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
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
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 [Time/Integer] the time to generate an OTP for, integer unix timestamp or Time object
def at(time)
generate_otp(timecode(time))
end
# Generate the current time OTP
# @return [Integer] the OTP as an integer
def now
generate_otp(timecode(Time.now))
end
# Verifies the OTP passed in against the current time OTP
# and adjacent intervals up to +drift+. Excludes OTPs
# from `after` and earlier. Returns time value of
# matching OTP code for use in subsequent call.
# @param otp [String] the one time password to verify
# @param drift_behind [Integer] how many seconds to look back
# @param drift_ahead [Integer] how many seconds to look ahead
# @param after [Integer] prevent token reuse, last login timestamp
# @param at [Time] time at which to generate and verify a particular
# otp. default Time.now
# @return [Integer, nil] the last successful timestamp
# interval
def verify(otp, drift_ahead: 0, drift_behind: 0, after: nil, at: Time.now)
timecodes = get_timecodes(at, drift_behind, drift_ahead)
timecodes = timecodes.select { |t| t > timecode(after) } if after
result = nil
timecodes.each do |t|
result = t * interval if super(otp, generate_otp(t))
end
result
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)
OTP::URI.new(self, account_name: name).to_s
end
private
# Get back an array of timecodes for a period
def get_timecodes(at, drift_behind, drift_ahead)
now = timeint(at)
timecode_start = timecode(now - drift_behind)
timecode_end = timecode(now + drift_ahead)
(timecode_start..timecode_end).step(1).to_a
end
# Ensure UTC int
def timeint(time)
return time.to_i unless time.class == Time
time.utc.to_i
end
def timecode(time)
timeint(time) / interval
end
end
end
|
