/*
* RC4
* (C) 1999-2008 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#ifndef BOTAN_RC4_H__
#define BOTAN_RC4_H__

#include <botan/stream_cipher.h>
#include <botan/types.h>

namespace Botan {

/**
* RC4 stream cipher
*/
class BOTAN_DLL RC4 : public StreamCipher
   {
   public:
      void cipher(const byte in[], byte out[], size_t length);

      void clear();
      std::string name() const;

      StreamCipher* clone() const { return new RC4(SKIP); }

      Key_Length_Specification key_spec() const
         {
         return Key_Length_Specification(1, 256);
         }

      /**
      * @param skip skip this many initial bytes in the keystream
      */
      RC4(size_t skip = 0);

      ~RC4() { clear(); }
   private:
      void key_schedule(const byte[], size_t);
      void generate();

      const size_t SKIP;

      byte X, Y;
      secure_vector<byte> state;

      secure_vector<byte> buffer;
      size_t position;
   };

}

#endif