xref: /linux/crypto/lskcipher.c (revision 0678df8271820bcf8fb4f877129f05d68a237de4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linear symmetric key cipher operations.
4  *
5  * Generic encrypt/decrypt wrapper for ciphers.
6  *
7  * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
8  */
9 
10 #include <linux/cryptouser.h>
11 #include <linux/err.h>
12 #include <linux/export.h>
13 #include <linux/kernel.h>
14 #include <linux/seq_file.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <net/netlink.h>
18 #include "skcipher.h"
19 
20 static inline struct crypto_lskcipher *__crypto_lskcipher_cast(
21 	struct crypto_tfm *tfm)
22 {
23 	return container_of(tfm, struct crypto_lskcipher, base);
24 }
25 
26 static inline struct lskcipher_alg *__crypto_lskcipher_alg(
27 	struct crypto_alg *alg)
28 {
29 	return container_of(alg, struct lskcipher_alg, co.base);
30 }
31 
32 static inline struct crypto_istat_cipher *lskcipher_get_stat(
33 	struct lskcipher_alg *alg)
34 {
35 	return skcipher_get_stat_common(&alg->co);
36 }
37 
38 static inline int crypto_lskcipher_errstat(struct lskcipher_alg *alg, int err)
39 {
40 	struct crypto_istat_cipher *istat = lskcipher_get_stat(alg);
41 
42 	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
43 		return err;
44 
45 	if (err)
46 		atomic64_inc(&istat->err_cnt);
47 
48 	return err;
49 }
50 
51 static int lskcipher_setkey_unaligned(struct crypto_lskcipher *tfm,
52 				      const u8 *key, unsigned int keylen)
53 {
54 	unsigned long alignmask = crypto_lskcipher_alignmask(tfm);
55 	struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm);
56 	u8 *buffer, *alignbuffer;
57 	unsigned long absize;
58 	int ret;
59 
60 	absize = keylen + alignmask;
61 	buffer = kmalloc(absize, GFP_ATOMIC);
62 	if (!buffer)
63 		return -ENOMEM;
64 
65 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
66 	memcpy(alignbuffer, key, keylen);
67 	ret = cipher->setkey(tfm, alignbuffer, keylen);
68 	kfree_sensitive(buffer);
69 	return ret;
70 }
71 
72 int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm, const u8 *key,
73 			    unsigned int keylen)
74 {
75 	unsigned long alignmask = crypto_lskcipher_alignmask(tfm);
76 	struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm);
77 
78 	if (keylen < cipher->co.min_keysize || keylen > cipher->co.max_keysize)
79 		return -EINVAL;
80 
81 	if ((unsigned long)key & alignmask)
82 		return lskcipher_setkey_unaligned(tfm, key, keylen);
83 	else
84 		return cipher->setkey(tfm, key, keylen);
85 }
86 EXPORT_SYMBOL_GPL(crypto_lskcipher_setkey);
87 
88 static int crypto_lskcipher_crypt_unaligned(
89 	struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned len,
90 	u8 *iv, int (*crypt)(struct crypto_lskcipher *tfm, const u8 *src,
91 			     u8 *dst, unsigned len, u8 *iv, bool final))
92 {
93 	unsigned ivsize = crypto_lskcipher_ivsize(tfm);
94 	unsigned bs = crypto_lskcipher_blocksize(tfm);
95 	unsigned cs = crypto_lskcipher_chunksize(tfm);
96 	int err;
97 	u8 *tiv;
98 	u8 *p;
99 
100 	BUILD_BUG_ON(MAX_CIPHER_BLOCKSIZE > PAGE_SIZE ||
101 		     MAX_CIPHER_ALIGNMASK >= PAGE_SIZE);
102 
103 	tiv = kmalloc(PAGE_SIZE, GFP_ATOMIC);
104 	if (!tiv)
105 		return -ENOMEM;
106 
107 	memcpy(tiv, iv, ivsize);
108 
109 	p = kmalloc(PAGE_SIZE, GFP_ATOMIC);
110 	err = -ENOMEM;
111 	if (!p)
112 		goto out;
113 
114 	while (len >= bs) {
115 		unsigned chunk = min((unsigned)PAGE_SIZE, len);
116 		int err;
117 
118 		if (chunk > cs)
119 			chunk &= ~(cs - 1);
120 
121 		memcpy(p, src, chunk);
122 		err = crypt(tfm, p, p, chunk, tiv, true);
123 		if (err)
124 			goto out;
125 
126 		memcpy(dst, p, chunk);
127 		src += chunk;
128 		dst += chunk;
129 		len -= chunk;
130 	}
131 
132 	err = len ? -EINVAL : 0;
133 
134 out:
135 	memcpy(iv, tiv, ivsize);
136 	kfree_sensitive(p);
137 	kfree_sensitive(tiv);
138 	return err;
139 }
140 
141 static int crypto_lskcipher_crypt(struct crypto_lskcipher *tfm, const u8 *src,
142 				  u8 *dst, unsigned len, u8 *iv,
143 				  int (*crypt)(struct crypto_lskcipher *tfm,
144 					       const u8 *src, u8 *dst,
145 					       unsigned len, u8 *iv,
146 					       bool final))
147 {
148 	unsigned long alignmask = crypto_lskcipher_alignmask(tfm);
149 	struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm);
150 	int ret;
151 
152 	if (((unsigned long)src | (unsigned long)dst | (unsigned long)iv) &
153 	    alignmask) {
154 		ret = crypto_lskcipher_crypt_unaligned(tfm, src, dst, len, iv,
155 						       crypt);
156 		goto out;
157 	}
158 
159 	ret = crypt(tfm, src, dst, len, iv, true);
160 
161 out:
162 	return crypto_lskcipher_errstat(alg, ret);
163 }
164 
165 int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src,
166 			     u8 *dst, unsigned len, u8 *iv)
167 {
168 	struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm);
169 
170 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
171 		struct crypto_istat_cipher *istat = lskcipher_get_stat(alg);
172 
173 		atomic64_inc(&istat->encrypt_cnt);
174 		atomic64_add(len, &istat->encrypt_tlen);
175 	}
176 
177 	return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->encrypt);
178 }
179 EXPORT_SYMBOL_GPL(crypto_lskcipher_encrypt);
180 
181 int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src,
182 			     u8 *dst, unsigned len, u8 *iv)
183 {
184 	struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm);
185 
186 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
187 		struct crypto_istat_cipher *istat = lskcipher_get_stat(alg);
188 
189 		atomic64_inc(&istat->decrypt_cnt);
190 		atomic64_add(len, &istat->decrypt_tlen);
191 	}
192 
193 	return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->decrypt);
194 }
195 EXPORT_SYMBOL_GPL(crypto_lskcipher_decrypt);
196 
197 static int crypto_lskcipher_crypt_sg(struct skcipher_request *req,
198 				     int (*crypt)(struct crypto_lskcipher *tfm,
199 						  const u8 *src, u8 *dst,
200 						  unsigned len, u8 *iv,
201 						  bool final))
202 {
203 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
204 	struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);
205 	struct crypto_lskcipher *tfm = *ctx;
206 	struct skcipher_walk walk;
207 	int err;
208 
209 	err = skcipher_walk_virt(&walk, req, false);
210 
211 	while (walk.nbytes) {
212 		err = crypt(tfm, walk.src.virt.addr, walk.dst.virt.addr,
213 			    walk.nbytes, walk.iv, walk.nbytes == walk.total);
214 		err = skcipher_walk_done(&walk, err);
215 	}
216 
217 	return err;
218 }
219 
220 int crypto_lskcipher_encrypt_sg(struct skcipher_request *req)
221 {
222 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
223 	struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);
224 	struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx);
225 
226 	return crypto_lskcipher_crypt_sg(req, alg->encrypt);
227 }
228 
229 int crypto_lskcipher_decrypt_sg(struct skcipher_request *req)
230 {
231 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
232 	struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher);
233 	struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx);
234 
235 	return crypto_lskcipher_crypt_sg(req, alg->decrypt);
236 }
237 
238 static void crypto_lskcipher_exit_tfm(struct crypto_tfm *tfm)
239 {
240 	struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm);
241 	struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher);
242 
243 	alg->exit(skcipher);
244 }
245 
246 static int crypto_lskcipher_init_tfm(struct crypto_tfm *tfm)
247 {
248 	struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm);
249 	struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher);
250 
251 	if (alg->exit)
252 		skcipher->base.exit = crypto_lskcipher_exit_tfm;
253 
254 	if (alg->init)
255 		return alg->init(skcipher);
256 
257 	return 0;
258 }
259 
260 static void crypto_lskcipher_free_instance(struct crypto_instance *inst)
261 {
262 	struct lskcipher_instance *skcipher =
263 		container_of(inst, struct lskcipher_instance, s.base);
264 
265 	skcipher->free(skcipher);
266 }
267 
268 static void __maybe_unused crypto_lskcipher_show(
269 	struct seq_file *m, struct crypto_alg *alg)
270 {
271 	struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg);
272 
273 	seq_printf(m, "type         : lskcipher\n");
274 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
275 	seq_printf(m, "min keysize  : %u\n", skcipher->co.min_keysize);
276 	seq_printf(m, "max keysize  : %u\n", skcipher->co.max_keysize);
277 	seq_printf(m, "ivsize       : %u\n", skcipher->co.ivsize);
278 	seq_printf(m, "chunksize    : %u\n", skcipher->co.chunksize);
279 }
280 
281 static int __maybe_unused crypto_lskcipher_report(
282 	struct sk_buff *skb, struct crypto_alg *alg)
283 {
284 	struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg);
285 	struct crypto_report_blkcipher rblkcipher;
286 
287 	memset(&rblkcipher, 0, sizeof(rblkcipher));
288 
289 	strscpy(rblkcipher.type, "lskcipher", sizeof(rblkcipher.type));
290 	strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
291 
292 	rblkcipher.blocksize = alg->cra_blocksize;
293 	rblkcipher.min_keysize = skcipher->co.min_keysize;
294 	rblkcipher.max_keysize = skcipher->co.max_keysize;
295 	rblkcipher.ivsize = skcipher->co.ivsize;
296 
297 	return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
298 		       sizeof(rblkcipher), &rblkcipher);
299 }
300 
301 static int __maybe_unused crypto_lskcipher_report_stat(
302 	struct sk_buff *skb, struct crypto_alg *alg)
303 {
304 	struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg);
305 	struct crypto_istat_cipher *istat;
306 	struct crypto_stat_cipher rcipher;
307 
308 	istat = lskcipher_get_stat(skcipher);
309 
310 	memset(&rcipher, 0, sizeof(rcipher));
311 
312 	strscpy(rcipher.type, "cipher", sizeof(rcipher.type));
313 
314 	rcipher.stat_encrypt_cnt = atomic64_read(&istat->encrypt_cnt);
315 	rcipher.stat_encrypt_tlen = atomic64_read(&istat->encrypt_tlen);
316 	rcipher.stat_decrypt_cnt =  atomic64_read(&istat->decrypt_cnt);
317 	rcipher.stat_decrypt_tlen = atomic64_read(&istat->decrypt_tlen);
318 	rcipher.stat_err_cnt =  atomic64_read(&istat->err_cnt);
319 
320 	return nla_put(skb, CRYPTOCFGA_STAT_CIPHER, sizeof(rcipher), &rcipher);
321 }
322 
323 static const struct crypto_type crypto_lskcipher_type = {
324 	.extsize = crypto_alg_extsize,
325 	.init_tfm = crypto_lskcipher_init_tfm,
326 	.free = crypto_lskcipher_free_instance,
327 #ifdef CONFIG_PROC_FS
328 	.show = crypto_lskcipher_show,
329 #endif
330 #if IS_ENABLED(CONFIG_CRYPTO_USER)
331 	.report = crypto_lskcipher_report,
332 #endif
333 #ifdef CONFIG_CRYPTO_STATS
334 	.report_stat = crypto_lskcipher_report_stat,
335 #endif
336 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
337 	.maskset = CRYPTO_ALG_TYPE_MASK,
338 	.type = CRYPTO_ALG_TYPE_LSKCIPHER,
339 	.tfmsize = offsetof(struct crypto_lskcipher, base),
340 };
341 
342 static void crypto_lskcipher_exit_tfm_sg(struct crypto_tfm *tfm)
343 {
344 	struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);
345 
346 	crypto_free_lskcipher(*ctx);
347 }
348 
349 int crypto_init_lskcipher_ops_sg(struct crypto_tfm *tfm)
350 {
351 	struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm);
352 	struct crypto_alg *calg = tfm->__crt_alg;
353 	struct crypto_lskcipher *skcipher;
354 
355 	if (!crypto_mod_get(calg))
356 		return -EAGAIN;
357 
358 	skcipher = crypto_create_tfm(calg, &crypto_lskcipher_type);
359 	if (IS_ERR(skcipher)) {
360 		crypto_mod_put(calg);
361 		return PTR_ERR(skcipher);
362 	}
363 
364 	*ctx = skcipher;
365 	tfm->exit = crypto_lskcipher_exit_tfm_sg;
366 
367 	return 0;
368 }
369 
370 int crypto_grab_lskcipher(struct crypto_lskcipher_spawn *spawn,
371 			  struct crypto_instance *inst,
372 			  const char *name, u32 type, u32 mask)
373 {
374 	spawn->base.frontend = &crypto_lskcipher_type;
375 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
376 }
377 EXPORT_SYMBOL_GPL(crypto_grab_lskcipher);
378 
379 struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,
380 						u32 type, u32 mask)
381 {
382 	return crypto_alloc_tfm(alg_name, &crypto_lskcipher_type, type, mask);
383 }
384 EXPORT_SYMBOL_GPL(crypto_alloc_lskcipher);
385 
386 static int lskcipher_prepare_alg(struct lskcipher_alg *alg)
387 {
388 	struct crypto_alg *base = &alg->co.base;
389 	int err;
390 
391 	err = skcipher_prepare_alg_common(&alg->co);
392 	if (err)
393 		return err;
394 
395 	if (alg->co.chunksize & (alg->co.chunksize - 1))
396 		return -EINVAL;
397 
398 	base->cra_type = &crypto_lskcipher_type;
399 	base->cra_flags |= CRYPTO_ALG_TYPE_LSKCIPHER;
400 
401 	return 0;
402 }
403 
404 int crypto_register_lskcipher(struct lskcipher_alg *alg)
405 {
406 	struct crypto_alg *base = &alg->co.base;
407 	int err;
408 
409 	err = lskcipher_prepare_alg(alg);
410 	if (err)
411 		return err;
412 
413 	return crypto_register_alg(base);
414 }
415 EXPORT_SYMBOL_GPL(crypto_register_lskcipher);
416 
417 void crypto_unregister_lskcipher(struct lskcipher_alg *alg)
418 {
419 	crypto_unregister_alg(&alg->co.base);
420 }
421 EXPORT_SYMBOL_GPL(crypto_unregister_lskcipher);
422 
423 int crypto_register_lskciphers(struct lskcipher_alg *algs, int count)
424 {
425 	int i, ret;
426 
427 	for (i = 0; i < count; i++) {
428 		ret = crypto_register_lskcipher(&algs[i]);
429 		if (ret)
430 			goto err;
431 	}
432 
433 	return 0;
434 
435 err:
436 	for (--i; i >= 0; --i)
437 		crypto_unregister_lskcipher(&algs[i]);
438 
439 	return ret;
440 }
441 EXPORT_SYMBOL_GPL(crypto_register_lskciphers);
442 
443 void crypto_unregister_lskciphers(struct lskcipher_alg *algs, int count)
444 {
445 	int i;
446 
447 	for (i = count - 1; i >= 0; --i)
448 		crypto_unregister_lskcipher(&algs[i]);
449 }
450 EXPORT_SYMBOL_GPL(crypto_unregister_lskciphers);
451 
452 int lskcipher_register_instance(struct crypto_template *tmpl,
453 				struct lskcipher_instance *inst)
454 {
455 	int err;
456 
457 	if (WARN_ON(!inst->free))
458 		return -EINVAL;
459 
460 	err = lskcipher_prepare_alg(&inst->alg);
461 	if (err)
462 		return err;
463 
464 	return crypto_register_instance(tmpl, lskcipher_crypto_instance(inst));
465 }
466 EXPORT_SYMBOL_GPL(lskcipher_register_instance);
467 
468 static int lskcipher_setkey_simple(struct crypto_lskcipher *tfm, const u8 *key,
469 				   unsigned int keylen)
470 {
471 	struct crypto_lskcipher *cipher = lskcipher_cipher_simple(tfm);
472 
473 	crypto_lskcipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
474 	crypto_lskcipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &
475 				   CRYPTO_TFM_REQ_MASK);
476 	return crypto_lskcipher_setkey(cipher, key, keylen);
477 }
478 
479 static int lskcipher_init_tfm_simple(struct crypto_lskcipher *tfm)
480 {
481 	struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);
482 	struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);
483 	struct crypto_lskcipher_spawn *spawn;
484 	struct crypto_lskcipher *cipher;
485 
486 	spawn = lskcipher_instance_ctx(inst);
487 	cipher = crypto_spawn_lskcipher(spawn);
488 	if (IS_ERR(cipher))
489 		return PTR_ERR(cipher);
490 
491 	*ctx = cipher;
492 	return 0;
493 }
494 
495 static void lskcipher_exit_tfm_simple(struct crypto_lskcipher *tfm)
496 {
497 	struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);
498 
499 	crypto_free_lskcipher(*ctx);
500 }
501 
502 static void lskcipher_free_instance_simple(struct lskcipher_instance *inst)
503 {
504 	crypto_drop_lskcipher(lskcipher_instance_ctx(inst));
505 	kfree(inst);
506 }
507 
508 /**
509  * lskcipher_alloc_instance_simple - allocate instance of simple block cipher
510  *
511  * Allocate an lskcipher_instance for a simple block cipher mode of operation,
512  * e.g. cbc or ecb.  The instance context will have just a single crypto_spawn,
513  * that for the underlying cipher.  The {min,max}_keysize, ivsize, blocksize,
514  * alignmask, and priority are set from the underlying cipher but can be
515  * overridden if needed.  The tfm context defaults to
516  * struct crypto_lskcipher *, and default ->setkey(), ->init(), and
517  * ->exit() methods are installed.
518  *
519  * @tmpl: the template being instantiated
520  * @tb: the template parameters
521  *
522  * Return: a pointer to the new instance, or an ERR_PTR().  The caller still
523  *	   needs to register the instance.
524  */
525 struct lskcipher_instance *lskcipher_alloc_instance_simple(
526 	struct crypto_template *tmpl, struct rtattr **tb)
527 {
528 	u32 mask;
529 	struct lskcipher_instance *inst;
530 	struct crypto_lskcipher_spawn *spawn;
531 	char ecb_name[CRYPTO_MAX_ALG_NAME];
532 	struct lskcipher_alg *cipher_alg;
533 	const char *cipher_name;
534 	int err;
535 
536 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);
537 	if (err)
538 		return ERR_PTR(err);
539 
540 	cipher_name = crypto_attr_alg_name(tb[1]);
541 	if (IS_ERR(cipher_name))
542 		return ERR_CAST(cipher_name);
543 
544 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
545 	if (!inst)
546 		return ERR_PTR(-ENOMEM);
547 
548 	spawn = lskcipher_instance_ctx(inst);
549 	err = crypto_grab_lskcipher(spawn,
550 				    lskcipher_crypto_instance(inst),
551 				    cipher_name, 0, mask);
552 
553 	ecb_name[0] = 0;
554 	if (err == -ENOENT && !!memcmp(tmpl->name, "ecb", 4)) {
555 		err = -ENAMETOOLONG;
556 		if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
557 			     cipher_name) >= CRYPTO_MAX_ALG_NAME)
558 			goto err_free_inst;
559 
560 		err = crypto_grab_lskcipher(spawn,
561 					    lskcipher_crypto_instance(inst),
562 					    ecb_name, 0, mask);
563 	}
564 
565 	if (err)
566 		goto err_free_inst;
567 
568 	cipher_alg = crypto_lskcipher_spawn_alg(spawn);
569 
570 	err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,
571 				  &cipher_alg->co.base);
572 	if (err)
573 		goto err_free_inst;
574 
575 	if (ecb_name[0]) {
576 		int len;
577 
578 		err = -EINVAL;
579 		len = strscpy(ecb_name, &cipher_alg->co.base.cra_name[4],
580 			      sizeof(ecb_name));
581 		if (len < 2)
582 			goto err_free_inst;
583 
584 		if (ecb_name[len - 1] != ')')
585 			goto err_free_inst;
586 
587 		ecb_name[len - 1] = 0;
588 
589 		err = -ENAMETOOLONG;
590 		if (snprintf(inst->alg.co.base.cra_name, CRYPTO_MAX_ALG_NAME,
591 			     "%s(%s)", tmpl->name, ecb_name) >=
592 		    CRYPTO_MAX_ALG_NAME)
593 			goto err_free_inst;
594 
595 		if (strcmp(ecb_name, cipher_name) &&
596 		    snprintf(inst->alg.co.base.cra_driver_name,
597 			     CRYPTO_MAX_ALG_NAME,
598 			     "%s(%s)", tmpl->name, cipher_name) >=
599 		    CRYPTO_MAX_ALG_NAME)
600 			goto err_free_inst;
601 	} else {
602 		/* Don't allow nesting. */
603 		err = -ELOOP;
604 		if ((cipher_alg->co.base.cra_flags & CRYPTO_ALG_INSTANCE))
605 			goto err_free_inst;
606 	}
607 
608 	err = -EINVAL;
609 	if (cipher_alg->co.ivsize)
610 		goto err_free_inst;
611 
612 	inst->free = lskcipher_free_instance_simple;
613 
614 	/* Default algorithm properties, can be overridden */
615 	inst->alg.co.base.cra_blocksize = cipher_alg->co.base.cra_blocksize;
616 	inst->alg.co.base.cra_alignmask = cipher_alg->co.base.cra_alignmask;
617 	inst->alg.co.base.cra_priority = cipher_alg->co.base.cra_priority;
618 	inst->alg.co.min_keysize = cipher_alg->co.min_keysize;
619 	inst->alg.co.max_keysize = cipher_alg->co.max_keysize;
620 	inst->alg.co.ivsize = cipher_alg->co.base.cra_blocksize;
621 
622 	/* Use struct crypto_lskcipher * by default, can be overridden */
623 	inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_lskcipher *);
624 	inst->alg.setkey = lskcipher_setkey_simple;
625 	inst->alg.init = lskcipher_init_tfm_simple;
626 	inst->alg.exit = lskcipher_exit_tfm_simple;
627 
628 	return inst;
629 
630 err_free_inst:
631 	lskcipher_free_instance_simple(inst);
632 	return ERR_PTR(err);
633 }
634 EXPORT_SYMBOL_GPL(lskcipher_alloc_instance_simple);
635