Class: GoogleAuthenticator

Inherits:
Object
  • Object
show all
Defined in:
lib/google_authenticator_auth.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key = nil) ⇒ GoogleAuthenticator

Load class with the provided secret key. If no key is provided generate a new random secret key



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# File 'lib/google_authenticator_auth.rb', line 18

def initialize(key=nil)
  @secret_key = key.nil? ? GoogleAuthenticator.generate_secret_key : key
end

Class Method Details

.generate_secret_key ⇒ Object

Generate a unique secret key



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# File 'lib/google_authenticator_auth.rb', line 23

def self.generate_secret_key
  Base32.encode( (0...10).map{(rand(255)).chr}.join )
end

Instance Method Details

#get_keys ⇒ Object

Found at gist.github.com/987839 Returns an array containing the previous, current, and next valid key for the current secret key



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# File 'lib/google_authenticator_auth.rb', line 52

def get_keys
  keys = []
  int = 30
  now = Time.now.to_i / int
  key = Base32.decode @secret_key
  sha = OpenSSL::Digest::Digest.new('sha1')

  (-1..1).each do |x|
    bytes = [ now + x ].pack('>q').reverse
    hmac = OpenSSL::HMAC.digest(sha, key.to_s, bytes)
    offset = nil
    if RUBY_VERSION > '1.9'
      offset = hmac[-1].ord & 0x0F
    else
      offset = hmac[-1] & 0x0F
    end
    hash = hmac[offset...offset + 4]

    code = hash.reverse.unpack('L')[0]
    code &= 0x7FFFFFFF
    code %= 1000000

    keys << code
  end

  keys
end

#key_valid?(key) ⇒ Boolean

Checks to see if the key is valid for the current secret key

Returns:

  • (Boolean) 


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# File 'lib/google_authenticator_auth.rb', line 45

def key_valid?(key)
  get_keys.include?(key.to_i)
end

#qrcode_image_url(label, wh = 350) ⇒ Object

Google Charts image URL (resulting image can be scanned by the Google Authenticator app to automaticly import secret key



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# File 'lib/google_authenticator_auth.rb', line 29

def qrcode_image_url(label,wh=350)
  "https://chart.googleapis.com/chart?chs=#{wh}x#{wh}&cht=qr&choe=UTF-8&chl=" + uri_parser.escape(qrcode_url(label))
end

#qrcode_url(label) ⇒ Object

QRCode URL used to generate a QRCode that can be scanned into Google Authenticator (see qrcode_image_url)



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# File 'lib/google_authenticator_auth.rb', line 35

def qrcode_url(label)
  "otpauth://totp/#{label}?secret=#{@secret_key}"
end

#secret_key ⇒ Object

Current secret key



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# File 'lib/google_authenticator_auth.rb', line 40

def secret_key
  @secret_key
end