I am trying to set specific bluetooth link keys for a device in Ubuntu 14.10 but I am unable to find where they are stored.
The purpose is to have a bluetooth mouse working in both Ubuntu and Windows without having to re-pair it after switching operating systems.
All the answers I found on AskUbuntu state that the keys are stored in /var/lib/bluetooth/<mac_address>/linkkeys and this used to be the case at least until 13.10, but in 14.10 this file is missing from a clean desktop install and creating it manually has no effect, it is ignored by bluetoothd.
EDIT: It seems that the mouse doesn't issue a pairing request and the link keys aren't stored in this case. However, connecting the mouse in Windows and then rebooting in Ubuntu causes the bluetooth connection to fail (and the mouse needs to be removed and re-added to the bluetooth device list), so there's definitely some key exchange/authentication going on that prevents the mouse from being shared in both OS. The question remains, how can I force bluetoothd to save and use the saved link keys when connecting this mouse?
Hardware details:
- Microsoft Bluetooth Notebook Mouse 5000
- 413c:8161 Dell Computer Corp. Wireless 365 Bluetooth (Broadcom BCM2046B1)
The two logs below show that for a pairable device (mobile phone) the keys are stored in the linkkeys file; this is not the case for the mouse. I know that older bluetoothd versions used to save the link keys for mice as well, because there are lots of answers/tutorials here on askubuntu and ubuntuforums about copying linkkeys from Windows to Ubuntu for the specific purpose of sharing a mouse between the two OS.
Here is the bluetoothd log for the mouse discovery and connection setup:
bluetoothd[15615]: plugins/mgmtops.c:mgmt_start_discovery() index 0
bluetoothd[15615]: Discovery session 0x7feb52b14130 with :1.137 activated
bluetoothd[15615]: src/adapter.c:session_ref() 0x7feb52b14130: ref=1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 10 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: plugins/mgmtops.c:start_discovery_complete() hci0 type 1 status 0
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 8 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_discovering() Controller 0 type 1 discovering 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 25 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_device_found() hci0 addr DE:AD:BE:EF:00:00, rssi -43 flags 0x0003 eir_len 5
bluetoothd[15615]: plugins/mgmtops.c:mgmt_confirm_name() hci0 bdaddr DE:AD:BE:EF:00:00 name_known 0
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 16 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: Unknown command complete for opcode 37
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 61 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_device_found() hci0 addr DE:AD:BE:EF:00:00, rssi -43 flags 0x0000 eir_len 41
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 8 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_discovering() Controller 0 type 1 discovering 0
bluetoothd[15615]: src/adapter.c:adapter_set_discovering() hci0 restarting discovery, disc_sessions 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_start_discovery() index 0
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 10 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: plugins/mgmtops.c:start_discovery_complete() hci0 type 1 status 0
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 8 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_discovering() Controller 0 type 1 discovering 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 25 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_device_found() hci0 addr DE:AD:BE:EF:00:00, rssi -43 flags 0x0003 eir_len 5
bluetoothd[15615]: src/adapter.c:session_unref() 0x7feb52b14130: ref=0
bluetoothd[15615]: src/adapter.c:session_remove() Discovery session 0x7feb52b14130 with :1.137 deactivated
bluetoothd[15615]: src/adapter.c:session_remove() Stopping discovery
bluetoothd[15615]: plugins/mgmtops.c:mgmt_stop_discovery() index 0
bluetoothd[15615]: Stopping discovery
bluetoothd[15615]: src/adapter.c:create_device() DE:AD:BE:EF:00:00
bluetoothd[15615]: src/adapter.c:adapter_create_device() DE:AD:BE:EF:00:00
bluetoothd[15615]: src/device.c:device_create() Creating device /org/bluez/15615/hci0/dev_DE:AD:BE:EF:00:00
bluetoothd[15615]: src/device.c:btd_device_ref() 0x7feb52b15680: ref=1
bluetoothd[15615]: src/device.c:device_set_temporary() temporary 1
bluetoothd[15615]: src/device.c:btd_device_ref() 0x7feb52b15680: ref=2
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 10 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete() stop_discovery complete
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 8 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_discovering() Controller 0 type 1 discovering 0
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 65 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_device_connected() hci0 device DE:AD:BE:EF:00:00 connected eir_len 46
bluetoothd[15615]: src/adapter.c:adapter_get_device() DE:AD:BE:EF:00:00
bluetoothd[15615]: src/device.c:device_probe_drivers() Probing drivers for DE:AD:BE:EF:00:00
bluetoothd[15615]: input/manager.c:hid_device_probe() path /org/bluez/15615/hci0/dev_DE:AD:BE:EF:00:00
bluetoothd[15615]: src/device.c:btd_device_ref() 0x7feb52b15680: ref=3
bluetoothd[15615]: input/device.c:input_device_new() Registered interface org.bluez.Input on path /org/bluez/15615/hci0/dev_DE:AD:BE:EF:00:00
bluetoothd[15615]: src/device.c:device_set_temporary() temporary 0
bluetoothd[15615]: src/device.c:btd_device_unref() 0x7feb52b15680: ref=2
Here is the bluetoothd log for the pairing of a mobile phone (user is asked to validate a code shown on both devices):
bluetoothd[15615]: plugins/mgmtops.c:mgmt_start_discovery() index 0
bluetoothd[15615]: Discovery session 0x7feb52b14ca0 with :1.138 activated
bluetoothd[15615]: src/adapter.c:session_ref() 0x7feb52b14ca0: ref=1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 10 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: plugins/mgmtops.c:start_discovery_complete() hci0 type 1 status 0
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 8 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_discovering() Controller 0 type 1 discovering 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 64 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_device_found() hci0 addr DE:AD:BE:EF:01:01, rssi -52 flags 0x0000 eir_len 44
bluetoothd[15615]: src/adapter.c:session_unref() 0x7feb52b14ca0: ref=0
bluetoothd[15615]: src/adapter.c:session_remove() Discovery session 0x7feb52b14ca0 with :1.138 deactivated
bluetoothd[15615]: src/adapter.c:session_remove() Stopping discovery
bluetoothd[15615]: plugins/mgmtops.c:mgmt_stop_discovery() index 0
bluetoothd[15615]: Stopping discovery
bluetoothd[15615]: src/adapter.c:adapter_create_device() DE:AD:BE:EF:01:01
bluetoothd[15615]: src/device.c:device_create() Creating device /org/bluez/15615/hci0/dev_DE:AD:BE:EF:01:01
bluetoothd[15615]: src/device.c:btd_device_ref() 0x7feb52b17cd0: ref=1
bluetoothd[15615]: src/device.c:device_set_temporary() temporary 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_create_bonding() hci0 bdaddr DE:AD:BE:EF:01:01 io_cap 0x01
bluetoothd[15615]: src/device.c:bonding_request_new() Requesting bonding for DE:AD:BE:EF:01:01
bluetoothd[15615]: src/device.c:bonding_request_new() Temporary agent registered for DE:AD:BE:EF:01:01 at :1.138:/org/bluez/agent/wizard
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 10 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete() stop_discovery complete
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 8 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_discovering() Controller 0 type 1 discovering 0
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 37 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_device_connected() hci0 device DE:AD:BE:EF:01:01 connected eir_len 18
bluetoothd[15615]: src/adapter.c:adapter_get_device() DE:AD:BE:EF:01:01
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 18 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_user_confirm_request() hci0 DE:AD:BE:EF:01:01 confirm_hint 0
bluetoothd[15615]: src/adapter.c:adapter_get_device() DE:AD:BE:EF:01:01
bluetoothd[15615]: src/device.c:new_auth() Requesting agent authentication for DE:AD:BE:EF:01:01
bluetoothd[15615]: src/agent.c:agent_request_confirmation() Calling Agent.RequestConfirmation: name=:1.138, path=/org/bluez/agent/wizard, passkey=436733
bluetoothd[15615]: plugins/mgmtops.c:mgmt_confirm_reply() index 0 addr DE:AD:BE:EF:01:01 success 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 16 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete() user_confirm_reply complete
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 32 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_new_link_key() Controller 0 new key of type 5 pin_len 0
bluetoothd[15615]: src/adapter.c:adapter_get_device() DE:AD:BE:EF:01:01
bluetoothd[15615]: src/event.c:btd_event_link_key_notify() storing link key of type 0x05
bluetoothd[15615]: src/device.c:device_set_bonded() bonded 1
bluetoothd[15615]: src/device.c:device_set_temporary() temporary 0
bluetoothd[15615]: src/adapter.c:adapter_get_device() DE:AD:BE:EF:01:01
bluetoothd[15615]: src/device.c:device_bonding_complete() bonding 0x7feb52b2d270 status 0x00
bluetoothd[15615]: src/device.c:device_bonding_complete() Proceeding with service discovery
bluetoothd[15615]: src/device.c:btd_device_ref() 0x7feb52b17cd0: ref=2
bluetoothd[15615]: src/agent.c:agent_release() Releasing agent :1.138, /org/bluez/agent/wizard
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() cond 1
bluetoothd[15615]: plugins/mgmtops.c:mgmt_event() Received 16 bytes from management socket
bluetoothd[15615]: plugins/mgmtops.c:mgmt_cmd_complete()
bluetoothd[15615]: plugins/mgmtops.c:pair_device_complete() hci0 DE:AD:BE:EF:01:01 pairing complete status 0
bluetoothd[15615]: src/adapter.c:adapter_get_device() DE:AD:BE:EF:01:01
bluetoothd[15615]: src/device.c:device_bonding_complete() bonding (nil) status 0x00
Best Answer
After a while, I finally solved the issue I was facing. I still haven't found an answer to the initial question (I couldn't determine where the link keys are stored for this particular bluez/adapter/peripheral combination) but I did find out that bluez will read the linkkeys file, if present, and will use the keys in the file.
So even though the link keys might not be written to the file after pairing, it is possible to override those keys by manually adding them to the linkkeys file.
It is important that the key type is set correctly, otherwise the key will be ignored.
For reference, the key type that worked in my case is shown here: https://askubuntu.com/a/246791/352576