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WPA Weak Key Cracker Posted

Posted by michael on Fri Nov 05, 2004 09:02 PM
from the bet-the-NSA-already-has-it dept.
Wireless Networking Encryption Security Hardware
Glenn Fleishman writes "The folks at TinyPEAP released a cracking tool to break Wi-Fi Protected Access (WPA) keys. WPA is the replacement for weak WEP keys in the original 802.11b specification. Robert Moskowitz of ICSA Labs released a paper almost exactly a year ago documenting how WPA keys that were short and lacked randomnness could be subject to cracks. This tool automates the process. Moskowitz advised choosing passphrases of more than 20 characters or generating random keys of at least 96 bits, but preferably 128 bits. Some tools exist to produce better keys, including chipmaker Broadcom's SecureEZSetup (in selected hardware) and Buffalo Technologies' hardware-based AOSS for automatic key generation and propagation. Enterprise-based WPA with 802.1X doesn't have this weakness: each user gets a long WPA key that's randomly generated and uniquely assigned--and can be frequently changed during a session."
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  • When you really think about it, by nature wireless networking can never be too secure. I mean, your data is being broadcasted across the air to another point. Think about it.

    • Re:By its nature... (Score:2, Insightful)

      by Anonymous Coward
      When you really think about it, by nature the internet can never be too secure. I mean, your data is being transmitted through dozens of other servers to another point. Think about it.

    • Re:By its nature... (Score:5, Insightful)

      by wcdw (179126) on Friday November 05 2004, @09:26PM (#10739940) Homepage
      Theoretically, perhaps - but how secure does it need to be? All wireless traffic in my home uses SSH tunnels between the laptop and the firewall.

      When it becomes possible to conveniently crack SSH tunnels, I'll start to worry. By then, I'm sure there will be something better available. Meanwhile, you can sniff those ESP packets to your heart's content.

      This is trivial under Linux, and not much more difficult under Winblows (clients), and I'm surprised more people don't suggest it as an alternative to WEP/WPA.

      (My girlfriend uses Winblows w/ SSH Sentinel, and has only had one problem that rebooting wouldn't fix - in over 3 years. That one? Installing XP / SP2 turns on the [useless] firewall, which blocks the ports needed by the VPN.)

      http://www.theboyz.biz/ [theboyz.biz]Computers, parts, electronics, small appliances and more!
        • <snort> The FACTs are that when SP2 was installed, it altered the system configuration, and installed a perfectly useless product. (Actively dangerous, as noted by the bug which enables file/printer sharing across ALL connections if you have it on any!)

          As for not knowing what happened, it took me about 10 seconds to solve the problem. And, in fact, DID require a reboot, but then again, that's Winblows.

          As for lacking sufficient knowledge of firewalls, you're welcome to try and hack mine. It's bee
          • still missing: session keys and host keys. :)
            Plus how good is your OS at getting entropy? What symmetric encryption algorithm? What key exchange algorithm?
            And about ssh over vpn... a friend (known player @ crypto) told me once that you should never assume that re-encrypting would improve security, unless you are using a well known and tested method of mixing both encryption systems.
            Intention of this post is not bitching, but to try to make ppl aware it's not just "i use XXX, so im safe", but a very co
            • All good points, from a security point of view. I should point out that I do stay current on security patches, including randomness issues, and that ALL of the connections in these networks involve at least one Linux box.

              Regarding SSH over VPN, I don't do it for added security, and am familiar with at least some of the dangers multiple encryption layers can present. I do it because when the laptop is wireless, it CAN'T talk to anything without the VPN -- and there is no command line access to any of my b
            • > /dev/urandom is not random at all, it is pseudo-random at best.

              On Linux, that's wrong. /dev/urandom returns very high quality pseudo-random at _worst_. /dev/random never resorts to mere pseudo randomness, and read(2)s on it block until the kernel has accumulated enough entropy in its pool. (yes, Linux maintains an entropy pool which it seeds from random events so there is some true randomness waiting for programs like gnupg or statistical simulations that need it.)

              You're correct about everything

    • Re:By its nature... (Score:5, Insightful)

      by slashdot.org (321932) on Friday November 05 2004, @09:37PM (#10739983) Homepage Journal
      When you really think about it, by nature wireless networking can never be too secure. I mean, your data is being broadcasted across the air to another point. Think about it.

      I guess that's an understandable misconception about security. But security has by nature nothing to do with wireless or wired.

      Good security is based on the principle that other people WILL have access to your encrypted data.

      Unfortunately, the people that implemented security in the wireless protocols did a piss-poor job and left it vulnerable to (known!) attacks.

      However, if you just ran IPSec or something over your wireless connection, you'd be fine.
    • When you really think about it, by nature wireless networking can never be too secure. I mean, your data is being broadcasted across the air to another point. Think about it.

      Your wired network can't be too secure either. All that you need to do is attach a listening device to a wire somewhere. Or just compromise a machine.

      See the sibling post about how the basis of cryptography is asuming that someone has access to your encrypted data and the encryption algorithm. All security rests in the key. Crypt

      • Asside: WEP = Wired Equivalency Protocol (Score:5, Insightful)

        by KillerCow (213458) on Friday November 05 2004, @10:48PM (#10740187)
        As an aside to the above point, the original "WEP" stood for "Wired Equivalency Protocol." They chose that because it acknowledged that wires weren't inherently secure either. It's name didn't claim security at all... just that it was equivalent to a wire. The inside joke was that that didn't mean anything from a security standpoint either.

      • This is why (Score:5, Funny)

        by zakezuke (229119) on Friday November 05 2004, @09:20PM (#10739912)
        This is why I setup a stand alone wifi network that when ever war-drivers discover my "wireless network" everything they visit gets redirected to goatse. The result, I've observed is usually a loud exclamation followed by the sound of screeching tires and burnt rubber.

        Next i'll observe when I secretly host a wifi network near starbucks and replace everything with a small mirror of www.khaaan.com [khaaan.com].

          • Re:This is why (Score:4, Funny)

            by zakezuke (229119) on Friday November 05 2004, @10:30PM (#10740137)
            If you want to get really evil, I assure you that some twisted people are perfectly capable of dreaming up even scarier things than goatse

            I don't know, hearing 20 laptops or so yelling "Khaaan! Khaaan!" I think is scarier than a penis bisection.

  • Better colours (Score:3, Interesting)

    by Anonymous Coward on Friday November 05 2004, @09:11PM (#10739862)
    http://shit.slashdot.org/article.pl?sid=04/11/05/2 143226 [slashdot.org]

  • Odds of implementation? (Score:4, Insightful)

    by IamGarageGuy 2 (687655) on Friday November 05 2004, @09:13PM (#10739870) Journal
    The odds of Joe sixpack going the extra step of making a 20 character key is not good. WiFi setups are all the rage and now can all be broken into even after you spend an hour telling someone that they have to use WEP.
  • What's the big deal? Kismac has had this feature for a while. I hope i'm missing something.

  • I'm all for this. (Score:5, Funny)

    by Anonymous Coward on Friday November 05 2004, @09:16PM (#10739889)
    Leaving my WAP wide open all the time allows experienced crackers to access all the best pr0n sites with ease via my connection. All I then have to do is check the logs and Voila! There they are! Saves me looking for them and having to wade thru the pop-ups and bogus sites!

  • no good excuse (Score:3, Interesting)

    by Misanthropy (31291) on Friday November 05 2004, @09:17PM (#10739896)
    there's not really any good excuse for a weak wpa key. My router will generate a random 128bit key.
    Kind of funny. I have our wireless router locked down with a 128bit key and only accepting connections from mine and my roommates' MAC addresses. But one of my neighbors has a wide open access point that I can connect to whenever I wan't.
    I don't really want to, but I could.

    No real point to this post except that you should attempt even minimal security (Unlike my neighbor).

  • In addition to a cracker (Score:5, Interesting)

    by slashdot.org (321932) on Friday November 05 2004, @09:18PM (#10739904) Homepage Journal
    I would have liked to see a tool that will verify if your chosen key is 'secure' or not.

    Would have made the crack software look a little less black-hat, to the uninitiated.

    Just an idea.
    • Just to clarify, before I'm getting wise-ass responses; I realize the crack software may be the ideal tool to confirm your key is A-OK. BUT, that software is not for the faint-of-heart.

      Getting raw packets etc, is not something everybody knows how to do, but it would be great if they could verify their key was fine.

      (and then that software could send the key back to the original web-site, so they can keep a list of fine keys that are now known, so they are not fine anymore. Yeah yeah, I know... ;-D)

  • don't blame WPA (Score:5, Insightful)

    by nbert (785663) on Friday November 05 2004, @09:27PM (#10739942) Homepage Journal
    ...if your key is asdf - the attack is based on a dictionary. This weakness relies on human nature after all.

    Btw: The Tips and Tricks section of this newsletter [slashdot.org] is a good ressource if you want to create passes which are harder to guess.

  • Ho hum (Score:3, Interesting)

    by Realistic_Dragon (655151) on Friday November 05 2004, @09:33PM (#10739963) Homepage
    Guess it's not time to abandon treating all wireless hosts as bastions and using SSH to tunnel/authenticate just yet then.

    Treat wireless just like you do a student network and everything will be fine.

    • Re:Ho hum (Score:3, Informative)

      by Dr. Evil (3501)

      Note that WPA is just like WEP but with quickly rotating keys and more secure key exchange. Yeah, you can't crack it in real-time to get on the network... but if you listen to the vendors carefully, they'll even say it... "Authentication, Authorization.... " But never will they formally say "Secure encryption of data"

      You can decode everything but the key exchange off-line.

      VPN software is the only way to go. The wireless vendors are liars.

      Does anyone want to comment on WPA2? Does it require new har

  • Suggestion (Score:3, Interesting)

    by cuteseal (794590) on Friday November 05 2004, @10:02PM (#10740064) Homepage
    From reading all the threads and flame wars going on here, it appears that WEP, WPA and even MAC address filtering is easy to crack, if someone was determined enough to do it.

    So, I know it's not foolproof, but does anyone have suggestions on how to increase wireless security?

    1. Regularly change WEP keys?
    2. Use a proxy server to access internet, and disable direct access via access point?
    3. Turn off router and computers when you're not using them?

    Any others?

    • The best thing you can do in addition to using WEP, changing keys, and locking down the MAC addresses allowed, is to use ssh or VPN software to encrypt your connections. If someone spends enough time to crack WEP and spoof a MAC address then the most they can get is access through your access point. They would have to break ssh or VPN to look at your data. Of course you would need to have tools in place to identify a man in the middle attack to prevent them from spoofing your connections.

      Of course if

    • Re:Suggestion (Score:5, Insightful)

      by igrp (732252) on Saturday November 06 2004, @05:19AM (#10741041)
      From reading all the threads and flame wars going on here, it appears that WEP, WPA and even MAC address filtering is easy to crack, if someone was determined enough to do it.

      Well, there are different schools of thought when it comes to SoHo/low bandwidth WAN access security.

      You are attempting to lock your network down so that a potential attacker cannot use your connection. The other approach lock your network down just enough to make a cracker not want to bother and to move on to the next, easier target (ie. your neighbors' access points).

      The former approach generally works just fine if your goal is to deny a potential attacker access to your network bandwidth. It won't really stop a determined attacker who isn't just in it for a free-ride but who wants to steal specific data. If that's part of your threat model, chances are wireless isn't really for you. The downside is that this is pretty inconvenient. And since convenience is the big selling point when it comes to wireless networking, most people just won't take that route.

      Those people who have WEP and MAC address filtering enabled, basically want to protect themselves against random, unsophisticated wardriving. It won't help defend against a determined attacker and probably won't even scare off the teenager next door with too much time on his hands. The point isn't really to have good access security. It's just to raise the bar enough to be unatractive enough of a target. Think of it as a "I don't have to outrun the bear, I just have to outrun you" scenario.

  • What about unsecured networks? (Score:4, Funny)

    by porkUpine (623110) on Saturday November 06 2004, @01:35AM (#10740600)
    Until people start securing their wireless networks with SOMETHING, wireless will always have a bad reputation. As nice as it would be, we aren't allowed to use wireless in office... period. BTW, I'm surfing /. from my neighbors unsecured WAP. *Sigh*

  • What are "short" WPA keys supposed to be? (Score:5, Insightful)

    by rpp3po (641313) on Saturday November 06 2004, @05:24AM (#10741046)
    It is easy to see, that the original poster of this story has no clue about encryption. There are several misconceptions in his posting:
    1. He writes: "WPA is the replacement for weak WEP keys in the original 802.11b specification". This is wrong. "weak key" ist a crypographic term for - wonder - weak keys, like 128 bit, consisting of 1's only (1111111111111...). For like 30 years, even WEP, has taken measures to prevent this kind of keys during use. WEP's problem in fact is the deterministic generation of IV's of the keystream, not weak keys.
    2. "Moskowitz advised choosing passphrases of more than 20 characters or generating random keys of at least 96 bits, but preferably 128 bits." That's also misunderstood. The PSK (pre shared key) even when not using 802.1X is always 256-bit. It's generated -from- a passphrase that you type in. A passphrase like "abc" e.g. contains less than 16 bits of security. So a WPA key generated from the passphrase "abc", although still being 256-bit, can be cracked within the time of a 16 bit brute force attack. This is done by simply generating WPA keys from all passphrases between "aaa" and "zzz". So you always use 256 bit keys (PSK's), but they can be generated from much smaller passphrases.
    3. "each user gets a long WPA key". See above. The keys are always the same size of 256 bit. When using 802.1X there is only maximum "randomness". That's the difference. It think the poster still thinks that WPA works like WEP where you actually use different key lengths.
    One could think that I'm very picky about his words. I think not. Especially in cryptography it is important to know exactly what part of a cryptographic chain you're talking about, when talking about weaknesses. TinyPEAP seems to be just a tool for people like the original poster and script kiddies, who are in fact NOT knowing what they are talking about. It's just a bruteforce tool to try out WPA passphrases. This is supposingly faster for people using short passphrases than bruteforcing keys directly.
    • I'm the original poster. You're reading what I wrote with the lack of knowledge necessary to comment on it.

      1. All WEP keys are susceptible to nearly the same degree of being broken by collecting enough data passively. Thus, they are all weak. From a definition of weak keys at an online dictionary: "In the extreme, a poor cipher design is simply one with a very large number of weak keys."

      2. No, you're misreading this, too. Moskowitz (see his paper) is talking about the seed data, not the resulting way in w

  • WPA er Old News! (Score:3, Informative)

    by fogez (635305) on Saturday November 06 2004, @08:52AM (#10741378)
    KisMAC has had this function for a long time. Someone used it at Hope 2004 to their wifi key. In addition, Josh Wright has had a working copy available for linux for some time. The LiveCD from Remote-exploit.org (Auditor) has included this tool for about a month now. This is not new...
    • It does not have to be cracked, MAC filtering does not prevent from others listening the network.

    • Re:What Morons (Score:2, Informative)

      by Anonymous Coward
      Um, do you know how easy it is to spoof MAC addresses? Very easy.
        • "ifconfig wlan0 hw ether [mac address]" sets your wlan card's mac address under Linux. There is probably a way to do so under Windows as well.

        • Re:What Morons (Score:4, Informative)

          by wcdw (179126) on Friday November 05 2004, @09:31PM (#10739953) Homepage
          NOT really a good idea to start a thread about morons, and then act like one.

          _YOUR_ wlan card may have the MAC address burned into it. Once ALL NIC did. I think it was more than 10 years ago that I saw my first NIC that DID NOT HAVE a MAC address (it was all zeroes, and expected to be set in software).

          _MY_ wlan card will _CERTAINLY_ let me change the MAC address - under Linux _or_ Windows.

          http://www.theboyz.biz/ [theboyz.biz]Computers, parts, electronics, small appliances and more!
        • My Linksys card allows me to change the MAC on Windows... it's trivial to do.

          The other poster sowed how easy it is to do this in Linux.

    • Re:What Morons (Score:5, Insightful)

      by PedanticSpellingTrol (746300) on Friday November 05 2004, @09:19PM (#10739907)
      Jesus christ, I hope you don't have a job in security. If all your packets are unencrypted, anybody can sniff them, see what MAC addresses are recieving traffic, and thus are on the whitelist. From there, it's a simple matter to spoof the MAC in software. This feature is built into linux, windows and OS X. The myth that MAC addresses are a universally unique identifier is dangerous and has to be dispelled.

      • Re:What Morons (Score:4, Informative)

        by wfberg (24378) on Saturday November 06 2004, @05:14AM (#10741036)
        MAC adresses are universally unique identifiers, except for a few duplicate runs in cheap-ass brand NICs.

        It's just that they cannot be authenticated in any way. It's like allowing only people who claim to be you on your network, rather than people who can prove it in some way.
      • Umm simple. I would just change the MAC address on my laptop to match the address in the WAP and reconnect. Many cards allow you to change the MAC address in software.

        Now, where do I pickup my monkey?

          • Re:What Morons (Score:4, Informative)

            by arth1 (260657) on Friday November 05 2004, @09:51PM (#10740035) Homepage Journal
            you need to brute-force check each MAC adress. there are ways to make this harder in the router.

            No, you don't have to do this. Once the WEP key is broken (or if there is no WEP key, just MAC filtering), you simply listen to the traffic to get a MAC address that's allowed, and use that.

            Regards,
            --
            *Art
      • Once again I draw your attention to the problems with making conclusions about the entire world based on your one example.

        This is a *trivial* exercise, and certainly does not require any hard-wiring.

        http://www.theboyz.biz/ [theboyz.biz]Computers, parts, electronics, small appliances and more!
    • Yes... Several..


      Do your homework. Look up Supplicant, XSupplication, HostAP, 802.11i for Linux, 802.1x for Linux, etc, etc, etc... Lots of things going on.


      ITMT... This crack is only for weak keys with WPA-PSK. Not applicable to WPA enterprise or WPA2.

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