When I first converted this plugin to use the zxcvbn meter, I looked at possibilities for having this run server-side. However, it’s a huge script, beyond my capacities to port to PHP, and no one else had tried.
There does seem to be a PHP port now:
https://github.com/bjeavons/zxcvbn-php
However, I don’t think I would include it in this plugin, it’s a little beyond its remit and I like to keep it focused.
It’s more likely to make it into a future version of my Developer’s Custom Fields plugin. This is due for an overhaul to work with the upcoming Metadata API, when that’s out. And while it doesn’t include anything for validation so far, this overhaul might be a time to add a validation layer to it.
