Merge pull request #293 from owncloud/backport_ldap_improved_obj_existance_check

Backport: ldap improved obj existance check

apps/user_ldap/lib/access.php

@@ -38,9 +38,11 @@ abstract class Access {
 	 * @brief reads a given attribute for an LDAP record identified by a DN
 	 * @param $dn the record in question
 	 * @param $attr the attribute that shall be retrieved
-	 * @returns the values in an array on success, false otherwise
+	 *        if empty, just check the record's existence
+	 * @returns an array of values on success or an empty
+	 *          array if $attr is empty, false otherwise
 	 *
-	 * Reads an attribute from an LDAP entry
+	 * Reads an attribute from an LDAP entry or check if entry exists
 	 */
 	public function readAttribute($dn, $attr) {
 		if(!$this->checkConnection()) {
@@ -55,10 +57,14 @@ abstract class Access {
 		}
 		$rr = @ldap_read($cr, $dn, 'objectClass=*', array($attr));
 		if(!is_resource($rr)) {
-			\OCP\Util::writeLog('user_ldap', 'readAttribute '.$attr.' failed for DN '.$dn, \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('user_ldap', 'readAttribute failed for DN '.$dn, \OCP\Util::DEBUG);
 			//in case an error occurs , e.g. object does not exist
 			return false;
 		}
+		if (empty($attr)) {
+			\OCP\Util::writeLog('user_ldap', 'readAttribute: '.$dn.' found', \OCP\Util::DEBUG);
+			return array();
+		}
 		$er = ldap_first_entry($cr, $rr);
 		//LDAP attributes are not case sensitive
 		$result = \OCP\Util::mb_array_change_key_case(ldap_get_attributes($cr, $er), MB_CASE_LOWER, 'UTF-8');

apps/user_ldap/user_ldap.php

@@ -141,9 +141,8 @@ class USER_LDAP extends lib\Access implements \OCP\UserInterface {
 			return false;
 		}
 
-		//if user really still exists, we will be able to read his objectclass
-		$objcs = $this->readAttribute($dn, 'objectclass');
-		if(!$objcs || empty($objcs)) {
+		//check if user really still exists by reading its entry
+		if(!is_array($this->readAttribute($dn, ''))) {
 			$this->connection->writeToCache('userExists'.$uid, false);
 			return false;
 		}