infrastructure for authorization systems - CSRF protection

 The Symfony Security Component - CSRF Library provides a class
 `CsrfTokenManager` for generating and validating CSRF (cross-site
 request forgery) tokens.
 .
 The Symfony Security Component makes it possible to easily separate
 authorization logic from user providers that hold the users credentials.
 It ships with facilities for authenticating using HTTP basic or digest
 authentication, interactive form login or X.509 certificate login.
 Furthermore it optionally also allows an application to implement its
 own authentication strategies.
 .
 Symfony is a PHP framework, a set of tools and a development methodology.