Prerequisites for SloopEngine

What is SSH?

SSH (Secure Shell) is a widely used cryptographic network protocol that provides a secure way to access and operate network services over an unsecured network, such as the internet. It was designed to replace insecure protocols like Telnet and Rlogin, which transmitted data in plain text and were susceptible to eavesdropping and unauthorized access.

The primary purpose of SSH is to establish a secure communication channel between two devices, typically a client (like a user's computer) and a server (remote machine). This secure channel ensures that data transmitted between the client and server remains encrypted and cannot be easily intercepted or manipulated by malicious actors.

Understanding SSH

The purpose of the SSH (Secure Shell) protocol is to secure remote login from one computer to another. It protects the communications security and integrity with strong encryption. It is a secure alternative to the non-protected login programs such as Telnet, Rlogin, and FTP.

The protocol works in the client-server model, which means that the connection is established by the SSH client connecting to the SSH server. The SSH client drives the connection setup process and uses public key cryptography to verify the identity of the SSH server. After the setup phase the SSH protocol uses strong symmetric encryption and hashing algorithms to ensure the privacy and integrity of the data that is exchanged between the client and server.

  • OpenSSH is the open source software that implements SSH protocol.
  • In any modern day Linux-based operating systems, SSH server runs as a daemon/service which is controlled by Systemd.
  • SSH protocol operates at OSI layer 7 and relies on TCP/IP protocol for host-to-host communication.
  • SSH is widely adopted protocol because of it's built-in encryption features. By default, all SSH connections are end-to-end encrypted.
  • SSH perfectly integrates with major Shells such as Bourne, BASH, etc., to provide a neat command-line interface experience.
  • By default, SSH is the only protocol allowed to login into Unix/Linux cloud servers running on AWS, GCP, and Azure.

How SSH key-based authentication works?

In SSH, key-based authentication is more secure than password-based authentication. SSH keys allows authentication between two hosts without the need of a password. SSH key authentication uses two keys, a private key and a public key. First, you need to generated a SSH key pair, then copy the public key to the user's home directory on the remote server.

  • A SSH key pair is machine independent as well as system user independent, so you can effectively reuse it.
  • The private key is a secret which is not meant to be shared whereas the public key is shareable.
  • It is highly recommended to configure SSH server to only accept key-based authentication and reject password-based authentication for security purposes.
  • You need to rotate SSH key pair frequently in production environment to avoid potential security issues.
  • SSH key pair is generated using cryptographic algorithms such as RSA, DSA, DSS, ECDSA, etc., and hashing functions such as SHA1, SHA2, SHA256, etc.
  • It is highly recommended to generate 2048 bit RSA key pair to use with SSH.

What is Git?

Git is a distributed Version Control System (VCS) primarily used to track and manage changes in source code during software development. It provides a robust and efficient platform for coordinating collaborative work among programmers, enabling them to work on the same project simultaneously and merge their changes seamlessly. However, its versatility extends beyond software development, making it valuable for tracking changes in any set of files.