diff --git a/html/includes/authentication/active_directory.inc.php b/html/includes/authentication/active_directory.inc.php
new file mode 100644
index 000000000..cb6753191
--- /dev/null
+++ b/html/includes/authentication/active_directory.inc.php
@@ -0,0 +1,263 @@
+<?php
+
+// easier to rewrite for Active Directory than to bash it into existing LDAP implementation
+
+$ds = @ldap_connect($config['auth_ad_url']);
+
+// disable referrals and force ldap version to 3
+
+ldap_set_option($ds, LDAP_OPT_REFERRALS, 0);
+ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
+
+// disable certificate checking if required
+
+if (isset($config['auth_ad_dont_check_certificates'] &&
+          $config['auth_ad_dont_check_certificates'] > 1) {
+    putenv('LDAPTLS_REQCERT=never');
+};
+
+function authenticate($username, $password) {
+    global $config, $ds;
+
+    if ($username && $ds) {
+        // bind with sAMAccountName instead of full LDAP DN
+        if (ldap_bind($ds, "{$username}@{$config['auth_ad_domain']}", $password)) {
+            return 1;
+        } else {
+            return 0;
+        }
+    } else {
+        echo ldap_error($ds);
+    }
+
+    return 0;
+    
+}
+
+function reauthenticate($sess_id, $token) {
+    return 0;
+}
+
+
+function passwordscanchange($username='') {
+    return 0;
+}
+
+
+function changepassword($username, $newpassword) {
+    return 0;
+}
+
+
+function auth_usermanagement() {
+    return 0;
+}
+
+
+function adduser($username, $password, $level, $email='', $realname='', $can_modify_passwd='1') {
+    return 0;
+}
+
+
+function user_exists($username) {
+    global $config, $ds;
+
+    $search = ldap_search($ds, $config['auth_ad_base_dn'],
+                          "(samaccountname={$username})",array('samaccountname'));
+    $entries = ldap_get_entries($ds, $search);
+
+
+    if ($entries['count']) {
+        return 1;
+    }
+
+    return 0;
+
+}
+
+
+function get_userlevel($username) {
+    global $config, $ds;
+
+    $userlevel = 0;
+
+    // Find all defined groups $username is in
+    $search = ldap_search($ds, $config['auth_ad_base_dn'],
+                          "(samaccountname={$username})", array('memberOf'));
+    $entries = ldap_get_entries($ds, $search);
+    
+    // Loop the list and find the highest level
+    foreach ($entries[0]['memberof'] as $entry) {
+        $group_cn = get_cn($entry);
+        if ($config['auth_ad_groups'][$group_cn]['level'] > $userlevel) {
+            $userlevel = $config['auth_ad_groups'][$group_cn]['level'];
+        }
+    }
+
+    return $userlevel;
+
+}
+
+
+function get_userid($username) {
+    global $config, $ds;
+
+    $attributes = array('objectsid');
+    $result = ldap_search($ds, $config['auth_ad_base_dn'],
+                          "(samaccountname={$username})", $attributes);    
+    $entries = ldap_get_entries($ds, $search);
+
+    if ($entries['count']) {
+        return preg_replace('/.*-(\d+)$/','$1',sid_from_ldap($entries[0]['objectsid'][0]));
+    }
+
+    return -1;
+
+}
+
+
+function deluser($username) {
+    // Not supported
+    return 0;
+
+}
+
+
+function get_userlist() {
+    global $config, $ds;
+    $userlist = array();
+
+    $ldap_groups = get_group_list();
+
+    foreach($ldap_groups as $ldap_group) {
+        $group_cn = get_cn($ldap_group);
+        $search = ldap_search($ds, $config['auth_ad_base_dn'], "(cn={$group_cn})", array('member'));
+        $entries = ldap_get_entries($ds, $search);
+        
+        foreach($entries[0]['member'] as $member) {
+            $member_cn = get_cn($member);
+            $search = ldap_search($ds, $config['auth_ad_base_dn'], "(cn={$member_cn})",
+                                  array('sAMAccountname', 'displayName', 'objectSID', 'mail'));
+            $results = ldap_get_entries($ds, $search);
+            foreach($results as $result) {
+                if(isset($result['samaccountname'][0])) {
+                    $userid = preg_replace('/.*-(\d+)$/','$1',
+                                           sid_from_ldap($result[0]['objectsid'][0]));
+                    $username = $result['samaccountname'][0];
+
+                    // don't make duplicates, user may be member of more than one group
+                    $userhash[$username] = array(
+                        'realname' => $result['displayName'][0],
+                        'user_id'  => $userid,
+                        'email'    => $result['mail'][0]
+                    );
+                }
+            }
+        }
+    }
+
+    foreach($userhash[] as $key) {
+        $userlist[] = array(
+            'username' => $key,
+            'realname' => $userhash[$key]['realname'],
+            'user_id'  => $userhash[$key]['user_id'],
+            'email'    => $userhash[$key]['email']
+        );
+    }
+    
+    return $userlist;
+}
+
+
+function can_update_users() {
+    // not supported so return 0
+    return 0;
+
+}
+
+
+function get_user($user_id) {
+    // not supported so return 0
+    return 0;
+
+}
+
+
+function update_user($user_id, $realname, $level, $can_modify_passwd, $email) {
+    // not supported so return 0 
+    return 0;
+
+}
+
+
+function get_fullname($username) {
+    global $config, $ds;
+
+    $attributes = array('name');
+    $result = ldap_search($ds, $config['auth_ad_base_dn'],
+                          "(samaccountname={$username})", $attributes);
+    $entries = ldap_get_entries($ds, $result);
+    if ($entries['count'] > 0) {
+        $membername = $entries[0]['name'][0];
+    } else {
+        $membername = $username;
+    }
+
+    return $membername;
+}
+
+
+function get_group_list() {
+    global $config;
+
+    $ldap_groups   = array();
+
+    // show all Active Directory Users by default
+    $default_group = 'Users';
+
+    if (isset($config['auth_ad_group'])) {
+        if ($config['auth_ad_group'] !== $default_group) {
+            $ldap_groups[] = $config['auth_ad_group'];
+        }
+    }
+
+    if (!isset($config['auth_ad_groups']) && !isset($config['auth_ad_group'])) {
+        $ldap_groups[] = get_dn($default_group);
+    }
+
+    foreach ($config['auth_ad_groups'] as $key => $value) {
+        $ldap_groups[] = get_dn($key);
+    }
+
+    return $ldap_groups;
+
+}
+
+function get_dn($samaccountname) {
+    global $config, $ds;
+
+
+    $attributes = array('dn');
+    $result = ldap_search($ds, $config['auth_ad_base_dn'],
+                          "(samaccountname={$samaccountname})", $attributes);
+    $entries = ldap_get_entries($ds, $result);
+    if ($entries['count'] > 0) {
+        return $entries[0]['dn'];
+    } else {
+        return '';
+    }
+}
+
+function get_cn($dn) {
+    preg_match('/[^,]*/', $dn, $matches, PREG_OFFSET_CAPTURE, 3);
+    return $matches[0][0];
+}
+
+function sid_from_ldap($sid)
+{
+        $sidHex = unpack('H*hex', $sid)['hex'];
+        $subAuths = unpack('H2/H2/n/N/V*', $sid);        
+        $revLevel = hexdec(substr($sidHex, 0, 2));
+        $authIdent = hexdec(substr($sidHex, 4, 12));      
+        return 'S-'.$revLevel.'-'.$authIdent.'-'.implode('-', $subAuths);
+}