title: PDF electronic signature ByteRange
body: <p>I'm working on some PDF files and I'm not finding a clear explanation for the questions posted here. On a digitally signed PDF file we have the below temporary signature:</p>
  
  <pre><code>&lt;&lt; /Type /Sig /Filter /Adobe.PPKLite /SubFilter /adbe.pkcs7.detached/ByteRange[O1 L1 O2 L2]                  /Contents&lt;0000....0000&gt;
  </code></pre>
  
  <p>O1 = offset 1 (zero)</p>
  
  <p>L1 = Length 1 (Content length before signature)</p>
  
  <p>O2 = offset 2 (L1 + signature length)</p>
  
  <p>L2 = Length 2 (Content length after signature)</p>
  
  <p>I have these questions:</p>
  
  <p>1 - The content to be "hashed" should include "&lt;" and ">" (In the begin and the end of signature placeholder 0000....0000)?</p>
  
  <p>2 - The length of signature is 11742? Does this includes "&lt;" and ">"?</p>
  
  <p>3 - On the <strong>ByteRange</strong> the second parameter is the length from the beginning of file up to "&lt;" (before signature placeholder 0000....0000) or including it? Same as on previous question, the last parameter on <strong>ByteRange</strong> does includes the ">" character (at the end of signature placeholder 0000....0000)?</p>
  
  <p>If someone can redirect me to a technical manual regarding this it will be very helpful.</p>