dodes.h

基于DES加密算法

/////////////////////////////////////////////
// File name:  ENCDEC.H
//	for Class CEncDec 
//	algrithom for DES ( data encryption standard)
//
//	used to encryption and decryption a segment of memory
// Interface:
//		setKey(char *s)
//				-----Set key for encryption or decrption
//		doEncryption(void *p,long size)
//				-----to encryption an area of memory p, length is size
//		doDecryption(void *p,long size)
//				----- see upper

//#include "c:\0\type.h"		//only for test class on console mode
#include "stdafx.h"
#ifndef SINMIN_DES_HEAD_FILE_12343245		// to assume only
#define	SINMIN_DES_HEAD_FILE_12343245		//include once

#define MAXKEYLENGTH	32

enum {	ERR_ALLOCATEMEMORY=1,	// allocte memory error
		ERR_LENGTH,				// encryption length not 8*X
		ERR_UNKNOW				// unknow error
};			

class CDES
{
	BOOL initializeDES(void);		//initialize, allocate memory,calcu tables....
	
	__int64 bitTable[64];	//1,2,4,8,16... only a bit is 1
	char key[8];				//Key
	__int64 subKey[16];		//16 sub-keys, 64bits each, 48bits
							//really used  
	void calculateSubKey(void);
	char *pTable;
	int	 errorNumber;
	
	void runCircle(char *dat, int iTms);
	char cv6to4(int tabNumber,char vu);
	//__int64 getBit(int pos);

	__int64 shuffle(__int64 d,char *p);
	__int64 shuffle32(__int64 d);

	__int64 expand(__int64 x);		//convert 32 bits to 48 bits
	__int64 deflate(__int64 x);	//convert 48bits to 32bits

public:
	//CDES();
	CDES(char *key=NULL);		// constructor
	~CDES();					//destructor

	int setKey(char *s);
	int encryption(void *p,DWORD size);
	int decryption(void *p,DWORD size);

	int getErrorNumber(void);
	char *getErrorDescription(int errNum);
};
		     
#endif