def CRC32(buffer, size, crc_byte): crc = 0 index = 0 if buffer and size > 0: while size > 0: size -= 1 crc ^= buffer[index] << 8 index += 1 for i in range(8): if crc & 0x8000: crc = (crc << 1) ^ 0x1021 else: crc = crc << 1 crc &= 0x0000FFFF crc_byte[0] = crc & 0xFF crc_byte[1] = (crc >> 8) & 0xFF crc_byte[2] = (crc >> 16) & 0xFF crc_byte[3] = (crc >> 24) & 0xFF 用crcmod的mkcrcfun实现

可以使用crcmod库中的mkCrcFun函数来实现CRC32校验。具体实现方法如下：

import crcmod

def CRC32(buffer, size, crc_byte):
    crc_fun = crcmod.mkCrcFun(0x104c11db7, initCrc=0xFFFFFFFF, xorOut=0xFFFFFFFF)
    crc = crc_fun(buffer[:size])
    crc_byte[0] = crc & 0xFF
    crc_byte[1] = (crc >> 8) & 0xFF
    crc_byte[2] = (crc >> 16) & 0xFF
    crc_byte[3] = (crc >> 24) & 0xFF

其中，crcmod库的mkCrcFun函数可以根据多项式生成一个用于CRC校验的函数，0x104c11db7是CRC32的多项式，initCrc和xorOut参数可以设置初始值和异或值。将buffer中的前size个字节作为输入传入crc_fun函数进行计算，得到的结果即为CRC校验值。最后将CRC校验值存入crc_byte数组中。

相关问题

public static void CRC32(byte[] buffer, UInt32 size, byte[] crc_byte) { UInt32 crc = 0; UInt32 index = 0; if ((null != buffer) && (size > 0)) { while (0 < size--) { crc = (UInt32)(crc ^ (UInt32)buffer[index++] << 8); for (UInt16 i = 0; i < 8; i++) { if (0 != (crc & 0x8000)) { crc = crc << 1 ^ 0x1021; } else { crc = crc << 1; } } } } crc = crc & 0x0000FFFF; crc_byte[0] = (byte)crc; crc_byte[1] = (byte)(crc >> 8); crc_byte[2] = (byte)(crc >> 16); crc_byte[3] = (byte)(crc >> 24); } C3转为python

以下是将该C#代码转换为Python的代码：

def CRC32(buffer, size, crc_byte):
crc = 0
index = 0
if buffer and size > 0:
while size > 0:
size -= 1
crc ^= buffer[index] << 8
index += 1
for i in range(8):
if crc & 0x8000:
crc = (crc << 1) ^ 0x1021
else:
crc = crc << 1
crc &= 0x0000FFFF
crc_byte[0] = crc & 0xFF
crc_byte[1] = (crc >> 8) & 0xFF
crc_byte[2] = (crc >> 16) & 0xFF
crc_byte[3] = (crc >> 24) & 0xFF