arc4.h

Go to the documentation of this file.

/*
* ARC4
* (C) 1999-2008 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
 
#ifndef BOTAN_ARC4_H__
#define BOTAN_ARC4_H__
 
#include <botan/stream_cipher.h>
#include <botan/types.h>
 
namespace Botan {
 
/**
* Alleged RC4
*/
class BOTAN_DLL ARC4 : public StreamCipher
   {
   public:
      void cipher(const byte in[], byte out[], size_t length);
 
      void clear();
      std::string name() const;
 
      StreamCipher* clone() const { return new ARC4(SKIP); }
 
      Key_Length_Specification key_spec() const
         {
         return Key_Length_Specification(1, 256);
         }
 
      /**
      * @param skip skip this many initial bytes in the keystream
      */
      ARC4(size_t skip = 0);
 
      ~ARC4() { clear(); }
   private:
      void key_schedule(const byte[], size_t);
      void generate();
 
      const size_t SKIP;
 
      byte X, Y;
      SecureVector<byte> state;
 
      SecureVector<byte> buffer;
      size_t position;
   };
 
}
 
#endif