Securing SignalR Connections - SignalR Authentication and Authorization

Syntax:

 services.AddSignalR();
 services.AddAuthentication(options =>
            {
                options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
            })
            .AddJwtBearer(options =>
            {
                options.RequireHttpsMetadata = false;
                options.SaveToken = true;
                options.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = true,
                    IssuerSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(Configuration.GetSection("AppSettings:Token").Value)),
                    ValidateIssuer = false,
                    ValidateAudience = false
                };
            });
            
 services.AddAuthorization(options =>
            {
                options.AddPolicy("RequireAdmin",
                    policy => policy.RequireClaim("Role", "admin"));
            });

Example:

Here is a simple example of how to use SignalR Authentication and Authorization.

[Authorize]
public class ChatHub : Hub
{
     public async Task SendMessage(string user, string message)
     {
          await Clients.All.SendAsync("ReceiveMessage", user, message);
     }
}

Output:

The user needs to be authorized before entering the ChatHub. If the user is authorized, they can call the SendMessage method and send a message.

Explanation:

SignalR is a powerful tool for real-time web applications. But with great power comes great responsibility. It is important to secure your SignalR connections, and one way to do that is with SignalR Authentication and Authorization.

Authentication is the process of verifying a user's identity. Authorization is the process of verifying that a user has the necessary permissions to perform a particular action.

In SignalR, Authentication and Authorization work in much the same way as they do in other parts of .NET Core. You first need to configure your authentication and authorization via services.AddAuthentication and services.AddAuthorization. Once configured, you can then use the [Authorize] attribute to require users to authenticate and/or authorize before accessing your hub methods.

Use:

1. Configure your authentication and authorization via services.AddAuthentication and services.AddAuthorization.

services.AddAuthentication(options =>
            {
                options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
            })
            .AddJwtBearer(options =>
            {
                options.RequireHttpsMetadata = false;
                options.SaveToken = true;
                options.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = true,
                    IssuerSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(Configuration.GetSection("AppSettings:Token").Value)),
                    ValidateIssuer = false,
                    ValidateAudience = false
                };
            });
            
services.AddAuthorization(options =>
            {
                options.AddPolicy("RequireAdmin",
                    policy => policy.RequireClaim("Role", "admin"));
            });

2. Use the [Authorize] attribute to require users to authenticate and/or authorize before accessing your hub methods.

[Authorize]
public class ChatHub : Hub
{
     public async Task SendMessage(string user, string message)
     {
          await Clients.All.SendAsync("ReceiveMessage", user, message);
     }
}

Important Points:

• Always secure your SignalR connections with Authentication and Authorization.
• Only allow authenticated and authorized users to access your hub methods.
• Use services.AddAuthentication and services.AddAuthorization to configure your Authentication and Authorization.
• Use the [Authorize] attribute to require users to authenticate and/or authorize before accessing your hub methods.

Summary:

In this article, we learned about SignalR Authentication and Authorization. We saw how to configure our authentication and authorization, and how to use the [Authorize] attribute to require users to authenticate and/or authorize before accessing our hub methods. We also saw the importance of securing our SignalR connections.