solving Security Error while starting Java WebStart (e.g. IPMI Remote)

Most of the IPMI Systems out there still using good old Java based Remote Applications to connect to the remote console.
Sine Java 8 update 111, the MD5 singing algorithm was marked as insecure (aka disabled) by Oracale (see Relase Notes for that Release ” Restrict JARs signed with weak algorithms and keys”).
You will get an “Security Error while using MD5withRSA Signature”:

The only solution to fix this error is to have your Hardware Vendor to update the IPMI Firmware with JARs, signed with a more up to date singing algorithm. A work around is to re-enable MD5 for the time being. For that you need to get into your Browser Java Installation.
On my Mac this is in


/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home


You need to edit lib/security/java.security and remove MD5 from jdk.jar.disabledAlgorithms.

Change


jdk.jar.disabledAlgorithms=MD2, MD5, RSA keySize < 1024


to


jdk.jar.disabledAlgorithms=MD2, RSA keySize < 1024