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
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
module ROTP
DEFAULT_INTERVAL = 30
class TOTP < OTP
attr_reader :interval, :issuer
# @option options [Integer] interval (30) the time interval in seconds for OTP
# This defaults to 30 which is standard.
def initialize(s, options = {})
@interval = options[:interval] || DEFAULT_INTERVAL
@issuer = options[:issuer]
super
end
# Accepts either a Unix timestamp integer or a Time object.
# Time objects will be adjusted to UTC automatically
# @param [Time/Integer] time the time to generate an OTP for
# @option [Boolean] padding (true) Issue the number as a 0 padded string
def at(time, padding=true)
unless time.class == Time
time = Time.at(time.to_i)
end
generate_otp(timecode(time), padding)
end
# Generate the current time OTP
# @return [Integer] the OTP as an integer
def now(padding=true)
generate_otp(timecode(Time.now), padding)
end
# Verifies the OTP passed in against the current time OTP
# @param [String/Integer] otp the OTP to check against
def verify(otp, time = Time.now)
super(otp, self.at(time))
end
# Verifies the OTP passed in against the current time OTP
# and adjacent intervals up to +drift+.
# @param [String] otp the OTP to check against
# @param [Integer] drift the number of seconds that the client
# and server are allowed to drift apart
def verify_with_drift(otp, drift, time = Time.now)
time = time.to_i
times = (time-drift..time+drift).step(interval).to_a
times << time + drift if times.last < time + drift
times.any? { |ti| verify(otp, ti) }
end
# Returns the provisioning URI for the OTP
# This can then be encoded in a QR Code and used
# to provision the Google Authenticator app
# @param [String] name of the account
# @return [String] provisioning uri
def provisioning_uri(name)
encode_params("otpauth://totp/#{URI.encode(name)}",
:secret => secret, :period => (interval==30 ? nil : interval), :issuer => issuer)
end
private
def timecode(time)
time.utc.to_i / interval
end
end
end
|
