Firejail

• Firejail wrapper for Nim. Isolate your Production App before its too late! 🔥 🔐👑🔥

Whats Firejail?

...and why should I use it?

• https://www.youtube.com/watch?v=UgddGZca5XU
• https://www.digitalocean.com/community/tutorials/how-to-use-firejail-to-set-up-a-wordpress-installation-in-a-jailed-environment
• https://l3net.wordpress.com/2014/06/08/securing-a-web-server-using-a-linux-namespaces-sandbox
• https://hans-hermann-bode.de/en/content/web-server-sandbox
• https://medium.com/@george.shuklin/on-using-firejail-for-network-isolation-in-tests-42f018ecdcac
• https://jaxenter.com/anti-docker-blog-114422.html
• Why your web server needs full access to the whole System?. 🤔

Requisites

• Firejail

Install

• nimble install firejail

Use

import firejail

# Create a Firejail, all args are optional, all options are Boolean, super easy!.
let myjail = Firejail(no3d=true, noDbus=true, noDvd=true, noRoot=true, noSound=true,
                      noVideo=true, noShell=true, noX=true, noNet=true, noIp=true)

echo myjail.list() # List all Firejails sandboxes running, return a seq[JsonNode] (computer friendly)

echo myjail.tree() # List all Firejails sandboxes running, return a string (human friendly)

echo myjail.shutdown(pid=42) # Shutdown a running Firejail sandbox by PID, return bool, true if Ok

echo myjail.exec("myApp --some-arg") # Run your App isolated inside the Firejail.

# For more info read the Docs...

API

• API is a 1-1 copy of the CLI Firejails API, so any Firejails Docs work too.
• Best Linux Security made super easy, just 4 proc, ~110 Lines of code.
• Timeout is on Hours, up to 255 hours, byte type, when the timeout is reached the Jail is auto stopped.
• dnsServers is 1 array of 4 strings, for 4 DNS Servers, array[4, string] type, 4 IP addresses must be provided.
• blacklist is 1 seq of strings, seq[string] type, paths must exist.
• whitelist is 1 seq of strings, seq[string] type, paths must exist.
• hostsFile is 1 file path string, will be the Jails /etc/hosts, string type, file must exist.
• chroot is 1 folder path string, will be the Jails chroot isolated filesystem, string type, folder must exist.
• tmpfs is 1 folder path string, will be the Jails tmpfs temporary isolated filesystem, string type, folder must exist.
• Run nim doc firejails.nim for more Documentation.
• Run nim genDepend firejail.nim for UML Graphics of internal code structure.
• Run nim c -r firejails.nim for an Example.
• Are you a Security Hacker?, Pull Requests welcome!

Real world usage

• NimWC has Firejail integrated on the core, making it the worlds first Self-Firejailing Web Framework, it Firejails itself. Live Demo.

FAQ

• Why Firejail?.

Written in C with no dependencies, runs on any Linux, can sandbox any type of processes.

• This works with Docker or Vagrant?.

Yes.

• I have Docker, I dont need this?.

https://snyk.io/blog/top-ten-most-popular-docker-images-each-contain-at-least-30-vulnerabilities

Hacking Docker with CURL.

Docker current issues is a lack of strong security, 1 security breach in 1 container can be exploited to access all containers on the server, since containers share resources with each others. This doesnt do virtualization but is more like a locked-down secure chroot jail, which grants a locked-down view of a system. Sometimes even basic tiny libs and drivers have security vulnerabilities, virtualized or not. With this your software can only access what it needs to access, and not a whole system, virtualized or not. This works with simple booleans, as example noDbus=true and DBus is gone, but good luck stripping all D-Bus from the Ubuntu running inside that Docker.

• This works with JavaScript?

No. firejail cant run on the browser.

• Whats the option useMtuJumbo9000?.

Network MTU Jumbo Frames. This is optional. This is just a shortcut to improve UX. https://wiki.archlinux.org/index.php/jumbo_frames

• Whats the option forceEnUsUtf8?.

Forces EN English as language and UTF-8 Unicode as encoding on Firejail. This is optional. This is just a shortcut to improve UX.

• Whats the option useRandomMac?.

Random Network MAC Address on Firejail. This is optional. This is just a shortcut to improve UX.

• Why use a Random MAC Address?.

Devices send a signal to look for networks, the signal contains the unique physical hardware (MAC) address for your device, this unique address can be used to track you on a network and "map" a network, you can use a random MAC address to make it harder to track. This is optional. This is just an extra feature so you dont have to do it manually if you need to.

• Why uses Xvfb as X Security instead of Xephyr, Xpra or none?.

Xephyr and Xpra quits complaining about the need to install extra libs. none quits complaining about the network, seems network dependent. Xvfb is the one that seems more standalone and dont complain while gets the job done. Xvfb is usually installed more frequently than Xephyr and Xpra. Xvfb is usually used for Continuous Integration and Testing. We need one that can run in a Non-Interactive way. Firejail by default is more strict than Docker.

• Why "~", "/dev", "/usr", "/etc", "/opt", "/var", "/bin", "/proc" fails to Whitelist?.

Those seems like invalid paths for Whitelisting, Firejail wont accept these paths. Your own home directory root path also seems invalid to whitelist, but you can whitelist any folder inside your own home directory root path. Firejail by default is more strict than Docker.