crypto/authenc.c - maze/linux - Git at Google

 /*
  * Authenc: Simple AEAD wrapper for IPsec
  *
  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
  *
  * 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/algapi.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>

 #include "scatterwalk.h"

 struct authenc_instance_ctx {
 	struct crypto_spawn auth;
 	struct crypto_spawn enc;

 	unsigned int authsize;
 	unsigned int enckeylen;
 };

 struct crypto_authenc_ctx {
 	spinlock_t auth_lock;
 	struct crypto_hash *auth;
 	struct crypto_ablkcipher *enc;
 };

 static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
 				 unsigned int keylen)
 {
 	struct authenc_instance_ctx *ictx =
 		crypto_instance_ctx(crypto_aead_alg_instance(authenc));
 	unsigned int enckeylen = ictx->enckeylen;
 	unsigned int authkeylen;
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 	struct crypto_hash *auth = ctx->auth;
 	struct crypto_ablkcipher *enc = ctx->enc;
 	int err = -EINVAL;

 	if (keylen < enckeylen) {
 		crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
 		goto out;
 	}
 	authkeylen = keylen - enckeylen;

 	crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
 	crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) &
 				    CRYPTO_TFM_REQ_MASK);
 	err = crypto_hash_setkey(auth, key, authkeylen);
 	crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) &
 				       CRYPTO_TFM_RES_MASK);

 	if (err)
 		goto out;

 	crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
 	crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
 					 CRYPTO_TFM_REQ_MASK);
 	err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
 	crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
 				       CRYPTO_TFM_RES_MASK);

 out:
 	return err;
 }

 static int crypto_authenc_hash(struct aead_request *req)
 {
 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 	struct authenc_instance_ctx *ictx =
 		crypto_instance_ctx(crypto_aead_alg_instance(authenc));
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 	struct crypto_hash *auth = ctx->auth;
 	struct hash_desc desc = {
 		.tfm = auth,
 	};
 	u8 *hash = aead_request_ctx(req);
 	struct scatterlist *dst = req->dst;
 	unsigned int cryptlen = req->cryptlen;
 	int err;

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

 	spin_lock_bh(&ctx->auth_lock);
 	err = crypto_hash_init(&desc);
 	if (err)
 		goto auth_unlock;

 	err = crypto_hash_update(&desc, req->assoc, req->assoclen);
 	if (err)
 		goto auth_unlock;

 	err = crypto_hash_update(&desc, dst, cryptlen);
 	if (err)
 		goto auth_unlock;

 	err = crypto_hash_final(&desc, hash);
 auth_unlock:
 	spin_unlock_bh(&ctx->auth_lock);

 	if (err)
 		return err;

 	scatterwalk_map_and_copy(hash, dst, cryptlen, ictx->authsize, 1);
 	return 0;
 }

 static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 					int err)
 {
 	if (!err)
 		err = crypto_authenc_hash(req->data);

 	aead_request_complete(req->data, err);
 }

 static int crypto_authenc_encrypt(struct aead_request *req)
 {
 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 	struct ablkcipher_request *abreq = aead_request_ctx(req);
 	int err;

 	ablkcipher_request_set_tfm(abreq, ctx->enc);
 	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 					crypto_authenc_encrypt_done, req);
 	ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen,
 				     req->iv);

 	err = crypto_ablkcipher_encrypt(abreq);
 	if (err)
 		return err;

 	return crypto_authenc_hash(req);
 }

 static int crypto_authenc_verify(struct aead_request *req)
 {
 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 	struct authenc_instance_ctx *ictx =
 		crypto_instance_ctx(crypto_aead_alg_instance(authenc));
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 	struct crypto_hash *auth = ctx->auth;
 	struct hash_desc desc = {
 		.tfm = auth,
 		.flags = aead_request_flags(req),
 	};
 	u8 *ohash = aead_request_ctx(req);
 	u8 *ihash;
 	struct scatterlist *src = req->src;
 	unsigned int cryptlen = req->cryptlen;
 	unsigned int authsize;
 	int err;

 	ohash = (u8 *)ALIGN((unsigned long)ohash + crypto_hash_alignmask(auth),
 			    crypto_hash_alignmask(auth) + 1);
 	ihash = ohash + crypto_hash_digestsize(auth);

 	spin_lock_bh(&ctx->auth_lock);
 	err = crypto_hash_init(&desc);
 	if (err)
 		goto auth_unlock;

 	err = crypto_hash_update(&desc, req->assoc, req->assoclen);
 	if (err)
 		goto auth_unlock;

 	err = crypto_hash_update(&desc, src, cryptlen);
 	if (err)
 		goto auth_unlock;

 	err = crypto_hash_final(&desc, ohash);
 auth_unlock:
 	spin_unlock_bh(&ctx->auth_lock);

 	if (err)
 		return err;

 	authsize = ictx->authsize;
 	scatterwalk_map_and_copy(ihash, src, cryptlen, authsize, 0);
 	return memcmp(ihash, ohash, authsize) ? -EINVAL : 0;
 }

 static void crypto_authenc_decrypt_done(struct crypto_async_request *req,
 					int err)
 {
 	aead_request_complete(req->data, err);
 }

 static int crypto_authenc_decrypt(struct aead_request *req)
 {
 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 	struct ablkcipher_request *abreq = aead_request_ctx(req);
 	int err;

 	err = crypto_authenc_verify(req);
 	if (err)
 		return err;

 	ablkcipher_request_set_tfm(abreq, ctx->enc);
 	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
 					crypto_authenc_decrypt_done, req);
 	ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen,
 				     req->iv);

 	return crypto_ablkcipher_decrypt(abreq);
 }

 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
 {
 	struct crypto_instance *inst = (void *)tfm->__crt_alg;
 	struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
 	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
 	struct crypto_hash *auth;
 	struct crypto_ablkcipher *enc;
 	unsigned int digestsize;
 	int err;

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

 	err = -EINVAL;
 	digestsize = crypto_hash_digestsize(auth);
 	if (ictx->authsize > digestsize)
 		goto err_free_hash;

 	enc = crypto_spawn_ablkcipher(&ictx->enc);
 	err = PTR_ERR(enc);
 	if (IS_ERR(enc))
 		goto err_free_hash;

 	ctx->auth = auth;
 	ctx->enc = enc;
 	tfm->crt_aead.reqsize = max_t(unsigned int,
 				      (crypto_hash_alignmask(auth) &
 				       ~(crypto_tfm_ctx_alignment() - 1)) +
 				      digestsize * 2,
 				      sizeof(struct ablkcipher_request) +
 				      crypto_ablkcipher_reqsize(enc));

 	spin_lock_init(&ctx->auth_lock);

 	return 0;

 err_free_hash:
 	crypto_free_hash(auth);
 	return err;
 }

 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
 {
 	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);

 	crypto_free_hash(ctx->auth);
 	crypto_free_ablkcipher(ctx->enc);
 }

 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
 {
 	struct crypto_instance *inst;
 	struct crypto_alg *auth;
 	struct crypto_alg *enc;
 	struct authenc_instance_ctx *ctx;
 	unsigned int authsize;
 	unsigned int enckeylen;
 	int err;

 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD);
 	if (err)
 		return ERR_PTR(err);

 	auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
 			       CRYPTO_ALG_TYPE_HASH_MASK);
 	if (IS_ERR(auth))
 		return ERR_PTR(PTR_ERR(auth));

 	err = crypto_attr_u32(tb[2], &authsize);
 	inst = ERR_PTR(err);
 	if (err)
 		goto out_put_auth;

 	enc = crypto_attr_alg(tb[3], CRYPTO_ALG_TYPE_BLKCIPHER,
 			      CRYPTO_ALG_TYPE_BLKCIPHER_MASK);
 	inst = ERR_PTR(PTR_ERR(enc));
 	if (IS_ERR(enc))
 		goto out_put_auth;

 	err = crypto_attr_u32(tb[4], &enckeylen);
 	if (err)
 		goto out_put_enc;

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

 	err = -ENAMETOOLONG;
 	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 		     "authenc(%s,%u,%s,%u)", auth->cra_name, authsize,
 		     enc->cra_name, enckeylen) >= CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;

 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 		     "authenc(%s,%u,%s,%u)", auth->cra_driver_name,
 		     authsize, enc->cra_driver_name, enckeylen) >=
 	    CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;

 	ctx = crypto_instance_ctx(inst);
 	ctx->authsize = authsize;
 	ctx->enckeylen = enckeylen;

 	err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK);
 	if (err)
 		goto err_free_inst;

 	err = crypto_init_spawn(&ctx->enc, enc, inst, CRYPTO_ALG_TYPE_MASK);
 	if (err)
 		goto err_drop_auth;

 	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC;
 	inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority;
 	inst->alg.cra_blocksize = enc->cra_blocksize;
 	inst->alg.cra_alignmask = auth->cra_alignmask | enc->cra_alignmask;
 	inst->alg.cra_type = &crypto_aead_type;

 	inst->alg.cra_aead.ivsize = enc->cra_blkcipher.ivsize;
 	inst->alg.cra_aead.authsize = authsize;

 	inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);

 	inst->alg.cra_init = crypto_authenc_init_tfm;
 	inst->alg.cra_exit = crypto_authenc_exit_tfm;

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

 out:
 	crypto_mod_put(enc);
 out_put_auth:
 	crypto_mod_put(auth);
 	return inst;

 err_drop_auth:
 	crypto_drop_spawn(&ctx->auth);
 err_free_inst:
 	kfree(inst);
 out_put_enc:
 	inst = ERR_PTR(err);
 	goto out;
 }

 static void crypto_authenc_free(struct crypto_instance *inst)
 {
 	struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);

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

 static struct crypto_template crypto_authenc_tmpl = {
 	.name = "authenc",
 	.alloc = crypto_authenc_alloc,
 	.free = crypto_authenc_free,
 	.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");
	/*
	* Authenc: Simple AEAD wrapper for IPsec
	*
	* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
	*
	* 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/algapi.h>
	#include <linux/err.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/spinlock.h>

	#include "scatterwalk.h"

	struct authenc_instance_ctx {
	struct crypto_spawn auth;
	struct crypto_spawn enc;

	unsigned int authsize;
	unsigned int enckeylen;
	};

	struct crypto_authenc_ctx {
	spinlock_t auth_lock;
	struct crypto_hash *auth;
	struct crypto_ablkcipher *enc;
	};

	static int crypto_authenc_setkey(struct crypto_aead authenc, const u8 key,
	unsigned int keylen)
	{
	struct authenc_instance_ctx *ictx =
	crypto_instance_ctx(crypto_aead_alg_instance(authenc));
	unsigned int enckeylen = ictx->enckeylen;
	unsigned int authkeylen;
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct crypto_hash *auth = ctx->auth;
	struct crypto_ablkcipher *enc = ctx->enc;
	int err = -EINVAL;

	if (keylen < enckeylen) {
	crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
	goto out;
	}
	authkeylen = keylen - enckeylen;

	crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
	crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) &
	CRYPTO_TFM_REQ_MASK);
	err = crypto_hash_setkey(auth, key, authkeylen);
	crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) &
	CRYPTO_TFM_RES_MASK);

	if (err)
	goto out;

	crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
	crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
	CRYPTO_TFM_REQ_MASK);
	err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
	crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
	CRYPTO_TFM_RES_MASK);

	out:
	return err;
	}

	static int crypto_authenc_hash(struct aead_request *req)
	{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct authenc_instance_ctx *ictx =
	crypto_instance_ctx(crypto_aead_alg_instance(authenc));
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct crypto_hash *auth = ctx->auth;
	struct hash_desc desc = {
	.tfm = auth,
	};
	u8 *hash = aead_request_ctx(req);
	struct scatterlist *dst = req->dst;
	unsigned int cryptlen = req->cryptlen;
	int err;

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

	spin_lock_bh(&ctx->auth_lock);
	err = crypto_hash_init(&desc);
	if (err)
	goto auth_unlock;

	err = crypto_hash_update(&desc, req->assoc, req->assoclen);
	if (err)
	goto auth_unlock;

	err = crypto_hash_update(&desc, dst, cryptlen);
	if (err)
	goto auth_unlock;

	err = crypto_hash_final(&desc, hash);
	auth_unlock:
	spin_unlock_bh(&ctx->auth_lock);

	if (err)
	return err;

	scatterwalk_map_and_copy(hash, dst, cryptlen, ictx->authsize, 1);
	return 0;
	}

	static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
	int err)
	{
	if (!err)
	err = crypto_authenc_hash(req->data);

	aead_request_complete(req->data, err);
	}

	static int crypto_authenc_encrypt(struct aead_request *req)
	{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct ablkcipher_request *abreq = aead_request_ctx(req);
	int err;

	ablkcipher_request_set_tfm(abreq, ctx->enc);
	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
	crypto_authenc_encrypt_done, req);
	ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen,
	req->iv);

	err = crypto_ablkcipher_encrypt(abreq);
	if (err)
	return err;

	return crypto_authenc_hash(req);
	}

	static int crypto_authenc_verify(struct aead_request *req)
	{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct authenc_instance_ctx *ictx =
	crypto_instance_ctx(crypto_aead_alg_instance(authenc));
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct crypto_hash *auth = ctx->auth;
	struct hash_desc desc = {
	.tfm = auth,
	.flags = aead_request_flags(req),
	};
	u8 *ohash = aead_request_ctx(req);
	u8 *ihash;
	struct scatterlist *src = req->src;
	unsigned int cryptlen = req->cryptlen;
	unsigned int authsize;
	int err;

	ohash = (u8 *)ALIGN((unsigned long)ohash + crypto_hash_alignmask(auth),
	crypto_hash_alignmask(auth) + 1);
	ihash = ohash + crypto_hash_digestsize(auth);

	spin_lock_bh(&ctx->auth_lock);
	err = crypto_hash_init(&desc);
	if (err)
	goto auth_unlock;

	err = crypto_hash_update(&desc, req->assoc, req->assoclen);
	if (err)
	goto auth_unlock;

	err = crypto_hash_update(&desc, src, cryptlen);
	if (err)
	goto auth_unlock;

	err = crypto_hash_final(&desc, ohash);
	auth_unlock:
	spin_unlock_bh(&ctx->auth_lock);

	if (err)
	return err;

	authsize = ictx->authsize;
	scatterwalk_map_and_copy(ihash, src, cryptlen, authsize, 0);
	return memcmp(ihash, ohash, authsize) ? -EINVAL : 0;
	}

	static void crypto_authenc_decrypt_done(struct crypto_async_request *req,
	int err)
	{
	aead_request_complete(req->data, err);
	}

	static int crypto_authenc_decrypt(struct aead_request *req)
	{
	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
	struct ablkcipher_request *abreq = aead_request_ctx(req);
	int err;

	err = crypto_authenc_verify(req);
	if (err)
	return err;

	ablkcipher_request_set_tfm(abreq, ctx->enc);
	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
	crypto_authenc_decrypt_done, req);
	ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen,
	req->iv);

	return crypto_ablkcipher_decrypt(abreq);
	}

	static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
	{
	struct crypto_instance inst = (void )tfm->__crt_alg;
	struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_hash *auth;
	struct crypto_ablkcipher *enc;
	unsigned int digestsize;
	int err;

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

	err = -EINVAL;
	digestsize = crypto_hash_digestsize(auth);
	if (ictx->authsize > digestsize)
	goto err_free_hash;

	enc = crypto_spawn_ablkcipher(&ictx->enc);
	err = PTR_ERR(enc);
	if (IS_ERR(enc))
	goto err_free_hash;

	ctx->auth = auth;
	ctx->enc = enc;
	tfm->crt_aead.reqsize = max_t(unsigned int,
	(crypto_hash_alignmask(auth) &
	~(crypto_tfm_ctx_alignment() - 1)) +
	digestsize * 2,
	sizeof(struct ablkcipher_request) +
	crypto_ablkcipher_reqsize(enc));

	spin_lock_init(&ctx->auth_lock);

	return 0;

	err_free_hash:
	crypto_free_hash(auth);
	return err;
	}

	static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
	{
	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);

	crypto_free_hash(ctx->auth);
	crypto_free_ablkcipher(ctx->enc);
	}

	static struct crypto_instance crypto_authenc_alloc(struct rtattr *tb)
	{
	struct crypto_instance *inst;
	struct crypto_alg *auth;
	struct crypto_alg *enc;
	struct authenc_instance_ctx *ctx;
	unsigned int authsize;
	unsigned int enckeylen;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD);
	if (err)
	return ERR_PTR(err);

	auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
	CRYPTO_ALG_TYPE_HASH_MASK);
	if (IS_ERR(auth))
	return ERR_PTR(PTR_ERR(auth));

	err = crypto_attr_u32(tb[2], &authsize);
	inst = ERR_PTR(err);
	if (err)
	goto out_put_auth;

	enc = crypto_attr_alg(tb[3], CRYPTO_ALG_TYPE_BLKCIPHER,
	CRYPTO_ALG_TYPE_BLKCIPHER_MASK);
	inst = ERR_PTR(PTR_ERR(enc));
	if (IS_ERR(enc))
	goto out_put_auth;

	err = crypto_attr_u32(tb[4], &enckeylen);
	if (err)
	goto out_put_enc;

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

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
	"authenc(%s,%u,%s,%u)", auth->cra_name, authsize,
	enc->cra_name, enckeylen) >= CRYPTO_MAX_ALG_NAME)
	goto err_free_inst;

	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	"authenc(%s,%u,%s,%u)", auth->cra_driver_name,
	authsize, enc->cra_driver_name, enckeylen) >=
	CRYPTO_MAX_ALG_NAME)
	goto err_free_inst;

	ctx = crypto_instance_ctx(inst);
	ctx->authsize = authsize;
	ctx->enckeylen = enckeylen;

	err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK);
	if (err)
	goto err_free_inst;

	err = crypto_init_spawn(&ctx->enc, enc, inst, CRYPTO_ALG_TYPE_MASK);
	if (err)
	goto err_drop_auth;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD \| CRYPTO_ALG_ASYNC;
	inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority;
	inst->alg.cra_blocksize = enc->cra_blocksize;
	inst->alg.cra_alignmask = auth->cra_alignmask \| enc->cra_alignmask;
	inst->alg.cra_type = &crypto_aead_type;

	inst->alg.cra_aead.ivsize = enc->cra_blkcipher.ivsize;
	inst->alg.cra_aead.authsize = authsize;

	inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);

	inst->alg.cra_init = crypto_authenc_init_tfm;
	inst->alg.cra_exit = crypto_authenc_exit_tfm;

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

	out:
	crypto_mod_put(enc);
	out_put_auth:
	crypto_mod_put(auth);
	return inst;

	err_drop_auth:
	crypto_drop_spawn(&ctx->auth);
	err_free_inst:
	kfree(inst);
	out_put_enc:
	inst = ERR_PTR(err);
	goto out;
	}

	static void crypto_authenc_free(struct crypto_instance *inst)
	{
	struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);

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

	static struct crypto_template crypto_authenc_tmpl = {
	.name = "authenc",
	.alloc = crypto_authenc_alloc,
	.free = crypto_authenc_free,
	.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");