LuaOTP/totp.lua at master · CodeGlitch0/LuaOTP · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42

-- please point this to proper location
local otp = require("otp")

local totp = {}

totp.at = function(instance, for_time, counter_offset)
	if (for_time == nil) then
		error("No for_time supplied.")
	end
	return otp.generate_otp(instance, totp.timecode(instance, tonumber(for_time)) + (counter_offset or 0))
end

totp.now = function(instance)
	return otp.generate_otp(instance, totp.timecode(instance, os.time()))
end

totp.valid_until = function(instance, for_time, valid_window)
	valid_window = valid_window or 0
	return for_time + ((self.interval + 1) * valid_window)
end

totp.verify = function(instance, key, for_time, valid_window)
	valid_window = valid_window or 0
	for_time = for_time or os.time()

	if (valid_window > 0) then
		for i=-valid_window, valid_window, 1 do
			if (tostring(key) == tostring(totp.at(instance, for_time, i))) then
				return true
			end
		end
		return false
	end
	return tostring(key) == tostring(totp.at(instance, for_time))
end

totp.timecode = function(instance, for_time)
	return math.floor(for_time/instance.interval)
end

return totp