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  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(struct crypto_async_request *areq, int err)
135{
136	struct skcipher_request *req = areq->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(struct crypto_async_request *areq, int err)
170{
171	struct aead_request *req = areq->data;
172	struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
173
174	kfree(rctx->assoc);
175	aead_request_complete(req, err);
176}
177
178static int essiv_aead_crypt(struct aead_request *req, bool enc)
179{
180	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
181	const struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
182	struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
183	struct aead_request *subreq = &rctx->aead_req;
184	struct scatterlist *src = req->src;
185	int err;
186
187	crypto_cipher_encrypt_one(tctx->essiv_cipher, req->iv, req->iv);
188
189	/*
190	 * dm-crypt embeds the sector number and the IV in the AAD region, so
191	 * we have to copy the converted IV into the right scatterlist before
192	 * we pass it on.
193	 */
194	rctx->assoc = NULL;
195	if (req->src == req->dst || !enc) {
196		scatterwalk_map_and_copy(req->iv, req->dst,
197					 req->assoclen - crypto_aead_ivsize(tfm),
198					 crypto_aead_ivsize(tfm), 1);
199	} else {
200		u8 *iv = (u8 *)aead_request_ctx(req) + tctx->ivoffset;
201		int ivsize = crypto_aead_ivsize(tfm);
202		int ssize = req->assoclen - ivsize;
203		struct scatterlist *sg;
204		int nents;
205
206		if (ssize < 0)
207			return -EINVAL;
208
209		nents = sg_nents_for_len(req->src, ssize);
210		if (nents < 0)
211			return -EINVAL;
212
213		memcpy(iv, req->iv, ivsize);
214		sg_init_table(rctx->sg, 4);
215
216		if (unlikely(nents > 1)) {
217			/*
218			 * This is a case that rarely occurs in practice, but
219			 * for correctness, we have to deal with it nonetheless.
220			 */
221			rctx->assoc = kmalloc(ssize, GFP_ATOMIC);
222			if (!rctx->assoc)
223				return -ENOMEM;
224
225			scatterwalk_map_and_copy(rctx->assoc, req->src, 0,
226						 ssize, 0);
227			sg_set_buf(rctx->sg, rctx->assoc, ssize);
228		} else {
229			sg_set_page(rctx->sg, sg_page(req->src), ssize,
230				    req->src->offset);
231		}
232
233		sg_set_buf(rctx->sg + 1, iv, ivsize);
234		sg = scatterwalk_ffwd(rctx->sg + 2, req->src, req->assoclen);
235		if (sg != rctx->sg + 2)
236			sg_chain(rctx->sg, 3, sg);
237
238		src = rctx->sg;
239	}
240
241	aead_request_set_tfm(subreq, tctx->u.aead);
242	aead_request_set_ad(subreq, req->assoclen);
243	aead_request_set_callback(subreq, aead_request_flags(req),
244				  essiv_aead_done, req);
245	aead_request_set_crypt(subreq, src, req->dst, req->cryptlen, req->iv);
246
247	err = enc ? crypto_aead_encrypt(subreq) :
248		    crypto_aead_decrypt(subreq);
249
250	if (rctx->assoc && err != -EINPROGRESS)
251		kfree(rctx->assoc);
252	return err;
253}
254
255static int essiv_aead_encrypt(struct aead_request *req)
256{
257	return essiv_aead_crypt(req, true);
258}
259
260static int essiv_aead_decrypt(struct aead_request *req)
261{
262	return essiv_aead_crypt(req, false);
263}
264
265static int essiv_init_tfm(struct essiv_instance_ctx *ictx,
266			  struct essiv_tfm_ctx *tctx)
267{
268	struct crypto_cipher *essiv_cipher;
269	struct crypto_shash *hash;
270	int err;
271
272	essiv_cipher = crypto_alloc_cipher(ictx->essiv_cipher_name, 0, 0);
273	if (IS_ERR(essiv_cipher))
274		return PTR_ERR(essiv_cipher);
275
276	hash = crypto_alloc_shash(ictx->shash_driver_name, 0, 0);
277	if (IS_ERR(hash)) {
278		err = PTR_ERR(hash);
279		goto err_free_essiv_cipher;
280	}
281
282	tctx->essiv_cipher = essiv_cipher;
283	tctx->hash = hash;
284
285	return 0;
286
287err_free_essiv_cipher:
288	crypto_free_cipher(essiv_cipher);
289	return err;
290}
291
292static int essiv_skcipher_init_tfm(struct crypto_skcipher *tfm)
293{
294	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
295	struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
296	struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
297	struct crypto_skcipher *skcipher;
298	int err;
299
300	skcipher = crypto_spawn_skcipher(&ictx->u.skcipher_spawn);
301	if (IS_ERR(skcipher))
302		return PTR_ERR(skcipher);
303
304	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
305				         crypto_skcipher_reqsize(skcipher));
306
307	err = essiv_init_tfm(ictx, tctx);
308	if (err) {
309		crypto_free_skcipher(skcipher);
310		return err;
311	}
312
313	tctx->u.skcipher = skcipher;
314	return 0;
315}
316
317static int essiv_aead_init_tfm(struct crypto_aead *tfm)
318{
319	struct aead_instance *inst = aead_alg_instance(tfm);
320	struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
321	struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
322	struct crypto_aead *aead;
323	unsigned int subreq_size;
324	int err;
325
326	BUILD_BUG_ON(offsetofend(struct essiv_aead_request_ctx, aead_req) !=
327		     sizeof(struct essiv_aead_request_ctx));
328
329	aead = crypto_spawn_aead(&ictx->u.aead_spawn);
330	if (IS_ERR(aead))
331		return PTR_ERR(aead);
332
333	subreq_size = sizeof_field(struct essiv_aead_request_ctx, aead_req) +
334		      crypto_aead_reqsize(aead);
335
336	tctx->ivoffset = offsetof(struct essiv_aead_request_ctx, aead_req) +
337			 subreq_size;
338	crypto_aead_set_reqsize(tfm, tctx->ivoffset + crypto_aead_ivsize(aead));
339
340	err = essiv_init_tfm(ictx, tctx);
341	if (err) {
342		crypto_free_aead(aead);
343		return err;
344	}
345
346	tctx->u.aead = aead;
347	return 0;
348}
349
350static void essiv_skcipher_exit_tfm(struct crypto_skcipher *tfm)
351{
352	struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
353
354	crypto_free_skcipher(tctx->u.skcipher);
355	crypto_free_cipher(tctx->essiv_cipher);
356	crypto_free_shash(tctx->hash);
357}
358
359static void essiv_aead_exit_tfm(struct crypto_aead *tfm)
360{
361	struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
362
363	crypto_free_aead(tctx->u.aead);
364	crypto_free_cipher(tctx->essiv_cipher);
365	crypto_free_shash(tctx->hash);
366}
367
368static void essiv_skcipher_free_instance(struct skcipher_instance *inst)
369{
370	struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
371
372	crypto_drop_skcipher(&ictx->u.skcipher_spawn);
373	kfree(inst);
374}
375
376static void essiv_aead_free_instance(struct aead_instance *inst)
377{
378	struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
379
380	crypto_drop_aead(&ictx->u.aead_spawn);
381	kfree(inst);
382}
383
384static bool parse_cipher_name(char *essiv_cipher_name, const char *cra_name)
385{
386	const char *p, *q;
387	int len;
388
389	/* find the last opening parens */
390	p = strrchr(cra_name, '(');
391	if (!p++)
392		return false;
393
394	/* find the first closing parens in the tail of the string */
395	q = strchr(p, ')');
396	if (!q)
397		return false;
398
399	len = q - p;
400	if (len >= CRYPTO_MAX_ALG_NAME)
401		return false;
402
403	memcpy(essiv_cipher_name, p, len);
404	essiv_cipher_name[len] = '\0';
405	return true;
406}
407
408static bool essiv_supported_algorithms(const char *essiv_cipher_name,
409				       struct shash_alg *hash_alg,
410				       int ivsize)
411{
412	struct crypto_alg *alg;
413	bool ret = false;
414
415	alg = crypto_alg_mod_lookup(essiv_cipher_name,
416				    CRYPTO_ALG_TYPE_CIPHER,
417				    CRYPTO_ALG_TYPE_MASK);
418	if (IS_ERR(alg))
419		return false;
420
421	if (hash_alg->digestsize < alg->cra_cipher.cia_min_keysize ||
422	    hash_alg->digestsize > alg->cra_cipher.cia_max_keysize)
423		goto out;
424
425	if (ivsize != alg->cra_blocksize)
426		goto out;
427
428	if (crypto_shash_alg_needs_key(hash_alg))
429		goto out;
430
431	ret = true;
432
433out:
434	crypto_mod_put(alg);
435	return ret;
436}
437
438static int essiv_create(struct crypto_template *tmpl, struct rtattr **tb)
439{
440	struct crypto_attr_type *algt;
441	const char *inner_cipher_name;
442	const char *shash_name;
443	struct skcipher_instance *skcipher_inst = NULL;
444	struct aead_instance *aead_inst = NULL;
445	struct crypto_instance *inst;
446	struct crypto_alg *base, *block_base;
447	struct essiv_instance_ctx *ictx;
448	struct skcipher_alg *skcipher_alg = NULL;
449	struct aead_alg *aead_alg = NULL;
450	struct crypto_alg *_hash_alg;
451	struct shash_alg *hash_alg;
452	int ivsize;
453	u32 type;
454	u32 mask;
455	int err;
456
457	algt = crypto_get_attr_type(tb);
458	if (IS_ERR(algt))
459		return PTR_ERR(algt);
460
461	inner_cipher_name = crypto_attr_alg_name(tb[1]);
462	if (IS_ERR(inner_cipher_name))
463		return PTR_ERR(inner_cipher_name);
464
465	shash_name = crypto_attr_alg_name(tb[2]);
466	if (IS_ERR(shash_name))
467		return PTR_ERR(shash_name);
468
469	type = algt->type & algt->mask;
470	mask = crypto_algt_inherited_mask(algt);
471
472	switch (type) {
473	case CRYPTO_ALG_TYPE_SKCIPHER:
474		skcipher_inst = kzalloc(sizeof(*skcipher_inst) +
475					sizeof(*ictx), GFP_KERNEL);
476		if (!skcipher_inst)
477			return -ENOMEM;
478		inst = skcipher_crypto_instance(skcipher_inst);
479		base = &skcipher_inst->alg.base;
480		ictx = crypto_instance_ctx(inst);
481
482		/* Symmetric cipher, e.g., "cbc(aes)" */
483		err = crypto_grab_skcipher(&ictx->u.skcipher_spawn, inst,
484					   inner_cipher_name, 0, mask);
485		if (err)
486			goto out_free_inst;
487		skcipher_alg = crypto_spawn_skcipher_alg(&ictx->u.skcipher_spawn);
488		block_base = &skcipher_alg->base;
489		ivsize = crypto_skcipher_alg_ivsize(skcipher_alg);
490		break;
491
492	case CRYPTO_ALG_TYPE_AEAD:
493		aead_inst = kzalloc(sizeof(*aead_inst) +
494				    sizeof(*ictx), GFP_KERNEL);
495		if (!aead_inst)
496			return -ENOMEM;
497		inst = aead_crypto_instance(aead_inst);
498		base = &aead_inst->alg.base;
499		ictx = crypto_instance_ctx(inst);
500
501		/* AEAD cipher, e.g., "authenc(hmac(sha256),cbc(aes))" */
502		err = crypto_grab_aead(&ictx->u.aead_spawn, inst,
503				       inner_cipher_name, 0, mask);
504		if (err)
505			goto out_free_inst;
506		aead_alg = crypto_spawn_aead_alg(&ictx->u.aead_spawn);
507		block_base = &aead_alg->base;
508		if (!strstarts(block_base->cra_name, "authenc(")) {
509			pr_warn("Only authenc() type AEADs are supported by ESSIV\n");
510			err = -EINVAL;
511			goto out_drop_skcipher;
512		}
513		ivsize = aead_alg->ivsize;
514		break;
515
516	default:
517		return -EINVAL;
518	}
519
520	if (!parse_cipher_name(ictx->essiv_cipher_name, block_base->cra_name)) {
521		pr_warn("Failed to parse ESSIV cipher name from skcipher cra_name\n");
522		err = -EINVAL;
523		goto out_drop_skcipher;
524	}
525
526	/* Synchronous hash, e.g., "sha256" */
527	_hash_alg = crypto_alg_mod_lookup(shash_name,
528					  CRYPTO_ALG_TYPE_SHASH,
529					  CRYPTO_ALG_TYPE_MASK | mask);
530	if (IS_ERR(_hash_alg)) {
531		err = PTR_ERR(_hash_alg);
532		goto out_drop_skcipher;
533	}
534	hash_alg = __crypto_shash_alg(_hash_alg);
535
536	/* Check the set of algorithms */
537	if (!essiv_supported_algorithms(ictx->essiv_cipher_name, hash_alg,
538					ivsize)) {
539		pr_warn("Unsupported essiv instantiation: essiv(%s,%s)\n",
540			block_base->cra_name, hash_alg->base.cra_name);
541		err = -EINVAL;
542		goto out_free_hash;
543	}
544
545	/* record the driver name so we can instantiate this exact algo later */
546	strscpy(ictx->shash_driver_name, hash_alg->base.cra_driver_name,
547		CRYPTO_MAX_ALG_NAME);
548
549	/* Instance fields */
550
551	err = -ENAMETOOLONG;
552	if (snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME,
553		     "essiv(%s,%s)", block_base->cra_name,
554		     hash_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
555		goto out_free_hash;
556	if (snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME,
557		     "essiv(%s,%s)", block_base->cra_driver_name,
558		     hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
559		goto out_free_hash;
560
561	/*
562	 * hash_alg wasn't gotten via crypto_grab*(), so we need to inherit its
563	 * flags manually.
564	 */
565	base->cra_flags        |= (hash_alg->base.cra_flags &
566				   CRYPTO_ALG_INHERITED_FLAGS);
567	base->cra_blocksize	= block_base->cra_blocksize;
568	base->cra_ctxsize	= sizeof(struct essiv_tfm_ctx);
569	base->cra_alignmask	= block_base->cra_alignmask;
570	base->cra_priority	= block_base->cra_priority;
571
572	if (type == CRYPTO_ALG_TYPE_SKCIPHER) {
573		skcipher_inst->alg.setkey	= essiv_skcipher_setkey;
574		skcipher_inst->alg.encrypt	= essiv_skcipher_encrypt;
575		skcipher_inst->alg.decrypt	= essiv_skcipher_decrypt;
576		skcipher_inst->alg.init		= essiv_skcipher_init_tfm;
577		skcipher_inst->alg.exit		= essiv_skcipher_exit_tfm;
578
579		skcipher_inst->alg.min_keysize	= crypto_skcipher_alg_min_keysize(skcipher_alg);
580		skcipher_inst->alg.max_keysize	= crypto_skcipher_alg_max_keysize(skcipher_alg);
581		skcipher_inst->alg.ivsize	= ivsize;
582		skcipher_inst->alg.chunksize	= crypto_skcipher_alg_chunksize(skcipher_alg);
583		skcipher_inst->alg.walksize	= crypto_skcipher_alg_walksize(skcipher_alg);
584
585		skcipher_inst->free		= essiv_skcipher_free_instance;
586
587		err = skcipher_register_instance(tmpl, skcipher_inst);
588	} else {
589		aead_inst->alg.setkey		= essiv_aead_setkey;
590		aead_inst->alg.setauthsize	= essiv_aead_setauthsize;
591		aead_inst->alg.encrypt		= essiv_aead_encrypt;
592		aead_inst->alg.decrypt		= essiv_aead_decrypt;
593		aead_inst->alg.init		= essiv_aead_init_tfm;
594		aead_inst->alg.exit		= essiv_aead_exit_tfm;
595
596		aead_inst->alg.ivsize		= ivsize;
597		aead_inst->alg.maxauthsize	= crypto_aead_alg_maxauthsize(aead_alg);
598		aead_inst->alg.chunksize	= crypto_aead_alg_chunksize(aead_alg);
599
600		aead_inst->free			= essiv_aead_free_instance;
601
602		err = aead_register_instance(tmpl, aead_inst);
603	}
604
605	if (err)
606		goto out_free_hash;
607
608	crypto_mod_put(_hash_alg);
609	return 0;
610
611out_free_hash:
612	crypto_mod_put(_hash_alg);
613out_drop_skcipher:
614	if (type == CRYPTO_ALG_TYPE_SKCIPHER)
615		crypto_drop_skcipher(&ictx->u.skcipher_spawn);
616	else
617		crypto_drop_aead(&ictx->u.aead_spawn);
618out_free_inst:
619	kfree(skcipher_inst);
620	kfree(aead_inst);
621	return err;
622}
623
624/* essiv(cipher_name, shash_name) */
625static struct crypto_template essiv_tmpl = {
626	.name	= "essiv",
627	.create	= essiv_create,
628	.module	= THIS_MODULE,
629};
630
631static int __init essiv_module_init(void)
632{
633	return crypto_register_template(&essiv_tmpl);
634}
635
636static void __exit essiv_module_exit(void)
637{
638	crypto_unregister_template(&essiv_tmpl);
639}
640
641subsys_initcall(essiv_module_init);
642module_exit(essiv_module_exit);
643
644MODULE_DESCRIPTION("ESSIV skcipher/aead wrapper for block encryption");
645MODULE_LICENSE("GPL v2");
646MODULE_ALIAS_CRYPTO("essiv");
647MODULE_IMPORT_NS(CRYPTO_INTERNAL);