Punbb-auth-compat is a project mainly written in PHP, based on the WTFPL license.
Provides backwards compatibility for PunBB passwords.
This WordPress plugin provides compatibility with PunBB hashes from PunBB 1.2.x and 1.3.x.
This plugin overrides the wp_check_password method and tries to match the
password hash in this order:
If the given password matches one of the former hashes, the user is
authenticated and the user's password hash is updated using
the wp_hash_password function (which is not overridden by
this plugin).
This plugin does not need any special configuration. However,
it assumes that you converted the PunBB userbase to the WordPress
database beforehand and copied the salt column from the PunBB
user table to the punbb_salt usermeta column in WordPress.