mtls-configuration

# mTLS Configuration Comprehensive guide to implementing mutual TLS for zero-trust service mesh communication. ## When to Use This Skill - Implementing zero-trust networking - Securing service-to-service communication - Certificate rotation and management - Debugging TLS handshake issues - Compliance requirements (PCI-DSS, HIPAA) - Multi-cluster secure communication ## Core Concepts ### 1. mTLS Flow ``` ┌─────────┐ ┌─────────┐ │ Service │ │ Service │ │ A │ │ B │ └────┬────┘ └────┬────┘ │ │ ┌────┴────┐ TLS Handshake ┌────┴────┐ │ Proxy │◄───────────────────────────►│ Proxy │ │(Sidecar)│ 1. ClientHello │(Sidecar)│ │ │ 2. ServerHello + Cert │ │ │ │ 3. Client Cert │ │ │ │ 4. Verify Both Certs │ │ │ │ 5. Encrypted Channel │ │ └─────────┘ └─────────┘ ``` ### 2. Certificate Hierarchy ``` Root CA (Self-signed, long-lived) │ ├── Intermediate CA (Cluster-level) │ │ │ ├── Workload Cert (Service A) │ └── Workload Cert (Service B) │ └── Intermediate CA (Multi-cluster) │ └── Cross-cluster certs ``` ## Templates and detailed worked examples Full template library and detailed worked examples live in `references/details.md`. Read that file when you need the concrete templates. ## Best Practices ### Do's - **Start with PERMISSIVE** - Migrate gradually to STRICT - **Monitor certificate expiry** - Set up alerts - **Use short-lived certs** - 24h or less for workloads - **Rotate CA periodically** - Plan for CA rotation - **Log TLS errors** - For debugging and audit ### Don'ts - **Don't disable mTLS** - For convenience in production - **Don't ignore cert expiry** - Automate rotation - **Don't use self-signed certs** - Use proper CA hierarchy - **Don't skip verification** - Verify the full chain