Resolving Cookie Authentication Failures in ASP.NET Core 3.1

Описание: Discover effective solutions for addressing `Cookie Authentication` failures in ASP.NET Core 3.1 and ensure a smooth sign-in process.
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This video is based on the question https://stackoverflow.com/q/66760312/ asked by the user 'Ross Kelly' ( https://stackoverflow.com/u/7492645/ ) and on the answer https://stackoverflow.com/a/66760472/ provided by the user 'Yinqiu' ( https://stackoverflow.com/u/13973037/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Resolving Cookie Authentication Failures in ASP.NET Core 3.1

When transitioning an ASP.NET Core project to a newer version, developers often encounter a multitude of challenges. One of the more perplexing issues arises with Cookie Authentication, particularly when it appears to function improperly—leading to unexpected redirects such as to the AccessDeniedPath. This guide will explore this common problem and guide you through a solution step by step.

The Problem at Hand

In a scenario where your new ASP.NET Core 3.1 project is up and running, it’s frustrating when a seemingly innocuous sign-in action ends in a redirect to an access denied page. This can leave you scratching your head, especially if there are no error messages. Here’s a succinct breakdown of the symptoms:

Framework: ASP.NET Core 3.1

Development Environment: Visual Studio 2019 using IIS Express on Windows 10

Behavior: The SignIn(...) method executes without issue, yet the system redirects to AccessDeniedPath unexpectedly.

The Configuration Code Snippet

The confusion can often stem from the Startup.cs file where middleware configuration is defined. Here's a glimpse of the related code sections involved in Cookie Authentication:

[[See Video to Reveal this Text or Code Snippet]]

From the configuration snippet above, you may see that the order of middleware setup is crucial and affects how authentication and authorization are processed.

Solution Overview

The core of the solution lies in ensuring that the middleware is set up in the correct order. In ASP.NET Core, the middleware pipeline executes in the order it is registered. For Cookie Authentication to work properly, it is essential that:

Authentication Middleware is called before Authorization Middleware.

This order must be strictly adhered to for the authentication to precede the authorization checks.

Steps to Fix

To resolve your Cookie Authentication failure, follow these steps:

Locate the Configure Method in your Startup.cs file.

Ensure Middleware Order: Adjust the order of app.UseAuthentication() and app.UseAuthorization() as such:

[[See Video to Reveal this Text or Code Snippet]]

Rebuild and Test: After making the adjustments, rebuild your project and test the sign-in functionality again to ensure that authentication is now being processed correctly.

Conclusion

Configuring Cookie Authentication can pose unique challenges when upgrading to newer frameworks like ASP.NET Core 3.1. However, by ensuring that the middleware is registered in the correct sequence, you can resolve common authentication problems effectively.

If you run into further issues, investigate other parts of your authentication logic, and keep an eye on your model state, claims setup, and error handling. A careful review can almost always unveil the source of the trouble. Happy coding!