NullPointerException in sun.security.ssl.HKDF.extract

Issue

• We see a NullPointerException like the following on Java 11:

  java.lang.NullPointerException
        at java.base/sun.security.ssl.HKDF.extract(HKDF.java:93)
        at java.base/sun.security.ssl.HKDF.extract(HKDF.java:119)
        at java.base/sun.security.ssl.ServerHello.setUpPskKD(ServerHello.java:1169)
        at java.base/sun.security.ssl.ServerHello$T13ServerHelloProducer.produce(ServerHello.java:547)
        at java.base/sun.security.ssl.SSLHandshake.produce(SSLHandshake.java:436)
        at java.base/sun.security.ssl.ClientHello$T13ClientHelloConsumer.goServerHello(ClientHello.java:1234)
        at java.base/sun.security.ssl.ClientHello$T13ClientHelloConsumer.consume(ClientHello.java:1170)
        at java.base/sun.security.ssl.ClientHello$ClientHelloConsumer.onClientHello(ClientHello.java:852)
        at java.base/sun.security.ssl.ClientHello$ClientHelloConsumer.consume(ClientHello.java:813)
        at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:392)
        at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:444)
        at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask$DelegatedAction.run(SSLEngineImpl.java:1074)
        at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask$DelegatedAction.run(SSLEngineImpl.java:1061)
        at java.base/java.security.AccessController.doPrivileged(Native Method)
        at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask.run(SSLEngineImpl.java:1008)
        at org.apache.tomcat.util.net.SecureNioChannel.tasks(SecureNioChannel.java:443)
        at org.apache.tomcat.util.net.SecureNioChannel.handshakeUnwrap(SecureNioChannel.java:507)
        at org.apache.tomcat.util.net.SecureNioChannel.handshake(SecureNioChannel.java:238)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1556)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.base/java.lang.Thread.run(Thread.java:834)