title: How to sign PDF with a x.509 signature/certificate
body: <p><strong><em>tl;dr:</em> I'm looking for a CLI tool that can be fed with a x.509 file and an input PDF and out comes a signed PDF. Best scenario for NodeJS</strong></p>
  
  <p>Hi there. I'm getting a little bit frustrated. I'm looking for a tool which can sign PDF files using the command line. I do use an online service called handy-signatur.at (A service from www.a-trust.at) that generates a x.509 certificate.</p>
  
  <p>I found a <a href="http://wiki.cacert.org/PdfSigning" rel="nofollow noreferrer">page</a> that mentions several tools but it seems that all of them are out of date.</p>
  
  <p>I tried PortableSigner in particular, but that needs Java 6 and I couldn't get it to work on Ubuntu (Server and Desktop edition) 17.04.</p>
  
  <p><strong>/edit:</strong> I can't get PortableSigner to work because Java 6 and 7 is no longer available and probably not even safe to use.</p>
  
  <p>Is there any commandline tool out there to sign PDFs?</p>
  
  <p>Thank you guys so much!</p>