Jan 3, 2011

What’s With Web Service Security???




Web service security is a tricky business.  EVERY service exposed by any service provider, be it .Net, Java, the Mainframe, or any other provider needs to be secured.  Certainly if it’s exposing sensitive data (say customer data), allowing activation of a business process, and most especially if it’s involving a financial transaction.

But how do you do it?  While every vendor and (almost) every technology announces compatibility with every web service security buzzword (WS-Security, SAML, X.509, etc.), they don’t describe how to actually make use of all this security data attached to the web service request.

I’ve had recent discussions with IBM, Oracle, and Software AG (as leading SOA middleware tool providers) on this exact topic and the results are disappointing.

The architecture model for this says that to provide SOA security I should use the tools as a SOA security layer, allowing my services to go about their business and the security tools to grab and process the security data added on to the requests.

This means, for example, that my service requesting systems could activate a SOA security module (provided by a vendor tool) and get an appropriate security context added on to the service request.  This might be composed of a WS-Security block with certificates or keys and a SAML block composed of requesting application context (instance information – production/test/etc) and user context (user name or user id or with federated identity management session id).

My middle step, the ESB usually, would automatically processes the security context, authenticate the source and authorize the requested action.  It would then make any calls to providing system with an updated security context.

The providing systems would filter the requests through a SOA security agent, which would perform the same security actions (process the security context, authenticate, authorize, log for auditing – triple-A security).

That’s a reasonable expectation for SOA security tools.  Now where are the vendors at?

Oracle used to be the closed to this, with Amberpoint offering agents for providers and a central-agent/server for environments that couldn’t handle agents or installations where agents weren’t desired.  However, Oracle has apparently removed security functionality from Oracle and built a new Oracle Web Services Manager tool that does not have agents.  Rather, it allows policies to be created and validates security as the services pass through the central security server or through security enabled Oracle SOA tools (such as their ESB.)  [They did say they intend to add agents for select environments, such as SAP and .Net, over the next year.]

IBM never fully detailed the model.  Rather, they allow Websphere Registry & Repository (WSRR) to define policies which can then be pushed to a Datapower (a physical XML firewall device), which can then act as a central security service doing the authentication, authorization and log for auditing.  The providing systems have to be manually programmed to only accept the requests from the Datatpower and the requesting systems have to manually generate the security header, completing the security picture.  This model is fine for external web service security (exposing internal web services across the firewall for internet requests) but isn’t so great for internal.

Software AG’s options are wider but more confusing.  Their design time repository, CentraSite, can define and generate security policies.  These policies can be pushed to the Mediator add-on for their ESB, which can then authenticate, authorize and log for auditing as service requests arrive at the ESB, or can be pushed to Layer-7 physical XML firewall devices {Layer-7 does have a “software appliance” as well} for enforcement like the Datapower in the IBM option.  Interestingly IF you have Software AG’s SOA runtime monitoring tool, Insight, the Insight agents can be tasked by the Mediator ESB add-on to perform authentication and authorization (with the monitoring tool already doing logging).

In all cases, the requesting system is responsible for generating the security information required.  No one (as far as I know) is providing an agent or client side plug-in that takes over the security layer tasks from the service requestor.

Now, it’s worth noting  that all the functionality mentioned above can be created manually without too much difficulty using the native features of ESB’s (whether from IBM, Oracle or Software AG, or others), and Java as well as .Net provide a host of included classes and API’s for handling web service security. (Even IBM CICS does nowadays.)

The question is can I just load in my web service security layer or do I have to take a tool from a vendor and STILL spend time, either on the requesting side, providing side, or both, to build the steps necessary to complete the web service security picture.

At the moment, it seems this is still the case.  No matter what tool combination is used, I’m still going to be defining the security standards I want to use and writing some code to inject those security protocols (or interpret them) into my web service requests.

10 years into web services this is disappointing.  And dealing with customers looking to increase the SOA maturity level of their environments as well as some late comers to SOA, they just don’t understand why this would be necessary.

2 comments:

frederick said...

I do agree, but about plugin that might help you to implement policy on the client side, SOA Software had something - need to checked if this is still available. More generally speaking, SOA Software offer must be considered among other you mentionned.
IMHO

Jonathan said...

Agreed - SOA Software has what they call the "Client Side Delegate" as part of their Service Manager product. It implements polices on the service consumer, as you suggest.

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