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Commit 3631c650 authored by Herbert Xu's avatar Herbert Xu
Browse files

[CRYPTO] null: Add null blkcipher algorithm 



This patch adds a null blkcipher algorithm called ecb(cipher_null) for
backwards compatibility.  Previously the null algorithm when used by
IPsec copied the data byte by byte.  This new algorithm optimises that
to a straight memcpy which lets us better measure inherent overheads in
our IPsec code.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 93cc74e0

crypto/crypto_null.c

+59 −10
Original line number Diff line number Diff line
@@ -16,15 +16,17 @@ 
 * (at your option) any later version.

 *

 */



#include <crypto/internal/skcipher.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/mm.h>

#include <linux/crypto.h>

#include <linux/string.h>



#define NULL_KEY_SIZE		0

#define NULL_BLOCK_SIZE		1

#define NULL_DIGEST_SIZE	0

#define NULL_IV_SIZE		0



static int null_compress(struct crypto_tfm *tfm, const u8 *src,

			 unsigned int slen, u8 *dst, unsigned int *dlen)
@@ -55,6 +57,26 @@ static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 
	memcpy(dst, src, NULL_BLOCK_SIZE);

}



static int skcipher_null_crypt(struct blkcipher_desc *desc,

			       struct scatterlist *dst,

			       struct scatterlist *src, unsigned int nbytes)

{

	struct blkcipher_walk walk;

	int err;



	blkcipher_walk_init(&walk, dst, src, nbytes);

	err = blkcipher_walk_virt(desc, &walk);



	while (walk.nbytes) {

		if (walk.src.virt.addr != walk.dst.virt.addr)

			memcpy(walk.dst.virt.addr, walk.src.virt.addr,

			       walk.nbytes);

		err = blkcipher_walk_done(desc, &walk, 0);

	}



	return err;

}



static struct crypto_alg compress_null = {

	.cra_name		=	"compress_null",

	.cra_flags		=	CRYPTO_ALG_TYPE_COMPRESS,
@@ -96,6 +118,25 @@ static struct crypto_alg cipher_null = { 
	.cia_decrypt		=	null_crypt } }

};



static struct crypto_alg skcipher_null = {

	.cra_name		=	"ecb(cipher_null)",

	.cra_driver_name	=	"ecb-cipher_null",

	.cra_priority		=	100,

	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,

	.cra_blocksize		=	NULL_BLOCK_SIZE,

	.cra_type		=	&crypto_blkcipher_type,

	.cra_ctxsize		=	0,

	.cra_module		=	THIS_MODULE,

	.cra_list		=	LIST_HEAD_INIT(skcipher_null.cra_list),

	.cra_u			=	{ .blkcipher = {

	.min_keysize		=	NULL_KEY_SIZE,

	.max_keysize		=	NULL_KEY_SIZE,

	.ivsize			=	NULL_IV_SIZE,

	.setkey			= 	null_setkey,

	.encrypt		=	skcipher_null_crypt,

	.decrypt		=	skcipher_null_crypt } }

};



MODULE_ALIAS("compress_null");

MODULE_ALIAS("digest_null");

MODULE_ALIAS("cipher_null");
@@ -108,27 +149,35 @@ static int __init init(void) 
	if (ret < 0)

		goto out;



	ret = crypto_register_alg(&skcipher_null);

	if (ret < 0)

		goto out_unregister_cipher;



	ret = crypto_register_alg(&digest_null);

	if (ret < 0) {

		crypto_unregister_alg(&cipher_null);

		goto out;

	}

	if (ret < 0)

		goto out_unregister_skcipher;



	ret = crypto_register_alg(&compress_null);

	if (ret < 0) {

		crypto_unregister_alg(&digest_null);

		crypto_unregister_alg(&cipher_null);

		goto out;

	}

	if (ret < 0)

		goto out_unregister_digest;



out:	

	return ret;



out_unregister_digest:

	crypto_unregister_alg(&digest_null);

out_unregister_skcipher:

	crypto_unregister_alg(&skcipher_null);

out_unregister_cipher:

	crypto_unregister_alg(&cipher_null);

	goto out;

}



static void __exit fini(void)

{

	crypto_unregister_alg(&compress_null);

	crypto_unregister_alg(&digest_null);

	crypto_unregister_alg(&skcipher_null);

	crypto_unregister_alg(&cipher_null);

}

include/crypto/internal/skcipher.h

+5 −0
Original line number Diff line number Diff line
@@ -88,5 +88,10 @@ static inline void skcipher_givcrypt_complete( 
	ablkcipher_request_complete(&req->creq, err);

}



static inline u32 ablkcipher_request_flags(struct ablkcipher_request *req)

{

	return req->base.flags;

}



#endif	/* _CRYPTO_INTERNAL_SKCIPHER_H */