# Authenticator

Utility functions for constructing and parsing authenticator data and client data JSON.

## Functions

| Name                | Description                         |
| ------------------- | ----------------------------------- |
| [`Authenticator.getAttestationObject`](/webauthn/webauthn/Authenticator/getAttestationObject) | Constructs a CBOR-encoded attestation object for testing WebAuthn registration verification. Combines the authenticator data with an attestation statement. |
| [`Authenticator.getAuthenticatorData`](/webauthn/webauthn/Authenticator/getAuthenticatorData) | Gets the authenticator data which contains information about the processing of an authenticator request (ie. from `Authentication.sign`). |
| [`Authenticator.getClientDataJSON`](/webauthn/webauthn/Authenticator/getClientDataJSON) | Constructs the Client Data in stringified JSON format which represents client data that was passed to `credentials.get()` or `credentials.create()`. |
| [`Authenticator.getSignCount`](/webauthn/webauthn/Authenticator/getSignCount) | Extracts the signature counter from the authenticator data. The counter is a 4-byte big-endian unsigned integer at bytes 33–36. |