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full-disclosure-uk: Re: [Full-disclosure] OpenID/Debian PRNG/DNS

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

From: Peter Gutmann <pgut001_at_nospam>
Date: Fri Aug 08 2008 - 17:49:42 GMT
To: dave.korn@artimi.com, ekr@networkresonance.com


Eric Rescorla <ekr@networkresonance.com> writes:

>It's easy to compute all the public keys that will be generated
>by the broken PRNG. The clients could embed that list and refuse
>to accept any certificate containing one of them. So, this
>is distinct from CRLs in that it doesn't require knowing
>which servers have which cert...

You'd also end up with a rather large list for the client to carry around, which would be especially problematic for lightweight clients. You'd need to represent it as something like a Bloom filter to avoid this (given that most users will just click OK on invalid certs, the small false positive rate shouldn't have much effect either :-).

Peter.



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