Internet Engineering Task Force T. Harrison
Internet-Draft G. Michaelson
Intended status: Standards Track APNIC
Expires: August 5, 2019 A. Newton
ARIN
February 1, 2019
RDAP Mirroring Protocol (RMP)
draft-harrison-regext-rdap-mirroring-00
Abstract
The Registration Data Access Protocol (RDAP) is used by Regional
Internet Registries (RIRs) and Domain Name Registries (DNRs) to
provide access to their resource registration information. While
most clients can retrieve the information they need on an ad hoc
basis from the public services maintained by each registry, there are
instances where local copies of those remote data sources need to be
maintained, for various reasons (e.g. performance requirements).
This document defines a protocol for transferring bulk RDAP response
data and for keeping a local copy of that data up to date.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 5, 2019.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
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publication of this document. Please review these documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. RDAP Mirroring Protocol Implementation . . . . . . . . . . . 3
2.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. File Definitions . . . . . . . . . . . . . . . . . . . . 4
2.2.1. Update Notification File . . . . . . . . . . . . . . 4
2.2.2. Snapshot File . . . . . . . . . . . . . . . . . . . . 5
2.2.3. Delta File . . . . . . . . . . . . . . . . . . . . . 6
2.3. RDAP Objects . . . . . . . . . . . . . . . . . . . . . . 7
2.4. Serial Numbers . . . . . . . . . . . . . . . . . . . . . 9
2.5. Server Use . . . . . . . . . . . . . . . . . . . . . . . 9
2.5.1. Initialization . . . . . . . . . . . . . . . . . . . 9
2.5.2. Publishing Updates . . . . . . . . . . . . . . . . . 10
2.5.3. Consolidation . . . . . . . . . . . . . . . . . . . . 10
2.6. Client Use . . . . . . . . . . . . . . . . . . . . . . . 11
2.6.1. Processing the Update Notification File . . . . . . . 11
2.6.1.1. Initial . . . . . . . . . . . . . . . . . . . . . 11
2.6.1.2. Subsequent . . . . . . . . . . . . . . . . . . . 12
3. Operational Considerations . . . . . . . . . . . . . . . . . 12
4. Security Considerations . . . . . . . . . . . . . . . . . . . 12
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
The Registration Data Access Protocol (RDAP) [RFC7480] is used by
Regional Internet Registries (RIRs) and Domain Name Registries (DNRs)
to provide access to their resource registration information. For a
client, this typically involves following the bootstrap process
[RFC7484] to determine the base URL for the query, constructing an
RDAP request, sending it, and then processing the response.
This mode of operation is appropriate for many use cases. However,
some clients may need local access to the whole data set:
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their performance requirements may be such that the time required
for sending/receiving HTTP requests to arbitrary remote servers is
not acceptable;
they may be conducting analysis of the data set as a whole; or
they may be providing access to the data set in their own right,
as an alternative to redirecting to the authoritative source for
the data.
This document defines a protocol that can be used by a client to
retrieve a local copy of a remote RDAP data set, as well as to
maintain that local copy as further remote updates occur.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. RDAP Mirroring Protocol Implementation
2.1. Overview
A registry that wants to make use of this protocol publishes an
Update Notification File to a specified URL. That file in turn links
to a Snapshot File and a series of Delta Files. The Snapshot File
contains all of the registry's RDAP state as at a given point in
time. The Delta Files contain changes that have been made to the
registry's RDAP state since the Snapshot File was generated.
As further changes are made to the registry's RDAP state, the
registry publishes new Delta Files, amends the Update Notification
File to include links to the new Delta Files, and then republishes
the Update Notification File. Periodically, the registry regenerates
and republishes the Snapshot File, which in turn allows for older
Delta Files to be removed from the Update Notification File.
All files in the protocol are signed by the server using JSON Web
Signature (JWS) [RFC7515]. The JSON Web Key (JWK) [RFC7517] used by
the server to sign the files is distributed out-of-band.
A client that wants to make use of this protocol needs to learn the
server's Update Notification File URL and JSON Web Key out-of-band.
Once these are known, the client retrieves the Update Notification
File, validates its signature, and follows the links in it to
retrieve the Snapshot File and Delta Files. It validates the
signatures on these files, and then uses them to initialize its local
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state. It then records the serial number of the most-recently-issued
Delta File, or of the Snapshot File if no Delta Files are present.
The client will then periodically retrieve the Update Notification
File, determine the Delta Files that have been added since it was
last retrieved by the client, retrieve those Delta Files, and update
its local state accordingly.
A server may opt not to publish a Snapshot File in the Update
Notification File. Such servers will only publish Delta Files in
their Update Notification File, and must distribute the Snapshot File
out-of-band.
2.2. File Definitions
2.2.1. Update Notification File
Example Update Notification File:
{
"version": 1,
"refresh": 3600,
"snapshot": { "uri": "https://example.com/1/snapshot.json",
"serial": 1 },
"deltas": [
{ "uri": "https://example.com/2/delta.json",
"serial": 2 },
{ "uri": "https://example.com/3/delta.json",
"serial": 3 },
]
}
The following validation rules MUST be observed when creating or
parsing Update Notification Files:
Update Notification Files MUST be well-formed JSON [RFC8259].
The "version" attribute in the root element MUST be present, with
a value of "1".
A "refresh" attribute MAY be present. If it is present, it is an
integer representing how long the client should wait (in seconds)
after retrieving the Update Notification File before attempting to
retrieve it again.
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A "snapshot" attribute containing a link to a Snapshot File MAY be
present.
A "deltas" attribute containing an array of links to Delta Files
MUST be present. If no Delta Files have been published by the
server, this array will be empty.
The Delta File entries in the "deltas" attribute MUST be in serial
number order, and the serial numbers MUST form a contiguous
sequence.
If a Snapshot File is included, its serial number MUST either be
equal to that of one of the Delta Files, or one less than the
smallest Delta File serial number.
2.2.2. Snapshot File
Example Snapshot File:
{
"version": 1,
"serial": 3,
"defaults": { "port43": "whois.example.com",
... },
"objects": [
{ "id": "https://example.org/I1",
"object": { "rdapConformance": [ "rdap_level_0" ],
"objectClassName": "ip network",
... } },
{ "id": "https://example.org/D2",
"object": { "rdapConformance": [ "rdap_level_0" ],
"objectClassName": "domain",
... } },
...
]
}
The following validation rules MUST be observed when creating or
parsing Snapshot Files:
Snapshot Files MUST be well-formed JSON [RFC8259].
The "version" attribute in the root element MUST be present, with
a value of "1".
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The "serial" attribute in the root element MUST be present, with a
value that is an unsigned 32-bit integer.
An "objects" attribute containing an array of RDAP object (see
[RFC7483]) and identifier pairs MUST be present. If no RDAP
objects have been published by the server, this array will be
empty.
A "defaults" attribute MAY be present. For each object received
from the server, the client should treat the object as also having
each attribute from the "defaults" attribute, except where the
object already contains an attribute with that name. This applies
to objects received both before and after the Snapshot File is
processed.
2.2.3. Delta File
Example Delta File:
{
"version": 1,
"serial": 4,
"defaults": { "port43": "whois-2.example.org",
... },
"removed_objects": [ "1" ],
"added_or_updated_objects": [
{ "id": "https://example.org/I3",
"object": { "rdapConformance": [ "rdap_level_0" ],
"objectClassName": "ip network",
... } },
{ "id": "https://example.org/D4",
"object": { "rdapConformance": [ "rdap_level_0" ],
"objectClassName": "domain",
... } },
...
]
}
The following validation rules MUST be observed when creating or
parsing Delta Files:
Snapshot Files MUST be well-formed JSON [RFC8259].
The "version" attribute in the root element MUST be present, with
a value of "1".
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The "serial" attribute in the root element MUST be present, with a
value that is an unsigned 32-bit integer.
A "defaults" attribute MAY be present. For each object received
from the server, the client should treat the object as also having
each attribute from the "defaults" attribute, except where the
object already contains an attribute with that name. This applies
to objects received both before and after the Delta File is
processed.
A "removed_objects" attribute containing an array of RDAP object
identifiers MUST be present. If no RDAP objects have been removed
since the previous Delta File was generated by the server, this
array will be empty.
An "added_or_updated_objects" attribute containing an array of
RDAP object (see [RFC7483]) and identifier pairs MUST be present.
If no RDAP objects have been added or updated since the previous
Delta File was generated by the server, this array will be empty.
2.3. RDAP Objects
The base RDAP object definitions from [RFC7483] do not contain any
mandatory attributes. For the purposes of this protocol, each RDAP
object MUST include an "rdapConformance" attribute, so that a client
can determine whether the object is one that it is able to process.
Each RDAP object is paired with an identifier (the "id" attribute in
the parent object). The "id" attribute value MUST be a URI
([RFC3986]). Its value uniquely identifies an RDAP object within the
data set, so as to support internal linking and for subsequent
removal of the object by a Delta File.
In each RDAP object, each link to an RDAP object that is a member of
the data set for which the server is providing mirroring MUST have as
the value of its "href" attribute the identifier for that object
(i.e. the value of the "id" attribute from the target's parent
object). This includes self-references (i.e. links with the "self"
relation type).
If a server includes a link object with the "self" relation type with
each of its RDAP objects, then using the value of the "href"
attribute of that link object as the identifier for each RDAP object
is RECOMMENDED.
For example, a Delta File containing an entity object, along with an
IP network object that links to it:
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{
"version": 1,
"serial": 5,
"removed_objects": [],
"added_or_updated_objects": [
{ "id": "https://example.org/E5",
"object": { "rdapConformance": [ "rdap_level_0" ],
"objectClassName": "entity",
"handle": "E5",
"links": [
{ "rel": "self",
"href": "https://example.org/E5",
... }
],
... } },
{ "id": "https://example.org/I6",
"object": { "rdapConformance": [ "rdap_level_0" ],
"objectClassName": "ip network",
"links": [
{ "rel": "self",
"href": "https://example.org/I6",
... }
],
"entities": [
{ "handle": "E5",
"links": [
{ "rel": "self",
"href": "https://example.org/E5",
... }
],
... }
],
... } }
...
]
}
A server MAY omit from an object data that it returns as part of its
corresponding public service response, when that data can be
determined by reference to another object in the data set. In such
cases, the server MUST include a "links" attribute containing a link
object with a "self" relation, so that the target object can be
resolved by the client.
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2.4. Serial Numbers
Serial numbers in the files defined in this protocol are unsigned
32-bit integers. For the purposes of this protocol, the serial
number arithmetic defined in [RFC1982] applies.
2.5. Server Use
2.5.1. Initialization
If a server is publishing a Snapshot File via the Update Notification
File, then initialization is like so:
generate an initial Snapshot File, with a serial number selected
by the server;
sign the Snapshot File using JWS, and publish the result using JWS
Compact Serialization at a URL that is unique to this serial
number;
generate an initial Update Notification File, with a serial number
equal to that of the Snapshot File, and containing a link to the
Snapshot File; and
sign the Update Notification File using JWS, and publish the
result using JWS Compact Serialization.
To avoid doubt, any RDAP object that is part of the data set for
which the server is providing mirroring, as well as being the target
of a link contained within another RDAP object, MUST be present
within the Snapshot File.
If a server is not publishing a Snapshot File via the Update
Notification File, then initialization is like so:
generate an initial Snapshot File, with a serial number selected
by the server;
sign the Snapshot File using JWS, and distribute the result to
clients out-of-band using JWS Compact Serialization;
generate an initial Update Notification File, containing no
Snapshot File link or Delta File links, with a serial number equal
to that of the Snapshot File (i.e. the one that will be
distributed out-of-band); and
sign the Update Notification File using JWS, and publish the
result using JWS Compact Serialization.
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2.5.2. Publishing Updates
The server periodically publishes changes that have been made to its
RDAP state as Delta Files. The timing and frequency of publication
is a local policy matter for the server. The process is like so:
if a Delta File has been generated previously: generate a new
Delta File, containing the changes that have been made to the RDAP
state since the last Delta File was generated, with a serial
number that is one greater than the serial number of the last
Delta File;
if no Delta File has been generated previously: generate a new
Delta File, containing the changes that have been made to the RDAP
state since the last Snapshot File was generated, with a serial
number that is one greater than the serial number of the last
Snapshot File;
sign the Delta File using JWS, and publish the result using JWS
Compact Serialization at a URL that is unique to its serial
number;
take the currently-published Update Notification File, increment
its serial number, add a link to the new Delta File, and
optionally perform the steps described in the "Consolidation"
section below; and
sign the Update Notification File using JWS, and publish the
result using JWS Compact Serialization.
Delta Files MUST NOT remove an RDAP object that would cause a
relative reference link within the client's local state to become
unresolvable.
2.5.3. Consolidation
On publishing an update, the server may optionally consolidate the
Snapshot File and Delta Files that it is publishing. The process is
like so:
if the server is publishing a Snapshot File: generate a new
Snapshot File based on the server's current state with a serial
number equal to that of the new Delta File, publish the new
Snapshot File, and replace the link in the Update Notification
File to the previous Snapshot File with a link to the new Snapshot
File; and
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remove Delta Files from the Update Notification File that have
become stale.
Whether a given Delta File is 'stale' is a local policy matter for
the server.
2.6. Client Use
2.6.1. Processing the Update Notification File
2.6.1.1. Initial
The client downloads the signed Update Notification File using the
URL provided by the server (out-of-band) and validates the signature
against the server's JWK.
The client validates the signature of the Snapshot File against the
server's JWK, and then uses that file to initialize its local state
by adding all of the objects from the "objects" attribute. It then
records the serial number of the Snapshot File. The signed Snapshot
File is either accessible from the Update Notification File, or made
available to the client out-of-band.
The client then processes each Delta File from the Update
Notification File in order, from the Delta File with a serial number
one greater than the client's recorded serial number, through to the
Delta File with the largest serial number, in order to update its
local state.
Processing a Delta File involves three steps:
verify the signature against the server's JWK;
for each entry in the "removed_objects" attribute, remove from the
local state any object with an "id" attribute value equal to the
entry;
for each entry in the "added_or_updated_objects" attribute: if an
object with the given values for the "id" attribute exists in the
local state, then replace that object with the new object;
otherwise, add the new object to the local state.
Once this is complete, the client records the serial number of the
last Delta File that it processed.
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2.6.1.2. Subsequent
The client downloads the signed Update Notification File using the
URL provided by the server (out-of-band), and validates the signature
against the server's JWK. If the frequency with which the client
should do this has been suggested by the server via the "refresh"
attribute, the client SHOULD honor that suggestion. If the "refresh"
attribute is not present, retrieval frequency is a local policy
matter for the client.
The client then processes each Delta File from the Update
Notification File in order, from the Delta File with a serial number
one greater than that which has been recorded, through to the Delta
File with the largest serial number. Processing of the Delta Files
is otherwise as per the instructions for initial processing.
If the Update Notification File retrieved by the client does not
contain a Delta File with a serial number one greater than that which
has been recorded, the client MUST delete all of its local state and
reinitialize itself. If the Update Notification File contains a
Snapshot File, then that Snapshot File can be used for
reinitialization. If it does not, then a new Snapshot File must be
located out-of-band.
3. Operational Considerations
A server may omit previously-published Delta Files from its Update
Notification File as a matter of local policy. If a server is
publishing its Snapshot Files out-of-band, then omitting a Delta File
that a client needs will result in the client needing to perform an
out-of-band action in order to reinitialize its state. Even if a
server is linking to its Snapshot Files from the Update Notification
File, reinitialization may be an expensive operation for a client.
Servers should consider adopting local policy that limits the chance
of reinitialization happening: for example, by using the "refresh"
attribute value in the Update Notification File.
4. Security Considerations
[RFC7481] describes security requirements and considerations for RDAP
generally. Those requirements and considerations also apply to the
use of this protocol.
This protocol requires the use of JWS ([RFC7515]) and JWK
([RFC7517]), which in turn refer to JSON Web Algorithms (JWA)
([RFC7518]). Implementations MUST support ES256 as defined in JWA
([RFC7518], section 3.4) for signing and validating files in this
protocol. Implementations MAY support other algorithms from the
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"JSON Web Signature and Encryption Algorithms" registry created by
[RFC7518].
5. Acknowledgements
This protocol is largely a repurposing of the RPKI Repository Delta
Protocol (RRDP) [RFC8182] for RDAP. Much of the terminology (e.g.
Update Notification File, Snapshot File, Delta File) is taken from
that document, and the structure is also quite similar.
Experience with the Near Real Time Mirroring (NRTM) [NRTM] protocol,
which serves a similar purpose for databases that are based on the
Routing Policy Specification Language (RPSL) [RFC2622], helped to
inform this corresponding effort in RDAP.
6. IANA Considerations
TBD
7. References
7.1. Normative References
[RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982,
DOI 10.17487/RFC1982, August 1996,
<https://www.rfc-editor.org/info/rfc1982>.
[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>.
[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>.
[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>.
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[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>.
[RFC7517] Jones, M., "JSON Web Key (JWK)", RFC 7517,
DOI 10.17487/RFC7517, May 2015,
<https://www.rfc-editor.org/info/rfc7517>.
[RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
DOI 10.17487/RFC7518, May 2015,
<https://www.rfc-editor.org/info/rfc7518>.
[RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>.
7.2. Informative References
[NRTM] "Near Real Time Mirroring", December 2010,
<https://www.ripe.net/manage-ips-and-
asns/db/support/documentation/mirroring>.
[RFC2622] Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D.,
Meyer, D., Bates, T., Karrenberg, D., and M. Terpstra,
"Routing Policy Specification Language (RPSL)", RFC 2622,
DOI 10.17487/RFC2622, June 1999,
<https://www.rfc-editor.org/info/rfc2622>.
[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>.
[RFC7484] Blanchet, M., "Finding the Authoritative Registration Data
(RDAP) Service", RFC 7484, DOI 10.17487/RFC7484, March
2015, <https://www.rfc-editor.org/info/rfc7484>.
[RFC8182] Bruijnzeels, T., Muravskiy, O., Weber, B., and R. Austein,
"The RPKI Repository Delta Protocol (RRDP)", RFC 8182,
DOI 10.17487/RFC8182, July 2017,
<https://www.rfc-editor.org/info/rfc8182>.
Authors' Addresses
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Tom Harrison
Asia-Pacific Network Information Centre
6 Cordelia St
South Brisbane, QLD 4101
Australia
Email: tomh@apnic.net
George G. Michaelson
Asia-Pacific Network Information Centre
6 Cordelia St
South Brisbane, QLD 4101
Australia
Email: ggm@apnic.net
Andrew Lee Newton
American Registry for Internet Numbers
PO Box 232290
Centreville, VA 20120
United States of America
Email: andy@arin.net
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