Disable self registration link

init.rb

@@ -7,6 +7,7 @@
 require 'redmine'
 require 'cas/account_controller_patch'
 require 'cas/application_controller_patch'
+require 'cas/setting_patch'
 require 'cas/user_patch'
 
 Redmine::Plugin.register :redmine_cas do

lib/cas/setting_patch.rb

@@ -0,0 +1,29 @@
+require 'dispatcher'
+
+# Patches Redmine's Setting dinamically. Disables self registration link.
+module CAS
+  module SettingPatch
+    def self.included(base) # :nodoc:
+      base.extend(ClassMethods)
+
+      base.class_eval do
+        unloadable # Mark as unloadable so it is reloaded in development
+
+        class << self
+          alias_method_chain :self_registration?, :cas
+        end
+      end
+    end
+
+    module ClassMethods
+      def self_registration_with_cas?
+        CAS::CONFIG['enabled'] ? false : self_registration_without_cas?
+      end
+    end
+  end
+end
+
+Dispatcher.to_prepare do
+  require_dependency 'setting'
+  Setting.send(:include, CAS::SettingPatch)
+end