added ip whitelisting

src/BirdsiteLive.Common/Settings/InstanceSettings.cs

@@ -16,5 +16,6 @@
         public int FailingFollowerCleanUpThreshold { get; set; } = -1;
 
         public int UserCacheCapacity { get; set; }
+        public string IpWhiteListing { get; set; }
     }
 }

src/BirdsiteLive/Middlewares/IpWhitelistingMiddleware.cs

@@ -0,0 +1,68 @@
+using BirdsiteLive.Common.Settings;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Threading.Tasks;
+
+namespace BirdsiteLive.Middlewares
+{
+    public class IpWhitelistingMiddleware
+    {
+        private readonly RequestDelegate _next;
+        private readonly ILogger<IpWhitelistingMiddleware> _logger;
+        private readonly byte[][] _safelist;
+        private readonly bool _ipWhitelistingSet;
+
+        public IpWhitelistingMiddleware(
+            RequestDelegate next,
+            ILogger<IpWhitelistingMiddleware> logger,
+            InstanceSettings instanceSettings)
+        {
+            if (!string.IsNullOrWhiteSpace(instanceSettings.IpWhiteListing))
+            {
+                var ips = instanceSettings.IpWhiteListing.Split(';');
+                _safelist = new byte[ips.Length][];
+                for (var i = 0; i < ips.Length; i++)
+                {
+                    _safelist[i] = IPAddress.Parse(ips[i]).GetAddressBytes();
+                }
+                _ipWhitelistingSet = true;
+            }
+
+            _next = next;
+            _logger = logger;
+        }
+
+        public async Task Invoke(HttpContext context)
+        {
+            //if (context.Request.Method != HttpMethod.Get.Method)
+            if (_ipWhitelistingSet)
+            {
+                var remoteIp = context.Connection.RemoteIpAddress;
+                _logger.LogDebug("Request from Remote IP address: {RemoteIp}", remoteIp);
+
+                var bytes = remoteIp.GetAddressBytes();
+                var badIp = true;
+                foreach (var address in _safelist)
+                {
+                    if (address.SequenceEqual(bytes))
+                    {
+                        badIp = false;
+                        break;
+                    }
+                }
+
+                if (badIp)
+                {
+                    _logger.LogWarning("Forbidden Request from Remote IP address: {RemoteIp}", remoteIp);
+                    context.Response.StatusCode = (int)HttpStatusCode.NotFound;
+                    return;
+                }
+            }
+
+            await _next.Invoke(context);
+        }
+    }
+}

src/BirdsiteLive/Startup.cs

@@ -8,6 +8,7 @@ using BirdsiteLive.Common.Structs;
 using BirdsiteLive.DAL.Contracts;
 using BirdsiteLive.DAL.Postgres.DataAccessLayers;
 using BirdsiteLive.DAL.Postgres.Settings;
+using BirdsiteLive.Middlewares;
 using BirdsiteLive.Models;
 using BirdsiteLive.Twitter;
 using BirdsiteLive.Twitter.Tools;
@@ -18,6 +19,7 @@ using Microsoft.AspNetCore.HttpsPolicy;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 
 namespace BirdsiteLive
 {
@@ -132,6 +134,9 @@ namespace BirdsiteLive
 
             app.UseAuthorization();
 
+            var instanceSettings = Configuration.GetSection("Instance").Get<InstanceSettings>();
+            app.UseMiddleware<IpWhitelistingMiddleware>(instanceSettings);
+
             app.UseEndpoints(endpoints =>
             {
                 endpoints.MapControllerRoute(