diff --git a/common/rfb/WinPasswdValidator.cxx b/common/rfb/WinPasswdValidator.cxx
new file mode 100644
index 0000000..7f8fbf2
--- /dev/null
+++ b/common/rfb/WinPasswdValidator.cxx
@@ -0,0 +1,51 @@
+/* Copyright (C) 2005-2006 Martin Koegler
+ * Copyright (C) 2006 OCCAM Financial Technology
+ * Copyright (C) 2010 TigerVNC Team
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#include <rfb/WinPasswdValidator.h>
+#include <windows.h>
+#include <tchar.h>
+
+using namespace rfb;
+
+// This method will only work for Windows NT, 2000, and XP (and possibly Vista)
+bool WinPasswdValidator::validateInternal(rfb::SConnection* sc,
+					  const char* username,
+					  const char* password)
+{
+	TCHAR* user = (TCHAR*) strDup(username);
+	TCHAR* pass = (TCHAR*) strDup(password);
+	TCHAR* domain = (TCHAR*) strDup(".");
+	HANDLE handle;
+
+	BOOL ret = LogonUser(user, domain, pass, LOGON32_LOGON_NETWORK,
+			     LOGON32_PROVIDER_DEFAULT, &handle);
+	delete [] user;
+	delete [] pass;
+	delete [] domain;
+
+	if (ret != 0) {
+		CloseHandle(handle);
+		return true;
+	}
+
+	int err = GetLastError();
+
+	return false;
+}