/*

* 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 RC4 final : public StreamCipher

   {

   public:

      void cipher(const uint8_t in[], uint8_t out[], size_t length) override;

      void set_iv(const uint8_t iv[], size_t iv_len) override;

      void clear() override;

      std::string name() const override;

      StreamCipher* clone() const override;

      Key_Length_Specification key_spec() const override;

      /**

      * @param skip skip this many initial bytes in the keystream

      */

      explicit RC4(size_t skip = 0);

      ~RC4() { clear(); }

      void seek(uint64_t offset) override;

   private:

      void key_schedule(const uint8_t[], size_t) override;

      void generate();

      const size_t m_SKIP;

      uint8_t m_X = 0;

      uint8_t m_Y = 0;

      secure_vector<uint8_t> m_state;

      secure_vector<uint8_t> m_buffer;

      size_t m_position = 0;

   };

}

#endif