Advertize list of authorized enrollee MAC addresses in Beacon and
Probe Response frames and use these when selecting the AP. In order
to provide the list, the enrollee MAC address should be specified
whenever adding a new PIN. In addition, add UUID-R into
SetSelectedRegistrar action to make it potentially easier for an AP
to figure out which ER sent the action should there be multiple ERs
using the same IP address.
A new hostapd_cli command, wps_ap_pin, can now be used to manage
AP PIN at runtime. This can be used to generate a random AP PIN and
to only enable the AP PIN for short period (e.g., based on user
action on the AP device). Use of random AP PIN that is only enabled
for short duration is highly recommended to avoid security issues
with a static AP PIN.