Adding digital signature using syncfusion adds two signatures instead of one

[Muhammad Ahmad]

I am evaluating syncfusion pdf component for adding digital signature to pdf documents. When I add the signature it adds two signatures in the document instead of one.

I am using the following code for adding signature

PdfLoadedDocument document = new PdfLoadedDocument("DigitalSignaturee3.pdf");

            PdfLoadedPage page = document.Pages[0] as PdfLoadedPage;

            //Creates a signature field.

            PdfSignatureField signatureField = new PdfSignatureField(page, "SignatureField");

            signatureField.Bounds = new RectangleF(0, 0, 100, 100);

            signatureField.Signature = new PdfSignature(document, page, new PdfCertificate(@"C:\Users\Public\Documents\Syncfusion\ASP.NET MVC - EJ2\16.3.0.21\App_Data\PDF\PDF.pfx", "syncfusion"), "SignatureField");

            signatureField.Signature.Reason = "I am author of this document";

            document.Form.Fields.Add(signatureField);

            document.Save();

            //Closes the document

            document.Close(true);

Can you please tell why is it happening so. Image is attached

[Karthikeyan Chandrasekar]

Hi Muhammad, 

Thank you for your update. 

When we create PdfSignature with the PdfLoadedDocument and PdfLoadedPage as a parameters, then the signature is added in to the PdfLoadedFormFieldCollection of PdfLoadedDocument. So it is not required to adding again in the PdfLoadedFormFieldCollection.  

Kindly use the below code snippet to sign an existing PDF document. 

 

PdfLoadedDocument document = new PdfLoadedDocument("../../data/Input.pdf"); 

PdfLoadedPage page = document.Pages[0] as PdfLoadedPage; 

 

//Creates a signature field. 

 

PdfSignatureField signatureField = new PdfSignatureField(page, "SignatureField"); 

 

signatureField.Bounds = new RectangleF(0, 0, 100, 100); 

 

signatureField.Signature = new PdfSignature(document, page, new PdfCertificate(@"../../data/PDF.pfx", "syncfusion"), "SignatureField"); 

 

signatureField.Signature.Reason = "I am author of this document"; 

 

signatureField.Signature.DocumentPermissions = PdfCertificationFlags.AllowComments | PdfCertificationFlags.AllowFormFill | PdfCertificationFlags.ForbidChanges; 

 

document.Save(); 

 

//Closes the document 

document.Close(true); 

 

 

Refer the below UG to sign an existing PDF document. 

Ug link: https://help.syncfusion.com/file-formats/pdf/working-with-digitalsignature#signing-an-existing-document 

 

Refer the below KB to add multiple signature to the PDF. 

KB link: https://www.syncfusion.com/kb/5853/how-to-add-multiple-digital-signature 

Regards, 

Karthikeyan