The AuthenticatorAssertionResponse interface of the Web Authentication API contains a digital signature from the private key of a particular WebAuthn credential. The relying party's server can verify this signature to authenticate a user, for example when they sign in.

An AuthenticatorAssertionResponse object instance is available in the response property of a PublicKeyCredential object returned by a successful navigator.credentials.get() call.

This interface inherits from AuthenticatorResponse.

Also inherits properties from its parent, AuthenticatorResponse.

AuthenticatorAssertionResponse.authenticatorData Secure context Read only

An ArrayBuffer containing information from the authenticator such as the Relying Party ID Hash (rpIdHash), a signature counter, test of user presence and user verification flags, and any extensions processed by the authenticator.

AuthenticatorResponse.clientDataJSON Secure context Read only

Contains the JSON-compatible serialization of the data passed from the browser to the authenticator in order to authenticate with this credential — i.e., when CredentialsContainer.get() is called with a publicKey option. This data contains some information from the options passed into the get() call, and some information controlled by the browser.

AuthenticatorAssertionResponse.signature Secure context Read only

An assertion signature over AuthenticatorAssertionResponse.authenticatorData and AuthenticatorResponse.clientDataJSON. The assertion signature is created with the private key of the key pair that was created during the originating navigator.credentials.create() call and verified using the public key of that same key pair.

AuthenticatorAssertionResponse.userHandle Secure context Read only

An ArrayBuffer containing an opaque user identifier, specified as user.id in the options passed to the originating navigator.credentials.create() call.

None.

See User login using the WebAuthn API for a detailed example.

• AuthenticatorAttestationResponse: the interface for the type of response given when creating a new credential
• AuthenticatorResponse: the parent interface