New to EJBCA, need info about DSS, PDF hashing etc

[PTDI]

Hi,
I am in a Digital Signature project and I am very new with EJBCA, We are trying to do a client side hashing, my question:

Do we need to prepare required signature fields before sending PDF hashing?
As we develop our API on Net Core platform, we need a software library recommendation for doing PDF concatenation after receive .p7s strings from EJBCA DSS.
Where can I find the EJBCA's article for client hashing and the C# example for doing this?
I need advice..

Thanks & Regards

[Markus Kilås]

Hi PTDI,

If you are going to implement client-side hashing for PDF signing you will need to take care of all the PDF parsing, preparing for signing, hashing and in the end including the signature within the PDF file. On the SignServer-side you could probably use the CMS Signer.

I am not familiar with PDF libraries in .NET. Possbly there could be some variant of iText that could be used or some other library.

We do not have any specific documentation for how to do client-side hashing for PDF signing yet. In fact we do not implement that in SignServer Enterprise yet either, so we have not done it.

Cheers,
Markus
PrimeKey Solutions