--- b/Core/Frameworks/Baikal/Core/AbstractExternalAuth.php
+++ b/Core/Frameworks/Baikal/Core/AbstractExternalAuth.php
@@ -0,0 +1,130 @@
+<?php
+
+namespace Baikal\Core;
+
+/**
+ * This is an abstract authentication, that allows to create external
+ * authentication backends. User are automatic created, when the does not exists
+ * in baikal (can disabled).
+ *
+ * @author Sascha Kuehndel (InuSasha) <dev@inusasha.de>
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+abstract class AbstractExternalAuth extends \Sabre\DAV\Auth\Backend\AbstractBasic {
+
+    /**
+     * enable autocreation of user
+     *
+     * @var PDO
+     */
+    protected $enableAutoCreation;
+
+    /**
+     * Reference to PDO connection
+     *
+     * @var PDO
+     */
+    private $pdo;
+
+    /**
+     * PDO table name we'll be using
+     *
+     * @var string
+     */
+    private $tableName;
+
+    /**
+     * Creates the backend object.
+     *
+     * If the filename argument is passed in, it will parse out the specified file fist.
+     *
+     * @param PDO $pdo
+     * @param string $realm
+     * @param string $tableName The PDO table name to use
+     */
+    public function __construct(\PDO $pdo, $realm = 'BaikalDAV', $tableName = 'users') {
+
+        $this->pdo = $pdo;
+        $this->tableName = $tableName;
+        $this->enableAutoCreation = true;
+    }
+
+    /**
+     * Validates a username and password
+     *
+     * This method should return true or false depending on if login
+     * succeeded.
+     *
+     * @param string $username
+     * @param string $password
+     * @return bool
+     */
+    public function validateUserPass($username, $password) {
+
+        if (!$this->validateUserPassExternal($username, $password))
+             return false;
+
+        $this->currentUser = $username;
+        if ($this->enableAutoCreation)
+             $this->autoUserCreation($username);
+
+        return true;
+    }
+
+    /**
+     * Validates a username and password agains external backend
+     *
+     * This method should return true or false depending on if login
+     * succeeded.
+     *
+     * @param string $username
+     * @param string $password
+     * @return bool
+     */
+    public abstract function validateUserPassExternal($username, $password);
+
+    /**
+     * return the displayname and email from the external Backend
+     *
+     * @param string $username
+     * @return array ('displayname' => string, 'email' => string)
+     */
+    public function getAccountValues($username) {
+
+        return array();
+    }
+
+    /**
+     * create an internal user, when user not exists
+     *
+     * @param string $username
+     */
+    private function autoUserCreation($username) {
+        
+        /* search user in DB and do nothing, when user exists */
+        $stmt = $this->pdo->prepare('SELECT username FROM '.$this->tableName.' WHERE username = ?');
+        $stmt->execute(array($username));
+        $result = $stmt->fetchAll();
+        if (count($result) != 0)
+             return;
+
+        /* get account values from backend */
+        $values = $this->getAccountValues($username);
+        if (!isset($values['displayname']) OR strlen($values['displayname']) === 0)
+             $values['displayname'] = $username;
+        if (!isset($values['email']) OR strlen($values['email']) === 0) {
+             if(filter_var($username, FILTER_VALIDATE_EMAIL))
+                 $values['email'] = $username;
+             else
+                 $values['email'] = 'unset-mail';
+        }
+
+        /* create user */
+        $user = new \Baikal\Model\User();
+        $user->set('username', $username);
+        $user->set('displayname', $values['displayname']);
+        $user->set('email', $values['email']);
+        $user->persist();
+    }
+
+}
--- b/Core/Frameworks/Baikal/Core/LDAPUserBindAuth.php
+++ b/Core/Frameworks/Baikal/Core/LDAPUserBindAuth.php
@@ -0,0 +1,75 @@
+<?php
+
+namespace Baikal\Core;
+
+/**
+ * This is an authentication backend that uses a ldap backend to authenticate user.
+ *
+ * @author Sascha Kuehndel (InuSasha) <dev@inusasha.de>
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class LDAPUserBindAuth extends AbstractExternalAuth {
+
+    /**
+     * AccountValues for getAccountValues
+     * 
+     * @var array ('displayname' => string, 'email' => string)
+     */
+    private $accountValues;
+
+    /**
+     * Validates a username and password over ldap
+     *
+     * @param string $username
+     * @param string $password
+     * @return bool
+     */
+    public function validateUserPassExternal($username, $password) {
+
+        /* create ldap connection */
+        $conn = ldap_connect(BAIKAL_DAV_LDAP_URI);
+        if (!$conn)
+            return false;
+        if (!ldap_set_option($conn, LDAP_OPT_PROTOCOL_VERSION, 3))
+            return false;
+
+        /* bind with user 
+         * error_handler have to change, because a failed bind raises an error
+         * this raise a secuity issue because in the stack trace is the password of user readable
+         */
+        $arr = explode('@', $username, 2);
+        $dn = str_replace('%n', $username, BAIKAL_DAV_LDAP_DN_TEMPLATE);
+        $dn = str_replace('%u', $arr[0], $dn);
+        if(isset($arr[1])) $dn = str_replace('%d', $arr[1], $dn);         
+
+        set_error_handler("\Baikal\Core\LDAPUserBindAuth::exception_error_handler");
+        $bind = ldap_bind($conn, $dn, $password);
+        restore_error_handler();
+        if (!$bind) {
+             ldap_close($conn);
+             return false;
+        }
+
+        /* read displayname and email from user */
+        $this->accountValues = array();
+        $sr = ldap_read($conn, $dn, '(objectclass=*)', array(BAIKAL_DAV_LDAP_DISPLAYNAME_ATTR, BAIKAL_DAV_LDAP_EMAIL_ATTR));
+        $entry = ldap_get_entries($conn, $sr);
+        if (isset($entry[0][BAIKAL_DAV_LDAP_DISPLAYNAME_ATTR][0]))
+             $this->accountValues['displayname'] = $entry[0][BAIKAL_DAV_LDAP_DISPLAYNAME_ATTR][0];
+        if (isset($entry[0][BAIKAL_DAV_LDAP_EMAIL_ATTR][0]))
+             $this->accountValues['email'] = $entry[0][BAIKAL_DAV_LDAP_EMAIL_ATTR][0];
+
+        /* close */
+        ldap_close($conn);
+        return true;
+    }
+
+    public function getAccountValues($username) {
+
+        return $this->accountValues;
+    }
+
+    # WorkAround error_handler in failed bind of LDAP
+    public static function exception_error_handler($errno, $errstr, $errfile, $errline) {
+    }
+}
diff --git a/Core/Frameworks/Baikal/Core/Server.php b/Core/Frameworks/Baikal/Core/Server.php
index 8026854..8d306fe 100644
--- a/Core/Frameworks/Baikal/Core/Server.php
+++ b/Core/Frameworks/Baikal/Core/Server.php
@@ -133,6 +133,8 @@ class Server {
 
         if ($this->authType === 'Basic') {
             $authBackend = new \Baikal\Core\PDOBasicAuth($this->pdo, $this->authRealm);
+	} elseif ($this->authType === 'LDAP-UserBind') {
+            $authBackend = new \Baikal\Core\LDAPUserBindAuth($this->pdo, $this->authRealm);
         } else {
             $authBackend = new \Sabre\DAV\Auth\Backend\PDO($this->pdo);
             $authBackend->setRealm($this->authRealm);
diff --git a/Core/Frameworks/Baikal/Model/Config/Standard.php b/Core/Frameworks/Baikal/Model/Config/Standard.php
index 6107377..39f90bd 100644
--- a/Core/Frameworks/Baikal/Model/Config/Standard.php
+++ b/Core/Frameworks/Baikal/Model/Config/Standard.php
@@ -46,6 +46,22 @@ class Standard extends \Baikal\Model\Config {
             "type"    => "string",
             "comment" => "HTTP authentication type for WebDAV; default Digest"
         ],
+        "BAIKAL_DAV_LDAP_URI" => [
+            "type" => "string",
+            "comment" => "URI to LDAP Server (for ldap-userbind auth); default ldapi:///"
+        ],
+        "BAIKAL_DAV_LDAP_DN_TEMPLATE" => [
+            "type" => "string",
+            "comment" => "User DN for bind; with replacments %n => username, %u => user part, %d => domain part of username"
+        ],
+        "BAIKAL_DAV_LDAP_DISPLAYNAME_ATTR" => [
+            "type" => "string",
+            "comment" => "LDAP-attribute for displayname; default cn"
+        ],
+        "BAIKAL_DAV_LDAP_EMAIL_ATTR" => [
+            "type" => "string",
+            "comment" => "LDAP-attribute for email; default mail"
+        ],
         "BAIKAL_ADMIN_PASSWORDHASH" => [
             "type"    => "string",
             "comment" => "Baïkal Web admin password hash; Set via Baïkal Web Admin",
@@ -58,6 +74,10 @@ class Standard extends \Baikal\Model\Config {
         "BAIKAL_CARD_ENABLED"       => true,
         "BAIKAL_CAL_ENABLED"        => true,
         "BAIKAL_DAV_AUTH_TYPE"      => "Digest",
+        "BAIKAL_DAV_LDAP_URI"              => "ldapi:///",
+        "BAIKAL_DAV_LDAP_DN_TEMPLATE"      => "uid=%n,dc=example,dc=com",
+        "BAIKAL_DAV_LDAP_DISPLAYNAME_ATTR" => "cn",
+        "BAIKAL_DAV_LDAP_EMAIL_ATTR"       => "mail",
         "BAIKAL_ADMIN_PASSWORDHASH" => ""
     ];
 
@@ -85,7 +105,31 @@ class Standard extends \Baikal\Model\Config {
         $oMorpho->add(new \Formal\Element\Listbox([
             "prop"    => "BAIKAL_DAV_AUTH_TYPE",
             "label"   => "WebDAV authentication type",
-            "options" => [ "Digest", "Basic" ]
+            "options" => [ "Digest", "Basic", "LDAP-UserBind" ]
+        ]));
+
+        $oMorpho->add(new \Formal\Element\Text([
+            "prop"  => "BAIKAL_DAV_LDAP_URI",
+            "label" => "LDAP URI"
+        ]));
+
+        $oMorpho->add(new \Formal\Element\Text([
+            "prop"    => "BAIKAL_DAV_LDAP_DN_TEMPLATE",
+            "label"   => "LDAP DN template",
+            "popover" => [
+                "title"   => "posible placeholder",
+                "content" => "<strong>%n</strong> - username<br /><strong>%u</strong> - user part of username , when it is an email address)<br /><strong>%d</strong> - domain part",
+            ]
+        ]));
+
+        $oMorpho->add(new \Formal\Element\Text([
+            "prop"  => "BAIKAL_DAV_LDAP_DISPLAYNAME_ATTR",
+            "label" => "LDAP attribute for DisplayName"
+        ]));
+
+        $oMorpho->add(new \Formal\Element\Text([
+            "prop"  => "BAIKAL_DAV_LDAP_EMAIL_ATTR",
+            "label" => "LDAP attribute for eMail"
         ]));
 
         $oMorpho->add(new \Formal\Element\Password([
@@ -180,6 +224,21 @@ define("BAIKAL_CAL_ENABLED", TRUE);
 # WebDAV authentication type; default Digest
 define("BAIKAL_DAV_AUTH_TYPE", "Digest");
 
+# Auth Backend LDAP-UserBind; LDAP URI
+define("BAIKAL_DAV_LDAP_URI", 'ldapi:///');
+
+# Auth Backend LDAP-UserBind; Template for userbind
+# %n => username
+# %u => user part of username when it is an email
+# %u => domain part of username when it is an email
+define("BAIKAL_DAV_LDAP_DN_TEMPLATE", 'cn=%u,dc=%d,ou=domains,o=server');
+
+# Auth Backend LDAP-UserBind; attribute for displayname
+define("BAIKAL_DAV_LDAP_DISPLAYNAME_ATTR", 'cn');
+
+# Auth Backend LDAP-UserBind; attribute for email
+define("BAIKAL_DAV_LDAP_EMAIL_ATTR", 'mail');
+
 # Baïkal Web admin password hash; Set via Baïkal Web Admin
 define("BAIKAL_ADMIN_PASSWORDHASH", "");
 CODE;