Digital Signature Certificate removed

Question

Hello,

I am trying to add Digital Signature Certificate after each sign. When I add the first one, all goes well, but when I add the second one, the first certificate is not there. I add the Certificate in the download method of the PdfViewerController. I found out that on load the updated document is there but when I try to call the download method (to save the document or just download it through the Vue library), information about the first digital signature is not there. I am using latest version of your libraries (Vue, ASP.NET Core - licensed). Thank you.

Ondřej Vrána

Dhivyabharathi Mohan · Answer

Hi Ondrej, 
 
 
Currently we are preparing the sample to replicate the reported issue. We will check and provide the further details on September 17, 2021. 
 
 
Regards, 
Dhivya.

Dhivyabharathi Mohan · Answer

Hi Ondrej, 
 
 
You can add multiple digital signatures in a PDF document by appending additional signatures to an already signed PDF file. If you want to add multiple signatures in a PDF document, kindly follow the steps from the below KB article. When you add the signature for the first time without a license key, the trial watermark will be added and the document to be modified. So that, the second signature is Invalid. So, you have to apply the registered license key to avoid a trial watermark and get a valid signature.      
   
 
We have attached the sample for your reference, kindly try the sample on your end and let us know the result. 
  
 
https://www.syncfusion.com/downloads/support/directtrac/general/ze/NETCoreConsoleApp_Mod1194316096  
 
 
Please refer the below link for more information,     
KB: https://www.syncfusion.com/kb/9801/how-to-apply-one-or-more-digital-signatures-to-a-pdf-using-c-and-vb-net       
 
 
UG: https://help.syncfusion.com/file-formats/pdf/working-with-digitalsignature  
      
 
Blogs: https://www.syncfusion.com/blogs/post/create-validate-pdf-digital-signatures-csharp.aspx#add-multiple-digital-signatures-in-a-single-PDF-document     
   
    
Kindly try this and revert us, if you have any concerns. 
 
Regards, 
Dhivya.