security: Enable exporting/importing ECDSA key

Change-Id: I58f722337f26cad4eb6a3c83d883814efc4ed8df
Refs: #1660
diff --git a/src/security/key-chain.cpp b/src/security/key-chain.cpp
index 9c5e000..5118468 100644
--- a/src/security/key-chain.cpp
+++ b/src/security/key-chain.cpp
@@ -274,8 +274,7 @@
 
   if (subjectDescription.empty())
     {
-      // OID 2.5.4.41 is the oid of subject name.
-      CertificateSubjectDescription subjectName("2.5.4.41", keyName.getPrefix(-1).toUri());
+      CertificateSubjectDescription subjectName(oid::ATTRIBUTE_NAME, keyName.getPrefix(-1).toUri());
       certificate->addSubjectDescription(subjectName);
     }
   else
@@ -333,9 +332,10 @@
 
   certificate->setName(certificateName);
   certificate->setNotBefore(time::system_clock::now());
-  certificate->setNotAfter(time::system_clock::now() + time::days(7300)/* ~20 years*/);
+  certificate->setNotAfter(time::system_clock::now() + time::days(7300)); // ~20 years
   certificate->setPublicKeyInfo(*pubKey);
-  certificate->addSubjectDescription(CertificateSubjectDescription("2.5.4.41", keyName.toUri()));
+  certificate->addSubjectDescription(CertificateSubjectDescription(oid::ATTRIBUTE_NAME,
+                                                                   keyName.toUri()));
   certificate->encode();
 
   selfSign(*certificate);