Improved CSRFGuard for CSRF attacks defense on Java EE platform

CSRFGuard is a tool running on the Java EE platform to defend Cross-Site Request Forgery (CSRF) attacks, but there are some shortcomings: scripts should be inserted manually, dynamically created requests cannot be effectively handled as well as defense can be bypassed through Cross-Site Scripting (XSS). Corresponding improvements were made according to the shortcomings. The Servlet filter was used to intercept responses, and responses of pages' source codes were stored by a custom response wrapper class to add script tags, so that scripts were automatically inserted. JavaScript event delegation mechanism was used to bind forms with onfocus and onsubmit events, then dynamically created requests were effectively handled. Token dynamically added through event triggered effectively prevented defense bypassed through XSS. The experimental results show that improved CSRFGuard can be effective to defend CSRF attacks.