text: /**
   * \file arc4.h
   *
   * \brief The ARCFOUR stream cipher
   *
   *  Copyright (C) 2006-2010, Brainspark B.V.
   *
   *  This file is part of PolarSSL (http://www.polarssl.org)
   *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
   *
   *  All rights reserved.
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License along
   *  with this program; if not, write to the Free Software Foundation, Inc.,
   *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   */
  
  #ifndef __DMRC_H_INCLUDE__
  #define __DMRC_H_INCLUDE__
  
  #include <string.h>
  
  /**
   * \brief          ARC4 context structure
   */
  typedef struct
  {
      int x;                      /*!< permutation index */
      int y;                      /*!< permutation index */
      unsigned char m[256];       /*!< permutation table */
  }
  arc4_context;
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**
   * \brief          ARC4 key schedule
   *
   * \param ctx      ARC4 context to be initialized
   * \param key      the secret key
   * \param keylen   length of the key
   */
  void arc4_setup( arc4_context *ctx, const unsigned char *key, unsigned int keylen );
  
  /**
   * \brief          ARC4 cipher function
   *
   * \param ctx      ARC4 context
   * \param length   length of the input data
   * \param input    buffer holding the input data
   * \param output   buffer for the output data
   *
   * \return         0 if successful
   */
  int arc4_crypt( arc4_context *ctx, size_t length, const unsigned char *input,
                  unsigned char *output );
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif // __DMRC_H_INCLUDE__
  