[Regression] 16:04 and later - Cannot pair with devices using (legacy LMP Link Management Protocol) PIN codes

[TJ]

Bluez 5.3 does not have support for pairing with devices (such as keyboards) that use a PIN code for pairing.

A mouse pairs correctly.

From my research it seems as if the ChromeOS project developed patches to fix this and they are supposed to have been included in Bluez 5.4 (that statement dated April 2013) but I've not yet identified them.

"The agent's implementation in bt_console/bluetoothctl upstream is incomplete, missing some functions like DisplayPincode."

https://code.google.com/p/chromium/issues/detail?id=222661

Along with the loss of Headset profiles meaning VoIP applications can no longer use HSP/HFP profiles (requiring functionality yet to land in Ofono) this cripples the use of Bluetooth for much else than A2DP or mouse input.

Attempting to pair with, for example, an Apple Wireless Keyboard that pairs and works correctly with 14.04 LTS, fails totally on 15.10.

The mouse shown below is already paired, connected, and working.

$ bluetoothctl
[NEW] Controller 00:1F:3A:E0:0A:AF hephaestion.lan.iam.tj [default]
[NEW] Device 00:0A:95:4B:BD:C2 Apple Wireless Keyboard
[NEW] Device 00:07:61:3B:86:98 Bluetooth Travel Mouse
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 00:1F:3A:E0:0A:AF Discovering: yes
[CHG] Device 00:0A:95:4B:BD:C2 LegacyPairing: yes
[CHG] Device 00:0A:95:4B:BD:C2 RSSI: -48
[bluetooth]# pair 00:0A:95:4B:BD:C2
Attempting to pair with 00:0A:95:4B:BD:C2

>>> at this point nothing is happening

>>> so I press Enter on the keyboard and...
[agent] PIN code: 791166
>>> I type 791166 Enter and ...
[agent] PIN code: 237744
>>> I type 237744 Enter and...
[agent] PIN code: 358866
>>> I type 358866 Enter and...
Request PIN code
[agent] Enter PIN code: 1234
>>> I type 1234 Enter on the keyboard and 1234 at the prompt...
Failed to pair: org.bluez.Error.AuthenticationFailed

This cycle repeats in various permuations. Sometimes the final "Request PIN code" does not appear.

[TJ (tj)]

This may be caused by bug #1490349 "15:10: bluetoothd reports "Not enough handles to register service" at start"

[TJ (tj)]

Another attempt, this time with

$ sudo /usr/sbin/bluetoothd -nd

and the log-file is attached.

$ bluetoothctl
[NEW] Controller 00:1F:3A:E0:0A:AF hephaestion.lan.iam.tj [default]
[NEW] Device 00:0A:95:4B:BD:C2 Apple Wireless Keyboard
[NEW] Device 00:07:61:3B:86:98 Bluetooth Travel Mouse
[bluetooth]# devices
Device 00:0A:95:4B:BD:C2 Apple Wireless Keyboard
Device 00:07:61:3B:86:98 Bluetooth Travel Mouse
[bluetooth]# paired-devices
Device 00:07:61:3B:86:98 Bluetooth Travel Mouse
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 00:1F:3A:E0:0A:AF Discovering: yes
[CHG] Device 00:07:61:3B:86:98 Connected: yes
[CHG] Device 00:0A:95:4B:BD:C2 LegacyPairing: yes
[CHG] Device 00:0A:95:4B:BD:C2 RSSI: -50
[Bluetooth Travel Mouse]# pair 00:0A:95:4B:BD:C2
Attempting to pair with 00:0A:95:4B:BD:C2
[agent] PIN code: 614003
[agent] PIN code: 201404
[agent] PIN code: 653338
Request PIN code
[agent] Enter PIN code: 1234
Failed to pair: org.bluez.Error.AuthenticationFailed

[TJ (tj)]

Tested the keyboards successfully with Lubuntu 12.04 Precise and Ubuntu 13.04 Raring which confirms this is a regression.

linux 3.2.0-30-generic-pae, bluez 4.98-2ubuntu7
linux 3.8.0-35-generic, bluez 4.101-0ubuntu8b1

[Simon Fels (morphis)]

Please note that 15.10 ships bluez 5.33!

Next the "15:10: bluetoothd reports "Not enough handles to register service" at start" message doesn't have anything to do with this.

Let me look at the log files to see if there is something obviously going wrong.

[Simon Fels (morphis)]

So what happens here is that the authentications fails with a MGMT_STATUS_AUTH_FAILED error code. Because of this bluez retries the authentication multiple times. That is why you get the multiple PIN code requests in a row.

Can you please elaborate a bit more on the exact steps you do? Please also include which keys/buttons you press on the keyboard and if the keyboard. Also from which year is this apple keyboard?

[Sebastien Bacher (seb128)]

Could you reply to the questions?

[TenLeftFingers (tenleftfingers)]

Ingredients:

1 Apple bluetooth keyboard
Ubuntu 15.10 install (64-bit) on a Dell Studio 1535
USB bluetooth adapter

The exact steps are:
Go to All Settings -> Bluetooth
Ensure Bluetooth is set to 'On' and Ubuntu device/machine 'Visibility' is 'ON'
Click the + sign to add a new bluetooth device
Turn on the bluetooth keyboard and wait for it to show up in the list of detected devices
Select from the list and choose one of the PIN options (I've tried them all).
Click Next
Text 'Connecting to...." appears

Actual outcome:
Then: "Setting up 'Jarlath Reidy's Keyboard' failed" displays with options to retry or quit.

Expected outcome:
Device should connect and be fully operational as it did with 14.04.

[ahmad haris (ahmadharis1982)]

It's also happen with me at 15.10. failed.

[Dainius (dainius-s)]

This happens on current version of Xenial as well.

[TJ (tj)]

Yes, confirmed still affecting 16.04, and now on a different PC - a 2105 Asus Transformer T300Chi with a dockable Bluetooth keyboard/mouse.

[TJ (tj)]

I've managed to connect the Asus Transformer T300Chi; this may work for other tablets/hybrids/modern Bluetooth devices.

I am working from the 16.04 GUI installer in 'Try' mode. Touch-screen and stylus input was working so I first went to System Settings > Universal Access and enabled the on-screen keyboard.

Then I was able to join to the WiFi network by entering its details. With that I opened a Terminal and installed the SSH server with:

$ sudo apt install openssh-server

I then set a default password for the 'ubuntu' user:

$ passwd

And then from another PC was able to ssh to the T300Chi:

$ ssh ubuntu@10.254.1.42

With shell access I then put the docking keyboard into pairing mode and did:

ubuntu@ubuntu:~$ bluetoothctl
[NEW] Controller 34:02:86:FC:AD:59 ubuntu [default]
[NEW] Device 1C:B7:2C:04:C7:FE ASUS T300CHI DOCKING
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 34:02:86:FC:AD:59 Discovering: yes
[NEW] Device 00:1F:3A:E0:0A:AF hephaestion.lan.iam.tj
[CHG] Device 1C:B7:2C:04:C7:FE RSSI: -36

[bluetooth]# pair 1C:B7:2C:04:C7:FE
Attempting to pair with 1C:B7:2C:04:C7:FE
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[agent] PIN code: 117372

At this point I typed the PIN code on the docking keyboard followed by Enter.

[CHG] Device 1C:B7:2C:04:C7:FE Modalias: usb:v0B05p8502d0001
[CHG] Device 1C:B7:2C:04:C7:FE UUIDs: 00001000-0000-1000-8000-00805f9b34fb
[CHG] Device 1C:B7:2C:04:C7:FE UUIDs: 00001124-0000-1000-8000-00805f9b34fb
[CHG] Device 1C:B7:2C:04:C7:FE UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 1C:B7:2C:04:C7:FE Paired: yes
Pairing successful

I then started pressing keys on the keyboard which caused lots of messages

[CHG] Device 1C:B7:2C:04:C7:FE Connected: no
[CHG] Device 1C:B7:2C:04:C7:FE Class: 0x0005c0
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[CHG] Device 1C:B7:2C:04:C7:FE Icon is nil
Authorize service
[CHG] Device 1C:B7:2C:04:C7:FE Connected: no
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[CHG] Device 1C:B7:2C:04:C7:FE Connected: no
[CHG] Device 1C:B7:2C:04:C7:FE Class: 0x0025c0
[CHG] Device 1C:B7:2C:04:C7:FE Icon is nil
[CHG] Device 1C:B7:2C:04:C7:FE Class: 0x0005c0
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[CHG] Device 1C:B7:2C:04:C7:FE Icon is nil
[CHG] Device 1C:B7:2C:04:C7:FE Connected: no
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[CHG] Device 1C:B7:2C:04:C7:FE Connected: no
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[CHG] Device 1C:B7:2C:04:C7:FE Connected: no
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[CHG] Device 1C:B7:2C:04:C7:FE Connected: no
[CHG] Device 1C:B7:2C:04:C7:FE Class: 0x0025c0
[CHG] Device 1C:B7:2C:04:C7:FE Icon is nil
Request canceled
[CHG] Device 1C:B7:2C:04:C7:FE Class: 0x0005c0
[CHG] Device 1C:B7:2C:04:C7:FE Connected: yes
[CHG] Device 1C:B7:2C:04:C7:FE Icon is nil

Until I noticed the following message and prompt

Authorize service
[agent] Authorize service 00001124-0000-1000-8000-00805f9b34fb (yes/no): yes

At which point the docking...

[TJ (tj)]

I'm still having to use the shell and bluetoothctl to re-connect the device when it has disconnected.

I think there are two causes for the same symptom here:

1) bluetooth agent/GUI not functioning correctly (as with the T300Chi)
2) no PIN-code entry as first reported, with no work around, due to upstream

[TJ (tj)]

In reply to Simon Fels (sorry for the long delay - I put the keyboards aside to focus on other things).

The "Apple Wireless Keyboard" are model A1016 105-key, including a numeric keypad.

Issue still affects 16.04.

From 16.04 attaching a bluetoothd debug log whilst trying to pair with the A1016. It reflects using

tj@T300CHI:~$ bluetoothctl
[NEW] Controller 34:02:86:FC:AD:59 T300CHI [default]
[NEW] Device 00:0A:95:44:37:11 Apple Wireless Keyboard
[NEW] Device 1C:B7:2C:04:C7:FE ASUS T300CHI DOCKING
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 34:02:86:FC:AD:59 Discovering: yes
[NEW] Device 00:1F:3A:E0:0A:AF hephaestion.lan.iam.tj
[CHG] Device 00:0A:95:44:37:11 LegacyPairing: yes
[CHG] Device 00:0A:95:44:37:11 RSSI: -43
[bluetooth]# pair 00:0A:95:44:37:11
Attempting to pair with 00:0A:95:44:37:11
[agent] PIN code: 412054
Failed to pair: org.bluez.Error.ConnectionAttemptFailed
[CHG] Device 00:1F:3A:E0:0A:AF RSSI: -66

Notice that the "[agent] PIN code: 412054" message doesn't appear until I press the A1016 keyboard's Enter key once. I then type the prompted PIN followed by Enter on the A1016 keyboard.

Sometimes I get three prompts to enter PIN codes (each PIN different) before it fails.

[Noah J. Chelliah (kernellinux)]

I was able to work around this issue by using the "blueman" package to pair the keyboard.

[Sebastien Bacher (seb128)]

is that the same issue than bug #1492443?

[TJ (tj)]

@Sebastian: No, this isn't the same as bug #1492443 (which as I read it is about failing to display the authentication prompt).

This particular bug has had me confused at times between symptoms of that issue, another issue with a BT regression in the kernel that affects some BT host adapters, and the issue here.

This issue affects mostly older 'original' Bluetooth devices (such as the Apple Wireless Keyboard A1016) that do not support BT SSP authentication but do support the original PIN-code LMP authentication method.

In this issue the BT device is expecting and can only use LMP mode but the host/bluez only supports SSP mode.

So a device supporting the SSP protocol can look to a user like it is accepting a PIN-code especially if that is how the host's user interface presents it, but the underlying protocol isn't the original BT LMP protocol.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Konrad Zapałowicz (kzapalowicz)]

Hey, could you retest with silo 68 installed?

Thanks

[John McAleely (john.mcaleely)]

@kzapalowicz - I think this was a desktop bug, so I think we need to know the status in Xenial or Yakkety. The recent landing of BlueZ on touch images seemed to be key to getting improved pairing on phones, alongside changes to ubuntu-system-settings. I assume the settings changes were phone only?

The comments in #16 don't seem to make sense from the perspective of the phone - legacy keyboards seem to have always worked. Or are SSP & LMP both 'legacy' from that perspective, and we have one set ('LMP devices') not working on all Ubuntu platforms?

[Konrad Zapałowicz (kzapalowicz)]

Right, I'll find out.

[R (cool123)]

Affects 16.04 with Bluez 5.37.

For me, when I try pairing an apple keyboard or an amazon basics keyboard with my ubuntu desktop on the GNOME bluetooth UI app; I do not see the pin code displayed.

Starting bluetooth with bluetooth -d -n in debug mode; I see the pin it tries to display. If I type that pin; the bluetooth pair succeeds. But this is horrible as it requires me to peek into the bluetooth debug logs to find the pin and the gnome bluetooth pairing window doesn't display this pin code.

Logs:
bluetoothd[14817]: src/agent.c:agent_display_pincode() Calling Agent.DisplayPinCode: name=:1.148, path=/org/bluez/agent/gnome, pincode=815447
bluetoothd[14817]: Agent replied with an error: org.bluez.Error.Rejected, Rejected bluetoothd generated PIN code

[R (cool123)]

Affects 16.04 with Bluez 5.37. I am on an ARM64 dev board.

For me, when I try pairing an apple keyboard or an amazon basics keyboard using the GNOME bluetooth UI ; I do not see the pin code displayed.

Starting bluetooth with bluetooth -d -n in debug mode; I see the pin it tries to display. If I type that pin; the bluetooth pair succeeds. But this is horrible as it requires me to peek into the bluetooth debug logs to find the pin and the gnome bluetooth pairing window doesn't display this pin code.

Logs:
bluetoothd[14817]: src/agent.c:agent_display_pincode() Calling Agent.DisplayPinCode: name=:1.148, path=/org/bluez/agent/gnome, pincode=815447
bluetoothd[14817]: Agent replied with an error: org.bluez.Error.Rejected, Rejected bluetoothd generated PIN code.

[space s (spaceshaman)]

hi! I'm on 16.10 and I can't connect my macbook to my ubuntu desktop. I have a non-apple keyboard and non-apple mouse, they connect fine. When I want to pair to my macbook both computers display the correct numbers, clicking "yes" tho says it failed to connect. It was the same with 16.04 during the summer. Just recently upgraded to 16.10 but the problem persists. Ty for looking into it.

[Roger Lawhorn (rll-m)]

Same here.

Linux Mint 18.1 64bit Cinnamon Desktop (ubuntu 16.04), Bluetoothctl v5.37.

After I wrote the below forum post I also implemented this udev change which helped somewhat as I have an onboard bluetooth that I wanted to disable after buying a "csr 4.0" usb dongle off of ebay. The GUI worked better, but still no pair:

>sudo gedit /etc/udev/rules.d/81-bluetooth-hci.rules
SUBSYSTEM=="usb", ATTRS{idVendor}=="0cf3", ATTRS{idProduct}=="3004", ATTR{authorized}="0"

Here is the article I posted in a facebook forum with all the gory details:

Been unable to use bluetooth for many years and many laptops. Bought a CSR v4.0 dongle off of ebay.
>lsusb Bus 003 Device 011: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)

Even worse results.

In bluetoothctl (skipping the GUI):
[bluetooth]# list
Controller 00:1A:7D:DA:71:13 GT70-2PE #1 [default]
Controller 48:5A:B6:19:7F:30 GT70-2PE

#1 is the usb dongle I bought.
The other is the built-in Atheros in the laptop.

[bluetooth]# power on
Changing power on succeeded

[bluetooth]# scan on
Discovery started
[CHG] Controller 00:1A:7D:DA:71:13 Discovering: yes
[CHG] Device 48:5A:B6:19:7F:30 RSSI: -64
[CHG] Device 00:07:62:18:3D:C5 RSSI: -51

[bluetooth]# info 00:07:62:18:3D:C5
Device 00:07:62:18:3D:C5
Name: iMT525
Alias: iMT525
Class: 0x240404
Icon: audio-card
Paired: no
Trusted: no
Blocked: no
Connected: no
LegacyPairing: yes
RSSI: -51

I am trying to connect to the iMT525 speaker phone by Altec Lansing.

[bluetooth]# pair 00:07:62:18:3D:C5
Attempting to pair with 00:07:62:18:3D:C5
[CHG] Device 00:07:62:18:3D:C5 Connected: yes
Failed to pair: org.bluez.Error.AuthenticationRejected
[CHG] Device 00:07:62:18:3D:C5 Connected: no

Cannot pair though the default pair code is 0000 for a sound device.

Any ideas?

[Roger Lawhorn (rll-m)]

UPDATE:

I created my own bluez 5.43 unsigned packages and installed them.
The issue is still present.

Here are the steps I took:

It was suggested that bluez 5.4 fixes the issue. However, that package is not available for ubuntu 16.04. I was able to build my own unsigned and upgradable package using the following steps and I have bluez 5.43. Still does not connect though.

sudo apt-get install debhelper devscripts dh-autoreconf flex bison libdbus-glib-1-dev libglib2.0-dev libcap-ng-dev libudev-dev libreadline-dev libical-dev check dh-systemd libebook1.2-dev

wget https://launchpad.net/ubuntu/+archive/primary/+files/bluez_5.43.orig.tar.xz
wget https://launchpad.net/ubuntu/+archive/primary/+files/bluez_5.43-0ubuntu1.debian.tar.xz
wget https://launchpad.net/ubuntu/+archive/primary/+files/bluez_5.43-0ubuntu1.dsc

tar xf bluez_5.43.orig.tar.xz
cd bluez-5.43
tar xf ../bluez_5.43-0ubuntu1.debian.tar.xz
debchange --local=~lorenzen 'Backport to Xenial'
debuild -b -j4 -us -uc
cd ..
sudo dpkg -i *.deb

[Yuan-Chen Cheng (ycheng-twn)]

seems not host hw related issue and no oem complain about it per comment log,
remove oem-priority (as tracking) per current status.

[Spike (spike-4)]

fwiw a lot of people here are talking about failing to pairing, but pairing for me actually works just fine, however the keyboard won't connect (it's a mac wireless keyboard).

BT adapter works fine as I have a wireless mouse connected through it.

thanks,

Spike

[Vidar Øvregaard (vidarov)]

On a fully patched Ubuntu Linux 16.04 LTS ( Toshiba Satellite-L550D / kernel 4.4.0-101-generic #124-Ubuntu SMP Fri Nov 10 18:29:59 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

BT-Adapter: D-Link DBT-120 HW-Ver: B4
Apple Wireless Keyboard A1016 (2003)

[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 00:0D:88:BE:8C:4F Discovering: yes
[CHG] Device 00:0A:95:4A:90:6F LegacyPairing: yes
[bluetooth]# list
Controller 00:0D:88:BE:8C:4F Satellite-L550D [default]
[bluetooth]# pair 00:0A:95:4A:90:6F
Attempting to pair with 00:0A:95:4A:90:6F
[agent] PIN code: 872621
[agent] PIN code: 632284
[agent] PIN code: 988496
Request PIN code
[agent] Enter PIN code: 111111
Failed to pair: org.bluez.Error.AuthenticationFailed

[bluetooth]# pair 00:0A:95:4A:90:6F
Attempting to pair with 00:0A:95:4A:90:6F
[agent] PIN code: 403055
[agent] PIN code: 014497
[agent] PIN code: 175752
Request PIN code
[agent] Enter PIN code: 175752
[CHG] Device 00:0A:95:4A:90:6F Connected: yes
[CHG] Device 00:0A:95:4A:90:6F Name: WLKEYB-A1016
[CHG] Device 00:0A:95:4A:90:6F Alias: WLKEYB-A1016
[CHG] Device 00:0A:95:4A:90:6F Modalias: usb:v05ACp0209d0110
[CHG] Device 00:0A:95:4A:90:6F UUIDs: 00001124-0000-1000-8000-00805f9b34fb
[CHG] Device 00:0A:95:4A:90:6F UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 00:0A:95:4A:90:6F Paired: yes
Pairing successful

Waited some secunds for the prompts. The symptoms mentioned in the above posts have been experienced
before this went o.k. as seen. Gui displays code to enter on keyboard, after pressing enter during pairing, but does not prompt for code to be typed locally on pc.
I am typing this on the A1016 - 1. gen. apple WL keyboard.

Best regards.

Vidar

[TJ (tj)]

I've just revisited this issue on 16.04 with the HWE v4.13 kernel and still having the same problem.

This time however I seem to have discovered a workaround that successfully pairs the Apple Wireless Keyboard A1016. This uses the 'bluetoothctl' CLI tool in the terminal.

In short, instead of initiating the pairing from the PC you must INITIATE PAIRING FROM THE KEYBOARD.

1. Activate the KeyboardDisplay PIN agent
2. Start the bluetooth controller scanning.
3. Power-on the BT Keyboard and ensure it is in pairing mode (LED flashing rapidly)
4. Once the PC discovers the BT Keyboard REMOVE it (this deletes any existing stored configuration)
5. After a few seconds the BT Keyboard should be re-discovered.
6. CONNECT to the BT Keyboard
7. Wait a few seconds then type a PIN code ON THE BT KEYBOARD and press Enter
8. The PC will prompt for the PIN code. Type it on an already-connected keyboard (built-in, USB, etc.)
9. Once the "Paired: yes" message is reported TRUST the BT Keyboard

 tj  ~  bluetoothctl
[NEW] Controller 00:1F:3A:E0:0A:AF XPS1530 [default]
[NEW] Device 00:0A:95:44:37:11 Apple Wireless Keyboard
[NEW] Device 2C:8A:72:15:A8:55 HTC One M8
[NEW] Device 00:07:61:3B:86:98 Bluetooth Travel Mouse
[NEW] Device 00:19:15:29:83:14 Think Outside Keyboard

[bluetooth]# power on

[CHG] Controller 00:1F:3A:E0:0A:AF Class: 0x3c010c
Changing power on succeeded
[CHG] Controller 00:1F:3A:E0:0A:AF Powered: yes

[bluetooth]# agent KeyboardDisplay

Agent registered

[bluetooth]# default-agent
Default agent request successful

[bluetooth]# scan on

Discovery started
[CHG] Controller 00:1F:3A:E0:0A:AF Discovering: yes
[CHG] Device 00:0A:95:44:37:11 LegacyPairing: yes
[CHG] Device 00:0A:95:44:37:11 RSSI: -56
[CHG] Device 00:0A:95:44:37:11 RSSI: -45
[CHG] Device 00:0A:95:44:37:11 RSSI: -60
[CHG] Device 00:0A:95:44:37:11 RSSI: -51
[CHG] Device 00:0A:95:44:37:11 RSSI: -42

[bluetooth]# devices

Device 00:0A:95:44:37:11 Apple Wireless Keyboard
Device 2C:8A:72:15:A8:55 HTC One M8
Device 00:07:61:3B:86:98 Bluetooth Travel Mouse
Device 00:19:15:29:83:14 Think Outside Keyboard
[CHG] Device 00:0A:95:44:37:11 RSSI: -50

[bluetooth]# remove 00:0A:95:44:37:11

[DEL] Device 00:0A:95:44:37:11 Apple Wireless Keyboard
Device has been removed
[NEW] Device 00:0A:95:44:37:11 Apple Wireless Keyboard

[bluetooth]# devices

Device 2C:8A:72:15:A8:55 HTC One M8
Device 00:07:61:3B:86:98 Bluetooth Travel Mouse
Device 00:19:15:29:83:14 Think Outside Keyboard
Device 00:0A:95:44:37:11 Apple Wireless Keyboard

[bluetooth]# connect 00:0A:95:44:37:11

Attempting to connect to 00:0A:95:44:37:11

Request PIN code
[agent] Enter PIN code: 1234

[CHG] Device 00:0A:95:44:37:11 Connected: yes
[CHG] Device 00:0A:95:44:37:11 Modalias: usb:v05ACp0209d0110
[CHG] Device 00:0A:95:44:37:11 UUIDs: 00001124-0000-1000-8000-00805f9b34fb
[CHG] Device 00:0A:95:44:37:11 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 00:0A:95:44:37:11 Paired: yes
Connection successful

[Apple Wireless Keyboard]# trust 00:0A:95:44:37:11

[CHG] Device 00:0A:95:44:37:11 Trusted: yes
Changing 00:0A:95:44:37:11 trust succeeded
[CHG] Device 00:07:61:3B:86:98 Connected: yes

[Apple Wireless Keyboard]#

[TJ (tj)]

Another follow-up. Had the same problem with 20.04 amd64. My solution detailed above would not work when using the GUI where the Blueman bluetooth applet was in the notification area.

Eventually I found it worked from a real tty console (switched from GUI to tty2 with Ctrl+Alt+F2) and running the bluetoothctl sequence as detailed.