src/EncryptedStreamSocket.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 /* This class supports obfuscation and encryption for a *Mule tcp connection.
  27    Right now only basic obfusication is supported, but this can be expanded, as their is a
  28    dedicated handshake to negotiate the encryption method used.
  29
  30    Please note, even if obfuscation uses encryption methods, it does not fulfill cryptographic standards since it
  31    doesn't use secret (and for rc4 important: unique) keys
  32 */
  33
  34 #ifndef __ENCRYPTEDSTREAMSOCKET_H__
  35 #define __ENCRYPTEDSTREAMSOCKET_H__
  36
  37 #include <wx/wx.h>
  38 #include <wx/string.h>
  39
  40 // cryptoPP used for DH integer calculations
  41 #include "CryptoPP_Inc.h"       // Needed for Crypto functions
  42 #include "Proxy.h"
  43 #include "Types.h"
  44
  45 #include "RC4Encrypt.h"
  46
  47 #define ERR_WRONGHEADER                 0x01
  48 #define ERR_TOOBIG                      0x02
  49 #define ERR_ENCRYPTION                  0x03
  50 #define ERR_ENCRYPTION_NOTALLOWED       0x04
  51
  52 enum EStreamCryptState {
  53         ECS_NONE = 0,                   // Disabled or not available
  54         ECS_UNKNOWN,                    // Incoming connection, will test the first incoming data for encrypted protocol
  55         ECS_PENDING,                    // Outgoing connection, will start sending encryption protocol
  56         ECS_PENDING_SERVER,             // Outgoing serverconnection, will start sending encryption protocol
  57         ECS_NEGOTIATING,                // Encryption supported, handshake still uncompleted
  58         ECS_ENCRYPTING                  // Encryption enabled
  59 };
  60
  61 enum ENegotiatingState {
  62         ONS_NONE,
  63
  64         ONS_BASIC_CLIENTA_RANDOMPART,
  65         ONS_BASIC_CLIENTA_MAGICVALUE,
  66         ONS_BASIC_CLIENTA_METHODTAGSPADLEN,
  67         ONS_BASIC_CLIENTA_PADDING,
  68
  69         ONS_BASIC_CLIENTB_MAGICVALUE,
  70         ONS_BASIC_CLIENTB_METHODTAGSPADLEN,
  71         ONS_BASIC_CLIENTB_PADDING,
  72
  73         ONS_BASIC_SERVER_DHANSWER,
  74         ONS_BASIC_SERVER_MAGICVALUE,
  75         ONS_BASIC_SERVER_METHODTAGSPADLEN,
  76         ONS_BASIC_SERVER_PADDING,
  77         ONS_BASIC_SERVER_DELAYEDSENDING,
  78
  79         ONS_COMPLETE
  80 };
  81
  82 enum EEncryptionMethods {
  83         ENM_OBFUSCATION = 0x00
  84 };
  85
  86
  87 class CEncryptedStreamSocket : public CSocketClientProxy
  88 {
  89 public:
  90         CEncryptedStreamSocket(wxSocketFlags flags = wxSOCKET_NONE, const CProxyData *proxyData = NULL);
  91         virtual ~CEncryptedStreamSocket();
  92
  93         void SetConnectionEncryption(bool bEnabled, const uint8_t *pTargetClientHash, bool bServerConnection);
  94
  95         //! Indicates how many bytes were received including obfuscation,
  96         //! so that the parent knows if the receive limit was reached
  97         uint32_t GetRealReceivedBytes() const           { return m_nObfusicationBytesReceived; }
  98
  99         bool    IsObfusicating() const                  { return m_StreamCryptState == ECS_ENCRYPTING && m_EncryptionMethod == ENM_OBFUSCATION; }
 100         bool    IsServerCryptEnabledConnection() const  { return m_bServerCrypt; }
 101
 102         uint8_t m_dbgbyEncryptionSupported;
 103         uint8_t m_dbgbyEncryptionRequested;
 104         uint8_t m_dbgbyEncryptionMethodSet;
 105
 106 protected:
 107         int     Write(const void* lpBuf, uint32_t nBufLen);
 108         int     Read(void* lpBuf, uint32_t nBufLen);
 109
 110         virtual void OnError(int /*nErrorCode*/) {};
 111         virtual void OnSend(int nErrorCode);
 112
 113         void            CryptPrepareSendData(uint8_t* pBuffer, uint32_t nLen);
 114         bool            IsEncryptionLayerReady();
 115         uint8_t         GetSemiRandomNotProtocolMarker() const;
 116
 117         uint32_t                m_nObfusicationBytesReceived;
 118         EStreamCryptState       m_StreamCryptState;
 119         EEncryptionMethods      m_EncryptionMethod;
 120         bool                    m_bFullReceive;
 121         bool                    m_bServerCrypt;
 122
 123 private:
 124         int     Negotiate(const uint8_t* pBuffer, uint32_t nLen);
 125         void    StartNegotiation(bool bOutgoing);
 126         int     SendNegotiatingData(const void *lpBuf, uint32_t nBufLen, uint32_t nStartCryptFromByte = 0, bool bDelaySend = false);
 127
 128         ENegotiatingState       m_NegotiatingState;
 129         CRC4EncryptableBuffer   m_pfiReceiveBuffer;
 130         uint32_t                m_nReceiveBytesWanted;
 131         CRC4EncryptableBuffer   m_pfiSendBuffer;
 132         uint32_t                m_nRandomKeyPart;
 133         CryptoPP::Integer       m_cryptDHA;
 134 };
 135
 136 #endif // __ENCRYPTEDSTREAMSOCKET_H__