As of Java 6 update 19 all beans, plugins and additional plugin/bean libraries in a Servoy installation need to be signed, due to tighter security restrictions in Java WebStart.
Without signing, Java WebStart will present the user with a warning dialog upon starting a Servoy Smart Client. Due to bugs in Java 6 update 19, this dialog cannot be dismissed, effectively stopping the user from using the Servoy Smart Client.
As of Servoy versions 5.1.2, 4.1.6 and 3.5.11, a default Servoy installation will only contain properly signed libraries and thus works out-of-the-box.
However, when additional beans and/or plugins (with or without additional libraries) are added to the Servoy installation, they need to be properly signed as well. Most 3rd party plugin and bean developers have released new versions of their plugins and/or beans with proper signing (or will do so shortly). However, if those are not (yet) available, the existing libraries need to be signed "manually".
This tutorial explains the process of signing unsigned libraries in Servoy installations.
"Signing" a library (.jar file) means the manifest.mf file (which is contained in the .jar file) will contain MD5 hashes for the contained classes. This way, when the library is used in a Java program, the Java program can verify the signatures and thus the integrity of signed JAR files.
The signing of a library is done using a certificate. There are two types of certificates:
- Self signed certificates: When a self signed certificate is used, the user of the Servoy Smart Client will be presented with a Java WebStart dialog when the Smart Client is started whether or not it trusts the certificate. This dialog has an "always trust" checkbox.
- Certificates signed by a trusted third party: When a certificate is used by a trusted 3rd party, the user will not be presented with the warning dialog.
See Creating a keystore with a self signed certificate for instructions how to create a self signed certificate
See Authorize a self signed certificate by a trusted 3rd party Certificate Authority for instructions how to create a certificate signed by a trusted 3rd party.
Once a certificate is available for signing, proceed to the next paragraph for more information on how to sign all unsigned beans and plugins.
Servoy has donated a tool to quickly validate the entire Servoy Application Server for the existence of unsigned libraries and optionally sign the unsigned libraries as well. For further support please go to ServoyForge
The Validation & Sign tool can be downloaded here.
Unzip the downloaded file into the ../application_server directory of the Servoy Application Server
To validate the Servoy Application Server installation, execute the following command from the command line in the ../application_server directory
If the tool finds unsigned libraries, it will report them.
Signing unsigned libraries
If the installation contains unsigned libraries for which no signed version is available, the Validation & Sign tool can be used to sign all the unsigned libraries. In order to sign the libraries a certificate is required, see Library signing for more information on obtaining a certificate.
Make sure the Servoy Application Server has been shut down, then run the Validation & Sign tool again with the following arguments:
- 1st argument: "mykeystore.ks": the location and name of the certificate/keystore file (see previous paragraph)
- 2nd argument: "yourpassword": the password used when generating the keystore
- 3rd argument: "MyPlugins": The alias used when generating the keystore
This will effectively sign all previously unsigned libraries with the provided certificate. After completing this step, proceed to the next paragraph.
When the Servoy installation utilized third party plugins that have dependencies on additional libraries which are managed through a plugin specific .jnlp file, the jnlp files also needs to be modified. The following needs to be added to the JNLP:
When the libraries are signed and the plugin jnlp files are updated, the Servoy Application Server can be started again and Servoy Smart Client should be able to connect again.
When still experiencing problems, first clear the Java WebStart cache on the client machine and see if the problem persists. If it persists, please post your findings on the Servoy Forum in this topic.