RPKI signed object for TAL
draft-ietf-sidrops-signed-tal-01
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (sidrops WG) | |
|---|---|---|---|
| Authors | Tim Bruijnzeels , Carlos M. MartÃnez | ||
| Last updated | 2018-06-08 | ||
| Replaces | draft-tbruijnzeels-sidrops-signed-tal | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text xml htmlized pdfized bibtex | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-sidrops-signed-tal-01
Network Working Group T. Bruijnzeels
Internet-Draft NLnet Labs
Intended status: Best Current Practice C. Martinez
Expires: December 10, 2018 LACNIC
June 8, 2018
RPKI signed object for TAL
draft-ietf-sidrops-signed-tal-01
Abstract
Trust Anchor Locators (TALs) [I-D.ietf-sidrops-https-tal] are used by
Relying Parties in the RPKI to locate and validate Trust Anchor
certificates used in RPKI validation. This document defines an RPKI
signed object [RFC6488] for a Trust Anchor Locator (TAL) that can be
used by Trust Anchors to perform a planned migration to a new key,
allowing Relying Parties to discover the new key up to one year after
the migration occurred.
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 December 10, 2018.
Copyright Notice
Copyright (c) 2018 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
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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. Requirements notation . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Signed TAL definition . . . . . . . . . . . . . . . . . . . . 3
3.1. The Signed TAL Content Type . . . . . . . . . . . . . . . 4
3.2. The Signed TAL eContent . . . . . . . . . . . . . . . . . 4
3.2.1. version . . . . . . . . . . . . . . . . . . . . . . . 4
3.2.2. activationTime . . . . . . . . . . . . . . . . . . . 4
3.2.3. certificateURIs . . . . . . . . . . . . . . . . . . . 4
3.2.4. subjectPublicKeyInfo . . . . . . . . . . . . . . . . 4
3.3. Signed TAL Validation . . . . . . . . . . . . . . . . . . 5
4. Signed TAL Generation . . . . . . . . . . . . . . . . . . . . 5
5. Signed TAL Publication . . . . . . . . . . . . . . . . . . . 6
6. Performing a planned Key Roll as a Trust Anchor . . . . . . . 6
6.1. Prepare a new Trust Anchor key and CA certificate . . . . 7
6.2. Publish the new CA certificate . . . . . . . . . . . . . 7
6.3. Verify the validity of the new CA certificate . . . . . . 7
6.4. Publish the objects under the current key under the new
key . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.5. Verify that the validity of objects under the new key . . 7
6.6. Publish a Signed TAL as the only object under the current
key . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.7. Delete the current key . . . . . . . . . . . . . . . . . 8
7. Relying Party Use . . . . . . . . . . . . . . . . . . . . . . 8
8. Deployment Considerations . . . . . . . . . . . . . . . . . . 8
9. Unplanned Key Roll operations . . . . . . . . . . . . . . . . 9
10. Changing a Trust Anchor Certificate URIs . . . . . . . . . . 9
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
11.1. OID . . . . . . . . . . . . . . . . . . . . . . . . . . 9
11.2. File Extension . . . . . . . . . . . . . . . . . . . . . 10
12. Security Considerations . . . . . . . . . . . . . . . . . . . 10
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
14.1. Normative References . . . . . . . . . . . . . . . . . . 10
14.2. Informative References . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Requirements notation
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
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14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Introduction
Trust Anchor Locators (TALs) [I-D.ietf-sidrops-https-tal] are used by
Relying Parties in the RPKI to locate and validate Trust Anchor
certificates used in RPKI validation. This document defines an RPKI
signed object [RFC6488] for a Trust Anchor Locator (TAL) that can be
used by Trust Anchors to perform a planned migration to a new key,
allowing Relying Parties to discover the new key up to one year after
the migration occurred. (Note "one year" is arbitrary, and may be
changed in a future version of this document)
Note that [RFC5011] describes Automated Updates of DNS Security
(DNSSEC) Trust Anchors and can provide some useful insight here as
well. However, concepts like a set of Trust Anchors, standby Trust
Anchors, and TTLs are not applicable to the RPKI. Therefore, an
alternative approach based on already existing concept of the Trust
Anchor Locator [I-D.ietf-sidrops-https-tal], and top-down validation
of an RPKI Trust Anchor certificate tree, where objects are retrieved
from the RPKI repositories, is appropriate.
3. Signed TAL definition
The Signed TAL makes use of the template for RPKI digitally signed
objects [RFC6488], which defines a Crytopgraphic Message Syntax (CMS)
[RFC5652] wrapper for the Signed TAL content as well as a generic
validation procedure for RPKI signed objects. Therefore, to complete
the specification of the Signed TAL (see Section 4 of [RFC6488]),
this document defines:
o The OID defined in Section 3.1 that identifies the signed object
as being a Signed TAL. (This OID appears within the eContentType
in the encapContentInfo object as well as the content-type signed
attribute in the signerInfo object).
o The ASN.1 syntax for the Signed TAL eContent defined in
Section 3.2. (This is the payload that specifies the AS being
authorized to originate routes as well as the prefixes to which
the AS may originate routes.)
o Additional steps to the validation steps specified in [RFC6488]
required to validate Signed TALs, defined in Section 3.3.
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3.1. The Signed TAL Content Type
This document requests an OID for signed-Tal as follows:
signed-Tal OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
rsadsi(113549) pkcs(1) pkcs9(9) 16 id-smime (1) TBD }
This OID MUST appear both within the eContentType in the
encapContentInfo object as well as the content-type signed attribute
in the signerInfo object (see [RFC6488])
3.2. The Signed TAL eContent
The content of a Signed TAL is ASN.1 encoded using the Distinguished
Encoding Rules (DER) [X.690], and is defined as follows:
SignedTAL ::= SEQUENCE {
version [0] INTEGER DEFAULT 0,
activationTime GeneralizedTime,
certificateURIs SEQUENCE SIZE (1..MAX) OF CertificateURI,
subjectPublicKeyInfo SubjectPublicKeyInfo }
CertificateURI ::= IA5String
SubjectPublicKeyInfo ::= IA5String
3.2.1. version
The version number of the SignedTAL MUST be 0.
3.2.2. activationTime
This field contains the time when this TAL is intended to replace any
previously known TAL for this Trust Anchor.
3.2.3. certificateURIs
This field is equivalent to the URI section in section 2.1 of
[I-D.ietf-sidrops-https-tal]. It MUST contain at least one
CertificateURI element. Each CertificateURI element contains the
IA5String representation of either an rsync URI [RFC5781], or an
HTTPS URI [RFC7230].
3.2.4. subjectPublicKeyInfo
This field is equivalent to the subjectPublicKeyInfo section in
section 2.1 of [I-D.ietf-sidrops-https-tal].
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3.3. Signed TAL Validation
To determine whether a Signed TAL is valid, the RP MUST perform the
following steps in addition to those specified in [RFC6488]:
o The eContentType OID matches the OID described in Section 3.1
o The Signed TAL appears as the product of a Trust Anchor CA
certificate.
o This Trust Anchor CA has published only one Signed TAL object in
its repository, and this object appears on the Manifest as the
only entry using the ".tal" extension (see [RFC6481]). In case
more than one Signed TAL object is found, all such objects MUST be
considered invalid.
o The EE certificate of this Signed TAL describes its Internet
Number Resources (INRs) using the "inherit" attribute
o The decoded TAL content conforms to the format defined in
Section 3.2.
If the above procedure indicates that the manifest is invalid, then
the Signed TAL MUST be discarded and treated as though no Signed TAL
were present.
4. Signed TAL Generation
A TA MAY choose to generate a single Singed TAL object to publish in
its TA certificate publication point(s) in the RPKI. The TA MUST
perform the following steps to generate the Signed TAL:
o Generate a key pair for a "one-time-use" EE certificate to use for
the Signed TAL
o Generate a one-time-use EE certificate for the Signed TAL
o This EE certificate MUST have an SIA extension access description
field with an accessMethod OID value of id-ad-signedobject, where
the associated accessLocation references the publication point of
the Sigend TAL as an object URL.
o As described in [RFC6487], an [RFC3779] extension is required in
the EE certificate used for this object. However, because the
resource set is irrelevant to this object type, this certificate
MUST describe its Internet Number Resources (INRs) using the
"inherit" attribute, rather than explicit description of a
resource set.
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o This EE certificate MUST have a "notBefore" time that is before
the moment that the Signed TAL will be published.
o This EE certificate MUST have a "notAfter" time that reflects the
intended time that this Signed TAL will be published. If the EE
certificate for a Signed TAL is expired, it MUST no longer be
publish, but of course it MAY be replaced by a newly generated
Signed TAL object with similar content and an updated "notAfter"
time.
o The Signed TAL MUST have an "activationTime" that reflects when
Relying Parties MUST use use this new TAL in place of any
previously known TAL for this Trust Anchor.
5. Signed TAL Publication
A TA MAY publish a single Signed TAL object directly under its CA
repository publication points. The TA MUST NOT publish multiple
Signed TAL objects at any time. It is RECOMMENDED that a TA
publishes a Signed TAL object for its current key and CA certificate
publication URIs at all times.
A non-normative guideline for naming this object is that the filename
chosen for the signed TAL in the publication repository be a value
derived from the public key part of the entity's key pair, using the
algorithm described for CRLs in section 2.2 of [RFC6481] for
generation of filenames. The filename extension of ".tal" MUST be
used to denote the object as a signed TAL. Note that this is in-line
with filename extensions defined in section 7.2 of [RFC6481]
6. Performing a planned Key Roll as a Trust Anchor
A Signed TAL SHOULD be used to communicate a planned key roll by a
Trust Anchor. From the Trust Anchor perspective a planned key roll
consists of the following steps:
o Prepare a new Trust Anchor key and CA certificate, see Section 6.1
o Publish the new CA certificate, see Section 6.2
o Verify the validity of the new CA certificate, see Section 6.3
o Publish the objects under the current key under the new key, see
Section 6.4
o Verify that the validity of objects under the new key, see
Section 6.5
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o Publish a Signed TAL as the only object under the current key, see
Section 6.6
o Delete the current key, see Section 6.7
6.1. Prepare a new Trust Anchor key and CA certificate
The Trust Anchors MUST a new key pair and generate a new TA
Certificate. For the Subject Information Access (see section 4.8.8.1
of [RFC6487]) this MUST use URIs that will be used by the new key to
publish objects. These URIs MUST be uniqe for use by this new key
only. The Internet Number Resources on this new certificate MUST be
equivalent to those found on the current certificate.
6.2. Publish the new CA certificate
The new CA certificate MUST be published under one or more new
Certificate URIs for use by this new key only.
6.3. Verify the validity of the new CA certificate
The Trust Anchor MUST generate a new (unsigned) TAL file
[I-D.ietf-sidrops-https-tal] and verify with RP software that the new
Trust Anchor certificate can be retrieved from all locations and that
it matches the subjectPublicKeyInfo
6.4. Publish the objects under the current key under the new key
ALL current signed certificates and other objects, with the exception
of the CRL, Manifest and existing Signed TAL, must be re-issued by
the new key and published under the new publication point(s).
It is RECOMMENDED that a new Signed TAL object is generated and
published, listing the Certificate URIs for this new key, the
subjectPublicKeyInfo of this new key, and using an "activationTime"
that is effective immediately. Note that Relying Parties will not
discover this new Signed TAL object until they have effectively
switched over from the current key.
6.5. Verify that the validity of objects under the new key
The Trust Anchor MUST verify that validation using the new TAL file
generated in Section 6.3 results in the set of valid objects as when
the current TAL file is used.
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6.6. Publish a Signed TAL as the only object under the current key
The Trust Anchor MUST publish a new Signed TAL, CRL and Manifest as
the only objects under the current, to be deleted, key. The
"nextUpdate" values of the Manifest and CRL objects SHOULD use a date
that is set at least one year into the future. (arbitrary value, open
to suggestions). The "notValidAfter" date on the Manifest and Signed
TAL EE certificate SHOULD use this same date. The Trust Anchor MUST
ensure that this Signed TAL, CRL and Manifest remain available for
download for this full period. Note that this is done to give RPs
the opportunity to discover the new key up to one year after the key
roll occurred.
6.7. Delete the current key
As the final step the current key, which has been replaced now,
SHOULD be deleted. The new key can now be marked as the current key.
7. Relying Party Use
When an RP discovers a valid Signed TAL signed under a TA, and it
notices that the "subjectPublicKeyInfo" has changed and/or the set of
"Certificate URIs" has changed from the values it knew for this TA,
and the "activationTime" is in the past, then the RP MUST accept
these new values for this TA, abort the current top-down validation
operation, and initiate a new top-down validation operation using the
updated information.
Note that the Trust Anchor MUST have verified that all objects are
available under the new key (Section 6.5) and that that the TA CA
certificate can be retrieved and validated for all new URIs
(Section 6.3).
8. Deployment Considerations
Including Signed TAL objects while RP tools do not support this
standard will result in these RPs rejecting these objects. It is not
expected that this will result in the invalidation of any other
object under a Trust Anchor.
That said, the flagging mechanism introduced here can only be trusted
on once a majority of RPs support it. Defining when that moment
arrives is by definition something that cannot be established at the
time of writing this document.
However, once the majority of RPs support this mechanism it would be
RECOMMENDED that Trust Anchor operators perform key rolls regularly.
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The most assured way to know that such planned rolls will work is by
making them a part of normal operations.
9. Unplanned Key Roll operations
The mechanism described in this document is not applicable to
uplanned key rolls. Unplanned key rolls could theoretically be
supported by a mechanism where a new key is introduced before it's
used, with the power to revoke the current key. This would have to
be signalled from the new key, as the TA may have lost access to its
current key.
However, this introduces a great amount of operational complexity as
well as a new vulnerability: an adversary would need access to only
one of these keys in order to compromise a TA.
With that in mind we believe, for now, that unplanned key rolls
should not be covered here, and would need to be communicated to
Relying Parties in some other out-of-band fashion.
10. Changing a Trust Anchor Certificate URIs
Earlier versions of this document included a description of how
Signed TAL objects could be used to signal a change of Certificate
URIs only; i.e. where the key is not changed.
However, Relying Parties that do not support the mechanism described
in this document would not be able to learn about the changes in
URIs. While for RPs that do support this mechanism a planned key
roll will be a normal part of RPKI validation.
Therefore we believe that a planned key roll should be used in cases
like this, and that the set of Certificate URIs for any given key
must never be changed.
11. IANA Considerations
11.1. OID
IANA is to add the following to the "RPKI Signed Objects" registry:
Decimal | Description | References
--------+--------------------------------+---------------
TBD | signed-Tal | [section 3.1]
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11.2. File Extension
IANA is to add an item for the Signed TAL file extension to the "RPKI
Repository Name Scheme" created by [RFC6481] as follows:
Extension | RPKI Object | References
-----------+-------------------------------------------
.tal | Signed TAL | [this document]
12. Security Considerations
TBD
13. Acknowledgements
TBD
14. References
14.1. Normative References
[I-D.ietf-sidrops-https-tal]
Huston, G., Weiler, S., Michaelson, G., Kent, S., and T.
Bruijnzeels, "Resource Public Key Infrastructure (RPKI)
Trust Anchor Locator", draft-ietf-sidrops-https-tal-03
(work in progress), June 2018.
[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>.
[RFC5011] StJohns, M., "Automated Updates of DNS Security (DNSSEC)
Trust Anchors", STD 74, RFC 5011, DOI 10.17487/RFC5011,
September 2007, <https://www.rfc-editor.org/info/rfc5011>.
[RFC5781] Weiler, S., Ward, D., and R. Housley, "The rsync URI
Scheme", RFC 5781, DOI 10.17487/RFC5781, February 2010,
<https://www.rfc-editor.org/info/rfc5781>.
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[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>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<https://www.rfc-editor.org/info/rfc7230>.
[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>.
[X.690] ITU-T Recommendation X.690 (2002) | ISO/IEC 8825-1:2002,
"Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER), Canonical
Encoding Rules (CER) and Distinguished Encoding Rules
(DER)", 2002.
14.2. Informative References
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, DOI 10.17487/RFC5652, September 2009,
<https://www.rfc-editor.org/info/rfc5652>.
Authors' Addresses
Tim Bruijnzeels
NLnet Labs
Email: tim@nlnetlabs.nl
URI: https://www.nlnetlabs.nl/
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Carlos Martinez
LACNIC
Email: carlos@lacnic.net
URI: https://www.lacnic.net/
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