#ifndef DES_H
#define DES_H

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