security: Change SHA256_DIGEST_LENGTH to SHA256_DIGEST_SIZE;

Change-Id: Ib490cfec5e9331575567b346810d1bc56bc97ea1
diff --git a/src/util/crypto.cpp b/src/util/crypto.cpp
index b0767fa..3aa114a 100644
--- a/src/util/crypto.cpp
+++ b/src/util/crypto.cpp
@@ -20,7 +20,7 @@
       
       CryptoPP::SHA256 hash;
       OBufferStream os;
-      StringSource(data, dataLength, true, new HashFilter(hash, new ArraySink(digest, crypto::SHA256_DIGEST_LENGTH)));
+      StringSource(data, dataLength, true, new HashFilter(hash, new ArraySink(digest, crypto::SHA256_DIGEST_SIZE)));
     }
   catch(CryptoPP::Exception& e)
     {