Weblogic Node Manager using Demo cert gives error: certificate_unknown

com.sun.xml.ws.client.ClientTransportException: HTTP transport error: 
javax.net.ssl.SSLHandshakeException: Received fatal alert: certificate_unknown

There are four possible solutions:

1. Upgrade to WLS 12.1.2

2. Create a new Demo Key with the larger key size

3. Obtain your own certificate, by submiting a new request to your CA, increasing its certificate strength (i.e. >1024)

4. Remove the key length restriction (not recommended but the fastest solution)
   The java.security file is located in your client machine’s Java/JRE installed directory $JAVA_HOME/jre/lib/security/java.security.

   In Java 1.7.0_40 the java.security by default has this setting:

   java.security file Snippet

   # Note: This property is currently used by Oracle's PKIX implementation. It # is not guaranteed to be examined and used by other implementations. # # Example: # jdk.certpath.disabledAlgorithms=MD2, DSA, RSA keySize < 2048 # # jdk.certpath.disabledAlgorithms=MD2, RSA keySize < 1024

   Changing the 1024 to 512 will allow the existing certificate to work.