Azure AD B2C Console App

ADB2C_TestClient.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.2</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Identity.Client" Version="4.1.0" />
  </ItemGroup>

</Project>

Program.cs

using Microsoft.Identity.Client;
using System;
using System.Threading.Tasks;

namespace ADB2C_TestClient
{
    class Program
    {
        private const string B2C_INSTANCE = "https://login.microsoftonline.com/tfp/{0}/{1}/";
        private const string CLIENT_ID = "[redacted]";
        private const string REDIRECT_URI = "http://localhost:44365"; // need to pin this to a specific url:port, and it has to be http://localhost, otherwise MSAL won't accept it :(
        private const string TENANT = "[redacted].onmicrosoft.com";
        private const string POLICY = "B2C_1_SIGNUP_POC";
        private static readonly string[] scopes = new[] { "https://[redacted]/user_impersonation" };

        static void Main(string[] args)
        {
            var app = PublicClientApplicationBuilder.Create(CLIENT_ID)
                .WithRedirectUri(REDIRECT_URI)
                .WithB2CAuthority(string.Format(B2C_INSTANCE, TENANT, POLICY))
                .WithLogging(Log, LogLevel.Warning, true)
                .Build();

            var result = AcquireTokenInteractive(app).GetAwaiter().GetResult();

            if (result != null)
            {
                Console.WriteLine($"User name: {result.Account.Username}");
                Console.WriteLine($"Access token: {result.AccessToken}");
            }
        }

        private static void Log(LogLevel level, string message, bool containsPii)
        {
            Console.WriteLine($"{level}: {message}");
        }

        private static async Task<AuthenticationResult> AcquireTokenInteractive(IPublicClientApplication app)
        {
            try
            {
                var authResult = await app.AcquireTokenInteractive(scopes)
                    .WithPrompt(Prompt.SelectAccount)
                    .WithUseEmbeddedWebView(false)
                    .WithSystemWebViewOptions(new SystemWebViewOptions
                    {
                        HtmlMessageSuccess = "Login succeeded. You can close this browser.",
                        HtmlMessageError = "Hmm, something went wrong... Please close this browser."
                    })
                    .ExecuteAsync();

                return authResult;
            }
            catch (MsalException msalex)
            {
                string msg = msalex.Message;
                if (msalex.InnerException != null)
                {
                    msg += $"Error Code: {msalex.ErrorCode} Inner Exception: {msalex.InnerException.Message}";
                }

                Console.WriteLine($"Error logging in: {msg}");
            }
            catch (Exception ex)
            {
                string msg = ex.Message;
                if (ex.InnerException != null)
                {
                    msg += $"Inner Exception: {ex.InnerException.Message}";
                }

                Console.WriteLine($"Error logging in: {msg}");
            }

            return null;
        }
    }
}