diff --git a/lib/qiniu/rs.rb b/lib/qiniu/rs.rb
index d248d15..fda7d68 100755
--- a/lib/qiniu/rs.rb
+++ b/lib/qiniu/rs.rb
@@ -28,11 +28,6 @@ module Qiniu
         Config.initialize_connect opts
       end
 
-      def login!(user, pwd)
-        code, data = Auth.exchange_by_password!(user, pwd)
-        code == StatusOK
-      end
-
       def mkbucket(bucket_name)
         code, data = RS.mkbucket(bucket_name)
         code == StatusOK
diff --git a/lib/qiniu/rs/auth.rb b/lib/qiniu/rs/auth.rb
index bd93a79..9c688c6 100755
--- a/lib/qiniu/rs/auth.rb
+++ b/lib/qiniu/rs/auth.rb
@@ -5,85 +5,21 @@ require 'qiniu/rs/exceptions'
 module Qiniu
   module RS
     module Auth
+
       class << self
+
         include Utils
 
-        def exchange_by_password!(username, password)
-          @username = username
-          @password = password
-          post_data = {
-            :client_id  => Config.settings[:client_id],
-            :grant_type => "password",
-            :username   => username,
-            :password   => password
-          }
-          code, data = http_request Config.settings[:auth_url], post_data
-          reset_token(data["access_token"], data["refresh_token"]) if Utils.is_response_ok?(code)
-          [code, data]
-        end
-
-        def exchange_by_refresh_token!(refresh_token)
-          post_data = {
-            :client_id     => Config.settings[:client_id],
-            :grant_type    => "refresh_token",
-            :refresh_token => refresh_token
-          }
-          code, data = http_request Config.settings[:auth_url], post_data
-          reset_token(data["access_token"], data["refresh_token"]) if Utils.is_response_ok?(code)
-          [code, data]
-        end
-
-        def reset_token(access_token, refresh_token)
-          @access_token  = access_token
-          @refresh_token = refresh_token
-        end
-
-        def call_with_logged_in(url, data, retry_times = 0)
-          raise MissingAccessToken if @access_token.nil?
-          code, data = http_request url, data, {:access_token => @access_token}
-          if code == 401
-            raise MissingRefreshToken if @refresh_token.nil?
-            code, data = exchange_by_refresh_token!(@refresh_token)
-            if code == 401
-              raise MissingUsernameOrPassword if (@username.nil? || @password.nil?)
-              code, data = exchange_by_password!(@username, @password)
-            end
-            if Utils.is_response_ok?(code)
-              retry_times += 1
-              if Config.settings[:auto_reconnect] && retry_times < Config.settings[:max_retry_times]
-                return call_with_logged_in(url, data, retry_times)
-              end
-            end
-          end
-          [code, data]
-        end
-
         def call_with_signature(url, data, retry_times = 0, options = {})
-          code, data = http_request url, data, options.merge({:qbox_signature_token => generate_qbox_signature(url, data)})
-          [code, data]
+          http_request url, data, options.merge({:qbox_signature_token => generate_qbox_signature(url, data)})
         end
 
         def request(url, data = nil, options = {})
-          begin
-            if Config.settings[:access_key].empty? || Config.settings[:secret_key].empty?
-              code, data = Auth.call_with_logged_in(url, data)
-            else
-              code, data = Auth.call_with_signature(url, data, 0, options)
-            end
-          rescue MissingAccessToken => e
-            Log.logger.error e
-            code, data = 401, {}
-          rescue MissingRefreshToken => e
-            Log.logger.error e
-            code, data = 401, {}
-          rescue MissingUsernameOrPassword => e
-            Log.logger.error e
-            code, data = 401, {}
-          end
-          [code, data]
+          Auth.call_with_signature(url, data, 0, options)
         end
 
       end
-    end
-  end
-end
+
+    end # module Auth
+  end # module RS
+end # module Qiniu