A user reported last week that after a Java upgrade, it was no longer possible to connect to the OMERO server using OMERO.insight. Since then we’ve been looking into the issue. A fix is ready as well as a few steps for the future.
A recent security vulnerability in Java
prompted Oracle to release critical patches for the JDK in versions 6u101, 7u85, and 8u51:
Among the changes in the new JDKs, support has been dropped for some SSL ciphers which OMERO uses, via the Ice library. This prevents Java clients connecting to an OMERO server due to a handshake error in Ice. Since the router used by OMERO (Glacier2) is not written in Java, just updating the Java version on the server is not enough to prevent the issue.
Instead, a small configuration change is needed in OMERO. This will remove the no-longer supported ciphers, allowing both old and new OMERO clients, whether with or without the Java patches, to work normally.
If you are an OMERO user, you should ensure your version of Java is upgraded to take advantage of the security update, and contact your system administrator to ask for the following procedure to be followed.
If you are an OMERO administrator and you either have received user complaints or want to forestall them, you can arrange a short restart with your users, download the patch from http://downloads.openmicroscopy.org/patches/java_issue_2015-07-21.txt, and take the following steps:
$ cd OMERO.server-5.1.2-ice35-b45
$ patch -p1 < ../java_issue_2015-07-21.txt
patching file etc/grid/templates.xml
$ bin/omero admin deploy
The patch above will be included in the next release of OMERO (5.1.3) but we are providing it in the meantime for users currently completely blocked by this issue as we encourage everyone to update their Java to take advantage of this latest security fix. We’re looking into further modifications to the IceSSL configuration to make your connections more secure.
One caveat may be that safer connections invariably include more processing overhead, which may be most notable in OMERO.web. We’ll provide suggestions in the release on how to have a faster connection to a local web server while keeping the safer connection for OMERO clients.
Further, we’ll make the connection settings configurable, so that should a future version of Java remove a cipher that OMERO is using, you’ll be able to handle the issue without a patch from us.
— July 21, 2015