within_realm? (Rack::Auth::OpenID)

    # File lib/rack/auth/openid.rb, line 335
          def within_realm? uri
            uri = URI.parse(uri.to_s)
            realm = URI.parse(self.realm)
            return false unless uri.absolute?
            return false unless uri.path[0, realm.path.size] == realm.path
            return false unless uri.host == realm.host or realm.host[/^\*\./]
            # for wildcard support, is awkward with URI limitations
            realm_match = Regexp.escape(realm.host).
              sub(/^\*\./,"^#{URI::REGEXP::PATTERN::URIC_NO_SLASH}+.")+'$'
            return false unless uri.host.match(realm_match)
            return true
          end