Signature validation fails saying the document was modified. Adobe validates OK.

Good day people,

I'm having an issue validating a signed PDF. I'm attaching the file so you can check it.

After calling the PdfLoadedSignatureField.Validate() method, I get the following status:

PdfSignatureValidationResult.IsSignatureValid : False
PdfSignatureValidationResult..IsDocumentModified: True
PdfSignatureValidationResult.ValidationErrors[0] : The document has been altered or corrupted since the signature was applied.

With both, Adobe Acrobat Reader DC, and Adobe Acrobat Lite, the PDF validates OK after adding the root certificate to the stores. The signature shows VALID.

I'm using these SF component versions:
Syncfusion.Pdf.AspNet.Mvc5 : 18.3.0.42

 Is this a bug, or should I check something in code?

Thank you



Attachment: Test_Firma_Contractia_(1)_262bd8e6.zip

10 Replies 1 reply marked as answer

GK Gowthamraj Kumar Syncfusion Team October 28, 2020 12:12 PM UTC

Hi Alejandro, 

Thank you for using Syncfusion product. 

We were able to reproduce the reported issue with provided details in our end. We will update the further details on October 30th 2020. 

Regards, 
Gowthamraj K 



GK Gowthamraj Kumar Syncfusion Team October 30, 2020 12:06 PM UTC

Hi Alejandro, 
 
Thank you for your patience. 
  
We confirmed the issue “Signature validation result shows invalid on particular PDF document” as a defect in our product. Since you are using a weekly NuGet release version 18.3.0.42, we will include the fix for this issue in our weekly NuGet release, which will be available on November 10, 2020. 
  
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 with this. 
 
Regards, 
Gowthamraj K 



AL Alejandro October 30, 2020 01:04 PM UTC

Hello Gowthamraj,

Thank you for your reply. I'll wait until the next weekly update release.

BTW, the link you provided shows a page with an "Access denied" message when I try to open it.

Thank you
Alex



GK Gowthamraj Kumar Syncfusion Team November 2, 2020 12:11 PM UTC

Hi Alejandro, 

Thank you for your update. We have provided the visibility to you for accessing this feedback link. 

Please use the below feedback link to track the status of the reported bug.  

As we said earlier, we will include the fix for this issue “Signature validation result shows invalid on particular PDF document” in our weekly NuGet release, which will be available on November 10, 2020.  
   
Regards, 
Gowthamraj K 



GK Gowthamraj Kumar Syncfusion Team November 10, 2020 01:14 PM UTC

Hi Alejandro,  
  
Thank you for your patience. 

We have fixed the issue and included the fix for this issue “Signature validation result shows invalid on particular PDF document” in our upcoming weekly NuGet release, which will be available on November 11th , 2020.   

Please use the below feedback link to track the status of the reported bug.   

Regards, 
Gowthamraj K 



AL Alejandro November 10, 2020 10:25 PM UTC

Hello Gowthamraj 

I upgraded to version 18.3.0.47, but the file still fails to be validated by synfusion components.

Please could you check with the file I attached in my first post on this topic, using this latest SF version?

Thank you
Alex



GK Gowthamraj Kumar Syncfusion Team November 11, 2020 07:38 AM UTC

Hi Alejandro, 
 
Thank you for your patience. 
 
We have included the fix for the reported issue “Signature validation result shows invalid on particular PDF document” in our latest weekly NuGet release (v18.3.0.48). Please use the below link to download our latest weekly NuGet,      
 
 
Please try the below NuGet package in your end and let us know the result. 
 
Regards, 
Gowthamraj K 


Marked as answer

AL Alejandro November 14, 2020 11:03 AM UTC

Hello Gowthamraj

I've updated to version 18.3.0.48 and the signature validation is now working.

Thank you very much for your help!
Regards
Alex



GK Gowthamraj Kumar Syncfusion Team November 16, 2020 12:02 PM UTC

Hi Alejandro, 

Thank you for your update. We are glad to know that your problem has been solved. 

Regards, 
Gowthamraj K 



GK Gowthamraj Kumar Syncfusion Team December 18, 2020 09:00 AM UTC

Hi Alejandro,   
 
We have included the fix for the issue “Signature validation result shows invalid on particular PDF document” in our Volume 4 release and we glad to announce that our Essential Studio Volume 4, 2020 is rolled out. Please find the download link from below, 
 
 
You can track the status of the issue by using the below feedback link.      
      
We thank you for your support and appreciate your patience in waiting for this release. Please get in touch with us if you would require any further assistance. 
 
Regards, 
Gowthamraj K 


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