Re: Pairing request ends in timeout

[Axelle <aafortinet@gmail.com>]

I managed to pair, by a mix of factory reset + ensuring that other
devices previously paired were unpaired.

Now, I can pair. However I continue to experience disconnections. Typically,

- I connect, I pair
- I send a Write Request
- I receive a Write Response which looks
- Immediately after I also receive a Disconnect Complete with reason
"Remote User Terminated Connection". This is not meant to happen.

Can I do something about this?

This behaviour is exactly the same on two different hosts: Linux Mint,
and a Rpi 3. Using Bluez 5.50.

< ACL Data TX: Hand.. flags 0x00 dlen 15  #47 [hci0] 2019-08-05 16:37:27.290456
      ATT: Write Request (0x12) len 10
        Handle: 0x0014
          Data: xxxxxxxxxxxxxxxx
> HCI Event: Number of C.. (0x13) plen 5  #48 [hci0] 2019-08-05 16:37:27.295258
        Num handles: 1
        Handle: 70
        Count: 1
> ACL Data RX: Handl.. flags 0x02 dlen 5  #49 [hci0] 2019-08-05 16:37:27.324637
      ATT: Write Response (0x13) len 0
> HCI Event: Disconnect... (0x05) plen 4  #50 [hci0] 2019-08-05 16:37:27.341258
        Status: Success (0x00)
        Handle: 70

        Reason: Remote User Terminated Connection (0x13)

Thanks

-- Axelle

On Thu, Aug 1, 2019 at 4:10 PM Axelle <aafortinet@gmail.com> wrote:
>
> Hello list,
>
> I (again) face problems pairing with a BLE device.
>
> Using bluetoothctl (v5.50), I connected to the device (connect).  Then
> I try to pair but it fails (org.bluez.Error.AuthenticationCanceled).
> The hcidump show a connection timeout.
>
> NB:
> - I have a registered agent (although I do not think it is useful in my case)
> - I am using Linux Mint 19.1. The same error occurs on a Raspberry Pi
> 3 with Raspbian.
> - I have some bluez distrib packages v5.48 installed. Can this be an issue?
> - I got this to work a while ago with the help of someone of bluez on
> IRC, doing power off/power on, but this is not working this time...
>
> Thanks
>
> -- Axelle
>
> What bluetoothctl says:
>
> [D2A74C76F3E0]# pair D2:A7:4C:76:F3:E0
> Attempting to pair with D2:A7:4C:76:F3:E0
> [CHG] Device D2:A7:4C:76:F3:E0 ServicesResolved: no
> [CHG] Device D2:A7:4C:76:F3:E0 Connected: no
> Failed to pair: org.bluez.Error.AuthenticationCanceled
>
> The corresponding hcidump shows that the connection times out:
>
> < ACL data: handle 71 flags 0x00 dlen 11
>     SMP: Pairing Request (0x01)
>       capability 0x04 oob 0x00 auth req 0x2d
>       max key size 0x10 init key dist 0x0d resp key dist 0x0f
>       Capability: KeyboardDisplay (OOB data not present)
>       Authentication: Bonding (MITM Protection)
>       Initiator Key Distribution:  LTK  CSRK
>       Responder Key Distribution:  LTK IRK CSRK
> > HCI Event: Number of Completed Packets (0x13) plen 5
>     handle 71 packets 1
> > HCI Event: Disconn Complete (0x05) plen 4
>     status 0x00 handle 71 reason 0x08
>     Reason: Connection Timeout