FIDO module

The FIDO module enables applications to authenticate WebAuthn credentials on a YubiKey.

The current implementation follows the Webauthn Level 2 and CTAP 2.0 specifications and can include more properties from newer standard versions.


To add the Fido module, along with the Android module as a dependencies to your project, add the following to your gradle configuration:

dependencies {
  implementation 'com.yubico.yubikit:android:(insert version here)'
  implementation 'com.yubico.yubikit:fido:(insert version here)'

This module depends on the core module, which will automatically be added as a transitive dependency to your project.

Communication with the FIDO Application

To communicate with the Fido application on a YubiKey, use the Ctap2Session class. The class provides constructors for Fido or SmartCard connections, as well as a factory method which takes a YubiKeyDevice and will use the best suited connection type available.

The SDK provides a WebAuthn client implementation which communicates with the YubiKey through CTAP2 and can make new credentials or assert existing credentials. The client has also functionality for working with the PIN.

Credential operations provided by BasicWebAuthnClient use classes which map to standard Webauthn types and allow easier interoperability with RPs. For example PublicKeyCredential.toMap() returns a standard Java Map object which can be serialized to JSON representation:

Ctap2Session session = ...;
BasicWebauthnClient client = new BasicWebAuthnClient(session);
PublicKeyCredential credential = client.makeCredential(params);
String response = JSONObject(credential.toMap()).toString();