cryptoencryptiondlg.cpp

一种使用动态公匙加密方式的加密算法

// CryptoEncryptionDlg.cpp : implementation file
//

#include "stdafx.h"
#include "CryptoEncryption.h"
#include "CryptoEncryptionDlg.h"
#include "key.h"

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

const char KEY_FILE[255] = "C:\\key.txt";

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CCryptoEncryptionDlg dialog

CCryptoEncryptionDlg::CCryptoEncryptionDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CCryptoEncryptionDlg::IDD, pParent)
{
	dwResult= 0;
	hProv = 0;
	hKey = 0;
	hSessionKey = 0;
	cbBlob = 0;
	pbBlob = NULL;

	
	cbBlob = file_length(KEY_FILE);
	pbBlob = (BYTE*)malloc(cbBlob + 1);
	memset(pbBlob, 0, cbBlob + 1); 

	FILE *fp = fopen(KEY_FILE, "rb");
	if (fp) {
		fread(pbBlob, 1, cbBlob, fp);
		fclose(fp);
	} else {
		free(pbBlob);
		pbBlob = NULL;
	}

	if (!CryptAcquireContext(&hProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, 0))
	{
		dwResult = GetLastError();
		if (dwResult == NTE_BAD_KEYSET)
		{
			if (!CryptAcquireContext(&hProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_NEWKEYSET))
			{
				dwResult = GetLastError();
				MessageBox("Error [0x%x]: CryptAcquireContext() failed.", "Information", MB_OK);
				return;
			}
		} else {
			dwResult = GetLastError();
			return;
		}
	}

	if (pbBlob) {
		if (!CryptImportKey(hProv, pbBlob, cbBlob, 0, 0, &hSessionKey))
		{
			dwResult = GetLastError();
			MessageBox("Error [0x%x]: CryptImportKey() failed.", "Information", MB_OK);
			return;
		}
	} else { 
		if (!CryptImportKey(hProv, PrivateKeyWithExponentOfOne, sizeof(PrivateKeyWithExponentOfOne), 0, 0, &hKey))
		{
			dwResult = GetLastError();
			MessageBox("Error CryptImportKey() failed.", "Information", MB_OK);
			return;
		}

		if (!CryptGenKey(hProv, CALG_RC4, CRYPT_EXPORTABLE, &hSessionKey))
		{
			dwResult = GetLastError();
			MessageBox("Error CryptGenKey() failed.", "Information", MB_OK);
			return;
		}	
	}


	//{{AFX_DATA_INIT(CCryptoEncryptionDlg)
	m_cipher = _T("");
	m_clear = _T("Encrypt me");
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CCryptoEncryptionDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CCryptoEncryptionDlg)
	DDX_Text(pDX, IDC_EDIT_CIPHER, m_cipher);
	DDX_Text(pDX, IDC_EDIT_CLEAR, m_clear);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CCryptoEncryptionDlg, CDialog)
	//{{AFX_MSG_MAP(CCryptoEncryptionDlg)
	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()

/////////////////////////////////////////////////////////////////////////////
// CCryptoEncryptionDlg message handlers

BOOL CCryptoEncryptionDlg::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
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CCryptoEncryptionDlg::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 CCryptoEncryptionDlg::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 CCryptoEncryptionDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CCryptoEncryptionDlg::OnButtonEncrypt() 
{
	UpdateData();

	unsigned long length = m_clear.GetLength() +1;
	unsigned char * cipherBlock = (unsigned char*)malloc(length);
	memset(cipherBlock, 0, length);
	memcpy(cipherBlock, m_clear, length -1);	

	if (!CryptEncrypt(hSessionKey, 0, TRUE, 0, cipherBlock, &length, length))
	{
		dwResult = GetLastError();
		MessageBox("Error CryptEncrypt() failed.", "Information", MB_OK);
		return;
	}

	m_cipher = cipherBlock;
	m_clear = "";

	free(cipherBlock);

	UpdateData(FALSE);
}

void CCryptoEncryptionDlg::OnButtonDecrypt() 
{
	UpdateData();

	unsigned long length = m_cipher.GetLength() +1;
	unsigned char * cipherBlock = (unsigned char*)malloc(length);
	memset(cipherBlock, 0, length);
	memcpy(cipherBlock, m_cipher, length -1);	

	if (!CryptDecrypt(hSessionKey, 0, TRUE, 0, cipherBlock, &length))
	{
		dwResult = GetLastError();
		MessageBox("Error CryptDecrypt() failed.", "Information", MB_OK);
		return;
	}
	
	m_clear = cipherBlock;
	m_cipher = "";

	free(cipherBlock);

	UpdateData(FALSE);
}