Re: Wireless WPA2 MSCHAPv2

[Steve Bohrer <skbohrer () SIMONS-ROCK EDU>]

On Jul 31, 2012, at 8:58 AM, Parker, Ben C wrote:

> Reading through the news, I saw that at Defcon MSCHAPv2  has been  
> effectively compromised. https://www.cloudcracker.com/blog/2012/07/29/cracking-ms-chap-v2/This 
>  includes the use of it in WPA2 connections to radius servers for  
> authentication.  Per the article, the current recommendation for  
> enterprise wireless deployments is to move to using client  
> certificates for authentication.

I'm over my head on crypto stuff, but in discussion about this crack  
on slashdot ( http://science.slashdot.org/story/12/07/30/167210/new-moxie-marlinspike-tool-cracks-crypto-passwords 
 ) a couple of commenters suggest that the PEAP layer of PEAP- 
MSCHAPv2 802.1x wireless auth protects the MSCHAPv2 from the sort of  
sniffing that this crack exploits.

Here's quotes from two comments:

From http://science.slashdot.org/comments.pl?sid=3014645&cid=40821639 :
"For WPA2-Enterprise the MSCHAPv2 session is usually wrapped in a PEAP  
(SSL) session. This should be safe as long as your client is  
configured to validate the server-side certificate only against CAs  
that are not likely to be compromised (i.e. a rougue cert generated).  
Preferably, one should also validate the certificate's subject  
(usually the name of the RADIUS server)."


From http://science.slashdot.org/comments.pl?sid=3014645&cid=40822837 :
"Those eduroam sites that use MSCHAPv2 use PEAP-MSCHAPv2. You have to  
crack the PEAP before you can crack the MSCHAPv2."

Any of the experts here wish to confirm or deny if PEAP-MSCHAPv2 is  
still okay in the face of this new tool?

Thanks,

Steve Bohrer
Network Admin
Bard College at Simon's Rock
413-528-7645