Disabling BlueZ request to pair with central on connect.

[WayneKeenan]

Hello,

tl;dr: Found a way to stop the pairing request, but what's the most correct and simplest way to disable the BlueZ pairing request from bluezero/Python code?

Environment:
BLE Client: LightBlue app on iOS 16.1.1, 
Pi:         Pi4  - Stretch - 2021-05-07
BlueZ:      5.50
Python:     3.7.3
Code:       heartrate_peripheral.py

Well, this is new (to me, today) behaviour. I guess BlueZ is trying to be 'more secure' by default, sensible, but kinda annoying...

> ACL Data RX: Handle 65 flags 0x02 dlen 11                                                                               #118 [hci0] 16.967848
      SMP: Pairing Request (0x01) len 6
        IO capability: KeyboardDisplay (0x04)
        OOB data: Authentication data not present (0x00)
        Authentication requirement: Bonding, No MITM, SC, No Keypresses, CT2 (0x29)
        Max encryption key size: 16
        Initiator key distribution: EncKey IdKey LinkKey (0x0b)
        Responder key distribution: EncKey IdKey LinkKey (0x0b)

The issue I have elsewhere is that the recommended React Native JS client library doesn't support pairing, joy.

So, until that library gets replaced with something sensible I found a way to disable the request:

sudo btmgmt
pairable off

Although it appears to work on the surface there are 2 issues:

1. The setting doesn't survive a reboot, so need to fathom which Bluez (runtime) config setting it is
2. There are lots of repeated entries of the form:

   > ACL Data RX: Handle 65 flags 0x02 dlen 11                                                                               #245 [hci0] 31.215209
     SMP: Pairing Request (0x01) len 6
       IO capability: KeyboardDisplay (0x04)
       OOB data: Authentication data not present (0x00)
       Authentication requirement: Bonding, No MITM, SC, No Keypresses, CT2 (0x29)
       Max encryption key size: 16
       Initiator key distribution: EncKey IdKey LinkKey (0x0b)
       Responder key distribution: EncKey IdKey LinkKey (0x0b)
   @ MGMT Event: Authentication Failed (0x0011) plen 8                                                                   {0x0003} [hci0] 31.215289
       LE Address: 72:0A:05:DA:BC:A5 (Resolvable)
       Status: Authentication Failed (0x05)

Regards Wayne

[ukBaz]

Can I check my understanding of what the problem is here... Are you saying that you've created a peripheral with Bluezero and when you connect to it from a central device it asks for pairing even though the Bluezero created peripheral has no requirement for pairing?

Is this the "battery" plugin issue? https://github.com/ukBaz/python-bluezero/issues/336#issuecomment-912915781

[WayneKeenan]

Correct and setting ReverseServiceDiscovery to false didn't work for me.

[ukBaz]

Would removing the Battery plugin be a better solution for you?

/usr/lib/bluetooth/bluetoothd -P battery

[WayneKeenan]

perfect, thanks, that worked.

[WayneKeenan]

also just to note that there's no more pairing request 'noise' in the logs.