84 lines
1.7 KiB
C
Executable File
84 lines
1.7 KiB
C
Executable File
/*
|
|
* Copyright (C) 2014 Allwinner Ltd.
|
|
*
|
|
* Author:
|
|
* Ryan Chen <ryanchen@allwinnertech.com>
|
|
*
|
|
* 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, version 2 of the
|
|
* License.
|
|
*
|
|
* File: fivm_crypto.c
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/file.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <linux/err.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/fs.h>
|
|
#include "fivm.h"
|
|
|
|
static char *fivm_hash = "sha256";
|
|
static int init_desc(struct hash_desc *desc)
|
|
{
|
|
int rc;
|
|
|
|
desc->tfm = crypto_alloc_hash(fivm_hash, 0, CRYPTO_ALG_ASYNC);
|
|
if (IS_ERR(desc->tfm)) {
|
|
pr_info("FIVM: failed to load %s transform: %ld\n",
|
|
fivm_hash, PTR_ERR(desc->tfm));
|
|
rc = PTR_ERR(desc->tfm);
|
|
return rc;
|
|
}
|
|
desc->flags = 0;
|
|
rc = crypto_hash_init(desc);
|
|
if (rc)
|
|
crypto_free_hash(desc->tfm);
|
|
return rc;
|
|
}
|
|
|
|
int fivm_calc_hash(struct file *file, char *digest)
|
|
{
|
|
struct hash_desc desc;
|
|
struct scatterlist sg[1];
|
|
loff_t i_size, offset = 0;
|
|
char *rbuf;
|
|
int rc;
|
|
|
|
rc = init_desc(&desc);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!rbuf) {
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
i_size = i_size_read(file->f_path.dentry->d_inode);
|
|
while (offset < i_size) {
|
|
int rbuf_len;
|
|
rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
|
|
if (rbuf_len < 0) {
|
|
rc = rbuf_len;
|
|
break;
|
|
}
|
|
if (rbuf_len == 0)
|
|
break;
|
|
offset += rbuf_len;
|
|
sg_init_one(sg, rbuf, rbuf_len);
|
|
|
|
rc = crypto_hash_update(&desc, sg, rbuf_len);
|
|
if (rc)
|
|
break;
|
|
}
|
|
kfree(rbuf);
|
|
if (!rc)
|
|
rc = crypto_hash_final(&desc, digest);
|
|
out:
|
|
crypto_free_hash(desc.tfm);
|
|
return rc;
|
|
}
|