[gnutls-devel] DER decoding errors due to time format

[Nikos Mavrogiannopoulos]

On Tue, 2017-05-09 at 14:04 +0100, Daniel P. Berrange wrote:
> On Tue, May 09, 2017 at 02:48:08PM +0200, Nikos Mavrogiannopoulos
> wrote:
> > Hi,
> >  gnutls 3.5.x is more strict in certificate decoding and performs
> > various checks in the Time fields to ensure they are properly DER
> > formatted. However, it is seems that this caused regressions with
> > certain certificates generated by ovirt as seen in [0]. I am not
> > sure
> > which software was used to generate the problematic ones, however,
> > it
> > is most likely openssl, or some other open source software. Are you
> > aware of other or similar decoding issues which were a result of
> > 3.5.x
> > being more strict in DER rules?
> > 
> > The options we have are:
> >  1. Ignore the error and insist on DER correctness in input
> > certificates.
> >  2. Allow incorrect formatted time fields in certificates
> > unconditionally, e.g., with a special libtasn1 flag:
> > https://gitlab.com/gnutls/libtasn1/commit/16bad0c72dcdfbe5512cdd6b4
> > 6b251ab7484e5dc
> > 
> > any other option I've missed? While I favor the first for its
> > simplicity, reality has shown over the years we must yield towards
> > the
> > 'work' part.
> 
> Have you succeeded in getting any contact with oVirt community to
> find
> out how they are generating their certs ? That might give some
> clarity
> on whether it is just a minor bug in their code, vs following common/
> wide practice. It isn't clear if it even affects all oVirt users or
> just some subset of them, vs likely to affect large numbers of non-
> oVirt users too

Seems like a good point. I wouldn't know where to ask. Any suggestions?

regards,
Nikos