How to get the access token in a service in .net core?

Question

I have an application and I want to use a hybrid flow to call an API from my MVC web application. The API is secured and requires an access token (JWT). The code part on the API side is done. But how can I send my access token from my MVC application to the API in a service? I want to use a "generic" service for this that uses an httpclient.

I know that in controllers you can use

var accessToken = await HttpContext.GetTokenAsync("access_token");

or

var accessToken = await HttpContext.GetUserAccessTokenAsync();

But how can I access the access token in a service? Tried this too, but didn't work

    var accessToken = _httpContextAccessor.HttpContext.Request.Headers[HeaderNames.Authorization];

Side question: how can I set the access token for the httpclient in the constructor of my service? (Using async methods is not possible) so I can't use this:

protected HttpClient HttpClient { get; private set; }

public MyGenericHttpClientService(IHttpContextAccessor httpContextAccessor)

{
            var accessToken = await httpContextAccessor.HttpContext.GetTokenAsync("access_token");
            HttpClient.SetBearerToken(accessToken);
}

I can do it before every method, but wanted to know if there is a better way to solve this. — Enrico
– Enrico, Commented Jun 8, 2020 at 16:02
how did you resolve the HttpClient? If you are using IHttpClientFactory, you can configure a DelegatingHandler in Startup that gets the token from IHttpContextAccessor and set it to outgoing requests. — scharnyw
– scharnyw, Commented Jun 8, 2020 at 16:13

scharnyw · Accepted Answer · 2021-03-18 08:33:55Z

If you are using IHttpClientFactory, you can configure your HttpClient as follows by adding a DelegatingHandler in Startup.cs:

services.AddTransient<TokenHandler>();
services.AddHttpClient().AddHttpMessageHandler<TokenHandler>();

And TokenHandler can be as follows:

public class TokenHandler : DelegatingHandler
{
    private readonly IHttpContextAccessor _httpContextAccessor;

    public TokenHandler(
        IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
        CancellationToken cancellationToken)
    {
        var token = await _httpContextAccessor.HttpContext.GetTokenAsync("access_token");
        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
        return await base.SendAsync(request, cancellationToken);
    }
}

For more information on IHttpClientFactory, you can see this article.

Collectives™ on Stack Overflow

How to get the access token in a service in .net core?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related