title: how reliable the signed PDF. (c#, Itextsharp )
body: <p>I sign a PDF file with a USB token I received from GlobalSign. However I cannot see any icon by Adobe indicating that the certificate is valid.</p>
  
  <p>The USB token I received from GlobalSign is a trustable (secure/trust) certificate. But I am not sure why I cannot see the trusted/secure certificate icon.</p>
  
  <p>Signed PDF is as shown below:</p>
  
  <p><a href="https://i.stack.imgur.com/k9UfI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/k9UfI.png" alt="enter image description here"></a></p>
  
  <p>I can also see the signing of this icon from Adobe Acrobat DC:</p>
  
  <p><a href="https://i.stack.imgur.com/HHc8X.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HHc8X.png" alt="enter image description here"></a></p>
  
  <hr>
  
  <pre><code>            ICollection&lt;ICrlClient&gt; crlList = new List&lt;ICrlClient&gt; { new               CrlClientOnline(chain) };
              ICrlClient crl = new CrlClientOnline(chain);
              IOcspClient ocsp;
  
              ocsp = new OcspClientBouncyCastle();
              //var sdf0= ocsp.GetEncoded(chain[0] , chain[1], "http://ocsp2.globalsign.com/gsalphag2");
              PdfReader r = new PdfReader(hedefPDFpath + "Emre.pdf");
              FileStream fos = new FileStream(hedefPDFpath + "Emre" + fi.Name, FileMode.Create);
              PdfStamper stp = PdfStamper.CreateSignature(r, fos, '\0', null, true);
              LtvVerification v = stp.LtvVerification;
              AcroFields fields = stp.AcroFields;
              List&lt;String&gt; names = fields.GetSignatureNames();
              String sigName = names[names.Count - 1];
              PdfPKCS7 pkcs7 = fields.VerifySignature(sigName);
              if (pkcs7.IsTsp)
                  v.AddVerification(sigName, ocsp, crl, LtvVerification.CertificateOption.SIGNING_CERTIFICATE, LtvVerification.Level.OCSP_CRL, LtvVerification.CertificateInclusion.YES);
              else foreach (String name in names)
                      v.AddVerification(name, ocsp, crl, LtvVerification.CertificateOption.WHOLE_CHAIN, LtvVerification.Level.OCSP_CRL, LtvVerification.CertificateInclusion.YES);
              PdfSignatureAppearance sap = pdfStamper.SignatureAppearance;
  
              MakeSignature.SignDetached(signatureAppearance, externalSignature, chain, crlList, ocsp, TsaCliente, estimatedSize, CryptoStandard.CMS);
  </code></pre>