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/skcipher.h>
24 #include <crypto/scatterwalk.h>
25 #include <linux/err.h>
26 #include <linux/module.h>
27 #include <linux/cpufeature.h>
28 #include <linux/init.h>
29 #include <linux/mutex.h>
30 #include <linux/fips.h>
31 #include <linux/string.h>
32 #include <crypto/xts.h>
33 #include <asm/cpacf.h>
34
35 static u8 *ctrblk;
36 static DEFINE_MUTEX(ctrblk_lock);
37
38 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
39 kma_functions;
40
41 struct s390_aes_ctx {
42 u8 key[AES_MAX_KEY_SIZE];
43 int key_len;
44 unsigned long fc;
45 union {
46 struct crypto_skcipher *skcipher;
47 } fallback;
48 };
49
50 struct s390_xts_ctx {
51 union {
52 u8 keys[64];
53 struct {
54 u8 key[32];
55 u8 pcc_key[32];
56 };
57 };
58 int key_len;
59 unsigned long fc;
60 struct crypto_skcipher *fallback;
61 };
62
63 struct gcm_sg_walk {
64 struct scatter_walk walk;
65 unsigned int walk_bytes;
66 unsigned int walk_bytes_remain;
67 u8 buf[AES_BLOCK_SIZE];
68 unsigned int buf_bytes;
69 u8 *ptr;
70 unsigned int nbytes;
71 };
72
setkey_fallback_skcipher(struct crypto_skcipher * tfm,const u8 * key,unsigned int len)73 static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key,
74 unsigned int len)
75 {
76 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
77
78 crypto_skcipher_clear_flags(sctx->fallback.skcipher,
79 CRYPTO_TFM_REQ_MASK);
80 crypto_skcipher_set_flags(sctx->fallback.skcipher,
81 crypto_skcipher_get_flags(tfm) &
82 CRYPTO_TFM_REQ_MASK);
83 return crypto_skcipher_setkey(sctx->fallback.skcipher, key, len);
84 }
85
fallback_skcipher_crypt(struct s390_aes_ctx * sctx,struct skcipher_request * req,unsigned long modifier)86 static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx,
87 struct skcipher_request *req,
88 unsigned long modifier)
89 {
90 struct skcipher_request *subreq = skcipher_request_ctx(req);
91
92 *subreq = *req;
93 skcipher_request_set_tfm(subreq, sctx->fallback.skcipher);
94 return (modifier & CPACF_DECRYPT) ?
95 crypto_skcipher_decrypt(subreq) :
96 crypto_skcipher_encrypt(subreq);
97 }
98
ecb_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)99 static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
100 unsigned int key_len)
101 {
102 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
103 unsigned long fc;
104
105 /* Pick the correct function code based on the key length */
106 fc = (key_len == 16) ? CPACF_KM_AES_128 :
107 (key_len == 24) ? CPACF_KM_AES_192 :
108 (key_len == 32) ? CPACF_KM_AES_256 : 0;
109
110 /* Check if the function code is available */
111 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
112 if (!sctx->fc)
113 return setkey_fallback_skcipher(tfm, in_key, key_len);
114
115 sctx->key_len = key_len;
116 memcpy(sctx->key, in_key, key_len);
117 return 0;
118 }
119
ecb_aes_crypt(struct skcipher_request * req,unsigned long modifier)120 static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier)
121 {
122 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
123 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
124 struct skcipher_walk walk;
125 unsigned int nbytes, n;
126 int ret;
127
128 if (unlikely(!sctx->fc))
129 return fallback_skcipher_crypt(sctx, req, modifier);
130
131 ret = skcipher_walk_virt(&walk, req, false);
132 while ((nbytes = walk.nbytes) != 0) {
133 /* only use complete blocks */
134 n = nbytes & ~(AES_BLOCK_SIZE - 1);
135 cpacf_km(sctx->fc | modifier, sctx->key,
136 walk.dst.virt.addr, walk.src.virt.addr, n);
137 ret = skcipher_walk_done(&walk, nbytes - n);
138 }
139 return ret;
140 }
141
ecb_aes_encrypt(struct skcipher_request * req)142 static int ecb_aes_encrypt(struct skcipher_request *req)
143 {
144 return ecb_aes_crypt(req, 0);
145 }
146
ecb_aes_decrypt(struct skcipher_request * req)147 static int ecb_aes_decrypt(struct skcipher_request *req)
148 {
149 return ecb_aes_crypt(req, CPACF_DECRYPT);
150 }
151
fallback_init_skcipher(struct crypto_skcipher * tfm)152 static int fallback_init_skcipher(struct crypto_skcipher *tfm)
153 {
154 const char *name = crypto_tfm_alg_name(&tfm->base);
155 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
156
157 sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0,
158 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
159
160 if (IS_ERR(sctx->fallback.skcipher)) {
161 pr_err("Allocating AES fallback algorithm %s failed\n",
162 name);
163 return PTR_ERR(sctx->fallback.skcipher);
164 }
165
166 crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
167 crypto_skcipher_reqsize(sctx->fallback.skcipher));
168 return 0;
169 }
170
fallback_exit_skcipher(struct crypto_skcipher * tfm)171 static void fallback_exit_skcipher(struct crypto_skcipher *tfm)
172 {
173 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
174
175 crypto_free_skcipher(sctx->fallback.skcipher);
176 }
177
178 static struct skcipher_alg ecb_aes_alg = {
179 .base.cra_name = "ecb(aes)",
180 .base.cra_driver_name = "ecb-aes-s390",
181 .base.cra_priority = 401, /* combo: aes + ecb + 1 */
182 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
183 .base.cra_blocksize = AES_BLOCK_SIZE,
184 .base.cra_ctxsize = sizeof(struct s390_aes_ctx),
185 .base.cra_module = THIS_MODULE,
186 .init = fallback_init_skcipher,
187 .exit = fallback_exit_skcipher,
188 .min_keysize = AES_MIN_KEY_SIZE,
189 .max_keysize = AES_MAX_KEY_SIZE,
190 .setkey = ecb_aes_set_key,
191 .encrypt = ecb_aes_encrypt,
192 .decrypt = ecb_aes_decrypt,
193 };
194
cbc_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)195 static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
196 unsigned int key_len)
197 {
198 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
199 unsigned long fc;
200
201 /* Pick the correct function code based on the key length */
202 fc = (key_len == 16) ? CPACF_KMC_AES_128 :
203 (key_len == 24) ? CPACF_KMC_AES_192 :
204 (key_len == 32) ? CPACF_KMC_AES_256 : 0;
205
206 /* Check if the function code is available */
207 sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
208 if (!sctx->fc)
209 return setkey_fallback_skcipher(tfm, in_key, key_len);
210
211 sctx->key_len = key_len;
212 memcpy(sctx->key, in_key, key_len);
213 return 0;
214 }
215
cbc_aes_crypt(struct skcipher_request * req,unsigned long modifier)216 static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier)
217 {
218 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
219 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
220 struct skcipher_walk walk;
221 unsigned int nbytes, n;
222 int ret;
223 struct {
224 u8 iv[AES_BLOCK_SIZE];
225 u8 key[AES_MAX_KEY_SIZE];
226 } param;
227
228 if (unlikely(!sctx->fc))
229 return fallback_skcipher_crypt(sctx, req, modifier);
230
231 ret = skcipher_walk_virt(&walk, req, false);
232 if (ret)
233 return ret;
234 memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
235 memcpy(param.key, sctx->key, sctx->key_len);
236 while ((nbytes = walk.nbytes) != 0) {
237 /* only use complete blocks */
238 n = nbytes & ~(AES_BLOCK_SIZE - 1);
239 cpacf_kmc(sctx->fc | modifier, ¶m,
240 walk.dst.virt.addr, walk.src.virt.addr, n);
241 memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
242 ret = skcipher_walk_done(&walk, nbytes - n);
243 }
244 memzero_explicit(¶m, sizeof(param));
245 return ret;
246 }
247
cbc_aes_encrypt(struct skcipher_request * req)248 static int cbc_aes_encrypt(struct skcipher_request *req)
249 {
250 return cbc_aes_crypt(req, 0);
251 }
252
cbc_aes_decrypt(struct skcipher_request * req)253 static int cbc_aes_decrypt(struct skcipher_request *req)
254 {
255 return cbc_aes_crypt(req, CPACF_DECRYPT);
256 }
257
258 static struct skcipher_alg cbc_aes_alg = {
259 .base.cra_name = "cbc(aes)",
260 .base.cra_driver_name = "cbc-aes-s390",
261 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */
262 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
263 .base.cra_blocksize = AES_BLOCK_SIZE,
264 .base.cra_ctxsize = sizeof(struct s390_aes_ctx),
265 .base.cra_module = THIS_MODULE,
266 .init = fallback_init_skcipher,
267 .exit = fallback_exit_skcipher,
268 .min_keysize = AES_MIN_KEY_SIZE,
269 .max_keysize = AES_MAX_KEY_SIZE,
270 .ivsize = AES_BLOCK_SIZE,
271 .setkey = cbc_aes_set_key,
272 .encrypt = cbc_aes_encrypt,
273 .decrypt = cbc_aes_decrypt,
274 };
275
xts_fallback_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int len)276 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key,
277 unsigned int len)
278 {
279 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
280
281 crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK);
282 crypto_skcipher_set_flags(xts_ctx->fallback,
283 crypto_skcipher_get_flags(tfm) &
284 CRYPTO_TFM_REQ_MASK);
285 return crypto_skcipher_setkey(xts_ctx->fallback, key, len);
286 }
287
xts_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)288 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
289 unsigned int key_len)
290 {
291 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
292 unsigned long fc;
293 int err;
294
295 err = xts_fallback_setkey(tfm, in_key, key_len);
296 if (err)
297 return err;
298
299 /* Pick the correct function code based on the key length */
300 fc = (key_len == 32) ? CPACF_KM_XTS_128 :
301 (key_len == 64) ? CPACF_KM_XTS_256 : 0;
302
303 /* Check if the function code is available */
304 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
305 if (!xts_ctx->fc)
306 return 0;
307
308 /* Split the XTS key into the two subkeys */
309 key_len = key_len / 2;
310 xts_ctx->key_len = key_len;
311 memcpy(xts_ctx->key, in_key, key_len);
312 memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
313 return 0;
314 }
315
xts_aes_crypt(struct skcipher_request * req,unsigned long modifier)316 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
317 {
318 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
319 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
320 struct skcipher_walk walk;
321 unsigned int offset, nbytes, n;
322 int ret;
323 struct {
324 u8 key[32];
325 u8 tweak[16];
326 u8 block[16];
327 u8 bit[16];
328 u8 xts[16];
329 } pcc_param;
330 struct {
331 u8 key[32];
332 u8 init[16];
333 } xts_param;
334
335 if (req->cryptlen < AES_BLOCK_SIZE)
336 return -EINVAL;
337
338 if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
339 struct skcipher_request *subreq = skcipher_request_ctx(req);
340
341 *subreq = *req;
342 skcipher_request_set_tfm(subreq, xts_ctx->fallback);
343 return (modifier & CPACF_DECRYPT) ?
344 crypto_skcipher_decrypt(subreq) :
345 crypto_skcipher_encrypt(subreq);
346 }
347
348 ret = skcipher_walk_virt(&walk, req, false);
349 if (ret)
350 return ret;
351 offset = xts_ctx->key_len & 0x10;
352 memset(pcc_param.block, 0, sizeof(pcc_param.block));
353 memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
354 memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
355 memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
356 memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
357 cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
358
359 memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
360 memcpy(xts_param.init, pcc_param.xts, 16);
361
362 while ((nbytes = walk.nbytes) != 0) {
363 /* only use complete blocks */
364 n = nbytes & ~(AES_BLOCK_SIZE - 1);
365 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
366 walk.dst.virt.addr, walk.src.virt.addr, n);
367 ret = skcipher_walk_done(&walk, nbytes - n);
368 }
369 memzero_explicit(&pcc_param, sizeof(pcc_param));
370 memzero_explicit(&xts_param, sizeof(xts_param));
371 return ret;
372 }
373
xts_aes_encrypt(struct skcipher_request * req)374 static int xts_aes_encrypt(struct skcipher_request *req)
375 {
376 return xts_aes_crypt(req, 0);
377 }
378
xts_aes_decrypt(struct skcipher_request * req)379 static int xts_aes_decrypt(struct skcipher_request *req)
380 {
381 return xts_aes_crypt(req, CPACF_DECRYPT);
382 }
383
xts_fallback_init(struct crypto_skcipher * tfm)384 static int xts_fallback_init(struct crypto_skcipher *tfm)
385 {
386 const char *name = crypto_tfm_alg_name(&tfm->base);
387 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
388
389 xts_ctx->fallback = crypto_alloc_skcipher(name, 0,
390 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
391
392 if (IS_ERR(xts_ctx->fallback)) {
393 pr_err("Allocating XTS fallback algorithm %s failed\n",
394 name);
395 return PTR_ERR(xts_ctx->fallback);
396 }
397 crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
398 crypto_skcipher_reqsize(xts_ctx->fallback));
399 return 0;
400 }
401
xts_fallback_exit(struct crypto_skcipher * tfm)402 static void xts_fallback_exit(struct crypto_skcipher *tfm)
403 {
404 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
405
406 crypto_free_skcipher(xts_ctx->fallback);
407 }
408
409 static struct skcipher_alg xts_aes_alg = {
410 .base.cra_name = "xts(aes)",
411 .base.cra_driver_name = "xts-aes-s390",
412 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */
413 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
414 .base.cra_blocksize = AES_BLOCK_SIZE,
415 .base.cra_ctxsize = sizeof(struct s390_xts_ctx),
416 .base.cra_module = THIS_MODULE,
417 .init = xts_fallback_init,
418 .exit = xts_fallback_exit,
419 .min_keysize = 2 * AES_MIN_KEY_SIZE,
420 .max_keysize = 2 * AES_MAX_KEY_SIZE,
421 .ivsize = AES_BLOCK_SIZE,
422 .setkey = xts_aes_set_key,
423 .encrypt = xts_aes_encrypt,
424 .decrypt = xts_aes_decrypt,
425 };
426
fullxts_aes_set_key(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)427 static int fullxts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
428 unsigned int key_len)
429 {
430 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
431 unsigned long fc;
432 int err;
433
434 err = xts_fallback_setkey(tfm, in_key, key_len);
435 if (err)
436 return err;
437
438 /* Pick the correct function code based on the key length */
439 fc = (key_len == 32) ? CPACF_KM_XTS_128_FULL :
440 (key_len == 64) ? CPACF_KM_XTS_256_FULL : 0;
441
442 /* Check if the function code is available */
443 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
444 if (!xts_ctx->fc)
445 return 0;
446
447 /* Store double-key */
448 memcpy(xts_ctx->keys, in_key, key_len);
449 xts_ctx->key_len = key_len;
450 return 0;
451 }
452
fullxts_aes_crypt(struct skcipher_request * req,unsigned long modifier)453 static int fullxts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
454 {
455 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
456 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
457 unsigned int offset, nbytes, n;
458 struct skcipher_walk walk;
459 int ret;
460 struct {
461 __u8 key[64];
462 __u8 tweak[16];
463 __u8 nap[16];
464 } fxts_param = {
465 .nap = {0},
466 };
467
468 if (req->cryptlen < AES_BLOCK_SIZE)
469 return -EINVAL;
470
471 if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
472 struct skcipher_request *subreq = skcipher_request_ctx(req);
473
474 *subreq = *req;
475 skcipher_request_set_tfm(subreq, xts_ctx->fallback);
476 return (modifier & CPACF_DECRYPT) ?
477 crypto_skcipher_decrypt(subreq) :
478 crypto_skcipher_encrypt(subreq);
479 }
480
481 ret = skcipher_walk_virt(&walk, req, false);
482 if (ret)
483 return ret;
484
485 offset = xts_ctx->key_len & 0x20;
486 memcpy(fxts_param.key + offset, xts_ctx->keys, xts_ctx->key_len);
487 memcpy(fxts_param.tweak, req->iv, AES_BLOCK_SIZE);
488 fxts_param.nap[0] = 0x01; /* initial alpha power (1, little-endian) */
489
490 while ((nbytes = walk.nbytes) != 0) {
491 /* only use complete blocks */
492 n = nbytes & ~(AES_BLOCK_SIZE - 1);
493 cpacf_km(xts_ctx->fc | modifier, fxts_param.key + offset,
494 walk.dst.virt.addr, walk.src.virt.addr, n);
495 ret = skcipher_walk_done(&walk, nbytes - n);
496 }
497 memzero_explicit(&fxts_param, sizeof(fxts_param));
498 return ret;
499 }
500
fullxts_aes_encrypt(struct skcipher_request * req)501 static int fullxts_aes_encrypt(struct skcipher_request *req)
502 {
503 return fullxts_aes_crypt(req, 0);
504 }
505
fullxts_aes_decrypt(struct skcipher_request * req)506 static int fullxts_aes_decrypt(struct skcipher_request *req)
507 {
508 return fullxts_aes_crypt(req, CPACF_DECRYPT);
509 }
510
511 static struct skcipher_alg fullxts_aes_alg = {
512 .base.cra_name = "xts(aes)",
513 .base.cra_driver_name = "full-xts-aes-s390",
514 .base.cra_priority = 403, /* aes-xts-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 = fullxts_aes_set_key,
525 .encrypt = fullxts_aes_encrypt,
526 .decrypt = fullxts_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 if (gw->walk_bytes_remain == 0)
684 return 0;
685 gw->walk_bytes = scatterwalk_next(&gw->walk, gw->walk_bytes_remain);
686 return gw->walk_bytes;
687 }
688
_gcm_sg_unmap_and_advance(struct gcm_sg_walk * gw,unsigned int nbytes,bool out)689 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
690 unsigned int nbytes, bool out)
691 {
692 gw->walk_bytes_remain -= nbytes;
693 if (out)
694 scatterwalk_done_dst(&gw->walk, nbytes);
695 else
696 scatterwalk_done_src(&gw->walk, nbytes);
697 }
698
gcm_in_walk_go(struct gcm_sg_walk * gw,unsigned int minbytesneeded)699 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
700 {
701 int n;
702
703 if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
704 gw->ptr = gw->buf;
705 gw->nbytes = gw->buf_bytes;
706 goto out;
707 }
708
709 if (gw->walk_bytes_remain == 0) {
710 gw->ptr = NULL;
711 gw->nbytes = 0;
712 goto out;
713 }
714
715 if (!_gcm_sg_clamp_and_map(gw)) {
716 gw->ptr = NULL;
717 gw->nbytes = 0;
718 goto out;
719 }
720
721 if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
722 gw->ptr = gw->walk.addr;
723 gw->nbytes = gw->walk_bytes;
724 goto out;
725 }
726
727 while (1) {
728 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
729 memcpy(gw->buf + gw->buf_bytes, gw->walk.addr, n);
730 gw->buf_bytes += n;
731 _gcm_sg_unmap_and_advance(gw, n, false);
732 if (gw->buf_bytes >= minbytesneeded) {
733 gw->ptr = gw->buf;
734 gw->nbytes = gw->buf_bytes;
735 goto out;
736 }
737 if (!_gcm_sg_clamp_and_map(gw)) {
738 gw->ptr = NULL;
739 gw->nbytes = 0;
740 goto out;
741 }
742 }
743
744 out:
745 return gw->nbytes;
746 }
747
gcm_out_walk_go(struct gcm_sg_walk * gw,unsigned int minbytesneeded)748 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
749 {
750 if (gw->walk_bytes_remain == 0) {
751 gw->ptr = NULL;
752 gw->nbytes = 0;
753 goto out;
754 }
755
756 if (!_gcm_sg_clamp_and_map(gw)) {
757 gw->ptr = NULL;
758 gw->nbytes = 0;
759 goto out;
760 }
761
762 if (gw->walk_bytes >= minbytesneeded) {
763 gw->ptr = gw->walk.addr;
764 gw->nbytes = gw->walk_bytes;
765 goto out;
766 }
767
768 scatterwalk_unmap(&gw->walk);
769
770 gw->ptr = gw->buf;
771 gw->nbytes = sizeof(gw->buf);
772
773 out:
774 return gw->nbytes;
775 }
776
gcm_in_walk_done(struct gcm_sg_walk * gw,unsigned int bytesdone)777 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
778 {
779 if (gw->ptr == NULL)
780 return 0;
781
782 if (gw->ptr == gw->buf) {
783 int n = gw->buf_bytes - bytesdone;
784 if (n > 0) {
785 memmove(gw->buf, gw->buf + bytesdone, n);
786 gw->buf_bytes = n;
787 } else
788 gw->buf_bytes = 0;
789 } else
790 _gcm_sg_unmap_and_advance(gw, bytesdone, false);
791
792 return bytesdone;
793 }
794
gcm_out_walk_done(struct gcm_sg_walk * gw,unsigned int bytesdone)795 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
796 {
797 int i, n;
798
799 if (gw->ptr == NULL)
800 return 0;
801
802 if (gw->ptr == gw->buf) {
803 for (i = 0; i < bytesdone; i += n) {
804 if (!_gcm_sg_clamp_and_map(gw))
805 return i;
806 n = min(gw->walk_bytes, bytesdone - i);
807 memcpy(gw->walk.addr, gw->buf + i, n);
808 _gcm_sg_unmap_and_advance(gw, n, true);
809 }
810 } else
811 _gcm_sg_unmap_and_advance(gw, bytesdone, true);
812
813 return bytesdone;
814 }
815
gcm_aes_crypt(struct aead_request * req,unsigned int flags)816 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
817 {
818 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
819 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
820 unsigned int ivsize = crypto_aead_ivsize(tfm);
821 unsigned int taglen = crypto_aead_authsize(tfm);
822 unsigned int aadlen = req->assoclen;
823 unsigned int pclen = req->cryptlen;
824 int ret = 0;
825
826 unsigned int n, len, in_bytes, out_bytes,
827 min_bytes, bytes, aad_bytes, pc_bytes;
828 struct gcm_sg_walk gw_in, gw_out;
829 u8 tag[GHASH_DIGEST_SIZE];
830
831 struct {
832 u32 _[3]; /* reserved */
833 u32 cv; /* Counter Value */
834 u8 t[GHASH_DIGEST_SIZE];/* Tag */
835 u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */
836 u64 taadl; /* Total AAD Length */
837 u64 tpcl; /* Total Plain-/Cipher-text Length */
838 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
839 u8 k[AES_MAX_KEY_SIZE]; /* Key */
840 } param;
841
842 /*
843 * encrypt
844 * req->src: aad||plaintext
845 * req->dst: aad||ciphertext||tag
846 * decrypt
847 * req->src: aad||ciphertext||tag
848 * req->dst: aad||plaintext, return 0 or -EBADMSG
849 * aad, plaintext and ciphertext may be empty.
850 */
851 if (flags & CPACF_DECRYPT)
852 pclen -= taglen;
853 len = aadlen + pclen;
854
855 memset(¶m, 0, sizeof(param));
856 param.cv = 1;
857 param.taadl = aadlen * 8;
858 param.tpcl = pclen * 8;
859 memcpy(param.j0, req->iv, ivsize);
860 *(u32 *)(param.j0 + ivsize) = 1;
861 memcpy(param.k, ctx->key, ctx->key_len);
862
863 gcm_walk_start(&gw_in, req->src, len);
864 gcm_walk_start(&gw_out, req->dst, len);
865
866 do {
867 min_bytes = min_t(unsigned int,
868 aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
869 in_bytes = gcm_in_walk_go(&gw_in, min_bytes);
870 out_bytes = gcm_out_walk_go(&gw_out, min_bytes);
871 bytes = min(in_bytes, out_bytes);
872
873 if (aadlen + pclen <= bytes) {
874 aad_bytes = aadlen;
875 pc_bytes = pclen;
876 flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
877 } else {
878 if (aadlen <= bytes) {
879 aad_bytes = aadlen;
880 pc_bytes = (bytes - aadlen) &
881 ~(AES_BLOCK_SIZE - 1);
882 flags |= CPACF_KMA_LAAD;
883 } else {
884 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
885 pc_bytes = 0;
886 }
887 }
888
889 if (aad_bytes > 0)
890 memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
891
892 cpacf_kma(ctx->fc | flags, ¶m,
893 gw_out.ptr + aad_bytes,
894 gw_in.ptr + aad_bytes, pc_bytes,
895 gw_in.ptr, aad_bytes);
896
897 n = aad_bytes + pc_bytes;
898 if (gcm_in_walk_done(&gw_in, n) != n)
899 return -ENOMEM;
900 if (gcm_out_walk_done(&gw_out, n) != n)
901 return -ENOMEM;
902 aadlen -= aad_bytes;
903 pclen -= pc_bytes;
904 } while (aadlen + pclen > 0);
905
906 if (flags & CPACF_DECRYPT) {
907 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
908 if (crypto_memneq(tag, param.t, taglen))
909 ret = -EBADMSG;
910 } else
911 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
912
913 memzero_explicit(¶m, sizeof(param));
914 return ret;
915 }
916
gcm_aes_encrypt(struct aead_request * req)917 static int gcm_aes_encrypt(struct aead_request *req)
918 {
919 return gcm_aes_crypt(req, CPACF_ENCRYPT);
920 }
921
gcm_aes_decrypt(struct aead_request * req)922 static int gcm_aes_decrypt(struct aead_request *req)
923 {
924 return gcm_aes_crypt(req, CPACF_DECRYPT);
925 }
926
927 static struct aead_alg gcm_aes_aead = {
928 .setkey = gcm_aes_setkey,
929 .setauthsize = gcm_aes_setauthsize,
930 .encrypt = gcm_aes_encrypt,
931 .decrypt = gcm_aes_decrypt,
932
933 .ivsize = GHASH_BLOCK_SIZE - sizeof(u32),
934 .maxauthsize = GHASH_DIGEST_SIZE,
935 .chunksize = AES_BLOCK_SIZE,
936
937 .base = {
938 .cra_blocksize = 1,
939 .cra_ctxsize = sizeof(struct s390_aes_ctx),
940 .cra_priority = 900,
941 .cra_name = "gcm(aes)",
942 .cra_driver_name = "gcm-aes-s390",
943 .cra_module = THIS_MODULE,
944 },
945 };
946
947 static struct skcipher_alg *aes_s390_skcipher_algs[5];
948 static int aes_s390_skciphers_num;
949 static struct aead_alg *aes_s390_aead_alg;
950
aes_s390_register_skcipher(struct skcipher_alg * alg)951 static int aes_s390_register_skcipher(struct skcipher_alg *alg)
952 {
953 int ret;
954
955 ret = crypto_register_skcipher(alg);
956 if (!ret)
957 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
958 return ret;
959 }
960
aes_s390_fini(void)961 static void aes_s390_fini(void)
962 {
963 while (aes_s390_skciphers_num--)
964 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]);
965 if (ctrblk)
966 free_page((unsigned long) ctrblk);
967
968 if (aes_s390_aead_alg)
969 crypto_unregister_aead(aes_s390_aead_alg);
970 }
971
aes_s390_init(void)972 static int __init aes_s390_init(void)
973 {
974 int ret;
975
976 /* Query available functions for KM, KMC, KMCTR and KMA */
977 cpacf_query(CPACF_KM, &km_functions);
978 cpacf_query(CPACF_KMC, &kmc_functions);
979 cpacf_query(CPACF_KMCTR, &kmctr_functions);
980 cpacf_query(CPACF_KMA, &kma_functions);
981
982 if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
983 cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
984 cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
985 ret = aes_s390_register_skcipher(&ecb_aes_alg);
986 if (ret)
987 goto out_err;
988 }
989
990 if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
991 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
992 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
993 ret = aes_s390_register_skcipher(&cbc_aes_alg);
994 if (ret)
995 goto out_err;
996 }
997
998 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128_FULL) ||
999 cpacf_test_func(&km_functions, CPACF_KM_XTS_256_FULL)) {
1000 ret = aes_s390_register_skcipher(&fullxts_aes_alg);
1001 if (ret)
1002 goto out_err;
1003 }
1004
1005 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1006 cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1007 ret = aes_s390_register_skcipher(&xts_aes_alg);
1008 if (ret)
1009 goto out_err;
1010 }
1011
1012 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1013 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1014 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1015 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1016 if (!ctrblk) {
1017 ret = -ENOMEM;
1018 goto out_err;
1019 }
1020 ret = aes_s390_register_skcipher(&ctr_aes_alg);
1021 if (ret)
1022 goto out_err;
1023 }
1024
1025 if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1026 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1027 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1028 ret = crypto_register_aead(&gcm_aes_aead);
1029 if (ret)
1030 goto out_err;
1031 aes_s390_aead_alg = &gcm_aes_aead;
1032 }
1033
1034 return 0;
1035 out_err:
1036 aes_s390_fini();
1037 return ret;
1038 }
1039
1040 module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init);
1041 module_exit(aes_s390_fini);
1042
1043 MODULE_ALIAS_CRYPTO("aes-all");
1044
1045 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1046 MODULE_LICENSE("GPL");
1047