Fernet for Java - Secure Token Implementation

Introduction

Fernet for Java is a lightweight, open-source implementation of the Fernet specification. It enables developers to generate, encrypt, and validate secure tokens with symmetric encryption, ensuring confidentiality and integrity in distributed systems.

With key rotation support, the library allows seamless migration between encryption keys without downtime, reducing the blast radius of potential key compromise.

Key Features

AES-128 CBC encryption for confidentiality
HMAC-SHA256 verification for integrity
Token expiration support for secure session handling
Key rotation mechanism with versioned keys and backward compatibility
Lightweight design with minimal dependencies
MIT License for open collaboration

Getting Started

<dependency>
  <groupId>dev.ercan</groupId>
  <artifactId>fernet</artifactId>
  <version>1.0.0</version>
</dependency>

Quick Start Example

import dev.ercan.fernet.Fernet;
String key = secretManager.get("fernet-key");

Fernet fernet = Fernet.of(key);

String token = fernet.encryptUtf8("secret message");
String message = fernet.decryptUtf8(token);

Use Cases

Secure API request validation
Authentication flows
Session management in microservices
Protecting sensitive payloads in distributed systems
Key rotation for compliance with PCI DSS, HIPAA, and security best practices

License

This project is licensed under the MIT License.

Contributing

Contributions are welcome! Please open issues or submit pull requests via GitHub.