desdlg.cpp

用VC做的数据加密标准DES算法可视化实现.简单易懂,有密码学和C或C++基础即可理解

	   { 
         m=(m+1)%4; 
         if(!m) j++; 
	   } 
	} 
} 

/********非常重要的成员函数：16轮变换的详细过程*********/
void CDESDlg::Encrypt_16(void){ 

int i=1; 
DWORDLONG L[17],R[17],B[9],EK,PSB; 
L[0]=m_dwlData>>32;	//右移32位将m_dwlData各二进制位右移32位,移到右端的低位舍去,高位补0.
R[0]=m_dwlData&0xffffffff;//m_dwlData与0xffffffff按位与运算可使得高32位置为0(即高32位被清零)
/* 所以64位的中间数据m_dwlData左右两部分分为独立的32位数据,但L[0]与R[0]仍是DWORDLONG类型64位,只是其高32位被置为0罢了*/

//以下循环为：16轮变换的详细过程
for(i=1;i<=16;i++){ 
	L[i]=R[i-1]; 
	R[i-1]=Permutation(R[i-1],dwlData_Expansion,48); //Expansion R 
	EK=R[i-1]^m_dwl_K[i]; //扩展后的48位R[i-1]与该轮密钥m_dwl_K[i]异或 
	PSB=Generate_B(EK,B); //代换函数F(R,k)中S盒的作用及置换函数P产生32位输出赋给PSB
	R[i]=L[i-1]^PSB; 
	} 
//32位互换
R[16]<<=32; 
m_dwlData=R[16]|L[16]; 
m_dwlData=Permutation(m_dwlData,dwlData_FP,64); //Inverse Initial Permutation IP-1
} 

//进入S盒时的作用函数
DWORDLONG CDESDlg::Generate_B(DWORDLONG EKPara,DWORDLONG *block){ 

int i,m,n; 
DWORDLONG tmp=0; 

for(i=8;i>0;i--){ 
block[i]=EKPara&0x3f; 
m=(int)(block[i]&0x20)>>4; 
m|=block[i]&0x01; 
n=(int)(block[i]<<1)>>2; 
block[i]=Des_S[i][m][n]; 
EKPara>>=6; 
} 

for(i=1;i<=8;i++){ 
tmp|=block[i]; 
tmp<<=4; 
} 
tmp>>=4; 
tmp=Permutation(tmp,dwlData_P,32); //P Permutation

return tmp; 
}


/**********加密函数*********/
unsigned char * CDESDlg::EncryptData(unsigned char *block){ 

	unsigned char *EncrytedData=new unsigned char(15);


	m_dwlData=Char_to_Byte(block,0); 	 
	m_dwlData=Permutation(m_dwlData,dwlData_IP,64); //Initial Permutation IP
	Encrypt_16();  //16轮变换的详细过程
/*加密后m_dwlData转化为字符串输出*/
	DWORDLONG bit8=m_dwlData; 
	for(int i=0;i<8;i++){ 
		EncrytedData[7-i]=(unsigned char)(bit8&0xff);
		bit8>>=8; 
		} 
	EncrytedData[8]='\0'; 
	return EncrytedData; 
} 

/**************解密函数***********/
unsigned char* CDESDlg::DecryptData(unsigned char *desData){ 

	int i=1; 
	unsigned char *DescryptedData=new unsigned char(15); 
	DWORDLONG L[17],R[17],B[9],EK,PSB; 
	DWORDLONG dataPara; 

	dataPara=Char_to_Byte(desData,0); 
	dataPara=Permutation(dataPara,dwlData_IP,64); 

	R[16]=dataPara>>32; 
	L[16]=dataPara&0xffffffff; 

    for(i=16;i>=1;i--){ 
		R[i-1]=L[i]; 
		L[i]=Permutation(L[i],dwlData_Expansion,48);  
		EK=L[i]^m_dwl_K[i];  
		PSB=Generate_B(EK,B); 
		L[i-1]=R[i]^PSB; 
		} 

	L[0]<<=32; 
	dataPara=L[0]|R[0]; 
	dataPara=Permutation(dataPara,dwlData_FP,64);  

    for(i=0;i<8;i++){ 
		DescryptedData[7-i]=(unsigned char)(dataPara&0xff); 
		dataPara>>=8; 
		} 
	DescryptedData[8]='\0'; 
	 

	return DescryptedData; 
} 



void CDESDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	
	//{{AFX_DATA_MAP(CDESDlg)
	DDX_Text(pDX, IDC_EDIT_DATA, m_strData);
	DDV_MaxChars(pDX, m_strData, 8);
	DDX_Text(pDX, IDC_EDIT_KEY, m_strKey);
	DDV_MaxChars(pDX, m_strKey, 8);
	DDX_Text(pDX, IDC_EDIT_OUTPUT, m_strOutput);
	DDV_MaxChars(pDX, m_strOutput, 8);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CDESDlg, CDialog)
	//{{AFX_MSG_MAP(CDESDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BUTTON_ENCRYPT, OnButtonEncrypt)
	ON_BN_CLICKED(IDC_BUTTON_DECRYPT, OnButtonDecrypt)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CDESDlg message handlers

BOOL CDESDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	CStatic*pWnd=(CStatic*)GetDlgItem(IDC_STATIC_OUTPUT);
	CString str1;
	str1="\n     姓名：林乃臻\n";
	str1=str1+"     学号：20042205041\n";
	
	pWnd->SetWindowText(str1);
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CDESDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CDESDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CDESDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

BOOL CDESDlg::IsValidate()
{
	UpdateData();
	m_strKey.TrimLeft();
    
	if(m_strKey.IsEmpty()||strlen(m_strKey)<8){
		MessageBox("密钥输入无效！"); return FALSE;
	}
			
	m_strData.TrimLeft();
	if(m_strData.IsEmpty()){
		MessageBox("明文/密文输入无效！"); return FALSE;
	}
	return TRUE;

}

void CDESDlg::OnButtonEncrypt() 
{
	if(!IsValidate()) return;
	UpdateData();
	CString str;
	char _key[9];
	unsigned char _data[9];
	for(int i=0;i<8;i++)
	{   
		_key[i]=m_strKey[i];
		_data[i]=m_strData[i];
	}
	_key[8]='\0';
	_data[8]='\0';
	EncryptKey(_key);
//	unsigned char *result=EncryptData((unsigned char*)_data);
	m_strOutput=EncryptData((unsigned char*)_data);

	str="密钥："+m_strKey;
	str=str+"\n明文："+m_strData;
	str=str+"\nAfter Encrypted："+m_strOutput;
	CStatic*pWnd=(CStatic*)GetDlgItem(IDC_STATIC_OUTPUT);
	pWnd->SetWindowText(str);
	UpdateData(FALSE);

	
}

void CDESDlg::OnButtonDecrypt() 
{

	if(!IsValidate()) return;
	UpdateData();
	CString str;
	char _key[9];
	unsigned char _data[9];
	for(int i=0;i<8;i++)
	{   
		_key[i]=m_strKey[i];
		_data[i]=m_strData[i];
	}
	_key[8]='\0';
	_data[8]='\0';
	EncryptKey(_key);
	unsigned char *result=DecryptData((unsigned char*)_data);

	m_strOutput=result;
	str="密钥："+m_strKey;
	str=str+"\n密文："+m_strData;
	str=str+"\nAfter Decrypted："+m_strOutput;
	CStatic*pWnd=(CStatic*)GetDlgItem(IDC_STATIC_OUTPUT);
	pWnd->SetWindowText(str);
	UpdateData(FALSE);
}

void CDESDlg::OnOK() 
{


	
	CDialog::OnOK();
}