Writing plugin in cakephp

I need help on plugin for keberosauthenticator. how to write plugin.
1.create new Kerberos principal (or update existing).
2.It should also do a few other things, like allow you to specify good rules for passwords. 3.define expiration dates.
please reply me.
Any available plugin for kerberosauthenticator in Cakephp

There’s documentation about how to create plugins. What part in particular are you having problems with?