Internet DRAFT - draft-timbru-sidrops-change-pubserver
draft-timbru-sidrops-change-pubserver
Network Working Group T. Bruijnzeels
Internet-Draft NLnet Labs
Intended status: Informational 24 October 2022
Expires: 27 April 2023
Change Publication Server used by an RPKI CA
draft-timbru-sidrops-change-pubserver-00
Abstract
This draft outlines how Krill, an RPKI CA and Publication Server,
implements the process that allows a CA to change the Publication
Server it uses, migrating its content from the old server, to the new
server's repository.
The current implementation is modelled after the RPKI CA Key Rollover
process defined in RFC 6489, except that in this case a new location
is used for the new key.
It incudes some discussion about possible improvements to the
process.
The goal of this draft is to serve as a starting point for a broader
discussion on how RPKI Repository Migration should be done. If
adopted as a working group item, the status could be changed to
standard or bcp, and the intent would of course be to update the
content to reflect working group consensus rather than what happens
to have been implemented in Krill at this time.
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
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This Internet-Draft will expire on 27 April 2023.
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Copyright Notice
Copyright (c) 2022 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
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Requirements notation . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Migration Process . . . . . . . . . . . . . . . . . . . . . . 3
3.1. Upload new Repository Response . . . . . . . . . . . . . 3
3.2. Create new Key . . . . . . . . . . . . . . . . . . . . . 3
3.3. Manifest and CRL for new Key . . . . . . . . . . . . . . 3
3.4. Staging Period . . . . . . . . . . . . . . . . . . . . . 4
3.5. Activate new Key . . . . . . . . . . . . . . . . . . . . 4
3.6. Revoke old Key . . . . . . . . . . . . . . . . . . . . . 4
4. Possible Improvements . . . . . . . . . . . . . . . . . . . . 4
4.1. AIA . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2. Timing Issues . . . . . . . . . . . . . . . . . . . . . . 5
4.3. Duplication? . . . . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . 6
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
8. Normative References . . . . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7
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. Introduction
There are a number of reasons why a CA may wish to migrate from its
current Publication Server to a new one.
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One reason may be that an organisation is running their own
Publication Server, but they wish to migrate to a server operated by
their parent (e.g. a Regional Internet Registry). Possibly because
their parent did not offer this service when they first set up their
CA, but now they do.
Another reason may be that the current Publication Server used by a
CA is failing behind in terms of their availability on either the
publication protocol [RFC8181], or the public rsync or RRDP [RFC8182]
repository compared to other options.
If the current Publication Server has become unavailable, and there
is no sign that it will become available again, then that may
constitute an even more urgent reason to migrate to a new server.
In this document we explain how Krill, an RPKI CA and Publication
Server implementation, currently uses a modified RPKI Key Rollover
[RFC6489] process to allow a CA to change the Publication Server
used.
3. Migration Process
3.1. Upload new Repository Response
The migration to a new Publication Server is initiated by uploading a
new [RFC8183] Repository Response XML for that new server.
When the XML is uploaded the CA verifies that it can communicate with
the new server by sending it an [RFC8181] list query. If the query
is successful, the new server is accepted and the CA proceeds to the
next step.
3.2. Create new Key
The second step in the process is that the CA generates a new key
pair, and then requests a new certificate for this key from its
parent (using [!@RFC6492]). The Certificate Sign Request for this
new key uses the URIs that pertain to the new Publication Server.
3.3. Manifest and CRL for new Key
When the CA receives a certificate for the new key, which uses the
new Publication Server, it generates a CRL and Manifest and publishes
these at the new server.
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RPKI signed objects such as ROAs or possibly CA certificates for its
own children are only published under the "current" key. I.e. they
are not yet published at the new server. This is similar to step 3
in the CA Key Rollover Procedure defined in section 2 of [!@RFC6489].
3.4. Staging Period
According to step 4, in section 2 of [!@RFC6489] a staging period of
at least 24 hours SHOULD be used. The current implementation in
Krill leaves this decision to the operators. A shorter period is
advisable if the current Publication Server is unavailable.
3.5. Activate new Key
When the new key is activated all RPKI signed objects are published
under the new key, and therefore published at the new Publication
Server, and they are removed from the current key's manifest and
publication point.
This is essentially the same as defined in step 5 of section 2 of
[!@RFC6489], except that keys use a different Publication Servers and
they will typically use a different [RFC8183] "sia_base" and
"rrdp_notification_uri".
3.6. Revoke old Key
The final step in the process is that the CA requests revocation of
its, previously CURRENT, now OLD key. When this key is revoked the
CA removes all content from the OLD publication server for this key.
4. Possible Improvements
4.1. AIA
It should be noted that the AIA URIs for delegated CA certificates
will change when the new repository is used, even if the child CA
keys and subjects did not change, and even if the produced .cer files
have the same name - they will be published in a different
publication point.
Relying Parties may warn when AIA URIs in the RPKI signed objects
(Manifest, ROAs, etc) and possible certificates (delegated CA or
BGPSec Router certificates) published do not match the location of
the signing CA certificate in the new publication point, but they
would accept them as long as they are otherwise valid.
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4.2. Timing Issues
One important thing to note is that the CA needs to publish in two
different locations when the new key is activated in the process
defined here.
This can lead to timing issues where Relying Parties see equivalent
objects under both keys. This happens if they get the NEW objects
before seeing them disappear from the OLD key. This is not expected
to lead to significant issues.
On the other hand, it may also turn out that the Relying Party sees
the objects disappear from under the OLD key, but it has not yet seen
the equivalent objects under the NEW key. This can have a big
impact. All ROAs would disappear temporarily which could impact
routing even if announcements would fall back to the ROV state "Not
Found" ([RFC6811]). But, any delegated CA certificates would also
disappear (temporarily) and as a consequence any ROAs or other
objects published by children. So, if this happens to a CA near the
top of the RPKI tree the impact can be quite significant.
For this reason we may want to change the "Activate Key" step to use
three separate steps:
* publish objects under the NEW key,
* enter a staging period
* only then remove the objects from the (now OLD) key
4.3. Duplication?
If we would use the staging period mentioned in the previous section,
then Relying Parties will find any possible delegated CA certificates
under both publication points for some time. Both CA certificates
will use the same subject key and SIA values. Therefore, Relying
Parties will find the published objects under two paths - and they
will appear valid under both.
This will cause RPs to keep more data. This is not expected to be a
huge issue.. as any duplicated Validated ROA Prefixes [RFC6811] would
be filtered out in the RPKI-RTR protocol ([RFC8210]).
5. IANA Considerations
OID needs to be requested.
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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>.
[RFC6489] Huston, G., Michaelson, G., and S. Kent, "Certification
Authority (CA) Key Rollover in the Resource Public Key
Infrastructure (RPKI)", BCP 174, RFC 6489,
DOI 10.17487/RFC6489, February 2012,
<https://www.rfc-editor.org/info/rfc6489>.
[RFC6811] Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R.
Austein, "BGP Prefix Origin Validation", RFC 6811,
DOI 10.17487/RFC6811, January 2013,
<https://www.rfc-editor.org/info/rfc6811>.
[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>.
[RFC8181] Weiler, S., Sonalker, A., and R. Austein, "A Publication
Protocol for the Resource Public Key Infrastructure
(RPKI)", RFC 8181, DOI 10.17487/RFC8181, July 2017,
<https://www.rfc-editor.org/info/rfc8181>.
[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>.
[RFC8183] Austein, R., "An Out-of-Band Setup Protocol for Resource
Public Key Infrastructure (RPKI) Production Services",
RFC 8183, DOI 10.17487/RFC8183, July 2017,
<https://www.rfc-editor.org/info/rfc8183>.
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[RFC8210] Bush, R. and R. Austein, "The Resource Public Key
Infrastructure (RPKI) to Router Protocol, Version 1",
RFC 8210, DOI 10.17487/RFC8210, September 2017,
<https://www.rfc-editor.org/info/rfc8210>.
Author's Address
Tim Bruijnzeels
NLnet Labs
Email: tim@nlnetlabs.nl
URI: https://www.nlnetlabs.nl/
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