[OpenID] Signing method for XRD

Fri Jun 12 08:48:47 UTC 2009

Hi Nat,

I completely agree with you, a single technology for those closely related
protocols would be better than forking. The main advantage using XMLdSIG is
that there are a huge amount of services currently working with this
technology. As far as I know there are mature libs for C, C++, Java, .net,
python, ruby, php .

Those libs are compliant with xmldsig interopt tests so this give us
warranties about their intertoperability. Message sign and verify primitives
are very simple from the point of view of the developer and the only problem
arises when trying to verify the signer certificate (path building,
validation, status validation vs CRL and OCSP...) but several "tricks" could
be made here to keep the process simple.

I'll feel very comfortable about using XMLdSIG because from the point of
view of the increase of complexity it won't be as easy as raw data
processing, but it won't be very painful if we use those sets of libs.

If you want maybe we can create a little project for a proof of concept and
make an interop between 2 different technologies signing and verifying
messages. If so please let me know :).

Best regards

Dave

2009/6/12 =nat <sakimura at gmail.com>

>
> Hi.
>
> Thanks for your great feedback.
>
> It is kind of interesting that OpenID side wants the simplest form while
> in the OAuth list, XML DSig is liked better somehow.
>
> From the spec point of view, it is better to not to fork as much as
> possible,
> so if we can stick to XML DSig, that's great.
>
> Now, here is another question then.
>
> If libraries with decent API becomes available to each language,
> written in that language, and is tested for compatibility to each other,
> would you be amiable to this constrained form of XML DSig?
>
> =nat
>
> On Thu, 11 Jun 2009 16:14:56 +0200, David Garcia <david.garcia at tractis.com
> >
> wrote:
> > Hi Hans,
> >
> > this project offers a set of wrappers over xmlsec library used on many
> c++
> > envs. I used it a lot and their equivalent in Java for some years on
> > critical production envs and they're very mature.
> >
> > Dealing with xml data as opaque bits (a simplified xml version of CMS
> > signature containers) instead of interpreting the infoset as proposed
> will
> > be a much simpler approach because it eliminates the need of using c14n
> > and
> > transform algorithms (not mandatory but recommended on some scenarios).
> >
> > Maybe this simpler approach will fit for message exchange.
> >
> > Best regards
> >
> > Dave Garcia
> >
> >
> > 2009/6/11 Hans Granqvist <hans at granqvist.com>
> >
> >> Perhaps someone from VeriSign (Barry? Gary?) can comment on the
> > viability
> >> of
> >> http://xmlsig.sourceforge.net/
> >>
> >> Hans
> >>
> >>
> >>
> >> On Wed, Jun 10, 2009 at 11:54 PM, John Panzer<jpanzer at acm.org> wrote:
> >> > My general impression is that something that requires two pieces of
> >> software
> >> > to agree on an exact, bit for bit infoset representation of an XML
> >> document
> >> > in order to get security to work is a poor idea.  I have seen no wide
> >> > deployments/usage of DSig in Atom feeds -- despite it being part of
> > the
> >> spec
> >> > -- and many complaints about how it's not possible to get it to work
> >> > reliably given the software stacks currently in use.  The difficulties
> >> with
> >> > canonicalization-for-signing in OAuth implementations have also
> >> reinforced
> >> > my belief that it's much better to err on the side of the robust and
> >> simple.
> >> >
> >> > Signing a stream of uninterpreted bytes cuts out a whole slew of
> > failure
> >> > modes, and the ones that remain are debuggable -- the bytes match or
> > they
> >> > don't, and standard tools can tell you which.  It means it's possible
> > to
> >> > verify a signature with curl + a command line utility.  These are all
> >> very
> >> > good things.
> >> >
> >> > (As a side note, it would also make the content type orthogonal to the
> >> > signature code -- this is a good thing.)
> >> >
> >> > So, +1 for the simplest form of signing that could possibly work.
> >> >
> >> > -John
> >> >
> >> >
> >> > Johannes Ernst wrote:
> >> >
> >> > I proposed something I called XML-RSig for similar reasons a few years
> >> ago:
> >> >
> >> http://netmesh.info/jernst/Technical/really-simple-xml-signatures.html
> >> >
> >> > "RSig" for "Really simple Signature".
> >> >
> >> > The trouble for OpenID and XRD and so forth is that it is not our core
> >> > competency -- and shouldn't be -- to innovate around things that
> > really
> >> > aren't our business. Signing XML documents isn't our business.
> >> >
> >> > On the other hand, the people whose business it should be somehow seem
> > to
> >> be
> >> > asleep at the wheel, as the problems are well-known and somehow aren't
> >> being
> >> > addressed, and haven't for years.
> >> >
> >> > It seems to me that the best way out of this conundrum is:
> >> > 1. to foresee, architecturally, the use of several different ways of
> >> > constructing signatures, as the matter clearly isn't settled
> >> > 2. to make sure that high-end approaches (like XML-DSIG) work well,
> > but
> >> > low-end approaches (like XML-RSIG) work just as well
> >> > 3. to maintain a best practices document that says "today, choice X is
> >> your
> >> > best bet, and we say that because based on our market research, X has
> > the
> >> > highest market share in terms of implementors today."
> >> >
> >> > As we all know, any problem in computer science can be solved by
> > adding a
> >> > level of indirection. This may well be one of those cases.
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > Johannes Ernst
> >> > NetMesh Inc.
> >> >
> >> >
> >> > ________________________________
> >> >
> >> >
> >> >
> >> > ________________________________
> >> >
> >> >  http://netmesh.info/jernst
> >> >
> >> >
> >> >
> >> > ________________________________
> >> > _______________________________________________
> >> > specs mailing list
> >> > specs at openid.net
> >> > http://openid.net/mailman/listinfo/specs
> >> >
> >> >
> >> > _______________________________________________
> >> > specs mailing list
> >> > specs at openid.net
> >> > http://openid.net/mailman/listinfo/specs
> >> >
> >> >
> >> _______________________________________________
> >> specs mailing list
> >> specs at openid.net
> >> http://openid.net/mailman/listinfo/specs
> >>
> >
> >
> >
> > --
> > David Garcia
> > CTO
> >
> > Tractis - Online contracts you can enforce
> > http://www.tractis.com
> > --
> > Tel: (34) 93 551 96 60 (ext. 260)
> >
> > Email: david.garcia at tractis.com
> > Blog: http://blog.negonation.com
> > Twitter: http://twitter.com/tractis
>

-- 
David Garcia
CTO

Tractis - Online contracts you can enforce
http://www.tractis.com
--
Tel: (34) 93 551 96 60 (ext. 260)

Email: david.garcia at tractis.com
Blog: http://blog.negonation.com
Twitter: http://twitter.com/tractis
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