Oniux: kernel-level Tor isolation for Linux applications

The Tor project has announced the oniux utility which provides Tor network isolation, using Linux namespaces, for third-party applications.

Namespaces are a powerful feature that gives us the ability to isolate Tor network access of an arbitrary application. We put each application in a network namespace that doesn't provide access to system-wide network interfaces (such as eth0), and instead provides a custom network interface onion0.

This allows us to isolate an arbitrary application over Tor in the most secure way possible software-wise, namely by relying on a security primitive offered by the operating system kernel. Unlike SOCKS, the application cannot accidentally leak data by failing to make some connection via the configured SOCKS, which may happen due to a mistake by the developer.

The Tor project cautions that oniux is considered experimental as the software it depends on, such as Arti and onionmasq, are still new.