John,

In these cases are you carrying information in the JWS object other than the
algorithm?  I am trying to figure out if the "protected header" field is
really used in this case.

Jim


> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of
> John Bradley
> Sent: Monday, August 19, 2013 12:49 PM
> To: Justin Richer
> Cc: [email protected]; [email protected]; jose issue tracker;
> [email protected]; [email protected]
> Subject: Re: [jose] #36: Algorithm "none" should be removed
> 
> In OAuth and Connect there are cases where you are receiving tokens from
> multiple sources.  By allowing none as a alg option we can process signed
or
> unsigned tokens with the same basic handler by inspecting the first
> segment.  I note currently that while none has three segments the last
> segment must be empty.   I think that is sufficient to keep people from
> becoming confused.
> 
> Making it two segments will break existing parsers for no good reason.
> 
> What we call it I am flexible about, if it is a unsigned JOSE object in
compact
> serialization i am fine.
> 
> John B.
> 
> On 2013-08-19, at 12:30 PM, Justin Richer <[email protected]> wrote:
> 
> > I don't normally jump into the discussion on this list, but I've been
using
> the output of JOSE for quite some time now and am a committer on the
> NimbusDS JOSE JWT library. However, with tonight's call coming up (which I
> won't be able to make) I wanted to jump in and say that from my
> perspective, alg:none makes a lot of sense. There's a need for being able
to
> send unsigned content with JOSE objects, and that's been pretty well
> established by others on the list here. As an implementor, though, I think
it
> makes the most sense to have the unsigned content be parallel in structure
> to the signed content. When reading a string and constructing objects, our
> library parses the header and dispatches the parser based on the "alg"
> parameter.
> >
> > And as Mike points out, alg:none has been in the spec as required to
> implement for ages now, and it hasn't caused the horrible security holes
> that people are predicting.
> >
> > -- Justin
> >
> > On 08/01/2013 07:23 AM, jose issue tracker wrote:
> >> #36: Algorithm "none" should be removed
> >>
> >>
> >> Comment (by [email protected]):
> >>
> >>  And sure enough, working groups across the IETF are having to
> >> explicitly  forbid the use of null ciphersuites.  They provide
> >> empirical evidence that  this design pattern is a bad idea.
> >>
> >>  As I've pointed out before, you can add that verification algorithm,
> >> but  you will not have a good time writing security considerations
around
> it.
> >>  Checking that you support "none" is not enough -- you have to check
> >> that
> >>  *nothing* *else* in the header could possibly indicate that a
> >> different  signature algorithm should be used.
> >>
> >>  So we have something that (1) causes a lot of spec work, (2) causes
> >> security vulnerabilities under likely implementaiton designs, and (3)
> >> has  no use case, and (4) will haunt us for years to come (how many
> >> times do  you want to write 'MUST NOT use "alg":"none"'?).  Sounds
> >> like a recipe for  success!
> >>
> >
> > _______________________________________________
> > jose mailing list
> > [email protected]
> > https://www.ietf.org/mailman/listinfo/jose


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