net-kingdom/docs/public-registration-orchestration-contract.md
tegwick 96266b9371
All checks were successful
CI Smoke / host-smoke (push) Successful in 0s
CI Smoke / container-smoke (push) Successful in 1s
Resume user-engine integration rollout
2026-08-13 14:56:53 +02:00

124 lines
6 KiB
Markdown

# Public registration orchestration contract
Status: implementation contract for NK-WP-0025-T02 and USER-WP-0022-T01/T02.
## Boundary
`user-engine` owns the public registration state machine. It never accepts an
LLDAP password or an LLDAP administrator credential. A verification service
proves mailbox control; the existing identity-provisioner creates the ordinary
LLDAP identity and returns a provider-owned, single-use password-setup URL.
The public browser is not an authenticated user-engine actor. It receives only
opaque registration and verification handles. A verified applicant actor is
constructed from consumed verification evidence and is authorized only for
the registration instance named by that evidence.
## Public flow
1. `POST /api/v1/public/registrations`
accepts `username`, `email`, `display_name`, `client_id`, and optional
`tenant_hint`. Client and tenant values must be registered allow-list
entries; browser-provided return URLs are rejected.
2. The response is always the same `202 Accepted` envelope for syntactically
valid requests, whether the username/email is new, duplicated, throttled,
or already pending. It contains no existence result.
3. user-engine records an expiring registration intent and emits
`registration.verification_requested` through its transactional outbox.
The mail receiver obtains the recipient and an opaque verification handle;
the general event receiver gets only `recipient_present=true`.
4. `POST /api/v1/public/registrations/verify` consumes the opaque handle.
Verification is single-use, expiry checked, purpose bound, and returns
normalized mailbox evidence bound to the registration ID and submitted
username.
5. user-engine attaches the verified email factor, completes registration,
and calls identity-provisioner using the registration ID as the stable
idempotency key. Only the baseline ordinary-user group may be requested.
6. The provisioner creates or resumes exactly one LLDAP identity, links the
provider subject to the user-engine user, and returns its single-use
password-setup URL. Provider collision is a reconciliation result, never a
second privileged identity.
7. After provider password setup, the browser starts a fresh KeyCape
authorization-code/PKCE flow for the allow-listed client. Registration
state is never accepted as an application session.
## Required state
Registration intent persistence must include:
- opaque registration ID and lifecycle status;
- normalized username and email hash, with display values separately
protected from general event/audit output;
- registered client ID and tenant;
- verification handle digest, issued/expiry/consumed timestamps, attempt
counters, and purpose;
- provisioning idempotency key and external provider result;
- allow-listed post-setup authorization target identifier, not a raw URL;
- correlation ID and redacted failure/compensation state.
No password, verification token plaintext, LLDAP admin credential, MFA seed,
or provider bearer token may enter registration state, logs, audit, State Hub,
or the general event lane.
## Validation and abuse controls
- Usernames use the LLDAP-compatible canonical grammar, length limit, and
reserved-name list; case folding happens before uniqueness checks.
- Email is normalized for comparison without provider-specific alias
rewriting. Mailbox verification proves control but does not authorize
linking to an existing user.
- Rate limits apply per source network bucket, normalized email digest, and
username digest. Responses and timing remain non-enumerating.
- CSRF applies to browser form submission; JSON callers additionally require
an allow-listed client registration and idempotency key.
- Verification handles are random, high entropy, stored only as a digest,
purpose-bound, expiring, and atomically consumed.
- Duplicate email/username, expired/replayed verification, and provider
conflict enter explicit reconciliation or terminal states. They never fall
back to auto-linking by email.
## Provider contract
The identity-provisioner request is the existing `ProvisioningRequest` plus a
validated canonical username. The response remains `ProvisioningResult` with
`external_subject`, `status`, and optional `password_setup_url`.
For public registration the adapter must guarantee:
- the same idempotency key returns the same external subject;
- baseline membership only; no tenant-admin or platform groups;
- password setup is provider-owned, single-use, and expiring;
- partial creation is resumable/reconcilable and observable without exposing
credentials;
- the external subject is linked before registration reports completion.
## Activation gates
Public registration stays disabled until all of the following pass together:
1. verification issuer and mail receiver conformance, including replay and
expiry;
2. user-engine persistence migration and anonymous-route abuse controls;
3. flex-auth policy limiting the verified applicant actor to its registration;
4. identity-provisioner canonical-username/idempotency conformance;
5. KeyCape fresh-login return flow and client allow-list checks;
6. disposable-user live tests and cleanup on railiance01.
## Runtime configuration
The source implementation is fail closed and remains disabled unless all of
these are configured together:
- `USER_ENGINE_PUBLIC_REGISTRATION=true`;
- `USER_ENGINE_REGISTRATION_VERIFICATION_URL` and its OpenBao-backed
`USER_ENGINE_REGISTRATION_VERIFICATION_TOKEN`;
- comma-separated `USER_ENGINE_REGISTRATION_CLIENTS` and
`USER_ENGINE_REGISTRATION_TENANTS` allow-lists;
- `USER_ENGINE_REGISTRATION_PASSWORD_SETUP_ORIGINS`, containing only the
trusted HTTPS provider origins allowed to receive the browser.
After verification, user-engine completes the local user, provisions with
the deterministic `public-registration-<registration-id>` idempotency key and
only the `user` role, then links the returned subject under the configured
KeyCape issuer. A setup URL outside the explicit HTTPS origin allow-list is
rejected.