Internet DRAFT - draft-sidrops-bruijnzeels-deprecate-rsync
draft-sidrops-bruijnzeels-deprecate-rsync
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: October 27, 2020 G. Michaelson
APNIC
April 25, 2020
Resource Public Key Infrastructure (RPKI) Repository Requirements
draft-sidrops-bruijnzeels-deprecate-rsync-01
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 only mandatory to implement access protocol.
In short this plan consists of the following phases.
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.
Once the proposed updates are implemented by all Repositories phase 2
will start. In this phase RRDP will become mandatory to implement
for all RP software, and rsync must no longer be used.
Measurements will need to be done to help determine when it will be
safe to transition to the final phase of this plan. During this
phase Repositories will no longer be required to provide rsync access
for RPKI validation purposes. However, they may still provide rsync
access for direct access to files for other purposes, if desired, at
a best effort basis.
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 separate documents for the plan, and each phase, so that it
might be more clear to all when the updates to RFCs take effect.
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Status of This Memo
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Table of Contents
1. Requirements notation . . . . . . . . . . . . . . . . . . . . 3
2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Phase 0 - RPKI repositories support rsync, and optionally
RRDP . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Phase 1 - RPKI repositories support both rsync and RRDP . 4
3.2.1. Current Support for RRDP in Repository Software . . . 4
3.2.2. Updates to RFC 6481 . . . . . . . . . . . . . . . . . 5
3.2.3. Measurements . . . . . . . . . . . . . . . . . . . . 6
3.3. Phase 2 - All RP software prefers RRDP . . . . . . . . . 6
3.3.1. RRDP support in Relying Party software . . . . . . . 6
3.3.2. Updates to RFC 8182 . . . . . . . . . . . . . . . . . 6
3.3.3. Measurements . . . . . . . . . . . . . . . . . . . . 7
3.4. Phase 3 - RPKI repositories support RRDP, and optionally
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rsync . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4.1. Updates to RFC 6481 . . . . . . . . . . . . . . . . . 7
4. Rsync URIs as object identifiers . . . . . . . . . . . . . . 8
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
8. Normative References . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
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.
A number of issues observed with rsync motivated the design of RRDP,
e.g.:
o rsync is CPU and memory heavy, and easy to DoS
o rsync library support is lacking
o rsync makes it somewhat difficult to publish sets of object
atomically
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 that updates are 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 RRDP is the better solution.
Therefore, this document outlines a transition plan where RRDP
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becomes mandatory to implement, and rsync becomes optional and
eventually deprecated.
3. Plan
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.
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 |
| 3 | RPKI repositories support RRDP, and optionally rsync |
+-------+------------------------------------------------------+
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, but they need to support
rsync until all RPKI repositories support RRDP. Therefore all
repositories should support RRDP at their earliest convenience.
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. Current Support for RRDP in Repository Software
The currently known support for RRDP for repositories is as follows:
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+---------------------------+------------------+
| Repository Implementation | Support for RRDP |
+---------------------------+------------------+
| afrinic | yes |
| apnic | yes |
| arin | yes |
| lacnic | planned |
| ripe ncc | yes |
| Dragon Research Labs | yes(1,2) |
| krill | yes(1) |
+---------------------------+------------------+
(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.
3.2.2. Updates to RFC 6481
During this phase the updates are applied to section 3 of [RFC6481].
OLD:
o The publication repository SHOULD be hosted on a highly available
service and high-capacity publication platform.
o The publication repository MUST be available using rsync [RFC5781]
[RSYNC]. Support of additional retrieval mechanisms is the choice
of the repository operator. The supported retrieval mechanisms
MUST be consistent with the accessMethod element value(s)
specified in the SIA of the associated CA or EE certificate.
NEW:
o The publication repository MUST be available using the RPKI
Repository Delta Protocol [RFC8182]. The RRDP server SHOULD be
hosted on a highly available platform.
o The publication repository MUST be available using rsync [RFC5781]
[RSYNC]. The rsync server SHOULD be hosted on a highly available
platform.
o Support of additional retrieval mechanisms is the choice of the
repository operator. The supported retrieval mechanisms MUST be
consistent with the accessMethod element value(s) specified in the
SIA of the associated CA or EE certificate.
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3.2.3. Measurements
We can find out whether all RPKI repositories support RRDP by running
(possibly) modified Relying Party software that keeps track of this.
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.
3.3.1. RRDP support in Relying Party software
The currently known support for RRDP in Relying Party software is as
follows:
+------------------------------+------+---------+----------+
| Relying Party Implementation | RRDP | version | since |
+------------------------------+------+---------+----------+
| FORT | yes | ? | ? |
| OctoRPKI | yes | ? | ? |
| rcynic | yes | ? | ? |
| RIPE NCC RPKI Validator 2.x | yes | ? | ? |
| RIPE NCC RPKI Validator 3.x | yes | ? | ? |
| Routinator | yes | 0.6.0 | Sep 2019 |
| rpki-client | no | ? | ? |
| RPSTIR | yes | ? | ? |
+------------------------------+------+---------+----------+
The authors kindly request Relying Party software implementers to let
us know in which version of their tool support for RRDP was
introduced, and when that version was released.
3.3.2. Updates to RFC 8182
From this phase onwards the updates are applied to section 3.4.1 of
[RFC8182].
OLD: When a Relying Party performs RPKI validation and learns about a
valid certificate with an SIA entry for the RRDP protocol, it SHOULD
use this protocol as follows.
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NEW: 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. It MUST NOT depend on object retrieval for this
certificate over rsync for validation, although it MAY still use
rsync access for other purposes under the understanding that
availability is not guaranteed.
3.3.3. 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 long, low volume, tail of users who did not upgrade and
still depend on rsync.
It is hard to quantify here now, what would be an acceptable moment
to conclude that it's safe to move to the next phase and make rsync
optional. A parallel to the so-called DNS Flag Day comes to mind.
3.4. Phase 3 - RPKI repositories support RRDP, and optionally rsync
The end goal of this phase is that there will be no operational
dependencies on rsync for Repositories, although they MAY still
choose to operate rsync at a best effort basis.
3.4.1. Updates to RFC 6481
From this phase onwards these updates are applied to section 3 of
[RFC6481] as it was updated during Phase 2 described above:
OLD:
o The publication repository MUST be available using the RPKI
Repository Delta Protocol [RFC8182]. The RRDP server SHOULD be
hosted on a highly available platform.
o The publication repository MUST be available using rsync [RFC5781]
[RSYNC]. The rsync server SHOULD be hosted on a highly available
platform.
o Support of additional retrieval mechanisms is the choice of the
repository operator. The supported retrieval mechanisms MUST be
consistent with the accessMethod element value(s) specified in the
SIA of the associated CA or EE certificate.
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NEW:
o The publication repository MUST be available using the RPKI
Repository Delta Protocol [RFC8182]. The RRDP server SHOULD be
hosted on a highly available platform.
o The publication repository MAY be available using rsync [RFC5781]
[RSYNC].
o Support of additional retrieval mechanisms is the choice of the
repository operator. The supported retrieval mechanisms MUST be
consistent with the accessMethod element value(s) specified in the
SIA of the associated CA or EE certificate.
4. Rsync URIs as object identifiers
If and when RPKI Repositories no longer need to support rsync, this
begs the question whether rsync should still be used in URIs used in
RPKI objects.
[RFC6481] defines a profile for the Resource Certificate Repository
Structure. In this profile objects are identified through rsync
URIs. E.g. a CA certificate has an Subject Information Access
descriptor which uses an rsync URI to identify its manifest
[RFC6486]. The manifest enumerates the relative names and hashes for
all objects published under the private key of the CA certificate.
The full rsync URI identifiers for each object can be resolved
relative to the manifest URI.
Though it would be possible in principle to build up an RPKI tree
hierarchy of objects based on key identifiers and hashes [RFC8488],
most Relying Party implementations have found it very useful to use
rsync URIs for this purpose. Furthermore, these identifiers make it
much easier to name object in case of validation problems, which help
operators to address issues.
For these reasons, RRDP still includes rsync URIs in the definition
of the publish, update and withdraw elements in the snapshot and
delta files that it uses. See section 3.5 of [RFC8182]. Thus,
objects retrieved through RRDP can be mapped easily to files and
URIs, similar to as though rsync would have been used to retrieve
them.
Even though objects are no longer guaranteed to be available over
rsync, we still use rsync as the mandatory scheme in the CRL
Distribution Points, Authority Information Access, and Subject
Information Access defined in [RFC6487]. Changing this would
introduce breaking changes which make deployment very hard indeed: we
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would need to invent an alternative naming scheme, which would need
to be supported by all Relying Parties, before Certification
Authorities can issue any certificate or RPKI signed objects using
these schemes.
Furthermore, it is very convenient to have direct access to RPKI
objects using rsync for troubleshooting, debugging and research
purposes. Therefore Repository operators MAY still choose to make an
rsync repository available for these purposes.
5. IANA Considerations
This document has no IANA actions.
6. Security Considerations
TBD
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>.
[RFC5781] Weiler, S., Ward, D., and R. Housley, "The rsync URI
Scheme", RFC 5781, DOI 10.17487/RFC5781, February 2010,
<https://www.rfc-editor.org/info/rfc5781>.
[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>.
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[RFC6487] Huston, G., Michaelson, G., and R. Loomans, "A Profile for
X.509 PKIX Resource Certificates", RFC 6487,
DOI 10.17487/RFC6487, February 2012,
<https://www.rfc-editor.org/info/rfc6487>.
[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>.
[RFC8488] Muravskiy, O. and T. Bruijnzeels, "RIPE NCC's
Implementation of Resource Public Key Infrastructure
(RPKI) Certificate Tree Validation", RFC 8488,
DOI 10.17487/RFC8488, December 2018,
<https://www.rfc-editor.org/info/rfc8488>.
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
George Michaelson
APNIC
Email: ggm@apnic.net
URI: http://www.apnic.net
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