Auth0 Support for ASP.NET Core

DZone 's Guide to

Auth0 Support for ASP.NET Core

Auth0's usage of open standards such as OAuth, OpenID Connect and JSON Web Tokens means that Auth0 supports ASP.NET Core out of the box. No extra libraries are required. Check out some of the documentation and samples in this article.

· Performance Zone ·
Free Resource


With the final release of ASP.NET Core 1.0 happening today, we are happy to announce that you can now also use Auth0 in your ASP.NET Core applications. Because Auth0 is built on open standards, such as OAuth, OpenID Connect, and JSON Web Tokens, and all of those are supported by ASP.NET Core middleware out of the box, there was in fact very little we had to do in order to help you use Auth0 in your applications.

Our support at this stage is therefore limited to new Quickstarts for MVC and Web API applications, as well as a number samples which demonstrates various usage scenarios. Over time our Quickstarts will be expanded to cover more of the typical onboarding steps, and our samples will also expand to cover more usage scenarios based on your feedback.

Embedded Lock

One usage scenario in particular which is a bit tricky is the one where you want to embed Lock into your ASP.NET Core MVC application, and still use the standard OAuth or OpenID Connect middleware.

When using the normal OAuth or OIDC middleware as-is, when a user wants to log in and the middleware is called, the user will be redirected to the Auth0 website to log in using the hosted version of Lock. This may not be the user experience you are looking for. You may, for example, want to embed Lock inside your application so it has more of the look-and-feel of your own application. In this instance, you can use both Lock and the OAuth/OIDC middleware together, but it requires a bit of extra work on your side.

Normally when the OAuth or OIDC middleware initiates the 1st leg of the authentication, it will send along information contained in a state parameter (and in the case of OIDC also a nonce parameter). It will also set a couple of cookies containing the values of the state and nonce.

After the user has authenticated and Auth0 redirects back to the redirect URL inside your application, it will pass back this state and nonce parameters. The OAuth/OIDC middleware is going to pick up that callback to the redirect URL because it will need to exchange the code for an access_token. It will, however, validate the state and nonce parameters to protect against CSRF.

The problem is that when you embed Lock in your application, the OAuth/OIDC middleware is not initiating the 1st leg of the OAuth/OIDC flow. Lock is.

So in this instance you will need to construct correct state and nonce parameters (as if the OAuth/OIDC middleware did it so that it can validate it correctly), and then be sure to specify the state and nonce parameters on Lock so that Auth0 can send back the correct values for these parameters after the user has authenticated.

We have very well documented samples for this scenario, however, but as mentioned before it requires some extra legwork from your side, and also to add a few extra files to your application. We would love to create a NuGet package which automatically adds the correct helper files to your project, but due to technical limitations with NuGet and project.json we cannot create a NuGet that adds content files to your project at this stage. Microsoft has stated that they are going to be reverting back to csproj files at some stage, so once this is technically feasible again we will create a NuGet package which will make your life a bit easier in this particular scenario.

Our ASP.NET Core Quickstarts and Samples

If you want to get started with Auth0 and ASP.NET Core, please check out these Quickstarts:

Here is a list of the samples we currently have available:

MVC Applications



Auth0 works great with the standard ASP.NET Core middleware out of the box due to our use of open standards. We have supplied samples demonstrating various usage scenarios, but please let us know if you would like us to expand on those.

.net, asp.net, asp.net core, core, json, microsoft, middleware, openid, tokens

Published at DZone with permission of Jerrie Pelser , DZone MVB. See the original article here.

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}