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TOMOYO Linux Cross Reference
Linux/arch/s390/crypto/aes_s390.c

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

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