src/EncryptedStreamSocket.h

   1 //
   2 // This file is part of the aMule Project.
   3 //
   4 // Copyright (c) 2003-2008 aMule Team ( admin@amule.org / http://www.amule.org )
   5 // Copyright (c) 2002-2008 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 class CRC4EncryptableBuffer;
  87
  88 class CEncryptedStreamSocket : public CSocketClientProxy
  89 {
  90 public:
  91         CEncryptedStreamSocket(
  92                 wxSocketFlags flags = wxSOCKET_NONE,
  93                 const CProxyData *proxyData = NULL);
  94         virtual ~CEncryptedStreamSocket();
  95
  96         void SetConnectionEncryption(
  97                 bool bEnabled,
  98                 const uint8 *pTargetClientHash,
  99                 bool bServerConnection);
 100
 101         //! Indicates how many bytes were received including obfusication
 102         //! so that the parent knows if the receive limit was reached
 103         uint32 GetRealReceivedBytes() const
 104         {
 105                 return m_nObfusicationBytesReceived;
 106         }
 107
 108         bool IsObfusicating() const
 109         {
 110                 return m_StreamCryptState == ECS_ENCRYPTING &&
 111                         m_EncryptionMethod == ENM_OBFUSCATION;
 112         }
 113
 114         bool IsServerCryptEnabledConnection() const { return m_bServerCrypt; }
 115
 116         uint8   m_dbgbyEncryptionSupported;
 117         uint8   m_dbgbyEncryptionRequested;
 118         uint8   m_dbgbyEncryptionMethodSet;
 119
 120 protected:
 121         int Write(const void* lpBuf, wxUint32 nBufLen);
 122         int Read(void* lpBuf, wxUint32 nBufLen);
 123
 124         virtual void OnError(int /*nErrorCode*/) {};
 125         virtual void OnSend(int nErrorCode);
 126
 127         wxString        DbgGetIPString();
 128         void            CryptPrepareSendData(uint8* pBuffer, uint32 nLen);
 129         bool            IsEncryptionLayerReady();
 130         uint8           GetSemiRandomNotProtocolMarker() const;
 131
 132         uint32  m_nObfusicationBytesReceived;
 133         EStreamCryptState m_StreamCryptState;
 134         EEncryptionMethods  m_EncryptionMethod;
 135         bool m_bFullReceive;
 136         bool m_bServerCrypt;
 137
 138 private:
 139         int Negotiate(const uint8* pBuffer, uint32 nLen);
 140         void StartNegotiation(bool bOutgoing);
 141         int SendNegotiatingData(
 142                 const void *lpBuf,
 143                 uint32 nBufLen,
 144                 uint32 nStartCryptFromByte = 0,
 145                 bool bDelaySend = false);
 146
 147         ENegotiatingState       m_NegotiatingState;
 148         CRC4EncryptableBuffer   m_pfiReceiveBuffer;
 149         uint32                  m_nReceiveBytesWanted;
 150         CRC4EncryptableBuffer   m_pfiSendBuffer;
 151         uint32                  m_nRandomKeyPart;
 152         CryptoPP::Integer       m_cryptDHA;
 153
 154 };
 155
 156 #endif // __ENCRYPTEDSTREAMSOCKET_H__