title: checking if pdf is password protected using itextsharp
body: <p>I want to check if a pdf file is password protected or not to view. That is i want to know if the pdf file has user password or not.</p>
  
  <p>I found some help in some forum about it to use <code>isencrypted</code> function but it does not give correct answer.</p>
  
  <p>Is it possible to check if a pdf is password protected?</p>