Configuring Duende IdentityServer as a SAML 2.0 Identity Provider (IdP): service provider registration, SSO and SLO flows, claim mappings, extensibility interfaces, and production deployment patterns.
Migrating Duende IdentityServer from v7.4 to v8.0: breaking changes, API replacements (ICache→HybridCache, IClock→TimeProvider), CancellationToken additions, EF migrations, and step-by-step upgrade guide.
ASP.NET Core authentication middleware configuration including OpenID Connect, JWT Bearer, cookie authentication, authentication schemes, challenge/forbid flows, and external identity provider integration.
ASP.NET Core authorization patterns including policy-based authorization, IAuthorizationHandler implementations, scope-based authorization for APIs, authorization middleware configuration, and minimal API authorization.
Claims transformation and profile service patterns for Duende IdentityServer — IProfileService, IClaimsTransformation, claim type mapping, token claim filtering, extension grant validators, and dynamic claims loading.
Duende BFF (Backend for Frontend) security framework for securing SPAs. Covers session management, API endpoint proxying, token management, anti-forgery protection, and integration with React/Angular/Blazor frontends.
Security hardening for Duende IdentityServer deployments including signing key rotation, HTTPS enforcement, CORS configuration, CSP headers, rate limiting, token lifetime tuning, and security audit patterns.
Testing patterns for IdentityServer-based systems including integration testing with WebApplicationFactory, mock token issuance, test authority configuration, protocol response validation, and end-to-end authentication flow testing.