zoreal-oauth2

Login with ZOREAL for Ruby backends: the relying-party half of the flow that @zoreal/oauth2-react starts in the browser.

The browser SDK runs the pairing (QR or app link), and hands your frontend an authorization code plus the code_verifier and nonce it generated. Your frontend posts all three to your backend, and this gem does the rest: the code exchange with your client authentication, ES256 verification of the ID token against the provider's JWKS, and the /userinfo read for personal claims.

zoreal-oauth2 (this gem)   your backend: exchange, verify, userinfo
@zoreal/oauth2-react       your frontend: the button, the QR, the polling

Install

# Gemfile
gem 'zoreal-oauth2'

Or directly: gem install zoreal-oauth2.

Ruby >= 3.1. One dependency: jwt.

Getting your credentials

Everything the client constructor needs comes from a ZOREAL asset.

Create an account at https://zoreal.com and open Assets.
Create an asset — a website (a domain you own) or an app bundle (a reverse-DNS bundle id). An asset is the thing users log in to; its token is your client_id and it looks like ast_....
On the asset, open the OAuth2 tab and set:
- the redirect URIs and JavaScript origins your app uses (requests from anything not registered are rejected — this is the core control),
- the scopes the client is allowed to request (see the catalogue below),
- your client authentication: generate a client secret (client_secret_basic), or register a JWKS for private_key_jwt. A public client authenticates with PKCE alone and no secret.
A website asset must verify its domain (a DNS or meta-tag proof, shown in the dashboard) before it can request personal-data scopes or sign users in; the verified domain is what your users' sub is pairwise against.

The client_id is public (it ships in your frontend). The client secret is not — keep it in your server's secret store, never in the browser.

There is no test-identity sandbox — and that is deliberate

ZOREAL never issues fake or sandbox humans: a pool of test identities would be a fraud vector against the exact thing the product proves. So you always authenticate real ZOREAL IDs.

To develop and test, create a free ZOREAL ID for yourself (enrol in the ZOREAL ID app) and sign in with it. Mark your asset's environment sandbox in the dashboard while building — a sandbox asset may register http://localhost origins and redirect URIs that a production asset may not — and flip it to production when you ship. The identities are real either way; only the allowed origins differ.

Quick start

Build one client at boot and share it; it is thread-safe.

ZOREAL_OAUTH = Zoreal::OAuth2::Client.new(
  client_id: ENV['ZOREAL_CLIENT_ID'],                                   # ast_...
  client_secret: Rails.application.credentials.dig(:zoreal, :client_secret),
  issuer: ENV.fetch('ZOREAL_ISSUER', 'https://id.zoreal.com'),
  cache: Rails.cache                                                    # optional, for the JWKS
)

The endpoint your frontend posts to:

login = ZOREAL_OAUTH.authenticate(
  code: params[:code],
  code_verifier: params[:code_verifier],   # PKCE is mandatory; the SDK hands it over
  nonce: params[:nonce]                    # binds the ID token to this login
)

login.sub          # "TC5X-JN7G-YTSE-6E63" — pairwise, stable for YOUR domain
login.acr          # "zoreal.live" | "zoreal.device" | "zoreal.session"
login.assurance    # uniqueness basis, verification month, chip liveness, trust tier
login.email        # from /userinfo, when your client has the email scope
login.email_verified?
login.name         # from /userinfo, profile.name scope

Account matching, the shape that works:

user = User.find_by(provider: 'zoreal', uid: login.sub)
if user.nil?
  user = User.find_by(email: login.email) if login.email_verified?  # claim, don't collide
  user ||= User.new(email: login.email)
  user.update!(provider: 'zoreal', uid: login.sub)
end

Assurance levels — `acr`, and requiring a liveness check

What `acr` is

acr is an OpenID Connect standard claim — Authentication Context Class Reference. It is a single string in the ID token that says how strongly this particular login was authenticated. Every ZOREAL login carries one, and it is the difference between "someone who once enrolled this identity is behind this request" and "a live human, verified to be the right one, is behind this request right now".

It answers a question the sub cannot. sub tells you who (a stable, pairwise identifier for this person at your site). acr tells you how sure ZOREAL is that the person is really there for this login. A stolen, unlocked phone can still produce a sub; it cannot produce a fresh zoreal.live.

The three levels

Ordered weakest to strongest. Each is what actually happened, never what was requested — a login that could only reach a weaker level says so honestly rather than claiming the level you asked for.

`acr`	What the holder did	`amr`	What it proves	What it does not prove
`zoreal.session`	Nothing — a returning holder at a site they have used before, resumed silently from an existing ZOREAL session, no phone interaction	`[]`	Continuity: the same browser/session ZOREAL already knew	That the holder is present, or even awake
`zoreal.device`	Approved the login on their enrolled phone: a signature from a key in the phone's secure element, released by a local biometric or passcode unlock	`["hwk","user"]`	Possession of the enrolled device and a local unlock on it	That a live face was captured for this login — an unlocked phone in the wrong hands still signs
`zoreal.live`	All of the above plus a fresh face capture this login: a flash-plus-zoom video scored for presentation attacks and screen replay (moire), matched 1:1 against the government document read at enrolment	`["hwk","face","user"]`	A live, real, unique human, verified to be the enrolled person, at the moment of this login	— (this is the strongest level)

amr (Authentication Methods References) is the companion claim listing the factors used: hwk a hardware key, user a user-presence/unlock gesture, face a face biometric. zoreal.live is exactly zoreal.device with face added, because a live login is a device approval with a capture on top.

The default is zoreal.device, never zoreal.session: a login that asks for nothing still requires the enrolled phone and a local unlock. Silence has to be explicitly asked for (prompt=none), and it succeeds only for a returning holder at a site whose consent they have already given.

When to require which

zoreal.session — you never require this; it is what a returning holder gets for a low-stakes convenience re-auth when they ask for the silent path.
zoreal.device (the default) — a forum, a community, a normal account login. Possession of the enrolled phone plus a local unlock is a high bar already; most sites want exactly this and should pass no acr at all.
zoreal.live — a bank onboarding, a high-value transaction, an age-gated purchase, a first login, a "confirm it is really you" step before a sensitive action. Anywhere a fresh, unforgeable proof of the live, right human is worth the few seconds a face capture costs.

Requesting versus verifying — the one rule that matters

Requesting a level and verifying it are two separate steps, and only the second is security:

Request it on the wire, in the frontend, with the SDK's acr_values: 'zoreal.live'. This is what makes the holder's ZOREAL ID app run the face capture before it will approve. It is advisory — it shapes what the holder is asked to do, nothing more. A browser is attacker-controlled; a value that only travels through it proves nothing.
Verify it here, at token exchange, by passing acr:. The signed acr claim in the ID token — minted by ZOREAL, not by the browser — is the proof.

login = ZOREAL_OAUTH.authenticate(
  code: params[:code], code_verifier: params[:code_verifier],
  nonce: params[:nonce],
  acr: 'zoreal.live'    # raises VerificationError unless the signed token says so
)

login.acr                            # "zoreal.live" — what actually happened
login.live?                          # convenience: acr == "zoreal.live"
login.satisfies_acr?('zoreal.device')# true (live is stronger than device)

An RP that requests zoreal.live on the wire but never passes acr: here has checked nothing — it has only asked the holder nicely and then trusted a value it never validated.

How the check behaves

Verification satisfies upward: zoreal.session < zoreal.device < zoreal.live, so a requirement of zoreal.device accepts a zoreal.live token (the holder gave you more assurance than you demanded). A token whose acr is below the requirement, missing entirely, or outside the vocabulary is refused with VerificationError. An unknown required value — a typo like 'zoreal.liveness' — raises ConfigurationError instead, because that is a bug in your code, not a bad token, and failing every login silently is worse than saying so.

If you prefer to branch rather than raise, omit acr: and inspect the result:

login = ZOREAL_OAUTH.authenticate(code:, code_verifier:, nonce:)
unless login.satisfies_acr?('zoreal.live')
  # step the user up, or refuse the sensitive action
end

`acr` versus the assurance block

Do not confuse acr with login.assurance. acr grades this login event. The assurance block (login.assurance) describes the identity behind it — how the person was verified at enrolment (uniqueness basis, verified_on month, whether chip liveness was proven, the trust_tier, the device's key_protection). One is about now; the other is about who they are. A high-value flow usually wants both: acr: 'zoreal.live' for presence, and the assurance block for the strength of the underlying identity proofing.

Client authentication: all four registered methods

`token_endpoint_auth_method`	Configuration	What travels
`none`	nothing	a public client: PKCE alone, Tier A scopes only
`client_secret_basic`	`client_secret:`	the secret, as HTTP Basic
`private_key_jwt`	`private_key:` (PEM or `OpenSSL::PKey`), `private_key_kid:` optional	a fresh RFC 7523 assertion per exchange: `iss`=`sub`=client id, `aud`=`{issuer}/token`, 60-second life, single-use `jti`. P-256 signs ES256, RSA signs RS256
`tls_client_auth`	`tls_client_cert:`, `tls_client_key:`	the TLS client certificate. Registrable today; the provider still answers 501 at `/token`, and that surfaces as the `ExchangeError` it is

auth_method: may be omitted: a client_secret implies client_secret_basic, a private_key implies private_key_jwt, neither means none.

What each call does

Call	What happens
`authenticate(code:, code_verifier:, nonce: nil)`	`exchange` + `verify_id_token`, returns a `Login`
`exchange(code:, code_verifier:)`	`POST {issuer}/token` with the configured client authentication
`verify_id_token(jwt, nonce: nil)`	ES256 against `{issuer}/jwks`, checks `iss`, `aud`, `exp`, and `nonce` when given
`userinfo(access_token)`	`GET {issuer}/userinfo` with the Bearer token
`Login#userinfo`	the above, once, memoized; `{}` when there is no access token

Login exposes every claim the scope catalogue can grant: sub, acr, amr, assurance, age_over?(n), nationality from the ID token; email, email_verified?, name, given_name, family_name, birthdate, document_type, document_number, issuing_country, document_expires_on and portrait from /userinfo (portrait is registrable but not served by the provider yet, and returns nil until it is).

Scopes and claims

Scopes are requested in the frontend (the SDK's scope string, always starting with openid), consented to by the holder, and pre-authorized on your asset. What each grants and where it is delivered:

Scope	Claims	Delivered in	Tier	Requires
`openid`	`sub`, `iss`, `aud`, `exp`, `iat`, `nonce`, `auth_time`, `acr`, `amr`, and the assurance block	ID token	A	any client
`zoreal.age`	`age_over_13/16/18/21/65` booleans — only the thresholds you registered, never an age or birthdate	ID token	A	any client
`zoreal.nationality`	`nationality` (ISO 3166-1 alpha-3)	ID token	A	any client
`email`	`email`, `email_verified`	`/userinfo`	B	confidential client + verified domain
`profile.name`	`name`, `given_name`, `family_name`	`/userinfo`	B	confidential client + verified domain
`profile.birthdate`	`birthdate` (full ISO 8601 date)	`/userinfo`	B	confidential client + verified domain
`profile.document`	`document_type`, `document_number`, `issuing_country`, `document_expires_on`	`/userinfo`	B	confidential client + verified domain
`profile.portrait`	`portrait` (the chip's facial image; GDPR Article 9 data)	`/userinfo`	C	confidential client + verified domain — registrable but not served yet

Tier A rides in the ID token and is available to every client, so the no-backend browser button can use it. Tier B and C are personal data, served only from /userinfo to a confidential client on a domain you have verified, and never placed in a browser token.
Age thresholds are a fixed set — 13, 16, 18, 21, 65 — that you register on the asset. login.age_over?(n) returns nil for a threshold you did not register (no claim was minted), which is different from false.

Error reference

exchange / authenticate raise ExchangeError, which carries the provider's own oauth_error code and description verbatim. What you will actually see:

`oauth_error`	Cause	Retryable?
`invalid_grant`	The code is spent — unknown, expired (60s), already used, PKCE mismatch, or the asset's domain verification lapsed mid-flow	No. Start a new login; the code cannot be reused
`invalid_request`	Client authentication failed — wrong secret, a bad `private_key_jwt` assertion, or `tls_client_auth` (not accepted at `/token` yet)	No. Fix your client configuration
`unsupported_grant_type`	Something other than `authorization_code` reached `/token`	No. A bug

Errors that surface in the frontend instead, before your backend is involved (from the SDK's onError / onNonOAuthError), so handle them there:

Where	Code	Meaning
`/pair`	`invalid_scope`	A scope not on the asset's allowed list, or a Tier B scope from a public client
`/pair`	`invalid_request`	Missing PKCE/nonce, an unverified sector, an unregistered `redirect_uri`, or an unknown `acr_values`
`/pair`	`login_required`	`prompt=none` with no silent session to resume — the expected quiet outcome, not a failure
pairing	`request_denied`	The holder declined in their ZOREAL ID app — not an error to alarm on; offer to try again
pairing	`request_expired`	The pairing window elapsed, or a required liveness the device could not meet — offer to try again

The gem's other error classes: ConfigurationError (you built the client wrong, or asked to verify an acr outside the vocabulary — a bug in your code, not a bad token), VerificationError (the ID token did not verify: signature, iss, aud, exp, nonce, or the acr floor), and UserinfoError (the /userinfo call failed). A returning user matched on sub can survive a rescued UserinfoError; a signup that needs the email cannot.

The assurance block

login.assurance is the ID token's zoreal claim — a hash describing the strength of the identity behind this login (distinct from acr, which grades the login event). Its keys and their value sets:

Key	Values	Meaning
`uniqueness`	`personal_number` \	`document` \	`none`	The anchor the holder is deduplicated on. `personal_number` (a national number from the chip) is strongest; `none` means no reliable anchor
`verified_on`	`"YYYY-MM"`	The month the underlying document was verified. Quantised to a month on purpose — a day-precision date is a cross-site correlator
`chip_liveness_proven`	`true` \	`false`	Whether the passport chip's active-authentication challenge was proven (a genuine chip, not a clone)
`trust_tier`	`high` \	`standard`	`high` when `chip_liveness_proven`, else `standard`
`key_protection`	`secure_enclave` \	`strongbox` \	`tee` \	`software`	How the holder's device key is protected. `software` means no hardware attestation

A high-value flow usually pairs acr: 'zoreal.live' (fresh presence) with a check on the assurance block (identity strength) — e.g. requiring uniqueness == 'personal_number' and trust_tier == 'high'.

A complete example

A Rails controller, end to end — the shape a real integration takes:

# config/routes.rb
post '/auth/zoreal', to: 'sessions#zoreal'

# app/controllers/sessions_controller.rb
class SessionsController < ApplicationController
  # Your frontend's ZorealLogin onSuccess posts { code, code_verifier, nonce }
  # here over your own TLS. Protect this endpoint with your normal CSRF /
  # same-origin controls, exactly as you would any login endpoint — the ZOREAL
  # nonce protects the token, not your route.
  def zoreal
    login = ZOREAL_OAUTH.authenticate(
      code: params[:code],
      code_verifier: params[:code_verifier],
      nonce: params[:nonce]
      # acr: 'zoreal.live'  # add for a step-up / high-value login
    )

    user = User.find_by(provider: 'zoreal', uid: login.sub)
    if user.nil?
      # Claim an existing account that owns this verified email rather than
      # colliding on the unique index; otherwise create one.
      user = User.find_by(email: login.email) if login.email_verified?
      user ||= User.new(email: login.email, full_name: login.name)
      user.update!(provider: 'zoreal', uid: login.sub)
    end

    reset_session                       # fixation defence
    session[:user_id] = user.id
    render json: { ok: true }
  rescue Zoreal::OAuth2::ExchangeError, Zoreal::OAuth2::VerificationError => e
    # A spent code or a token that did not verify: the login must be restarted.
    Rails.logger.warn("ZOREAL login failed: #{e.message}")
    render json: { error: 'sign_in_failed' }, status: :unauthorized
  rescue Zoreal::OAuth2::UserinfoError => e
    # Personal data was unreachable. Fine for a returning user matched on sub;
    # fatal for a signup that needs the email.
    render json: { error: 'sign_in_failed' }, status: :unauthorized
  end
end

Things worth knowing before you integrate

The ID token never carries personal data. sub, timing, acr/amr, the assurance block, and — if registered — age_over_* booleans and nationality. Email, names, birthdate and document fields come only from /userinfo, which is why authenticate alone is not enough for a signup.
The access token lives 10 minutes. Read /userinfo while handling the login; do not store the token for later.
sub is pairwise per verified domain. It is the right account key and it is derived from your registered sector: changing your asset's domain rotates every sub you have stored. Plan domain changes as a migration.
ES256 only. The provider signs with nothing else, and this gem refuses other algorithms rather than negotiating.
Always pass the nonce through, and protect your own endpoint too. The SDK generates the nonce and gives it to your frontend in onSuccess; passing it here lets the gem confirm the ID token was minted for this login rather than substituted. Two things it does not do: it is not your endpoint's CSRF token (protect your /auth/zoreal route with your framework's normal CSRF / same-origin defence), and PKCE — not the nonce — is what proves whoever exchanges the code is whoever started the flow.
Email is a deliberate choice. It is a Tier B scope precisely because a shared email defeats the unlinkability the pairwise sub provides. Request it because you need it, not because the checkbox is familiar.
The issuer must match the token's iss exactly — it is compared, not normalized. Production is https://id.zoreal.com; override issuer: only when pointing at a non-production provider you were given.

Verifying this release

Every version is published from GitHub Actions by RubyGems trusted publishing: the workflow authenticates to rubygems.org over OIDC and no long-lived API key is stored. Each build is also attested with Sigstore build provenance and recorded in a public transparency log, so you can confirm which commit and workflow produced the gem:

gem fetch zoreal-oauth2
gh attestation verify zoreal-oauth2-*.gem --repo Bynn-Intelligence/zoreal-oauth2-ruby

The ZOREAL OAuth2 library family

Repository	Package	Role
zoreal-oauth2-react	@zoreal/oauth2-react (npm)	React frontend: the button, the QR, the polling
zoreal-oauth2-js	@zoreal/oauth2-js (npm)	Framework-free browser core
zoreal-oauth2-react-native	@zoreal/oauth2-react-native (npm)	React Native frontend
zoreal-oauth2-node	@zoreal/oauth2-node (npm)	Node.js backend
zoreal-oauth2-ruby	zoreal-oauth2 (RubyGems)	Ruby backend
zoreal-oauth2-python	zoreal-oauth2 (PyPI)	Python backend
zoreal-oauth2-php	zoreal/oauth2 (Packagist)	PHP backend
zoreal-oauth2-go	github.com/Bynn-Intelligence/zoreal-oauth2-go	Go backend
zoreal-oauth2-java	com.zoreal:oauth2 (Maven Central)	JVM backend
zoreal-oauth2-dotnet	Zoreal.OAuth2 (NuGet)	.NET backend

The repository always carries the platform suffix; the package drops it where the registry already scopes the ecosystem. None of them are named after a framework, because none of them depend on one.

License

MIT.