Chapter 6. Authentication

Table of Contents

Ownership
User account
User definition
Group definition
Resetting Linux Passwords
Resetting Windows Passwords
Working with different computers
Commands and behavior
Backup files
Administrator
Sudo
Switching users
Login
PAM
PAM applications
PAM modules
PAM configuration files
How it fits together
PAM Examples
Password Hash
Gnupg
Keys
Key servers
Getting public keys
Produce your keys
Modifying keys
Cryptographic signature
Encryption and decryption
Gui tools
Gpg Agent
Network Information Service
pinentry
Passkeys
FIDO
FIDO setup
Working with FIDO devices
FIDO and Linux PAM Login
Using FIDO

Unix and Linux support multi users and are not single persons operating system. Therefore it has natively built in methods that unwanted users can access any data.

It is common to run some programs using a not human users (process owners), so those programs have a limited disaster potential.

As general rule: When running in troubles, check if it works as root, if so then it is an authentication problem.


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