diff --git a/app/models/grader_configuration.rb b/app/models/grader_configuration.rb
--- a/app/models/grader_configuration.rb
+++ b/app/models/grader_configuration.rb
@@ -9,6 +9,9 @@
   TEST_REQUEST_EARLY_TIMEOUT_KEY = 'contest.test_request.early_timeout'
   MULTICONTESTS_KEY = 'system.multicontests'
   CONTEST_TIME_LIMIT_KEY = 'contest.time_limit'
+  MULTIPLE_IP_LOGIN_KEY = 'right.multiple_ip_login'
+  VIEW_TESTCASE = 'right.view_testcase'
+  SINGLE_USER_KEY = 'system.single_user_mode'
 
   cattr_accessor :config_cache
   cattr_accessor :task_grading_info_cache
@@ -69,6 +72,10 @@
     return (get(SYSTEM_MODE_CONF_KEY)=='analysis')
   end
 
+  def  self.show_testcase
+    return get(VIEW_TESTCASE)
+  end
+
   def self.allow_test_request(user)
     mode = get(SYSTEM_MODE_CONF_KEY)
     early_timeout = get(TEST_REQUEST_EARLY_TIMEOUT_KEY)
@@ -151,7 +158,7 @@
 
   def self.read_config
     GraderConfiguration.config_cache = {}
-    GraderConfiguration.find(:all).each do |conf|
+    GraderConfiguration.all.each do |conf|
       key = conf.key
       val = conf.value
       GraderConfiguration.config_cache[key] = GraderConfiguration.convert_type(val,conf.value_type)