Register MessageHandler in Program.cs

Question

I am trying to build the ASP.NET Core Web API from this link (https://docs.microsoft.com/en-us/azure/notification-hubs/push-notifications-android-specific-users-firebase-cloud-messaging). It wants me to register the MessageHandler using the following code:

config.MessageHandlers.Add(new AuthenticationTestHandler());

It says to "add the following code at the end of the Register method in the Program.cs file. There is no register method in the Program.cs file. Everything I have found indicates that the Register method is part of a class called WebApiConfig, but I don't have one of those either, and when I create one, it cannot find HttpConfiguration. How do I register the MessageHandler?

user_10839134 · Answer

In ASP.NET Core the equivalent to a MessageHandler is middleware. I converted AuthenticationTestHandler to middleware:

AuthenticationTestMiddleware.cs:

public class AuthenticationTestMiddleware
{
    private readonly RequestDelegate _next;

    public AuthenticationTestMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        var authorizationHeader = context.Request.Headers["Authorization"].FirstOrDefault();

        if (authorizationHeader != null && authorizationHeader
            .StartsWith("Basic ", StringComparison.InvariantCultureIgnoreCase))
        {
            string authorizationUserAndPwdBase64 =
                authorizationHeader.Substring("Basic ".Length);
            string authorizationUserAndPwd = Encoding.Default
                .GetString(Convert.FromBase64String(authorizationUserAndPwdBase64));
            string user = authorizationUserAndPwd.Split(':')[0];
            string password = authorizationUserAndPwd.Split(':')[1];

            if (VerifyUserAndPwd(user, password))
            {
                var claims = new List
                {
                    new Claim(ClaimTypes.Name, user)
                };

                var claimsIdentity = new ClaimsIdentity(
                    claims: claims,
                    authenticationType: "password");

                context.User.AddIdentity(claimsIdentity);
                await _next(context);
            }
            else
            {
                context.Response.StatusCode = (int)HttpStatusCode.Forbidden;
            }
        }
        else
        {
            context.Response.StatusCode = (int)HttpStatusCode.Forbidden;
        }
    }

    private bool VerifyUserAndPwd(string user, string password)
    {
        // This is not a real authentication scheme.
        return user == password;
    }
}

Now in Program.cs you can register like this:

app.UseMiddleware();

Questions I found regarding converting MessageHandler to middleware:

https://docs.microsoft.com/en-us/aspnet/core/fundamentals/middleware/write?view=aspnetcore-6.0

Edit:

Found an official sample that is updated for ASP.NET Core:

https://github.com/Azure/azure-notificationhubs-dotnet/tree/main/Samples/WebApiSample/WebApiSample

Register MessageHandler in Program.cs

1 Answers