BPF-based readline_events table in osquery

by alessandrogario 4 years ago

GNU/Linux ◆ xterm-256color ◆ zsh 320 views

The readline_events table is able to capture readline invocations system wide making use of BPF and Uprobes. Does not require kernel headers or external libraries.

In this demo, we are capturing the prompt and the user input from bash in real time from a user that has logged into the system using SSH. Does not matter how/when bash is started.

Implemented using the ebpfpub library (https://github.com/trailofbits/ebpfpub).

More by alessandrogario

osquery, user tracers demo 01:31

by alessandrogario 2 years ago

ebpfault #1 00:30

by alessandrogario 10 months ago

Capturing bash events by tracing libreadline with ebpfpub 00:37

by alessandrogario 3 years ago

BPF-based dns_events table in osquery with uprobes 00:39

by alessandrogario 4 years ago

See all

You can download this recording in asciicast v2 format, as a .cast file.

Download

Replay in terminal

You can replay the downloaded recording in your terminal using the asciinema play command:

asciinema play 297802.cast

If you don't have asciinema CLI installed then see installation instructions.

Use with stand-alone player on your website

Download asciinema player from the releases page (you only need .js and .css file), then use it like this:

<!DOCTYPE html>
<html>
<head>
  <link rel="stylesheet" type="text/css" href="asciinema-player.css" />
</head>
<body>
  <div id="player"></div>
  <script src="asciinema-player.min.js"></script>
  <script>
    AsciinemaPlayer.create(
      '/assets/297802.cast',
      document.getElementById('player'),
      { cols: 160, rows: 51 }
    );
  </script>
</body>
</html>

See asciinema player quick-start guide for full usage instructions.

While this site doesn't offer GIF conversion at the moment, you can still do it yourself with the help of asciinema GIF generator utility - agg.

Once you have it installed run the following command to create GIF file:

agg https://asciinema.org/a/297802 297802.gif

Or, if you already downloaded the recording file:

agg 297802.cast 297802.gif

Check agg --help for all available options. You can change font family and size, select color theme, adjust speed and more.

See agg manual for full usage instructions.