[linux-2.6-block.git] / crypto / authenc.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Authenc: Simple AEAD wrapper for IPsec
 *
 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <crypto/internal/aead.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
#include <crypto/authenc.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

struct authenc_instance_ctx {
	struct crypto_ahash_spawn auth;
	struct crypto_skcipher_spawn enc;
	unsigned int reqoff;
};

struct crypto_authenc_ctx {
	struct crypto_ahash *auth;
	struct crypto_skcipher *enc;
};

struct authenc_request_ctx {
	struct scatterlist src[2];
	struct scatterlist dst[2];
	char tail[];
};

static void authenc_request_complete(struct aead_request *req, int err)
{
	if (err != -EINPROGRESS)
		aead_request_complete(req, err);
}

int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
			       unsigned int keylen)
{
	struct rtattr *rta = (struct rtattr *)key;
	struct crypto_authenc_key_param *param;

	if (!RTA_OK(rta, keylen))
		return -EINVAL;
	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
		return -EINVAL;

	/*
	 * RTA_OK() didn't align the rtattr's payload when validating that it
	 * fits in the buffer.  Yet, the keys should start on the next 4-byte
	 * aligned boundary.  To avoid confusion, require that the rtattr
	 * payload be exactly the param struct, which has a 4-byte aligned size.
	 */
	if (RTA_PAYLOAD(rta) != sizeof(*param))
		return -EINVAL;
	BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);

	param = RTA_DATA(rta);
	keys->enckeylen = be32_to_cpu(param->enckeylen);

	key += rta->rta_len;
	keylen -= rta->rta_len;

	if (keylen < keys->enckeylen)
		return -EINVAL;

	keys->authkeylen = keylen - keys->enckeylen;
	keys->authkey = key;
	keys->enckey = key + keys->authkeylen;

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);

static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
				 unsigned int keylen)
{
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct crypto_ahash *auth = ctx->auth;
	struct crypto_skcipher *enc = ctx->enc;
	struct crypto_authenc_keys keys;
	int err = -EINVAL;

	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
		goto out;

	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
				    CRYPTO_TFM_REQ_MASK);
	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
	if (err)
		goto out;

	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
				       CRYPTO_TFM_REQ_MASK);
	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
out:
	memzero_explicit(&keys, sizeof(keys));
	return err;
}

static void authenc_geniv_ahash_done(void *data, int err)
{
	struct aead_request *req = data;
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct aead_instance *inst = aead_alg_instance(authenc);
	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);

	if (err)
		goto out;

	scatterwalk_map_and_copy(ahreq->result, req->dst,
				 req->assoclen + req->cryptlen,
				 crypto_aead_authsize(authenc), 1);

out:
	aead_request_complete(req, err);
}

static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct aead_instance *inst = aead_alg_instance(authenc);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	struct crypto_ahash *auth = ctx->auth;
	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
	u8 *hash = areq_ctx->tail;
	int err;

	ahash_request_set_tfm(ahreq, auth);
	ahash_request_set_crypt(ahreq, req->dst, hash,
				req->assoclen + req->cryptlen);
	ahash_request_set_callback(ahreq, flags,
				   authenc_geniv_ahash_done, req);

	err = crypto_ahash_digest(ahreq);
	if (err)
		return err;

	scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
				 crypto_aead_authsize(authenc), 1);

	return 0;
}

static void crypto_authenc_encrypt_done(void *data, int err)
{
	struct aead_request *areq = data;

	if (err)
		goto out;

	err = crypto_authenc_genicv(areq, 0);

out:
	authenc_request_complete(areq, err);
}

static int crypto_authenc_encrypt(struct aead_request *req)
{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct aead_instance *inst = aead_alg_instance(authenc);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	struct crypto_skcipher *enc = ctx->enc;
	unsigned int cryptlen = req->cryptlen;
	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
						  ictx->reqoff);
	struct scatterlist *src, *dst;
	int err;

	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
	dst = src;

	if (req->src != req->dst) {
		memcpy_sglist(req->dst, req->src, req->assoclen);
		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
	}

	skcipher_request_set_tfm(skreq, enc);
	skcipher_request_set_callback(skreq, aead_request_flags(req),
				      crypto_authenc_encrypt_done, req);
	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);

	err = crypto_skcipher_encrypt(skreq);
	if (err)
		return err;

	return crypto_authenc_genicv(req, aead_request_flags(req));
}

static int crypto_authenc_decrypt_tail(struct aead_request *req,
				       unsigned int flags)
{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct aead_instance *inst = aead_alg_instance(authenc);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
						  ictx->reqoff);
	unsigned int authsize = crypto_aead_authsize(authenc);
	u8 *ihash = ahreq->result + authsize;
	struct scatterlist *src, *dst;

	scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);

	if (crypto_memneq(ihash, ahreq->result, authsize))
		return -EBADMSG;

	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
	dst = src;

	if (req->src != req->dst)
		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);

	skcipher_request_set_tfm(skreq, ctx->enc);
	skcipher_request_set_callback(skreq, flags,
				      req->base.complete, req->base.data);
	skcipher_request_set_crypt(skreq, src, dst,
				   req->cryptlen - authsize, req->iv);

	return crypto_skcipher_decrypt(skreq);
}

static void authenc_verify_ahash_done(void *data, int err)
{
	struct aead_request *req = data;

	if (err)
		goto out;

	err = crypto_authenc_decrypt_tail(req, 0);

out:
	authenc_request_complete(req, err);
}

static int crypto_authenc_decrypt(struct aead_request *req)
{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	unsigned int authsize = crypto_aead_authsize(authenc);
	struct aead_instance *inst = aead_alg_instance(authenc);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	struct crypto_ahash *auth = ctx->auth;
	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
	u8 *hash = areq_ctx->tail;
	int err;

	ahash_request_set_tfm(ahreq, auth);
	ahash_request_set_crypt(ahreq, req->src, hash,
				req->assoclen + req->cryptlen - authsize);
	ahash_request_set_callback(ahreq, aead_request_flags(req),
				   authenc_verify_ahash_done, req);

	err = crypto_ahash_digest(ahreq);
	if (err)
		return err;

	return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
}

static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
{
	struct aead_instance *inst = aead_alg_instance(tfm);
	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
	struct crypto_ahash *auth;
	struct crypto_skcipher *enc;
	int err;

	auth = crypto_spawn_ahash(&ictx->auth);
	if (IS_ERR(auth))
		return PTR_ERR(auth);

	enc = crypto_spawn_skcipher(&ictx->enc);
	err = PTR_ERR(enc);
	if (IS_ERR(enc))
		goto err_free_ahash;

	ctx->auth = auth;
	ctx->enc = enc;

	crypto_aead_set_reqsize(
		tfm,
		sizeof(struct authenc_request_ctx) +
		ictx->reqoff +
		max_t(unsigned int,
		      crypto_ahash_reqsize(auth) +
		      sizeof(struct ahash_request),
		      sizeof(struct skcipher_request) +
		      crypto_skcipher_reqsize(enc)));

	return 0;

err_free_ahash:
	crypto_free_ahash(auth);
	return err;
}

static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
{
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);

	crypto_free_ahash(ctx->auth);
	crypto_free_skcipher(ctx->enc);
}

static void crypto_authenc_free(struct aead_instance *inst)
{
	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);

	crypto_drop_skcipher(&ctx->enc);
	crypto_drop_ahash(&ctx->auth);
	kfree(inst);
}

static int crypto_authenc_create(struct crypto_template *tmpl,
				 struct rtattr **tb)
{
	u32 mask;
	struct aead_instance *inst;
	struct authenc_instance_ctx *ctx;
	struct skcipher_alg_common *enc;
	struct hash_alg_common *auth;
	struct crypto_alg *auth_base;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
	if (err)
		return err;

	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
	if (!inst)
		return -ENOMEM;
	ctx = aead_instance_ctx(inst);

	err = crypto_grab_ahash(&ctx->auth, aead_crypto_instance(inst),
				crypto_attr_alg_name(tb[1]), 0, mask);
	if (err)
		goto err_free_inst;
	auth = crypto_spawn_ahash_alg(&ctx->auth);
	auth_base = &auth->base;

	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
				   crypto_attr_alg_name(tb[2]), 0, mask);
	if (err)
		goto err_free_inst;
	enc = crypto_spawn_skcipher_alg_common(&ctx->enc);

	ctx->reqoff = 2 * auth->digestsize;

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
		     "authenc(%s,%s)", auth_base->cra_name,
		     enc->base.cra_name) >=
	    CRYPTO_MAX_ALG_NAME)
		goto err_free_inst;

	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "authenc(%s,%s)", auth_base->cra_driver_name,
		     enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
		goto err_free_inst;

	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
				      auth_base->cra_priority;
	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
	inst->alg.base.cra_alignmask = enc->base.cra_alignmask;
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);

	inst->alg.ivsize = enc->ivsize;
	inst->alg.chunksize = enc->chunksize;
	inst->alg.maxauthsize = auth->digestsize;

	inst->alg.init = crypto_authenc_init_tfm;
	inst->alg.exit = crypto_authenc_exit_tfm;

	inst->alg.setkey = crypto_authenc_setkey;
	inst->alg.encrypt = crypto_authenc_encrypt;
	inst->alg.decrypt = crypto_authenc_decrypt;

	inst->free = crypto_authenc_free;

	err = aead_register_instance(tmpl, inst);
	if (err) {
err_free_inst:
		crypto_authenc_free(inst);
	}
	return err;
}

static struct crypto_template crypto_authenc_tmpl = {
	.name = "authenc",
	.create = crypto_authenc_create,
	.module = THIS_MODULE,
};

static int __init crypto_authenc_module_init(void)
{
	return crypto_register_template(&crypto_authenc_tmpl);
}

static void __exit crypto_authenc_module_exit(void)
{
	crypto_unregister_template(&crypto_authenc_tmpl);
}

module_init(crypto_authenc_module_init);
module_exit(crypto_authenc_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
MODULE_ALIAS_CRYPTO("authenc");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* Authenc: Simple AEAD wrapper for IPsec
	4	*
	5	* Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
	6	*/
	7
	8	#include <crypto/internal/aead.h>
	9	#include <crypto/internal/hash.h>
	10	#include <crypto/internal/skcipher.h>
	11	#include <crypto/authenc.h>
	12	#include <crypto/scatterwalk.h>
	13	#include <linux/err.h>
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
	17	#include <linux/rtnetlink.h>
	18	#include <linux/slab.h>
	19	#include <linux/spinlock.h>
	20
	21	struct authenc_instance_ctx {
	22	struct crypto_ahash_spawn auth;
	23	struct crypto_skcipher_spawn enc;
	24	unsigned int reqoff;
	25	};
	26
	27	struct crypto_authenc_ctx {
	28	struct crypto_ahash *auth;
	29	struct crypto_skcipher *enc;
	30	};
	31
	32	struct authenc_request_ctx {
	33	struct scatterlist src[2];
	34	struct scatterlist dst[2];
	35	char tail[];
	36	};
	37
	38	static void authenc_request_complete(struct aead_request *req, int err)
	39	{
	40	if (err != -EINPROGRESS)
	41	aead_request_complete(req, err);
	42	}
	43
	44	int crypto_authenc_extractkeys(struct crypto_authenc_keys keys, const u8 key,
	45	unsigned int keylen)
	46	{
	47	struct rtattr rta = (struct rtattr )key;
	48	struct crypto_authenc_key_param *param;
	49
	50	if (!RTA_OK(rta, keylen))
	51	return -EINVAL;
	52	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
	53	return -EINVAL;
	54
	55	/*
	56	* RTA_OK() didn't align the rtattr's payload when validating that it
	57	* fits in the buffer. Yet, the keys should start on the next 4-byte
	58	* aligned boundary. To avoid confusion, require that the rtattr
	59	* payload be exactly the param struct, which has a 4-byte aligned size.
	60	*/
	61	if (RTA_PAYLOAD(rta) != sizeof(*param))
	62	return -EINVAL;
	63	BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
	64
	65	param = RTA_DATA(rta);
	66	keys->enckeylen = be32_to_cpu(param->enckeylen);
	67
	68	key += rta->rta_len;
	69	keylen -= rta->rta_len;
	70
	71	if (keylen < keys->enckeylen)
	72	return -EINVAL;
	73
	74	keys->authkeylen = keylen - keys->enckeylen;
	75	keys->authkey = key;
	76	keys->enckey = key + keys->authkeylen;
	77
	78	return 0;
	79	}
	80	EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
	81
	82	static int crypto_authenc_setkey(struct crypto_aead authenc, const u8 key,
	83	unsigned int keylen)
	84	{
	85	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	86	struct crypto_ahash *auth = ctx->auth;
	87	struct crypto_skcipher *enc = ctx->enc;
	88	struct crypto_authenc_keys keys;
	89	int err = -EINVAL;
	90
	91	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
	92	goto out;
	93
	94	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
	95	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
	96	CRYPTO_TFM_REQ_MASK);
	97	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
	98	if (err)
	99	goto out;
	100
	101	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
	102	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
	103	CRYPTO_TFM_REQ_MASK);
	104	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
	105	out:
	106	memzero_explicit(&keys, sizeof(keys));
	107	return err;
	108	}
	109
	110	static void authenc_geniv_ahash_done(void *data, int err)
	111	{
	112	struct aead_request *req = data;
	113	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	114	struct aead_instance *inst = aead_alg_instance(authenc);
	115	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	116	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	117	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
	118
	119	if (err)
	120	goto out;
	121
	122	scatterwalk_map_and_copy(ahreq->result, req->dst,
	123	req->assoclen + req->cryptlen,
	124	crypto_aead_authsize(authenc), 1);
	125
	126	out:
	127	aead_request_complete(req, err);
	128	}
	129
	130	static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
	131	{
	132	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	133	struct aead_instance *inst = aead_alg_instance(authenc);
	134	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	135	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	136	struct crypto_ahash *auth = ctx->auth;
	137	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	138	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
	139	u8 *hash = areq_ctx->tail;
	140	int err;
	141
	142	ahash_request_set_tfm(ahreq, auth);
	143	ahash_request_set_crypt(ahreq, req->dst, hash,
	144	req->assoclen + req->cryptlen);
	145	ahash_request_set_callback(ahreq, flags,
	146	authenc_geniv_ahash_done, req);
	147
	148	err = crypto_ahash_digest(ahreq);
	149	if (err)
	150	return err;
	151
	152	scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
	153	crypto_aead_authsize(authenc), 1);
	154
	155	return 0;
	156	}
	157
	158	static void crypto_authenc_encrypt_done(void *data, int err)
	159	{
	160	struct aead_request *areq = data;
	161
	162	if (err)
	163	goto out;
	164
	165	err = crypto_authenc_genicv(areq, 0);
	166
	167	out:
	168	authenc_request_complete(areq, err);
	169	}
	170
	171	static int crypto_authenc_encrypt(struct aead_request *req)
	172	{
	173	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	174	struct aead_instance *inst = aead_alg_instance(authenc);
	175	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	176	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	177	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	178	struct crypto_skcipher *enc = ctx->enc;
	179	unsigned int cryptlen = req->cryptlen;
	180	struct skcipher_request skreq = (void )(areq_ctx->tail +
	181	ictx->reqoff);
	182	struct scatterlist src, dst;
	183	int err;
	184
	185	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
	186	dst = src;
	187
	188	if (req->src != req->dst) {
	189	memcpy_sglist(req->dst, req->src, req->assoclen);
	190	dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
	191	}
	192
	193	skcipher_request_set_tfm(skreq, enc);
	194	skcipher_request_set_callback(skreq, aead_request_flags(req),
	195	crypto_authenc_encrypt_done, req);
	196	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
	197
	198	err = crypto_skcipher_encrypt(skreq);
	199	if (err)
	200	return err;
	201
	202	return crypto_authenc_genicv(req, aead_request_flags(req));
	203	}
	204
	205	static int crypto_authenc_decrypt_tail(struct aead_request *req,
	206	unsigned int flags)
	207	{
	208	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	209	struct aead_instance *inst = aead_alg_instance(authenc);
	210	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	211	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	212	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	213	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
	214	struct skcipher_request skreq = (void )(areq_ctx->tail +
	215	ictx->reqoff);
	216	unsigned int authsize = crypto_aead_authsize(authenc);
	217	u8 *ihash = ahreq->result + authsize;
	218	struct scatterlist src, dst;
	219
	220	scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
	221
	222	if (crypto_memneq(ihash, ahreq->result, authsize))
	223	return -EBADMSG;
	224
	225	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
	226	dst = src;
	227
	228	if (req->src != req->dst)
	229	dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
	230
	231	skcipher_request_set_tfm(skreq, ctx->enc);
	232	skcipher_request_set_callback(skreq, flags,
	233	req->base.complete, req->base.data);
	234	skcipher_request_set_crypt(skreq, src, dst,
	235	req->cryptlen - authsize, req->iv);
	236
	237	return crypto_skcipher_decrypt(skreq);
	238	}
	239
	240	static void authenc_verify_ahash_done(void *data, int err)
	241	{
	242	struct aead_request *req = data;
	243
	244	if (err)
	245	goto out;
	246
	247	err = crypto_authenc_decrypt_tail(req, 0);
	248
	249	out:
	250	authenc_request_complete(req, err);
	251	}
	252
	253	static int crypto_authenc_decrypt(struct aead_request *req)
	254	{
	255	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	256	unsigned int authsize = crypto_aead_authsize(authenc);
	257	struct aead_instance *inst = aead_alg_instance(authenc);
	258	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	259	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	260	struct crypto_ahash *auth = ctx->auth;
	261	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	262	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
	263	u8 *hash = areq_ctx->tail;
	264	int err;
	265
	266	ahash_request_set_tfm(ahreq, auth);
	267	ahash_request_set_crypt(ahreq, req->src, hash,
	268	req->assoclen + req->cryptlen - authsize);
	269	ahash_request_set_callback(ahreq, aead_request_flags(req),
	270	authenc_verify_ahash_done, req);
	271
	272	err = crypto_ahash_digest(ahreq);
	273	if (err)
	274	return err;
	275
	276	return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
	277	}
	278
	279	static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
	280	{
	281	struct aead_instance *inst = aead_alg_instance(tfm);
	282	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	283	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
	284	struct crypto_ahash *auth;
	285	struct crypto_skcipher *enc;
	286	int err;
	287
	288	auth = crypto_spawn_ahash(&ictx->auth);
	289	if (IS_ERR(auth))
	290	return PTR_ERR(auth);
	291
	292	enc = crypto_spawn_skcipher(&ictx->enc);
	293	err = PTR_ERR(enc);
	294	if (IS_ERR(enc))
	295	goto err_free_ahash;
	296
	297	ctx->auth = auth;
	298	ctx->enc = enc;
	299
	300	crypto_aead_set_reqsize(
	301	tfm,
	302	sizeof(struct authenc_request_ctx) +
	303	ictx->reqoff +
	304	max_t(unsigned int,
	305	crypto_ahash_reqsize(auth) +
	306	sizeof(struct ahash_request),
	307	sizeof(struct skcipher_request) +
	308	crypto_skcipher_reqsize(enc)));
	309
	310	return 0;
	311
	312	err_free_ahash:
	313	crypto_free_ahash(auth);
	314	return err;
	315	}
	316
	317	static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
	318	{
	319	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
	320
	321	crypto_free_ahash(ctx->auth);
	322	crypto_free_skcipher(ctx->enc);
	323	}
	324
	325	static void crypto_authenc_free(struct aead_instance *inst)
	326	{
	327	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
	328
	329	crypto_drop_skcipher(&ctx->enc);
	330	crypto_drop_ahash(&ctx->auth);
	331	kfree(inst);
	332	}
	333
	334	static int crypto_authenc_create(struct crypto_template *tmpl,
	335	struct rtattr **tb)
	336	{
	337	u32 mask;
	338	struct aead_instance *inst;
	339	struct authenc_instance_ctx *ctx;
	340	struct skcipher_alg_common *enc;
	341	struct hash_alg_common *auth;
	342	struct crypto_alg *auth_base;
	343	int err;
	344
	345	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
	346	if (err)
	347	return err;
	348
	349	inst = kzalloc(sizeof(inst) + sizeof(ctx), GFP_KERNEL);
	350	if (!inst)
	351	return -ENOMEM;
	352	ctx = aead_instance_ctx(inst);
	353
	354	err = crypto_grab_ahash(&ctx->auth, aead_crypto_instance(inst),
	355	crypto_attr_alg_name(tb[1]), 0, mask);
	356	if (err)
	357	goto err_free_inst;
	358	auth = crypto_spawn_ahash_alg(&ctx->auth);
	359	auth_base = &auth->base;
	360
	361	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
	362	crypto_attr_alg_name(tb[2]), 0, mask);
	363	if (err)
	364	goto err_free_inst;
	365	enc = crypto_spawn_skcipher_alg_common(&ctx->enc);
	366
	367	ctx->reqoff = 2 * auth->digestsize;
	368
	369	err = -ENAMETOOLONG;
	370	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
	371	"authenc(%s,%s)", auth_base->cra_name,
	372	enc->base.cra_name) >=
	373	CRYPTO_MAX_ALG_NAME)
	374	goto err_free_inst;
	375
	376	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	377	"authenc(%s,%s)", auth_base->cra_driver_name,
	378	enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
	379	goto err_free_inst;
	380
	381	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
	382	auth_base->cra_priority;
	383	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
	384	inst->alg.base.cra_alignmask = enc->base.cra_alignmask;
	385	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
	386
	387	inst->alg.ivsize = enc->ivsize;
	388	inst->alg.chunksize = enc->chunksize;
	389	inst->alg.maxauthsize = auth->digestsize;
	390
	391	inst->alg.init = crypto_authenc_init_tfm;
	392	inst->alg.exit = crypto_authenc_exit_tfm;
	393
	394	inst->alg.setkey = crypto_authenc_setkey;
	395	inst->alg.encrypt = crypto_authenc_encrypt;
	396	inst->alg.decrypt = crypto_authenc_decrypt;
	397
	398	inst->free = crypto_authenc_free;
	399
	400	err = aead_register_instance(tmpl, inst);
	401	if (err) {
	402	err_free_inst:
	403	crypto_authenc_free(inst);
	404	}
	405	return err;
	406	}
	407
	408	static struct crypto_template crypto_authenc_tmpl = {
	409	.name = "authenc",
	410	.create = crypto_authenc_create,
	411	.module = THIS_MODULE,
	412	};
	413
	414	static int __init crypto_authenc_module_init(void)
	415	{
	416	return crypto_register_template(&crypto_authenc_tmpl);
	417	}
	418
	419	static void __exit crypto_authenc_module_exit(void)
	420	{
	421	crypto_unregister_template(&crypto_authenc_tmpl);
	422	}
	423
	424	module_init(crypto_authenc_module_init);
	425	module_exit(crypto_authenc_module_exit);
	426
	427	MODULE_LICENSE("GPL");
	428	MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
	429	MODULE_ALIAS_CRYPTO("authenc");