# Local Identity

Local Identity is a zero-dependency, file-based user management capability
for net-kingdom bootstrap environments — systems that do not yet have (or do
not need) a running Keycloak instance.

## Why it exists

In net-kingdom, Keycloak is the production identity provider. But Keycloak
requires a running Kubernetes cluster, a database, and a configured realm
before it can authenticate anyone. This creates a bootstrapping paradox:

> You need identity to set up infrastructure, but the infrastructure provides
> identity.

Local Identity breaks this cycle. An operator with only a Linux home directory
can establish their identity, generate deterministic test users, and run
dev/test applications with OIDC authentication — before any service is
deployed.

## Design principles

1. **Zero dependencies** — only the Linux filesystem; no Docker, no K8s, no
   running services required.
2. **Derived identity** — the primary user is derived from `$USER`,
   `/etc/passwd` (GECOS), and a configured email address. No manual setup
   required for the basic case.
3. **Deterministic test users** — two test users are auto-generated from the
   primary user at `init` time using `N` and `+testN` suffixes:

   | Field    | Primary     | Test 1              | Test 2              |
   |----------|-------------|---------------------|---------------------|
   | username | `$USER`     | `${USER}1`          | `${USER}2`          |
   | fullname | GECOS field | `<fullname>+test1`  | `<fullname>+test2`  |
   | email    | configured  | `<user>+test1@…`    | `<user>+test2@…`    |

   Email aliases follow the Gmail `+xxx` convention so test emails route to
   the operator's inbox without extra accounts.

4. **Hard isolation** — test users carry `environment: local`; production
   connectors reject this flag by default. Test users cannot authenticate in
   production without an explicit override.
5. **Minimal OIDC** — a lightweight native OIDC provider backed by the file
   store, for apps that require OIDC in dev/test without a running Keycloak.
   Tokens carry `iss: local-identity`; production systems are configured to
   reject this issuer.
6. **Secure by default** — `~/.local-identity/` is created with mode `700`;
   individual user files with mode `600`; the tool validates permissions on
   every startup and refuses to run if the store is world-readable.

## What it is not

- **Not a production identity provider.** Local Identity is never exposed to
  the internet. It has no MFA. It is not hardened for public traffic.
- **Not a replacement for Keycloak.** Once a cluster is operational, Keycloak
  is the IdP. Local Identity provides an on-ramp, not an alternative.
- **Not multi-user.** Local Identity is single-operator: one primary user
  derived from the Linux session, plus generated test users.
- **Not an LDAP/AD/Entra bridge.** Enterprise federation is handled by
  Keycloak. See EP-NK-001 in the State Hub.
- **No MFA.** Second factors are out of scope; this is intentionally minimal.

## User schema

Users are stored as YAML files under `~/.local-identity/users/`:

```yaml
# ~/.local-identity/users/tegwick.yaml
schema_version: "1"
username: tegwick
fullname: "Bernd Worsch"
email: "bernd.worsch@gmail.com"
environment: local          # never "production" for local-identity users
generated: false            # true for auto-generated test users
production_identity:        # optional: maps this user to a production identity
  username: tegwick
  realm: net-kingdom
```

Test users are generated at `init` time and stored alongside:

```yaml
# ~/.local-identity/users/tegwick1.yaml
schema_version: "1"
username: tegwick1
fullname: "Bernd Worsch+test1"
email: "bernd.worsch+test1@gmail.com"
environment: local
generated: true
source_user: tegwick
production_identity:        # optional: can map to a test/staging account
  username: tegwick-test1
  realm: net-kingdom
```

## Sandbox → production mapping

Each user file can optionally carry a `production_identity` block. When an
entity owned by a local-identity user needs to be transferred to a production
environment (e.g. a resource created during local development), the mapping
provides the correct production user ID.

`local-identity export <user>` produces a Keycloak-compatible user JSON that
respects this mapping. The schema is validated against the Keycloak user
representation to prevent silent drift.

## CLI reference

```
local-identity init              # derive primary user, generate test users
local-identity list              # list all users in the store
local-identity show <username>   # display user file
local-identity export <username> # emit Keycloak-compatible JSON
local-identity security-check    # validate filesystem permissions and config
```

## OIDC provider (Stage 3)

When running `local-identity serve`, a minimal OIDC Authorization Code flow
server starts on localhost. It supports:

- `GET /.well-known/openid-configuration` — discovery document
- Authorization endpoint, token endpoint, userinfo endpoint
- JWT tokens with `iss: local-identity` (hard-coded; production systems
  reject this issuer by default)
- Auto-generated self-signed TLS certificate

This allows dev/test applications to use standard OIDC libraries against
Local Identity without any Keycloak dependency.

**Security note:** the OIDC server binds to `127.0.0.1` only. Never expose
it on a public interface.

## Risks and mitigations

| Risk | Mitigation |
|------|------------|
| World-readable credential files | `~/.local-identity/` mode `700`; startup check fails loudly |
| Test users leaking into production | `environment: local` flag; production connectors reject by default |
| Local Identity tokens accepted in production | `iss: local-identity`; configure production Keycloak to reject this issuer |
| File schema drifting from Keycloak model | `export` command validates against Keycloak representation; schema is versioned |
| Bootstrap store becoming a long-lived crutch | Explicit scope limit: once Keycloak is operational, migrate and stop using Local Identity |

## Relationship to the SSO platform

Local Identity is a complementary workstream to the SSO & MFA Platform
(NK-WP-0001). The SSO platform provides production-grade identity; Local
Identity provides the bootstrap path that allows the SSO platform itself to
be set up and tested.

When the Keycloak realm (NK-WP-0001 T06) is operational, primary and test
users can be exported from Local Identity into Keycloak using
`local-identity export` and the Keycloak admin API.

Implementation: see [NK-WP-0002](../workplans/NK-WP-0002-local-identity.md).