Away lock (lock when the iPhone goes away)¶

BlueFerry can lock your desktop session after the paired iPhone has been disconnected for a while. It is a "forgot to lock my screen" safety net for people who keep the phone connected to BlueFerry all day.

The away lock is off by default and it only locks. BlueFerry never unlocks the desktop when the iPhone comes back.

Turn it on¶

In the Qt (KDE) client, open the iPhone settings and use the Away Lock section: a switch, the grace period, the current state and a warning.

From a terminal:

blueferry proximity-lock enable --grace 60   # opt in, lock after 60 s away
blueferry proximity-lock status              # current state
blueferry proximity-lock test                # dry run, never locks
blueferry proximity-lock disable

The GTK and Quickshell clients have an Away Lock switch in their iPhone settings. It turns the lock on or off and keeps the saved grace period; change the grace period in the Qt client or with the CLI. The terminal client (TUI) has no setting for this; use the CLI there.

Settings in local.env¶

These only set the initial values. A choice saved from a client or the CLI takes precedence, and the service logs once at startup when it ignores a different local.env value for that reason.

How it decides¶

BlueFerry uses the Bluetooth link state it already watches (Classic or LE connected, checked every 5 seconds). There is no extra scanning and no signal-strength measurement.

stateDiagram-v2
    [*] --> disabled
    disabled --> idle: enabled
    idle --> armed: iPhone seen connected
    armed --> grace: iPhone disconnected
    grace --> armed: iPhone back within grace period
    grace --> locked: grace period over
    locked --> armed: iPhone seen again
    armed --> idle: suspend, Bluetooth off, discovery, ...
    grace --> idle: suspend, Bluetooth off, discovery, ...

• It arms only after it has seen the iPhone connected since the service started, the system resumed, or the last pause. A service that starts without the phone nearby never locks.
• A disconnect starts the grace period; a reconnect within it cancels the lock. The next disconnect starts a full new period.
• After locking once it waits until the iPhone is seen again, so it never locks repeatedly while you are away.
• It never locks while the system is suspending, while Bluetooth on the desktop is off, during Bluetooth discovery or pairing, while BlueFerry is recovering the adapter, or after the iPhone was forgotten.
• When this computer ends the connection itself (for example Disconnect in the desktop Bluetooth applet), the lock pauses until the iPhone is connected again. Older BlueZ versions without this report do not pause.

How the screen is locked¶

BlueFerry first asks org.freedesktop.ScreenSaver.Lock on the session bus (KDE Plasma and others). Only if that is not available does it fall back to Lock on your own logind or elogind session. KDE answers only once the lock screen is shown; a slow answer is reported as screensaver-requested.

Limits¶

• Delay: the real time to lock is the grace period plus the time the iPhone needs to drop the Bluetooth link (often several seconds) plus up to 5 seconds of polling.
• Bluetooth off on the iPhone looks exactly like walking away and locks the desktop.
• Any app that starts Bluetooth discovery pauses the lock while it runs.
• Disabled locking: if screen locking is disabled by policy (for example a KDE Kiosk lock_screen=false restriction), Plasma reports success without locking, and BlueFerry cannot tell.
• The away lock has only been tested with simulated Bluetooth and D-Bus so far, not with a real phone walking away.

Security and privacy¶

• This is a lock trigger, not a security feature. Bluetooth presence can be relayed or spoofed. Keep your normal password or PIN. Automatic unlocking was left out on purpose.
• Any program running as your user can turn the away lock on or off. The worst outcome is a locked screen.
• Nothing new is broadcast to other programs. The status only reports a lock state (disabled, idle, armed, grace, locked).
• Logs contain states, durations and BlueZ reason codes, never names, numbers or addresses.