Francois Lascelles

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Top Stories by Francois Lascelles

The WS Secure Conversation specification describes a mechanism letting multiple parties establish a context (using the WS Trust Request Security Token standard) and secure subsequent SOAP exchanges. Each WS Secure Conversation session has an associated shared secret. Instead of using this shared secret directly to sign and encrypt the conversation's messages, symmetric keys are derived from the secret itself. Deriving new keys for each message and different keys for signature and encryption limits the amount of data that an attacker can analyze in attempting to compromise the context. Derived Key Tokens are tokens in a SOAP Security Header that refer to the derived keys. Using the context's shared secret and hints provided by the Derived Key Token element, the message's recipient derives the key used by the requestor either to verify a signature or decrypt parts of t... (more)


SOA & WOA Magazine on Ulitzer Existing brokered authentication standards such as SAML Web Browser SSO or OpenID accommodate RESTful web services for browser driven use cases. However, what about RESTful service composition patterns where identities need to be propagated across nested service invocations, or any RESTful Web service client that is not browser based for that matter? How should brokered authentication for such RESTful service calls be handled? An interesting example of a RESTful Security Token Service (STS) was described in March 2009 by Pablo Cibraro (aka ‘cibrax’).... (more)

Connecting the Enterprise to the Cloud Marketplace

With Google launching its new cloud-based enterprise apps marketplace these days, many people are paying closer attention to a maturing overall cloud offering. One of its components which caught my attention today is ironically something that you are meant to install enterprise-side: the Secure Data Connector (SDC). The SDC lets the enterprise control access to its private resources (resources behind the enterprise’s firewall) from google apps. This illustrates an increasingly popular pattern relating to enterprise cloud adoption where applications deployed on the cloud need to ... (more)

Agile, Decoupled Security for Better Service Orientation

Service orientation is about agility. Without a resulting agility, there is no point of doing SOA. Unfortunately, enterprise SOA infrastructure initiatives sometimes fail in part because its security mechanisms and processes demolish any agility that was built into the SOA itself. This happens when security is an afterthought. Simple barriers are good for security but they can easily become preventers of agility. When security fails to maintain agility, one of following two possible consequences seems to emerge. The first is a failure of the corporate SOA initiative – without ag... (more)

JSON Schema Validation for RESTful Web Services

In the article "The importance of threat protection for restful web services", I presented a number of content-based threats for XML. When protecting an endpoint from XML based attacks, not only are payloads scanned for code injections, malicious entity declarations and parser attacks, XML documents are actually validated against strict schemas that clearly describe expected document structures. Enforcing this type of compliance at the edge, in a SOA gateway for example, minimizes the risk of attacks of the Web service endpoint. Structure definition languages such as XML Schema ... (more)