Re: [jose] Adding a X509/PKIX JWK type? [WAS: issues with x5c in JWE]

[John Bradley <[e-mail]>]

I agree that being able to include a x5c or reference a x5u form a JWK allows for more consistency around key references and key use.

I support developing an ID to discuss this.

John B.
On 2013-02-08, at 11:47 AM, "Matt Miller (mamille2)" <[e-mail]> wrote:

> After some off-list discussions, a couple of us believe it would be worthwhile to somehow wrap a PKIX certificate chain in a JSON Web Key.  A couple of us are leaning toward a new JWK type to do this.  One impact, I think, is that anywhere we currently have "x5c" (and potentially "x5t" and "x5u") are effectively replaced by an actual JWK object.  However, a few of us have other use cases where a PKIX certificate JWK would solve some problems.
> 
> Unless there's strong objection, Brian Campbell and I are likely to start work on a new I-D that documents our musings.
> 
> 
> Thoughts?
> 
> - m&m
> 
> Matt Miller < [e-mail] >
> Cisco Systems, Inc.
> 
> On Jan 31, 2013, at 3:15 PM, Matt Miller (mamille2) <[e-mail]> wrote:
> 
>> I could also see it like the following:
>> 
>> {
>> "kty":"RSA",
>> "kid":"[e-mail]",
>> "n":".....",
>> "e":"AQAB",
>> "x5u":"https://capulet.lit/juliet.crt"
>> // and/or "x5c":[....]
>> }
>> 
>> Having a "X509" JWK type might solve one problem I can see having in XMPP-E2E, but it that same problem could be solved with the above.
>> 
>> Then again, I could be completely off in the weeds.
>> 
>> 
>> - m&m
>> 
>> Matt Miller < [e-mail] >
>> Cisco Systems, Inc.
>> 
>> On Jan 31, 2013, at 2:45 PM, Brian Campbell <[e-mail]>
>> wrote:
>> 
>>> John and Mike beat me to it but yeah, the general idea of some kind of X509
>>> support in JWK has now independently come up in my world twice in as many
>>> days.
>>> 
>>> I must say that, from a general design of things perspective, it seems like
>>> a total abomination. But maybe, just maybe, it'd be useful enough to
>>> overcome such pity objections?
>>> 
>>> Though, to be fair, Matt's idea is pretty different than what John has in
>>> mind. Getting to some level of agreement would likely be more than just a
>>> formality.
>>> 
>>> 
>>> On Thu, Jan 31, 2013 at 9:54 AM, John Bradley <[e-mail]> wrote:
>>> 
>>>> Brian and I were discussing a couple of options off the list.
>>>> 
>>>> One possible thing might be to add x5c and/or x5u elements to jwk.
>>>> 
>>>> In Connect we are looking at how to deal with key rollover for signing.
>>>> 
>>>> The problem with specifying a x5u is that while it is a vert chain it is a
>>>> single cert chain, so you need to have multiple and there is no easy way to
>>>> have the same keyid for a jwk key and a x5u key.
>>>> 
>>>> My idea was to allow x5u elements in a jwk so that you can have a single
>>>> keyid and key use that apples to both formats.
>>>> 
>>>> I can see a use for x5c in jwk as well especially where it is being sent
>>>> in band.
>>>> 
>>>> So while it may sound crazy a number of us may be thinking the same thing.
>>>> 
>>>> John B.
>>>> 
>>>> On 2013-01-31, at 1:42 PM, "Matt Miller (mamille2)" <[e-mail]>
>>>> wrote:
>>>> 
>>>>> 
>>>>> On Jan 31, 2013, at 9:20 AM, Brian Campbell <[e-mail]>
>>>> wrote:
>>>>> 
>>>>>> Seems to me that something like x5c would be a lot more meaningful and
>>>>>> useful for a possible future ECDH-SS algorithm for JWE. But it would be
>>>>>> about the encrypting party or sender's certs in that case, right? Which
>>>>>> would be different than how it's currently being used. And that might be
>>>>>> another argument for not having it in JWE right now.
>>>>>> 
>>>>>> Of course that starts to beg the "must understand headers" question but
>>>> I
>>>>>> digress...
>>>>> 
>>>>> I was starting to come to similar conclusions.
>>>>> 
>>>>> This probably sounds crazy, but maybe we can pretend x.509 certs can be
>>>> wrapped into a JSON Web Key?
>>>>> 
>>>>> {
>>>>> "kty":"X509",
>>>>> "x5c": [....]
>>>>> }
>>>>> 
>>>>> 
>>>>> - m&m
>>>>> 
>>>>> Matt Miller < [e-mail] >
>>>>> Cisco Systems, Inc.
>>>>> 
>>>>>> On Tue, Jan 29, 2013 at 8:04 PM, John Bradley <[e-mail]>
>>>> wrote:
>>>>>> 
>>>>>>> Yes for encryption (Leaving ECDH-SS aside ) the recipoient decrypts
>>>> with a
>>>>>>> secret.  I would expect a kid in the header.
>>>>>>> 
>>>>>>> I suppose they if the recipient published a x5c that the sender used to
>>>>>>> encrypt with then you could include the x5c as a reference though a
>>>>>>> thumbprint would be simpler as the recipient is probably keeping its
>>>>>>> private keys in a key-store of some sort.
>>>>>>> 
>>>>>>> In any event we would minimally want to change that to
>>>>>>> 
>>>>>>> "The certificate containing the public key of the entity that is to
>>>>>>> decrypt the JWE MUST be the first certificate."
>>>>>>> 
>>>>>>> 
>>>>>>> Thanks Brian
>>>>>>> 
>>>>>>> John B.
>>>>>>> 
>>>>>>> 
>>>>>>> On 2013-01-29, at 11:08 PM, Brian Campbell <[e-mail]
>>>>> 
>>>>>>> wrote:
>>>>>>> 
>>>>>>> I just noticed a couple of things in the JWE's x5c definition that
>>>> struck
>>>>>>> me as maybe not right.
>>>>>>> 
>>>>>>> From
>>>>>>> 
>>>> http://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-08#section-4.1.9
>>>>>>> 
>>>>>>> "The certificate containing the public key of the entity that encrypted
>>>>>>> the JWE MUST be the first certificate." - but it's not the public key
>>>> of
>>>>>>> the entity that encrypted, is it? It's the public key of the entity
>>>> that
>>>>>>> will decrypt. The other entity.
>>>>>>> 
>>>>>>> "The recipient MUST verify the certificate chain according to [RFC5280]
>>>>>>> and reject the JWE if any validation failure occurs." - maybe I'm
>>>> missing
>>>>>>> something but why would the recipient verify it's own certificate
>>>> chain?
>>>>>>> 
>>>>>>> And the first hyperlink in "See Appendix B<
>>>> http://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-08#appendix-B>of
>>>> [
>>>>>>> JWS<
>>>> http://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-08#ref-JWS
>>>>> ]
>>>>>>> for an example "x5c" value" takes you to Appendix B of JWE, which is
>>>>>>> Acknowledgements, rather than JWS as the text would suggest.
>>>>>>> 
>>>>>>> So all those little nits could be fixed. But maybe it'd be better to
>>>> just
>>>>>>> remove x5c from JWE all together? As Richard pointed out previously,
>>>>>>> http://www.ietf.org/mail-archive/web/jose/current/msg01434.html,
>>>> there's
>>>>>>> really no point in sending a whole chain to help the recipient
>>>> identify its
>>>>>>> own key.
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> _______________________________________________
>>>>>>> jose mailing list
>>>>>>> [e-mail]
>>>>>>> https://www.ietf.org/mailman/listinfo/jose
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>> _______________________________________________
>>>>>> jose mailing list
>>>>>> [e-mail]
>>>>>> https://www.ietf.org/mailman/listinfo/jose
>>>>> 
>>>> 
>>>> 
>> 
>> _______________________________________________
>> jose mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/jose
> 
> _______________________________________________
> jose mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/jose