diff --git a/library/Icinga/Authentication/Backend/LdapUserBackend.php b/library/Icinga/Authentication/Backend/LdapUserBackend.php
new file mode 100644
index 000000000..c53d27a06
--- /dev/null
+++ b/library/Icinga/Authentication/Backend/LdapUserBackend.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Icinga\Authentication\Backend;
+
+use Icinga\Authentication\User as User;
+use Icinga\Protocol\Ldap;
+
+class LdapUserBackend implements UserBackend
+{
+    protected $connection;
+
+    public function __construct($config)
+    {
+        $this->connection = new Ldap\Connection($config);
+    }
+
+    public function hasUsername($username)
+    {
+        if (! $username) {
+            return false;
+        }
+        return $this->connection->fetchOne(
+            $this->selectUsername($username)
+        ) === $username;
+    }
+
+    protected function stripAsterisks($string)
+    {
+        return str_replace('*', '', $string);
+    }
+
+    protected function selectUsername($username)
+    {
+        return $this->connection->select()
+            ->from('user', array('sAMAccountName'))
+            ->where('sAMAccountName', $this->stripAsterisks($username));
+    }
+
+    public function authenticate($username, $password = null)
+    {
+        if (empty($username) || empty($password)) {
+            return false;
+        }
+        if (! $this->connection->testCredentials(
+            $this->connection->fetchDN($this->selectUsername($username)),
+            $password
+        )) {
+            return false;
+        }
+        $user = new User($username);
+        return $user;
+    }
+}
diff --git a/test/php/library/Icinga/Authentication/LdapUserBackendTest.php b/test/php/library/Icinga/Authentication/LdapUserBackendTest.php
index bc37d8c76..4a797bedc 100644
--- a/test/php/library/Icinga/Authentication/LdapUserBackendTest.php
+++ b/test/php/library/Icinga/Authentication/LdapUserBackendTest.php
@@ -4,11 +4,95 @@ namespace Tests\Icinga\Authentication;
 /**
 *
 * Test class for Ldapuserbackend 
-* Created Fri, 07 Jun 2013 10:38:16 +0000 
+* Created Mon, 10 Jun 2013 07:54:34 +0000 
 *
 **/
 class LdapuserbackendTest extends \PHPUnit_Framework_TestCase
 {
+    // Change this according to your ldap test server
+    const ADMIN_DN = "cn=admin,dc=icinga,dc=org";
+    const ADMIN_PASS = "admin";
+
+    private $users = array(
+        "cn=John Doe, dc=icinga, dc=org" =>  array(
+            "cn" => "John Doe",
+            "sn" => "Doe",
+            "objectclass" => "inetOrgPerson",
+            "givenName" => "John",
+            "mail" => "john@doe.local"
+        ),
+        "cn=Jane Woe, dc=icinga, dc=org" => array(
+            "cn" => "Jane Woe",
+            "sn" => "Woe",
+            "objectclass" => "inetOrgPerson",
+            "givenName" => "Jane",
+            "mail" => "jane@woe.local"
+        )
+    );
+
+    private function getLDAPConnection()
+    {
+        $this->markTestSkipped("LDAP User Backend is currently not testable, as it would require to Boostrap most of the application (see Protocol\Ldap\Connection)");
+        return;
+        $ldapConn = ldap_connect("localhost", 389);
+        if (!$ldapConn) {
+            $this->markTestSkipped("Could not connect to test-ldap server, skipping test");
+            return null;
+        }
+        $bind = ldap_bind($ldapConn, self::ADMIN_DN, self::ADMIN_PASS);
+        if (!$bind) {
+            $this->markTestSkipped("Could not bind to test-ldap server, skipping test");
+            return null;
+        }
+        return $ldapConn;
+    }
+    
+    private function clearTestData($connection)
+    {
+        foreach ($this->users as $ou => $info) {
+            @ldap_delete($connection, $ou);
+        }
+    }
+
+    private function insertTestdata($connection)
+    {
+        foreach ($this->users as $ou => $info) {
+            if (ldap_add($connection, $ou, $info) === false) {
+                $this->markTestSkipped("Couldn't set up test-ldap users, skipping test");
+            }
+        }
+
+    }
+
+    protected function setUp()
+    {
+        $conn = $this->getLDAPConnection();
+        if ($conn == null) {
+            return;
+        }
+        $this->clearTestData($conn);
+        $this->insertTestData($conn);
+        $result = ldap_list($conn, "dc=icinga, dc=org", "(cn=John Doe)");
+        if (ldap_count_entries($conn, $result) < 1) {
+            $this->markTestSkipped("Couldn't set up test users, skipping test");
+        }
+        $result = ldap_list($conn, "dc=icinga, dc=org", "(cn=Jane Woe)");
+        if (ldap_count_entries($conn, $result) < 1) {
+            $this->markTestSkipped("Couldn't set up test users, skipping test");
+        }
+        ldap_close($conn);
+    }
+
+    public function tearDown()
+    {
+        $conn = $this->getLDAPConnection();
+        if ($conn == null) {
+            return;
+        }
+
+        $this->clearTestData($conn);
+        ldap_close($conn);
+    }
 
     /**
     * Test for LdapUserBackend::HasUsername() 
@@ -16,7 +100,6 @@ class LdapuserbackendTest extends \PHPUnit_Framework_TestCase
     **/
     public function testHasUsername()
     {
-        $this->markTestIncomplete('testHasUsername is not implemented yet');
     }
 
     /**
@@ -27,5 +110,4 @@ class LdapuserbackendTest extends \PHPUnit_Framework_TestCase
     {
         $this->markTestIncomplete('testAuthenticate is not implemented yet');
     }
-
 }