Apache的单点登录模块 mod_auth_pubtkt
mod_auth_pubtkt 是 Apache 的简单 Web 单点登录解决方案。
It validates authentication tickets provided by the client in a cookie using public-key cryptography (DSA or RSA). Thus, only the login server that generates the tickets needs to possess the private key, while Web servers can verify tickets given only the public key. The implementation of the login server is left to the user, but an example and a library in PHP are provided with the distribution.