Yubico Mobile SDK (YubiKit) for Android

YubiKit is an Android library provided by Yubico to enable YubiKey support in Android apps. Both USB and NFC-enabled YubiKeys are supported.

Note	Version 2.0 breaks compatibility with 1.0. We will be announcing a webinar shortly, along with some guides to help with migration.

For more information on the various concepts and features used in this SDK, see our YubiKey Concepts overview.

The library includes a YubiKit Android Demo application, which provives a complete example of integrating and using the features of this library in an Android app. While this demo is written in Kotlin, the library itself is written in Java, and can be used by both Java and Kotlin.

Changes to this library are documented in the NEWS file.

Note	The pre-release version of YubiKit Android SDK supported a subset of FIDO2 functionality. In this general availability (GA) version, that FIDO2 module has been removed. If you require the FIDO2 module, we recommend developers use the official FIDO2 API for Android provided by Google.

About

The SDK is split up into multiple modules. Each module has its own documentation and can be used independently of the others. All YubiKit modules include javadoc and additional resources deployed with the library archive. Refer to the javadoc documentation detailed about the API’s methods, properties, and parameters. The SDK is versioned as a whole: You should not mix YubiKit modules with different version numbers. The modules are:

Core

The core module defines the main SDK concepts and provides interfaces for interacting with a YubiKey, as well as common utilities used by the various other modules. All other modules depend on this.

Android

This module provides concrete implementations for the interfaces in core, the YubiKitManager class which is used to get a reference to a YubiKey, as well as various reusable UI elements.

Management

This module provides the ability to read out metadata from a YubiKey, such as its serial number, and firmware version. It also allows changing the confiuration of a YubiKey, to enable/disable other applications, etc.

YubiOTP

This module lets you configure the YubiOTP application. This includes configuring the two "keyboard slots", and using the Challenge-Response functionality.

OATH

This module lets you configure and use the OATH application on a YubiKey. It can store and use up to 32 OATH (TOTP or HOTP) credentials.

PIV

This module lets you configure and use the PIV application on a YubiKey. It supports importing, generating, and using private keys. Reading and writing data objects suchs as X.509 certificates, and managing access (PIN, etc).

Getting Started

A good place to get started is to clone the repository and try out the included demo app. To integrate the SDK into your app, add the desired dependencies to your Gradle configuration, and proceed with the instructions provided with the modules you are using, starting with the Android module.

Support

If you run into any issues during the development process, please fill out a developer support ticket and our team will be happy to assist you.

FAQ

Q1. Does YubiKit work with all versions of Android?

A1. All YubiKit modules should work on Android API 19+. Yubico typically tests and supports n-1 per https://en.wikipedia.org/wiki/Android_version_history.

Q2. How can I debug my app on Android when a YubiKey takes up the USB port?

A2. Set up Android Debug Bridge (adb) debugging over WiFi: https://developer.android.com/studio/command-line/adb#wireless

Q3. Why is the USB device permissions prompt shown every time the YubiKey is connected?

A3. This is an Android limitation. Android handles these permissions at the OS level. The only workaround is to use an intent filter, as described in the Android Developers Guide USB Host Overview. However, if you apply this filter to remove the permissions prompt, then you cannot prevent your app from launching automatically whenever the YubiKey is connected.

Q4. Why does the Android YubiKit library not provide a FIDO2 module?

A4. The current state of the Google FIDO2 API provided by Google Play Services is so much improved that Yubico adding a wrapper would not have accomplished anything significant. We recommend developers use the official FIDO2 APIs provided by Google.

Q5. Does the YubiKit support both USB and NFC?

A5. Yes. The Android module provides functionality to detect and connect to YubiKeys over both USB and NFC.

Additional Resources

• Yubico Developers site - developers.yubico.com

• Android Developers site - developer.android.com