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

/// \file skipjack.h

/// \brief Classes for the SKIPJACK block cipher

/// \details The Crypto++ implementation conforms to SKIPJACK and KEA

///  Algorithm Specifications published by NIST in May 1998. The library passes

///  known answer tests available in NIST SP800-17, Table 6, pp. 140-42.

/// \sa <a href ="http://csrc.nist.gov/encryption/skipjack/skipjack.pdf">SKIPJACK

///  and KEA Algorithm Specifications</a> (May 1998),

///  <a href="http://www.cryptopp.com/wiki/SKIPJACK">SKIPJACK</a> on the

//   Crypto++ wiki

#ifndef CRYPTOPP_SKIPJACK_H

#define CRYPTOPP_SKIPJACK_H

#include "seckey.h"

#include "secblock.h"

NAMESPACE_BEGIN(CryptoPP)

/// \brief SKIPJACK block cipher information

struct SKIPJACK_Info : public FixedBlockSize<8>, public FixedKeyLength<10>

{

  CRYPTOPP_DLL static const char * CRYPTOPP_API StaticAlgorithmName() {return "SKIPJACK";}

};

/// \brief SKIPJACK block cipher

/// \details The Crypto++ implementation conforms to SKIPJACK and KEA

///  Algorithm Specifications published by NIST in May 1998. The library passes

///  known answer tests available in NIST SP800-17, Table 6, pp. 140-42.

/// \sa <a href ="http://csrc.nist.gov/encryption/skipjack/skipjack.pdf">SKIPJACK

///  and KEA Algorithm Specifications</a> (May 1998),

///  <a href="http://www.cryptopp.com/wiki/SKIPJACK">SKIPJACK</a> on the

///  Crypto++ wiki

class SKIPJACK : public SKIPJACK_Info, public BlockCipherDocumentation

{

  /// \brief SKIPJACK block cipher default operation

  class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE Base : public BlockCipherImpl<SKIPJACK_Info>

  {

  public:

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

    unsigned int OptimalDataAlignment() const {return GetAlignmentOf<word16>();}

  protected:

    static const byte fTable[256];

    FixedSizeSecBlock<byte, 10*256> tab;

  };

  /// \brief SKIPJACK block cipher encryption operation

  class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE Enc : public Base

  {

  public:

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

  private:

    static const byte Se[256];

    static const word32 Te[4][256];

  };

  /// \brief SKIPJACK block cipher decryption operation

  class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE Dec : public Base

  {

  public:

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

  private:

    static const byte Sd[256];

    static const word32 Td[4][256];

  };

public:

  typedef BlockCipherFinal<ENCRYPTION, Enc> Encryption;

  typedef BlockCipherFinal<DECRYPTION, Dec> Decryption;

};

typedef SKIPJACK::Encryption SKIPJACKEncryption;

typedef SKIPJACK::Decryption SKIPJACKDecryption;

NAMESPACE_END

#endif