Ginzametrics Open Sources Odin, A Cookie-Based Single Sign On for Apache

Re:Ginzametrics Open Sources Odin, A Cookie-Based Single Sig... by gose1 on Tuesday August 14, 2012 @06:18PM (#4383357)

Also, using sha1_hex(secret+...) and calling it HMAC is a slippery slope (see http://netifera.com/research/flickr_api_signature_forgery.pd...). Although it's seemingly not exploitable due to the structure of the data, look into using a proper HMAC (RFC 2104) to prevent length-extension attacks.

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Re:Ginzametrics Open Sources Odin, A Cookie-Based Single Sig... by tptacek on Tuesday August 14, 2012 @08:37PM (#4383818)

Whoah. That is a good catch. I admit, I skimmed this, saw "hmac_for", thought "I'm not a Perl programmer", and assumed it was HMAC.

Guys, fix this ASAP. SHA1(secret || data) (secret-prefix MAC) is totally insecure. (In practice, every valid forgery to this MAC is going to look like x-y-z-useragent-GIBBERISH-evil-content, but you don't want to be relying on that for your security).

Embarrassing (for me).

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Re:Ginzametrics Open Sources Odin, A Cookie-Based Single Sig... by mpasternacki on Wednesday August 15, 2012 @06:37AM (#4385342)

Thank you! This will be closed up by end of this week. As I wrote in the article and in the presentation, one of main points of open sourcing it is to have people smarter than myself look at the crypto and protocols to find any issues like this. It should be fairly easy to close up.

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Re:Ginzametrics Open Sources Odin, A Cookie-Based Single Sig... by rgrieselhuber on Wednesday August 15, 2012 @12:46AM (#4384627)

Glad to have more eyeballs on this. Thanks guys. We're on it.

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