[Chromoting] Factor out common code for pin hashing.

remoting/host/verify_config_window_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/host/verify_config_window_win.h"
 
 #include <atlbase.h>
 #include <windows.h>
 
 #include "base/base64.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 #include "remoting/host/elevated_controller_resource.h"
+#include "remoting/host/pin_hash.h"
 #include "remoting/protocol/authentication_method.h"
 
 namespace remoting {
 
 VerifyConfigWindowWin::VerifyConfigWindowWin(const std::string& email,
     const std::string& host_id, const std::string& host_secret_hash)
   : hwnd_(NULL),
     email_(email),
     host_id_(host_id),
     host_secret_hash_(host_secret_hash) {
@@ skipping 85 matching lines @@
   }
 }
 
 bool VerifyConfigWindowWin::VerifyHostSecretHash() {
   const int kMaxPinLength = 256;
   // TODO(simonmorris): Use ATL's string class, if it's more convenient.
   scoped_array<WCHAR> pinWSTR(new WCHAR[kMaxPinLength]);
   HWND hwndPin = GetDlgItem(hwnd_, IDC_PIN);
   CHECK(hwndPin);
   GetWindowText(hwndPin, pinWSTR.get(), kMaxPinLength);
-
-  // TODO(simonmorris): This code was copied from host_script_object.cc.
-  // Refactor to use PinIsValid(), from CL 10008092.
   std::string pin(UTF16ToUTF8(pinWSTR.get()));
-  std::string hash = protocol::AuthenticationMethod::ApplyHashFunction(
-      protocol::AuthenticationMethod::HMAC_SHA256, host_id_, pin);
-  std::string hash_base64;
-  bool base64_result = base::Base64Encode(hash, &hash_base64);
-  if (!base64_result) {
-    LOG(FATAL) << "Base64Encode failed";
-    return false;
-  }
-  hash_base64 = "hmac:" + hash_base64;
-
-  return (hash_base64 == host_secret_hash_);
+  return VerifyHostPinHash(host_secret_hash_, host_id_, pin);
 }
 
 }  // namespace remoting