security: Add failureInfo in ValidationFailed callback

Change-Id: I98e49fc88665ad7b7c268bd6a8fdddf6b7071021
diff --git a/src/security/validator.hpp b/src/security/validator.hpp
index 7a75f70..4aae107 100644
--- a/src/security/validator.hpp
+++ b/src/security/validator.hpp
@@ -71,11 +71,15 @@
 
   /// @brief Verify the data using the publicKey against the SHA256-RSA signature.
   static bool
-  verifySignature (const Data& data, const SignatureSha256WithRsa& sig, const PublicKey& publicKey);
+  verifySignature (const Data& data, const SignatureSha256WithRsa& sig, const PublicKey& publicKey)
+  { return verifySignature (data.wireEncode().value(), 
+                            data.wireEncode().value_size() - data.getSignature().getValue().size(), 
+                            sig, publicKey); }
 
   /// @brief Verify the blob using the publicKey against the SHA256-RSA signature.
   static bool
-  verifySignature (const Buffer &blob, const SignatureSha256WithRsa &sig, const PublicKey &publicKey);
+  verifySignature (const Buffer &blob, const SignatureSha256WithRsa &sig, const PublicKey &publicKey)
+  { return verifySignature (blob.buf(), blob.size(), sig, publicKey); }
   
   /// @brief Verify the blob using the publicKey against the SHA256-RSA signature.
   static bool
@@ -121,7 +125,7 @@
                std::vector<shared_ptr<ValidationRequest> > &nextSteps) = 0;
 
 private:
-  typedef function< void () > OnFailure;
+  typedef function< void (const std::string&) > OnFailure;
   
   /// @brief Process the received certificate.
   void