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Hey David,

1. and 5. The delegate is not always known to keystone. The delegate (I
like to say consumer) would use an oauth client (web-based one here
http://term.ie/oauth/example/client.php); in an oauth flow, the delegate
requires a key/secret pair, they don't have to be already known to
keystone. (Apologies if my keystoneclient example led you to believe that)

3. The authorizing step happens later on, 1e; any user with sufficient
credentials (the role matching the requested role), can authorize the
request token. If you don't expect the delegate to have knowledge of roles,
they shouldn't have knowledge of users either; so specifying one wouldn't
make things easier.

2. Continuing with my previous answer, to authorize a request token, the
requested role would have to be a subset of the delegator roles. Otherwise
any user could authorize the token.

4. When using an oauth client, the delegate would input both the key and
secret; the client would then sign the request and send only the key and
*other oauth specific variables* over to the server side.


Thanks,

_____________________________________________
Steve Martinelli | A4-317 @ IBM Toronto Software Lab
Software Developer - OpenStack
Phone: (905) 413-2851
E-Mail: stevemar at ca.ibm.com



From:	David Chadwick <d.w.chadwick at kent.ac.uk>
To:	OpenStack Development Mailing List
            <openstack-dev at lists.openstack.org>,
Cc:	Steve Martinelli/Toronto/IBM at IBMCA
Date:	06/14/2013 10:45 AM
Subject:	Re: [openstack-dev] [Keystone] Reviewers wanted: Delegated Auth
            a la Oauth



Hi Steve

Can I ask a few questions about this please

1. Step 0b. Why do we need a new consumers table containing essentially
un/pw pairs for the delegate (called key/secret in the spec) when the
delegate is already known to keystone and can authenticate using its
existing credentials?

2. Step 1b. How does the delegate know which role to request? This is
unintuitive. A delegator (rather than delegate) knows the role he wants
to delegate. One would normally expect the delegator to request Keystone
to delegate this role to the named delegate, rather than the delegate
asking for a role to be delegated to it, since it requires an out of
band communications between the delegator and delegate to take place
before the delegation, in which the delegator tells the delegate its
un/pw and the role it should ask for. This seems to be a rather
contrived exchange of messages.

3. Step 1b. Why does the delegate not specify who should do the
delegation?. This is another unintuitive feature. A delegate would not
normally simply ask a service to give it a role, since the service is
not empowered to do this. It has to be the existing role holder (the
delegator) who has to authorise this, but in step 1b the delegator is
not mentioned.

4. In step 1b the delegate is only authenticating itself via its
username/key, and this was specified by the delegator when he created
the new consumer in step 0b. So the delegator could have used a simple
name/key like Fred, which means that it would then be very easy for
anyone to masquerade as the delegate. Wouldnt it be better to require
both the un/pw (key/secret) in this exchange rather than simply the key?
The same security weakness is in step 1f as well.

5. What is the purpose of having the delegate's secret?

regards

David


On 14/06/2013 14:31, Steve Martinelli wrote:
> Greetings!
>
> I've implemented the following blueprint for keystone: Delegated Auth a
> la Oauth [1
> <https://blueprints.launchpad.net/keystone/+spec/delegated-auth-via-oauth
>].
>   The original spec [2 <https://gist.github.com/termie/5225817>] has a
> use case to help understand why we are providing this ability in
Keystone.
> If you're familiar with keystone, or just familiar with Oauth, I'd
> really appreciate your input. There are two change sets; a keystone
> patch [3 <https://review.openstack.org/#/c/29130/>] and keystoneclient
> patch [4 <https://review.openstack.org/#/c/30043/>].
>
> Thanks!
>
> References:
> 1.
https://blueprints.launchpad.net/keystone/+spec/delegated-auth-via-oauth
> 2. https://gist.github.com/termie/5225817
> 3. https://review.openstack.org/#/c/29130/
> 4. https://review.openstack.org/#/c/30043/
>
>
> Thanks,
>
> _____________________________________________
> Steve Martinelli | A4-317 @ IBM Toronto Software Lab
> Software Developer - OpenStack
> Phone: (905) 413-2851
> E-Mail: stevemar at ca.ibm.com
>
>
> _______________________________________________
> OpenStack-dev mailing list
> OpenStack-dev at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>

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