title: Digital Signing using certificate and key from USB token
body: <p>I want to sign a file using the user's key and certificate from a USB token (dongle).</p>
  
  <p>I have been searching on this for sometime, on stackoverflow and other sites, but didn't get anything useful apart from some good capabilities in .NET framework (which I am not using).</p>
  
  <p>It seems that since the key is not exposed, the encryption is done by the hardware itself. Does that mean that each hardware manufacturer provides his own APIs and that there is no generic method to address this problem?</p>
  
  <p>Also, I read that once the token is plugged into the computer, its certificate is loaded into the system store. Is it possible to use the certificate from the store? How can such a certificate be identified and accessed among others in the store? and what about the private key?</p>
  
  <p>I have used OpenSSL for digital signing when the certificate can be extracted from a .p12 or .pfx file.</p>
  
  <p>Correct me if I am wrong somewhere, I am new to this topic.</p>