Platform: Windows, Solaris
JDK: Oracle JDK7
(not reproducible on Sun's JDK6 as NTLMServer is not present there)

The com.sun.security.sasl.ntlm.NTLMServer implementaiton of method
 http://download.java.net/jdk7/docs/api/javax/security/sasl/SaslClientFactory.html#createSaslClient%28java.lang.String[],%20java.lang.String,%20java.lang.String,%20java.lang.String,%20java.util.Map,%20javax.security.auth.callback.CallbackHandler%29

Throws "java.lang.NullPointerException" when null callback handler is passed
though the spec says implementation should accept null without any problems:

Parameters:
    ...
    cbh - The possibly null callback handler


Please see the following code sample:

--------------------------------------------------------------------------------------------
package sasl;

import javax.security.sasl.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;

public class CreateSaslClient {

    public static void main(String[] args) throws SaslException {
        ArrayList<SaslClientFactory> list = Collections.list(Sasl.getSaslClientFactories());
        for (SaslClientFactory clientFactory : list) {
            System.err.println("clientFactory = " + clientFactory);
            String[] mechanismNames = clientFactory.getMechanismNames(null);
            if (mechanismNames.length == 1 && "NTLM".equals(mechanismNames[0])) {
                System.err.println("Calling createSaslClient(..)");
                    clientFactory.createSaslClient(
                        new String[] {"NTLM"}, "abc", "ldap", "server", new HashMap<String, Object>(), null);
            }
        }
    }
}
--------------------------------------------------------------------------------------------

The output will look like:

clientFactory = com.sun.security.sasl.digest.FactoryImpl@11a0d8b
clientFactory = com.sun.security.sasl.ntlm.FactoryImpl@d32ea0
Calling createSaslClient(..)
Exception in thread "main" java.lang.NullPointerException
at com.sun.security.sasl.ntlm.NTLMClient.<init>(NTLMClient.java:146)
at com.sun.security.sasl.ntlm.FactoryImpl.createSaslClient(FactoryImpl.java:73)
at sasl.CreateSaslClient.main(CreateSaslClient.java:17)