security: Add IdentityCertificate copy constructor.
diff --git a/include/ndn-cpp/security/certificate/identity-certificate.hpp b/include/ndn-cpp/security/certificate/identity-certificate.hpp
index f2b585f..4d3a9db 100644
--- a/include/ndn-cpp/security/certificate/identity-certificate.hpp
+++ b/include/ndn-cpp/security/certificate/identity-certificate.hpp
@@ -32,6 +32,11 @@
   IdentityCertificate(const Data& data);
   
   /**
+   * The copy constructor. 
+   */
+  IdentityCertificate(const IdentityCertificate& identityCertificate);
+  
+  /**
    * The virtual destructor.
    */
   virtual 
diff --git a/src/security/certificate/identity-certificate.cpp b/src/security/certificate/identity-certificate.cpp
index 95f6c1b..7e4bca7 100644
--- a/src/security/certificate/identity-certificate.cpp
+++ b/src/security/certificate/identity-certificate.cpp
@@ -22,6 +22,12 @@
   setPublicKeyName();
 }
 
+IdentityCertificate::IdentityCertificate(const IdentityCertificate& identityCertificate)
+  : Certificate(identityCertificate)
+  , publicKeyName_(identityCertificate.publicKeyName_)
+{
+}
+
 IdentityCertificate::~IdentityCertificate()
 {
 }