xref: /openbmc/linux/arch/s390/crypto/aes_s390.c (revision d68ac388)
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 KMSG_COMPONENT "aes_s390"
18 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
19 
20 #include <crypto/aes.h>
21 #include <crypto/algapi.h>
22 #include <crypto/ghash.h>
23 #include <crypto/internal/aead.h>
24 #include <crypto/internal/cipher.h>
25 #include <crypto/internal/skcipher.h>
26 #include <crypto/scatterwalk.h>
27 #include <linux/err.h>
28 #include <linux/module.h>
29 #include <linux/cpufeature.h>
30 #include <linux/init.h>
31 #include <linux/mutex.h>
32 #include <linux/fips.h>
33 #include <linux/string.h>
34 #include <crypto/xts.h>
35 #include <asm/cpacf.h>
36 
37 static u8 *ctrblk;
38 static DEFINE_MUTEX(ctrblk_lock);
39 
40 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
41 		    kma_functions;
42 
43 struct s390_aes_ctx {
44 	u8 key[AES_MAX_KEY_SIZE];
45 	int key_len;
46 	unsigned long fc;
47 	union {
48 		struct crypto_skcipher *skcipher;
49 		struct crypto_cipher *cip;
50 	} fallback;
51 };
52 
53 struct s390_xts_ctx {
54 	u8 key[32];
55 	u8 pcc_key[32];
56 	int key_len;
57 	unsigned long fc;
58 	struct crypto_skcipher *fallback;
59 };
60 
61 struct gcm_sg_walk {
62 	struct scatter_walk walk;
63 	unsigned int walk_bytes;
64 	u8 *walk_ptr;
65 	unsigned int walk_bytes_remain;
66 	u8 buf[AES_BLOCK_SIZE];
67 	unsigned int buf_bytes;
68 	u8 *ptr;
69 	unsigned int nbytes;
70 };
71 
setkey_fallback_cip(struct crypto_tfm * tfm,const u8 * in_key,unsigned int key_len)72 static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key,
73 		unsigned int key_len)
74 {
75 	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
76 
77 	sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
78 	sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags &
79 			CRYPTO_TFM_REQ_MASK);
80 
81 	return crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len);
82 }
83 
aes_set_key(struct crypto_tfm * tfm,const u8 * in_key,unsigned int key_len)84 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
85 		       unsigned int key_len)
86 {
87 	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
88 	unsigned long fc;
89 
90 	/* Pick the correct function code based on the key length */
91 	fc = (key_len == 16) ? CPACF_KM_AES_128 :
92 	     (key_len == 24) ? CPACF_KM_AES_192 :
93 	     (key_len == 32) ? CPACF_KM_AES_256 : 0;
94 
95 	/* Check if the function code is available */
96 	sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
97 	if (!sctx->fc)
98 		return setkey_fallback_cip(tfm, in_key, key_len);
99 
100 	sctx->key_len = key_len;
101 	memcpy(sctx->key, in_key, key_len);
102 	return 0;
103 }
104 
crypto_aes_encrypt(struct crypto_tfm * tfm,u8 * out,const u8 * in)105 static void crypto_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
106 {
107 	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
108 
109 	if (unlikely(!sctx->fc)) {
110 		crypto_cipher_encrypt_one(sctx->fallback.cip, out, in);
111 		return;
112 	}
113 	cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE);
114 }
115 
crypto_aes_decrypt(struct crypto_tfm * tfm,u8 * out,const u8 * in)116 static void crypto_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
117 {
118 	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
119 
120 	if (unlikely(!sctx->fc)) {
121 		crypto_cipher_decrypt_one(sctx->fallback.cip, out, in);
122 		return;
123 	}
124 	cpacf_km(sctx->fc | CPACF_DECRYPT,
125 		 &sctx->key, out, in, AES_BLOCK_SIZE);
126 }
127 
fallback_init_cip(struct crypto_tfm * tfm)128 static int fallback_init_cip(struct crypto_tfm *tfm)
129 {
130 	const char *name = tfm->__crt_alg->cra_name;
131 	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
132 
133 	sctx->fallback.cip = crypto_alloc_cipher(name, 0,
134 						 CRYPTO_ALG_NEED_FALLBACK);
135 
136 	if (IS_ERR(sctx->fallback.cip)) {
137 		pr_err("Allocating AES fallback algorithm %s failed\n",
138 		       name);
139 		return PTR_ERR(sctx->fallback.cip);
140 	}
141 
142 	return 0;
143 }
144 
fallback_exit_cip(struct crypto_tfm * tfm)145 static void fallback_exit_cip(struct crypto_tfm *tfm)
146 {
147 	struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
148 
149 	crypto_free_cipher(sctx->fallback.cip);
150 	sctx->fallback.cip = NULL;
151 }
152 
153 static struct crypto_alg aes_alg = {
154 	.cra_name		=	"aes",
155 	.cra_driver_name	=	"aes-s390",
156 	.cra_priority		=	300,
157 	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER |
158 					CRYPTO_ALG_NEED_FALLBACK,
159 	.cra_blocksize		=	AES_BLOCK_SIZE,
160 	.cra_ctxsize		=	sizeof(struct s390_aes_ctx),
161 	.cra_module		=	THIS_MODULE,
162 	.cra_init               =       fallback_init_cip,
163 	.cra_exit               =       fallback_exit_cip,
164 	.cra_u			=	{
165 		.cipher = {
166 			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
167 			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
168 			.cia_setkey		=	aes_set_key,
169 			.cia_encrypt		=	crypto_aes_encrypt,
170 			.cia_decrypt		=	crypto_aes_decrypt,
171 		}
172 	}
173 };
174 
setkey_fallback_skcipher(struct crypto_skcipher * tfm,const u8 * key,unsigned int len)175 static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key,
176 				    unsigned int len)
177 {
178 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
179 
180 	crypto_skcipher_clear_flags(sctx->fallback.skcipher,
181 				    CRYPTO_TFM_REQ_MASK);
182 	crypto_skcipher_set_flags(sctx->fallback.skcipher,
183 				  crypto_skcipher_get_flags(tfm) &
184 				  CRYPTO_TFM_REQ_MASK);
185 	return crypto_skcipher_setkey(sctx->fallback.skcipher, key, len);
186 }
187 
fallback_skcipher_crypt(struct s390_aes_ctx * sctx,struct skcipher_request * req,unsigned long modifier)188 static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx,
189 				   struct skcipher_request *req,
190 				   unsigned long modifier)
191 {
192 	struct skcipher_request *subreq = skcipher_request_ctx(req);
193 
194 	*subreq = *req;
195 	skcipher_request_set_tfm(subreq, sctx->fallback.skcipher);
196 	return (modifier & CPACF_DECRYPT) ?
197 		crypto_skcipher_decrypt(subreq) :
198 		crypto_skcipher_encrypt(subreq);
199 }
200 
ecb_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)201 static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
202 			   unsigned int key_len)
203 {
204 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
205 	unsigned long fc;
206 
207 	/* Pick the correct function code based on the key length */
208 	fc = (key_len == 16) ? CPACF_KM_AES_128 :
209 	     (key_len == 24) ? CPACF_KM_AES_192 :
210 	     (key_len == 32) ? CPACF_KM_AES_256 : 0;
211 
212 	/* Check if the function code is available */
213 	sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
214 	if (!sctx->fc)
215 		return setkey_fallback_skcipher(tfm, in_key, key_len);
216 
217 	sctx->key_len = key_len;
218 	memcpy(sctx->key, in_key, key_len);
219 	return 0;
220 }
221 
ecb_aes_crypt(struct skcipher_request * req,unsigned long modifier)222 static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier)
223 {
224 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
225 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
226 	struct skcipher_walk walk;
227 	unsigned int nbytes, n;
228 	int ret;
229 
230 	if (unlikely(!sctx->fc))
231 		return fallback_skcipher_crypt(sctx, req, modifier);
232 
233 	ret = skcipher_walk_virt(&walk, req, false);
234 	while ((nbytes = walk.nbytes) != 0) {
235 		/* only use complete blocks */
236 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
237 		cpacf_km(sctx->fc | modifier, sctx->key,
238 			 walk.dst.virt.addr, walk.src.virt.addr, n);
239 		ret = skcipher_walk_done(&walk, nbytes - n);
240 	}
241 	return ret;
242 }
243 
ecb_aes_encrypt(struct skcipher_request * req)244 static int ecb_aes_encrypt(struct skcipher_request *req)
245 {
246 	return ecb_aes_crypt(req, 0);
247 }
248 
ecb_aes_decrypt(struct skcipher_request * req)249 static int ecb_aes_decrypt(struct skcipher_request *req)
250 {
251 	return ecb_aes_crypt(req, CPACF_DECRYPT);
252 }
253 
fallback_init_skcipher(struct crypto_skcipher * tfm)254 static int fallback_init_skcipher(struct crypto_skcipher *tfm)
255 {
256 	const char *name = crypto_tfm_alg_name(&tfm->base);
257 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
258 
259 	sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0,
260 				CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
261 
262 	if (IS_ERR(sctx->fallback.skcipher)) {
263 		pr_err("Allocating AES fallback algorithm %s failed\n",
264 		       name);
265 		return PTR_ERR(sctx->fallback.skcipher);
266 	}
267 
268 	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
269 				    crypto_skcipher_reqsize(sctx->fallback.skcipher));
270 	return 0;
271 }
272 
fallback_exit_skcipher(struct crypto_skcipher * tfm)273 static void fallback_exit_skcipher(struct crypto_skcipher *tfm)
274 {
275 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
276 
277 	crypto_free_skcipher(sctx->fallback.skcipher);
278 }
279 
280 static struct skcipher_alg ecb_aes_alg = {
281 	.base.cra_name		=	"ecb(aes)",
282 	.base.cra_driver_name	=	"ecb-aes-s390",
283 	.base.cra_priority	=	401,	/* combo: aes + ecb + 1 */
284 	.base.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
285 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
286 	.base.cra_ctxsize	=	sizeof(struct s390_aes_ctx),
287 	.base.cra_module	=	THIS_MODULE,
288 	.init			=	fallback_init_skcipher,
289 	.exit			=	fallback_exit_skcipher,
290 	.min_keysize		=	AES_MIN_KEY_SIZE,
291 	.max_keysize		=	AES_MAX_KEY_SIZE,
292 	.setkey			=	ecb_aes_set_key,
293 	.encrypt		=	ecb_aes_encrypt,
294 	.decrypt		=	ecb_aes_decrypt,
295 };
296 
cbc_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)297 static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
298 			   unsigned int key_len)
299 {
300 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
301 	unsigned long fc;
302 
303 	/* Pick the correct function code based on the key length */
304 	fc = (key_len == 16) ? CPACF_KMC_AES_128 :
305 	     (key_len == 24) ? CPACF_KMC_AES_192 :
306 	     (key_len == 32) ? CPACF_KMC_AES_256 : 0;
307 
308 	/* Check if the function code is available */
309 	sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
310 	if (!sctx->fc)
311 		return setkey_fallback_skcipher(tfm, in_key, key_len);
312 
313 	sctx->key_len = key_len;
314 	memcpy(sctx->key, in_key, key_len);
315 	return 0;
316 }
317 
cbc_aes_crypt(struct skcipher_request * req,unsigned long modifier)318 static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier)
319 {
320 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
321 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
322 	struct skcipher_walk walk;
323 	unsigned int nbytes, n;
324 	int ret;
325 	struct {
326 		u8 iv[AES_BLOCK_SIZE];
327 		u8 key[AES_MAX_KEY_SIZE];
328 	} param;
329 
330 	if (unlikely(!sctx->fc))
331 		return fallback_skcipher_crypt(sctx, req, modifier);
332 
333 	ret = skcipher_walk_virt(&walk, req, false);
334 	if (ret)
335 		return ret;
336 	memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
337 	memcpy(param.key, sctx->key, sctx->key_len);
338 	while ((nbytes = walk.nbytes) != 0) {
339 		/* only use complete blocks */
340 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
341 		cpacf_kmc(sctx->fc | modifier, &param,
342 			  walk.dst.virt.addr, walk.src.virt.addr, n);
343 		memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
344 		ret = skcipher_walk_done(&walk, nbytes - n);
345 	}
346 	memzero_explicit(&param, sizeof(param));
347 	return ret;
348 }
349 
cbc_aes_encrypt(struct skcipher_request * req)350 static int cbc_aes_encrypt(struct skcipher_request *req)
351 {
352 	return cbc_aes_crypt(req, 0);
353 }
354 
cbc_aes_decrypt(struct skcipher_request * req)355 static int cbc_aes_decrypt(struct skcipher_request *req)
356 {
357 	return cbc_aes_crypt(req, CPACF_DECRYPT);
358 }
359 
360 static struct skcipher_alg cbc_aes_alg = {
361 	.base.cra_name		=	"cbc(aes)",
362 	.base.cra_driver_name	=	"cbc-aes-s390",
363 	.base.cra_priority	=	402,	/* ecb-aes-s390 + 1 */
364 	.base.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
365 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
366 	.base.cra_ctxsize	=	sizeof(struct s390_aes_ctx),
367 	.base.cra_module	=	THIS_MODULE,
368 	.init			=	fallback_init_skcipher,
369 	.exit			=	fallback_exit_skcipher,
370 	.min_keysize		=	AES_MIN_KEY_SIZE,
371 	.max_keysize		=	AES_MAX_KEY_SIZE,
372 	.ivsize			=	AES_BLOCK_SIZE,
373 	.setkey			=	cbc_aes_set_key,
374 	.encrypt		=	cbc_aes_encrypt,
375 	.decrypt		=	cbc_aes_decrypt,
376 };
377 
xts_fallback_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int len)378 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key,
379 			       unsigned int len)
380 {
381 	struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
382 
383 	crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK);
384 	crypto_skcipher_set_flags(xts_ctx->fallback,
385 				  crypto_skcipher_get_flags(tfm) &
386 				  CRYPTO_TFM_REQ_MASK);
387 	return crypto_skcipher_setkey(xts_ctx->fallback, key, len);
388 }
389 
xts_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)390 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
391 			   unsigned int key_len)
392 {
393 	struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
394 	unsigned long fc;
395 	int err;
396 
397 	err = xts_fallback_setkey(tfm, in_key, key_len);
398 	if (err)
399 		return err;
400 
401 	/* Pick the correct function code based on the key length */
402 	fc = (key_len == 32) ? CPACF_KM_XTS_128 :
403 	     (key_len == 64) ? CPACF_KM_XTS_256 : 0;
404 
405 	/* Check if the function code is available */
406 	xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
407 	if (!xts_ctx->fc)
408 		return 0;
409 
410 	/* Split the XTS key into the two subkeys */
411 	key_len = key_len / 2;
412 	xts_ctx->key_len = key_len;
413 	memcpy(xts_ctx->key, in_key, key_len);
414 	memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
415 	return 0;
416 }
417 
xts_aes_crypt(struct skcipher_request * req,unsigned long modifier)418 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
419 {
420 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
421 	struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
422 	struct skcipher_walk walk;
423 	unsigned int offset, nbytes, n;
424 	int ret;
425 	struct {
426 		u8 key[32];
427 		u8 tweak[16];
428 		u8 block[16];
429 		u8 bit[16];
430 		u8 xts[16];
431 	} pcc_param;
432 	struct {
433 		u8 key[32];
434 		u8 init[16];
435 	} xts_param;
436 
437 	if (req->cryptlen < AES_BLOCK_SIZE)
438 		return -EINVAL;
439 
440 	if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
441 		struct skcipher_request *subreq = skcipher_request_ctx(req);
442 
443 		*subreq = *req;
444 		skcipher_request_set_tfm(subreq, xts_ctx->fallback);
445 		return (modifier & CPACF_DECRYPT) ?
446 			crypto_skcipher_decrypt(subreq) :
447 			crypto_skcipher_encrypt(subreq);
448 	}
449 
450 	ret = skcipher_walk_virt(&walk, req, false);
451 	if (ret)
452 		return ret;
453 	offset = xts_ctx->key_len & 0x10;
454 	memset(pcc_param.block, 0, sizeof(pcc_param.block));
455 	memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
456 	memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
457 	memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
458 	memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
459 	cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
460 
461 	memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
462 	memcpy(xts_param.init, pcc_param.xts, 16);
463 
464 	while ((nbytes = walk.nbytes) != 0) {
465 		/* only use complete blocks */
466 		n = nbytes & ~(AES_BLOCK_SIZE - 1);
467 		cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
468 			 walk.dst.virt.addr, walk.src.virt.addr, n);
469 		ret = skcipher_walk_done(&walk, nbytes - n);
470 	}
471 	memzero_explicit(&pcc_param, sizeof(pcc_param));
472 	memzero_explicit(&xts_param, sizeof(xts_param));
473 	return ret;
474 }
475 
xts_aes_encrypt(struct skcipher_request * req)476 static int xts_aes_encrypt(struct skcipher_request *req)
477 {
478 	return xts_aes_crypt(req, 0);
479 }
480 
xts_aes_decrypt(struct skcipher_request * req)481 static int xts_aes_decrypt(struct skcipher_request *req)
482 {
483 	return xts_aes_crypt(req, CPACF_DECRYPT);
484 }
485 
xts_fallback_init(struct crypto_skcipher * tfm)486 static int xts_fallback_init(struct crypto_skcipher *tfm)
487 {
488 	const char *name = crypto_tfm_alg_name(&tfm->base);
489 	struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
490 
491 	xts_ctx->fallback = crypto_alloc_skcipher(name, 0,
492 				CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
493 
494 	if (IS_ERR(xts_ctx->fallback)) {
495 		pr_err("Allocating XTS fallback algorithm %s failed\n",
496 		       name);
497 		return PTR_ERR(xts_ctx->fallback);
498 	}
499 	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
500 				    crypto_skcipher_reqsize(xts_ctx->fallback));
501 	return 0;
502 }
503 
xts_fallback_exit(struct crypto_skcipher * tfm)504 static void xts_fallback_exit(struct crypto_skcipher *tfm)
505 {
506 	struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
507 
508 	crypto_free_skcipher(xts_ctx->fallback);
509 }
510 
511 static struct skcipher_alg xts_aes_alg = {
512 	.base.cra_name		=	"xts(aes)",
513 	.base.cra_driver_name	=	"xts-aes-s390",
514 	.base.cra_priority	=	402,	/* ecb-aes-s390 + 1 */
515 	.base.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
516 	.base.cra_blocksize	=	AES_BLOCK_SIZE,
517 	.base.cra_ctxsize	=	sizeof(struct s390_xts_ctx),
518 	.base.cra_module	=	THIS_MODULE,
519 	.init			=	xts_fallback_init,
520 	.exit			=	xts_fallback_exit,
521 	.min_keysize		=	2 * AES_MIN_KEY_SIZE,
522 	.max_keysize		=	2 * AES_MAX_KEY_SIZE,
523 	.ivsize			=	AES_BLOCK_SIZE,
524 	.setkey			=	xts_aes_set_key,
525 	.encrypt		=	xts_aes_encrypt,
526 	.decrypt		=	xts_aes_decrypt,
527 };
528 
ctr_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)529 static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
530 			   unsigned int key_len)
531 {
532 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
533 	unsigned long fc;
534 
535 	/* Pick the correct function code based on the key length */
536 	fc = (key_len == 16) ? CPACF_KMCTR_AES_128 :
537 	     (key_len == 24) ? CPACF_KMCTR_AES_192 :
538 	     (key_len == 32) ? CPACF_KMCTR_AES_256 : 0;
539 
540 	/* Check if the function code is available */
541 	sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
542 	if (!sctx->fc)
543 		return setkey_fallback_skcipher(tfm, in_key, key_len);
544 
545 	sctx->key_len = key_len;
546 	memcpy(sctx->key, in_key, key_len);
547 	return 0;
548 }
549 
__ctrblk_init(u8 * ctrptr,u8 * iv,unsigned int nbytes)550 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
551 {
552 	unsigned int i, n;
553 
554 	/* only use complete blocks, max. PAGE_SIZE */
555 	memcpy(ctrptr, iv, AES_BLOCK_SIZE);
556 	n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
557 	for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
558 		memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
559 		crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
560 		ctrptr += AES_BLOCK_SIZE;
561 	}
562 	return n;
563 }
564 
ctr_aes_crypt(struct skcipher_request * req)565 static int ctr_aes_crypt(struct skcipher_request *req)
566 {
567 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
568 	struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
569 	u8 buf[AES_BLOCK_SIZE], *ctrptr;
570 	struct skcipher_walk walk;
571 	unsigned int n, nbytes;
572 	int ret, locked;
573 
574 	if (unlikely(!sctx->fc))
575 		return fallback_skcipher_crypt(sctx, req, 0);
576 
577 	locked = mutex_trylock(&ctrblk_lock);
578 
579 	ret = skcipher_walk_virt(&walk, req, false);
580 	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
581 		n = AES_BLOCK_SIZE;
582 
583 		if (nbytes >= 2*AES_BLOCK_SIZE && locked)
584 			n = __ctrblk_init(ctrblk, walk.iv, nbytes);
585 		ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
586 		cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr,
587 			    walk.src.virt.addr, n, ctrptr);
588 		if (ctrptr == ctrblk)
589 			memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE,
590 			       AES_BLOCK_SIZE);
591 		crypto_inc(walk.iv, AES_BLOCK_SIZE);
592 		ret = skcipher_walk_done(&walk, nbytes - n);
593 	}
594 	if (locked)
595 		mutex_unlock(&ctrblk_lock);
596 	/*
597 	 * final block may be < AES_BLOCK_SIZE, copy only nbytes
598 	 */
599 	if (nbytes) {
600 		memset(buf, 0, AES_BLOCK_SIZE);
601 		memcpy(buf, walk.src.virt.addr, nbytes);
602 		cpacf_kmctr(sctx->fc, sctx->key, buf, buf,
603 			    AES_BLOCK_SIZE, walk.iv);
604 		memcpy(walk.dst.virt.addr, buf, nbytes);
605 		crypto_inc(walk.iv, AES_BLOCK_SIZE);
606 		ret = skcipher_walk_done(&walk, 0);
607 	}
608 
609 	return ret;
610 }
611 
612 static struct skcipher_alg ctr_aes_alg = {
613 	.base.cra_name		=	"ctr(aes)",
614 	.base.cra_driver_name	=	"ctr-aes-s390",
615 	.base.cra_priority	=	402,	/* ecb-aes-s390 + 1 */
616 	.base.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
617 	.base.cra_blocksize	=	1,
618 	.base.cra_ctxsize	=	sizeof(struct s390_aes_ctx),
619 	.base.cra_module	=	THIS_MODULE,
620 	.init			=	fallback_init_skcipher,
621 	.exit			=	fallback_exit_skcipher,
622 	.min_keysize		=	AES_MIN_KEY_SIZE,
623 	.max_keysize		=	AES_MAX_KEY_SIZE,
624 	.ivsize			=	AES_BLOCK_SIZE,
625 	.setkey			=	ctr_aes_set_key,
626 	.encrypt		=	ctr_aes_crypt,
627 	.decrypt		=	ctr_aes_crypt,
628 	.chunksize		=	AES_BLOCK_SIZE,
629 };
630 
gcm_aes_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)631 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key,
632 			  unsigned int keylen)
633 {
634 	struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
635 
636 	switch (keylen) {
637 	case AES_KEYSIZE_128:
638 		ctx->fc = CPACF_KMA_GCM_AES_128;
639 		break;
640 	case AES_KEYSIZE_192:
641 		ctx->fc = CPACF_KMA_GCM_AES_192;
642 		break;
643 	case AES_KEYSIZE_256:
644 		ctx->fc = CPACF_KMA_GCM_AES_256;
645 		break;
646 	default:
647 		return -EINVAL;
648 	}
649 
650 	memcpy(ctx->key, key, keylen);
651 	ctx->key_len = keylen;
652 	return 0;
653 }
654 
gcm_aes_setauthsize(struct crypto_aead * tfm,unsigned int authsize)655 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
656 {
657 	switch (authsize) {
658 	case 4:
659 	case 8:
660 	case 12:
661 	case 13:
662 	case 14:
663 	case 15:
664 	case 16:
665 		break;
666 	default:
667 		return -EINVAL;
668 	}
669 
670 	return 0;
671 }
672 
gcm_walk_start(struct gcm_sg_walk * gw,struct scatterlist * sg,unsigned int len)673 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
674 			   unsigned int len)
675 {
676 	memset(gw, 0, sizeof(*gw));
677 	gw->walk_bytes_remain = len;
678 	scatterwalk_start(&gw->walk, sg);
679 }
680 
_gcm_sg_clamp_and_map(struct gcm_sg_walk * gw)681 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw)
682 {
683 	struct scatterlist *nextsg;
684 
685 	gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
686 	while (!gw->walk_bytes) {
687 		nextsg = sg_next(gw->walk.sg);
688 		if (!nextsg)
689 			return 0;
690 		scatterwalk_start(&gw->walk, nextsg);
691 		gw->walk_bytes = scatterwalk_clamp(&gw->walk,
692 						   gw->walk_bytes_remain);
693 	}
694 	gw->walk_ptr = scatterwalk_map(&gw->walk);
695 	return gw->walk_bytes;
696 }
697 
_gcm_sg_unmap_and_advance(struct gcm_sg_walk * gw,unsigned int nbytes)698 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
699 					     unsigned int nbytes)
700 {
701 	gw->walk_bytes_remain -= nbytes;
702 	scatterwalk_unmap(gw->walk_ptr);
703 	scatterwalk_advance(&gw->walk, nbytes);
704 	scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
705 	gw->walk_ptr = NULL;
706 }
707 
gcm_in_walk_go(struct gcm_sg_walk * gw,unsigned int minbytesneeded)708 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
709 {
710 	int n;
711 
712 	if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
713 		gw->ptr = gw->buf;
714 		gw->nbytes = gw->buf_bytes;
715 		goto out;
716 	}
717 
718 	if (gw->walk_bytes_remain == 0) {
719 		gw->ptr = NULL;
720 		gw->nbytes = 0;
721 		goto out;
722 	}
723 
724 	if (!_gcm_sg_clamp_and_map(gw)) {
725 		gw->ptr = NULL;
726 		gw->nbytes = 0;
727 		goto out;
728 	}
729 
730 	if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
731 		gw->ptr = gw->walk_ptr;
732 		gw->nbytes = gw->walk_bytes;
733 		goto out;
734 	}
735 
736 	while (1) {
737 		n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
738 		memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
739 		gw->buf_bytes += n;
740 		_gcm_sg_unmap_and_advance(gw, n);
741 		if (gw->buf_bytes >= minbytesneeded) {
742 			gw->ptr = gw->buf;
743 			gw->nbytes = gw->buf_bytes;
744 			goto out;
745 		}
746 		if (!_gcm_sg_clamp_and_map(gw)) {
747 			gw->ptr = NULL;
748 			gw->nbytes = 0;
749 			goto out;
750 		}
751 	}
752 
753 out:
754 	return gw->nbytes;
755 }
756 
gcm_out_walk_go(struct gcm_sg_walk * gw,unsigned int minbytesneeded)757 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
758 {
759 	if (gw->walk_bytes_remain == 0) {
760 		gw->ptr = NULL;
761 		gw->nbytes = 0;
762 		goto out;
763 	}
764 
765 	if (!_gcm_sg_clamp_and_map(gw)) {
766 		gw->ptr = NULL;
767 		gw->nbytes = 0;
768 		goto out;
769 	}
770 
771 	if (gw->walk_bytes >= minbytesneeded) {
772 		gw->ptr = gw->walk_ptr;
773 		gw->nbytes = gw->walk_bytes;
774 		goto out;
775 	}
776 
777 	scatterwalk_unmap(gw->walk_ptr);
778 	gw->walk_ptr = NULL;
779 
780 	gw->ptr = gw->buf;
781 	gw->nbytes = sizeof(gw->buf);
782 
783 out:
784 	return gw->nbytes;
785 }
786 
gcm_in_walk_done(struct gcm_sg_walk * gw,unsigned int bytesdone)787 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
788 {
789 	if (gw->ptr == NULL)
790 		return 0;
791 
792 	if (gw->ptr == gw->buf) {
793 		int n = gw->buf_bytes - bytesdone;
794 		if (n > 0) {
795 			memmove(gw->buf, gw->buf + bytesdone, n);
796 			gw->buf_bytes = n;
797 		} else
798 			gw->buf_bytes = 0;
799 	} else
800 		_gcm_sg_unmap_and_advance(gw, bytesdone);
801 
802 	return bytesdone;
803 }
804 
gcm_out_walk_done(struct gcm_sg_walk * gw,unsigned int bytesdone)805 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
806 {
807 	int i, n;
808 
809 	if (gw->ptr == NULL)
810 		return 0;
811 
812 	if (gw->ptr == gw->buf) {
813 		for (i = 0; i < bytesdone; i += n) {
814 			if (!_gcm_sg_clamp_and_map(gw))
815 				return i;
816 			n = min(gw->walk_bytes, bytesdone - i);
817 			memcpy(gw->walk_ptr, gw->buf + i, n);
818 			_gcm_sg_unmap_and_advance(gw, n);
819 		}
820 	} else
821 		_gcm_sg_unmap_and_advance(gw, bytesdone);
822 
823 	return bytesdone;
824 }
825 
gcm_aes_crypt(struct aead_request * req,unsigned int flags)826 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
827 {
828 	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
829 	struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
830 	unsigned int ivsize = crypto_aead_ivsize(tfm);
831 	unsigned int taglen = crypto_aead_authsize(tfm);
832 	unsigned int aadlen = req->assoclen;
833 	unsigned int pclen = req->cryptlen;
834 	int ret = 0;
835 
836 	unsigned int n, len, in_bytes, out_bytes,
837 		     min_bytes, bytes, aad_bytes, pc_bytes;
838 	struct gcm_sg_walk gw_in, gw_out;
839 	u8 tag[GHASH_DIGEST_SIZE];
840 
841 	struct {
842 		u32 _[3];		/* reserved */
843 		u32 cv;			/* Counter Value */
844 		u8 t[GHASH_DIGEST_SIZE];/* Tag */
845 		u8 h[AES_BLOCK_SIZE];	/* Hash-subkey */
846 		u64 taadl;		/* Total AAD Length */
847 		u64 tpcl;		/* Total Plain-/Cipher-text Length */
848 		u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
849 		u8 k[AES_MAX_KEY_SIZE];	/* Key */
850 	} param;
851 
852 	/*
853 	 * encrypt
854 	 *   req->src: aad||plaintext
855 	 *   req->dst: aad||ciphertext||tag
856 	 * decrypt
857 	 *   req->src: aad||ciphertext||tag
858 	 *   req->dst: aad||plaintext, return 0 or -EBADMSG
859 	 * aad, plaintext and ciphertext may be empty.
860 	 */
861 	if (flags & CPACF_DECRYPT)
862 		pclen -= taglen;
863 	len = aadlen + pclen;
864 
865 	memset(&param, 0, sizeof(param));
866 	param.cv = 1;
867 	param.taadl = aadlen * 8;
868 	param.tpcl = pclen * 8;
869 	memcpy(param.j0, req->iv, ivsize);
870 	*(u32 *)(param.j0 + ivsize) = 1;
871 	memcpy(param.k, ctx->key, ctx->key_len);
872 
873 	gcm_walk_start(&gw_in, req->src, len);
874 	gcm_walk_start(&gw_out, req->dst, len);
875 
876 	do {
877 		min_bytes = min_t(unsigned int,
878 				  aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
879 		in_bytes = gcm_in_walk_go(&gw_in, min_bytes);
880 		out_bytes = gcm_out_walk_go(&gw_out, min_bytes);
881 		bytes = min(in_bytes, out_bytes);
882 
883 		if (aadlen + pclen <= bytes) {
884 			aad_bytes = aadlen;
885 			pc_bytes = pclen;
886 			flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
887 		} else {
888 			if (aadlen <= bytes) {
889 				aad_bytes = aadlen;
890 				pc_bytes = (bytes - aadlen) &
891 					   ~(AES_BLOCK_SIZE - 1);
892 				flags |= CPACF_KMA_LAAD;
893 			} else {
894 				aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
895 				pc_bytes = 0;
896 			}
897 		}
898 
899 		if (aad_bytes > 0)
900 			memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
901 
902 		cpacf_kma(ctx->fc | flags, &param,
903 			  gw_out.ptr + aad_bytes,
904 			  gw_in.ptr + aad_bytes, pc_bytes,
905 			  gw_in.ptr, aad_bytes);
906 
907 		n = aad_bytes + pc_bytes;
908 		if (gcm_in_walk_done(&gw_in, n) != n)
909 			return -ENOMEM;
910 		if (gcm_out_walk_done(&gw_out, n) != n)
911 			return -ENOMEM;
912 		aadlen -= aad_bytes;
913 		pclen -= pc_bytes;
914 	} while (aadlen + pclen > 0);
915 
916 	if (flags & CPACF_DECRYPT) {
917 		scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
918 		if (crypto_memneq(tag, param.t, taglen))
919 			ret = -EBADMSG;
920 	} else
921 		scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
922 
923 	memzero_explicit(&param, sizeof(param));
924 	return ret;
925 }
926 
gcm_aes_encrypt(struct aead_request * req)927 static int gcm_aes_encrypt(struct aead_request *req)
928 {
929 	return gcm_aes_crypt(req, CPACF_ENCRYPT);
930 }
931 
gcm_aes_decrypt(struct aead_request * req)932 static int gcm_aes_decrypt(struct aead_request *req)
933 {
934 	return gcm_aes_crypt(req, CPACF_DECRYPT);
935 }
936 
937 static struct aead_alg gcm_aes_aead = {
938 	.setkey			= gcm_aes_setkey,
939 	.setauthsize		= gcm_aes_setauthsize,
940 	.encrypt		= gcm_aes_encrypt,
941 	.decrypt		= gcm_aes_decrypt,
942 
943 	.ivsize			= GHASH_BLOCK_SIZE - sizeof(u32),
944 	.maxauthsize		= GHASH_DIGEST_SIZE,
945 	.chunksize		= AES_BLOCK_SIZE,
946 
947 	.base			= {
948 		.cra_blocksize		= 1,
949 		.cra_ctxsize		= sizeof(struct s390_aes_ctx),
950 		.cra_priority		= 900,
951 		.cra_name		= "gcm(aes)",
952 		.cra_driver_name	= "gcm-aes-s390",
953 		.cra_module		= THIS_MODULE,
954 	},
955 };
956 
957 static struct crypto_alg *aes_s390_alg;
958 static struct skcipher_alg *aes_s390_skcipher_algs[4];
959 static int aes_s390_skciphers_num;
960 static struct aead_alg *aes_s390_aead_alg;
961 
aes_s390_register_skcipher(struct skcipher_alg * alg)962 static int aes_s390_register_skcipher(struct skcipher_alg *alg)
963 {
964 	int ret;
965 
966 	ret = crypto_register_skcipher(alg);
967 	if (!ret)
968 		aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
969 	return ret;
970 }
971 
aes_s390_fini(void)972 static void aes_s390_fini(void)
973 {
974 	if (aes_s390_alg)
975 		crypto_unregister_alg(aes_s390_alg);
976 	while (aes_s390_skciphers_num--)
977 		crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]);
978 	if (ctrblk)
979 		free_page((unsigned long) ctrblk);
980 
981 	if (aes_s390_aead_alg)
982 		crypto_unregister_aead(aes_s390_aead_alg);
983 }
984 
aes_s390_init(void)985 static int __init aes_s390_init(void)
986 {
987 	int ret;
988 
989 	/* Query available functions for KM, KMC, KMCTR and KMA */
990 	cpacf_query(CPACF_KM, &km_functions);
991 	cpacf_query(CPACF_KMC, &kmc_functions);
992 	cpacf_query(CPACF_KMCTR, &kmctr_functions);
993 	cpacf_query(CPACF_KMA, &kma_functions);
994 
995 	if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
996 	    cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
997 	    cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
998 		ret = crypto_register_alg(&aes_alg);
999 		if (ret)
1000 			goto out_err;
1001 		aes_s390_alg = &aes_alg;
1002 		ret = aes_s390_register_skcipher(&ecb_aes_alg);
1003 		if (ret)
1004 			goto out_err;
1005 	}
1006 
1007 	if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
1008 	    cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
1009 	    cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
1010 		ret = aes_s390_register_skcipher(&cbc_aes_alg);
1011 		if (ret)
1012 			goto out_err;
1013 	}
1014 
1015 	if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1016 	    cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1017 		ret = aes_s390_register_skcipher(&xts_aes_alg);
1018 		if (ret)
1019 			goto out_err;
1020 	}
1021 
1022 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1023 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1024 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1025 		ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1026 		if (!ctrblk) {
1027 			ret = -ENOMEM;
1028 			goto out_err;
1029 		}
1030 		ret = aes_s390_register_skcipher(&ctr_aes_alg);
1031 		if (ret)
1032 			goto out_err;
1033 	}
1034 
1035 	if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1036 	    cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1037 	    cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1038 		ret = crypto_register_aead(&gcm_aes_aead);
1039 		if (ret)
1040 			goto out_err;
1041 		aes_s390_aead_alg = &gcm_aes_aead;
1042 	}
1043 
1044 	return 0;
1045 out_err:
1046 	aes_s390_fini();
1047 	return ret;
1048 }
1049 
1050 module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init);
1051 module_exit(aes_s390_fini);
1052 
1053 MODULE_ALIAS_CRYPTO("aes-all");
1054 
1055 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1056 MODULE_LICENSE("GPL");
1057 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
1058