essiv.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * ESSIV skcipher and aead template for block encryption
  4 *
  5 * This template encapsulates the ESSIV IV generation algorithm used by
  6 * dm-crypt and fscrypt, which converts the initial vector for the skcipher
  7 * used for block encryption, by encrypting it using the hash of the
  8 * skcipher key as encryption key. Usually, the input IV is a 64-bit sector
  9 * number in LE representation zero-padded to the size of the IV, but this
 10 * is not assumed by this driver.
 11 *
 12 * The typical use of this template is to instantiate the skcipher
 13 * 'essiv(cbc(aes),sha256)', which is the only instantiation used by
 14 * fscrypt, and the most relevant one for dm-crypt. However, dm-crypt
 15 * also permits ESSIV to be used in combination with the authenc template,
 16 * e.g., 'essiv(authenc(hmac(sha256),cbc(aes)),sha256)', in which case
 17 * we need to instantiate an aead that accepts the same special key format
 18 * as the authenc template, and deals with the way the encrypted IV is
 19 * embedded into the AAD area of the aead request. This means the AEAD
 20 * flavor produced by this template is tightly coupled to the way dm-crypt
 21 * happens to use it.
 22 *
 23 * Copyright (c) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
 24 *
 25 * Heavily based on:
 26 * adiantum length-preserving encryption mode
 27 *
 28 * Copyright 2018 Google LLC
 29 */
 30
 31#include <crypto/authenc.h>
 32#include <crypto/internal/aead.h>
 33#include <crypto/internal/cipher.h>
 34#include <crypto/internal/hash.h>
 35#include <crypto/internal/skcipher.h>
 36#include <crypto/scatterwalk.h>
 37#include <linux/module.h>
 38
 39#include "internal.h"
 40
 41struct essiv_instance_ctx {
 42	union {
 43		struct crypto_skcipher_spawn	skcipher_spawn;
 44		struct crypto_aead_spawn	aead_spawn;
 45	} u;
 46	char	essiv_cipher_name[CRYPTO_MAX_ALG_NAME];
 47	char	shash_driver_name[CRYPTO_MAX_ALG_NAME];
 48};
 49
 50struct essiv_tfm_ctx {
 51	union {
 52		struct crypto_skcipher	*skcipher;
 53		struct crypto_aead	*aead;
 54	} u;
 55	struct crypto_cipher		*essiv_cipher;
 56	struct crypto_shash		*hash;
 57	int				ivoffset;
 58};
 59
 60struct essiv_aead_request_ctx {
 61	struct scatterlist		sg[4];
 62	u8				*assoc;
 63	struct aead_request		aead_req;
 64};
 65
 66static int essiv_skcipher_setkey(struct crypto_skcipher *tfm,
 67				 const u8 *key, unsigned int keylen)
 68{
 69	struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 70	u8 salt[HASH_MAX_DIGESTSIZE];
 71	int err;
 72
 73	crypto_skcipher_clear_flags(tctx->u.skcipher, CRYPTO_TFM_REQ_MASK);
 74	crypto_skcipher_set_flags(tctx->u.skcipher,
 75				  crypto_skcipher_get_flags(tfm) &
 76				  CRYPTO_TFM_REQ_MASK);
 77	err = crypto_skcipher_setkey(tctx->u.skcipher, key, keylen);
 78	if (err)
 79		return err;
 80
 81	err = crypto_shash_tfm_digest(tctx->hash, key, keylen, salt);
 82	if (err)
 83		return err;
 84
 85	crypto_cipher_clear_flags(tctx->essiv_cipher, CRYPTO_TFM_REQ_MASK);
 86	crypto_cipher_set_flags(tctx->essiv_cipher,
 87				crypto_skcipher_get_flags(tfm) &
 88				CRYPTO_TFM_REQ_MASK);
 89	return crypto_cipher_setkey(tctx->essiv_cipher, salt,
 90				    crypto_shash_digestsize(tctx->hash));
 91}
 92
 93static int essiv_aead_setkey(struct crypto_aead *tfm, const u8 *key,
 94			     unsigned int keylen)
 95{
 96	struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
 97	SHASH_DESC_ON_STACK(desc, tctx->hash);
 98	struct crypto_authenc_keys keys;
 99	u8 salt[HASH_MAX_DIGESTSIZE];
100	int err;
101
102	crypto_aead_clear_flags(tctx->u.aead, CRYPTO_TFM_REQ_MASK);
103	crypto_aead_set_flags(tctx->u.aead, crypto_aead_get_flags(tfm) &
104					    CRYPTO_TFM_REQ_MASK);
105	err = crypto_aead_setkey(tctx->u.aead, key, keylen);
106	if (err)
107		return err;
108
109	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
110		return -EINVAL;
111
112	desc->tfm = tctx->hash;
113	err = crypto_shash_init(desc) ?:
114	      crypto_shash_update(desc, keys.enckey, keys.enckeylen) ?:
115	      crypto_shash_finup(desc, keys.authkey, keys.authkeylen, salt);
116	if (err)
117		return err;
118
119	crypto_cipher_clear_flags(tctx->essiv_cipher, CRYPTO_TFM_REQ_MASK);
120	crypto_cipher_set_flags(tctx->essiv_cipher, crypto_aead_get_flags(tfm) &
121						    CRYPTO_TFM_REQ_MASK);
122	return crypto_cipher_setkey(tctx->essiv_cipher, salt,
123				    crypto_shash_digestsize(tctx->hash));
124}
125
126static int essiv_aead_setauthsize(struct crypto_aead *tfm,
127				  unsigned int authsize)
128{
129	struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
130
131	return crypto_aead_setauthsize(tctx->u.aead, authsize);
132}
133
134static void essiv_skcipher_done(void *data, int err)
135{
136	struct skcipher_request *req = data;
137
138	skcipher_request_complete(req, err);
139}
140
141static int essiv_skcipher_crypt(struct skcipher_request *req, bool enc)
142{
143	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
144	const struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
145	struct skcipher_request *subreq = skcipher_request_ctx(req);
146
147	crypto_cipher_encrypt_one(tctx->essiv_cipher, req->iv, req->iv);
148
149	skcipher_request_set_tfm(subreq, tctx->u.skcipher);
150	skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
151				   req->iv);
152	skcipher_request_set_callback(subreq, skcipher_request_flags(req),
153				      essiv_skcipher_done, req);
154
155	return enc ? crypto_skcipher_encrypt(subreq) :
156		     crypto_skcipher_decrypt(subreq);
157}
158
159static int essiv_skcipher_encrypt(struct skcipher_request *req)
160{
161	return essiv_skcipher_crypt(req, true);
162}
163
164static int essiv_skcipher_decrypt(struct skcipher_request *req)
165{
166	return essiv_skcipher_crypt(req, false);
167}
168
169static void essiv_aead_done(void *data, int err)
170{
171	struct aead_request *req = data;
172	struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
173
174	if (err == -EINPROGRESS)
175		goto out;
176
177	kfree(rctx->assoc);
178
179out:
180	aead_request_complete(req, err);
181}
182
183static int essiv_aead_crypt(struct aead_request *req, bool enc)
184{
185	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
186	const struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
187	struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
188	struct aead_request *subreq = &rctx->aead_req;
189	int ivsize = crypto_aead_ivsize(tfm);
190	int ssize = req->assoclen - ivsize;
191	struct scatterlist *src = req->src;
192	int err;
193
194	if (ssize < 0)
195		return -EINVAL;
196
197	crypto_cipher_encrypt_one(tctx->essiv_cipher, req->iv, req->iv);
198
199	/*
200	 * dm-crypt embeds the sector number and the IV in the AAD region, so
201	 * we have to copy the converted IV into the right scatterlist before
202	 * we pass it on.
203	 */
204	rctx->assoc = NULL;
205	if (req->src == req->dst || !enc) {
206		scatterwalk_map_and_copy(req->iv, req->dst, ssize, ivsize, 1);
207	} else {
208		u8 *iv = (u8 *)aead_request_ctx(req) + tctx->ivoffset;
209		struct scatterlist *sg;
210		int nents;
211
212		nents = sg_nents_for_len(req->src, ssize);
213		if (nents < 0)
214			return -EINVAL;
215
216		memcpy(iv, req->iv, ivsize);
217		sg_init_table(rctx->sg, 4);
218
219		if (unlikely(nents > 1)) {
220			/*
221			 * This is a case that rarely occurs in practice, but
222			 * for correctness, we have to deal with it nonetheless.
223			 */
224			rctx->assoc = kmalloc(ssize, GFP_ATOMIC);
225			if (!rctx->assoc)
226				return -ENOMEM;
227
228			scatterwalk_map_and_copy(rctx->assoc, req->src, 0,
229						 ssize, 0);
230			sg_set_buf(rctx->sg, rctx->assoc, ssize);
231		} else {
232			sg_set_page(rctx->sg, sg_page(req->src), ssize,
233				    req->src->offset);
234		}
235
236		sg_set_buf(rctx->sg + 1, iv, ivsize);
237		sg = scatterwalk_ffwd(rctx->sg + 2, req->src, req->assoclen);
238		if (sg != rctx->sg + 2)
239			sg_chain(rctx->sg, 3, sg);
240
241		src = rctx->sg;
242	}
243
244	aead_request_set_tfm(subreq, tctx->u.aead);
245	aead_request_set_ad(subreq, req->assoclen);
246	aead_request_set_callback(subreq, aead_request_flags(req),
247				  essiv_aead_done, req);
248	aead_request_set_crypt(subreq, src, req->dst, req->cryptlen, req->iv);
249
250	err = enc ? crypto_aead_encrypt(subreq) :
251		    crypto_aead_decrypt(subreq);
252
253	if (rctx->assoc && err != -EINPROGRESS && err != -EBUSY)
254		kfree(rctx->assoc);
255	return err;
256}
257
258static int essiv_aead_encrypt(struct aead_request *req)
259{
260	return essiv_aead_crypt(req, true);
261}
262
263static int essiv_aead_decrypt(struct aead_request *req)
264{
265	return essiv_aead_crypt(req, false);
266}
267
268static int essiv_init_tfm(struct essiv_instance_ctx *ictx,
269			  struct essiv_tfm_ctx *tctx)
270{
271	struct crypto_cipher *essiv_cipher;
272	struct crypto_shash *hash;
273	int err;
274
275	essiv_cipher = crypto_alloc_cipher(ictx->essiv_cipher_name, 0, 0);
276	if (IS_ERR(essiv_cipher))
277		return PTR_ERR(essiv_cipher);
278
279	hash = crypto_alloc_shash(ictx->shash_driver_name, 0, 0);
280	if (IS_ERR(hash)) {
281		err = PTR_ERR(hash);
282		goto err_free_essiv_cipher;
283	}
284
285	tctx->essiv_cipher = essiv_cipher;
286	tctx->hash = hash;
287
288	return 0;
289
290err_free_essiv_cipher:
291	crypto_free_cipher(essiv_cipher);
292	return err;
293}
294
295static int essiv_skcipher_init_tfm(struct crypto_skcipher *tfm)
296{
297	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
298	struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
299	struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
300	struct crypto_skcipher *skcipher;
301	int err;
302
303	skcipher = crypto_spawn_skcipher(&ictx->u.skcipher_spawn);
304	if (IS_ERR(skcipher))
305		return PTR_ERR(skcipher);
306
307	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
308				         crypto_skcipher_reqsize(skcipher));
309
310	err = essiv_init_tfm(ictx, tctx);
311	if (err) {
312		crypto_free_skcipher(skcipher);
313		return err;
314	}
315
316	tctx->u.skcipher = skcipher;
317	return 0;
318}
319
320static int essiv_aead_init_tfm(struct crypto_aead *tfm)
321{
322	struct aead_instance *inst = aead_alg_instance(tfm);
323	struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
324	struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
325	struct crypto_aead *aead;
326	unsigned int subreq_size;
327	int err;
328
329	BUILD_BUG_ON(offsetofend(struct essiv_aead_request_ctx, aead_req) !=
330		     sizeof(struct essiv_aead_request_ctx));
331
332	aead = crypto_spawn_aead(&ictx->u.aead_spawn);
333	if (IS_ERR(aead))
334		return PTR_ERR(aead);
335
336	subreq_size = sizeof_field(struct essiv_aead_request_ctx, aead_req) +
337		      crypto_aead_reqsize(aead);
338
339	tctx->ivoffset = offsetof(struct essiv_aead_request_ctx, aead_req) +
340			 subreq_size;
341	crypto_aead_set_reqsize(tfm, tctx->ivoffset + crypto_aead_ivsize(aead));
342
343	err = essiv_init_tfm(ictx, tctx);
344	if (err) {
345		crypto_free_aead(aead);
346		return err;
347	}
348
349	tctx->u.aead = aead;
350	return 0;
351}
352
353static void essiv_skcipher_exit_tfm(struct crypto_skcipher *tfm)
354{
355	struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
356
357	crypto_free_skcipher(tctx->u.skcipher);
358	crypto_free_cipher(tctx->essiv_cipher);
359	crypto_free_shash(tctx->hash);
360}
361
362static void essiv_aead_exit_tfm(struct crypto_aead *tfm)
363{
364	struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
365
366	crypto_free_aead(tctx->u.aead);
367	crypto_free_cipher(tctx->essiv_cipher);
368	crypto_free_shash(tctx->hash);
369}
370
371static void essiv_skcipher_free_instance(struct skcipher_instance *inst)
372{
373	struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
374
375	crypto_drop_skcipher(&ictx->u.skcipher_spawn);
376	kfree(inst);
377}
378
379static void essiv_aead_free_instance(struct aead_instance *inst)
380{
381	struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
382
383	crypto_drop_aead(&ictx->u.aead_spawn);
384	kfree(inst);
385}
386
387static bool parse_cipher_name(char *essiv_cipher_name, const char *cra_name)
388{
389	const char *p, *q;
390	int len;
391
392	/* find the last opening parens */
393	p = strrchr(cra_name, '(');
394	if (!p++)
395		return false;
396
397	/* find the first closing parens in the tail of the string */
398	q = strchr(p, ')');
399	if (!q)
400		return false;
401
402	len = q - p;
403	if (len >= CRYPTO_MAX_ALG_NAME)
404		return false;
405
406	strscpy(essiv_cipher_name, p, len + 1);
407	return true;
408}
409
410static bool essiv_supported_algorithms(const char *essiv_cipher_name,
411				       struct shash_alg *hash_alg,
412				       int ivsize)
413{
414	struct crypto_alg *alg;
415	bool ret = false;
416
417	alg = crypto_alg_mod_lookup(essiv_cipher_name,
418				    CRYPTO_ALG_TYPE_CIPHER,
419				    CRYPTO_ALG_TYPE_MASK);
420	if (IS_ERR(alg))
421		return false;
422
423	if (hash_alg->digestsize < alg->cra_cipher.cia_min_keysize ||
424	    hash_alg->digestsize > alg->cra_cipher.cia_max_keysize)
425		goto out;
426
427	if (ivsize != alg->cra_blocksize)
428		goto out;
429
430	if (crypto_shash_alg_needs_key(hash_alg))
431		goto out;
432
433	ret = true;
434
435out:
436	crypto_mod_put(alg);
437	return ret;
438}
439
440static int essiv_create(struct crypto_template *tmpl, struct rtattr **tb)
441{
442	struct skcipher_alg_common *skcipher_alg = NULL;
443	struct crypto_attr_type *algt;
444	const char *inner_cipher_name;
445	const char *shash_name;
446	struct skcipher_instance *skcipher_inst = NULL;
447	struct aead_instance *aead_inst = NULL;
448	struct crypto_instance *inst;
449	struct crypto_alg *base, *block_base;
450	struct essiv_instance_ctx *ictx;
451	struct aead_alg *aead_alg = NULL;
452	struct crypto_alg *_hash_alg;
453	struct shash_alg *hash_alg;
454	int ivsize;
455	u32 type;
456	u32 mask;
457	int err;
458
459	algt = crypto_get_attr_type(tb);
460	if (IS_ERR(algt))
461		return PTR_ERR(algt);
462
463	inner_cipher_name = crypto_attr_alg_name(tb[1]);
464	if (IS_ERR(inner_cipher_name))
465		return PTR_ERR(inner_cipher_name);
466
467	shash_name = crypto_attr_alg_name(tb[2]);
468	if (IS_ERR(shash_name))
469		return PTR_ERR(shash_name);
470
471	type = algt->type & algt->mask;
472	mask = crypto_algt_inherited_mask(algt);
473
474	switch (type) {
475	case CRYPTO_ALG_TYPE_LSKCIPHER:
476		skcipher_inst = kzalloc(sizeof(*skcipher_inst) +
477					sizeof(*ictx), GFP_KERNEL);
478		if (!skcipher_inst)
479			return -ENOMEM;
480		inst = skcipher_crypto_instance(skcipher_inst);
481		base = &skcipher_inst->alg.base;
482		ictx = crypto_instance_ctx(inst);
483
484		/* Symmetric cipher, e.g., "cbc(aes)" */
485		err = crypto_grab_skcipher(&ictx->u.skcipher_spawn, inst,
486					   inner_cipher_name, 0, mask);
487		if (err)
488			goto out_free_inst;
489		skcipher_alg = crypto_spawn_skcipher_alg_common(
490			&ictx->u.skcipher_spawn);
491		block_base = &skcipher_alg->base;
492		ivsize = skcipher_alg->ivsize;
493		break;
494
495	case CRYPTO_ALG_TYPE_AEAD:
496		aead_inst = kzalloc(sizeof(*aead_inst) +
497				    sizeof(*ictx), GFP_KERNEL);
498		if (!aead_inst)
499			return -ENOMEM;
500		inst = aead_crypto_instance(aead_inst);
501		base = &aead_inst->alg.base;
502		ictx = crypto_instance_ctx(inst);
503
504		/* AEAD cipher, e.g., "authenc(hmac(sha256),cbc(aes))" */
505		err = crypto_grab_aead(&ictx->u.aead_spawn, inst,
506				       inner_cipher_name, 0, mask);
507		if (err)
508			goto out_free_inst;
509		aead_alg = crypto_spawn_aead_alg(&ictx->u.aead_spawn);
510		block_base = &aead_alg->base;
511		if (!strstarts(block_base->cra_name, "authenc(")) {
512			pr_warn("Only authenc() type AEADs are supported by ESSIV\n");
513			err = -EINVAL;
514			goto out_drop_skcipher;
515		}
516		ivsize = aead_alg->ivsize;
517		break;
518
519	default:
520		return -EINVAL;
521	}
522
523	if (!parse_cipher_name(ictx->essiv_cipher_name, block_base->cra_name)) {
524		pr_warn("Failed to parse ESSIV cipher name from skcipher cra_name\n");
525		err = -EINVAL;
526		goto out_drop_skcipher;
527	}
528
529	/* Synchronous hash, e.g., "sha256" */
530	_hash_alg = crypto_alg_mod_lookup(shash_name,
531					  CRYPTO_ALG_TYPE_SHASH,
532					  CRYPTO_ALG_TYPE_MASK | mask);
533	if (IS_ERR(_hash_alg)) {
534		err = PTR_ERR(_hash_alg);
535		goto out_drop_skcipher;
536	}
537	hash_alg = __crypto_shash_alg(_hash_alg);
538
539	/* Check the set of algorithms */
540	if (!essiv_supported_algorithms(ictx->essiv_cipher_name, hash_alg,
541					ivsize)) {
542		pr_warn("Unsupported essiv instantiation: essiv(%s,%s)\n",
543			block_base->cra_name, hash_alg->base.cra_name);
544		err = -EINVAL;
545		goto out_free_hash;
546	}
547
548	/* record the driver name so we can instantiate this exact algo later */
549	strscpy(ictx->shash_driver_name, hash_alg->base.cra_driver_name);
550
551	/* Instance fields */
552
553	err = -ENAMETOOLONG;
554	if (snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME,
555		     "essiv(%s,%s)", block_base->cra_name,
556		     hash_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
557		goto out_free_hash;
558	if (snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME,
559		     "essiv(%s,%s)", block_base->cra_driver_name,
560		     hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
561		goto out_free_hash;
562
563	/*
564	 * hash_alg wasn't gotten via crypto_grab*(), so we need to inherit its
565	 * flags manually.
566	 */
567	base->cra_flags        |= (hash_alg->base.cra_flags &
568				   CRYPTO_ALG_INHERITED_FLAGS);
569	base->cra_blocksize	= block_base->cra_blocksize;
570	base->cra_ctxsize	= sizeof(struct essiv_tfm_ctx);
571	base->cra_alignmask	= block_base->cra_alignmask;
572	base->cra_priority	= block_base->cra_priority;
573
574	if (type == CRYPTO_ALG_TYPE_LSKCIPHER) {
575		skcipher_inst->alg.setkey	= essiv_skcipher_setkey;
576		skcipher_inst->alg.encrypt	= essiv_skcipher_encrypt;
577		skcipher_inst->alg.decrypt	= essiv_skcipher_decrypt;
578		skcipher_inst->alg.init		= essiv_skcipher_init_tfm;
579		skcipher_inst->alg.exit		= essiv_skcipher_exit_tfm;
580
581		skcipher_inst->alg.min_keysize	= skcipher_alg->min_keysize;
582		skcipher_inst->alg.max_keysize	= skcipher_alg->max_keysize;
583		skcipher_inst->alg.ivsize	= ivsize;
584		skcipher_inst->alg.chunksize	= skcipher_alg->chunksize;
585
586		skcipher_inst->free		= essiv_skcipher_free_instance;
587
588		err = skcipher_register_instance(tmpl, skcipher_inst);
589	} else {
590		aead_inst->alg.setkey		= essiv_aead_setkey;
591		aead_inst->alg.setauthsize	= essiv_aead_setauthsize;
592		aead_inst->alg.encrypt		= essiv_aead_encrypt;
593		aead_inst->alg.decrypt		= essiv_aead_decrypt;
594		aead_inst->alg.init		= essiv_aead_init_tfm;
595		aead_inst->alg.exit		= essiv_aead_exit_tfm;
596
597		aead_inst->alg.ivsize		= ivsize;
598		aead_inst->alg.maxauthsize	= crypto_aead_alg_maxauthsize(aead_alg);
599		aead_inst->alg.chunksize	= crypto_aead_alg_chunksize(aead_alg);
600
601		aead_inst->free			= essiv_aead_free_instance;
602
603		err = aead_register_instance(tmpl, aead_inst);
604	}
605
606	if (err)
607		goto out_free_hash;
608
609	crypto_mod_put(_hash_alg);
610	return 0;
611
612out_free_hash:
613	crypto_mod_put(_hash_alg);
614out_drop_skcipher:
615	if (type == CRYPTO_ALG_TYPE_LSKCIPHER)
616		crypto_drop_skcipher(&ictx->u.skcipher_spawn);
617	else
618		crypto_drop_aead(&ictx->u.aead_spawn);
619out_free_inst:
620	kfree(skcipher_inst);
621	kfree(aead_inst);
622	return err;
623}
624
625/* essiv(cipher_name, shash_name) */
626static struct crypto_template essiv_tmpl = {
627	.name	= "essiv",
628	.create	= essiv_create,
629	.module	= THIS_MODULE,
630};
631
632static int __init essiv_module_init(void)
633{
634	return crypto_register_template(&essiv_tmpl);
635}
636
637static void __exit essiv_module_exit(void)
638{
639	crypto_unregister_template(&essiv_tmpl);
640}
641
642module_init(essiv_module_init);
643module_exit(essiv_module_exit);
644
645MODULE_DESCRIPTION("ESSIV skcipher/aead wrapper for block encryption");
646MODULE_LICENSE("GPL v2");
647MODULE_ALIAS_CRYPTO("essiv");
648MODULE_IMPORT_NS("CRYPTO_INTERNAL");