DES算法介绍

DES算法,头文件


自己改写过，请指教
#ifndef __DES_H
#define __DES_H

class DES
{
public:
// Encrypt/decrypt the data in "data", according to the "key".
// Caller is responsible for confirming the buffer size of "data"
// points to is 8*"blocks" bytes.
// The data encrypted/decrypted is stored in data.
// The return code is 1:success, other:failed.
int encrypt ( char key[8], char* data, int blocks = 1 );
int decrypt ( char key[8], char* data, int blocks = 1 );

// Encrypt/decrypt any size data,according to a special method.
// Before calling yencrypt, copy data to a new buffer with size
// calculated by extend.
int yencrypt ( char key[8], char* data, int size );
int ydecrypt ( char key[8], char* in, int blocks, int* size = 0 );

int extend ( int size ) { return (size/8+1)*8; };

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

private:
unsigned long KnL[32];
enum Mode { ENCRYPT, DECRYPT };
void deskey(unsigned char key[8], Mode md);
void usekey(unsigned long *);
void cookey(unsigned long *);

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

private:
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


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