Linked by Thom Holwerda on Tue 8th Apr 2014 22:06 UTC
Privacy, Security, Encryption

Heartbleed, a long-undiscovered bug in cryptographic software called OpenSSL that secures Web communications, may have left roughly two-thirds of the Web vulnerable to eavesdropping for the past two years. Heartbleed isn't your garden-variety vulnerability, so here's a quick guide to what it is, why it's so serious, and what you can do to keep your data safe.


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RE[2]: Comment by Gone fishing
by Alfman on Wed 9th Apr 2014 14:47 UTC in reply to "RE: Comment by Gone fishing"
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Generating new key is not the problem. blacklisting the existing key is not the problem. Distributing the blacklists and making sure that EVERY application/appliance consults the blacklist before trusting the other party is the problem.

Unfortunately it is a big problem. Public key encryption can scale extremely well due to the fact that no communications are necessary to validate a certificate. This increases not only certificate validation speed but reliability. However the revocation protocol (OCSP) lacks this scalability, and due to the slow/unreliable nature of it many browsers intentionally ignore non-responses.

Something I learned is that many browsers change their revocation checking behavior depending on whether certs are EV certs or not. Some browsers don't even bother checking revocation on non-EV certs.

Closing this hole completely means each and every SSL certificate needs to be untrusted until completing validation against the CA's revocation database. It's doable but mostly negates the benefits of using PKI in the first place. Assuming every certificate has to be checked anyways, then logically it makes more sense for the client to ask the CA if the certificate is in the "good list" rather than whether it's in the "bad list".

There's a poorly supported hack in place today called "OCSP stapling" that allows the negative revokation status information to be cached by the web server to reduce the need for clients to individually lookup certificate revocation, which should dramatically lesson the bottleneck on a CA's servers. However at this point I'd argue we have a system of hacks built on top of hacks, and we'd be better off ditching the revocation infrastructure all together and just using short lived certificates. Not only is this approach simpler, but it would be more secure too.

Ultimately I will be glad if/when DNSSEC reaches a point where we will no longer have to deal with CAs at all.

Edited 2014-04-09 14:51 UTC

Reply Parent Score: 3