/*

** The Sleuth Kit

**

** Brian Carrier [carrier <at> sleuthkit [dot] org]

** Copyright (c) 2003-2011 Brian Carrier.  All rights reserved

**

** TASK

** Copyright (c) 2015 Stefan Pöschel.  All rights reserved

**

** This software is distributed under the Common Public License 1.0

*/

/*

 * Contains the checksum part for Btrfs file system support.

 */

#include "tsk/base/crc.h"

/**

 * Returns the CRC32C checksum of a specific amount of data.

 * @param a_data pointer to data

 * @param a_len data len

 * @return calculated checksum

 */

extern "C" unsigned long

btrfs_csum_crc32c(const unsigned char *a_data, const int a_len)

{

    cm_t cm;

    cm.cm_width = 32;

    cm.cm_poly = 0x1EDC6F41;

    cm.cm_init = 0xFFFFFFFF;

    cm.cm_refin = true;

    cm.cm_refot = true;

    cm.cm_xorot = 0xFFFFFFFF;

    cm_ini(&cm);

    cm_blk(&cm, (unsigned char *) a_data, a_len);

    return cm_crc(&cm);

}