Lua scripts stored in memory - lua

Question

I'm facing problem with lua,
Everytime I'm executing a function/command or even define a variable, everything is stored as a string in memory.
And it can be read via programs like Cheat Engine or HxD
For example
x = 'Test'
If I search for the string x = '
I will be able to extra the whole command from memory.
Same for functions
function Test()
print(1);
end
Searching Test() will allow me to obtain the whole function script.
Here's an example image
http://i40.tinypic.com/6oh281.png
as you can see in the bottom of the Memory Viewer window, theres the whole function information.
Now how could I prevent lua from creating 'extra' copies of the script in memory?
Garbagecollector does not wipe it out.
Any solution or idea to prevent this would be welcomed.

Answer 1

I’m not sure what you mean but try luaL_loadbuffer(L,script,strlen(script),”=noname”)for loading scripts. If you use luaL_dostring then the entire script is saved as its own name.
Note also that you can load a script once and run it multiple times, without having to load it again.

Answer 2

You don't need to load the Lua source of a script at all. Pre-compile the script with luac -s. Of course, the Lua bytecode and strings will still be accessible in memory and just as easily found.
Update
The output of luac is a script in binary form. Use it just like a Lua script. You can use it with loadstring, loadfile etc.
Make your test.lua:
print("testing")
Test:
luac -o test.lub -s test.lua
lua test.lua
lua test.lub
To see what you are exposing vs the Lua source:
luac -l test.lub

Answer 3

By default lua stores the key(x) as string, and value as object on memory, There's not much you can do with it except managing your scripts and storing values inside a block only. Still, This way can be detected by cheat-engines but it's a lot more secure than default.
safe.lua:
local protected = {}
protected.x = "Test"
safe = {}
function safe.Get(pass, val)
if pass == "0x012345" then
if not protected[val] then return nil end
return protected[val]
end
return nil
end
function safe.Set(pass, val, key)
if not pass == "0x012345" then return end
protected[val] = key
end
function safe.Remove(pass, val)
if not pass == "0x012345" then return end
if not protected[val] then return end
protected[val] = nil
end
test.lua:
safe.Set("0x012345", "b", {C = "111"})
print(safe.Get("0x012345", "b").C)
If you want to use a custom pass for each key, then use this safe.lua:
local protected = {}
safe = {}
function safe.Get(pass, val)
if protected[val] then
if not protected[val][pass] then return nil end
return protected[val][pass]
end
return nil
end
function safe.Set(pass, val, key)
protected[val] = {}
protected[val][pass] = key
end
function safe.Remove(pass, val)
if not protected[val] then return end
if not protected[val][pass] then return end
protected[val][pass] = nil
end
and test.lua:
safe.Set("tsting", "x", "keey")
print(safe.Get("tsting", "x"))
print(safe.Get("testing", "x"))