How to authorize webapi endpoint for 3rd party to use

Question

I have to create a endpoint that will use used by a 3rd party. We use identity server when people log in to our application. What do I need to do to only allow access to this 3rd party to call the endpoint? I dont want just anyone to be able to call the endpoint. For example, if I gave you my endpoint URL and you used postman to post to it, I would only allow you if you were authorised

Answer 1

I think you need to enable CORS (Cross-Origin Requests) as outlined by Microsoft here .

For example, you would decorate your controller as so:

using System.Net.Http;
using System.Web.Http;
using System.Web.Http.Cors;

namespace WebService.Controllers
{
    [EnableCors(origins: "http://mywebclient.azurewebsites.net", headers: "*", methods: "*")]
    public class TestController : ApiController
    {
        // Controller methods not shown...
    }
}

Answer 2

There are a number of ways to secure an ASP.NET web app/api.

I typically use a SQL user store or active directory and issue JWT tokens. A nice guide can be found here.

https://jonhilton.net/2017/10/11/secure-your-asp.net-core-2.0-api-part-1---issuing-a-jwt/

Here is the documentation for identity server - as you mentioned you wanted to use that - about this very topic.

http://docs.identityserver.io/en/release/topics/apis.html