Table of Contents

Interface IRestoreCredentialProvider

Namespace
VpnHood.AppLib.Abstractions.Accounts
Assembly
VpnHood.AppLib.Abstractions.dll

The device side of zero-tap sign-in restoration (Android "Restore Credentials", a Play requirement for sign-in apps from April 2027): a platform-held key pair that follows the person through device-to-device transfer and cloud restore. The portal is the relying party and OWNS every options document — implementations pass the JSON through to the platform credential API verbatim and hand its response back verbatim, composing nothing themselves.

Each call takes the window, null where none is open; a platform API that needs one fails then. 

public interface IRestoreCredentialProvider : IDisposable
Inherited Members

Methods

Clear(IUiContext?, CancellationToken)

Clear this device's restore credential (sign-out). Idempotent.

Task Clear(IUiContext? uiContext, CancellationToken cancellationToken)

Parameters

uiContext IUiContext

The window, or null where none is open.

cancellationToken CancellationToken

The token to monitor for cancellation requests.

Returns

Task

A task that represents the asynchronous operation.

Exceptions

UiContextNotAvailableException

uiContext is null, and the platform needs a window.

ApiException

The platform failed to clear it, as Google's credential manager reports a failure or a cancel.

Create(IUiContext?, string, CancellationToken)

Create (or silently replace) this device's restore credential for the portal's WebAuthn creation options. Returns the platform's registration response JSON, to be posted back to the portal verbatim.

Task<string> Create(IUiContext? uiContext, string requestJson, CancellationToken cancellationToken)

Parameters

uiContext IUiContext

The window, or null where none is open.

requestJson string

The portal's WebAuthn creation options, as JSON.

cancellationToken CancellationToken

The token to monitor for cancellation requests.

Returns

Task<string>

A task whose result is the platform's registration response, as JSON.

Exceptions

UiContextNotAvailableException

uiContext is null, and the platform needs a window.

InvalidOperationException

The platform answered with a response of another type.

OperationCanceledException

cancellationToken was canceled.

TryGet(IUiContext?, string, CancellationToken)

Sign the portal's WebAuthn request options with the restored credential — the zero-tap moment on a new device. Returns the assertion response JSON verbatim, or null when this device holds no restore credential (a fresh install that was never restored).

Task<string?> TryGet(IUiContext? uiContext, string requestJson, CancellationToken cancellationToken)

Parameters

uiContext IUiContext

The window, or null where none is open.

requestJson string

The portal's WebAuthn request options, as JSON.

cancellationToken CancellationToken

The token to monitor for cancellation requests.

Returns

Task<string>

A task whose result is the assertion response, as JSON, or null where the device holds no restore credential.

Exceptions

UiContextNotAvailableException

uiContext is null, and the platform needs a window.

InvalidOperationException

The platform answered with a credential of another type.

OperationCanceledException

cancellationToken was canceled.