[Task 6] Real-time Revocation List Updates

[thejhh]

Phase 6 of the gomiddleman project introduces real-time updates for revocation lists, a crucial security enhancement that ensures our mTLS proxy can immediately respond to changes in certificate status. This phase aims to implement mechanisms for live updating of Certificate Revocation Lists (CRLs) and immediate termination of connections using compromised certificates, thereby maintaining a high-security standard.

Goals

• Live CRL Updates: Implement a mechanism to periodically check for and apply updates to the CRL, ensuring the proxy uses the most current list for revocation checks.
• Inotify Integration: Utilize inotify (or a similar mechanism) to monitor changes to CRL files, allowing for instant updates without needing to restart the proxy.
• Signal Handling for Manual Updates: Introduce signal handling (e.g., SIGUSR1) to manually trigger CRL updates, providing an alternative update method.
• Connection Termination: Develop the capability to immediately terminate any ongoing connections that are identified as using revoked certificates upon CRL update.
• Cache Management: Ensure that any cached revocation status (e.g., from OCSP responses) is appropriately invalidated when a CRL update indicates a change in certificate status.
• Configuration and Flexibility: Offer configurable options for the frequency of CRL checks, the choice between automatic and manual updates, and the specific signals used for manual intervention.

Testing and Validation

• Update Mechanism Tests: Verify the effectiveness of the live update mechanisms, ensuring that CRL updates are detected and applied without service interruption.
• Connection Termination Tests: Test the immediate termination feature to confirm that connections using revoked certificates are correctly and promptly terminated upon CRL update.
• Signal Handling Tests: Evaluate the reliability and responsiveness of signal-based manual CRL updates, ensuring the system reacts as expected.
• Performance and Reliability Analysis: Assess the impact of real-time CRL updates on the proxy's performance and reliability, particularly under high load conditions.

Documentation

• Real-time Update Guide: Document the implementation of real-time CRL updates, including detailed instructions for configuring and managing the update process.
• Operational Best Practices: Offer guidelines on managing and monitoring certificate revocation, including tips for optimizing update frequencies and handling manual updates.
• Troubleshooting: Provide troubleshooting advice for common issues related to revocation list updates and connection termination.

The completion of Phase 6 will significantly enhance gomiddleman's capability to maintain secure and trusted communications by ensuring it can rapidly adapt to changes in certificate revocation status. Feedback and contributions to this phase are highly valued to achieve an efficient and secure implementation.