Keygen.sh License Validation Demo

A Java demo application that authenticates and validates license keys using the Keygen.sh API.

Prerequisites

• Java 21 or later
• Maven 3.x
• A Keygen.sh account (get one at https://keygen.sh)

Building the Application

mvn clean compile

Running the Application

mvn exec:java -Dexec.mainClass="org.example.Main"

Or compile and run directly:

mvn clean compile
java -cp target/classes org.example.Main

Usage

When you run the application, you'll be prompted for:

1. Account ID: Your Keygen.sh account ID (found in your Keygen dashboard)
2. License Key: The license key you want to validate
3. Machine Fingerprint: Automatically generated based on system properties, or you can provide a custom one

Example Session

=== Keygen.sh License Validation Demo ===

Enter your Keygen.sh Account ID: your-account-id
Enter the license key to validate: DEMO-LICKEY-12345

Auto-generated machine fingerprint: 7B3A5F9C2E8D1A6F
Use auto-generated fingerprint? (Y/n): y
Using auto-generated fingerprint.

Validating license key...
Validating with fingerprint: 7B3A5F9C2E8D1A6F
Machine fingerprint not activated. Attempting to activate...
Machine activated successfully! ID: machine_abc123

=== Validation Result ===
Valid: true
Detail: The license is valid
Code: VALID

=== License Details ===
License ID: abc123
Status: ACTIVE
Scheme: ED25519_SIGN
Uses: 0
Suspended: false

Features

• License key validation via Keygen.sh API
• Automatic machine fingerprint generation based on system properties
• Automatic machine activation when fingerprint is not yet activated
• Optional custom machine fingerprint support
• Detailed validation response display
• Error handling for network and API errors

Project Structure

keygen-demo/
├── src/main/java/org/example/
│   ├── Main.java                    # Main application entry point
│   ├── KeygenConfig.java            # API configuration
│   ├── KeygenLicenseValidator.java  # License validation logic
│   ├── MachineFingerprint.java      # Machine fingerprint generation
│   └── model/                       # Response model classes
│       ├── LicenseValidationResponse.java
│       ├── LicenseData.java
│       ├── LicenseAttributes.java
│       └── ValidationMeta.java
└── pom.xml                          # Maven configuration

API Documentation

For more information about Keygen.sh API:

• API Reference
• License Validation
• Authentication

Machine Fingerprint Generation

The application automatically generates a unique machine fingerprint based on:

• Operating system name and architecture
• User name and home directory
• Primary network interface MAC address
• System hostname
• Java vendor information

The fingerprint is generated as a SHA-256 hash of these combined properties, ensuring uniqueness across different machines while remaining consistent on the same machine.

Automatic Machine Activation

When a license validation fails with the error "fingerprint is not activated (has no associated machines)" and error code NO_MACHINES, the application automatically attempts to activate the machine fingerprint:

1. Detection: Recognizes NO_MACHINES error code in validation response
2. Activation: Sends a machine activation request using the license key
3. Retry: Re-validates the license after successful activation
4. Reporting: Displays activation status and machine ID

This feature eliminates the manual step of machine activation, providing a seamless user experience for new machines while respecting license limits.

Security Notes

• Never commit your account ID or license keys to version control
• The license validation endpoint doesn't require authentication
• Machine fingerprints help enforce license restrictions per device
• For production use, consider implementing proper error handling and logging
• Store sensitive configuration in environment variables or secure configuration files