Advanced PDF Digital Signature Options in C#

void AdvancedPdfSignature(string unsignedDocument, string signedDocument)
    PdfSignature ps = new PdfSignature("");

    //load the PDF document

    //Load the signature certificate from a PFX or P12 file
    //ps.DigitalSignatureCertificate = DigitalCertificate.LoadCertificate("cert.pfx", "123456");
    //Load the certificate from Microsoft Store. 
    //The smart card or USB token certificates are usually available on Microsoft Certificate Store (start - run - certmgr.msc).
    //If the smart card certificate not appears on Microsoft Certificate Store it cannot be used by the library
    ps.DigitalSignatureCertificate = DigitalCertificate.LoadCertificate(false, DigitalCertificateSearchCriteria.Thumbprint, "thumbprint", true);

    //The smart card PIN dialog can be bypassed for some smart cards/USB Tokens. 
    DigitalCertificate.SmartCardPin = "123456";

    ps.SigningReason = "I approve this document";
    ps.SigningLocation = "Accounting department";

    //custom digital signature rectangle position
    ps.SignatureAdvancedPosition = new System.Drawing.Rectangle(10, 10, 400, 150);

    //add an image to the digital signature rectangle
    ps.SignatureImage = File.ReadAllBytes("signature_image.jpg");
    ps.SignatureImageType = SignatureImageType.ImageAndText;
    //customize the digital signature text
    ps.SignatureText = "Siganture created by: " + ps.DigitalSignatureCertificate.Subject 
+ Environment.NewLine + "Date: " + DateTime.Now.ToString("dd.MM.yyyy HH:mm");

    //add green tick
    ps.OldStyleAdobeSignature = true;

    //digital signature hash algorithm
    ps.HashAlgorithm = SignLib.HashAlgorithm.SHA256;
    //PAdES signature. Requires Adobe X
    ps.SignatureStandard = SignLib.Pdf.PdfSignatureStandard.Cades;

    //add document certification
    ps.CertifySignature = CertifyMethod.AnnotationsAndFormFilling;

    //the signature will be timestamped.
    ps.TimeStamping.ServerUrl = new Uri("");
    ps.TimeStamping.UserName = "your_username";
    ps.TimeStamping.Password = "your_password";

    //add signature rectangle to all pages
    ps.SignatureAppearsOnAllPages = true;

    //write the signed file
    File.WriteAllBytes(signedDocument, ps.ApplyDigitalSignature());

See also: