From 8e5446e198643bc9e6c9e053da3b52e2133a31ee Mon Sep 17 00:00:00 2001
From: momo5502 <mauriceheumann@gmail.com>
Date: Fri, 3 Mar 2017 11:33:13 +0100
Subject: [PATCH] [Proxy] Cleaner interface disassembly

---
 src/Steam/Proxy.cpp | 16 ++++++++--------
 src/Steam/Proxy.hpp | 40 +++++++++++++++++++++++++---------------
 2 files changed, 33 insertions(+), 23 deletions(-)

diff --git a/src/Steam/Proxy.cpp b/src/Steam/Proxy.cpp
index 9578011a..cf968356 100644
--- a/src/Steam/Proxy.cpp
+++ b/src/Steam/Proxy.cpp
@@ -39,7 +39,7 @@ namespace Steam
 			return this->methodCache[method];
 		}
 
-		auto methodData = Interface::lookupMethod(method);
+		auto methodData = this->lookupMethod(method);
 		this->methodCache[method] = methodData;
 		return methodData;
 	}
@@ -48,16 +48,16 @@ namespace Steam
 	{
 		if (!::Utils::Memory::IsBadReadPtr(this->interfacePtr))
 		{
-			unsigned char** vftbl = *static_cast<unsigned char***>(this->interfacePtr);
+			auto* vftbl = this->interfacePtr->vftbl;
 
-			while (!::Utils::Memory::IsBadReadPtr(vftbl) && !::Utils::Memory::IsBadCodePtr((FARPROC(*vftbl))))
+			while (!::Utils::Memory::IsBadReadPtr(vftbl) && !::Utils::Memory::IsBadCodePtr(vftbl->func))
 			{
 				std::string name;
 				uint16_t params;
 
 				if (this->getMethodData(*vftbl, &name, &params) && name == method)
 				{
-					return{ *vftbl, params };
+					return{ vftbl->data, params };
 				}
 
 				++vftbl;
@@ -67,17 +67,17 @@ namespace Steam
 		return { nullptr, 0 };
 	}
 
-	bool Interface::getMethodData(unsigned char* methodPtr, std::string* name, uint16_t* params)
+	bool Interface::getMethodData(VInterface::VMethod method, std::string* name, uint16_t* params)
 	{
 		name->clear();
 		*params = 0;
-		if (::Utils::Memory::IsBadCodePtr(methodPtr)) return false;
+		if (::Utils::Memory::IsBadCodePtr(method.data)) return false;
 
 		ud_t ud;
 		ud_init(&ud);
 		ud_set_mode(&ud, 32);
-		ud_set_pc(&ud, reinterpret_cast<uint64_t>(methodPtr));
-		ud_set_input_buffer(&ud, reinterpret_cast<uint8_t*>(methodPtr), INT32_MAX);
+		ud_set_pc(&ud, method.value);
+		ud_set_input_buffer(&ud, method.data, INT32_MAX);
 
 		while (true)
 		{
diff --git a/src/Steam/Proxy.hpp b/src/Steam/Proxy.hpp
index f0a95d53..0d1ab502 100644
--- a/src/Steam/Proxy.hpp
+++ b/src/Steam/Proxy.hpp
@@ -146,7 +146,7 @@ namespace Steam
 	{
 	public:
 		Interface() : interfacePtr(nullptr) {}
-		Interface(void* _interfacePtr) : interfacePtr(_interfacePtr) {}
+		Interface(void* _interfacePtr) : interfacePtr(static_cast<VInterface*>(_interfacePtr)) {}
 
 		template<typename T, typename... Args>
 		T invoke(std::string methodName, Args... args)
@@ -195,56 +195,66 @@ namespace Steam
 		template<std::size_t X, std::size_t ... Xs>
 		struct AddSizes<X, Xs...> : std::integral_constant<std::size_t, X + ((AddSizes<Xs...>::value + (sizeof(void*) - 1)) & ~(sizeof(void*) - 1))> {};
 
-		void* interfacePtr;
+		struct VInterface
+		{
+			union VMethod
+			{
+				unsigned char* data;
+				unsigned int value;
+				FARPROC func;
+			}* vftbl;
+		};
+
+		VInterface* interfacePtr;
 		std::unordered_map<std::string, std::pair<void*, uint16_t>> methodCache;
 		std::pair<void*, uint16_t> getMethod(std::string method);
 		std::pair<void*, uint16_t> lookupMethod(std::string method);
-		bool getMethodData(unsigned char* methodPtr, std::string* name, uint16_t* params);
+		bool getMethodData(VInterface::VMethod method, std::string* name, uint16_t* params);
 	};
 
 	class KeyValuesBuilder
 	{
 	private:
-		std::stringstream m_buffer;
+		std::string buffer;
 
 		inline void packBytes(const void* bytes, size_t size)
 		{
-			m_buffer << std::string(reinterpret_cast<const char*>(bytes), size);
+			this->buffer.append(reinterpret_cast<const char*>(bytes), size);
 		}
 
 		inline void packDataType(uint8_t type)
 		{
-			packBytes(&type, 1);
+			this->packBytes(&type, 1);
 		}
 
 		inline void packNullTerminated(const char* string)
 		{
-			packBytes(string, strlen(string) + 1);
+			this->packBytes(string, strlen(string) + 1);
 		}
 
 	public:
 		inline void packString(const char* key, const char* value)
 		{
-			packDataType(1);
-			packNullTerminated(key);
-			packNullTerminated(value);
+			this->packDataType(1);
+			this->packNullTerminated(key);
+			this->packNullTerminated(value);
 		}
 
 		inline void packUint64(const char* key, uint64_t value)
 		{
-			packDataType(7);
-			packNullTerminated(key);
-			packBytes(&value, sizeof(value));
+			this->packDataType(7);
+			this->packNullTerminated(key);
+			this->packBytes(&value, sizeof(value));
 		}
 
 		inline void packEnd()
 		{
-			packDataType(8);
+			this->packDataType(8);
 		}
 
 		inline std::string getString()
 		{
-			return m_buffer.str();
+			return this->buffer;
 		}
 	};