YubiKit YubiOTP Module

This module provides an interface to configure the YubiKey OTP application, which can be used to program a YubiKey slot with a Yubico OTP, OATH-HOTP, HMAC-SHA1 Challenge-Response, or static password credential.

Note
If you only need to read an OTP payload (over USB or NFC) and don’t need to configure the slots, or access the challenge-response functionality, then using the OtpActivity from the Android module is sufficient.

Dependency

To add the YubiOTP 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:yubiotp:(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 YubiOTP Application

To communicate with the YubiOTP application on a YubiKey, use the YubiOtpSession class. The class provides constructors for all supported types of YubiKeyConnections (OtpConnection over USB, and SmartCardConnection over NFC), as well as a factory method which takes a YubiKeyDevice and will use the best suited connection type available:

YubiOtpSession.create(device, result -> {
  try {
    YubiOtpSession otp = result.getValue();
    // Program a Challenge-Response credential in slot 2:
    otp.putConfiguration(
      Slot.TWO,
      new HmacSha1SlotConfiguration(hmacKey),
      null,
      null,
    );

    // Use the credential:
    byte[] response = otp.calculateHmacSha1(Slot.TWO, challenge, null);
  } catch (...) {
    // Handle errors
  }
});

Additional Resources