/*
* Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
*
* All rights reserved.
*
* This file is part of ObjFW. It may be distributed under the terms of the
* Q Public License 1.0, which can be found in the file LICENSE.QPL included in
* the packaging of this file.
*
* Alternatively, it may be distributed under the terms of the GNU General
* Public License, either version 2 or 3, which can be found in the file
* LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
* file.
*/
#include "config.h"
#import "OFCRC16.h"
static const uint16_t CRC16Magic = 0xA001;
uint16_t
OFCRC16(uint16_t CRC, const void *bytes_, size_t length)
{
const unsigned char *bytes = bytes_;
for (size_t i = 0; i < length; i++) {
CRC ^= bytes[i];
for (uint8_t j = 0; j < 8; j++)
CRC = (CRC >> 1) ^ (CRC16Magic & (~(CRC & 1) + 1));
}
return CRC;
}