Keith C. Perry on 24 Jun 2015 19:42:37 -0700

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Re: [PLUG] Home wifi access point & router recommendation

Just a technical point about WPA2 (and yes you should force the use of WPA2 because that uses 256 bit AES.  WPA is NOT completely RSN rated even with TKIP- it was a stop gap measure until 802.11i was ratified and that protocol is CCMP which is part of AES).  Your passphrase is run through a key expansion algorithm called PBKDF2.  Its essentially a MAC (cryptographic hash) generator.  Regardless of what you enter, in the case of WPA2, the key generated is going to be 256 bits and then salted to further prevent attacks.

With that in mind you still need to be "smart" about passwords but the best thing to do is use a clever passphrase that means something to you and only you.  In that regard, I've heard minimums of 6 characters are good.  I would say 12 but really, anything reasonable you come up with is going to be longer- probably much longer.

BTW,  LUKS encryption also use that algorithm 

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Keith C. Perry, MS E.E.
Owner, DAO Technologies LLC
(O) +1.215.525.4165 x2033
(M) +1.215.432.5167

From: "Michael Zaleski" <>
To: "Philadelphia Linux User's Group Discussion List" <>
Sent: Wednesday, June 24, 2015 10:15:03 PM
Subject: Re: [PLUG] Home wifi access point & router recommendation

Some routers have enabled rate limiting, that just means an attacker has to send a trickle of traffic rather than a fire hose worth. I suppose slowing down an attack is better nothing, but still, it doesn't mitigate the problem. Also be sure to use as long as password as possible for wpa2, longer is better than more complicated. And be sure to disable remote management too.

On Jun 24, 2015 9:09 PM, "brent saner" <> wrote:

I really with Google Inbox let you properly inline-reply. is a good introduction to the evils of WPS.

Pay close attention, though- some models give you an option to disable WPS, but *it does nothing*. Nada. Zilch. Exploits against the WPS spec still work fine.

And honestly, I wouldn't even trust the button method either- if someone (aherm.) happened to have a static station and a good card with an external antenna attached (say, an alfa awus036neh, and a directional 9 or 15dB antenna pointed at your AP....), they can push auth packets at your router till the cows come home. As soon as you press that little button, guess whose auth packets get there first? Hint: not who you want.

That's why I always, always flash with OpenWRT. And why I *always* pentest new wireless kit before putting it live on my network.

On that note, would anyone want a wifi pentesting preso or anything like that?

On Wed, Jun 24, 2015, 19:52 Rich Freeman <> wrote:
On Wed, Jun 24, 2015 at 5:31 PM, Michael Zaleski
<> wrote:
> Yes, WPS is bad, even if the router does rate limiting,  UPnP is also not
> too safe.

Note that some routers let you turn off WPS, in which case having the
feature is harmless.  Also, if you can at least turn off the PIN side
of WPS then you're fine - the push-button part of WPS is secure, well,
aside from the window of opportunity it creates.  The problem is that
routers rarely let you have the one without the other, and if PIN mode
is enabled you are very unsafe.

Also, if your router isn't updated I'd be wary of heartbleed.  I
believe some routers use openssl for WPA2 key exchange, and this could
be vulnerable.  However, I've seen very little attention given to this
so I'm not certain about the risk here.

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