Internet DRAFT - draft-ietf-sidrops-prefer-rrdp
draft-ietf-sidrops-prefer-rrdp
Network Working Group T. Bruijnzeels
Internet-Draft NLnet Labs
Updates: 6841, 8182 (if approved) R. Bush
Intended status: Standards TrackInternet Initiative Japan & Arrcus, Inc.
Expires: 26 June 2023 G. Michaelson
APNIC
23 December 2022
Resource Public Key Infrastructure (RPKI) Repository Requirements
draft-ietf-sidrops-prefer-rrdp-02
Abstract
This document formulates a plan of a phased transition to a state
where RPKI repositories and Relying Party software performing RPKI
Validation will use the RPKI Repository Delta Protocol (RRDP)
[RFC8182] as the preferred access protocol, and require rsync as a
fallback option only.
In phase 0, today's deployment, RRDP is supported by most, but not
all Repositories, and most but not all RP software.
In the proposed phase 1 RRDP will become mandatory to implement for
Repositories, in addition to rsync. This phase can start as soon as
this document is published.
Phase 2 will start once the proposed updates are implemented by all
compliant Repositories. In this phase RRDP will become mandatory to
implement for all compliant RP software, and rsync will be required
as a fallback option only.
It should be noted that although this document currently includes
descriptions and updates to RFCs for each of these phases, we may
find that it will be beneficial to have one or more separate
documents for these phases, so that it might be more clear to all
when the updates to RFCs take effect.
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-
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Internet-Drafts are draft documents valid for a maximum of six months
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This Internet-Draft will expire on 26 June 2023.
Copyright Notice
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Requirements notation . . . . . . . . . . . . . . . . . . . . 3
2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Plan to prefer RRDP . . . . . . . . . . . . . . . . . . . . . 3
3.1. Phase 0 - RPKI repositories support rsync, and optionally
RRDP . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1.1. Updates to RFC 8182 . . . . . . . . . . . . . . . . . 4
3.1.2. Updates to RFC 6481 . . . . . . . . . . . . . . . . . 5
3.2. Phase 1 - RPKI repositories support both rsync and
RRDP . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2.1. Updates to RFC 6481 . . . . . . . . . . . . . . . . . 5
3.2.2. Measurements . . . . . . . . . . . . . . . . . . . . 5
3.3. Phase 2 - All RP software prefers RRDP . . . . . . . . . 6
3.3.1. Updates to RFC 8182 . . . . . . . . . . . . . . . . . 6
3.3.2. Measurements . . . . . . . . . . . . . . . . . . . . 6
4. Appendix - Implementation Status . . . . . . . . . . . . . . 6
4.1. Current RRDP Support in Repository Software . . . . . . . 7
4.2. Current RRDP Support in Relying Party software . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
8. Normative References . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
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1. Requirements notation
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.
2. Motivation
The Resource Public Key Infrastructure (RPKI) [RFC6480] as originally
defined uses rsync as its distribution protocol, as outlined in
[RFC6481]. Later, the RPKI Repository Delta Protocol (RRDP)
[RFC8182] was designed to provide an alternative. In order to
facilitate incremental deployment RRDP has been deployed as an
additional optional protocol, while rsync was still mandatory to
implement.
While rsync has been very useful in the initial deployment of RPKI, a
number of issues observed with it motivated the design of RRDP, e.g.:
* rsync is CPU and memory heavy on the server side, and easy to DoS
* rsync library support is lacking, complicating RP efficiency and
error logging
RRDP was designed to leverage HTTPS CDN infrastructure to provide
RPKI Repository content in a resilient way, while reducing the load
on the Repository server. It supports updates being published as
atomic deltas, which can help prevent most of the issues described in
section 6 of [RFC6486].
For a longer discussion please see section 1 of [RFC8182].
In conclusion: we believe that while RRDP is not perfect, and we may
indeed need future work to improve it, it is an improvement over
using rsync in the context of RPKI. Therefore, this document
outlines a transition plan where RRDP becomes mandatory to implement,
and the operational dependency on rsync is reduced to that of a
fallback option.
3. Plan to prefer RRDP
Changing the RPKI infrastructure to rely on RRDP instead of rsync is
a delicate operation. There is current deployment of Certification
Authorities, Repository Servers and Relying Party software which
relies on rsync, and which may not yet support RRDP.
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Therefore we need to have a plan that ultimately updates the relevant
RFCs, but which uses a phased approach combined with measurements to
limit the operational impact of doing this to (almost) zero.
The general outline of the plan is as follows. We will describe each
step in more detail below.
+=======+======================================================+
| Phase | Description |
+=======+======================================================+
| 0 | RPKI repositories support rsync, and optionally RRDP |
+-------+------------------------------------------------------+
| 1 | RPKI repositories support both rsync and RRDP |
+-------+------------------------------------------------------+
| 2 | All RP software prefers RRDP |
+-------+------------------------------------------------------+
Table 1
3.1. Phase 0 - RPKI repositories support rsync, and optionally RRDP
This is the situation at the time of writing this document. Relying
Parties can prefer RRDP over rsync today. Therefore all repositories
should support RRDP at their earliest convenience.
3.1.1. Updates to RFC 8182
Section 3.4.5 of [RFC8182] has the following on "Considerations
Regarding Operational Failures in RRDP":
Relying Parties could attempt to use alternative repository access
mechanisms, if they are available, according to the accessMethod
element value(s) specified in the SIA of the associated certificate
(see Section 4.8.8 of [RFC6487]).
The use of the lower case 'could' in this sentence has led some older
versions of RP implementations to conclude that any fallback from
RRDP to rsync as an alternative access mechanism is a local choice.
However, following discussions on this subject it has become clear
that there is a preference to instruct RP software to make use of all
possible data sources. The main motivation being that because of
RPKI object security using a secondary source of data can never lead
to a worse outcome in terms of validation.
Per this document text mentioned above is replaced by the following:
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Relying Parties MUST attempt to use alternative repository access
mechanisms, if they are available, according to the accessMethod
element value(s) specified in the SIA of the associated certificate
(see Section 4.8.8 of [RFC6487]).
Note that there is a risk that the rsync repository, as the
alternative access mechanism, becomes overloaded in case all Relying
Parties fall back to it at roughly the same time due to an issue with
RRDP. Therefore it is RECOMMENDED that Relying Parties use a retry
strategy and/or random jitter time before falling back to rsync.
But, the fallback to rsync MUST NOT be postponed for more than 1
hour.
3.1.2. Updates to RFC 6481
Section 3.3 of [RFC8182] stipulates that RRDP files MUST be made
available by repositories which support RRDP. In other words
[RFC8182] expects that RRDP repository availability is treated as a
critical service wherever it is supported.
Per this document the following bullet point is added to the
considerations listed in in section 3 of [RFC6481]:
* The publication repository MAY be available using the RPKI
Repository Delta Protocol [RFC8182]. If RPDP is provided, it
SHOULD be hosted on a highly available platform.
3.2. Phase 1 - RPKI repositories support both rsync and RRDP
During this phase we will make RRDP mandatory to support for
Repository Servers, and measure whether the deployed Repository
Servers have been upgraded to do so, in as far as they don't support
RRDP already.
3.2.1. Updates to RFC 6481
In this phase the bullet point update to section 3 of [RFC6481]
mentioned above, where it was said the publication repository MAY be
available using the RPKI Repository Delta Protocol is replaced by:
* The publication repository MUST be available using the RPKI
Repository Delta Protocol [RFC8182]. The RRDP server SHOULD be
hosted on a highly available platform.
3.2.2. Measurements
We can find out whether all RPKI repositories support RRDP by running
(possibly) modified Relying Party software that keeps track of this.
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When it is found that Repositories do not yet support RRDP, outreach
should be done to them individually. Since the number of
Repositories is fairly low, and it is in their interest to run RRDP
because it addresses availability concerns, we have confidence that
we will find these Repositories willing to make changes.
3.3. Phase 2 - All RP software prefers RRDP
Once all Repositories support RRDP we can proceed to make RRDP
mandatory to implement for Relying Party software. But note that RP
software is not prohibited from implementing this support sooner. At
the time of this writing all known RP software supports RRDP,
although it is not known to the authors whether all of them have RRDP
enabled and use it as the preferred protocol.
3.3.1. Updates to RFC 8182
From this phase onwards the first paragraph of section 3.4.1 of
[RFC8182] is replaced by the following:
When a Relying Party performs RPKI validation and learns about a
valid certificate with an SIA entry for the RRDP protocol, it MUST
use this protocol with preference.
Relying Parties MUST NOT attempt to fetch objects using alternate
access mechanisms, if object retrieval through this protocol is
successful.
However, as stipulated in section 3.4.5, Relying Parties MUST attempt
to use alternative repository access mechanisms, if object retrieval
through RRDP is unsuccessful.
3.3.2. Measurements
Although the tools may support RRDP, users will still need to install
updated versions of these tools in their infrastructure. Any
Repository operator can measure this transition by observing access
to their RRDP and rsync repositories respectively.
But even after new versions have been available, it is expected that
there will be a long, low volume, tail of users who did not upgrade
and still depend on rsync.
4. Appendix - Implementation Status
Note that this section is included for tracking purposes during the
discussion phase of this document and is not intended to be included
in an RFC.
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4.1. Current RRDP Support in Repository Software
The currently known support for RRDP for repositories is as follows:
+===========================+==================+
| Repository Implementation | Support for RRDP |
+===========================+==================+
| afrinic | yes |
+---------------------------+------------------+
| apnic | yes |
+---------------------------+------------------+
| arin | yes |
+---------------------------+------------------+
| lacnic | ongoing |
+---------------------------+------------------+
| ripe ncc | yes |
+---------------------------+------------------+
| Dragon Research Labs | yes(1,2) |
+---------------------------+------------------+
| krill | yes(1) |
+---------------------------+------------------+
Table 2
(1) in use at various National Internet Registries, as well as other
resource holders under RIRs. (2) not all organizations using this
software have upgraded to using RRDP.
4.2. Current RRDP Support in Relying Party software
All current versions of known Relying Party software support RRDP:
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+==============================+=========+=========+=========+
| Relying Party Implementation | support | version | since |
+==============================+=========+=========+=========+
| DRL | yes | ? | ? |
+------------------------------+---------+---------+---------+
| FORT | yes | 1.2.0 | 02/2021 |
+------------------------------+---------+---------+---------+
| OctoRPKI | yes | 1.0.0 | 02/2019 |
+------------------------------+---------+---------+---------+
| Routinator | yes | 0.6.0 | 09/2019 |
+------------------------------+---------+---------+---------+
| rpki-client | yes | 0.7.0 | 04/2021 |
+------------------------------+---------+---------+---------+
| RPSTIR2 | yes | 2.0 | 04/2020 |
+------------------------------+---------+---------+---------+
Table 3
But, support for RRDP does not necessarily mean that it is also
enabled and preferred over rsync by default. The authors kindly
request that RP implementors provide the following information:
+==============================+========+=========+=========+
| Relying Party Implementation | prefer | version | since |
+==============================+========+=========+=========+
| DRL | ? | ? | ? |
+------------------------------+--------+---------+---------+
| FORT | yes | ? | ? |
+------------------------------+--------+---------+---------+
| OctoRPKI | ? | ? | ? |
+------------------------------+--------+---------+---------+
| Routinator | yes | 0.6.0 | 09/2019 |
+------------------------------+--------+---------+---------+
| rpki-client | ? | ? | ? |
+------------------------------+--------+---------+---------+
| RPSTIR2 | ? | ? | ? |
+------------------------------+--------+---------+---------+
Table 4
5. IANA Considerations
This document has no IANA actions.
6. Security Considerations
TBD
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7. Acknowledgements
TBD
8. Normative References
[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>.
[RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support
Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480,
February 2012, <https://www.rfc-editor.org/info/rfc6480>.
[RFC6481] Huston, G., Loomans, R., and G. Michaelson, "A Profile for
Resource Certificate Repository Structure", RFC 6481,
DOI 10.17487/RFC6481, February 2012,
<https://www.rfc-editor.org/info/rfc6481>.
[RFC6486] Austein, R., Huston, G., Kent, S., and M. Lepinski,
"Manifests for the Resource Public Key Infrastructure
(RPKI)", RFC 6486, DOI 10.17487/RFC6486, February 2012,
<https://www.rfc-editor.org/info/rfc6486>.
[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>.
[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
Tim Bruijnzeels
NLnet Labs
Email: tim@nlnetlabs.nl
URI: https://www.nlnetlabs.nl/
Randy Bush
Internet Initiative Japan & Arrcus, Inc.
Email: randy@psg.com
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George Michaelson
APNIC
Email: ggm@apnic.net
URI: http://www.apnic.net
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