SSH and SCP

Objectives

• Refresh on security
• Acquire a virtual machine (= a server) on the cloud
• Install and configure the virtual machine/server
• Learn how to use the SSH protocol to connect to a remote server
• Learn how to use the SCP protocol to transfer files to a remote server

A quick reminder about security

• A secure protocol ensures the confidentiality of the data exchanged
• Most secure protocols rely on cryptography
• Cryptography is based on algorithms and keys

SSH

• Secure Shell
• Uses TCP port 22
• A protocol to connect to a remote server
• Can be used to execute commands on a remote server
• The standard way to connect to a remote server

SSH key algorithms

The most common key algorithms are:

• RSA
• DSA
• ECDSA
• Ed25519

Ed25519 and ECDSA are the recommended algorithms.

SSH key fingerprint

• Short version of a public key
• Used to verify the identity of a public key
• Can help detect man-in-the-middle attacks
• Stored in the ~/.ssh/known_hosts file

SSH key generation

• Use the ssh-keygen command
• Choose the key algorithm
• Generate a private key and a public key
• Can be done with or without a passphrase

SCP

• Secure Copy
• Uses TCP port 22
• A protocol to transfer files to/from a remote server
• Can be used to transfer files between two remote servers as well

What will you do?

• Acquire a virtual machine (= a server) on the cloud
• Install and configure the virtual machine (SSH, Docker and Docker Compose)
• Transfer files to/from the virtual machine with SCP

Finished? Was it easy? Was it hard?

Can you let us know what was easy and what was difficult for you during this chapter?

This will help us to improve the course and adapt the content to your needs. If we notice some difficulties, we will come back to you to help you.

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What will you do next?

In the next chapter, you will learn the following topics:

• Learn how to use HTTP, a high-level protocol for the web
• Create your own simple web API with CRUD operations with Java

Sources

• Main illustration by Mathew Schwartz on Unsplash
• Illustration by Aline de Nadai on Unsplash
• Illustration by Kelly Sikkema on Unsplash
• Illustration by Carl Nenzen Loven on Unsplash