+++ /dev/null
-// 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/cipher.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);
- const u8 *src = walk->src.virt.addr;
- unsigned int nbytes = walk->nbytes;
- 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 *dst = walk->dst.virt.addr;
- u8 * const iv = walk->iv;
- u8 tmpbuf[MAX_CIPHER_BLOCKSIZE];
-
- do {
- memcpy(tmpbuf, dst, bsize);
- crypto_xor(iv, dst, bsize);
- crypto_cipher_encrypt_one(tfm, dst, iv);
- crypto_xor_cpy(iv, tmpbuf, dst, bsize);
-
- dst += 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 (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);
- const u8 *src = walk->src.virt.addr;
- unsigned int nbytes = walk->nbytes;
- 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 *dst = walk->dst.virt.addr;
- u8 * const iv = walk->iv;
- u8 tmpbuf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(u32));
-
- do {
- memcpy(tmpbuf, dst, bsize);
- crypto_cipher_decrypt_one(tfm, dst, dst);
- crypto_xor(dst, iv, bsize);
- crypto_xor_cpy(iv, dst, tmpbuf, bsize);
-
- dst += 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 (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;
- int err;
-
- inst = skcipher_alloc_instance_simple(tmpl, tb);
- 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);
-
- 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);
-}
-
-module_init(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");
-MODULE_IMPORT_NS("CRYPTO_INTERNAL");
projects / thirdparty / linux.git / commitdiff
