Move validation-request.hpp to public API.  Moved static verifySha256WithRsaSignature to new Sha256WithRsaHandler::verify.
diff --git a/src/security/signature/sha256-with-rsa-handler.cpp b/src/security/signature/sha256-with-rsa-handler.cpp
new file mode 100644
index 0000000..905fc3e
--- /dev/null
+++ b/src/security/signature/sha256-with-rsa-handler.cpp
@@ -0,0 +1,52 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/**
+ * Copyright (C) 2013 Regents of the University of California.
+ * @author: Yingdi Yu <yingdi@cs.ucla.edu>
+ * See COPYING for copyright and distribution information.
+ */
+
+#include "../../c/util/crypto.h"
+#include <ndn-cpp/sha256-with-rsa-signature.hpp>
+#include <ndn-cpp/security/security-exception.hpp>
+#include <ndn-cpp/security/signature/sha256-with-rsa-handler.hpp>
+
+using namespace std;
+using namespace ndn::ptr_lib;
+
+namespace ndn {
+
+bool
+Sha256WithRsaHandler::verify(const Data& data, const PublicKey& publicKey)
+{
+  const Sha256WithRsaSignature *signature = dynamic_cast<const Sha256WithRsaSignature*>(data.getSignature());
+  if (!signature)
+    throw SecurityException("signature is not Sha256WithRsaSignature.");
+  
+  // Set the data packet's default wire encoding if it is not already there.
+  if (signature->getDigestAlgorithm().size() != 0)
+    // TODO: Allow a non-default digest algorithm.
+    throw UnrecognizedDigestAlgorithmException("Cannot verify a data packet with a non-default digest algorithm.");
+  if (!data.getDefaultWireEncoding())
+    data.wireEncode();
+  
+  // Set signedPortionDigest to the digest of the signed portion of the wire encoding.
+  uint8_t signedPortionDigest[SHA256_DIGEST_LENGTH];
+  ndn_digestSha256(data.getDefaultWireEncoding().signedBuf(), data.getDefaultWireEncoding().signedSize(), signedPortionDigest);
+  
+  // Verify the signedPortionDigest.
+  // Use a temporary pointer since d2i updates it.
+  const uint8_t *derPointer = publicKey.getKeyDer().buf();
+  RSA *rsaPublicKey = d2i_RSA_PUBKEY(NULL, &derPointer, publicKey.getKeyDer().size());
+  if (!rsaPublicKey)
+    throw UnrecognizedKeyFormatException("Error decoding public key in d2i_RSAPublicKey");
+  int success = RSA_verify
+    (NID_sha256, signedPortionDigest, sizeof(signedPortionDigest), (uint8_t *)signature->getSignature().buf(),
+     signature->getSignature().size(), rsaPublicKey);
+  // Free the public key before checking for success.
+  RSA_free(rsaPublicKey);
+  
+  // RSA_verify returns 1 for a valid signature.
+  return (success == 1);
+}
+
+}