Welcome!

Microservices Expo Authors: Liz McMillan, Pat Romanski, Elizabeth White, Derek Weeks, Mehdi Daoudi

Related Topics: Microservices Expo

Microservices Expo: Article

Enterprise Web Services Security: A Reference Architecture, part II

Focus on design and functionality

Last month (WSJ, Vol. 4, issue 2), we looked at how Web services should not depend on specific security environments and rules but should be managed as part of all of an enterprise's corporate data assets such as Web applications, ERP systems, and in-house applications.

We recommended that Web services security be integrated with the overall enterprise security infrastructure at the very beginning of the Web services deployment phase. This month, we'll look at some of those possible deployment models.

Deployment Models
There are four deployment models based on the guidelines presented in our earlier article.

Terminology
The terms used in the deployment models are defined as follows:

  • Reverse proxy server: Intermediary server (e.g., a Web server) configured to filter requests coming from Internet users into the enterprise, providing security, management, and caching capabilities.
  • User repository (or user store): A persistent data store that maintains user information. A user repository can be implemented in LDAP, RDBMS, Microsoft's Active Directory, and mainframe applications. Information related to a single user may be maintained in multiple, separate user stores, each of which needs to be queried for authentication and authorization purposes.
  • Web Services Management Point (WSMP): Enforcement point for implementing a Web service management policy
  • Web Services Security Enforcement (WSSE): Enforcement point for implementing a Web service security policy
Simple Proxy Deployment
Access to enterprise resources is achieved via a reverse proxy server. The first line of defense is the network firewall, which filters requests to the reverse proxy server (see Figure 1).

The request for a Web service is submitted using a SOAP message that can be sent over a variety of transport protocols (HyperText Transport Protocol [HTTP], Simple Mail Transport Protocol [SMTP], File Transfer Protocol [FTP], Java Message Service [JMS], and other message queue [MQ] services). The sender's identity is expressed in transport protocol headers or in the SOAP document submitted for the request. WSSE authenticates against the submitted credentials, binds the message to an identity, and, if authorized, grants access to the Web service.

The outer network firewall ensures that resources cannot be accessed externally. The inner network firewall ensures that the enterprise resources (including the IAM security policies and the user repositories) are protected against internal attacks.

Low-level access control methods are used to ensure that only the reverse proxy server can forward requests to back-end resources. This means that back-end resources (.NET, J2EE, and legacy) require additional container-level security configuration outside the IAM policy model.

WSSE enforces security across all types of transport. It supports both inbound and outbound flows (i.e., requests received by the enterprise from a third party and requests sent by the enterprise to a third-party). WSSE communicates with the IAM security policy server for security policy decisions.

This deployment template does not include many moving parts and does not require a complex and costly implementation. On the other hand, it does not scale very well because the container of each back-end resource needs its own access management layer.

Full IAM Deployment
All of the enterprise resources are protected by a single IAM system. WSSE points for J2EE and .NET containers may be deployed in two ways:

  • Interceptors (or "agents"): The agent can be integrated with a variety of Web services containers. The agent interacts with the IAM policies to provide security services.
  • SOAP message handlers: Use either the Java API for XML-based remote procedure calls (JAX-RPC) or .NET pipelines. SOAP message handlers have the benefit of being transport independent.
Legacy applications continue to use proprietary security but may synchronize with the enterprise user repositories. SAML may be used as a means of communicating with "opaque" containers that cannot accommodate WSSE points, such as legacy applications or more proprietary application servers (see Figure 2).

Once a Web service requester has successfully been identified, authenticated, and authorized, the IAM platform provides the ability to leverage the user identity to personalize the behavior of the Web service.

The Web service can be bound to aspects of an identity through user entitlement information passed to the Web service by the IAM platform. For example, when a user has successfully been authenticated and authorized to access a Web service, the IAM platform can identify which entitlements should be obtained about that user, retrieve them from the user store(s), and associate them with the Web service request by binding them to the XML message.

This eliminates the need for a Web service to keep its own entitlement database and handle the retrieval of entitlements in the application logic. Thanks to the IAM platform, these entitlements can be centrally and securely managed and associated directly with a user's identity.

In some variations of this deployment model, the reverse proxy is optional.

IAM + WSM Deployment
The SOAP message is first received by the WSM enforcement point (WSMP). The WSMP makes a call to the WSSE point to ensure that the SOAP flow is secured.

WSSE authenticates the requester against IAM policies and returns security information to the WSMP. The WSMP can then enforce the WSM policy once the SOAP message is bound to a Web service consumer's identity.

The WSM platform can integrate with the IAM platform in two ways:

  • The WSM platform can explicitly invoke the WSSE through the IAM application programming interface (API)
  • The WSM platform can use the WSSE agent or the message handler model described above.
In this deployment model, the WSM platform takes advantage of the IAM platform, which links it to the enterprise-wide IAM infrastructure (see Figure 3).

This deployment model allows the enterprise to leverage a corporate infrastructure for security (the IAM platform) and Web services management (the WSM platform). Both provide a layer of abstraction that relieves Web services developers from security and management tasks so that they can concentrate on the design of the Web service business functions.

Network Appliance Deployment
This is the full-blown integration including a network appliance. The network appliance is added to provide wire-speed XML processing (see Figure 4).

In this deployment model, the network appliance delivers network security services combined with an authentication service, as described last month (see Protection and Threat Prevention Layer).

Typically, the network appliance interacts with Web services flows by intercepting the incoming request as soon as it passes through the network firewall. The network appliance decrypts the request, parses the XML document, validates the document against an XML Schema, and applies transformations if required.

The network appliance may provide authentication against a user store configured with the IAM platform. The result of authentication is then communicated downstream, using SAML for example. The WSSE and WSM enforcement points can also benefit from authentication information provided by the network appliance.

Once the Web service requester is authenticated, the IAM platform can move to grant access to the Web service, and the WSM system can apply business-level management policies.

Conclusion
With a focus on security and management, a Web Services Reference Architecture can help the prevention (network security), enablement (identity and access management), and enforcement (Web services management) layers of a Web services architecture fit together.

Web services providers can focus on the design and functionality of the Web services they expose to their employees, customers, or partners, while relying on enterprise-wide security and management services that increase overall availability, scalability, interoperability, and manageability.

References

  • www.w3.org/XML: The W3C's XML 1.0 Second Edition Recommendation describes the Extensible Markup Language (XML), "the universal format for structured documents and data on the Web."
  • www.w3.org/Security: The W3C's security-resources home page includes many links to various aspects of Web and Internet security (cryptography, authentication, authorization, etc.).
  • http://searchwebservices.techtarget.com: Web services–specific information resource for enterprise IT professionals Includes useful articles and technical notes covering all aspects of Web services, in particular security.
  • www.w3.org/DSig/Overview.html: The W3C's XML Signature (XML-DSIG) Recommendation describes digital signatures as applied to XML documents.
  • www.w3.org/Encryption/2001: The W3C's XML Encryption Recommendation defines a process for encrypting and decrypting XML documents.
  • www.w3.org/TR/xkms: The W3C's XML Key Information Service Specification (XKMS) Recommendation defines protocols for distributing and registering public keys, used together with XML Signature and XML Encryption.
  • http://xml.coverpages.org/xrml.html: The Extensible Rights Markup Language (XrML) home page.
  • www.oasis-open.org/committees/security: The OASIS specification for the Security Assertion Markup Language (SAML) defines an XML-based security framework for exchanging authentication and authorization information.
  • www.w3.org/TR/SOAP: The W3C's SOAP Recommendation (v1.1) describes the Simple Object Access Protocol, designed as a messaging framework for exchanging XML documents between peers in a platform-neutral environment.
  • www.oasis-open.org/committees/ wss/documents/WSS-Core-08-1212-merged.pdf: Working draft of the Web Services Security core specification.
  • www.w3.org/TR/wsdl: The W3C's WSDL submission specifies the Web Services Description Language, a framework providing definitions for network services and the automation of application communication through XML documents.
  • www.uddi.org/about.html: The Universal Description, Discovery, and Integration (UDDI) project is an industry initiative designed to create an XML framework for describing Web services providers and a description of the services they provide.
  • More Stories By Marc Chanliau

    Marc Chanliau has been in the software industry for more than 20 years and is currently a director of product management at Oracle where he is responsible for Identity Management solutions and innovations. He is heavily involved in security and XML standards groups including serving as the first chair person of the OASIS Security Services Technical Committee (SSTC), which culminated in the adoption of SAML as an official OASIS standard, participating on the WS-Security Technical Committee, helping to define the Liberty Alliance 2.0 specifications, and participating in the Java Specification Request (JSR) committee.

    More Stories By Prateek Mishra

    Prateek Mishra, Ph.D. has more than ten years experience with enterprise-class distributed systems. He is Director of Technology at Netegrity and works on Strategy and Standards. He was an Editor of the SAML 1.0 specification and is co-chair of the SSTC (SAML) Committee and participates in the WSS (WS-Security) Committee.

    Comments (0)

    Share your thoughts on this story.

    Add your comment
    You must be signed in to add a comment. Sign-in | Register

    In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


    @MicroservicesExpo Stories
    As many know, the first generation of Cloud Management Platform (CMP) solutions were designed for managing virtual infrastructure (IaaS) and traditional applications. But that's no longer enough to satisfy evolving and complex business requirements. In his session at 21st Cloud Expo, Scott Davis, Embotics CTO, explored how next-generation CMPs ensure organizations can manage cloud-native and microservice-based application architectures, while also facilitating agile DevOps methodology. He expla...
    SYS-CON Events announced today that Synametrics Technologies will exhibit at SYS-CON's 22nd International Cloud Expo®, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Synametrics Technologies is a privately held company based in Plainsboro, New Jersey that has been providing solutions for the developer community since 1997. Based on the success of its initial product offerings such as WinSQL, Xeams, SynaMan and Syncrify, Synametrics continues to create and hone in...
    DevOps promotes continuous improvement through a culture of collaboration. But in real terms, how do you: Integrate activities across diverse teams and services? Make objective decisions with system-wide visibility? Use feedback loops to enable learning and improvement? With technology insights and real-world examples, in his general session at @DevOpsSummit, at 21st Cloud Expo, Andi Mann, Chief Technology Advocate at Splunk, explored how leading organizations use data-driven DevOps to clos...
    "I focus on what we are calling CAST Highlight, which is our SaaS application portfolio analysis tool. It is an extremely lightweight tool that can integrate with pretty much any build process right now," explained Andrew Siegmund, Application Migration Specialist for CAST, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
    The dynamic nature of the cloud means that change is a constant when it comes to modern cloud-based infrastructure. Delivering modern applications to end users, therefore, is a constantly shifting challenge. Delivery automation helps IT Ops teams ensure that apps are providing an optimal end user experience over hybrid-cloud and multi-cloud environments, no matter what the current state of the infrastructure is. To employ a delivery automation strategy that reflects your business rules, making r...
    The past few years have brought a sea change in the way applications are architected, developed, and consumed—increasing both the complexity of testing and the business impact of software failures. How can software testing professionals keep pace with modern application delivery, given the trends that impact both architectures (cloud, microservices, and APIs) and processes (DevOps, agile, and continuous delivery)? This is where continuous testing comes in. D
    Modern software design has fundamentally changed how we manage applications, causing many to turn to containers as the new virtual machine for resource management. As container adoption grows beyond stateless applications to stateful workloads, the need for persistent storage is foundational - something customers routinely cite as a top pain point. In his session at @DevOpsSummit at 21st Cloud Expo, Bill Borsari, Head of Systems Engineering at Datera, explored how organizations can reap the bene...
    Admiral Calcote - also known as Lee Calcote (@lcalcote) or the Ginger Geek to his friends - gave a presentation entitled Characterizing and Contrasting Container Orchestrators at the 2016 All Day DevOps conference. Okay, he isn't really an admiral - nor does anyone call him that - but he used the title admiral to describe what container orchestrators do, relating it to an admiral directing a fleet of container ships. You could also say that they are like the conductor of an orchestra, directing...
    The past few years have seen a huge increase in the amount of critical IT services that companies outsource to SaaS/IaaS/PaaS providers, be it security, storage, monitoring, or operations. Of course, along with any outsourcing to a service provider comes a Service Level Agreement (SLA) to ensure that the vendor is held financially responsible for any lapses in their service which affect the customer’s end users, and ultimately, their bottom line. SLAs can be very tricky to manage for a number ...
    Our work, both with clients and with tools, has lead us to wonder how it is that organizations are handling compliance issues in the cloud. The big cloud vendors offer compliance for their infrastructure, but the shared responsibility model requires that you take certain steps to meet compliance requirements. Which lead us to start poking around a little more. We wanted to get a picture of what was available, and how it was being used. There is a lot of fluidity in this space, as in all things c...
    Gaining visibility in today’s sprawling cloud infrastructure is complex and laborious, involving drilling down into tools offered by various cloud services providers. Enterprise IT organizations need smarter and effective tools at their disposal in order to address this pertinent problem. Gaining a 360 - degree view of the cloud costs requires collection and analysis of the cost data across all cloud infrastructures used inside an enterprise.
    Some people are directors, managers, and administrators. Others are disrupters. Eddie Webb (@edwardawebb) is an IT Disrupter for Software Development Platforms at Liberty Mutual and was a presenter at the 2016 All Day DevOps conference. His talk, Organically DevOps: Building Quality and Security into the Software Supply Chain at Liberty Mutual, looked at Liberty Mutual's transformation to Continuous Integration, Continuous Delivery, and DevOps. For a large, heavily regulated industry, this task...
    The goal of Microservices is to improve software delivery speed and increase system safety as scale increases. Microservices being modular these are faster to change and enables an evolutionary architecture where systems can change, as the business needs change. Microservices can scale elastically and by being service oriented can enable APIs natively. Microservices also reduce implementation and release cycle time and enables continuous delivery. This paper provides a logical overview of the Mi...
    The notion of improving operational efficiency is conspicuously absent from the healthcare debate - neither Obamacare nor the newly proposed GOP plan discusses the impact that a step-function improvement in efficiency could have on access to healthcare (through more capacity), quality of healthcare services (through reduced wait times for patients) or cost (through better utilization of scarce, expensive assets).
    Gone are the days when application development was the daunting task of the highly skilled developers backed with strong IT skills, low code application development has democratized app development and empowered a new generation of citizen developers. There was a time when app development was in the domain of people with complex coding and technical skills. We called these people by various names like programmers, coders, techies, and they usually worked in a world oblivious of the everyday pri...
    The “Digital Era” is forcing us to engage with new methods to build, operate and maintain applications. This transformation also implies an evolution to more and more intelligent applications to better engage with the customers, while creating significant market differentiators. In both cases, the cloud has become a key enabler to embrace this digital revolution. So, moving to the cloud is no longer the question; the new questions are HOW and WHEN. To make this equation even more complex, most ...
    Some journey to cloud on a mission, others, a deadline. Change management is useful when migrating to public, private or hybrid cloud environments in either case. For most, stakeholder engagement peaks during the planning and post migration phases of a project. Legacy engagements are fairly direct: projects follow a linear progression of activities (the “waterfall” approach) – change managers and application coders work from the same functional and technical requirements. Enablement and develo...
    Kubernetes is an open source system for automating deployment, scaling, and management of containerized applications. Kubernetes was originally built by Google, leveraging years of experience with managing container workloads, and is now a Cloud Native Compute Foundation (CNCF) project. Kubernetes has been widely adopted by the community, supported on all major public and private cloud providers, and is gaining rapid adoption in enterprises. However, Kubernetes may seem intimidating and complex ...
    You know you need the cloud, but you’re hesitant to simply dump everything at Amazon since you know that not all workloads are suitable for cloud. You know that you want the kind of ease of use and scalability that you get with public cloud, but your applications are architected in a way that makes the public cloud a non-starter. You’re looking at private cloud solutions based on hyperconverged infrastructure, but you’re concerned with the limits inherent in those technologies.
    For DevOps teams, the concepts behind service-oriented architecture (SOA) are nothing new. A style of software design initially made popular in the 1990s, SOA was an alternative to a monolithic application; essentially a collection of coarse-grained components that communicated with each other. Communication would involve either simple data passing or two or more services coordinating some activity. SOA served as a valid approach to solving many architectural problems faced by businesses, as app...