How do you automate SSH certificate renewal and revocation?

To streamline the process of renewing and revoking SSH certificates you can utilize tools such, as certbot for managing certificates and ssh keygen for generating SSH keys. To automate the renewal set up a cron job to run certbot renew on a basis which will automatically renew certificates that're close, to expiration. When it comes to revocation employ certbot revoke cert path /path/to/cert to revoke a certificate. Furthermore integrate these procedures with your SSH configuration to ensure updates of both SSH keys and certificates.

Revoking access with SSH certificates is more straightforward compared to SSH keys. If a user's access needs to be revoked, it can be done centrally at the CA level, without the need to individually update each server's authorized_keys file.

SSH certificates enhance security by binding identities to keys, confirmed by an SSH CA, ensuring only verified individuals have access. The time-bound nature of certificates minimizes the threat posed by compromised keys, as they expire regularly. Metadata engrained within certificates facilitates precise access control and permissions. These elements strongly advocate for the adoption of SSH certificates over traditional key pairs in security-focused environments.

To set up an SSH CA, I've found that using a dedicated tool minimizes complexity. One such tool I recommend is `step-ca` from Smallstep, notable for its simplicity. Here’s a stepwise approach: ➜ Install `step-ca` and initialize it with `step ca init`, creating a root certificate and CA configuration. ➜ Generate your CA key pair using `step ca provisioner add` to set up a provisioner. ➜ Define certificate lifetimes and renewal policies aligning with security best practices. ➜ Distribute the CA public key using your preferred configuration management system, ensuring secure access by clients and hosts. This maintains a balance between automation and control, crucial for modern infrastructure.

To request an SSH certificate, start by generating an SSH key pair using ssh-keygen. For renewals, create a script that utilizes 'ssh-certview' to check expiry dates, triggering a renewal with 'ssh-keygen' if the certificate is nearing expiration. This can be scheduled via a cron job for automation. For environments where I've advised on workflow optimization, leveraging tools like certbot, integrated with cron, ensures seamless certificate renewals, reducing manual oversight. Remember, timely renewals prevent service disruptions and maintain security compliance.

For revoking SSH certificates, I rely on step-cli for its scripting capabilities. It's effective for multiple backends and cloud environments I handle at Peenak Solutions. With a single command, such as 'step ssh revoke <cert>', I can invalidate a certificate. For distribution, I use Ansible playbooks; ensuring all nodes in my infrastructure fetch revocation lists efficiently & securely. Combining step-cli with automation tools maintains the integrity and security of the SSH access within our systems.

➜ By leveraging SSH certificates, you enhance security with public key infrastructure (PKI) minus the hassle of manual key management. ➜ To operationalize the certificates, integrate them into your SSH config files, which enables automatic application for every connection. ➜ Utilise the 'IdentityFile' directive in your client's ssh_config for seamless certificate authentication on routine connections. ➜ On the server end, updating sshd_config with 'CertificateFile' ensures that your server consistently authenticates in line with your PKI. ➜ Remember, the key lies in your SSH daemon's configuration to trust the appropriate CA public key and to acknowledge any revocation lists for robust security.

Monitoring and auditing SSH certificates ensure robust security and compliance. Here's a streamlined approach: ➜ Implement periodic scans using ssh-audit to identify potential vulnerabilities. ➜ Utilize monitoring tools like Prometheus coupled with Grafana for real-time dashboards. ➜ Use step-cli for regular reports, coupled with automated email alerts for certificate lifecycle events. ➜ Set up system logs to capture all SSH activities, centralizing them for easier analysis. By maintaining continuous oversight, we ensure the integrity and security of SSH infrastructure.

Are we talking about SSH (Secure SHell) key pairs or SSL (Secure Sockets Layers). Although both are used for encryption, they are completely different. SSH key pairs don't need to be renewed. SSL certificates do.