# Platform Identity and Security Architecture

Status: draft architecture baseline for NetKingdom/Railiance/Coulomb
Date: 2026-05-17

## Purpose

This document captures the production-oriented identity, authorization,
MFA, credential, and bootstrap architecture for the platform we are
building. It deliberately treats Coulomb as the first internal tenant and
reference workload, not as the platform itself.

The architecture must be recursive: the same platform that protects
future tenants also protects the services and repositories used to build
and operate the platform. That recursion is useful, but it is also where
many security designs accidentally collapse into self-administering root
power. This document exists to prevent that.

## Core Model

```text
Bootstrap plane
  establishes initial trust before normal platform services exist

Platform control plane
  operates identity, MFA, secrets, policy, audit, and authorization

Tenant planes
  run Coulomb and future customer/project/domain workloads
```

Coulomb is the first internal tenant. It is also the reference tenant that
helps validate the platform. It must not become the platform root of
trust merely because it is first.

## Planes

### Bootstrap Plane

The bootstrap plane exists before the full platform is alive. It owns the
minimal authority needed to create and recover the control plane.

Responsibilities:

- host provisioning and hardening
- root age/SOPS material and emergency bundles
- initial cluster access
- initial identity service deployment
- initial secret injection
- break-glass recovery
- transition to managed runtime authority

Owned primarily by `railiance-infra`, `railiance-cluster`, and the
credential bootstrap work in `net-kingdom`.

### Platform Control Plane

The platform control plane owns shared security services.

Responsibilities:

- NetKingdom IAM Profile
- lightweight identity mode through key-cape
- expanded identity mode through Keycloak
- MFA/token lifecycle through privacyIDEA where applicable
- canonical authorization through flex-auth
- delegated authorization runtime through Topaz first, with other PDPs as
  adapters
- audit and explanation records
- platform service secrets and rotation

Owned conceptually by `net-kingdom`; deployed through the Railiance stack.

### Tenant Plane

Tenant planes are where workloads live. Coulomb is tenant zero/reference
tenant; later tenants may be projects, customers, domains, sandboxes, or
isolated deployments.

Responsibilities:

- protected services and repositories
- tenant-owned resources
- tenant-specific groups, policies, and service accounts
- local enforcement of authorization decisions
- workload audit events and diagnostics

Tenant administrators may manage their tenant resources. They must not be
able to alter platform root trust, global identity configuration,
platform break-glass material, or the policy pipeline that governs the
platform itself.

## Component Responsibilities

| Component | Primary role | Must not become |
| --- | --- | --- |
| `net-kingdom` | canonical security architecture, IAM Profile, SSO/MFA, credential bootstrap decisions | a deployment repo for every stack layer |
| `key-cape` | lightweight IAM implementation of the NetKingdom IAM Profile | a general-purpose IAM platform or authorization engine |
| Keycloak | expanded-mode IAM and optional Keycloak Authorization Services adapter | the canonical model for all platform authorization |
| privacyIDEA | MFA/token authority, especially in lightweight/key-cape mode | a policy decision point for application resources |
| `flex-auth` | authorization control plane, CARING descriptors, policy packages, decision envelopes, audit/explain | an identity provider or backend-specific wrapper |
| Topaz | first delegated authorization runtime/PDP for flex-auth | the platform control plane or identity provider |
| Railiance repos | converged infrastructure, cluster, platform services, enablement, and app deployment | the source of security policy semantics |

## Identity Path

```text
Human/service/agent principal
        |
        v
NetKingdom IAM Profile
        |
        +-- lightweight mode: key-cape
        |       Authelia + LLDAP + privacyIDEA
        |
        +-- expanded mode: Keycloak
                Keycloak + LDAP/Entra federation + MFA integration
```

Applications depend on the IAM Profile, not on the concrete provider.
key-cape is the lightweight profile implementation. Keycloak is the
expanded-mode profile implementation. privacyIDEA provides MFA/token
capabilities where the deployment mode uses it.

Identity answers: who is this actor, how was the actor authenticated,
what coarse claims are asserted, and what assurance evidence exists?

Identity does not answer final resource-specific authorization.

## Authorization Path

```text
Identity claims from IAM Profile
        |
        v
flex-auth
  resource registry
  policy packages
  CARING descriptors
  decision/audit/explain envelope
        |
        +-- standalone evaluator
        +-- Topaz delegated PDP
        +-- optional Keycloak AuthZ adapter
        +-- future OpenFGA/SpiceDB/OPA/Cedar adapters
        |
        v
Protected service enforcement
```

Authorization answers: may this actor perform this action on this
resource in this context, and what explanation/audit/CARING metadata
supports that answer?

Protected services enforce decisions locally. flex-auth is the canonical
policy and decision boundary; delegated PDPs are runtime implementations
behind it.

## Recursive Trust Rule

Normal tenant administration must never be sufficient to alter the
platform root of trust.

This applies even when the tenant is Coulomb. Coulomb can be a tenant and
a reference workload, but platform-root actions require platform control
plane authority and appropriate bootstrap/break-glass safeguards.

Examples of platform-root actions:

- changing IAM Profile semantics
- rotating root bootstrap keys
- changing break-glass access
- changing global MFA requirements
- activating authorization policy that governs platform administration
- changing flex-auth/Topaz policy import pipelines
- changing audit retention or tamper-evidence settings

## Tenant Model

Every protected resource should belong to a tenant or to the platform
control plane.

Suggested identifiers:

```text
tenant:platform          # platform control plane resources
tenant:coulomb           # first internal/reference tenant
tenant:sandbox:<name>    # sandbox tenants
tenant:customer:<name>   # future customer tenants
```

Tenant membership and platform membership are distinct. A subject may be
an administrator in `tenant:coulomb` without being a platform operator.

CARING descriptors should explicitly identify scope and tenant when the
access is tenant-scoped. Platform-scoped descriptors should be rare,
audited, and usually condition-bound.

## Bootstrap To Runtime Transition

Production setup should move through explicit trust states:

1. **Bare host trust** - provisioned and verified by Railiance infra.
2. **Cluster trust** - Kubernetes runtime exists and is verified.
3. **Secret trust** - age/SOPS and emergency bundles are established.
4. **Bootstrap identity trust** - local/bootstrap identity can operate
   enough to install full identity services.
5. **Runtime identity trust** - key-cape or Keycloak becomes the normal
   IAM Profile issuer.
6. **Runtime authorization trust** - flex-auth and Topaz are initialized
   with platform and tenant policies.
7. **Tenant onboarding trust** - Coulomb and later tenants register
   resources and receive scoped authority.

Each transition needs a verification check and a rollback/recovery path.

## Production Topology

For an initial production-capable Coulomb deployment:

```text
railiance-infra
  host baseline, SSH, age keys, emergency material

railiance-cluster
  Kubernetes, ingress, cert-manager, network policy

railiance-platform
  PostgreSQL, object storage, secret management
  key-cape or Keycloak
  privacyIDEA where used
  flex-auth
  Topaz

railiance-apps
  Coulomb services as tenant:coulomb workloads
```

`net-kingdom` owns the architecture and standards. Railiance owns the
converged deployment layers. Component repos own their implementation
contracts.

## Orchestration Implication

A future orchestration repo may be justified, but only after the state
machine is clear. It should not own resources directly. It should own
safe sequencing across repos.

Possible responsibilities:

- verify Railiance preconditions
- initialize credential bootstrap
- deploy or validate identity services
- deploy or validate flex-auth and Topaz
- run IAM Profile conformance checks
- run authorization conformance checks
- produce a platform security readiness report

This orchestration layer should build on Railiance capabilities rather
than bypassing the Railiance stack boundaries.

## Open Questions

- Where is the durable audit log stored for platform-root decisions?
- Which actions require dual control or human confirmation?
- How is break-glass use recorded when normal identity is unavailable?
- Which tenant metadata is required before a service can register
  resources with flex-auth?
- When does the platform switch from key-cape lightweight mode to
  Keycloak expanded mode?
- Does Topaz run centrally for the platform, per tenant, or per service
  for the first production deployment?