How to distribute the Internet from an access point with an authorization page?

Question

WiFi

In the residence, when connecting to Wifi, a page for authorization opens (login and password), while Wifi network without a password. It is necessary to install a router (so that it has its own subnet with a firewall + so that the Internet received via the residence's wifi is distributed), but how best to implement this?
So far, the following option is spinning in my head: use a Raspberry pi with wifi as a wifi receiver, it will connect to the residence's wifi network. Write an authorization page parser in python and implement automatic login-password entry. Set up routing and connect via twisted pair Rpi to a regular router that will work as an access point with dhcp, firewall, and so on.
Maybe there are easier options? Or some ready-made firmware for routers like openwrt, where there is a similar functionality? Router wrt54gl

Answer 1

OPenWRT, DDwrt - firmware.
A separate machine on Linux and a server part on it >> any wifi router for distribution.
Mikrotik router...