Yes, that's my point.

David's point is that we need two tokens to defend against these scenarios.

On Thu, May 20, 2010 at 10:02, Allen Tom <[email protected]> wrote:
> Isn't this currently the case with the OpenID/Oauth Hybrid? If the RP has an
> Access Token for the user, and the RP's login cookies are compromised, the
> attacker will be able to use the RP as a proxy to the user's data on the OP.
>
> Is there a new attack scenario that has been introduced that was not already
> present in the existing OpenID 2.0/Hybrid?
>
> Allen
>
>
> On 5/19/10 11:06 PM, "Breno de Medeiros" <[email protected]> wrote:
>
>> I am saying that if someone steals the user login cookie for
>> coolcalendar.com and coolcalendar also has a token to access the user
>> contact data, it's pretty likely that the attacker will recover the
>> contacts even if the login cookie is not the same token as the contact
>> access token.
>>
>> It is probably more effective as a security mechanism to restrict
>> lifetime of access token in this case.
>>
>> On Wednesday, May 19, 2010, Allen Tom <[email protected]> wrote:
>>> Hi Breno,
>>>
>>> Can you describe the attack scenario with an example?
>>>
>>> Thanks,
>>> Allen
>>>
>>>
>>>
>>> On 5/19/10 8:38 PM, "Breno de Medeiros" <[email protected]> wrote:
>>>
>>>> On Wed, May 19, 2010 at 20:36, David Recordon <[email protected]> wrote:
>>>>> So because one thing is potentially insecure we should knowingly make two
>>>>> things insecure? I'm not following your logic here. :-\
>>>>
>>>> I am saying that the first insecure thing unlocks the second.
>>>>
>>>>>
>>>>> On Wed, May 19, 2010 at 8:34 PM, Breno de Medeiros <[email protected]>
>>>>> wrote:
>>>>>>
>>>>>> On Wed, May 19, 2010 at 20:28, David Recordon <[email protected]> 
>>>>>> wrote:
>>>>>>> And given that the server would return one token good for both the
>>>>>>> `openid`
>>>>>>> and `calendar` scopes, leaking it via HTTP cookies would be bad. Thus in
>>>>>>> my
>>>>>>> proposal the access token remains secret and is useful for a variety of
>>>>>>> scopes while the signature ­ sure another form of a "token" ­ can become
>>>>>>> public and not compromise security.
>>>>>>
>>>>>> Isn't it likely that compromising the logged-in state at the client
>>>>>> exposes the data protected by the access token anyway, since the
>>>>>> client has access to the token and therefore the data was probably
>>>>>> imported and is available in the client?
>>>>>>
>>>>>>> --David
>>>>>>>
>>>>>>> On Wed, May 19, 2010 at 8:18 PM, Allen Tom <[email protected]> wrote:
>>>>>>>>
>>>>>>>> Whoa, I think it¹s premature to say that Yahoo supports OpenID Connect,
>>>>>>>> but I would imagine that only a single Access Token would be returned
>>>>>>>> to
>>>>>>>> coolcalendar.com ­ the Access Token would presumably be good for both
>>>>>>>> ³openid² and ³calendar² scope. Why would the OP want to return 2
>>>>>>>> tokens?
>>>>>>>>
>>>>>>>> Allen
>>>>>>>>
>>>>>>>>
>>>>>>>> On 5/19/10 5:27 PM, "Dirk Balfanz" <[email protected]> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>> Let's say I'm coolcalendar.com <http://coolcalendar.com> , and I want
>>>>>>>> to
>>>>>>>> "connect" one of my user's accounts to his Yahoo! account. I don't want
>>>>>>>> to
>>>>>>>> roll my own auth system, so I'm happy to see that Yahoo! supports
>>>>>>>> OpenID
>>>>>>>> Connect. To connect, I'll send the user over to Yahoo! with
>>>>>>>> scope=openid%20yahoo-calendar. What I get back, in your proposal, is
>>>>>>>> two
>>>>>>>> different kinds of "tokens": the access token that my servers use to
>>>>>>>> access
>>>>>>>> Yahoo! and something I'll call "openid connect token" (which in your
>>>>>>>> proposal comprises a few different parameters - user id, timestamp,
>>>>>>>> signature, etc.) that browsers use (in form of a cookie) to access my
>>>>>>>> own
>>>>>>>> servers at coolcalendar.com <http://coolcalendar.com> .
>>>>>>>>
>>>>>>>> Why do those two tokens look different? They serve the same purpose -
>>>>>>>> authenticating access from a client to a server, so they should look
>>>>>>>> the
>>>>>>>> same.
>>>>>>>>
>>>>>>>> Why should Yahoo! run different code to authenticate requests coming
>>>>>>>> from
>>>>>>>> my server than the code I'm running on my servers to authenticate
>>>>>>>> requests
>>>>>>>> coming from browsers - we have to solve the same task, so we should run
>>>>>>>> the
>>>>>>>> same code. It's simpler.
>>>>>
>
>



-- 
--Breno

+1 (650) 214-1007 desk
+1 (408) 212-0135 (Grand Central)
MTV-41-3 : 383-A
PST (GMT-8) / PDT(GMT-7)
_______________________________________________
specs mailing list
[email protected]
http://lists.openid.net/mailman/listinfo/openid-specs

Reply via email to