Signing a PDF that already contains one signature invalidates the first one

Aspose.PDF Product Family
1

Hello,
We have a PDF file that already has been signed using an unknown program and when we try to add another signature to it it invalidates the first signature. Testing with other libraries it doesnt happen.
Can you help us understand if we are doing something wrong or it’s a problem with the Aspose library?

We are using aspose.pdf 21.12

The code that we are using is as follows,

    Using finalStream As New IO.MemoryStream()
        Using document As New Aspose.Pdf.Document(New IO.MemoryStream(inputFile))

            Using signature As New Aspose.Pdf.Facades.PdfFileSignature(document)

                PKCS7.ShowProperties = False

                signature.Sign(1, False, Nothing, PKCS7)

                'Save output PDF file
                signature.Save(finalStream)

                result = finalStream.ToArray()

            End Using
        End Using
    End Using

Here is the file,

original.pdf (137.8 KB)

2

@filedoc

There are similar issues already logged in our issue tracking system to investigate this behavior of the API. We will surely generate another ticket for your case. Can you please share the sample .pfx file that you are using?

3

Here is the .pfx that i used.
I tried with others but the result was the same.

Password: “123456789”

Cert.zip (2.6 KB)

4

@filedoc

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-56182

You can obtain Paid Support Services if you need support on a priority basis, along with the direct access to our Paid Support management team.

5

Hello,

Any news regarding this?

6

@filedoc

We are afraid that the ticket has not been yet investigated fully. It will be prioritized on a first come first serve basis and as soon as it is resolved, we will share news with you in this forum thread. Please spare us some time.

We are sorry for the inconvenience.