Re: UID/GID mapping system

From: Jesse Pollard
Date: Mon Mar 15 2004 - 12:07:23 EST

On Friday 12 March 2004 09:00, Søren Hansen wrote:
> fre, 2004-03-12 kl. 14:52 skrev Jesse Pollard:
> > > Let's just for a second assume that I'm the slow one here. Why is the
> > > world a less secure place after this system is incorporated into the
> > > kernel?
> >
> > Because a rogue client will have access to every uid on the server.
> As opposed to now when a rogue client is very well contained?
> > Mapping provides a shield to protect the server.
> A mapping system could provide extra security if implemented on the
> server. That's true. This is, however, not what I'm trying to do. This
> system is NOT a security related one (it doesn't increase nor decrease
> security), but rather a convenience related one.

Then it becomes an identity mapping (as in 1:1) and is therefore
not usefull.

If you are doing double mapping, then I (as a server administrator)
would not export the filesystem to you.

The current situation is always a 1:1 mapping (NFS version < 4). Therefore
any filesystem export is by definition within the same security domain.

If you as an administrator of a client host violate the UIDs assigned to
you (by hiding the audit trail), then you are violating the rules established
in that security domain; and should not be trusted - and the client host
should not have an available export.

It is never necessary to map on a client. It means that the server has been
improperly setup, or that the client is not within the proper security domain.
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