911183: Update the github sample.

Digital Signature/Create-LTV-when-signing-PDF-documents-externally/.NET/Create-LTV-when-signing-PDF-documents-externally/Program.cs

@@ -7,21 +7,41 @@
 using System.Security.Cryptography.Pkcs;
 using System.Security.Cryptography.X509Certificates;
 
+
 //Get the stream from the document.
 FileStream documentStream = new FileStream(Path.GetFullPath(@"Data/Input.pdf"), FileMode.Open, FileAccess.Read);
 
 //Load an existing PDF document.
-PdfLoadedDocument loadedDocument = new PdfLoadedDocument(documentStream);
+PdfLoadedDocument document = new PdfLoadedDocument(documentStream);
+
+//Get the page of the existing PDF document.
+PdfLoadedPage loadedPage = document.Pages[0] as PdfLoadedPage;
+
+//Create a new PDF signature without PdfCertificate instance.
+PdfSignature signature = new PdfSignature(document, loadedPage, null, "Signature1");
+
+//Hook up the ComputeHash event.
+signature.ComputeHash += Signature_ComputeHash;
+
+//Save the document into stream
+MemoryStream stream = new MemoryStream();
+document.Save(stream);
+//Close the document
+document.Close(true);
+
+
+//Load an existing PDF stream..
+PdfLoadedDocument loadedDocument = new PdfLoadedDocument(stream);
 
 //Gets the first signature field of the PDF document
 PdfLoadedSignatureField signatureField = loadedDocument.Form.Fields[0] as PdfLoadedSignatureField;
-PdfSignature signature = signatureField.Signature;
+PdfSignature pdfSignature = signatureField.Signature;
 
 //Create X509Certificate2 from your certificate to create a long-term validity.
 X509Certificate2 x509 = new X509Certificate2(Path.GetFullPath(@"Data/PDF.pfx"), "syncfusion");
 
 //Create LTV with your public certificates.
-signature.CreateLongTermValidity(new List<X509Certificate2> { x509 });
+pdfSignature.CreateLongTermValidity(new List<X509Certificate2> { x509 });
 
 //Create file stream.
 using (FileStream outputFileStream = new FileStream(Path.GetFullPath(@"Output/Output.pdf"), FileMode.Create, FileAccess.ReadWrite))
@@ -34,3 +54,22 @@
 loadedDocument.Close(true);
 
 
+void Signature_ComputeHash(object sender, PdfSignatureEventArgs ars)
+{
+    //Get the document bytes
+    byte[] documentBytes = ars.Data;
+
+    SignedCms signedCms = new SignedCms(new ContentInfo(documentBytes), detached: true);
+
+    //Compute the signature using the specified digital ID file and the password
+    X509Certificate2 certificate = new X509Certificate2(Path.GetFullPath(@"Data/PDF.pfx"), "syncfusion");
+    CmsSigner cmsSigner = new CmsSigner(certificate);
+
+    //Set the digest algorithm SHA256
+    cmsSigner.DigestAlgorithm = new Oid("2.16.840.1.101.3.4.2.1");
+
+    signedCms.ComputeSignature(cmsSigner);
+
+    //Embed the encoded digital signature to the PDF document
+    ars.SignedData = signedCms.Encode();
+}

Digital Signature/Enable-LTV-PDF-signature/.NET/Enable-LTV-PDF-signature/Enable-LTV-PDF-signature.csproj

@@ -13,7 +13,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <None Update="Data\Input.pdf">
+    <None Update="Data\PDF.pfx">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>
     <None Update="Output\.gitkeep">

Digital Signature/Enable-LTV-PDF-signature/.NET/Enable-LTV-PDF-signature/Program.cs

@@ -6,18 +6,39 @@
 using Syncfusion.Pdf.Parsing;
 using Syncfusion.Pdf.Security;
 
-//Get the stream from the document.
-FileStream documentStream = new FileStream(Path.GetFullPath(@"Data/Input.pdf"), FileMode.Open, FileAccess.Read);
+//Creates a new PDF document.
+PdfDocument document = new PdfDocument();
 
-//Load an existing PDF document.
-PdfLoadedDocument loadedDocument = new PdfLoadedDocument(documentStream);
+//Adds a new page.
+PdfPageBase page = document.Pages.Add();
+
+//Create graphics for the page. 
+PdfGraphics graphics = page.Graphics;
+
+//Creates a certificate instance from PFX file with private key.
+FileStream certificateStream = new FileStream(Path.GetFullPath(@"Data/PDF.pfx"), FileMode.Open, FileAccess.Read);
+PdfCertificate pdfCert = new PdfCertificate(certificateStream, "DigitalPass123");
+
+//Creates a digital signature.
+PdfSignature signature = new PdfSignature(document, page, pdfCert, "Signature");
+signature.Settings.CryptographicStandard = CryptographicStandard.CADES;
+signature.Settings.DigestAlgorithm = DigestAlgorithm.SHA256;
+
+//Save the document into stream
+MemoryStream stream = new MemoryStream();
+document.Save(stream);
+//Close the document
+document.Close(true);
+
+//Load an existing PDF stream.
+PdfLoadedDocument loadedDocument = new PdfLoadedDocument(stream);
 
 //Gets the first signature field of the PDF document
 PdfLoadedSignatureField signatureField = loadedDocument.Form.Fields[0] as PdfLoadedSignatureField;
-PdfSignature signature = signatureField.Signature;
+PdfSignature pdfSignature = signatureField.Signature;
 
 //Enable LTV on Signature.
-signature.EnableLtv = true;
+pdfSignature.EnableLtv = true;
 
 
 //Create file stream.