xtunnelscvsdes.h

xtunnel nat/fw traversal source code

/*

	File:		XTunnelsCVsDES.h

	Contains:   DES routines 

	Copyright:  (c) 2003 by Xten Networks, Inc., all rights reserved.

*/

#ifndef CVSDES_H__29AB99C3_80C0_475e_80BB_19AC81E50D44_
#define CVSDES_H__29AB99C3_80C0_475e_80BB_19AC81E50D44_

#ifdef __MWERKS__
#pragma once
#endif // __MWERKS__

#include <iostream>
#include <strstream>

struct STDESPrivateData;

class CVsDES
{
public:
   enum DESMode
   {
      DES = 1,
      DES2 = 2,
      TripleDES = 3
   };

   enum DESLength
   {
      SingleLength = 1,
      DoubleLength = 2,
      TripleLength = 3
   };

public:
   CVsDES()          {Init();}
   virtual ~CVsDES() {Destroy();}

   unsigned long GetBlockSize()  {return sizeof(unsigned long);}

   void OpenRead(                         // for decrypting
      const char * szKey,
      std::istrstream *ipInputStream,
      DESMode eMode = TripleDES,          // default maximum encryption
      DESLength eLength = TripleLength    // default maximum length blocks
   );

   void OpenWrite(                        // for encrypting
      const char * szKey,
      std::ostrstream *ipOuputStream,
      DESMode eMode = TripleDES,
      DESLength eLength = TripleLength    // default maximum length blocks
   );

   virtual bool Read( 
      char  *pbyBuffer,
      unsigned long  dwBytesToRead,
      unsigned long *pBytesRead = NULL
   );

   virtual bool Write(
      const char *pBuffer,
      unsigned long dwBufferLength,
      unsigned long *pBytesWritten = NULL
   );

   // WARNING: The last write before a close will be padded with zeros and aligned to the
   // nearest 8, 16 or 32 bits depending on the encryption scheme choosen (SingleLength,
   // DoubleLength, TripleLength). These zeros will be part of the output stream, and
   // nothing can be done about it. When you read back the decrypted stream, you will see
   // these padded zeros at the end of the stream read block.
   virtual void Close(unsigned long *pBytesWritten = NULL);

private:
   void Init();
   void Destroy();

private:
   STDESPrivateData *m_pData;
	std::istrstream *m_iStream;
	std::ostrstream *m_oStream;
   bool m_bReadMode;
};

#endif //CVSDES_H__29AB99C3_80C0_475e_80BB_19AC81E50D44_