Digitally signed a pdf file with multiple different visible digital signatures

Question

Using Devexpress or anything else can I sign a pdf file with multiple digital signatures of multiple signatories in visible form at different locations in a page?

Please see my sample code. It is working for only one digital signature and not showing the visible form of signature.

[C#]
    #region #export 
    private void Export() {
        XtraReport1 report = new XtraReport1();


        // Create a new X509Certificate2 object.
        X509Certificate2 certificate = new X509Certificate2();


        // Initialize a local certificate storage and define its options.
        X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);
        store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);


        // Initialize a certificate collection and adjust its work.
        X509Certificate2Collection collection = (X509Certificate2Collection)store.Certificates;
        //X509Certificate2Collection fcollection =
        //    (X509Certificate2Collection)collection.Find(X509FindType.FindByTimeValid, DateTime.Now, true);
        //X509Certificate2Collection scollection =
        //    X509Certificate2UI.SelectFromCollection(fcollection, "Test Certificate Select",
        //        "Select a certificate from the following list to get information on that certificate",
        //        X509SelectionFlag.SingleSelection);
        //if(scollection.Count > 0)
        //    certificate = scollection[0];
        certificate = collection[1];


        // Define the remaining PDF signature options.
        report.ExportOptions.Pdf.SignatureOptions.ContactInfo = "contact info";
        report.ExportOptions.Pdf.SignatureOptions.Location = "location";
        report.ExportOptions.Pdf.SignatureOptions.Reason = "reason";


        // Assign the created certificate to the signature options of the PDF export options.
        report.ExportOptions.Pdf.SignatureOptions.Certificate = certificate;


        // Export the report to a PDF file
        // created in the same folder where the application's .exe file is located.
        report.ExportToPdf("test.pdf");
    }
    #endregion #export

Please see this code I'm using in case of C# iText Sharp

    public string DigiSigTest(string src, string dest, X509Certificate2 pk, string reason, string location, string test_path, string WatermarkLocation, string PageNo, string PdfPassword, string SignPos, string[] Custm, string TokenPin, string[] SignImgLoc, string SignImgPath, string Printdocpath, string[] PrintPageNo)
    {
        PdfReader reader1 = (PdfReader)null;
        PdfReader pdfReader = (PdfReader)null;
        PdfStamper pdfStamper1 = (PdfStamper)null;
        PdfStamper pdfStamper2 = (PdfStamper)null;
        PdfReader reader2 = (PdfReader)null;
        MemoryStream memoryStream1 = new MemoryStream();
        MemoryStream memoryStream2 = new MemoryStream();
        try
        {
            string str1 = src;
            pdfReader = new PdfReader(src);
            int num1 = 1;
            int numberOfPages = pdfReader.NumberOfPages;
            pdfReader.Close();
            int num2 = 0;
            int Width = 0;
            int num3 = 0;
            int Height = 0;
            if ((uint)SignImgLoc.Length > 0U)
            {
                num2 = (int)Convert.ToDecimal(SignImgLoc[0]);
                int num4 = (int)Convert.ToDecimal(SignImgLoc[1]);
                int num5 = (int)Convert.ToDecimal(SignImgLoc[2]);
                int num6 = (int)Convert.ToDecimal(SignImgLoc[3]);
                Width = Math.Abs(num5 - num2);
                Height = Math.Abs(num6 - num4);
                num3 = num4 - Height;
            }
            if (DigiSign.IsPasswordProtected(str1))
            {
                byte[] bytes = Encoding.ASCII.GetBytes(PdfPassword);
                pdfReader = new PdfReader(str1, bytes);
            }
            else
                pdfReader = new PdfReader(str1);
            Rectangle rect = new Rectangle((float)(int)Convert.ToDecimal(Custm[0]), (float)(int)Convert.ToDecimal(Custm[1]), (float)(int)Convert.ToDecimal(Custm[2]), (float)(int)Convert.ToDecimal(Custm[3]));
            string str2 = test_path + "/pdf/" + System.IO.Path.GetFileName(dest);
            PdfReader.unethicalreading = true;
            if (DigiSign.IsPasswordProtected(str1))
            {
                byte[] bytes = Encoding.ASCII.GetBytes(PdfPassword);
                reader1 = new PdfReader(str1, bytes);
            }
            else
                reader1 = new PdfReader(str1);
            pdfStamper1 = new PdfStamper(reader1, (Stream)memoryStream1, char.MinValue, true);
            PdfFormField signature = PdfFormField.CreateSignature(pdfStamper1.Writer);
            signature.SetWidget(rect, (PdfName)null);
            signature.Flags = 4;
            signature.FieldName = "Signature";
            signature.SetPage();
            for (int index = num1; index <= numberOfPages; ++index)
            {
                pdfStamper1.AddAnnotation((PdfAnnotation)signature, index);
                if (PageNo == "FL")
                {
                    pdfStamper1.AddAnnotation((PdfAnnotation)signature, numberOfPages);
                    break;
                }
            }
            pdfStamper1.Close();
            reader1.Close();
            File.WriteAllBytes(str2, memoryStream1.ToArray());
            memoryStream1.Close();
            if (TokenPin.Trim() != "")
            {
                SecureString securePin = this.GetSecurePin(TokenPin);
                RSACryptoServiceProvider privateKey = (RSACryptoServiceProvider)pk.PrivateKey;
                RSACryptoServiceProvider cryptoServiceProvider = new RSACryptoServiceProvider(new CspParameters(1, privateKey.CspKeyContainerInfo.ProviderName, privateKey.CspKeyContainerInfo.KeyContainerName, new CryptoKeySecurity(), securePin));
            }
            if (DigiSign.IsPasswordProtected(str2))
            {
                byte[] bytes = Encoding.ASCII.GetBytes(PdfPassword);
                reader2 = new PdfReader(str2, bytes);
            }
            else
                reader2 = new PdfReader(str2);
            pdfStamper2 = PdfStamper.CreateSignature(reader2, (Stream)memoryStream2, char.MinValue, null, true);
            PdfSignatureAppearance signatureAppearance = pdfStamper2.SignatureAppearance;
            if (reason.Trim() != "")
                signatureAppearance.Reason = reason;
            if (location.Trim() != "")
                signatureAppearance.Location = location;
            signatureAppearance.CertificationLevel = 0;
            signatureAppearance.SignatureRenderingMode = PdfSignatureAppearance.RenderingMode.DESCRIPTION;
            signatureAppearance.Acro6Layers = false;
            signatureAppearance.SetVisibleSignature("Signature");
            if ((uint)SignImgLoc.Length > 0U)
            {
                Image image = DigiSign.resizeImage(Width, Height, SignImgPath);
                image.SetAbsolutePosition((float)num2, (float)num3);
                for (int pageNum = num1; pageNum <= numberOfPages; ++pageNum)
                {
                    pdfStamper2.GetOverContent(pageNum).AddImage(image);
                    if (PageNo == "FL")
                    {
                        pdfStamper2.GetOverContent(numberOfPages).AddImage(image);
                        break;
                    }
                }
            }
            List<Org.BouncyCastle.X509.X509Certificate> x509CertificateList = new List<Org.BouncyCastle.X509.X509Certificate>()
    {
      DotNetUtilities.FromX509Certificate((System.Security.Cryptography.X509Certificates.X509Certificate) pk)
    };
            IExternalSignature externalSignature = (IExternalSignature)new X509Certificate2Signature(pk, "SHA-256");
            MakeSignature.SignDetached(signatureAppearance, externalSignature, (ICollection<Org.BouncyCastle.X509.X509Certificate>)x509CertificateList, (ICollection<ICrlClient>)null, (IOcspClient)null, (ITSAClient)null, 0, CryptoStandard.CMS);
            File.WriteAllBytes(dest, memoryStream2.ToArray());
            File.Delete(str2);
            pdfStamper2.Close();
            reader2.Close();
            return "SUCCESS";
        }
        catch (Exception ex)
        {
            return ex.Message;
        }
        finally
        {
            if (pdfStamper1 != null)
                pdfStamper1.Close();
            if (pdfStamper2 != null)
                pdfStamper2.Close();
            if (reader1 != null)
                reader1.Close();
            if (reader2 != null)
                reader2.Close();
            if (memoryStream1 != null)
                memoryStream1.Close();
            if (memoryStream2 != null)
                memoryStream2.Close();
            if (pdfReader != null)
                pdfReader.Close();
        }
    }

Answer 1

As per mkl says, I have replace

signature.FieldName = "Signature";

to

signature.FieldName = (pk.GetNameInfo(X509NameType.SimpleName, false)).Replace(' ', '_');

AND

signatureAppearance.SetVisibleSignature("Signature1");

to

signatureAppearance.SetVisibleSignature((pk.GetNameInfo(X509NameType.SimpleName, false)).Replace(' ', '_'));

Thank you mkl.