Showing posts from July, 2010

Sniffing on a Mac (updated)

One of my first posts for this blog was a discussion of how Mac OS X users might perform WiFi sniffing. Enterprise-class sniffers only run on Windows, so my earlier post is about using a combination of KisMAC and Wireshark. This brief post is about using WildPackets OmniPeek.

Keith Parsons, the WiFi expert who runs, informed me after my post that I should try running professional grade analyzers using a virtual machine like Parallels or VMWare Fusion. Well, here we are a mere 6 months later and I've finally taken the time to do it. And it works. And it is superb.

My basic setup includes the following:

MacBook Pro running Mac OS X 10.6.4 (Snow Leopard) with a 2.4 GHz processor and 4 GB of RAMWindows XP Service Pack 3Parallels Desktop 5WildPackets OmniPeek Enterprise 6Linksys WUSB600N 802.11n dual-band USB adapterOmniPeek starts up and runs fine under this setup, though I did wonder if running in a virtual machine would compromise performance. I have yet to get a good an…

Debunking A Vulnerability Myth (Not That One...)

The Wi-Fi world was set aflutter today by a wireless IDS/IPS vendor sending out a press release advertising a flaw in WPA2 security that will be detailed during a pair of security conferences at the end of the month. (They're also holding a Webinar early next month that will detail the same flaw.) Much of the commentary on this WPA2 vulnerability has been focused on discrediting its real-world impact, but I am going to abstain from my initial temptation to join those critics. Instead, I'll take this time to discredit a supposed flaw in TKIP that was touted a couple of years ago, but for some reason never analyzed thoroughly.

The TKIP flaw has been nicknamed Beck/Tews after the researchers that discovered it. Their whitepaper and an excellent analysis of the technical theory behind the flaw by Glenn Fleishman of the superb blog are both available online.

A quick summary of the flaw goes something like this:

TKIP relies on a sequence counter called the TSC (TKIP …

Channelyzer Pro... This Could Be Big

Metageek has announced that WiSpy USB spectrum analyzers can now be used with Channelyzer Pro. This could make things interesting...

Readers of this blog may know me as an anti-open source kind of guy, but I try to be fair. I've talked about popular products like AirPcap NX, Wireshark, WiSpy and Channelyzer and I've always tried to give a fair appraisal of their usefulness for enterprise-class wireless environments. The problem is that I usually just don't find them to be that useful.

Of these products the one that has always been closest to enterprise-class is WiSpy DBx. It competes with the hardware for Fluke Networks' AirMagnet Spectrum XT and the Cisco Spectrum Expert at a much lower cost ($600), and in many ways it measures up. It can be used in the both the 2.4 GHz and 5 GHz frequency bands, it uses the USB form factor (which beats the PC card form factor for Cisco Spectrum Expert) and it comes with free software in Channelyzer. The big problem was that using the…