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Commit cc868d82 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: cbc - Export CBC implementation 



This patch moves the core CBC implementation into a header file
so that it can be reused by drivers implementing CBC.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 79c65d17

crypto/cbc.c

+2 −127
Original line number Diff line number Diff line 
/*

 * CBC: Cipher Block Chaining mode

 *

 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>

 * Copyright (c) 2006-2016 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
@@ -10,6 +10,7 @@ 
 *

 */



#include <crypto/cbc.h>

#include <crypto/internal/skcipher.h>

#include <linux/err.h>

#include <linux/init.h>
@@ -38,71 +39,6 @@ static int crypto_cbc_setkey(struct crypto_skcipher *parent, const u8 *key, 
	return err;

}



static inline int crypto_cbc_encrypt_segment(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	u8 *iv = walk->iv;



	do {

		crypto_xor(iv, src, bsize);

		fn(tfm, iv, dst);

		memcpy(iv, dst, bsize);



		src += bsize;

		dst += bsize;

	} while ((nbytes -= bsize) >= bsize);



	return nbytes;

}



static inline int crypto_cbc_encrypt_inplace(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *iv = walk->iv;



	do {

		crypto_xor(src, iv, bsize);

		fn(tfm, src, src);

		iv = src;



		src += bsize;

	} while ((nbytes -= bsize) >= bsize);



	memcpy(walk->iv, iv, bsize);



	return nbytes;

}



static inline int crypto_cbc_encrypt_walk(struct skcipher_request *req,

					  void (*fn)(struct crypto_skcipher *,

						     const u8 *, u8 *))

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct skcipher_walk walk;

	int err;



	err = skcipher_walk_virt(&walk, req, false);



	while (walk.nbytes) {

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

			err = crypto_cbc_encrypt_inplace(&walk, tfm, fn);

		else

			err = crypto_cbc_encrypt_segment(&walk, tfm, fn);

		err = skcipher_walk_done(&walk, err);

	}



	return err;

}



static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,

					  const u8 *src, u8 *dst)

{
@@ -116,67 +52,6 @@ static int crypto_cbc_encrypt(struct skcipher_request *req) 
	return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);

}



static inline int crypto_cbc_decrypt_segment(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	u8 *iv = walk->iv;



	do {

		fn(tfm, src, dst);

		crypto_xor(dst, iv, bsize);

		iv = src;



		src += bsize;

		dst += bsize;

	} while ((nbytes -= bsize) >= bsize);



	memcpy(walk->iv, iv, bsize);



	return nbytes;

}



static inline int crypto_cbc_decrypt_inplace(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 last_iv[bsize];



	/* Start of the last block. */

	src += nbytes - (nbytes & (bsize - 1)) - bsize;

	memcpy(last_iv, src, bsize);



	for (;;) {

		fn(tfm, src, src);

		if ((nbytes -= bsize) < bsize)

			break;

		crypto_xor(src, src - bsize, bsize);

		src -= bsize;

	}



	crypto_xor(src, walk->iv, bsize);

	memcpy(walk->iv, last_iv, bsize);



	return nbytes;

}



static inline int crypto_cbc_decrypt_blocks(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	if (walk->src.virt.addr == walk->dst.virt.addr)

		return crypto_cbc_decrypt_inplace(walk, tfm, fn);

	else

		return crypto_cbc_decrypt_segment(walk, tfm, fn);

}



static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,

					  const u8 *src, u8 *dst)

{

include/crypto/cbc.h

0 → 100644
+146 −0
Original line number Diff line number Diff line 
/*

 * CBC: Cipher Block Chaining mode

 *

 * Copyright (c) 2016 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.

 *

 */



#ifndef _CRYPTO_CBC_H

#define _CRYPTO_CBC_H



#include <crypto/internal/skcipher.h>

#include <linux/string.h>

#include <linux/types.h>



static inline int crypto_cbc_encrypt_segment(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	u8 *iv = walk->iv;



	do {

		crypto_xor(iv, src, bsize);

		fn(tfm, iv, dst);

		memcpy(iv, dst, bsize);



		src += bsize;

		dst += bsize;

	} while ((nbytes -= bsize) >= bsize);



	return nbytes;

}



static inline int crypto_cbc_encrypt_inplace(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *iv = walk->iv;



	do {

		crypto_xor(src, iv, bsize);

		fn(tfm, src, src);

		iv = src;



		src += bsize;

	} while ((nbytes -= bsize) >= bsize);



	memcpy(walk->iv, iv, bsize);



	return nbytes;

}



static inline int crypto_cbc_encrypt_walk(struct skcipher_request *req,

					  void (*fn)(struct crypto_skcipher *,

						     const u8 *, u8 *))

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct skcipher_walk walk;

	int err;



	err = skcipher_walk_virt(&walk, req, false);



	while (walk.nbytes) {

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

			err = crypto_cbc_encrypt_inplace(&walk, tfm, fn);

		else

			err = crypto_cbc_encrypt_segment(&walk, tfm, fn);

		err = skcipher_walk_done(&walk, err);

	}



	return err;

}



static inline int crypto_cbc_decrypt_segment(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	u8 *iv = walk->iv;



	do {

		fn(tfm, src, dst);

		crypto_xor(dst, iv, bsize);

		iv = src;



		src += bsize;

		dst += bsize;

	} while ((nbytes -= bsize) >= bsize);



	memcpy(walk->iv, iv, bsize);



	return nbytes;

}



static inline int crypto_cbc_decrypt_inplace(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 last_iv[bsize];



	/* Start of the last block. */

	src += nbytes - (nbytes & (bsize - 1)) - bsize;

	memcpy(last_iv, src, bsize);



	for (;;) {

		fn(tfm, src, src);

		if ((nbytes -= bsize) < bsize)

			break;

		crypto_xor(src, src - bsize, bsize);

		src -= bsize;

	}



	crypto_xor(src, walk->iv, bsize);

	memcpy(walk->iv, last_iv, bsize);



	return nbytes;

}



static inline int crypto_cbc_decrypt_blocks(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	if (walk->src.virt.addr == walk->dst.virt.addr)

		return crypto_cbc_decrypt_inplace(walk, tfm, fn);

	else

		return crypto_cbc_decrypt_segment(walk, tfm, fn);

}



#endif	/* _CRYPTO_CBC_H */