linux-imx

/**

 * eCryptfs: Linux filesystem encryption layer

 *

 * Copyright (C) 1997-2004 Erez Zadok

 * Copyright (C) 2001-2004 Stony Brook University

 * Copyright (C) 2004-2007 International Business Machines Corp.

 *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>

 *          Michael C. Thompson <mcthomps@us.ibm.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; either version 2 of the

 * License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA

 * 02111-1307, USA.

 */

​

#include <crypto/hash.h>

#include <crypto/skcipher.h>

#include <linux/fs.h>

#include <linux/mount.h>

#include <linux/pagemap.h>

#include <linux/random.h>

#include <linux/compiler.h>

#include <linux/key.h>

#include <linux/namei.h>

#include <linux/file.h>

#include <linux/scatterlist.h>

#include <linux/slab.h>

#include <asm/unaligned.h>

#include <linux/kernel.h>

#include "ecryptfs_kernel.h"

​

#define DECRYPT     0

#define ENCRYPT     1

​

/**

 * ecryptfs_from_hex

 * @dst: Buffer to take the bytes from src hex; must be at least of

 *       size (src_size / 2)

 * @src: Buffer to be converted from a hex string representation to raw value

 * @dst_size: size of dst buffer, or number of hex characters pairs to convert

 */

void ecryptfs_from_hex(char *dst, char *src, int dst_size)

{

    int x;

    char tmp[3] = { 0, };

​

    for (x = 0; x < dst_size; x++) {

        tmp[0] = src[x * 2];

        tmp[1] = src[x * 2 + 1];

        dst[x] = (unsigned char)simple_strtol(tmp, NULL, 16);

    }

}

​

static int ecryptfs_hash_digest(struct crypto_shash *tfm,

                char *src, int len, char *dst)

{

    SHASH_DESC_ON_STACK(desc, tfm);

    int err;

​

    desc->tfm = tfm;

    desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

    err = crypto_shash_digest(desc, src, len, dst);

    shash_desc_zero(desc);

    return err;

}

​

/**

 * ecryptfs_calculate_md5 - calculates the md5 of @src

 * @dst: Pointer to 16 bytes of allocated memory

 * @crypt_stat: Pointer to crypt_stat struct for the current inode

 * @src: Data to be md5'd

 * @len: Length of @src

 *

 * Uses the allocated crypto context that crypt_stat references to

 * generate the MD5 sum of the contents of src.

 */

static int ecryptfs_calculate_md5(char *dst,

                  struct ecryptfs_crypt_stat *crypt_stat,

                  char *src, int len)

{

    struct crypto_shash *tfm;

    int rc = 0;