We have some PDF files which are secured by a .pfx certificate. On Windows we can use Adobe Reader to read these PDF files (with previously imported certificate).

I've googled for a long time but I can't find a PDF reader which can open this.

NOTE: Just so it's clear. If I were to open a PDF file that had this digital signature applied to it, and it was opened in say, Evince it would display like this:


While Acrobat Reader (acroread) like this:



PDF File for the above is here: http://adobetrainer.co.uk/Resources/sign-a-pdf-with-reader-enabled.pdf

  • If this feature is only available in proprietary software, and you do not value your freedom, then you can use Adode Reader. Commented Aug 25, 2014 at 15:20
  • 1
    What exactly does secured by a .pfx certificate mean? Does the .pfx fole contain the encrypted PDF? In such case you could try openssl pkcs12 to decrypt it (provided you have the appropriate key) - see the pkcs12 man page.
    – peterph
    Commented Aug 25, 2014 at 22:18
  • Sry but the latest adobe reader for unix is 9.5.5. - there are many bad notifications for security reasons.
    – AgentTux
    Commented Aug 26, 2014 at 13:02
  • No the .pfx doesnt contain the encrypted pdf file. There are two files: PDF and PFX. The pdf file is secured by these certificate and can only be opened with the attached certificate.
    – AgentTux
    Commented Aug 26, 2014 at 13:04
  • This blog post shows how to sign PDF files using a .pfx cert on Linux: paulbradley.org/digitally-sign-pdf-files
    – slm
    Commented Oct 1, 2014 at 2:33

5 Answers 5


To open the file, use any PDF reader. I tested this by opening a self-signed pdf file in linux using epdfviewer. Even though the .pfx file was not in the system, the viewer did not complain, or even asked for the .pfx file.

I believe that the .pfx file is only needed for signing the document, not for opening it. In this way, it acts as a private key file.

Update: The updated question clarifies the requirements. You're looking for a PDF viewer that shows the signature field and also allows you to sign the document in the signature field. epdfviewer does not do that.

As I mentioned in the comments, CabaretStage does show the signature field and allows you to place the signature on that field as well. The free version adds a watermark, so you need to purchase it.

Apparently, Foxit Reader also works, but I was not able to get it to work on my system, so I cannot confirm it.

  • I've tried several signed documents and they open but do not display things properly.
    – slm
    Commented Oct 9, 2014 at 23:21
  • Can you obtain a copy of the unsigned PDF, to compare them with the signed PDF? What exactly is not displaying properly, the signature itself, or the whole document?
    – aprad046
    Commented Oct 30, 2014 at 2:27
  • @slm Visually, the difference I noticed between Adobe Reader and other PDF viewers Adobe highlights the signature field. CabaretStage allows you to "see" the signature field. However, I think you're looking for a viewer that also allows you to sign the document in the signature field. CabaretStage does that, but the free version adds a watermark, so you need to purchase it. Apparently Foxit Reader also works, but I didn't try it.
    – aprad046
    Commented Oct 30, 2014 at 12:50
  • The differences I notice are that the digital signing feature is completely ignored in all the free viewers I've tried. I worked this problem for the better part of a week and came up empty. When I researched this there's a lot of confusion about electronic vs. digital signature. The latter has to do with an actual digital certificate being used to "sign" the document. The free viewers typically ignored this aspect of the PDF. I'm not the OP of this Q but as a mod of the site was trying to help by answering it.
    – slm
    Commented Oct 30, 2014 at 12:54

I recommend pdf-xchange-viewer. It runs using wine. In my Debian 7 works very well. I use it a lot to annotate PDFs, add/remove pages, bookmarks, etc.

According to their web page for signatures support you need the Pro version (paid).


PDF Studio Viewer can render signed PDF documents. It can validate digital signatures. It comes with default trusted certificates (Oracle's) but users can customize them. PS: I am a developer at Qoppa.


Check out Intisign. Free by the Ecuadorian Goverment.


It can sign and check signatures of pdfs. Additionally, it supports time stamping.


Did you ever try LibreOffice Draw? https://help.libreoffice.org/Common/About_Digital_Signatures

It can read and write digital signatures in pdf as well as other formats, however I don't know it would fit this particular use case.

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