Will PDF-XChange support detached signature files one day (CAdES)?

[xchangeit]

Hello!

PDF-XChange Editor shows embedded qualified signatures and offers to proof them (PAdES).

Some signatures are coming not embedded in the PDF file, but in a detached .pkcs7 signature file (CAdES). Will you add support to proof these signatures in the future?

Thank you,

xchangeit

[TrackerSupp-Daniel]

Hi, xchangeit

WE have actually supported this fully for quite a while not, although it is not the default setting. A detached .pkcs7 file is simply how the certificate is generated in the document initially, which can be changed.
To change this, before placing the signature, open the Preferences (Ctrl+K) and look under the "signatures" category, then click "more" in the "creation and appearance" section:

Here you can change the creation method. I hope this helps!

Kind regards,

[xchangeit]

Hello Daniel,

I'm afraid not. I would like to proof an existing detached signature in a .pkcs7 file that comes along with a corresponding PDF file and contains the signature for the PDF file. File and signature are already existing and come from another person.

xchangeit

[TrackerSupp-Daniel]

Hi, xchangeit

My apologies for misunderstanding. By Proof I assume you mean validating the signature, yes? In that case we do still support this, do you have an example of this not working that you could send us a copy of, along with screenshots? As it has signatures which would clearly be sensitive information, I would ask that you email <support@pdf-xchange.com> with those files attached.

Kind regards,

[xchangeit]

Hello Daniel,

yes, I mean validating, sorry.

I do not have an example at the moment, but perhaps you can describe what to do with the .pkcs7 signature file?

An embedded signature is shown automatically when the PDF file is opened. But a detached signature is not recognized by PDF-XChange Editor by himself, when it is next to the pdf file in the same folder. How can I "give" the file to PDF-XChange Editor?

Thank you,

xchangeit

[lev]

Are we talking about a self-signed certificate by chance?

[xchangeit]

No, we are talking about XChange Editor not being able to process signatures that are saved in a .pkcs7 file. Validating the signature would be a second step. In my case it is a qualified signature (eIDAS, electronic IDentification, Authentication and trust Services).

[TrackerSupp-Daniel]

Hi, xchangeit

I am afraid that I do not understand. When signing, even with "detached PKCS#7" selected no separate file is generated outside of the document. There would not be a separate *.pkcs7 file independent from the PDF document, it would still be "within" the PDF document in any situation.

How have you signed a PDF document in a way that you end up with a completely separated file which appears in the file browser window to act as the signature?

Kind regards,

[xchangeit]

Hello Daniel,

When signing, even with "detached PKCS#7" selected no separate file is generated outside of the document.

I suspected that your software uses a different meaning of "detached" in the options you showed me. In qualified signature software as Seccommerce Secsigner for example the option "detached" or CAdES produces an additional file next to the signed PDF file. Perhaps your option means something like "internally detached".

German authorities (my main use case) produce detached signatures in standalone .pkcs7 files. And that is what would be nice to have validated just by opening the PDF file, having the signature file next to it with the same file name: file.pdf and file.pdf.pkcs7

Best regards,

xchangeit

[lev]

A proper term for this appears to be Qualified Electronic Signature defined by the eIDAS (electronic IDentification, Authentication and trust Services) (an EU regulation).
SecSigner 7 offers an Acrobat plugin. Question to Tracker Software: Can this plugin be used with PDF_XChange? An item of interest is that section 8.2 of the software manual recommends using SecSegner to verify signatures, rather than using the plugin.