vigeneredlg.cpp

包涵了密码学教程里面的大部分加密算法

// VigenereDlg.cpp : implementation file
//

#include "stdafx.h"
#include "Crypt.h"
#include "VigenereDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif


static CString alphabet = "abcdefghijklmnopqrstuvwxyz";
static CString ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

/////////////////////////////////////////////////////////////////////////////
// CVigenereDlg dialog
CVigenereDlg::CVigenereDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CVigenereDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CVigenereDlg)
	m_strCipher = _T("");
	m_strKey = _T("");
	m_strPlainText = _T("");
	//}}AFX_DATA_INIT
}


void CVigenereDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CVigenereDlg)
	DDX_Text(pDX, IDC_Cipher, m_strCipher);
	DDX_Text(pDX, IDC_Key, m_strKey);
	DDX_Text(pDX, IDC_PlainText, m_strPlainText);
	//}}AFX_DATA_MAP
}


BEGIN_MESSAGE_MAP(CVigenereDlg, CDialog)
	//{{AFX_MSG_MAP(CVigenereDlg)
	ON_BN_CLICKED(IDC_Encrypt, OnVigenereEncrypt)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CVigenereDlg message handlers

/*
	Vigenere加密体制：
	  设明文m=m1m2...mn,密钥k=k1k2...kp,则密文为：
	  c=Ek(m)=(mi+ki)mod26
*/
void CVigenereDlg::OnVigenereEncrypt()
{
	// TODO: Add your control notification handler code here
	int  m_iPlainTextLen, m_iKeyLen;
	int  i, j, num1, num2, pos;
	char m_chPlainText[1000], m_chKey[1000], m_chCipher[1000];
	int  m_iPlainText[1000], m_iKey[1000], m_iCipher[1000];
    
	for(i=0; i<1000; i++)
	{
		m_chPlainText[i] = '\0';
		m_chKey[i] = '\0';
		m_chCipher[i] = '\0';
	}
    
	UpdateData(true);
	
	//得到明文，并建立明文整数数组
	m_iPlainTextLen = m_strPlainText.GetLength();
	if(m_iPlainTextLen <= 0)
	{
		AfxMessageBox("No PlainText to encrypt!", MB_ICONSTOP|MB_OK);
		exit(0);
	}
	char* m_pPlainText = new char[m_iPlainTextLen];
	m_pPlainText = m_strPlainText.GetBuffer(0);
	num1 = 0;
	while(num1 < m_iPlainTextLen)
	{
		if(97<=*m_pPlainText && *m_pPlainText<=122)
			pos = alphabet.Find(*m_pPlainText);
		else if(65<=*m_pPlainText && *m_pPlainText<=90)
			pos = ALPHABET.Find(*m_pPlainText);

		m_iPlainText[num1] = pos;
		m_pPlainText ++;
		num1 ++;
	}
	
	//得到密文，并建立密文整数数组
	m_iKeyLen = m_strKey.GetLength();
	if(m_iKeyLen <= 0)
	{
		AfxMessageBox("No Key to use!", MB_ICONSTOP|MB_OK);
		exit(0);
	}
    char* m_pKey = new char[m_iKeyLen];
	m_pKey = m_strKey.GetBuffer(0);
	num2 = 0;
	while(num2 < m_iKeyLen)
	{
		if(65<=*m_pKey && *m_pKey<=90)
			pos = ALPHABET.Find(*m_pKey);
		else if(97<=*m_pKey && *m_pKey<=122)
			pos = alphabet.Find(*m_pKey);

		m_iKey[num2] = pos;
		m_pKey ++;
		num2 ++;
	}
    
	//如果明文没有密钥长
	if(num1 <= num2)
	{
		for(i=0; i<num1; i++)
		{
			m_iCipher[i] = (m_iPlainText[i] + m_iKey[i]) % 26;
			m_chCipher[i] = alphabet.GetAt(m_iCipher[i]);
		}		
	}
	//如果明文比密文长
	else
	{
		int quotient = (int)(num1/num2);
		int compliment = num1 % num2;

		for(i=0; i<quotient; i++)
		{
			for(j=0; j<num2; j++)
			{
				m_iCipher[i*num2+j] = (m_iPlainText[i*num2+j] + m_iKey[j]) % 26;
				m_chCipher[i*num2+j] = alphabet.GetAt(m_iCipher[i*num2+j]);
			}
		}
		
		if(compliment > 0)
		{
			for(i=0; i<compliment; i++)
			{
				m_iCipher[quotient*num2+i] = (m_iPlainText[quotient*num2+i] + m_iKey[i]) % 26;
				m_chCipher[quotient*num2+i] = alphabet.GetAt(m_iCipher[quotient*num2+i]);
			}
		}
	}

	m_strCipher.Format("%s", m_chCipher);
	UpdateData(false);
}