Initial commit

README.md

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+# tor-detector
+A library to detect if your website visitor is from a TOR network or not

composer.json

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+{
+  "name": "onlinesid/tor-detector",
+  "type": "library",
+  "description": "Detect if your website visitor is from a TOR exit node",
+  "keywords": [
+    "tor",
+    "tor browser",
+    "detector"
+  ],
+  "homepage": "https://github.com/onlinesid/tor-detector",
+  "license": "MIT",
+  "autoload": {
+    "psr-4": { "OnlineSid\\" : "src/" }
+  }
+}

src/Tor/TorDetector.php

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+<?php
+
+namespace OnlineSid\Tor;
+
+/**
+ * Class TorDetector
+ *
+ * Helps to detect if visitors are using a Tor browser to surf the website.
+ *
+ * Thanks to https://trac.torproject.org/projects/tor/wiki/doc/TorDNSExitList
+ *
+ * Thanks to https://jrnv.nl/detecting-the-use-of-proxies-and-tor-network-6c240d6cc5f#.k8ldcs21o
+ *
+ */
+class TorDetector
+{
+    /**
+     * Checks if the remote IP is from a TOR exit node or not
+     *
+     * @param string $remoteIp The IP of the visitor you'd like to check.
+     * @param int    $port     The port on which your server is running, e.g.: port 80.
+     * @param string $serverIp Your server IP.
+     *
+     * @return bool
+     */
+    public function check($remoteIp, $port, $serverIp)
+    {
+        $detectHost = sprintf(
+            '%s.%s.%s.ip-port.exitlist.torproject.org',
+            $this->reverseIPOctets($remoteIp),
+            $port,
+            $this->reverseIPOctets($serverIp)
+        );
+
+        // According to the guide, if this returns 127.0.0.2, it's a Tor exit node
+        return gethostbyname($detectHost) === '127.0.0.2';
+    }
+
+    /**
+     * This function simply reverses the IP's octets.
+     *
+     * @param string $ip The IP to be reversed.
+     *
+     * @return string
+     */
+    protected function reverseIPOctets($ip)
+    {
+        return implode(array_reverse(explode('.', $ip)), '.');
+    }
+}

usage_example.php

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+<?php
+
+require_once "src/Tor/TorDetector.php";
+
+$tor_detector = new OnlineSid\Tor\TorDetector();
+
+$your_server_ip = '1.2.3.4'; // the IP address of your server (web server)
+$user_ip = '62.102.148.67'; // is this IP from TOR exit node?
+
+if ($tor_detector->check($user_ip, 80, $your_server_ip)) {
+    echo "Tor!\n";
+} else {
+    echo "Not TOR!\n";
+}
+