Enforcing TLS and managing certificate rotation for RDS and Amazon Aurora PostgreSQL

This article explains how to enforce TLS encryption, manage certificate rotation, and automate expiry monitoring for RDS and Aurora PostgreSQL databases.

• Enable rds.force_ssl=1 parameter to reject all non-encrypted connections at the server level
• Configure clients with sslmode=verify-full for certificate validation and hostname verification
• Choose from three modern CAs (RSA-2048, RSA-4096, or ECC-384) with automatic server certificate rotation
• Download and distribute RDS CA bundles to all application servers for trust store validation
• Deploy AWS Lambda and EventBridge to monitor certificate expiry 30 days in advance
• Validate encryption with pg_stat_ssl queries to confirm zero plaintext connections
• Test certificate rotation in non-production environments before production deployment

A defense-in-depth approach combining server-side enforcement, client-side verification, and automated lifecycle monitoring eliminates unplanned downtime from certificate expiration and ensures all database traffic remains encrypted.