ccnx: Rename Key to Cert; fix bug with the usage of Hash

Change-Id: Ic7656e6d8d46729d663ccfa5412e78443aff76bc
diff --git a/src/hash-helper.h b/src/hash-helper.h
index 64a625e..9050573 100644
--- a/src/hash-helper.h
+++ b/src/hash-helper.h
@@ -27,6 +27,7 @@
 #include <boost/shared_ptr.hpp>
 #include <boost/exception/all.hpp>
 #include <boost/filesystem.hpp>
+#include "ccnx-common.h"
 
 // Other options: VP_md2, EVP_md5, EVP_sha, EVP_sha1, EVP_sha256, EVP_dss, EVP_dss1, EVP_mdc2, EVP_ripemd160
 #define HASH_FUNCTION EVP_sha256
@@ -72,6 +73,9 @@
   static HashPtr
   FromFileContent (const boost::filesystem::path &fileName);
 
+  static HashPtr
+  FromBytes (const Ccnx::Bytes &bytes);
+
   ~Hash ()
   {
     if (m_length != 0)