Adding two-factor authentication to ASP.NET

DRAFT DOCUMENT - WORK IN PROGRESS

Description

If you wish to add two factor authentication to your site you can use Lachlan Barclay's NuGet Package which contains all the code you need.

This method is uses ASP.NET's Identity and Google's "Authenticator" app. The authenticator app is simple, very widely used (GitHub and Slack, to name two) and works very well.

If you are adding two-factor authentication to an existing site or codebase, I start by creating a brand new project and adding the already-prepared NuGet package. This will add all of the necessary code, web pages, references and dependencies.