Internet DRAFT - draft-spaghetti-sidrops-rpki-doa
draft-spaghetti-sidrops-rpki-doa
Network Working Group J. Snijders
Internet-Draft Fastly
Intended status: Standards Track M. Abrahamsson
Expires: 8 September 2022 NTT
B. Maddison
Workonline
7 March 2022
Resource Public Key Infrastructure (RPKI) object profile for Discard
Origin Authorizations (DOA)
draft-spaghetti-sidrops-rpki-doa-00
Abstract
This document defines a Cryptographic Message Syntax (CMS) profile
for Discard Origin Authorizations (DOAs), for use with the Resource
Public Key Infrastructure (RPKI). A DOA is a digitally signed object
that provides a means of verifying that an IP address block holder
has authorized an Autonomous System (AS) to originate routes to one
or more prefixes within the address block tagged with a specific set
of Border Gateway Protocol (BGP) Communities, to signal a request to
discard IP traffic destined towards the tagged IP prefix.
Requirements Language
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.
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-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 8 September 2022.
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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
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. DOA EncapsulatedContentInfo . . . . . . . . . . . . . . . . . 3
2.1. ASN.1 Module . . . . . . . . . . . . . . . . . . . . . . 3
2.2. The DOA eContentType . . . . . . . . . . . . . . . . . . 5
2.3. The DOA eContent . . . . . . . . . . . . . . . . . . . . 5
2.3.1. version . . . . . . . . . . . . . . . . . . . . . . . 5
2.3.2. ipAddrBlocks . . . . . . . . . . . . . . . . . . . . 5
2.3.3. originAsID . . . . . . . . . . . . . . . . . . . . . 5
2.3.4. peerAsIDs . . . . . . . . . . . . . . . . . . . . . . 6
2.3.5. communities . . . . . . . . . . . . . . . . . . . . . 6
3. DOA Validation . . . . . . . . . . . . . . . . . . . . . . . 6
4. RPKI-RTR protocol extensions . . . . . . . . . . . . . . . . 6
5. BGP Route Matching . . . . . . . . . . . . . . . . . . . . . 6
6. Route Origin Validation Co-Existance . . . . . . . . . . . . 7
7. Exporting RTBH Routes . . . . . . . . . . . . . . . . . . . . 8
8. Operational Considerations . . . . . . . . . . . . . . . . . 8
9. Security Considerations . . . . . . . . . . . . . . . . . . . 8
10. Implementation status . . . . . . . . . . . . . . . . . . . . 8
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
11.1. SMI Security for S/MIME CMS Module Identifier
(1.2.840.113549.1.9.16.0) . . . . . . . . . . . . . . . 9
11.2. SMI Security for S/MIME CMS Content Type
(1.2.840.113549.1.9.16.1) . . . . . . . . . . . . . . . 9
11.3. RPKI Signed Objects registry . . . . . . . . . . . . . . 9
11.4. RPKI Repository Name Schemes registry . . . . . . . . . 10
11.5. Media Types registry . . . . . . . . . . . . . . . . . . 10
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
12.1. Normative References . . . . . . . . . . . . . . . . . . 11
12.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 12
Appendix B. Document Changelog . . . . . . . . . . . . . . . . . 12
B.1. Individual Submission Phase . . . . . . . . . . . . . . . 12
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
Internet operators commonly provide a means for adjacent networks to
advertise routes in BGP with the intention that traffic matching such
a route be discarded, rather than being forwarded towards the
advertising network. This is referred to as Remotely Triggered
Blackholing (RTBH), and is typically acheived through the use of a
BGP Community [RFC1997]. [RFC7999] defines a "well known" community
value for this purpose. The route used to signal an RTBH request is
referred to as an RTBH route.
Inter-AS RTBH signalling, however, is in tension with the deployment
of Route Origin Validation (ROV) based on the Resource Public Key
Infrastructure (RPKI) [RFC6811]. Because a blackhole route is likely
to have a prefix length greater than permitted in any covering ROA,
an operator wishing to deploy routing policy to discard BGP paths
with an ROV status of "Invalid", and simultaneously maintain a
blackhole signalling service must choose either:
1. to exempt blackhole routes from processing based on ROV status,
thus foregoing the benefit of ROV altogether; or
2. to insist that users of the blackhole signalling service create
ROAs with a sufficiently large "maxLength" values to accomodate
blackhole routes.
This document defines a Cryptographic Message Syntax (CMS) [RFC5652]
profile for Discard Origin Authorizations (DOAs), for use with the
Resource Public Key Infrastructure (RPKI) [RFC6480], along with
associated processing rules.
DOAs can be used to validate whether incoming BGP route announcements
carrying specific BGP Communities are meant to signify a request to
discard IP traffic towards the IP destination carried in the BGP
route. This enhances the concepts of [RFC3882] and [RFC7999], and
can co-exist with deployed ROV policy.
2. DOA EncapsulatedContentInfo
DOA follows the Signed Object Template for the RPKI [RFC6488].
2.1. ASN.1 Module
The following ASN.1 module specifies the encapContentInfo component
for DOA objects:
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RpkiDiscardOriginAuthorization-2021
{ iso(1) member-body(2) us(840) rsadsi(113549)
pkcs(1) pkcs9(9) smime(16) mod(0) TBD }
DEFINITIONS EXPLICIT TAGS ::=
BEGIN
IMPORTS
CONTENT-TYPE
FROM CryptographicMessageSyntax-2010 -- in [RFC6268]
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
pkcs-9(9) smime(16) modules(0) id-mod-cms-2009(58) }
IPAddressOrRange, IPAddressRange, IPAddress, ASId
FROM IPAddrAndASCertExtn -- in [RFC3779]
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) mod(0)
id-mod-ip-addr-and-as-ident(30) } ;
ct-discardOriginAuthorization CONTENT-TYPE ::=
{ TYPE DiscardOriginAuthorization IDENTIFIED BY
id-ct-discardOriginAuthorization }
id-ct-discardOriginAuthorization OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
pkcs-9(9) id-smime(16) id-ct(1) TBD }
DiscardOriginAuthorization ::= SEQUENCE {
version [0] INTEGER DEFAULT 0,
ipAddrBlocks IPListRange,
originAsID ASId,
peerAsIDs [1] SEQUENCE SIZE(1..MAX) OF ASId OPTIONAL,
communities [2] SEQUENCE SIZE(1..MAX) OF Community
}
IPListRange ::= SEQUENCE (SIZE(1..MAX)) OF IPAddressFamilyRange
IPAddressFamilyRange ::= SEQUENCE {
addressFamily OCTET STRING (SIZE(2..3)),
addressOrRange IPAddressOrRange,
prefixLengthRange PrefixLengthRange OPTIONAL -- if omitted, assume hostroutes
}
PrefixLengthRange ::= SEQUENCE {
minLength INTEGER,
maxLength INTEGER
}
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Community ::= CHOICE {
bgpCommunity [0] OCTET STRING (SIZE(4)),
bgpLargeCommunity [1] OCTET STRING (SIZE(12))
}
END
2.2. The DOA eContentType
The eContentType for a DOA is defined as id-ct-
discardOriginAuthorization as specified in Section 2.1.
This OID MUST appear both within the eContentType in the
encapContentInfo object as well as the ContentType signed attribute
in the signerInfo object (see [RFC6488]).
2.3. The DOA eContent
The content of a DOA is formally defined as
DiscardOriginAuthorization as specified in Section 2.1
2.3.1. version
The version number of the DiscardOriginAuthorization MUST be 0.
2.3.2. ipAddrBlocks
The IP address prefixes for which the announcement of RTBH routes is
authorized. The IP address resources contained here are the
resources used to mark the authorization, and MUST match the set of
resources listed by the EE certificate carried in the CMS
certificates field. See [RFC6482] Section 3.3 for a similar, but not
entirely similar appraoch. A notable difference is the absense of
MaxLength, and instead a PrefixLengthRange is used. If no
PrefixLengthRange is present, only the "host route" prefix length
(i.e. 32 for IPv4 and 128 for IPv6) is authorized.
2.3.3. originAsID
The asID field contains the AS number that is authorized to originate
RTBH routes for the given IP address prefixes. The asID does not
have to be contained by the resources listed on the EE certificate.
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2.3.4. peerAsIDs
The peerAsIDs field contains zero or more AS numbers that are
authorized to propagate routes intended to signal an RTBH request for
the given IP address prefixes. The peerAsIDs do not have to be
contained by the resources listed on the EE certificate. Network
operators MUST only accept the RTBH request if it was received from
any listed peerAsIDs. The peerAsIDs field allows DOAs to be used to
validate RTBH routes with one AS hop between originator and
receipient.
2.3.5. communities
The communities field contains the Classic BGP communities or Large
BGP Communities which are to be the 'trigger' to start RTBH. TBD:
are communities 'and' or 'or'?
3. DOA Validation
To validate a DOA the relying party MUST perform all the validation
checks specified in [RFC6488] as well as the following additional
DOA-specific validation step:
* The IP delegation extension [RFC3779] MUST be present in the end-
entity certificate (contained in the DOA), and every IP address
prefix present in the ipAddrBlocks component of the DOA eContent
is contained within the set of IP addresses specified in the EE
certificate's IP address delegation extension.
4. RPKI-RTR protocol extensions
TODO: Seperate document?
5. BGP Route Matching
TODO: Seperate document?
A BGP speaker MAY assign to each path it receives from its peers one
of 3 RTBH request validation states:
* Matched: a validated DOA object was found covering the prefix of
the received path, and matching the contraints of the DOA;
* Unmatched: a validated DOA object was found covering the prefix of
the received path, but the constraints of the DOA were not
matched; or
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* NotFound: a validated DOA object covering the prefix of the
receieved path was not found.
Where "covering" is used as in its definition in Section 2 [RFC6811].
In order for a BGP path to be considered to have matched the
constraints of a DOA object, the following conditions MUST be met:
* The route originated from the ASN listed in the ASId.
* The route was received from a PeerAS which is either the ASId or
listed in the peerAsIDs field.
* The route's prefix length matches the listed permissible prefix
lengths.
* The route is tagged with (TODO: one or more of?) the designated
BGP community.
6. Route Origin Validation Co-Existance
It is important to observe that ROAs and DOAs can and will be issued
for the same covered address space, and that the resulting ROV
validation state MUST be entirely independent of the resulting DOA
validation state.
In particular it is expected that legitimate RTBH routes will
commonly receive a DOA validation state of 'Matched' whilst also
receiving a ROV validation state of 'Invalid' due to the (likely)
longer prefix-length of an RTBH route.
For this reason, it is recommended that operators construct policy so
as to act on the DOA validation early in the routing policy
application process, such that routes that are 'Matched' may be
installed as RTBH routes, and routes that are 'Unmatched' or
'NotFound' can "fall-through" to be processed as "normal" routes,
including the possible application of policy based on their ROV
validation state.
Critically, in order that operators are able to construct policy
according to their needs conforming implementations MUST NOT take any
policy action on a route based on either its DOA or ROV validation
state by default. See also [RFC8481].
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7. Exporting RTBH Routes
The guidance of Section 3.2 [RFC7999] that, in general, RTBH routes
SHOULD NOT be propagated beyond the receiving AS continues to apply
to RTBH routes validated in terms of the above mechanisms.
The exception to this guidance is that an operator MAY propagate a
received RTBH route to neighboring ASes if its own AS number appears
in the peerAsIDs field of the matched DOA, since this indicates a
desire by the issuer that neighbors of the local AS honour the route
as a legitimate RTBH signal.
To facilitate the construction of routing policies by operators that
implemented this behaviour, conforming BGP speaker implementations
SHOULD provide a means of distinguishing between 'Matched' routes for
which the local AS appears in the peerAsIDs of the matched DOA from
those for which it does not.
8. Operational Considerations
TODO
9. Security Considerations
TODO
10. Implementation status
This section is to be removed before publishing as an RFC.
This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in RFC 7942.
The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may
exist.
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According to RFC 7942, "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as
they see fit".
* A signer implementation [rpkimancer-doa] written in Python has
been developed by Ben Maddison.
11. IANA Considerations
11.1. SMI Security for S/MIME CMS Module Identifier
(1.2.840.113549.1.9.16.0)
The IANA is requested to register the following entry for this
document in the "SMI Security for S/MIME CMS Module Identifier
(1.2.840.113549.1.9.16.0)" registry:
Decimal Description References
-----------------------------------------------------------------------------
[TBD] id-mod-rpkiDOA [draft-spaghetti-sidrops-rpki-doa]
Upon publication of this document, IANA is requested to reference the
RFC publication instead of this draft.
11.2. SMI Security for S/MIME CMS Content Type
(1.2.840.113549.1.9.16.1)
The IANA is requested to register the following entry for this
document in the "SMI Security for S/MIME CMS Content Type
(1.2.840.113549.1.9.16.1)" registry:
Decimal Description References
-----------------------------------------------------------------------------
[TBD] id-ct-discardOriginAuthorization [draft-spaghetti-sidrops-rpki-doa]
Upon publication of this document, IANA is requested to reference the
RFC publication instead of this draft.
11.3. RPKI Signed Objects registry
The IANA is requested to register the OID for the RPKI Discard Origin
Authorization in the "RPKI Signed Objects" registry ([RFC6488]) as
follows:
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Name OID Reference
----------------------------------------------------
DOA 1.2.840.113549.1.9.16.1.TBD [RFC-TBD]
11.4. RPKI Repository Name Schemes registry
The IANA is requested to register the RPKI Discard Origin
Authorization file extension in the "RPKI Repository Name Schemes"
registry ([RFC6481]) as follows:
Filename Extension RPKI Object Reference
----------------------------------------------------------
.doa Discard Origin Authorization [RFC-TBD]
11.5. Media Types registry
The IANA is requested to register the media type application/rpki-doa
in the "Media Types" registry ([RFC6838]) as follows:
Type name: application
Subtype name: rpki-doa
Required parameters: None
Optional parameters: None
Encoding considerations: binary
Security considerations: Carries an RPKI Discard Origin Authorization
[RFC-TBD].
Interoperability considerations: None
Published specification: This document.
Applications that use this media type: RPKI operators.
Additional information:
Content: This media type is a signed object, as defined
in [RFC6488], which contains a payload of a set of matching
criteria as defined above in [RFC-TBD].
Magic number(s): None
File extension(s): .doa
Macintosh file type code(s):
Person & email address to contact for further information:
Job Snijders <job@fastly.com>
Intended usage: COMMON
Restrictions on usage: None
Author: Job Snijders <job@fastly.com>
Change controller: Job Snijders <job@fastly.com>
12. References
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12.1. 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>.
[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>.
[RFC3882] Turk, D., "Configuring BGP to Block Denial-of-Service
Attacks", RFC 3882, DOI 10.17487/RFC3882, September 2004,
<https://www.rfc-editor.org/info/rfc3882>.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, DOI 10.17487/RFC5652, September 2009,
<https://www.rfc-editor.org/info/rfc5652>.
[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>.
[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>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13,
RFC 6838, DOI 10.17487/RFC6838, January 2013,
<https://www.rfc-editor.org/info/rfc6838>.
[RFC7999] King, T., Dietzel, C., Snijders, J., Doering, G., and G.
Hankins, "BLACKHOLE Community", RFC 7999,
DOI 10.17487/RFC7999, October 2016,
<https://www.rfc-editor.org/info/rfc7999>.
[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>.
12.2. Informative References
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[RFC1997] Chandra, R., Traina, P., and T. Li, "BGP Communities
Attribute", RFC 1997, DOI 10.17487/RFC1997, August 1996,
<https://www.rfc-editor.org/info/rfc1997>.
[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>.
[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>.
[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>.
[RFC8481] Bush, R., "Clarifications to BGP Origin Validation Based
on Resource Public Key Infrastructure (RPKI)", RFC 8481,
DOI 10.17487/RFC8481, September 2018,
<https://www.rfc-editor.org/info/rfc8481>.
[rpkimancer-doa]
Maddison, B., "rpkimancer-doa", June 2021,
<https://pypi.org/project/rpkimancer-doa/>.
Appendix A. Acknowledgements
TODO
Appendix B. Document Changelog
This section is to be removed before publishing as an RFC.
B.1. Individual Submission Phase
Authors' Addresses
Job Snijders
Fastly
Amsterdam
Netherlands
Email: job@fastly.com
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Mikael Abrahamsson
NTT Ltd.
Stockholm
Sweden
Email: mikael@swm.pp.se
Ben Maddison
Workonline Communications
Cape Town
South Africa
Email: benm@workonline.africa
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