Invalid digital signature and message document has been altered

[KarlTH]

Hello Tracker-Support,

I upgraded our signature system yesterday and now my pants are on fire!
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 ( 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 ( see attachment) which works with PDF-XChange Viewer 2.5 (Build 322.4) fine.

Many thanks for your fast help!

Karl

[KarlTH]

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]

The Viewer does not support ETSI.CAdES.detached signatures formally introduced in PDF 2.0

[KarlTH]

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 and now it's clear for me why PDF-XChange Viewer shows the digital signatures as invalid.
Sorry to bother you but the vendor hadn't given any information to me about the signature algorithm change before!

Many thanks,

Karl

[Tracker Supp-Stefan]

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]

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

[Tracker Supp-Stefan]

Hi Karl,

Glad we got that sorted!

Cheers,
Stefan