urn:mace:dir:attribute-def:eduPersonTargetedID only username part not scope

[Peter Schober]

* damian.hall at canterbury.ac.uk <damian.hall at canterbury.ac.uk> [2012-10-17 13:28]:
> I am currently using Shibboleth 2.5.0 and am having an issue trying to
> transform the urn:mace:dir:attribute-def:eduPersonTargetedID to just
> output the username part.

>From the defintion of this SAML1 attribut follows:
(cf. http://macedir.org/specs/eduperson/#eduPersonTargetedID )

a. it's an opaque identifier, so the part which is specific to the
   principal is not a username in any common sense, and more
   importantly
b. the part specific to the principal is only guaranteed to be unique
   when used together with the other info. if you're sure your service
   provider's entityId never changes then you'd need at least the
   issuer (the IdP's entityID) and the principal part.

> Currently the value getting passed back to the Shibboleth SP is
> username\@domain, I cant seem to figure out how to filter the attribute
> using the NameIDFromScopedAttributeDecoder.

Also this is completely wrong as the eduPersonTargetedID is not a
scoped attribute. This should all be explained in the documentation:
https://wiki.shibboleth.net/confluence/display/SHIB2/NativeSPTargetedID
-peter