[linux.git] / crypto / authenc.c

/*
 * Authenc: Simple AEAD wrapper for IPsec
 *
 * Copyright (c) 2007-2015 Herbert Xu <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#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 badkey;

	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);
	crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
				       CRYPTO_TFM_RES_MASK);

	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);
	crypto_aead_set_flags(authenc, crypto_skcipher_get_flags(enc) &
				       CRYPTO_TFM_RES_MASK);

out:
	memzero_explicit(&keys, sizeof(keys));
	return err;

badkey:
	crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
	goto out;
}

static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
{
	struct aead_request *req = areq->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;

	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
			   crypto_ahash_alignmask(auth) + 1);

	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(struct crypto_async_request *req,
					int err)
{
	struct aead_request *areq = req->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, aead_request_flags(req),
				      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(struct crypto_async_request *areq,
				      int err)
{
	struct aead_request *req = areq->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;

	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
			   crypto_ahash_alignmask(auth) + 1);

	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)
{
	struct crypto_attr_type *algt;
	struct aead_instance *inst;
	struct hash_alg_common *auth;
	struct crypto_alg *auth_base;
	struct skcipher_alg *enc;
	struct authenc_instance_ctx *ctx;
	const char *enc_name;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
		return -EINVAL;

	auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
			      CRYPTO_ALG_TYPE_AHASH_MASK |
			      crypto_requires_sync(algt->type, algt->mask));
	if (IS_ERR(auth))
		return PTR_ERR(auth);

	auth_base = &auth->base;

	enc_name = crypto_attr_alg_name(tb[2]);
	err = PTR_ERR(enc_name);
	if (IS_ERR(enc_name))
		goto out_put_auth;

	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
	err = -ENOMEM;
	if (!inst)
		goto out_put_auth;

	ctx = aead_instance_ctx(inst);

	err = crypto_init_ahash_spawn(&ctx->auth, auth,
				      aead_crypto_instance(inst));
	if (err)
		goto err_free_inst;

	crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst));
	err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
				   crypto_requires_sync(algt->type,
							algt->mask));
	if (err)
		goto err_drop_auth;

	enc = crypto_spawn_skcipher_alg(&ctx->enc);

	ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
			    auth_base->cra_alignmask + 1);

	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_drop_enc;

	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_drop_enc;

	inst->alg.base.cra_flags = (auth_base->cra_flags |
				    enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
	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 = auth_base->cra_alignmask |
				       enc->base.cra_alignmask;
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);

	inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
	inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
	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)
		goto err_drop_enc;

out:
	crypto_mod_put(auth_base);
	return err;

err_drop_enc:
	crypto_drop_skcipher(&ctx->enc);
err_drop_auth:
	crypto_drop_ahash(&ctx->auth);
err_free_inst:
	kfree(inst);
out_put_auth:
	goto out;
}

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
3c09f17c HX	1	/*
	2	* Authenc: Simple AEAD wrapper for IPsec
	3	*
92d95ba9	4	* Copyright (c) 2007-2015 Herbert Xu <[email protected]>
3c09f17c HX	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*
	11	*/
	12
68acbf84	13	#include <crypto/internal/aead.h>
5f7082ed	14	#include <crypto/internal/hash.h>
9ffde35a	15	#include <crypto/internal/skcipher.h>
e236d4a8	16	#include <crypto/authenc.h>
92d95ba9	17	#include <crypto/null.h>
42c271c6	18	#include <crypto/scatterwalk.h>
3c09f17c HX	19	#include <linux/err.h>
	20	#include <linux/init.h>
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
e236d4a8	23	#include <linux/rtnetlink.h>
3c09f17c HX	24	#include <linux/slab.h>
	25	#include <linux/spinlock.h>
	26
3c09f17c	27	struct authenc_instance_ctx {
cbdcf80d	28	struct crypto_ahash_spawn auth;
9ffde35a	29	struct crypto_skcipher_spawn enc;
92d95ba9	30	unsigned int reqoff;
3c09f17c HX	31	};
	32
	33	struct crypto_authenc_ctx {
cbdcf80d	34	struct crypto_ahash *auth;
7217d49f	35	struct crypto_skcipher *enc;
8d605398	36	struct crypto_sync_skcipher *null;
3c09f17c HX	37	};
3c09f17c HX	38
cbdcf80d	39	struct authenc_request_ctx {
92d95ba9 HX	40	struct scatterlist src[2];
92d95ba9 HX	41	struct scatterlist dst[2];
cbdcf80d SK	42	char tail[];
	43	};
	44
180ce7e8 HX	45	static void authenc_request_complete(struct aead_request *req, int err)
	46	{
	47	if (err != -EINPROGRESS)
	48	aead_request_complete(req, err);
	49	}
	50
bc6e2bdb MK	51	int crypto_authenc_extractkeys(struct crypto_authenc_keys keys, const u8 key,
bc6e2bdb MK	52	unsigned int keylen)
3c09f17c	53	{
bc6e2bdb	54	struct rtattr rta = (struct rtattr )key;
e236d4a8	55	struct crypto_authenc_key_param *param;
3c09f17c	56
12dc5e62	57	if (!RTA_OK(rta, keylen))
bc6e2bdb	58	return -EINVAL;
e236d4a8	59	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
bc6e2bdb	60	return -EINVAL;
8f9c4693 EB	61
	62	/*
	63	* RTA_OK() didn't align the rtattr's payload when validating that it
	64	* fits in the buffer. Yet, the keys should start on the next 4-byte
	65	* aligned boundary. To avoid confusion, require that the rtattr
	66	* payload be exactly the param struct, which has a 4-byte aligned size.
	67	*/
	68	if (RTA_PAYLOAD(rta) != sizeof(*param))
bc6e2bdb	69	return -EINVAL;
8f9c4693	70	BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
e236d4a8 HX	71
e236d4a8 HX	72	param = RTA_DATA(rta);
bc6e2bdb	73	keys->enckeylen = be32_to_cpu(param->enckeylen);
e236d4a8	74
8f9c4693 EB	75	key += rta->rta_len;
8f9c4693 EB	76	keylen -= rta->rta_len;
e236d4a8	77
bc6e2bdb MK	78	if (keylen < keys->enckeylen)
	79	return -EINVAL;
	80
	81	keys->authkeylen = keylen - keys->enckeylen;
	82	keys->authkey = key;
	83	keys->enckey = key + keys->authkeylen;
e236d4a8	84
bc6e2bdb MK	85	return 0;
	86	}
	87	EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
	88
	89	static int crypto_authenc_setkey(struct crypto_aead authenc, const u8 key,
	90	unsigned int keylen)
	91	{
	92	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	93	struct crypto_ahash *auth = ctx->auth;
7217d49f	94	struct crypto_skcipher *enc = ctx->enc;
bc6e2bdb MK	95	struct crypto_authenc_keys keys;
	96	int err = -EINVAL;
	97
	98	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
	99	goto badkey;
3c09f17c	100
cbdcf80d SK	101	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
cbdcf80d SK	102	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
3c09f17c	103	CRYPTO_TFM_REQ_MASK);
bc6e2bdb	104	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
cbdcf80d	105	crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
3c09f17c HX	106	CRYPTO_TFM_RES_MASK);
	107
	108	if (err)
	109	goto out;
	110
7217d49f HX	111	crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
	112	crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
	113	CRYPTO_TFM_REQ_MASK);
	114	err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
	115	crypto_aead_set_flags(authenc, crypto_skcipher_get_flags(enc) &
3c09f17c HX	116	CRYPTO_TFM_RES_MASK);
	117
	118	out:
ad2fdcdf	119	memzero_explicit(&keys, sizeof(keys));
3c09f17c	120	return err;
e236d4a8 HX	121
	122	badkey:
	123	crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
	124	goto out;
3c09f17c HX	125	}
3c09f17c HX	126
cbdcf80d SK	127	static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
	128	{
	129	struct aead_request *req = areq->data;
	130	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
92d95ba9 HX	131	struct aead_instance *inst = aead_alg_instance(authenc);
92d95ba9 HX	132	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
cbdcf80d	133	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
92d95ba9	134	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
cbdcf80d SK	135
	136	if (err)
	137	goto out;
	138
92d95ba9 HX	139	scatterwalk_map_and_copy(ahreq->result, req->dst,
92d95ba9 HX	140	req->assoclen + req->cryptlen,
cbdcf80d SK	141	crypto_aead_authsize(authenc), 1);
	142
	143	out:
	144	aead_request_complete(req, err);
	145	}
	146
92d95ba9	147	static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
cbdcf80d SK	148	{
cbdcf80d SK	149	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
92d95ba9	150	struct aead_instance *inst = aead_alg_instance(authenc);
cbdcf80d	151	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
92d95ba9	152	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
cbdcf80d SK	153	struct crypto_ahash *auth = ctx->auth;
cbdcf80d SK	154	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
92d95ba9	155	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
cbdcf80d SK	156	u8 *hash = areq_ctx->tail;
cbdcf80d SK	157	int err;
3c09f17c	158
cbdcf80d SK	159	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
	160	crypto_ahash_alignmask(auth) + 1);
	161
	162	ahash_request_set_tfm(ahreq, auth);
92d95ba9 HX	163	ahash_request_set_crypt(ahreq, req->dst, hash,
	164	req->assoclen + req->cryptlen);
	165	ahash_request_set_callback(ahreq, flags,
	166	authenc_geniv_ahash_done, req);
cbdcf80d SK	167
cbdcf80d SK	168	err = crypto_ahash_digest(ahreq);
3c09f17c	169	if (err)
92d95ba9	170	return err;
3c09f17c	171
92d95ba9	172	scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
7ba683a6	173	crypto_aead_authsize(authenc), 1);
92d95ba9	174
3c09f17c HX	175	return 0;
	176	}
	177
	178	static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
	179	int err)
	180	{
a697690b HX	181	struct aead_request *areq = req->data;
a697690b HX	182
92d95ba9 HX	183	if (err)
92d95ba9 HX	184	goto out;
e56dd564	185
92d95ba9	186	err = crypto_authenc_genicv(areq, 0);
3c09f17c	187
92d95ba9	188	out:
180ce7e8	189	authenc_request_complete(areq, err);
3c09f17c HX	190	}
3c09f17c HX	191
92d95ba9 HX	192	static int crypto_authenc_copy_assoc(struct aead_request *req)
	193	{
	194	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	195	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
8d605398	196	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
92d95ba9	197
8d605398	198	skcipher_request_set_sync_tfm(skreq, ctx->null);
7217d49f HX	199	skcipher_request_set_callback(skreq, aead_request_flags(req),
	200	NULL, NULL);
	201	skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
	202	NULL);
	203
	204	return crypto_skcipher_encrypt(skreq);
92d95ba9 HX	205	}
92d95ba9 HX	206
3c09f17c HX	207	static int crypto_authenc_encrypt(struct aead_request *req)
	208	{
	209	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
92d95ba9	210	struct aead_instance *inst = aead_alg_instance(authenc);
3c09f17c	211	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
92d95ba9	212	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
50beceba	213	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
7217d49f	214	struct crypto_skcipher *enc = ctx->enc;
e56dd564	215	unsigned int cryptlen = req->cryptlen;
7217d49f HX	216	struct skcipher_request skreq = (void )(areq_ctx->tail +
7217d49f HX	217	ictx->reqoff);
92d95ba9	218	struct scatterlist src, dst;
3c09f17c HX	219	int err;
3c09f17c HX	220
92d95ba9 HX	221	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
	222	dst = src;
	223
	224	if (req->src != req->dst) {
	225	err = crypto_authenc_copy_assoc(req);
	226	if (err)
	227	return err;
	228
92d95ba9 HX	229	dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
	230	}
	231
7217d49f HX	232	skcipher_request_set_tfm(skreq, enc);
	233	skcipher_request_set_callback(skreq, aead_request_flags(req),
	234	crypto_authenc_encrypt_done, req);
	235	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
3c09f17c	236
7217d49f	237	err = crypto_skcipher_encrypt(skreq);
3c09f17c HX	238	if (err)
	239	return err;
	240
92d95ba9	241	return crypto_authenc_genicv(req, aead_request_flags(req));
e56dd564 HX	242	}
e56dd564 HX	243
92d95ba9 HX	244	static int crypto_authenc_decrypt_tail(struct aead_request *req,
92d95ba9 HX	245	unsigned int flags)
e56dd564	246	{
92d95ba9 HX	247	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	248	struct aead_instance *inst = aead_alg_instance(authenc);
	249	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	250	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	251	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	252	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
7217d49f HX	253	struct skcipher_request skreq = (void )(areq_ctx->tail +
7217d49f HX	254	ictx->reqoff);
92d95ba9 HX	255	unsigned int authsize = crypto_aead_authsize(authenc);
	256	u8 *ihash = ahreq->result + authsize;
	257	struct scatterlist src, dst;
e56dd564	258
92d95ba9	259	scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
e56dd564	260
92d95ba9 HX	261	if (crypto_memneq(ihash, ahreq->result, authsize))
92d95ba9 HX	262	return -EBADMSG;
e56dd564	263
92d95ba9 HX	264	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
92d95ba9 HX	265	dst = src;
e56dd564	266
c34252fd	267	if (req->src != req->dst)
92d95ba9	268	dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
e56dd564	269
7217d49f HX	270	skcipher_request_set_tfm(skreq, ctx->enc);
	271	skcipher_request_set_callback(skreq, aead_request_flags(req),
	272	req->base.complete, req->base.data);
	273	skcipher_request_set_crypt(skreq, src, dst,
	274	req->cryptlen - authsize, req->iv);
3c09f17c	275
7217d49f	276	return crypto_skcipher_decrypt(skreq);
3c09f17c HX	277	}
3c09f17c HX	278
92d95ba9 HX	279	static void authenc_verify_ahash_done(struct crypto_async_request *areq,
92d95ba9 HX	280	int err)
3c09f17c	281	{
92d95ba9	282	struct aead_request *req = areq->data;
cbdcf80d	283
92d95ba9 HX	284	if (err)
92d95ba9 HX	285	goto out;
e56dd564	286
92d95ba9	287	err = crypto_authenc_decrypt_tail(req, 0);
cbdcf80d	288
92d95ba9 HX	289	out:
92d95ba9 HX	290	authenc_request_complete(req, err);
3c09f17c HX	291	}
	292
	293	static int crypto_authenc_decrypt(struct aead_request *req)
	294	{
	295	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
481f34ae	296	unsigned int authsize = crypto_aead_authsize(authenc);
92d95ba9 HX	297	struct aead_instance *inst = aead_alg_instance(authenc);
	298	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	299	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	300	struct crypto_ahash *auth = ctx->auth;
	301	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
	302	struct ahash_request ahreq = (void )(areq_ctx->tail + ictx->reqoff);
	303	u8 *hash = areq_ctx->tail;
3c09f17c HX	304	int err;
3c09f17c HX	305
92d95ba9 HX	306	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
92d95ba9 HX	307	crypto_ahash_alignmask(auth) + 1);
481f34ae	308
92d95ba9 HX	309	ahash_request_set_tfm(ahreq, auth);
	310	ahash_request_set_crypt(ahreq, req->src, hash,
	311	req->assoclen + req->cryptlen - authsize);
	312	ahash_request_set_callback(ahreq, aead_request_flags(req),
	313	authenc_verify_ahash_done, req);
	314
	315	err = crypto_ahash_digest(ahreq);
3c09f17c HX	316	if (err)
	317	return err;
	318
92d95ba9	319	return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
3c09f17c HX	320	}
3c09f17c HX	321
92d95ba9	322	static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
3c09f17c	323	{
92d95ba9 HX	324	struct aead_instance *inst = aead_alg_instance(tfm);
	325	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
	326	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
cbdcf80d	327	struct crypto_ahash *auth;
7217d49f	328	struct crypto_skcipher *enc;
8d605398	329	struct crypto_sync_skcipher *null;
3c09f17c HX	330	int err;
3c09f17c HX	331
cbdcf80d	332	auth = crypto_spawn_ahash(&ictx->auth);
3c09f17c HX	333	if (IS_ERR(auth))
	334	return PTR_ERR(auth);
	335
60425a8b	336	enc = crypto_spawn_skcipher(&ictx->enc);
3c09f17c HX	337	err = PTR_ERR(enc);
3c09f17c HX	338	if (IS_ERR(enc))
cbdcf80d	339	goto err_free_ahash;
3c09f17c	340
3a2d4fb5	341	null = crypto_get_default_null_skcipher();
92d95ba9 HX	342	err = PTR_ERR(null);
	343	if (IS_ERR(null))
	344	goto err_free_skcipher;
	345
3c09f17c HX	346	ctx->auth = auth;
3c09f17c HX	347	ctx->enc = enc;
92d95ba9	348	ctx->null = null;
f3542e6d	349
92d95ba9 HX	350	crypto_aead_set_reqsize(
92d95ba9 HX	351	tfm,
25df9194	352	sizeof(struct authenc_request_ctx) +
92d95ba9	353	ictx->reqoff +
25df9194	354	max_t(unsigned int,
92d95ba9 HX	355	crypto_ahash_reqsize(auth) +
92d95ba9 HX	356	sizeof(struct ahash_request),
7217d49f HX	357	sizeof(struct skcipher_request) +
7217d49f HX	358	crypto_skcipher_reqsize(enc)));
3c09f17c HX	359
	360	return 0;
	361
92d95ba9	362	err_free_skcipher:
7217d49f	363	crypto_free_skcipher(enc);
cbdcf80d SK	364	err_free_ahash:
cbdcf80d SK	365	crypto_free_ahash(auth);
3c09f17c HX	366	return err;
	367	}
	368
92d95ba9	369	static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
3c09f17c	370	{
92d95ba9	371	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
3c09f17c	372
cbdcf80d	373	crypto_free_ahash(ctx->auth);
7217d49f	374	crypto_free_skcipher(ctx->enc);
3a2d4fb5	375	crypto_put_default_null_skcipher();
3c09f17c HX	376	}
3c09f17c HX	377
92d95ba9 HX	378	static void crypto_authenc_free(struct aead_instance *inst)
	379	{
	380	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
	381
	382	crypto_drop_skcipher(&ctx->enc);
	383	crypto_drop_ahash(&ctx->auth);
	384	kfree(inst);
	385	}
	386
	387	static int crypto_authenc_create(struct crypto_template *tmpl,
	388	struct rtattr **tb)
3c09f17c	389	{
9ffde35a	390	struct crypto_attr_type *algt;
92d95ba9	391	struct aead_instance *inst;
cbdcf80d SK	392	struct hash_alg_common *auth;
cbdcf80d SK	393	struct crypto_alg *auth_base;
7217d49f	394	struct skcipher_alg *enc;
3c09f17c	395	struct authenc_instance_ctx *ctx;
9ffde35a	396	const char *enc_name;
3c09f17c HX	397	int err;
3c09f17c HX	398
9ffde35a	399	algt = crypto_get_attr_type(tb);
9ffde35a	400	if (IS_ERR(algt))
92d95ba9	401	return PTR_ERR(algt);
3c09f17c	402
5e4b8c1f	403	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
92d95ba9	404	return -EINVAL;
9ffde35a	405
cbdcf80d	406	auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
927ef32d HX	407	CRYPTO_ALG_TYPE_AHASH_MASK \|
927ef32d HX	408	crypto_requires_sync(algt->type, algt->mask));
3c09f17c	409	if (IS_ERR(auth))
92d95ba9	410	return PTR_ERR(auth);
3c09f17c	411
cbdcf80d SK	412	auth_base = &auth->base;
cbdcf80d SK	413
9ffde35a HX	414	enc_name = crypto_attr_alg_name(tb[2]);
	415	err = PTR_ERR(enc_name);
	416	if (IS_ERR(enc_name))
3c09f17c HX	417	goto out_put_auth;
3c09f17c HX	418
3c09f17c HX	419	inst = kzalloc(sizeof(inst) + sizeof(ctx), GFP_KERNEL);
	420	err = -ENOMEM;
	421	if (!inst)
9ffde35a	422	goto out_put_auth;
3c09f17c	423
92d95ba9	424	ctx = aead_instance_ctx(inst);
3c09f17c	425
92d95ba9 HX	426	err = crypto_init_ahash_spawn(&ctx->auth, auth,
92d95ba9 HX	427	aead_crypto_instance(inst));
3c09f17c HX	428	if (err)
	429	goto err_free_inst;
	430
92d95ba9	431	crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst));
a35528ec EB	432	err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
	433	crypto_requires_sync(algt->type,
	434	algt->mask));
3c09f17c HX	435	if (err)
	436	goto err_drop_auth;
	437
7217d49f	438	enc = crypto_spawn_skcipher_alg(&ctx->enc);
9ffde35a	439
92d95ba9 HX	440	ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
	441	auth_base->cra_alignmask + 1);
	442
9ffde35a	443	err = -ENAMETOOLONG;
92d95ba9	444	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
7217d49f HX	445	"authenc(%s,%s)", auth_base->cra_name,
7217d49f HX	446	enc->base.cra_name) >=
9ffde35a HX	447	CRYPTO_MAX_ALG_NAME)
	448	goto err_drop_enc;
	449
92d95ba9	450	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
cbdcf80d	451	"authenc(%s,%s)", auth_base->cra_driver_name,
7217d49f	452	enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
9ffde35a HX	453	goto err_drop_enc;
9ffde35a HX	454
7217d49f HX	455	inst->alg.base.cra_flags = (auth_base->cra_flags \|
	456	enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
	457	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
92d95ba9	458	auth_base->cra_priority;
7217d49f	459	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
92d95ba9	460	inst->alg.base.cra_alignmask = auth_base->cra_alignmask \|
7217d49f	461	enc->base.cra_alignmask;
92d95ba9 HX	462	inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
92d95ba9 HX	463
7217d49f HX	464	inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
7217d49f HX	465	inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
92d95ba9	466	inst->alg.maxauthsize = auth->digestsize;
3c09f17c	467
92d95ba9 HX	468	inst->alg.init = crypto_authenc_init_tfm;
92d95ba9 HX	469	inst->alg.exit = crypto_authenc_exit_tfm;
3c09f17c	470
92d95ba9 HX	471	inst->alg.setkey = crypto_authenc_setkey;
	472	inst->alg.encrypt = crypto_authenc_encrypt;
	473	inst->alg.decrypt = crypto_authenc_decrypt;
3c09f17c	474
92d95ba9	475	inst->free = crypto_authenc_free;
3c09f17c	476
92d95ba9 HX	477	err = aead_register_instance(tmpl, inst);
	478	if (err)
	479	goto err_drop_enc;
3c09f17c HX	480
3c09f17c HX	481	out:
cbdcf80d	482	crypto_mod_put(auth_base);
92d95ba9	483	return err;
3c09f17c	484
9ffde35a HX	485	err_drop_enc:
9ffde35a HX	486	crypto_drop_skcipher(&ctx->enc);
3c09f17c	487	err_drop_auth:
cbdcf80d	488	crypto_drop_ahash(&ctx->auth);
3c09f17c HX	489	err_free_inst:
3c09f17c HX	490	kfree(inst);
9ffde35a	491	out_put_auth:
3c09f17c HX	492	goto out;
	493	}
	494
3c09f17c HX	495	static struct crypto_template crypto_authenc_tmpl = {
3c09f17c HX	496	.name = "authenc",
92d95ba9	497	.create = crypto_authenc_create,
3c09f17c HX	498	.module = THIS_MODULE,
	499	};
	500
	501	static int __init crypto_authenc_module_init(void)
	502	{
	503	return crypto_register_template(&crypto_authenc_tmpl);
	504	}
	505
	506	static void __exit crypto_authenc_module_exit(void)
	507	{
	508	crypto_unregister_template(&crypto_authenc_tmpl);
	509	}
	510
	511	module_init(crypto_authenc_module_init);
	512	module_exit(crypto_authenc_module_exit);
	513
	514	MODULE_LICENSE("GPL");
	515	MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
4943ba16	516	MODULE_ALIAS_CRYPTO("authenc");