class ROTP::OTP

def int_to_bytestring(int, padding = 8)


along with the secret
bytestring, which is fed to the HMAC
Turns an integer to the OATH specified 
def int_to_bytestring(int, padding = 8)
  unless int >= 0
    raise ArgumentError, '#int_to_bytestring requires a positive number'
  end
  result = []
  until int == 0
    result << (int & 0xFF).chr
    int >>= 8
  end
  result.reverse.join.rjust(padding, 0.chr)
end