Internet DRAFT - draft-denniss-oauth-device-flow
draft-denniss-oauth-device-flow
OAuth W. Denniss
Internet-Draft Google
Intended status: Standards Track S. Myrseth
Expires: May 8, 2016 Forgerock
J. Bradley
Ping Identity
M. Jones
Microsoft
H. Tschofenig
ARM Limited
November 5, 2015
OAuth 2.0 Device Flow
draft-denniss-oauth-device-flow-00.txt
Abstract
The device flow is suitable for OAuth 2.0 clients executing on
devices which do not have an easy data-entry method (e.g., game
consoles, TVs, picture frames, and media hubs), but where the end-
user has separate access to a user-agent on another computer or
device (e.g., desktop computer, a laptop, a smart phone, or a
tablet).
Note: This version of the document is a continuation of an earlier,
long expired draft. The content of the expired draft has been copied
almost unmodified. The goal of the work on this document is to
capture deployment experience.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 8, 2016.
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Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Specification . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Client Requests Authorization . . . . . . . . . . . . . . 4
3.2. Client Requests Access Token . . . . . . . . . . . . . . 6
3.3. Additional Error Responses . . . . . . . . . . . . . . . 6
4. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Normative References . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
The device flow is suitable for clients executing on devices which do
not have an easy data-entry method and where the client is incapable
of receiving incoming requests from the authorization server
(incapable of acting as an HTTP server).
Instead of interacting with the end-user's user-agent, the client
instructs the end-user to use another computer or device and connect
to the authorization server to approve the access request. Since the
client cannot receive incoming requests, it polls the authorization
server repeatedly until the end-user completes the approval process.
Note that this device flow does not utilize the client secret.
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+----------+ +----------------+
| |>---(A)-- Client Identifier --->| |
| | | |
| |<---(B)-- Verification Code, --<| |
| | User Code, | |
| | & Verification URI | |
| Device | | |
| Client | Client Identifier & | |
| |>---(E)-- Verification Code --->| |
| | ... | |
| |>---(E)---> | |
| | | Authorization |
| |<---(F)-- Access Token --------<| Server |
+----------+ (w/ Optional Refresh Token) | |
v | |
: | |
(C) User Code & Verification URI | |
: | |
v | |
+----------+ | |
| End-user | | |
| at |<---(D)-- User authenticates -->| |
| Browser | | |
+----------+ +----------------+
Figure 1: Device Flow.
The device flow illustrated in Figure 1 includes the following steps:
(A) The client requests access from the authorization server and
includes its client identifier in the request.
(B) The authorization server issues a verification code, an end-
user code, and provides the end-user verification URI.
(C) The client instructs the end-user to use its user-agent
(elsewhere) and visit the provided end-user verification URI. The
client provides the end-user with the end-user code to enter in
order to grant access.
(D) The authorization server authenticates the end-user (via the
user-agent) and prompts the end-user to grant the client's access
request. If the end-user agrees to the client's access request,
the end-user enters the end-user code provided by the client. The
authorization server validates the end-user code provided by the
end-user.
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(E) While the end-user authorizes (or denies) the client's request
(D), the client repeatedly polls the authorization server to find
out if the end-user completed the end-user authorization step.
The client includes the verification code and its client
identifier.
(F) Assuming the end-user granted access, the authorization server
validates the verification code provided by the client and
responds back with the access token.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC2119].
Device Endpoint:
The authorization server's endpoint capable of issuing
verification codes, user codes, and verification URLs.
Device Verification Code:
A short-lived token representing an authorization session.
End-User Verification Code:
A short-lived token which the device displays to the end user, is
entered by the end-user on the authorization sever, and is thus
used to bind the device to the end-user.
3. Specification
3.1. Client Requests Authorization
The client initiates the flow by requesting a set of verification
codes from the authorization server by making an HTTP "POST" request
to the device endpoint. The client constructs a request URI by
adding the following parameters to the request:
response_type:
REQUIRED. The parameter value MUST be set to "device_code".
client_id:
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REQUIRED. The client identifier as described in Section 2.2 of
[RFC6749].
scope:
OPTIONAL. The scope of the access request as described by
Section 3.3 of [RFC6749].
For example, the client makes the following HTTPS request (line
breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Content-Type: application/x-www-form-urlencoded
response_type=device_code&client_id=s6BhdRkqt3
In response, the authorization server generates a verification code
and an end-user code and includes them in the HTTP response body
using the "application/json" format with a 200 status code (OK). The
response contains the following parameters:
device_code
REQUIRED. The verification code.
user_code
REQUIRED. The end-user verification code.
verification_uri
REQUIRED. The end-user verification URI on the authorization
server. The URI should be short and easy to remember as end-
users will be asked to manually type it into their user-agent.
expires_in
OPTIONAL. The duration in seconds of the verification code
lifetime.
interval
OPTIONAL. The minimum amount of time in seconds that the client
SHOULD wait between polling requests to the token endpoint.
For example:
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HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: no-store
{
"device_code":"74tq5miHKB",
"user_code":"94248",
"verification_uri":"http://www.example.com/device",
"interval"=5
}
The client displays the end-user code and the end-user verification
URI to the end-user, and instructs the end-user to visit the URI
using a user-agent and enter the end-user code.
The end-user manually types the provided verification URI and
authenticates with the authorization server. The authorization
server prompts the end-user to authorize the client's request by
entering the end-user code provided by the client. Once the end-user
approves or denies the request, the authorization server informs the
end-user to return to the device for further instructions.
3.2. Client Requests Access Token
Since the client is unable to receive incoming requests from the
authorization server, it polls the authorization server repeatedly
until the end-user grants or denies the request, or the verification
code expires.
The client makes the following request at an arbitrary but reasonable
interval which MUST NOT exceed the minimum interval rate provided by
the authorization server (if present via the "interval" parameter).
Alternatively, the client MAY provide a user interface for the end-
user to manually inform it when authorization was granted.
The client requests an access token by making an HTTP "POST" request
to the token endpoint as described in Section 4.1.1 of [RFC6749] .
The "redirect_uri" parameter is NOT REQUIRED as part of this request.
3.3. Additional Error Responses
The following error responses are defined in addition to those within
Section 4.2.2.1. of [RFC6749]:
authorization_pending
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The authorization request is still pending as the end-user hasn't
yet visited the authorization server and entered their
verification code.
slow_down
The client is polling too quickly and should back off at a
reasonable rate.
4. Contributors
The -00 version of this document is based on a previous edited by
David Recordon and Brent Goldman. The content of that document was
initially part of the OAuth 2.0 protocol specificaiton but was later
removed due to the lack of sufficient deployment expertise at that
time. We would therefore also like to thank the OAuth working group
for their work on this document around 2010.
5. Acknowledgements
Add your name here.
6. Security Considerations
TBD
7. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
RFC 6749, DOI 10.17487/RFC6749, October 2012,
<http://www.rfc-editor.org/info/rfc6749>.
Authors' Addresses
William Denniss
Google
1600 Amphitheatre Pkwy
Mountain View, CA 94043
USA
Phone: +1 650-253-0000
Email: wdenniss@google.com
URI: http://google.com/
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Stein Myrseth
Forgerock
Lysaker torg 2
Lysaker 1366
NORWAY
Email: stein.myrseth@forgerock.com
John Bradley
Ping Identity
Email: ve7jtb@ve7jtb.com
URI: http://www.thread-safe.com/
Michael B. Jones
Microsoft
Email: mbj@microsoft.com
URI: http://self-issued.info/
Hannes Tschofenig
ARM Limited
Austria
Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at
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