SSH server security is an important task for system administrators. SSH (Secure Shell), is a popular network protocol that allows remote management of devices and secure connections to them. These are the steps to take in order to secure your SSH Server.
- Strong passwords are essential: Use strong passwords to secure your SSH server. This will prevent unauthorised access to your server through dictionary attacks or password guessing. To ensure strong passwords are stored and generated for user accounts, you should use password management software.
- Use key-based security authentication: You should not only use strong passwords but also use key-based security authentication to your SSH server. This requires you to generate a public/private pair of keys and store the public key on your server. The private key is stored on the user’s computer and will be required to log in to the server. This authentication method is more secure than passwords because it is harder to crack or guess than passwords.
- Limit access to certain users: This is a better option than allowing everyone to log in to your SSH server. This can be done by modifying the “AllowUsers” or “AllowGroups” directive in the SSH configuration file (/etc/ssh/sshd_config). This will allow users and groups to be granted access to the server.
- A firewall is a must: To control the access to your SSH server, you should also use one. A firewall is a network security device that monitors outgoing and incoming network traffic and denies or allows access according to a set of rules. A firewall can be used to block connections to your SSH server coming from untrusted IP addresses or networks. This will help to prevent unauthorized access.
- Enable two-factor authentication. Two-factor authentication (FFA) adds security to your SSH server. It requires users to provide additional authentication to their password. This could be a one time code sent to the user’s phone via SMS, a physical token, or a biometric element such as a fingerprint, face scan, or fingerprint. Even if the password of a user is compromised, 2FA can be enabled to prevent unauthorised access to your server.
- Login warnings can be enabled: To alert you when someone logs into your server, you can enable login warnings in the SSH configuration file. This will help you quickly respond to any unauthorized access attempts.
- Secure protocols are recommended: You should use secure protocols like SSH version 2 and later when configuring your SSH servers. These protocols are more secure than older versions of SSH and have stronger encryption algorithms.
- Regular updates and patches: You should keep your SSH server up-to-date with security patches and other updates. This will protect your server from known vulnerabilities and make it as secure as possible.
- Log activity and monitor activity: You should log all activity on your SSH server. This will allow you to quickly respond to security threats and detect them. Log analyzers and intrusion detection systems can be used to detect suspicious activity on your server.
These steps will help you improve your SSH server’s security and protect it from unauthorized access. You should regularly review and update security measures in order to keep your server safe from new threats.