gistfile1

# Thanks http://devblog.mixlr.com/2012/09/01/nginx-lua/
class CsrfTokenEndpoint
  def self.call(env)
    if env["PATH_INFO"] =~ /^\/csrf_token_endpoint/
      session = env["rack.session"] || {}

      token = session[:_csrf_token]
      if token.nil?
        token = SecureRandom.base64(32)
        session[:_csrf_token] = token
      end

      [ 200, { "Content-Type" => "text/plain" }, [ token ] ]
    else      
      [404, {"Content-Type" => "text/html"}, ["Not Found"]]
    end
  end
end

# This would go into config/routes.rb 
#get 'csrf_token_endpoint' => CsrfTokenEndpoint