Internet DRAFT - draft-madi-sidrops-rp
draft-madi-sidrops-rp
SIDROPS D. Ma
Internet-Draft ZDNS
Intended status: Informational S. Kent
Expires: December 28, 2017 BBN
June 26, 2017
Requirements for Resource Public Key Infrastructure (RPKI) Relying
Parties
draft-madi-sidrops-rp-00
Abstract
This document provides a single reference point for requirements for
Relying Party (RP) software for use in the Resource Public Key
Infrastructure (RPKI). 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
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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 . . . . . . . . . . . . . . . . . . . . . 5
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 . . . . . . . . . . . . . . . . . . . . . . . . . 6
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. Delivering Validated Cache to BGP Speakers . . . . . . . . . 8
6. Security considerations . . . . . . . . . . . . . . . . . . . 8
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
The RPKI 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.
Noting that the essential requirements imposed on RPs are scattered
throughout numerous RFC documents that are protocol specific or
provide best practices, as follows:
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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 7730 (Trust Anchor Locator)
RFC 7935 (Algorithms)
RFC XXXX (Router Certificates)[ID.sidr-bgpsec-pki-profiles]
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 'RP role' 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 Delivering Validated Cache Data to BGP Speakers
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]) 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
routes for address prefixes, and which routers are authorized to sign
BGP updates on behalf of ASes.
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2.1. TAL Acquisition and Processing
In the RPKI, each relying party (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 trust anchor.
TAL acquisition and processing are specified in Section 3 of
[RFC7730].
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 SIA and 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].
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 [RFC6487]. This means that all extensions mandated by
[RFC6487] must be present and value of each extension must be within
the range specified by this RFC. Moreover, any extension excluded by
[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
In the RPKI, issuer can only assign and/or allocate public INRs
belong to it, thus 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.
3.3. CRL Processing
The CRL processing requirements imposed on CAs and RP are described
in [RFC6487]. CRLs in the RPKI are tightly constrained; only the
AuthorityKeyIndetifier and CRLNumber extensions are allowed, and they
MUST be present. No other CRL extensions are allowed, and no
CRLEntry extensions are permitted. RPs are required to verify that
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these constraints have been met. Each CRL in the RPI 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.
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.
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More details for ROA validation are specified in section 2 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
[ID.sidr-bgpsec-pki-profiles].
Note that the cryptographic algorithms used by BGPsec routers are
found in [ID.sidr-bgpsec-algs]. Currently, the algorithms specified
in [ID.sidr-bgpsec-algs] 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 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 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 this document recommends that this behavior
be adopted uniformly.
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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 (see [RFC6486]) and an RP has no way to acquire a more recent
Manifest, the RP is expected to (TBD).
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. Delivering Validated Cache to BGP Speakers
On a periodic basis, BGP speakers within an AS request updated
validated origin AS data and router/ASN data from the RP's cache.
The RP passes this information to BGP speakers to enable them to
verify the authenticity of routing announcements. The specification
of the protocol designed to deliver validated cache data from an RP
to a BGP Speaker is provided in [RFC6810].
6. Security considerations
TBD
7. IANA Considerations
This document has no actions for IANA.
8. Acknowledgements
The authors thank David Mandelberg and Wei Wang for their review,
feedback and editorial assistance in preparing this document.
9. References
9.1. Normative References
[ID.sidr-bgpsec-algs]
Turner, S., "BGPsec Algorithms, Key Formats and Signature
Formats", work-in-progress, <draft-ietf-sidr-bgpsec-algs>.
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[ID.sidr-bgpsec-pki-profiles]
Reynolds, M., Turner, S., and S. Kent, "A Profile for
BGPsec Router Certificates, Certificate Revocation Lists,
and Certification Requests", work-in-progress, <draft-
ietf-sidr-bgpsec-pki-profiles>.
[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,
<http://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,
<http://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,
<http://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,
<http://www.rfc-editor.org/info/rfc6482>.
[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,
<http://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,
<http://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,
<http://www.rfc-editor.org/info/rfc6488>.
[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,
<http://www.rfc-editor.org/info/rfc6489>.
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[RFC6493] Bush, R., "The Resource Public Key Infrastructure (RPKI)
Ghostbusters Record", RFC 6493, DOI 10.17487/RFC6493,
February 2012, <http://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,
<http://www.rfc-editor.org/info/rfc6810>.
[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, <http://www.rfc-editor.org/info/rfc6916>.
[RFC7730] Huston, G., Weiler, S., Michaelson, G., and S. Kent,
"Resource Public Key Infrastructure (RPKI) Trust Anchor
Locator", RFC 7730, DOI 10.17487/RFC7730, January 2016,
<http://www.rfc-editor.org/info/rfc7730>.
[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, <http://www.rfc-editor.org/info/rfc7935>.
9.2. Informative References
[RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support
Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480,
February 2012, <http://www.rfc-editor.org/info/rfc6480>.
[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
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Stephen Kent
BBN
10 Moulton St
Cambridge, MA 02138-1119
USA
Email: kent@alum.mit.edu
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