GNU ARM Eclipse plug-ins: sun.security.validator.ValidatorException
For historical reasons, the GNU ARM Eclipse update sites for installing new software are hosted by SourceForge, and up to now they successfuly handled more than 4.500.000 downloaded files for this project.
In Nov. 2016 SourceForge did a change in the security settings used by their download servers and mirrors. For most of the users this was transparent, but for some, the result when trying to install new software, was the following:
An error occurred while collecting items to be installed session context was:(profile=epp.package.cpp, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=). Unable to read repository at http://gnuarmeclipse.sourceforge.net/updates-test/plugins/ilg.gnuarmeclipse.templates.ad_184.108.40.206611031134.jar. sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target Unable to read repository at http://gnuarmeclipse.sourceforge.net/updates-test/plugins/ilg.gnuarmeclipse.templates.freescale_220.127.116.11611031134.jar. sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
The problem is caused by SourceForge using certificates issued by Let’s Encrypt, a new provider not yet in the list of root providers on many environments.
Not finding it on the list, Java tries to authenticate these certificates using additional steps.
Unfortunately, some corporate firewalls prevent these additional steps, and install attempts will fail with the above messages.
The easiest solution is to update your Java JDK to 8u101 or later, since in JDK 8u101 Oracle added Let’s Encrypt to the list of trusted root certificates, and the additional accesses should no longer be needed.
If this is not possible, try to convince your network administrator to reconfigure the firewall to allow Java access to the certificate sites.
As a temporary workaround, you can always download the plug-ins as an archive, and install from it.
Or, you can configure your mobile phone as a hot spot, and try to connect to the internet directly; please note that sometimes this does not work, since local firewals or antivirus configurations might prevent direct access.