pyhanko-beid-plugin 0.1.0

pyHanko plugin for Belgian ID cards

Introduction

This package provides a plugin for pyHanko’s PDF signing CLI. The implementation is a very thin convenience wrapper around the PKCS#11 functionality included within the “core” pyHanko library.

It used to be part of pyHanko’s core feature set until version 0.22.0 for historical reasons.

Installation

Assuming you are installing with pip, running pip install pyhanko-beid-plugin will install both pyHanko and the plugin. If you already have a working pyHanko install, take care to ensure that the plugin is installed in the same Python environment.

PyHanko makes use of Python’s package entry point mechanism to discover plugins, so installing both side-by-side should suffice. To test whether everything works, run pyhanko sign addsig and verify that beid appears in the list of subcommands.

Installation troubleshooting

If you’re having issues getting the plugin autodection to work, you can also add the following snippet to your PyHanko configuration file:

plugins:
  - pyhanko_beid.cli:BEIDPlugin

This will work as long as you ensure that pyhanko_beid is importable.

Signing a PDF file using a Belgian eID card

To sign a PDF file using your eID card and pyHanko’s CLI (with this plugin), use the beid subcommand to addsig, with the --lib parameter to tell pyHanko where to look for the eID PKCS#11 library.

Note

Of course, you can also use the pkcs11 subcommand, but beid provides an extra layer of convenience.

On Linux, it is named libbeidpkcs11.so and can usually be found under /usr/lib or /usr/local/lib. On macOS, it is named libbeidpkcs11.dylib, and can similarly be found under /usr/local/lib. The Windows version is typically installed to C:\Windows\System32 and is called beidpkcs11.dll.

On Linux, this boils down to the following:

pyhanko sign addsig --field Sig1 beid \
    --lib /path/to/libbeidpkcs11.so input.pdf output.pdf

On all platforms, the eID middleware will prompt you to enter your PIN to create the signature.

Warning

This command will produce a non-repudiable signature using the ‘Signature’ certificate on your eID card (as opposed to the ‘Authentication’ certificate). These signatures are legally equivalent to a normal “wet” signature wherever they are allowed, so use them with care.

In particular, you should only allow software you trust[1] to use the ‘Signature’ certificate!

Warning

You should also be aware that your national registry number (rijksregisternummer, no. de registre national) is embedded into the metadata of the signature certificate on your eID card[2]. As such, it can also be read off from any digital signature you create. While national registry numbers aren’t secret per se, they are nevertheless often considered sensitive personal information, so you may want to be careful where you send documents containing your eID signature or that of someone else.

[1]

This obviously also applies to pyHanko itself.

[2]

In the current implementation, the certificate’s serial number is in fact equal to the holder’s national registry number.