[linux-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/null.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 crypto_sync_skcipher *null;
};

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_copy_assoc(struct aead_request *req)
{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);

	skcipher_request_set_sync_tfm(skreq, ctx->null);
	skcipher_request_set_callback(skreq, aead_request_flags(req),
				      NULL, NULL);
	skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
				   NULL);

	return crypto_skcipher_encrypt(skreq);
}

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) {
		err = crypto_authenc_copy_assoc(req);
		if (err)
			return err;

		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;
	struct crypto_sync_skcipher *null;
	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;

	null = crypto_get_default_null_skcipher();
	err = PTR_ERR(null);
	if (IS_ERR(null))
		goto err_free_skcipher;

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

	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_skcipher:
	crypto_free_skcipher(enc);
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);
	crypto_put_default_null_skcipher();
}

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);
}

subsys_initcall(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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
3c09f17c HX	2	/*
	3	* Authenc: Simple AEAD wrapper for IPsec
	4	*
92d95ba9	5	* Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
3c09f17c HX	6	*/
3c09f17c HX	7
68acbf84	8	#include <crypto/internal/aead.h>
5f7082ed	9	#include <crypto/internal/hash.h>
9ffde35a	10	#include <crypto/internal/skcipher.h>
e236d4a8	11	#include <crypto/authenc.h>
92d95ba9	12	#include <crypto/null.h>
42c271c6	13	#include <crypto/scatterwalk.h>
3c09f17c HX	14	#include <linux/err.h>
	15	#include <linux/init.h>
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
e236d4a8	18	#include <linux/rtnetlink.h>
3c09f17c HX	19	#include <linux/slab.h>
	20	#include <linux/spinlock.h>
	21
3c09f17c	22	struct authenc_instance_ctx {
cbdcf80d	23	struct crypto_ahash_spawn auth;
9ffde35a	24	struct crypto_skcipher_spawn enc;
92d95ba9	25	unsigned int reqoff;
3c09f17c HX	26	};
	27
	28	struct crypto_authenc_ctx {
cbdcf80d	29	struct crypto_ahash *auth;
7217d49f	30	struct crypto_skcipher *enc;
8d605398	31	struct crypto_sync_skcipher *null;
3c09f17c HX	32	};
3c09f17c HX	33
cbdcf80d	34	struct authenc_request_ctx {
92d95ba9 HX	35	struct scatterlist src[2];
92d95ba9 HX	36	struct scatterlist dst[2];
cbdcf80d SK	37	char tail[];
	38	};
	39
180ce7e8 HX	40	static void authenc_request_complete(struct aead_request *req, int err)
	41	{
	42	if (err != -EINPROGRESS)
	43	aead_request_complete(req, err);
	44	}
	45
bc6e2bdb MK	46	int crypto_authenc_extractkeys(struct crypto_authenc_keys keys, const u8 key,
bc6e2bdb MK	47	unsigned int keylen)
3c09f17c	48	{
bc6e2bdb	49	struct rtattr rta = (struct rtattr )key;
e236d4a8	50	struct crypto_authenc_key_param *param;
3c09f17c	51
12dc5e62	52	if (!RTA_OK(rta, keylen))
bc6e2bdb	53	return -EINVAL;
e236d4a8	54	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
bc6e2bdb	55	return -EINVAL;
8f9c4693 EB	56
	57	/*
	58	* RTA_OK() didn't align the rtattr's payload when validating that it
	59	* fits in the buffer. Yet, the keys should start on the next 4-byte
	60	* aligned boundary. To avoid confusion, require that the rtattr
	61	* payload be exactly the param struct, which has a 4-byte aligned size.
	62	*/
	63	if (RTA_PAYLOAD(rta) != sizeof(*param))
bc6e2bdb	64	return -EINVAL;
8f9c4693	65	BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
e236d4a8 HX	66
e236d4a8 HX	67	param = RTA_DATA(rta);
bc6e2bdb	68	keys->enckeylen = be32_to_cpu(param->enckeylen);
e236d4a8	69
8f9c4693 EB	70	key += rta->rta_len;
8f9c4693 EB	71	keylen -= rta->rta_len;
e236d4a8	72
bc6e2bdb MK	73	if (keylen < keys->enckeylen)
	74	return -EINVAL;
	75
	76	keys->authkeylen = keylen - keys->enckeylen;
	77	keys->authkey = key;
	78	keys->enckey = key + keys->authkeylen;
e236d4a8	79
bc6e2bdb MK	80	return 0;
	81	}
	82	EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
	83
	84	static int crypto_authenc_setkey(struct crypto_aead authenc, const u8 key,
	85	unsigned int keylen)
	86	{
	87	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	88	struct crypto_ahash *auth = ctx->auth;
7217d49f	89	struct crypto_skcipher *enc = ctx->enc;
bc6e2bdb MK	90	struct crypto_authenc_keys keys;
	91	int err = -EINVAL;
	92
	93	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
674f368a	94	goto out;
3c09f17c	95
cbdcf80d SK	96	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
cbdcf80d SK	97	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
3c09f17c	98	CRYPTO_TFM_REQ_MASK);
bc6e2bdb	99	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
3c09f17c HX	100	if (err)
	101	goto out;
	102
7217d49f HX	103	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
	104	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
	105	CRYPTO_TFM_REQ_MASK);
	106	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
3c09f17c	107	out:
ad2fdcdf	108	memzero_explicit(&keys, sizeof(keys));
3c09f17c HX	109	return err;
	110	}
	111
255e48eb	112	static void authenc_geniv_ahash_done(void *data, int err)
cbdcf80d	113	{
255e48eb	114	struct aead_request *req = data;
cbdcf80d	115	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
92d95ba9 HX	116	struct aead_instance *inst = aead_alg_instance(authenc);
92d95ba9 HX	117	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
cbdcf80d	118	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
92d95ba9	119	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
cbdcf80d SK	120
	121	if (err)
	122	goto out;
	123
92d95ba9 HX	124	scatterwalk_map_and_copy(ahreq->result, req->dst,
92d95ba9 HX	125	req->assoclen + req->cryptlen,
cbdcf80d SK	126	crypto_aead_authsize(authenc), 1);
	127
	128	out:
	129	aead_request_complete(req, err);
	130	}
	131
92d95ba9	132	static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
cbdcf80d SK	133	{
cbdcf80d SK	134	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
92d95ba9	135	struct aead_instance *inst = aead_alg_instance(authenc);
cbdcf80d	136	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
92d95ba9	137	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
cbdcf80d SK	138	struct crypto_ahash *auth = ctx->auth;
cbdcf80d SK	139	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
92d95ba9	140	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
cbdcf80d SK	141	u8 *hash = areq_ctx->tail;
cbdcf80d SK	142	int err;
3c09f17c	143
cbdcf80d	144	ahash_request_set_tfm(ahreq, auth);
92d95ba9 HX	145	ahash_request_set_crypt(ahreq, req->dst, hash,
	146	req->assoclen + req->cryptlen);
	147	ahash_request_set_callback(ahreq, flags,
	148	authenc_geniv_ahash_done, req);
cbdcf80d SK	149
cbdcf80d SK	150	err = crypto_ahash_digest(ahreq);
3c09f17c	151	if (err)
92d95ba9	152	return err;
3c09f17c	153
92d95ba9	154	scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
7ba683a6	155	crypto_aead_authsize(authenc), 1);
92d95ba9	156
3c09f17c HX	157	return 0;
	158	}
	159
255e48eb	160	static void crypto_authenc_encrypt_done(void *data, int err)
3c09f17c	161	{
255e48eb	162	struct aead_request *areq = data;
a697690b	163
92d95ba9 HX	164	if (err)
92d95ba9 HX	165	goto out;
e56dd564	166
92d95ba9	167	err = crypto_authenc_genicv(areq, 0);
3c09f17c	168
92d95ba9	169	out:
180ce7e8	170	authenc_request_complete(areq, err);
3c09f17c HX	171	}
3c09f17c HX	172
92d95ba9 HX	173	static int crypto_authenc_copy_assoc(struct aead_request *req)
	174	{
	175	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	176	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
8d605398	177	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
92d95ba9	178
8d605398	179	skcipher_request_set_sync_tfm(skreq, ctx->null);
7217d49f HX	180	skcipher_request_set_callback(skreq, aead_request_flags(req),
	181	NULL, NULL);
	182	skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
	183	NULL);
	184
	185	return crypto_skcipher_encrypt(skreq);
92d95ba9 HX	186	}
92d95ba9 HX	187
3c09f17c HX	188	static int crypto_authenc_encrypt(struct aead_request *req)
	189	{
	190	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
92d95ba9	191	struct aead_instance *inst = aead_alg_instance(authenc);
3c09f17c	192	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
92d95ba9	193	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
50beceba	194	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
7217d49f	195	struct crypto_skcipher *enc = ctx->enc;
e56dd564	196	unsigned int cryptlen = req->cryptlen;
7217d49f HX	197	struct skcipher_request skreq = (void )(areq_ctx->tail +
7217d49f HX	198	ictx->reqoff);
92d95ba9	199	struct scatterlist src, dst;
3c09f17c HX	200	int err;
3c09f17c HX	201
92d95ba9 HX	202	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
	203	dst = src;
	204
	205	if (req->src != req->dst) {
	206	err = crypto_authenc_copy_assoc(req);
	207	if (err)
	208	return err;
	209
92d95ba9 HX	210	dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
	211	}
	212
7217d49f HX	213	skcipher_request_set_tfm(skreq, enc);
	214	skcipher_request_set_callback(skreq, aead_request_flags(req),
	215	crypto_authenc_encrypt_done, req);
	216	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
3c09f17c	217
7217d49f	218	err = crypto_skcipher_encrypt(skreq);
3c09f17c HX	219	if (err)
	220	return err;
	221
92d95ba9	222	return crypto_authenc_genicv(req, aead_request_flags(req));
e56dd564 HX	223	}
e56dd564 HX	224
92d95ba9 HX	225	static int crypto_authenc_decrypt_tail(struct aead_request *req,
92d95ba9 HX	226	unsigned int flags)
e56dd564	227	{
92d95ba9 HX	228	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	229	struct aead_instance *inst = aead_alg_instance(authenc);
	230	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	231	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	232	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	233	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
7217d49f HX	234	struct skcipher_request skreq = (void )(areq_ctx->tail +
7217d49f HX	235	ictx->reqoff);
92d95ba9 HX	236	unsigned int authsize = crypto_aead_authsize(authenc);
	237	u8 *ihash = ahreq->result + authsize;
	238	struct scatterlist src, dst;
e56dd564	239
92d95ba9	240	scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
e56dd564	241
92d95ba9 HX	242	if (crypto_memneq(ihash, ahreq->result, authsize))
92d95ba9 HX	243	return -EBADMSG;
e56dd564	244
92d95ba9 HX	245	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
92d95ba9 HX	246	dst = src;
e56dd564	247
c34252fd	248	if (req->src != req->dst)
92d95ba9	249	dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
e56dd564	250
7217d49f	251	skcipher_request_set_tfm(skreq, ctx->enc);
66eae850	252	skcipher_request_set_callback(skreq, flags,
7217d49f HX	253	req->base.complete, req->base.data);
	254	skcipher_request_set_crypt(skreq, src, dst,
	255	req->cryptlen - authsize, req->iv);
3c09f17c	256
7217d49f	257	return crypto_skcipher_decrypt(skreq);
3c09f17c HX	258	}
3c09f17c HX	259
255e48eb	260	static void authenc_verify_ahash_done(void *data, int err)
3c09f17c	261	{
255e48eb	262	struct aead_request *req = data;
cbdcf80d	263
92d95ba9 HX	264	if (err)
92d95ba9 HX	265	goto out;
e56dd564	266
92d95ba9	267	err = crypto_authenc_decrypt_tail(req, 0);
cbdcf80d	268
92d95ba9 HX	269	out:
92d95ba9 HX	270	authenc_request_complete(req, err);
3c09f17c HX	271	}
	272
	273	static int crypto_authenc_decrypt(struct aead_request *req)
	274	{
	275	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
481f34ae	276	unsigned int authsize = crypto_aead_authsize(authenc);
92d95ba9 HX	277	struct aead_instance *inst = aead_alg_instance(authenc);
	278	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	279	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	280	struct crypto_ahash *auth = ctx->auth;
	281	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	282	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
	283	u8 *hash = areq_ctx->tail;
3c09f17c HX	284	int err;
3c09f17c HX	285
92d95ba9 HX	286	ahash_request_set_tfm(ahreq, auth);
	287	ahash_request_set_crypt(ahreq, req->src, hash,
	288	req->assoclen + req->cryptlen - authsize);
	289	ahash_request_set_callback(ahreq, aead_request_flags(req),
	290	authenc_verify_ahash_done, req);
	291
	292	err = crypto_ahash_digest(ahreq);
3c09f17c HX	293	if (err)
	294	return err;
	295
92d95ba9	296	return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
3c09f17c HX	297	}
3c09f17c HX	298
92d95ba9	299	static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
3c09f17c	300	{
92d95ba9 HX	301	struct aead_instance *inst = aead_alg_instance(tfm);
	302	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	303	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
cbdcf80d	304	struct crypto_ahash *auth;
7217d49f	305	struct crypto_skcipher *enc;
8d605398	306	struct crypto_sync_skcipher *null;
3c09f17c HX	307	int err;
3c09f17c HX	308
cbdcf80d	309	auth = crypto_spawn_ahash(&ictx->auth);
3c09f17c HX	310	if (IS_ERR(auth))
	311	return PTR_ERR(auth);
	312
60425a8b	313	enc = crypto_spawn_skcipher(&ictx->enc);
3c09f17c HX	314	err = PTR_ERR(enc);
3c09f17c HX	315	if (IS_ERR(enc))
cbdcf80d	316	goto err_free_ahash;
3c09f17c	317
3a2d4fb5	318	null = crypto_get_default_null_skcipher();
92d95ba9 HX	319	err = PTR_ERR(null);
	320	if (IS_ERR(null))
	321	goto err_free_skcipher;
	322
3c09f17c HX	323	ctx->auth = auth;
3c09f17c HX	324	ctx->enc = enc;
92d95ba9	325	ctx->null = null;
f3542e6d	326
92d95ba9 HX	327	crypto_aead_set_reqsize(
92d95ba9 HX	328	tfm,
25df9194	329	sizeof(struct authenc_request_ctx) +
92d95ba9	330	ictx->reqoff +
25df9194	331	max_t(unsigned int,
92d95ba9 HX	332	crypto_ahash_reqsize(auth) +
92d95ba9 HX	333	sizeof(struct ahash_request),
7217d49f HX	334	sizeof(struct skcipher_request) +
7217d49f HX	335	crypto_skcipher_reqsize(enc)));
3c09f17c HX	336
	337	return 0;
	338
92d95ba9	339	err_free_skcipher:
7217d49f	340	crypto_free_skcipher(enc);
cbdcf80d SK	341	err_free_ahash:
cbdcf80d SK	342	crypto_free_ahash(auth);
3c09f17c HX	343	return err;
	344	}
	345
92d95ba9	346	static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
3c09f17c	347	{
92d95ba9	348	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
3c09f17c	349
cbdcf80d	350	crypto_free_ahash(ctx->auth);
7217d49f	351	crypto_free_skcipher(ctx->enc);
3a2d4fb5	352	crypto_put_default_null_skcipher();
3c09f17c HX	353	}
3c09f17c HX	354
92d95ba9 HX	355	static void crypto_authenc_free(struct aead_instance *inst)
	356	{
	357	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
	358
	359	crypto_drop_skcipher(&ctx->enc);
	360	crypto_drop_ahash(&ctx->auth);
	361	kfree(inst);
	362	}
	363
	364	static int crypto_authenc_create(struct crypto_template *tmpl,
	365	struct rtattr **tb)
3c09f17c	366	{
b9f76ddd	367	u32 mask;
92d95ba9	368	struct aead_instance *inst;
37a861ad	369	struct authenc_instance_ctx *ctx;
cae33043	370	struct skcipher_alg_common *enc;
cbdcf80d SK	371	struct hash_alg_common *auth;
cbdcf80d SK	372	struct crypto_alg *auth_base;
3c09f17c HX	373	int err;
3c09f17c HX	374
7bcb2c99 EB	375	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
	376	if (err)
	377	return err;
b9f76ddd	378
3c09f17c	379	inst = kzalloc(sizeof(inst) + sizeof(ctx), GFP_KERNEL);
3c09f17c	380	if (!inst)
37a861ad	381	return -ENOMEM;
92d95ba9	382	ctx = aead_instance_ctx(inst);
3c09f17c	383
37a861ad EB	384	err = crypto_grab_ahash(&ctx->auth, aead_crypto_instance(inst),
37a861ad EB	385	crypto_attr_alg_name(tb[1]), 0, mask);
3c09f17c HX	386	if (err)
3c09f17c HX	387	goto err_free_inst;
37a861ad EB	388	auth = crypto_spawn_ahash_alg(&ctx->auth);
37a861ad EB	389	auth_base = &auth->base;
3c09f17c	390
b9f76ddd	391	err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
37a861ad	392	crypto_attr_alg_name(tb[2]), 0, mask);
3c09f17c	393	if (err)
37a861ad	394	goto err_free_inst;
cae33043	395	enc = crypto_spawn_skcipher_alg_common(&ctx->enc);
9ffde35a	396
58e4bb5f	397	ctx->reqoff = 2 * auth->digestsize;
92d95ba9	398
9ffde35a	399	err = -ENAMETOOLONG;
92d95ba9	400	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
7217d49f HX	401	"authenc(%s,%s)", auth_base->cra_name,
7217d49f HX	402	enc->base.cra_name) >=
9ffde35a	403	CRYPTO_MAX_ALG_NAME)
37a861ad	404	goto err_free_inst;
9ffde35a	405
92d95ba9	406	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
cbdcf80d	407	"authenc(%s,%s)", auth_base->cra_driver_name,
7217d49f	408	enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
37a861ad	409	goto err_free_inst;
9ffde35a	410
7217d49f	411	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
92d95ba9	412	auth_base->cra_priority;
7217d49f	413	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
58e4bb5f	414	inst->alg.base.cra_alignmask = enc->base.cra_alignmask;
92d95ba9 HX	415	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
92d95ba9 HX	416
cae33043 HX	417	inst->alg.ivsize = enc->ivsize;
cae33043 HX	418	inst->alg.chunksize = enc->chunksize;
92d95ba9	419	inst->alg.maxauthsize = auth->digestsize;
3c09f17c	420
92d95ba9 HX	421	inst->alg.init = crypto_authenc_init_tfm;
92d95ba9 HX	422	inst->alg.exit = crypto_authenc_exit_tfm;
3c09f17c	423
92d95ba9 HX	424	inst->alg.setkey = crypto_authenc_setkey;
	425	inst->alg.encrypt = crypto_authenc_encrypt;
	426	inst->alg.decrypt = crypto_authenc_decrypt;
3c09f17c	427
92d95ba9	428	inst->free = crypto_authenc_free;
3c09f17c	429
92d95ba9	430	err = aead_register_instance(tmpl, inst);
37a861ad	431	if (err) {
3c09f17c	432	err_free_inst:
37a861ad EB	433	crypto_authenc_free(inst);
	434	}
	435	return err;
3c09f17c HX	436	}
3c09f17c HX	437
3c09f17c HX	438	static struct crypto_template crypto_authenc_tmpl = {
3c09f17c HX	439	.name = "authenc",
92d95ba9	440	.create = crypto_authenc_create,
3c09f17c HX	441	.module = THIS_MODULE,
	442	};
	443
	444	static int __init crypto_authenc_module_init(void)
	445	{
	446	return crypto_register_template(&crypto_authenc_tmpl);
	447	}
	448
	449	static void __exit crypto_authenc_module_exit(void)
	450	{
	451	crypto_unregister_template(&crypto_authenc_tmpl);
	452	}
	453
c4741b23	454	subsys_initcall(crypto_authenc_module_init);
3c09f17c HX	455	module_exit(crypto_authenc_module_exit);
	456
	457	MODULE_LICENSE("GPL");
	458	MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
4943ba16	459	MODULE_ALIAS_CRYPTO("authenc");