t otherwise arbitrary amounts of whitespace
         wherever a response allows it
      8. MUST be able to receive and correctly process standard OTP
         responses

   A generator compliant with this specification:

      1. MUST be able to generate standard OTP responses
      2. MUST use standard responses unless an extended challenge
         has been received for the particular server AND seed
      3. MUST generate the type field in lower case
      4. MUST NOT send a response type for which the 