insecure-lock

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#+TITLE: insecure-lock - Screen locker in pure Emacs Lisp

#+html:

=insecure-lock= is an extensible screen lock framework. It is implemented within Emacs itself rather than interfacing with underlying window system, so it is best used together with EXWM as a screen locker. Otherwise, it can be used as a screen saver.

As its name suggest, currently security is not a strength of this package. It's more of an advice rather than defense against your intruders. Nevertheless, any suggestions about improving security are more than welcomed!

• Gallery =(setq 'insecure-lock-mode-hook '(insecure-lock-redact insecure-lock-posframe))= [[/screenshot1.png]]

=(setq insecure-lock-mode-hook '(vampire-time-screensaver insecure-lock-blank-screen))= (=vampire-time-screensaver= is a function for my personal use, haven't been published yet. Curious people may check my =.emacs.d=.) [[/screenshot2.png]]

=(setq insecure-lock-mode-hook '(insecure-lock-blank-screen insecure-lock-posframe))=, with some tweaks to =insecure-lock-blank-screen-face= and =insecure-lock-posframe-parameters= [[/screenshot3.png]]

• Configuration

Add the following lines to your =init.el= #+BEGIN_SRC emacs-lisp (require 'insecure-lock) (insecure-lock-run-idle 300) ;; Lock screen after 300 seconds (require 'posframe) (setq 'insecure-lock-mode-hook '(insecure-lock-blank-screen insecure-lock-posframe)) ;; Enable date time display #+END_SRC

Note that currently =insecure-lock= is not very robust against errors from modules. To avoid hanging your Emacs session because of misconfiguration, it's strongly advised to try your new configurations in a separate Emacs instance before using it in your main Emacs session!

** Variables for customization

*** =insecure-lock-require-password= If set, intercept input events and require login password to unlock. Otherwise unlock with any key stroke, acting more like a screen saver.

*** =insecure-lock-mode-hook= You can turn on screen lock "modules" by adding functions to this variable. The default value is =(insecure-lock-blank-screen)=.

The order of modules matters! For example, usually you want to put =insecure-lock-posframe= after the rest so that the posframe doesn't get blanked/redacted.

Available "modules" (in fact just plain functions):

• =insecure-lock-blank-screen= :: Display a blank buffer without modeline in place of any displaying buffers/windows.
• =insecure-lock-redact= :: Available only if the =redacted= package is loaded. Turn on =redact-mode= and disable mode line on any displaying buffer.
• =insecure-lock-posframe= :: Available only if the =posframe= package is loaded. Display a posframe to show some status. This can be customized by:
  • =insecure-lock-posframe-parameters= :: Parameters to the posframe.
  • =insecure-lock-posframe-update-function= :: Function to populate the posframe. The default one, =insecure-lock-posframe-default-update-function=, shows current time and date in two lines, padded and centered. It's a good starting point for writing your own snippet!

• Writing a module

A primary goal for =insecure-lock= is to be composable and extensible. It should be quite easy to get hands on extending =insecure-lock=. Start Writing your module for your own amusement! And contribute to spread the joy!

** An example =insecure-lock= module A minimal example of a =insecure-lock= module: #+BEGIN_SRC emacs-lisp (defvar blackout--saved-background-color nil) (defun blackout () (if insecure-lock-mode (progn (setq blackout--saved-background-color (face-background 'default)) (set-background-color "black")) (set-background-color blackout--saved-background-color)) #+END_SRC You can enable it via =(add-hook 'insecure-lock-mode-hook 'blackout)=. This sets Emacs background color to black when screen is locked, and recover the original background color when unlocked.

In general, a module look like: #+BEGIN_SRC emacs-lisp (defun my-module () (if insecure-lock-mode '(code to setup when entering screen lock) '(code to clean up when leaving screen lock)) #+END_SRC ** Useful Variables

• =insecure-lock-update-functions= :: Add periodic update functions for your module to this variable! The =insecure-lock-update-timer= will call functions in this list every =insecure-lock-update-timer-interval= seconds (default to 1). #+BEGIN_SRC emacs-lisp (defun my-module-update () '(code to update display)) (defun my-module () (if insecure-lock-mode (progn (add-hook 'insecure-lock-update-functions 'my-module-update) '(code to setup when entering screen lock)) '(code to clean up when leaving screen lock)) #+END_SRC

  There's no need to bother removing the update functions when cleanup. =insecure-lock-update-functions= will be set to =nil= at the beginning of screen lock setup.