Looking for a "Kerberos Router"?

[Ken Hornstein]

>Looking at Apple documentation I see the support for something I had
>never heard of: Kerberos Key Distribution Center Proxy.
>
>Looks like a solution to encapsulate Kerberos requests into an HTTPS.
>
>Any experience on this here?

I personally have not used that, but I know that MIT Kerberos supports
that (as far as I can tell, that protocol exists just because firewall
people are dumb, but that's neither here nor there).  That contains
a wrapper ASN.1 structure which has the target realm in it so you
could use that for routing (although the target domain is listed as an
optional element to the KDC_PROXY_MESSAGE so that suggests to me you
can't rely on it).  So you're still going to have to write code to parse
an ASN.1 structure to do backend routing.

It does occur to me that maybe if you have different KDC hostnames but
the same IP address you could use TLS SNI or hostname routing which
you indicated you already use and maybe that would be simpler?  That
presumes the client implementations set the SNI field (I see that it
does send a "Host" header, and it looks like MIT Kerberos does set the
SNI hostname).

--Ken