Re: 'Padding Oracle' Crypto Attack Affects Millions of ASP.NET Apps
On Wed, Sep 15, 2010 at 11:07 AM, Peter Gutmann pgut...@cs.auckland.ac.nz wrote: Tom Ritter t...@ritter.vg writes: What's weird is I find confusing literature about what *is* the default for protecting the viewstate. I still haven't seen the paper/slides from the talk so it's a bit hard to comment on the specifics, but if you're using .NET's FormsAuthenticationTicket (for cookie-based auth, not viewstate protection) then you get MAC protection built-in, along with other nice features like sliding cookie expiration (the cookie expires relative to the last active use of the site rather than an absolute time after it was set). I've used it in the past as an example of how to do cookie-based auth right Peter. I'm one of the authors of the attack. Actually if you look closer, you'll see that they do it wrong in many ways. Here is a video that we just release this morning at EKOPARTY: http://www.youtube.com/watch?v=yghiC_U2RaM Slide, paper, and tools will be released on http://www.netifera.com/research. Thai. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com
Re: 'Padding Oracle' Crypto Attack Affects Millions of ASP.NET Apps
On Tue, Sep 28, 2010 at 12:49 PM, Peter Gutmann pgut...@cs.auckland.ac.nz wrote: Ye gods, how can you screw something that simple up that much? They use the appropriate, and secure, HMAC-SHA1 and AES, but manage to apply it backwards! I guess they just follow SSL. BTW, they screw up more badly in other places. Download .NET Reflector, decompile .NET source, and do a grep 'DecryptString', you'll see at least three places where they don't even use a MAC at all. Thai. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to majord...@metzdowd.com
