Azure Web App + Node.js + Azure AD = Error 431

I created a Node.js based web application, running in an Azure Web App, that I wanted to put behind an Azure Active Directory authentication. After activating “App Service Authentication”, the login process works normally, however upon returning to my app, it just returns a HTTP 431 “Request Header Fields Too Large”.

IdentityServer4 loading certificates in a Linux Web App in Azure

At the moment I have a web app that works in developer mode, but I am trying to make it work with a self-signed certificate in a Linux Web App in Azure. I have already uploaded the .pfx file to Azure and loaded it into the container by setting the WEBSITE_LOAD_CERTIFICATES application setting. At first, I tried using the store, however, this does not work in Linux.