Architecture of a Production-Grade High-Level KMS using AES-256 GCM

Alright, folks. We’ve all seen fancy-schmancy KMS solutions in the wild—wrapped in marketing lingo, throwing AWS, GCP, and Azure like they own encryption itself. But what if you want full control over your own high-level Key Management System (KMS) that is built for production, scales like a beast, and runs on Go?

Let's break it down. No fluff. Just architecture.

Go Microservice: We coded our own key management microservice in Go—because we love speed, concurrency, and that sweet, sweet sense of smug satisfaction.

AES-256 GCM: The real MVP. If cryptography were a roast, GCM mode would be that no-nonsense relative who ensures no one sneaks extra slices of cake without detection. It protects both confidentiality AND integrity.

Master Keys & Data Keys: We store carefully rotated master keys in a secure vault (some top-secret place). Each time we need to encrypt data, we spawn a fresh Data Encryption Key, wrap it with the master key, and stash the ciphertext in our DB.

MongoDB for DEK Storage: Because who doesn’t love a good NoSQL to keep us on our toes? Each DEK is sealed up tight, so the microservice can unwrap it on demand (but we never let the plaintext float in the wind).

Authentication & RBAC: We wired up our own role-based access control. Only those special “SERVICE” or “ADMIN” folks get to push the big red “Encrypt” or “Rotate Master Key” buttons. Everyone else can read the logs and dream of world domination.

Rotation Routines: Our weekly “key rotation party” ensures that if anyone’s sniffing around, they better do it fast—because the old keys become worthless as soon as we generate new ones.

Hardened Endpoints: We made sure our endpoints demand tokens, check roles, and throw fits (HTTP 403) if someone tries to sweet-talk their way in without the right credentials.

And here’s the kicker: I’ve already spent 35 + hours wrestling with this in Go, so trust me when I say it’s like discovering a new galaxy, except the stars are error logs, the planets are memory leaks, and you’re the astronaut screaming into the void.

https://github.com/debrajrout/kms_using-AES-GCM (just for a reference obviously you can have yours own more advanced)