diff --git a/buffet/privet/openssl_utils.h b/buffet/privet/openssl_utils.h
new file mode 100644
index 0000000..587b60c
--- /dev/null
+++ b/buffet/privet/openssl_utils.h
@@ -0,0 +1,22 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BUFFET_PRIVET_OPENSSL_UTILS_H_
+#define BUFFET_PRIVET_OPENSSL_UTILS_H_
+
+#include <string>
+#include <vector>
+
+#include <chromeos/secure_blob.h>
+
+namespace privetd {
+
+const size_t kSha256OutputSize = 32;
+
+chromeos::Blob HmacSha256(const chromeos::SecureBlob& key,
+                          const chromeos::Blob& data);
+
+}  // namespace privetd
+
+#endif  // BUFFET_PRIVET_OPENSSL_UTILS_H_