Re: [Opensc-devel] pam_pkcs11 -- Pull requests and advice for another bug fix

[Logan G. <lo...@ie...>]

Ah, understood. I missed that part of the mailing list, it's a shame no one
from Canonical or Red Hat have stepped in as they both advertise smart card
support using pam_pkcs11!

I will happily help with some basic maintenance so getting write access
would be greatly appreciated.

I'm unlikely to have time, but if a rewrite is in order is the best path
still through libp11 as mentioned four years ago?

Best,
Logan

On Mon, Aug 3, 2020 at 2:34 AM Ludovic Rousseau <lud...@gm...>
wrote:

> Hello,
>
> I used to be the maintainer of pam_pkcs11.
> 4 years ago I asked for help
>
> https://opensc-devel.narkive.com/iYD5vBPl/pam-pkcs-11-needs-a-new-maintainer-s-soon-or-it-will-die
>
> If you plan to use pam_pkcs11 personally and professionally then it is
> a good idea to engage in its development.
> I can add you to the pam_pkcs11-maintainers team so you have write access.
>
> Regards,
>
> Le lun. 3 août 2020 à 11:15, Logan Garbarini <lo...@ie...> a écrit :
> >
> > Hi all,
> >
> > I've been starting to use OpenSC and pam_pkcs11 personally and
> professionally and have discovered a couple issues in `pam_pkcs11`. It
> looks like the mailing list is the proper avenue for raising some of these
> issues so here I go.
> >
> > 1) I've put up a pull request for one bug that has been verified by
> another user here, this seems to be primarily an issue with OpenSSL
> versions and how they are handled:
> >
> > https://github.com/OpenSC/pam_pkcs11/pull/45
> >
> > 2) I've found what appears to be a much trickier issue in the ECDSA
> signature verification of cert_vfy.c (
> https://github.com/OpenSC/pam_pkcs11/issues/44). I'll reproduce the
> salient parts of the issue below:
> >
> >> When using signature verification in pam_pkcs11, I immediately run into
> the following verification issue on ECDSA certs/keys in verify_signature():
> >>
> >> verify_signature() failed: EVP_VerifyFinal() failed: error:25066067:DSO
> support routines:dlfcn_load
> >>
> >> The primary issues seems to be "Signed big-endian encoding of minimal
> length", from the stackexchange post How can I convert a DER ECDSA
> signature to ASN.1?. The current upstream code doesn't seem to even yield a
> properly terminated ASN1 signatures on modern OpenSSL versions (1.1.0) and
> even if it did lacks handling of BIGNUMs that may be interpreted as signed
> integers if not properly padded (see above stack exchange).
> >
> >
> > I have attached a hacky demo patch file that along with the linked stack
> exchange posts clarifies my issue and what appears to be the necessary
> solution.
> >
> > This leads me into my primary question, as someone who hasn't had too
> much exposure to OpenSC and is certainly not an expert in the OpenSSL API,
> what is the best way to contribute?
> >
> > It seems like EVP_Verify is a much older API and EVP_DigestVerify is now
> recommended, has better documentation, and has better support for ECDSA
> signatures (https://wiki.openssl.org/index.php/EVP_Signing_and_Verifying).
> However, this would be a much bigger change than trying to reassemble the
> ASN1 encoding using BN_bin2bn and ECDSA_SIG_get0_*.
> >
> > Best,
> > Logan
> >
> > _______________________________________________
> > Opensc-devel mailing list
> > Ope...@li...
> > https://lists.sourceforge.net/lists/listinfo/opensc-devel
>
>
>
> --
>  Dr. Ludovic Rousseau
>