Core/Battle.net: Decrypt remainder of the packet that arrives together with EnableEncryption

src/server/bnetserver/Packets/BitStream.h

@@ -217,6 +217,7 @@ namespace Battlenet
         uint8* GetBuffer() { return _buffer.data(); }
         uint8 const* GetBuffer() const { return _buffer.data(); }
 
+        uint32 GetReadPos() const { return _readPos; }
         size_t GetSize() const { return ((_writePos + 7) & ~7) / 8; }
 
         // These methods are meant to only be used when their corresponding actions in the client ignore the value completely

src/server/bnetserver/Packets/ConnectionPackets.h

@@ -63,6 +63,8 @@ namespace Battlenet
             void Read() override { }
             std::string ToString() const override;
             void CallHandler(Session* session) override;
+            uint8* GetRemainingData() { return _stream.GetBuffer() + (((_stream.GetReadPos() + 7) & ~7) / 8); }
+            size_t GetRemainingSize() { return _stream.GetSize() - (((_stream.GetReadPos() + 7) & ~7) / 8); }
         };
 
         class LogoutRequest final : public ClientPacket

src/server/bnetserver/Server/Session.cpp

@@ -393,9 +393,10 @@ void Battlenet::Session::HandlePing(Connection::Ping const& /*ping*/)
     AsyncWrite(new Connection::Pong());
 }
 
-void Battlenet::Session::HandleEnableEncryption(Connection::EnableEncryption const& /*enableEncryption*/)
+void Battlenet::Session::HandleEnableEncryption(Connection::EnableEncryption& enableEncryption)
 {
     _crypt.Init(&K);
+    _crypt.DecryptRecv(enableEncryption.GetRemainingData(), enableEncryption.GetRemainingSize());
 }
 
 void Battlenet::Session::HandleLogoutRequest(Connection::LogoutRequest const& /*logoutRequest*/)

src/server/bnetserver/Server/Session.h

@@ -69,7 +69,7 @@ namespace Battlenet
 
         // Connection
         void HandlePing(Connection::Ping const& ping);
-        void HandleEnableEncryption(Connection::EnableEncryption const& enableEncryption);
+        void HandleEnableEncryption(Connection::EnableEncryption& enableEncryption);
         void HandleLogoutRequest(Connection::LogoutRequest const& logoutRequest);
         void HandleConnectionClosing(Connection::ConnectionClosing const& connectionClosing);