net-kingdom/docs/platform-identity-security-architecture.md

Platform Identity and Security Architecture

Status: implemented architecture baseline for NetKingdom/Railiance/Coulomb Date: 2026-05-18

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

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
• runtime secret authority through OpenBao
• audit and explanation records
• platform service secrets, dynamic credentials, leases, 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
OpenBao	runtime platform secrets service, dynamic credential broker, lease/revocation point, and audit source for secret access	the bootstrap root of trust or an application-specific configuration store
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

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

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.

Secret And Credential Path

Bootstrap SOPS/age material
        |
        v
OpenBao platform secrets service
  KV v2 platform configuration
  dynamic database credentials
  Kubernetes auth / workload identity
  future object-storage credential brokering
  audit devices and lease/revocation records
        |
        +-- direct OpenBao clients
        +-- External Secrets Operator / synced Kubernetes Secrets
        +-- CSI-mounted secrets where appropriate
        |
        v
Platform and tenant workloads

SOPS/age remains the bootstrap and Git-at-rest protection mechanism. It can create the initial cluster secrets and emergency recovery bundles, but it should not become the long-lived runtime authority for every workload secret.

OpenBao is the runtime platform secrets service once the control plane is alive. It owns secret leases, revocation, audit, dynamic credentials, and workload-facing secret delivery patterns. Workloads should receive scoped secrets or short-lived credentials, not platform-root material. Tenant administrators may manage tenant-scoped secrets through approved policy paths; they must not gain access to OpenBao root tokens, unseal keys, platform mounts, or global secret engine configuration.

OpenBao does not replace identity or authorization. NetKingdom IAM identifies actors and workloads; flex-auth decides whether a credential or secret request is allowed; OpenBao stores, issues, audits, and revokes the resulting secret material.

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 OpenBao root tokens, unseal policy, platform mounts, or global auth methods
• 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:

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. Bootstrap 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 secret trust - OpenBao is deployed, initialized, unsealed, audited, backed up, and ready to issue scoped secrets.
6. Runtime identity trust - key-cape or Keycloak becomes the normal IAM Profile issuer.
7. Runtime authorization trust - flex-auth and Topaz are initialized with platform and tenant policies.
8. 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:

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

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

railiance-platform
  OpenBao, PostgreSQL, object storage, platform service secret delivery
  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.

ADR-0007 records the current decision: keep orchestration in Railiance playbooks for now, with NetKingdom defining the trust-state model, readiness checks, OpenBao boundaries, and security semantics.

flex-auth And Topaz Implications

flex-auth work must preserve the recursive boundary between platform control-plane resources and tenant resources.

Required implications:

• CARING descriptors must include scope and tenant metadata for tenant-scoped access, and must mark rare platform-scoped access explicitly.
• Policy packages must distinguish tenant:platform policy from tenant-local packages such as tenant:coulomb.
• Decision envelopes must carry subject, issuer, audience, tenant, protected-system id, resource, action, requested TTL where relevant, assurance evidence, obligations, deny reasons, and audit correlation ids.
• Topaz is a delegated PDP runtime behind flex-auth. It must not become the canonical policy model, identity provider, or platform control plane.
• Audit and explain records must be durable enough to reconstruct why a platform-root, secret, credential, or tenant-administration decision was allowed or denied.
• Platform-root guardrails must deny tenant administrators the ability to alter IAM Profile semantics, OpenBao platform mounts/auth methods, flex-auth policy import pipelines, Topaz runtime configuration, or platform audit retention.

OpenBao secret access and dynamic credential requests follow the same authorization rule: identity proves the actor or workload, flex-auth decides whether the request is permitted, and OpenBao stores, issues, leases, audits, and revokes the secret material.

Coulomb Tenant Onboarding Path

The first Coulomb tenant onboarding path should be repeatable before it becomes automated:

1. Register tenant:coulomb as a tenant distinct from tenant:platform.
2. Map Coulomb human, service, and agent principals to IAM Profile claims with issuer, audience, subject, group, tenant, and assurance evidence.
3. Register Coulomb protected systems and resources in flex-auth with stable protected-system ids.
4. Import tenant-scoped policy packages and CARING descriptors for Coulomb resources.
5. Initialize the delegated PDP runtime, starting with Topaz, using only the policy packages approved for the tenant and platform boundary.
6. Provision Coulomb workload secret paths, Kubernetes auth roles, or delivery mechanisms in OpenBao without granting access to platform mounts, unseal/recovery material, or global auth configuration.
7. Run audit readiness checks before admitting production traffic: identity issuance, flex-auth decision envelope, Topaz health, OpenBao audit event, workload enforcement event, and correlation id.

The onboarding path is complete when a Coulomb workload can authenticate, receive a scoped authorization decision, obtain only the allowed secret or short-lived credential, enforce the decision locally, and produce an auditable record without receiving platform-root authority.

Production Readiness Checks

Before the security platform is production-ready, each trust state needs an explicit check:

Area	Readiness check
MFA and identity	key-cape or Keycloak issues IAM Profile-compatible tokens; privacyIDEA or the selected MFA provider enforces required assurance for privileged actions
Bootstrap and recovery	age/SOPS material, emergency bundle, and break-glass credentials are present, tested, and separated from tenant administration
OpenBao runtime secrets	OpenBao is initialized, unsealed or auto-unsealed by the approved mechanism, backed up, audited, and using scoped auth methods and mounts
Secret rotation	service, database, OpenBao-issued, and break-glass rotation paths have documented blast radius and verification steps
flex-auth policy state	platform and tenant policy packages are versioned, reviewable, imported, and explainable
Topaz runtime	delegated PDP health, data freshness, policy load status, and fail-closed behavior are verified
Tenant onboarding	tenant:coulomb resources, claims, policies, OpenBao paths, and audit correlation are registered and tested
Audit sink	identity, flex-auth, Topaz, OpenBao, Kubernetes, and workload audit records land in durable storage with restore/drill coverage
Break-glass	emergency access works when normal identity is unavailable and produces a post-event review record

Open Questions

• Where is the durable audit log stored for platform-root decisions?
• Where are OpenBao audit logs durably shipped, and how are they included in tamper-evidence and restore drills?
• Which actions require dual control or human confirmation?
• How is break-glass use recorded when normal identity is unavailable?
• Which workloads consume OpenBao directly, via External Secrets Operator, or via CSI-mounted secrets?
• 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?