Internet DRAFT - draft-ietf-sidrops-rp
draft-ietf-sidrops-rp
SIDROPS D. Ma
Internet-Draft ZDNS
Intended status: Informational S. Kent
Expires: April 9, 2020 Independent
October 7, 2019
Requirements for Resource Public Key Infrastructure (RPKI) Relying
Parties
draft-ietf-sidrops-rp-06
Abstract
This document provides a single reference point for requirements for
Relying Party (RP) software for use in the Resource Public Key
Infrastructure (RPKI) in the context of securing Internet routing.
It cites requirements that appear in several RPKI RFCs, making it
easier for implementers to become aware of these requirements that
are segmented with orthogonal functionalities.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on April 9, 2020.
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
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Fetching and Caching RPKI Repository Objects . . . . . . . . 3
2.1. TAL Acquisition and Processing . . . . . . . . . . . . . 4
2.2. Locating RPKI Objects Using Authority and Subject
Information Extensions . . . . . . . . . . . . . . . . . 4
2.3. Dealing with Key Rollover . . . . . . . . . . . . . . . . 4
2.4. Dealing with Algorithm Transition . . . . . . . . . . . . 4
2.5. Strategies for Efficient Cache Maintenance . . . . . . . 5
3. Certificate and CRL Processing . . . . . . . . . . . . . . . 5
3.1. Verifying Resource Certificate and Syntax . . . . . . . . 5
3.2. Certificate Path Validation . . . . . . . . . . . . . . . 5
3.3. CRL Processing . . . . . . . . . . . . . . . . . . . . . 6
4. Processing RPKI Repository Signed Objects . . . . . . . . . . 6
4.1. Basic Signed Object Syntax Checks . . . . . . . . . . . . 6
4.2. Syntax and Validation for Each Type of Signed Object . . 6
4.2.1. Manifest . . . . . . . . . . . . . . . . . . . . . . 6
4.2.2. ROA . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2.3. Ghostbusters . . . . . . . . . . . . . . . . . . . . 7
4.2.4. Verifying BGPsec Router Certificate . . . . . . . . . 7
4.3. How to Make Use of Manifest Data . . . . . . . . . . . . 7
4.4. What to Do with Ghostbusters Information . . . . . . . . 8
5. Distributing Validated Cache . . . . . . . . . . . . . . . . 8
6. Local Control . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 9
10.2. Informative References . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
The RPKI Relying Party (RP) software is used by network operators and
others to acquire and verify Internet Number Resource (INR) data
stored in the RPKI repository system. RPKI data, when verified,
allow an RP to verify assertions about which Autonomous Systems
(ASes) are authorized to originate routes for IP address prefixes.
RPKI data also establishes binding between public keys and BGP
routers, and indicates the AS numbers that each router is authorized
to represent.
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Noting that the essential requirements imposed on RPs to support
securing Internet routing ([RFC6480]) are scattered throughout
numerous RFC documents that are protocol specific or provide best
practices, as follows:
RFC 6481 (Repository Structure)
RFC 6482 (ROA format)
RFC 6486 (Manifests)
RFC 6487 (Certificate and CRL profile)
RFC 6488 (RPKI Signed Objects)
RFC 6489 (Key Rollover)
RFC 6810 (RPKI to Router Protocol)
RFC 6916 (Algorithm Agility)
RFC 7935 (Algorithms)
RFC 8209 (Router Certificates)
RFC 8210 (RPKI to Router Protocol,Version 1)
RFC 8360 (Certificate Validation Procedure)
RFC 8630 (Trust Anchor Locator)
This makes it hard for an implementer to be confident that he/she has
addressed all of these generalized requirements. Besides, software
engineering calls for how to segment the RP system into components
with orthogonal functionalities, so that those components could be
distributed across the operational timeline of the user. Taxonomy of
generalized RP requirements is going to help have 'the role of the
RP' well framed.
To consolidate RP requirements in one document, with pointers to all
the relevant RFCs, this document outlines a set of baseline
requirements imposed on RPs and provides a single reference point for
requirements for RP software for use in the RPKI, as segmented with
orthogonal functionalities:
o Fetching and Caching RPKI Repository Objects
o Processing Certificates and CRLs
o Processing RPKI Repository Signed Objects
o Distributing Validated Cache of the RPKI Data
This document will be update to reflect new or changed requirements
as these RFCs are updated, or new RFCs are written.
2. Fetching and Caching RPKI Repository Objects
RP software uses synchronization mechanisms supported by targeted
repositories (e.g., [rsync], RRDP [RFC8182]) to download all RPKI
changed data objects in the repository system and cache them locally.
The software validates the RPKI data and uses it to generate
authenticated data identifying which ASes are authorized to originate
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routes for address prefixes, and which routers are authorized to sign
BGP updates on behalf of ASes.
2.1. TAL Acquisition and Processing
In the RPKI, each RP chooses its own set of trust anchors (TAs).
Consistent with the extant INR allocation hierarchy, the IANA and/or
the five RIRs are obvious candidates to be default TAs for the RP.
An RP does not retrieve TAs directly. A set of Trust Anchor Locators
(TALs) is used by each RP to retrieve and verify the authenticity of
each TA.
TAL acquisition and processing are specified in Section 3 of
[RFC8630].
2.2. Locating RPKI Objects Using Authority and Subject Information
Extensions
The RPKI repository system is a distributed one, consisting of
multiple repository instances. Each repository instance contains one
or more repository publication points. An RP discovers publication
points using the Subject Information Access (SIA) and the Authority
Information Access (AIA) extensions from (validated) certificates.
Section 5 of [RFC6481] specifies how an RP locates all RPKI objects
by using the SIA and AIA extensions. Detailed specifications of SIA
and AIA extensions in a resource certificate are described in
Section 4 of [RFC6487].
2.3. Dealing with Key Rollover
An RP takes the key rollover period into account with regard to its
frequency of synchronization with RPKI repository system.
RP requirements in dealing with key rollover are described in
Section 3 of [RFC6489] and Section 3 of [RFC8634].
2.4. Dealing with Algorithm Transition
The set of cryptographic algorithms used with the RPKI is expected to
change over time. Each RP is expected to be aware of the milestones
established for the algorithm transition and what actions are
required at every juncture.
RP requirements for dealing with algorithm transition are specified
in Section 4 of [RFC6916].
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2.5. Strategies for Efficient Cache Maintenance
Each RP is expected to maintain a local cache of RPKI objects. The
cache needs to be as up to date and consistent with repository
publication point data as the RP's frequency of checking permits.
The last paragraph of Section 5 of [RFC6481] provides guidance for
maintenance of a local cache.
3. Certificate and CRL Processing
The RPKI make use of X.509 certificates and CRLs, but it profiles
these standard formats [RFC6487]. The major change to the profile
established in [RFC5280] is the mandatory use of a new extension to
X.509 certificate [RFC3779].
3.1. Verifying Resource Certificate and Syntax
Certificates in the RPKI are called resource certificates, and they
are required to conform to the profile [RFC6487]. An RP is required
to verify that a resource certificate adheres to the profile
established by Section 4 of [RFC6487]. This means that all
extensions mandated by Section 4.8 of [RFC6487] must be present and
value of each extension must be within the range specified by this
RFC. Moreover, any extension excluded by Section 4.8 of [RFC6487]
must be omitted.
Section 7.1 of [RFC6487] gives the procedure that the RP should
follow to verify resource certificate and syntax.
3.2. Certificate Path Validation
The INRs in issuer's certificate are required to encompass the INRs
in the subject's certificate. This is one of necessary principles of
certificate path validation in addition to cryptographic verification
i.e., verification of the signature on each certificate using the
public key of the parent certificate).
Section 7.2 of [RFC6487] gives the procedure that the RP should
follow to perform certificate path validation.
Certificate Authorities that want to reduce aspects of operational
fragility will migrate to the new OIDs [RFC8360], informing the RP of
using an alternative RPKI validation algorithm. An RP is expected to
support the amended procedure to handle with accidental over-claim.
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3.3. CRL Processing
The CRL processing requirements imposed on CAs and RP are described
in Section 5 of [RFC6487]. CRLs in the RPKI are tightly constrained;
only the AuthorityKeyIndetifier and CRLNumber extensions are allowed,
and they are required to be present. No other CRL extensions are
allowed, and no CRLEntry extensions are permitted. RPs are required
to verify that these constraints have been met. Each CRL in the RPKI
must be verified using the public key from the certificate of the CA
that issued the CRL.
In the RPKI, RPs are expected to pay extra attention when dealing
with a CRL that is not consistent with the Manifest associated with
the publication point associated with the CRL.
Processing of a CRL that is not consistent with a manifest is a
matter of local policy, as described in the fourth paragraph of
Section 6.6 of [RFC6486].
4. Processing RPKI Repository Signed Objects
4.1. Basic Signed Object Syntax Checks
Before an RP can use a signed object from the RPKI repository, the RP
is required to check the signed object syntax.
Section 3 of [RFC6488] lists all the steps that the RP is required to
execute in order to validate the top level syntax of a repository
signed object.
Note that these checks are necessary, but not sufficient. Additional
validation checks must be performed based on the specific type of
signed object.
4.2. Syntax and Validation for Each Type of Signed Object
4.2.1. Manifest
To determine whether a manifest is valid, the RP is required to
perform manifest-specific checks in addition to those specified in
[RFC6488].
Specific checks for a Manifest are described in Section 4 of
[RFC6486]. If any of these checks fails, indicating that the
manifest is invalid, then the manifest will be discarded and treated
as though no manifest were present.
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4.2.2. ROA
To validate a ROA, the RP is required perform all the checks
specified in [RFC6488] as well as the additional ROA-specific
validation steps. The IP address delegation extension [RFC3779]
present in the end-entity (EE) certificate (contained within the
ROA), must encompass each of the IP address prefix(es) in the ROA.
More details for ROA validation are specified in Section 4 of
[RFC6482].
4.2.3. Ghostbusters
The Ghostbusters Record is optional; a publication point in the RPKI
can have zero or more associated Ghostbuster Records. If a CA has at
least one Ghostbuster Record, RP is required to verify that this
Ghostbusters Record conforms to the syntax of signed object defined
in [RFC6488].
The payload of this signed object is a (severely) profiled vCard. An
RP is required to verify that the payload of Ghostbusters conforms to
format as profiled in [RFC6493].
4.2.4. Verifying BGPsec Router Certificate
A BGPsec Router Certificate is a resource certificate, so it is
required to comply with [RFC6487]. Additionally, the certificate
must contain an AS Identifier Delegation extension, and must not
contain an IP Address Delegation extension. The validation procedure
used for BGPsec Router Certificates is identical to the validation
procedure described in Section 7 of [RFC6487], but using the
constraints applied come from specification of Section 7 of
[RFC8209].
Note that the cryptographic algorithms used by BGPsec routers are
found in [RFC8208]. Currently, the algorithms specified in
[RFC8208]and [RFC7935] are different. BGPsec RPs will need to
support algorithms that are used to validate BGPsec signatures as
well as the algorithms that are needed to validate signatures on
BGPsec certificates, RPKI CA certificates, and RPKI CRLs.
4.3. How to Make Use of Manifest Data
For a given publication point, the RP ought to perform tests, as
specified in Section 6.1 of [RFC6486], to determine the state of the
Manifest at the publication point. A Manifest can be classified as
either valid or invalid, and a valid Manifest is either current and
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stale. An RP decides how to make use of a Manifest based on its
state, according to local (RP) policy.
If there are valid objects in a publication point that are not
present on a Manifest, [RFC6486] does not mandate specific RP
behavior with respect to such objects. However, most RP software
ignores such objects and the authors of this document suggest this
behavior be adopted uniformly.
In the absence of a Manifest, an RP is expected to accept all valid
signed objects present in the publication point. If a Manifest is
stale or invalid (see [RFC6486]) and an RP has no way to acquire a
more recently valid Manifest, the RP is expected to contact the
repository manager via Ghostbusters record and thereafter make
decision according to local (RP) policy.
4.4. What to Do with Ghostbusters Information
An RP may encounter a stale Manifest or CRL, or an expired CA
certificate or ROA at a publication point. An RP is expected to use
the information from the Ghostbusters record to contact the
maintainer of the publication point where any stale/expired objects
were encountered. The intent here is to encourage the relevant CA
and/or repository manager to update the slate or expired objects.
5. Distributing Validated Cache
On a periodic basis, BGP speakers within an AS request updated
validated origin AS data and router/ASN data from the validated cache
of RPKI data. The RP may either transfer the validated data to the
BGP speakers directly, or it may transfer the validated data to a
cache server that is responsible for provisioning such data to BGP
speakers. The specification of the protocol designed to deliver
validated cache data to a BGP Speaker is provided in [RFC6810] and
[RFC8210].
6. Local Control
ISPs may want to establish a local view of exceptions to the RPKI
data in the form of local filters and additions. For instance, a
network operator might wish to make use of a local override
capability to protect routes from adverse actions [RFC8211] . The
mechanisms developed to provide this capability to network operators
are called "Simplified Local Internet Number Resource Management with
the RPKI (SLURM). If an ISP wants to implement SLURM, its RP system
can follow the instruction specified in [RFC8416] .
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7. Security Considerations
The RP links the RPKI provisioning side and the routing system,
establishing the local view of global RPKI data to BGP speakers. The
security of the RP is critical to BGP messages exchanging. The RP
implementation is expected to offer cache backup management to
facilitate recovery from outage state. The RP implementation also
should support application of secure transport (e.g., IPsec
[RFC4301]) that is able to protect validated cache delivery in a
unsafe environment.
8. IANA Considerations
This document has no actions for IANA.
9. Acknowledgements
The authors thank David Mandelberg, Wei Wang, Tim Bruijnzeels, George
Michaelson and Oleg Muravskiy for their review, feedback and
editorial assistance in preparing this document.
10. References
10.1. Normative References
[RFC3779] Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP
Addresses and AS Identifiers", RFC 3779,
DOI 10.17487/RFC3779, June 2004,
<https://www.rfc-editor.org/info/rfc3779>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<https://www.rfc-editor.org/info/rfc5280>.
[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>.
[RFC6482] Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
Origin Authorizations (ROAs)", RFC 6482,
DOI 10.17487/RFC6482, February 2012,
<https://www.rfc-editor.org/info/rfc6482>.
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[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>.
[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>.
[RFC6488] Lepinski, M., Chi, A., and S. Kent, "Signed Object
Template for the Resource Public Key Infrastructure
(RPKI)", RFC 6488, DOI 10.17487/RFC6488, February 2012,
<https://www.rfc-editor.org/info/rfc6488>.
[RFC6493] Bush, R., "The Resource Public Key Infrastructure (RPKI)
Ghostbusters Record", RFC 6493, DOI 10.17487/RFC6493,
February 2012, <https://www.rfc-editor.org/info/rfc6493>.
[RFC6810] Bush, R. and R. Austein, "The Resource Public Key
Infrastructure (RPKI) to Router Protocol", RFC 6810,
DOI 10.17487/RFC6810, January 2013,
<https://www.rfc-editor.org/info/rfc6810>.
[RFC7935] Huston, G. and G. Michaelson, Ed., "The Profile for
Algorithms and Key Sizes for Use in the Resource Public
Key Infrastructure", RFC 7935, DOI 10.17487/RFC7935,
August 2016, <https://www.rfc-editor.org/info/rfc7935>.
[RFC8208] Turner, S. and O. Borchert, "BGPsec Algorithms, Key
Formats, and Signature Formats", RFC 8208,
DOI 10.17487/RFC8208, September 2017,
<https://www.rfc-editor.org/info/rfc8208>.
[RFC8209] Reynolds, M., Turner, S., and S. Kent, "A Profile for
BGPsec Router Certificates, Certificate Revocation Lists,
and Certification Requests", RFC 8209,
DOI 10.17487/RFC8209, September 2017,
<https://www.rfc-editor.org/info/rfc8209>.
[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>.
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[RFC8360] Huston, G., Michaelson, G., Martinez, C., Bruijnzeels, T.,
Newton, A., and D. Shaw, "Resource Public Key
Infrastructure (RPKI) Validation Reconsidered", RFC 8360,
DOI 10.17487/RFC8360, April 2018,
<https://www.rfc-editor.org/info/rfc8360>.
[RFC8630] Huston, G., Weiler, S., Michaelson, G., Kent, S., and T.
Bruijnzeels, "Resource Public Key Infrastructure (RPKI)
Trust Anchor Locator", RFC 8630, DOI 10.17487/RFC8630,
August 2019, <https://www.rfc-editor.org/info/rfc8630>.
10.2. Informative References
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[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>.
[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>.
[RFC6916] Gagliano, R., Kent, S., and S. Turner, "Algorithm Agility
Procedure for the Resource Public Key Infrastructure
(RPKI)", BCP 182, RFC 6916, DOI 10.17487/RFC6916, April
2013, <https://www.rfc-editor.org/info/rfc6916>.
[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>.
[RFC8211] Kent, S. and D. Ma, "Adverse Actions by a Certification
Authority (CA) or Repository Manager in the Resource
Public Key Infrastructure (RPKI)", RFC 8211,
DOI 10.17487/RFC8211, September 2017,
<https://www.rfc-editor.org/info/rfc8211>.
[RFC8416] Ma, D., Mandelberg, D., and T. Bruijnzeels, "Simplified
Local Internet Number Resource Management with the RPKI
(SLURM)", RFC 8416, DOI 10.17487/RFC8416, August 2018,
<https://www.rfc-editor.org/info/rfc8416>.
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[RFC8634] Weis, B., Gagliano, R., and K. Patel, "BGPsec Router
Certificate Rollover", BCP 224, RFC 8634,
DOI 10.17487/RFC8634, August 2019,
<https://www.rfc-editor.org/info/rfc8634>.
[rsync] "rsync web page", <http://rsync.samba.org/>.
Authors' Addresses
Di Ma
ZDNS
4 South 4th St. Zhongguancun
Haidian, Beijing 100190
China
Email: madi@zdns.cn
Stephen Kent
Independent
Email: kent@alum.mit.edu
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