full-disclosure-uk August 2008 archive
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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: Florian Weimer <fw_at_nospam>
Date: Fri Aug 08 2008 - 21:28:19 GMT
To: Eric Rescorla <ekr@networkresonance.com>

  • Eric Rescorla:

> Why do you say a couple of megabytes? 99% of the value would be
> 1024-bit RSA keys. There are ~32,000 such keys.

There are three sets of keys, for big-endian 32-bit, little-endian 32-bit and little-endian 64-bit. On top of that, "openssl genrsa" generates different keys depending on the existence of $HOME/.rnd (and -3 creates yet another set of keys, but this is more in the league of "different key length"). If the library is used for key generation (instead of the command line tool), different keys might result.

On the other hand, the on-disk size would be comparable to the phishing filter database.

Part of the problem of the CRL approach is that CAs usually have policies against obtaining private keys and therefore can't prove to the customer that their keys are compromised. And adding a CRL entry when the customer isn't convinced that they've got a problem is probably not a good idea, either.

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