security: Adding supports to signed interest

refs: #1161

Change-Id: I042381b171d44417f296397d872cd639935a89e9
diff --git a/src/security/sec-policy.hpp b/src/security/sec-policy.hpp
index 0d17e41..5158f61 100644
--- a/src/security/sec-policy.hpp
+++ b/src/security/sec-policy.hpp
@@ -41,7 +41,7 @@
    */
   virtual ptr_lib::shared_ptr<ValidationRequest>
   checkVerificationPolicy
-    (const ptr_lib::shared_ptr<Data>& data, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
+    (const ptr_lib::shared_ptr<const Data>& data, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
   {
     onVerifyFailed();
     return ptr_lib::shared_ptr<ValidationRequest>();
@@ -59,7 +59,7 @@
    */
   virtual ptr_lib::shared_ptr<ValidationRequest>
   checkVerificationPolicy
-    (const ptr_lib::shared_ptr<Interest>& interest, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
+    (const ptr_lib::shared_ptr<const Interest>& interest, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
   {
     onVerifyFailed();
     return ptr_lib::shared_ptr<ValidationRequest>();