security: Continue porting security elements to the updated framework

Change-Id: I682156142a8714b2756ca429903a19d2b9064e13
diff --git a/src/security/identity/memory-identity-storage.cpp b/src/security/identity/memory-identity-storage.cpp
index fae1f14..117ca35 100644
--- a/src/security/identity/memory-identity-storage.cpp
+++ b/src/security/identity/memory-identity-storage.cpp
@@ -138,17 +138,13 @@
 Name 
 MemoryIdentityStorage::getDefaultKeyNameForIdentity(const Name& identityName)
 {
-#if 1
-  throw runtime_error("MemoryIdentityStorage::getDefaultKeyNameForIdentity not implemented");
-#endif
+  return defaultKeyName_;
 }
 
 Name 
 MemoryIdentityStorage::getDefaultCertificateNameForKey(const Name& keyName)
 {
-#if 1
-  throw runtime_error("MemoryIdentityStorage::getDefaultCertificateNameForKey not implemented");
-#endif
+  return defaultCert_;
 }
 
 void 
@@ -165,17 +161,13 @@
 void 
 MemoryIdentityStorage::setDefaultKeyNameForIdentity(const Name& keyName, const Name& identityNameCheck)
 {
-#if 1
-  throw runtime_error("MemoryIdentityStorage::setDefaultKeyNameForIdentity not implemented");
-#endif
+  defaultKeyName_ = identityNameCheck;
 }
 
 void 
 MemoryIdentityStorage::setDefaultCertificateNameForKey(const Name& keyName, const Name& certificateName)  
 {
-#if 1
-  throw runtime_error("MemoryIdentityStorage::setDefaultCertificateNameForKey not implemented");
-#endif
+  defaultCert_ = certificateName;
 }