Decrypt Teardown ".tde" files.

tdetool2.lua

#!/usr/bin/env luajit
local argparse = require("argparse") -- https://github.com/mpeterv/argparse
local parser = argparse("./tdetool2.lua", "Decrypt and reencrypt Teardown's \".tde\" files.")
parser:argument("input", "Input file(s)."):args("+")
parser:option("-o --output", "Output file.")
parser:option("--working-directory"):hidden(true)
local args = parser:parse()
if #args.input > 1 and args.output ~= nil then
	parser:error("cannot use output option with more than one input argument")
end
local keys = {
	"599Cc51887A8cb0C20F9CdE34cf9e0A535E5cAd1C26c7b562596ACC207Ae9A0bfB3E3161f31af5bEf1c2f064b3628174D83BF6E0739D9D6918fD9C2Eba02D5aD",
	"0C3b676fe8d7188Cde022F71632830F36b98b181aD48Fed160006eA59",
}
local root = args.working_directory
if root == nil then
	root = ""
else
	root = root.."/"
end
for i=1, #args.input do
	local inpath = args.input[i]
	local infile = assert(io.open(root..inpath, "rb"))
	local outpath = args.output
	if outpath == inpath then
		parser:error("cannot output to same path as input path")
	elseif outpath == nil then
		if inpath:sub(-4) == ".tde" then
			outpath = inpath:gsub("%.tde$", "")
		else
			outpath = inpath..".tde"
		end
	end
	local outfile = assert(io.open(root..outpath, "wb"))
	local length = infile:seek("end", 0)
	infile:seek("set", 0)
	for i=0, length-1 do
		local byte = infile:read(1):byte()
		for j=1, #keys do
			local key = keys[j]
			local k = i%#key+1
			byte = bit.bxor(byte, key:byte(k, k))
		end
		outfile:write(string.char(byte))
	end
	infile:close()
	outfile:close()
end