ECMA to access SubjectCanonicalizationContext in Resolver

[Michael A Grady]

Based on the conversation on Shib Users, I've been trying to put an attribute definition in the resolver to access the underlying username the user entered at login. I started with the pretty simple one liner that Scott had suggested, but keep getting "null" returned from trying to bring in the SubjectCanonicalizationContext. At the moment, I've expanded to the following:

                subjectP = Java.type("javax.security.auth.Subject");
                subjectContext = profileContext.getSubcontext(
                        "net.shibboleth.idp.authn.context.SubjectCanonicalizationContext");
                subjectP = subjectContext.getSubject();

but keep getting: 

Caused by: javax.script.ScriptException: TypeError: null has no such function "getSubject" in <eval> at line number 13
        at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:455)
Caused by: jdk.nashorn.internal.runtime.ECMAException: TypeError: null has no such function "getSubject"

I'm sure I must be missing some obvious piece, but I can't figure out what.

--
Michael A. Grady
IAM Architect, Unicon, Inc.