src: Another round of source updates: moving all headers close to implementation files

Change-Id: I3d47076504950e67746174623c75383948e9d93d
diff --git a/src/util/crypto.hpp b/src/util/crypto.hpp
new file mode 100644
index 0000000..5fb5d35
--- /dev/null
+++ b/src/util/crypto.hpp
@@ -0,0 +1,27 @@
+/**
+ * Copyright (C) 2013 Regents of the University of California.
+ * @author: Jeff Thompson <jefft0@remap.ucla.edu>
+ * See COPYING for copyright and distribution information.
+ */
+
+#ifndef NDN_UTIL_CRYPTO_HPP
+#define NDN_UTIL_CRYPTO_HPP
+
+#include "common.hpp"
+
+#include <openssl/ssl.h>
+#include <openssl/rsa.h>
+
+namespace ndn {
+
+/**
+ * Compute the sha-256 digest of data.
+ * @param data Pointer to the input byte array.
+ * @param dataLength The length of data.
+ * @param digest A pointer to a buffer of size SHA256_DIGEST_LENGTH to receive the data.
+ */
+void ndn_digestSha256(const uint8_t *data, size_t dataLength, uint8_t *digest);
+
+} // namespace ndn
+
+#endif // NDN_UTIL_CRYPTO_HPP