Constants
      | RequestField | = | "Authorization" | 
| ResponseField | = | "WWW-Authenticate" | 
| ResponseInfoField | = | "Authentication-Info" | 
| AuthException | = | HTTPStatus::Unauthorized | 
| AuthScheme | = | nil | 
Method of authentication, must be overridden by the including class  | 
            ||
Attributes
      | [R] | logger | The logger for this authenticator  | 
          
| [R] | realm | The realm this authenticator covers  | 
          
| [R] | userdb | The user database for this authenticator  |