Encoding and decoding cookies to bypass WAF rules

dotnet add package Microsoft.AspNetCore.Authentication
dotnet add package Microsoft.AspNetCore.Authentication.Cookies

// CustomMiddleware.cs
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Http;
using System.Threading.Tasks;

public class CustomMiddleware
{
    private readonly RequestDelegate _next;

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

    public async Task Invoke(HttpContext context)
    {
        // Decode or encode your cookies here
        // For example, decoding:
        // var decodedCookie = context.Request.Cookies["YourCookieName"];
        // var decodedValue = DecodeYourCookie(decodedCookie);
        
        // Encoding example:
        // var encodedValue = EncodeYourCookie(originalValue);
        // context.Response.Cookies.Append("YourCookieName", encodedValue);

        // Call the next delegate/middleware in the pipeline
        await _next(context);
    }
}

// Startup.cs
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

public class Startup
{
    // Other configurations...

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // Other middleware configurations...

        app.UseMiddleware<CustomMiddleware>();

        // Other middleware configurations...
    }
}