const CFStringRef kSecTransformPreviousErrorKey = CFSTR("PreviousError");
const CFStringRef kSecTransformAbortOriginatorKey = CFSTR("Originating Transform");
const CFStringRef kSecTransformActionCanExecute = CFSTR("CanExecute");
-const CFStringRef kSecCustomTransformWhatIsRequired = CFSTR("WhatIsRequired");
-const CFStringRef kSecCustomTransformAttributesToExternalize = CFSTR("AttributesToExternalize");
const CFStringRef kSecTransformActionStartingExecution = CFSTR("ExecuteStarting");
const CFStringRef kSecTransformActionProcessData = CFSTR("TransformProcessData");
const CFStringRef kSecTransformActionAttributeNotification = CFSTR("GenericAttributeSetNotification");