linux/crypto/pcbc.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

195 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PCBC: Propagating Cipher Block Chaining mode
*
* Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* Derived from cbc.c
* - Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/algapi.h>
#include <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
static int crypto_pcbc_encrypt_segment(struct skcipher_request *req,
struct skcipher_walk *walk,
struct crypto_cipher *tfm)
{
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
u8 * const iv = walk->iv;
do {
crypto_xor(iv, src, bsize);
crypto_cipher_encrypt_one(tfm, dst, iv);
crypto_xor_cpy(iv, dst, src, bsize);
src += bsize;
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
return nbytes;
}
static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req,
struct skcipher_walk *walk,
struct crypto_cipher *tfm)
{
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE];
do {
memcpy(tmpbuf, src, bsize);
crypto_xor(iv, src, bsize);
crypto_cipher_encrypt_one(tfm, src, iv);
crypto_xor_cpy(iv, tmpbuf, src, bsize);
src += bsize;
} while ((nbytes -= bsize) >= bsize);
return nbytes;
}
static int crypto_pcbc_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
struct skcipher_walk walk;
unsigned int nbytes;
int err;
err = skcipher_walk_virt(&walk, req, false);
while ((nbytes = walk.nbytes)) {
if (walk.src.virt.addr == walk.dst.virt.addr)
nbytes = crypto_pcbc_encrypt_inplace(req, &walk,
cipher);
else
nbytes = crypto_pcbc_encrypt_segment(req, &walk,
cipher);
err = skcipher_walk_done(&walk, nbytes);
}
return err;
}
static int crypto_pcbc_decrypt_segment(struct skcipher_request *req,
struct skcipher_walk *walk,
struct crypto_cipher *tfm)
{
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
u8 * const iv = walk->iv;
do {
crypto_cipher_decrypt_one(tfm, dst, src);
crypto_xor(dst, iv, bsize);
crypto_xor_cpy(iv, dst, src, bsize);
src += bsize;
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
return nbytes;
}
static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req,
struct skcipher_walk *walk,
struct crypto_cipher *tfm)
{
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(u32));
do {
memcpy(tmpbuf, src, bsize);
crypto_cipher_decrypt_one(tfm, src, src);
crypto_xor(src, iv, bsize);
crypto_xor_cpy(iv, src, tmpbuf, bsize);
src += bsize;
} while ((nbytes -= bsize) >= bsize);
return nbytes;
}
static int crypto_pcbc_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
struct skcipher_walk walk;
unsigned int nbytes;
int err;
err = skcipher_walk_virt(&walk, req, false);
while ((nbytes = walk.nbytes)) {
if (walk.src.virt.addr == walk.dst.virt.addr)
nbytes = crypto_pcbc_decrypt_inplace(req, &walk,
cipher);
else
nbytes = crypto_pcbc_decrypt_segment(req, &walk,
cipher);
err = skcipher_walk_done(&walk, nbytes);
}
return err;
}
static int crypto_pcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct crypto_alg *alg;
int err;
inst = skcipher_alloc_instance_simple(tmpl, tb, &alg);
if (IS_ERR(inst))
return PTR_ERR(inst);
inst->alg.encrypt = crypto_pcbc_encrypt;
inst->alg.decrypt = crypto_pcbc_decrypt;
err = skcipher_register_instance(tmpl, inst);
if (err)
inst->free(inst);
crypto_mod_put(alg);
return err;
}
static struct crypto_template crypto_pcbc_tmpl = {
.name = "pcbc",
.create = crypto_pcbc_create,
.module = THIS_MODULE,
};
static int __init crypto_pcbc_module_init(void)
{
return crypto_register_template(&crypto_pcbc_tmpl);
}
static void __exit crypto_pcbc_module_exit(void)
{
crypto_unregister_template(&crypto_pcbc_tmpl);
}
subsys_initcall(crypto_pcbc_module_init);
module_exit(crypto_pcbc_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PCBC block cipher mode of operation");
MODULE_ALIAS_CRYPTO("pcbc");