Scalable Human Blog

⚡️In a rush? Here is the TLDR.. ☕️
Java 25 introduces a preview feature that adds support for reading and writing cryptographic objects in PEM format. This makes it easier to work with widely used key and certificate formats directly in Java, improving interoperability and reducing the need for external libraries.

🎯 Why Java Developers Should Care About PEM Encoding
If you’ve ever juggled Base64-encoded certificates, private keys, or public keys in Java, you know it hasn’t always been smooth sailing. In Java 25, JEP 470 brings a long-awaited feature: native support for PEM (Privacy-Enhanced Mail) encoding of cryptographic objects. While still in preview, this addition simplifies how Java apps handle common cryptographic formats, no more relying on third-party libraries just to parse a certificate.

This post breaks down what this feature is, how to enable it, and why it matters.

What Is PEM and Why Does It Matter?

PEM is a widely-used text-based format for storing cryptographic data like certificates and keys. It wraps Base64-encoded binary data in header and footer lines such as:

-----BEGIN CERTIFICATE-----
...Base64 data...
-----END CERTIFICATE-----

Until now, Java didn’t support PEM natively. Developers often had to use libraries like Bouncy Castle or write custom parsers. JEP 470 changes that.

What’s in JEP 470?

JEP 470 introduces new APIs in the java.security and javax.security packages to:

• Read and write PEM-encoded data for keys and certificates
• Support standard PEM headers like CERTIFICATE, PRIVATE KEY, PUBLIC KEY
• Use existing Java security classes to handle PEM content without external dependencies

According to the OpenJDK JEP 470 page, this feature aims to “enhance interoperability with other systems and tools that use PEM format.”

What Does “Preview Feature” Mean?

Preview features are new capabilities in the JDK that are fully implemented but not yet permanent. They’re included so developers can try them out and provide feedback. They may be refined or removed in future versions.

To enable this preview feature:

• Compile with --enable-preview
• Run with --enable-preview
• Use JDK 25 or later

Example:

javac --enable-preview --release 25 MyApp.java
java --enable-preview MyApp

Example: Reading a PEM-Encoded Certificate

Here’s a quick snippet showing how this might look in Java 25:

Path path = Paths.get("cert.pem");
X509Certificate cert;
try (Reader reader = Files.newBufferedReader(path)) {
    cert = PemReader.readCertificate(reader);
}
System.out.println(cert.getSubjectX500Principal());

This is much cleaner than previous workarounds and removes the need to decode Base64 manually or depend on third-party libraries.

Why This Matters

• Simplifies development: No more boilerplate or external dependencies for basic crypto tasks.
• Improves interoperability: PEM is the de facto standard in many systems (e.g., OpenSSL, Kubernetes, AWS).
• Reduces security risk: Less custom code means fewer chances for subtle bugs or vulnerabilities.

✅ Key Takeaways

• PEM support is now native in Java 25, making it easier to handle certificates and keys.
• It’s a preview feature, so you must explicitly enable it during compile and runtime.
• No more third-party libraries are needed for basic PEM parsing and encoding.
• Cleaner, safer, and more standard-compliant code is now possible in Java security workflows.
• Ideal for cloud-native and security-focused applications that rely on PEM-formatted credentials.

🎉 Conclusion
Java 25’s native support for PEM encoding is a small but impactful step forward for the Java ecosystem. It streamlines cryptographic workflows, enhances compatibility with other systems, and reduces reliance on external tools. While it’s still a preview, it’s worth experimenting with, especially if your applications deal with certificates or keys.

Try it out, share your feedback with the OpenJDK community, and help shape the future of Java security features.

Have thoughts or questions? Drop them in the comments or share this with your Java team!

📚 Further Reading & Related Topics
If you’re exploring Java 25 PEM Encodings and cryptographic object previews, these related articles will provide deeper insights:
• Understanding Key Certificates in Microservices Key PEM and CRT Files Explained – This article offers a foundational overview of PEM and CRT files, which are central to cryptographic data handling, making it a perfect companion to understanding Java 25’s enhancements.
• Deciphering the Relationship Between TLS and SSL The Backbone of Secure Online Communication – Since PEM encodings are often used in TLS/SSL certificates, this article helps contextualize their role in secure communication protocols.
• SSL vs TLS in Spring Boot Applications Understanding the Security Configuration – For developers integrating PEM-encoded certificates into Java applications, this guide explains how to configure SSL/TLS in Spring Boot, bridging theory with practical implementation.