💬 What is SSH protocol?
💬 It is also referred to as Secure Shell, is a method for secure remote login from one computer to another. It is an alternative to
telnetandrlogin
💬 It protects the communications security and integrity with strong encryption.
💬 How does it work?
💬 – It works in client server model.
– The SSH client drives the connection setup and uses
public key cryptographyto verify the identity of the SSH server.– Once a connection is established data that is transmitted is encrypted according to the parameters negotiated in the setup.
💬 After the setup phase is done, SSH protocol uses strong symmetric encryption and hashing algorithms to ensure the privacy and integrity of the data that is exchanged.
RFC – Link
💬 What are the options to initiate SSH?
💬 Amongst the several methods available the most common ones are
passwordsandpublic key authentication.
💬 In most of automation cases the public key authentication method is preferred. (ANSIBLE uses it)
💬 Is it driven via a cryptographic key pair – public key and private key?
💬 Duh?
The keys used for authentication are called SSH keys.
Configure the public key on a server to authorize access and grant anyone who has a copy of the private key access to the server.
💬 But WHY Public key?
💬 – Why not – It is passwordless login, and yet more secure?
– The motivation for using public key authentication over simple passwords is security.
– Public key authentication provides cryptographic strength that even extremely long passwords can not offer
