YubiKit
· This library provides a way to parse Yubikey OTP from NFC tag, UI dialog to show user that OTP reading requires his action and detecting OTP from device than connected over NFC or USB. And also provides method for validation of OTP on server.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window otp-1.0.0.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.
