XOR Decryptor

local args = {...}

if #args < 2 then
    print("USAGE: decryptor [key] [side]")
end

local key = tonumber(args[1])
math.randomseed(os.time())

local chars = {
    "a",
    "b",
    "c",
    "d",
    "e",
    "f",
    "g",
    "h",
    "i",
    "j",
    "k",
    "l",
    "m",
    "n",
    "o",
    "p",
    "q",
    "r",
    "s",
    "t",
    "u",
    "v",
    "w",
    "x",
    "y",
    "z",
    " ",
    "_",
    "#",
    "@",
    "!",
    "*",
    "^",
    "1",
    "2",
    "3",
    "4",
    "5",
    "6",
    "7",
    "8",
    "9",
    "0",
    "+",
    "-",
    "~",
    "`",
    "%",
    "$",
    "{",
    "}",
    "\\",
    "/",
    ">",
    "<",
    ";",
    ":",
}
local function generateRandomChar(includeUpper)
    local char = chars[math.random(1,#chars)]
    if includeUpper then
        local doUpper = math.random(1,2)
        if doUpper == 2 then
            char = string.upper(char)
        end
    end
    return char
end

local function doDecrypt(side)
    local lines = {}
    local currentLine = ""
    local path = fs.combine(disk.getMountPath(side), "data")
    local handle = fs.open(path, "rb")
    while true do
        local byte = handle.read()
        if byte then
            byte = bit.bxor(byte, key)
            currentLine = currentLine..string.char(byte)
            if string.char(byte) == "\n" then
                table.insert(lines, currentLine)
                currentLine = ""
            end
        else
            break
        end
    end
    handle.close()
    return lines
end

local function lookCool(lines)
    for i,v in ipairs(lines) do
        local coolStr = ""
        for progress=1, 20 do
            for i=1, #v do
                coolStr = coolStr..generateRandomChar(true)
            end
            term.clear()
            term.setCursorPos(1,1)
            print("Currently decrypting line "..i.."...")
            print("Line Progress: "..math.floor((progress/20)*100).."%")
            print("Total Progress: "..math.floor((i/#lines)*100).."%")
            print("Current Attempt:")
            print(coolStr)
            coolStr = ""
            os.sleep(0.5)
        end
        local handle = fs.open("decrypted.data", "a")
        handle.write(v)
        handle.close()
    end
    term.clear()
    term.setCursorPos(1,1)
    print("Done!")
    print("Data written to \"decrypted.data\".")
end

lookCool(doDecrypt(args[2]))