/*++

   Copyright    (c)    1994-2002    Microsoft Corporation

   Module  Name :
        strpass.h

   Abstract:
        Message Functions Definitions

   Author:
        Aaron Lee (aaronl)

   Project:
        Internet Services Manager

   Revision History:

--*/

#ifndef _STRPASS_H_
#define _STRPASS_H_


// ----------------------------------------
// This class was created to allow a class to
// keep passwords in it's member variables.
//
// In the event that the process get's paged out to
// the swapfile, any user will be able to read the 
// swapfile.  if the member variables contained 
// passwords, they wil be there in clear text.
//
// Usage1 -- with LPTSTR:
//   CStrPassword m_strPassword;
//   // assign a password into member variable
//   m_strPassword = _T("MyPassword");
//   // get a password out
//   LPTSTR lpPassword = m_strPassword.GetClearTextPassword();
//   // use it...
//   FunctionToUsePassword(lpPassword);
//   // erase it -- this will erase memory where cleartext password was stored
//   m_strPassword.DestroyClearTextPassword();
//
// Usage2 -- with CString:
//   CStrPassword m_strPassword(_T("MyPassword"));
//   // get a password out into CString
//   CString csPassword;
//   m_strPassword.CopyTo(csPassword);
//   // use it...
//   FunctionToUsePassword(csPassword);
//   // erase it by overwritting
//   csPassword = _T("        ");
//   csPassword.Empty();
//
// DO NOT DO THIS -- this will allocate a cleartext password and it will never be Freed!
//   FunctionToUsePassword( (LPTSTR) m_strPassword.GetClearTextPassword());
// 
// ----------------------------------------
#ifdef _COMEXPORT
    class COMDLL CStrPassword
#elif defined(_DLLEXP)
    class _EXPORT CStrPassword
#else
    class CStrPassword
#endif
{
public:

    // constructor/destructor
	CStrPassword();
	~CStrPassword();

    // copy constructors
    CStrPassword(LPTSTR lpsz);
    CStrPassword(LPCTSTR lpsz);
    CStrPassword(CStrPassword& csPassword);

	// get character count
	int GetLength() const;
    // get byte count
    int GetByteLength() const;
	// TRUE if zero length
	BOOL IsEmpty() const;
	// clear contents to empty
	void Empty();

	// straight character comparison
	int Compare(LPCTSTR lpsz) const;
    int Compare(CString& lpsz) const;
    int Compare(CStrPassword& lpsz) const;

	// copy string content from UNICODE string (converts to TCHAR)
	const CStrPassword& operator=(LPCTSTR lpsz);
    const CStrPassword& operator=(CStrPassword& lpStrPass);

    // copy to...
    void CopyTo(CString& stringSrc);
    void CopyTo(CStrPassword& stringSrc);

    // Get Data out from it (unencrypted)
    // Each call to GetClearTextPassword() should have an equal
    // DestroyClearTextPassword() call to it.
    LPTSTR GetClearTextPassword();
    void DestroyClearTextPassword(LPTSTR lpClearTextPassword) const;

    // not implemented
    operator TCHAR*();

    // returns CString
    operator CString();

    bool operator== (CStrPassword& csCompareToMe);

    bool operator!= (CStrPassword& csCompareToMe)
    {
        return !(operator==(csCompareToMe));
    }
   
private:
    void ClearPasswordBuffers(void);

protected:
    LPTSTR m_pszDataEncrypted;
    DWORD  m_cbDataEncrypted;
};

#endif