title: Signing a Visual Studio app with LetsEncrypt.org SSL certificate
body: <p>I'm quite new to digital signatures and I'm trying to make my .NET application appear as secure when people run it on different computers. I have generated myself a <a href="https://letsencrypt.org" rel="noreferrer">Let's Encrypt</a> certificate and it works as expected on my web page. Following various resources I <a href="https://stackoverflow.com/questions/6307886/how-to-create-pfx-file-from-cer-certificate-and-private-key">converted the certificate to PFX</a> and tried to use it for digital signing, but then VS yells that "The selected certificate file is not valid for code signing". When I ran SignTool on my EXE file, I got an error "No certificates were found that met all the given criteria" and debugging showed that my cert didn't pass the EKU filter.</p>
  
  <p>Is what I'm trying to achieve even possible? And if so, what am I doing wrong?</p>