ASP.NET MVC - Set custom IIdentity or IPrincipal

How to Set Custom IIdentity or IPrincipal in ASP.NET MVC

Are you struggling to set a custom IIdentity or IPrincipal in your ASP.NET MVC application? Do you find all the related concepts and components confusing? Don't worry, I've got you covered! In this blog post, I'll guide you through the common issues and provide simple and efficient solutions to set a custom IIdentity with extra properties. So let's dive in!

Understanding the Problem

The first step is understanding the problem at hand. The user wants to extend the default IIdentity or IPrincipal to include extra properties (Id and Role) and make them accessible through the User.Identity object. However, they want to avoid unnecessary database calls on every request.

Solution Approach

To achieve our goal, we need to follow a simple and elegant solution approach. Here are the steps we'll take:

1. Define a custom IIdentity implementation with the desired extra properties.

2. Create a custom IPrincipal implementation that utilizes our custom IIdentity.

3. Set an instance of our custom IPrincipal as the current user principal during the authentication process.

Step 1: Custom IIdentity Implementation

Let's start by creating a custom IIdentity implementation that extends the default GenericIdentity class. This will allow us to add the desired extra properties. Here's an example:

public class CustomIdentity : GenericIdentity
{
    public int Id { get; }
    public string Role { get; }

    public CustomIdentity(string name, int id, string role)
        : base(name)
    {
        Id = id;
        Role = role;
    }
}

In this code, we define Id and Role properties along with the necessary constructor to set their values.

Step 2: Custom IPrincipal Implementation

Next, we'll create a custom IPrincipal implementation that utilizes our CustomIdentity. This will allow us to access our extra properties through the User.Identity object. Here's an example:

public class CustomPrincipal : IPrincipal
{
    public IIdentity Identity { get; }

    public CustomPrincipal(string name, int id, string role)
    {
        Identity = new CustomIdentity(name, id, role);
    }

    public bool IsInRole(string role)
    {
        // Implement your role-checking logic here
    }
}

In this code, we define the Identity property as an instance of our CustomIdentity implementation.

Step 3: Set Custom IPrincipal during Authentication

Now that we have our custom IIdentity and IPrincipal, we need to set an instance of our CustomPrincipal as the current user principal during the authentication process. To do this, we can utilize the Application_PostAuthenticateRequest event in the global.asax file. Here's an example:

protected void Application_PostAuthenticateRequest(object sender, EventArgs e)
{
    // Retrieve user data from the session or database
    int userId = GetUserIdFromSessionOrDatabase();
    string userName = GetUserNameFromSessionOrDatabase();
    string userRole = GetUserRoleFromSessionOrDatabase();

    // Create an instance of our custom principal
    var customPrincipal = new CustomPrincipal(userName, userId, userRole);

    // Set the custom principal as the current user principal
    HttpContext.Current.User = customPrincipal;
}

In this code, we retrieve the necessary user data from the session or database, create an instance of our CustomPrincipal, and set it as the current user principal.

Conclusion and Call to Action

Congratulations! You've successfully set a custom IIdentity or IPrincipal with extra properties in your ASP.NET MVC application. By following the simple and efficient solution approach explained in this blog post, you were able to tackle the problem in an elegant way.

I hope this guide helped you understand and solve the issue you were facing. If you have any questions or need further assistance, feel free to leave a comment below. And don't forget to share this blog post with others who might find it helpful. Happy coding! 👩‍💻🔥

Source: Stack Overflow