lib/rack/protection/xss_header.rb
require 'rack/protection' module Rack module Protection ## # Prevented attack:: Non-permanent XSS # Supported browsers:: Internet Explorer 8+ and Chrome # More infos:: http://blogs.msdn.com/b/ie/archive/2008/07/01/ie8-security-part-iv-the-xss-filter.aspx # # Sets X-XSS-Protection header to tell the browser to block attacks. # # Options: # xss_mode:: How the browser should prevent the attack (default: :block) class XSSHeader < Base default_options :xss_mode => :block, :nosniff => true def call(env) status, headers, body = @app.call(env) headers['X-XSS-Protection'] ||= "1; mode=#{options[:xss_mode]}" if html? headers headers['X-Content-Type-Options'] ||= 'nosniff' if options[:nosniff] [status, headers, body] end end end end