How do I mitigate weak SSL/TLS key exchanges for the on-prem Controller?

[Shravani.G N]

Configuring the on-premises Controller to use stronger Key Exchanges

You may want to change the SSL/TLS configuration of the on-premises Controller to allow only strong key exchanges. This can be done by defining a minimum key size for Diffie Hellman Key Exchanges. 

Here is the procedure: 

1. Take a backup of the file, <controller_home>/appserver/glassfish/domains/domain1/config/domain.xml and make the following change: 
   FROM -
   

   § <jvm-options>-javaagent:${com.sun.aas.instanceRoot}/appagent/javaagent.jar</jvm-options> 

   CHANGE TO -

   § <jvm-options>-Djdk.tls.ephemeralDHKeySize=prefered_key_size</jvm-options> 
   § <jvm-options>-javaagent:${com.sun.aas.instanceRoot}/appagent/javaagent.jar</jvm-options> 

   EXAMPLE - 
   

   § <jvm-options>-Djdk.tls.ephemeralDHKeySize=2048</jvm-options> 
   § <jvm-options>-javaagent:${com.sun.aas.instanceRoot}/appagent/javaagent.jar</jvm-options> 

   
   
2. Take a backup of <jre_used_by_the_controller>/lib/security/java.security and make the following change: 
   FROM -
   

   § jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, RC4, DES, MD5withRSA, \ 
   DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL, \ 
   include jdk.disabled.namedCurves 

   CHANGE TO -
   

   § jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, RC4, DES, MD5withRSA, \ 
   DH keySize < prefered_key_size, EC keySize < 224, 3DES_EDE_CBC, anon, NULL, \ 
   include jdk.disabled.namedCurves

   EXAMPLE -
   

   § jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, RC4, DES, MD5withRSA, \ 
   DH keySize < 2048, EC keySize < 224, 3DES_EDE_CBC, anon, NULL, \ 
   include jdk.disabled.namedCurves

3. Restart the Controller Appserver for the change to take effect.

NOTE | This step involves Controller downtime. 

4. Rediscover the Controller back to EC.