常用CRC校验计算代码示例
目录
-
- 一、前言
- 二、代码示例
-
- CRC4
- CRC5
- CRC6
- CRC7
- CRC8
- CRC16
- CRC32
- 三、结束语
一、前言
特别说明：本文转载于https://blog.csdn.net/leumber/article/details/54311811
这是我第一次转载别人的文章，因为觉得这篇博客的代码写的挺好的，很实用，所以就推荐给大家，如果你们在项目中正好需要用到crc校验的话没必要自己浪费时间去写，可以直接到这里拷贝代码片段快速加入到自己的程序里面。
关于crc校验的原理我就不说了，感兴趣的同学可以去原文看一下，我这里只贴上代码片段。
二、代码示例
CRC4
/****************************Info**********************************************
* Name: InvertUint8
* Note: 把字节颠倒过来，如0x12变成0x48
0x12: 0001 0010
0x48: 0100 1000
*****************************************************************************/
void InvertUint8(unsigned char *dBuf,unsigned char *srcBuf)
{
int i;
unsigned char tmp[4]={
0};
for(i=0;i< 8;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(7-i);
}
dBuf[0] = tmp[0];
}
/****************************Info**********************************************
* Name: CRC-4/ITU x4+x+1
* Width: 4
* Poly: 0x03
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
unsigned char CRC4_ITU(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x03;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ (wCPoly << 4);
else
wCRCin = wCRCin << 1;
}
}
InvertUint8(&wCRCin,&wCRCin);
return (wCRCin);
}
CRC5
/****************************Info**********************************************
* Name: InvertUint8
* Note: 把字节颠倒过来，如0x12变成0x48
0x12: 0001 0010
0x48: 0100 1000
*****************************************************************************/
void InvertUint8(unsigned char *dBuf,unsigned char *srcBuf)
{
int i;
unsigned char tmp[4]={
0};
for(i=0;i< 8;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(7-i);
}
dBuf[0] = tmp[0];
}
/****************************Info**********************************************
* Name: CRC-5/EPC x5+x3+1
* Width: 5
* Poly: 0x09
* Init: 0x09
* Refin: False
* Refout: False
* Xorout: 0x00
* Note:
*****************************************************************************/
unsigned char CRC5_EPC(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x09<<3;
unsigned char wCPoly = 0x09<<3;
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ (wCPoly);
else
wCRCin = wCRCin << 1;
}
}
return (wCRCin >> 3);
}
/****************************Info**********************************************
* Name: CRC-5/USB x5+x2+1
* Width: 5
* Poly: 0x05
* Init: 0x1F
* Refin: True
* Refout: True
* Xorout: 0x1F
* Note:
*****************************************************************************/
#if 0
unsigned char CRC5_USB(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x1F<<3;
unsigned char wCPoly = 0x05;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ (wCPoly << 3);
else
wCRCin = wCRCin << 1;
}
}
InvertUint8(&wCRCin,&wCRCin);
return (wCRCin^0x1F);
}
#else
unsigned char CRC5_USB(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x1F;
unsigned char wCPoly = 0x05;
InvertUint8(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ (wCPoly >> 3);
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin^0x1F);
}
#endif
/****************************Info**********************************************
* Name: CRC-5/ITU x5+x4+x2+1
* Width: 5
* Poly: 0x15
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
#if 0
unsigned char CRC5_ITU(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x15;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ (wCPoly << 3);
else
wCRCin = wCRCin << 1;
}
}
InvertUint8(&wCRCin,&wCRCin);
return (wCRCin);
}
#else
unsigned char CRC5_ITU(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x15;
InvertUint8(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ (wCPoly >> 3);
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin);
}
#endif
CRC6
/****************************Info**********************************************
* Name: InvertUint8
* Note: 把字节颠倒过来，如0x12变成0x48
0x12: 0001 0010
0x48: 0100 1000
*****************************************************************************/
void InvertUint8(unsigned char *dBuf,unsigned char *srcBuf)
{
int i;
unsigned char tmp[4]={
0};
for(i=0;i< 8;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(7-i);
}
dBuf[0] = tmp[0];
}
/****************************Info**********************************************
* Name: CRC-6/ITU x6+x+1
* Width: 6
* Poly: 0x03
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
unsigned char CRC6_ITU(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x03;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ (wCPoly << 2);
else
wCRCin = wCRCin << 1;
}
}
InvertUint8(&wCRCin,&wCRCin);
return (wCRCin);
}
CRC7
/****************************Info**********************************************
* Name: CRC-7/MMC x7+x3+1
* Width: 7
* Poly: 0x09
* Init: 0x00
* Refin: False
* Refout: False
* Xorout: 0x00
* Use: MultiMediaCard,SD,ect.
*****************************************************************************/
unsigned char CRC7_MMC(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x09;
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ (wCPoly<<1);
else
wCRCin = wCRCin << 1;
}
}
return (wCRCin>>1);
}
CRC8
/****************************Info**********************************************
* Name: InvertUint8
* Note: 把字节颠倒过来，如0x12变成0x48
0x12: 0001 0010
0x48: 0100 1000
*****************************************************************************/
void InvertUint8(unsigned char *dBuf,unsigned char *srcBuf)
{
int i;
unsigned char tmp[4]={
0};
for(i=0;i< 8;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(7-i);
}
dBuf[0] = tmp[0];
}
/****************************Info**********************************************
* Name: CRC-8 x8+x2+x+1
* Width: 8
* Poly: 0x07
* Init: 0x00
* Refin: False
* Refout: False
* Xorout: 0x00
* Note:
*****************************************************************************/
unsigned char CRC8(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x07;
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
return (wCRCin);
}
/****************************Info**********************************************
* Name: CRC-8/ITU x8+x2+x+1
* Width: 8
* Poly: 0x07
* Init: 0x00
* Refin: False
* Refout: False
* Xorout: 0x55
* Alias: CRC-8/ATM
*****************************************************************************/
unsigned char CRC8_ITU(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x07;
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
return (wCRCin^0x55);
}
/****************************Info**********************************************
* Name: CRC-8/ROHC x8+x2+x+1
* Width: 8
* Poly: 0x07
* Init: 0xFF
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
#if 0
unsigned char CRC8_ROHC(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0xFF;
unsigned char wCPoly = 0x07;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 0);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint8(&wCRCin,&wCRCin);
return (wCRCin);
}
#else
unsigned char CRC8_ROHC(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0xFF;
unsigned char wCPoly = 0x07;
InvertUint8(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin);
}
#endif
/****************************Info**********************************************
* Name: CRC-8/MAXIM x8+x5+x4+1
* Width: 8
* Poly: 0x31
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Alias: DOW-CRC,CRC-8/IBUTTON
* Use: Maxim(Dallas)'s some devices,e.g. DS18B20
*****************************************************************************/
#if 0
unsigned char CRC8_MAXIM(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x31;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 0);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint8(&wCRCin,&wCRCin);
return (wCRCin);
}
#else
unsigned char CRC8_MAXIM(unsigned char *data, unsigned int datalen)
{
unsigned char wCRCin = 0x00;
unsigned char wCPoly = 0x31;
InvertUint8(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin);
}
#endif
CRC16
/****************************Info**********************************************
* Name: InvertUint8
* Note: 把字节颠倒过来，如0x12变成0x48
0x12: 0001 0010
0x48: 0100 1000
*****************************************************************************/
void InvertUint8(unsigned char *dBuf,unsigned char *srcBuf)
{
int i;
unsigned char tmp[4]={
0};
for(i=0;i< 8;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(7-i);
}
dBuf[0] = tmp[0];
}
void InvertUint16(unsigned short *dBuf,unsigned short *srcBuf)
{
int i;
unsigned short tmp[4]={
0};
for(i=0;i< 16;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(15 - i);
}
dBuf[0] = tmp[0];
}
/****************************Info**********************************************
* Name: CRC-16/CCITT x16+x12+x5+1
* Width: 16
* Poly: 0x1021
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0x0000
* Alias: CRC-CCITT,CRC-16/CCITT-TRUE,CRC-16/KERMIT
*****************************************************************************/
#if 0
unsigned short CRC16_CCITT(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x1021;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint16(&wCRCin,&wCRCin);
return (wCRCin);
}
#else
//这里为了效率，我们不需要将所有Refin和refout为true的输入输出数据移位转换
//只需要将poly二项式转换后，运算时将左移变为右移
unsigned short CRC16_CCITT(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x1021;
unsigned char wChar = 0;
InvertUint16(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin);
}
#endif
/****************************Info**********************************************
* Name: CRC-16/CCITT-FALSE x16+x12+x5+1
* Width: 16
* Poly: 0x1021
* Init: 0xFFFF
* Refin: False
* Refout: False
* Xorout: 0x0000
* Note:
*****************************************************************************/
unsigned short CRC16_CCITT_FALSE(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0xFFFF;
unsigned short wCPoly = 0x1021;
while (datalen--)
{
wCRCin ^= *(data++) << 8;
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
return (wCRCin);
}
/****************************Info**********************************************
* Name: CRC-16/XMODEM x16+x12+x5+1
* Width: 16
* Poly: 0x1021
* Init: 0x0000
* Refin: False
* Refout: False
* Xorout: 0x0000
* Alias: CRC-16/ZMODEM,CRC-16/ACORN
*****************************************************************************/
unsigned short CRC16_XMODEM(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x1021;
while (datalen--)
{
wCRCin ^= (*(data++) << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
return (wCRCin);
}
/****************************Info**********************************************
* Name: CRC-16/X25 x16+x12+x5+1
* Width: 16
* Poly: 0x1021
* Init: 0xFFFF
* Refin: True
* Refout: True
* Xorout: 0XFFFF
* Note:
*****************************************************************************/
#if 0
unsigned short CRC16_X25(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0xFFFF;
unsigned short wCPoly = 0x1021;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint16(&wCRCin,&wCRCin);
return (wCRCin^0xFFFF);
}
#else
unsigned short CRC16_X25(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0xFFFF;
unsigned short wCPoly = 0x1021;
InvertUint16(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin^0xFFFF);
}
#endif
/****************************Info**********************************************
* Name: CRC-16/MODBUS x16+x15+x2+1
* Width: 16
* Poly: 0x8005
* Init: 0xFFFF
* Refin: True
* Refout: True
* Xorout: 0x0000
* Note:
*****************************************************************************/
#if 0
unsigned short CRC16_MODBUS(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0xFFFF;
unsigned short wCPoly = 0x8005;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint16(&wCRCin,&wCRCin);
return (wCRCin);
}
#else
unsigned short CRC16_MODBUS(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0xFFFF;
unsigned short wCPoly = 0x8005;
InvertUint16(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin);
}
#endif
/****************************Info**********************************************
* Name: CRC-16/IBM x16+x15+x2+1
* Width: 16
* Poly: 0x8005
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0x0000
* Alias: CRC-16,CRC-16/ARC,CRC-16/LHA
*****************************************************************************/
#if 0
unsigned short CRC16_IBM(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x8005;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint16(&wCRCin,&wCRCin);
return (wCRCin);
}
#else
unsigned short CRC16_IBM(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x8005;
InvertUint16(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin);
}
#endif
/****************************Info**********************************************
* Name: CRC-16/MAXIM x16+x15+x2+1
* Width: 16
* Poly: 0x8005
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0xFFFF
* Note:
*****************************************************************************/
#if 0
unsigned short CRC16_MAXIM(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x8005;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint16(&wCRCin,&wCRCin);
return (wCRCin^0xFFFF);
}
#else
unsigned short CRC16_MAXIM(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x8005;
InvertUint16(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin^0xFFFF);
}
#endif
/****************************Info**********************************************
* Name: CRC-16/USB x16+x15+x2+1
* Width: 16
* Poly: 0x8005
* Init: 0xFFFF
* Refin: True
* Refout: True
* Xorout: 0xFFFF
* Note:
*****************************************************************************/
#if 0
unsigned short CRC16_USB(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0xFFFF;
unsigned short wCPoly = 0x8005;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint16(&wCRCin,&wCRCin);
return (wCRCin^0xFFFF);
}
#else
unsigned short CRC16_USB(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0xFFFF;
unsigned short wCPoly = 0x8005;
InvertUint16(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin^0xFFFF);
}
#endif
/****************************Info**********************************************
* Name: CRC-16/DNP x16+x13+x12+x11+x10+x8+x6+x5+x2+1
* Width: 16
* Poly: 0x3D65
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0xFFFF
* Use: M-Bus,ect.
*****************************************************************************/
#if 0
unsigned short CRC16_DNP(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x3D65;
unsigned char wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8(&wChar,&wChar);
wCRCin ^= (wChar << 8);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x8000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint16(&wCRCin,&wCRCin);
return (wCRCin^0xFFFF) ;
}
#else
unsigned short CRC16_DNP(unsigned char *data, unsigned int datalen)
{
unsigned short wCRCin = 0x0000;
unsigned short wCPoly = 0x3D65;
InvertUint16(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = (wCRCin >> 1);
}
}
return (wCRCin^0xFFFF);
}
#endif
CRC32
/****************************Info**********************************************
* Name: InvertUint8
* Note: 把字节颠倒过来，如0x12变成0x48
0x12: 0001 0010
0x48: 0100 1000
*****************************************************************************/
void InvertUint8(unsigned char *dBuf,unsigned char *srcBuf)
{
int i;
unsigned char tmp[4]={
0};
for(i=0;i< 8;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(7-i);
}
dBuf[0] = tmp[0];
}
void InvertUint32(unsigned int *dBuf,unsigned int *srcBuf)
{
int i;
unsigned int tmp[4]={
0};
for(i=0;i< 32;i++)
{
if(srcBuf[0]& (1 << i))
tmp[0]|=1<<(31 - i);
}
dBuf[0] = tmp[0];
}
/****************************Info**********************************************
* Name: CRC-32 x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
* Width: 32
* Poly: 0x4C11DB7
* Init: 0xFFFFFFF
* Refin: True
* Refout: True
* Xorout: 0xFFFFFFF
* Alias: CRC_32/ADCCP
* Use: WinRAR,ect.
*****************************************************************************/
#if 0
unsigned int CRC32(unsigned char *data, unsigned int datalen)
{
unsigned int wCRCin = 0xFFFFFFFF;
unsigned int wCPoly = 0x04C11DB7;
unsigned int wChar = 0;
while (datalen--)
{
wChar = *(data++);
InvertUint8((unsigned char *)&wChar,(unsigned char *)&wChar);
wCRCin ^= (wChar << 24);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80000000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
InvertUint32(&wCRCin,&wCRCin);
return (wCRCin ^ 0xFFFFFFFF) ;
}
#else
unsigned int CRC32(unsigned char *data, unsigned int datalen)
{
unsigned int wCRCin = 0xFFFFFFFF;
unsigned int wCPoly = 0x04C11DB7;
InvertUint32(&wCPoly,&wCPoly);
while (datalen--)
{
wCRCin ^= *(data++);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x01)
wCRCin = (wCRCin >> 1) ^ wCPoly;
else
wCRCin = wCRCin >> 1;
}
}
return (wCRCin ^ 0xFFFFFFFF) ;
}
#endif
/****************************Info**********************************************
* Name: CRC-32/MPEG-2 x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
* Width: 32
* Poly: 0x4C11DB7
* Init: 0xFFFFFFF
* Refin: False
* Refout: False
* Xorout: 0x0000000
* Note:
*****************************************************************************/
unsigned int CRC32_MPEG(unsigned char *data, unsigned int datalen)
{
unsigned int wCRCin = 0xFFFFFFFF;
unsigned int wCPoly = 0x04C11DB7;
unsigned int wChar = 0;
while (datalen--)
{
wChar = *(data++);
wCRCin ^= (wChar << 24);
for(int i = 0;i < 8;i++)
{
if(wCRCin & 0x80000000)
wCRCin = (wCRCin << 1) ^ wCPoly;
else
wCRCin = wCRCin << 1;
}
}
return (wCRCin) ;
}
三、结束语
在这里先感谢一下原文博主的分享，然后感谢大家能够看到这里（大部分人应该拷贝完代码就走人了），如果你觉得这篇博客能够帮到你，可以点赞收藏，后续博主也会继续发布更多实用的博客，感兴趣的同学可以关注一下，谢谢！！！