Index: base/password.py
--- base/password.py.orig
+++ base/password.py
@@ -272,7 +272,11 @@ class Password(object):
 
     def __get_password_utils(self):
         if self.__authType == "su":
-            AuthType, AuthCmd = 'su', 'su -c "%s"'
+            # in this context, `-c' refers to the BSD login class
+            if sys.platform.startswith('openbsd'):
+                AuthType, AuthCmd = 'su', 'su root -c "%s"'
+            else:
+                AuthType, AuthCmd = 'su', 'su -c "%s"'
         else:
             AuthType, AuthCmd = 'sudo', 'sudo %s'
 
@@ -285,7 +289,11 @@ class Password(object):
         if self.__authType == "sudo":
             AuthType, AuthCmd = 'sudo', 'sudo %s'
         else:
-            AuthType, AuthCmd = 'su', 'su -c "%s"'
+            # in this context, `-c' refers to the BSD login class
+            if sys.platform.startswith('openbsd'):
+                AuthType, AuthCmd = 'su', 'su root -c "%s"'
+            else:
+                AuthType, AuthCmd  = 'su', 'su -c "%s"'
         '''
         if utils.which('kdesu'):
             AuthType, AuthCmd = 'kdesu', 'kdesu -- %s'