openstack team mailing list archive

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

I would see the major blocking issue on this:

"However, imo an IaaS provider that claims to offer trusted hosts but hesitates to reveal the software stack of it's hosts to an external auditor (CA in this case) would have issues with credibility"

every IaaS provide has its own software stack, picking different components, with different versions, possibly adding different patches. The stack can be changed frequently. Rackspace says they can publish a build in less than 1hrs to deploy a new stack. Having an external CA to hold credentials for such large uncertain combos is almost a mission impossible. :)

Thanks
Kevin


From: Nicolae Paladi [mailto:n.paladi@xxxxxxxxx]
Sent: Tuesday, November 13, 2012 11:46 PM
To: Dugger, Donald D
Cc: openstack; Tian, Kevin; Li, Susie; Wei, Gang; Maliszewski, Richard L
Subject: Re: [Openstack] Plans for Trusted Computing in OpenStack

Hi,

I agree that the use case of a trusted IaaS provider (with possibly compromised nodes) is a valid one and should have support in the openstack codebase, although it seems rather dicey to trust the IaaS provider which does not trust it's own hosts.
And your understanding is correct, the idea is to add a 3rd party 'CA' with the aim to assess the integrity of the hosts based on the data produced by the TPM.

What I am advocating here is the scenario where the IaaS can not be trusted.
In this case the CA would only gain information about the software stack of the IaaS provider's hosts, necessary to perform the attestation. However, imo an IaaS provider that claims to offer trusted hosts but hesitates to reveal the software stack of it's hosts to an external auditor (CA in this case) would have issues with credibility.

Wrt complexity, this would require:

* sending the attestation information externally to the 'CA' and taking a launch/not launch decision based on the result of the attestation. Even if the untrusted IaaS launches the VM, the client can easily detect the fraud.

* on the compute host, decrypting the nonce provided by the client (and _sealed_ by the CA to the trusted configuration of the host). That will add up to the codebase but is rather trivial (involves mostly interacting with the TPM).

Now, there are some design choices to be made, e.g. whether the host communicates its attestation credentials directly to the CA in an https session or the scheduler does that. However, it does not change the important point that the client can verify that the VM was started on a trusted host, without having to rely on the IaaS provider.

A common topic to both models (trusted or untrusted IaaS provider) is the question of "security profiles" for the hosts -- are you considering binary values (trusted/untrusted) or some finer-grained scale?

Happy to hear your opinions and continue the discussion;

cheers,
/Nico.


On 12 November 2012 21:23, Dugger, Donald D <donald.d.dugger@xxxxxxxxx<mailto:donald.d.dugger@xxxxxxxxx>> wrote:
Nicolae-

We've been working under the assumption you have trust the IaaS provider (individual nodes might have been compromised somehow but you trust the provider itself).  I think what you are looking at is adding a 3rd party CA which is significantly increasing the complexity of the solution and potentially exposing the IaaS's infrastructure to a 3rd party, probably not desirable to the IaaS provider.

I've added some others to the thread who can chime in with their opinions.

--
Don Dugger
"Censeo Toto nos in Kansa esse decisse." - D. Gale
Ph: 303/443-3786<tel:303%2F443-3786>

From: Nicolae Paladi [mailto:n.paladi@xxxxxxxxx<mailto:n.paladi@xxxxxxxxx>]
Sent: Wednesday, November 07, 2012 7:42 AM
To: Dugger, Donald D
Cc: openstack
Subject: Re: [Openstack] Plans for Trusted Computing in OpenStack

Hi,

so basically my questions/thoughts about support for TC in OpenStack are based on a
somewhat different attack model where the IaaS is actually not trusted.

That is in contrast with the Trusted Compute Pools, where the scheduler/trusted_filter
is assumed to reject the host as a candidate for running the VM if it does not have a
corresponding "trust value". However, nothing prevents a really evil IaaS deployment
to ignore this trust value and go ahead, launch the VM and return it to the client. So
there's an improvement suggestion focusing on that part.

The model that I have in mind assumes both no trust in the IaaS setup/provider.

So the gist is that:

1. Client could upload a secret encrypted with the public key of the authentication service
(possible to include in the extra_specs)

2. The Attestation Service, after verifying the compute host could bind the secret to the
hosts trusted configuration, so that the host can inject the secret into the VM

With this approach, a malicious IaaS provider can still launch the VM on an untrusted host, but
now he client can verify that the VM has been started on a 'trusted' host.

So the questions around this are --
1. Is the scenario of an untrusted IaaS deployment considered for Trusted Compute Pools?

2. Is there any work ongoing to extend Trusted Compute Polls for storage as well? Or otherwise
put, what about the storage, is the solution to encrypt all data on the compute host prior to
storing it in the object store?

3. Is there any work ongoing on the evaluation side, namely the evaluation of the trust attributes
obtained from the host -- and do Trusted Compute Pools consider a binary value (trusted/untrusted)
or a scale of security profiles?

Cheers,
/Nico.


On 6 November 2012 19:07, Dugger, Donald D <donald.d.dugger@xxxxxxxxx<mailto:donald.d.dugger@xxxxxxxxx>> wrote:
Nico-

This is the appropriate place for discussions about Trusted Compute Pools under OpenStack.  Feel free to send out any ideas you have, I know I and others would be very interested in what you have.

--
Don Dugger
"Censeo Toto nos in Kansa esse decisse." - D. Gale
Ph: 303/443-3786<tel:303%2F443-3786>

From: openstack-bounces+donald.d.dugger=intel.com@xxxxxxxxxxxxxxxxxxx<mailto:intel.com@xxxxxxxxxxxxxxxxxxx> [mailto:openstack-bounces+donald.d.dugger<mailto:openstack-bounces%2Bdonald.d.dugger>=intel.com@xxxxxxxxxxxxxxxxxxx<mailto:intel.com@xxxxxxxxxxxxxxxxxxx>] On Behalf Of Nicolae Paladi
Sent: Tuesday, November 06, 2012 8:35 AM
To: openstack
Subject: [Openstack] Plans for Trusted Computing in OpenStack

Hi,

I am involved in a project that aims to use TPM modules to ensure that
the compute nodes run a 'trusted' software stack in a public IaaS deployment.

I've read about trusted computing pools (http://wiki.openstack.org/TrustedComputingPools)
checked out the OpenAttestation project and seen a presentation from the OpenStack
summit (Putting Trust in OpenStack<http://www.openstack.org/summit/san-diego-2012/openstack-summit-sessions/presentation/putting-trust-in-openstack>) in order to get a better understading of where
OpenStack is heading towards wrt TPM support.

Are there any more resources, discussions, mailing lists that I could check out and
where I could potentially bounce ideas?

Cheers,
/Nico.