i used itext sharp to get digital signature.
but after signed
it is in invisible mode.
please help me to make signature as visible mode
this the following code:
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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using iTextSharp.text.pdf;
using iTextSharp.text.pdf.security;
namespace Saturday
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private SecureString GetSecurePin(string PinCode)
{
SecureString pwd = new SecureString();
foreach (var c in PinCode.ToCharArray()) pwd.AppendChar(c);
return pwd;
}
private void button1_Click(object sender, EventArgs e)
{
X509Store store = new X509Store(StoreLocation.CurrentUser);
store.Open(OpenFlags.ReadOnly);
X509Certificate2 cert = null;
//manually chose the certificate in the store
X509Certificate2Collection sel = X509Certificate2UI.SelectFromCollection(store.Certificates, null, null, X509SelectionFlag.SingleSelection);
if (sel.Count > 0)
cert = sel[0];
else
{
MessageBox.Show("Certificate not found");
return;
}
SignWithThisCert(cert);
}
private void SignWithThisCert(X509Certificate2 cert)
{
OpenFileDialog b = new OpenFileDialog();
openFileDialog1.ShowDialog();
textBox1.Text= openFileDialog1.FileName;
string SourcePdfFileName = textBox1.Text;
string DestPdfFileName = textBox1.Text + "-Signed.pdf";
Org.BouncyCastle.X509.X509CertificateParser cp = new Org.BouncyCastle.X509.X509CertificateParser();
Org.BouncyCastle.X509.X509Certificate[] chain = new Org.BouncyCastle.X509.X509Certificate[] { cp.ReadCertificate(cert.RawData) };
IExternalSignature externalSignature = new X509Certificate2Signature(cert, "SHA-1");
PdfReader pdfReader = new PdfReader(SourcePdfFileName);
FileStream signedPdf = new FileStream(DestPdfFileName, FileMode.Create); //the output pdf file
PdfStamper pdfStamper = PdfStamper.CreateSignature(pdfReader, signedPdf, '\0');
PdfSignatureAppearance signatureAppearance = pdfStamper.SignatureAppearance;
//here set signatureAppearance at your will
signatureAppearance.Reason = "Because I can";
signatureAppearance.Location = "My location";
signatureAppearance.SignatureRenderingMode = PdfSignatureAppearance.RenderingMode.DESCRIPTION;
MakeSignature.SignDetached(signatureAppearance, externalSignature, chain, null, null, null, 0, CryptoStandard.CMS);
//MakeSignature.SignDetached(signatureAppearance, externalSignature, chain, null, null, null, 0, CryptoStandard.CADES);
MessageBox.Show("Done");
}
}
}