Re: [Ksummit-discuss] [TECH TOPIC] Containerisation, namespaces and keyrings

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Fri, 2016-07-22 at 12:01 +0100, David Howells wrote:
> I'm not sure this is the right venue for this, but keyrings will need 
> to be namespaced/containerised at some point.

There are various unvirtualised subsystems within Linux.  There has
been discussion on the containers mailing list about how:

http://thread.gmane.org/gmane.linux.kernel.containers/30371

So far Eric has advocated for making things like this properties of the
user namespace; I'm more inclined to a separate namespace for
delegates, but nothing's been decided.

Proposing on the containers list should be your first step (I've added
the list to the cc).

> The problem is that it's an icky problem given that different key 
> types really want to live in different namespaces, and upcalls may 
> want to done in different containers, depending on the key type.

Surely if you virtualize, you'll have a namespace label per key (or
keyring) so they'll be in one and only one namespace.

The upcall problem sounds like it might be similar to the nfsd one,
which is nasty.  Describing it on the list would help people
understand.

> For example, DNS resolver keys - should they be in the network, the 
> filesystem namespace or neither?  Should the upcall be in the current 
> container or the root container?

Depends what the upcall does.

> Authentication keys, such as used by kafs and AF_RXRPC - should they 
> be in the filesystem namespace (kafs is an fs), the network namespace 
> (AF_RXRPC is a net protocol) or the user namespace?

I'm sort of starting to see Eric's point now, since every namespace has
an owning user namespace, if they were in that the question is
naturally answered.

> Should crypto keys, such as the asymmetric key type, be in the user 
> namespace? What about use by module signing?  Should key operations 
> in the current container have access to a blacklist in the root 
> container?  Should key verification in the current container have 
> access to system keyrings?   The TPM?
> 
> This might actually be right for a hallway track.

Actually, I really think this isn't a KS issue, it should be proposed
for the Plumbers Containers MC:

http://www.linuxplumbersconf.org/2016/ocw/events/LPC2016/tracks/519

You have all the correct people in that session.  At KS you'll have 50%
bored, 48% hostile because they hate cgroups and 2% interested.

James