bluetooth classic: verify if paired phone is in reached

[psy0rz]

I want an esp32 to connect to a phone to see if its in reach and is still paired.

The usecase is to unlock an ebike by pressing a button on the bike and having it check if your phone is nearby.

I dont want to use BLE or any apps on the phone. I simple pairing should be enough i think?

Im able to do a GAP request to the mac address and get the rssi, but this requires no pairing and thus is insecure.

I tried to do a simple l2cap connect but i think im doing it wrong. Any tips?