Mandos is an open source shell script crafted as a feature-complete system that implements unattended reboots and remote reboots functionality on server systems that have encrypted root file systems and are powered by a GNU/Linux operating system.

A small bootloader will handle the authentication process by connecting securely to another server machine and grabbing the required password from it, which is decrypted by the client machine using OpenPGP keys.

The OpenPGP keys are unique to each client and all the network communication is encrypted using TLS (Transport Layer Security) at all times. Various examples and more documentation can be found on the project’s official homepage.

The software comes with a plugin architecture, which will extend its default functionality, providing compatibility with the  "askpass" program, which is part of the cryptsetup package, listening to the same FIFO method, as well as to prompt users for a password when using Splashy, Usplash or Plymouth boot splash technologies.

Being distributed as a universal source archive, Mandos is virtually installable on any GNU/Linux platform, but it’s officially supported on the Ubuntu and Debian GNU/Linux operating systems from 2009 and 2011 respectively. Both 32-bit and 64-bit hardware platforms are supported at the moment.

A quick look under the hood will show us that the application is written in the UNIX Shell scripting language and the C programming language. It is a very secure application that requires no additional packages to be installed on the Linux server system where it is deployed.

Mandos is a very secure solution that can be installed on many Linux kernel-based operating systems, directly from the default software repositories or using the source/binary packages provided on the project’s website.