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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