draft-ietf-oauth-jwsreq-08.txt   draft-ietf-oauth-jwsreq-09.txt 
OAuth Working Group N. Sakimura OAuth Working Group N. Sakimura
Internet-Draft Nomura Research Institute Internet-Draft Nomura Research Institute
Intended status: Standards Track J. Bradley Intended status: Standards Track J. Bradley
Expires: February 3, 2017 Ping Identity Expires: April 1, 2017 Ping Identity
August 2, 2016 September 28, 2016
OAuth 2.0 JWT Authorization Request (JAR) The OAuth 2.0 Authorization Framework: JWT Secured Authorization Request
draft-ietf-oauth-jwsreq-08 (JAR)
draft-ietf-oauth-jwsreq-09
Abstract Abstract
The authorization request in OAuth 2.0 [RFC6749] utilizes query The authorization request in OAuth 2.0 described in RFC 6749 utilizes
parameter serialization, which means that Authorization Request query parameter serialization, which means that Authorization Request
parameters are encoded in the URI of the request and sent through parameters are encoded in the URI of the request and sent through
user agents such as web browsers. While it is easy to implement, it user agents such as web browsers. While it is easy to implement, it
means that (a) the communication through the user agents are not means that (a) the communication through the user agents are not
integrity protected and thus the parameters can be tainted, and (b) integrity protected and thus the parameters can be tainted, and (b)
the source of the communication is not authentciated. Because of the source of the communication is not authenticated. Because of
these weaknesses, several attacks to the protocol have now been put these weaknesses, several attacks to the protocol have now been put
forward. forward.
This document introduces the ability to send request parameters in a This document introduces the ability to send request parameters in a
JSON Web Token (JWT) instead, which allows the request to be JWS JSON Web Token (JWT) instead, which allows the request to be JWS
signed and/or JWE encrypted so that the integrity, source signed and/or JWE encrypted so that the integrity, source
authentication and confidentiallity property of the Authorization authentication and confidentiallity property of the Authorization
Request is attained. The request can be sent by value or by Request is attained. The request can be sent by value or by
reference. reference.
skipping to change at page 1, line 46 skipping to change at page 1, line 47
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 3, 2017. This Internet-Draft will expire on April 1, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 33 skipping to change at page 2, line 33
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 5 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Request Object . . . . . . . . . . . . . . . . . . . . . 6 2.1. Request Object . . . . . . . . . . . . . . . . . . . . . 6
2.2. Request Object URI . . . . . . . . . . . . . . . . . . . 6 2.2. Request Object URI . . . . . . . . . . . . . . . . . . . 6
3. Symbols and abbreviated terms . . . . . . . . . . . . . . . . 6 3. Symbols and abbreviated terms . . . . . . . . . . . . . . . . 6
4. Request Object . . . . . . . . . . . . . . . . . . . . . . . 6 4. Request Object . . . . . . . . . . . . . . . . . . . . . . . 6
5. Authorization Request . . . . . . . . . . . . . . . . . . . . 8 5. Authorization Request . . . . . . . . . . . . . . . . . . . . 8
5.1. Passing a Request Object by Value . . . . . . . . . . . . 9 5.1. Passing a Request Object by Value . . . . . . . . . . . . 9
5.2. Passing a Request Object by Reference . . . . . . . . . . 10 5.2. Passing a Request Object by Reference . . . . . . . . . . 10
5.2.1. URL Referencing the Request Object . . . . . . . . . 12 5.2.1. URL Referencing the Request Object . . . . . . . . . 12
5.2.2. Request using the "request_uri" Request Parameter . . 12 5.2.2. Request using the "request_uri" Request Parameter . . 13
5.2.3. Authorization Server Fetches Request Object . . . . . 12 5.2.3. Authorization Server Fetches Request Object . . . . . 13
6. Validating JWT-Based Requests . . . . . . . . . . . . . . . . 13 6. Validating JWT-Based Requests . . . . . . . . . . . . . . . . 13
6.1. Encrypted Request Object . . . . . . . . . . . . . . . . 13 6.1. Encrypted Request Object . . . . . . . . . . . . . . . . 13
6.2. JWS Signed Request Object . . . . . . . . . . . . . . . . 13 6.2. JWS Signed Request Object . . . . . . . . . . . . . . . . 14
6.3. Request Parameter Assembly and Validation . . . . . . . . 13 6.3. Request Parameter Assembly and Validation . . . . . . . . 14
7. Authorization Server Response . . . . . . . . . . . . . . . . 13 7. Authorization Server Response . . . . . . . . . . . . . . . . 14
8. TLS Requirements . . . . . . . . . . . . . . . . . . . . . . 14 8. TLS Requirements . . . . . . . . . . . . . . . . . . . . . . 14
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . 14 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . 15
10. Security Considerations . . . . . . . . . . . . . . . . . . . 14 10. Security Considerations . . . . . . . . . . . . . . . . . . . 15
10.1. Choice of Algorithms . . . . . . . . . . . . . . . . . . 14 10.1. Choice of Algorithms . . . . . . . . . . . . . . . . . . 15
10.2. Choice of Parameters to include in the Request Object . 14 10.2. Choice of Parameters to include in the Request Object . 15
10.3. Request Source Authentication . . . . . . . . . . . . . 15 10.3. Request Source Authentication . . . . . . . . . . . . . 15
11. Privacy Considerations . . . . . . . . . . . . . . . . . . . 15 10.4. Explicit Endpoints . . . . . . . . . . . . . . . . . . . 16
11.1. Collection limitation . . . . . . . . . . . . . . . . . 16 11. Privacy Considerations . . . . . . . . . . . . . . . . . . . 16
11.2. Disclosure Limitation . . . . . . . . . . . . . . . . . 16 11.1. Collection limitation . . . . . . . . . . . . . . . . . 17
11.2.1. Request Disclosure . . . . . . . . . . . . . . . . . 16 11.2. Disclosure Limitation . . . . . . . . . . . . . . . . . 17
11.2.2. Tracking using Request Object URI . . . . . . . . . 17 11.2.1. Request Disclosure . . . . . . . . . . . . . . . . . 17
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17 11.2.2. Tracking using Request Object URI . . . . . . . . . 18
13. Revision History . . . . . . . . . . . . . . . . . . . . . . 17 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 19 13. Revision History . . . . . . . . . . . . . . . . . . . . . . 18
14.1. Normative References . . . . . . . . . . . . . . . . . . 19 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
14.2. Informative References . . . . . . . . . . . . . . . . . 20 14.1. Normative References . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 14.2. Informative References . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
The Authorization Request in OAuth 2.0 [RFC6749] utilizes query The Authorization Request in OAuth 2.0 [RFC6749] utilizes query
parameter serialization and typically sent through user agents such parameter serialization and typically sent through user agents such
as web browsers. as web browsers.
For example, the parameters 'response_type', 'client_id', 'state', For example, the parameters "response_type", "client_id", "state",
and 'redirect_uri' are encoded in the URI of the request: and "redirect_uri" are encoded in the URI of the request:
GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1 &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1
Host: server.example.com Host: server.example.com
While it is easy to implement, the encoding in the URI does not allow While it is easy to implement, the encoding in the URI does not allow
application layer security with confidentiality and integrity application layer security with confidentiality and integrity
protection to be used. While TLS is used to offer communication protection to be used. While TLS is used to offer communication
security between the Client and the user-agent and the user-agent and security between the Client and the user-agent and the user-agent and
the Authorization Server, TLS sessions are terminated in the user- the Authorization Server, TLS sessions are terminated in the user-
agent. In addition, TLS sessions are terminated prematurely at some agent. In addition, TLS sessions may be terminated prematurely at
middlebox (such as a load balancer). some middlebox (such as a load balancer).
As the result, the Authorization Request of [RFC6749] has a property As the result, the Authorization Request of [RFC6749] has a property
that that
(a) the communication through the user agents are not integrity (a) the communication through the user agents are not integrity
protected and thus the parameters can be tainted (integrity protected and thus the parameters can be tainted (integrity
protection failure); protection failure);
(b) the source of the communication is not authentciated (source (b) the source of the communication is not authenticated (source
authentication failure); and authentication failure); and
(c) the communication through the user agents can be monitored (c) the communication through the user agents can be monitored
(containment failure). (containment / confidentiality failure).
Because of these weaknesses, several attacks to the protocol such as Because of these weaknesses, several attacks against the protocol,
Redirection URI rewrite has been put forward by now. such as Redirection URI rewriting, has been discovered.
The use of application layer security mitigates these issues. The use of application layer security mitigates these issues.
In addition, it allows requests to be prepared by a third party so In addition, it allows requests to be prepared by a third party so
that a client application cannot request more permissions than that a client application cannot request more permissions than
previously agreed. This offers an additional degree of privacy previously agreed. This offers an additional degree of privacy
protection. protection.
Further, the request by reference allows the reduction of over-the- Furthermore, the request by reference allows the reduction of over-
wire overhead. the- wire overhead.
There are other potential formats that could be used for this purpose The JWT [RFC7519] encoding has been chosen because of
instead of JWT [RFC7519]. The JWT was chosen because of
(1) its close relationship with JSON, which is used as OAuth's (1) its close relationship with JSON, which is used as OAuth's
response format; response format;
(2) its developer friendliness due to its textual nature; (2) its developer friendliness due to its textual nature;
(3) its relative compactness compared to XML; (3) its relative compactness compared to XML;
(4) its development status that it is an RFC and so is its (4) its development status that it is an RFC and so is its
associated signing and encryption methods as [RFC7515] and associated signing and encryption methods as [RFC7515] and
skipping to change at page 4, line 45 skipping to change at page 4, line 46
Using JWT [RFC7519] as the request encoding instead of query Using JWT [RFC7519] as the request encoding instead of query
parameters has several advantages: parameters has several advantages:
(a) (integrity protection) The request can be signed so that the (a) (integrity protection) The request can be signed so that the
integrity of the request can be checked ; integrity of the request can be checked ;
(b) (source authentication) The request can be signed so that the (b) (source authentication) The request can be signed so that the
signer can be authenticated ; signer can be authenticated ;
(c) (containment) The request can be encrypted so that end-to-end (c) (confidentiality protection) The request can be encrypted so
confidentiality can be provided even if the TLS connection is that end-to-end confidentiality can be provided even if the TLS
terminated at one point or another ; and connection is terminated at one point or another ; and
(d) (collection minimization) The request can be signed by a third (d) (collection minimization) The request can be signed by a third
party attesting that the authorization request is compliant to party attesting that the authorization request is compliant to
certain policy. For example, a request can be pre-examined by a certain policy. For example, a request can be pre-examined by a
third party that all the personal data requested is strictly third party that all the personal data requested is strictly
necessary to perform the process that the end-user asked for, necessary to perform the process that the end-user asked for,
and statically signed by that third party. The client would and statically signed by that third party. The client would
then send the request along with dynamic parameters such as then send the request along with dynamic parameters such as
state. The authorization server then examines the signature and state. The authorization server then examines the signature and
shows the conformance status to the end-user, who would have shows the conformance status to the end-user, who would have
skipping to change at page 5, line 26 skipping to change at page 5, line 28
The use of application layer security increases the size of the The use of application layer security increases the size of the
request, particularly when public key cryptography is used. request, particularly when public key cryptography is used.
2. The client can make a signed Request Object and put it at a place 2. The client can make a signed Request Object and put it at a place
that the Authorization Server can access. This may just be done that the Authorization Server can access. This may just be done
by a client utility or other process, so that the private key by a client utility or other process, so that the private key
does not have to reside on the client, simplifying programming. does not have to reside on the client, simplifying programming.
Downside of it is that the signed portion just become a token. Downside of it is that the signed portion just become a token.
3. When the server wants the requests to be cacheable: The 3. When the server wants the requests to be cacheable: The
request_uri may include a SHA-256 hash of the contents of the "request_uri" may include a SHA-256 hash of the contents of the
resources referenced by the Request Object URI. With this, the resources referenced by the Request Object URI. With this, the
server knows if the resource has changed without fetching it, so server knows if the resource has changed without fetching it, so
it does not have to re-fetch the same content, which is a win as it does not have to re-fetch the same content, which is a win as
well. This is explained in Section 5.2. well. This is explained in Section 5.2.
4. When the client does not want to do the crypto: The Authorization 4. When the client does not want to do the crypto: The Authorization
Server may provide an endpoint to accept the Authorization Server may provide an endpoint to accept the Authorization
Request through direct communication with the Client so that the Request through direct communication with the Client so that the
Client is authentcicated and the channel is TLS protected. Client is authenticated and the channel is TLS protected.
This capability is in use by OpenID Connect [OpenID.Core]. This capability is in use by OpenID Connect [OpenID.Core].
1.1. Requirements Language 1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
2. Terminology 2. Terminology
skipping to change at page 9, line 5 skipping to change at page 9, line 5
"e":"AQAB" "e":"AQAB"
} }
5. Authorization Request 5. Authorization Request
The client constructs the authorization request URI by adding one of The client constructs the authorization request URI by adding one of
the following parameters but not both to the query component of the the following parameters but not both to the query component of the
authorization endpoint URI using the "application/x-www-form- authorization endpoint URI using the "application/x-www-form-
urlencoded" format: urlencoded" format:
request The Request Object (Section 4) that holds authorization request The Request Object (Section 2.1) that holds authorization
request parameters stated in the section 4 of OAuth 2.0 [RFC6749]. request parameters stated in the section 4 of OAuth 2.0 [RFC6749].
request_uri The absolute URL that points to the Request Object request_uri The absolute URL that points to the Request Object
(Section 4) that holds authorization request parameters stated in (Section 2.1) that holds authorization request parameters stated
the section 4 of OAuth 2.0 [RFC6749]. in the section 4 of OAuth 2.0 [RFC6749].
The client directs the resource owner to the constructed URI using an The client directs the resource owner to the constructed URI using an
HTTP redirection response, or by other means available to it via the HTTP redirection response, or by other means available to it via the
user-agent. user-agent.
For example, the client directs the end-user's user-agent to make the For example, the client directs the end-user's user-agent to make the
following HTTPS request: following HTTPS request:
GET /authz?request=eyJhbG..AlMGzw HTTP/1.1 GET /authz?request=eyJhbG..AlMGzw HTTP/1.1
Host: server.example.com Host: server.example.com
skipping to change at page 9, line 34 skipping to change at page 9, line 34
The authorization request object MUST be either The authorization request object MUST be either
(a) JWS signed; or (a) JWS signed; or
(b) JWE encrypted; or (b) JWE encrypted; or
(c) JWS signed and JWE encrypted. (c) JWS signed and JWE encrypted.
When the Request Object is used, the OAuth 2.0 request parameter When the Request Object is used, the OAuth 2.0 request parameter
values contained in the JWS Signed and/or JWE Encrypted JWT supersede values contained in the JWS Signed and/or JWE Encrypted JWT supersede
those passed using the OAuth 2.0 request syntax. However, parameters those passed using the OAuth 2.0 request syntax. Parameters MAY also
MAY also be passed using the OAuth 2.0 request syntax even when a be passed using the OAuth 2.0 request syntax even when a Request
Request Object is used; this would typically be done to enable a Object is used in the cases such as (a) to achieve backward
cached, pre-signed (and possibly pre-encrypted) Request Object value compatibility with [RFC6749] or (b) to enable a cached, pre-signed
to be used containing the fixed request parameters, while parameters (and possibly pre-encrypted) Request Object value to be used
that can vary with each request, such as "state" and "nonce" of containing the fixed request parameters, while parameters that can
OpenID Connect, are passed as OAuth 2.0 parameters. vary with each request, such as "state" and "nonce" of OpenID
Connect, are passed as OAuth 2.0 parameters. In such case, one needs
to carefully assess the risk associated with it as unprotected
parameters would create additional attack surfaces. See Section 10.2
as well.
5.1. Passing a Request Object by Value 5.1. Passing a Request Object by Value
The Client sends the Authorization Request as a Request Object to the The Client sends the Authorization Request as a Request Object to the
Authorization Endpoint as the "request" parameter value. Authorization Endpoint as the "request" parameter value.
The following is a non-normative example of an Authorization Request The following is a non-normative example of an Authorization Request
using the "request" parameter (with line wraps within values for using the "request" parameter (with line wraps within values for
display purposes only): display purposes only):
skipping to change at page 10, line 41 skipping to change at page 10, line 41
5.2. Passing a Request Object by Reference 5.2. Passing a Request Object by Reference
The "request_uri" Authorization Request parameter enables OAuth The "request_uri" Authorization Request parameter enables OAuth
authorization requests to be passed by reference, rather than by authorization requests to be passed by reference, rather than by
value. This parameter is used identically to the "request" value. This parameter is used identically to the "request"
parameter, other than that the Request Object value is retrieved from parameter, other than that the Request Object value is retrieved from
the resource at the specified URL, rather than passed by value. the resource at the specified URL, rather than passed by value.
When the "request_uri" parameter is used, the OAuth 2.0 authorization When the "request_uri" parameter is used, the OAuth 2.0 authorization
request parameter values contained in the referenced JWT supersede request parameter values contained in the referenced JWT supersede
those passed using the OAuth 2.0 request syntax. However, parameters those passed using the OAuth 2.0 request syntax. Parameters MAY also
MAY also be passed using the OAuth 2.0 request syntax even when a be passed using the OAuth 2.0 request syntax even when a Request
"request_uri" is used; this would typically be done to enable a Object is used in the cases such as (a) to achieve backward
cached, pre-signed (and possibly pre-encrypted) Request Object value compatibility with [RFC6749] or (b) to enable a cached, pre-signed
to be used containing the fixed request parameters, while parameters (and possibly pre-encrypted) Request Object value to be used
that can vary with each request, such as "state" and "nonce", are containing the fixed request parameters, while parameters that can
passed as OAuth 2.0 parameters. vary with each request, such as "state" and "nonce" of OpenID
Connect, are passed as OAuth 2.0 parameters. In such case, one needs
to carefully assess the risk associated with it as unprotected
parameters would create additional attack surfaces. See Section 10.2
as well.
Servers MAY cache the contents of the resources referenced by Request Servers MAY cache the contents of the resources referenced by Request
Object URIs. If the contents of the referenced resource could ever Object URIs. If the contents of the referenced resource could ever
change, the URI SHOULD include the base64url encoded SHA-256 hash as change, the URI SHOULD include the base64url encoded SHA-256 hash as
defined in RFC6234 [RFC6234] of the referenced resource contents as defined in RFC6234 [RFC6234] of the referenced resource contents as
the fragment component of the URI. If the fragment value used for a the fragment component of the URI. If the fragment value used for a
URI changes, that signals the server that any cached value for that URI changes, it signals the server that any cached value for that URI
URI with the old fragment value is no longer valid. with the old fragment value is no longer valid.
The entire Request URI MUST NOT exceed 512 ASCII characters. There The entire Request URI MUST NOT exceed 512 ASCII characters. There
are three reasons for this restriction. are three reasons for this restriction.
1. Many WAP / feature phones do not accept large payloads. The 1. Many WAP / feature phones do not accept large payloads. The
restriction are typically either 512 or 1024 ASCII characters. restriction are typically either 512 or 1024 ASCII characters.
2. The maximum URL length supported by older versions of Internet 2. The maximum URL length supported by older versions of Internet
Explorer is 2083 ASCII characters. Explorer is 2083 ASCII characters.
skipping to change at page 12, line 19 skipping to change at page 12, line 43
be HTTPS URL. This URL is the Request Object URI, "request_uri". be HTTPS URL. This URL is the Request Object URI, "request_uri".
It is possible for the Request Object to include values that is to be It is possible for the Request Object to include values that is to be
revealed only to the Authorization Server. As such, the revealed only to the Authorization Server. As such, the
"request_uri" MUST have appropriate entropy for its lifetime. It is "request_uri" MUST have appropriate entropy for its lifetime. It is
RECOMMENDED that it be removed if it is known that it will not be RECOMMENDED that it be removed if it is known that it will not be
used again or after a reasonable timeout unless access control used again or after a reasonable timeout unless access control
measures are taken. measures are taken.
Unless the access to the "request_uri" over TLS provides adequate Unless the access to the "request_uri" over TLS provides adequate
authentciation of the source of the Request Object, the Request authentication of the source of the Request Object, the Request
Object MUST be JWS Signed. Object MUST be JWS Signed.
The following is a non-normative example of a Request Object URI The following is a non-normative example of a Request Object URI
value (with line wraps within values for display purposes only): value (with line wraps within values for display purposes only):
https://client.example.org/request.jwt# https://client.example.org/request.jwt#
GkurKxf5T0Y-mnPFCHqWOMiZi4VS138cQO_V7PZHAdM GkurKxf5T0Y-mnPFCHqWOMiZi4VS138cQO_V7PZHAdM
5.2.2. Request using the "request_uri" Request Parameter 5.2.2. Request using the "request_uri" Request Parameter
skipping to change at page 15, line 6 skipping to change at page 15, line 36
parameter, it MUST either be JWS signed with then considered parameter, it MUST either be JWS signed with then considered
appropriate algorithm or encrypted using [RFC7516]. appropriate algorithm or encrypted using [RFC7516].
10.2. Choice of Parameters to include in the Request Object 10.2. Choice of Parameters to include in the Request Object
Unless there is a compelling reasons to do otherwise, it is strongly Unless there is a compelling reasons to do otherwise, it is strongly
recommended to create a request object that covers all the parameters recommended to create a request object that covers all the parameters
so that the entire request is integrity protected. so that the entire request is integrity protected.
This means that the request object is going to be prepared fresh each This means that the request object is going to be prepared fresh each
time an authorization request is made and cacheing cannot be used. time an authorization request is made and caching cannot be used. It
It has a performance disadvantage, but where such disadvantage is has a performance disadvantage, but where such disadvantage is
permissible, it should be considered. permissible, it should be considered.
Unless the server and the client have agreed prior to the Unless the server and the client have agreed prior to the
authorization request to use the non-protected parameters, the authorization request to use the non-protected parameters, the
authorization server SHOULD reject a request that is not fully authorization server SHOULD reject a request that is not fully
integrity protected and source authenticated. integrity protected and source authenticated.
10.3. Request Source Authentication 10.3. Request Source Authentication
The source of the Authorization Request MUST always be verified. The source of the Authorization Request MUST always be verified.
There are several ways to do it in this sepcification. There are several ways to do it in this specification.
(a) Verifying the JWS Signature of the Request Object. (a) Verifying the JWS Signature of the Request Object.
(b) Verifying the TLS Server Identity of the Request Object URI. In (b) Verifying the TLS Server Identity of the Request Object URI. In
this case, the Authorization Server MUST know out of band that this case, the Authorization Server MUST know out of band that
the Client uses Request Object URI and only the Client is the Client uses Request Object URI and only the Client is
covered by the TLS certificate. In general, it is not a covered by the TLS certificate. In general, it is not a
reliable method. reliable method.
(c) Authorization Server is providing an endpoint that provides a (c) Authorization Server is providing an endpoint that provides a
Request Object URI in exchange for a Request Object. In this Request Object URI in exchange for a Request Object. In this
case, the Authorization Server MUST peform Client Authentication case, the Authorization Server MUST perform Client
to accept the Request Object and bind the Client Identifier to Authentication to accept the Request Object and bind the Client
the Request Object URI it is providing. Since Request Object Identifier to the Request Object URI it is providing. Since
URI can be replayed, the lifetime of the Request Object URI MUST Request Object URI can be replayed, the lifetime of the Request
be short and preferably one-time use. The entropy of the Object URI MUST be short and preferably one-time use. The
Request Object URI MUST be sufficiently large. entropy of the Request Object URI MUST be sufficiently large.
(d) A third party, such as a Trust Framework Provider, provides an (d) A third party, such as a Trust Framework Provider, provides an
endpoint that provides a Request Object URI in exchange for a endpoint that provides a Request Object URI in exchange for a
Request Object. The same requirements as (b) above applies. In Request Object. The same requirements as (b) above applies. In
addition, the Authorization Server MUST know out-of-band that addition, the Authorization Server MUST know out-of-band that
the Client utilizes the Trust Framework Operator. the Client utilizes the Trust Framework Operator.
10.4. Explicit Endpoints
Although this specification does not require them, researchs such as
[BASIN] points out that it is a good practice to explicitly state the
intended interaction endpoints and the message position in the
sequence in a tamper evident manner so that the intent of the
initiator is unambiguous. The endpoints that comes into question in
this specification are
(a) Protected Resources ("protected_resources");
(b) Authorization Endpoint ("authorization_endpoint");
(c) Redirection URI ("redirect_uri"); and
(d) Token Endpoint ("token_endpoint").
While Redirection URI is included, others are not included in the
Authorization Request Object. It is probably a good idea to include
these in it to reduce the attack surface. An extension specification
should be created.
11. Privacy Considerations 11. Privacy Considerations
When the Client is being granted access to a protected resource When the Client is being granted access to a protected resource
containing personal data, both the Client and the Authorization containing personal data, both the Client and the Authorization
Server need to adhere to Privacy Principles. ISO/IEC 29100 Server need to adhere to Privacy Principles. ISO/IEC 29100
[ISO29100] is a freely accessible International Standard and its [ISO29100] is a freely accessible International Standard and its
Privacy Principles are good to follow. Privacy Principles are good to follow.
Most of the provision would apply to The OAuth 2.0 Authorization Most of the provision would apply to The OAuth 2.0 Authorization
Framework [RFC6749] and The OAuth 2.0 Authorization Framework: Bearer Framework [RFC6749] and The OAuth 2.0 Authorization Framework: Bearer
Token Usage [RFC6750] and not specific to this specification. In Token Usage [RFC6750] and not specific to this specification. In
what follows, only the specific provisions to this specification are what follows, only the specific provisions to this specification are
noted. noted.
11.1. Collection limitation 11.1. Collection limitation
skipping to change at page 16, line 27 skipping to change at page 17, line 33
user by examining the Client request and comparing to the proposed user by examining the Client request and comparing to the proposed
processing by the Client and certifying the request. After the processing by the Client and certifying the request. After the
certification, the Client, when making an Authorization Request, can certification, the Client, when making an Authorization Request, can
submit Authorization Request to the Trust Framework Provider to submit Authorization Request to the Trust Framework Provider to
obtain the Request Object URI. obtain the Request Object URI.
Upon receiving such Request Object URI in the Authorization Request, Upon receiving such Request Object URI in the Authorization Request,
the Authorization Server first verifies that the authority portion of the Authorization Server first verifies that the authority portion of
the Request Object URI is a legitimate one for the Trust Framework the Request Object URI is a legitimate one for the Trust Framework
Provider. Then, the Auhtorization Server issues HTTP GET request to Provider. Then, the Auhtorization Server issues HTTP GET request to
the Request Object URI. Uppon connecting, the Authorization Server the Request Object URI. Upon connecting, the Authorization Server
MUST verify the server identity represented in the TLS certificate is MUST verify the server identity represented in the TLS certificate is
legitimate for the Request Object URI. Then, the Authorization legitimate for the Request Object URI. Then, the Authorization
Server can obtain the Request Object, which includes the "client_id" Server can obtain the Request Object, which includes the "client_id"
representing the Client. representing the Client.
The Consent screen MUST indicate the Client and SHOULD indicate that The Consent screen MUST indicate the Client and SHOULD indicate that
the request has been vetted by the Trust Framework Operator for the the request has been vetted by the Trust Framework Operator for the
adherance to the Collection Limitation principle. adherence to the Collection Limitation principle.
11.2. Disclosure Limitation 11.2. Disclosure Limitation
11.2.1. Request Disclosure 11.2.1. Request Disclosure
This specification allows extension parameters. These may include This specification allows extension parameters. These may include
potentially sensitive information. Since URI query parameter may potentially sensitive information. Since URI query parameter may
leak through various means but most notably through referrer and leak through various means but most notably through referrer and
browser history, if the authorization request contains poteintially browser history, if the authorization request contains potentially
sensitive parameter, the Client SHOULD JWE [RFC7516] encrypt the sensitive parameter, the Client SHOULD JWE [RFC7516] encrypt the
request object. request object.
Where Request Object URI method is being used, if the request object Where Request Object URI method is being used, if the request object
contains personally identifiable or sensitive information, the contains personally identifiable or sensitive information, the
"request_uri" SHOULD be of one-time use and MUST have large enough "request_uri" SHOULD be of one-time use and MUST have large enough
entropy deemed necessary with applicable security policy unless the entropy deemed necessary with applicable security policy unless the
Request Object itself is JWE [RFC7516] Encrypted. Request Object itself is JWE [RFC7516] Encrypted.
11.2.2. Tracking using Request Object URI 11.2.2. Tracking using Request Object URI
Even if the protected resource does not include a personally Even if the protected resource does not include a personally
identifiable information, it is sometimes possible to identify the identifiable information, it is sometimes possible to identify the
user through the Request Object URI if persistent per-user Request user through the Request Object URI if persistent per-user Request
Object URI is used. A third party may observe it through borwser Object URI is used. A third party may observe it through browser
history etc. and start corrilating the user's activity using it. It history etc. and start correlating the user's activity using it. It
is in a way a data disclosure as well and should be avoided. is in a way a data disclosure as well and should be avoided.
Therefore, per-user Request Object URI should be avoided. Therefore, per-user Request Object URI should be avoided.
12. Acknowledgements 12. Acknowledgements
Follwoing people contributed to the creation of this document in The following people contributed to the creation of this document in
OAuth WG. (Affiliations at the time of the contribution is used.) the OAuth WG. (Affiliations at the time of the contribution is
used.)
Sergey Beryozkin, Brian Campbell (Ping Identity), Vladimir Dzhuvinov Sergey Beryozkin, Brian Campbell (Ping Identity), Vladimir Dzhuvinov
(Connect2id), Michael B. Jones (Microsoft), Torsten Lodderstedt (Connect2id), Michael B. Jones (Microsoft), Torsten Lodderstedt
(Deutche Telecom) Jim Manico, Axel Nenker(Deutche Telecom), Hannes (Deutche Telecom) Jim Manico, Axel Nenker(Deutche Telecom), Hannes
Tschofenig (ARM), (add yourself). Tschofenig (ARM).
Following people contributed to creating this document through the The following people contributed to creating this document through
OpenID Connect Core 1.0 [OpenID.Core]. the OpenID Connect Core 1.0 [OpenID.Core].
Brian Campbell (Ping Identity), George Fletcher (AOL), Ryo Itou Brian Campbell (Ping Identity), George Fletcher (AOL), Ryo Itou
(Mixi), Edmund Jay (Illumila), Michael B. Jones (Microsoft), Breno (Mixi), Edmund Jay (Illumila), Michael B. Jones (Microsoft), Breno
de Medeiros (Google), Hideki Nara (TACT), Justin Richer (MITRE), (add de Medeiros (Google), Hideki Nara (TACT), Justin Richer (MITRE).
yourself).
In addition following people contributed to this and previous In addition, the following people contributed to this and previous
versions through The OAuth Working Group. versions through the OAuth Working Group.
Dirk Balfanz (Google), James H. Manger (Telstra), John Panzer Dirk Balfanz (Google), James H. Manger (Telstra), John Panzer
(Google), David Recordon (Facebook), Marius Scurtescu (Google), Luke (Google), David Recordon (Facebook), Marius Scurtescu (Google), Luke
Shepard (Facebook). Shepard (Facebook).
13. Revision History 13. Revision History
-09
o Minor Editorial Nits.
o Section 10.4 added.
o Explicit reference to Security consideration (10.2) added in
section 5 and section 5.2.
o , (add yourself) removed from the acknowledgement.
-08 -08
o Applied changes proposed by Hannes on 2016-06-29 on IETF OAUth o Applied changes proposed by Hannes on 2016-06-29 on IETF OAuth
list recorded as https://bitbucket.org/Nat/oauth-jwsreq/ list recorded as https://bitbucket.org/Nat/oauth-jwsreq/
issues/12/. issues/12/.
o TLS requirements added. o TLS requirements added.
o Security Consideration reinforced. o Security Consideration reinforced.
o Privacy Consideration added. o Privacy Consideration added.
o Introduction improved. o Introduction improved.
skipping to change at page 18, line 37 skipping to change at page 20, line 5
o Generalized the language in 4.2.1 to convey the intent more o Generalized the language in 4.2.1 to convey the intent more
clearly. clearly.
o Changed "Server" to "Authorization Server" as a clarification. o Changed "Server" to "Authorization Server" as a clarification.
o Stopped talking about request_object_signing_alg. o Stopped talking about request_object_signing_alg.
o IANA considerations now reflect the current status. o IANA considerations now reflect the current status.
o Added Brian Campbell to the contributers list. Made the lists o Added Brian Campbell to the contributors list. Made the lists
alphabetic order based on the last names. Clarified that the alphabetic order based on the last names. Clarified that the
affiliation is at the time of the contribution. affiliation is at the time of the contribution.
o Added "older versions of " to the reference to IE uri length o Added "older versions of " to the reference to IE uri length
limitations. limitations.
o Stopped talking about signed or unsigned JWS etc. o Stopped talking about signed or unsigned JWS etc.
o 1.Introduction improved. o 1.Introduction improved.
skipping to change at page 20, line 48 skipping to change at page 22, line 17
<http://www.rfc-editor.org/info/rfc7519>. <http://www.rfc-editor.org/info/rfc7519>.
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer "Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
2015, <http://www.rfc-editor.org/info/rfc7525>. 2015, <http://www.rfc-editor.org/info/rfc7525>.
14.2. Informative References 14.2. Informative References
[BASIN] Basin, D., Cremers, C., and S. Meier, "Provably Repairing
the ISO/IEC 9798 Standard for Entity Authentication",
Journal of Computer Security - Security and Trust
Principles Volume 21 Issue 6, Pages 817-846, November
2013,
<https://www.cs.ox.ac.uk/people/cas.cremers/downloads/
papers/BCM2012-iso9798.pdf>.
[ISO29100] [ISO29100]
"ISO/IEC 29100 Information technology - Security "ISO/IEC 29100 Information technology - Security
techniques - Privacy framework", December 2011, techniques - Privacy framework", December 2011,
<http://standards.iso.org/ittf/PubliclyAvailableStandards/ <http://standards.iso.org/ittf/PubliclyAvailableStandards/
c045123_ISO_IEC_29100_2011.zip>. c045123_ISO_IEC_29100_2011.zip>.
[OpenID.Core] [OpenID.Core]
Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and
C. Mortimore, "OpenID Connect Core 1.0", February 2014, C. Mortimore, "OpenID Connect Core 1.0", OpenID
Foundation Standards, February 2014,
<http://openid.net/specs/openid-connect-core-1_0.html>. <http://openid.net/specs/openid-connect-core-1_0.html>.
Authors' Addresses Authors' Addresses
Nat Sakimura Nat Sakimura
Nomura Research Institute Nomura Research Institute
1-6-5 Marunouchi, Marunouchi Kitaguchi Bldg. 1-6-5 Marunouchi, Marunouchi Kitaguchi Bldg.
Chiyoda-ku, Tokyo 100-0005 Chiyoda-ku, Tokyo 100-0005
Japan Japan
 End of changes. 44 change blocks. 
91 lines changed or deleted 143 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/