I am using Elytron on WildFly 12 to store a datasource password encoded.
I use the following CLI commands to store the password:
/subsystem=elytron/credential-store=ds_credentials:add( \
    location="credentials/csstore.jceks", \
    relative-to=jboss.server.data.dir, \
    credential-reference={clear-text="changeit"}, \
    create=true)
/subsystem=datasources/data-source=mydatasource/:undefine-attribute(name=password)
/subsystem=elytron/credential-store=ds_credentials:add-alias(alias=db_password, \
    secret-value="datasource_password_clear_text")
/subsystem=datasources/data-source=mydatasource/:write-attribute( \
    name=credential-reference, \
    value={store=ds_credentials, alias=db_password})
This works very well so far. Now I need a way to read this password programmatically, so I can create a PostgreSQL database dump.