src/RC4Encrypt.h

   1 //
   2 // This file is part of the aMule Project.
   3 //
   4 // Copyright (c) 2003-2011 aMule Team ( admin@amule.org / http://www.amule.org )
   5 // Copyright (c) 2002-2011 Merkur ( devs@emule-project.net / http://www.emule-project.net )
   6 //
   7 // Any parts of this program derived from the xMule, lMule or eMule project,
   8 // or contributed by third-party developers are copyrighted by their
   9 // respective authors.
  10 //
  11 // This program is free software; you can redistribute it and/or modify
  12 // it under the terms of the GNU General Public License as published by
  13 // the Free Software Foundation; either version 2 of the License, or
  14 // (at your option) any later version.
  15 //
  16 // This program is distributed in the hope that it will be useful,
  17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 // GNU General Public License for more details.
  20 //
  21 // You should have received a copy of the GNU General Public License
  22 // along with this program; if not, write to the Free Software
  23 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
  24 //
  25
  26 #ifndef __RC4ENCRYPT_H__
  27 #define __RC4ENCRYPT_H__
  28
  29
  30 #include <vector>
  31
  32
  33 #include "Types.h"
  34 #include <common/StringFunctions.h>
  35 #include "MemFile.h"
  36
  37 // Helper class
  38
  39 class MD5Sum;
  40
  41 struct RC4_Key_Struct
  42 {
  43         uint8 abyState[256];
  44         uint8 byX;
  45         uint8 byY;
  46 };
  47
  48
  49 class CRC4EncryptableBuffer : public CMemFile
  50 {
  51 public:
  52         // Create, empty
  53         CRC4EncryptableBuffer();
  54
  55         // Clear memory
  56         ~CRC4EncryptableBuffer();
  57
  58         // Appends to the end, checking encrypted state.
  59         void Append(const uint8* buffer, int n);
  60
  61         // Sets the encryption key
  62         void SetKey(const MD5Sum& keyhash, bool bSkipDiscard = false);
  63
  64         // RC4 encrypts the internal buffer. Marks it as encrypted, any other further call
  65         // to add data, as Append(), must assert if the inner data is encrypted.
  66         // Make sure to check SetKey has been called!
  67         void Encrypt();
  68
  69         // RC4 encrypts an external buffer with the current key.
  70         void RC4Crypt(const uint8 *pachIn, uint8 *pachOut, uint32 nLen);
  71
  72         // Returns a uint8* buffer with a copy of the internal data, and clears the internal one.
  73         uint8* Detach();
  74
  75         // Also clears the encryption flag
  76         void ResetData();
  77
  78         // Resets everything, as if the object has just been created.
  79         void FullReset();
  80
  81 private:
  82         bool m_encrypted;
  83         bool m_hasKey;
  84         RC4_Key_Struct m_key;
  85
  86         void RC4CreateKey(const uint8* pachKeyData, uint32 nLen, bool bSkipDiscard);
  87 };
  88
  89 #endif // __RC4ENCRYPT_H__