This adds the opportunity to register new SASL schemes via the default
java service-loader mechanism.
Implementors have to provide an implementation of the ServerSASLFactory
that is responsible for providing instances of the actual scheme.
If an application wants to use a special key/truststore for Artemis but
have the remainder of the application use the default Java store, the
org.apache.activemq.ssl.keyStore needs to take precedence over Java's
javax.net.ssl.keyStore. However, the current implementation takes the
first non-null value from
System.getProperty(JAVAX_KEYSTORE_PATH_PROP_NAME),
System.getProperty(ACTIVEMQ_KEYSTORE_PATH_PROP_NAME),
keyStorePath
So if the default Java property is set, no override is possible. Swap
the order of the JAVAX_... and ACTIVEMQ_... property names so that the
ActiveMQ ones come first (as a component-specific overrides), the
standard Java ones comes second, and finally a local attribute value
(through Stream.of(...).firstFirst()).
(In our case the application uses the default Java truststore location
at $JAVA_HOME/lib/security/jssecacerts, and only supplies its password
in javax.net.ssl.trustStorePassword, and then uses a dedicated
truststore for Artemis. Defining both org.apache.activemq.ssl.trustStore
and org.apache.activemq.ssl.trustStorePassword now makes Artemis use the
dedicated truststore (javax.net.ssl.trustStore is not set as we use the
default location, so the second choice
org.apache.activemq.ssl.trustStore applies), but with the Java default
truststore password (first choice javax.net.ssl.trustStorePassword
applies instead of the second choice because it is set for the default
truststore). Obviously, this does not work unless both passwords are
identical!)