Detect DDoS-Guard and Custom Cloudflare challenges

Author: ngosang

src/FlareSolverrSharp/ChallengeDetector.cs

@@ -23,14 +23,22 @@ public static class ChallengeDetector
         /// <returns>True if the site is protected</returns>
         private static bool IsCloudflareProtected(HttpResponseMessage response)
         {
-            // check status code
+            // check response headers
+            if (!response.Headers.Server.Any(i =>
+                    i.Product != null && CloudflareServerNames.Contains(i.Product.Name.ToLower())))
+                return false;
+
+            // detect CloudFlare and DDoS-GUARD
             if (response.StatusCode.Equals(HttpStatusCode.ServiceUnavailable) ||
                 response.StatusCode.Equals(HttpStatusCode.Forbidden))
-            {
-                // check response headers
-                return response.Headers.Server.Any(i =>
-                    i.Product != null && CloudflareServerNames.Contains(i.Product.Name.ToLower()));
-            }
+                return true; // Defected CloudFlare and DDoS-GUARD
+
+            // detect Custom CloudFlare for EbookParadijs, Film-Paleis, MuziekFabriek and Puur-Hollands
+            if (response.Headers.Vary.ToString() == "Accept-Encoding,User-Agent" &&
+                response.Content.Headers.ContentEncoding.ToString() == "" &&
+                response.Content.ReadAsStringAsync().Result.ToLower().Contains("ddos"))
+                return true; 
+
             return false;
         }
 

test/FlareSolverrSharp.Tests/ClearanceHandlerTests.cs

@@ -95,6 +95,35 @@ public async Task SolveOkProxy()
             Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
         }
 
+        [TestMethod]
+        public async Task SolveOkCloudflareDDoSGuardGet()
+        {
+            var handler = new ClearanceHandler(Settings.FlareSolverrApiUrl)
+            {
+                MaxTimeout = 60000
+            };
+
+            var client = new HttpClient(handler);
+            var response = await client.GetAsync(Settings.ProtectedDdgUri);
+            Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
+            Assert.IsTrue(!response.Content.ReadAsStringAsync().Result.ToLower().Contains("ddos"));
+        }
+
+        [TestMethod]
+        public async Task SolveOkCloudflareCustomGet()
+        {
+            // Custom CloudFlare for EbookParadijs, Film-Paleis, MuziekFabriek and Puur-Hollands
+            var handler = new ClearanceHandler(Settings.FlareSolverrApiUrl)
+            {
+                MaxTimeout = 60000
+            };
+
+            var client = new HttpClient(handler);
+            var response = await client.GetAsync(Settings.ProtectedCcfUri);
+            Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
+            Assert.IsTrue(!response.Content.ReadAsStringAsync().Result.ToLower().Contains("ddos"));
+        }
+
         [TestMethod]
         public async Task SolveErrorUrl()
         {

test/FlareSolverrSharp.Tests/Settings.cs

@@ -7,6 +7,8 @@ internal static class Settings
         internal const string FlareSolverrApiUrl = "http://localhost:8191/";
         internal const string ProxyUrl = "http://127.0.0.1:8888/";
         internal static readonly Uri ProtectedUri = new Uri("https://pirateiro.com/torrents/?search=harry");
+        internal static readonly Uri ProtectedDdgUri = new Uri("https://www.erai-raws.info/feed/?type=magnet");
+        internal static readonly Uri ProtectedCcfUri = new Uri("https://www.muziekfabriek.org");
 
         /*
         To configure TinyProxy in local: