Enterprise Signing in OAUTH2

From IIW

Tuesday – Session 2 - I

Convener: Brian Eaton

Notes-taker(s): William Mills

A. Tags for the session - technology discussed/ideas considered:

B. Discussion notes, key understandings, outstanding questions, observations, and, if appropriate to this discussion: action items, next steps:

Brian: "I'm really happy with Oaut2, except for the signing... Can we take section 5.3 of the spec and set it on fire?"

Problems seeen: - HMAC covers the situation where people don't want to do SSL, but requires the whole ugly key management thing. Brina proposes (with a long list of others interested) that we need public key signing.

- The signing is not extensible, you can't add additional fields to the signature. This seems to be a problem in the current spec.

- New protocol substrates.

- One signing choice doesn't seem enough. Extensibility seems key here, can we do this with some form of discovery?

Proposed fixes:

- Create a JSON blob we want signed.

   -    an example...  does not require reconstruction of the string to be signed
   -    BUT how do you verify the signed stuff is part of the request?
   -    ALSO not great: duplication of data.

- We need key versioning - Needs key discovery

   -    Can use something liek https://<app>.appspot.com/.well-known/oauth or some such.
       -    This might not work for folks that are white label, because there isn't a separate URL for all the entities that need to be discovered.
   -    There is a google group for the OAuth Key Discovery spec.  See Brian's copy of the slides.
   -    It's worthwhile to join the OAuth2 mailing list to comment on this.
   -    This is a big discussion topic, I don't type that fast.
   -    XKMS is again, good reference reading for this.

Discussion: - How does it work with firewalls -- in and out... - XMLDSIG is very similar to this, it would be worthwhile to learn from that. Also CMS (Crypto Message Sig). - Does have the whole PKI problem. - Can we solve this with SSL? SSL with client certs? Maybe...

   -    MUch discussion here about how key excahnge and key management should work.

- Comment -- If you want to sign arbitrary parts of an HTTP request then use SAML. you don't really want to duplicate that here. - Need to make sure we get the key exchange right, if you try to put it in here people will get it wrong. - KeyID/key discovery.

   -    comment: see XKMS for related reading.
   -    keyID probably belongs in the envelope and not the payload (from his modified example.