Can't get any cookies with C# HttpClient

Question

I'm trying to get cookies on the Spotify login page with C# and the HttpClient class. However, the CookieContainer is always empty when I know cookies are being set. I'm not sending any headers, but it should still give me the cookie(s) because when I send a GET request without any headers with python (requests module) I get the csrf token. Here's my code:

using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Collections;
using System.Web;

class Program
{
    static void Main()
    {
        Task t = new Task(MakeRequest);
        t.Start();
        Console.WriteLine("Getting cookies!");
        Console.ReadLine();
    }

    static async void MakeRequest()
    {
        CookieContainer cookies = new CookieContainer();
        HttpClientHandler handler = new HttpClientHandler();

        handler.CookieContainer = cookies;
        Uri uri = new Uri("https://accounts.spotify.com/en/login/?_locale=en-US&continue=https:%2F%2Fwww.spotify.com%2Fus%2Faccount%2Foverview%2F");
        HttpClient client = new HttpClient(handler);
        var response = await client.GetAsync(uri);
        string res = await response.Content.ReadAsStringAsync();
        Console.WriteLine(cookies.Count);
        foreach (var cookie in cookies.GetCookies(uri)) {
            Console.WriteLine(cookie.ToString());
        }
    }
}

It seems pretty simple to me, but the program always says there's 0 cookies. Anyone know what's going on?

Answer 1

I tried to write the response headers to the console with Console.WriteLine(response.Headers) and a Set-Cookie header with the csrf token was printed to the console. So it seems that HttpClient doesn’t count cookies in this header as actual cookies, thus not adding these said cookies to the CookieContainer.

Answer 2

You need to enable the use of cookies using HttpClientHandler.UseCookies Property

public bool UseCookies { get; set; }

Gets or sets a value that indicates whether the handler uses the CookieContainer property to store server cookies and uses these cookies when sending requests.

//...

CookieContainer cookies = new CookieContainer();
HttpClientHandler handler = new HttpClientHandler();
handler.CookieContainer = cookies;
handler.UseCookies = true; //<-- Enable the use of cookies.

//...

Answer 3

Make sure you are decompression the response automatically. See my answer here: https://stackoverflow.com/a/74750572/1158313

An example of what I use:

var clientHandler = new HttpClientHandler {
    AllowAutoRedirect = true,
    UseCookies = true,
    CookieContainer = cookieContainer,
    AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate, // <--
};