Invalid digital signature and message document has been altered

PDF-XChange Viewer SDK for Developer's
(ActiveX and Simple DLL Versions)

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KarlTH
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Invalid digital signature and message document has been altered

Post by KarlTH » Wed Jun 07, 2017 4:21 am

Hello Tracker-Support,

I upgraded our signature system yesterday and now my pants are on fire! :evil:
Since the upgrade all new digital signatures are shown as invalid in my own application with the PDF-XChange Viewer 2.5 (Build 322.4) ActiveX SDK and also with the standalone PDF-XChange Viewer 2.5 (Build 322.4). The strange thing is when I open the file CoSign80_New_signatures_invalid.pdf ( :arrow: see attachment) with PDF-XChange Editor 5.5 (Build 316.1) and also with Adobe Acrobat 11.0.12 the digital signatures are shown as valid. :?:
What's wrong with the new digital signatures?

To compare, I added the file CoSign76_Old_signatures_valid.pdf ( :arrow: see attachment) which works with PDF-XChange Viewer 2.5 (Build 322.4) fine.

Many thanks for your fast help!

Karl
Attachments
CoSign76_Old_signatures_valid.pdf
PDF with digital signature shown as valid
(33.63 KiB) Downloaded 79 times
CoSign80_New_signatures_invalid.pdf
PDF with digital signature shown as invalid (but in PDF-XChange Editor or Adobe they are shown as valid)
(101.96 KiB) Downloaded 83 times

KarlTH
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Re: Invalid digital signature and message document has been altered

Post by KarlTH » Wed Jun 07, 2017 5:37 am

In addition to my posting here are the screenshots of the certificate details:

PDF-XChange Viewer 2.5 (Build 322.4)
Invalid_digital_signature_PDF-XChange_Viewer.png
Adobe Acrobat 11.0.12
Valid_digital_signature_Acrobat.png

Ivan - Tracker Software
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Re: Invalid digital signature and message document has been altered

Post by Ivan - Tracker Software » Wed Jun 07, 2017 11:05 am

The Viewer does not support ETSI.CAdES.detached signatures formally introduced in PDF 2.0
Tracker Software (Project Director)

When attaching files to any message - please ensure they are archived and posted as a .ZIP, .RAR or .7z format - or they will not be posted - thanks.

KarlTH
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Re: Invalid digital signature and message document has been altered

Post by KarlTH » Thu Jun 08, 2017 12:09 pm

Hello Ivan,

thank you for your fast reply! The vendor of our digital signature solution informed me an hour ago that they changed the signature algorithm from adbe.pkcs7 to ETSI.CAdES :evil: and now it's clear for me why PDF-XChange Viewer shows the digital signatures as invalid.
:x Sorry to bother you but the vendor hadn't given any information to me about the signature algorithm change before!

Many thanks,

Karl

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Tracker Supp-Stefan
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Re: Invalid digital signature and message document has been altered

Post by Tracker Supp-Stefan » Thu Jun 08, 2017 12:30 pm

Glad we could clarify this Karl,

But given that the Viewer is now no longer developed - I doubt that we will be able to fix this for the Viewer SDK, so the way to move forward would be to consider a switch to the Editor SDK.

Regards,
Stefan

KarlTH
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Re: Invalid digital signature and message document has been altered

Post by KarlTH » Thu Jun 08, 2017 12:42 pm

Hello Stefan,

it's clear for me that we have to switch from PDF-XChange Viewer SDK to PDF-XChange Editor SDK! :)
But I was confused what's wrong with the digital signature because I don't know that the vendor changed the signature algorithm.


Thanks,

Karl

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Tracker Supp-Stefan
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Re: Invalid digital signature and message document has been altered

Post by Tracker Supp-Stefan » Thu Jun 08, 2017 1:52 pm

Hi Karl,

Glad we got that sorted!

Cheers,
Stefan

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