How to make an open point with authorization by answer mat. tasks?

Question

WiFi

Good afternoon!
This summer, during the holidays, we plan to make free and unlimited Internet access in the daytime for schoolchildren near the school. We bought an Ubiquiti NanoStation Loco M2 access point, until we installed it on the mast.
Here we want to make authorization to the point through the answer of the solved mathematical problem.

Tasks are very simple

Two trains left the same station in opposite directions at the same time. One was moving at a speed of 62 km / h, and the second - 56 km / h. What distance will be between them 7 hours after the start of the movement?

But for each student (user) a new task should be generated. How to implement an example schema?
Thanks for the answer!

Answer 1

Use CaptivePortal, Ubiquiti has its own implementation, https://help.ubnt.com/hc/en-us/articles/1150001668...
If not Ubiquiti, then as a working OpenWRT + CoovaChilli link
https://openwrt.org/ docs/guide-user/services/capti...
You can attach a radius server to CaptivePortal, manage authorization and have more statistics + all sorts of speed limits, etc.
The described functionality with tasks can be implemented just on the side of this portal. As for me, the scheme would be seen as follows:
1) The user enters the portal
2) One of the tasks from the database is sent to him, fixed by a certain identifier (MAC, IP, etc.) which one was sent
3) The user sends a response, it is checked for compliance with the task that was sent, if successful, a rule allowing access is created on the radius server and a redirect occurs, otherwise a new task, etc.
Checking responses and receiving tasks through the simplest REST API