Friday, February 24, 2012

IOActive's IOAsis at RSA 2012


This is not a technical post as usual. This is an invitation for an important event if you are going to RSA 2012 and want to escape the chaos and experience the luxury at IOAsis while enjoying great technical
talks and meeting with industry experts. If you want to feel like a VIP and have great time then don’t miss this opportunity!

Friday, February 17, 2012

Estimating Password and Token Entropy (Randomness) in Web Applications

Entropy

“In information theory, entropy is a measure of the uncertainty associated with a random variable. In this context, the term usually refers to the Shannon entropy, which quantifies the expected value of the information contained in a message, usually in units such as bits. In this context, a 'message' means a specific realization of the random variable.” [1]

1. http://en.wikipedia.org/wiki/Entropy_%28information_theory%29

I find myself analyzing password and token entropy quite frequently and I’ve come to rely upon Wolfram Alpha and Burp Suite Pro to get my estimates for these values. It’s understandable why we’d want to check a password’s entropy. It gives us an indication of how long it would take an attacker to brute force it, whether in a login form or a stolen database of hashes. However, an overlooked concern is the entropy contained in tokens for session and object identifiers. These values can also be brute forced to steal active sessions and gain access to objects to which we do not have permission. Not only are these tokens sometimes too short, they sometimes also contain much less entropy than appears.

Wednesday, February 8, 2012

I can still see your actions on Google Maps over SSL

A while ago, yours truly gave two talks on SSL traffic analysis: one at 44Con and one at RuxCon. A demonstration of the tool was also given at last year's BlackHat Arsenal by two of my co-workers. The presented research and tool may not have been as groundbreaking as some of the other talks at those conferences, but attendees seemed to like it, so I figured it might make some good blog content. 

Friday, February 3, 2012

Solving a Little Mystery

Firmware analysis is a fascinating area within the vast world of reverse engineering, although not very extended. Sometimes you end up in an impasse until noticing a minor (or major) detail you initially overlooked. That's why sharing methods and findings is a great way to advance into this field.