diff --git a/html/includes/authentication/ad-authorization.inc.php b/html/includes/authentication/ad-authorization.inc.php
new file mode 100644
index 0000000000..2f30129984
--- /dev/null
+++ b/html/includes/authentication/ad-authorization.inc.php
@@ -0,0 +1,359 @@
+<?php
+
+if (! isset ($_SESSION['username'])) {
+    $_SESSION['username'] = '';
+}
+
+// Disable certificate checking before connect if required
+if (isset($config['auth_ad_check_certificates']) &&
+        $config['auth_ad_check_certificates'] == 0) {
+    putenv('LDAPTLS_REQCERT=never');
+};
+
+// Set up connection to LDAP server
+$ds = @ldap_connect($config['auth_ad_url']);
+if (! $ds) {
+    echo '<h2>Fatal error while connecting to AD url ' . $config['auth_ad_url'] . ': ' . ldap_error($ds) . '</h2>';
+    exit;
+}
+
+// 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);
+
+// Bind to AD
+if (isset($config['auth_ad_binduser']) && isset($config['auth_ad_bindpassword'])) {
+    // With specified bind user
+    if (! ldap_bind($ds, "${config['auth_ad_binduser']}@${config['auth_ad_domain']}", "${config['auth_ad_bindpassword']}")) {
+        echo ldap_error($ds);
+    }
+}
+else {
+    // Anonymous
+    if (! ldap_bind($ds)) {
+        echo ldap_error($ds);
+    }
+}
+
+function authenticate ($username, $password) {
+    global $config;
+
+    if (isset ($_SERVER['REMOTE_USER'])) {
+        $_SESSION['username'] = mres ($_SERVER['REMOTE_USER']);
+
+        if (user_exists ($_SESSION['username'])) {
+            adduser($username);
+            return 1;
+
+        }
+
+        $_SESSION['username'] = $config['http_auth_guest'];
+        return 1;
+    }
+
+    return 0;
+}
+
+
+function reauthenticate() {
+    // not supported so return 0
+    return 0;
+}
+
+
+function passwordscanchange() {
+    // not supported so return 0
+    return 0;
+}
+
+
+function changepassword() {
+    // not supported so return 0
+    return 0;
+}
+
+
+function auth_usermanagement() {
+    // not supported so return 0
+    return 0;
+}
+
+
+function adduser($username, $level=0, $email='', $realname='', $can_modify_passwd=0, $description='', $twofactor=0) {
+    // Check to see if user is already added in the database
+    if (!user_exists_in_db($username)) {
+        $userid = dbInsert(array('username' => $username, 'realname' => $realname, 'email' => $email, 'descr' => $description, 'level' => $level, 'can_modify_passwd' => $can_modify_passwd, 'twofactor' => $twofactor, 'user_id' => get_userid($username)), 'users');
+        if ($userid == false) {
+            return false;
+        }
+        else {
+            foreach (dbFetchRows('select notifications.* from notifications where not exists( select 1 from notifications_attribs where notifications.notifications_id = notifications_attribs.notifications_id and notifications_attribs.user_id = ?) order by notifications.notifications_id desc',array($userid)) as $notif) {
+                dbInsert(array('notifications_id'=>$notif['notifications_id'],'user_id'=>$userid,'key'=>'read','value'=>1),'notifications_attribs');
+            }
+        }
+        return $userid;
+    }
+    else {
+        return false;
+    }
+}
+
+function user_exists_in_db($username) {
+    $return = dbFetchCell('SELECT COUNT(*) FROM users WHERE username = ?', array($username), true);
+    return $return;
+}
+
+function user_exists($username) {
+    global $config, $ds;
+
+    if (auth_ldap_session_cache_get ('user_exists'))
+        return 1;
+
+    $search = ldap_search($ds, $config['auth_ad_base_dn'],
+            "(samaccountname=${username})",array('samaccountname'));
+    $entries = ldap_get_entries($ds, $search);
+
+    if ($entries['count']) {
+        /*
+         * Cache positiv result as this will result in more queries which we
+         * want to speed up.
+         */
+        auth_ldap_session_cache_set ('user_exists', 1);
+        return 1;
+    }
+
+    return 0;
+}
+
+
+function get_userlevel($username) {
+    global $config, $ds;
+
+    $userlevel = auth_ldap_session_cache_get ('userlevel');
+    if ($userlevel) {
+        return $userlevel;
+    } 
+    else {
+        $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'];
+        }
+    }
+
+    auth_ldap_session_cache_set ('userlevel', $userlevel);
+    return $userlevel;
+}
+
+
+function get_userid($username) {
+    global $config, $ds;
+
+    $user_id = auth_ldap_session_cache_get ('userid');
+    if (isset ($user_id)) {
+        return $user_id;
+    } 
+    else {
+        $user_id = -1;
+    }
+
+    $attributes = array('objectsid');
+    $search = ldap_search($ds, $config['auth_ad_base_dn'],
+            "(samaccountname={$username})", $attributes);    
+    $entries = ldap_get_entries($ds, $search);
+
+    if ($entries['count']) {
+        $user_id = preg_replace('/.*-(\d+)$/','$1',sid_from_ldap($entries[0]['objectsid'][0]));
+    }
+
+    auth_ldap_session_cache_set ('userid', $user_id);
+    return $user_id;
+}
+
+
+function deluser($username) {
+    dbDelete('bill_perms', '`user_name` =  ?', array($username));
+    dbDelete('devices_perms', '`user_name` =  ?', array($username));
+    dbDelete('ports_perms', '`user_name` =  ?', array($username));
+    dbDelete('users_prefs', '`user_name` =  ?', array($username));
+    dbDelete('users', '`user_name` =  ?', array($username));
+    return dbDelete('users', '`username` =  ?', array($username));
+}
+
+
+function get_userlist() {
+    global $config, $ds;
+    $userlist = array();
+    $userhash = 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['objectsid'][0]));
+
+                    // don't make duplicates, user may be member of more than one group
+                    $userhash[$result['samaccountname'][0]] = array(
+                            'realname' => $result['displayName'][0],
+                            'user_id'  => $userid,
+                            'email'    => $result['mail'][0]
+                            );
+                }
+            }
+        }
+    }
+
+    foreach(array_keys($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 dbFetchRow('SELECT * FROM `users` WHERE `user_id` = ?', array($user_id), true);
+}
+
+
+function update_user($user_id, $realname, $level, $can_modify_passwd, $email) {
+    dbUpdate(array('realname' => $realname, 'can_modify_passwd' => $can_modify_passwd, 'email' => $email), 'users', '`user_id` = ?', array($user_id));
+}
+
+
+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);
+    $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('-', $subAuths);
+}
+
+function auth_ldap_session_cache_get ($attr) {
+    global $config;
+
+    $ttl = 300;
+    if ($config['auth_ldap_cache_ttl'])
+        $ttl = $config['auth_ldap_cache_ttl'];
+
+    // auth_ldap cache present in this session?
+    if (! isset ($_SESSION['auth_ldap']))
+        return Null;
+
+    $cache = $_SESSION['auth_ldap'];
+
+    // $attr present in cache?
+    if (! isset ($cache[$attr]))
+        return Null;
+
+    // Value still valid?
+    if (time () - $cache[$attr]['last_updated'] >= $ttl)
+        return Null;
+
+    return $cache[$attr]['value'];
+}
+
+
+function auth_ldap_session_cache_set ($attr, $value) {
+    $_SESSION['auth_ldap'][$attr]['value'] = $value;
+    $_SESSION['auth_ldap'][$attr]['last_updated'] = time ();
+}
+