Blog

Articles, tutorials, and field notes on identity, integration, API management, and application security — spanning nearly two decades of hands-on work.

API Gateways and Multiple Consumer Types

Sometimes at client sites, I see a separation of APIs advertised on an API Gateway based upon consumer type. Sometimes, this is unavoidable, but there should be a core set of APIs and a general push to create APIs that are reusable. Reusability of APIs is a foundational building block of API…

API GatewaysAPIs

RFC 9068: A JWT-Based OAuth2 Access Token Format Standard

For anyone who has been paying attention, this blog post has been a long-time coming for multiple reasons. First, this is my first blog post in a couple of years — I’ve been heads down on a couple of projects for awhile now. This is literally the first time I’ve “come up for air” since the last…

Access TokensJWTOAuth2

Making Authorization Decisions

This blog post continues our discussion of Authorization in the API space. It will explore common authorization patterns with API Gateways and the backend API Providers. Generally, the API Gateway will apply a Coarse Grained Authorization (CGA) decision and the API Provider will implement Fine…

API GatewaysAuthorizationAPIs

Delegation — A General Discussion

This blog post expands on delegation and related concepts introduced in my Kerberos Delegation blog post. It also brings together two blog series I’ve been working on over the years: SAML2 vs. JWT Series and Kerberos and Windows Security Series. Delegation is a critical building block of end-to-end…

DelegationJWTKerberos

Kerberos and Windows Security: Delegation

In this next post in the Kerberos and Windows Security Series, we are going to explore a very useful, but abstract feature of the Kerberos Authentication Protocol: Delegation. In particular, we are going to focus on the Windows implementation of this feature. Delegation allows downstream actors to…

AuthenticationDelegationKerberos

HTTP POST vs GET: Is One More Secure For Use In REST APIs?

The use of HTTP POST vs HTTP GET for read-only (or query) operations in REST APIs recently came up in a conversation. For this particular shop, there had been a long-standing ban on the use of GET requests for use in homegrown applications. This had been the case since before REST APIs were in…

RESTHTTPAPIs