Federated Authentication for the Registration Data Access Protocol (RDAP) using OpenID Connect
draft-ietf-regext-rdap-openid-06
REGEXT Working Group S. Hollenbeck
Internet-Draft Verisign Labs
Intended status: Standards Track January 5, 2021
Expires: July 9, 2021
Federated Authentication for the Registration Data Access Protocol
(RDAP) using OpenID Connect
draft-ietf-regext-rdap-openid-06
Abstract
The Registration Data Access Protocol (RDAP) provides "RESTful" web
services to retrieve registration metadata from domain name and
regional internet registries. RDAP allows a server to make access
control decisions based on client identity, and as such it includes
support for client identification features provided by the Hypertext
Transfer Protocol (HTTP). Identification methods that require
clients to obtain and manage credentials from every RDAP server
operator present management challenges for both clients and servers,
whereas a federated authentication system would make it easier to
operate and use RDAP without the need to maintain server-specific
client credentials. This document describes a federated
authentication system for RDAP based on OpenID Connect.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on July 9, 2021.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Problem Statement . . . . . . . . . . . . . . . . . . . . 3
1.2. Proposal . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. Federated Authentication for RDAP . . . . . . . . . . . . . . 4
3.1. RDAP and OpenID Connect . . . . . . . . . . . . . . . . . 5
3.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 5
3.1.2. Overview . . . . . . . . . . . . . . . . . . . . . . 5
3.1.3. RDAP Authentication and Authorization Steps . . . . . 6
3.1.3.1. Provider Discovery . . . . . . . . . . . . . . . 6
3.1.3.2. Authentication Request . . . . . . . . . . . . . 6
3.1.3.3. End-User Authorization . . . . . . . . . . . . . 7
3.1.3.4. Authorization Response and Validation . . . . . . 7
3.1.3.5. Token Processing . . . . . . . . . . . . . . . . 7
3.1.3.6. Delivery of User Information . . . . . . . . . . 7
3.1.4. Specialized Claims for RDAP . . . . . . . . . . . . . 8
3.1.4.1. Stated Purpose . . . . . . . . . . . . . . . . . 8
3.1.4.2. Do Not Track . . . . . . . . . . . . . . . . . . 9
4. Protocol Parameters . . . . . . . . . . . . . . . . . . . . . 9
4.1. Client Authentication Request and Response . . . . . . . 10
4.2. Token Request and Response . . . . . . . . . . . . . . . 10
4.3. Token Refresh and Revocation . . . . . . . . . . . . . . 11
4.4. Token Exchange . . . . . . . . . . . . . . . . . . . . . 14
4.5. Parameter Processing . . . . . . . . . . . . . . . . . . 14
4.6. RDAP Conformance . . . . . . . . . . . . . . . . . . . . 15
5. Clients with Limited User Interfaces . . . . . . . . . . . . 15
5.1. OAuth 2.0 Device Authorization Grant . . . . . . . . . . 16
5.2. Manual Token Management . . . . . . . . . . . . . . . . . 16
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
6.1. RDAP Extensions Registry . . . . . . . . . . . . . . . . 17
6.2. JSON Web Token Claims Registry . . . . . . . . . . . . . 17
6.3. RDAP Query Purpose Registry . . . . . . . . . . . . . . . 17
7. Implementation Status . . . . . . . . . . . . . . . . . . . . 20
7.1. Verisign Labs . . . . . . . . . . . . . . . . . . . . . . 21
7.2. Viagenie . . . . . . . . . . . . . . . . . . . . . . . . 21
8. Security Considerations . . . . . . . . . . . . . . . . . . . 22
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8.1. Authentication and Access Control . . . . . . . . . . . . 22
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 22
10.1. Normative References . . . . . . . . . . . . . . . . . . 22
10.2. Informative References . . . . . . . . . . . . . . . . . 24
10.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 25
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 25
1. Introduction
The Registration Data Access Protocol (RDAP) provides "RESTful" web
services to retrieve registration metadata from domain name and
regional internet registries. RDAP allows a server to make access
control decisions based on client identity, and as such it includes
support for client identification features provided by the Hypertext
Transfer Protocol (HTTP) [RFC7230].
RDAP is specified in multiple documents, including "HTTP Usage in the
Registration Data Access Protocol (RDAP)" [RFC7480], "Security
Services for the Registration Data Access Protocol (RDAP)" [RFC7481],
"Registration Data Access Protocol Query Format" [RFC7482], and "JSON
Responses for the Registration Data Access Protocol (RDAP)"
[RFC7483]. RFC 7481 describes client identification and
authentication services that can be used with RDAP, but it does not
specify how any of these services can (or should) be used with RDAP.
1.1. Problem Statement
The traditional "user name and password" authentication method does
not scale well in the RDAP ecosystem. Assuming that all domain name
and address registries will eventually provide RDAP service, it is
impractical and inefficient for users to secure login credentials
from the hundreds of different server operators. Authentication
methods based on user names and passwords do not provide information
that describes the user in sufficient detail (while protecting the
personal privacy of the user) for server operators to make fine-
grained access control decisions based on the user's identity. The
authentication system used for RDAP needs to address all of these
needs.
1.2. Proposal
A basic level of RDAP service can be provided to users who possess an
identifier issued by a recognized provider who is able to
authenticate and validate the user. The identifiers issued by social
media services, for example, can be used. Users who require higher
levels of service (and who are willing to share more information
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about them self to gain access to that service) can secure
identifiers from specialized providers who are or will be able to
provide more detailed information about the user. Server operators
can then make access control decisions based on the identification
information provided by the user.
A federated authentication system would make it easier to operate and
use RDAP by re-using existing identifiers to provide a basic level of
access. It can also provide the ability to collect additional user
identification information, and that information can be shared with
the consent of the user. This document describes a federated
authentication system for RDAP based on OpenID Connect [OIDC] that
meets all of these needs.
2. Conventions Used in This Document
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 BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Federated Authentication for RDAP
RDAP itself does not include native security services. Instead, RDAP
relies on features that are available in other protocol layers to
provide needed security services including access control,
authentication, authorization, availability, data confidentiality,
data integrity, and identification. A description of each of these
security services can be found in "Internet Security Glossary,
Version 2" [RFC4949]. This document focuses on a federated
authentication system for RDAP that provides services for
authentication, authorization, and identification, allowing a server
operator to make access control decisions. Section 3 of RFC 7481
[RFC7481] describes general considerations for RDAP access control,
authentication, and authorization.
The traditional client-server authentication model requires clients
to maintain distinct credentials for every RDAP server. This
situation can become unwieldy as the number of RDAP servers
increases. Federated authentication mechanisms allow clients to use
one credential to access multiple RDAP servers and reduce client
credential management complexity.
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3.1. RDAP and OpenID Connect
OpenID Connect 1.0 [OIDCC] is a decentralized, single sign-on (SSO)
federated authentication system that allows users to access multiple
web resources with one identifier instead of having to create
multiple server-specific identifiers. Users acquire identifiers from
OpenID Providers, or OPs. Relying Parties, or RPs, are applications
(such as RDAP) that outsource their user authentication function to
an OP. OpenID Connect is built on top of the authorization framework
provided by the OAuth 2.0 [RFC6749] protocol.
The OAuth authorization framework describes a method for users to
access protected web resources without having to hand out their
credentials. Instead, clients are issued Access Tokens by
authorization servers with the permission of the resource owners.
Using OpenID Connect and OAuth, multiple RDAP servers can form a
federation and clients can access any server in the federation by
providing one credential registered with any OP in that federation.
The OAuth authorization framework is designed for use with HTTP and
thus can be used with RDAP.
3.1.1. Terminology
This document uses the terms "client" and "server" defined by RDAP
[RFC7480]. An RDAP client performs the role of an OpenID Connect
Core [OIDCC] Entity or End-User. An RDAP server performs the role of
an OpenID Connect Core Relying Party (RP). Additional terms from
Section 1.2 of the OpenID Connect Core specification are incorporated
by reference.
3.1.2. Overview
At a high level, RDAP authentication of a browser-based client using
OpenID Connect requires completion of the following steps:
1. An RDAP client (acting as an OpenID End-User) sends an HTTP (or
HTTPS) query containing OAuth 2.0 request parameters to an RDAP
server.
2. The RDAP server (acting as an OpenID Relying Party (RP)) prepares
an Authentication Request containing the desired request
parameters.
3. The RDAP server sends the RDAP client and Authentication Request
to an Authorization Server operated by an OpenID Provider (OP)
using an HTTP redirect.
4. The Authorization Server authenticates the RDAP Client.
5. The Authorization Server obtains RDAP Client consent/
authorization.
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6. The Authorization Server sends the RDAP Client back to the RDAP
server with an Authorization Code using an HTTP redirect.
7. The RDAP server requests a response using the Authorization Code
at the Token Endpoint.
8. The RDAP server receives a response that contains an ID Token and
Access Token in the response body.
9. The RDAP server validates the ID Token and retrieves the RDAP
client's Subject Identifier.
The RDAP server can then make identification, authorization, and
access control decisions based on local policies, the ID Token
received from the OP, and the received Claims. Note that OpenID
Connect describes different process flows for other types of clients,
such as script-based or command line clients.
3.1.3. RDAP Authentication and Authorization Steps
End-Users MUST possess an identifier (an OpenID) issued by an OP to
use OpenID Connect with RDAP. An OP MUST include support for the
claims described in Section 3.1.4 to provide additional information
needed for RDAP End-User authorization. OpenID Connect requires RPs
to register with OPs to use OpenID Connect services for an End-User.
That process is described by the "OpenID Connect Dynamic Client
Registration" protocol [OIDCR].
3.1.3.1. Provider Discovery
An RDAP server/RP needs to receive an identifier from an End-User
that can be used to discover the End-User's OP. That process is
required and is documented in the "OpenID Connect Discovery" protocol
[OIDCD].
3.1.3.2. Authentication Request
Once the OP is known, an RP MUST form an Authentication Request and
send it to the OP as described in Section 3 of the OpenID Connect
Core protocol [OIDCC]. The authentication path followed
(authorization, implicit, or hybrid) will depend on the
Authentication Request response_type set by the RP. The remainder of
the processing steps described here assume that the Authorization
Code Flow is being used by setting "response_type=code" in the
Authentication Request.
The benefits of using the Authorization Code Flow for authenticating
a human user are described in Section 3.1 of the OpenID Connect Core
protocol. The Implicit Flow is more commonly used by clients
implemented in a web browser using a scripting language; it is
described in Section 3.2 of the OpenID Connect Core protocol. The
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Hybrid Flow (described in Section 3.3 of the OpenID Connect Core
protocol) combines elements of the Authorization and Implicit Flows
by returning some tokens from the Authorization Endpoint and others
from the Token Endpoint.
An Authentication Request can contain several parameters. REQUIRED
parameters are specified in Section 3.1.2.1 of the OpenID Connect
Core protocol [OIDCC]. Other parameters MAY be included.
The OP receives the Authentication Request and attempts to validate
it as described in Section 3.1.2.2 of the OpenID Connect Core
protocol [OIDCC]. If the request is valid, the OP attempts to
authenticate the End-User as described in Section 3.1.2.3 of the
OpenID Connect Core protocol [OIDCC]. The OP returns an error
response if the request is not valid or if any error is encountered.
3.1.3.3. End-User Authorization
After the End-User is authenticated, the OP MUST obtain authorization
information from the End-User before releasing information to the
RDAP Server/RP. This process is described in Section 3.1.2.4 of the
OpenID Connect Core protocol [OIDCC].
3.1.3.4. Authorization Response and Validation
After the End-User is authenticated, the OP will send a response to
the RP that describes the result of the authorization process in the
form of an Authorization Grant. The RP MUST validate the response.
This process is described in Sections 3.1.2.5 - 3.1.2.7 of the OpenID
Connect Core protocol [OIDCC].
3.1.3.5. Token Processing
The RP sends a Token Request using the Authorization Grant to a Token
Endpoint to obtain a Token Response containing an Access Token, ID
Token, and an OPTIONAL Refresh Token. The RP MUST validate the Token
Response. This process is described in Section 3.1.3 of the OpenID
Connect Core protocol [OIDCC].
3.1.3.6. Delivery of User Information
The set of Claims can be retrieved by sending a request to a UserInfo
Endpoint using the Access Token. The Claims MAY be returned in the
ID Token. The process of retrieving Claims from a UserInfo Endpoint
is described in Section 5.3 of the OpenID Connect Core protocol
[OIDCC].
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OpenID Connect specified a set of standard Claims in Section 5.1.
Additional Claims for RDAP are described in Section 3.1.4.
3.1.4. Specialized Claims for RDAP
OpenID Connect claims are pieces of information used to make
assertions about an entity. Section 5 of the OpenID Connect Core
protocol [OIDCC] describes a set of standard claims that can be used
to identify a person. Section 5.1.2 notes that additional claims MAY
be used, and it describes a method to create them.
3.1.4.1. Stated Purpose
There are communities of RDAP users and operators who wish to make
and validate claims about a user's "need to know" when it comes to
requesting access to a resource. For example, a law enforcement
agent or a trademark attorney may wish to be able to assert that they
have a legal right to access a protected resource, and a server
operator will need to be able to receive and validate that claim.
These needs can be met by defining and using an additional "purpose"
claim.
The "purpose" claim identifies the purpose for which access to a
protected resource is being requested. Use of the "purpose" claim is
OPTIONAL; processing of this claim is subject to server acceptance of
the purpose and successful authentication of the End-User.
Unrecognized purpose values MUST be ignored and the associated query
MUST be processed as if the unrecognized purpose value was not
present at all.
The "purpose" value is a case-sensitive string containing a
StringOrURI value as specified in Section 2 of the JSON Web Token
(JWT) specification ([RFC7519]). An example:
{"purpose" : "domainNameControl"}
Purpose values are themselves registered with IANA. Each entry in
the registry contains the following fields:
Value: the purpose string value being registered. Value strings can
contain upper case characters from "A" to "Z", lower case ASCII
characters from "a" to "z", and the underscore ("_") character.
Value strings contain at least one character and no more than 64
characters.
Description: a one- or two-sentence description of the meaning of the
purpose value, how it might be used, and/or how it should be
interpreted by clients and servers.
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This registry is operated under the "Specification Required" policy
defined in RFC 5226 ([RFC5226]). The set of initial values used to
populate the registry as described in Section 6.3 are taken from the
final report [1] produced by the Expert Working Group on gTLD
Directory Services chartered by the Internet Corporation for Assigned
Names and Numbers (ICANN).
3.1.4.2. Do Not Track
There are also communities of RDAP users and operators who wish to
make and validate claims about a user's wish to not have their
queries logged, tracked, or recorded. For example, a law enforcement
agent may wish to be able to assert that their queries are part of a
criminal investigation and should not be tracked due to a risk of
query exposure compromising the investigation, and a server operator
will need to be able to receive and validate that claim. These needs
can be met by defining and using an additional "do not track" claim.
The "do not track" ("dnt") claim can be used to identify an End-User
that is authorized to perform queries without the End-User's
association with those queries being logged, tracked, or recorded by
the server. Client use of the "dnt" claim is OPTIONAL. Server
operators MUST NOT log, track, or record any association of the query
and the End-User's identity if the End-User is successfully
identified and authorized, the "dnt" claim is present, and the value
of the claim is "true".
The "dnt" value is represented as a JSON boolean literal. An
example:
{"dnt" : true}
No special query tracking processing is required if this claim is not
present or if the value of the claim is "false". Use of this claim
MUST be limited to End-Users who are granted "do not track"
priviliges in accordance with service policies and regulations.
Specification of these policies and regulations is beyond the scope
of this document.
4. Protocol Parameters
This specification adds the following protocol parameters to RDAP:
1. A query parameter to request authentication for a specific end-
user identity.
2. A path segment to request an ID Token and an Access Token for a
specific end-user identity.
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3. A query parameter to deliver an ID Token and an Access Token for
use with an RDAP query.
4.1. Client Authentication Request and Response
Client authentication is requested by adding a query component to an
RDAP request URI using the syntax described in Section 3.4 of RFC
3986 [RFC3986]. The query used to request client authentication is
represented as a "key=value" pair using a key value of "id" and a
value component that contains the client identifier issued by an OP.
An example:
https://example.com/rdap/domain/example.com?id=user.idp.example
The response to an authenticated query MUST use the response
structures specified in RFC 7483 [RFC7483]. Information that the
end-user is not authorized to receive MUST be omitted from the
response.
4.2. Token Request and Response
Clients MAY send a request to an RDAP server to authenticate an end-
user and return an ID Token and an Access Token from an OP that can
be then be passed to the RP/RDAP server to authenticate and process
subsequent queries. Identity provider authentication is requested
using a "tokens" path segment and a query parameter with key value of
"id" and a value component that contains the client identifier issued
by an OP. An example:
https://example.com/rdap/tokens?id=user.idp.example
In addition to any core RDAP response elements, the response to this
query MUST contain four name-value pairs, in any order, representing
the returned ID Token and Access Token. The ID Token is represented
using a key value of "id_token". The Access Token is represented
using a key value of "access_token". The access token type is
represented using a key value of "token_type" and a value of "bearer"
as described in Sections 4.2.2 and 7.1 of RFC 6749 [RFC6749]. The
lifetime of the access token is represented using a key value of
"expires_in" and a numerical value that describes the lifetime in
seconds of the access token as described in Section 4.2.2 of RFC 6749
[RFC6749]. The token values returned in the RDAP server response
MUST be Base64url encoded as described in RFCs 7515 [RFC7515] and
7519 [RFC7519].
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An example (the encoded tokens have been abbreviated for clarity):
{
"access_token" : "eyJ0...NiJ9",
"id_token" : "eyJ0...EjXk",
"token_type" : "bearer",
"expires_in" : "3600"
}
Figure 1
An RDAP server that processes this type of query MUST determine if
the identifier is associated with an OP that is recognized and
supported by the server. Servers MUST reject queries that include an
identifier associated with an unsupported OP with an HTTP 501 (Not
Implemented) response. An RDAP server that receives a query
containing an identifier associated with a recognized OP MUST perform
the steps required to authenticate the user with the OP using a
browser or browser-like client and return encoded tokens to the
client. Note that tokens are typically valid for a limited period of
time and new tokens will be required when an existing token's
validity period has expired.
The tokens can then be passed to the server for use with an RDAP
query by passing the encoded ID Token as a query parameter with a key
value of "id_token" and the encoded Access Token in an HTTP Bearer
authorization header [RFC6750]. An example (the encoded tokens have
been abbreviated and the URI split across multiple lines for
clarity):
https://example.com/rdap/domain/example.com?id_token=eyJ0...EjXk
Authorization: Bearer eyJ0...NiJ9
The response to an authenticated query MUST use the response
structures specified in RFC 7483 [RFC7483]. Information that the
end-user is not authorized to receive MUST be omitted from the
response.
4.3. Token Refresh and Revocation
An access token can be refreshed as described in Section 12 of the
OpenID Connect Core protocol [OIDCC] and Section 6 of OAuth 2.0
[RFC6749]. Clients can take advantage of this functionality if it is
supported by the OP and accepted by the RDAP server.
A refresh token is requested using a "tokens" path segment and two
query parameters. The first query parameter includes a key value of
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"id" and a value component that contains the client identifier issued
by an OP. The second query parameter includes a key value of
"refresh" and a value component of "true". A value component of
"false" MUST be processed to return a result that is consistent with
not including a "refresh" parameter at all as described in
Section 4.2. An example using "refresh=true":
https://example.com/rdap/tokens?id=user.idp.example
&refresh=true
The response to this query MUST contain all of the response elements
described in Section 4.2. In addition, the response MUST contain a
name-value pair that represents a refresh token. The name-value pair
includes a key value of "refresh_token" and a Base64url-encoded value
that represents the refresh token.
Example refresh token request response (the encoded tokens have been
abbreviated for clarity):
{
"access_token" : "eyJ0...NiJ9",
"id_token" : "eyJ0...EjXk",
"token_type" : "bearer",
"expires_in" : "3600",
"refresh_token" : "eyJ0...c8da"
}
Figure 2
Once acquired, a refresh token can be used to refresh an access
token. An access token is refreshed using a "tokens" path segment
and two query parameters. The first query parameter includes a key
value of "id" and a value component that contains the client
identifier issued by an OP. The second query parameter includes a
key value of "refresh_token" and a Base64url-encoded value that
represents the refresh token. An example:
https://example.com/rdap/tokens?id=user.idp.example
&refresh_token=eyJ0...f3jE
In addition to any core RDAP response elements, the response to this
query MUST contain four name-value pairs, in any order, representing
a returned Refresh Token and Access Token. The Refresh Token is
represented using a key value of "refresh_token". The Access Token
is represented using a key value of "access_token". The access token
type is represented using a key value of "token_type" and a value of
"bearer" as described in Sections 4.2.2 and 7.1 of RFC 6749
[RFC6749]. The lifetime of the access token is represented using a
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key value of "expires_in" and a numerical value that describes the
lifetime in seconds of the access token as described in Section 4.2.2
of RFC 6749 [RFC6749]. The token values returned in the RDAP server
response MUST be Base64url encoded as described in RFCs 7515
[RFC7515] and 7519 [RFC7519].
Example access token refresh response (the encoded tokens have been
abbreviated for clarity):
{
"access_token" : "0dac...13b0",
"refresh_token" : "f735...d30c",
"token_type" : "bearer",
"expires_in" : "3600"
}
Figure 3
Access and refresh tokens can be revoked as described in RFC 7009
[RFC7009] by sending a request to an RDAP server that contains a
"tokens/revoke" path segment and two query parameters. The first
query parameter includes a key value of "id" and a value component
that contains the client identifier issued by an OP. The second
query parameter includes a key value of "token" and a Base64url-
encoded value that represents either the current refresh token or the
associated access token. An example:
https://example.com/rdap/tokens/revoke?id=user.idp.example
&token=f735...d30c
Note that this command will revoke both access and refresh tokens at
the same time. In addition to any core RDAP response elements, the
response to this query MUST contain a description of the result of
processing the revocation request within the RDAP "notices" data
structure.
Example token revocation success:
"notices" :
[
{
"title" : "Token Revocation Result",
"description" : "Token revocation succeeded.",
}
],
"lang" : "en-US"
Figure 4
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Example token revocation failure:
"notices" :
[
{
"title" : "Token Revocation Result",
"description" : "Token revocation failed.",
}
],
"errorCode" : 400,
"lang" : "en-US"
Figure 5
4.4. Token Exchange
ID tokens include an audience parameter that contains the OAuth 2.0
client_id of the RP as an audience value. In some operational
scenarios (such as a client that is providing a proxy service), an RP
can receive tokens with an audience value that does not include the
RP's client_id. These tokens might not be trusted by the RP, and the
RP might refuse to accept the tokens. This situation can be remedied
by having the RP exchange these tokens with the OP for a set of
trusted tokens that reset the audience parameter. This token
exchange protocol is described in RFC 8693 [RFC8693].
4.5. Parameter Processing
Unrecognized query parameters MUST be ignored. An RDAP request that
does not include an "id" query component MUST be processed as an
unauthenticated query. An RDAP server that processes an
authenticated query MUST determine if the identifier is associated
with an OP that is recognized and supported by the server. Servers
MUST reject queries that include an identifier associated with an
unsupported OP with an HTTP 501 (Not Implemented) response. An RDAP
server that receives a query containing an identifier associated with
a recognized OP MUST perform the steps required to authenticate the
user with the OP, process the query, and return an RDAP response that
is appropriate for the end user's level of authorization and access.
An RDAP server that receives a query containing tokens associated
with a recognized OP and authenticated end user MUST process the
query and return an RDAP response that is appropriate for the end
user's level of authorization and access. Errors based on processing
either the ID Token or the Access Token MUST be signaled with an
appropriate HTTP status code as described in Section 3.1 of RFC 6750
[RFC6750].
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On receiving a query containing tokens, the RDAP server MUST validate
the ID Token. It can do this independently of the OP, because the ID
Token is a JWT that contains all the data necessary for validation.
The Access Token, however, is an opaque value, and can only be
validated by sending a request using it to the UserInfo Endpoint and
confirming that a successful response is received. This is different
from the OpenID Connect Authorization Code and Implicit flows, where
the Access Token can be validated against the at_hash claim from the
ID Token. With a query containing tokens, the Access Token might not
validate against the at_hash claim because the Access Token may have
been refreshed since the ID Token was issued.
An RDAP server that processes requests without needing the UserInfo
claims does not need to retrieve the claims merely in order to
validate the Access Token. Similarly, an RDAP server that has cached
the UserInfo claims for an end user, in accordance with the HTTP
headers of a previous UserInfo Endpoint response, does not need to
retrieve those claims again in order to revalidate the Access Token.
4.6. RDAP Conformance
RDAP responses that contain values described in this document MUST
indicate conformance with this specification by including an
rdapConformance ([RFC7483]) value of "rdap_openidc_level_0". The
information needed to register this value in the RDAP Extensions
Registry is described in Section 6.1.
Example rdapConformance structure with extension specified:
"rdapConformance" :
[
"rdap_level_0",
"rdap_openidc_level_0"
]
Figure 6
5. Clients with Limited User Interfaces
The flow described in Section 3.1.3 requires a client to interact
with a server using a web browser. This will not work well in
situations where the client is automated or an end-user is using a
command line user interface such as curl [2] or wget [3]. There are
multiple ways to address this limitation using a web browser on a
second device. Two are described here.
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5.1. OAuth 2.0 Device Authorization Grant
The "OAuth 2.0 Device Authorization Grant" [RFC8628] provides one
method to request user authorization from devices that have an
Internet connection, but lack a suitable browser for a more
traditional OAuth flow. This method requires a client to use a
second device (such as a smart telephone) that has access to a web
browser for entry of a code sequence that is presented on the
constrained device.
5.2. Manual Token Management
A second method of requesting user authorization from a constrained
device is possible by producing and managing tokens manually as
follows:
1. Authenticate with the OP as described in Section 4.2 using a
browser or browser-like client.
2. Store the returned ID Token and Access Token locally.
3. Send a request to the content provider/RP along with the ID Token
and Access Token received from the OP.
The Access Token MAY be passed to the RP in an HTTP "Authorization"
header [RFC7235] or as a query parameter. The Access Token MUST be
specified using the "Bearer" authentication scheme [RFC6750] if it is
passed in an "Authorization" header. The ID Token MUST be passed to
the RP as a query parameter.
Here are two examples using the curl and wget utilities. Start by
authenticating with the OP:
https://example.com/rdap/tokens?id=user.idp.example
Save the token information and pass it to the RP along with the URI
representing the RDAP query. Using curl (encoded tokens have been
abbreviated for clarity:
curl -H "Authorization: Bearer eyJ0...NiJ9"\
-k https://example.com/rdap/domain/example.com\
?id_token=eyJ0...EjXk
curl -k https://example.com/rdap/domain/example.com\
?id_token=eyJ0...EjXk&access_token=eyJ0...NiJ9
Using wget:
wget --header="Authorization: Bearer eyJ0...NiJ9"\
https://example.com/rdap/domain/example.com\
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?id_token=eyJ0...EjXk
wget https://example.com/rdap/domain/example.com\
?id_token=eyJ0...EjXk&access_token=eyJ0...NiJ9
Refresh tokens can be useful to automated or command line clients who
wish to continue a session without explicitly re-authenticating an
end user. See Section 4.3 for more information.
6. IANA Considerations
6.1. RDAP Extensions Registry
IANA is requested to register the following value in the RDAP
Extensions Registry:
Extension identifier: rdap_openidc_level_0
Registry operator: Any
Published specification: This document.
Contact: IESG <iesg@ietf.org>
Intended usage: This extension describes a federated
authentication method for RDAP using OAuth 2.0 and OpenID Connect.
6.2. JSON Web Token Claims Registry
IANA is requested to register the following values in the JSON Web
Token Claims Registry:
Claim Name: "purpose"
Claim Description: This claim describes the stated purpose for
submitting a request to access a protected RDAP resource.
Change Controller: IESG
Specification Document(s): Section 3.1.4.1 of this document.
Claim Name: "dnt"
Claim Description: This claim contains a JSON boolean literal that
describes an End-User's "do not track" preference for identity
tracking, logging, or recording when accessing a protected RDAP
resource.
Change Controller: IESG
Specification Document(s): Section 3.1.4.2 of this document.
6.3. RDAP Query Purpose Registry
IANA is requested to create a new protocol registry to manage RDAP
query purpose values. This registry should appear under its own
heading on IANA's protocol listings, using the same title as the name
of the registry. The information to be registered and the procedures
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to be followed in populating the registry are described in
Section 3.1.4.1.
Name of registry: Registration Data Access Protocol (RDAP) Query
Purpose Values
Section at http://www.iana.org/protocols:
Registry Title: Registration Data Access Protocol (RDAP) Query
Purpose Values
Registry Name: Registration Data Access Protocol (RDAP) Query Purpose
Values
Registration Procedure: Specification Required
Reference: This draft
Required information: See Section 3.1.4.1.
Review process: "Specification Required" as described in RFC 5226
[RFC5226].
Size, format, and syntax of registry entries: See Section 3.1.4.1.
Initial assignments and reservations:
-----BEGIN FORM-----
Value: domainNameControl
Description: Tasks within the scope of this purpose include creating
and managing and monitoring a registrant's own domain name, including
creating the domain name, updating information about the domain name,
transferring the domain name, renewing the domain name, deleting the
domain name, maintaining a domain name portfolio, and detecting
fraudulent use of the Registrant's own contact information.
-----END FORM-----
-----BEGIN FORM-----
Value: personalDataProtection
Description: Tasks within the scope of this purpose include
identifying the accredited privacy/proxy provider associated with a
domain name and reporting abuse, requesting reveal, or otherwise
contacting the provider.
-----END FORM-----
-----BEGIN FORM-----
Value: technicalIssueResolution
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Description: Tasks within the scope of this purpose include (but are
not limited to) working to resolve technical issues, including email
delivery issues, DNS resolution failures, and web site functional
issues.
-----END FORM-----
-----BEGIN FORM-----
Value: domainNameCertification
Description: Tasks within the scope of this purpose include a
Certification Authority (CA) issuing an X.509 certificate to a
subject identified by a domain name.
-----END FORM-----
-----BEGIN FORM-----
Value: individualInternetUse
Description: Tasks within the scope of this purpose include
identifying the organization using a domain name to instill consumer
trust, or contacting that organization to raise a customer complaint
to them or file a complaint about them.
-----END FORM-----
-----BEGIN FORM-----
Value: businessDomainNamePurchaseOrSale
Description: Tasks within the scope of this purpose include making
purchase queries about a domain name, acquiring a domain name from a
registrant, and enabling due diligence research.
-----END FORM-----
-----BEGIN FORM-----
Value: academicPublicInterestDNSRResearch
Description: Tasks within the scope of this purpose include academic
public interest research studies about domain names published in the
registration data service, including public information about the
registrant and designated contacts, the domain name's history and
status, and domain names registered by a given registrant (reverse
query).
-----END FORM-----
-----BEGIN FORM-----
Value: legalActions
Description: Tasks within the scope of this purpose include
investigating possible fraudulent use of a registrant's name or
address by other domain names, investigating possible trademark
infringement, contacting a registrant/licensee's legal representative
prior to taking legal action and then taking a legal action if the
concern is not satisfactorily addressed.
-----END FORM-----
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-----BEGIN FORM-----
Value: regulatoryAndContractEnforcement
Description: Tasks within the scope of this purpose include tax
authority investigation of businesses with online presence, Uniform
Dispute Resolution Policy (UDRP) investigation, contractual
compliance investigation, and registration data escrow audits.
-----END FORM-----
-----BEGIN FORM-----
Value: criminalInvestigationAndDNSAbuseMitigation
Description: Tasks within the scope of this purpose include reporting
abuse to someone who can investigate and address that abuse, or
contacting entities associated with a domain name during an offline
criminal investigation.
-----END FORM-----
-----BEGIN FORM-----
Value: dnsTransparency
Description: Tasks within the scope of this purpose involve querying
the registration data made public by registrants to satisfy a wide
variety of use cases around informing the general public.
-----END FORM-----
7. Implementation Status
NOTE: Please remove this section and the reference to RFC 7942 prior
to publication as an RFC.
This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in RFC 7942
[RFC7942]. The description of implementations in this section is
intended to assist the IETF in its decision processes in progressing
drafts to RFCs. Please note that the listing of any individual
implementation here does not imply endorsement by the IETF.
Furthermore, no effort has been spent to verify the information
presented here that was supplied by IETF contributors. This is not
intended as, and must not be construed to be, a catalog of available
implementations or their features. Readers are advised to note that
other implementations may exist.
According to RFC 7942, "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as
they see fit".
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7.1. Verisign Labs
Responsible Organization: Verisign Labs
Location: https://rdap.verisignlabs.com/
Description: This implementation includes support for domain
registry RDAP queries using live data from the .cc and .tv country
code top-level domains and the .career generic top-level domain.
Three access levels are provided based on the authenticated
identity of the client:
1. Unauthenticated: Limited information is returned in response
to queries from unauthenticated clients.
2. Basic: Clients who authenticate using a publicly available
identity provider like Google Gmail or Microsoft Hotmail will
receive all of the information available to an unauthenticated
client plus additional registration metadata, but no
personally identifiable information associated with entities.
3. Advanced: Clients who authenticate using a more restrictive
identity provider will receive all of the information
available to a Basic client plus whatever information the
server operator deems appropriate for a fully authorized
client. Currently supported identity providers include those
developed by Verisign Labs
(https://testprovider.rdap.verisignlabs.com/) and CZ.NIC
(https://www.mojeid.cz/).
Level of Maturity: This is a "proof of concept" research
implementation.
Coverage: This implementation includes all of the features
described in this specification.
Contact Information: Scott Hollenbeck, shollenbeck@verisign.com
7.2. Viagenie
Responsible Organization: Viagenie
Location: https://auth.viagenie.ca
Description: This implementation is an OpenID identity provider
enabling users and registries to connect to the federation. It
also includes a barebone RDAP client and RDAP server in order to
test the authentication framework. Various level of purposes are
available for testing.
Level of Maturity: This is a "proof of concept" research
implementation.
Coverage: This implementation includes most features described in
this specification as an identity provider.
Contact Information: Marc Blanchet, marc.blanchet@viagenie.ca
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8. Security Considerations
Security considerations for RDAP can be found in RFC 7481 [RFC7481].
Security considerations for OpenID Connect Core [OIDCC] and OAuth 2.0
[RFC6749] can be found in their reference specifications. OpenID
Connect defines optional mechanisms for robust signing and encryption
that can be used to provide data integrity and data confidentiality
services as needed. Security services for ID Tokens and Access
Tokens (with references to the JWT specification) are described in
the OpenID Connect Core protocol.
8.1. Authentication and Access Control
Having completed the client identification, authorization, and
validation process, an RDAP server can make access control decisions
based on a comparison of client-provided information and local
policy. For example, a client who provides an email address (and
nothing more) might be entitled to receive a subset of the
information that would be available to a client who provides an email
address, a full name, and a stated purpose. Development of these
access control policies is beyond the scope of this document.
9. Acknowledgements
The author would like to acknowledge the following individuals for
their contributions to the development of this document: Tom
Harrison, Russ Housley, Rhys Smith, Jaromir Talir, and Alessandro
Vesely. In addition, the Verisign Registry Services Lab development
team of Joseph Harvey, Andrew Kaizer, Sai Mogali, Anurag Saxena,
Swapneel Sheth, Nitin Singh, and Zhao Zhao provided critical "proof
of concept" implementation experience that helped demonstrate the
validity of the concepts described in this document.
10. References
10.1. Normative References
[OIDC] OpenID Foundation, "OpenID Connect",
<http://openid.net/connect/>.
[OIDCC] OpenID Foundation, "OpenID Connect Core incorporating
errata set 1", November 2014,
<http://openid.net/specs/openid-connect-core-1_0.html>.
[OIDCD] OpenID Foundation, "OpenID Connect Discovery 1.0
incorporating errata set 1", November 2014,
<http://openid.net/specs/openid-connect-discovery-
1_0.html>.
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[OIDCR] OpenID Foundation, "OpenID Connect Dynamic Client
Registration 1.0 incorporating errata set 1", November
2014, <http://openid.net/specs/openid-connect-
registration-1_0.html>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<https://www.rfc-editor.org/info/rfc5226>.
[RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
RFC 6749, DOI 10.17487/RFC6749, October 2012,
<https://www.rfc-editor.org/info/rfc6749>.
[RFC6750] Jones, M. and D. Hardt, "The OAuth 2.0 Authorization
Framework: Bearer Token Usage", RFC 6750,
DOI 10.17487/RFC6750, October 2012,
<https://www.rfc-editor.org/info/rfc6750>.
[RFC7009] Lodderstedt, T., Ed., Dronia, S., and M. Scurtescu, "OAuth
2.0 Token Revocation", RFC 7009, DOI 10.17487/RFC7009,
August 2013, <https://www.rfc-editor.org/info/rfc7009>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<https://www.rfc-editor.org/info/rfc7230>.
[RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Authentication", RFC 7235,
DOI 10.17487/RFC7235, June 2014,
<https://www.rfc-editor.org/info/rfc7235>.
[RFC7480] Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
Registration Data Access Protocol (RDAP)", RFC 7480,
DOI 10.17487/RFC7480, March 2015,
<https://www.rfc-editor.org/info/rfc7480>.
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[RFC7481] Hollenbeck, S. and N. Kong, "Security Services for the
Registration Data Access Protocol (RDAP)", RFC 7481,
DOI 10.17487/RFC7481, March 2015,
<https://www.rfc-editor.org/info/rfc7481>.
[RFC7482] Newton, A. and S. Hollenbeck, "Registration Data Access
Protocol (RDAP) Query Format", RFC 7482,
DOI 10.17487/RFC7482, March 2015,
<https://www.rfc-editor.org/info/rfc7482>.
[RFC7483] Newton, A. and S. Hollenbeck, "JSON Responses for the
Registration Data Access Protocol (RDAP)", RFC 7483,
DOI 10.17487/RFC7483, March 2015,
<https://www.rfc-editor.org/info/rfc7483>.
[RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
2015, <https://www.rfc-editor.org/info/rfc7515>.
[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
<https://www.rfc-editor.org/info/rfc7519>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8628] Denniss, W., Bradley, J., Jones, M., and H. Tschofenig,
"OAuth 2.0 Device Authorization Grant", RFC 8628,
DOI 10.17487/RFC8628, August 2019,
<https://www.rfc-editor.org/info/rfc8628>.
[RFC8693] Jones, M., Nadalin, A., Campbell, B., Ed., Bradley, J.,
and C. Mortimore, "OAuth 2.0 Token Exchange", RFC 8693,
DOI 10.17487/RFC8693, January 2020,
<https://www.rfc-editor.org/info/rfc8693>.
10.2. Informative References
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2",
FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
<https://www.rfc-editor.org/info/rfc4949>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016,
<https://www.rfc-editor.org/info/rfc7942>.
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10.3. URIs
[1] https://www.icann.org/en/system/files/files/final-report-
06jun14-en.pdf
[2] http://curl.haxx.se/
[3] https://www.gnu.org/software/wget/
Appendix A. Change Log
00: Initial working group version ported from draft-hollenbeck-
regext-rdap-openid-10.
01: Modified ID Token delivery approach to note proper use of an
HTTP bearer authorization header.
02: Modified token delivery approach (access token is the bearer
token) to note proper use of an HTTP bearer authorization header,
fixing the change made in -01.
03: Updated OAuth 2.0 Device Authorization Grant description and
reference due to publication of RFC 8628.
04: Updated OAuth 2.0 token exchange description and reference due
to publication of RFC 8693. Corrected the RDAP conformance
identifier to be registered with IANA.
05: Keepalive refresh.
06: Keepalive refresh.
Author's Address
Scott Hollenbeck
Verisign Labs
12061 Bluemont Way
Reston, VA 20190
USA
Email: shollenbeck@verisign.com
URI: http://www.verisignlabs.com/
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