src: Minor corrections and improvements

Change-Id: If1041d13b7c469e64e3523297438067baf96b1d6
diff --git a/src/security/key-chain.hpp b/src/security/key-chain.hpp
index d4b6580..dcf2079 100644
--- a/src/security/key-chain.hpp
+++ b/src/security/key-chain.hpp
@@ -887,7 +887,7 @@
   Block sigValue = m_tpm->signInTpm(signedName.wireEncode().value(),
                                     signedName.wireEncode().value_size(),
                                     keyName,
-                                    DIGEST_ALGORITHM_SHA256);
+                                    digestAlgorithm);
   sigValue.encode();
   signedName.append(sigValue);
   interest.setName(signedName);