Book Image

Ubuntu 20.04 Essentials

By : Neil Smyth
Book Image

Ubuntu 20.04 Essentials

By: Neil Smyth

Overview of this book

Ubuntu is undeniably one of the most highly regarded and widely used Debian-based Linux distributions available today. Thanks to its ease of use and reliability, Ubuntu has a loyal following of Linux users and an active community of developers. Ubuntu 20.04 Essentials is designed to take you through the installation, use, and administration of the Ubuntu 20.04 distribution in detail. For beginners, the book covers topics such as operating system installation, the basics of the GNOME desktop environment, configuring email and web servers, and installing packages and system updates. Additional installation topics such as dual booting with Microsoft Windows are also covered along with crucial security topics such as configuring a firewall and user and group administration. For the experienced user, the book delves into topics such as remote desktop access, the Cockpit web interface, logical volume management (LVM), disk partitioning, and swap management. Further, it also explores KVM virtualization, Secure Shell (SSH), Linux containers, and file sharing using both Samba and NFS to provide a thorough overview of this enterprise-class operating system.
Table of Contents (38 chapters)
38
Index

18.5 SSH Key-based Authentication from Linux and macOS Clients

The first step in setting up SSH key-based authentication is to generate the key pairs on the client system. If the client system is running Linux or macOS, this is achieved using the ssh-keygen utility:

# ssh-keygen

This will result in output similar to the following:

Generating public/private rsa key pair.

Enter file in which to save the key (/home/<username>/.ssh/id_rsa):

Press the Enter key to accept the default location for the key files. This will place two files in the .ssh sub-directory of the current user’s home directory. The private key will be stored in a file named id_rsa while the public key will reside in the file named id_rsa.pub.

Next, ssh-keygen will prompt for a passphrase with which to protect the private key. If a passphrase is provided, the private key will be encrypted on the local disk and the passphrase required in order to gain access to the remote system. For better...