PDF Two signatures using two different certificate - First Broken

[Michal Stachyra]

Hello, I have a problem with signing PDF file with 2 signatures.

I use the latest version Syncfusion.Pdf.WinForms 18.1.0.46 from nuget.

Steps:

1. I have clean PDF file
2. Sign by First cert
3. Sign by Second cert

Result is that this First signature is broken and we can't see first Cert details. 

It' look like if we sign the second time the library didn't know details about the first certificate.

Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense("XXX");

            var cert1 = new X509Certificate2(@"../../Data/keyStore1.p12", "pass1234");

            var cert2 = new X509Certificate2(@"../../Data/keyStore2.p12", "pass1234");

            //Creates a certificate instance from PFX file with private key

            PdfCertificate pdfCert = new PdfCertificate(cert1);

            PdfCertificate pdfCert2 = new PdfCertificate(cert2);

            //Loads a PDF document

            PdfLoadedDocument loadedDocument = new PdfLoadedDocument("../../Data/TestPDF.pdf");

            //Creates a digital signature

            PdfSignature signature = new PdfSignature(loadedDocument, loadedDocument.Pages[0], pdfCert, "First");

            //Saves and closes the document

            MemoryStream ms = new MemoryStream();

            loadedDocument.Save(ms);

            loadedDocument.Close(true);

            //Loads a PDF document

            PdfLoadedDocument loadedDocument1 = new PdfLoadedDocument(ms);

            //Creates a digital signature

            PdfSignature pdfSignature = new PdfSignature(loadedDocument1, loadedDocument1.Pages[0], pdfCert2, "Sec");

            loadedDocument1.Save("Output.pdf");

            loadedDocument1.Close(true);

            Process.Start("Output.pdf");

Attachment: Sign2Certs_eee3fd50.zip

[Gowthamraj Kumar]

Hi Michal, 

  

Thank you for using Syncfusion products. 

We were able to reproduce the reported signature issue in our latest NuGet with the provided details. Currently, we are validating this and we will update the further details on 5th May 2020.  

  

Regards, 

Gowthamraj K 

[Gowthamraj Kumar]

Hi Michal, 

On further analysis, we found that the first signature is broken due to adding of a trial watermark. So kindly use the licensed assemblies to overcome this issue. 

Output: https://www.syncfusion.com/downloads/support/forum/153794/ze/Output-418976768.zip  

Regards, 

Gowthamraj K 

[Michal Stachyra]

Yes, but if you look at signature details in Adobe you will see that two signatures has the same certificate called 'sec'.

Is it correct behavior? 

Attachment: screen_pdf_sign_4318c32d.zip

[Gowthamraj Kumar]

Hi Michal, 

 

Thank you for your update. 

 

We have checked the reported issue with the provided details. We have modified the code snippet and tried the conversion, now the signature added properly. We have shared the output document for your reference. To overcome this issue, you can use this below code snippet in your end and let us know the result.   

   

Document: https://www.syncfusion.com/downloads/support/forum/153794/ze/Document391661107     

   

Please refer the below code snippet to overcome this issue,   

 

var cert1 = new X509Certificate2(@"../../Data/keyStore1.p12", "pass1234"); 

var cert2 = new X509Certificate2(@"../../Data/keyStore2.p12", "pass1234"); 

 

//Creates a certificate instance from PFX file with private key 

PdfCertificate pdfCert = new PdfCertificate(cert1); 

             

//Loads a PDF document 

PdfLoadedDocument loadedDocument = new PdfLoadedDocument("../../Data/TestPDF.pdf"); 

//Creates a digital signature 

PdfSignature signature = new PdfSignature(loadedDocument, loadedDocument.Pages[0], pdfCert, "First"); 

 

//Saves and closes the document 

MemoryStream ms = new MemoryStream(); 

loadedDocument.Save(ms); 

loadedDocument.Close(true); 

 

//Loads a PDF document 

PdfLoadedDocument loadedDocument1 = new PdfLoadedDocument(ms); 

PdfCertificate pdfCert2 = new PdfCertificate(cert2); 

//Creates a digital signature 

PdfSignature pdfSignature = new PdfSignature(loadedDocument1, loadedDocument1.Pages[0], pdfCert2, "Sec"); 

 

loadedDocument1.Save("Output.pdf"); 

loadedDocument1.Close(true); 

 

Process.Start("Output.pdf"); 

 

 

Please let us know if you any further assistance with this.   

 

Regards, 

Gowthamraj K 

[Michal Stachyra]

It's works :) 

So if we move this line "PdfCertificate pdfCert2 = new PdfCertificate(cert2);" close to creating next Signature will fix that.

Thanks for helping and quick solve my issue.