// gost.h - originally written and placed in the public domain by Wei Dai

/// \file gost.h

/// \brief Classes for the GIST block cipher

#ifndef CRYPTOPP_GOST_H

#define CRYPTOPP_GOST_H

#include "seckey.h"

#include "secblock.h"

NAMESPACE_BEGIN(CryptoPP)

/// \brief GOST block cipher information

/// \since Crypto++ 2.1

struct GOST_Info : public FixedBlockSize<8>, public FixedKeyLength<32>

{

  CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() {return "GOST";}

};

/// \brief GOST block cipher

/// \sa <a href="http://www.cryptopp.com/wiki/GOST">GOST</a>

/// \since Crypto++ 2.1

class GOST : public GOST_Info, public BlockCipherDocumentation

{

  /// \brief GOST block cipher default operation

  class CRYPTOPP_NO_VTABLE Base : public BlockCipherImpl<GOST_Info>

  {

  public:

    void UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &params);

  protected:

    static void PrecalculateSTable();

    static const byte sBox[8][16];

    static volatile bool sTableCalculated;

    static word32 sTable[4][256];

    FixedSizeSecBlock<word32, 8> m_key;

  };

  /// \brief GOST block cipher encryption operation

  class CRYPTOPP_NO_VTABLE Enc : public Base

  {

  public:

    void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;

  };

  /// \brief GOST block cipher decryption operation

  class CRYPTOPP_NO_VTABLE Dec : public Base

  {

  public:

    void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;

  };

public:

  typedef BlockCipherFinal<ENCRYPTION, Enc> Encryption;

  typedef BlockCipherFinal<DECRYPTION, Dec> Decryption;

};

typedef GOST::Encryption GOSTEncryption;

typedef GOST::Decryption GOSTDecryption;

NAMESPACE_END

#endif