draft-ietf-oauth-dyn-reg-management-06.txt   draft-ietf-oauth-dyn-reg-management-07.txt 
OAuth Working Group J. Richer OAuth Working Group J. Richer
Internet-Draft The MITRE Corporation Internet-Draft The MITRE Corporation
Intended status: Experimental M. Jones Intended status: Experimental M. Jones
Expires: June 9, 2015 Microsoft Expires: July 19, 2015 Microsoft
J. Bradley J. Bradley
Ping Identity Ping Identity
M. Machulak M. Machulak
Newcastle University Newcastle University
December 6, 2014 January 15, 2015
OAuth 2.0 Dynamic Client Registration Management Protocol OAuth 2.0 Dynamic Client Registration Management Protocol
draft-ietf-oauth-dyn-reg-management-06 draft-ietf-oauth-dyn-reg-management-07
Abstract Abstract
This specification defines methods for management of dynamic OAuth This specification defines methods for management of dynamic OAuth
2.0 client registrations for use cases in which the properties of a 2.0 client registrations for use cases in which the properties of a
registered client may need to be changed during the lifetime of the registered client may need to be changed during the lifetime of the
client. Not all authorization servers supporting dynamic client client. Not all authorization servers supporting dynamic client
registration will support these management methods. registration will support these management methods.
Status of This Memo Status of This Memo
skipping to change at page 1, line 39 skipping to change at page 1, line 39
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 June 9, 2015. This Internet-Draft will expire on July 19, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2015 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
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 2
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.3. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 3 1.3. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 3
2. Client Configuration Endpoint . . . . . . . . . . . . . . . . 5 2. Client Configuration Endpoint . . . . . . . . . . . . . . . . 5
2.1. Client Read Request . . . . . . . . . . . . . . . . . . . 6 2.1. Client Read Request . . . . . . . . . . . . . . . . . . . 6
2.2. Client Update Request . . . . . . . . . . . . . . . . . . 6 2.2. Client Update Request . . . . . . . . . . . . . . . . . . 6
2.3. Client Delete Request . . . . . . . . . . . . . . . . . . 9 2.3. Client Delete Request . . . . . . . . . . . . . . . . . . 9
3. Responses . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3. Client Information Response . . . . . . . . . . . . . . . . . 10
3.1. Client Information Response . . . . . . . . . . . . . . . 10
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
5. Security Considerations . . . . . . . . . . . . . . . . . . . 12 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12
6. Normative References . . . . . . . . . . . . . . . . . . . . 13 6. Normative References . . . . . . . . . . . . . . . . . . . . 13
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 13 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 13
Appendix B. Registration Tokens and Client Credentials . . . . . 14 Appendix B. Registration Tokens and Client Credentials . . . . . 14
B.1. Credential Rotation . . . . . . . . . . . . . . . . . . . 15 B.1. Credential Rotation . . . . . . . . . . . . . . . . . . . 15
Appendix C. Forming the Client Configuration Endpoint URL . . . 15 Appendix C. Forming the Client Configuration Endpoint URL . . . 15
Appendix D. Document History . . . . . . . . . . . . . . . . . . 16 Appendix D. Document History . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
In order for an OAuth 2.0 client to utilize an OAuth 2.0 In order for an OAuth 2.0 client to utilize an OAuth 2.0
authorization server, the client needs specific information to authorization server, the client needs specific information to
interact with the server, including an OAuth 2.0 client identifier to interact with the server, including an OAuth 2.0 client identifier to
use at that server. The OAuth 2.0 Dynamic Client Registration use at that server. The OAuth 2.0 Dynamic Client Registration
Protocol [OAuth.Registration] specification describes how an OAuth Protocol [OAuth.Registration] specification describes how an OAuth
2.0 client can be dynamically registered with an authorization server 2.0 client can be dynamically registered with an authorization server
to obtain this information and how metadata about the client can be to obtain this information and how metadata about the client can be
skipping to change at page 5, line 38 skipping to change at page 5, line 38
(H) The authorization server deprovisions the client and responds (H) The authorization server deprovisions the client and responds
with a confirmation that the deletion has taken place. with a confirmation that the deletion has taken place.
2. Client Configuration Endpoint 2. Client Configuration Endpoint
The client configuration endpoint is an OAuth 2.0 protected resource The client configuration endpoint is an OAuth 2.0 protected resource
that is provisioned by the server to facilitate viewing, updating, that is provisioned by the server to facilitate viewing, updating,
and deleting a client's registered information. The location of this and deleting a client's registered information. The location of this
endpoint is communicated to the client through the endpoint is communicated to the client through the
"registration_client_uri" member of the client information response, "registration_client_uri" member of the client information response,
as specified in Section 3.1. The client MUST use its registration as specified in Section 3. The client MUST use its registration
access token in all calls to this endpoint as an OAuth 2.0 Bearer access token in all calls to this endpoint as an OAuth 2.0 Bearer
Token [RFC6750]. Token [RFC6750].
The client configuration endpoint MUST require transport-layer The client configuration endpoint MUST require transport-layer
security. The server MUST support TLS 1.2 RFC 5246 [RFC5246] and MAY security. The server MUST support TLS 1.2 RFC 5246 [RFC5246] and MAY
support additional transport-layer mechanisms meeting its security support additional transport-layer mechanisms meeting its security
requirements. When using TLS, the client MUST perform a TLS/SSL requirements. When using TLS, the client MUST perform a TLS/SSL
server certificate check, per RFC 6125 [RFC6125]. Implementation server certificate check, per RFC 6125 [RFC6125]. Implementation
security considerations can be found in Recommendations for Secure security considerations can be found in Recommendations for Secure
Use of TLS and DTLS [TLS.BCP]. Use of TLS and DTLS [TLS.BCP].
skipping to change at page 6, line 25 skipping to change at page 6, line 25
display purposes only): display purposes only):
GET /register/s6BhdRkqt3 HTTP/1.1 GET /register/s6BhdRkqt3 HTTP/1.1
Accept: application/json Accept: application/json
Host: server.example.com Host: server.example.com
Authorization: Bearer reg-23410913-abewfq.123483 Authorization: Bearer reg-23410913-abewfq.123483
Upon successful read of the information for a currently active Upon successful read of the information for a currently active
client, the authorization server responds with an HTTP 200 OK with client, the authorization server responds with an HTTP 200 OK with
content type of "application/json" and a payload, as described in content type of "application/json" and a payload, as described in
Section 3.1. Some values in the response, including the Section 3. Some values in the response, including the
"client_secret" and "registration_access_token", MAY be different "client_secret" and "registration_access_token", MAY be different
from those in the initial registration response. If the from those in the initial registration response. If the
authorization server includes a new client secret and/or registration authorization server includes a new client secret and/or registration
access token in its response, the client MUST immediately discard its access token in its response, the client MUST immediately discard its
previous client secret and/or registration access token. The value previous client secret and/or registration access token. The value
of the "client_id" MUST NOT change from the initial registration of the "client_id" MUST NOT change from the initial registration
response. response.
If the registration access token used to make this request is not If the registration access token used to make this request is not
valid, the server MUST respond with an error as described in OAuth valid, the server MUST respond with an error as described in OAuth
skipping to change at page 7, line 14 skipping to change at page 7, line 14
The client sends an HTTP PUT to the client configuration endpoint The client sends an HTTP PUT to the client configuration endpoint
with a content type of "application/json". The HTTP entity payload with a content type of "application/json". The HTTP entity payload
is a JSON [RFC7159] document consisting of a JSON object and all is a JSON [RFC7159] document consisting of a JSON object and all
parameters as top- level members of that JSON object. parameters as top- level members of that JSON object.
This request MUST include all client metadata fields as returned to This request MUST include all client metadata fields as returned to
the client from a previous registration, read, or update operation. the client from a previous registration, read, or update operation.
The client MUST NOT include the "registration_access_token", The client MUST NOT include the "registration_access_token",
"registration_client_uri", "client_secret_expires_at", or "registration_client_uri", "client_secret_expires_at", or
"client_id_issued_at" fields described in Section 3.1. "client_id_issued_at" fields described in Section 3.
Valid values of client metadata fields in this request MUST replace, Valid values of client metadata fields in this request MUST replace,
not augment, the values previously associated with this client. not augment, the values previously associated with this client.
Omitted fields MUST be treated as null or empty values by the server, Omitted fields MUST be treated as null or empty values by the server,
indicating the client's request to delete them from the client's indicating the client's request to delete them from the client's
registration. The authorization server MAY ignore any null or empty registration. The authorization server MAY ignore any null or empty
value in the request just as any other value. value in the request just as any other value.
The client MUST include its "client_id" field in the request, and it The client MUST include its "client_id" field in the request, and it
MUST be the same as its currently-issued client identifier. If the MUST be the same as its currently-issued client identifier. If the
skipping to change at page 8, line 33 skipping to change at page 8, line 33
"client_name#fr":"Mon Nouvel Exemple", "client_name#fr":"Mon Nouvel Exemple",
"logo_uri":"https://client.example.org/newlogo.png", "logo_uri":"https://client.example.org/newlogo.png",
"logo_uri#fr":"https://client.example.org/fr/newlogo.png" "logo_uri#fr":"https://client.example.org/fr/newlogo.png"
} }
This example uses client metadata values defined in This example uses client metadata values defined in
[OAuth.Registration]. [OAuth.Registration].
Upon successful update, the authorization server responds with an Upon successful update, the authorization server responds with an
HTTP 200 OK Message with content type "application/json" and a HTTP 200 OK Message with content type "application/json" and a
payload, as described in Section 3.1. Some values in the response, payload, as described in Section 3. Some values in the response,
including the "client_secret" and "registration_access_token", MAY be including the "client_secret" and "registration_access_token", MAY be
different from those in the initial registration response. If the different from those in the initial registration response. If the
authorization server includes a new client secret and/or registration authorization server includes a new client secret and/or registration
access token in its response, the client MUST immediately discard its access token in its response, the client MUST immediately discard its
previous client secret and/or registration access token. The value previous client secret and/or registration access token. The value
of the "client_id" MUST NOT change from the initial registration of the "client_id" MUST NOT change from the initial registration
response. response.
If the registration access token used to make this request is not If the registration access token used to make this request is not
valid, the server MUST respond with an error as described in OAuth valid, the server MUST respond with an error as described in OAuth
skipping to change at page 9, line 32 skipping to change at page 9, line 32
A successful delete action will invalidate the "client_id", A successful delete action will invalidate the "client_id",
"client_secret", and "registration_access_token" for this client, "client_secret", and "registration_access_token" for this client,
thereby preventing the "client_id" from being used at either the thereby preventing the "client_id" from being used at either the
authorization endpoint or token endpoint of the authorization server. authorization endpoint or token endpoint of the authorization server.
If possible, the authorization server SHOULD immediately invalidate If possible, the authorization server SHOULD immediately invalidate
all existing authorization grants and currently-active access tokens, all existing authorization grants and currently-active access tokens,
refresh tokens, and other tokens associated with this client. refresh tokens, and other tokens associated with this client.
If a client has been successfully deprovisioned, the authorization If a client has been successfully deprovisioned, the authorization
server MUST responsd with an HTTP 204 No Content message. server MUST respond with an HTTP 204 No Content message.
If the server does not support the delete method, the server MUST If the server does not support the delete method, the server MUST
respond with an HTTP 405 Not Supported. respond with an HTTP 405 Not Supported.
If the registration access token used to make this request is not If the registration access token used to make this request is not
valid, the server MUST respond with an error as described in OAuth valid, the server MUST respond with an error as described in OAuth
Bearer Token Usage [RFC6750]. Bearer Token Usage [RFC6750].
If the client does not exist on this server, the server MUST respond If the client does not exist on this server, the server MUST respond
with HTTP 401 Unauthorized and the registration access token used to with HTTP 401 Unauthorized and the registration access token used to
skipping to change at page 10, line 5 skipping to change at page 10, line 5
If the client is not allowed to delete itself, the server MUST If the client is not allowed to delete itself, the server MUST
respond with HTTP 403 Forbidden. respond with HTTP 403 Forbidden.
Following is a non-normative example response: Following is a non-normative example response:
HTTP/1.1 204 No Content HTTP/1.1 204 No Content
Cache-Control: no-store Cache-Control: no-store
Pragma: no-cache Pragma: no-cache
3. Responses 3. Client Information Response
In response to certain requests from the client to either the client
registration endpoint or the client configuration endpoint as
described in this specification, the authorization server sends the
following response bodies.
3.1. Client Information Response
This specification extends the client information response defined in This specification extends the client information response defined in
OAuth 2.0 Client Dynamic Registration [OAuth.Registration]. The OAuth 2.0 Client Dynamic Registration [OAuth.Registration], which
response contains the client identifier as well as the client secret, states that the response contains the client identifier as well as
if the client is a confidential client. The response also contains the client secret, if the client is a confidential client. When used
the fully qualified URL of the client configuration endpoint with this specification, the client information response also
(Section 2) for this specific client that the client may use to contains the fully qualified URL of the client configuration endpoint
obtain and update information about itself. The response also (Section 2) for this specific client that the client or developer may
contains a registration access token that is to be used by the client use to manage the client's registration configuration, as well as a
to perform subsequent operations at the client configuration registration access token that is to be used by the client or
endpoint. developer to perform subsequent operations at the client
configuration endpoint.
client_id
REQUIRED. OAuth 2.0 client identifier.
client_secret
OPTIONAL. OAuth 2.0 client secret.
client_id_issued_at
OPTIONAL. Time at which the client identifier was issued, as
defined by [OAuth.Registration].
client_secret_expires_at
REQUIRED if "client_secret" is issued. Time at which the
"client_secret" will expire, as defined by [OAuth.Registration].
registration_access_token registration_access_token
REQUIRED. Access token used at the client configuration endpoint REQUIRED. Access token used at the client configuration endpoint
to perform subsequent operations upon the client registration. to perform subsequent operations upon the client registration.
registration_client_uri registration_client_uri
REQUIRED. Fully qualified URL of the client configuration REQUIRED. Fully qualified URL of the client configuration
endpoint for this client. endpoint for this client.
Additionally, the authorization server MUST return all registered Additionally, the authorization server MUST return all registered
skipping to change at page 14, line 23 skipping to change at page 14, line 23
token that is used to authorize the initial client registration token that is used to authorize the initial client registration
request. The content, structure, generation, and validation of request. The content, structure, generation, and validation of
this token are out of scope for this specification. The this token are out of scope for this specification. The
authorization server can use this token to verify that the authorization server can use this token to verify that the
presenter is allowed to dynamically register new clients. This presenter is allowed to dynamically register new clients. This
token may be shared among multiple instances of a client to allow token may be shared among multiple instances of a client to allow
them to each register separately, thereby letting the them to each register separately, thereby letting the
authorization server use this token to tie multiple instances of authorization server use this token to tie multiple instances of
registered clients (each with their own distinct client registered clients (each with their own distinct client
identifier) back to the party to whom the initial access token was identifier) back to the party to whom the initial access token was
issued, usually an application developer. This token should be issued, usually an application developer. This token is usually
used only at the client registration endpoint. intended to be used only at the client registration endpoint.
o The registration access token is used by the client or developer o The registration access token is used by the client or developer
at the client configuration endpoint and represents the holder's at the client configuration endpoint and represents the holder's
authorization to manage the registration of a client. This is an authorization to manage the registration of a client. This is an
OAuth 2.0 bearer token that is issued from the client registration OAuth 2.0 bearer token that is issued from the client registration
endpoint in response to a client registration request and is endpoint in response to a client registration request and is
returned in a client information response. The registration returned in a client information response. The registration
access token is uniquely bound to the client identifier and is access token is uniquely bound to the client identifier and is
required to be presented with all calls to the client required to be presented with all calls to the client
configuration endpoint. The registration access token should be configuration endpoint. The registration access token should be
protected and should not be shared between instances of a client protected as described in [RFC6750] and should not be shared
(otherwise, one instance could change or delete registration between instances of a client. If a registration access token is
values for all instances of the client). The registration access shared between client instances, one instance could change or
token can be rotated through the use of the client update method delete registration values for all other instances of the client.
on the client configuration endpoint. The registration access The registration access token can be rotated through the use of
token should be used only at the client configuration endpoint. the client read or update method on the client configuration
endpoint. The registration access token is intended to be used
only at the client configuration endpoint.
o The client credentials (such as "client_secret") are optional o The client credentials (such as "client_secret") are optional
depending on the type of client and are used to retrieve OAuth depending on the type of client and are used to retrieve OAuth
tokens. Client credentials are most often bound to particular tokens. Client credentials are most often bound to particular
instances of a client and should not be shared between instances. instances of a client and should not be shared between instances.
Note that since not all types of clients have client credentials, Note that since not all types of clients have client credentials,
they cannot be used to manage client registrations at the client they cannot be used to manage client registrations at the client
configuration endpoint. The client credentials can be rotated configuration endpoint. The client credentials can be rotated
through the use of the client update method on the client through the use of the client read or update method on the client
configuration endpoint. The client credentials cannot be used for configuration endpoint. The client credentials are intended to be
authentication at the client registration endpoint or at the used only at the token endpoint.
client configuration endpoint.
B.1. Credential Rotation B.1. Credential Rotation
The authorization server MAY rotate the client's registration access The authorization server may be configured to issue new registration
token and/or client credentials (such as a "client_secret") access token and/or client credentials (such as a "client_secret")
throughout the lifetime of the client in order to minimize the risk throughout the lifetime of the client. This map help minimize the
of leakage of these credentials. The client can discover that these impact of exposed credentials. The authorization server conveys new
values have changed by reading the client information response registration access tokens and client credentials (if applicable) to
returned from either a read or update request to the client the client in the client information response of either a read or
configuration endpoint. The client's current registration access update request to the client configuration endpoint. The client's
token and client credentials (if applicable) MUST be included in this current registration access token and client credentials (if
response. applicable) MUST be included in the client information response.
The registration access token SHOULD be rotated only in response to The registration access token SHOULD be rotated only in response to a
an update request to the client configuration endpoint, at which read or update request to the client configuration endpoint, at which
point the new registration access token is returned to the client and point the new registration access token is returned to the client and
the old registration access token SHOULD be discarded by both the old registration access token MUST be discarded by the client and
parties. If the registration access token were to expire or be SHOULD be discarded by the server, if possible. If instead the
rotated outside of such requests, the client or developer might be registration access token were to expire or be invalidated outside of
locked out of managing the client's configuration. such requests, the client or developer might be locked out of
managing the client's configuration.
Methods by which the client can request credential rotation are Note that the authorization server decides the frequency of the
outside the scope of this document. credential rotation and not the client. Methods by which the client
can request credential rotation are outside the scope of this
document.
Appendix C. Forming the Client Configuration Endpoint URL Appendix C. Forming the Client Configuration Endpoint URL
The authorization server MUST provide the client with the fully The authorization server MUST provide the client with the fully
qualified URL in the "registration_client_uri" element of the Client qualified URL in the "registration_client_uri" element of the Client
Information Response, as specified in Section 3.1. The authorization Information Response, as specified in Section 3. The authorization
server MUST NOT expect the client to construct or discover this URL server MUST NOT expect the client to construct or discover this URL
on its own. The client MUST use the URL as given by the server and on its own. The client MUST use the URL as given by the server and
MUST NOT construct this URL from component pieces. MUST NOT construct this URL from component pieces.
Depending on deployment characteristics, the client configuration Depending on deployment characteristics, the client configuration
endpoint URL may take any number of forms. It is RECOMMENDED that endpoint URL may take any number of forms. It is RECOMMENDED that
this endpoint URL be formed through the use of a server-constructed this endpoint URL be formed through the use of a server-constructed
URL string which combines the client registration endpoint's URL and URL string which combines the client registration endpoint's URL and
the issued "client_id" for this client, with the latter as either a the issued "client_id" for this client, with the latter as either a
path parameter or a query parameter. For example, a client with the path parameter or a query parameter. For example, a client with the
skipping to change at page 16, line 4 skipping to change at page 16, line 10
client identifier "s6BhdRkqt3" could be given a client configuration client identifier "s6BhdRkqt3" could be given a client configuration
endpoint URL of "https://server.example.com/register/s6BhdRkqt3" endpoint URL of "https://server.example.com/register/s6BhdRkqt3"
(path parameter) or of "https://server.example.com/ (path parameter) or of "https://server.example.com/
register?client_id=s6BhdRkqt3" (query parameter). In both of these register?client_id=s6BhdRkqt3" (query parameter). In both of these
cases, the client simply uses the URL as given by the authorization cases, the client simply uses the URL as given by the authorization
server. server.
These common patterns can help the server to more easily determine These common patterns can help the server to more easily determine
the client to which the request pertains, which MUST be matched the client to which the request pertains, which MUST be matched
against the client to which the registration access token was issued. against the client to which the registration access token was issued.
If desired, the server MAY simply return the client registration If desired, the server MAY simply return the client registration
endpoint URL as the client configuration endpoint URL and change endpoint URL as the client configuration endpoint URL and change
behavior based on the authentication context provided by the behavior based on the authentication context provided by the
registration access token. registration access token.
Appendix D. Document History Appendix D. Document History
[[ to be removed by the RFC editor before publication as an RFC ]] [[ to be removed by the RFC editor before publication as an RFC ]]
-07
o Editorial clarifications due to document shepherd feedback.
-06
o Removed TLS 1.0.
o Moved several explanatory sections to the appendix.
o Clarified read operations.
o Added IANA request.
-05 -05
o Removed Phil Hunt from authors list, per request. o Removed Phil Hunt from authors list, per request.
o Applied various minor editorial changes from working group o Applied various minor editorial changes from working group
comments. comments.
-04 -04
o Incorrect XML uploaded for -03 o Incorrect XML uploaded for -03
 End of changes. 25 change blocks. 
76 lines changed or deleted 72 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/