DEV: implemented function to anonymize ip-addresses

LimeSurvey · Mar 17, 2020 · 62553bd · 62553bd
1 parent 48d60c0
commit 62553bd
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Showing 2 changed files with 41 additions and 6 deletions.
diff --git a/application/controllers/admin/globalsettings.php b/application/controllers/admin/globalsettings.php
@@ -404,6 +404,22 @@ public function surveySettings()
         $oSurvey = SurveysGroupsettings::model()->findByPk($gsid);
         $oSurvey->setOptions();
 
+        // TEST anonymize IP adresses
+        $ipToAnonymize = "192.168.2.5"; //this one should be anonymized ...
+        $result = anonymizeIpAddress($ipToAnonymize); // tested OK
+        // Test already anonymized ip
+        $result = anonymizeIpAddress($result); // tested OK
+        // TEST no ip address
+        $result = anonymizeIpAddress("not.an.ip"); // tested OK
+        $ipV6 = "2a03:2880:2110:df07:face:b00c::1";
+        $result = anonymizeIpAddress($ipV6);
+        $ipV6 = "2a03:2880:2110:df07:face:b00c::";
+        $result = anonymizeIpAddress($ipV6);
+        $ipV6 = "2a03::2110:df07:face:b00c::"; //this one is not a valid ipv6
+        $result = anonymizeIpAddress($ipV6);
+        $ipV6 = "2a03::2110:df07:face:b00c:3:4"; //this one is not a valid ipv6
+        $result = anonymizeIpAddress($ipV6);
+
         $sPartial = Yii::app()->request->getParam('partial', '_generaloptions_panel');
 
         if (isset($_POST)) {

diff --git a/application/helpers/common_helper.php b/application/helpers/common_helper.php
@@ -4888,14 +4888,33 @@ function resourceExtractFilter($p_event, &$p_header) {
  * the ip address without changing it.
  *
  * @param string $ipAddress
- * @return string
+ * @return string|boolean if ip is not anonymised false will be returned (in case of not a valid ip or ip has already been
+ *                        anonymised), else the anonymise ip will be returned as a string
  */
-function anonymizeIpAdress($ipAddress){
-    $anonymizedIp = "";
+function anonymizeIpAddress($ipAddress){
+    $anonymizedIp = false;
+
+    if(filter_var($ipAddress,FILTER_VALIDATE_IP,FILTER_FLAG_IPV4)){ //check if it is valid ipv4
+        $ipArray = explode('.', $ipAddress);
+        $last_digit = array_pop($ipArray);
+        if($last_digit!=0){ //check if it has already been anonymized
+            //set last number to 0
+            $anonymizedIp = implode('.',$ipArray); //without last digit ?!?
+            $anonymizedIp .= '.0';
+        }
+    } elseif (filter_var($ipAddress, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) { //check if it is valid ipv6
+        $ipArray = explode(':', $ipAddress);
+        //the last 5 blocks have to be set to 0 ...
+        for ($i = 0; $i < 5; $i++) {
+            array_pop($ipArray);
+        }
 
-    //check if it is ipv4 or ipv6
-    //check if it has already been anonymized
-    //if not anonymize it ...
+        $anonymizedIp = implode(':', $ipArray);
+        //append last 5 blocks with 0
+        for ($i = 0; $i < 5; $i++) {
+            $anonymizedIp .= ':0';
+        }
+    }
 
     return $anonymizedIp;
 }