Introduction to SSH Key Management

by Hexagon, , Updated: 2 minutes read ssh security developer-tips guide-to-ssh

SSH keys are cryptographic keys that enable user authentication to servers, providing a secure alternative to traditional passwords. They not only increase security but also greatly simplify daily tasks for developers.



By employing an SSH key, you can:

  • Elevate the security of your environment by disabling regular password access and mandating a passphrase-protected SSH key.

  • Streamline your login process by either eliminating the need for a password or opting for a passphrase simpler than those typically necessary for secure SSH logins, although it's crucial to note that this isn’t a best practice and should be reserved for less critical setups, such as personal home networks.

Moreover, platforms like Visual Studio Code and GitHub support remote SSH sessions using key authentication, ensuring secure and seamless remote coding experiences.

This introduction is a gateway to a series focused on SSH keys. Below is a quick guide containing essential commands to generate and use SSH keys swiftly. For those interested in diving deeper into the details, refer to Creating SSH Keys which is the next article in this series.

Quick Start: Generate an SSH Key

Linux/MacOS:

ssh-keygen -t rsa -b 4096

Windows (PowerShell as administrator):

Add-WindowsCapability -Online -Name OpenSSH.Client
Get-Service -Name ssh-agent | Set-Service -StartupType Automatic
ssh-keygen -t rsa -b 4096

Press Enter for default settings and decide whether to set a passphrase.

Start SSH Agent & Add Your Key

Linux/MacOS:

eval $(ssh-agent -s)
ssh-add ~/.ssh/id_rsa

Windows:

Start-Service ssh-agent
ssh-add ~\.ssh\id_rsa

Distribute the Public Key to the Remote Server

For a server with the address your_server_ip:

Linux:

ssh-copy-id username@your_server_ip

Windows using Powershell:

type $env:USERPROFILE\.ssh\id_rsa.pub | ssh user@host "cat >> .ssh/authorized_keys"

Manually:

Append the public key (~/.ssh/id_rsa.pub) content to ~/.ssh/authorized_keys on the server.

Test SSH Connection

ssh username@your_server_ip

If everything is set up correctly, you should be able to log into the server without entering a password.

(Optional) Disable Password Authentication on Server

After ensuring that the SSH key-based access is successful:

  1. Edit the SSH configuration:
sudo nano /etc/ssh/sshd_config
  1. Change the line #PasswordAuthentication yes to:
PasswordAuthentication no
  1. Restart the SSH service:
sudo systemctl restart sshd

(Optional) Use with GitHub

  • Copy the public key content:

    Linux: cat ~/.ssh/id_rsa.pub | xclip -selection clipboard

    Windows (Git Bash): clip < ~/.ssh/id_rsa.pub

    Windows (Powershell): Get-Content ~/.ssh/id_rsa.pub | Set-Clipboard

  • Go to GitHub account settings > "SSH and GPG keys" > "New SSH key". Paste the copied key and save.

That's it! You've quickly set up SSH key management for both remote server access and GitHub. Adjust and dive deeper into the configurations as needed using the information provided in the upcoming sections.

Creating SSH Keys