From acf2d1afb5edfa1ce572688ca6b1e749b9d9b7fd Mon Sep 17 00:00:00 2001
From: "NullDev (Shadow)" <chris@nulldev.org>
Date: Mon, 13 Nov 2023 05:35:57 +0100
Subject: [PATCH] added basic fingerprinting

---
 web/src/challange/challanges.js     | 32 ++++++++++++++++-
 web/src/challange/fingerprinting.js | 55 +++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 web/src/challange/fingerprinting.js

diff --git a/web/src/challange/challanges.js b/web/src/challange/challanges.js
index fc1cf31..2f2d7c3 100644
--- a/web/src/challange/challanges.js
+++ b/web/src/challange/challanges.js
@@ -1,9 +1,15 @@
+import Fingerprinting from "./fingerprinting";
+
 /**
  * Collection of challenges.
  *
  * @class Challenges
  */
-class Challenges {
+class Challenges extends Fingerprinting {
+    constructor(){
+        super();
+    }
+
     /**
      * Calculate native hash.
      *
@@ -18,6 +24,20 @@ class Challenges {
         return hashArray.map(b => b.toString(16).padStart(2, "0")).join("");
     }
 
+    /**
+     * Send failed fingerprinting to server.
+     *
+     * @param {string} reason
+     * @return {Promise<void>}
+     * @memberof Challenger
+     */
+    async #sendFingerprintingResult(reason){
+        fetch("/cdn-cgi/challenge-platform/challenge", {
+            method: "POST",
+            body: reason,
+        });
+    }
+
     /**
      * Challenge POW.
      *
@@ -51,6 +71,16 @@ class Challenges {
      * @memberof Challenger
      */
     async challengeFingerprinting(){
+        const usualUa = this.isUsualBrowserBasedOnUa();
+        if (!usualUa) return await this.#sendFingerprintingResult("ua");
+
+        const notHeadless = this.isNotHeadless();
+        if (!notHeadless) return await this.#sendFingerprintingResult("headless");
+
+        const canvasSupported = this.isCanvasSupported();
+        if (!canvasSupported) return await this.#sendFingerprintingResult("canvas");
+
+        return await this.#sendFingerprintingResult("ok");
     }
 
     /**
diff --git a/web/src/challange/fingerprinting.js b/web/src/challange/fingerprinting.js
new file mode 100644
index 0000000..544d232
--- /dev/null
+++ b/web/src/challange/fingerprinting.js
@@ -0,0 +1,55 @@
+/**
+ * Browser based fingerprinting
+ *
+ * @class Fingerprinting
+ */
+class Fingerprinting {
+    /**
+     * Check user agent string for usual browsers.
+     *
+     * @return {boolean}
+     * @memberof Fingerprinting
+     */
+    isUsualBrowserBasedOnUa(){
+        const ua = navigator.userAgent;
+        const isUsualBrowser = ua.includes("Chrome")
+            || ua.includes("Firefox")
+            || ua.includes("Safari")
+            || ua.includes("Edge")
+            || ua.includes("Opera")
+            || ua.includes("OPR")
+            || ua.includes("MSIE")
+            || ua.includes("Trident");
+        return isUsualBrowser;
+    }
+
+    /**
+     * Check if browser is headless.
+     *
+     * @return {boolean}
+     * @memberof Fingerprinting
+     */
+    isNotHeadless(){
+        const isHeadless = !!navigator.webdriver // @ts-ignore
+            || !!window.chrome
+            || !!navigator.languages
+            || navigator.userAgent.toLowerCase().includes("headless");
+        return !isHeadless;
+    }
+
+    /**
+     * Check if canvas is supported.
+     *
+     * @return {boolean}
+     * @memberof Fingerprinting
+     */
+    isCanvasSupported(){
+        const canvas = document.createElement("canvas");
+        const gl = canvas.getContext("webgl") || canvas.getContext("experimental-webgl");
+        return !!gl;
+    }
+
+    // more to come
+}
+
+export default Fingerprinting;