Implement RSAPrivateKey::Copy()

crypto/rsa_private_key_win.cc

Index: crypto/rsa_private_key_win.cc
diff --git a/crypto/rsa_private_key_win.cc b/crypto/rsa_private_key_win.cc
index f7363422db8b18928e95c8b2bd98690a0bc7f3d4..c07e2239b35aeadc5b33bd231796f01b2545612f 100644
--- a/crypto/rsa_private_key_win.cc
+++ b/crypto/rsa_private_key_win.cc
@@ -134,6 +134,14 @@ bool RSAPrivateKey::InitProvider() {
                                       PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
 }
 
+RSAPrivateKey* RSAPrivateKey::Copy() const {
+  scoped_ptr<RSAPrivateKey> copy(new RSAPrivateKey());
+  copy->provider_ = CryptContextAddRef(provider_, NULL, 0);
+  if (!CryptDuplicateKey(key_.get(), NULL, 0, copy->key_.receive()))
+    return NULL;
+  return copy.release();
+}
+
 bool RSAPrivateKey::ExportPrivateKey(std::vector<uint8>* output) {
   // Export the key
   DWORD blob_length = 0;