Fake Keygen in LUA

math.clamp = function(val, low, high)
    return math.max(low, math.min(val, high))
end

substr = function(str, idx, len)
    return str:sub(idx, idx + len - 1)
end


function keygen(arg1, arg2)
    local chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
    local sect = arg1 > 0 and math.clamp(arg1, 3, 10) or 5
    local len = arg2 > 0 and math.clamp(arg2, 3, 8) or 4
    local tmp = ""

    math.randomseed(os.time())

    for i=1,sect do
        for p=1,len do
            tmp = tmp..substr(chars, math.random(1, #chars), 1)
        end
        if i < sect then tmp = tmp.."-" end
    end
    return(tmp)
end



print(keygen(5, 5))