Implement authentication with LDAP

Enable an additional lookup against an LDAP directory
during login and user creation to ensure that only
specific users can login and register on the EteBase
server instance.

django_etebase/app_settings.py

@@ -78,6 +78,34 @@ class AppSettings:
     @cached_property
     def CHALLENGE_VALID_SECONDS(self):  # pylint: disable=invalid-name
         return self._setting("CHALLENGE_VALID_SECONDS", 60)
+    
+    @cached_property
+    def USE_LDAP(self): # pylint: disable=invalid-name
+        return self._setting("USE_LDAP", False)
+
+    @cached_property
+    def LDAP_FILTER(self): # pylint: disable=invalid-name
+        return self._setting("LDAP_FILTER", "")
+
+    @cached_property
+    def LDAP_SEARCH_BASE(self): # pylint: disable=invalid-name
+        return self._setting("LDAP_SEARCH_BASE", "")
+
+    @cached_property
+    def LDAP_SERVER(self): # pylint: disable=invalid-name
+        return self._setting("LDAP_SERVER", "")
+
+    @cached_property
+    def LDAP_BIND_DN(self): # pylint: disable=invalid-name
+        return self._setting("LDAP_BIND_DN", "")
+
+    @cached_property
+    def LDAP_BIND_PASSWORD(self): # pylint: disable=invalid-name
+        return self._setting("LDAP_BIND_PW", "")
+
+    @cached_property
+    def LDAP_SEARCH_BASE(self): # pylint: disable=invalid-name
+        return self._setting("LDAP_SEARCH_BASE", "")
 
 
 app_settings = AppSettings('ETEBASE_')