129}
130
131static int fallback_init_cip(struct crypto_tfm *tfm)
132{
133 const char *name = tfm->__crt_alg->cra_name;
134 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
135
136 sctx->fallback.cip = crypto_alloc_cipher(alg_name: name, type: 0,
137 CRYPTO_ALG_NEED_FALLBACK);
138
139 if (IS_ERR(ptr: sctx->fallback.cip)) {
140 pr_err("Allocating AES fallback algorithm %s failed\n",
141 name);
142 return PTR_ERR(ptr: sctx->fallback.cip);
143 }
144
145 return 0;
146}
147
148static void fallback_exit_cip(struct crypto_tfm *tfm)
149{
150 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
151
152 crypto_free_cipher(tfm: sctx->fallback.cip);
153 sctx->fallback.cip = NULL;
154}
155
156static struct crypto_alg aes_alg = {
157 .cra_name = "aes",
158 .cra_driver_name = "aes-s390",
159 .cra_priority = 300,
160 .cra_flags = CRYPTO_ALG_TYPE_CIPHER |
161 CRYPTO_ALG_NEED_FALLBACK,
162 .cra_blocksize = AES_BLOCK_SIZE,
163 .cra_ctxsize = sizeof(struct s390_aes_ctx),
164 .cra_module = THIS_MODULE,
165 .cra_init = fallback_init_cip,
166 .cra_exit = fallback_exit_cip,
167 .cra_u = {
168 .cipher = {
169 .cia_min_keysize = AES_MIN_KEY_SIZE,
170 .cia_max_keysize = AES_MAX_KEY_SIZE,
171 .cia_setkey = aes_set_key,
172 .cia_encrypt = crypto_aes_encrypt,
173 .cia_decrypt = crypto_aes_decrypt,
174 }
175 }
176};
177
178static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key,
179 unsigned int len)
180{
181 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
182
183 crypto_skcipher_clear_flags(tfm: sctx->fallback.skcipher,
184 CRYPTO_TFM_REQ_MASK);
185 crypto_skcipher_set_flags(tfm: sctx->fallback.skcipher,
186 flags: crypto_skcipher_get_flags(tfm) &
187 CRYPTO_TFM_REQ_MASK);
188 return crypto_skcipher_setkey(tfm: sctx->fallback.skcipher, key, keylen: len);
189}
190
191static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx,
192 struct skcipher_request *req,
193 unsigned long modifier)
194{
195 struct skcipher_request *subreq = skcipher_request_ctx(req);
196
197 *subreq = *req;
198 skcipher_request_set_tfm(req: subreq, tfm: sctx->fallback.skcipher);
199 return (modifier & CPACF_DECRYPT) ?
200 crypto_skcipher_decrypt(subreq) :
201 crypto_skcipher_encrypt(subreq);
202}
203
204static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
205 unsigned int key_len)
206{
207 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
208 unsigned long fc;
209
210 /* Pick the correct function code based on the key length */
211 fc = (key_len == 16) ? CPACF_KM_AES_128 :
212 (key_len == 24) ? CPACF_KM_AES_192 :
213 (key_len == 32) ? CPACF_KM_AES_256 : 0;
214
215 /* Check if the function code is available */
216 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
217 if (!sctx->fc)
218 return setkey_fallback_skcipher(tfm, key: in_key, len: key_len);
219
220 sctx->key_len = key_len;
221 memcpy(sctx->key, in_key, key_len);
222 return 0;
223}
224
225static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier)
226{
227 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
228 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
229 struct skcipher_walk walk;
230 unsigned int nbytes, n;
231 int ret;
232
233 if (unlikely(!sctx->fc))
234 return fallback_skcipher_crypt(sctx, req, modifier);
235
236 ret = skcipher_walk_virt(walk: &walk, req, atomic: false);
237 while ((nbytes = walk.nbytes) != 0) {
238 /* only use complete blocks */
239 n = nbytes & ~(AES_BLOCK_SIZE - 1);
240 cpacf_km(sctx->fc | modifier, sctx->key,
241 walk.dst.virt.addr, walk.src.virt.addr, n);
242 ret = skcipher_walk_done(walk: &walk, res: nbytes - n);
243 }
244 return ret;
245}
246
247static int ecb_aes_encrypt(struct skcipher_request *req)
248{
249 return ecb_aes_crypt(req, modifier: 0);
250}
251
252static int ecb_aes_decrypt(struct skcipher_request *req)
253{
254 return ecb_aes_crypt(req, modifier: CPACF_DECRYPT);
255}
256
257static int fallback_init_skcipher(struct crypto_skcipher *tfm)
258{
259 const char *name = crypto_tfm_alg_name(tfm: &tfm->base);
260 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
261
262 sctx->fallback.skcipher = crypto_alloc_skcipher(alg_name: name, type: 0,
263 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
264
265 if (IS_ERR(ptr: sctx->fallback.skcipher)) {
266 pr_err("Allocating AES fallback algorithm %s failed\n",
267 name);
268 return PTR_ERR(ptr: sctx->fallback.skcipher);
269 }
270
271 crypto_skcipher_set_reqsize(skcipher: tfm, reqsize: sizeof(struct skcipher_request) +
272 crypto_skcipher_reqsize(tfm: sctx->fallback.skcipher));
273 return 0;
274}
275
276static void fallback_exit_skcipher(struct crypto_skcipher *tfm)
277{
278 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
279
280 crypto_free_skcipher(tfm: sctx->fallback.skcipher);
281}
282
283static struct skcipher_alg ecb_aes_alg = {
284 .base.cra_name = "ecb(aes)",
285 .base.cra_driver_name = "ecb-aes-s390",
286 .base.cra_priority = 401, /* combo: aes + ecb + 1 */
287 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
288 .base.cra_blocksize = AES_BLOCK_SIZE,
289 .base.cra_ctxsize = sizeof(struct s390_aes_ctx),
290 .base.cra_module = THIS_MODULE,
291 .init = fallback_init_skcipher,
292 .exit = fallback_exit_skcipher,
293 .min_keysize = AES_MIN_KEY_SIZE,
294 .max_keysize = AES_MAX_KEY_SIZE,
295 .setkey = ecb_aes_set_key,
296 .encrypt = ecb_aes_encrypt,
297 .decrypt = ecb_aes_decrypt,
298};
299
300static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
301 unsigned int key_len)
302{
303 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
304 unsigned long fc;
305
306 /* Pick the correct function code based on the key length */
307 fc = (key_len == 16) ? CPACF_KMC_AES_128 :
308 (key_len == 24) ? CPACF_KMC_AES_192 :
309 (key_len == 32) ? CPACF_KMC_AES_256 : 0;
310
311 /* Check if the function code is available */
312 sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
313 if (!sctx->fc)
314 return setkey_fallback_skcipher(tfm, key: in_key, len: key_len);
315
316 sctx->key_len = key_len;
317 memcpy(sctx->key, in_key, key_len);
318 return 0;
319}
320
321static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier)
322{
323 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
324 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
325 struct skcipher_walk walk;
326 unsigned int nbytes, n;
327 int ret;
328 struct {
329 u8 iv[AES_BLOCK_SIZE];
330 u8 key[AES_MAX_KEY_SIZE];
331 } param;
332
333 if (unlikely(!sctx->fc))
334 return fallback_skcipher_crypt(sctx, req, modifier);
335
336 ret = skcipher_walk_virt(walk: &walk, req, atomic: false);
337 if (ret)
338 return ret;
339 memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
340 memcpy(param.key, sctx->key, sctx->key_len);
341 while ((nbytes = walk.nbytes) != 0) {
342 /* only use complete blocks */
343 n = nbytes & ~(AES_BLOCK_SIZE - 1);
344 cpacf_kmc(sctx->fc | modifier, &param,
345 walk.dst.virt.addr, walk.src.virt.addr, n);
346 memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
347 ret = skcipher_walk_done(walk: &walk, res: nbytes - n);
348 }
349 memzero_explicit(s: &param, count: sizeof(param));
350 return ret;
351}
352
353static int cbc_aes_encrypt(struct skcipher_request *req)
354{
355 return cbc_aes_crypt(req, modifier: 0);
356}
357
358static int cbc_aes_decrypt(struct skcipher_request *req)
359{
360 return cbc_aes_crypt(req, modifier: CPACF_DECRYPT);
361}
362
363static struct skcipher_alg cbc_aes_alg = {
364 .base.cra_name = "cbc(aes)",
365 .base.cra_driver_name = "cbc-aes-s390",
366 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */
367 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
368 .base.cra_blocksize = AES_BLOCK_SIZE,
369 .base.cra_ctxsize = sizeof(struct s390_aes_ctx),
370 .base.cra_module = THIS_MODULE,
371 .init = fallback_init_skcipher,
372 .exit = fallback_exit_skcipher,
373 .min_keysize = AES_MIN_KEY_SIZE,
374 .max_keysize = AES_MAX_KEY_SIZE,
375 .ivsize = AES_BLOCK_SIZE,
376 .setkey = cbc_aes_set_key,
377 .encrypt = cbc_aes_encrypt,
378 .decrypt = cbc_aes_decrypt,
379};
380
381static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key,
382 unsigned int len)
383{
384 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
385
386 crypto_skcipher_clear_flags(tfm: xts_ctx->fallback, CRYPTO_TFM_REQ_MASK);
387 crypto_skcipher_set_flags(tfm: xts_ctx->fallback,
388 flags: crypto_skcipher_get_flags(tfm) &
389 CRYPTO_TFM_REQ_MASK);
390 return crypto_skcipher_setkey(tfm: xts_ctx->fallback, key, keylen: len);
391}
392
393static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
394 unsigned int key_len)
395{
396 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
397 unsigned long fc;
398 int err;
399
400 err = xts_fallback_setkey(tfm, key: in_key, len: key_len);
401 if (err)
402 return err;
403
404 /* Pick the correct function code based on the key length */
405 fc = (key_len == 32) ? CPACF_KM_XTS_128 :
406 (key_len == 64) ? CPACF_KM_XTS_256 : 0;
407
408 /* Check if the function code is available */
409 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
410 if (!xts_ctx->fc)
411 return 0;
412
413 /* Split the XTS key into the two subkeys */
414 key_len = key_len / 2;
415 xts_ctx->key_len = key_len;
416 memcpy(xts_ctx->key, in_key, key_len);
417 memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
418 return 0;
419}
420
421static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
422{
423 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
424 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
425 struct skcipher_walk walk;
426 unsigned int offset, nbytes, n;
427 int ret;
428 struct {
429 u8 key[32];
430 u8 tweak[16];
431 u8 block[16];
432 u8 bit[16];
433 u8 xts[16];
434 } pcc_param;
435 struct {
436 u8 key[32];
437 u8 init[16];
438 } xts_param;
439
440 if (req->cryptlen < AES_BLOCK_SIZE)
441 return -EINVAL;
442
443 if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
444 struct skcipher_request *subreq = skcipher_request_ctx(req);
445
446 *subreq = *req;
447 skcipher_request_set_tfm(req: subreq, tfm: xts_ctx->fallback);
448 return (modifier & CPACF_DECRYPT) ?
449 crypto_skcipher_decrypt(subreq) :
450 crypto_skcipher_encrypt(subreq);
451 }
452
453 ret = skcipher_walk_virt(walk: &walk, req, atomic: false);
454 if (ret)
455 return ret;
456 offset = xts_ctx->key_len & 0x10;
457 memset(pcc_param.block, 0, sizeof(pcc_param.block));
458 memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
459 memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
460 memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
461 memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
462 cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
463
464 memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
465 memcpy(xts_param.init, pcc_param.xts, 16);
466
467 while ((nbytes = walk.nbytes) != 0) {
468 /* only use complete blocks */
469 n = nbytes & ~(AES_BLOCK_SIZE - 1);
470 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
471 walk.dst.virt.addr, walk.src.virt.addr, n);
472 ret = skcipher_walk_done(walk: &walk, res: nbytes - n);
473 }
474 memzero_explicit(s: &pcc_param, count: sizeof(pcc_param));
475 memzero_explicit(s: &xts_param, count: sizeof(xts_param));
476 return ret;
477}
478
479static int xts_aes_encrypt(struct skcipher_request *req)
480{
481 return xts_aes_crypt(req, modifier: 0);
482}
483
484static int xts_aes_decrypt(struct skcipher_request *req)
485{
486 return xts_aes_crypt(req, modifier: CPACF_DECRYPT);
487}
488
489static int xts_fallback_init(struct crypto_skcipher *tfm)
490{
491 const char *name = crypto_tfm_alg_name(tfm: &tfm->base);
492 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
493
494 xts_ctx->fallback = crypto_alloc_skcipher(alg_name: name, type: 0,
495 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
496
497 if (IS_ERR(ptr: xts_ctx->fallback)) {
498 pr_err("Allocating XTS fallback algorithm %s failed\n",
499 name);
500 return PTR_ERR(ptr: xts_ctx->fallback);
501 }
502 crypto_skcipher_set_reqsize(skcipher: tfm, reqsize: sizeof(struct skcipher_request) +
503 crypto_skcipher_reqsize(tfm: xts_ctx->fallback));
504 return 0;
505}
506
507static void xts_fallback_exit(struct crypto_skcipher *tfm)
508{
509 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
510
511 crypto_free_skcipher(tfm: xts_ctx->fallback);
512}
513
514static struct skcipher_alg xts_aes_alg = {
515 .base.cra_name = "xts(aes)",
516 .base.cra_driver_name = "xts-aes-s390",
517 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */
518 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
519 .base.cra_blocksize = AES_BLOCK_SIZE,
520 .base.cra_ctxsize = sizeof(struct s390_xts_ctx),
521 .base.cra_module = THIS_MODULE,
522 .init = xts_fallback_init,
523 .exit = xts_fallback_exit,
524 .min_keysize = 2 * AES_MIN_KEY_SIZE,
525 .max_keysize = 2 * AES_MAX_KEY_SIZE,
526 .ivsize = AES_BLOCK_SIZE,
527 .setkey = xts_aes_set_key,
528 .encrypt = xts_aes_encrypt,
529 .decrypt = xts_aes_decrypt,
530};
531
532static int fullxts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
533 unsigned int key_len)
534{
535 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
536 unsigned long fc;
537 int err;
538
539 err = xts_fallback_setkey(tfm, key: in_key, len: key_len);
540 if (err)
541 return err;
542
543 /* Pick the correct function code based on the key length */
544 fc = (key_len == 32) ? CPACF_KM_XTS_128_FULL :
545 (key_len == 64) ? CPACF_KM_XTS_256_FULL : 0;
546
547 /* Check if the function code is available */
548 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
549 if (!xts_ctx->fc)
550 return 0;
551
552 /* Store double-key */
553 memcpy(xts_ctx->keys, in_key, key_len);
554 xts_ctx->key_len = key_len;
555 return 0;
556}
557
558static int fullxts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
559{
560 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
561 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
562 unsigned int offset, nbytes, n;
563 struct skcipher_walk walk;
564 int ret;
565 struct {
566 __u8 key[64];
567 __u8 tweak[16];
568 __u8 nap[16];
569 } fxts_param = {
570 .nap = {0},
571 };
572
573 if (req->cryptlen < AES_BLOCK_SIZE)
574 return -EINVAL;
575
576 if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
577 struct skcipher_request *subreq = skcipher_request_ctx(req);
578
579 *subreq = *req;
580 skcipher_request_set_tfm(req: subreq, tfm: xts_ctx->fallback);
581 return (modifier & CPACF_DECRYPT) ?
582 crypto_skcipher_decrypt(subreq) :
583 crypto_skcipher_encrypt(subreq);
584 }
585
586 ret = skcipher_walk_virt(walk: &walk, req, atomic: false);
587 if (ret)
588 return ret;
589
590 offset = xts_ctx->key_len & 0x20;
591 memcpy(fxts_param.key + offset, xts_ctx->keys, xts_ctx->key_len);
592 memcpy(fxts_param.tweak, req->iv, AES_BLOCK_SIZE);
593 fxts_param.nap[0] = 0x01; /* initial alpha power (1, little-endian) */
594
595 while ((nbytes = walk.nbytes) != 0) {
596 /* only use complete blocks */
597 n = nbytes & ~(AES_BLOCK_SIZE - 1);
598 cpacf_km(xts_ctx->fc | modifier, fxts_param.key + offset,
599 walk.dst.virt.addr, walk.src.virt.addr, n);
600 ret = skcipher_walk_done(walk: &walk, res: nbytes - n);
601 }
602 memzero_explicit(s: &fxts_param, count: sizeof(fxts_param));
603 return ret;
604}
605
606static int fullxts_aes_encrypt(struct skcipher_request *req)
607{
608 return fullxts_aes_crypt(req, modifier: 0);
609}
610
611static int fullxts_aes_decrypt(struct skcipher_request *req)
612{
613 return fullxts_aes_crypt(req, modifier: CPACF_DECRYPT);
614}
615
616static struct skcipher_alg fullxts_aes_alg = {
617 .base.cra_name = "xts(aes)",
618 .base.cra_driver_name = "full-xts-aes-s390",
619 .base.cra_priority = 403, /* aes-xts-s390 + 1 */
620 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
621 .base.cra_blocksize = AES_BLOCK_SIZE,
622 .base.cra_ctxsize = sizeof(struct s390_xts_ctx),
623 .base.cra_module = THIS_MODULE,
624 .init = xts_fallback_init,
625 .exit = xts_fallback_exit,
626 .min_keysize = 2 * AES_MIN_KEY_SIZE,
627 .max_keysize = 2 * AES_MAX_KEY_SIZE,
628 .ivsize = AES_BLOCK_SIZE,
629 .setkey = fullxts_aes_set_key,
630 .encrypt = fullxts_aes_encrypt,
631 .decrypt = fullxts_aes_decrypt,
632};
633
634static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
635 unsigned int key_len)
636{
637 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
638 unsigned long fc;
639
640 /* Pick the correct function code based on the key length */
641 fc = (key_len == 16) ? CPACF_KMCTR_AES_128 :
642 (key_len == 24) ? CPACF_KMCTR_AES_192 :
643 (key_len == 32) ? CPACF_KMCTR_AES_256 : 0;
644
645 /* Check if the function code is available */
646 sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
647 if (!sctx->fc)
648 return setkey_fallback_skcipher(tfm, key: in_key, len: key_len);
649
650 sctx->key_len = key_len;
651 memcpy(sctx->key, in_key, key_len);
652 return 0;
653}
654
655static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
656{
657 unsigned int i, n;
658
659 /* only use complete blocks, max. PAGE_SIZE */
660 memcpy(ctrptr, iv, AES_BLOCK_SIZE);
661 n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
662 for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
663 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
664 crypto_inc(a: ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
665 ctrptr += AES_BLOCK_SIZE;
666 }
667 return n;
668}
669
670static int ctr_aes_crypt(struct skcipher_request *req)
671{
672 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
673 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
674 u8 buf[AES_BLOCK_SIZE], *ctrptr;
675 struct skcipher_walk walk;
676 unsigned int n, nbytes;
677 int ret, locked;
678
679 if (unlikely(!sctx->fc))
680 return fallback_skcipher_crypt(sctx, req, modifier: 0);
681
682 locked = mutex_trylock(&ctrblk_lock);
683
684 ret = skcipher_walk_virt(walk: &walk, req, atomic: false);
685 while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
686 n = AES_BLOCK_SIZE;
687
688 if (nbytes >= 2*AES_BLOCK_SIZE && locked)
689 n = __ctrblk_init(ctrptr: ctrblk, iv: walk.iv, nbytes);
690 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
691 cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr,
692 walk.src.virt.addr, n, ctrptr);
693 if (ctrptr == ctrblk)
694 memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE,
695 AES_BLOCK_SIZE);
696 crypto_inc(a: walk.iv, AES_BLOCK_SIZE);
697 ret = skcipher_walk_done(walk: &walk, res: nbytes - n);
698 }
699 if (locked)
700 mutex_unlock(lock: &ctrblk_lock);
701 /*
702 * final block may be < AES_BLOCK_SIZE, copy only nbytes
703 */
704 if (nbytes) {
705 memset(buf, 0, AES_BLOCK_SIZE);
706 memcpy(buf, walk.src.virt.addr, nbytes);
707 cpacf_kmctr(sctx->fc, sctx->key, buf, buf,
708 AES_BLOCK_SIZE, walk.iv);
709 memcpy(walk.dst.virt.addr, buf, nbytes);
710 crypto_inc(a: walk.iv, AES_BLOCK_SIZE);
711 ret = skcipher_walk_done(walk: &walk, res: 0);
712 }
713
714 return ret;
715}
716
717static struct skcipher_alg ctr_aes_alg = {
718 .base.cra_name = "ctr(aes)",
719 .base.cra_driver_name = "ctr-aes-s390",
720 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */
721 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
722 .base.cra_blocksize = 1,
723 .base.cra_ctxsize = sizeof(struct s390_aes_ctx),
724 .base.cra_module = THIS_MODULE,
725 .init = fallback_init_skcipher,
726 .exit = fallback_exit_skcipher,
727 .min_keysize = AES_MIN_KEY_SIZE,
728 .max_keysize = AES_MAX_KEY_SIZE,
729 .ivsize = AES_BLOCK_SIZE,
730 .setkey = ctr_aes_set_key,
731 .encrypt = ctr_aes_crypt,
732 .decrypt = ctr_aes_crypt,
733 .chunksize = AES_BLOCK_SIZE,
734};
735
736static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key,
737 unsigned int keylen)
738{
739 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
740
741 switch (keylen) {
742 case AES_KEYSIZE_128:
743 ctx->fc = CPACF_KMA_GCM_AES_128;
744 break;
745 case AES_KEYSIZE_192:
746 ctx->fc = CPACF_KMA_GCM_AES_192;
747 break;
748 case AES_KEYSIZE_256:
749 ctx->fc = CPACF_KMA_GCM_AES_256;
750 break;
751 default:
752 return -EINVAL;
753 }
754
755 memcpy(ctx->key, key, keylen);
756 ctx->key_len = keylen;
757 return 0;
758}
759
760static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
761{
762 switch (authsize) {
763 case 4:
764 case 8:
765 case 12:
766 case 13:
767 case 14:
768 case 15:
769 case 16:
770 break;
771 default:
772 return -EINVAL;
773 }
774
775 return 0;
776}
777
778static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
779 unsigned int len)
780{
781 memset(gw, 0, sizeof(*gw));
782 gw->walk_bytes_remain = len;
783 scatterwalk_start(walk: &gw->walk, sg);
784}
785
786static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw)
787{
788 if (gw->walk_bytes_remain == 0)
789 return 0;
790 gw->walk_bytes = scatterwalk_next(walk: &gw->walk, total: gw->walk_bytes_remain);
791 return gw->walk_bytes;
792}
793
794static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
795 unsigned int nbytes, bool out)
796{
797 gw->walk_bytes_remain -= nbytes;
798 if (out)
799 scatterwalk_done_dst(walk: &gw->walk, nbytes);
800 else
801 scatterwalk_done_src(walk: &gw->walk, nbytes);
802}
803
804static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
805{
806 int n;
807
808 if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
809 gw->ptr = gw->buf;
810 gw->nbytes = gw->buf_bytes;
811 goto out;
812 }
813
814 if (gw->walk_bytes_remain == 0) {
815 gw->ptr = NULL;
816 gw->nbytes = 0;
817 goto out;
818 }
819
820 if (!_gcm_sg_clamp_and_map(gw)) {
821 gw->ptr = NULL;
822 gw->nbytes = 0;
823 goto out;
824 }
825
826 if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
827 gw->ptr = gw->walk.addr;
828 gw->nbytes = gw->walk_bytes;
829 goto out;
830 }
831
832 while (1) {
833 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
834 memcpy(gw->buf + gw->buf_bytes, gw->walk.addr, n);
835 gw->buf_bytes += n;
836 _gcm_sg_unmap_and_advance(gw, nbytes: n, out: false);
837 if (gw->buf_bytes >= minbytesneeded) {
838 gw->ptr = gw->buf;
839 gw->nbytes = gw->buf_bytes;
840 goto out;
841 }
842 if (!_gcm_sg_clamp_and_map(gw)) {
843 gw->ptr = NULL;
844 gw->nbytes = 0;
845 goto out;
846 }
847 }
848
849out:
850 return gw->nbytes;
851}
852
853static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
854{
855 if (gw->walk_bytes_remain == 0) {
856 gw->ptr = NULL;
857 gw->nbytes = 0;
858 goto out;
859 }
860
861 if (!_gcm_sg_clamp_and_map(gw)) {
862 gw->ptr = NULL;
863 gw->nbytes = 0;
864 goto out;
865 }
866
867 if (gw->walk_bytes >= minbytesneeded) {
868 gw->ptr = gw->walk.addr;
869 gw->nbytes = gw->walk_bytes;
870 goto out;
871 }
872
873 scatterwalk_unmap(walk: &gw->walk);
874
875 gw->ptr = gw->buf;
876 gw->nbytes = sizeof(gw->buf);
877
878out:
879 return gw->nbytes;
880}
881
882static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
883{
884 if (gw->ptr == NULL)
885 return 0;
886
887 if (gw->ptr == gw->buf) {
888 int n = gw->buf_bytes - bytesdone;
889 if (n > 0) {
890 memmove(gw->buf, gw->buf + bytesdone, n);
891 gw->buf_bytes = n;
892 } else
893 gw->buf_bytes = 0;
894 } else
895 _gcm_sg_unmap_and_advance(gw, nbytes: bytesdone, out: false);
896
897 return bytesdone;
898}
899
900static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
901{
902 int i, n;
903
904 if (gw->ptr == NULL)
905 return 0;
906
907 if (gw->ptr == gw->buf) {
908 for (i = 0; i < bytesdone; i += n) {
909 if (!_gcm_sg_clamp_and_map(gw))
910 return i;
911 n = min(gw->walk_bytes, bytesdone - i);
912 memcpy(gw->walk.addr, gw->buf + i, n);
913 _gcm_sg_unmap_and_advance(gw, nbytes: n, out: true);
914 }
915 } else
916 _gcm_sg_unmap_and_advance(gw, nbytes: bytesdone, out: true);
917
918 return bytesdone;
919}
920
921static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
922{
923 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
924 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
925 unsigned int ivsize = crypto_aead_ivsize(tfm);
926 unsigned int taglen = crypto_aead_authsize(tfm);
927 unsigned int aadlen = req->assoclen;
928 unsigned int pclen = req->cryptlen;
929 int ret = 0;
930
931 unsigned int n, len, in_bytes, out_bytes,
932 min_bytes, bytes, aad_bytes, pc_bytes;
933 struct gcm_sg_walk gw_in, gw_out;
934 u8 tag[GHASH_DIGEST_SIZE];
935
936 struct {
937 u32 _[3]; /* reserved */
938 u32 cv; /* Counter Value */
939 u8 t[GHASH_DIGEST_SIZE];/* Tag */
940 u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */
941 u64 taadl; /* Total AAD Length */
942 u64 tpcl; /* Total Plain-/Cipher-text Length */
943 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
944 u8 k[AES_MAX_KEY_SIZE]; /* Key */
945 } param;
946
947 /*
948 * encrypt
949 * req->src: aad||plaintext
950 * req->dst: aad||ciphertext||tag
951 * decrypt
952 * req->src: aad||ciphertext||tag
953 * req->dst: aad||plaintext, return 0 or -EBADMSG
954 * aad, plaintext and ciphertext may be empty.
955 */
956 if (flags & CPACF_DECRYPT)
957 pclen -= taglen;
958 len = aadlen + pclen;
959
960 memset(&param, 0, sizeof(param));
961 param.cv = 1;
962 param.taadl = aadlen * 8;
963 param.tpcl = pclen * 8;
964 memcpy(param.j0, req->iv, ivsize);
965 *(u32 *)(param.j0 + ivsize) = 1;
966 memcpy(param.k, ctx->key, ctx->key_len);
967
968 gcm_walk_start(gw: &gw_in, sg: req->src, len);
969 gcm_walk_start(gw: &gw_out, sg: req->dst, len);
970
971 do {
972 min_bytes = min_t(unsigned int,
973 aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
974 in_bytes = gcm_in_walk_go(gw: &gw_in, minbytesneeded: min_bytes);
975 out_bytes = gcm_out_walk_go(gw: &gw_out, minbytesneeded: min_bytes);
976 bytes = min(in_bytes, out_bytes);
977
978 if (aadlen + pclen <= bytes) {
979 aad_bytes = aadlen;
980 pc_bytes = pclen;
981 flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
982 } else {
983 if (aadlen <= bytes) {
984 aad_bytes = aadlen;
985 pc_bytes = (bytes - aadlen) &
986 ~(AES_BLOCK_SIZE - 1);
987 flags |= CPACF_KMA_LAAD;
988 } else {
989 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
990 pc_bytes = 0;
991 }
992 }
993
994 if (aad_bytes > 0)
995 memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
996
997 cpacf_kma(ctx->fc | flags, &param,
998 gw_out.ptr + aad_bytes,
999 gw_in.ptr + aad_bytes, pc_bytes,
1000 gw_in.ptr, aad_bytes);
1001
1002 n = aad_bytes + pc_bytes;
1003 if (gcm_in_walk_done(gw: &gw_in, bytesdone: n) != n)
1004 return -ENOMEM;
1005 if (gcm_out_walk_done(gw: &gw_out, bytesdone: n) != n)
1006 return -ENOMEM;
1007 aadlen -= aad_bytes;
1008 pclen -= pc_bytes;
1009 } while (aadlen + pclen > 0);
1010
1011 if (flags & CPACF_DECRYPT) {
1012 scatterwalk_map_and_copy(buf: tag, sg: req->src, start: len, nbytes: taglen, out: 0);
1013 if (crypto_memneq(a: tag, b: param.t, size: taglen))
1014 ret = -EBADMSG;
1015 } else
1016 scatterwalk_map_and_copy(buf: param.t, sg: req->dst, start: len, nbytes: taglen, out: 1);
1017
1018 memzero_explicit(s: &param, count: sizeof(param));
1019 return ret;
1020}
1021
1022static int gcm_aes_encrypt(struct aead_request *req)
1023{
1024 return gcm_aes_crypt(req, flags: CPACF_ENCRYPT);
1025}
1026
1027static int gcm_aes_decrypt(struct aead_request *req)
1028{
1029 return gcm_aes_crypt(req, flags: CPACF_DECRYPT);
1030}
1031
1032static struct aead_alg gcm_aes_aead = {
1033 .setkey = gcm_aes_setkey,
1034 .setauthsize = gcm_aes_setauthsize,
1035 .encrypt = gcm_aes_encrypt,
1036 .decrypt = gcm_aes_decrypt,
1037
1038 .ivsize = GHASH_BLOCK_SIZE - sizeof(u32),
1039 .maxauthsize = GHASH_DIGEST_SIZE,
1040 .chunksize = AES_BLOCK_SIZE,
1041
1042 .base = {
1043 .cra_blocksize = 1,
1044 .cra_ctxsize = sizeof(struct s390_aes_ctx),
1045 .cra_priority = 900,
1046 .cra_name = "gcm(aes)",
1047 .cra_driver_name = "gcm-aes-s390",
1048 .cra_module = THIS_MODULE,
1049 },
1050};
1051
1052static struct crypto_alg *aes_s390_alg;
1053static struct skcipher_alg *aes_s390_skcipher_algs[5];
1054static int aes_s390_skciphers_num;
1055static struct aead_alg *aes_s390_aead_alg;
1056
1057static int aes_s390_register_skcipher(struct skcipher_alg *alg)
1058{
1059 int ret;
1060
1061 ret = crypto_register_skcipher(alg);
1062 if (!ret)
1063 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
1064 return ret;
1065}
1066
1067static void aes_s390_fini(void)
1068{
1069 if (aes_s390_alg)
1070 crypto_unregister_alg(alg: aes_s390_alg);
1071 while (aes_s390_skciphers_num--)
1072 crypto_unregister_skcipher(alg: aes_s390_skcipher_algs[aes_s390_skciphers_num]);
1073 if (ctrblk)
1074 free_page((unsigned long) ctrblk);
1075
1076 if (aes_s390_aead_alg)
1077 crypto_unregister_aead(alg: aes_s390_aead_alg);
1078}
1079
1080static int __init aes_s390_init(void)
1081{
1082 int ret;
1083
1084 /* Query available functions for KM, KMC, KMCTR and KMA */
1085 cpacf_query(CPACF_KM, &km_functions);
1086 cpacf_query(CPACF_KMC, &kmc_functions);
1087 cpacf_query(CPACF_KMCTR, &kmctr_functions);
1088 cpacf_query(CPACF_KMA, &kma_functions);
1089
1090 if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
1091 cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
1092 cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
1093 ret = crypto_register_alg(alg: &aes_alg);
1094 if (ret)
1095 goto out_err;
1096 aes_s390_alg = &aes_alg;
1097 ret = aes_s390_register_skcipher(alg: &ecb_aes_alg);
1098 if (ret)
1099 goto out_err;
1100 }
1101
1102 if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
1103 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
1104 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
1105 ret = aes_s390_register_skcipher(alg: &cbc_aes_alg);
1106 if (ret)
1107 goto out_err;
1108 }
1109
1110 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128_FULL) ||
1111 cpacf_test_func(&km_functions, CPACF_KM_XTS_256_FULL)) {
1112 ret = aes_s390_register_skcipher(alg: &fullxts_aes_alg);
1113 if (ret)
1114 goto out_err;
1115 }
1116
1117 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1118 cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1119 ret = aes_s390_register_skcipher(alg: &xts_aes_alg);
1120 if (ret)
1121 goto out_err;
1122 }
1123
1124 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1125 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1126 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1127 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1128 if (!ctrblk) {
1129 ret = -ENOMEM;
1130 goto out_err;
1131 }
1132 ret = aes_s390_register_skcipher(alg: &ctr_aes_alg);
1133 if (ret)
1134 goto out_err;
1135 }
1136
1137 if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1138 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1139 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1140 ret = crypto_register_aead(alg: &gcm_aes_aead);
1141 if (ret)
1142 goto out_err;
1143 aes_s390_aead_alg = &gcm_aes_aead;
1144 }
1145
1146 return 0;
1147out_err:
1148 aes_s390_fini();
1149 return ret;
1150}
1151
1152module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init);
1153module_exit(aes_s390_fini);
1154
1155MODULE_ALIAS_CRYPTO("aes-all");
1156
1157MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1158MODULE_LICENSE("GPL");
1159MODULE_IMPORT_NS("CRYPTO_INTERNAL");
1160

source code of linux/arch/s390/crypto/aes_s390.c