无法通过Big Endian获得CRC功能

Question

我无法在C＃中使用CRC功能。下面是给出的示例C代码，下面是我使用的C＃代码。我怀疑罪魁祸首是大端，但是当我切换校验和的字节顺序时，它仍然给出了不同的值。

我出错的任何想法？

非常感谢

马特

使用CRC-CCITT（Kermit）算法（http://www.lammertbies.nl/comm/info/crccalculation.html）计算CRC。

参数长度 - 2个字节。格式是大端。这就是字节0和1被“切换”的原因。

CRC计算算法如下所示（C编程语言）。

/*----------------------------------------------------------------------------
 * FUNCTION: CRC16
 *---------------------------------------------------------------------------    
 */
unsigned short crc_16_rec (unsigned char *pucData, unsigned short ucLen) {
    //--------------------------------------------------------------------
    unsigned int i;
    unsigned char ucBit, ucCarry;
    //--------------------------------------------------------------------
    unsigned short usPoly = 0x8408;//reversed 0x1021
    unsigned short usCRC = 0;
    //--------------------------------------------------------------------
    for (i = 0; i < ucLen; i++) {
        usCRC ^= pucData[i];
        for (ucBit = 0; ucBit < 8; ucBit++) {
            ucCarry = usCRC & 1;
            usCRC >>= 1;
            if (ucCarry) {
                usCRC ^= usPoly;
            }
        }
    }
    //--------------------------------------------------------------------
    return usCRC;
    //--------------------------------------------------------------------
}

我使用的代码

public enum Crc16Mode : ushort { Standard = 0xA001, CcittKermit = 0x8408 }

Crc16 CRC = new Crc16(Crc16Mode.CcittKermit);

public class Crc16
    {


        readonly ushort[] table = new ushort[256];

        public ushort ComputeChecksum(params byte[] bytes)
        {
            ushort crc = 0;
            for (int i = 0; i < bytes.Length - 2; ++i)
            {
                byte index = (byte)(crc ^ bytes[i]);
                crc = (ushort)((crc >> 8) ^ table[index]);
            }
            return crc;
        }

        public bool ChecksumValid(ref byte[] bytes)
        {
            ushort checksum = (ushort)((bytes[bytes.Length - 2] << 8) | bytes[bytes.Length - 1]);
            ushort checksum_received = CRC16(bytes);
            if (checksum == checksum_received)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        public ushort CRC16(byte[] bytes)
        {
            ushort crc = 0; //(ushort.maxvalue, 65535)

            for (int j = 0; j < bytes.Length; j++)
            {
                crc = (ushort)(crc ^ bytes[j]);
                for (int i = 0; i < 8; i++)
                {
                    if ((crc & 0x0001) == 1)
                        crc = (ushort)((crc >> 1) ^ 0x8408);
                    else
                        crc >>= 1;
                }
            }
            return (ushort)~(uint)crc;
        }

        public byte[] ComputeChecksumBytes(params byte[] bytes)
        {
            ushort crc = ComputeChecksum(bytes);
            return BitConverter.GetBytes(crc);
        }

        public Crc16(Crc16Mode mode)
        {
            ushort polynomial = (ushort)mode;
            ushort value;
            ushort temp;
            for (ushort i = 0; i < table.Length; ++i)
            {
                value = 0;
                temp = i;
                for (byte j = 0; j < 8; ++j)
                {
                    if (((value ^ temp) & 0x0001) != 0)
                    {
                        value = (ushort)((value >> 1) ^ polynomial);
                    }
                    else
                    {
                        value >>= 1;
                    }
                    temp >>= 1;
                }
                table[i] = value;
            }
        }
    }