How complete BSD Heimdal to actual Heimdal

All,

I want to make use of a feature present in both MIT kerberos and heimdal kerberos: k5login_directory -- basically to force users to have to use an alternate principal to log in, without letting them muck with their own .k5login files.

This would be set in the [libdefaults] section of krb5.conf(5), and both the mainline MIT and Heimdal manpages make mention of it, but the stock FreeBSD one doesn't.

Nor does man kerberos(8) list at what point the builtin was lifted and branched from Heimdal.

Is there a way to figure out what version of heimdal (and with what features added/stripped out) are present in FreeBSD?  Trying to compile sshd against a different kerberos lib in ports basically makes this a non-starter for us if we can't do it in base.

Is there a better place to ask?

-Dan