Account Center & Device Unlock

The calls are blocking (run them off the main thread). Each takes an HTTP client and the Aduki ID base, https://id.aduki.pro/v1.

pro.aduki.net.http.Center talks to Aduki ID’s Account Center (ADK-AUTH-002 §5) and device-bound unlock (ADK-AUTH-001 §9).

Device unlock

A device credential is Ed25519 (EdDSA) or ECDSA P-256 (ES256, what the Android Keystore, StrongBox and the Secure Enclave hold). The algorithm and the public key encoding come from the Key you pass; they are never guessed by the server.

1. Keep the private key in the platform keystore. The SDK only asks the Key (or a sign callback) for a signature and never sees the private part.
2. Register it with Center.register(client, identity, bearer, device, key, code, center) (a fresh TOTP step-up code is required; center = true registers it for the Account Center instead of one account). The call sends alg and the public key: ES256 sends the 65-byte uncompressed point 0x04 || x || y (x and y left-padded to 32 bytes) in base64url without padding; EdDSA the 32-byte key. It checks that the server answered with the same alg. A P-256 key sent without alg: "ES256" is 422 at Aduki ID, so the old overload register(..., public: ByteArray, ...) is for Ed25519 only.
3. To unlock, call Center.unlock(client, identity, credential, key) (or the sign callback form). The server issues a single-use nonce (valid for 2 minutes, {nonce, expires}); the key signs the raw nonce bytes (not the base64url text). ES256 uses SHA-256 and the 64-byte r || s form: Software already returns it and AndroidKey converts the Keystore’s DER with crypto.dpop.Der.toRaw(der, 32). S is not normalised: low-S and high-S are both accepted. The server returns tier-1 sessions for every account that allows center unlock.

Errors: every unlock failure (bad signature, wrong key, spent, expired or foreign nonce) is the same 401 auth.invalid, thrown as AdukiException.Unauthorized; the call is one attempt and does not retry, and the next call fetches a fresh nonce. A refused attempt does not spend the nonce at the server, a successful one does. 404 (AdukiException.Network, code 404) means the credential is revoked or lapsed: sign in fully. 422 at registration (Network, code 422) is a refused key or label, or an old Aduki ID that does not know ES256. A signature that is not 64 bytes (for example a DER signature) is refused locally with IllegalArgumentException and is never sent.

A credential works for 60 days after the full authentication that registered it. Once that window lapses, the user must sign in with their password again.

Status: built against the contract of Aduki ID PR 35 and tested on the JVM against a fake server with an independent verifier. Not yet run against a real Aduki ID.

Android authenticator

The android module keeps the linked accounts as separate AccountManager entries under the type pro.aduki.account (Accounts.reconcile, AdukiAuthenticator; see Android module). When Aduki ID removes a link (tenant links = deny, forced unlink), Accounts.refresh drops the entry and its tokens. The center token is stored in a separate sealed file and sent to Aduki ID only.

Accounts.registerDevice and Accounts.unlockWithDevice use AndroidKey.open(AndroidKey.DEVICE) (P-256, ES256) as the signer of this flow and store each unlocked session. This glue is UNVERIFIED: it could not be compiled or run without the Android SDK (see guide/ANDROID-TESTS.md).