I think, this is not the source of the problem, but for your information... this is the code used.. very similar than yours, but selecting certificate from window store...
private void Button1_Click(object sender, EventArgs e)
{
//Load PDF document
PdfLoadedDocument loadedDocument = new PdfLoadedDocument("../../Data/caratula.pdf");
//Load PDF page
PdfLoadedPage page = loadedDocument.Pages[0] as PdfLoadedPage;
//Creates a certificate instance from PFX file with private key
PdfCertificate pdfCert =
new PdfCertificate(selectCert("My", StoreLocation.CurrentUser, "Elige un certificado", "please..."));
//Creates a digital signature
PdfSignature signature = new PdfSignature(loadedDocument, page, pdfCert, "Signature");
//Sets signature settings to customize digest algorithm specified
PdfSignatureSettings settings = signature.Settings;
settings.CryptographicStandard = CryptographicStandard.CADES;
settings.DigestAlgorithm = DigestAlgorithm.SHA256;
//Sets an image for signature field
PdfBitmap signatureImage = new PdfBitmap(@"../../Data/logo.png");
//Sets signature information
signature.Bounds = new RectangleF(new PointF(0, 0), signatureImage.PhysicalDimension);
signature.ContactInfo = "johndoe@owned.us";
signature.LocationInfo = "Honolulu, Hawaii";
signature.Reason = "I am author of this document.";
//Draws the signature image
page.Graphics.DrawImage(signatureImage, 0, 0);
//Saves and closes the document
loadedDocument.Save("Output.pdf");
loadedDocument.Close(true);
Process.Start("Output.pdf");
}
static private X509Certificate2 selectCert(/*StoreName */string store, StoreLocation location, string windowTitle, string windowMsg)
{
X509Certificate2 certSelected = null;
X509Store x509Store = new X509Store(store, location);
x509Store.Open(OpenFlags.ReadOnly);
X509Certificate2Collection col = x509Store.Certificates;
X509Certificate2Collection sel = X509Certificate2UI.SelectFromCollection(col, windowTitle, windowMsg, X509SelectionFlag.SingleSelection);
if (sel.Count > 0)
{
X509Certificate2Enumerator en = sel.GetEnumerator();
en.MoveNext();
certSelected = en.Current;
}
x509Store.Close();
return certSelected;
}
