unauthorized error when using HttpClient

Question

using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;

namespace ConsoleProgram
{
    public class Class1
    {
        private const string URL = "https://sun.domain.com/v1/service/token";
        static void Main(string[] args)
        {
            var handler = new HttpClientHandler();
            handler.Credentials = new System.Net.NetworkCredential("admin@client", "admin");
            HttpClient client = new HttpClient(handler);
            //client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes(String.Format("{0}:{1}", "admin", "admin"))));
            //  client.BaseAddress = new Uri(URL);
            // Add an Accept header for JSON format.
            client.DefaultRequestHeaders.Accept.Add(
            new MediaTypeWithQualityHeaderValue("application/json"));
            // List data response.
            HttpResponseMessage response = client.GetAsync(URL).Result;  // Blocking call!
            String res = response.ToString();
            Console.WriteLine(res);
        }
    }
}

I am getting unauthorized error even though I am passing the correct credentials. Any ideas?

I tried almost all the answers posted on StackOverflow.

Solution

For Basic Authentication, you need to send the credentials in an authorization header called "Basic" with base64-encoded "username:password" as the value. This should get the job done:

var headerVal = Convert.ToBase64String(Encoding.UTF8.GetBytes("admin@client:admin"));
var header = new AuthenticationHeaderValue("Basic", headerVal);
client.DefaultRequestHeaders.Authorization = header;