ASP.NET Core Web API v1.1: Authorization
This tutorial demonstrates how to add authorization to an ASP.NET Core 1.x Web API using the standard JWT middleware. We recommend you to Log in to follow this quickstart with examples configured for your account.
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Get a sample configured with your account settings or check it out on Github.
Configure Auth0 APIs
Create an API
In the APIs section of the Auth0 dashboard, click Create API. Provide a name and an identifier for your API, for example
https://quickstarts/api. You will use the identifier as an
audience later, when you are configuring the Access Token verification. For Signing Algorithm, select RS256.
By default, your API uses RS256 as the algorithm for signing tokens. Since RS256 uses a private/public keypair, it verifies the tokens against the public key for your Auth0 account. The public key is in the JSON Web Key Set (JWKS) format, and can be accessed here.
Scopes let you define which resources can be accessed by the user with a given Access Token. For example, you might choose to grant read access to the
messages resource if users have the manager access level, and a write access to that resource if they have the administrator access level.
You can add the required scopes in the Scopes tab of the Auth0 Dashboard's APIs section.
This example demonstrates:
Configure the Sample Project
The sample code has an
appsettings.json file which configures it to use the correct Auth0 Domain and API Identifier for your API. If you download the code from this page while logged in, it will be automatically filled. If you use the example from Github, you will need to fill it yourself.
Validate Access Tokens
To use Auth0 Access Tokens with ASP.NET Core you will use the JWT Middleware. Add the
Microsoft.AspNetCore.Authentication.JwtBearer package to your application.
Configure the middleware
The ASP.NET Core JWT middleware will handle downloading the JSON Web Key Set (JWKS) file containing the public key for you, and will use that to verify the Access Token signature.
To add the JWT middleware to your application's middleware pipeline, go to the
Configure method of your
Startup class and add a call to
UseJwtBearerAuthentication passing in the configured
JwtBearerOptions needs to specify your Auth0 API Identifier as the
Audience, and the full path to your Auth0 domain as the
To make sure that an Access Token contains the correct scope, use the Policy-Based Authorization in ASP.NET Core.
Create a new Authorization Requirement called
HasScopeRequirement. This requirement will check that the
scope claim issued by your Auth0 tenant is present, and if so it will ensure that the
scope claim contains the requested scope. If it does then the Authorization Requirement is met.
Next, you can define a policy for each of the scopes in your application in the
ConfigureServices method of your
Protect API Endpoints
The JWT middleware integrates with the standard ASP.NET Core Authentication and Authorization mechanisms. To secure an endpoint you only need to decorate your controller action with the
To secure endpoints that require specific scopes, we need to make sure that the correct scope is present in the Access Token. To do that, add the
Authorize attribute to the
Scoped action, passing
read:messages as the