[ASP.NET Core Middleware Sample] 範例中包含只允許特定 IP 區段才能存取的功能 #dotnet

Middleware.cs

using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;

namespace App.Middleware
{
    /// <summary></summary>
    public class MyAuthorizedMiddleware
    {
        private readonly RequestDelegate _next;

        /// <summary></summary>
        public MyAuthorizedMiddleware(RequestDelegate next)
        {
            _next = next;
        }
        /// <summary></summary>
        public async Task Invoke(HttpContext context)
        {
            if (context.Request.Path.StartsWithSegments("/api")
                && !context.Connection.RemoteIpAddress.ToString().StartsWith("192.168"))
            {
                context.Response.StatusCode = StatusCodes.Status401Unauthorized;
                return;
            }

            //do work before the invoking the rest of the pipeline
            await _next.Invoke(context); //let the rest of the pipeline run
            //do work after the rest of the pipeline has run
        }
    }

    /// <summary></summary>
    public static class MyAuthorizeExtensions
    {
        /// <summary></summary>
        /// <param name="builder">中介程序建構器</param>
        public static IApplicationBuilder UseMyAuthorized(this IApplicationBuilder builder)
        {
            return builder.UseMiddleware<MyAuthorizedMiddleware>();
        }
    }
}

Startup.cs

using System.Collections.Generic;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Primitives;
using Newtonsoft.Json;

namespace Phishing
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services) {}

        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            app.Use(async (context, next) =>
            {
                await next();

                // 判斷是否是要存取網頁，而不是發送 API 需求
                if (context.Response.StatusCode == 404 &&                       // 該資源不存在
                    !System.IO.Path.HasExtension(context.Request.Path.Value) && // 網址最後沒有帶副檔名
                    !context.Request.Path.Value.StartsWith("/api"))             // 網址不是 /api 開頭
                {
                    context.Request.Path = "/index.html";                       // 將網址改成 /index.html
                    context.Response.StatusCode = 200;                          // 並將 HTTP 狀態碼修改為 200 成功
                    await next();
                }
            });

            // 使用 Middleware
            app.UseMyAuthorized();
        }
    }
}