[1.12.1] Dll Injection - Get Object Pointer

[Lywbringer]

Hello I am new on this forum and I have a question:

I followed a guide on internet on how to make a bot (https://drewkestell.us/Article/6/Chapter/1) and I suceeded to inject a dll and get the player GUID and a list of all visible objects GUIDs.

But when I try to use the function GetObjectPtr(ulong guid) defined at GET_OBJECT_PTR_FUN_PTR = 0x00464870 it always returns 0 !

This is an important function and I can't keep following the tutorial without it.

I don't know where to start to learn reverse engineering, if you have courses online or tutorials I'll be glad to read them.

Before making this in-process bot I already made an out of process bot using pixels and lua only but I am limited in my capabilities so I started to look for DLL injection.


This is the function I am using:

const int GET_OBJECT_PTR_FUN_PTR = 0x00464870;

[UnmanagedFunctionPointer(CallingConvention.StdCall)]
delegate IntPtr GetObjectPtrDelegate(ulong guid);

static readonly GetObjectPtrDelegate GetObjectPtrFunction =
    Marshal.GetDelegateForFunctionPointer<GetObjectPtrDelegate>((IntPtr)GET_OBJECT_PTR_FUN_PTR);

internal static IntPtr GetObjectPtr(ulong guid) => GetObjectPtrFunction(guid);

[namreeb]

This looks right to me. Maybe try attaching a debugger with a breakpoint at 0x464870 to see what comes in for guid? My only guess is that somehow the arguments are not being passed on the stack correctly by the marshaller.

[Lywbringer]

I solved my problem by adding:

[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
delegate int EnumerateVisibleObjectsCallback(ulong guid, int filter);

now it returns the GUIDs and Pointers but at the very end the program crash with System.AccessViolationException.

I tested the code a bit and I think it comes from the function inside the client.

I simply put:

try {
    EnumerateVisibleObjectsFunction(callback, filter, (IntPtr)ENUMERATE_VISIBLE_OBJECTS_FUN_PTR);
} catch { }

And now it works even though it's an ugly way to do it