title: Where can I find "digital signatures for PDF documents" code download URL?
body: <p>Bruno Lowagie has published <a href="http://itextpdf.com/book/digitalsignatures" rel="nofollow">this excellent white paper</a> about digital signatures for PDF documents. </p>
  
  <p>However, I can't find nowhere the corresponding source code with all the examples provided in this book.</p>
  
  <p>Could you publish the URL where I can download this source code ? Thank you.</p>