/*********************************************************************

* Filename: des.h

* Author: Brad Conte (brad AT bradconte.com)

* Copyright:

* Disclaimer: This code is presented "as is" without any guarantees.

* Details: Defines the API for the corresponding DES implementation.

Note that encryption and decryption are defined by how

the key setup is performed, the actual en/de-cryption is

performed by the same function.

*********************************************************************/

#ifndef DES_H

#define DESH

/*************************** HEADER FILES ***************************/

#include <stddef.h>

/****************************** MACROS ******************************/

#define DES_BLOCK_SIZE 8 // DES operates on 8 bytes at a time

/**************************** DATA TYPES ****************************/

typedef unsigned char BYTE; // 8-bit byte

typedef unsigned int WORD; // 32-bit word, change to "long" for 16-bit machines

typedef enum {

DES_ENCRYPT,

DES_DECRYPT

} DES_MODE;

/*********************** FUNCTION DECLARATIONS **********************/

void des_key_setup(const BYTE key[], BYTE schedule[][6], DES_MODE mode);

void des_crypt(const BYTE in[], BYTE out[], const BYTE key[][6]);

void three_des_key_setup(const BYTE key[], BYTE schedule[][16][6], DES_MODE mode);

void three_des_crypt(const BYTE in[], BYTE out[], const BYTE key[][16][6]);

#endif // DES_H