Full Disclosure mailing list archives

Re: HTTP AUTH BASIC monowall.


From: Simon Smith <simon () snosoft com>
Date: Thu, 16 Mar 2006 10:58:06 -0500

Mike,
    Flames like yours are useless. If you do not know how to answer the
question that I am asking, then just be quiet. Mark Coleman is one of
the few people that seems to have understood my question and provided me
with a viable solution. Again, thanks Mark!

Michael Holstein wrote:
First off, I think 3 days spent on this topic is sufficient --
epically since you fail to grasp some of the more basic concepts which
underly the OSI model.

Encoding a username and password combination using base64 is not
secure, but, I understand why it is encoded in base64. Having said that,
I am trying to discover/create an alternate method for authentication
that is secure even if the SSL pipe is compromised. I liked the idea of
creating a secondary tunnel within the initial SSL tunnel but I am not
certain that it would be the best way to do it.

Basic Auth via SSL is secure. I could use ROT-13 encoding inside SSL,
and it'd still be 128 bit encryption over the pipe. What matters here
is not how the password is encoded for transmission, but HOW it's
transmitted (in this case, via a SSL session).

    This concern came about initially because I was sniffing a LAN and I
noticed a lot of clear text http communications. Within those
communications was the basic authentication header. When I decoded the
auth string I successfully logged into the system receiving the packets.
Very quickly I found that I was connected to a centralized IT management
system that allowed me to control any other computer on the network. Not
only that, but it also allowed me to record emails, key strokes, install
software, remove software, etc.

Duh. If I can sniff a network, I can do all sorts of stuff. Welcome to
the world of tcpdump, ethereal, and promiscious capture.

I took the liberty of hardening the system by implementing SSL
internally. That really didn't do much for the security of the system
though. I had one of my co-workers attempt a Man in the Middle attack,
and he did it successfully. Sure enough, once the SSL session was had
the encoded string could be decoded and access to the main console could
be gained.

Then he tricked you into accepting the bogus certificate. Shame on you.

    My concern isn't firewall management. My concern isn't with SSL
going over the Internet. My concern is more with SSL on a LAN and that
this IT tool and other similar tools can be compromised easily once a
LAN is penetrated. Providing an extra layer of security within the SSL
tunnel would help to prevent this tool and others like it from being
compromised so easily. My first thought was on how to harden the
authentication because the basic auth didn't cut it for me. Thats what I
am looking for ideas for.

Good grief .. if you're that worried about it, use client-side
certificates (with a password). If you're even MORE worried, put that
certificate on a hardware token that protects the key in hardware.

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-- 
Regards, 
        Jackass


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