fixes #692 - plugin (deactivated by default) to anonymize visitor IP addresses; the number of octets to mask is configurable; let me know if I've missed any edge cases in the unit tests

2 files changed, 126 insertions, 0 deletions

diff --git a/plugins/AnonymizeIP/AnonymizeIP.php b/plugins/AnonymizeIP/AnonymizeIP.php
new file mode 100644
index 0000000000..67082cb7ac
--- /dev/null
+++ b/plugins/AnonymizeIP/AnonymizeIP.php
@@ -0,0 +1,80 @@
+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html Gpl v3 or later
+ * @version $Id$
+ *
+ * @category Piwik_Plugins
+ * @package Piwik_AnonymizeIP
+ */
+
+/**
+ * Anonymize visitor IP addresses to comply with the privacy laws/guidelines in countries, such as Germany.
+ *
+ * @package Piwik_AnonymizeIP
+ */
+class Piwik_AnonymizeIP extends Piwik_Plugin
+{
+	/**
+	 * Get plugin information
+	 */
+	public function getInformation()
+	{
+		return array(
+			'name' => 'AnonymizeIP',
+			'description' => Piwik_Translate('AnonymizeIP_PluginDescription'),
+			'author' => 'Piwik',
+			'author_homepage' => 'http://piwik.org/',
+			'version' => Piwik_Version::VERSION,
+			'TrackerPlugin' => true,
+		);
+	}
+
+	/**
+	 * Get list of hooks to register
+	 */
+	public function getListHooksRegistered()
+	{
+		return array(
+			'Tracker.saveVisitorInformation' => 'anonymizeVisitorIpAddress',
+		);
+	}
+
+	/**
+	 * Internal function to mask portions of the visitor IP address
+	 *
+	 * @param $ip Unsigned long representation of IP address
+	 * @param $maskLength Number of octets to reset
+	 */
+	static public function applyIPMask($ip, $maskLength)
+	{
+		$maskedIP = pack('V', (float)$ip);
+
+		switch($maskLength) {
+			case 4:
+				$maskedIP[3] = "\0";
+			case 3:
+				$maskedIP[2] = "\0";
+			case 2:
+				$maskedIP[1] = "\0";
+			case 1:
+				$maskedIP[0] = "\0";
+			case 0:
+			default:
+		}
+
+		$res = unpack('V', $maskedIP);
+		return sprintf("%u", $res[1]);
+	}
+
+	/**
+	 * Hook on Tracker.saveVisitorInformation to anonymize visitor IP addresses
+	 */
+	function anonymizeVisitorIpAddress($notification)
+	{
+		$visitorInfo =& $notification->getNotificationObject();
+		$visitorInfo['location_ip'] = self::applyIPMask($visitorInfo['location_ip'], Piwik_Tracker_Config::getInstance()->Tracker['ip_address_mask_length']);
+	}
+}
diff --git a/plugins/AnonymizeIP/tests/AnonymizeIP.test.php b/plugins/AnonymizeIP/tests/AnonymizeIP.test.php
new file mode 100644
index 0000000000..7afd3e68bc
--- /dev/null
+++ b/plugins/AnonymizeIP/tests/AnonymizeIP.test.php
@@ -0,0 +1,46 @@
+<?php
+if(!defined("PIWIK_PATH_TEST_TO_ROOT")) {
+	define('PIWIK_PATH_TEST_TO_ROOT', getcwd().'/../../..');
+}
+if(!defined('PIWIK_CONFIG_TEST_INCLUDED'))
+{
+	require_once PIWIK_PATH_TEST_TO_ROOT . "/tests/config_test.php";
+}
+
+if(!class_exists('Piwik_AnonymizeIP', false))
+{
+	require_once dirname(__FILE__) . '/../AnonymizeIP.php';
+}
+
+class Test_Piwik_AnonymizeIP extends UnitTestCase
+{
+	// IP addresses and expected results
+	protected $ipAddresses = array(
+		// long => array( expected0, expected1, expected2, expected3, expected4 ),
+		'0'   => array( 0, 0, 0, 0, 0 ),													// 00 00 00 00
+		'1'   => array( 1, 0, 0, 0, 0 ),													// 00 00 00 01
+		'255' => array( 255, 0, 0, 0, 0 ),													// 00 00 00 FF
+		'256' => array( 256, 256, 0, 0, 0 ),												// 00 00 01 00
+		'257' => array( 257, 256, 0, 0, 0 ),												// 00 00 01 01
+		'65535' => array( 65535, 65280, 0, 0, 0),											// 00 00 FF FF
+		'65536' => array( 65536, 65536, 65536, 0, 0),										// 00 01 00 00
+		'65793' => array( 65793, 65792, 65536, 0, 0),										// 00 01 01 01
+		'16777215' => array( 16777215, 16776960, 16711680, 0, 0),							// 00 FF FF FF
+		'16777216' => array( 16777216, 16777216, 16777216, 16777216, 0),					// 01 00 00 00
+		'2147483647' => array( 2147483647, 2147483392, 2147418112, 2130706432, 0),			// 7F FF FF FF
+		'2147483648' => array( '2147483648', '2147483648', '2147483648', '2147483648', 0),	// 80 00 00 00
+		'4294967295' => array( '4294967295', '4294967040', '4294901760', '4278190080', 0),	// FF FF FF FF
+	);
+
+	public function test_applyIPMask()
+	{
+		foreach($this->ipAddresses as $ip => $expected)
+		{
+			// each IP is tested with 0 to 4 octets masked
+			for($maskLength = 0; $maskLength <= 4; $maskLength++)
+			{
+				$this->assertTrue( Piwik_AnonymizeIP::applyIPMask($ip, $maskLength) == $expected[$maskLength] );
+			}
+		}
+	}
+}