/** 
 * @file llmd5.h
 *
 * $LicenseInfo:firstyear=2001&license=viewergpl$
 * 
 * Copyright (c) 2001-2007, Linden Research, Inc.
 * 
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 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlife.com/developers/opensource/gplv2
 * 
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
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 * By copying, modifying or distributing this software, you acknowledge
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 */

#ifndef LL_LLMD5_H
#define LL_LLMD5_H

// LLMD5.CC - source code for the C++/object oriented translation and 
//          modification of MD5.

// Translation and modification (c) 1995 by Mordechai T. Abzug 

// This translation/ modification is provided "as is," without express or 
// implied warranty of any kind.

// The translator/ modifier does not claim (1) that MD5 will do what you think 
// it does; (2) that this translation/ modification is accurate; or (3) that 
// this software is "merchantible."  (Language for this disclaimer partially 
// copied from the disclaimer below).

/* based on:

   MD5.H - header file for MD5C.C
   MDDRIVER.C - test driver for MD2, MD4 and MD5

   Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
rights reserved.

License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD5 Message-Digest
Algorithm" in all material mentioning or referencing this software
or this function.

License is also granted to make and use derivative works provided
that such works are identified as "derived from the RSA Data
Security, Inc. MD5 Message-Digest Algorithm" in all material
mentioning or referencing the derived work.

RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.

These notices must be retained in any copies of any part of this
documentation and/or software.

*/

// use for the raw digest output
const int MD5RAW_BYTES = 16;

// use for outputting hex digests
const int MD5HEX_STR_SIZE = 33;  // char hex[MD5HEX_STR_SIZE]; with null
const int MD5HEX_STR_BYTES = 32; // message system fixed size

class LLMD5 {
// first, some types:
  typedef unsigned       int uint4; // assumes integer is 4 words long
  typedef unsigned short int uint2; // assumes short integer is 2 words long
  typedef unsigned      char uint1; // assumes char is 1 word long

// how many bytes to grab at a time when checking files
  static const int BLOCK_LEN;

public:
// methods for controlled operation:
  LLMD5              ();  // simple initializer
  void  update     (const uint1 *input, const uint4 input_length);
  void  update     (std::istream& stream);
  void  update     (FILE *file);
  void  finalize   ();

// constructors for special circumstances.  All these constructors finalize
// the MD5 context.
  LLMD5              (const unsigned char *string); // digest string, finalize
  LLMD5              (std::istream& stream);       // digest stream, finalize
  LLMD5              (FILE *file);            // digest file, close, finalize
  LLMD5              (const unsigned char *string, const unsigned int number);
  
// methods to acquire finalized result
  void				raw_digest(unsigned char *array);	// provide 16-byte array for binary data
  void				hex_digest(char *string);			// provide 33-byte array for ascii-hex string
  friend std::ostream&   operator<< (std::ostream&, LLMD5 context);



private:


// next, the private data:
  uint4 state[4];
  uint4 count[2];     // number of *bits*, mod 2^64
  uint1 buffer[64];   // input buffer
  uint1 digest[16];
  uint1 finalized;

// last, the private methods, mostly static:
  void init             ();               // called by all constructors
  void transform        (const uint1 *buffer);  // does the real update work.  Note 
                                          // that length is implied to be 64.

  static void encode    (uint1 *dest, const uint4 *src, const uint4 length);
  static void decode    (uint4 *dest, const uint1 *src, const uint4 length);

};

#endif // LL_LLMD5_H