/* * Copyright (c) 2008-2022 Jonathan Schleifer * * 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; }