Network Working Group J. Snijders
Internet-Draft Fastly
Intended status: Standards Track T. Harrison
Expires: December 2, 2021 APNIC
B. Maddison
Workonline
May 31, 2021
Resource Public Key Infrastructure (RPKI) object profile for Signed
Checklist (RSC)
draft-ietf-sidrops-rpki-rsc-04
Abstract
This document defines a Cryptographic Message Syntax (CMS) profile
for a general purpose listing of checksums (a 'checklist'), for use
with the Resource Public Key Infrastructure (RPKI). The objective is
to allow an attestation, in the form of a listing of one or more
checksums of arbitrary digital objects (files), to be signed "with
resources", and for validation to provide a means to confirm a
specific Internet Resource Holder produced the Signed Checklist. The
profile is intended to provide for the signing of an arbitrary
checksum listing with a specific set of Internet Number Resources.
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."
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This Internet-Draft will expire on December 2, 2021.
Copyright Notice
Copyright (c) 2021 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 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 . . . . . . . . . . . . . . . . . . . . . . . . 3
2. RSC Profile and Distribution . . . . . . . . . . . . . . . . 3
3. The RSC ContentType . . . . . . . . . . . . . . . . . . . . . 3
4. The RSC eContent . . . . . . . . . . . . . . . . . . . . . . 4
4.1. version . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2. resources . . . . . . . . . . . . . . . . . . . . . . . . 5
4.3. digestAlgorithm . . . . . . . . . . . . . . . . . . . . . 5
4.4. checkList . . . . . . . . . . . . . . . . . . . . . . . . 5
5. RSC Validation . . . . . . . . . . . . . . . . . . . . . . . 5
6. Operational Considerations . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
8. Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION 7
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
9.1. SMI Security for S/MIME CMS Content Type
(1.2.840.113549.1.9.16.1) . . . . . . . . . . . . . . . . 8
9.2. RPKI Signed Objects sub-registry . . . . . . . . . . . . 8
9.3. File Extension . . . . . . . . . . . . . . . . . . . . . 8
9.4. SMI Security for S/MIME Module Identifier
(1.2.840.113549.1.9.16.0) . . . . . . . . . . . . . . . . 9
9.5. Media Type . . . . . . . . . . . . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 9
10.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 11
Appendix B. Document changelog - RFC EDITOR: REMOVE BEFORE
PUBLICATION . . . . . . . . . . . . . . . . . . . . 11
B.1. changes from -03 -> -04 . . . . . . . . . . . . . . . . . 11
B.2. changes from -02 -> -03 . . . . . . . . . . . . . . . . . 11
B.3. changes from -01 -> -02 . . . . . . . . . . . . . . . . . 12
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B.4. changes from -00 -> -01 . . . . . . . . . . . . . . . . . 12
B.5. individual submission phase . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
This document defines a Cryptographic Message Syntax (CMS) [RFC5652]
profile for a general purpose listing of checksums (a 'checklist'),
for use with the Resource Public Key Infrastructure (RPKI) [RFC6480].
The objective is to allow an attestation, in the form of a listing of
one or more checksums of arbitrary files, to be signed "with
resources", and for validation to provide a means to confirm a given
Internet Resource Holder produced the RPKI Signed Checklist (RSC).
The profile is intended to provide for the signing of a checksum
listing with a specific set of Internet Number Resources.
Signed Checklists are expected to facilitate inter-domain business
use-cases which depend on an ability to verify resource holdership.
RPKI-based validation processes are expected to become the industry
norm for automated Bring Your Own IP (BYOIP) on-boarding or
establishment of physical interconnection between Autonomous Systems.
The RSC concept borrows heavily from RTA [I-D.ietf-sidrops-rpki-rta],
Manifests [RFC6486], and OpenBSD's [signify] utility. The main
difference between RSC and RTA is that the RTA profile allows
multiple signers to attest a single digital object through a checksum
of its content, while the RSC profile allows a single signer to
attest the existence of multiple digital objects. A single signer
profile is considered a simplification for both implementers and
operators.
2. RSC Profile and Distribution
RSC follows the Signed Object Template for the RPKI [RFC6488] with
one exception. Because RSCs MUST NOT be distributed through the
global RPKI repository system, the Subject Information Access (SIA)
extension MUST be omitted from the RSC's X.509 EE certificate.
What constitutes suitable transport for RSC files is deliberately
unspecified. It might be a USB stick, a web interface secured with
conventional HTTPS, PGP-signed email, a T-shirt printed with a QR
code, or a carrier pigeon.
3. The RSC ContentType
The ContentType for an RSC is defined as rpkiSignedChecklist, and has
the numerical value of 1.2.840.113549.1.9.16.1.48.
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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]).
4. The RSC eContent
The content of an RSC indicates that a checklist for arbitrary
digital objects has been signed "with resources". An RSC is formally
defined as:
RpkiSignedChecklist-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, Digest, DigestAlgorithmIdentifier
FROM CryptographicMessageSyntax-2009 -- in [RFC5911]
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
pkcs-9(9) smime(16) modules(0) id-mod-cms-2004-02(41) }
ASIdOrRange, IPAddressOrRange
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-rpkiSignedChecklist CONTENT-TYPE ::=
{ TYPE RpkiSignedChecklist IDENTIFIED BY
id-ct-signedChecklist }
id-ct-signedChecklist OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
pkcs-9(9) id-smime(16) id-ct(1) 48 }
RpkiSignedChecklist ::= SEQUENCE {
version [0] INTEGER DEFAULT 0,
resources ResourceBlock,
digestAlgorithm DigestAlgorithmIdentifier,
checkList SEQUENCE SIZE (1..MAX) OF FileNameAndHash }
FileNameAndHash ::= SEQUENCE {
fileName IA5String OPTIONAL,
hash Digest }
ResourceBlock ::= SEQUENCE {
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asID [0] AsList OPTIONAL,
ipAddrBlocks [1] IPList OPTIONAL }
-- at least one of asID or ipAddrBlocks MUST be present
( WITH COMPONENTS { ..., asID PRESENT} |
WITH COMPONENTS { ..., ipAddrBlocks PRESENT } )
AsList ::= SEQUENCE (SIZE(1..MAX)) OF ASIdOrRange
IPList ::= SEQUENCE (SIZE(1..MAX)) OF IPAddressFamilyItem
IPAddressFamilyItem ::= SEQUENCE { -- AFI & optional SAFI --
addressFamily OCTET STRING (SIZE (2..3)),
iPAddressOrRange IPAddressOrRange }
END
4.1. version
The version number of the RpkiSignedChecklist MUST be 0.
4.2. resources
The resources contained here are the resources used to mark the
attestation, and MUST match the set of resources listed by the EE
certificate carried in the CMS certificates field.
4.3. digestAlgorithm
The digest algorithm used to create the message digest of the
attested digital object. This algorithm MUST be a hashing algorithm
defined in [RFC7935].
4.4. checkList
This field is a sequence of FilenameAndHash objects. There is one
FilenameAndHash entry for each arbitrary object referenced on the
Signed Checklist. Each FilenameAndHash is an ordered pair of the
name of the directory entry containing the digital object and the
message digest of the digital object. The filename field is
OPTIONAL.
5. RSC Validation
Before a relying party can use an RSC to validate a set of digital
objects, the relying party MUST first validate the RSC. To validate
an RSC, the relying party MUST perform all the validation checks
specified in [RFC6488] as well as the following additional RSC-
specific validation steps.
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o The IP Addresses and AS Identifiers extension [RFC3779] is present
in the end-entity (EE) certificate (contained within the RSC), and
each IP address prefix(es) and/or AS Identifier(s) in the RSC is
contained within the set of IP addresses specified by the EE
certificate's IP address delegation extension.
o For each FilenameAndHash entry in the RSC, if a filename field is
present, the field's content MUST contain only characters
specified in the Portable Filename Character Set as defined in
[POSIX].
To validate a set of digital objects against an RSC:
o The message digest of each referenced digital object, using the
digest algorithm specified in the the digestAlgorithm field, MUST
be calculated and MUST match the value given in the messageDigest
field of the associated FilenameAndHash, for the digital object to
be considered valid as against the RSC.
6. Operational Considerations
When creating digital objects of a plain-text nature (such as ASCII,
UTF-8, HTML, Javascript, XML, etc) it is RECOMMENDED to convert such
objects into a lossless compressed form. Distributing plain-text
objects within a compression envelope (such as GZIP [RFC1952]) might
help avoid unexpected canonicalization at intermediate systems (which
in turn would lead to checksum verification errors). Validator
implementations are expected to treat a checksummed digital object as
string of arbitrary single octets.
If a filename field is present, but no referenced digital object has
a filename that matches the content of that field, a validator
implementation SHOULD compare the message digest of each digital
object to the value from the messageDigest field of the associated
FilenameAndHash, and report matches to the client for further
consideration.
7. Security Considerations
Relying parties are hereby warned that the data in a RPKI Signed
Checklist is self-asserted. When determining the meaning of any data
contained in an RPKI Signed Checklist, Relying Parties MUST NOT make
any assuptions about the signer beyond the fact that it had
sufficient control of the issuing CA to create the object. These
data have not been verified by the Certificate Authority (CA) that
issued the CA certificate to the entity that issued the EE
certificate used to validate the Signed Checklist.
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RPKI Certificates are not bound to real world identities, see
[I-D.ymbk-sidrops-rpki-has-no-identity] for an elaboration. Relying
Parties can only associate real world entities to Internet Number
Resources by additionally consulting an exogenous authority. Signed
Checklists are a tool to communicate assertions 'signed with Internet
Number Resources', not about any other aspect of the resource
holder's business operations such as the identity of the resource
holder itself.
RSC objects are not distributed through the global RPKI repository
system, so whether a given CA is making use of them is not
immediately apparent from the state of the repository. However,
because RSC objects depend on EE certificates, and because all
existing applications for EE certificates involve their publication
in the repository, an observer may be able to infer indirectly from
the state of the repository that RSC objects are in use. For
example, if the CA sets the serial number on a new EE certificate to
be one greater than the serial number used for the previous EE
certificate, then an observer could infer that RSCs are in use if
there is a gap between serial numbers used in published EE
certificates. Similarly, if the CA includes an unpublished serial
number in a CRL, an observer could infer that an RSC object has been
revoked.
8. Implementation status - RFC EDITOR: REMOVE BEFORE PUBLICATION
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.
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".
o A signer and validator implementation [rpki-rsc-demo] written in
Perl based on OpenSSL was provided by Tom Harrison from APNIC.
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o A signer implementation [rpkimancer] written in Python was
developed by Ben Maddison.
o Example .sig files were created by Job Snijders with the use of
OpenSSL.
o A validator implementation based on OpenBSD rpki-client and
LibreSSL was developed by Job Snijders.
o A validator implementation [FORT] based on the FORT validator was
developed by Alberto Leiva.
9. IANA Considerations
9.1. SMI Security for S/MIME CMS Content Type (1.2.840.113549.1.9.16.1)
The IANA has permanently allocated 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
---------------------------------------------------------------
48 id-ct-signedChecklist [draft-ietf-sidrops-rpki-rsc]
Upon publication of this document, IANA is requested to reference the
RFC publication instead of this draft.
9.2. RPKI Signed Objects sub-registry
The IANA is requested to register the OID for the RPKI Signed
Checklist in the registry created by [RFC6488] as following:
Name OID Specification
-------------------------------------------------------------
Signed Checklist 1.2.840.113549.1.9.16.1.48 [draft-ietf-sidrops-rpki-rsc]
9.3. File Extension
The IANA is requested to add an item for the Signed Checklist file
extension to the "RPKI Repository Name Scheme" registry created by
[RFC6481] as follows:
Filename Extension RPKI Object Reference
-----------------------------------------------------------------------
.sig Signed Checklist [draft-ietf-sidrops-rpki-rsc]
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9.4. SMI Security for S/MIME Module Identifier
(1.2.840.113549.1.9.16.0)
The IANA is requested to add an item to the "SMI Security for S/MIME
Module Identifier" registry as follows:
Decimal Description References
-------------------------------------------------------------------------
TBD id-mod-rpkiSignedChecklist-2021 [draft-ietf-sidrops-rpki-rsc]
9.5. Media Type
The IANA is requested to register the media type application/rpki-
checklist in the Provisional Standard Media Type registry as follows:
Type name: application
Subtype name: rpki-checklist
Required parameters: None
Optional parameters: None
Encoding considerations: binary
Security considerations: Carries an RPKI Signed Checklist
[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 list of
checksums as defined above in this document.
Magic number(s): None
File extension(s): .sig
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>
10. References
10.1. 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>.
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[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>.
[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>.
[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>.
[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>.
[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>.
[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>.
10.2. Informative References
[FORT] LACNIC and NIC.MX, "FORT", May 2021,
<https://github.com/NICMx/FORT-validator>.
[I-D.ietf-sidrops-rpki-rta]
Michaelson, G., Huston, G., Harrison, T., Bruijnzeels, T.,
and M. Hoffmann, "A profile for Resource Tagged
Attestations (RTAs)", draft-ietf-sidrops-rpki-rta-00 (work
in progress), January 2021.
[I-D.ymbk-sidrops-rpki-has-no-identity]
Bush, R. and R. Housley, "The I in RPKI does not stand for
Identity", draft-ymbk-sidrops-rpki-has-no-identity-00
(work in progress), March 2021.
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[POSIX] IEEE and The Open Group, "The Open Group's Base
Specifications, Issue 7", 2016,
<https://publications.opengroup.org/standards/unix/c165>.
[RFC1952] Deutsch, P., "GZIP file format specification version 4.3",
RFC 1952, DOI 10.17487/RFC1952, May 1996,
<https://www.rfc-editor.org/info/rfc1952>.
[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>.
[rpki-rsc-demo]
Harrison, T., "A proof-of-concept for constructing and
validating RPKI Signed Checklists (RSCs).", February 2021,
<https://github.com/APNIC-net/rpki-rsc-demo>.
[rpkimancer]
Maddison, B., "rpkimancer", May 2021,
<https://github.com/benmaddison/rpkimancer>.
[signify] Unangst, T. and M. Espie, "signify - cryptographically
sign and verify files", May 2014,
<https://man.openbsd.org/signify>.
Appendix A. Acknowledgements
The authors wish to thank George Michaelson, Tom Harrison, Geoff
Huston, Randy Bush, Stephen Kent, Matt Lepinski, Rob Austein, Ted
Unangst, and Marc Espie for prior art. The authors thank Russ
Housley for reviewing the ASN.1 notation and providing suggestions.
The authors would like to thank Nimrod Levy, Tim Bruijnzeels, and
Alberto Leiva for document review and suggestions.
Appendix B. Document changelog - RFC EDITOR: REMOVE BEFORE PUBLICATION
B.1. changes from -03 -> -04
o Alberto pointed out the asID validation also needs to be
documented.
B.2. changes from -02 -> -03
o Reference the IANA assigned OID
o Clarify validation rules
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B.3. changes from -01 -> -02
o Clarify RSC is part of a puzzle, not panacea. Thanks Randy & Russ
B.4. changes from -00 -> -01
o Readability improvements
o Update document category to match the registry allocation policy
requirement.
B.5. individual submission phase
o On-the-wire change: the 'Filename' switched from 'required' to
'optional'. Some SIDROPS Working Group participants proposed a
checksum itself is the most minimal information required to
address digital objects.
Authors' Addresses
Job Snijders
Fastly
Amsterdam
Netherlands
Email: job@fastly.com
Tom Harrison
Asia Pacific Network Information Centre
6 Cordelia St
South Brisbane, QLD 4101
Australia
Email: tomh@apnic.net
Ben Maddison
Workonline Communications
Cape Town
South Africa
Email: benm@workonline.africa
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