diff --git a/common/rfb/SSecurityStack.h b/common/rfb/SSecurityStack.h
new file mode 100644
index 0000000..0630dac
--- /dev/null
+++ b/common/rfb/SSecurityStack.h
@@ -0,0 +1,41 @@
+/* Copyright (C) 2005 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.
+ */
+#ifndef __RFB_SSECURITYSTACK_H__
+#define __RFB_SSECURITYSTACK_H__
+
+#include <rfb/SSecurity.h>
+
+namespace rfb {
+
+  class SSecurityStack : public SSecurity {
+  public:
+    SSecurityStack(int Type, SSecurity* s0 = 0, SSecurity* s1 = 0);
+    ~SSecurityStack();
+    virtual bool processMsg(SConnection* cc);
+    virtual int getType() const { return type; };
+    virtual const char* getUserName() const;
+  protected:
+    short state;
+    SSecurity* state0;
+    SSecurity* state1;
+    int type;
+  };
+}
+#endif