Re: [OAUTH-WG] I-D Action: draft-ietf-oauth-token-exchange-07.txt

[Brian Campbell <[e-mail]>]

The actor_token is a security token so that's not an issue that needs to be
addressed.





On Mon, May 8, 2017 at 11:00 AM, Denis <[e-mail]> wrote:

> Brian,
>
> The current text is:
>
> actor_token OPTIONAL. A security token that represents the identity of the
> party that is authorized to use the requested security token and act on
> behalf of the subject.
>
> This sentence is indeed wrong since an actor-token is not a security token.
>
> So your proposed change does not solve this issue: actor_token
> OPTIONAL.  A security token that represents the identity of the acting
> party.
>
> The current text states:
>
> Typically, in the request, the subject_token represents the identity of
> the party on behalf of whom
> the token is being requested while the actor_token represents the identity
> of the party to whom the access
> rights of the issued token are being delegated.
>
> Logically, the definition should be along the following lines:
>
>  actor_token OPTIONAL. Indicates the identity of the party to whom the
> access rights of the issued token are being delegated.
>
> If there is no delegation, then this field (which is optional) will not be
> used.
>
> Anyway, thank you for requesting the change, otherwise this would have
> been a left error.
>
> Denis
>
> I do have one minor issue I'd like to raise that relates to some
> conversations I've been a party to recently about implementations and
> applications of token exchange.
>
> I think that the current text in §2.1 for the "actor_token" is overly
> specific towards the delegation scenario. I'd propose the language be
> generalized somewhat to allow more versatility in applications/deployments
> of the token exchange framework. Here's that text:
>
>    actor_token
>       OPTIONAL.  A security token that represents the identity of the
>       acting party.
>
>
>
>
> On Mon, May 8, 2017 at 8:01 AM, Rifaat Shekh-Yusef <[e-mail]>
> wrote:
>
>> Hi All,
>>
>> The last email from Brian addresses the multiple audiences/resources
>> issue with an error code, and we did not see any objection to this approach
>> so far.
>>
>>
>> *Authors,*
>>
>> Are there any other open issues with this draft?
>> Do you believe it is ready for WGLC?
>>
>> Thanks,
>>  Rifaat & Hannes
>>
>>
>>
>> On Fri, Mar 31, 2017 at 11:03 AM, Brian Campbell <
>> [e-mail]> wrote:
>>
>>> As mentioned during the Chicago meeting the "invalid_target" error code
>>> that was added in -07 was intended to give the AS a standard way to reject
>>> request with multiple audiences/resources that it doesn't understand or is
>>> unwilling or unable to process based on policy or whatever criteria . It
>>> was intended as a compromise, of sorts, to allow for the multiple
>>> resources/audiences in the request but provide an easy out for the AS of
>>> saying it can't be supported based on whatever implementation or security
>>> or policy it has.
>>>
>>> On Tue, Mar 28, 2017 at 1:32 AM, Nat Sakimura <[e-mail]>
>>> wrote:
>>>
>>>> There are cases where tokens are supposed to be consumed at multiple
>>>> places and the `aud` needed to capture them. That's why `aud` is a
>>>> multi-valued field.
>>>>
>>>> On Mon, Mar 27, 2017 at 11:35 AM Torsten Lodderstedt <
>>>> [e-mail]> wrote:
>>>>
>>>>> May I ask you to explain this reason?
>>>>>
>>>>> Am 27.03.2017 um 08:48 schrieb Mike Jones <[e-mail]
>>>>> >:
>>>>>
>>>>> For the same reason that the “aud” claim is multi-valued in JWTs, the
>>>>> audience needs to stay multi-valued in Token Exchange.  Ditto for resources.
>>>>>
>>>>>
>>>>>
>>>>>                                                        Thanks,
>>>>>
>>>>>                                                        -- Mike
>>>>>
>>>>>
>>>>>
>>>>> *From:* OAuth [mailto:[e-mail] <[e-mail]>]
>>>>> *On Behalf Of *Brian Campbell
>>>>> *Sent:* Monday, March 27, 2017 8:45 AM
>>>>> *To:* Torsten Lodderstedt <[e-mail]>
>>>>> *Cc:* oauth <[e-mail]>
>>>>> *Subject:* Re: [OAUTH-WG] I-D Action: draft-ietf-oauth-token-exchang
>>>>> e-07.txt
>>>>>
>>>>>
>>>>>
>>>>> Thanks for the review and question, Torsten.
>>>>>
>>>>> The desire to support multiple audience/resource values in the request
>>>>> came up during a review and discussion among the authors of the document
>>>>> when preparing the -03 draft. As I recall, it was said that both Salesforce
>>>>> and Microsoft had use-cases for it. I incorporated support for it into the
>>>>> draft acting in the role of editor.
>>>>>
>>>>> From an individual perspective, I tend to agree with you that allowing
>>>>> for multiple audiences/resources adds a lot of complexity that's like not
>>>>> needed in many (or most) cases. And I would personally be open to making
>>>>> audience and resource mutual exclusive and single valued. A question for
>>>>> the WG I suppose.
>>>>>
>>>>> The "invalid_target" error code that was added in -07 was intended to
>>>>> give the AS a standard way to deal with the complexity and reject request
>>>>> with multiple audiences/resources that it doesn't understand or is
>>>>> unwilling or unable to process. It was intended as a compromise, of sorts,
>>>>> to allow for the multiples but provide an easy out of saying it can't be
>>>>> supported based on whatever implementation or policy of the AS.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Sun, Mar 26, 2017 at 9:00 AM, Torsten Lodderstedt <
>>>>> [e-mail]> wrote:
>>>>>
>>>>> Hi Brian,
>>>>>
>>>>>
>>>>>
>>>>> thanks for the clarification around resource, audience and scope.
>>>>>
>>>>>
>>>>>
>>>>> Here are my comments on the draft:
>>>>>
>>>>>
>>>>>
>>>>> In section 2.1 it states: „Multiple "resource" parameters may be used
>>>>> to indicate
>>>>>
>>>>>       that the issued token is intended to be used at the multiple
>>>>>
>>>>>       resources listed.“
>>>>>
>>>>>
>>>>>
>>>>> Can you please explain the rational in more detail? I don’t understand
>>>>> why there is a need to ask for access tokens, which are good for multiple
>>>>> resources at once. This is a request type more or less exclusively used in
>>>>> server to server scenarios, right? So the only reason I can think of is
>>>>> call reduction.
>>>>>
>>>>>
>>>>>
>>>>> On the other side, this feature increases the AS's complexity, e.g.
>>>>> its policy may prohibit to issue tokens for multiple resources in general
>>>>> or the particular set the client is asking for. How shall the AS handles
>>>>> such cases?
>>>>>
>>>>>
>>>>>
>>>>> And it is getting even more complicated given there could also be
>>>>> multiple audience values and the client could mix them:
>>>>>
>>>>>
>>>>>
>>>>> "Multiple "audience" parameters
>>>>>
>>>>>       may be used to indicate that the issued token is intended to be
>>>>>
>>>>>       used at the multiple audiences listed.  The "audience" and
>>>>>
>>>>>       "resource" parameters may be used together to indicate multiple
>>>>>
>>>>>       target services with a mix of logical names and physical
>>>>>
>>>>>       locations.“
>>>>>
>>>>>
>>>>>
>>>>> And in the end the client may add some scope values to the „meal“,
>>>>> which brings us to
>>>>>
>>>>>
>>>>>
>>>>> „Effectively, the requested access rights of the
>>>>>
>>>>>    token are the cartesian product of all the scopes at all the target
>>>>>
>>>>>    services."
>>>>>
>>>>>
>>>>>
>>>>> I personally would suggest to drop support for multiple audience and
>>>>> resource parameters and make audience and resource mutual exclusive. I
>>>>> think this is sufficient and much easier to implement.
>>>>>
>>>>>
>>>>>
>>>>> kind regards,
>>>>>
>>>>> Torsten.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Am 11.01.2017 um 20:04 schrieb Brian Campbell <
>>>>> [e-mail]>:
>>>>>
>>>>>
>>>>>
>>>>> Draft -07 of "OAuth 2.0 Token Exchange" has been published. The
>>>>> primary change in -07 is the addition of a description of the relationship
>>>>> between audience/resource/scope, which was a request or comment that came
>>>>> up during the f2f meeting in Seoul.
>>>>>
>>>>> Excerpted from the Document History:
>>>>>
>>>>>    -07
>>>>>
>>>>>    o  Fixed typo (desecration -> discretion).
>>>>>    o  Added an explanation of the relationship between scope, audience
>>>>>       and resource in the request and added an "invalid_target" error
>>>>>       code enabling the AS to tell the client that the requested
>>>>>       audiences/resources were too broad.
>>>>>
>>>>> ---------- Forwarded message ----------
>>>>> From: <[e-mail]>
>>>>> Date: Wed, Jan 11, 2017 at 12:00 PM
>>>>> Subject: [OAUTH-WG] I-D Action: draft-ietf-oauth-token-exchange-07.txt
>>>>> To: [e-mail]
>>>>> Cc: [e-mail]
>>>>>
>>>>>
>>>>>
>>>>> A New Internet-Draft is available from the on-line Internet-Drafts
>>>>> directories.
>>>>> This draft is a work item of the Web Authorization Protocol of the
>>>>> IETF.
>>>>>
>>>>>         Title           : OAuth 2.0 Token Exchange
>>>>>         Authors         : Michael B. Jones
>>>>>                           Anthony Nadalin
>>>>>                           Brian Campbell
>>>>>                           John Bradley
>>>>>                           Chuck Mortimore
>>>>>         Filename        : draft-ietf-oauth-token-exchange-07.txt
>>>>>         Pages           : 31
>>>>>         Date            : 2017-01-11
>>>>>
>>>>> Abstract:
>>>>>    This specification defines a protocol for an HTTP- and JSON- based
>>>>>    Security Token Service (STS) by defining how to request and obtain
>>>>>    security tokens from OAuth 2.0 authorization servers, including
>>>>>    security tokens employing impersonation and delegation.
>>>>>
>>>>>
>>>>> The IETF datatracker status page for this draft is:
>>>>> https://datatracker.ietf.org/doc/draft-ietf-oauth-token-exchange/
>>>>>
>>>>> There's also a htmlized version available at:
>>>>> https://tools.ietf.org/html/draft-ietf-oauth-token-exchange-07
>>>>>
>>>>> A diff from the previous version is available at:
>>>>> https://www.ietf.org/rfcdiff?url2=draft-ietf-oauth-token-exchange-07
>>>>>
>>>>>
>>>>> Please note that it may take a couple of minutes from the time of
>>>>> submission
>>>>> until the htmlized version and diff are available at tools.ietf.org.
>>>>>
>>>>> Internet-Drafts are also available by anonymous FTP at:
>>>>> ftp://ftp.ietf.org/internet-drafts/
>>>>>
>>>>> _______________________________________________
>>>>> OAuth mailing list
>>>>> [e-mail]
>>>>> https://www.ietf.org/mailman/listinfo/oauth
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> OAuth mailing list
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>>>>>
>>>> --
>>>>
>>>> Nat Sakimura
>>>>
>>>> Chairman of the Board, OpenID Foundation
>>>>
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>>>>
>>>
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>>
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