Constrained Voucher Artifacts for Bootstrapping Protocols
draft-ietf-anima-constrained-voucher-10
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| Authors | Michael Richardson , Peter Van der Stok , Panos Kampanakis , Esko Dijk | ||
| Last updated | 2021-05-17 (Latest revision 2021-02-21) | ||
| Replaces | draft-richardson-anima-ace-constrained-voucher | ||
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draft-ietf-anima-constrained-voucher-10
anima Working Group M. Richardson
Internet-Draft Sandelman Software Works
Intended status: Standards Track P. van der Stok
Expires: August 24, 2021 vanderstok consultancy
P. Kampanakis
Cisco Systems
E. Dijk
IoTconsultancy.nl
February 20, 2021
Constrained Voucher Artifacts for Bootstrapping Protocols
draft-ietf-anima-constrained-voucher-10
Abstract
This document defines a protocol to securely assign a Pledge to an
owner and to enroll it into the owner's network. The protocol uses
an artifact that is signed by the Pledge's manufacturer. This
artifact is known as a "voucher".
This document builds upon the work in [RFC8366] and [BRSKI], but
defines an encoding of the voucher in CBOR rather than JSON, and
enables the Pledge to perform its transactions using CoAP rather than
HTTPS.
The use of Raw Public Keys instead of X.509 certificates for security
operations is also explained.
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 August 24, 2021.
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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. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Requirements Language . . . . . . . . . . . . . . . . . . . . 4
4. Survey of Voucher Types . . . . . . . . . . . . . . . . . . . 5
5. Discovery and URI . . . . . . . . . . . . . . . . . . . . . . 6
6. BRSKI-EST Protocol . . . . . . . . . . . . . . . . . . . . . 7
6.1. Discovery, URIs and Content Formats . . . . . . . . . . . 7
6.2. Discovery, URIs and Content Formats . . . . . . . . . . . 7
6.3. Extensions to BRSKI . . . . . . . . . . . . . . . . . . . 8
6.4. Extensions to EST-coaps . . . . . . . . . . . . . . . . . 8
6.4.1. Pledge Extensions . . . . . . . . . . . . . . . . . . 8
6.4.2. Registrar Extensions . . . . . . . . . . . . . . . . 10
7. BRSKI-MASA Protocol . . . . . . . . . . . . . . . . . . . . . 10
8. Pinning in Voucher Artifacts . . . . . . . . . . . . . . . . 11
8.1. Registrar Identity Selection and Encoding . . . . . . . . 11
8.2. MASA Pinning Policy . . . . . . . . . . . . . . . . . . . 12
8.3. Pinning of Raw Public Keys . . . . . . . . . . . . . . . 13
9. Artifacts . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Voucher Request artifact . . . . . . . . . . . . . . . . 15
9.1.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 15
9.1.2. SID values . . . . . . . . . . . . . . . . . . . . . 16
9.1.3. YANG Module . . . . . . . . . . . . . . . . . . . . . 17
9.1.4. Example voucher request artifact . . . . . . . . . . 21
9.2. Voucher artifact . . . . . . . . . . . . . . . . . . . . 21
9.2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . 21
9.2.2. SID values . . . . . . . . . . . . . . . . . . . . . 22
9.2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . 22
9.2.4. Example voucher artifacts . . . . . . . . . . . . . . 25
9.3. Signing voucher and voucher-request artifacts with COSE . 26
10. Design Considerations . . . . . . . . . . . . . . . . . . . . 26
11. Security Considerations . . . . . . . . . . . . . . . . . . . 27
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11.1. Clock Sensitivity . . . . . . . . . . . . . . . . . . . 27
11.2. Protect Voucher PKI in HSM . . . . . . . . . . . . . . . 27
11.3. Test Domain Certificate Validity when Signing . . . . . 27
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
12.1. Resource Type Registry . . . . . . . . . . . . . . . . . 27
12.2. The IETF XML Registry . . . . . . . . . . . . . . . . . 27
12.3. The YANG Module Names Registry . . . . . . . . . . . . . 28
12.4. The RFC SID range assignment sub-registry . . . . . . . 28
12.5. Media-Type Registry . . . . . . . . . . . . . . . . . . 28
12.5.1. application/voucher-cose+cbor . . . . . . . . . . . 28
12.6. CoAP Content-Format Registry . . . . . . . . . . . . . . 29
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 29
14. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 30
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
15.1. Normative References . . . . . . . . . . . . . . . . . . 30
15.2. Informative References . . . . . . . . . . . . . . . . . 32
Appendix A. EST messages to EST-coaps . . . . . . . . . . . . . 33
A.1. enrollstatus . . . . . . . . . . . . . . . . . . . . . . 33
A.2. voucher_status . . . . . . . . . . . . . . . . . . . . . 34
Appendix B. COSE examples . . . . . . . . . . . . . . . . . . . 35
B.1. Pledge, Registrar and MASA keys . . . . . . . . . . . . . 38
B.1.1. Pledge private key . . . . . . . . . . . . . . . . . 38
B.1.2. Registrar private key . . . . . . . . . . . . . . . . 39
B.1.3. MASA private key . . . . . . . . . . . . . . . . . . 39
B.2. Pledge, Registrar and MASA certificates . . . . . . . . . 40
B.2.1. Pledge IDevID certificate . . . . . . . . . . . . . . 40
B.2.2. Registrar Certificate . . . . . . . . . . . . . . . . 41
B.2.3. MASA Certificate . . . . . . . . . . . . . . . . . . 43
B.3. COSE signed voucher request from Pledge to Registrar . . 45
B.4. COSE signed voucher request from Registrar to MASA . . . 47
B.5. COSE signed voucher from MASA to Pledge via Registrar . . 48
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 49
1. Introduction
Secure enrollment of new nodes into constrained networks with
constrained nodes presents unique challenges. There are network
bandwidth and code size issues to contend with. A solution for
autonomous enrollment such as [I-D.ietf-anima-bootstrapping-keyinfra]
may be too large in terms of code size or bandwidth required.
Therefore, this document defines a constrained version of the voucher
artifact [RFC8366], along with a constrained version of BRSKI
[I-D.ietf-anima-bootstrapping-keyinfra] that makes use of the
constrained CoAP-based version of EST, EST-coaps
[I-D.ietf-ace-coap-est] rather than EST over HTTPS [RFC7030].
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While the [RFC8366] voucher is by default serialized to JSON with a
signature in CMS, this document defines a new voucher serialization
to CBOR ([RFC7049]) with a signature in COSE
[I-D.ietf-cose-rfc8152bis-struct]. This COSE-signed CBOR-encoded
voucher can be transported using secured CoAP or HTTP. The CoAP
connection (between Pledge and Registrar) is to be protected by
either OSCORE+EDHOC, or DTLS (CoAPS). The HTTP connection (between
Registrar and MASA) is to be protected using TLS (HTTPS).
This document has a similar structure to [RFC8366] but adds sections
concerning:
1. Voucher-request artifact specification based on Section 3 of
[I-D.ietf-anima-bootstrapping-keyinfra],
2. Voucher(-request) transport over CoAP based on Section 3 of
[I-D.ietf-anima-bootstrapping-keyinfra] and on
[I-D.ietf-ace-coap-est].
The CBOR definitions for the constrained voucher format are defined
using the mechanism described 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 a 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.
There is additional work when the voucher is integrated into the key-
exchange, described in [I-D.selander-ace-ake-authz]. This work is
not in scope for this document.
2. Terminology
The following terms are defined in [RFC8366], and are used
identically as in that document: artifact, domain, imprint, Join
Registrar/Coordinator (JRC), Manufacturer Authorized Signing
Authority (MASA), Pledge, Registrar, Trust of First Use (TOFU), and
Voucher.
The following terms from [I-D.ietf-anima-bootstrapping-keyinfra] are
used identically as in that document: Domain CA, enrollment, IDevID,
Join Proxy, LDevID, manufacturer, nonced, nonceless, PKIX.
3. 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
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BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
4. Survey of Voucher Types
[RFC8366] provides for vouchers that assert proximity, that
authenticate the Registrar and that can offer varying levels of anti-
replay protection.
This document does not make any extensions to the semantic meanings
of vouchers, only the encoding has been changed to optimize for
constrained devices and networks.
Time-based vouchers are supported in this definition, but given that
constrained devices are extremely unlikely to have accurate time,
their use is very unlikely. Most Pledges using these constrained
vouchers will be online during enrollment and will use live nonces to
provide anti-replay protection.
[RFC8366] 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 a "voucher"
response as this is the order that they occur in the protocol.
The constrained voucher request MUST be signed by the Pledge. It can
sign using its IDevID X.509 certificate, or if an IDevID is not
available its manufacturer-installed raw public key (RPK). The
constrained voucher MUST be signed by the MASA.
For the constrained voucher request this document defines two
distinct methods for the Pledge to identify the Registrar: using
either the Registrar's X.509 certificate, or using a raw public key
(RPK) of the Registrar. For the constrained voucher also these two
methods are supported to indicate (pin) a trusted domain identity:
using either a pinned domain X.509 certificate, or a pinned raw
public key (RPK).
When the Pledge is known by MASA to support RPK but not X.509
certificates, the voucher produced by the MASA pins the raw public
key of the Registrar in the "pinned-domain-subject-public-key-info"
field of a voucher. This is described in more detail in the YANG
definition for the constrained voucher and in section Section 8.
When the Pledge is known by MASA to support PKIX format certificates,
the "pinned-domain-cert" field present in a voucher typically pins a
domain certificate. That can be either the End-Entity certificate of
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the Registrar, or the certificate of a domain CA of the Registrar's
domain. However, if the Pledge is known to also support RPK pinning
and the MASA intends to pin the Registrar's identity (not a CA), then
MASA MAY pin the RPK of the Registrar instead of the Registrar's End-
Entity certificate in order to save space in the voucher.
5. Discovery and URI
This section describes the BRSKI extensions to EST-coaps
[I-D.ietf-ace-coap-est] to transport the voucher between Registrar,
join proxy and Pledge over CoAP. The extensions are targeted to low-
resource networks with small packets. Saving header space is
important and the EST-coaps URI is shorter than the EST URI.
The presence and location of (path to) the management data are
discovered by sending a GET request to "/.well-known/core" including
a resource type (RT) parameter with the value "ace.est" [RFC6690].
Upon success, the return payload will contain the root resource of
the EST resources. It is up to the implementation to choose its root
resource; throughout this document the example root resource /est is
used.
The EST-coaps server URIs differ from the EST URI by replacing the
scheme https by coaps and by specifying shorter resource path names:
coaps://www.example.com/est/short-name
Figure 5 in section 3.2.2 of [RFC7030] enumerates the operations and
corresponding paths which are supported by EST. Table 1 provides the
mapping from the BRSKI extension URI path to the EST-coaps URI path.
+-----------------+-----------+
| BRSKI | EST-coaps |
+-----------------+-----------+
| /requestvoucher | /rv |
| | |
| /voucher_status | /vs |
| | |
| /enrollstatus | /es |
+-----------------+-----------+
Table 1: BRSKI path to EST-coaps path
/requestvoucher, /voucher_status and /enrollstatus occur between the
Pledge and Registrar (the BRSKI-EST protocol) and also between
Registrar and MASA, but, as described in Section 7, this document
addresses only the BRSKI-EST portion of the protocol.
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When discovering the root path for the EST resources, the server MAY
return the full resource paths and the used content types. This is
useful when multiple content types are specified for EST-coaps
server. For example, the following more complete response is
possible.
6. BRSKI-EST Protocol
The constrained BRSKI-EST protocol described in this section is
between the Pledge and the Registrar only. (probably via a join
proxy, such as described in [I-D.ietf-anima-constrained-join-proxy])
It extends both the BRSKI and EST-coaps protocols.
6.1. Discovery, URIs and Content Formats
The constrained BRSKI-EST protocol described in this section is
between the Pledge and the Registrar only. (probably via a join
proxy, such as described in [I-D.ietf-anima-constrained-join-proxy])
It extends both the BRSKI and EST-coaps protocols.
6.2. Discovery, URIs and Content Formats
TBD: content overlaps with Section 5, to be fixed - issue #79
The Pledge MAY perform a discovery operation on the "/.well-known/
core?rt=brski*" resource of the Registrar if it wishes to discover
possibly shorter URLs for the functions, or if it has the possibility
to use a variety of onboarding protocols or certificate enrollment
protocols and it wants to discover which of these protocols are
available.
For example, if the Registrar supports a short BRSKI URL (/b) and
supports the voucher format "application/voucher-cose+cbor" (TBD3),
and status reporting in both CBOR and JSON formats:
REQ: GET /.well-known/core?rt=brski*
RES: 2.05 Content
Content-Format: 40
Payload:
</b>;rt=brski,
</b/rv>;rt=brski.rv;ct=TBD3,
</b/vs>;rt=brski.vs;ct="50 60",
</b/es>;rt=brski.es;ct="50 60"
The Registrar is under no obligation to provide shorter URLs, and MAY
respond to this query with only the "/.well-known/brski" end points
defined in [I-D.ietf-anima-bootstrapping-keyinfra] section 5.
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Registrars that have implemented shorter URLs MUST also respond in
equivalent ways to the "/.well-known/brski" URLs, and MUST NOT
distinguish between them. In particular, a Pledge MAY use the longer
and shorter URLs in combination.
The return of multiple content-types in the "ct" attribute allows the
Pledge to choose the most appropriate one. Note that Content-Format
TBD3 is defined in this document.
The Content-Format ("application/json") 50 MAY be supported and 60
MUST be supported by the Registrar for the /vs and /es resources.
Content-Format TBD3 MUST be supported by the Registrar for the /rv
resource. If the "ct" attribute is not indicated for this resource,
this implies that at least TBD3 is supported.
The Pledge and MASA need to support one or more formats (at least
TBD3) for the voucher and for the voucher request. The MASA needs to
support all formats that the Pledge, produced by that manufacturer,
supports.
6.3. Extensions to BRSKI
A Pledge that only supports the EST-coaps enrollment method SHOULD
NOT use discovery for BRSKI resources, since it is more efficient to
just try the supported enrollment method via the well-known BRSKI/
EST-coaps resources, and it avoids the Pledge having to do complex
CoRE Link Format parsing. A Registrar SHOULD host any discoverable
BRSKI resources on the same (UDP) server port that the Pledge's DTLS
connection is using. This avoids the Pledge having to reconnect
using DTLS, in order to access these resources.
6.4. Extensions to EST-coaps
A Pledge that only supports the EST-coaps enrollment method SHOULD
NOT use discovery for EST-coaps resources, for similar reasons as
stated in the previous section. A Registrar SHOULD host any
discoverable EST-coaps resources on the same (UDP) server port that
the Pledge's DTLS connection is using. This avoids the Pledge having
to reconnect using DTLS, in order to access these resources.
6.4.1. Pledge Extensions
A constrained Pledge SHOULD NOT perform the optional "CSR attributes
request" (/att) to minimize network traffic and reduce code size
(i.e. by not implementing the complex CSR attributes parsing code).
When creating the CSR, the Pledge selects itself which attributes to
include. One or more Subject Distinguished Name fields MUST be
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included. If the Pledge has no specific information on what
attributes/fields are desired in the CSR, it MUST use the Subject
Distinguished Name fields from its IDevID unmodified. The Pledge may
receive such information via the voucher (encoded in a vendor-
specific way) or some other, out-of-band means.
A constrained Pledge MAY use the following optimized EST-coaps
procedure to minimize both network traffic and code size:
1. if the BRSKI-received voucher, validating the current EST server,
contains a pinned domain CA certificate, the Pledge provisionally
considers this single certificate as the sole EST trust anchor,
in other words, the single result of "CA certificates request"
(/crts) to the EST server.
2. Using this trust anchor it proceeds with EST simple enrollment
(/sen) to obtain its provisionally trusted LDevID.
3. Then, the Pledge attempts to validate that the trust anchor CA is
the signer of the LDevID. If this is the case, the Pledge
finally accepts the pinned domain CA certificate as the
legitimate trust anchor CA for its domain and it also accepts its
LDevID.
4. If this is not the case, the Pledge MUST perform an actual "CA
certificates request" (/crts) to the EST server to obtain the EST
CA trust anchors since these obviously differ from the
(temporary) pinned domain CA.
5. When doing this request, the Pledge MAY use a CoAP Accept Option
with value TBD287 ("application/pkix-cert") to limit the number
of returned EST CA trust anchors to only one. Such limiting to
only one has the advantages that storage requirements for CA
certificates are reduced, network traffic can be reduced, and
code size can be reduced (by not having to parse the alternative
format 281 "application/pkcs7-mime;smime-type=certs-only" and not
having to support CoAP block-wise transfer).
6. If the Pledge cannot obtain the single CA certificate or the
finally validated CA certificate cannot be chained to the LDevID,
then the Pledge MUST abort the enrollment process and report the
error using the enrollment status telemetry (/es).
The Content-Format ("application/json") 50 MAY be supported and 60
MUST be supported by the Registrar for the /vs and /es resources.
Content-Format TBD3 MUST be supported by the Registrar for the /rv
resource. If the "ct" attribute is not indicated for this resource,
this implies that at least TBD3 is supported.
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When a Registrar receives a "CA certificates request" (/crts) request
with a CoAP Accept Option with value TBD287 it SHOULD return only the
single CA certificate that is the envisioned or actual authority for
the current, authenticated Pledge making the request. The only
exception case is when the Registrar is configured to not support a
request for a single CA certificate for operational or security
reasons, e.g. because every device enrolled into the domain needs to
use at least multiple CAs. In such exception case the Registrar
returns the CoAP response 4.06 Not Acceptable to indicate that only
the default Content-Format of 281 "application/pkcs7-mime;smime-
type=certs-only" is available.
6.4.2. Registrar Extensions
When a Registrar receives a "CA certificates request" (/crts) request
with a CoAP Accept Option with value TBD287 it SHOULD return only the
single CA certificate that is the envisioned or actual authority for
the current, authenticated Pledge making the request. The only
exception case is when the Registrar is configured to not support a
request for a single CA certificate for operational or security
reasons, e.g. because every device enrolled into the domain needs to
use at least multiple CAs. In such exception case the Registrar
returns the CoAP response 4.06 Not Acceptable to indicate that only
the default Content-Format of 281 "application/pkcs7-mime;smime-
type=certs-only" is available.
7. BRSKI-MASA Protocol
[I-D.ietf-anima-bootstrapping-keyinfra] section 5.4 describes a
connection between the Registrar and the MASA as being a normal TLS
connection using HTTPS. This document does not change that. The use
of CoAP for the BRSKI-MASA connection is NOT supported.
Some consideration was made to specify CoAP support for consistency
but:
o the Registrar is not expected to be so constrained that it cannot
support HTTPS client connections.
o the technology and experience to build Internet-scale HTTPS
responders (which the MASA is) is common, while the experience
doing the same for CoAP is much less common.
o in many Enterprise networks, outgoing UDP connections are often
treated as suspicious, and there seems to be no advantage to using
CoAP in that environment.
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o a Registrar is likely to provide onboarding services to both
constrained and non-constrained devices. Such a Registrar would
need to speak HTTPS anyway.
o similarly, a manufacturer is likely to offer both constrained and
non-constrained devices, so there may in practice be no situation
in which the MASA could be CoAP-only. Additionally, as the MASA
is intended to be a function that can easily be oursourced to a
third-party service provider, reducing the complexity would also
seem to reduce the cost of that function.
8. Pinning in Voucher Artifacts
The voucher is a statement from the MASA to the Pledge indicating who
the Pledge's owner is. This section deals with the question of how
that owner's identity is determined and how it is encoded within the
voucher.
8.1. Registrar Identity Selection and Encoding
Section 5.5 of [I-D.ietf-anima-bootstrapping-keyinfra] describes
BRSKI policies for selection of the owner identity. It indicates
some of the flexibility that is possible for the Registrar. The
recommendation made there is for the Registrar to include only
certificates in the (CMS) signing structure which participate in the
certificate chain that is to be pinned.
The MASA is expected to evaluate the certificates included by the
Registrar in its voucher request, forming them into a chain with the
Registrar's (signing) identity on one end. Then, it pins a
certificate selected from the chain. For instance, for a domain with
a two-level certification authority, where the voucher-request has
been signed by "Registrar" its signing structure includes two
additional CA certificates:
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.-------------.
| priv-CA (1) |
'-------------'
|
v
.------------.
| Int-CA (2) |
'------------'
|
v
.--------------.
| Registrar(3) |
'--------------'
Figure 1: Two Level PKI
When the Registrar is using a COSE-signed constrained format voucher
request towards MASA, instead of a regular CMS-signed voucher
request, the COSE_Sign1 object contains a protected and an
unprotected header, and according to [I-D.ietf-cose-x509], would
carry all the certificates of the chain in an "x5bag" attribute
placed in the unprotected header.
8.2. MASA Pinning Policy
The MASA, having assembled and verified the chain in the signing
structure, will now need to select a certificate to pin in the
voucher in case there are multiple available. (For the case that
only the Registrar's End-Entity certificate is included, only this
certificate can be selected and this section does not apply.) The
BRSKI policy for pinning by the MASA as described in Section 5.5.2 of
[I-D.ietf-anima-bootstrapping-keyinfra] leaves much flexibility to
the manufacturer. The present document adds the following rules to
the MASA pinning policy, in order to reduce on average the duration
of BRSKI/EST on constrained, low-bandwidth networks:
1. for a voucher containing a nonce, it SHOULD select the most
specific (lowest-level) CA certificate in the chain.
2. for a nonceless voucher, it SHOULD select the least-specific
(highest-level) CA certificate in the chain that is allowed under
the MASA's policy for this specific customer (domain).
The rationale for 1. is that in case of a voucher with nonce, the
voucher is valid only in scope of the present DTLS connection between
Pledge and Registrar anyway, so it would have no benefit to pin a
higher-level CA. By pinning the most specific CA the constrained
Pledge can validate its DTLS connection using less crypto operations.
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The rationale for pinning a CA instead of the Registrar's End-Entity
certificate directly is the following benefit on constrained
networks: the pinned certificate in the voucher can in common cases
be re-used as a Domain CA trust anchor during the EST enrollment and
during the operational phase that follows after EST enrollment, as
explained elsewhere in this document. Doing so avoids an additional
transmission of this trust anchor over the network during the EST
enrollment, saving potentially 100s of bytes and a CoAP transaction.
The rationale for 2. follows from the flexible BRSKI trust model for,
and purpose of, nonceless vouchers (Sections 5.5.* and 7.4.1 of
[I-D.ietf-anima-bootstrapping-keyinfra]).
Using the previous example of a domain with a two-level certification
authority, the most specific CA ("Sub-CA") is the identity that is
pinned by MASA in a nonced voucher. A Registrar that wished to have
only the Registrar's End-Entity certificate pinned would omit the
"priv-CA" and "Sub-CA" certificates from the voucher-request.
In case of a nonceless voucher, the MASA would depending on trust
level pin only "Registrar" certificate (low trust in customer), or
the "Sub-CA" certificate (in case of medium trust, implying that any
Registrar of that sub-domain is acceptable), or even the "priv-CA"
certificate (in case of high trust in the customer, and possibly a
pre-agreed need of the customer to obtain flexible long-lived
vouchers).
8.3. Pinning of Raw Public Keys
Specifically for constrained use cases, the pinning of the raw public
key (RPK) of the Registrar is also supported in the constrained
voucher, instead of an X.509 certificate. If an RPK is pinned it
MUST be the RPK of the Registrar.
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.------------.
| pub-CA (1) |
'------------'
|
v
.------------.
| sub-CA (2) |
'------------'
|
v
.--------------.
| Registrar(3) |
| [RPK3] |
'--------------'
Figure 2: Raw Public Key pinning
When the Pledge is known by MASA to support RPK but not X.509
certificates, the voucher produced by the MASA pins the RPK of the
Registrar in the "pinned-domain-subject-public-key-info" field of a
voucher. This is described in more detail in the YANG definition for
the constrained voucher. A Pledge that does not support X.509
certificates cannot use EST to enroll; it has to use another method
for certificate-less enrollment and the Registrar has to support this
method also. It is possible that the Pledge will not enroll, but
instead only a network join operation will occur, such as described
in [I-D.ietf-6tisch-minimal-security]. How the Pledge discovers this
method and details of the enrollment method are out of scope of this
document.
When the Pledge is known by MASA to support PKIX format certificates,
the "pinned-domain-cert" field present in a voucher typically pins a
domain certificate. That can be either the End-Entity certificate of
the Registrar, or the certificate of a domain CA of the Registrar's
domain. However, if the Pledge is known to also support RPK pinning
and the MASA intends to pin the Registrar's identity (not a CA), then
MASA SHOULD pin the RPK (RPK3 in figure Figure 2) of the Registrar
instead of the Registrar's End-Entity certificate in order to save
space in the voucher.
To Be Completed further (TBD): Note, the above paragraphs are
duplicated from the section Section 4 so we may have to resolve this
duplication.
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9. 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-sid], with an allocation that was
made via the http://comi.space service.
9.1. Voucher Request artifact
9.1.1. Tree Diagram
The following diagram is largely a duplicate of the contents of
[RFC8366], with the addition of proximity-registrar-subject-public-
key-info, proximity-registrar-cert, and prior-signed-voucher-request.
prior-signed-voucher-request is only used between the Registrar and
the MASA. proximity-registrar-subject-public-key-info replaces
proximity-registrar-cert for the extremely constrained cases.
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module: ietf-constrained-voucher-request
grouping voucher-request-constrained-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
+-- proximity-registrar-sha256-of-subject-public-key-info?
| binary
+-- proximity-registrar-cert?
| binary
+-- prior-signed-voucher-request?
binary
9.1.2. SID values
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SID Assigned to
--------- --------------------------------------------------
2501 data /ietf-constrained-voucher-request:voucher
2502 data .../assertion
2503 data .../created-on
2504 data .../domain-cert-revocation-checks
2505 data .../expires-on
2506 data .../idevid-issuer
2507 data .../last-renewal-date
2508 data /ietf-constrained-voucher-request:voucher/nonce
2509 data .../pinned-domain-cert
2510 data .../prior-signed-voucher-request
2511 data .../proximity-registrar-cert
2512 data mity-registrar-sha256-of-subject-public-key-info
2513 data .../proximity-registrar-subject-public-key-info
2514 data .../serial-number
WARNING, obsolete definitions
9.1.3. YANG Module
In the constrained-voucher-request YANG module, the voucher is
"augmented" within the "used" grouping statement such that one
continuous set of SID values is generated for the constrained-
voucher-request module name, all voucher attributes, and the
constrained-voucher-request attribute. Two attributes of the voucher
are "refined" to be optional.
<CODE BEGINS> file "ietf-constrained-voucher-request@2019-09-01.yang"
module ietf-constrained-voucher-request {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-constrained-voucher-request";
prefix "constrained";
import ietf-restconf {
prefix rc;
description
"This import statement is only present to access
the yang-data extension defined in RFC 8040.";
reference "RFC 8040: RESTCONF Protocol";
}
import ietf-voucher {
prefix "v";
}
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organization
"IETF ANIMA Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/anima/>
WG List: <mailto:anima@ietf.org>
Author: Michael Richardson
<mailto:mcr+ietf@sandelman.ca>
Author: Peter van der Stok
<mailto: consultancy@vanderstok.org>
Author: Panos Kampanakis
<mailto: pkampana@cisco.com>";
description
"This module defines the format for a voucher request,
which is produced by a pledge to request a voucher.
The voucher-request is sent to the potential owner's
Registrar, which in turn sends the voucher request to
the manufacturer or delegate (MASA).
A voucher is then returned to the pledge, binding the
pledge to the owner. This is a constrained version of the
voucher-request present in
draft-ietf-anima-bootstrap-keyinfra.txt.
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 "2019-09-01" {
description
"Initial version";
reference
"RFC XXXX: Voucher Profile for Constrained Devices";
}
rc:yang-data voucher-request-constrained-artifact {
// YANG data template for a voucher.
uses voucher-request-constrained-grouping;
}
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// Grouping defined for future usage
grouping voucher-request-constrained-grouping {
description
"Grouping to allow reuse/extensions in future work.";
uses v:voucher-artifact-grouping {
refine voucher/created-on {
mandatory false;
}
refine voucher/pinned-domain-cert {
mandatory false;
}
augment "voucher" {
description "Base the constrained 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 MAY, but due to
size is discouraged.";
}
leaf proximity-registrar-sha256-of-subject-public-key-info {
type binary;
description
"The proximity-registrar-sha256-of-subject-public-key-info
is an alternative to
proximity-registrar-subject-public-key-info.
and pinned-domain-cert. In many cases the
public key of the domain has already been transmitted
during the key agreement protocol, and it is wasteful
to transmit the public key another two times.
The use of a hash of public key info, at 32-bytes for
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sha256 is a significant savings compared to an RSA
public key, but is only a minor savings compared to
a 256-bit ECDSA public-key.
Algorithm agility is provided by extensions to this
specifications which define new leaf for other hash
types.";
}
leaf proximity-registrar-cert {
type binary;
description
"An X.509 v3 certificate structure as specified by
RFC 5280,
Section 4 encoded using the ASN.1 distinguished encoding
rules (DER), as specified in ITU-T X.690.
The first certificate in the Registrar TLS server
certificate_list sequence (see [RFC5246]) presented by
the Registrar to the Pledge. This MUST be populated in a
Pledge's voucher request if the proximity assertion is
populated.";
}
leaf prior-signed-voucher-request {
type binary;
description
"If it is necessary to change a voucher, or re-sign and
forward a voucher that was previously provided along a
protocol path, then the previously signed voucher
SHOULD be included in this field.
For example, a pledge might sign a proximity voucher,
which an intermediate registrar then re-signs to
make its own proximity assertion. This is a simple
mechanism for a chain of trusted parties to change a
voucher, while maintaining the prior signature
information.
The pledge MUST ignore all prior voucher information
when accepting a voucher for imprinting. Other
parties MAY examine the prior signed voucher
information for the purposes of policy decisions.
For example this information could be useful to a
MASA to determine that both pledge and registrar
agree on proximity assertions. The MASA SHOULD
remove all prior-signed-voucher-request information when
signing a voucher for imprinting so as to minimize the
final voucher size.";
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}
}
}
}
}
<CODE ENDS>
9.1.4. Example voucher request artifact
Below is a CBOR serialization of an example constrained voucher
request from a Pledge to a Registrar, shown in CBOR diagnostic
notation. The enum value of the assertion field is calculated to be
2 by following the algorithm described in section 9.6.4.2 of
[RFC7950]. Four dots ("....") in a CBOR byte string denotes a
sequence of bytes that are not shown for brevity.
{
2501: {
+2 : "2016-10-07T19:31:42Z", / SID= 2503, created-on /
+4 : "2016-10-21T19:31:42Z", / SID= 2505, expires-on /
+1 : 2, / SID= 2502, assertion /
/ "proximity" /
+13: "JADA123456789", / SID= 2514, serial-number /
+5 : h'01020D0F', / SID= 2506, idevid-issuer /
+10: h'cert.der', / SID=2511, proximity-registrar-cert/
+3 : true, / SID= 2504, domain-cert
-revocation-checks/
+6 : "2017-10-07T19:31:42Z", / SID= 2507, last-renewal-date /
+12: h'key_info' / SID= 2513, proximity-registrar
-subject-public-key-info /
}
}
<CODE ENDS>
9.2. 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.
9.2.1. Tree Diagram
The following diagram is largely a duplicate of the contents of
[RFC8366], with only the addition of pinned-domain-subject-public-
key-info.
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module: ietf-constrained-voucher
grouping voucher-constrained-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
+-- pinned-sha256-of-subject-public-key-info? binary
<CODE ENDS>
9.2.2. SID values
SID Assigned to
--------- --------------------------------------------------
2451 data /ietf-constrained-voucher:voucher
2452 data /ietf-constrained-voucher:voucher/assertion
2453 data /ietf-constrained-voucher:voucher/created-on
2454 data .../domain-cert-revocation-checks
2455 data /ietf-constrained-voucher:voucher/expires-on
2456 data /ietf-constrained-voucher:voucher/idevid-issuer
2457 data .../last-renewal-date
2458 data /ietf-constrained-voucher:voucher/nonce
2459 data .../pinned-domain-cert
2460 data .../pinned-domain-subject-public-key-info
2461 data .../pinned-sha256-of-subject-public-key-info
2462 data /ietf-constrained-voucher:voucher/serial-number
WARNING, obsolete definitions
<CODE ENDS>
9.2.3. YANG Module
In the constrained-voucher YANG module, the voucher is "augmented"
within the "used" grouping statement such that one continuous set of
SID values is generated for the constrained-voucher module name, all
voucher attributes, and the constrained-voucher attribute. Two
attributes of the voucher are "refined" to be optional.
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<CODE BEGINS> file "ietf-constrained-voucher@2019-09-01.yang"
module ietf-constrained-voucher {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-constrained-voucher";
prefix "constrained";
import ietf-restconf {
prefix rc;
description
"This import statement is only present to access
the yang-data extension defined in RFC 8040.";
reference "RFC 8040: RESTCONF Protocol";
}
import ietf-voucher {
prefix "v";
}
organization
"IETF ANIMA Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/anima/>
WG List: <mailto:anima@ietf.org>
Author: Michael Richardson
<mailto:mcr+ietf@sandelman.ca>
Author: Peter van der Stok
<mailto: consultancy@vanderstok.org>
Author: Panos Kampanakis
<mailto: pkampana@cisco.com>";
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
establis 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',
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and 'OPTIONAL' in the module text are to be interpreted as
described in RFC 2119.";
revision "2019-09-01" {
description
"Initial version";
reference
"RFC XXXX: Voucher Profile for Constrained Devices";
}
rc:yang-data voucher-constrained-artifact {
// YANG data template for a voucher.
uses voucher-constrained-grouping;
}
// Grouping defined for future usage
grouping voucher-constrained-grouping {
description
"Grouping to allow reuse/extensions in future work.";
uses v:voucher-artifact-grouping {
refine voucher/created-on {
mandatory false;
}
refine voucher/pinned-domain-cert {
mandatory false;
}
augment "voucher" {
description "Base the constrained voucher
upon the regular one";
leaf pinned-domain-subject-public-key-info {
type binary;
description
"The pinned-domain-subject-public-key-info replaces the
pinned-domain-cert in constrained uses of
the voucher. The pinned-domain-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.";
}
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leaf pinned-sha256-of-subject-public-key-info {
type binary;
description
"The pinned-hash-subject-public-key-info is a second
alternative to pinned-domain-cert. In many cases the
public key of the domain has already been transmitted
during the key agreement process, and it is wasteful
to transmit the public key another two times.
The use of a hash of public key info, at 32-bytes for
sha256 is a significant savings compared to an RSA
public key, but is only a minor savings compared to
a 256-bit ECDSA public-key.
Algorithm agility is provided by extensions to this
specifications which define new leaf for other hash types";
}
}
}
}
}
<CODE ENDS>
9.2.4. Example voucher artifacts
Below the CBOR serialization of an example constrained voucher is
shown in CBOR diagnostic notation. The enum value of the assertion
field is calculated to be zero by following the algorithm described
in section 9.6.4.2 of [RFC7950]. Four dots ("....") in a CBOR byte
string denotes a sequence of bytes that are not shown for brevity.
{
2451: {
+2 : "2016-10-07T19:31:42Z", / SID = 2453, created-on /
+4 : "2016-10-21T19:31:42Z", / SID = 2455, expires-on /
+1 : 0, / SID = 2452, assertion "verified" /
+11: "JADA123456789", / SID = 2462, serial-number /
+5 : h'E40393B4....68A3', / SID = 2456, idevid-issuer /
+8 : h'30820275....C35F', / SID = 2459, pinned-domain-cert/
+3 : true, / SID = 2454, domain-cert /
/ -revocation-checks /
+6 : "2017-10-07T19:31:42Z" / SID = 2457, last-renewal-date /
}
}
<CODE ENDS>
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9.3. Signing voucher and voucher-request artifacts with COSE
The COSE-Sign1 structure is discussed in section 4.2 of
[I-D.ietf-cose-rfc8152bis-struct]. The CBOR object that carries the
body, the signature, and the information about the body and signature
is called the COSE_Sign1 structure. It is used when only one
signature is used on the body. Support for ECDSA with sha256
(secp256k1 and prime256v1 curves) is compulsory.
The supported COSE-sign1 object stucture is shown in Figure 3.
Support for EdDSA is encouraged. [EDNOTE: Expand and add a reference
why. ]
COSE_Sign1(
[
h'A101382E', # { "alg": EC256K1 }
{
"kid" : h'789' # hash256(public key)
},
h'123', #voucher-request binary content
h'456', #voucher-request binary public signature
]
)
Figure 3: cose-sign1 example
The [COSE-registry] specifies the integers that replace the strings
and the mnemonics in Figure 3. The value of the "kid" parameter is
an example value. Usually a hash of the public key is used to
idientify the public key. The public key and its hash are derived
from the relevant certificate (Pledge, Registrar or MASA
certificate).
In Appendix B a binary cose-sign1 object is shown based on the
voucher-request example of Section 9.1.4.
10. Design Considerations
The design considerations for the CBOR encoding of vouchers is much
the same as for [RFC8366].
One key difference is that the names of the leaves in the YANG does
not have a material effect on the size of the resulting CBOR, as the
SID translation process assigns integers to the names.
Any POST request to the Registrar with resource /est/vs or /est/es
returns a 2.05 response with empty payload. The client should be
aware that the server may use a piggybacked CoAP response (ACK, 2.05)
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but may also respond with a separate CoAP response, i.e. first an
(ACK, 0.0) that is an acknowledgement of the request reception
followed by a (CON, 2.05) response in a separate CoAP message.
11. Security Considerations
11.1. Clock Sensitivity
TBD.
11.2. Protect Voucher PKI in HSM
TBD.
11.3. Test Domain Certificate Validity when Signing
TBD.
12. IANA Considerations
12.1. Resource Type Registry
Additions to the sub-registry "CoAP Resource Type", within the "CoRE
parameters" registry are specified below. These can be registered
either in the Expert Review range (0-255) or IETF Review range
(256-9999).
ace.rt.rv needs registration with IANA
ace.rt.vs needs registration with IANA
ace.rt.es needs registration with IANA
ace.rt.ra needs registration with IANA
12.2. 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-constrained-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-constrained-voucher-request
Registrant Contact: The ANIMA WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
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12.3. 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-constrained-voucher
namespace: urn:ietf:params:xml:ns:yang:ietf-constrained-voucher
prefix: vch
reference: RFC XXXX
name: ietf-constrained-voucher-request
namespace: urn:ietf:params:xml:ns:yang:ietf-constrained
-voucher-request
prefix: vch
reference: RFC XXXX
12.4. The RFC SID range assignment sub-registry
------------ ------ --------------------------- ------------
Entry-point | Size | Module name | RFC Number
------------ ------ --------------------------- ------------
2450 50 ietf-constrained-voucher [ThisRFC]
2500 50 ietf-constrained-voucher [ThisRFC}
-request
----------- ------ --------------------------- ------------
Warning: These SID values are defined in [I-D.ietf-core-sid], not as
an Early Allocation.
12.5. Media-Type Registry
This section registers the the 'application/voucher-cose+cbor' in the
"Media Types" registry. These media types are used to indicate that
the content is a CBOR voucher either signed with a COSE_Sign1
structure [I-D.ietf-cose-rfc8152bis-struct].
12.5.1. application/voucher-cose+cbor
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Type name: application
Subtype name: voucher-cose+cbor
Required parameters: none
Optional parameters: cose-type
Encoding considerations: COSE_Sign1 CBOR vouchers are COSE objects
signed with one signer.
Security considerations: See Security Considerations, Section
Interoperability considerations: The format is designed to be
broadly interoperable.
Published specification: THIS RFC.
Applications that use this media type: ANIMA, 6tisch, and other
zero-touch imprinting systems
Additional information:
Magic number(s): None
File extension(s): .vch
Macintosh file type code(s): none
Person & email address to contact for further information: IETF
ANIMA WG
Intended usage: LIMITED
Restrictions on usage: NONE
Author: ANIMA WG
Change controller: IETF
Provisional registration? (standards tree only): NO
12.6. CoAP Content-Format Registry
Additions to the sub-registry "CoAP Content-Formats", within the
"CoRE Parameters" registry are needed for two media types. These can
be registered either in the Expert Review range (0-255) or IETF
Review range (256-9999).
Media type mime type Encoding ID References
---------------------------- ----------- --------- ---- ----------
application/voucher-cose+cbor "COSE-Sign1" CBOR TBD3 [This RFC]
13. Acknowledgements
We are very grateful to Jim Schaad for explaining COSE and CMS
choices. Also thanks to Jim Schaad for correctinging earlier version
of the COSE Sign1 objects.
Michel Veillette did extensive work on pyang to extend it to support
the SID allocation process, and this document was among the first
users.
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14. Changelog
-10 Design considerations extended Examples made consistent
-08 Examples for cose_sign1 are completed and improved.
-06 New SID values assigned; regenerated examples
-04 voucher and request-voucher MUST be signed examples for signed
request are added in appendix IANA SID registration is updated SID
values in examples are aligned signed cms examples aligned with new
SIDs
-03
Examples are inverted.
-02
Example of requestvoucher with unsigned appllication/cbor is added
attributes of voucher "refined" to optional
CBOR serialization of vouchers improved
Discovery port numbers are specified
-01
application/json is optional, application/cbor is compulsory
Cms and cose mediatypes are introduced
15. References
15.1. Normative References
[I-D.ietf-6tisch-minimal-security]
Vucinic, M., Simon, J., Pister, K., and M. Richardson,
"Constrained Join Protocol (CoJP) for 6TiSCH", draft-ietf-
6tisch-minimal-security-15 (work in progress), December
2019.
[I-D.ietf-ace-coap-est]
Stok, P. V. D., Kampanakis, P., Richardson, M. C., and S.
Raza, "EST over secure CoAP (EST-coaps)", draft-ietf-ace-
coap-est-18 (work in progress), January 2020.
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[I-D.ietf-anima-bootstrapping-keyinfra]
Pritikin, M., Richardson, M. C., Eckert, T., Behringer, M.
H., and K. Watsen, "Bootstrapping Remote Secure Key
Infrastructures (BRSKI)", draft-ietf-anima-bootstrapping-
keyinfra-45 (work in progress), November 2020.
[I-D.ietf-core-sid]
Veillette, M., Pelov, A., and I. Petrov, "YANG Schema Item
iDentifier (YANG SID)", draft-ietf-core-sid-15 (work in
progress), January 2021.
[I-D.ietf-core-yang-cbor]
Veillette, M., Petrov, I., and A. Pelov, "CBOR Encoding of
Data Modeled with YANG", draft-ietf-core-yang-cbor-15
(work in progress), January 2021.
[I-D.ietf-cose-rfc8152bis-struct]
Schaad, J., "CBOR Object Signing and Encryption (COSE):
Structures and Process", draft-ietf-cose-rfc8152bis-
struct-15 (work in progress), February 2021.
[I-D.ietf-cose-x509]
Schaad, J., "CBOR Object Signing and Encryption (COSE):
Header parameters for carrying and referencing X.509
certificates", draft-ietf-cose-x509-08 (work in progress),
December 2020.
[I-D.selander-ace-ake-authz]
Selander, G., Mattsson, J. P., Vucinic, M., Richardson,
M., and A. Schellenbaum, "Lightweight Authorization for
Authenticated Key Exchange.", draft-selander-ace-ake-
authz-02 (work in progress), November 2020.
[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>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, DOI 10.17487/RFC5652, September 2009,
<https://www.rfc-editor.org/info/rfc5652>.
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[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[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>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[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>.
[RFC8366] Watsen, K., Richardson, M., Pritikin, M., and T. Eckert,
"A Voucher Artifact for Bootstrapping Protocols",
RFC 8366, DOI 10.17487/RFC8366, May 2018,
<https://www.rfc-editor.org/info/rfc8366>.
15.2. Informative References
[COSE-registry]
IANA, ., "CBOR Object Signing and Encryption (COSE)
registry", 2017,
<https://www.iana.org/assignments/cose/cose.xhtml>.
[I-D.ietf-anima-constrained-join-proxy]
Richardson, M., Stok, P. V. D., and P. Kampanakis,
"Constrained Join Proxy for Bootstrapping Protocols",
draft-ietf-anima-constrained-join-proxy-02 (work in
progress), February 2021.
[I-D.ietf-netmod-yang-tree-diagrams]
Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
ietf-netmod-yang-tree-diagrams-06 (work in progress),
February 2018.
[RFC6690] Shelby, Z., "Constrained RESTful Environments (CoRE) Link
Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
<https://www.rfc-editor.org/info/rfc6690>.
[RFC7030] Pritikin, M., Ed., Yee, P., Ed., and D. Harkins, Ed.,
"Enrollment over Secure Transport", RFC 7030,
DOI 10.17487/RFC7030, October 2013,
<https://www.rfc-editor.org/info/rfc7030>.
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Appendix A. EST messages to EST-coaps
This section extends the examples from Appendix A of
[I-D.ietf-ace-coap-est]. The CoAP headers are only worked out for
the enrollstatus example.
A.1. enrollstatus
A coaps enrollstatus message can be :
POST coaps://192.0.2.1:8085/est/es
The corresponding coap header fields are shown below.
Ver = 1
T = 0 (CON)
Code = 0x02 (0.02 is POST)
Options
Option (Uri-Path)
Option Delta = 0xb (option nr = 11)
Option Length = 0x3
Option Value = "est"
Option (Uri-Path)
Option Delta = 0x0 (option nr = 11)
Option Length = 0x2
Option Value = "es"
Payload = [Empty]
The Uri-Host and Uri-Port Options are omitted because they coincide
with the transport protocol destination address and port
respectively.
A 2.05 Content response with an unsigned voucher status (ct=60) will
then be:
2.05 Content (Content-Format: application/cbor)
With CoAP fields and payload:
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Ver=1
T=2 (ACK)
Code = 0x45 (2.05 Content)
Options
Option1 (Content-Format)
Option Delta = 0xC (option nr 12)
Option Length = 0x2
Option Value = 60 (application/cbor)
Payload (CBOR diagnostic) =
{
"version":"1",
"Status": 1, / 1 = Success, 0 = Fail /
"Reason":"Informative human readable message",
"reason-context": "Additional information"
}
The binary payload is:
A46776657273696F6E6131665374617475730166526561736F6E7822
496E666F726D61746976652068756D616E207265616461626C65206D
6573736167656e726561736F6E2D636F6E74657874
764164646974696F6E616C20696E666F726D6174696F6E
The binary payload disassembles to the above CBOR diagnostic code.
A.2. voucher_status
A coaps voucher_status message can be:
POST coaps://[2001:db8::2:1]:61616/est/vs
A 2.05 Content response with a non signed CBOR voucher status (ct=60)
will then be:
2.05 Content (Content-Format: application/cbor)
Payload =
a46776657273696f6e6131665374617475730166526561736f6e7822496e666f7
26d61746976652068756d616e207265616461626c65206d6573736167656e7265
61736f6e2d636f6e74657874764164646974696f6e616c20696e666f726d61746
96f6e<CODE ENDS>
The payload above is represented in hexadecimal.
{"version": "1", "Status": 1, "Reason": "Informative human
readable message", "reason-context": "Additional information"}<CODE ENDS>
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Appendix B. COSE examples
These examples are generated on a pie 4 and a PC running BASH. Keys
and Certificates have been generated with openssl with the following
shell script:
#!/bin/bash
#try-cert.sh
export dir=./brski/intermediate
export cadir=./brski
export cnfdir=./conf
export format=pem
export default_crl_days=30
sn=8
DevID=pledge.1.2.3.4
serialNumber="serialNumber=$DevID"
export hwType=1.3.6.1.4.1.6715.10.1
export hwSerialNum=01020304 # Some hex
export subjectAltName="otherName:1.3.6.1.5.5.7.8.4;SEQ:hmodname"
echo $hwType - $hwSerialNum
echo $serialNumber
OPENSSL_BIN="openssl"
# remove all files
rm -r ./brski/*
#
# initialize file structure
# root level
cd $cadir
mkdir certs crl csr newcerts private
chmod 700 private
touch index.txt
touch serial
echo 11223344556600 >serial
echo 1000 > crlnumber
# intermediate level
mkdir intermediate
cd intermediate
mkdir certs crl csr newcerts private
chmod 700 private
touch index.txt
echo 11223344556600 >serial
echo 1000 > crlnumber
cd ../..
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# file structure is cleaned start filling
echo "#############################"
echo "create registrar keys and certificates "
echo "#############################"
echo "create root registrar certificate using ecdsa with sha 256 key"
$OPENSSL_BIN ecparam -name prime256v1 -genkey \
-noout -out $cadir/private/ca-regis.key
$OPENSSL_BIN req -new -x509 \
-config $cnfdir/openssl-regis.cnf \
-key $cadir/private/ca-regis.key \
-out $cadir/certs/ca-regis.crt \
-extensions v3_ca\
-days 365 \
-subj "/C=NL/ST=NB/L=Helmond/O=vanderstok/OU=consultancy \
/CN=registrar.stok.nl"
# Combine authority certificate and key
echo "Combine authority certificate and key"
$OPENSSL_BIN pkcs12 -passin pass:watnietweet -passout pass:watnietweet\
-inkey $cadir/private/ca-regis.key \
-in $cadir/certs/ca-regis.crt -export \
-out $cadir/certs/ca-regis-comb.pfx
# converteer authority pkcs12 file to pem
echo "converteer authority pkcs12 file to pem"
$OPENSSL_BIN pkcs12 -passin pass:watnietweet -passout pass:watnietweet\
-in $cadir/certs/ca-regis-comb.pfx \
-out $cadir/certs/ca-regis-comb.crt -nodes
#show certificate in registrar combined certificate
$OPENSSL_BIN x509 -in $cadir/certs/ca-regis-comb.crt -text
#
# Certificate Authority for MASA
#
echo "#############################"
echo "create MASA keys and certificates "
echo "#############################"
echo "create root MASA certificate using ecdsa with sha 256 key"
$OPENSSL_BIN ecparam -name prime256v1 -genkey -noout \
-out $cadir/private/ca-masa.key
$OPENSSL_BIN req -new -x509 \
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-config $cnfdir/openssl-masa.cnf \
-days 1000 -key $cadir/private/ca-masa.key \
-out $cadir/certs/ca-masa.crt \
-extensions v3_ca\
-subj "/C=NL/ST=NB/L=Helmond/O=vanderstok/OU=manufacturer\
/CN=masa.stok.nl"
# Combine authority certificate and key
echo "Combine authority certificate and key for masa"
$OPENSSL_BIN pkcs12 -passin pass:watnietweet -passout pass:watnietweet\
-inkey $cadir/private/ca-masa.key \
-in $cadir/certs/ca-masa.crt -export \
-out $cadir/certs/ca-masa-comb.pfx
# converteer authority pkcs12 file to pem for masa
echo "converteer authority pkcs12 file to pem for masa"
$OPENSSL_BIN pkcs12 -passin pass:watnietweet -passout pass:watnietweet\
-in $cadir/certs/ca-masa-comb.pfx \
-out $cadir/certs/ca-masa-comb.crt -nodes
#show certificate in pledge combined certificate
$OPENSSL_BIN x509 -in $cadir/certs/ca-masa-comb.crt -text
#
# Certificate for Pledge derived from MASA certificate
#
echo "#############################"
echo "create pledge keys and certificates "
echo "#############################"
# Pledge derived Certificate
echo "create pledge derived certificate using ecdsa with sha 256 key"
$OPENSSL_BIN ecparam -name prime256v1 -genkey -noout \
-out $dir/private/pledge.key
echo "create pledge certificate request"
$OPENSSL_BIN req -nodes -new -sha256 \
-key $dir/private/pledge.key -out $dir/csr/pledge.csr \
-subj "/C=NL/ST=NB/L=Helmond/O=vanderstok/OU=manufacturing\
/CN=uuid:$DevID/$serialNumber"
# Sign pledge derived Certificate
echo "sign pledge derived certificate "
$OPENSSL_BIN ca -config $cnfdir/openssl-pledge.cnf \
-extensions 8021ar_idevid\
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-days 365 -in $dir/csr/pledge.csr \
-out $dir/certs/pledge.crt
# Add pledge key and pledge certificate to pkcs12 file
echo "Add derived pledge key and derived pledge \
certificate to pkcs12 file"
$OPENSSL_BIN pkcs12 -passin pass:watnietweet -passout pass:watnietweet\
-inkey $dir/private/pledge.key \
-in $dir/certs/pledge.crt -export \
-out $dir/certs/pledge-comb.pfx
# converteer pledge pkcs12 file to pem
echo "converteer pledge pkcs12 file to pem"
$OPENSSL_BIN pkcs12 -passin pass:watnietweet -passout pass:watnietweet\
-in $dir/certs/pledge-comb.pfx \
-out $dir/certs/pledge-comb.crt -nodes
#show certificate in pledge-comb.crt
$OPENSSL_BIN x509 -in $dir/certs/pledge-comb.crt -text
#show private key in pledge-comb.crt
$OPENSSL_BIN ecparam -name prime256v1\
-in $dir/certs/pledge-comb.crt -text
<CODE ENDS>
The xxxx-comb certificates have been generated as required by libcoap
for the DTLS connection generation.
B.1. Pledge, Registrar and MASA keys
This first section documents the public and private keys used in the
subsequent test vectors below. These keys come from test code and
are not used in any production system, and should only be used only
to validate implementations.
B.1.1. Pledge private key
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Private-Key: (256 bit)
priv:
9b:4d:43:b6:a9:e1:7c:04:93:45:c3:13:d9:b5:f0:
41:a9:6a:9c:45:79:73:b8:62:f1:77:03:3a:fc:c2:
9c:9a
pub:
04:d6:b7:6f:74:88:bd:80:ae:5f:28:41:2c:72:02:
ef:5f:98:b4:81:e1:d9:10:4c:f8:1b:66:d4:3e:5c:
ea:da:73:e6:a8:38:a9:f1:35:11:85:b6:cd:e2:04:
10:be:fe:d5:0b:3b:14:69:2e:e1:b0:6a:bc:55:40:
60:eb:95:5c:54
ASN1 OID: prime256v1
NIST CURVE: P-256
<CODE ENDS>
B.1.2. Registrar private key
Private-Key: (256 bit)
priv:
81:df:bb:50:a3:45:58:06:b5:56:3b:46:de:f3:e9:
e9:00:ae:98:13:9e:2f:36:68:81:fc:d9:65:24:fb:
21:7e
pub:
04:50:7a:c8:49:1a:8c:69:c7:b5:c3:1d:03:09:ed:
35:ba:13:f5:88:4c:e6:2b:88:cf:30:18:15:4f:a0:
59:b0:20:ec:6b:eb:b9:4e:02:b8:93:40:21:89:8d:
a7:89:c7:11:ce:a7:13:39:f5:0e:34:8e:df:0d:92:
3e:d0:2d:c7:b7
ASN1 OID: prime256v1
NIST CURVE: P-256
<CODE ENDS>
B.1.3. MASA private key
Private-Key: (256 bit)
priv:
c6:bb:a5:8f:b6:d3:c4:75:28:d8:d3:d9:46:c3:31:
83:6d:00:0a:9a:38:ce:22:5c:e9:d9:ea:3b:98:32:
ec:31
pub:
04:59:80:94:66:14:94:20:30:3c:66:08:85:55:86:
db:e7:d4:d1:d7:7a:d2:a3:1a:0c:73:6b:01:0d:02:
12:15:d6:1f:f3:6e:c8:d4:84:60:43:3b:21:c5:83:
80:1e:fc:e2:37:85:77:97:94:d4:aa:34:b5:b6:c6:
ed:f3:17:5c:f1
ASN1 OID: prime256v1
NIST CURVE: P-256
<CODE ENDS>
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B.2. Pledge, Registrar and MASA certificates
Below the certificates that accompany the keys. The certificate
description is followed by the hexadecimal DER of the certificate
B.2.1. Pledge IDevID certificate
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 4822678189204992 (0x11223344556600)
Signature Algorithm: ecdsa-with-SHA256
Issuer: C=NL, ST=NB, L=Helmond, O=vanderstok, OU=manufacturer,
CN=masa.stok.nl
Validity
Not Before: Dec 9 10:02:36 2020 GMT
Not After : Dec 31 23:59:59 9999 GMT
Subject: C=NL, ST=NB, L=Helmond, O=vanderstok, OU=manufacturing,
CN=uuid:pledge.1.2.3.4/serialNumber=pledge.1.2.3.4
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:d6:b7:6f:74:88:bd:80:ae:5f:28:41:2c:72:02:
ef:5f:98:b4:81:e1:d9:10:4c:f8:1b:66:d4:3e:5c:
ea:da:73:e6:a8:38:a9:f1:35:11:85:b6:cd:e2:04:
10:be:fe:d5:0b:3b:14:69:2e:e1:b0:6a:bc:55:40:
60:eb:95:5c:54
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Basic Constraints:
CA:FALSE
X509v3 Authority Key Identifier:
keyid:
E4:03:93:B4:C3:D3:F4:2A:80:A4:77:18:F6:96:49:03:01:17:68:A3
Signature Algorithm: ecdsa-with-SHA256
30:46:02:21:00:d2:e6:45:3b:b0:c3:00:b3:25:8d:f1:83:fe:
d9:37:c1:a2:49:65:69:7f:6b:b9:ef:2c:05:07:06:31:ac:17:
bd:02:21:00:e2:ce:9e:7b:7f:74:50:33:ad:9e:ff:12:4e:e9:
a6:f3:b8:36:65:ab:7d:80:bb:56:88:bc:03:1d:e5:1e:31:6f
<CODE ENDS>
This is the hexadecimal representation in (request-)voucher examples
referred to as pledge-cert-hex.
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30820226308201cba003020102020711223344556600300a06082a8648ce3d04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<CODE ENDS>
B.2.2. Registrar Certificate
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Certificate:
Data:
Version: 3 (0x2)
Serial Number:
70:56:ea:aa:30:66:d8:82:6a:55:5b:90:88:d4:62:bf:9c:f2:8c:fd
Signature Algorithm: ecdsa-with-SHA256
Issuer: C=NL, ST=NB, L=Helmond, O=vanderstok, OU=consultancy,
CN=registrar.stok.nl
Validity
Not Before: Dec 9 10:02:36 2020 GMT
Not After : Dec 9 10:02:36 2021 GMT
Subject: C=NL, ST=NB, L=Helmond, O=vanderstok, OU=consultancy,
CN=registrar.stok.nl
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:50:7a:c8:49:1a:8c:69:c7:b5:c3:1d:03:09:ed:
35:ba:13:f5:88:4c:e6:2b:88:cf:30:18:15:4f:a0:
59:b0:20:ec:6b:eb:b9:4e:02:b8:93:40:21:89:8d:
a7:89:c7:11:ce:a7:13:39:f5:0e:34:8e:df:0d:92:
3e:d0:2d:c7:b7
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Subject Key Identifier:
08:C2:BF:36:88:7F:79:41:21:85:87:2F:16:A7:AC:A6:EF:B3:D2:B3
X509v3 Authority Key Identifier:
keyid:
08:C2:BF:36:88:7F:79:41:21:85:87:2F:16:A7:AC:A6:EF:B3:D2:B3
X509v3 Basic Constraints: critical
CA:TRUE
X509v3 Extended Key Usage:
CMC Registration Authority, TLS Web Server
Authentication, TLS Web Client Authentication
X509v3 Key Usage: critical
Digital Signature, Non Repudiation, Key Encipherment,
Data Encipherment, Certificate Sign, CRL Sign
Signature Algorithm: ecdsa-with-SHA256
30:44:02:20:74:4c:99:00:85:13:b2:f1:bc:fd:f9:02:1a:46:
fb:17:4c:f8:83:a2:7c:a1:d9:3f:ae:ac:f3:1e:4e:dd:12:c6:
02:20:11:47:14:db:f5:1a:5e:78:f5:81:b9:42:1c:6e:47:02:
ab:53:72:70:c5:ba:fb:2d:16:c3:de:9a:a1:82:c3:5f
<CODE ENDS>
Richardson, et al. Expires August 24, 2021 [Page 42]
Internet-Draft Constrained Voucher February 2021
This the hexadecimal representation, in (request-)voucher examples
referred to as regis-cert-hex
308202753082021ca00302010202147056eaaa3066d8826a555b9088d462bf9c
f28cfd300a06082a8648ce3d0403023073310b3009060355040613024e4c310b
300906035504080c024e423110300e06035504070c0748656c6d6f6e64311330
11060355040a0c0a76616e64657273746f6b31143012060355040b0c0b636f6e
73756c74616e6379311a301806035504030c117265676973747261722e73746f
6b2e6e6c301e170d3230313230393130303233365a170d323131323039313030
3233365a3073310b3009060355040613024e4c310b300906035504080c024e42
3110300e06035504070c0748656c6d6f6e6431133011060355040a0c0a76616e
64657273746f6b31143012060355040b0c0b636f6e73756c74616e6379311a30
1806035504030c117265676973747261722e73746f6b2e6e6c3059301306072a
8648ce3d020106082a8648ce3d03010703420004507ac8491a8c69c7b5c31d03
09ed35ba13f5884ce62b88cf3018154fa059b020ec6bebb94e02b8934021898d
a789c711cea71339f50e348edf0d923ed02dc7b7a3818d30818a301d0603551d
0e0416041408c2bf36887f79412185872f16a7aca6efb3d2b3301f0603551d23
04183016801408c2bf36887f79412185872f16a7aca6efb3d2b3300f0603551d
130101ff040530030101ff30270603551d250420301e06082b0601050507031c
06082b0601050507030106082b06010505070302300e0603551d0f0101ff0404
030201f6300a06082a8648ce3d04030203470030440220744c99008513b2f1bc
fdf9021a46fb174cf883a27ca1d93faeacf31e4edd12c60220114714dbf51a5e
78f581b9421c6e4702ab537270c5bafb2d16c3de9aa182c35f<CODE ENDS>
B.2.3. MASA Certificate
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
14:26:b8:1c:ce:d8:c3:e8:14:05:cb:87:67:0d:be:ef:d5:81:25:b4
Signature Algorithm: ecdsa-with-SHA256
Issuer: C=NL, ST=NB, L=Helmond, O=vanderstok,
OU=manufacturer, CN=masa.stok.nl
Validity
Not Before: Dec 9 10:02:36 2020 GMT
Not After : Sep 5 10:02:36 2023 GMT
Subject: C=NL, ST=NB, L=Helmond, O=vanderstok,
OU=manufacturer, CN=masa.stok.nl
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:59:80:94:66:14:94:20:30:3c:66:08:85:55:86:
db:e7:d4:d1:d7:7a:d2:a3:1a:0c:73:6b:01:0d:02:
12:15:d6:1f:f3:6e:c8:d4:84:60:43:3b:21:c5:83:
80:1e:fc:e2:37:85:77:97:94:d4:aa:34:b5:b6:c6:
Richardson, et al. Expires August 24, 2021 [Page 43]
Internet-Draft Constrained Voucher February 2021
ed:f3:17:5c:f1
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Subject Key Identifier:
E4:03:93:B4:C3:D3:F4:2A:80:A4:77:18:F6:96:49:03:01:17:68:A3
X509v3 Authority Key Identifier:
keyid:
E4:03:93:B4:C3:D3:F4:2A:80:A4:77:18:F6:96:49:03:01:17:68:A3
X509v3 Basic Constraints: critical
CA:TRUE
X509v3 Extended Key Usage:
CMC Registration Authority,
TLS Web Server Authentication,
TLS Web Client Authentication
X509v3 Key Usage: critical
Digital Signature, Non Repudiation, Key Encipherment,
Data Encipherment, Certificate Sign, CRL Sign
Signature Algorithm: ecdsa-with-SHA256
30:44:02:20:2e:c5:f2:24:72:70:20:ea:6e:74:8b:13:93:67:
8a:e6:fe:fb:8d:56:7f:f5:34:18:a9:ef:a5:0f:c3:99:ca:53:
02:20:3d:dc:91:d0:e9:6a:69:20:01:fb:e4:20:40:de:7c:7d:
98:ed:d8:84:53:61:84:a7:f9:13:06:4c:a9:b2:8f:5c
<CODE ENDS>
This is the hexadecimal representation, in (request-)voucher examples
referred to as masa-cert-hex.
Richardson, et al. Expires August 24, 2021 [Page 44]
Internet-Draft Constrained Voucher February 2021
3082026d30820214a00302010202141426b81cced8c3e81405cb87670dbeefd5
8125b4300a06082a8648ce3d040302306f310b3009060355040613024e4c310b
300906035504080c024e423110300e06035504070c0748656c6d6f6e64311330
11060355040a0c0a76616e64657273746f6b31153013060355040b0c0c6d616e
7566616374757265723115301306035504030c0c6d6173612e73746f6b2e6e6c
301e170d3230313230393130303233365a170d3233303930353130303233365a
306f310b3009060355040613024e4c310b300906035504080c024e423110300e
06035504070c0748656c6d6f6e6431133011060355040a0c0a76616e64657273
746f6b31153013060355040b0c0c6d616e756661637475726572311530130603
5504030c0c6d6173612e73746f6b2e6e6c3059301306072a8648ce3d02010608
2a8648ce3d0301070342000459809466149420303c6608855586dbe7d4d1d77a
d2a31a0c736b010d021215d61ff36ec8d48460433b21c583801efce237857797
94d4aa34b5b6c6edf3175cf1a3818d30818a301d0603551d0e04160414e40393
b4c3d3f42a80a47718f6964903011768a3301f0603551d23041830168014e403
93b4c3d3f42a80a47718f6964903011768a3300f0603551d130101ff04053003
0101ff30270603551d250420301e06082b0601050507031c06082b0601050507
030106082b06010505070302300e0603551d0f0101ff0404030201f6300a0608
2a8648ce3d040302034700304402202ec5f224727020ea6e748b1393678ae6fe
fb8d567ff53418a9efa50fc399ca5302203ddc91d0e96a692001fbe42040de7c
7d98edd884536184a7f913064ca9b28f5c<CODE ENDS>
B.3. COSE signed voucher request from Pledge to Registrar
In this example the voucher request has been signed by the Pledge,
and has been sent to the JRC over CoAPS. The Pledge uses the
proximity assertion together with an included proximity-registrar-
cert field to inform MASA about its proximity to the specific
Registrar.
POST coaps://registrar.example.com/est/rv
(Content-Format: application/voucher-cose+cbor)
signed_request_voucher
The payload signed_request_voucher is shown as hexadecimal dump (with
lf added):
Richardson, et al. Expires August 24, 2021 [Page 45]
Internet-Draft Constrained Voucher February 2021
d28444a101382ea104582097113db094eee8eae48683e7337875c0372164be89d023a5f3d
f52699c0fbfb55902d2a11909c5a60274323032302d31322d32335431323a30353a32325a
0474323032322d31322d32335431323a30353a32325a01020750684ca83e27230aff97630
cf2c1ec409a0d6e706c656467652e312e322e332e340a590279308202753082021ca00302
010202147056eaaa3066d8826a555b9088d462bf9cf28cfd300a06082a8648ce3d0403023
073310b3009060355040613024e4c310b300906035504080c024e423110300e0603550407
0c0748656c6d6f6e6431133011060355040a0c0a76616e64657273746f6b3114301206035
5040b0c0b636f6e73756c74616e6379311a301806035504030c117265676973747261722e
73746f6b2e6e6c301e170d3230313230393130303233365a170d323131323039313030323
3365a3073310b3009060355040613024e4c310b300906035504080c024e423110300e0603
5504070c0748656c6d6f6e6431133011060355040a0c0a76616e64657273746f6b3114301
2060355040b0c0b636f6e73756c74616e6379311a301806035504030c1172656769737472
61722e73746f6b2e6e6c3059301306072a8648ce3d020106082a8648ce3d0301070342000
4507ac8491a8c69c7b5c31d0309ed35ba13f5884ce62b88cf3018154fa059b020ec6bebb9
4e02b8934021898da789c711cea71339f50e348edf0d923ed02dc7b7a3818d30818a301d0
603551d0e0416041408c2bf36887f79412185872f16a7aca6efb3d2b3301f0603551d2304
183016801408c2bf36887f79412185872f16a7aca6efb3d2b3300f0603551d130101ff040
530030101ff30270603551d250420301e06082b0601050507031c06082b06010505070301
06082b06010505070302300e0603551d0f0101ff0404030201f6300a06082a8648ce3d040
30203470030440220744c99008513b2f1bcfdf9021a46fb174cf883a27ca1d93faeacf31e
4edd12c60220114714dbf51a5e78f581b9421c6e4702ab537270c5bafb2d16c3de9aa182c
35f58473045022063766c7bbd1b339dbc398e764af3563e93b25a69104befe9aac2b3336b
8f56e1022100cd0419559ad960ccaed4dee3f436eca40b7570b25a52eb60332bc1f299148
4e9
<CODE ENDS>
The representiation of signed_voucher_request in CBOR diagnostic
format is:
Diagnose(signed_request_voucher) =
18([
h'A101382E', # {"alg": -47}
{4: h'97113DB094EEE8EAE48683E7337875C0372164BE89D023A5F3DF52699C0FBFB5'},
h'request_voucher',
h'3045022063766C7BBD1B339DBC398E764AF3563E93B25A69104BEFE9AAC2B3336B8F56E
1022100CD0419559AD960CCAED4DEE3F436ECA40B7570B25A52EB60332BC1F2991484E9'
])
Diagnose(request_voucher) =
{2501: {2: "2020-12-23T12:05:22Z",
4: "2022-12-23T12:05:22Z",
1: 2,
7: h'684CA83E27230AFF97630CF2C1EC409A',
13: "pledge.1.2.3.4",
10: h'regis-cert-hex'}}
<CODE ENDS>
Richardson, et al. Expires August 24, 2021 [Page 46]
Internet-Draft Constrained Voucher February 2021
B.4. COSE signed voucher request from Registrar to MASA
In this example the voucher request has been signed by the JRC using
the private key from Appendix B.1.2. Contained within this voucher
request is the voucher request from the Pledge to JRC.
POST coaps://masa.example.com/est/rv
(Content-Format: application/voucher-cose+cbor)
signed_masa_request_voucher
The payload signed_masa_voucher_request is shown as hexadecimal dump
(with lf added):
d28444a101382ea1045820e8735bc4b470c3aa6a7aa9aa8ee584c09c11131b205efec5d03
13bad84c5cd05590414a11909c5a60274323032302d31322d32385431303a30333a33355a
0474323032322d31322d32385431303a30333a33355a07501551631f6e0416bd162ba53ea
00c2a050d6e706c656467652e312e322e332e3405587131322d32385431303a30333a3335
5a07501551631f6e0416bd162ba53ea00c2a050d6e706c656467652e312e322e332e34055
87131322d32385431303a300000000000000000000000000416bd162ba53ea00c2a050d6e
706c656467652e312e322e332e3405587131322d32385431303a09590349d28444a101382
ea104582097113db094eee8eae48683e7337875c0372164be89d023a5f3df52699c0fbfb5
5902d2a11909c5a60274323032302d31322d32385431303a30333a33355a0474323032322
d31322d32385431303a30333a33355a010207501551631f6e0416bd162ba53ea00c2a050d
6e706c656467652e312e322e332e340a590279308202753082021ca00302010202147056e
aaa3066d8826a555b9088d462bf9cf28cfd300a06082a8648ce3d0403023073310b300906
0355040613024e4c310b300906035504080c024e423110300e06035504070c0748656c6d6
f6e6431133011060355040a0c0a76616e64657273746f6b31143012060355040b0c0b636f
6e73756c74616e6379311a301806035504030c117265676973747261722e73746f6b2e6e6
c301e170d3230313230393130303233365a170d3231313230393130303233365a3073310b
3009060355040613024e4c310b300906035504080c024e423110300e06035504070c07486
56c6d6f6e6431133011060355040a0c0a76616e64657273746f6b31143012060355040b0c
0b636f6e73756c74616e6379311a301806035504030c117265676973747261722e73746f6
b2e6e6c3059301306072a8648ce3d020106082a8648ce3d03010703420004507ac8491a8c
69c7b5c31d0309ed35ba13f5884ce62b88cf3018154fa059b020ec6bebb94e02b89340218
98da789c711cea71339f50e348edf0d923ed02dc7b7a3818d30818a301d0603551d0e0416
041408c2bf36887f79412185872f16a7aca6efb3d2b3301f0603551d2304183016801408c
2bf36887f79412185872f16a7aca6efb3d2b3300f0603551d130101ff040530030101ff30
270603551d250420301e06082b0601050507031c06082b0601050507030106082b0601050
5070302300e0603551d0f0101ff0404030201f6300a06082a8648ce3d0403020347003044
0220744c99008513b2f1bcfdf9021a46fb174cf883a27ca1d93faeacf31e4edd12c602201
14714dbf51a5e78f581b9421c6e4702ab537270c5bafb2d16c3de9aa182c35f5847304502
2063766c7bbd1b339dbc398e764af3563e93b25a69104befe9aac2b3336b8f56e1022100c
d0419559ad960ccaed4dee3f436eca40b7570b25a52eb60332bc1f2991484e95847304502
2100e6b45558c1b806bba23f4ac626c9bdb6fd354ef4330d8dfb7c529f29cca934c802203
c1f2ccbbac89733d17ee7775bc2654c5f1cc96afba2741cc31532444aa8fed8
<CODE ENDS>
Richardson, et al. Expires August 24, 2021 [Page 47]
Internet-Draft Constrained Voucher February 2021
The representiation of signed_masa_voucher_request in CBOR diagnostic
format is:
Diagnose(signed_registrar_request-voucher)
18([
h'A101382E', # {"alg": -47}
h'E8735BC4B470C3AA6A7AA9AA8EE584C09C11131B205EFEC5D0313BAD84C5CD0
5'},
h'registrar_request_voucher',
h'3045022100E6B45558C1B806BBA23F4AC626C9BDB6FD354EF4330D8DFB7C529
F29CCA934C802203C1F2CCBBAC89733D17EE7775BC2654C5F1CC96AFBA2741CC3
1532444AA8FED8'
])
Diagnose(registrar_request_voucher)
{2501:
{2: "2020-12-28T10:03:35Z",
4: "2022-12-28T10:03:35Z",
7: h'1551631F6E0416BD162BA53EA00C2A05',
13: "pledge.1.2.3.4",
5: h'31322D32385431303A30333A33355A07501551631F6E0416BD162BA53EA00C2
A050D6E706C656467652E312E322E332E3405587131322D32385431303A300000
000000000000000000000416BD162BA53EA00C2A050D6E706C656467652E312E3
22E332E3405587131322D32385431303A',
9: h'signed_request_voucher'}}
<CODE ENDS>
B.5. COSE signed voucher from MASA to Pledge via Registrar
The resulting voucher is created by the MASA and returned via the JRC
to the Pledge. It is signed by the MASA's private key Appendix B.1.3
and can be verified by the Pledge using the MASA's public key
contained within the MASA certificate.
This is the raw binary signed_voucher, encoded in hexadecimal (with
lf added):
d28444a101382ea104582039920a34ee92d3148ab3a729f58611193270c9029f7784daf11
2614b19445d5158cfa1190993a70274323032302d31322d32335431353a30333a31325a04
74323032302d31322d32335431353a32333a31325a010007506508e06b2959d5089d7a316
9ea889a490b6e706c656467652e312e322e332e340858753073310b300906035504061302
4e4c310b300906035504080c024e423110300e06035504070c0748656c6d6f6e643113301
1060355040a0c0a76616e64657273746f6b31143012060355040b0c0b636f6e73756c7461
6e6379311a301806035504030c117265676973747261722e73746f6b2e6e6c03f45847304
5022022515d96cd12224ee5d3ac673237163bba24ad84815699285d9618f463ee73fa0221
00a6bff9d8585c1c9256371ece94da3d26264a5dfec0a354fe7b3aef58344c512f
<CODE ENDS>
Richardson, et al. Expires August 24, 2021 [Page 48]
Internet-Draft Constrained Voucher February 2021
The representiation of signed_voucher in CBOR diagnostic format is:
Diagnose(signed_voucher) =
18([
h'A101382E', # {"alg": -47}
{4: h'39920A34EE92D3148AB3A729F58611193270C9029F7784DAF112614B194
45D51'},
h'voucher',
h'3045022022515D96CD12224EE5D3AC673237163BBA24AD84815699285D9618F
463EE73FA022100A6BFF9D8585C1C9256371ECE94DA3D26264A5DFEC0A354FE7B
3AEF58344C512F'
])
Diagnose(voucher) =
{2451:
{2: "2020-12-23T15:03:12Z",
4: "2020-12-23T15:23:12Z",
1: 0,
7: h'6508E06B2959D5089D7A3169EA889A49',
11: "pledge.1.2.3.4",
8: h'regis-cert-hex',
3: false}}
<CODE ENDS>
Authors' Addresses
Michael Richardson
Sandelman Software Works
Email: mcr+ietf@sandelman.ca
Peter van der Stok
vanderstok consultancy
Email: consultancy@vanderstok.org
Panos Kampanakis
Cisco Systems
Email: pkampana@cisco.com
Richardson, et al. Expires August 24, 2021 [Page 49]
Internet-Draft Constrained Voucher February 2021
Esko Dijk
IoTconsultancy.nl
Email: esko.dijk@iotconsultancy.nl
Richardson, et al. Expires August 24, 2021 [Page 50]