mediatore

mediatore (Italian: broker, go-between; IPA /me.dja.ˈto.re/, "meh-dyah-TOH-reh")

A trusted go-between for banlieue sandbox VMs. mediatore takes a person's login at the front, an attested virtual machine at the back, and makes sure the two are bound to each other before anything inside the VM can act on that person's behalf.

banlieue schedules VMs and hands them out through VirtualMachineClaims, but deliberately carries no credential: a claim records who a sandbox is for, and stops there. mediatore is the component that finishes the story.

• Front door. Accepts an Entra ID token (or a Dex-bridged GitHub login in a homelab), validates it, and creates the VirtualMachineClaim with the subject taken from the token.
• Binding. When the claim binds to a pool member that has already attested its vTPM to SPIRE, mediatore registers a SPIFFE identity for that claim, scoped to that VM and to the per-subject Linux user the in-guest agent creates.
• Delegation. The jailed workload presents its SVID and asks for a token for one downstream audience. mediatore answers with a short-lived, audience-scoped token, minted via Entra On-Behalf-Of or by its own STS. The user's original token never enters the VM.
• Cut-off. When the claim expires or is deleted, mediatore removes the SPIFFE entry and the tokens stop.

Where to start

• Running workloads on a claimed VM: the user, OBO-agent and app-only paths, end to end.
• System architecture and flows, rendered from the CALM architecture-as-code model.
• ADRs: every decision that shaped the trust boundaries, token shapes and SPIFFE ID scheme.
• Threat model: the living STRIDE pass over every trust boundary, re-verified after each implemented ADR.

Project

mediatore is Apache-2.0 licensed and developed in the open at firestoned/mediatore. The roadmap status board lives in ROADMAPS.md.