Hi Henrik, all,

On 06/08/14 15:12, Henrik Thostrup Jensen wrote:

First, a +1 on what Mischa Salle wrote.

There are several misconceptions in the presentation: Presenting the java trust/key store as a TLS protocol concept, client certificates should probably be host certificates, though the difference is limited to some certificate attributes.

The boxed text on slide 11 seems to be the main "problem" in the presentation. However it is a fundemental concept of PKI, and it is NOT a weakness or a problem. I know some TLS implementations tend to hide the DN or make it overly complicated to get it, which is pretty bad (generally wrappers for http clients). The whole thing seems like an eloborate attempt to overcome this problem.

The suggestion to use self-signed certs essentially makes authN and authZ the same thing removing the need to do any in-app checking. This is extremely inflexible though and just moves the AuthZ to TLS certificate configuration (which is not where it is supposed to be), while adding manual certificate handling.

Finally it also unenforceable and the options does not exclude each other. GEANT and NORDUnet uses TERENA certs (and I doubt that will change), where SURFnet uses self-signed certs.

Just to be correct, from the start SURFnet has been using TERENA certificates to secure NSI control plane session.

Yet the NSI agents of these networks trust each other and communicate just fine. Personally I only add the needed CAs to the NORDUnet NSI Agent CA list, as there have been a bit too many CA slips recently.

The first point on slide 16 is complete bullshit (and manipulative). While PKI isn't perfect, switching to a fully manual self-signed setup is extremely error-prone as it is generally difficult to manage certificates.

Finally: Why exactly do we need to standardize how NSI agents thrust each other besides what is mentioned in the NSI Security section?

That was always my intention, and that is why the text is phrase as it is right now. How particular deployments want to implement control plane security is up to them, I do not want to enforce the use of self-signed certs or the use of any particular CA or rules on what attributes need to be checked or not. What I do expect to happen, if for example NSI is deployed in a grid environments, is that NSAs will most likely start using existing CA infrastructure and existing attributes to check, just because it is already there and convenient to use. But in general, the whole idea is that you decide with your peer what means of authorization is sufficient to you both, and if it is acceptable to you this can mean that you will have different ways to authorize different peers.

Cheers,
HansT.

On Wed, 30 Jul 2014, Sill, Alan wrote:

Dear folks in the OGF CAOPS, VOMS-PROC and NSI working groups.
I'd like to initiate some discussion among the participants in these working groups for the use case
referred to in the talk at the link below.

Some review of the conditions for this use case would be helpful. Note this is also a use case that
comes up in Internet-of-Things discussions, and has caused some discussion on the PKIX group list
(though that group is now dormant of course) and other related lists lately.

To me this is a familiar situation with well-known parameters, but possibly some additional
considerations, and might possibly lead to some useful communication among the members in these groups
about solutions that could be applied using existing technologies that would avoid the possible
downsides associated with the proposed use of self-signed certificates. (For example, extended
attribute certificates as used in VOMS, though the same or perhaps through a different implementation,
might be a good solution here; other solutions might be contemplated that would be more attractive than
self-signed certificates for this situation.)

Your comments, discussion and input are recruited (by me -- I'm not speaking for the NIS-WG members per
se!), and I hope that all parties will regard this as useful discussion for information exchange only.

Thanks,
Alan

Begin forwarded message:

      From: Guy Roberts <Guy.Roberts@dante.net>
Subject: RE: [Nsi-wg] Wednesday's NSI conf call
Date: July 30, 2014 at 1:30:19 PM GMT+2
To: Alan Sill <kilohoku150@gmail.com>

Hi Alan,

Please find the slides on NSI security here:

https://redmine.ogf.org/dmsf/nsi-wg?folder_id=6592

The proposal is that NSAs will run their own private Certificate Authorities (self-signing)
rather than using public Certificate Authorities. Participating NSAs will then exchange
information about each other’s Certificates in an ad hoc way.

This solution does not scale well as private Certificates have to be manually shared, but it
reduces the size of the certificate pool.

Guy

From: Alan Sill [mailto:kilohoku150@gmail.com]
Sent: 30 July 2014 10:56
To: Guy Roberts
Cc: Alan Sill
Subject: Re: [Nsi-wg] Wednesday's NSI conf call

Guy,

On Jul 30, 2014, at 11:02 AM, Guy Roberts <Guy.Roberts@dante.net> wrote:

      - comments/feedback from last week’s presentation from John on ‘Secure Communications
      with Self Signed Certificates’

Are copies of these slides available? I would like to understand the context.

(In general, use of self-signed certificates is risky at best, so I would like to understand the
use case here.)

Alan

    Best regards, Henrik

Henrik Thostrup Jensen <htj at nordu.net>
Software Developer, NORDUnet
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