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Internet Engineering Task Force (IETF) J. Snijders
Request for Comments: 9323 Fastly
Category: Standards Track T. Harrison
ISSN: 2070-1721 APNIC
B. Maddison
Workonline
November 2022
A Profile for RPKI Signed Checklists (RSCs)
Abstract
This document defines a Cryptographic Message Syntax (CMS) protected
content type for use with the Resource Public Key Infrastructure
(RPKI) to carry a general-purpose listing of checksums (a
'checklist'). The objective is to allow for the creation of an
attestation, termed an "RPKI Signed Checklist (RSC)", which contains
one or more checksums of arbitrary digital objects (files) that are
signed with a specific set of Internet Number Resources. When
validated, an RSC confirms that the respective Internet resource
holder produced the RSC.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9323.
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
1.1. Requirements Language
2. RSC Profile and Distribution
2.1. RSC EE Certificates
3. The RSC eContentType
4. The RSC eContent
4.1. Version
4.2. Resources
4.2.1. ConstrainedASIdentifiers Type
4.2.2. ConstrainedIPAddrBlocks Type
4.3. digestAlgorithm
4.4. checkList
4.4.1. FileNameAndHash
5. RSC Validation
6. Verifying Files or Data Using RSC
7. Operational Considerations
8. Security Considerations
9. IANA Considerations
9.1. SMI Security for S/MIME CMS Content Type
(1.2.840.113549.1.9.16.1)
9.2. RPKI Signed Objects
9.3. RPKI Repository Name Schemes
9.4. SMI Security for S/MIME Module Identifier
(1.2.840.113549.1.9.16.0)
9.5. Media Types
10. References
10.1. Normative References
10.2. Informative References
Acknowledgements
Authors' Addresses
1. Introduction
This document defines a Cryptographic Message Syntax (CMS) [RFC5652]
[RFC6268] protected content type for a general-purpose listing of
checksums (a 'checklist'), for use with the Resource Public Key
Infrastructure (RPKI) [RFC6480]. The CMS protected content type is
intended to provide for the creation and validation of an RPKI Signed
Checklist (RSC), a checksum listing signed with a specific set of
Internet Number Resources. The objective is to allow for the
creation of an attestation that, when validated, provides a means to
confirm a given Internet resource holder produced the RSC.
RPKI Signed Checklists are expected to facilitate inter-domain
business use cases that 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 interconnections between Autonomous
Systems (ASes).
The RSC concept borrows heavily from Resource Tagged Attestation
(RTA) [RPKI-RTA], Manifests [RFC9286], and OpenBSD's signify utility
[signify]. The main difference between an 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 content of multiple digital objects. A
single signer profile is considered a simplification for both
implementers and operators.
1.1. 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.
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 End-Entity (EE)
certificate.
What constitutes suitable transport for RSC files is deliberately
unspecified. For example, it might be a USB stick, a web interface
secured with HTTPS, an email signed with Pretty Good Privacy (PGP), a
T-shirt printed with a QR code, or a carrier pigeon.
2.1. RSC EE Certificates
The Certification Authority (CA) MUST only sign one RSC with each EE
certificate and MUST generate a new key pair for each new RSC. This
type of EE certificate is termed a "one-time-use" EE certificate (see
Section 3 of [RFC6487]).
3. The RSC eContentType
The eContentType for an RSC is defined as id-ct-signedChecklist, with
Object Identifier (OID) 1.2.840.113549.1.9.16.1.48.
This OID MUST appear within both the eContentType in the
encapContentInfo object and 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 a specific set of Internet
Number Resources. An RSC is formally defined as follows:
RpkiSignedChecklist-2022
{ iso(1) member-body(2) us(840) rsadsi(113549)
pkcs(1) pkcs9(9) smime(16) mod(0)
id-mod-rpkiSignedChecklist-2022(73) }
DEFINITIONS EXPLICIT TAGS ::=
BEGIN
IMPORTS
CONTENT-TYPE, Digest, DigestAlgorithmIdentifier
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, ASIdOrRange
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 PortableFilename OPTIONAL,
hash Digest }
PortableFilename ::=
IA5String (FROM("a".."z" | "A".."Z" | "0".."9" | "." | "_" | "-"))
ResourceBlock ::= SEQUENCE {
asID [0] ConstrainedASIdentifiers OPTIONAL,
ipAddrBlocks [1] ConstrainedIPAddrBlocks OPTIONAL }
-- at least one of asID or ipAddrBlocks MUST be present
( WITH COMPONENTS { ..., asID PRESENT} |
WITH COMPONENTS { ..., ipAddrBlocks PRESENT } )
ConstrainedIPAddrBlocks ::=
SEQUENCE (SIZE(1..MAX)) OF ConstrainedIPAddressFamily
ConstrainedIPAddressFamily ::= SEQUENCE {
addressFamily OCTET STRING (SIZE(2)),
addressesOrRanges SEQUENCE (SIZE(1..MAX)) OF IPAddressOrRange }
ConstrainedASIdentifiers ::= SEQUENCE {
asnum [0] SEQUENCE (SIZE(1..MAX)) OF ASIdOrRange }
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 be a subset of the set of resources listed by
the EE certificate carried in the CMS certificates field.
If the asID field is present, it MUST contain an instance of
ConstrainedASIdentifiers.
If the ipAddrBlocks field is present, it MUST contain an instance of
ConstrainedIPAddrBlocks.
At least one of asID or ipAddrBlocks MUST be present.
ConstrainedASIdentifiers and ConstrainedIPAddrBlocks are specified
such that the resulting DER-encoded data instances are binary
compatible with ASIdentifiers and IPAddrBlocks (defined in
[RFC3779]), respectively.
Implementations encountering decoding errors whilst attempting to
read DER-encoded data using this specification should be aware of the
possibility that the data may have been encoded using an
implementation intended for use with [RFC3779]. Such data may
contain elements prohibited by the current specification.
Attempting to decode the errored data using the more permissive
specification contained in [RFC3779] may enable implementors to
gather additional context for use when reporting errors to the user.
However, implementations MUST NOT ignore errors resulting from the
more restrictive definitions contained herein; in particular, such
errors MUST cause the validation procedure described in Section 5 to
fail.
4.2.1. ConstrainedASIdentifiers Type
ConstrainedASIdentifiers is a SEQUENCE consisting of a single field,
asnum, which in turn contains a SEQUENCE OF one or more ASIdOrRange
instances as defined in [RFC3779].
ConstrainedASIdentifiers is defined such that the resulting DER-
encoded data are binary compatible with ASIdentifiers defined in
[RFC3779].
4.2.2. ConstrainedIPAddrBlocks Type
ConstrainedIPAddrBlocks is a SEQUENCE OF one or more instances of
ConstrainedIPAddressFamily.
There MUST be only one instance of ConstrainedIPAddressFamily per
unique Address Family Identifier (AFI).
The elements of ConstrainedIPAddressFamily MUST be ordered by
ascending addressFamily values (treating the octets as unsigned
numbers). Thus, when both IPv4 and IPv6 addresses are specified, the
IPv4 addresses MUST precede the IPv6 addresses (since the IPv4 AFI of
0001 is less than the IPv6 AFI of 0002).
ConstrainedIPAddrBlocks is defined such that the resulting DER-
encoded data are binary compatible with IPAddrBlocks defined in
[RFC3779].
4.2.2.1. ConstrainedIPAddressFamily Type
4.2.2.1.1. addressFamily Field
The addressFamily field is an OCTET STRING containing a 2-octet AFI,
in network byte order. Unlike IPAddrBlocks [RFC3779], a third octet
containing a Subsequent Address Family Identifier (SAFI) MUST NOT be
present. AFIs are specified in the "Address Family Numbers" registry
[IANA.ADDRESS-FAMILY-NUMBERS] maintained by IANA.
4.2.2.1.2. addressesOrRanges Field
The addressesOrRanges element is a SEQUENCE OF one or more
IPAddressOrRange values, as defined in [RFC3779]. The rules for
canonicalization and encoding defined in Section 2.2.3.6 of [RFC3779]
apply to the value of addressesOrRanges.
4.3. digestAlgorithm
The digest algorithm is used to create the message digest of the
attested digital object(s). This algorithm MUST be a hashing
algorithm defined in [RFC7935].
4.4. checkList
This field is a SEQUENCE OF one or more FileNameAndHash values.
There is one FileNameAndHash entry for each digital object referenced
on the RSC.
4.4.1. FileNameAndHash
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 hash field is mandatory. The value of the hash field is the
calculated message digest of the digital object. The hashing
algorithm is specified in the digestAlgorithm field.
The fileName field is OPTIONAL. This is to allow RSCs to be used in
a "stand-alone" fashion in which nameless digital objects are
addressed directly through their respective message digest rather
than through a file system abstraction.
If the fileName field is present, then its value:
* MUST contain only characters specified in the Portable Filename
Character Set as defined in [POSIX].
* MUST be unique with respect to the other FileNameAndHash elements
of checkList for which the fileName field is also present.
Conversely, if the fileName field is omitted, then the value of the
hash field MUST be unique with respect to the other FileNameAndHash
elements of checkList for which the fileName field is also omitted.
5. RSC Validation
Before a Relying Party (RP) can use an RSC to validate a set of
digital objects, the RP MUST first validate the RSC. To validate an
RSC, the RP MUST perform all the validation checks specified in
[RFC6488], except for checking for the presence of an SIA extension,
which MUST NOT be present in the EE certificate (see Section 2). In
addition, the RP MUST perform the following RSC-specific validation
steps:
1. The contents of the CMS eContent field MUST conform to all of the
constraints described in Section 4, including the constraints
described in Section 4.4.1.
2. If the asID field is present within the contents of the resources
field, then the AS identifier delegation extension [RFC3779] MUST
be present in the EE certificate contained in the CMS
certificates field. The AS identifiers present in the eContent
resources field MUST be a subset of those present in the
certificate extension. The EE certificate's AS identifier
delegation extension MUST NOT contain "inherit" elements.
3. If the ipAddrBlocks field is present within the contents of the
resources field, then the IP address delegation extension
[RFC3779] MUST be present in the EE certificate contained in the
CMS certificates field. The IP addresses present in the eContent
resources field MUST be a subset of those present in the
certificate extension. The EE certificate's IP address
delegation extension MUST NOT contain "inherit" elements.
6. Verifying Files or Data Using RSC
To verify a set of digital objects with an RSC:
* The RSC MUST be validated according to the procedure described in
Section 5. If the RSC cannot be validated, verification MUST
fail. This error SHOULD be reported to the user.
* For every digital object to be verified:
1. If the verification procedure is provided with a filename for
the object being verified (e.g., because the user has provided
a file system path from which to read the object), then
verification SHOULD proceed in "filename-aware" mode.
Otherwise, verification SHOULD proceed in "filename-unaware"
mode.
Implementations MAY provide an option to override the
verification mode, for example, to ignore the fact that the
object is to be read from a file.
2. The message digest MUST be computed from the file contents or
data using the digest algorithm specified in the
digestAlgorithm field of the RSC.
3. The digest computed in Step 2 MUST be compared to the value
appearing in the hash field of all FileNameAndHash elements of
the checkList field of the RSC.
One or more FileNameAndHash elements MUST be found with a
matching hash value; otherwise, verification MUST fail, and
the error SHOULD be reported to the user.
4. If the mode selected in Step 1 is "filename-aware", then
exactly one of the FileNameAndHash elements matched in Step 3
MUST contain a fileName field value exactly matching the
filename of the object being verified.
Alternatively, if the mode selected in Step 1 is "filename-
unaware", then exactly one of the FileNameAndHash elements
matched in Step 3 MUST have the fileName field omitted.
Otherwise, verification MUST fail, and the error SHOULD be
reported to the user.
Note that in the above procedure, not all elements of checkList
necessarily need be used. That is, it is not an error if the length
of checkList is greater than the size of the set of digital objects
to be verified. However, in this situation, implementations SHOULD
issue a warning to the user, allowing for corrective action to be
taken if necessary.
7. Operational Considerations
When creating digital objects of a plain-text nature (such as ASCII,
UTF-8, HTML, Javascript, and XML), converting such objects into a
lossless compressed form is RECOMMENDED. 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
a string of arbitrary single octets.
If a fileName field is present, but no digital object within the set
of to-be-verified digital objects 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 hash
field of the associated FileNameAndHash and report matches to the
user for further consideration.
8. Security Considerations
RPs are hereby warned that the data in an RSC is self-asserted. When
determining the meaning of any data contained in an RSC, RPs MUST NOT
make any assumptions 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 RSC.
RPKI certificates are not bound to real-world identities; see
[RFC9255] for an elaboration. RPs can only associate real-world
entities to Internet Number Resources by additionally consulting an
exogenous authority. RSCs are a tool to communicate assertions
signed with Internet Number Resources and do not communicate 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 RPKI repository system.
From this, it follows that third parties who do not have a copy of a
given RSC may not be aware of the existence of that RSC. Since RSC
objects use EE certificates but all other currently defined types of
RPKI object profiles are published in public CA repositories, an
observer may infer from discrepancies in the repository that RSC
object(s) may exist. For example, if a CA does not use random serial
numbers for certificates, an observer could detect gaps between the
serial numbers of the published EE certificates. Similarly, if the
CA includes a serial number on a Certificate Revocation List (CRL)
that does not match any published object, an observer could postulate
that an RSC EE certificate was revoked.
Conversely, a gap in serial numbers does not imply that an RSC
exists. Nor does the presence in a CRL of a serial number unknown to
the RP imply an RSC object exists: the implicitly referenced object
might not be an RSC, it might have never been published, or it may
have been revoked before it was visible to RPs. In general, it is
not possible to confidently infer the existence or non-existence of
RSCs from the repository state without access to a given RSC.
While a one-time-use EE certificate must only be used to generate and
sign a single RSC object, CAs technically are not restricted from
generating and signing multiple different RSC objects with a single
key pair. Any RSC objects sharing the same EE certificate cannot be
revoked individually.
9. IANA Considerations
9.1. SMI Security for S/MIME CMS Content Type (1.2.840.113549.1.9.16.1)
IANA has allocated the following 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 | RFC 9323 |
+---------+-----------------------+------------+
Table 1
9.2. RPKI Signed Objects
IANA has registered the OID for the RSC in the "RPKI Signed Objects"
registry [RFC6488] as follows:
+==================+============================+===========+
| Name | OID | Reference |
+==================+============================+===========+
| Signed Checklist | 1.2.840.113549.1.9.16.1.48 | RFC 9323 |
+------------------+----------------------------+-----------+
Table 2
9.3. RPKI Repository Name Schemes
IANA has added the Signed Checklist file extension to the "RPKI
Repository Name Schemes" registry [RFC6481] as follows:
+====================+==================+===========+
| Filename Extension | RPKI Object | Reference |
+====================+==================+===========+
| .sig | Signed Checklist | RFC 9323 |
+--------------------+------------------+-----------+
Table 3
9.4. SMI Security for S/MIME Module Identifier
(1.2.840.113549.1.9.16.0)
IANA has allocated the following in the "SMI Security for S/MIME
Module Identifier (1.2.840.113549.1.9.16.0)" registry:
+=========+=================================+============+
| Decimal | Description | References |
+=========+=================================+============+
| 73 | id-mod-rpkiSignedChecklist-2022 | RFC 9323 |
+---------+---------------------------------+------------+
Table 4
9.5. Media Types
IANA has registered the media type "application/rpki-checklist" in
the "Media Types" registry as follows:
Type name: application
Subtype name: rpki-checklist
Required parameters: N/A
Optional parameters: N/A
Encoding considerations: binary
Security considerations: Carries an RPKI Signed Checklist. This
media type contains no active content. See Section 5 of RFC 9323
for further information.
Interoperability considerations: N/A
Published specification: RFC 9323
Applications that use this media type: RPKI operators
Fragment identifier considerations: N/A
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 in RFC 9323.
Magic number(s): N/A
File extension(s): .sig
Macintosh file type code(s): N/A
Person & email address to contact for further information: Job
Snijders (job@fastly.com)
Intended usage: COMMON
Restrictions on usage: N/A
Author: Job Snijders (job@fastly.com)
Change controller: IETF
10. References
10.1. Normative References
[POSIX] IEEE and The Open Group, "Base Specifications", Issue 7,
DOI 10.1109/IEEESTD.2016.7582338, 2016,
<https://publications.opengroup.org/standards/unix/c165>.
[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>.
[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>.
[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>.
[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>.
[RFC9286] Austein, R., Huston, G., Kent, S., and M. Lepinski,
"Manifests for the Resource Public Key Infrastructure
(RPKI)", RFC 9286, DOI 10.17487/RFC9286, June 2022,
<https://www.rfc-editor.org/info/rfc9286>.
10.2. Informative References
[IANA.ADDRESS-FAMILY-NUMBERS]
IANA, "Address Family Numbers",
<https://www.iana.org/assignments/address-family-numbers>.
[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>.
[RFC6268] Schaad, J. and S. Turner, "Additional New ASN.1 Modules
for the Cryptographic Message Syntax (CMS) and the Public
Key Infrastructure Using X.509 (PKIX)", RFC 6268,
DOI 10.17487/RFC6268, July 2011,
<https://www.rfc-editor.org/info/rfc6268>.
[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>.
[RFC9255] Bush, R. and R. Housley, "The 'I' in RPKI Does Not Stand
for Identity", RFC 9255, DOI 10.17487/RFC9255, June 2022,
<https://www.rfc-editor.org/info/rfc9255>.
[RPKI-RTA] Michaelson, G., Huston, G., Harrison, T., Bruijnzeels, T.,
and M. Hoffman, "A profile for Resource Tagged
Attestations (RTAs)", Work in Progress, Internet-Draft,
draft-ietf-sidrops-rpki-rta-00, 17 January 2021,
<https://datatracker.ietf.org/doc/html/draft-ietf-sidrops-
rpki-rta-00>.
[signify] Unangst, T. and M. Espie, "signify - cryptographically
sign and verify files", <https://man.openbsd.org/signify>.
Acknowledgements
The authors wish to thank George Michaelson, 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, Alberto Leiva, Ties de Kock,
Peter Peele, Claudio Jeker, Theo Buehler, Donald Eastlake 3rd, Erik
Kline, Robert Wilton, Roman Danyliw, Éric Vyncke, Lars Eggert, Paul
Wouters, and Murray S. Kucherawy for document review and suggestions.
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