[Obfuscation] How do I Deobfuscate the Obfuscated code correctly?
local function Obfuscate(code)
local oCode = ''
for i = 1,code:len() do
oCode = oCode .. string.byte(string.sub(code,i,i)) .. ','
end
oCode = string.sub(oCode,1,oCode:len() - 1)
return oCode
end
local function Deobfuscate(code)
local dCode = ''
for i = 1,code:len(),2 do
--if string.sub(code,i,i + 1) ~= ',' then
dCode = dCode .. string.char(tonumber(string.sub(code,i,i + 1)))
print(dCode)
--else
--end
end
return dCode
end
local Code = Obfuscate('Print')
print(Code)
local oCode = Deobfuscate(Code)
print(oCode)
Errors:
14: bad argument #1 to 'char' (number expected, got nil)
1 answer
Obfuscate doesn't result in a string of alternating commas and digits like you seem to be assuming it does.
It doesn't form any nice pattern, and since Lua doesn't provide a split method, you won't want to implement it the way you are.
One option is to use the :gmatch string method as an iterator:
for numerals in code:gmatch("%d+") do
dCode = dCode .. string.char(tonumber(numerals))
end
While it's not related directly to your question, I would like to point out that doing obfuscation in this form is futile. Since everything has to be piped through some function like Deobfuscate to run it, whoever wants to discover the original just has to change loadstring (or whatever other evaluation) to print.
Successful code obfuscation requires that the code runs as it is, without having to do some post-processing on it.
E.g., consider this:
function g(a, b, u, v)
return b > 0 and u(b - 1, a * b, u, v) or a;
end
function f(x, y, u, v)
return x == 0 and y or v(y * x,x - 1, u, v)
end
function e(n)
return f(n, (n + 1) / (n + 1), f, g);
end
any idea what e does? Any idea how it works?
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