Full Disclosure mailing list archives

Re: OpenID. The future of authentication on the web?


From: "Petko D. Petkov" <pdp.gnucitizen () googlemail com>
Date: Mon, 24 Mar 2008 15:38:25 +0000

comments inlined

On Mon, Mar 24, 2008 at 3:10 PM, Paul Schmehl <pauls () utdallas edu> wrote:
--On Monday, March 24, 2008 09:13:38 +0000 "Petko D. Petkov"

<pdp.gnucitizen () googlemail com> wrote:
 >>

 Yes, and convenience is often the enemy of security.
 >>
 >
 > Not always. I think complexity is the enemy of security. The simpler
 > the system is the less chance to screw up, the more secure it is. It
 > is much easier to secure a single port then a class B network, don't
 > you think?
 >

 Of course.  Both complexity *and* convenience of often the enemies of security.
 :-)


 > First of all, we've proved time and time again that people do reuse
 > passwords. Password reuse is a huge problem and it is due to our
 > inefficiency of memorizing partial information which is not associated
 > with anything substrantial. In psychology this is known as the process
 > of anchoring and if you master how to anchor then you can master
 > memorizing large sets of useless data without getting corrupted
 > sectors in your brain. A good start is reading Darren Brown's book
 > "Trick of the Mind".
 >

 I don't disagree.


 > On another note, capturing my OpenID credentials wouldn't be as easy
 > as you say. First of all if the OpenID provider has a valid,
 > authorized SSL certificate you won't be even able to see when creds
 > are flaying around. Second, I've mentioned one-time passwords in terms
 > of keyfobs, rsa tokens, whatever. Even if you capture these
 > credentials you wont be able to use them and believe me, carrying one
 > keyfob just for your OpenID provider is a lot easer then having what
 > they call keyfob necklace in order to ensure a good security for every
 > single site you visit. I think that verisign provides OpenID service
 > which is based on all that.
 >

 Verisign *requires* only alpha-numeric characters for my password for my *CA
 ADMIN* account for our PKI system.  That should tell you something aobut their
 dedication to security.


 > Last but not least, lets say that you have access to the machine or
 > network and you can sniff the cookies and as such get access to the
 > openid account. Well, some OpenID providers have features where you
 > can configure the account to automatically destroy the session cookie
 > once an OpenID authentication is authorized. Your best chance is to
 > sniff or attack the sites where the user is logging into but any
 > problems associated with them are not problems withing OpenID and they
 > will work independently of the authorization/identification mechanism.
 >

 Getting access inside networks these days is trivial.  There are hundreds and
 hundreds of compromised machines inside of corporate networks due to phishing
 scams and the ignorance of the average user.  Furthermore, you can get access
 to at least 10% of the machines on any network simply by logging in as
 administrator or root (pick your OS) using either blank, password or
 root/administrator as the password.

 Add to that hundreds of trivial sql injection attacks and other easy attacks,
 and most networks are like swiss cheese.

 Once you're on one box inside, you can roam around freely and find a way to
 capture id information in the clear.


SSL + KeyFob (2 factor authentication) + Session destruction after
authorization - I don't think that you can do anything useful with
that. If the OpenID does not have any SQL Injection or other problems
such as auth-bypass, it is mission impossible. And even if the site is
vulnerable to some bugs that has nothing to do with OpenID.



 > Well, PayPal is a lot more secure when it comes to money
 > transfers/transactions. Do you feel comfortable giving away your
 > credit card details to every single merchant from which you want to
 > purchase some goods. I don't!
 >

 You frame the question wrong.  The real question is, do I feel comfortable
 exposing $50 to risk by using a credit card or exposing every dollar I've
 deposited with Paypal to risk.  And the $50 is waived if the vendor is culpable
 for the loss.

 I scanned a card through a gas pump while on a vacation trip last year.  WIthin
 two hours someone had charged $1005 on that card.  It cost me nothing.  The
 charges were reversed, because it was clearly fraud.  (I was in South Carolina
 - timestamped just two hours before - the charge was in El Paso.)

 The credit card industry is quite robust and equipped to handle fraud.  What
 happens when an OpenID account is compromised and *every* account is drained
 and thousands of dollars are charged and *according to OpenID* it was me?


Paul, that's cool. You are covered. :) What about the inconvenience?
What if someone withdraws all your funds right at the end of the month
you have no money for a couple of days. You know that it takes time to
detect fraud and there are all sorts of complications around that.



 > Well, roll your own OpenID service. It takes 5 minutes and a couple of
 > lines with PHP and you can make it as secure as you want.Isn't that
 > much better then trusting every single login prompt you see?
 >

 No, it's not, because a poorly secured site exposes only that data I have
 revealed to them.  OpenID opens a whole new realm of theft.

 But don't take my word for it.  Just wait for the first big scam to occur.
 First I phish your credentials.  Or I induce you into installing a trojan on

You won't be able to phish them. And even if you install a trojan you
won be able to capture them :)

 your box.  Then I get your OpenID username and password.  Now I have everything.

You need more then username and password.


 It *will* happen.


It will happen for purely implemented sites.


 > true but as I mentioned above and in my previous email, you can spend
 > good time securing your OpenID to the extend it is not feasible for
 > someone to attack it. We know that all encryption mechanisms are
 > vulnerable to brute force attacks but is it feasible to crack them?
 > No, not at all. Not now! Maybe when we get to personal quantum
 > computing we might have a chance but by that time we will switch to
 > quantum based cryptography.
 >

 Now you sound like Larry Ellison.  :-)


 >>
 >>  Now, there is no doubt that we need better user education.  User *must*
 >>  learn not to trust everything they get in email.  They must also learn to
 >>  use good passwords and not reuse them on every site they visit.  There's
 >>  also no doubt that some sites will do a lousy job of security and end up
 >>  exposing a person's credentials (which is why you should use different
 >>  credentials on every site.)
 >>
 >
 > This is impossible! :)
 >

 Spoken like a true advocate for technological solutions to every human problem.


Not really! I was one of the first to speak against OpenID. :)


 >>
 >>  We also need some sites to do a better job of requiring strong passwords.
 >>  (Some still require only alpha-numeric characters and two few maximum
 >>  characters.)
 >>
 >
 > This is also impossible! :)
 >

 Not really.  Think Sox, GLBA, PCI, etc., etc.


How many sites do you know that enforce good password policies :) ?



 >>
 >>  But the idea that SSO makes sense outside the context of a single entity
 >>  that controls its userbase is misbegotten, in my opinion.  The individual
 >>  *user* should control their credentials, not some "foreign" entity, no
 >>  matter how trustworthy they may claim to be.
 >>
 >
 > As I said, if you don't trust public OpenID providers, roll your own.
 > It is very, very, very easy.
 >

 You're misunderstanding my point.  It's not that I necessarily distrust OpenID
 providers or the software itself.  It's that I think the entire approach to
 solving the problem is wrong-headed.  Data owners should control the access to
 their data, not third parties.


OpenID is explicitly designed to enable you to control your data. At
the moment the service provider controls your data not you.


 --


Paul Schmehl (pauls () utdallas edu)
 Senior Information Security Analyst
 The University of Texas at Dallas
 http://www.utdallas.edu/ir/security/

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-- 

Petko D. (pdp) Petkov | GNUCITIZEN | Hakiri | Spin Hunters

gnucitizen.org | hakiri.org | spinhunters.org

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