Tips to secure SSh

SSh (Secure Shell) is a protocol that allows for secure remote access to a server, and it is commonly used to manage servers, configure systems, and perform other administrative tasks. However, SSH can also be a security risk if it is not properly configured.

Here are some steps that you can take to secure your SSH server:

1. Keep your SSH server software up to date. This will ensure that you have the latest security patches and features.
2. Change the default SSH port. By default, SSH servers listen on port 22, but attackers often scan for this port and target servers that have not changed it.
3. Use key-based authentication instead of password-based authentication. Key-based authentication is much more secure than password-based authentication, as it is less vulnerable to brute-force attacks.
4. Disable root login. By disabling root login, you can prevent attackers from trying to guess the root password.
5. Use a firewall to restrict incoming SSH traffic. This will help to protect your server from unauthorized access.
6. Limit the number of login attempts. By limiting the number of login attempts, you can prevent attackers from guessing your password.
7. Set up two-factor authentication for SSH. Two-factor authentication adds an extra layer of security, as it requires the user to provide a second form of authentication.
8. Use SSH tunneling to encrypt your data. SSH tunneling allows you to encrypt your data when it is transmitted over the network.
9. Use a security tool such as fail2ban to detect and block malicious login attempts.
10. Keep an eye on your SSH logs. By monitoring your SSH logs, you can detect any suspicious activity and take action quickly.
11. Use Public Key infrastructure (PKI) to establish trust between the client and the server.
12. Use the ssh-keyscan command to securely exchange the keys between the client and the server.
13. Configure SSH to use only the latest version of the SSH protocol.
14. Disable X11 forwarding and forwarding of TCP connections unless necessary.
15. Use the ssh-audit tool to check the configuration of the server.
16. Use the ssh-hardening tool to apply best practices on SSH configuration.
17. Use sshguard to protect against brute force attacks.
18. Use ssh-keygen to generate and manage ssh keys.
19. Use ssh-copy-id to copy ssh key to the server.
20. Use ssh-add to add ssh key to ssh-agent.
21. Use ssh-keysign to improve the performance of ssh.
22. Use ssh-vulnkey to check for vulnerable ssh keys.
23. Set up an intrusion detection system to monitor for unauthorized access to your server.
24. Use security groups or firewall rules to restrict access to your server based on IP address or other criteria.
25. Use the ssh-keyscan command to create a list of known hosts.
26. Configure your ssh server to only allow specific IP addresses or ranges to connect.
27. Use SSH port knocking to hide the SSH port from the public.
28. Use SSH certificate authentication instead of password-based authentication.
29. Use a hardware security module (HSM) to store ssh keys.
30. Set up a VPN to encrypt your data when you are accessing your server remotely.