ASP.NET Core Authentication Behind Proxies

ASP.NET Core applications can encounter authentication issues when running behind proxies, load balancers, or containers. These issues often arise due to incorrect URL schemes or domains being used in callback URLs. The article discusses the role of `X-Forwarded-*` headers and how to use ASP.NET Core's Forwarded Headers middleware to resolve these problems by correctly handling the original HTTP request values. Configurations and code examples are provided to help developers ensure their authentication flow works seamlessly in complex infrastructures.