Firewall Wizards mailing list archives
Re: XML firewalls
From: Eugene Kuznetsov <ekuznets () us ibm com>
Date: Mon, 20 Feb 2006 10:08:46 -0500
Well, naturally, I cannot resist*. There is quite a few things that are commonly considered part of best practice. You mention some of them already. First, there is verifying that the XML is well-formed and does not have malicious characteristics. Second, there's verifying the structure and value ranges, usually accomplished using XML schema validation. In web services setting, there are WSDL files that can be thought of as describing the schema structures of all the RPC requests & responses. Third, there is various kinds of additional policy filters (e.g., do not allow "deleteAllInvoices" method to be called from the outside), and this is achieved using standards such as XPath or some the policy languages. The user interface to almost all of this should be an easy-to-use UI, of course, but underneath it is these specs that make things works. Fourth, there is good old authentication, authorization and audit, where SAML, XACML and integration with LDAP or various existing SSO systems make their appearance. At this stage you can apply fine-grained policies such as: "user Arkanoid not allowed to invoke "getInvoice" method iwth argument greater than 100 after 5pm", all at the network level (outside the application code). Fifth is various message-level crypto, transcription, routing and service virtualization steps. And there are some more, potentially. Gartner had put out a list of best practices at some point, as well. I'll include some links below for more information and further reading, but the above is the really interesting thing here that's happened with XML firewalls, web services security and the like. For the first time, security professionals can both enforce a positive security model (with known-good protocol descriptions & schemas) and apply application-level policy (down to parameters in a function call) in the network, using a secure device. All using open standards that are decoupled from the application. This isn't easily done with DCOM, CORBA or other types of old-style RPC traffic, you just can't get an operationally scalable level of control, and everyone spends a lot of time trying to block "known bad" traffic. So quite aside from whether you have an XML security problem today, this is an interesting development for security in general, and something that is only made possible by standardization of the application-to-application protocols around XML, SOAP, web services, etc. --- * Disclaimer: I founded DataPower, a maker of XML-aware network devices that was recently acquired by IBM, which now sells XML Security Gateway, among other products. http://www.datapower.com --- Links: XML Schema - http://www.w3.org/XML/Schema XACML - http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=xacml Misc XML security info - http://www.securewebservices.org IBM DataPower XS40 product info - http://www.datapower.com/products/xs40.html ArkanoiD <ark () eltex net> Sent by: firewall-wizards-admin () honor icsalabs com 02/13/2006 06:35 AM To firewall-wizards () honor icsalabs com cc Subject [fw-wiz] XML firewalls nuqneH, I wrote this to the list a couple of years ago, but no one answered , though i see some XML firewall people here. Could anyone provide some comments on this lines:
On SOAP and other http+xml combos: how do you create security polices for passing xml-based messages through firewall?
I've read WS-SecurityPolicy paper, seen some ads of XML firewalls but have not seen any good example on how that works for any simple XML-based protocol. Let's start with, say, jabber: i'd like to write a policy that logs sender ids and restricts everything other to fit official jabber schema without vendor extensions. Could anyone show me how can that be achieved with current products? ----- Forwarded message from ArkanoiD <ark () eltex ru> ----- Delivered-To: firewall-wizards () honor icsalabs com From: ArkanoiD <ark () eltex ru> To: firewall-wizards () honor icsalabs com Reply-To: ark () eltex net X-Mailer: Mutt 1.0.1i Subject: [fw-wiz] Future and past firewalls (was "firewalls comparison") Errors-To: firewall-wizards-admin () honor icsalabs com X-BeenThere: firewall-wizards () honor icsalabs com X-Mailman-Version: 2.0.13 Precedence: bulk List-Help: < mailto:firewall-wizards-request () honor icsalabs com?subject=help> List-Post: <mailto:firewall-wizards () honor icsalabs com> List-Subscribe: < http://honor.icsalabs.com/mailman/listinfo/firewall-wizards>, < mailto:firewall-wizards-request () honor icsalabs com?subject=subscribe> List-Id: Firewall Wizards Security Mailing List <firewall-wizards.honor.icsalabs.com> List-Unsubscribe: < http://honor.icsalabs.com/mailman/listinfo/firewall-wizards>, < mailto:firewall-wizards-request () honor icsalabs com?subject=unsubscribe> List-Archive: <http://honor.icsalabs.com/pipermail/firewall-wizards/> Date: Fri Jun 25 06:35:37 2004 X-Original-Date: Fri, 25 Jun 2004 14:23:44 +0400 nuqneH, I've read "Advanced Screening" article on Infosecuritymag site and i'd like to share some thoughts on it. The fist impression was quite good, i'd say, things are not as bad as i supposed ;-) There still IS market for advanced firewalling as i see it and there are professionals that are interested in tools for having things controlled. But some questions are still unanswered. Those are: As i stated before, there are TWO completely different things, both called "firewall". Devices for protecting DMZ servers, focused on scalability, fault tolerance, high performance, IPS capabilities and DoS resistance. And there are devices for protecting LANs, with completely different feature requirements: advanced application ispection and granular control. Why do everyone mix those two? Diffrent boxes, different designs and sure, different vendors. (I've found it to be a very good sign that VPN features are left aside in this comparison, looks like people finally realized the obvious thing firewall itself is not required to be VPN box, though it usually can ;-)) On SOAP and other http+xml combos: how do you create security polices for passing xml-based messages through firewall? I still do not have this feature, but i definitely need it and i'd like to see a wishlist and references on how do others implement it. The same question applies to IIOP, which was not even noted in the article, though 2 years ago everyone talked about it. Is IPS in its traditional meaning important for proxy firewalls? My personal impression that it is more important to have advanced protocol parsing that will drop questionable content regardless if there is known vulnerability abused this way or not rather that to have up to date "signature database". When i see new vulnerability, i often do check if my proxies are paranoid enough. For http/html, it is about 70% of "unknown" bad things being blocked a priori. For lpd, it is about 100% ;-), for cvs-pserver - 50%, etc etc, YMMV. Does not look good enough to rely on it? Sure, but it is just because of my lack of resources to analyse vulnerabilities and making content ispection more deep. What's wrong with Cyberguard? It was blamed in the article for "legacy design", what do they mean? Does Netscreen really do in-depth IMAP inspection? The protocol is terribly complicated :-( P.S. (some advertising ;-) Though there still are some corporate, goverment and bank installations of my creature, it becomes mostly like academic project at the moment ;-). Here is the core code snapshot (sorry, almost no documentation, but it should look familliar to you if you have expirience with TIS/NAI fwtk, there even is an API that resembles old one so you may compile any fwtk proxy with it). We are interested in any commercial proposals on the thing. http://milliways.chance.ru/~ark/soft/ADVAopenfwtk-pre2.tar.gz $ md5sum ADVAopenfwtk-pre2.tar.gz 86065d63d96e03479bdba627f279753b ADVAopenfwtk-pre2.tar.gz It is pre-release code, so no public license - if you want to use it, just write me a email. Legacy proxies that did not pass QA are not included, you may get them at fwtk.org in "patches" section. ----- End forwarded message ----- _______________________________________________ firewall-wizards mailing list firewall-wizards () honor icsalabs com http://honor.icsalabs.com/mailman/listinfo/firewall-wizards
Current thread:
- XML firewalls ArkanoiD (Feb 20)
- Re: XML firewalls Eugene Kuznetsov (Feb 20)