crcfiledlg.cpp

CRC 算法源代码 工程测试确定可用

	// Perform the algorithm on each character
	// in the string, using the lookup table values.
	while(len--)
		crc = (crc >> 8) ^ crc32_table[(crc & 0xFF) ^ *buffer++];
	// Exclusive OR the result with the beginning value.
	return crc^0xffffffff;
}

// Handler for Close program messages
void CCRCfileDlg::OnCancel() 
{
	// TODO: Add extra cleanup here
	
	// I like to override this function so the dialog
	// doesn't close when the Escape key is pressed.
	if(GetKeyState(VK_ESCAPE) & 128)
		return;

	CDialog::OnCancel();
}

// This function adds file Drag and Drop support.
// It isn't needed to calculate the CRC.
void CCRCfileDlg::OnDropFiles(HDROP hDropInfo) 
{
	char lpszFile[MAX_PATH];
	CFileFind file;

	DragQueryFile(hDropInfo, 0, lpszFile, MAX_PATH);

	BOOL trufal = file.FindFile(lpszFile);
	if(trufal)
	{
		file.FindNextFile();
		if(!file.IsDirectory())
		{
			m_csFileName = lpszFile;
			//Open the file and read it.
			Open_File();
		}
	}
	// Let CDialog release the memory used in hDropInfo
	CDialog::OnDropFiles(hDropInfo);
}

// Open the file, read it, and obtain the CRC from Get_CRC()
void CCRCfileDlg::Open_File()
{
	HANDLE hFile = {NULL};
	DWORD dwSize, bytes_read;

	// Open the file and get ready to read it.
	// Don't be confused by the CreateFile() function,
	// we're only opening an existing file.
	hFile = CreateFile(m_csFileName, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE,
		NULL, OPEN_EXISTING,
		FILE_FLAG_SEQUENTIAL_SCAN, NULL);
	if(hFile == INVALID_HANDLE_VALUE)
	{
		MessageBox("Failed to open the file.\n\n" + m_csFileName, "Error - CRC File Demo");
		return;
	}
	// Get the file size so we know how long to make our buffer.
	dwSize = GetFileSize(hFile, NULL);
	// Create a CString buffer of the proper length
	// and fill it with spaces.
	CString csData(' ', dwSize);
	// Read the file into the buffer
	ReadFile(hFile, csData.GetBuffer(dwSize), dwSize, &bytes_read, NULL);
	// We're done with the file handle so close it.
	CloseHandle(hFile);
	// Always release the buffer after writing to it.
	csData.ReleaseBuffer();
	// Check to be sure we read the whole file.
	if(dwSize != bytes_read)
	{
		MessageBox("Failed to read the file.\n\n" + m_csFileName, "Error - CRC File Demo");
		return;
	}
	// Note: At this point, we can't use normal string functions
	// on csData because it might contain NULL characters.
	// In other words, GetLength() will only return the count
	// up to the first NULL. Always include dwSize when passing
	// the string so we know the full length.
	int nCRC = Get_CRC(csData, dwSize);
	// Convert the returned integer into a character string.
	char ch[20];
	itoa(nCRC, ch, 16);  // Note that the integer is a 16 bit hex
	// Send the CRC string to the dialog.
	m_csCRCtext = ch;
	// If the file path is likely to be too long to display shorten it.
	int nMax = 60;
	if(m_csFileName.GetLength() > nMax)
		m_csFileName = m_csFileName.Left(3) + "..." + m_csFileName.Right(nMax -6);
	UpdateData(FALSE);
}
// ******* End custom code *******

void ByteCRC(unsigned int &CRC, unsigned char Ch,unsigned int genPoly)
{
	//unsigned int genPoly = 0x178;
	
	CRC ^= Ch;

	for(int i = 0; i<8; i++)
		if( (CRC & 0x0080) != 0 )   //CRC为0x80时，才是FALSE,无论如何都会左移
		{
			CRC = (CRC << 1) ^ genPoly;
		}
		else
			CRC <<= 1;

	//CRC ^= 0xff;
}

//----------------------------------------------------------
unsigned int BlockCRC(unsigned char *Block,int BlockLen,unsigned int g )
{
	unsigned int CRC = 0xE3;

	for (int i=0; i<BlockLen; i++)		ByteCRC(CRC, Block[i],g);
    //CRC ^= 0xff;
	
	return CRC;
}

 

BYTE CRC_8_tab[16] = //参数表
{
0x00,0x07,0x0e,0x09,
0x1c,0x1b,0x12,0x15,
0x38,0x3f,0x36,0x31,
0x24,0x23,0x2a,0x2d,
};
 

BYTE CRC8Generator(BYTE *DataBuf, unsigned long len)
{
	BYTE CRC8;
	BYTE tabdata;
	unsigned int datanum;
	BYTE c,t;

	CRC8 = 0x00; //初值为0
	datanum = 0;

	while(len--) //每次循环处理一个字节
	{
		c = DataBuf[datanum];    //新移进来的字节值

		t = (CRC8>>4) & 0x0F;    //要移出的半字节的值
		tabdata = CRC_8_tab[t];  //根据移出的半字节的值查表
		CRC8 = (CRC8<<4) | c>>4; //将新移进来的高位半字节值添在寄存器末字节中
		CRC8 = CRC8^tabdata;     //将寄存器与查出的值进行异或运算

		t = (CRC8>>4) & 0x0F;    //要移出的半字节的值
		tabdata = CRC_8_tab[t];  //根据移出的半字节的值查表
		CRC8 = (CRC8<<4) | (c&0x0F); //将新移进来的低位半字节值添在寄存器末字节中
		CRC8 = CRC8^tabdata;         //将寄存器与查出的值进行异或运算
		datanum++;                   //下一个字节
	}
	
	return CRC8;
}

// CRC-ITU查找表
const unsigned int crctab16[] =  // x16+x12+x5+1=0x1021  反转后为 0x8408=1+x5+x12+x16
{
    0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
    0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
    0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
    0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
    0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
    0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
    0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
    0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
    0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
    0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
    0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
    0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
    0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
    0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
    0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
    0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
    0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
    0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
    0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
    0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
    0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
    0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
    0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
    0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
    0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
    0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
    0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
    0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
    0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
    0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
    0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
    0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78,
};

// 计算给定长度数据的16位CRC。
unsigned int GetCrc16(const byte* pData, int nLength)
{
    unsigned int fcs = 0xffff;    // 初始化
    
    while(nLength>0)
    {
        fcs = (fcs >> 8) ^ crctab16[(fcs ^ *pData) & 0xff];
        nLength--;
        pData++;
    }
    
    return ~fcs;    // 取反
}

// 检查给定长度数据的16位CRC是否正确。
bool IsCrc16Good(const byte* pData, int nLength)
{
    unsigned int fcs = 0xffff;    // 初始化
    
    while(nLength>0)
    {
        fcs = (fcs >> 8) ^ crctab16[(fcs ^ *pData) & 0xff];
        nLength--;
        pData++;
    }
    
    return (fcs == 0xf0b8);  // 0xf0b8是CRC-ITU的"Magic Value"
}

void CCRCfileDlg::OnBnClickedButton1()
{
	// TODO: 在此添加控件通知处理程序代码
	unsigned char c,buf[40]={0x01,0x01,0x08,0x01,0x08,0x01,0x08,0,0,0,0,0,0,0x04,0,0x03,0x10,0x03,0x10,0x02,0x10,0x02,0x10,0,0,0,0,0,0,0x11,0x30};
	unsigned char data[10]={0x61,0x62,0x63,0x64};
	unsigned int  crc;
	unsigned int  g;
	byte ppp[13] = {0xFF, 0x03, 0xC0, 0x21, 0x04, 0x03, 0x00, 0x07, 0x0D, 0x03, 0x06, 0x00, 0x00};
    unsigned int  result;

	g=0x107;
	crc= BlockCRC(data,3,g);
	for(g=285;g<512;g++)
	{
		crc= BlockCRC(buf,31,g);
		if( crc == 0x89 ) 
			break;
	}

	c=CRC8Generator(data,2);

    // 计算CRC
    result = GetCrc16(ppp, 11);
    
    // 填写FCS，先低后高
    ppp[11] = result & 0xff;
    ppp[12] = (result >> 8) & 0xff;
    
    // 验证FCS
    if(IsCrc16Good(ppp, 13))
    {
        c=c;
    }


}