vernamdlg.cpp

包涵了密码学教程里面的大部分加密算法

// VernamDlg.cpp : implementation file
//

#include "stdafx.h"
#include "Crypt.h"
#include "VernamDlg.h"
#include <stdio.h>
#include <math.h>
#include <stdlib.h>

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

/////////////////////////////////////////////////////////////////////////////
// CVernamDlg dialog


CVernamDlg::CVernamDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CVernamDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CVernamDlg)
	m_strBCipher = _T("");
	m_strBKey = _T("");
	m_strBPlainText = _T("");
	m_strCipher = _T("");
	m_strKey = _T("");
	m_strPlainText = _T("");
	m_strToPlainText = _T("");
	//}}AFX_DATA_INIT
}


void CVernamDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CVernamDlg)
	DDX_Text(pDX, IDC_BCipher, m_strBCipher);
	DDX_Text(pDX, IDC_BKey, m_strBKey);
	DDX_Text(pDX, IDC_BPlainText, m_strBPlainText);
	DDX_Text(pDX, IDC_Cipher, m_strCipher);
	DDX_Text(pDX, IDC_Key, m_strKey);
	DDX_Text(pDX, IDC_PlainText, m_strPlainText);
	DDX_Text(pDX, IDC_ToPlainText, m_strToPlainText);
	//}}AFX_DATA_MAP
}


BEGIN_MESSAGE_MAP(CVernamDlg, CDialog)
	//{{AFX_MSG_MAP(CVernamDlg)
	ON_BN_CLICKED(IDC_Encrypt, OnVernamEncrypt)
	ON_BN_CLICKED(IDC_Decrypt, OnVernamDecrypt)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CVernamDlg message handlers

BOOL CVernamDlg::pick(char ch, int n)
{
	//return(( ch & char(1)<<(8-n) )!=0);
	return (ch & char(1)<<(8-n));
}

/*
	Vernam体制：
		Vernam密码在对明文加密前首先将明文编码为（0，1）字符串。
*/
void CVernamDlg::OnVernamEncrypt() 
{
	// TODO: Add your control notification handler code here
	int i, j, k, milestone;
	int pos;
	int m_iPlainTextLen, m_iKeyLen;
	char m_chPlainText[1000], m_chKey[1000], m_chCipher[1000];
    
	for(i=0; i<1000; i++)
	{
		m_chPlainText[i] = '\0';
		m_chKey[i] = '\0';
		m_chCipher[i] = '\0';
	}

	UpdateData(true);
	
	//首先或得明文和密钥，然后将字符串转换为二进制字符串
	//然后按照加密算法进行运算，或得二进制密文流
	//最后将二进制密文流转换成密文字符串。
    m_iPlainTextLen = m_strPlainText.GetLength();
	for(i=0; i<m_iPlainTextLen; i++)
		m_chPlainText[i] = m_strPlainText.GetAt(i);
	
	//--------------------------------------------------------------------
	//显示明文的二进制表示
    char* m_pBPlainText = new char[m_iPlainTextLen*8+m_iPlainTextLen];
	int h = 0;
	for(i=0; i<m_iPlainTextLen; i++)
	{
		for(j=1; j<=8; j++)
		{
			if(pick(m_chPlainText[i], j))
				m_pBPlainText[h++] = '1';
			else
				m_pBPlainText[h++] = '0';
		}
		
		m_pBPlainText[h++] = ' ';
	}
    m_pBPlainText[h] = '\0';
	m_strBPlainText.Format("%s", m_pBPlainText);
	//--------------------------------------------------------------------

    //-------------------------------------------------------------------
	//显示密钥的二进制表示
	m_iKeyLen = m_strKey.GetLength();
	for(i=0; i<m_iKeyLen; i++)
		m_chKey[i] = m_strKey.GetAt(i);
	char* m_pBKey = new char[m_iKeyLen*8+m_iKeyLen];
	h = 0;
	for(i=0; i<m_iKeyLen; i++)
	{
		for(j=1; j<=8; j++)
		{
			if(pick(m_chKey[i], j))
				m_pBKey[h++] = '1';
			else
				m_pBKey[h++] = '0';
		}

		m_pBKey[h++] = ' ';
	}
	m_pBKey[h++] = '\0';
	m_strBKey.Format("%s", m_pBKey);
    //--------------------------------------------------------------------

	//建立密文空间，用来存放二进制密文
	char* m_pBCipher = new char[m_iPlainTextLen*8+m_iPlainTextLen];
	//char* m_pBCipher = new char[m_iPlainTextLen*8];
	pos = 0;
	//如果明文没有密钥长
	if(m_iPlainTextLen <= m_iKeyLen)
	{
		for(i=0; i<m_iPlainTextLen; i++)
		{
			for(j=1; j<=8; j++)
			{
				if(pick(m_chPlainText[i],j) ^ pick(m_chKey[i],j))
					m_pBCipher[pos++] = '1';
				else
					m_pBCipher[pos++] = '0';
			}

			m_pBCipher[pos++] = ' ';
		}
	}
	//明文长度大于密钥长度
    else
	{
		int quotient = m_iPlainTextLen / m_iKeyLen;
		int compliment = m_iPlainTextLen % m_iKeyLen;
		for(i=0; i<quotient; i++)
		{
			for(j=0; j<m_iKeyLen; j++)
			{
				for(k=1; k<=8; k++)
				{
					if(pick(m_chPlainText[i*m_iKeyLen+j],k) ^ pick(m_chKey[j], k))
						m_pBCipher[pos++] = '1';
					else
						m_pBCipher[pos++] = '0';
				}

				m_pBCipher[pos++] = ' ';
			}
		}
        
		milestone = quotient * m_iKeyLen;
		for(i=0; i<compliment; i++)
		{
			for(j=1; j<=8; j++)
			{
				if(pick(m_chPlainText[milestone+i], j) ^ pick(m_chKey[i], j))
					m_pBCipher[pos++] = '1';
				else
					m_pBCipher[pos++] = '0';
			}

			m_pBCipher[pos++] = ' ';
		}
	}

	m_pBKey[pos++] = '\0';
	m_strBCipher.Format("%s", m_pBCipher);
	
	//将二进制密文转换为ASCII字符串
	char* m_pCipher = new char[m_iPlainTextLen];
	//AfxMessageBox(m_pBCipher);
	
	if(BinToString(m_pBCipher, m_pCipher))
	{
		m_pCipher[m_iPlainTextLen] = '\0';
		m_strCipher.Format("%s", m_pCipher);
		//AfxMessageBox(m_pCipher);
	}
	
	UpdateData(false);
}


//将二进制字符串数组转换为字符串
bool CVernamDlg::BinToString(char *scStr, char *dsStr)
{
	char ch = '\0';

	if(scStr == NULL || strlen(scStr)==0)
		return false;

	while(strlen(scStr) >= 8)
	{
		if(!BinToChar(scStr, ch))
			return false;
		*dsStr = *dsStr + ch;
		scStr += 8;
	}
   
	return true;
}

//将八位二进制数据转换为字符
bool CVernamDlg::BinToChar(char scStr[], char dsCh)
{
	int i;
	char ch = '\0';

	if(scStr == NULL)
		return false;

	for(i=0; i<8; i++)
	{
		if(scStr[i] != '0' && scStr[i] != '1')
			return false;
		ch = scStr[i] - 48;
		ch = ch << (8-i-1);
		dsCh |= ch;
	}

	return true;
}

/*
	通过明文的二进制表示恢复明文
*/
void CVernamDlg::OnVernamDecrypt() 
{
	// TODO: Add your control notification handler code here
	int i;
	int m_iBPlainTextLen, pos;
	char m_Bch;
	char m_chArr[8];
	char m_chBPlainText[1000], m_chPlainText[1000];

	for(i=0; i<1000; i++)
	{
		m_chBPlainText[i] = '\0';
		m_chPlainText[i] = '\0';
	}

	UpdateData(true);
	
	m_iBPlainTextLen = m_strBPlainText.GetLength();

	for(i=0; i<m_iBPlainTextLen; i++)
	{
		m_Bch = m_strBPlainText.GetAt(i);
		m_chBPlainText[i] = m_Bch;
	}

	//将二进制明文转换为字符串
    pos = m_iBPlainTextLen;
	int position = 0;
	int num = 0;
	while(pos > 0)
	{		
		for(i=position; i<position+8; i++)
			m_chArr[i-position] = m_chBPlainText[i];

		for(i=0; i<8; i++)
		{
			if(m_chArr[i] == '1')
				m_chPlainText[num] += (int)pow(2, 7-i);
		}

		num ++;
		position += 9;
		pos -= 9;
	}

	m_strToPlainText.Format("%s", m_chPlainText);
	UpdateData(false);
}