Constrained Voucher Profile for Bootstrapping Protocols
draft-richardson-anima-ace-constrained-voucher-02
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
|
|
|---|---|---|---|
| Author | Michael Richardson | ||
| Last updated | 2017-12-11 | ||
| Replaced by | draft-ietf-anima-constrained-voucher, draft-ietf-anima-constrained-voucher, draft-ietf-anima-constrained-voucher | ||
| RFC stream | (None) | ||
| Formats | |||
| Additional resources | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
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| Send notices to | (None) |
draft-richardson-anima-ace-constrained-voucher-02
6tisch Working Group M. Richardson
Internet-Draft Sandelman Software Works
Intended status: Informational December 11, 2017
Expires: June 14, 2018
Constrained Voucher Profile for Bootstrapping Protocols
draft-richardson-anima-ace-constrained-voucher-02
Abstract
This document defines a strategy to securely assign a pledge to an
owner, using an artifact signed, directly or indirectly, by the
pledge's manufacturer. This artifact is known as a "voucher".
This document builds upon the work in [I-D.ietf-anima-voucher],
encoding the resulting artifact in CBOR. Use with two signature
technologies are described.
Additionally, this document explains how constrained vouchers may be
transported in the [I-D.vanderstok-ace-coap-est] protocol.
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 June 14, 2018.
Copyright Notice
Copyright (c) 2017 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
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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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
4. Survey of Voucher Types . . . . . . . . . . . . . . . . . . . 3
5. Artifacts . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5.1. Voucher Request artifact . . . . . . . . . . . . . . . . 4
5.1.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 4
5.1.2. SID values . . . . . . . . . . . . . . . . . . . . . 5
5.1.3. YANG Module . . . . . . . . . . . . . . . . . . . . . 5
5.1.4. Example voucher request artifacts . . . . . . . . . . 6
5.2. Voucher artifact . . . . . . . . . . . . . . . . . . . . 6
5.3. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 7
5.4. SID values . . . . . . . . . . . . . . . . . . . . . . . 7
5.5. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 7
5.5.1. Example voucher artifacts . . . . . . . . . . . . . . 9
5.6. CMS format voucher and voucher-request artifacts . . . . 9
5.7. COSE format voucher and voucher-request artifacts . . . . 10
6. Design Considerations . . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7.1. Clock Sensitivity . . . . . . . . . . . . . . . . . . . . 10
7.2. Protect Voucher PKI in HSM . . . . . . . . . . . . . . . 10
7.3. Test Domain Certificate Validity when Signing . . . . . . 10
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 11
8.2. The YANG Module Names Registry . . . . . . . . . . . . . 11
8.3. The SMI Security for S/MIME CMS Content Type Registry . . 11
8.4. The SID registry . . . . . . . . . . . . . . . . . . . . 11
8.5. CoAP Content-Type . . . . . . . . . . . . . . . . . . . . 12
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
10.1. Normative References . . . . . . . . . . . . . . . . . . 12
10.2. Informative References . . . . . . . . . . . . . . . . . 13
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
Enrollment of new nodes into constrained networks with constrained
nodes present unique challenges.
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There are bandwidth and code space issues to contend. A solution
such as [I-D.ietf-anima-bootstrapping-keyinfra] may be too large in
terms of code space or bandwidth required.
This document defines a constrained version of
[I-D.ietf-anima-voucher]. Rather than serializing the YANG
definition in JSON, it is serialized into CBOR ([RFC7049]).
This document follows a similar, but not identical structure as
[I-D.ietf-anima-voucher]. Some sections are left out entirely.
The CBOR definitions for this constrained voucher format are defined
using the mechanism describe in [I-D.ietf-core-yang-cbor] using the
SID mechanism explained in [I-D.ietf-core-sid]. As the tooling to
convert YANG documents into an list of SID keys is still in its
infancy, the table of SID values presented here should be considered
normative rather than the output of the pyang tool.
Two methods of signing the resulting CBOR object are described in
this document. One is CMS [RFC5652]. The other is COSE [RFC8152]
signatures.
2. Terminology
The following terms are defined in [I-D.ietf-anima-voucher], and are
used identically as in that document: artifact, imprint, domain, Join
Registrar/Coordinator (JRC), Manufacturer Authorized Signing
Authority (MASA), pledge, Trust of First Use (TOFU), and Voucher.
3. Requirements Language
In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119
[RFC2119] and indicate requirement levels for compliant STuPiD
implementations.
4. Survey of Voucher Types
[I-D.ietf-anima-voucher] provides for vouchers that assert proximity,
that authenticate the registrar and that include different amounts of
anti-replay protection.
This document does not make any extensions to the types of vouchers.
Time based vouchers are included in this definition, but given that
constrained devices are extremely unlikely to know the correct time,
their use is very unlikely. Most users of these constrained vouchers
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will be online and will use live nonces to provide anti-replay
protection.
[I-D.ietf-anima-voucher] defined only the voucher artifact, and not
the Voucher Request artifact, which was defined in
[I-D.ietf-anima-bootstrapping-keyinfra].
This document defines both a constrained voucher and a constrained
voucher-request. They are presented in the order voucher-request,
followed by voucher response as this is the time order that they
occur.
5. Artifacts
This section describes the abstract (tree) definition as explained in
[I-D.ietf-netmod-yang-tree-diagrams] first. This provides a high-
level view of the contents of each artifact.
Then the assigned SID values are presented. These have been assigned
using the rules in [I-D.ietf-core-yang-cbor], with an allocation that
was made via the http://comi.space service. ((EDNOTE: it is unclear
if there is further IANA work))
5.1. Voucher Request artifact
5.1.1. Tree Diagram
module: ietf-cwt-voucher-request
grouping voucher-request-cwt-grouping
+---- voucher
+---- created-on
| yang:date-and-time
+---- expires-on?
| yang:date-and-time
+---- assertion
| enumeration
+---- serial-number string
+---- idevid-issuer? binary
+---- pinned-domain-cert binary
+---- domain-cert-revocation-checks? boolean
+---- nonce? binary
+---- last-renewal-date?
| yang:date-and-time
+---- proximity-registrar-subject-public-key-info? binary
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5.1.2. SID values
5.1.3. YANG Module
<CODE BEGINS> file "ietf-cwt-voucher-request@2017-12-11.yang"
/* -*- c -*- */
module ietf-cwt-voucher-request {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-cwt-voucher-request";
prefix "vcwt";
import ietf-voucher {
prefix "v";
}
organization
"IETF 6tisch Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/6tisch/>
WG List: <mailto:6tisch@ietf.org>
Author: Michael Richardson
<mailto:mcr+ietf@sandelman.ca>";
description
"This module defines the format for a voucher, which is produced by
a pledge's manufacturer or delegate (MASA) to securely assign one
or more pledges to an 'owner', so that the pledges may establish a
secure connection to the owner's network infrastructure.
This version provides a very restricted subset appropriate
for very constrained devices.
In particular, it assumes that nonce-ful operation is
always required, that expiration dates are rather weak, as no
clocks can be assumed, and that the Registrar is identified
by a pinned Raw Public Key.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT',
'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in
the module text are to be interpreted as described in RFC 2119.";
revision "2017-12-11" {
description
"Initial version";
reference
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"RFC XXXX: Voucher Profile for Constrained Devices";
}
// Grouping defined for future usage
grouping voucher-request-cwt-grouping {
description
"Grouping to allow reuse/extensions in future work.";
uses v:voucher-artifact-grouping {
augment "voucher" {
description "Base the CWT voucher-request upon the regular one";
leaf proximity-registrar-subject-public-key-info {
type binary;
description
"The proximity-registrar-subject-public-key-info replaces
the proximit-registrar-cert in constrained uses of
the voucher-request.
The proximity-registrar-subject-public-key-info is the
Raw Public Key of the Registrar. This field is encoded
as specified in RFC7250, section 3.
The ECDSA algorithm MUST be supported.
The EdDSA algorithm as specified in
draft-ietf-tls-rfc4492bis-17 SHOULD be supported.
Support for the DSA algorithm is not recommended.
Support for the RSA algorithm is a MAY.";
}
}
}
}
}
<CODE ENDS>
5.1.4. Example voucher request artifacts
TBD
5.2. Voucher artifact
The voucher's primary purpose is to securely assign a pledge to an
owner. The voucher informs the pledge which entity it should
consider to be its owner.
This document defines a voucher that is a CBOR encoded instance of
the YANG module defined in Section 5.3 that has been signed with CMS
or with COSE.
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5.3. Tree Diagram
module: ietf-cwt-voucher
grouping voucher-cwt-grouping
+---- voucher
+---- created-on
| yang:date-and-time
+---- expires-on?
| yang:date-and-time
+---- assertion enumeration
+---- serial-number string
+---- idevid-issuer? binary
+---- pinned-domain-cert binary
+---- domain-cert-revocation-checks? boolean
+---- nonce? binary
+---- last-renewal-date?
| yang:date-and-time
+---- pinned-domain-subject-public-key-info? binary
5.4. SID values
SID Assigned to
--------- --------------------------------------------------
1001100 module ietf-cwt-voucher
1001101 module ietf-restconf
1001102 module ietf-voucher
1001103 module ietf-yang-types
1001104 data .../ietf-cwt-voucher:voucher
1001105 data .../assertion
1001106 data .../created-on
1001107 data .../domain-cert-revocation-checks
1001108 data .../expires-on
1001109 data .../idevid-issuer
1001110 data .../last-renewal-date
1001111 data .../nonce
1001112 data .../pinned-domain-cert
1001113 data .../pinned-domain-subject-public-key-info
1001114 data .../serial-number
No .sid file
5.5. YANG Module
<CODE BEGINS> file "ietf-cwt-voucher@2017-12-11.yang"
/* -*- c -*- */
module ietf-cwt-voucher {
yang-version 1.1;
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namespace
"urn:ietf:params:xml:ns:yang:ietf-cwt-voucher";
prefix "vcwt";
import ietf-voucher {
prefix "v";
}
organization
"IETF 6tisch Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/6tisch/>
WG List: <mailto:6tisch@ietf.org>
Author: Michael Richardson
<mailto:mcr+ietf@sandelman.ca>";
description
"This module defines the format for a voucher, which is produced by
a pledge's manufacturer or delegate (MASA) to securely assign one
or more pledges to an 'owner', so that the pledges may establish a
secure connection to the owner's network infrastructure.
This version provides a very restricted subset appropriate
for very constrained devices.
In particular, it assumes that nonce-ful operation is
always required, that expiration dates are rather weak, as no
clocks can be assumed, and that the Registrar is identified
by a pinned Raw Public Key.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT',
'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in
the module text are to be interpreted as described in RFC 2119.";
revision "2017-12-11" {
description
"Initial version";
reference
"RFC XXXX: Voucher Profile for Constrained Devices";
}
// Grouping defined for future usage
grouping voucher-cwt-grouping {
description
"Grouping to allow reuse/extensions in future work.";
uses v:voucher-artifact-grouping {
augment "voucher" {
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description "Base the CWT voucher upon the regular one";
leaf pinned-domain-subject-public-key-info {
type binary;
description
"The pinned-domain-subject replaces the
pinned-domain-certificate in constrained uses of
the voucher. The pinned-domain-public-key-info is the
Raw Public Key of the Registrar. This field is encoded
as specified in RFC7250, section 3.
The ECDSA algorithm MUST be supported.
The EdDSA algorithm as specified in
draft-ietf-tls-rfc4492bis-17 SHOULD be supported.
Support for the DSA algorithm is not recommended.
Support for the RSA algorithm is a MAY.";
}
}
}
}
}
<CODE ENDS>
5.5.1. Example voucher artifacts
TBD
5.6. CMS format voucher and voucher-request artifacts
The IETF evolution of PKCS#7 is CMS [RFC5652]. The CMS signed
voucher is much like the equivalent voucher defined in
[I-D.ietf-anima-voucher].
A different eContentType of TBD1 is used to indicate that the
contents are in a different format than in [I-D.ietf-anima-voucher].
The ContentInfo structure contains a payload consisting of the CBOR
encoded voucher. The [I-D.ietf-core-yang-cbor] use of delta encoding
creates a canonical ordering for the keys on the wire. This
canonical ordering is not important as there is no expectation that
the content will be reproduced during the validation process.
Normally the recipient is the pledge and the signer is the MASA.
[I-D.ietf-anima-bootstrapping-keyinfra] supports both signed and
unsigned voucher requests from the pledge to the JRC. In this
specification, voucher-request artifact is not signed from the pledge
to the registrar. From the JRC to the MASA, the voucher-request
artifact MUST be signed by the domain owner key which is requesting
ownership.
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The considerations of [RFC5652] section 5.1, concerning validating
CMS objects which are really PKCS7 objects (cmsVersion=1) applies.
The CMS structure SHOULD also contain all the certificates leading up
to and including the signer's trust anchor certificate known to the
recipient. The inclusion of the trust anchor is unusual in many
applications, but without it third parties can not accurately audit
the transaction.
The CMS structure MAY also contain revocation objects for any
intermediate certificate authorities (CAs) between the voucher-issuer
and the trust anchor known to the recipient. However, the use of
CRLs and other validity mechanisms is discouraged, as the pledge is
unlikely to be able to perform online checks, and is unlikely to have
a trusted clock source. As described below, the use of short-lived
vouchers and/or pledge provided nonce provides a freshness guarantee.
5.7. COSE format voucher and voucher-request artifacts
This section to be added.
6. Design Considerations
The design considerations for the CBOR encoding of vouchers is much
the same as for [I-D.ietf-anima-voucher].
One key difference is that the names of the leafs in the YANG does
not have a material affect on the size of the resulting CBOR, as the
SID translation process assigns integers to the names.
7. Security Considerations
7.1. Clock Sensitivity
TBD.
7.2. Protect Voucher PKI in HSM
TBD.
7.3. Test Domain Certificate Validity when Signing
TBD.
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8. IANA Considerations
8.1. The IETF XML Registry
This document registers two URIs in the IETF XML registry [RFC3688].
Following the format in [RFC3688], the following registration is
requested:
URI: urn:ietf:params:xml:ns:yang:ietf-cwt-voucher
Registrant Contact: The ANIMA WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-cwt-voucher-request
Registrant Contact: The ANIMA WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
8.2. The YANG Module Names Registry
This document registers two YANG modules in the YANG Module Names
registry [RFC6020]. Following the format defined in [RFC6020], the
the following registration is requested:
name: ietf-cwt-voucher
namespace: urn:ietf:params:xml:ns:yang:ietf-cwt-voucher
prefix: vch
reference: RFC XXXX
name: ietf-cwt-voucher-request
namespace: urn:ietf:params:xml:ns:yang:ietf-cwt-voucher-request
prefix: vch
reference: RFC XXXX
8.3. The SMI Security for S/MIME CMS Content Type Registry
This document registers an OID in the "SMI Security for S/MIME CMS
Content Type" registry (1.2.840.113549.1.9.16.1), with the value:
Decimal Description References
------- -------------------------------------- ----------
TBD1 id-ct-animaCBORVoucher [ThisRFC]
EDNOTE: should a seperate value be used for Voucher Requests?
8.4. The SID registry
The SID range 1001100 was allocated by comi.space to the IETF-CWT-
VOUCHER yang module.
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The SID range 1001150 was allocated by comi.space to the IETF-CWT-
VOUCHER-REQUEST yang module.
EDNOTE: it is unclear if there is further IANA work required.
8.5. CoAP Content-Type
A CoAP Content-Type may be have to be defined to match application/
cms.
9. Acknowledgements
TBD
10. References
10.1. Normative References
[I-D.ietf-ace-cbor-web-token]
Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
"CBOR Web Token (CWT)", draft-ietf-ace-cbor-web-token-09
(work in progress), October 2017.
[I-D.ietf-anima-bootstrapping-keyinfra]
Pritikin, M., Richardson, M., Behringer, M., Bjarnason,
S., and K. Watsen, "Bootstrapping Remote Secure Key
Infrastructures (BRSKI)", draft-ietf-anima-bootstrapping-
keyinfra-09 (work in progress), October 2017.
[I-D.ietf-anima-voucher]
Watsen, K., Richardson, M., Pritikin, M., and T. Eckert,
"Voucher Profile for Bootstrapping Protocols", draft-ietf-
anima-voucher-06 (work in progress), October 2017.
[I-D.ietf-core-object-security]
Selander, G., Mattsson, J., Palombini, F., and L. Seitz,
"Object Security for Constrained RESTful Environments
(OSCORE)", draft-ietf-core-object-security-07 (work in
progress), November 2017.
[I-D.ietf-core-sid]
Veillette, M. and A. Pelov, "YANG Schema Item iDentifier
(SID)", draft-ietf-core-sid-03 (work in progress),
December 2017.
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[I-D.ietf-core-yang-cbor]
Veillette, M., Pelov, A., Somaraju, A., Turner, R., and A.
Minaburo, "CBOR Encoding of Data Modeled with YANG",
draft-ietf-core-yang-cbor-05 (work in progress), August
2017.
[I-D.vanderstok-ace-coap-est]
Kumar, S., Stok, P., Kampanakis, P., Furuhed, M., and S.
Raza, "EST over secure CoAP (EST-coaps)", draft-
vanderstok-ace-coap-est-02 (work in progress), June 2017.
[ieee802-1AR]
IEEE Standard, ., "IEEE 802.1AR Secure Device Identifier",
2009, <http://standards.ieee.org/findstds/
standard/802.1AR-2009.html>.
[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>.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, DOI 10.17487/RFC5652, September 2009,
<https://www.rfc-editor.org/info/rfc5652>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <https://www.rfc-editor.org/info/rfc7049>.
[RFC7250] Wouters, P., Ed., Tschofenig, H., Ed., Gilmore, J.,
Weiler, S., and T. Kivinen, "Using Raw Public Keys in
Transport Layer Security (TLS) and Datagram Transport
Layer Security (DTLS)", RFC 7250, DOI 10.17487/RFC7250,
June 2014, <https://www.rfc-editor.org/info/rfc7250>.
[RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)",
RFC 8152, DOI 10.17487/RFC8152, July 2017,
<https://www.rfc-editor.org/info/rfc8152>.
10.2. Informative References
[duckling]
Stajano, F. and R. Anderson, "The resurrecting duckling:
security issues for ad-hoc wireless networks", 1999,
<https://www.cl.cam.ac.uk/~fms27/
papers/1999-StajanoAnd-duckling.pdf>.
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[I-D.ietf-netmod-yang-tree-diagrams]
Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
ietf-netmod-yang-tree-diagrams-02 (work in progress),
October 2017.
[pledge] Dictionary.com, ., "Dictionary.com Unabridged", 2015,
<http://dictionary.reference.com/browse/pledge>.
Author's Address
Michael Richardson
Sandelman Software Works
Email: mcr+ietf@sandelman.ca
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