RadPdfViewer always shows the digital signature as invalid

[Giovanni]

Hi, I'm using a RadPdfViewer to show a Pdf.

If the pdf is signed the signatures panel is showed, but the signature is always showed as not valid, even if it is valid.
The error is that the "The signer's identity isunknown".

I tried also to call the SignatureField.Signature.Validate() method and it throws an exception like this:

No signature validation handler was found for the subfilter: ETSI.CAdES.detached

 

Any suggestion?

Thanks.

[Yoan]

Hello Giovanni,

I am sorry to hear you are experiencing unexpected results. I would gladly like to help you with this case however without having any resources at my disposal which I can examine, my assistance is very limited.

With that in mind, in order for me to get a better context and understanding of the scenario you are experiencing, would you be able to share with us a sample document you are using to reproduce this behavior? This way I can try to achieve the same results on my end, investigate the issue further, try to identify the cause, and get back to you with details and feedback.

That said, please keep in mind that this is a Q&A Forum and any attached resources will be publicly accessible to everyone. If you have any concerns please feel free to open a separate ticket for PdfProcessing regarding this issue where we can continue our conversations in private. 

Thank you in advance for your cooperation.

Regards,
Yoan

[Giovanni]

Hi Yoan, thanks for your reply.

I've attached a simple project that loads a pdf signed file when started.
The file is included in the project (FileSigned.pdf), so you can simply launch the project.

Regards.

 

[Yoan]

Hello Giovanni,

Thank you for the provided project. The results you are experiencing are expected. To evaluate a certificate as trusted, it must be added to the trusted certificates on your machine. If you haven't already you can see how to do that and follow the steps in the View certificates in the MMC snap-in Microsoft article.

After following the steps, the PdfViewer should recognize the certificate and the validation should pass.

Let me know how it goes.

Regards,
Yoan
Progress Telerik

[Giovanni]

Hi Yoan, thank you,

I tried to follow your suggestion adding the root certificate to the Trusted root certification authorities on my local machine: is it right?

Unfortunately, after this, the signature panel still shows the same alert.

 

 

[Yoan]

Hello Giovanni,

Thank you for trying the suggested approach. After further investigation, I managed to verify that you are experiencing these results due to missing support from the library. We already have a feature request logged in our Feedback Portal regarding the implementation of this functionality - PdfProcessing: Add support for ETSI.CAdES.detached signature encoding when validating signature fields.

Please accept my apologies for the inconvenience this is causing you but there is no workaround I can offer you in this scenario. I can only suggest you cast your vote for the task in order to increase its priority in our backlog and to subscribe so you can track its progress by receiving status update notifications.

Thank you for your understanding. If you have any additional questions or feedback, please know that I remain at your disposal.

Regards,

Yoan

[Giovanni]

Thank you Yoan, I voted! ;)

Regards.