1. A method for discovery profile based unified credential processing for disparate security domains comprising: loading a discovery profile specifying types of manageable resources to be discovered during discovery of manageable resources and authentication protocols for use in accessing each type of the manageable resources; discovering manageable resources according to the discovery profile across disparate security domains in a computer communications network; selecting a discovered one of the manageable resources in a particular one of the disparate security domains for a systems management task; transforming an authentication credential not specific to the particular one of the disparate security domains to a mapped authentication credential specific to the particular one of the disparate security domains; and, authenticating into the particular one of the disparate security domains with the mapped authentication credential utilizing an authentication protocol specified by the discovery profile in order to perform the systems management task on the selected discovered one of the manageable resources.