full-disclosure-uk August 2008 archive
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full-disclosure-uk: Re: [Full-disclosure] [OpenID] OpenID/Debian

Re: [Full-disclosure] [OpenID] OpenID/Debian PRNG/DNS Cache poisoning advisory

From: Ben Laurie <benl_at_nospam>
Date: Fri Aug 08 2008 - 19:41:01 GMT
To: "Eddy Nigg (StartCom Ltd.)" <eddy_nigg@startcom.org>


On Fri, Aug 8, 2008 at 8:27 PM, Eddy Nigg (StartCom Ltd.) <eddy_nigg@startcom.org> wrote:
> Ben Laurie:
>
> On Fri, Aug 8, 2008 at 12:44 PM, Eddy Nigg (StartCom Ltd.)
> <eddy_nigg@startcom.org> wrote:
>
>
> This affects any web site and service provider of various natures. It's not
> exclusive for OpenID nor for any other protocol / standard / service! It may
> affect an OpenID provider if it uses a compromised key in combination with
> unpatched DNS servers. I don't understand why OpenID is singled out, since
> it can potentially affect any web site including Google's various services
> (if Google would have used Debian systems to create their private keys).
>
>
> OpenID is "singled out" because I am not talking about a potential
> problem but an actual problem.
>
>
> Sorry Ben, but any web site or service (HTTP, SMPT, IMAP, SSH, VPN, etc)
> which makes use of a compromised key has an actual problem and not a
> potential problem. Open ID as a standard isn't more affected than, lets say
> XMPP...If there are servers and providers relying on such keys the have a
> real actual problem.

I do not dispute this.

> I don't see your point about Open ID nor didn't I see
> anything new....

The point is I found OpenID servers with weak keys.

> The problem of weak keys should be dealt at the CA level, many which have
> failed to do anything serious about it.

Indeed.

> We have spotted other actual problems in other services. Details will
> be forthcoming at appropriate times.
>
>
> I think it's superfluous to single out different services since any service
> making use of the weak keys is affected, with recent discovery of DNS
> poisoning making the matter worse. I suggest you try a forum which can
> potentially reach many CAs, they in fact have everything at their disposal
> to remove this threat!

If you have a better forum, bring it on.

However, CAs do not have everything at their disposal to remove the threat. Browsers,OpenID libraries and RPs must also participate.

Just as saying "buffer overflows are bad" has not magically caused all buffer overflows to be fixed, I am confident that the only way to get this problem fixed is to chase down all the culprits individually. I am sure that OpenID is not the only thing with problems, as you say.



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