des.h

实现DES的加密解密,有MFC界面,语言为C

// DES.h: interface for the CDES class.
//
//////////////////////////////////////////////////////////////////////

#ifndef _DES_H_
#define _DES_H_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class CDES  
{
public:
	CDES();

	virtual ~CDES();

	int encrypt(unsigned char key[8], unsigned char* data, int blocks = 1); 
	int decrypt(unsigned char key[8], unsigned char* data, int blocks = 1); 

	int yencrypt(unsigned char key[8], unsigned char* data, int size); 
	int ydecrypt(unsigned char key[8], unsigned char* in, int blocks, int* size = 0); 
	int extend(int size) { return (size/8+1)*8; }; 

	enum Mode { ENCRYPT, DECRYPT };

private: 
	void des(unsigned char* in, unsigned char* out, int blocks); 
	void des_block(unsigned char* in, unsigned char* out); 

	void deskey(unsigned char key[8], Mode md); 
	void usekey(unsigned long *); 
	void cookey(unsigned long *); 

	void scrunch(unsigned char *, unsigned long *); 
	void unscrun(unsigned long *, unsigned char *); 
	void desfunc(unsigned long *, unsigned long *); 

private: 
    unsigned long         KnL[32];

	static unsigned char  Df_Key[24]; 
	static unsigned short bytebit[8]; 
	static unsigned long  bigbyte[24]; 
	static unsigned char  pc1[56]; 
	static unsigned char  totrot[16]; 
	static unsigned char  pc2[48]; 
	static unsigned long  SP1[64]; 
	static unsigned long  SP2[64]; 
	static unsigned long  SP3[64]; 
	static unsigned long  SP4[64]; 
	static unsigned long  SP5[64]; 
	static unsigned long  SP6[64]; 
	static unsigned long  SP7[64]; 
	static unsigned long  SP8[64]; 
};

#endif //#ifndef _DES_H_