rngd command not found

Introduction

When you run more command in linux terminal / console, you get the following error message

rngd: command not found

or when using sudo you get the following error message

sudo: rngd: command not found

Solutions to rngd: command not found

How To Fix rngd: command not found in Ubuntu / Debian / Kali Linux / Raspbian

In Ubuntu rngd is provided by rng-tools-debian package.

rng-tools-debian is:

The rngd daemon acts as a bridge between a Hardware RNG (random number generator), such as the ones in some Intel/AMD/VIA chipsets, and the kernel’s PRNG (pseudo-random number generator).

It tests the data received from the HWRNG using the FIPS 140-2 (2002-10-10) tests to verify that it is indeed random then feeds the random data to the kernel entropy pool.

This increases the bandwidth of the /dev/random device, from a source that does not depend on outside activity. It may also improve the quality (entropy) of the randomness of /dev/random.

An HWRNG kernel module such as hw_random, or some other source of true entropy that is accessible as a device or fifo, is required to use this package. Securely tunneling entropy over the network and feeding it to rngd is also possible.

This is an unofficial version of rng-tools (as classically shipped by Debian up to and including release 10 “buster”), version 2, extensively modified to add multithreading and a lot of new functionality. However, most users of newer or high-bandwidth HWRNGs might wish to install the latest version of upstream rng-tools (packaged as rng-tools5) instead; that package offers more performant support for those, even if it lacks the new functionality from this version.

To fix this problem, we can install more using the command below.

sudo apt-get -y install rng-tools-debian

This command might take some time to finish depending on your machine internet connection.

You can also use apt command to install rng-tools-debian.

sudo apt -y install rng-tools-debian

Or if you have aptitude installed you can use the following command.

sudo aptitude install rng-tools-debian

Summary

In this tutorial we learn how to fix rngd command not found error in Ubuntu / Debian / Kali Linux or Raspbian distribution.