To be completed

Currently, we don't check user credentials. Once the XCAT and XSOAP libraries are updated to Alek's latest (see Section 3.2.3.3 for more information), we can get the the delegated proxy credential and check it against the mapfile (see Section 2.3.0.2). The mapfile contains user dn patterns so we need to user use a regular expression library to perform the pattern matching. If they don't match, we should raise an AuthorizationException (this exception needs to be written too).