Struggling to authenticate chat: Context.User.Identity.Name is null in SignalR Core hub

Question

User-1142747527 posted

I'm a little lost as how to implement authentication on SignalR. So the Javascript client is sending my ASP .Net Core 2.2 Web API an access/bearer token on the SignalR connection:

this.hubConnection = new HubConnectionBuilder()
  .withUrl("http://mywebapi.com/chatHub", { accessTokenFactory: () => this.loginToken })
  .build();

Now on the API side, I've got this on Startup.cs

 public void ConfigureServices(IServiceCollection services)
    {
        services.AddSignalR(hubOptions =>
        {
            hubOptions.EnableDetailedErrors = true;
            hubOptions.KeepAliveInterval = TimeSpan.FromSeconds(15);
        });
        services.AddSingleton<IUserIdProvider, NameUserIdProvider>();

        string domain = $"https://{Configuration["Auth0:Domain"]}/";
        services.AddAuthentication(options =>
        {
            options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
            options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;

        }).AddJwtBearer(options =>
        {
            options.Authority = domain;
            options.Audience = Configuration["Auth0:ApiIdentifier"];
            options.RequireHttpsMetadata = false;
            options.Events = new JwtBearerEvents
            {
                OnMessageReceived = chatContext =>
                {
                    var accessToken = chatContext.Request.Query["access_token"];

                    // If the request is for our hub...
                    var httpContextRequestPath = chatContext.HttpContext.Request.Path;
                    if (!string.IsNullOrEmpty(accessToken) &&
                        (httpContextRequestPath.StartsWithSegments("/hubs/chat")))
                    {
                        // Read the token out of the query string
                        chatContext.Token = accessToken;
                    }
                    return Task.CompletedTask;
                }
            };
        });
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerManager logger)
    {
        app.UseSignalR(routes =>
        {
            routes.MapHub<ChatHub>("/chatHub");
       });
    }

Then I have this class:

public class NameUserIdProvider : IUserIdProvider
{
    public string GetUserId(HubConnectionContext connection)
    {
        return connection.User?.Identity?.Name;
    }
}

And finally, on my SignalR Core hub I have:

[Authorize]
public class ChatHub : Hub
{
    private readonly static ConnectionMapping<string> _connections = new ConnectionMapping<string>();

    public override async Task OnConnectedAsync()
    {
        string name = Context.User.Identity.Name;
        _connections.Add(name, Context.ConnectionId);
        await Clients.All.SendAsync("UserConnected", Context.ConnectionId);
        await base.OnConnectedAsync();
    }
}

However, Context.User.Identity.Name is null. In fact, most of the properties of Context.User.Identity are null. What am I doing wrong? Thanks...

Answer 1

User475983607 posted

Have you gone through the reference documentation?
https://docs.microsoft.com/en-us/aspnet/core/signalr/authn-and-authz?view=aspnetcore-2.2

Answer 2

User-1142747527 posted

Ok, I see I forgot this line:

services.AddSingleton<IUserIdProvider, NameUserIdProvider>();

And this:

public class NameUserIdProvider : IUserIdProvider
{
    public string GetUserId(HubConnectionContext connection)
    {
        return connection.User?.Identity?.Name;
    }
}

I will edit my original question to show this. But even after adding this, it's still nor working? Everything else, as far as I can see, seems to be ok?

Answer 3

User475983607 posted

You are also musing [Authorize] attributes.  Please go through the linked documentation and double check your work.

https://docs.microsoft.com/en-us/aspnet/core/signalr/authn-and-authz?view=aspnetcore-2.2#authorize-users-to-access-hubs-and-hub-methods

Answer 4

User-1142747527 posted

Oh yes, indeed. Thanks for that. I've added it (and updated my original question correspondingly) and still not working. But I will now compare the two in detail and see if I've missed anything else. Thanks

Answer 5

User-1142747527 posted

Ok seems to be working now, sort of.  Context.User.Identity.Name is still null. But Context.User.FindFirst(ClaimTypes.NameIdentifier).Value works.

Thanks again for all your help!

Answer 6

User283571144 posted

Hi f.a.rodriguez,

Ok seems to be working now, sort of.  Context.User.Identity.Name is still null. But Context.User.FindFirst(ClaimTypes.NameIdentifier).Value works

As far as I know, the rason about  Context.User.Identity.Name is null is the JwtSecurityToken's claim doesn't contains the ClaimTypes.Name value.

If you want to add it , you should modify your claims to genreate the claims token.

More details, you could refer to below codes:

Notice:Since I don't know your generate token method, I juest add my codes:

        public string GetToken() {
  

            var claims = new[] {
                  new Claim(JwtRegisteredClaimNames.NameId,"name1"),
                  new Claim(JwtRegisteredClaimNames.Sub,"name1"),
                  new Claim("customer","customer1"),
                  new Claim(JwtRegisteredClaimNames.Email,"wuxiyuan@sina,com"),
                  new Claim("role","user"),
                  new Claim(ClaimTypes.Name, "Brando")
            };
            var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("myStringsadasdasdasdsadadasdasdsdadasdd"));
            var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
            var token = new JwtSecurityToken("name1",
             "name1",
            claims,
            expires: DateTime.Now.AddDays(1),
            signingCredentials: creds);

            return new JwtSecurityTokenHandler().WriteToken(token);
        }

Result:

Best Regards,

Brando

Answer 7

User-1142747527 posted

Thanks Brando. I will try that out