/*
  Copyright (c) 2006-2009 by Jakob Schroeter <js@camaya.net>
  This file is part of the gloox library. http://camaya.net/gloox

  This software is distributed under a license. The full license
  agreement can be found in the file LICENSE in this distribution.
  This software may not be copied, modified, sold or distributed
  other than expressed in the named license agreement.

  This software is distributed without any warranty.
*/

/*
  Copyright (C) 1999, 2002 Aladdin Enterprises.  All rights reserved.

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.

  L. Peter Deutsch
  ghost@aladdin.com

 */
/* $Id: md5.h,v 1.4 2002/04/13 19:20:28 lpd Exp $ */
/*
  Independent implementation of MD5 (RFC 1321).

  This code implements the MD5 Algorithm defined in RFC 1321, whose
  text is available at
        http://www.ietf.org/rfc/rfc1321.txt
  The code is derived from the text of the RFC, including the test suite
  (section A.5) but excluding the rest of Appendix A.  It does not include
  any code or documentation that is identified in the RFC as being
  copyrighted.

  The original and principal author of md5.h is L. Peter Deutsch
  <ghost@aladdin.com>.  Other authors are noted in the change history
  that follows (in reverse chronological order):

  2002-04-13 lpd Removed support for non-ANSI compilers; removed
        references to Ghostscript; clarified derivation from RFC 1321;
        now handles byte order either statically or dynamically.
  1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
  1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5);
        added conditionalization for C++ compilation from Martin
        Purschke <purschke@bnl.gov>.
  1999-05-03 lpd Original version.
 */

#ifndef MD4_H__
#define MD4_H__

#include "macros.h"

#include <string>

namespace gloox
{

  /**
   * @brief An MD4 implementation.
   *
   * This is an implementation of the Message Digest Algorithm as decribed in RFC 1320.
   * The original code has been taken from an MD5 implementation by L. Peter Deutsch.
   *
   * @author Jakob Schroeter <js@camaya.net>
   * @since 1.1
   */
  class GLOOX_API MD4
  {
    public:
      /**
       * Static function that returns a hash of the given data.
       * @param data Input data to hash.
       * @return The data's hash in hex notation.
       */
      static const std::string md4( const std::string& data );

      /**
       * Constructs a new MD4 object.
       */
      MD4();

      /**
       * Virtual Destructor.
       */
      virtual ~MD4();

      /**
       * Use this function to feed the hash.
       * @param data The data to hash.
       * @param bytes The size of @c data in bytes.
       */
      void feed( const unsigned char* data, int bytes );

      /**
       * Use this function to feed the hash.
       * @param data The data to hash.
       */
      void feed( const std::string& data );

      /**
       * This function is used to finalize the hash operation. Use it after the last feed() and
       * before calling hex().
       */
      void finalize();

      /**
       * Use this function to retrieve the hash value in hex.
       * @return The hash in hex notation.
       */
      const std::string hex();

      /**
       * Use this function to retrieve the raw binary hash.
       * @return The raw binary hash.
       */
      const std::string binary();

      /**
       * Use this function to reset the hash.
       */
      void reset();

    private:
      struct MD4State
      {
          unsigned int count[2]; /* message length in bits, lsw first */
          unsigned int abcd[4]; /* digest buffer */
          unsigned char buf[64]; /* accumulate block */
      } m_state;

      void init();
      void process( const unsigned char* data );

      static const unsigned char pad[64];

      bool m_finished;

  };

}

#endif // MD4_H__
