How to digitally sign PDF in C# and VB.NET? | Syncfusion (2024)

using Syncfusion.Pdf;using Syncfusion.Pdf.Graphics;using Syncfusion.Pdf.Security;using System.Drawing;

Imports Syncfusion.PdfImports Syncfusion.Pdf.GraphicsImports Syncfusion.Pdf.SecurityImports System.Drawing

// Creates a new PDF documentPdfDocument document = new PdfDocument();//Adds a new pagePdfPageBase page = document.Pages.Add();PdfGraphics graphics = page.Graphics;//Creating a X509Certificate2 instance from PFX file with private keyX509Certificate2 cert = new X509Certificate2("pdf.pfx", "syncfusion");//Creating PdfCertificate object with X509Certificate2 class objectPdfCertificate pdfCert = new PdfCertificate(cert);//Creates a digital signaturePdfSignature signature = new PdfSignature(document, page, pdfCert, "Signature");//Sets an image for signature fieldPdfBitmap signatureImage = new PdfBitmap(@"signature.png");//Sets signature informationsignature.Bounds = new RectangleF(0, 0, 200, 100);signature.ContactInfo = "johndoe@owned.us";signature.LocationInfo = "Honolulu, Hawaii";signature.Reason = "I am author of this document.";//Draws the signature imagegraphics.DrawImage(signatureImage, signature.Bounds);//Save the documentdocument.Save("Signature.pdf");//Close the documentdocument.Close(true);//This will open the PDF file so, the result will be seen in default PDF ViewerProcess.Start("Signature.pdf");

'Creates a new PDF documentDim document As New PdfDocument()'Adds a new pageDim page As PdfPageBase = document.Pages.Add()Dim graphics As PdfGraphics = page.Graphics'Creating a X509Certificate2 instance from PFX file with private keyDim cert As New X509Certificate2("pdf.pfx", "syncfusion")'Creating PdfCertificate object with X509Certificate2 class objectDim pdfCert As New PdfCertificate(cert)'Creates a digital signatureDim signature As New PdfSignature(document, page, pdfCert, "Signature")'Sets an image for signature fieldDim signatureImage As New PdfBitmap("signature.png")'Sets signature informationsignature.Bounds = New RectangleF(0, 0, 200, 100)signature.ContactInfo = "johndoe@owned.us"signature.LocationInfo = "Honolulu, Hawaii"signature.Reason = "I am author of this document."'Draws the signature imagegraphics.DrawImage(signatureImage, signature.Bounds)'Save the documentdocument.Save("Signature.pdf")'Close the documentdocument.Close(True)'This will open the PDF file so, the result will be seen in default PDF ViewerProcess.Start("Signature.pdf")