有没有可用的解决方案为Google应用引擎提供xsrf / csrf支持？

Cross-site request forgery is common on web now a days. I am facing this in my own site deployed on Google App engine. I got to know this by examining access logs. Is there any XSRF/CSRF library or other solution available for App engine that I can use. And, how much load it will add to my site? is common on web now