Internet DRAFT - draft-bradley-stateless-oauth-client
draft-bradley-stateless-oauth-client
Network Working Group J. Bradley, Ed.
Internet-Draft
Intended status: Experimental J. Richer
Expires: October 9, 2014
April 07, 2014
Stateless Client Identifier for OAuth 2
draft-bradley-stateless-oauth-client-01
Abstract
This draft provides a method for communicating information about an
OAuth client through its client identifier allowing for fully
stateless operation.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Status of This Memo
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provisions of BCP 78 and BCP 79.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Stateless Client Identifier . . . . . . . . . . . . . . . . . 2
3. Validating the Stateless Client Identifier . . . . . . . . . 3
4. Obtaining a Stateless Client Identifier . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
8. Normative References . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
In the OAuth 2.0 Authorization protocol, the Client must provide a
Client Identifier that the Authorization Server recognizes.
Additionally, an Autorization Server needs to know about a client's
details, such as its name and redirect URIs. Traditionally, this is
handled through a registration process, which may be either manual or
automated, where the authorization server maintains a stateful
relationship between the Client Identifier and its associated
metadata. This draft proposes a mechanism whereby the essential
metadata can be encoded into the Client Identifier itself, signed by
the issuer, and validated by the authorization server, thus allowing
the authorization server to be stateless in regard to client
information.
2. Stateless Client Identifier
The stateless client identifier consists of a [JWT], optionally
signed with [JWS], whose payload contains claims as defined here.
iss REQUIRED. URL identifying the party that issued this client
identifier.
sub REQUIRED. Identifier of the client, locally unique to the
issuer.
iat OPTIONAL. Timestamp of when this client identifier was issued.
exp OPTIONAL. Timestamp of when this client identifier will expire.
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kid RECOMMENDED if signed. Identifier of the key used to sign this
client identifier at the issuer.
reg REQUIRED. JSON Object containing a set of metadata claims of
client information such as its redirect URIs, display name, and
other items as defined in [Dyn Reg] and its extensions.
The issuer SHOULD sign the JWT with JWS in such a way that the
signature can be verified by the authorization server.
The issuer MAY encrypt the JWT with JWE.
3. Validating the Stateless Client Identifier
Upon receiving a stateless client identifier at either the
authorization endpoint or the token endpoint, the authorization
server parses it as a JWT. It first checks the iss field to
determine if it trusts identifiers issued by the party represented.
It then verifies the signature if the JWT (if signed) using JWS. The
key used to sign the JWT MAY be indicated by the kid field. The
authorization server MAY use other means to validate the JWT and
determine its authenticity.
The authorization server then reads the fields inside the reg claim
and uses these to configure the user experience and security
parameters of the authorization.
4. Obtaining a Stateless Client Identifier
The client identifier is intended to be opaque to the client, and as
such a stateless client identifier is intended to be obtained and
used in exactly the same way as a stateful client identifer would be
for any OAuth client.
o Manual registration: a developer uses an out-of-band adminstrative
process to generate the client identifier and related credentials.
o Dynamic registration: a developer or client uses the process
described in [Dyn Reg] to generate the client identifier and
related credentials.
o Self assertion: a developer or client generates the client
identifier on their own, often signing it with their own public
key.
It is completely up to the purview of particular authorization
servers which generation methods, and which client identifiers, they
will accept.
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5. IANA Considerations
[ maybe we register the "reg" claim above? ]
This document makes no request of IANA.
Note to RFC Editor: this section may be removed on publication as an
RFC.
6. Security Considerations
Since many OAuth systems assume that a change in the client
identifier indicates a change in the client itself, systems using
stateless client identifiers SHOULD NOT allow clients to update their
information post registration.
Since the client identifier is passed through the browser to the
authorization endpoint, it MUST NOT contain any sensitive
information. Additionally, as in standard OAuth, posession of the
client identifier itself MUST NOT be assumed to be sufficient
authentication [in many cases? except implicit mode?].
7. Acknowledgements
8. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
Authors' Addresses
John Bradley (editor)
Justin Richer
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