A new whitepaper describing the XML firewall features available in NetScaler version 9.x is available here.
It includes a concise summary of the feature capabilities and the types of applications that the Application firewall can secure. Security is a core component of the Application Delivery Controller (ADC) platform. For a broad overview of the security related features available in the NetScaler, get Citrix NetScaler - A Comprehensive Application Security Solution.

XML firewall

In 9.0, the Application Firewall can be used to protect applications that use XML payloads. These applications include SOAP-based Web services, AJAX applications and REST-based applications that use XML. XML specific security features include

•     XML Denial of Service protection,
•     XML Well-formedness check,
•     XML attachment detection,
•     Message validation (Schema)
•     Cross Site scripting and SQL Injection protection
•     Web services Interoperability (WSI) check

 XML protection is integrated into the Application Firewall. So all applicable firewall features including Start and Deny URLs, Buffer overflow, Cookie protection and Safe Object checks are available. More details on the XML firewall functionality can be found at XML Security Features in Netscaler 9.0

Application Firewall - Integrated Caching interoperability

The 9.0 release has full interoperability between the Application firewall and the Integrated Caching (IC) module on the Netscaler. In the 8.1 release, the Application firewall supports IC for features that do not require parsing the response body.  In 9.0, this restriction is removed. This results in better performance if the application html pages are cacheable. Features like Form field consistency and URL closure benefit from this new functionality.

URL Transform module

URL transform module provides an easy regular expression based approach to rewrite requests and response URLs. This feature is available separate from the application firewall license. It builds on the application firewall parsing technology to rewrite only valid html links.

Custom error pages

When the Application Firewall detects and blocks an invalid request, it can serve out a custom HTML response that has been uploaded or do a 302 redirect to a configured URL. Previous releases could only do the 302 redirect.

NetScaler's Application Firewall offers great protection for Web Applications via a positive security model that lets the user decide what is allowed to reach their web server. Web site vulnerability and compliance requirements can be met by deploying this integrated firewall.

But the concept of the web is changing. Expanding beyond the traditional web pages, many sites now include programmable interfaces accessible via XML based APIs. While web sites are mainly for consumers, the programmable APIs are used by business partners and customers to automate and integrate systems. The APIs are also getting used by emerging Web 2.0 enabled Rich Internet Applications (such as Adobe Flex and Microsoft Silverlight) that get deployed inside a consumer's browser. Once deployed, these RIAs will make active and passive calls to the exposed APIs of a web site. Often exchanging information in the background using an XML based protocol like REST or Web Services.

As the Web and programmatic APIs continue to become more of an integrated offering, it is important to provide security for the APIs as well as for the Web site. NetScaler 9.0 introduces a major new module inside the Application Firewall centered on XML Security. With these new capabilities, users will be able to simultaneously secure HTML based web sites as well as XML based REST and Web Services APIs.      

_{Useful Links}

• XML Security Features in Netscaler 9.0

_XML

_{Extensible Markup Language (XML) is a W3C standard for creating custom markup language to representing structured data in text.}

_{Characteristics of XML}

• Simple and Plain Text
  • Easy to read and understand both for humans and computers
  • Supports "all" platforms and programming languages
  • Supports multi-lingual documents
• Self-description
  • Meta data in the form of tags and attributes
  • Simplifies tools/programs development
• Open
  • Widely adopted World Wide Web Consortium (W3C) standard since 1998
• Extensibility
  • No fixed set of tags. New tags can be created as they are needed.
  • Can express complex messages.

_{Sample XML}

<?xml version="1.0" encoding="UTF-8"?>
<Bio>
     <Name>
        <First> John </First>
        <Last> Smith </Last>
     </Name>
     <Company current="Yes">
         Acme Open Source Software Center
     </Company>
</Bio>

_{Useful Links}

• XML Security Features in Netscaler 9.0
• XML Specification: http://www.w3.org/TR/REC-xml/
• Wikipedia: http://en.wikipedia.org/wiki/XML

One of the long awaited new features in NetScaler 9.0 is XML security.  In 2007, Citrix acquired QuickTree, a small privately-held software technology provider on the forefront of addressing the key security and performance challenges of XML, web services and Web 2.0.  With Netscaler 9.0 the XML security capabilities acquired from QuickTree are fully integrated into the Netscaler web application delivery appliance.

Some the XML Security Features available in the new NetScaler release:

The SAP Enterprise Service Oriented Architecture (SOA) provides a blueprint for services-based, enterprise scale business solutions that are adaptable, flexible, and open. Enterprise Services Architecture takes the concept of service-oriented architecture to a new level by transforming Web services into enterprise services. Bringing Citrix and SAP Enterprise Services Architecture together reduces the dependence on customized applications, and increases flexibility and reduces time to deployment while reducing operational expenses.

Watch this Load Balancing Tip:

Tap into the power of AppExpert

We recently had a meeting with a large partner of ours and they handed down some hefty requirements.  An average of 100 partners using their portal on any given month to access their development environments on the backend.  It was clear that NetScaler could scale, but the question was how to keep all of those partners separated from each other, without them peeking into each others traffic. It turned out to be easier than we thought using the NetScaler as an SSL VPN with the addition of some policies bound to each partner's user group.  The following is an overview of the network diagram, and there are some deployment guides to walk you through these installations.