Re: [OAUTH-WG] Last Call: <draft-ietf-oauth-device-flow-09.txt> (OAuth 2.0 Device Flow for Browserless and Input Constrained Devices) to Proposed Standard

Hello

Do we feel that the document should be more specific in addressing how the
authorization service should respond to a device access token request when
the user has refused to grant access to the device?

The document currently indicates in section 3.5 that a success response
defined in section 5.1 of RFC6749, an error as defined in section 5.2 of
RFC6749 (this includes invalid_request, invalid_client, invalid_grant,
unauthorized_client, unsupported_grant_type, and invalid_scope), or a new
device flow error code (authorization_pending, slow_down, and
expired_token) may be returned in a response to a device token request.

It doesn’t seem that any of these options are appropriate to convey that a
user has refused to grant access to the device.

The Google implementation appears to be using the access_denied error code
from section 4.1.2.1 of RFC6749. While this would seem to be the most
suitable error code, the document does not explicitly indicate it as a
permitted response.

I believe that clarifying the response error code in the condition where a
user has refused access to the client would be beneficial, remove
ambiguity, and promote greater consistency across implementations.

Regards

Andrew Sciberras

On Wed, May 30, 2018 at 8:20 AM, The IESG <iesg-secretary@ietf.org> wrote:

>
> The IESG has received a request from the Web Authorization Protocol WG
> (oauth) to consider the following document: - 'OAuth 2.0 Device Flow for
> Browserless and Input Constrained Devices'
>   <draft-ietf-oauth-device-flow-09.txt> as Proposed Standard
>
> The IESG plans to make a decision in the next few weeks, and solicits final
> comments on this action. Please send substantive comments to the
> ietf@ietf.org mailing lists by 2018-06-12. Exceptionally, comments may be
> sent to iesg@ietf.org instead. In either case, please retain the
> beginning of
> the Subject line to allow automated sorting.
>
> Abstract
>
>
>    This OAuth 2.0 authorization flow for browserless and input
>    constrained devices, often referred to as the device flow, enables
>    OAuth clients to request user authorization from devices that have an
>    Internet connection, but don't have an easy input method (such as a
>    smart TV, media console, picture frame, or printer), or lack a
>    suitable browser for a more traditional OAuth flow.  This
>    authorization flow instructs the user to perform the authorization
>    request on a secondary device, such as a smartphone.  There is no
>    requirement for communication between the constrained device and the
>    user's secondary device.
>
>
>
>
> The file can be obtained via
> https://datatracker.ietf.org/doc/draft-ietf-oauth-device-flow/
>
> IESG discussion can be tracked via
> https://datatracker.ietf.org/doc/draft-ietf-oauth-device-flow/ballot/
>
>
> No IPR declarations have been submitted directly on this I-D.
>
>
> The document contains these normative downward references.
> See RFC 3967 for additional information:
>     rfc6819: OAuth 2.0 Threat Model and Security Considerations
> (Informational - IETF stream)
>     draft-recordon-oauth-v2-device: OAuth 2.0 Device Profile
>  (None - )
>     rfc6755: An IETF URN Sub-Namespace for OAuth (Informational - IETF
> stream)
>
>
>
> _______________________________________________
> OAuth mailing list
> OAuth@ietf.org
> https://www.ietf.org/mailman/listinfo/oauth
>

-- 
_CONFIDENTIALITY NOTICE: This email may contain confidential and privileged 
material for the sole use of the intended recipient(s). Any review, use, 
distribution or disclosure by others is strictly prohibited.  If you have 
received this communication in error, please notify the sender immediately 
by e-mail and delete the message and any file attachments from your 
computer. Thank you._