--- /usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py	2019-04-05 05:13:18.000000000 +0200
+++ /usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py.updated	2019-09-27 09:19:55.126000000 +0200
@@ -1493,8 +1493,12 @@

     @driver_hints.truncated
     def _ldap_get_all(self, hints, ldap_filter=None):
+        try:
+            _ldap_filter = ldap_filter.decode('utf-8')
+        except:
+            _ldap_filter = ldap_filter
         query = u'(&%s(objectClass=%s)(%s=*))' % (
-            ldap_filter or self.ldap_filter or '',
+            _ldap_filter or self.ldap_filter or '',
             self.object_class,
             self.id_attr)
         sizelimit = 0