I need help - I can help - Document has been altered, incompatible signatures

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Document has been altered, incompatible signatures

Printed From: Debenu Quick PDF Library - PDF SDK Community Forum
Category: For Users of the Library
Forum Name: I need help - I can help
Forum Description: Problems and solutions while programming with the Debenu Quick PDF Library and Debenu PDF Viewer SDK
URL: http://www.quickpdf.org/forum/forum_posts.asp?TID=3732
Printed Date: 25 Apr 25 at 10:51AM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com

Topic: Document has been altered, incompatible signatures

Posted By: Puty
Subject: Document has been altered, incompatible signatures
Date Posted: 21 Aug 19 at 6:34PM

Hi,

I have a curious problem.

I use Debenu (iOS version 16.13) as framework to working with a PDF document and add signature.

If I insert signatures only through Debenu everything is OK, Adobe Reader show that signatures are valid and OK. However, if I add another signature through another application that uses iText or Apitron technology, for example, all signatures entered through the Debenu are invalid. The bug is not in other applications, they are tested among themselves and work well.

Next example, if I have 2 signature fields and I sign one through the Debenu, I can't sign the other through the Adobe reader.

If I sign the first signature field through another application, I can also insert the second signature through Adobe Reader.

I use Debenu iOS, version 16.13, I use incremental save, after added new signature I call method:

- "getSignProcessResult" - that return value: "1 - The file was signed successfully"

after that I call

- "releaseSignProcess" - that return value: "1 - Successfully deleted the signing process"

Adobe Reader show signatures as valid, unless someone else inserts the signature as I wrote.

I have linked a link to two PDFs,

http://drive.google.com/drive/folders/1j6Tj7gDKLWZ97TTm_xKFo47fVPR5rTw_?usp=sharing" rel="nofollow - http://drive.google.com/drive/folders/1j6Tj7gDKLWZ97TTm_xKFo47fVPR5rTw_?usp=sharing

first "iText_android.pdf" is signed via iText on Android and Adobe Reader can sign the second signature field (after allow editing)

second file "Debenu_ios.pdf" is signed via Debenu on iPad and Adobe Reader CAN'T sign the second signature field (after allow editing).

I think there's something wrong with the signature process in Debenu

Please what is wrong? How can I fix it?

Replies:

Posted By: Ingo
Date Posted: 21 Aug 19 at 9:35PM

Hi Puty,

perhaps this link can help:
http://www.quickpdf.org/forum/digital-signature-destroyed_topic1584.html
There's described what happens when QuickPDF load and save a pdf.
This could result into the issues you've described.
Try it with incremental...

-------------
Cheers,
Ingo

Posted By: Puty
Date Posted: 21 Aug 19 at 9:54PM

Hi,

thanks for your reply, I read this post, but this is not the same problem.

I don't have problem with Save/ Load, I use incremental Save (setAppendInput method).

I have problem with incompatible signature with another technologies.

Posted By: Ingo
Date Posted: 21 Aug 19 at 10:00PM

"...
if I add another signature through another application that uses iText or Apitron technology, for example, all signatures entered through the Debenu are invalid
..."

For me that's (above) a bug from the other apps.
The other thing: The link should gib´ve you an idea cause QP damaged other signatures if you're doing a normal load and (later) save for your new signature?

Let us wait few days if another user have an idea for you...

-------------
Cheers,
Ingo

Posted By: Puty
Date Posted: 22 Aug 19 at 9:04PM

Hi Ingo,

I probably found the source of the problem.

In the page http://www.pdf-online.com/osa/validate.aspx" rel="nofollow - http://www.pdf-online.com/osa/validate.aspx you can validate PDF file.

If I try validate a PDF file signed via Debenu on iOS, validation show this errors

Result Document does not conform to PDF/A.

Details Validating file "ios2.pdf" for conformance level pdf1.7

The value of the key S must not be of type integer.

The key Subtype is required but missing.

The document does not conform to the requested standard.

The document doesn't conform to the PDF reference (missing required entries, wrong value types, etc.).

The document doesn't provide appropriate logical structure information.

The document does not conform to the PDF 1.7 standard.

Done.

I'm worried about these alerts:

The document does not conform to the requested standard.

The document doesn't conform to the PDF reference (missing required entries, wrong value types, etc.).

The document doesn't provide appropriate logical structure information.

The document does not conform to the PDF 1.7 standard.

Please can you tell me how to fix these errors?

Posted By: Ingo
Date Posted: 22 Aug 19 at 10:09PM

Hi,

i'm using this online checker, too.
Try to use function CheckFileCompliance first:
https://www.debenu.com/docs/pdf_library_reference/CheckFileCompliance.php
Perhaps then you'll see immediately what's wrong.

I don't have iOS-experiences.
If you've still probs you should contact the official support pages.

-------------
Cheers,
Ingo

Posted By: Puty
Date Posted: 26 Aug 19 at 2:13PM

Hi Ingo,

I found a solution to my problem. :)

I had set the SetNeedAppearance while load the document, as recommended in best practice, but it caused problems in the next insertion of signatures.

Now it's all ok :)