JASigning Platform Issues

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Code Signing

JASigning components are digitally signed using a Code Signing Certificate issues by GlobalSign to UEA Consulting Ltd. Before 2014, certificates were issued to SYS Consulting Limited. When installing applications or applets, users will be asked to confirm that they trust the publisher. Users can choose to trust the publisher permanently to avoid future confirmation requests.

Java Web Start

JASigning applications and applets are launched using Java Web Start through Java Network Launching Protocol (JNLP) files, which have extension .jnlp. Web pages using the more recent JASigning implementation for HTML5 using JavaScript and WebGL is not dependent on JNLP.

The use of JNLP files for applets is deprecated in modern browsers. Where it is supported, it is fairly seamless, but changes to the Java security regime mean that some messages will be seen for the latest release of JASigning with older Java versions.

For applications, launching of Java Web Start is sometimes automatic, but sometimes requires further action. Apple makes it increasingly difficult to deploy components using JNLP so for recent versions of OS X it is necessary to override the default protection regime even though the components are correctly signed. See below for notes on using particular browsers.


Applications for the current version of JASigning are intended to run on Windows (XP, Vista, 7) and on the latest releases of OS X 10.5 and later. JASigning apps are not supported on Linux at present. It is preferable to run JASigning with an up-to-date Java 7 run-time (JRE), although it should run with the latest versions of Java 6.

On the supported platforms, that is, Windows and Mac OS X, JASigning supports both 32-bit and 64-bit operation. Which of this modes it actually runs in on any given occasion depends on several factors:

  • Whether or not the processor supports 64-bit operation.
  • Whether or not the operating system supports 64-bit operation.
  • Whether the system has a 32-bit or a 64-bit Java installation (or both) -- and what options are set in the Java Control Panel (Windows) or Java Preferences app (OS X).
  • For a JASigning applet: whether the browser is running in 32-bit or 64-bit mode.


JASigning applications and applets (apart from the SiGML Service Client) on Windows may require the appropriate Microsoft Visual Studio C++ 2010 Redistributable Package to be installed on the system.

On many Windows systems the required Redistributable package will already have been installed. But if not, each JASigning application and applet will display a message at launch time giving the URLs from which the package can easily be downloaded and installed. These URLs can be copied from the Java console and pasted into a web browser.

There is a 32-bit (x86) and a 64-bit (x64) version of the Redistributable package. One or both of these should be installed, to match the system's JRE (Java Runtime Environment) installation(s).


Before installing and running JASigning applications, the corresponding JNLP file must be downloaded. The application is then launched using Java Web Start. The user will be warned that the application (its JNLP file) has been downloaded from the Internet. The user will also be asked to confirm that they trust the publisher.

Under the default settings for GateKeeper on OS X 10.10 Yosemite, 10.9 Mavericks, 10.8 Mountain Lion, and 10.7.5 Lion onwards, JASigning applications are blocked from running because they do not come from the App Store or an identified developer. To run blocked applications it is necessary to locate the JNLP file, typically in the Downloads folder, and open it by double-clicking with the control-key down or by right-clicking and choosing Open. GateKeeper can be disabled using the General tab of Security & Privacy in the System Preferences.

As documented in JASigning Release Notes, on OS X 10.6 Snow Leopard some rendering artefacts can appear with the freestanding SiGML URL Player and SiGML Service Player. This seems to be related to use of Java 6 so can occur with OS 10.7 Lion and 10.8 Mountain Lion as initially installed.

Browsers : HTML5 JavaScript and WebGL

The core JASigning software is supported in HTML5 using JavaScript and WebGL. It functions on Windows, OS X, and iOS. It may work on other platforms. Processing of SiGML files takes place on a server, so freestanding operation is difficult.


JASigning WebGL software should work with Firefox, Chrome, Opera, and Internet Explorer.


JASigning WebGL software should work with Firefox, Chrome, Opera, and Safari.


JASigning WebGL software should work with Safari.

Browsers : Java Applets

Support for Java Applets is declining and the HTML5 approach should be used wherever possible.

Firefox is generally the easiest browser to use for running JASigning applets and launching JASigning applications.

JASigning applets may work with browsers other than those mentioned below, but our testing in such cases is at best limited. Let us know!


JASigning web applets should work with Safari, Firefox, Opera, Chrome, and Internet Explorer.


JASigning web applets should work with Firefox and Safari. Recent versions of OS X require applets from JASigning 095j or JASigning 095l and later. JASigning applets from older releases should work with Firefox 3.6.28 (which is no longer supported).

Safari will block applets by default but clicking on the avatar display area will allow the applet plug-in to be enabled. Safari 7 imposes a safe mode which blocks access to the local disk even though requested by the Java security settings. JASigning will operate in safe mode but will operate more slowly and will not work so well offline as a local cache will be disabled. The Safari Security preferences can be used to disable safe mode for JASigning applets, allowing the local cache to be used.

Chrome does not support Java 7 on the Mac so can only be used to run JASigning applets on OS X 10.6 Snow Leopard or on OS X 10.7 Lion or 10.8 Mountain Lion as initially installed.

If GateKeeper is active, launching of applications will be blocked. See the Platforms section above. Even if GateKeeper is disabled: Safari does not consider Java Web Start to be safe so JNLP files may be downloaded to a temporary area and can only be launched by clicking on the icon for the downloaded file in the Downloads window; JNLP files for applications can be downloaded and launched from Chrome but a warning suggests that JNLP files can be harmful.

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