text: // 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
  