// Rename this file DES.H
// DES Encryption and Decryption
// from efgh.com/software

const int DES_KEY_SIZE      =  56;
const int DES_DATA_SIZE     =  64;
const int DES_SBUFFER_SIZE  =  48;
const int DES_ROUNDS =  16;

#ifdef TRIPLEDES
  class triple_des;
#endif

class des
{
  private:
    const char *xmix(const char *, unsigned char [DES_DATA_SIZE],
      const unsigned char [DES_KEY_SIZE]);
    void encrypt_decrypt(unsigned char [DES_DATA_SIZE], int /* boolean */);
    unsigned char compressed_shifted_key[DES_ROUNDS][DES_SBUFFER_SIZE];
  public:
    void initialize(const unsigned char[DES_KEY_SIZE]);
    void password(const char *);
    void encrypt(unsigned char data[DES_DATA_SIZE])
    {
      encrypt_decrypt(data, 1 /* true */);
    }
    void decrypt(unsigned char data[DES_DATA_SIZE])
    {
      encrypt_decrypt(data, 0 /* false */);
    }
    friend triple_des;
};

#ifdef TRIPLEDES

class triple_des
{
  private:
    des part[3];
    void encrypt_decrypt(unsigned char [DES_DATA_SIZE], int /* boolean */);
  public:
    void initialize(const unsigned char key[3*DES_KEY_SIZE])
    {
      part[0].initialize(key);
      part[1].initialize(key + DES_KEY_SIZE);
      part[2].initialize(key + 2*DES_KEY_SIZE);
    }
    void password(const char *);
    void encrypt(unsigned char data[DES_DATA_SIZE])
    {
      part[0].encrypt(data);
      part[1].decrypt(data);
      part[2].encrypt(data);
    }
    void decrypt(unsigned char data[DES_DATA_SIZE])
    {
      part[2].decrypt(data);
      part[1].encrypt(data);
      part[0].decrypt(data);
    }
};

#endif