On 08/16/2012 01:19 AM, Mike Jones wrote:
Thanks for writing, Harry and WebCrypto WG.
1) About private keys, given the WebCrypto use case, I personally think it would be valuable for JOSE to define a JSON private key representation. To make this concrete, I would propose the private key representations specified in http://tools.ietf.org/html/draft-jones-jose-json-private-key. You'll see that doing this is very simple; it just defines two additional members for the JWK structure for representing the private parts of Elliptic Curve and RSA keys. This could either remain a separate spec from JWK/JWA or be merged in, at the working group's preference.
cheer
If that could be done, that would be great. Just keep WebCrypto in the loop.
I had previously agreed with the position that it was not necessary for JOSE to
define private key representations because we didn't have a use case for it.
However, as I see it, the W3C WebCrypto API use case changes things. Better
for JOSE to be responsive to WebCrypto and add this simple extension, either as
a new spec or in the existing specs, than to leave this undone, and have it
potentially be an area where otherwise standards-compliant implementations
diverge, and where JSON-only solutions are not possible.
Finally, I'll note that the JOSE charter
http://datatracker.ietf.org/wg/jose/charter/ does not preclude defining private
key formats. (It simply requires the definition of public key formats and is
silent on the topic of private keys.)
2) I agree on the likely need for WebCrypto support ASN.1 for backwards
compatibility in some cases (just as the JOSE specs allow the use of X.509
certificates). However, I believe it would be a shame to preclude JSON-only
solutions by not supporting key import/export in JWK format, where such
solutions make sense.
My feeling, and we've expressed this on telecons, is that we want JOSE
compatibility, especially to encourage WebApp developers who are not
crypto experts, as I imagine they would likely rather deal with JOSE
than ASN.1. Our API is likely going to have a "lower-level" for general
application programming version that will support ASN.1 due , and a
"higher-level" one for WebApp developers come out later (in about 6
months).
3) It appears to me the JWK format is stable. I believe the JWS format is
stable as well. The JWE format has known changes that will be applied shortly,
based upon working group discussions at IETF 84 in Vancouver two weeks ago.
Some JWA changes will occur that are part of the JWE changes. I don't
anticipate significant changes after that. (Making these changes is my highest
priority as JOSE editor. I'm hoping to have drafts out containing them by the
end of August, which hopefully fits well with the WebCrypto schedule.) I write
all of the above with the caveat that the working group is, of course, free to
change things as they see fit.
I think the JOSE WG is moving ahead of us nicely, so I imagine having
things stabilized in about 6 months would be perfect in order to be used
with the "higher-level" API.
cheers,
harry
I look forward to a productive discussion of this coordination request in both
working groups.
Best wishes,
-- Mike
P.S. If you prefer, a HTML-formatted version of the private key spec is
available at
http://self-issued.info/docs/draft-jones-jose-json-private-key.html. I also
blogged about this draft specification at http://self-issued.info/?p=816.
-----Original Message-----
From: Harry Halpin [mailto:[email protected]]
Sent: Sunday, August 12, 2012 8:03 AM
To: Jim Schaad; Karen O'Donoghue; [email protected]; Mike Jones
Subject: JOSE WG request from W3C WebCrypto API
[cc'ing Mike Jones and Richard Barnes, who participate inboth WGs]
JOSE Chairs,
The Web Cryptography Working group has noted that the API requires some access
to raw key material, and the issue of whether or not to use JWK or ASN.1 as the
default format came up. Two issues have come out that we'd like to know the
answer to:
1) JWK does not define a private key format. Does the JOSE WG plan to support a
JOSE-format for private keys? If so, when? Or 'maybe'?
2) While we'd like encourage the use of JOSE over ASN.1, it seems like for
backwards compatibility having some level of ASN.1 support would be useful and
we *need* a format that allows key material (both private and
public) to be exported. Folks seem to leaning towards ASN.1 as a default format
in the low-level API, and having JWK as a format that can be built on top of
that in a possible high-level API. Would that be OK?
3) How stable do you believe the JOSE formats are right now? Do you think
they are stable enough now we can reference them in our API draft at end of
August? If not, when? The W3C would like to and plan to use these formats
where possible.
Feel free to forward this by JOSE WG for discussion. We'd like an answer before
we send our document to FPWD at end of August.
cheers,
harry
_______________________________________________
jose mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/jose
