How to use NFS with multiple principals in different realms?

[Cedric Blancher]

On 17 September 2014 17:05, Simo Sorce <simo at redhat.com> wrote:
> On Wed, 17 Sep 2014 13:20:19 +0200
> Cedric Blancher <cedric.blancher at gmail.com> wrote:
>
>> What happens if there is no relation between KRB Realm names and
>> FQDN/DNS? Can the NFS client find out which KRB Realm is used by the
>> server?
>
> Depending on the environment you may have 1 or 2 ways.
>
> 1. add domain to realm mapping in the appropriate section in krb5.conf
> on the client.
> 2. allow the KDC to send back a referral (but not all clients will ask
> their own KDC, some can do only 1).

But how can 1. help? Sure I can have my own krb5.conf but AFAIK
rpc.gssd only looks at he system /etc/krb5.conf and not at any custom
user defined location. Basically mount(8) would have to pass the
location of the custom krb5.conf file to rpc.gssd to facilitate the
mount, right?

I *think* we have a bigger problem here: Kerberos5 support in NFS
appears to be designed around the philosophy of one realm per machine
(one-to-rule-them'-all) and not that a single user or machine has
mounts from many different realms, right?

Ced
-- 
Cedric Blancher <cedric.blancher at gmail.com>
Institute Pasteur