Subject: RE: Software for PKI

From: Ryan Hurst <[email-masked]>
Date: Wed, 07 Nov 2001 19:53:17 -0800

Excellent points Bob! 

PKI is a piece in a big puzzle, all of the digital signatures and session
encryption in the world will not protect a system that takes un-validated
user input to access its back end databases as system/manager :)

One encouraging (and somewhat off-topic) thing is all of the books/text on
the topic of information security. Unfortunately there are probably more bad
ones than good ones but it in either case it has done wonders for awareness
of the types of problems people should look for. Maybe in a few years what
we all see as common sense will become "common"!

Ryan M. Hurst

-----Original Message-----
From: Bob Jueneman [mailto:[email-masked]] 
Sent: Wednesday, November 07, 2001 6:12 PM
To: [email-masked]; [email-masked]; [email-masked]
Cc: [email-masked]; [email-masked]
Subject: Re: Software for PKI

That happens to be a particularly interesting point, because it illustrates
a fundamental flaw in how SSL is most often used (which is off the topic of
PKI, but perhaps relevant).

You went to www.united.com or www.ual.com using an unauthenticated http
session (https doesn't work -- they didn't make that page available.)
Therefore you don't really know whether you are connected to United Air
Lines or to Untied Air Taliban.  Then if you select say the Request Upgrade
option, this untrusted site refers you off to some other site that you never
heard of, with a DNS name
(https://www.ua2go.com/ci/Login.jsp?return_to=eug_req) that has little if
any obvious connection with United Air Lines except for the "ua" prefix (if
you bothered to check the certificate).  and that site then asks you to log
in, and presumably will get around to asking for your credit card number
sooner or later.

And you are supposed to get all warm and fuzzy inside, knowing that your
credit card number was encrypted over your gigabit LAN interface that no one
could intercept as a practical matter anyway.  Meanwhile, your sacred credit
card information is sitting at a site that you never heard of, protected by
God knows what form of computer security if any at all, after you were sent
there by a site that you had no technically sound reason to trust in the
first place!

And oh by the way, I didn't mention the fact that IE didn't allow you to
control what algorithms or keys sizes were selected, so you might very well
be trusting your data to an outmoded 40-bit algorithm, or (even more
insanely) to a Null crypto algorithm!  (You did remember to click on the
properties button each time, to see what crypto strength was used, and what
the certificate path said?  Sure you did -- every time, too.)

So ubiquitous, almost.  But secure, I'm not so sure. The PKI works, but the
result is just window dressing.

But fortunately that's a different IETF group, so we can blame them.

Bob

>>> Peter Gutmann <[email-masked]> 11/07/01 05:08PM >>>

Eric Rescorla <[email-masked]> writes:
[email-masked] (Peter Gutmann) writes:
>>My favourite example: Go to www.united.com and have a look at the cert you
>>get.
>I can't seem to connect to www.united.com:443 

You have to go there with HTTP and then select one of the HTTPS links.

>I assume your point here is that it www.united.com redirects you to
>www.ual.com? If so, I don't see the problem with this. 

You end up (once you're using SSL) talking to a site which is completely
unrelated to United (itn.net) although there's no indication from the
browser
that you've ended up talking to who knows what (that is, no warning unless
you've got the appropriate warning option enabled in your browser, if you do
enable it you get so many false alarms you tend to turn it off again fairly
quickly.  Also, the URL is so long you can't see the server name).  As a
result
unless you go out of your way to check, it looks like you're talking SSL to
United when it's actually to itn.net.

(The same is true for any virtual hosting and whatnot system, I'm just using
United as an example).

Peter.

---

From: Rick Wessman <[email-masked]>
Date: Thu, 08 Nov 2001 10:35:50 -0500

I agree with all of your points, Ryan and Bob.

I don't know how many times I've seen on a web site that transactions
are "protected" with SSL. I try to explain it to people that the tunnel
may be protected, but you have know idea what is on the other end.

Speaking as an employee of said database company, we have been hammering
on customers to change their administrator passwords. Unfortunately,
there is little that we can do to enforce it. However, in 9i, all
non-essential accounts are expired and locked at installation. So, we're
trying.

                                              Rick