Wrong certification status reported for signatures

Hello people,
I'm having an issue with the class PDFLoadedSignatureField: I have a PDF file which has 2 signatures:
#1: Approval (standard) signature
#2: Certification signature (i.e. it was created usingPdfSignature.Certificated = true).

When opening that PDF with Adobe, the first signature shows as an approval signature (green check mark) and the second signature shows with the blue ribbon, so both signature types are correctly shown as "approval" and "certification" respectively.

If I use the Syncfusion class PDFLoadedSignature to verify them, and call its ValidateSignature on each of the signature fields, BOTH returnIsCertificationSignature = True, which is inconsistent since only the last one is a certification signature.

I'm attaching a screenshot of adobe and a test file.

Is this a bug?
I'm using Syncfusion.Pdf.AspNet.Mvc5 versions 19.1.0.67

Thanks for your help

Attachment: CertificateSignatureProblem_fe83c4e6.zip

9 Replies 1 reply marked as answer

GK Gowthamraj Kumar Syncfusion Team June 15, 2021 02:37 PM UTC

Hi Alejandro, 
 
Thank you for contacting Syncfusion support. 
 
We have checked the provided document on our end, but both the signatures are invalid in Adobe reader. Please find the below screenshot,

We request you to share the complete code snippet, input document, signature details, product version to check the issue on our end.
So, that it will be helpful for us to analyze and assist you further on this.   
 
Regards, 
Gowthamraj K 



AL Alejandro June 18, 2021 01:51 PM UTC

Hello Gowthamraj 

The problem you see with adobe is not because the signing process is wrong, or the PDF is corrupted. It has to do with some policy Adobe enforces regarding the certificate from Actalis used to sign the file.

If you remove from Adobe's trust manager (Preferences -> Signatures -> Identities & Trustes Certificates -> Trusted certificates) all the certificates from Actalis (the root cert used), and revalidate the signatures, you'll see that the signatures ARE OK, but validity is unknown (yellow triangle).


But that's not the point, the real issue is that PDFLoadedSignature.ValidateSignature shows ALL signatures as Certificated when only the last one should be so.

You can test this with the same file I attached the first time, or with any file you have at hand with at least 2 signatures, one of which is certified.

Thank you










GK Gowthamraj Kumar Syncfusion Team June 21, 2021 12:56 PM UTC

Hi Alejandro, 
 
Thank you for your update. 
 
We were able to reproduce the reported issue with provided details on our end. Currently, we are validating on this and we will update the further details on June 23rd 2021. 
 
Regards, 
Gowthamraj K 



GK Gowthamraj Kumar Syncfusion Team June 23, 2021 11:59 AM UTC

Hi Alejandro, 
 
Thank you for your patience. 
  
We confirmed the issue “Incorrect certification status returns for the existing signature field” as a defect in our product. Since you are using a weekly NuGet release version 19.1.0.67, we will include the fix for this issue in our weekly NuGet release, which will be available on July 6th, 2021. 
  
Please use the below feedback link to track the status of the reported bug. 
 
Note: If you require patch for the reported issue in any of our Essential Studio Main or SP release version, then kindly let us know the version, so that we can provide a patch in that version based on our SLA policy. 
  
Please let us know if you need any further assistances in this. 

Regards,
 
Gowthamraj K 



AL Alejandro June 24, 2021 09:51 AM UTC

Hello  Gowthamraj,


Thank you for your prompt reply,


I'll wait until the patch from july is released.


Regards

Alex




GK Gowthamraj Kumar Syncfusion Team July 6, 2021 01:31 PM UTC

Hi Alejandro, 
 
Sorry for the inconvenience caused. 
 
The fix for the reported issue “Incorrect certification status returns for the existing signature field” in not included our latest weekly NuGet release. However, We have generated the custom NuGet package for this issue with the latest NuGet release version (v19.2.0.46). We will include the fix for this issue in our weekly NuGet release, which will be available on July 13th, 2021. 
 
Please refer to the custom NuGet package below, 
 
Please refer the below KB steps to install the custom NuGet package,  
 
Please use the below feedback link to track the status of the reported bug.  
 
Regards, 
Gowthamraj K 



GK Gowthamraj Kumar Syncfusion Team July 13, 2021 10:23 AM UTC

Hi Alejandro,  

Thank you for your patience. 
 
  
We have included the fix for the reported issue “Incorrect certification status returns for the existing signature field” in our latest weekly NuGet release (v19.2.0.47).  
 
Please use the below link to download our latest weekly NuGet,      
 
Please let us know if you have any concerns on this. 
 
Regards, 
Gowthamraj K 


Marked as answer

AL Alejandro July 13, 2021 08:31 PM UTC

Hello Gowthamraj,


I downloaded the 19.2.0.47 version of the nuget packages and I can confirm that only the last signature in the test PDF is shown as a certification signature (and not all the other).


Thank you very much for your support,

Regards

Alex





GK Gowthamraj Kumar Syncfusion Team July 14, 2021 07:43 AM UTC

Hi Alejandro,   
 
Thank you for your update. We are glad to know that your issue has been solved. 
 
Please let us know if you need any further assistance with this. 
 
Regards, 
Gowthamraj K 


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