Green Screens for IBM i, Release v6

A large and significant update has arrived. The major changes are switch to Java JEE 10 - Jakarta, significant digital certificate improvements, OCSP responder and CRL service support and many more.

This update is also significant for future versions coming next year. We made several internal changes (preparation) for arrival of Java 21. Why this is so important?! Java 21 brings Virtual Threads, which brings significant performance and memory improvements, especially for Java server environments. Exact release depends on Java server runtime environments adoptions. Once implemented, already high performant Green Screens Server will be even better with even less memory usage.

Java EE 10

Major changes are made by switching from "javax" namespace to "jakarta". From this update and onward, only Java EE 10 certified servers will be supported. The previous version supported servlet-only containers, which is not the case anymore. This change required complete library and package namespace replacement and hundreds of hours of testing, however it is the first step stone to open the path for new Java features incoming in new Java LTS releases which will allow even better and faster Green Screens Terminal for IBM i.

Java Runtime

For MS Windows environments, Java Runtime is updated to the latest security patch Eclipse Temurin-17.0.8+7. Version 6 of Green Screens Terminal for IBM i is still Java 11 fully compatible and can run on any hardware supporting Java 11 including IBM i. Our commitment is to always support 2 LTS releases behind the current one. However, we are slowly introducing Java 17 and soon a new Java 21 LTS.

Server certificates improvements

Many improvements were made to the certificate generation and overall certificate security. We added support for OCSP/CRL certificate verification at the Green Screens Sever side, CA authority URL support for certificate auto download; better linking between signing-certificates and end-certificates; intermediate certificate support, and many more small improvements.

Security improvements

In previous versions, we used RSA for encryption key exchange used to encrypt data flows. Introducing GSv6, we started to replace RSA with ECDH/ECDSA. In this release, we fully replaced RSA with new more modern, more secure and more performant ECDH/ECDSA. Also, we developed our own WebAssembly based Crypto API as a fallback mechanism for browsers native API. Full source code used as a base for Web Crypto API polyfill can be found at our Github Repo.

OCSP Reponder service

OCSP is part of Digital certificate specification for certificate online verification. Green Screens Server now fully supports OCSP protocol for certificate validation.

CRL service

CRL (Certificate Revocation Lists) is a standard older than OCSP, but we added full support for it. CRLs are automatically updated when intermediate, server or client certificates are regenerated.

Software License updates

We improved product Software license to make it more clear about warranties, liability, 3rd party modules and many more.

Product reinstallation improvement

We improved reinstallation procedure on MS Windows platform to keep some server settings, allowing faster server startups after reinstall.

Reintroduced new modern key bar

New modern key bar based on Green Screens WebComponents is reintroduced into the Web 5250 Terminal to better support tablet devices.

Inter context messaging channel

Messaging channel for inter context communication is part of a new browser API allowing to easily exchange structural JSON messaged between Green Screens Terminal and other browser tabs or IFRAMES. This will simplify integration and automation with other web products such as CRM's and other portal system, future modernization UI engine for GSv6 and other 3rd party tools.

WebSocket channel stability

In some proxies or load balancers, WebSocket channels (used for full-duplex 5250 web terminal) might stay stalled also keeping licensing locked due to the networking, security or improper configurations issues, or even possible bugs in such products. We improved signaling and network issues detection mechanism to better recognize such situations and to prevent stalled channels or locked workstation licenses.

WebComponents updates

All Web UI interfaces are updated with the latest Green Screens WebComponents for Bootstrap. Fixing small issues, and adding better support for touch devices. Parts of WebComponents are significantly rewritten while keeping backward compatibility with previous version. The biggest change relates to the data engine that connects various components such as GSTable/GSStore and others. Another notable feature added is JSON object node path for input fields to be able to use structural multilevel JSON data as data input.

Quark Engine v6.0.0

Our Quark Engine is an open source Java to Web RPC framework for fast server-to-web API development with simplicity and security as main focus. Versions 6 and 5 are significantly improved, bringing even better performance. Internal workings are switched from Reflection API to InvokeVirtual improving performance by factor of ~5. Intern API descriptors are optimized, and anonymized. While doing a call, all data is in new GS binary format without explicit virtualized class and method names sent. Security is fully upgraded to ECDH and AES derived key, with performance of about 2million transactions / second on a single core. No matter if TLS is used or not, data remains encrypted, protecting from MITM attacks. Because of excellent, superb encryption performance, and almost nonexistent influence to overall system performance, such double-layered protection can satisfy even the most demanding tasks.

Mobile app updates

Android version of Green Screens Terminal for IBM i is updated to support latest Android devices, including future Android 14. A few small non-critical bugs are fixed, and full support for Green Screens Server 6 is finally added.

For last +4 years, Green Screens Terminal for Android is based on a multimodule packaging allowing segmented installation only from Google Play platform. This technology brings faster, and lighter updates tailored for targeted device.

However, there were cases of 3rd party non-certified sideload installations causing errors and crashes by misuse. Please, install our Android app Green Screens Terminal for IBM i only from Google Play.

In the latest release, we introduced a new Google API flag which should prevent such installations of Green Screens Terminal for Android into virtual environments. This is still experimental Google technology and will be most likely ignored by older Android versions. However, you might expect that manually installed Android Greens Screen Terminal for IBM i might not work on more modern versions of Android devices.