title: Visible signature created using iText 7 not shown in chrome
body: <p>I am using iText 7 to sign pdf documents. 
  This works without problems, and the signature is shown as valid. </p>
  
  <p>In addition to the digital signature, i want to show a visual representation on the pdf. This is described in the digital signature book chapter 2.4 Creating different signature appearances. </p>
  
  <p>The produced pdf shows this appearance if i open it using adobe reader. 
  <a href="https://i.stack.imgur.com/GU7FS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GU7FS.png" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/6rWWZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6rWWZ.png" alt="enter image description here"></a></p>
  
  <p>The first image is a pdf created using word and the <strong>save as pdf</strong> functionality. 
  The second image is a demo pdf i just downloaded random. </p>
  
  <p>If i open the first pdf in chrome, the signature appearance text is not shown, but if i open the pdf which was initially created using word, the signature apperance is missing. 
  <a href="https://i.stack.imgur.com/og59R.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/og59R.png" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/g1Xz5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/g1Xz5.png" alt="enter image description here"></a></p>
  
  <p>Any ideas on whats wrong with the pdf which doesn't show the signature appearance in chrome?</p>
  
  <h1>edit: Links to the documents</h1>
  
  <ul>
  <li>Pdf which shows signature in chrome
  
  <ul>
  <li><a href="https://1drv.ms/b/s!AkROTDoCWFJnkd5VOFjUHZfpQXzJWQ?e=MeyZje" rel="nofollow noreferrer">https://1drv.ms/b/s!AkROTDoCWFJnkd5VOFjUHZfpQXzJWQ?e=MeyZje</a></li>
  </ul></li>
  <li>Pdf which doesn't show signature in chrome
  
  <ul>
  <li><a href="https://1drv.ms/b/s!AkROTDoCWFJnkd5W5P3MCbb8fwLASA?e=zsmks0" rel="nofollow noreferrer">https://1drv.ms/b/s!AkROTDoCWFJnkd5W5P3MCbb8fwLASA?e=zsmks0</a></li>
  </ul></li>
  </ul>
  
  <h1>edit 2: Code sample</h1>
  
  <p>The following code sample will sign a pdf document using a local certificate and place some text into the SignatureAppearance which is not shown in chrome. </p>
  
  <pre><code>using iText.Kernel.Geom;
  using iText.Kernel.Pdf;
  using iText.Signatures;
  using System.IO;
  using System.Security.Cryptography.X509Certificates;
  
  namespace PdfSigning.Lib.Helpers
  {
      public class SignPdfTest
      {
          public static byte[] SingPdfUsingCertificate(X509Certificate2 cert2, byte[] pdfToSign)
          {
              var apk = Org.BouncyCastle.Security.DotNetUtilities.GetKeyPair(cert2.PrivateKey).Private;
  
              IExternalSignature pks = new PrivateKeySignature(apk, DigestAlgorithms.SHA512);
  
              var cp = new Org.BouncyCastle.X509.X509CertificateParser();
              var chain = new[] { cp.ReadCertificate(cert2.RawData) };
  
              using (PdfReader reader = new PdfReader(new MemoryStream(pdfToSign)))
              {
                  using (MemoryStream fout = new MemoryStream())
                  {
                      StampingProperties sp = new StampingProperties();
                      sp.UseAppendMode();
  
                      PdfSigner signer = new PdfSigner(reader, fout, sp);
                      PdfSignatureAppearance appearance = signer.GetSignatureAppearance();
  
                      appearance.SetPageNumber(1);
                      appearance.SetLayer2Text("Hello world");
                      appearance.SetLayer2FontSize(8);
  
                      Rectangle pr = new Rectangle(10, 10, 200, 100);
                      appearance.SetPageRect(pr);
  
                      appearance.SetRenderingMode(PdfSignatureAppearance.RenderingMode.DESCRIPTION);
                      appearance.SetPageRect(pr);
  
                      signer.SignDetached(pks, chain, null, null, null, 0, PdfSigner.CryptoStandard.CMS);
                      return fout.ToArray();
                  }
              }
          }
      }
  }
  
  
  
      private static void SignDocumentUsingCertificateConfiguration()
      {
          try
          {
              var certificateSignatureConfiguration = new CertificateSignatureConfiguration();
              var cert2 = new X509Certificate2(@"C:\temp\MyCertificate.pfx", "mypassword", X509KeyStorageFlags.Exportable);
              CertificatePdfSigner certPdfSigner = new CertificatePdfSigner(certificateSignatureConfiguration);
  
              byte[] signedPdf = PdfSigning.Lib.Helpers.SignPdfTest.SingPdfUsingCertificate(cert2, File.ReadAllBytes(@"C:\temp\WordSaveAsPdf.pdf"));
  
              File.WriteAllBytes(@"C:\temp\WordSaveAsPdf_Signed.pdf", signedPdf);
              Console.WriteLine("Done");
          }
          catch (Exception ex)
          {
              Console.WriteLine(ex.Message);
          }
      }
  </code></pre>