--- /dev/null
+//
+// der_set.h
+// utilities
+//
+// Created by Richard Murphy on 1/22/15.
+// Copyright © 2015 Apple Inc. All rights reserved.
+//
+
+#ifndef _utilities_der_set_
+#define _utilities_der_set_
+
+#include <stdio.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <corecrypto/ccder.h>
+
+// If you provide a set in *set, we will add elements to it and return the union.
+const uint8_t* der_decode_set(CFAllocatorRef allocator, CFOptionFlags mutability,
+ CFSetRef* set, CFErrorRef *error,
+ const uint8_t* der, const uint8_t *der_end);
+
+size_t der_sizeof_set(CFSetRef dict, CFErrorRef *error);
+
+uint8_t* der_encode_set(CFSetRef set, CFErrorRef *error,
+ const uint8_t *der, uint8_t *der_end);
+
+
+#endif /* defined(_utilities_der_set_) */