Concatenate the signatures become invalid

after concatenation of all the files in a folder that contains one or more files with e-signatures the final document (combined PSF) cannot be edited with Adobe pro because all the signatures are invalid. can you please provide a workaround?

We created 3 different source folders of multiple PDF files as follows
1, No source pdf file has any digital signature
2. One source pdf file with digital signature , with already validated Signature in Acrobat reader
3. One source pdf file with digital signature , with not previously validated Signature in Acrobat reader

We are using latest ASPOSE.PDF for .NET v 23.7.0
We used Concatenate function of Aspose.Pdf.Facades.PdfFileEditor class to create the combined PDF file for each folder.

After we open the combined PDF files with Acrobat reader, we found that it created PDF files for each source folder

  1. For the the combined PDF files with digital signature ( with validated and not validated signature source folders 1 and 2 above ), the combined PDF files open in Acrobat reader but shows the following error
    **Error during signature verification. **
    Signature contains incorrect, unrecognized, corrupted or suspicious data.
    Support Information: SigDict /Contents illegal data

  2. The combined PDF file for source pdf files from source 3 folder above, opens in Acrobat reader with no error.

Please see the snapshot of the error message that we see
image.png (19.6 KB)

@prashant.kamble

Can you please share one or more sample files for our reference including the output generated at your end? We will test the scenario in our environment and address it accordingly.

Hi @asad.ali
please find the attached documents before and after concatenation.

SampleConcatenated.zip (556.6 KB)
SampleSource.zip (559.0 KB)

although we validate th e signature on the source file … it cannot be done on the concatenated file.
2023-08-03_10-55-21.jpg (240.0 KB)

@Jarita

We were able to reproduce the issue in our environment. Therefore, we need to investigate in more details.

We have opened the following new ticket(s) in our internal issue tracking system and will deliver their fixes according to the terms mentioned in Free Support Policies.

Issue ID(s): PDFNET-55200

We will look into the details of the ticket and keep you posted with the status of its rectification. Please be patient and spare us some time.

We are sorry for the inconvenience.

@asad.ali
Any updates on this ?

@bkashefipour

This ticket was recently logged and it is not yet analyzed yet. We will investigate and resolve it on a first come first serve basis. As soon as we have some updates about its fix, we will inform you via this forum thread. Please be patient and spare us some time.

We are sorry for the inconvenience.