Internet DRAFT - draft-ietf-anima-bootstrapping-keyinfra
draft-ietf-anima-bootstrapping-keyinfra
ANIMA WG M. Pritikin
Internet-Draft Cisco
Intended status: Standards Track M. Richardson
Expires: 15 May 2021 Sandelman
T.T.E. Eckert
Futurewei USA
M.H. Behringer
K.W. Watsen
Watsen Networks
11 November 2020
Bootstrapping Remote Secure Key Infrastructures (BRSKI)
draft-ietf-anima-bootstrapping-keyinfra-45
Abstract
This document specifies automated bootstrapping of an Autonomic
Control Plane. To do this a Secure Key Infrastructure is
bootstrapped. This is done using manufacturer-installed X.509
certificates, in combination with a manufacturer's authorizing
service, both online and offline. We call this process the
Bootstrapping Remote Secure Key Infrastructure (BRSKI) protocol.
Bootstrapping a new device can occur using a routable address and a
cloud service, or using only link-local connectivity, or on limited/
disconnected networks. Support for deployment models with less
stringent security requirements is included. Bootstrapping is
complete when the cryptographic identity of the new key
infrastructure is successfully deployed to the device. The
established secure connection can be used to deploy a locally issued
certificate to the device as well.
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."
Pritikin, et al. Expires 15 May 2021 [Page 1]
Internet-Draft BRSKI November 2020
This Internet-Draft will expire on 15 May 2021.
Copyright Notice
Copyright (c) 2020 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 . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1. Prior Bootstrapping Approaches . . . . . . . . . . . . . 6
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 8
1.3. Scope of solution . . . . . . . . . . . . . . . . . . . . 11
1.3.1. Support environment . . . . . . . . . . . . . . . . . 11
1.3.2. Constrained environments . . . . . . . . . . . . . . 11
1.3.3. Network Access Controls . . . . . . . . . . . . . . . 12
1.3.4. Bootstrapping is not Booting . . . . . . . . . . . . 12
1.4. Leveraging the new key infrastructure / next steps . . . 12
1.5. Requirements for Autonomic Network Infrastructure (ANI)
devices . . . . . . . . . . . . . . . . . . . . . . . . . 13
2. Architectural Overview . . . . . . . . . . . . . . . . . . . 13
2.1. Behavior of a Pledge . . . . . . . . . . . . . . . . . . 15
2.2. Secure Imprinting using Vouchers . . . . . . . . . . . . 16
2.3. Initial Device Identifier . . . . . . . . . . . . . . . . 17
2.3.1. Identification of the Pledge . . . . . . . . . . . . 18
2.3.2. MASA URI extension . . . . . . . . . . . . . . . . . 19
2.4. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 20
2.5. Architectural Components . . . . . . . . . . . . . . . . 23
2.5.1. Pledge . . . . . . . . . . . . . . . . . . . . . . . 23
2.5.2. Join Proxy . . . . . . . . . . . . . . . . . . . . . 23
2.5.3. Domain Registrar . . . . . . . . . . . . . . . . . . 23
2.5.4. Manufacturer Service . . . . . . . . . . . . . . . . 23
2.5.5. Public Key Infrastructure (PKI) . . . . . . . . . . . 24
2.6. Certificate Time Validation . . . . . . . . . . . . . . . 24
2.6.1. Lack of realtime clock . . . . . . . . . . . . . . . 24
2.6.2. Infinite Lifetime of IDevID . . . . . . . . . . . . . 24
2.7. Cloud Registrar . . . . . . . . . . . . . . . . . . . . . 25
2.8. Determining the MASA to contact . . . . . . . . . . . . . 25
3. Voucher-Request artifact . . . . . . . . . . . . . . . . . . 26
Pritikin, et al. Expires 15 May 2021 [Page 2]
Internet-Draft BRSKI November 2020
3.1. Nonceless Voucher Requests . . . . . . . . . . . . . . . 27
3.2. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 27
3.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . 27
3.4. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 29
4. Proxying details (Pledge - Proxy - Registrar) . . . . . . . . 33
4.1. Pledge discovery of Proxy . . . . . . . . . . . . . . . . 34
4.1.1. Proxy GRASP announcements . . . . . . . . . . . . . . 35
4.2. CoAP connection to Registrar . . . . . . . . . . . . . . 37
4.3. Proxy discovery and communication of Registrar . . . . . 37
5. Protocol Details (Pledge - Registrar - MASA) . . . . . . . . 38
5.1. BRSKI-EST TLS establishment details . . . . . . . . . . . 40
5.2. Pledge Requests Voucher from the Registrar . . . . . . . 41
5.3. Registrar Authorization of Pledge . . . . . . . . . . . . 43
5.4. BRSKI-MASA TLS establishment details . . . . . . . . . . 43
5.4.1. MASA authentication of customer Registrar . . . . . . 44
5.5. Registrar Requests Voucher from MASA . . . . . . . . . . 45
5.5.1. MASA renewal of expired vouchers . . . . . . . . . . 47
5.5.2. MASA pinning of registrar . . . . . . . . . . . . . . 48
5.5.3. MASA checking of voucher request signature . . . . . 48
5.5.4. MASA verification of domain registrar . . . . . . . . 49
5.5.5. MASA verification of pledge
prior-signed-voucher-request . . . . . . . . . . . . 50
5.5.6. MASA nonce handling . . . . . . . . . . . . . . . . . 50
5.6. MASA and Registrar Voucher Response . . . . . . . . . . . 50
5.6.1. Pledge voucher verification . . . . . . . . . . . . . 53
5.6.2. Pledge authentication of provisional TLS
connection . . . . . . . . . . . . . . . . . . . . . 54
5.7. Pledge BRSKI Status Telemetry . . . . . . . . . . . . . . 55
5.8. Registrar audit-log request . . . . . . . . . . . . . . . 56
5.8.1. MASA audit log response . . . . . . . . . . . . . . . 58
5.8.2. Calculation of domainID . . . . . . . . . . . . . . . 60
5.8.3. Registrar audit log verification . . . . . . . . . . 61
5.9. EST Integration for PKI bootstrapping . . . . . . . . . . 62
5.9.1. EST Distribution of CA Certificates . . . . . . . . . 63
5.9.2. EST CSR Attributes . . . . . . . . . . . . . . . . . 63
5.9.3. EST Client Certificate Request . . . . . . . . . . . 64
5.9.4. Enrollment Status Telemetry . . . . . . . . . . . . . 64
5.9.5. Multiple certificates . . . . . . . . . . . . . . . . 65
5.9.6. EST over CoAP . . . . . . . . . . . . . . . . . . . . 66
6. Clarification of transfer-encoding . . . . . . . . . . . . . 66
7. Reduced security operational modes . . . . . . . . . . . . . 66
7.1. Trust Model . . . . . . . . . . . . . . . . . . . . . . . 66
7.2. Pledge security reductions . . . . . . . . . . . . . . . 67
7.3. Registrar security reductions . . . . . . . . . . . . . . 68
7.4. MASA security reductions . . . . . . . . . . . . . . . . 69
7.4.1. Issuing Nonceless vouchers . . . . . . . . . . . . . 69
7.4.2. Trusting Owners on First Use . . . . . . . . . . . . 70
7.4.3. Updating or extending voucher trust anchors . . . . . 71
Pritikin, et al. Expires 15 May 2021 [Page 3]
Internet-Draft BRSKI November 2020
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 72
8.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 72
8.2. YANG Module Names Registry . . . . . . . . . . . . . . . 72
8.3. BRSKI well-known considerations . . . . . . . . . . . . . 72
8.3.1. BRSKI .well-known registration . . . . . . . . . . . 72
8.3.2. BRSKI .well-known registry . . . . . . . . . . . . . 73
8.4. PKIX Registry . . . . . . . . . . . . . . . . . . . . . . 73
8.5. Pledge BRSKI Status Telemetry . . . . . . . . . . . . . . 73
8.6. DNS Service Names . . . . . . . . . . . . . . . . . . . . 74
8.7. GRASP Objective Names . . . . . . . . . . . . . . . . . . 74
9. Applicability to the Autonomic Control Plane (ACP) . . . . . 74
9.1. Operational Requirements . . . . . . . . . . . . . . . . 76
9.1.1. MASA Operational Requirements . . . . . . . . . . . . 76
9.1.2. Domain Owner Operational Requirements . . . . . . . . 77
9.1.3. Device Operational Requirements . . . . . . . . . . . 77
10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 78
10.1. MASA audit log . . . . . . . . . . . . . . . . . . . . . 78
10.2. What BRSKI-EST reveals . . . . . . . . . . . . . . . . . 78
10.3. What BRSKI-MASA reveals to the manufacturer . . . . . . 79
10.4. Manufacturers and Used or Stolen Equipment . . . . . . . 81
10.5. Manufacturers and Grey market equipment . . . . . . . . 83
10.6. Some mitigations for meddling by manufacturers . . . . . 83
10.7. Death of a manufacturer . . . . . . . . . . . . . . . . 84
11. Security Considerations . . . . . . . . . . . . . . . . . . . 85
11.1. Denial of Service (DoS) against MASA . . . . . . . . . . 86
11.2. DomainID must be resistant to second-preimage attacks . 86
11.3. Availability of good random numbers . . . . . . . . . . 87
11.4. Freshness in Voucher-Requests . . . . . . . . . . . . . 87
11.5. Trusting manufacturers . . . . . . . . . . . . . . . . . 88
11.6. Manufacturer Maintenance of trust anchors . . . . . . . 89
11.6.1. Compromise of Manufacturer IDevID signing keys . . . 91
11.6.2. Compromise of MASA signing keys . . . . . . . . . . 91
11.6.3. Compromise of MASA web service . . . . . . . . . . . 93
11.7. YANG Module Security Considerations . . . . . . . . . . 94
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 94
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 94
13.1. Normative References . . . . . . . . . . . . . . . . . . 94
13.2. Informative References . . . . . . . . . . . . . . . . . 98
Appendix A. IPv4 and non-ANI operations . . . . . . . . . . . . 102
A.1. IPv4 Link Local addresses . . . . . . . . . . . . . . . . 102
A.2. Use of DHCPv4 . . . . . . . . . . . . . . . . . . . . . . 102
Appendix B. mDNS / DNSSD proxy discovery options . . . . . . . . 102
Appendix C. Example Vouchers . . . . . . . . . . . . . . . . . . 103
C.1. Keys involved . . . . . . . . . . . . . . . . . . . . . . 103
C.1.1. Manufacturer Certificate Authority for IDevID
signatures . . . . . . . . . . . . . . . . . . . . . 104
C.1.2. MASA key pair for voucher signatures . . . . . . . . 105
C.1.3. Registrar Certificate Authority . . . . . . . . . . . 107
Pritikin, et al. Expires 15 May 2021 [Page 4]
Internet-Draft BRSKI November 2020
C.1.4. Registrar key pair . . . . . . . . . . . . . . . . . 108
C.1.5. Pledge key pair . . . . . . . . . . . . . . . . . . . 110
C.2. Example process . . . . . . . . . . . . . . . . . . . . . 111
C.2.1. Pledge to Registrar . . . . . . . . . . . . . . . . . 111
C.2.2. Registrar to MASA . . . . . . . . . . . . . . . . . . 115
C.2.3. MASA to Registrar . . . . . . . . . . . . . . . . . . 121
Appendix D. Additional References . . . . . . . . . . . . . . . 125
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 125
1. Introduction
The Bootstrapping Remote Secure Key Infrastructure (BRSKI) protocol
provides a solution for secure zero-touch (automated) bootstrap of
new (unconfigured) devices that are called pledges in this document.
Pledges have an IDevID installed in them at the factory.
"BRSKI" is pronounced like "brewski", a colloquial term for beer in
Canada and parts of the US-midwest. [brewski]
This document primarily provides for the needs of the ISP and
Enterprise focused ANIMA Autonomic Control Plane (ACP)
[I-D.ietf-anima-autonomic-control-plane]. This bootstrap process
satisfies the [RFC7575] requirements of section 3.3 of making all
operations secure by default. Other users of the BRSKI protocol will
need to provide separate applicability statements that include
privacy and security considerations appropriate to that deployment.
Section 9 explains the detailed applicability for this the ACP usage.
The BRSKI protocol requires a significant amount of communication
between manufacturer and owner: in its default modes it provides a
cryptographic transfer of control to the initial owner. In its
strongest modes, it leverages sales channel information to identify
the owner in advance. Resale of devices is possible, provided that
the manufacturer is willing to authorize the transfer. Mechanisms to
enable transfers of ownership without manufacturer authorization are
not included in this version of the protocol, but could be designed
into future versions.
This document describes how pledges discover (or are discovered by)
an element of the network domain to which the pledge belongs that
will perform the bootstrap. This element (device) is called the
registrar. Before any other operation, pledge and registrar need to
establish mutual trust:
1. Registrar authenticating the pledge: "Who is this device? What
is its identity?"
Pritikin, et al. Expires 15 May 2021 [Page 5]
Internet-Draft BRSKI November 2020
2. Registrar authorizing the pledge: "Is it mine? Do I want it?
What are the chances it has been compromised?"
3. Pledge authenticating the registrar: "What is this registrar's
identity?"
4. Pledge authorizing the registrar: "Should I join this network?"
This document details protocols and messages to answer the above
questions. It uses a TLS connection and an PKIX-shaped (X.509v3)
certificate (an IEEE 802.1AR [IDevID] IDevID) of the pledge to answer
points 1 and 2. It uses a new artifact called a "voucher" that the
registrar receives from a "Manufacturer Authorized Signing Authority"
(MASA) and passes to the pledge to answer points 3 and 4.
A proxy provides very limited connectivity between the pledge and the
registrar.
The syntactic details of vouchers are described in detail in
[RFC8366]. This document details automated protocol mechanisms to
obtain vouchers, including the definition of a 'voucher-request'
message that is a minor extension to the voucher format (see
Section 3) defined by [RFC8366].
BRSKI results in the pledge storing an X.509 root certificate
sufficient for verifying the registrar identity. In the process a
TLS connection is established that can be directly used for
Enrollment over Secure Transport (EST). In effect BRSKI provides an
automated mechanism for the "Bootstrap Distribution of CA
Certificates" described in [RFC7030] Section 4.1.1 wherein the pledge
"MUST [...] engage a human user to authorize the CA certificate using
out-of-band" information. With BRSKI the pledge now can automate
this process using the voucher. Integration with a complete EST
enrollment is optional but trivial.
BRSKI is agile enough to support bootstrapping alternative key
infrastructures, such as a symmetric key solutions, but no such
system is described in this document.
1.1. Prior Bootstrapping Approaches
To literally "pull yourself up by the bootstraps" is an impossible
action. Similarly the secure establishment of a key infrastructure
without external help is also an impossibility. Today it is commonly
accepted that the initial connections between nodes are insecure,
until key distribution is complete, or that domain-specific keying
material (often pre-shared keys, including mechanisms like SIM cards)
is pre-provisioned on each new device in a costly and non-scalable
Pritikin, et al. Expires 15 May 2021 [Page 6]
Internet-Draft BRSKI November 2020
manner. Existing automated mechanisms are known as non-secured
'Trust on First Use' (TOFU) [RFC7435], 'resurrecting duckling'
[Stajano99theresurrecting] or 'pre-staging'.
Another prior approach has been to try and minimize user actions
during bootstrapping, but not eliminate all user-actions. The
original EST protocol [RFC7030] does reduce user actions during
bootstrap but does not provide solutions for how the following
protocol steps can be made autonomic (not involving user actions):
* using the Implicit Trust Anchor [RFC7030] database to authenticate
an owner specific service (not an autonomic solution because the
URL must be securely distributed),
* engaging a human user to authorize the CA certificate using out-
of-band data (not an autonomic solution because the human user is
involved),
* using a configured Explicit TA database (not an autonomic solution
because the distribution of an explicit TA database is not
autonomic),
* and using a Certificate-Less TLS mutual authentication method (not
an autonomic solution because the distribution of symmetric key
material is not autonomic).
These "touch" methods do not meet the requirements for zero-touch.
There are "call home" technologies where the pledge first establishes
a connection to a well known manufacturer service using a common
client-server authentication model. After mutual authentication,
appropriate credentials to authenticate the target domain are
transferred to the pledge. This creates several problems and
limitations:
* the pledge requires realtime connectivity to the manufacturer
service,
* the domain identity is exposed to the manufacturer service (this
is a privacy concern),
* the manufacturer is responsible for making the authorization
decisions (this is a liability concern),
BRSKI addresses these issues by defining extensions to the EST
protocol for the automated distribution of vouchers.
Pritikin, et al. Expires 15 May 2021 [Page 7]
Internet-Draft BRSKI November 2020
1.2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The following terms are defined for clarity:
ANI: The Autonomic Network Infrastructure as defined by
[I-D.ietf-anima-reference-model]. Section 9 details specific
requirements for pledges, proxies and registrars when they are
part of an ANI.
Circuit Proxy: A stateful implementation of the join proxy. This is
the assumed type of proxy.
drop-ship: The physical distribution of equipment containing the
"factory default" configuration to a final destination. In zero-
touch scenarios there is no staging or pre-configuration during
drop-ship.
Domain: The set of entities that share a common local trust anchor.
This includes the proxy, registrar, Domain Certificate Authority,
Management components and any existing entity that is already a
member of the domain.
domainID: The domain IDentity is a unique value based upon the
Registrar CA's certificate. Section 5.8.2 specifies how it is
calculated.
Domain CA: The domain Certification Authority (CA) provides
certification functionalities to the domain. At a minimum it
provides certification functionalities to a registrar and manages
the private key that defines the domain. Optionally, it certifies
all elements.
enrollment: The process where a device presents key material to a
network and acquires a network-specific identity. For example
when a certificate signing request is presented to a certification
authority and a certificate is obtained in response.
imprint: The process where a device obtains the cryptographic key
material to identify and trust future interactions with a network.
This term is taken from Konrad Lorenz's work in biology with new
ducklings: during a critical period, the duckling would assume
that anything that looks like a mother duck is in fact their
Pritikin, et al. Expires 15 May 2021 [Page 8]
Internet-Draft BRSKI November 2020
mother. An equivalent for a device is to obtain the fingerprint
of the network's root certification authority certificate. A
device that imprints on an attacker suffers a similar fate to a
duckling that imprints on a hungry wolf. Securely imprinting is a
primary focus of this document [imprinting]. The analogy to
Lorenz's work was first noted in [Stajano99theresurrecting].
IDevID: An Initial Device Identity X.509 certificate installed by
the vendor on new equipment. This is a term from 802.1AR [IDevID]
IPIP Proxy: A stateless proxy alternative.
Join Proxy: A domain entity that helps the pledge join the domain.
A join proxy facilitates communication for devices that find
themselves in an environment where they are not provided
connectivity until after they are validated as members of the
domain. For simplicity this document sometimes uses the term of
'proxy' to indicate the join proxy. The pledge is unaware that
they are communicating with a proxy rather than directly with a
registrar.
Join Registrar (and Coordinator): A representative of the domain
that is configured, perhaps autonomically, to decide whether a new
device is allowed to join the domain. The administrator of the
domain interfaces with a "join registrar (and coordinator)" to
control this process. Typically a join registrar is "inside" its
domain. For simplicity this document often refers to this as just
"registrar". Within [I-D.ietf-anima-reference-model] this is
referred to as the "join registrar autonomic service agent".
Other communities use the abbreviation "JRC".
LDevID: A Local Device Identity X.509 certificate installed by the
owner of the equipment. This is a term from 802.1AR [IDevID]
manufacturer: the term manufacturer is used throughout this document
to be the entity that created the device. This is typically the
"original equipment manufacturer" or OEM, but in more complex
situations it could be a "value added retailer" (VAR), or possibly
even a systems integrator. In general, it a goal of BRSKI to
eliminate small distinctions between different sales channels.
The reason for this is that it permits a single device, with a
uniform firmware load, to be shipped directly to all customers.
This eliminates costs for the manufacturer. This also reduces the
number of products supported in the field increasing the chance
that firmware will be more up to date.
MASA Audit-Log: An anonymized list of previous owners maintained by
Pritikin, et al. Expires 15 May 2021 [Page 9]
Internet-Draft BRSKI November 2020
the MASA on a per device (per pledge) basis. Described in
Section 5.8.1.
MASA Service: A third-party Manufacturer Authorized Signing
Authority (MASA) service on the global Internet. The MASA signs
vouchers. It also provides a repository for audit-log information
of privacy protected bootstrapping events. It does not track
ownership.
nonced: a voucher (or request) that contains a nonce (the normal
case).
nonceless: a voucher (or request) that does not contain a nonce,
relying upon accurate clocks for expiration, or which does not
expire.
offline: When an architectural component cannot perform realtime
communications with a peer, either due to network connectivity or
because the peer is turned off, the operation is said to be
occurring offline.
Ownership Tracker: An Ownership Tracker service on the global
Internet. The Ownership Tracker uses business processes to
accurately track ownership of all devices shipped against domains
that have purchased them. Although optional, this component
allows vendors to provide additional value in cases where their
sales and distribution channels allow for accurate tracking of
such ownership. Ownership tracking information is indicated in
vouchers as described in [RFC8366]
Pledge: The prospective (unconfigured) device, which has an identity
installed at the factory.
(Public) Key Infrastructure: The collection of systems and processes
that sustain the activities of a public key system. The registrar
acts as an [RFC5280] and [RFC5272] (see section 7) "Registration
Authority".
TOFU: Trust on First Use. Used similarly to [RFC7435]. This is
where a pledge device makes no security decisions but rather
simply trusts the first registrar it is contacted by. This is
also known as the "resurrecting duckling" model.
Voucher: A signed artifact from the MASA that indicates to a pledge
the cryptographic identity of the registrar it should trust.
There are different types of vouchers depending on how that trust
is asserted. Multiple voucher types are defined in [RFC8366]
Pritikin, et al. Expires 15 May 2021 [Page 10]
Internet-Draft BRSKI November 2020
1.3. Scope of solution
1.3.1. Support environment
This solution (BRSKI) can support large router platforms with multi-
gigabit inter-connections, mounted in controlled access data centers.
But this solution is not exclusive to large equipment: it is intended
to scale to thousands of devices located in hostile environments,
such as ISP provided CPE devices which are drop-shipped to the end
user. The situation where an order is fulfilled from distributed
warehouse from a common stock and shipped directly to the target
location at the request of a domain owner is explicitly supported.
That stock ("SKU") could be provided to a number of potential domain
owners, and the eventual domain owner will not know a-priori which
device will go to which location.
The bootstrapping process can take minutes to complete depending on
the network infrastructure and device processing speed. The network
communication itself is not optimized for speed; for privacy reasons,
the discovery process allows for the pledge to avoid announcing its
presence through broadcasting.
Nomadic or mobile devices often need to acquire credentials to access
the network at the new location. An example of this is mobile phone
roaming among network operators, or even between cell towers. This
is usually called handoff. BRSKI does not provide a low-latency
handoff which is usually a requirement in such situations. For these
solutions BRSKI can be used to create a relationship (an LDevID) with
the "home" domain owner. The resulting credentials are then used to
provide credentials more appropriate for a low-latency handoff.
1.3.2. Constrained environments
Questions have been posed as to whether this solution is suitable in
general for Internet of Things (IoT) networks. This depends on the
capabilities of the devices in question. The terminology of
[RFC7228] is best used to describe the boundaries.
The solution described in this document is aimed in general at non-
constrained (i.e., class 2+ [RFC7228]) devices operating on a non-
Challenged network. The entire solution as described here is not
intended to be useable as-is by constrained devices operating on
challenged networks (such as 802.15.4 Low-power Lossy Networks
(LLN)s).
Specifically, there are protocol aspects described here that might
result in congestion collapse or energy-exhaustion of intermediate
battery powered routers in an LLN. Those types of networks should
Pritikin, et al. Expires 15 May 2021 [Page 11]
Internet-Draft BRSKI November 2020
not use this solution. These limitations are predominately related
to the large credential and key sizes required for device
authentication. Defining symmetric key techniques that meet the
operational requirements is out-of-scope but the underlying protocol
operations (TLS handshake and signing structures) have sufficient
algorithm agility to support such techniques when defined.
The imprint protocol described here could, however, be used by non-
energy constrained devices joining a non-constrained network (for
instance, smart light bulbs are usually mains powered, and speak
802.11). It could also be used by non-constrained devices across a
non-energy constrained, but challenged network (such as 802.15.4).
The certificate contents, and the process by which the four questions
above are resolved do apply to constrained devices. It is simply the
actual on-the-wire imprint protocol that could be inappropriate.
1.3.3. Network Access Controls
This document presumes that network access control has either already
occurred, is not required, or is integrated by the proxy and
registrar in such a way that the device itself does not need to be
aware of the details. Although the use of an X.509 Initial Device
Identity is consistent with IEEE 802.1AR [IDevID], and allows for
alignment with 802.1X network access control methods, its use here is
for pledge authentication rather than network access control.
Integrating this protocol with network access control, perhaps as an
Extensible Authentication Protocol (EAP) method (see [RFC3748]), is
out-of-scope.
1.3.4. Bootstrapping is not Booting
This document describes "bootstrapping" as the protocol used to
obtain a local trust anchor. It is expected that this trust anchor,
along with any additional configuration information subsequently
installed, is persisted on the device across system restarts
("booting"). Bootstrapping occurs only infrequently such as when a
device is transferred to a new owner or has been reset to factory
default settings.
1.4. Leveraging the new key infrastructure / next steps
As a result of the protocol described herein, the bootstrapped
devices have the Domain CA trust anchor in common. An end entity
certificate has optionally been issued from the Domain CA. This
makes it possible to securely deploy functionalities across the
domain, e.g:
* Device management.
Pritikin, et al. Expires 15 May 2021 [Page 12]
Internet-Draft BRSKI November 2020
* Routing authentication.
* Service discovery.
The major intended benefit is that it possible to use the credentials
deployed by this protocol to secure the Autonomic Control Plane (ACP)
([I-D.ietf-anima-autonomic-control-plane]).
1.5. Requirements for Autonomic Network Infrastructure (ANI) devices
The BRSKI protocol can be used in a number of environments. Some of
the options in this document are the result of requirements that are
out of the ANI scope. This section defines the base requirements for
ANI devices.
For devices that intend to become part of an Autonomic Network
Infrastructure (ANI) ([I-D.ietf-anima-reference-model]) that includes
an Autonomic Control Plane
([I-D.ietf-anima-autonomic-control-plane]), the BRSKI protocol MUST
be implemented.
The pledge must perform discovery of the proxy as described in
Section 4.1 using Generic Autonomic Signaling Protocol (GRASP)'s DULL
[I-D.ietf-anima-grasp] M_FLOOD announcements.
Upon successfully validating a voucher artifact, a status telemetry
MUST be returned. See Section 5.7.
An ANIMA ANI pledge MUST implement the EST automation extensions
described in Section 5.9. They supplement the [RFC7030] EST to
better support automated devices that do not have an end user.
The ANI Join Registrar Autonomic Service Agent (ASA) MUST support all
the BRSKI and above listed EST operations.
All ANI devices SHOULD support the BRSKI proxy function, using
circuit proxies over the ACP. (See Section 4.3)
2. Architectural Overview
The logical elements of the bootstrapping framework are described in
this section. Figure 1 provides a simplified overview of the
components.
Pritikin, et al. Expires 15 May 2021 [Page 13]
Internet-Draft BRSKI November 2020
+------------------------+
+--------------Drop Ship----------------| Vendor Service |
| +------------------------+
| | M anufacturer| |
| | A uthorized |Ownership|
| | S igning |Tracker |
| | A uthority | |
| +--------------+---------+
| ^
| | BRSKI-
V | MASA
+-------+ ............................................|...
| | . | .
| | . +------------+ +-----------+ | .
| | . | | | | | .
|Pledge | . | Join | | Domain <-------+ .
| | . | Proxy | | Registrar | .
| <-------->............<-------> (PKI RA) | .
| | | BRSKI-EST | | .
| | . | | +-----+-----+ .
|IDevID | . +------------+ | e.g. RFC7030 .
| | . +-----------------+----------+ .
| | . | Key Infrastructure | .
| | . | (e.g., PKI Certificate | .
+-------+ . | Authority) | .
. +----------------------------+ .
. .
................................................
"Domain" components
Figure 1: Architecture Overview
We assume a multi-vendor network. In such an environment there could
be a Manufacturer Service for each manufacturer that supports devices
following this document's specification, or an integrator could
provide a generic service authorized by multiple manufacturers. It
is unlikely that an integrator could provide Ownership Tracking
services for multiple manufacturers due to the required sales channel
integrations necessary to track ownership.
The domain is the managed network infrastructure with a Key
Infrastructure the pledge is joining. The domain provides initial
device connectivity sufficient for bootstrapping through a proxy.
The domain registrar authenticates the pledge, makes authorization
decisions, and distributes vouchers obtained from the Manufacturer
Service. Optionally the registrar also acts as a PKI Certification
Authority.
Pritikin, et al. Expires 15 May 2021 [Page 14]
Internet-Draft BRSKI November 2020
2.1. Behavior of a Pledge
The pledge goes through a series of steps, which are outlined here at
a high level.
------------
/ Factory \
\ default /
-----+------
|
+------v-------+
| (1) Discover |
+------------> |
| +------+-------+
| |
| +------v-------+
| | (2) Identify |
^------------+ |
| rejected +------+-------+
| |
| +------v-------+
| | (3) Request |
| | Join |
| +------+-------+
| |
| +------v-------+
| | (4) Imprint |
^------------+ |
| Bad MASA +------+-------+
| response | send Voucher Status Telemetry
| +------v-------+
| | (5) Enroll |<---+ (non-error HTTP codes )
^------------+ |\___/ (e.g. 202 'Retry-After')
| Enroll +------+-------+
| Failure |
| -----v------
| / Enrolled \
^------------+ |
Factory \------------/
reset
Figure 2: Pledge State Diagram
State descriptions for the pledge are as follows:
1. Discover a communication channel to a registrar.
Pritikin, et al. Expires 15 May 2021 [Page 15]
Internet-Draft BRSKI November 2020
2. Identify itself. This is done by presenting an X.509 IDevID
credential to the discovered registrar (via the proxy) in a TLS
handshake. (The registrar credentials are only provisionally
accepted at this time).
3. Request to join the discovered registrar. A unique nonce is
included ensuring that any responses can be associated with this
particular bootstrapping attempt.
4. Imprint on the registrar. This requires verification of the
manufacturer-service-provided voucher. A voucher contains
sufficient information for the pledge to complete authentication
of a registrar. This document details this step in depth.
5. Enroll. After imprint an authenticated TLS (HTTPS) connection
exists between pledge and registrar. Enrollment over Secure
Transport (EST) [RFC7030] can then be used to obtain a domain
certificate from a registrar.
The pledge is now a member of, and can be managed by, the domain and
will only repeat the discovery aspects of bootstrapping if it is
returned to factory default settings.
This specification details integration with EST enrollment so that
pledges can optionally obtain a locally issued certificate, although
any Representational State Transfer (REST) (see [REST]) interface
could be integrated in future work.
2.2. Secure Imprinting using Vouchers
A voucher is a cryptographically protected artifact (using a digital
signature) to the pledge device authorizing a zero-touch imprint on
the registrar domain.
The format and cryptographic mechanism of vouchers is described in
detail in [RFC8366].
Pritikin, et al. Expires 15 May 2021 [Page 16]
Internet-Draft BRSKI November 2020
Vouchers provide a flexible mechanism to secure imprinting: the
pledge device only imprints when a voucher can be validated. At the
lowest security levels the MASA can indiscriminately issue vouchers
and log claims of ownership by domains. At the highest security
levels issuance of vouchers can be integrated with complex sales
channel integrations that are beyond the scope of this document. The
sales channel integration would verify actual (legal) ownership of
the pledge by the domain. This provides the flexibility for a number
of use cases via a single common protocol mechanism on the pledge and
registrar devices that are to be widely deployed in the field. The
MASA services have the flexibility to leverage either the currently
defined claim mechanisms or to experiment with higher or lower
security levels.
Vouchers provide a signed but non-encrypted communication channel
among the pledge, the MASA, and the registrar. The registrar
maintains control over the transport and policy decisions, allowing
the local security policy of the domain network to be enforced.
2.3. Initial Device Identifier
Pledge authentication and pledge voucher-request signing is via a
PKIX-shaped certificate installed during the manufacturing process.
This is the 802.1AR Initial Device Identifier (IDevID), and it
provides a basis for authenticating the pledge during the protocol
exchanges described here. There is no requirement for a common root
PKI hierarchy. Each device manufacturer can generate its own root
certificate. Specifically, the IDevID enables:
1. Uniquely identifying the pledge by the Distinguished Name (DN)
and subjectAltName (SAN) parameters in the IDevID. The unique
identification of a pledge in the voucher objects are derived
from those parameters as described below. Section 10.3 discusses
privacy implications of the identifier.
2. Provides a cryptographic authentication of the pledge to the
Registrar (see Section 5.3).
3. Secure auto-discovery of the pledge's MASA by the registrar (see
Section 2.8).
4. Signing of voucher-request by the pledge's IDevID (see
Section 3).
5. Provides a cryptographic authentication of the pledge to the MASA
(see Section 5.5.5).
Pritikin, et al. Expires 15 May 2021 [Page 17]
Internet-Draft BRSKI November 2020
Section 7.2.13 (2009 edition) and section 8.10.3 (2018 edition) of
[IDevID] discusses keyUsage and extendedKeyUsage extensions in the
IDevID certificate. [IDevID] acknowledges that adding restrictions
in the certificate limits applicability of these long-lived
certificates. This specification emphasizes this point, and
therefore RECOMMENDS that no key usage restrictions be included.
This is consistent with [RFC5280] section 4.2.1.3, which does not
require key usage restrictions for end entity certificates.
2.3.1. Identification of the Pledge
In the context of BRSKI, pledges have a 1:1 relationship with a
"serial-number". This serial-number is used both in the "serial-
number" field of voucher or voucher-requests (see Section 3) and in
local policies on registrar or MASA (see Section 5).
There is a (certificate) serialNumber field is defined in [RFC5280]
section 4.1.2.2. In the ASN.1, this is referred to as the
CertificateSerialNumber. This field is NOT relevant to this
specification. Do not confuse this field with the "serial-number"
defined by this document, or by [IDevID] and [RFC4519] section 2.31.
The device serial number is defined in [RFC5280] section A.1 and A.2
as the X520SerialNumber, with the OID tag id-at-serialNumber.
The device serial number field (X520SerialNumber) is used as follows
by the pledge to build the "serial-number" that is placed in the
voucher-request. In order to build it, the fields need to be
converted into a serial-number of "type string".
An example of a printable form of the "serialNumber" field is
provided in [RFC4519] section 2.31 ("WI-3005"). That section further
provides equality and syntax attributes.
Due to the reality of existing device identity provisioning
processes, some manufacturers have stored serial-numbers in other
fields. Registrar's SHOULD be configurable, on a per-manufacturer
basis, to look for serial-number equivalents in other fields.
As explained in Section 5.5 the Registrar MUST extract the serial-
number again itself from the pledge's TLS certificate. It can
consult the serial-number in the pledge-request if there are any
possible confusion about the source of the serial-number.
Pritikin, et al. Expires 15 May 2021 [Page 18]
Internet-Draft BRSKI November 2020
2.3.2. MASA URI extension
This document defines a new PKIX non-critical certificate extension
to carry the MASA URI. This extension is intended to be used in the
IDevID certificate. The URI is represented as described in
Section 7.4 of [RFC5280].
The URI provides the authority information. The BRSKI "/.well-known"
tree ([RFC5785]) is described in Section 5.
A complete URI MAY be in this extension, including the 'scheme',
'authority', and 'path', The complete URI will typically be used in
diagnostic or experimental situations. Typically, (and in
consideration to constrained systems), this SHOULD be reduced to only
the 'authority', in which case a scheme of "https://" ([RFC7230]
section 2.7.3) and 'path' of "/.well-known/brski" is to be assumed.
The registrar can assume that only the 'authority' is present in the
extension, if there are no slash ("/") characters in the extension.
Section 7.4 of [RFC5280] calls out various schemes that MUST be
supported, including LDAP, HTTP and FTP. However, the registrar MUST
use HTTPS for the BRSKI-MASA connection.
The new extension is identified as follows:
Pritikin, et al. Expires 15 May 2021 [Page 19]
Internet-Draft BRSKI November 2020
<CODE BEGINS>
MASAURLExtnModule-2016 { iso(1) identified-organization(3) dod(6)
internet(1) security(5) mechanisms(5) pkix(7)
id-mod(0) id-mod-MASAURLExtn2016(TBD) }
DEFINITIONS IMPLICIT TAGS ::= BEGIN
-- EXPORTS ALL --
IMPORTS
EXTENSION
FROM PKIX-CommonTypes-2009
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkixCommon-02(57) }
id-pe FROM PKIX1Explicit-2009
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkix1-explicit-02(51) } ;
MASACertExtensions EXTENSION ::= { ext-MASAURL, ... }
ext-MASAURL EXTENSION ::= { SYNTAX MASAURLSyntax
IDENTIFIED BY id-pe-masa-url }
id-pe-masa-url OBJECT IDENTIFIER ::= { id-pe TBD }
MASAURLSyntax ::= IA5String
END
<CODE ENDS>
Figure 3: MASAURL ASN.1 Module
The choice of id-pe is based on guidance found in Section 4.2.2 of
[RFC5280], "These extensions may be used to direct applications to
on-line information about the issuer or the subject". The MASA URL
is precisely that: online information about the particular subject.
2.4. Protocol Flow
A representative flow is shown in Figure 4
Pritikin, et al. Expires 15 May 2021 [Page 20]
Internet-Draft BRSKI November 2020
+--------+ +---------+ +------------+ +------------+
| Pledge | | Circuit | | Domain | | Vendor |
| | | Join | | Registrar | | Service |
| | | Proxy | | (JRC) | | (MASA) |
+--------+ +---------+ +------------+ +------------+
| | | Internet |
[discover] | | |
|<-RFC4862 IPv6 addr | | |
|<-RFC3927 IPv4 addr | Appendix A | Legend |
|-++++++++++++++++++->| | C - circuit |
| optional: mDNS query| Appendix B | join proxy |
| RFC6763/RFC6762 (+) | | P - provisional |
|<-++++++++++++++++++-| | TLS connection |
| GRASP M_FLOOD | | |
| periodic broadcast| | |
[identity] | | |
|<------------------->C<----------------->| |
| TLS via the Join Proxy | |
|<--Registrar TLS server authentication---| |
[PROVISIONAL accept of server cert] | |
P---X.509 client authentication---------->| |
[request join] | |
P---Voucher Request(w/nonce for voucher)->| |
P /------------------- | |
P | [accept device?] |
P | [contact Vendor] |
P | |--Pledge ID-------->|
P | |--Domain ID-------->|
P | |--optional:nonce--->|
P optional: | [extract DomainID]
P can occur in advance | [update audit log]
P if nonceleess | |
P | |<- voucher ---------|
P \------------------- | w/nonce if provided|
P<------voucher---------------------------| |
[imprint] | |
|-------voucher status telemetry--------->| |
| |<-device audit log--|
| [verify audit log and voucher] |
|<--------------------------------------->| |
[enroll] | |
| Continue with RFC7030 enrollment | |
| using now bidirectionally authenticated | |
| TLS session. | |
[enrolled] | |
Figure 4: Protocol Time Sequence Diagram
Pritikin, et al. Expires 15 May 2021 [Page 21]
Internet-Draft BRSKI November 2020
On initial bootstrap, a new device (the pledge) uses a local service
autodiscovery (GRASP or mDNS) to locate a join proxy. The join proxy
connects the pledge to a local registrar (the JRC).
Having found a candidate registrar, the fledgling pledge sends some
information about itself to the registrar, including its serial
number in the form of a voucher request and its device identity
certificate (IDevID) as part of the TLS session.
The registrar can determine whether it expected such a device to
appear, and locates a MASA. The location of the MASA is usually
found in an extension in the IDevID. Having determined that the MASA
is suitable, the entire information from the initial voucher request
(including device serial number) is transmitted over the internet in
a TLS protected channel to the manufacturer, along with information
about the registrar/owner.
The manufacturer can then apply policy based on the provided
information, as well as other sources of information (such as sales
records), to decide whether to approve the claim by the registrar to
own the device; if the claim is accepted, a voucher is issued that
directs the device to accept its new owner.
The voucher is returned to the registrar, but not immediately to the
device -- the registrar has an opportunity to examine the voucher,
the MASA's audit-logs, and other sources of information to determine
whether the device has been tampered with, and whether the bootstrap
should be accepted.
No filtering of information is possible in the signed voucher, so
this is a binary yes-or-no decision. If the registrar accepts the
voucher as a proper one for its device, the voucher is returned to
the pledge for imprinting.
The voucher also includes a trust anchor that the pledge uses as
representing the owner. This is used to successfully bootstrap from
an environment where only the manufacturer has built-in trust by the
device into an environment where the owner now has a PKI footprint on
the device.
When BRSKI is followed with EST this single footprint is further
leveraged into the full owner's PKI and a LDevID for the device.
Subsequent reporting steps provide flows of information to indicate
success/failure of the process.
Pritikin, et al. Expires 15 May 2021 [Page 22]
Internet-Draft BRSKI November 2020
2.5. Architectural Components
2.5.1. Pledge
The pledge is the device that is attempting to join. The pledge is
assumed to talk to the Join Proxy using link-local network
connectivity. In most cases, the pledge has no other connectivity
until the pledge completes the enrollment process and receives some
kind of network credential.
2.5.2. Join Proxy
The join proxy provides HTTPS connectivity between the pledge and the
registrar. A circuit proxy mechanism is described in Section 4.
Additional mechanisms, including a CoAP mechanism and a stateless
IPIP mechanism are the subject of future work.
2.5.3. Domain Registrar
The domain's registrar operates as the BRSKI-MASA client when
requesting vouchers from the MASA (see Section 5.4). The registrar
operates as the BRSKI-EST server when pledges request vouchers (see
Section 5.1). The registrar operates as the BRSKI-EST server
"Registration Authority" if the pledge requests an end entity
certificate over the BRSKI-EST connection (see Section 5.9).
The registrar uses an Implicit Trust Anchor database for
authenticating the BRSKI-MASA connection's MASA TLS Server
Certificate. Configuration or distribution of trust anchors is out-
of-scope for this specification.
The registrar uses a different Implicit Trust Anchor database for
authenticating the BRSKI-EST connection's Pledge TLS Client
Certificate. Configuration or distribution of the BRSKI-EST client
trust anchors is out-of-scope of this specification. Note that the
trust anchors in/excluded from the database will affect which
manufacturers' devices are acceptable to the registrar as pledges,
and can also be used to limit the set of MASAs that are trusted for
enrollment.
2.5.4. Manufacturer Service
The Manufacturer Service provides two logically separate functions:
the Manufacturer Authorized Signing Authority (MASA) described in
Section 5.5 and Section 5.6, and an ownership tracking/auditing
function described in Section 5.7 and Section 5.8.
Pritikin, et al. Expires 15 May 2021 [Page 23]
Internet-Draft BRSKI November 2020
2.5.5. Public Key Infrastructure (PKI)
The Public Key Infrastructure (PKI) administers certificates for the
domain of concern, providing the trust anchor(s) for it and allowing
enrollment of pledges with domain certificates.
The voucher provides a method for the distribution of a single PKI
trust anchor (as the "pinned-domain-cert"). A distribution of the
full set of current trust anchors is possible using the optional EST
integration.
The domain's registrar acts as an [RFC5272] Registration Authority,
requesting certificates for pledges from the Key Infrastructure.
The expectations of the PKI are unchanged from EST [RFC7030]. This
document does not place any additional architectural requirements on
the Public Key Infrastructure.
2.6. Certificate Time Validation
2.6.1. Lack of realtime clock
Many devices when bootstrapping do not have knowledge of the current
time. Mechanisms such as Network Time Protocols cannot be secured
until bootstrapping is complete. Therefore bootstrapping is defined
with a framework that does not require knowledge of the current time.
A pledge MAY ignore all time stamps in the voucher and in the
certificate validity periods if it does not know the current time.
The pledge is exposed to dates in the following five places:
registrar certificate notBefore, registrar certificate notAfter,
voucher created-on, and voucher expires-on. Additionally, CMS
signatures contain a signingTime.
A pledge with a real time clock in which it has confidence, MUST
check the above time fields in all certificates and signatures that
it processes.
If the voucher contains a nonce then the pledge MUST confirm the
nonce matches the original pledge voucher-request. This ensures the
voucher is fresh. See Section 5.2.
2.6.2. Infinite Lifetime of IDevID
[RFC5280] explains that long lived pledge certificates "SHOULD be
assigned the GeneralizedTime value of 99991231235959Z" for the
notAfter field.
Pritikin, et al. Expires 15 May 2021 [Page 24]
Internet-Draft BRSKI November 2020
Some deployed IDevID management systems are not compliant with the
802.1AR requirement for infinite lifetimes, and put in typical <= 3
year certificate lifetimes. Registrars SHOULD be configurable on a
per-manufacturer basis to ignore pledge lifetimes when the pledge did
not follow the RFC5280 recommendations.
2.7. Cloud Registrar
There exist operationally open networks wherein devices gain
unauthenticated access to the Internet at large. In these use cases
the management domain for the device needs to be discovered within
the larger Internet. The case where a device can boot and get access
to larger Internet are less likely within the ANIMA ACP scope but may
be more important in the future. In the ANIMA ACP scope, new devices
will be quarantined behind a Join Proxy.
There are additionally some greenfield situations involving an
entirely new installation where a device may have some kind of
management uplink that it can use (such as via 3G network for
instance). In such a future situation, the device might use this
management interface to learn that it should configure itself to
become the local registrar.
In order to support these scenarios, the pledge MAY contact a well
known URI of a cloud registrar if a local registrar cannot be
discovered or if the pledge's target use cases do not include a local
registrar.
If the pledge uses a well known URI for contacting a cloud registrar
a manufacturer-assigned Implicit Trust Anchor database (see
[RFC7030]) MUST be used to authenticate that service as described in
[RFC6125]. The use of a DNS-ID for validation is appropriate, and it
may include wildcard components on the left-mode side. This is
consistent with the human user configuration of an EST server URI in
[RFC7030] which also depends on RFC6125.
2.8. Determining the MASA to contact
The registrar needs to be able to contact a MASA that is trusted by
the pledge in order to obtain vouchers. There are three mechanisms
described:
The device's Initial Device Identifier (IDevID) will normally contain
the MASA URL as detailed in Section 2.3. This is the RECOMMENDED
mechanism.
Pritikin, et al. Expires 15 May 2021 [Page 25]
Internet-Draft BRSKI November 2020
It can be operationally difficult to ensure the necessary X.509
extensions are in the pledge's IDevID due to the difficulty of
aligning current pledge manufacturing with software releases and
development. As a final fallback the registrar MAY be manually
configured or distributed with a MASA URL for each manufacturer.
Note that the registrar can only select the configured MASA URL based
on the trust anchor -- so manufacturers can only leverage this
approach if they ensure a single MASA URL works for all pledges
associated with each trust anchor.
3. Voucher-Request artifact
Voucher-requests are how vouchers are requested. The semantics of
the voucher-request are described below, in the YANG model.
A pledge forms the "pledge voucher-request", signs it with it's
IDevID and submits it to the registrar.
The registrar in turn forms the "registrar voucher-request", signs it
with it's Registrar keypair and submits it to the MASA.
The "proximity-registrar-cert" leaf is used in the pledge voucher-
requests. This provides a method for the pledge to assert the
registrar's proximity.
This network proximity results from the following properties in the
ACP context: the pledge is connected to the Join Proxy (Section 4)
using a Link-Local IPv6 connection. While the Join Proxy does not
participate in any meaningful sense in the cryptography of the TLS
connection (such as via a Channel Binding), the Registrar can observe
that the connection is via the private ACP (ULA) address of the join
proxy, and could not come from outside the ACP. The Pledge must
therefore be at most one IPv6 Link-Local hop away from an existing
node on the ACP.
Other users of BRSKI will need to define other kinds of assertions if
the network proximity described above does not match their needs.
The "prior-signed-voucher-request" leaf is used in registrar voucher-
requests. If present, it is the signed pledge voucher-request
artifact. This provides a method for the registrar to forward the
pledge's signed request to the MASA. This completes transmission of
the signed "proximity-registrar-cert" leaf.
Unless otherwise signaled (outside the voucher-request artifact), the
signing structure is as defined for vouchers, see [RFC8366].
Pritikin, et al. Expires 15 May 2021 [Page 26]
Internet-Draft BRSKI November 2020
3.1. Nonceless Voucher Requests
A registrar MAY also retrieve nonceless vouchers by sending nonceless
voucher-requests to the MASA in order to obtain vouchers for use when
the registrar does not have connectivity to the MASA. No "prior-
signed-voucher-request" leaf would be included. The registrar will
also need to know the serial number of the pledge. This document
does not provide a mechanism for the registrar to learn that in an
automated fashion. Typically this will be done via scanning of bar-
code or QR-code on packaging, or via some sales channel integration.
3.2. Tree Diagram
The following tree diagram illustrates a high-level view of a
voucher-request document. The voucher-request builds upon the
voucher artifact described in [RFC8366]. The tree diagram is
described in [RFC8340]. Each node in the diagram is fully described
by the YANG module in Section 3.4. Please review the YANG module for
a detailed description of the voucher-request format.
module: ietf-voucher-request
grouping voucher-request-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
+-- prior-signed-voucher-request? binary
+-- proximity-registrar-cert? binary
Figure 5: YANG Tree diagram for Voucher-Request
3.3. Examples
This section provides voucher-request examples for illustration
purposes. These examples show the JSON prior to CMS wrapping. JSON
encoding rules specify that any binary content be base64 encoded
([RFC4648] section 4). The contents of the (base64) encoded
certificates have been elided to save space. For detailed examples,
see Appendix C.2. These examples conform to the encoding rules
defined in [RFC7951].
Pritikin, et al. Expires 15 May 2021 [Page 27]
Internet-Draft BRSKI November 2020
Example (1) The following example illustrates a pledge voucher-
request. The assertion leaf is indicated as 'proximity'
and the registrar's TLS server certificate is included
in the 'proximity-registrar-cert' leaf. See
Section 5.2.
{
"ietf-voucher-request:voucher": {
"assertion": "proximity",
"nonce": "62a2e7693d82fcda2624de58fb6722e5",
"serial-number" : "JADA123456789",
"created-on": "2017-01-01T00:00:00.000Z",
"proximity-registrar-cert": "base64encodedvalue=="
}
}
Figure 6: JSON representation of example Voucher-Request
Example (2) The following example illustrates a registrar voucher-
request. The 'prior-signed-voucher-request' leaf is
populated with the pledge's voucher-request (such as the
prior example). The pledge's voucher-request is a
binary CMS signed object. In the JSON encoding used
here it must be base64 encoded. The nonce and assertion
have been carried forward from the pledge request to the
registrar request. The serial-number is extracted from
the pledge's Client Certificate from the TLS connection.
See Section 5.5.
{
"ietf-voucher-request:voucher": {
"assertion" : "proximity",
"nonce": "62a2e7693d82fcda2624de58fb6722e5",
"created-on": "2017-01-01T00:00:02.000Z",
"idevid-issuer": "base64encodedvalue==",
"serial-number": "JADA123456789",
"prior-signed-voucher-request": "base64encodedvalue=="
}
}
Figure 7: JSON representation of example Prior-Signed Voucher-Request
Example (3) The following example illustrates a registrar voucher-
request. The 'prior-signed-voucher-request' leaf is not
populated with the pledge's voucher-request nor is the
nonce leaf. This form might be used by a registrar
requesting a voucher when the pledge can not communicate
with the registrar (such as when it is powered down, or
Pritikin, et al. Expires 15 May 2021 [Page 28]
Internet-Draft BRSKI November 2020
still in packaging), and therefore could not submit a
nonce. This scenario is most useful when the registrar
is aware that it will not be able to reach the MASA
during deployment. See Section 5.5.
{
"ietf-voucher-request:voucher": {
"created-on": "2017-01-01T00:00:02.000Z",
"idevid-issuer": "base64encodedvalue==",
"serial-number": "JADA123456789"
}
}
Figure 8: JSON representation of Offline Voucher-Request
3.4. YANG Module
Following is a YANG [RFC7950] module formally extending the [RFC8366]
voucher into a voucher-request.
<CODE BEGINS> file "ietf-voucher-request@2018-02-14.yang"
module ietf-voucher-request {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-voucher-request";
prefix "vcr";
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 vch;
description "This module defines the format for a voucher,
which is produced by a pledge's manufacturer or
delegate (MASA) to securely assign a pledge to
an 'owner', so that the pledge may establish a secure
connection to the owner's network infrastructure";
reference "RFC 8366: Voucher Artifact for
Bootstrapping Protocols";
}
organization
Pritikin, et al. Expires 15 May 2021 [Page 29]
Internet-Draft BRSKI November 2020
"IETF ANIMA Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/anima/>
WG List: <mailto:anima@ietf.org>
Author: Kent Watsen
<mailto:kent+ietf@watsen.net>
Author: Michael H. Behringer
<mailto:Michael.H.Behringer@gmail.com>
Author: Toerless Eckert
<mailto:tte+ietf@cs.fau.de>
Author: Max Pritikin
<mailto:pritikin@cisco.com>
Author: Michael Richardson
<mailto:mcr+ietf@sandelman.ca>";
description
"This module defines the format for a voucher request.
It is a superset of the voucher itself.
It provides content to the MASA for consideration
during a voucher request.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
'MAY', and 'OPTIONAL' in this document are to be interpreted as
described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.
Copyright (c) 2019 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see the RFC
itself for full legal notices.";
revision "2018-02-14" {
description
"Initial version";
reference
"RFC XXXX: Bootstrapping Remote Secure Key Infrastructure";
}
Pritikin, et al. Expires 15 May 2021 [Page 30]
Internet-Draft BRSKI November 2020
// Top-level statement
rc:yang-data voucher-request-artifact {
uses voucher-request-grouping;
}
// Grouping defined for future usage
grouping voucher-request-grouping {
description
"Grouping to allow reuse/extensions in future work.";
uses vch:voucher-artifact-grouping {
refine "voucher/created-on" {
mandatory false;
}
refine "voucher/pinned-domain-cert" {
mandatory false;
description "A pinned-domain-cert field
is not valid in a voucher request, and
any occurrence MUST be ignored";
}
refine "voucher/last-renewal-date" {
description "A last-renewal-date field
is not valid in a voucher request, and
any occurrence MUST be ignored";
}
refine "voucher/domain-cert-revocation-checks" {
description "The domain-cert-revocation-checks field
is not valid in a voucher request, and
any occurrence MUST be ignored";
}
refine "voucher/assertion" {
mandatory false;
description "Any assertion included in registrar voucher
requests SHOULD be ignored by the MASA.";
}
augment "voucher" {
description
"Adds leaf nodes appropriate for requesting vouchers.";
leaf prior-signed-voucher-request {
type binary;
description
"If it is necessary to change a voucher, or re-sign and
Pritikin, et al. Expires 15 May 2021 [Page 31]
Internet-Draft BRSKI November 2020
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 voucher request
with a proximity-registrar-cert, and the registrar
then includes it as the prior-signed-voucher-request
field. This is a simple mechanism for a chain of
trusted parties to change a voucher request, while
maintaining the prior signature information.
The Registrar and MASA 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.";
}
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.X690.1994].
The first certificate in the Registrar TLS server
certificate_list sequence (the end-entity TLS
certificate, see [RFC8446]) presented by the Registrar
to the Pledge.
This MUST be populated in a Pledge's voucher request
when a proximity assertion is requested.";
}
}
}
}
}
<CODE ENDS>
Figure 9: YANG module for Voucher-Request
Pritikin, et al. Expires 15 May 2021 [Page 32]
Internet-Draft BRSKI November 2020
4. Proxying details (Pledge - Proxy - Registrar)
This section is normative for uses with an ANIMA ACP. The use of the
GRASP mechanism is part of the ACP. Other users of BRSKI will need
to define an equivalent proxy mechanism, and an equivalent mechanism
to configure the proxy.
The role of the proxy is to facilitate communications. The proxy
forwards packets between the pledge and a registrar that has been
provisioned to the proxy via full GRASP ACP discovery.
This section defines a stateful proxy mechanism which is referred to
as a "circuit" proxy. This is a form of Application Level Gateway
([RFC2663] section 2.9).
The proxy does not terminate the TLS handshake: it passes streams of
bytes onward without examination. A proxy MUST NOT assume any
specific TLS version. Please see [RFC8446] section 9.3 for details
on TLS invariants.
A Registrar can directly provide the proxy announcements described
below, in which case the announced port can point directly to the
Registrar itself. In this scenario the pledge is unaware that there
is no proxying occurring. This is useful for Registrars which are
servicing pledges on directly connected networks.
As a result of the proxy Discovery process in Section 4.1.1, the port
number exposed by the proxy does not need to be well known, or
require an IANA allocation.
During the discovery of the Registrar by the Join Proxy, the Join
Proxy will also learn which kinds of proxy mechanisms are available.
This will allow the Join Proxy to use the lowest impact mechanism
which the Join Proxy and Registrar have in common.
In order to permit the proxy functionality to be implemented on the
maximum variety of devices the chosen mechanism should use the
minimum amount of state on the proxy device. While many devices in
the ANIMA target space will be rather large routers, the proxy
function is likely to be implemented in the control plane CPU of such
a device, with available capabilities for the proxy function similar
to many class 2 IoT devices.
The document [I-D.richardson-anima-state-for-joinrouter] provides a
more extensive analysis and background of the alternative proxy
methods.
Pritikin, et al. Expires 15 May 2021 [Page 33]
Internet-Draft BRSKI November 2020
4.1. Pledge discovery of Proxy
The result of discovery is a logical communication with a registrar,
through a proxy. The proxy is transparent to the pledge. The
communication between the pledge and Join Proxy is over IPv6 Link-
Local addresses.
To discover the proxy the pledge performs the following actions:
1. MUST: Obtains a local address using IPv6 methods as described in
[RFC4862] IPv6 Stateless Address AutoConfiguration. Use of
[RFC4941] temporary addresses is encouraged. To limit pervasive
monitoring ( [RFC7258]), a new temporary address MAY use a short
lifetime (that is, set TEMP_PREFERRED_LIFETIME to be short).
Pledges will generally prefer use of IPv6 Link-Local addresses,
and discovery of proxy will be by Link-Local mechanisms. IPv4
methods are described in Appendix A
2. MUST: Listen for GRASP M_FLOOD ([I-D.ietf-anima-grasp])
announcements of the objective: "AN_Proxy". See section
Section 4.1.1 for the details of the objective. The pledge MAY
listen concurrently for other sources of information, see
Appendix B.
Once a proxy is discovered the pledge communicates with a registrar
through the proxy using the bootstrapping protocol defined in
Section 5.
While the GRASP M_FLOOD mechanism is passive for the pledge, the non-
normative other methods (mDNS, and IPv4 methods) described in
Appendix B are active. The pledge SHOULD run those methods in
parallel with listening to for the M_FLOOD. The active methods
SHOULD back-off by doubling to a maximum of one hour to avoid
overloading the network with discovery attempts. Detection of change
of physical link status (Ethernet carrier for instance) SHOULD reset
the back off timers.
The pledge could discover more than one proxy on a given physical
interface. The pledge can have a multitude of physical interfaces as
well: a layer-2/3 Ethernet switch may have hundreds of physical
ports.
Each possible proxy offer SHOULD be attempted up to the point where a
valid voucher is received: while there are many ways in which the
attempt may fail, it does not succeed until the voucher has been
validated.
Pritikin, et al. Expires 15 May 2021 [Page 34]
Internet-Draft BRSKI November 2020
The connection attempts via a single proxy SHOULD exponentially back-
off to a maximum of one hour to avoid overloading the network
infrastructure. The back-off timer for each MUST be independent of
other connection attempts.
Connection attempts SHOULD be run in parallel to avoid head of queue
problems wherein an attacker running a fake proxy or registrar could
perform protocol actions intentionally slowly. Connection attempts
to different proxies SHOULD be sent with an interval of 3 to 5s. The
pledge SHOULD continue to listen to for additional GRASP M_FLOOD
messages during the connection attempts.
Each connection attempt through a distinct Join Proxy MUST have a
unique nonce in the voucher-request.
Once a connection to a registrar is established (e.g. establishment
of a TLS session key) there are expectations of more timely
responses, see Section 5.2.
Once all discovered services are attempted (assuming that none
succeeded) the device MUST return to listening for GRASP M_FLOOD. It
SHOULD periodically retry any manufacturer-specific mechanisms. The
pledge MAY prioritize selection order as appropriate for the
anticipated environment.
4.1.1. Proxy GRASP announcements
A proxy uses the DULL GRASP M_FLOOD mechanism to announce itself.
This announcement can be within the same message as the ACP
announcement detailed in [I-D.ietf-anima-autonomic-control-plane].
The formal Concise Data Definition Language (CDDL) [RFC8610]
definition is:
Pritikin, et al. Expires 15 May 2021 [Page 35]
Internet-Draft BRSKI November 2020
<CODE BEGINS> file "proxygrasp.cddl"
flood-message = [M_FLOOD, session-id, initiator, ttl,
+[objective, (locator-option / [])]]
objective = ["AN_Proxy", objective-flags, loop-count,
objective-value]
ttl = 180000 ; 180,000 ms (3 minutes)
initiator = ACP address to contact Registrar
objective-flags = sync-only ; as in GRASP spec
sync-only = 4 ; M_FLOOD only requires synchronization
loop-count = 1 ; one hop only
objective-value = any ; none
locator-option = [ O_IPv6_LOCATOR, ipv6-address,
transport-proto, port-number ]
ipv6-address = the v6 LL of the Proxy
$transport-proto /= IPPROTO_TCP ; note this can be any value from the
; IANA protocol registry, as per
; [GRASP] section 2.9.5.1, note 3.
port-number = selected by Proxy
<CODE ENDS>
Figure 10: CDDL definition of Proxy Discovery message
Here is an example M_FLOOD announcing a proxy at fe80::1, on TCP port
4443.
[M_FLOOD, 12340815, h'fe800000000000000000000000000001', 180000,
[["AN_Proxy", 4, 1, ""],
[O_IPv6_LOCATOR,
h'fe800000000000000000000000000001', IPPROTO_TCP, 4443]]]
Figure 11: Example of Proxy Discovery message
On a small network the Registrar MAY include the GRASP M_FLOOD
announcements to locally connected networks.
The $transport-proto above indicates the method that the pledge-
proxy-registrar will use. The TCP method described here is
mandatory, and other proxy methods, such as CoAP methods not defined
in this document are optional. Other methods MUST NOT be enabled
unless the Join Registrar ASA indicates support for them in it's own
announcement.
Pritikin, et al. Expires 15 May 2021 [Page 36]
Internet-Draft BRSKI November 2020
4.2. CoAP connection to Registrar
The use of CoAP to connect from pledge to registrar is out of scope
for this document, and is described in future work. See
[I-D.ietf-anima-constrained-voucher].
4.3. Proxy discovery and communication of Registrar
The registrar SHOULD announce itself so that proxies can find it and
determine what kind of connections can be terminated.
The registrar announces itself using ACP instance of GRASP using
M_FLOOD messages, with the "AN_join_registrar" objective. A
registrar may announce any convenient port number, including using a
stock port 443. ANI proxies MUST support GRASP discovery of
registrars.
The M_FLOOD is formatted as follows:
[M_FLOOD, 51804321, h'fda379a6f6ee00000200000064000001', 180000,
[["AN_join_registrar", 4, 255, "EST-TLS"],
[O_IPv6_LOCATOR,
h'fda379a6f6ee00000200000064000001', IPPROTO_TCP, 8443]]]
Figure 12: An example of a Registrar announcement message
The formal CDDL definition is:
<CODE BEGINS> file "jrcgrasp.cddl"
flood-message = [M_FLOOD, session-id, initiator, ttl,
+[objective, (locator-option / [])]]
objective = ["AN_join_registrar", objective-flags, loop-count,
objective-value]
initiator = ACP address to contact Registrar
objective-flags = sync-only ; as in GRASP spec
sync-only = 4 ; M_FLOOD only requires synchronization
loop-count = 255 ; mandatory maximum
objective-value = text ; name of the (list of) of supported
; protocols: "EST-TLS" for RFC7030.
<CODE ENDS>
Figure 13: CDDL definition for Registrar announcement message
Pritikin, et al. Expires 15 May 2021 [Page 37]
Internet-Draft BRSKI November 2020
The M_FLOOD message MUST be sent periodically. The default period
SHOULD be 60 seconds, the value SHOULD be operator configurable but
SHOULD NOT be smaller than 60 seconds. The frequency of sending MUST
be such that the aggregate amount of periodic M_FLOODs from all
flooding sources cause only negligible traffic across the ACP.
Here are some examples of locators for illustrative purposes. Only
the first one ($transport-protocol = 6, TCP) is defined in this
document and is mandatory to implement.
locator1 = [O_IPv6_LOCATOR, fd45:1345::6789, 6, 443]
locator2 = [O_IPv6_LOCATOR, fd45:1345::6789, 17, 5683]
locator3 = [O_IPv6_LOCATOR, fe80::1234, 41, nil]
A protocol of 6 indicates that TCP proxying on the indicated port is
desired.
Registrars MUST announce the set of protocols that they support.
They MUST support TCP traffic.
Registrars MUST accept HTTPS/EST traffic on the TCP ports indicated.
Registrars MUST support ANI TLS circuit proxy and therefore BRSKI
across HTTPS/TLS native across the ACP.
In the ANI, the Autonomic Control Plane (ACP) secured instance of
GRASP ([I-D.ietf-anima-grasp]) MUST be used for discovery of ANI
registrar ACP addresses and ports by ANI proxies. The TCP leg of the
proxy connection between ANI proxy and ANI registrar therefore also
runs across the ACP.
5. Protocol Details (Pledge - Registrar - MASA)
The pledge MUST initiate BRSKI after boot if it is unconfigured. The
pledge MUST NOT automatically initiate BRSKI if it has been
configured or is in the process of being configured.
BRSKI is described as extensions to EST [RFC7030]. The goal of these
extensions is to reduce the number of TLS connections and crypto
operations required on the pledge. The registrar implements the
BRSKI REST interface within the "/.well-known/brski" URI tree, as
well as implementing the existing EST URIs as described in EST
[RFC7030] section 3.2.2. The communication channel between the
pledge and the registrar is referred to as "BRSKI-EST" (see
Figure 1).
Pritikin, et al. Expires 15 May 2021 [Page 38]
Internet-Draft BRSKI November 2020
The communication channel between the registrar and MASA is a new
communication channel, similar to EST, within the newly registred
"/.well-known/brski" tree. For clarity this channel is referred to
as "BRSKI-MASA". (See Figure 1).
The MASA URI is "https://" authority "/.well-known/brski".
BRSKI uses existing CMS message formats for existing EST operations.
BRSKI uses JSON [RFC8259] for all new operations defined here, and
voucher formats. In all places where a binary value must be carried
in a JSON string, the use of base64 format ([RFC4648] section 4) is
to be used, as per [RFC7951] section 6.6.
While EST section 3.2 does not insist upon use of HTTP persistent
connections ([RFC7230] section 6.3), BRSKI-EST connections SHOULD use
persistent connections. The intention of this guidance is to ensure
the provisional TLS state occurs only once, and that the subsequent
resolution of the provision state is not subject to a MITM attack
during a critical phase.
If non-persistent connections are used, then both the pledge and the
registrar MUST remember the certificates seen, and also sent for the
first connection. They MUST check each subsequent connections for
the same certificates, and each end MUST use the same certificates as
well. This places a difficult restriction on rolling certificates on
the Registrar.
Summarized automation extensions for the BRSKI-EST flow are:
* The pledge either attempts concurrent connections via each
discovered proxy, or it times out quickly and tries connections in
series, as explained at the end of Section 5.1.
* The pledge provisionally accepts the registrar certificate during
the TLS handshake as detailed in Section 5.1.
* The pledge requests a voucher using the new REST calls described
below. This voucher is then validated.
* The pledge completes authentication of the server certificate as
detailed in Section 5.6.1. This moves the BRSKI-EST TLS
connection out of the provisional state.
* Mandatory bootstrap steps conclude with voucher status telemetry
(see Section 5.7).
The BRSKI-EST TLS connection can now be used for EST enrollment.
Pritikin, et al. Expires 15 May 2021 [Page 39]
Internet-Draft BRSKI November 2020
The extensions for a registrar (equivalent to EST server) are:
* Client authentication is automated using Initial Device Identity
(IDevID) as per the EST certificate based client authentication.
The subject field's DN encoding MUST include the "serialNumber"
attribute with the device's unique serial number as explained in
Section 2.3.1
* The registrar requests and validates the voucher from the MASA.
* The registrar forwards the voucher to the pledge when requested.
* The registrar performs log verifications (described in
Section 5.8.3) in addition to local authorization checks before
accepting optional pledge device enrollment requests.
5.1. BRSKI-EST TLS establishment details
The pledge establishes the TLS connection with the registrar through
the circuit proxy (see Section 4) but the TLS handshake is with the
registrar. The BRSKI-EST pledge is the TLS client and the BRSKI-EST
registrar is the TLS server. All security associations established
are between the pledge and the registrar regardless of proxy
operations.
Use of TLS 1.3 (or newer) is encouraged. TLS 1.2 or newer is
REQUIRED on the Pledge side. TLS 1.3 (or newer) SHOULD be available
on the Registrar server interface, and the Registrar client
interface, but TLS 1.2 MAY be used. TLS 1.3 (or newer) SHOULD be
available on the MASA server interface, but TLS 1.2 MAY be used.
Establishment of the BRSKI-EST TLS connection is as specified in EST
[RFC7030] section 4.1.1 "Bootstrap Distribution of CA Certificates"
[RFC7030] wherein the client is authenticated with the IDevID
certificate, and the EST server (the registrar) is provisionally
authenticated with an unverified server certificate. Configuration
or distribution of the trust anchor database used for validating the
IDevID certificate is out-of-scope of this specification. Note that
the trust anchors in/excluded from the database will affect which
manufacturers' devices are acceptable to the registrar as pledges,
and can also be used to limit the set of MASAs that are trusted for
enrollment.
The signature in the certificate MUST be validated even if a signing
key can not (yet) be validated. The certificate (or chain) MUST be
retained for later validation.
Pritikin, et al. Expires 15 May 2021 [Page 40]
Internet-Draft BRSKI November 2020
A self-signed certificate for the Registrar is acceptable as the
voucher can validate it upon successful enrollment.
The pledge performs input validation of all data received until a
voucher is verified as specified in Section 5.6.1 and the TLS
connection leaves the provisional state. Until these operations are
complete the pledge could be communicating with an attacker.
The pledge code needs to be written with the assumption that all data
is being transmitted at this point to an unauthenticated peer, and
that received data, while inside a TLS connection, MUST be considered
untrusted. This particularly applies to HTTP headers and CMS
structures that make up the voucher.
A pledge that can connect to multiple Registrars concurrently SHOULD
do so. Some devices may be unable to do so for lack of threading, or
resource issues. Concurrent connections defeat attempts by a
malicious proxy from causing a TCP Slowloris-like attack (see
[slowloris]).
A pledge that can not maintain as many connections as there are
eligible proxies will need to rotate among the various choices,
terminating connections that do not appear to be making progress. If
no connection is making progress after 5 seconds then the pledge
SHOULD drop the oldest connection and go on to a different proxy: the
proxy that has been communicated with least recently. If there were
no other proxies discovered, the pledge MAY continue to wait, as long
as it is concurrently listening for new proxy announcements.
5.2. Pledge Requests Voucher from the Registrar
When the pledge bootstraps it makes a request for a voucher from a
registrar.
This is done with an HTTPS POST using the operation path value of
"/.well-known/brski/requestvoucher".
The pledge voucher-request Content-Type is:
application/voucher-cms+json [RFC8366] defines a "YANG-defined JSON
document that has been signed using a CMS structure", and the
voucher-request described in Section 3 is created in the same way.
The media type is the same as defined in [RFC8366]. This is also
used for the pledge voucher-request. The pledge MUST sign the
request using the Section 2.3 credential.
Registrar implementations SHOULD anticipate future media types but of
course will simply fail the request if those types are not yet known.
Pritikin, et al. Expires 15 May 2021 [Page 41]
Internet-Draft BRSKI November 2020
The pledge SHOULD include an [RFC7231] section 5.3.2 "Accept" header
field indicating the acceptable media type for the voucher response.
The "application/voucher-cms+json" media type is defined in [RFC8366]
but constrained voucher formats are expected in the future.
Registrars and MASA are expected to be flexible in what they accept.
The pledge populates the voucher-request fields as follows:
created-on: Pledges that have a realtime clock are RECOMMENDED to
populate this field with the current date and time in yang:date-
and-time format. This provides additional information to the
MASA. Pledges that have no real-time clocks MAY omit this field.
nonce: The pledge voucher-request MUST contain a cryptographically
strong random or pseudo-random number nonce (see [RFC4086] section
6.2). As the nonce is usually generated very early in the boot
sequence there is a concern that the same nonce might generated
across multiple boots, or after a factory reset. Different nonces
MUST be generated for each bootstrapping attempt, whether in
series or concurrently. The freshness of this nonce mitigates
against the lack of real-time clock as explained in Section 2.6.1.
assertion: The pledge indicates support for the mechanism described
in this document, by putting the value "proximity" in the voucher-
request, MUST include the "proximity-registrar-cert" field
(below).
proximity-registrar-cert: In a pledge voucher-request this is the
first certificate in the TLS server 'certificate_list' sequence
(see [RFC5246]) presented by the registrar to the pledge. That
is, it is the end-entity certificate. This MUST be populated in a
pledge voucher-request.
serial-number The serial number of the pledge is included in the
voucher-request from the Pledge. This value is included as a
sanity check only, but it is not to be forwarded by the Registrar
as described in Section 5.5.
All other fields MAY be omitted in the pledge voucher-request.
An example JSON payload of a pledge voucher-request is in Section 3.3
Example 1.
The registrar confirms that the assertion is 'proximity' and that
pinned 'proximity-registrar-cert' is the Registrar's certificate. If
this validation fails, then there is an On-Path Attacker (MITM), and
the connection MUST be closed after the returning an HTTP 401 error
code.
Pritikin, et al. Expires 15 May 2021 [Page 42]
Internet-Draft BRSKI November 2020
5.3. Registrar Authorization of Pledge
In a fully automated network all devices must be securely identified
and authorized to join the domain.
A Registrar accepts or declines a request to join the domain, based
on the authenticated identity presented. For different networks,
examples of automated acceptance may include:
* allow any device of a specific type (as determined by the X.509
IDevID),
* allow any device from a specific vendor (as determined by the
X.509 IDevID),
* allow a specific device from a vendor (as determined by the X.509
IDevID) against a domain white list. (The mechanism for checking
a shared white list potentially used by multiple Registrars is out
of scope).
If validation fails the registrar SHOULD respond with the HTTP 404
error code. If the voucher-request is in an unknown format, then an
HTTP 406 error code is more appropriate. A situation that could be
resolved with administrative action (such as adding a vendor to a
whitelist) MAY be responded with an 403 HTTP error code.
If authorization is successful the registrar obtains a voucher from
the MASA service (see Section 5.5) and returns that MASA signed
voucher to the pledge as described in Section 5.6.
5.4. BRSKI-MASA TLS establishment details
The BRSKI-MASA TLS connection is a 'normal' TLS connection
appropriate for HTTPS REST interfaces. The registrar initiates the
connection and uses the MASA URL obtained as described in
Section 2.8. The mechanisms in [RFC6125] SHOULD be used in
authentication of the MASA using a DNS-ID that matches that which is
found in the IDevID. Registrars MAY include a mechanism to override
the MASA URL on a manufacturer-by-manufacturer basis, and within that
override it is appropriate to provide alternate anchors. This will
typically used by some vendors to establish explicit (or private)
trust anchors for validating their MASA that is part of a sales
channel integration.
Use of TLS 1.3 (or newer) is encouraged. TLS 1.2 or newer is
REQUIRED. TLS 1.3 (or newer) SHOULD be available.
Pritikin, et al. Expires 15 May 2021 [Page 43]
Internet-Draft BRSKI November 2020
As described in [RFC7030], the MASA and the registrars SHOULD be
prepared to support TLS client certificate authentication and/or HTTP
Basic, Digest, or SCRAM authentication. This connection MAY also
have no client authentication at all.
Registrars SHOULD permit trust anchors to be pre-configured on a per-
vendor(MASA) basis. Registrars SHOULD include the ability to
configure a TLS ClientCertificate on a per-MASA basis, or to use no
client certificate. Registrars SHOULD also permit HTTP Basic and
Digest authentication to be configured.
The authentication of the BRSKI-MASA connection does not change the
voucher-request process, as voucher-requests are already signed by
the registrar. Instead, this authentication provides access control
to the audit-log as described in Section 5.8.
Implementors are advised that contacting the MASA is to establish a
secured API connection with a web service and that there are a number
of authentication models being explored within the industry.
Registrars are RECOMMENDED to fail gracefully and generate useful
administrative notifications or logs in the advent of unexpected HTTP
401 (Unauthorized) responses from the MASA.
5.4.1. MASA authentication of customer Registrar
Providing per-customer options requires that the customer's registrar
be uniquely identified. This can be done by any stateless method
that HTTPS supports such as with HTTP Basic or Digest authentication
(that is using a password), but the use of TLS Client Certificate
authentication is RECOMMENDED.
Stateful methods involving API tokens, or HTTP Cookies, are not
recommended.
It is expected that the setup and configuration of per-customer
Client Certificates is done as part of a sales ordering process.
The use of public PKI (i.e. WebPKI) End-Entity Certificates to
identify the Registrar is reasonable, and if done universally this
would permit a MASA to identify a customers' Registrar simply by a
FQDN.
The use of DANE records in DNSSEC signed zones would also permit use
of a FQDN to identify customer Registrars.
A third (and simplest, but least flexible) mechanism would be for the
MASA to simply store the Registrar's certificate pinned in a
database.
Pritikin, et al. Expires 15 May 2021 [Page 44]
Internet-Draft BRSKI November 2020
A MASA without any supply chain integration can simply accept
Registrars without any authentication, or can accept them on a blind
Trust-on-First-Use basis as described in Section 7.4.2.
This document does not make a specific recommendation on how the MASA
authenticates the Registrar as there are likely different tradeoffs
in different environments and product values. Even within the ANIMA
ACP applicability, there is a significant difference between supply
chain logistics for $100 CPE devices and $100,000 core routers.
5.5. Registrar Requests Voucher from MASA
When a registrar receives a pledge voucher-request it in turn submits
a registrar voucher-request to the MASA service via an HTTPS
interface ([RFC7231]).
This is done with an HTTP POST using the operation path value of
"/.well-known/brski/requestvoucher".
The voucher media type "application/voucher-cms+json" is defined in
[RFC8366] and is also used for the registrar voucher-request. It is
a JSON document that has been signed using a CMS structure. The
registrar MUST sign the registrar voucher-request.
MASA implementations SHOULD anticipate future media ntypes but of
course will simply fail the request if those types are not yet known.
The voucher-request CMS object includes some number of certificates
that are input to the MASA as it populates the 'pinned-domain-cert'.
As the [RFC8366] is quite flexible in what may be put into the
'pinned-domain-cert', the MASA needs some signal as to what
certificate would be effective to populate the field with: it may
range from the End Entity (EE) Certificate that the Registrar uses,
to the entire private Enterprise CA certificate. More specific
certificates result in a tighter binding of the voucher to the
domain, while less specific certificates result in more flexibility
in how the domain is represented by certificates.
A Registrar which is seeking a nonceless voucher for later offline
use benefits from a less specific certificate, as it permits the
actual keypair used by a future Registrar to be determined by the
pinned certificate authority.
Pritikin, et al. Expires 15 May 2021 [Page 45]
Internet-Draft BRSKI November 2020
In some cases, a less specific certificate, such a public WebPKI
certificate authority, could be too open, and could permit any entity
issued a certificate by that authority to assume ownership of a
device that has a voucher pinned. Future work may provide a solution
to pin both a certificate and a name that would reduce such risk of
malicious ownership assertions.
The Registrar SHOULD request a voucher with the most specificity
consistent with the mode that it is operating in. In order to do
this, when the Registrar prepares the CMS structure for the signed
voucher-request, it SHOULD include only certificates which are part
of the chain that it wishes the MASA to pin. This MAY be as small as
only the End-Entity certificate (with id-kp-cmcRA set) that it uses
as it's TLS Server Certificate, or it MAY be the entire chain,
including the Domain CA.
The Registrar SHOULD include an [RFC7231] section 5.3.2 "Accept"
header field indicating the response media types that are acceptable.
This list SHOULD be the entire list presented to the Registrar in the
Pledge's original request (see Section 5.2) but MAY be a subset. The
MASA is expected to be flexible in what it accepts.
The registrar populates the voucher-request fields as follows:
created-on: The Registrars SHOULD populate this field with the
current date and time when the Registrar formed this voucher
request. This field provides additional information to the MASA.
nonce: This value, if present, is copied from the pledge voucher-
request. The registrar voucher-request MAY omit the nonce as per
Section 3.1.
serial-number: The serial number of the pledge the registrar would
like a voucher for. The registrar determines this value by
parsing the authenticated pledge IDevID certificate. See
Section 2.3. The registrar MUST verify that the serial number
field it parsed matches the serial number field the pledge
provided in its voucher-request. This provides a sanity check
useful for detecting error conditions and logging. The registrar
MUST NOT simply copy the serial number field from a pledge voucher
request as that field is claimed but not certified.
idevid-issuer: The Issuer value from the pledge IDevID certificate
is included to ensure unique interpretation of the serial-number.
In the case of nonceless (offline) voucher-request, then an
appropriate value needs to be configured from the same out-of-band
source as the serial-number.
Pritikin, et al. Expires 15 May 2021 [Page 46]
Internet-Draft BRSKI November 2020
prior-signed-voucher-request: The signed pledge voucher-request
SHOULD be included in the registrar voucher-request. The entire
CMS signed structure is to be included, base64 encoded for
transport in the JSON structure.
A nonceless registrar voucher-request MAY be submitted to the MASA.
Doing so allows the registrar to request a voucher when the pledge is
offline, or when the registrar anticipates not being able to connect
to the MASA while the pledge is being deployed. Some use cases
require the registrar to learn the appropriate IDevID SerialNumber
field and appropriate 'Accept header field' values from the physical
device labeling or from the sales channel (out-of-scope for this
document).
All other fields MAY be omitted in the registrar voucher-request.
The "proximity-registrar-cert" field MUST NOT be present in the
registrar voucher-request.
Example JSON payloads of registrar voucher-requests are in
Section 3.3 Examples 2 through 4.
The MASA verifies that the registrar voucher-request is internally
consistent but does not necessarily authenticate the registrar
certificate since the registrar MAY be unknown to the MASA in
advance. The MASA performs the actions and validation checks
described in the following sub-sections before issuing a voucher.
5.5.1. MASA renewal of expired vouchers
As described in [RFC8366] vouchers are normally short lived to avoid
revocation issues. If the request is for a previous (expired)
voucher using the same registrar (that is, a Registrar with the same
Domain CA) then the request for a renewed voucher SHOULD be
automatically authorized. The MASA has sufficient information to
determine this by examining the request, the registrar
authentication, and the existing audit-log. The issuance of a
renewed voucher is logged as detailed in Section 5.6.
To inform the MASA that existing vouchers are not to be renewed one
can update or revoke the registrar credentials used to authorize the
request (see Section 5.5.4 and Section 5.5.3). More flexible methods
will likely involve sales channel integration and authorizations
(details are out-of-scope of this document).
Pritikin, et al. Expires 15 May 2021 [Page 47]
Internet-Draft BRSKI November 2020
5.5.2. MASA pinning of registrar
A certificate chain is extracted from the Registrar's signed CMS
container. This chain may be as short as a single End-Entity
Certificate, up to the entire registrar certificate chain, including
the Domain CA certificate, as specified in Section 5.5.
If the domain's CA is unknown to the MASA, then it is to be
considered a temporary trust anchor for the rest of the steps in this
section. The intention is not to authenticate the message as having
come from a fully validated origin, but to establish the consistency
of the domain PKI.
The MASA MAY use the certificate farthest in the chain chain that it
received from the Registrar from the end-entity, as determined by
MASA policy. A MASA MAY have a local policy that it only pins the
End-Entity certificate. This is consistent with [RFC8366]. Details
of the policy will typically depend upon the degree of Supply Chain
Integration, and the mechanism used by the Registrar to authenticate.
Such a policy would also determine how the MASA will respond to a
request for a nonceless voucher.
5.5.3. MASA checking of voucher request signature
As described in Section 5.5.2, the MASA has extracted Registrar's
domain CA. This is used to validate the CMS signature ([RFC5652]) on
the voucher-request.
Normal PKIX revocation checking is assumed during voucher-request
signature validation. This CA certificate MAY have Certificate
Revocation List distribution points, or Online Certificate Status
Protocol (OCSP) information ([RFC6960]). If they are present, the
MASA MUST be able to reach the relevant servers belonging to the
Registrar's domain CA to perform the revocation checks.
The use of OCSP Stapling is preferred.
Pritikin, et al. Expires 15 May 2021 [Page 48]
Internet-Draft BRSKI November 2020
5.5.4. MASA verification of domain registrar
The MASA MUST verify that the registrar voucher-request is signed by
a registrar. This is confirmed by verifying that the id-kp-cmcRA
extended key usage extension field (as detailed in EST RFC7030
section 3.6.1) exists in the certificate of the entity that signed
the registrar voucher-request. This verification is only a
consistency check that the unauthenticated domain CA intended the
voucher-request signer to be a registrar. Performing this check
provides value to the domain PKI by assuring the domain administrator
that the MASA service will only respect claims from authorized
Registration Authorities of the domain.
Even when a domain CA is authenticated to the MASA, and there is
strong sales channel integration to understand who the legitimate
owner is, the above id-kp-cmcRA check prevents arbitrary End-Entity
certificates (such as an LDevID certificate) from having vouchers
issued against them.
Other cases of inappropriate voucher issuance are detected by
examination of the audit log.
If a nonceless voucher-request is submitted the MASA MUST
authenticate the registrar as described in either EST [RFC7030]
section 3.2.3, section 3.3.2, or by validating the registrar's
certificate used to sign the registrar voucher-request using a
configured trust anchor. Any of these methods reduce the risk of
DDoS attacks and provide an authenticated identity as an input to
sales channel integration and authorizations (details are out-of-
scope of this document).
In the nonced case, validation of the Registrar's identity (via TLS
Client Certificate or HTTP authentication) MAY be omitted if the
device policy is to accept audit-only vouchers.
Pritikin, et al. Expires 15 May 2021 [Page 49]
Internet-Draft BRSKI November 2020
5.5.5. MASA verification of pledge prior-signed-voucher-request
The MASA MAY verify that the registrar voucher-request includes the
'prior-signed-voucher-request' field. If so the prior-signed-
voucher-request MUST include a 'proximity-registrar-cert' that is
consistent with the certificate used to sign the registrar voucher-
request. Additionally the voucher-request serial-number leaf MUST
match the pledge serial-number that the MASA extracts from the
signing certificate of the prior-signed-voucher-request. The
consistency check described above is checking that the 'proximity-
registrar-cert' SPKI fingerprint exists within the registrar voucher-
request CMS signature's certificate chain. This is substantially the
same as the pin validation described in in [RFC7469] section 2.6,
paragraph three.
If these checks succeed the MASA updates the voucher and audit-log
assertion leafs with the "proximity" assertion, as defined by
[RFC8366] section 5.3.
5.5.6. MASA nonce handling
The MASA does not verify the nonce itself. If the registrar voucher-
request contains a nonce, and the prior-signed-voucher-request
exists, then the MASA MUST verify that the nonce is consistent.
(Recall from above that the voucher-request might not contain a
nonce, see Section 5.5 and Section 5.5.4).
The MASA populates the audit-log with the nonce that was verified.
If a nonceless voucher is issued, then the audit-log is to be
populated with the JSON value "null".
5.6. MASA and Registrar Voucher Response
The MASA voucher response to the registrar is forwarded without
changes to the pledge; therefore this section applies to both the
MASA and the registrar. The HTTP signaling described applies to both
the MASA and registrar responses.
When a voucher request arrives at the registrar, if it has a cached
response from the MASA for the corresponding registrar voucher-
request, that cached response can be used according to local policy;
otherwise the registrar constructs a new registrar voucher-request
and sends it to the MASA.
Registrar evaluation of the voucher itself is purely for transparency
and audit purposes to further inform log verification (see
Section 5.8.3) and therefore a registrar could accept future voucher
formats that are opaque to the registrar.
Pritikin, et al. Expires 15 May 2021 [Page 50]
Internet-Draft BRSKI November 2020
If the voucher-request is successful, the server (MASA responding to
registrar or registrar responding to pledge) response MUST contain an
HTTP 200 response code. The server MUST answer with a suitable 4xx
or 5xx HTTP [RFC7230] error code when a problem occurs. In this
case, the response data from the MASA MUST be a plaintext human-
readable (UTF-8) error message containing explanatory information
describing why the request was rejected.
The registrar MAY respond with an HTTP 202 ("the request has been
accepted for processing, but the processing has not been completed")
as described in EST [RFC7030] section 4.2.3 wherein the client "MUST
wait at least the specified 'Retry-After' time before repeating the
same request". (see [RFC7231] section 6.6.4) The pledge is
RECOMMENDED to provide local feedback (blinked LED etc) during this
wait cycle if mechanisms for this are available. To prevent an
attacker registrar from significantly delaying bootstrapping the
pledge MUST limit the 'Retry-After' time to 60 seconds. Ideally the
pledge would keep track of the appropriate Retry-After header field
values for any number of outstanding registrars but this would
involve a state table on the pledge. Instead the pledge MAY ignore
the exact Retry-After value in favor of a single hard coded value (a
registrar that is unable to complete the transaction after the first
60 seconds has another chance a minute later). A pledge SHOULD only
maintain a 202 retry-state for up to 4 days, which is longer than a
long weekend, after which time the enrollment attempt fails and the
pledge returns to discovery state.
A pledge that retries a request after receiving a 202 message MUST
resend the same voucher-request. It MUST NOT sign a new voucher-
request each time, and in particular, it MUST NOT change the nonce
value.
In order to avoid infinite redirect loops, which a malicious
registrar might do in order to keep the pledge from discovering the
correct registrar, the pledge MUST NOT follow more than one
redirection (3xx code) to another web origin. EST supports
redirection but requires user input; this change allows the pledge to
follow a single redirection without a user interaction.
A 403 (Forbidden) response is appropriate if the voucher-request is
not signed correctly, stale, or if the pledge has another outstanding
voucher that cannot be overridden.
A 404 (Not Found) response is appropriate when the request is for a
device that is not known to the MASA.
Pritikin, et al. Expires 15 May 2021 [Page 51]
Internet-Draft BRSKI November 2020
A 406 (Not Acceptable) response is appropriate if a voucher of the
desired type or using the desired algorithms (as indicated by the
Accept: header fields, and algorithms used in the signature) cannot
be issued such as because the MASA knows the pledge cannot process
that type. The registrar SHOULD use this response if it determines
the pledge is unacceptable due to inventory control, MASA audit-logs,
or any other reason.
A 415 (Unsupported Media Type) response is appropriate for a request
that has a voucher-request or Accept: value that is not understood.
The voucher response format is as indicated in the submitted Accept
header fields or based on the MASA's prior understanding of proper
format for this Pledge. Only the [RFC8366] "application/voucher-
cms+json" media type is defined at this time. The syntactic details
of vouchers are described in detail in [RFC8366]. Figure 14 shows a
sample of the contents of a voucher.
{
"ietf-voucher:voucher": {
"nonce": "62a2e7693d82fcda2624de58fb6722e5",
"assertion": "logged",
"pinned-domain-cert": "base64encodedvalue==",
"serial-number": "JADA123456789"
}
}
Figure 14: An example voucher
The MASA populates the voucher fields as follows:
nonce: The nonce from the pledge if available. See Section 5.5.6.
assertion: The method used to verify the relationship between pledge
and registrar. See Section 5.5.5.
pinned-domain-cert: A certificate. See Section 5.5.2. This figure
is illustrative, for an example, see Appendix C.2 where an End
Entity certificate is used.
serial-number: The serial-number as provided in the voucher-request.
Also see Section 5.5.5.
domain-cert-revocation-checks: Set as appropriate for the pledge's
Pritikin, et al. Expires 15 May 2021 [Page 52]
Internet-Draft BRSKI November 2020
capabilities and as documented in [RFC8366]. The MASA MAY set
this field to 'false' since setting it to 'true' would require
that revocation information be available to the pledge and this
document does not make normative requirements for [RFC6961] or
equivalent integrations.
expires-on: This is set for nonceless vouchers. The MASA ensures
the voucher lifetime is consistent with any revocation or pinned-
domain-cert consistency checks the pledge might perform. See
section Section 2.6.1. There are three times to consider: (a) a
configured voucher lifetime in the MASA, (b) the expiry time for
the registrar's certificate, (c) any certificate revocation
information (CRL) lifetime. The expires-on field SHOULD be before
the earliest of these three values. Typically (b) will be some
significant time in the future, but (c) will typically be short
(on the order of a week or less). The RECOMMENDED period for (a)
is on the order of 20 minutes, so it will typically determine the
lifespan of the resulting voucher. 20 minutes is sufficient time
to reach the post-provisional state in the pledge, at which point
there is an established trust relationship between pledge and
registrar. The subsequent operations can take as long as required
from that point onwards. The lifetime of the voucher has no
impact on the lifespan of the ownership relationship.
Whenever a voucher is issued the MASA MUST update the audit-log
sufficiently to generate the response as described in Section 5.8.1.
The internal state requirements to maintain the audit-log are out-of-
scope.
5.6.1. Pledge voucher verification
The pledge MUST verify the voucher signature using the manufacturer-
installed trust anchor(s) associated with the manufacturer's MASA
(this is likely included in the pledge's firmware). Management of
the manufacturer-installed trust anchor(s) is out-of-scope of this
document; this protocol does not update these trust anchor(s).
The pledge MUST verify the serial-number field of the signed voucher
matches the pledge's own serial-number.
The pledge MUST verify the nonce information in the voucher. If
present, the nonce in the voucher must match the nonce the pledge
submitted to the registrar; vouchers with no nonce can also be
accepted (according to local policy, see Section 7.2)
Pritikin, et al. Expires 15 May 2021 [Page 53]
Internet-Draft BRSKI November 2020
The pledge MUST be prepared to parse and fail gracefully from a
voucher response that does not contain a 'pinned-domain-cert' field.
Such a thing indicates a failure to enroll in this domain, and the
pledge MUST attempt joining with other available Join Proxy.
The pledge MUST be prepared to ignore additional fields that it does
not recognize.
5.6.2. Pledge authentication of provisional TLS connection
Following the process described in [RFC8366], the pledge should
consider the public key from the pinned-domain-cert as the sole
temporary trust anchor.
The pledge then evaluates the TLS Server Certificate chain that it
received when the TLS connection was formed using this trust anchor.
It is possible that the pinned-domain-cert matches the End-Entity
Certificate provided in the TLS Server.
If a registrar's credentials cannot be verified using the pinned-
domain-cert trust anchor from the voucher then the TLS connection is
immediately discarded and the pledge abandons attempts to bootstrap
with this discovered registrar. The pledge SHOULD send voucher
status telemetry (described below) before closing the TLS connection.
The pledge MUST attempt to enroll using any other proxies it has
found. It SHOULD return to the same proxy again after unsuccessful
attempts with other proxies. Attempts should be made repeated at
intervals according to the backoff timer described earlier. Attempts
SHOULD be repeated as failure may be the result of a temporary
inconsistency (an inconsistently rolled registrar key, or some other
mis-configuration). The inconsistency could also be the result an
active MITM attack on the EST connection.
The registrar MUST use a certificate that chains to the pinned-
domain-cert as its TLS server certificate.
The pledge's PKIX path validation of a registrar certificate's
validity period information is as described in Section 2.6.1. Once
the PKIX path validation is successful the TLS connection is no
longer provisional.
The pinned-domain-cert MAY be installed as a trust anchor for future
operations such as enrollment (e.g. [RFC7030] as recommended) or
trust anchor management or raw protocols that do not need full PKI
based key management. It can be used to authenticate any dynamically
discovered EST server that contain the id-kp-cmcRA extended key usage
extension as detailed in EST RFC7030 section 3.6.1; but to reduce
system complexity the pledge SHOULD avoid additional discovery
Pritikin, et al. Expires 15 May 2021 [Page 54]
Internet-Draft BRSKI November 2020
operations. Instead the pledge SHOULD communicate directly with the
registrar as the EST server. The 'pinned-domain-cert' is not a
complete distribution of the [RFC7030] section 4.1.3 CA Certificate
Response, which is an additional justification for the recommendation
to proceed with EST key management operations. Once a full CA
Certificate Response is obtained it is more authoritative for the
domain than the limited 'pinned-domain-cert' response.
5.7. Pledge BRSKI Status Telemetry
The domain is expected to provide indications to the system
administrators concerning device lifecycle status. To facilitate
this it needs telemetry information concerning the device's status.
The pledge MUST indicate its pledge status regarding the voucher. It
does this by sending a status message to the Registrar.
The posted data media type: application/json
The client sends an HTTP POST to the server at the URI ".well-
known/brski/voucher_status".
The format and semantics described below are for version 1. A
version field is included to permit significant changes to this
feedback in the future. A Registrar that receives a status message
with a version larger than it knows about SHOULD log the contents and
alert a human.
The Status field indicates if the voucher was acceptable. Boolean
values are acceptable, where "true" indicates the voucher was
acceptable.
If the voucher was not acceptable the Reason string indicates why.
In the failure case this message may be sent to an unauthenticated,
potentially malicious registrar and therefore the Reason string
SHOULD NOT provide information beneficial to an attacker. The
operational benefit of this telemetry information is balanced against
the operational costs of not recording that an voucher was ignored by
a client the registrar expected to continue joining the domain.
The reason-context attribute is an arbitrary JSON object (literal
value or hash of values) which provides additional information
specific to this pledge. The contents of this field are not subject
to standardization.
Pritikin, et al. Expires 15 May 2021 [Page 55]
Internet-Draft BRSKI November 2020
The version and status fields MUST be present. The Reason field
SHOULD be present whenever the status field is false. The Reason-
Context field is optional. In the case of a SUCCESS the Reason
string MAY be omitted.
The keys to this JSON object are case-sensitive and MUST be
lowercase. Figure 16 shows an example JSON.
<CODE BEGINS> file "voucherstatus.cddl"
voucherstatus-post = {
"version": uint,
"status": bool,
? "reason": text,
? "reason-context" : { $$arbitrary-map }
}
}
<CODE ENDS>
Figure 15: CDDL for voucher status POST
{
"version": 1,
"status":false,
"reason":"Informative human readable message",
"reason-context": { "additional" : "JSON" }
}
Figure 16: Example Status Telemetry
The server SHOULD respond with an HTTP 200 but MAY simply fail with
an HTTP 404 error. The client ignores any response. Within the
server logs the server SHOULD capture this telemetry information.
Additional standard JSON fields in this POST MAY be added, see
Section 8.5. A server that sees unknown fields should log them, but
otherwise ignore them.
5.8. Registrar audit-log request
After receiving the pledge status telemetry Section 5.7, the
registrar SHOULD request the MASA audit-log from the MASA service.
This is done with an HTTP POST using the operation path value of
"/.well-known/brski/requestauditlog".
The registrar SHOULD HTTP POST the same registrar voucher-request as
it did when requesting a voucher (using the same Content-Type). It
is posted to the /requestauditlog URI instead. The "idevid-issuer"
Pritikin, et al. Expires 15 May 2021 [Page 56]
Internet-Draft BRSKI November 2020
and "serial-number" informs the MASA which log is requested so the
appropriate log can be prepared for the response. Using the same
media type and message minimizes cryptographic and message operations
although it results in additional network traffic. The relying MASA
implementation MAY leverage internal state to associate this request
with the original, and by now already validated, voucher-request so
as to avoid an extra crypto validation.
A registrar MAY request logs at future times. If the registrar
generates a new request then the MASA is forced to perform the
additional cryptographic operations to verify the new request.
A MASA that receives a request for a device that does not exist, or
for which the requesting owner was never an owner returns an HTTP 404
("Not found") code.
It is reasonable for a Registrar, that the MASA does not believe to
be the current owner, to request the audit-log. There are probably
reasons for this which are hard to predict in advance. For instance,
such a registrar may not be aware that the device has been resold; it
may be that the device has been resold inappropriately, and this is
how the original owner will learn of the occurance. It is also
possible that the device legitimately spends time in two different
networks.
Rather than returning the audit-log as a response to the POST (with a
return code 200), the MASA MAY instead return a 201 ("Created")
response ([RFC7231] sections 6.3.2 and 7.1), with the URL to the
prepared (and idempotent, therefore cachable) audit response in the
Location: header field.
In order to avoid enumeration of device audit-logs, MASA that return
URLs SHOULD take care to make the returned URL unguessable.
[W3C.WD-capability-urls-20140218] provides very good additional
guidance. For instance, rather than returning URLs containing a
database number such as https://example.com/auditlog/1234 or the EUI
of the device such https://example.com/auditlog/10-00-00-11-22-33,
the MASA SHOULD return a randomly generated value (a "slug" in web
parlance). The value is used to find the relevant database entry.
A MASA that returns a code 200 MAY also include a Location: header
for future reference by the registrar.
Pritikin, et al. Expires 15 May 2021 [Page 57]
Internet-Draft BRSKI November 2020
5.8.1. MASA audit log response
A log data file is returned consisting of all log entries associated
with the device selected by the IDevID presented in the request. The
audit log may be abridged by removal of old or repeated values as
explained below. The returned data is in JSON format ([RFC8259]),
and the Content-Type SHOULD be "application/json".
The following CDDL ([RFC8610]) explains the structure of the JSON
format audit-log response:
<CODE BEGINS> file "auditlog.cddl"
audit-log-response = {
"version": uint,
"events": [ + event ]
"truncation": {
? "nonced duplicates": uint,
? "nonceless duplicates": uint,
? "arbitrary": uint,
}
}
event = {
"date": text,
"domainID": text,
"nonce": text / null,
"assertion": "verified" / "logged" / "proximity",
? "truncated": uint,
}
<CODE ENDS>
Figure 17: CDDL for audit-log response
An example:
Pritikin, et al. Expires 15 May 2021 [Page 58]
Internet-Draft BRSKI November 2020
{
"version":"1",
"events":[
{
"date":"2019-05-15T17:25:55.644-04:00",
"domainID":"BduJhdHPpfhQLyponf48JzXSGZ8=",
"nonce":"VOUFT-WwrEv0NuAQEHoV7Q",
"assertion":"proximity",
"truncated":"0"
},
{
"date":"2017-05-15T17:25:55.644-04:00",
"domainID":"BduJhdHPpfhQLyponf48JzXSGZ8=",
"nonce":"f4G6Vi1t8nKo/FieCVgpBg==",
"assertion":"proximity"
}
],
"truncation": {
"nonced duplicates": "0",
"nonceless duplicates": "1",
"arbitrary": "2"
}
}
Figure 18: Example of audit-log response
The domainID is a binary SubjectKeyIdentifier value calculated
according to Section 5.8.2. It is encoded once in base64 in order to
be transported in this JSON container.
The date is in [RFC3339] format, which is consistent with typical
JavaScript usage of JSON.
The truncation structure MAY be omitted if all values are zero. Any
counter missing from the truncation structure is the be assumed to be
zero.
The nonce is a string, as provided in the voucher-request, and used
in the voucher. If no nonce was placed in the resulting voucher,
then a value of null SHOULD be used in preference to omitting the
entry. While the nonce is often created as a base64 encoded random
series of bytes, this should not be assumed.
Distribution of a large log is less than ideal. This structure can
be optimized as follows: Nonced or Nonceless entries for the same
domainID MAY be abridged from the log leaving only the single most
recent nonced or nonceless entry for that domainID. In the case of
truncation the 'event' truncation value SHOULD contain a count of the
Pritikin, et al. Expires 15 May 2021 [Page 59]
Internet-Draft BRSKI November 2020
number of events for this domainID that were omitted. The log SHOULD
NOT be further reduced but there could exist operational situation
where maintaining the full log is not possible. In such situations
the log MAY be arbitrarily abridged for length, with the number of
removed entries indicated as 'arbitrary'.
If the truncation count exceeds 1024 then the MASA MAY use this value
without further incrementing it.
A log where duplicate entries for the same domain have been omitted
("nonced duplicates" and/or "nonceless duplicates) could still be
acceptable for informed decisions. A log that has had "arbitrary"
truncations is less acceptable but manufacturer transparency is
better than hidden truncations.
A registrar that sees a version value greater than 1 indicates an
audit log format that has been enhanced with additional information.
No information will be removed in future versions; should an
incompatible change be desired in the future, then a new HTTP end
point will be used.
This document specifies a simple log format as provided by the MASA
service to the registrar. This format could be improved by
distributed consensus technologies that integrate vouchers with
technologies such as block-chain or hash trees or optimized logging
approaches. Doing so is out of the scope of this document but is an
anticipated improvement for future work. As such, the registrar
SHOULD anticipate new kinds of responses, and SHOULD provide operator
controls to indicate how to process unknown responses.
5.8.2. Calculation of domainID
The domainID is a binary value (a BIT STRING) that uniquely
identifies a Registrar by the "pinned-domain-cert".
If the "pinned-domain-cert" certificate includes the
SubjectKeyIdentifier (Section 4.2.1.2 [RFC5280]), then it is to be
used as the domainID. If not, the SPKI Fingerprint as described in
[RFC7469] section 2.4 is to be used. This value needs to be
calculated by both MASA (to populate the audit-log), and by the
Registrar (to recognize itself in the audit log).
[RFC5280] section 4.2.1.2 does not mandate that the
SubjectKeyIdentifier extension be present in non-CA certificates. It
is RECOMMENDED that Registrar certificates (even if self-signed),
always include the SubjectKeyIdentifier to be used as a domainID.
Pritikin, et al. Expires 15 May 2021 [Page 60]
Internet-Draft BRSKI November 2020
The domainID is determined from the certificate chain associated with
the pinned-domain-cert and is used to update the audit-log.
5.8.3. Registrar audit log verification
Each time the Manufacturer Authorized Signing Authority (MASA) issues
a voucher, it appends details of the assignment to an internal audit
log for that device. The internal audit log is processed when
responding to requests for details as described in Section 5.8. The
contents of the audit log can express a variety of trust levels, and
this section explains what kind of trust a registrar can derive from
the entries.
While the audit log provides a list of vouchers that were issued by
the MASA, the vouchers are issued in response to voucher-requests,
and it is the contents of the voucher-requests which determines how
meaningful the audit log entries are.
A registrar SHOULD use the log information to make an informed
decision regarding the continued bootstrapping of the pledge. The
exact policy is out of scope of this document as it depends on the
security requirements within the registrar domain. Equipment that is
purchased pre-owned can be expected to have an extensive history.
The following discussion is provided to help explain the value of
each log element:
date: The date field provides the registrar an opportunity to divide
the log around known events such as the purchase date. Depending
on context known to the registrar or administrator events before/
after certain dates can have different levels of importance. For
example for equipment that is expected to be new, and thus have no
history, it would be a surprise to find prior entries.
domainID: If the log includes an unexpected domainID then the pledge
could have imprinted on an unexpected domain. The registrar can
be expected to use a variety of techniques to define "unexpected"
ranging from white lists of prior domains to anomaly detection
(e.g. "this device was previously bound to a different domain than
any other device deployed"). Log entries can also be compared
against local history logs in search of discrepancies (e.g. "this
device was re-deployed some number of times internally but the
external audit log shows additional re-deployments our internal
logs are unaware of").
nonce: Nonceless entries mean the logged domainID could
theoretically trigger a reset of the pledge and then take over
management by using the existing nonceless voucher.
Pritikin, et al. Expires 15 May 2021 [Page 61]
Internet-Draft BRSKI November 2020
assertion: The assertion leaf in the voucher and audit log indicates
why the MASA issued the voucher. A "verified" entry means that
the MASA issued the associated voucher as a result of positive
verification of ownership. However, this entry does not indicate
whether the pledge was actually deployed in the prior domain, or
not. A "logged" assertion informs the registrar that the prior
vouchers were issued with minimal verification. A "proximity"
assertion assures the registrar that the pledge was truly
communicating with the prior domain and thus provides assurance
that the prior domain really has deployed the pledge.
A relatively simple policy is to white list known (internal or
external) domainIDs, and require all vouchers to have a nonce. An
alternative is to require that all nonceless vouchers be from a
subset (e.g. only internal) of domainIDs. If the policy is violated
a simple action is to revoke any locally issued credentials for the
pledge in question or to refuse to forward the voucher. The
Registrar MUST then refuse any EST actions, and SHOULD inform a human
via a log. A registrar MAY be configured to ignore (i.e. override
the above policy) the history of the device but it is RECOMMENDED
that this only be configured if hardware assisted (i.e. TPM
anchored) Network Endpoint Assessment (NEA) [RFC5209] is supported.
5.9. EST Integration for PKI bootstrapping
The pledge SHOULD follow the BRSKI operations with EST enrollment
operations including "CA Certificates Request", "CSR Attributes" and
"Client Certificate Request" or "Server-Side Key Generation", etc.
This is a relatively seamless integration since BRSKI API calls
provide an automated alternative to the manual bootstrapping method
described in [RFC7030]. As noted above, use of HTTP persistent
connections simplifies the pledge state machine.
Although EST allows clients to obtain multiple certificates by
sending multiple Certificate Signing Requests (CSR) requests, BRSKI
does not support this mechanism directly. This is because BRSKI
pledges MUST use the CSR Attributes request ([RFC7030] section 4.5).
The registrar MUST validate the CSR against the expected attributes.
This implies that client requests will "look the same" and therefore
result in a single logical certificate being issued even if the
client were to make multiple requests. Registrars MAY contain more
complex logic but doing so is out-of-scope of this specification.
BRSKI does not signal any enhancement or restriction to this
capability.
Pritikin, et al. Expires 15 May 2021 [Page 62]
Internet-Draft BRSKI November 2020
5.9.1. EST Distribution of CA Certificates
The pledge SHOULD request the full EST Distribution of CA
Certificates message. See RFC7030, section 4.1.
This ensures that the pledge has the complete set of current CA
certificates beyond the pinned-domain-cert (see Section 5.6.2 for a
discussion of the limitations inherent in having a single certificate
instead of a full CA Certificates response.) Although these
limitations are acceptable during initial bootstrapping, they are not
appropriate for ongoing PKIX end entity certificate validation.
5.9.2. EST CSR Attributes
Automated bootstrapping occurs without local administrative
configuration of the pledge. In some deployments it is plausible
that the pledge generates a certificate request containing only
identity information known to the pledge (essentially the X.509
IDevID information) and ultimately receives a certificate containing
domain specific identity information. Conceptually the CA has
complete control over all fields issued in the end entity
certificate. Realistically this is operationally difficult with the
current status of PKI certificate authority deployments, where the
CSR is submitted to the CA via a number of non-standard protocols.
Even with all standardized protocols used, it could operationally be
problematic to expect that service specific certificate fields can be
created by a CA that is likely operated by a group that has no
insight into different network services/protocols used. For example,
the CA could even be outsourced.
To alleviate these operational difficulties, the pledge MUST request
the EST "CSR Attributes" from the EST server and the EST server needs
to be able to reply with the attributes necessary for use of the
certificate in its intended protocols/services. This approach allows
for minimal CA integrations and instead the local infrastructure (EST
server) informs the pledge of the proper fields to include in the
generated CSR (such as rfc822Name). This approach is beneficial to
automated bootstrapping in the widest number of environments.
In networks using the BRSKI enrolled certificate to authenticate the
ACP (Autonomic Control Plane), the EST CSR attributes MUST include
the ACP Domain Information Fields defined in
[I-D.ietf-anima-autonomic-control-plane] section 6.1.1.
Pritikin, et al. Expires 15 May 2021 [Page 63]
Internet-Draft BRSKI November 2020
The registrar MUST also confirm that the resulting CSR is formatted
as indicated before forwarding the request to a CA. If the registrar
is communicating with the CA using a protocol such as full CMC, which
provides mechanisms to override the CSR attributes, then these
mechanisms MAY be used even if the client ignores CSR Attribute
guidance.
5.9.3. EST Client Certificate Request
The pledge MUST request a new client certificate. See RFC7030,
section 4.2.
5.9.4. Enrollment Status Telemetry
For automated bootstrapping of devices, the administrative elements
providing bootstrapping also provide indications to the system
administrators concerning device lifecycle status. This might
include information concerning attempted bootstrapping messages seen
by the client. The MASA provides logs and status of credential
enrollment. [RFC7030] assumes an end user and therefore does not
include a final success indication back to the server. This is
insufficient for automated use cases.
The client MUST send an indicator to the Registrar about its
enrollment status. It does this by using an HTTP POST of a JSON
dictionary with the of attributes described below to the new EST
endpoint at "/.well-known/brski/enrollstatus". (XXX ?)
When indicating a successful enrollment the client SHOULD first re-
establish the EST TLS session using the newly obtained credentials.
TLS 1.2 supports doing this in-band, but TLS 1.3 does not. The
client SHOULD therefore always close the existing TLS connection, and
start a new one.
In the case of a failed enrollment, the client MUST send the
telemetry information over the same TLS connection that was used for
the enrollment attempt, with a Reason string indicating why the most
recent enrollment failed. (For failed attempts, the TLS connection
is the most reliable way to correlate server-side information with
what the client provides.)
The version and status fields MUST be present. The Reason field
SHOULD be present whenever the status field is false. In the case of
a SUCCESS the Reason string MAY be omitted.
Pritikin, et al. Expires 15 May 2021 [Page 64]
Internet-Draft BRSKI November 2020
The reason-context attribute is an arbitrary JSON object (literal
value or hash of values) which provides additional information
specific to the failure to unroll from this pledge. The contents of
this field are not subject to standardization. This is represented
by the group-socket "$$arbitrary-map" in the CDDL.
In the case of a SUCCESS the Reason string is omitted.
<CODE BEGINS> file "enrollstatus.cddl"
enrollstatus-post = {
"version": uint,
"status": bool,
? "reason": text,
? "reason-context" : { $$arbitrary-map }
}
}
<CODE ENDS>
Figure 19: CDDL for enrollment status POST
An example status report can be seen below. It is sent with with the
media type: application/json
{
"version": 1,
"status":true,
"reason":"Informative human readable message",
"reason-context": { "additional" : "JSON" }
}
Figure 20: Example of enrollment status POST
The server SHOULD respond with an HTTP 200 but MAY simply fail with
an HTTP 404 error.
Within the server logs the server MUST capture if this message was
received over an TLS session with a matching client certificate.
5.9.5. Multiple certificates
Pledges that require multiple certificates could establish direct EST
connections to the registrar.
Pritikin, et al. Expires 15 May 2021 [Page 65]
Internet-Draft BRSKI November 2020
5.9.6. EST over CoAP
This document describes extensions to EST for the purposes of
bootstrapping of remote key infrastructures. Bootstrapping is
relevant for CoAP enrollment discussions as well. The definition of
EST and BRSKI over CoAP is not discussed within this document beyond
ensuring proxy support for CoAP operations. Instead it is
anticipated that a definition of CoAP mappings will occur in
subsequent documents such as [I-D.ietf-ace-coap-est] and that CoAP
mappings for BRSKI will be discussed either there or in future work.
6. Clarification of transfer-encoding
[RFC7030] defines its endpoints to include a "Content-Transfer-
Encoding" heading, and the payloads to be [RFC4648] Base64 encoded
DER.
When used within BRSKI, the original RFC7030 EST endpoints remain
Base64 encoded, but the new BRSKI end points which send and receive
binary artifacts (specifically, "/.well-known/brski/requestvoucher")
are binary. That is, no encoding is used.
In the BRSKI context, the EST "Content-Transfer-Encoding" header
field if present, SHOULD be ignored. This header field does not need
to be included.
7. Reduced security operational modes
A common requirement of bootstrapping is to support less secure
operational modes for support specific use cases. This section
suggests a range of mechanisms that would alter the security
assurance of BRSKI to accommodate alternative deployment
architectures and mitigate lifecycle management issues identified in
Section 10. They are presented here as informative (non-normative)
design guidance for future standardization activities. Section 9
provides standardization applicability statements for the ANIMA ACP.
Other users would be expected that subsets of these mechanisms could
be profiled with an accompanying applicability statements similar to
the one described in Section 9.
This section is considered non-normative in the generality of the
protocol. Use of the suggested mechanisms here MUST be detailed in
specific profiles of BRSKI, such as in Section 9.
7.1. Trust Model
This section explains the trust relationships detailed in
Section 2.4:
Pritikin, et al. Expires 15 May 2021 [Page 66]
Internet-Draft BRSKI November 2020
+--------+ +---------+ +------------+ +------------+
| Pledge | | Join | | Domain | |Manufacturer|
| | | Proxy | | Registrar | | Service |
| | | | | | | (Internet) |
+--------+ +---------+ +------------+ +------------+
Figure 10
Pledge: The pledge could be compromised and providing an attack
vector for malware. The entity is trusted to only imprint using
secure methods described in this document. Additional endpoint
assessment techniques are RECOMMENDED but are out-of-scope of this
document.
Join Proxy: Provides proxy functionalities but is not involved in
security considerations.
Registrar: When interacting with a MASA a registrar makes all
decisions. For Ownership Audit Vouchers (see [RFC8366]) the
registrar is provided an opportunity to accept MASA decisions.
Vendor Service, MASA: This form of manufacturer service is trusted
to accurately log all claim attempts and to provide authoritative
log information to registrars. The MASA does not know which
devices are associated with which domains. These claims could be
strengthened by using cryptographic log techniques to provide
append only, cryptographic assured, publicly auditable logs.
Vendor Service, Ownership Validation: This form of manufacturer
service is trusted to accurately know which device is owned by
which domain.
7.2. Pledge security reductions
The following is a list of alternative behaviours that the pledge can
be programmed to implement. These behaviours are not mutually
exclusive, nor are they dependent upon each other. Some of these
methods enable offline and emergency (touch based) deployment use
cases. Normative language is used as these behaviours are referenced
in later sections in a normative fashion.
1. The pledge MUST accept nonceless vouchers. This allows for a use
case where the registrar can not connect to the MASA at the
deployment time. Logging and validity periods address the
security considerations of supporting these use cases.
Pritikin, et al. Expires 15 May 2021 [Page 67]
Internet-Draft BRSKI November 2020
2. Many devices already support "trust on first use" for physical
interfaces such as console ports. This document does not change
that reality. Devices supporting this protocol MUST NOT support
"trust on first use" on network interfaces. This is because
"trust on first use" over network interfaces would undermine the
logging based security protections provided by this
specification.
3. The pledge MAY have an operational mode where it skips voucher
validation one time. For example if a physical button is
depressed during the bootstrapping operation. This can be useful
if the manufacturer service is unavailable. This behavior SHOULD
be available via local configuration or physical presence methods
(such as use of a serial/craft console) to ensure new entities
can always be deployed even when autonomic methods fail. This
allows for unsecured imprint.
4. A craft/serial console could include a command such as "est-
enroll [2001:db8:0:1]:443" that begins the EST process from the
point after the voucher is validated. This process SHOULD
include server certificate verification using an on-screen
fingerprint.
It is RECOMMENDED that "trust on first use" or any method of skipping
voucher validation (including use of craft serial console) only be
available if hardware assisted Network Endpoint Assessment (NEA:
[RFC5209]) is supported. This recommendation ensures that domain
network monitoring can detect inappropriate use of offline or
emergency deployment procedures when voucher-based bootstrapping is
not used.
7.3. Registrar security reductions
A registrar can choose to accept devices using less secure methods.
They MUST NOT be the default behavior. These methods may be
acceptable in situations where threat models indicate that low
security is adequate. This includes situations where security
decisions are being made by the local administrator:
1. A registrar MAY choose to accept all devices, or all devices of a
particular type, at the administrator's discretion. This could
occur when informing all registrars of unique identifiers of new
entities might be operationally difficult.
2. A registrar MAY choose to accept devices that claim a unique
identity without the benefit of authenticating that claimed
identity. This could occur when the pledge does not include an
X.509 IDevID factory installed credential. New Entities without
Pritikin, et al. Expires 15 May 2021 [Page 68]
Internet-Draft BRSKI November 2020
an X.509 IDevID credential MAY form the Section 5.2 request using
the Section 5.5 format to ensure the pledge's serial number
information is provided to the registrar (this includes the
IDevID AuthorityKeyIdentifier value, which would be statically
configured on the pledge.) The pledge MAY refuse to provide a
TLS client certificate (as one is not available.) The pledge
SHOULD support HTTP-based or certificate-less TLS authentication
as described in EST RFC7030 section 3.3.2. A registrar MUST NOT
accept unauthenticated New Entities unless it has been configured
to do so by an administrator that has verified that only expected
new entities can communicate with a registrar (presumably via a
physically secured perimeter.)
3. A registrar MAY submit a nonceless voucher-requests to the MASA
service (by not including a nonce in the voucher-request.) The
resulting vouchers can then be stored by the registrar until they
are needed during bootstrapping operations. This is for use
cases where the target network is protected by an air gap and
therefore cannot contact the MASA service during pledge
deployment.
4. A registrar MAY ignore unrecognized nonceless log entries. This
could occur when used equipment is purchased with a valid history
being deployed in air gap networks that required offline
vouchers.
5. A registrar MAY accept voucher formats of future types that can
not be parsed by the Registrar. This reduces the Registrar's
visibility into the exact voucher contents but does not change
the protocol operations.
7.4. MASA security reductions
Lower security modes chosen by the MASA service affect all device
deployments unless the lower-security behavior is tied to specific
device identities. The modes described below can be applied to
specific devices via knowledge of what devices were sold. They can
also be bound to specific customers (independent of the device
identity) by authenticating the customer's Registrar.
7.4.1. Issuing Nonceless vouchers
A MASA has the option of not including a nonce in the voucher, and/or
not requiring one to be present in the voucher-request. This results
in distribution of a voucher that may never expire and in effect
makes the specified Domain an always trusted entity to the pledge
during any subsequent bootstrapping attempts. That a nonceless
voucher was issued is captured in the log information so that the
Pritikin, et al. Expires 15 May 2021 [Page 69]
Internet-Draft BRSKI November 2020
registrar can make appropriate security decisions when a pledge joins
the Domain. Nonceless vouchers are useful to support use cases where
registrars might not be online during actual device deployment.
While a nonceless voucher may include an expiry date, a typical use
for a nonceless voucher is for it to be long-lived. If the device
can be trusted to have an accurate clock (the MASA will know), then a
nonceless voucher CAN be issued with a limited lifetime.
A more typical case for a nonceless voucher is for use with offline
onboarding scenarios where it is not possible to pass a fresh
voucher-request to the MASA. The use of a long-lived voucher also
eliminates concern about the availability of the MASA many years in
the future. Thus many nonceless vouchers will have no expiry dates.
Thus, the long lived nonceless voucher does not require the proof
that the device is online. Issuing such a thing is only accepted
when the registrar is authenticated by the MASA and the MASA is
authorized to provide this functionality to this customer. The MASA
is RECOMMENDED to use this functionality only in concert with an
enhanced level of ownership tracking, the details of which are out of
scope for this document.
If the pledge device is known to have a real-time-clock that is set
from the factory, use of a voucher validity period is RECOMMENDED.
7.4.2. Trusting Owners on First Use
A MASA has the option of not verifying ownership before responding
with a voucher. This is expected to be a common operational model
because doing so relieves the manufacturer providing MASA services
from having to track ownership during shipping and supply chain and
allows for a very low overhead MASA service. A registrar uses the
audit log information as a defense in depth strategy to ensure that
this does not occur unexpectedly (for example when purchasing new
equipment the registrar would throw an error if any audit log
information is reported.) The MASA SHOULD verify the 'prior-signed-
voucher-request' information for pledges that support that
functionality. This provides a proof-of-proximity check that reduces
the need for ownership verification. The proof-of-proximity comes
from the assumption that the pledge and Join Proxy are on the same
link-local connection.
Pritikin, et al. Expires 15 May 2021 [Page 70]
Internet-Draft BRSKI November 2020
A MASA that practices Trust-on-First-Use (TOFU) for Registrar
identity may wish to annotate the origin of the connection by IP
address or netblock, and restrict future use of that identity from
other locations. A MASA that does this SHOULD take care to not
create nuisance situations for itself when a customer has multiple
registrars, or uses outgoing IPv4 NAT44 connections that change
frequently.
7.4.3. Updating or extending voucher trust anchors
This section deals with the problem of a MASA that is no longer
available due to a failed business, or the situation where a MASA is
uncooperative to a secondary sale.
A manufacturer could offer a management mechanism that allows the
list of voucher verification trust anchors to be extended.
[I-D.ietf-netconf-keystore] is one such interface that could be
implemented using YANG. Pretty much any configuration mechanism used
today could be extended to provide the needed additional update. A
manufacturer could even decide to install the domain CA trust anchors
received during the EST "cacerts" step as voucher verification
anchors. Some additional signals will be needed to clearly identify
which keys have voucher validation authority from among those signed
by the domain CA. This is future work.
With the above change to the list of anchors, vouchers can be issued
by an alternate MASA. This could be the previous owner (the seller),
or some other trusted third party who is mediating the sale. If it
was a third party, then the seller would need to have taken steps to
introduce the third party configuration to the device prior
disconnection. The third party (e.g. a wholesaler of used equipment)
could however use a mechanism described in Section 7.2 to take
control of the device after receiving it physically. This would
permit the third party to act as the MASA for future onboarding
actions. As the IDevID certificate probably can not be replaced, the
new owner's Registrar would have to support an override of the MASA
URL.
To be useful for resale or other transfers of ownership one of two
situations will need to occur. The simplest is that the device is
not put through any kind of factory default/reset before going
through onboarding again. Some other secure, physical signal would
be needed to initiate it. This is most suitable for redeploying a
device within the same Enterprise. This would entail having previous
configuration in the system until entirely replaced by the new owner,
and represents some level of risk.
Pritikin, et al. Expires 15 May 2021 [Page 71]
Internet-Draft BRSKI November 2020
The second mechanism is that there would need to be two levels of
factory reset. One would take the system back entirely to
manufacturer state, including removing any added trust anchors, and
the second (more commonly used) one would just restore the
configuration back to a known default without erasing trust anchors.
This weaker factory reset might leave valuable credentials on the
device and this may be unacceptable to some owners.
As a third option, the manufacturer's trust anchors could be entirely
overwritten with local trust anchors. A factory default would never
restore those anchors. This option comes with a lot of power, but
also a lot of responsibility: if access to the private part of the
new anchors are lost the manufacturer may be unable to help.
8. IANA Considerations
This document requires the following IANA actions:
8.1. The IETF XML Registry
This document registers a URI in the "IETF XML Registry" [RFC3688].
IANA is asked to register the following:
URI: urn:ietf:params:xml:ns:yang:ietf-voucher-request
Registrant Contact: The ANIMA WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
8.2. YANG Module Names Registry
This document registers a YANG module in the "YANG Module Names"
registry [RFC6020]. IANA is asked to register the following:
name: ietf-voucher-request
namespace: urn:ietf:params:xml:ns:yang:ietf-voucher-request
prefix: vch
reference: THIS DOCUMENT
8.3. BRSKI well-known considerations
8.3.1. BRSKI .well-known registration
To the Well-Known URIs Registry, at:
"https://www.iana.org/assignments/well-known-uris/well-known-
uris.xhtml", this document registers the well-known name "brski" with
the following filled-in template from [RFC5785]:
URI suffix: brski
Change Controller: IETF
Pritikin, et al. Expires 15 May 2021 [Page 72]
Internet-Draft BRSKI November 2020
IANA is asked to change the registration of "est" to now only include
RFC7030 and no longer this document. Earlier versions of this
document used "/.well-known/est" rather than "/.well-known/brski".
8.3.2. BRSKI .well-known registry
IANA is requested to create a new Registry entitled: "BRSKI well-
known URIs". The registry shall have at least three columns: URI,
description, and reference. New items can be added using the
Specification Required process. The initial contents of this
registry shall be:
URI document description
requestvoucher [THISRFC] pledge to registrar, and from registrar to MASA
voucher_status [THISRFC] pledge to registrar
requestauditlog [THISRFC] registrar to MASA
enrollstatus [THISRFC] pledge to registrar
8.4. PKIX Registry
IANA is requested to register the following:
This document requests a number for id-mod-MASAURLExtn2016(TBD) from
the pkix(7) id-mod(0) Registry.
This document has received an early allocation from the id-pe
registry (SMI Security for PKIX Certificate Extension) for id-pe-
masa-url with the value 32, resulting in an OID of
1.3.6.1.5.5.7.1.32.
8.5. Pledge BRSKI Status Telemetry
IANA is requested to create a new Registry entitled: "BRSKI
Parameters", and within that Registry to create a table called:
"Pledge BRSKI Status Telemetry Attributes". New items can be added
using the Specification Required process. The following items are to
be in the initial registration, with this document (Section 5.7) as
the reference:
* version
* Status
* Reason
* reason-context
Pritikin, et al. Expires 15 May 2021 [Page 73]
Internet-Draft BRSKI November 2020
8.6. DNS Service Names
IANA is requested to register the following Service Names:
Service Name: brski-proxy
Transport Protocol(s): tcp
Assignee: IESG <iesg@ietf.org>.
Contact: IESG <iesg@ietf.org>
Description: The Bootstrapping Remote Secure Key
Infrastructures Proxy
Reference: [This document]
Service Name: brski-registrar
Transport Protocol(s): tcp
Assignee: IESG <iesg@ietf.org>.
Contact: IESG <iesg@ietf.org>
Description: The Bootstrapping Remote Secure Key
Infrastructures Registrar
Reference: [This document]
8.7. GRASP Objective Names
IANA is requested to register the following GRASP Objective Names:
The IANA is requested to register the value "AN_Proxy" (without
quotes) to the GRASP Objectives Names Table in the GRASP Parameter
Registry. The specification for this value is this document,
Section 4.1.1.
The IANA is requested to register the value "AN_join_registrar"
(without quotes) to the GRASP Objectives Names Table in the GRASP
Parameter Registry. The specification for this value is this
document, Section 4.3.
9. Applicability to the Autonomic Control Plane (ACP)
This document provides a solution to the requirements for secure
bootstrap set out in Using an Autonomic Control Plane for Stable
Connectivity of Network Operations, Administration, and Maintenance
[RFC8368], A Reference Model for Autonomic Networking
[I-D.ietf-anima-reference-model] and specifically the An Autonomic
Control Plane (ACP) [I-D.ietf-anima-autonomic-control-plane], section
3.2 (Secure Bootstrap), and section 6.1 (ACP Domain, Certificate and
Network).
The protocol described in this document has appeal in a number of
other non-ANIMA use cases. Such uses of the protocol will be
deploying into other environments with different tradeoffs of
Pritikin, et al. Expires 15 May 2021 [Page 74]
Internet-Draft BRSKI November 2020
privacy, security, reliability and autonomy from manufacturers. As
such those use cases will need to provide their own applicability
statements, and will need to address unique privacy and security
considerations for the environments in which they are used.
The autonomic control plane (ACP) that is bootstrapped by the BRSKI
protocol is typically used in medium to large Internet Service
Provider organizations. Equivalent enterprises that have significant
layer-3 router connectivity also will find significant benefit,
particularly if the Enterprise has many sites. (A network consisting
of primarily layer-2 is not excluded, but the adjacencies that the
ACP will create and maintain will not reflect the topology until all
devices participate in the ACP).
In the ACP, the Join Proxy is found to be proximal because
communication between the pledge and the join proxy is exclusively on
IPv6 Link-Local addresses. The proximity of the Join Proxy to the
Registrar is validated by the Registrar using ANI ACP IPv6 Unique
Local Addresses (ULA). ULAs are not routable over the Internet, so
as long as the Join Proxy is operating correctly the proximity
asssertion is satisfied. Other uses of BRSKI will need make similar
analysis if they use proximity assertions.
As specified in the ANIMA charter, this work "..focuses on
professionally-managed networks." Such a network has an operator and
can do things like install, configure and operate the Registrar
function. The operator makes purchasing decisions and is aware of
what manufacturers it expects to see on its network.
Such an operator is also capable of performing bootstrapping of a
device using a serial-console (craft console). The zero-touch
mechanism presented in this and the ACP document
[I-D.ietf-anima-autonomic-control-plane] represents a significiant
efficiency: in particular it reduces the need to put senior experts
on airplanes to configure devices in person.
There is a recognition as the technology evolves that not every
situation may work out, and occasionally a human may still have to
visit. In recognition of this, some mechanisms are presented in
Section 7.2. The manufacturer MUST provide at least one of the one-
touch mechanisms described that permit enrollment to be proceed
without availability of any manufacturer server (such as the MASA).
The BRSKI protocol is going into environments where there have
already been quite a number of vendor proprietary management systems.
Those are not expected to go away quickly, but rather to leverage the
secure credentials that are provisioned by BRSKI. The connectivity
requirements of said management systems are provided by the ACP.
Pritikin, et al. Expires 15 May 2021 [Page 75]
Internet-Draft BRSKI November 2020
9.1. Operational Requirements
This section collects operational requirements based upon the three
roles involved in BRSKI: The Manufacturer Authorized Signing
Authority (MASA), the (Domain) Owner and the Device. It should be
recognized that the manufacturer may be involved in two roles, as it
creates the software/firmware for the device, and also may be the
operator of the MASA.
The requirements in this section are presented using BCP14
([RFC2119], [RFC8174]) language. These do not represent new
normative statements, just a review of a few such things in one place
by role. They also apply specifically to the ANIMA ACP use case.
Other use cases likely have similar, but MAY have different
requirements.
9.1.1. MASA Operational Requirements
The manufacturer MUST arrange for an online service to be available
called the MASA. It MUST be available at the URL which is encoded in
the IDevID certificate extensions described in Section 2.3.2.
The online service MUST have access to a private key with which to
sign [RFC8366] format voucher artifacts. The public key,
certificate, or certificate chain MUST be built in to the device as
part of the firmware.
It is RECOMMENDED that the manufacturer arrange for this signing key
(or keys) to be escrowed according to typical software source code
escrow practices [softwareescrow].
The MASA accepts voucher requests from Domain Owners according to an
operational practice appropriate for the device. This can range from
any domain owner (first-come first-served, on a TOFU-like basis), to
full sales channel integration where Domain Owners need to be
positively identified by TLS Client Certicate pinned, or HTTP
Authentication process. The MASA creates signed voucher artifacts
according to its internally defined policies.
The MASA MUST operate an audit log for devices that is accessible.
The audit log is designed to be easily cacheable and the MASA MAY
find it useful to put this content on a CDN.
Pritikin, et al. Expires 15 May 2021 [Page 76]
Internet-Draft BRSKI November 2020
9.1.2. Domain Owner Operational Requirements
The domain owner MUST operate an EST ([RFC7030]) server with the
extensions described in this document. This is the JRC or Registrar.
This JRC/EST server MUST announce itself using GRASP within the ACP.
This EST server will typically reside with the Network Operations
Center for the organization.
The domain owner MAY operate an internal certificate authority (CA)
that is seperate from the EST server, or it MAY combine all
activities into a single device. The determination of the
architecture depends upon the scale and resiliency requirements of
the organization. Multiple JRC instances MAY be announced into the
ACP from multiple locations to achieve an appropriate level of
redundancy.
In order to recognize which devices and which manufacturers are
welcome on the domain owner's network, the domain owner SHOULD
maintain a white list of manufacturers. This MAY extend to
integration with purchasing departments to know the serial numbers of
devices.
The domain owner SHOULD use the resulting overlay ACP network to
manage devices, replacing legacy out-of-band mechanisms.
The domain owner SHOULD operate one or more EST servers which can be
used to renew the domain certificates (LDevIDs) which are deployed to
devices. These servers MAY be the same as the JRC, or MAY be a
distinct set of devices, as approriate for resiliency.
The organization MUST take appropriate precautions against loss of
access to the certificate authority private key. Hardware security
modules and/or secret splitting are appropriate.
9.1.3. Device Operational Requirements
Devices MUST come with built-in trust anchors that permit the device
to validate vouchers from the MASA.
Device MUST come with (unique, per-device) IDevID certificates that
include their serial numbers, and the MASA URL extension.
Devices are expected to find Join Proxies using GRASP, and then
connect to the JRC using the protocol described in this document.
Pritikin, et al. Expires 15 May 2021 [Page 77]
Internet-Draft BRSKI November 2020
Once a domain owner has been validated with the voucher, devices are
expected to enroll into the domain using EST. Devices are then
expected to form ACPs using IPsec over IPv6 Link-Local addresses as
described in [I-D.ietf-anima-autonomic-control-plane].
Once a device has been enrolled it SHOULD listen for the address of
the JRC using GRASP, and it SHOULD enable itself as a Join Proxy, and
announce itself on all links/interfaces using GRASP DULL.
Devices are expected to renew their certificates before they expire.
10. Privacy Considerations
10.1. MASA audit log
The MASA audit log includes the domainID for each domain a voucher
has been issued to. This information is closely related to the
actual domain identity. A MASA may need additional defenses against
Denial of Service attacks (Section 11.1), and this may involve
collecting additional (unspecified here) information. This could
provide sufficient information for the MASA service to build a
detailed understanding the devices that have been provisioned within
a domain.
There are a number of design choices that mitigate this risk. The
domain can maintain some privacy since it has not necessarily been
authenticated and is not authoritatively bound to the supply chain.
Additionally the domainID captures only the unauthenticated subject
key identifier of the domain. A privacy sensitive domain could
theoretically generate a new domainID for each device being deployed.
Similarly a privacy sensitive domain would likely purchase devices
that support proximity assertions from a manufacturer that does not
require sales channel integrations. This would result in a
significant level of privacy while maintaining the security
characteristics provided by Registrar based audit log inspection.
10.2. What BRSKI-EST reveals
During the provisional phase of the BRSKI-EST connection between the
Pledge and the Registrar, each party reveals its certificates to each
other. For the Pledge, this includes the serialNumber attribute, the
MASA URL, and the identity that signed the IDevID certificate.
TLS 1.2 reveals the certificate identities to on-path observers,
including the Join Proxy.
Pritikin, et al. Expires 15 May 2021 [Page 78]
Internet-Draft BRSKI November 2020
TLS 1.3 reveals the certificate identities only to the end parties,
but as the connection is provisional, an on-path attacker (MTIM) can
see the certificates. This includes not just malicious attackers,
but also Registrars that are visible to the Pledge, but which are not
part of the intended domain.
The certificate of the Registrar is rather arbitrary from the point
of view of the BRSKI protocol. As no [RFC6125] validations are
expected to be done, the contents could be easily pseudonymized. Any
device that can see a join proxy would be able to connect to the
Registrar and learn the identity of the network in question. Even if
the contents of the certificate are pseudonymized, it would be
possible to correlate different connections in different locations
belong to the same entity. This is unlikely to present a significant
privacy concern to ANIMA ACP uses of BRSKI, but may be a concern to
other users of BRSKI.
The certificate of the Pledge could be revealed by a malicious Join
Proxy that performed a MITM attack on the provisional TLS connection.
Such an attacker would be able to reveal the identity of the Pledge
to third parties if it chose to so.
Research into a mechanism to do multi-step, multi-party authenticated
key agreement, incorporating some kind of zero-knowledge proof would
be valuable. Such a mechanism would ideally avoid disclosing
identities until pledge, registrar and MASA agree to the transaction.
Such a mechanism would need to discover the location of the MASA
without knowing the identity of the pledge, or the identity of the
MASA. This part of the problem may be unsolveable.
10.3. What BRSKI-MASA reveals to the manufacturer
With consumer-oriented devices, the "call-home" mechanism in IoT
devices raises significant privacy concerns. See [livingwithIoT] and
[IoTstrangeThings] for exemplars. The Autonomic Control Plane (ACP)
usage of BRSKI is not targeted at individual usage of IoT devices,
but rather at the Enterprise and ISP creation of networks in a zero-
touch fashion where the "call-home" represents a different class of
privacy and lifecycle management concerns.
Pritikin, et al. Expires 15 May 2021 [Page 79]
Internet-Draft BRSKI November 2020
It needs to be re-iterated that the BRSKI-MASA mechanism only occurs
once during the commissioning of the device. It is well defined, and
although encrypted with TLS, it could in theory be made auditable as
the contents are well defined. This connection does not occur when
the device powers on or is restarted for normal routines. (It is
conceivable, but remarkably unusual, that a device could be forced to
go through a full factory reset during an exceptional firmware update
situation, after which enrollment would have be repeated, and a new
connection would occur)
The BRSKI call-home mechanism is mediated via the owner's Registrar,
and the information that is transmitted is directly auditable by the
device owner. This is in stark contrast to many "call-home"
protocols where the device autonomously calls home and uses an
undocumented protocol.
While the contents of the signed part of the pledge voucher request
can not be changed, they are not encrypted at the registrar. The
ability to audit the messages by the owner of the network is a
mechanism to defend against exfiltration of data by a nefarious
pledge. Both are, to re-iterate, encrypted by TLS while in transit.
The BRSKI-MASA exchange reveals the following information to the
manufacturer:
* the identity of the device being enrolled. This is revealed by
transmission of a signed voucher-request containing the serial-
number. The manufacturer can usually link the serial number to a
device model.
* an identity of the domain owner in the form of the domain trust
anchor. However, this is not a global PKI anchored name within
the WebPKI, so this identity could be pseudonymous. If there is
sales channel integration, then the MASA will have authenticated
the domain owner, either via pinned certificate, or perhaps
another HTTP authentication method, as per Section 5.5.4.
* the time the device is activated,
* the IP address of the domain Owner's Registrar. For ISPs and
Enterprises, the IP address provides very clear geolocation of the
owner. No amount of IP address privacy extensions ([RFC4941]) can
do anything about this, as a simple whois lookup likely identifies
the ISP or Enterprise from the upper bits anyway. A passive
attacker who observes the connection definitely may conclude that
the given enterprise/ISP is a customer of the particular equipment
vendor. The precise model that is being enrolled will remain
private.
Pritikin, et al. Expires 15 May 2021 [Page 80]
Internet-Draft BRSKI November 2020
Based upon the above information, the manufacturer is able to track a
specific device from pseudonymous domain identity to the next
pseudonymous domain identity. If there is sales-channel integration,
then the identities are not pseudonymous.
The manufacturer knows the IP address of the Registrar, but it can
not see the IP address of the device itself. The manufacturer can
not track the device to a detailed physical or network location, only
to the location of the Registrar. That is likely to be at the
Enterprise or ISPs headquarters.
The above situation is to be distinguished from a residential/
individual person who registers a device from a manufacturer.
Individuals do not tend to have multiple offices, and their registrar
is likely on the same network as the device. A manufacturer that
sells switching/routing products to enterprises should hardly be
surprised if additional purchases switching/routing products are
made. Deviations from a historical trend or an establish baseline
would, however, be notable.
The situation is not improved by the enterprise/ISP using
anonymization services such as ToR [Dingledine2004], as a TLS 1.2
connection will reveal the ClientCertificate used, clearly
identifying the enterprise/ISP involved. TLS 1.3 is better in this
regard, but an active attacker can still discover the parties
involved by performing a Man-In-The-Middle-Attack on the first
attempt (breaking/killing it with a TCP RST), and then letting
subsequent connection pass through.
A manufacturer could attempt to mix the BRSKI-MASA traffic in with
general traffic their site by hosting the MASA behind the same (set)
of load balancers that the companies normal marketing site is hosted
behind. This makes lots of sense from a straight capacity planning
point of view as the same set of services (and the same set of
Distributed Denial of Service mitigations) may be used.
Unfortunately, as the BRSKI-MASA connections include TLS
ClientCertificate exchanges, this may easily be observed in TLS 1.2,
and a traffic analysis may reveal it even in TLS 1.3. This does not
make such a plan irrelevant. There may be other organizational
reasons to keep the marketing site (which is often subject to
frequent re-designs, outsourcing, etc.) separate from the MASA, which
may need to operate reliably for decades.
10.4. Manufacturers and Used or Stolen Equipment
As explained above, the manufacturer receives information each time
that a device which is in factory-default mode does a zero-touch
bootstrap, and attempts to enroll into a domain owner's registrar.
Pritikin, et al. Expires 15 May 2021 [Page 81]
Internet-Draft BRSKI November 2020
The manufacturer is therefore in a position to decline to issue a
voucher if it detects that the new owner is not the same as the
previous owner.
1. This can be seen as a feature if the equipment is believed to
have been stolen. If the legitimate owner notifies the
manufacturer of the theft, then when the new owner brings the
device up, if they use the zero-touch mechanism, the new
(illegitimate) owner reveals their location and identity.
2. In the case of Used equipment, the initial owner could inform the
manufacturer of the sale, or the manufacturer may just permit
resales unless told otherwise. In which case, the transfer of
ownership simply occurs.
3. A manufacturer could however decide not to issue a new voucher in
response to a transfer of ownership. This is essentially the
same as the stolen case, with the manufacturer having decided
that the sale was not legitimate.
4. There is a fourth case, if the manufacturer is providing
protection against stolen devices. The manufacturer then has a
responsibility to protect the legitimate owner against fraudulent
claims that the equipment was stolen. In the absence of such
manufacturer protection, such a claim would cause the
manufacturer to refuse to issue a new voucher. Should the device
go through a deep factory reset (for instance, replacement of a
damaged main board component, the device would not bootstrap.
5. Finally, there is a fifth case: the manufacturer has decided to
end-of-line the device, or the owner has not paid a yearly
support amount, and the manufacturer refuses to issue new
vouchers at that point. This last case is not new to the
industry: many license systems are already deployed that have
significantly worse effect.
This section has outlined five situations in which a manufacturer
could use the voucher system to enforce what are clearly license
terms. A manufacturer that attempted to enforce license terms via
vouchers would find it rather ineffective as the terms would only be
enforced when the device is enrolled, and this is not (to repeat), a
daily or even monthly occurrence.
Pritikin, et al. Expires 15 May 2021 [Page 82]
Internet-Draft BRSKI November 2020
10.5. Manufacturers and Grey market equipment
Manufacturers of devices often sell different products into different
regional markets. Which product is available in which market can be
driven by price differentials, support issues (some markets may
require manuals and tech-support to be done in the local language),
government export regulation (such as whether strong crypto is
permitted to be exported, or permitted to be used in a particular
market). When an domain owner obtains a device from a different
market (they can be new) and transfers it to a different location,
this is called a Grey Market.
A manufacturer could decide not to issue a voucher to an enterprise/
ISP based upon their location. There are a number of ways which this
could be determined: from the geolocation of the registrar, from
sales channel knowledge about the customer, and what products are
(un-)available in that market. If the device has a GPS the
coordinates of the device could even be placed into an extension of
the voucher.
The above actions are not illegal, and not new. Many manufacturers
have shipped crypto-weak (exportable) versions of firmware as the
default on equipment for decades. The first task of an enterprise/
ISP has always been to login to a manufacturer system, show one's
"entitlement" (country information, proof that support payments have
been made), and receive either a new updated firmware, or a license
key that will activate the correct firmware.
BRSKI permits the above process to automated (in an autonomic
fashion), and therefore perhaps encourages this kind of
differentiation by reducing the cost of doing it.
An issue that manufacturers will need to deal with in the above
automated process is when a device is shipped to one country with one
set of rules (or laws or entitlements), but the domain registry is in
another one. Which rules apply is something will have to be worked
out: the manufacturer could come to believe they are dealing with
Grey market equipment, when it is simply dealing with a global
enterprise.
10.6. Some mitigations for meddling by manufacturers
The most obvious mitigation is not to buy the product. Pick
manufacturers that are up-front about their policies, who do not
change them gratuitously.
Pritikin, et al. Expires 15 May 2021 [Page 83]
Internet-Draft BRSKI November 2020
Section 7.4.3 describes some ways in which a manufacturer could
provide a mechanism to manage the trust anchors and built-in
certificates (IDevID) as an extension. There are a variety of
mechanism, and some may take a substantial amount of work to get
exactly correct. These mechanisms do not change the flow of the
protocol described here, but rather allow the starting trust
assumptions to be changed. This is an area for future
standardization work.
Replacement of the voucher validation anchors (usually pointing to
the original manufacturer's MASA) with those of the new owner permits
the new owner to issue vouchers to subsequent owners. This would be
done by having the selling (old) owner to run a MASA.
The BRSKI protocol depends upon a trust anchor on the device and an
identity on the device. Management of these entities facilitates a
few new operational modes without making any changes to the BRSKI
protocol. Those modes include: offline modes where the domain owner
operates an internal MASA for all devices, resell modes where the
first domain owner becomes the MASA for the next (resold-to) domain
owner, and services where an aggregator acquires a large variety of
devices, and then acts as a pseudonymized MASA for a variety of
devices from a variety of manufacturers.
Although replacement of the IDevID is not required for all modes
described above, a manufacturers could support such a thing. Some
may wish to consider replacement of the IDevID as an indication that
the device's warrantee is terminated. For others, the privacy
requirements of some deployments might consider this a standard
operating practice.
As discussed at the end of Section 5.8.1, new work could be done to
use a distributed consensus technology for the audit log. This would
permit the audit log to continue to be useful, even when there is a
chain of MASA due to changes of ownership.
10.7. Death of a manufacturer
A common concern has been that a manufacturer could go out of
business, leaving owners of devices unable to get new vouchers for
existing products. Said products might have been previously
deployed, but need to be re-initialized, they might have been
purchased used, or they might have kept in a warehouse as long-term
spares.
The MASA was named the Manufacturer *Authorized* Signing Authority to
emphasize that it need not be the manufacturer itself that performs
this. It is anticipated that specialist service providers will come
Pritikin, et al. Expires 15 May 2021 [Page 84]
Internet-Draft BRSKI November 2020
to exist that deal with the creation of vouchers in much the same way
that many companies have outsourced email, advertising and janitorial
services.
Further, it is expected that as part of any service agreement that
the manufacturer would arrange to escrow appropriate private keys
such that a MASA service could be provided by a third party. This
has routinely been done for source code for decades.
11. Security Considerations
This document details a protocol for bootstrapping that balances
operational concerns against security concerns. As detailed in the
introduction, and touched on again in Section 7, the protocol allows
for reduced security modes. These attempt to deliver additional
control to the local administrator and owner in cases where less
security provides operational benefits. This section goes into more
detail about a variety of specific considerations.
To facilitate logging and administrative oversight, in addition to
triggering Registrar verification of MASA logs, the pledge reports on
voucher parsing status to the registrar. In the case of a failure,
this information is informative to a potentially malicious registrar.
This is mandated anyway because of the operational benefits of an
informed administrator in cases where the failure is indicative of a
problem. The registrar is RECOMMENDED to verify MASA logs if voucher
status telemetry is not received.
To facilitate truly limited clients EST RFC7030 section 3.3.2
requirements that the client MUST support a client authentication
model have been reduced in Section 7 to a statement that the
registrar "MAY" choose to accept devices that fail cryptographic
authentication. This reflects current (poor) practices in shipping
devices without a cryptographic identity that are NOT RECOMMENDED.
During the provisional period of the connection the pledge MUST treat
all HTTP header and content data as untrusted data. HTTP libraries
are regularly exposed to non-secured HTTP traffic: mature libraries
should not have any problems.
Pledges might chose to engage in protocol operations with multiple
discovered registrars in parallel. As noted above they will only do
so with distinct nonce values, but the end result could be multiple
vouchers issued from the MASA if all registrars attempt to claim the
device. This is not a failure and the pledge choses whichever
voucher to accept based on internal logic. The registrars verifying
log information will see multiple entries and take this into account
for their analytics purposes.
Pritikin, et al. Expires 15 May 2021 [Page 85]
Internet-Draft BRSKI November 2020
11.1. Denial of Service (DoS) against MASA
There are uses cases where the MASA could be unavailable or
uncooperative to the Registrar. They include active DoS attacks,
planned and unplanned network partitions, changes to MASA policy, or
other instances where MASA policy rejects a claim. These introduce
an operational risk to the Registrar owner in that MASA behavior
might limit the ability to bootstrap a pledge device. For example
this might be an issue during disaster recovery. This risk can be
mitigated by Registrars that request and maintain long term copies of
"nonceless" vouchers. In that way they are guaranteed to be able to
bootstrap their devices.
The issuance of nonceless vouchers themselves creates a security
concern. If the Registrar of a previous domain can intercept
protocol communications then it can use a previously issued nonceless
voucher to establish management control of a pledge device even after
having sold it. This risk is mitigated by recording the issuance of
such vouchers in the MASA audit log that is verified by the
subsequent Registrar and by Pledges only bootstrapping when in a
factory default state. This reflects a balance between enabling MASA
independence during future bootstrapping and the security of
bootstrapping itself. Registrar control over requesting and auditing
nonceless vouchers allows device owners to choose an appropriate
balance.
The MASA is exposed to DoS attacks wherein attackers claim an
unbounded number of devices. Ensuring a registrar is representative
of a valid manufacturer customer, even without validating ownership
of specific pledge devices, helps to mitigate this. Pledge
signatures on the pledge voucher-request, as forwarded by the
registrar in the prior-signed-voucher-request field of the registrar
voucher-request, significantly reduce this risk by ensuring the MASA
can confirm proximity between the pledge and the registrar making the
request. Supply chain integration ("know your customer") is an
additional step that MASA providers and device vendors can explore.
11.2. DomainID must be resistant to second-preimage attacks
The domainID is used as the reference in the audit log to the domain.
The domainID is expected to be calculated by a hash that is resistant
to a second-preimage attack. Such an attack would allow a second
registrar to create audit log entries that are fake.
Pritikin, et al. Expires 15 May 2021 [Page 86]
Internet-Draft BRSKI November 2020
11.3. Availability of good random numbers
The nonce used by the Pledge in the voucher-request SHOULD be
generated by a Strong Cryptographic Sequence ([RFC4086] section 6.2).
TLS has a similar requirement.
In particular implementations should pay attention to the advance in
[RFC4086] section 3, particularly section 3.4. The random seed used
by a device at boot MUST be unique across all devices and all
bootstraps. Resetting a device to factory default state does not
obviate this requirement.
11.4. Freshness in Voucher-Requests
A concern has been raised that the pledge voucher-request should
contain some content (a nonce) provided by the registrar and/or MASA
in order for those actors to verify that the pledge voucher-request
is fresh.
There are a number of operational problems with getting a nonce from
the MASA to the pledge. It is somewhat easier to collect a random
value from the registrar, but as the registrar is not yet vouched
for, such a registrar nonce has little value. There are privacy and
logistical challenges to addressing these operational issues, so if
such a thing were to be considered, it would have to provide some
clear value. This section examines the impacts of not having a fresh
pledge voucher-request.
Because the registrar authenticates the pledge, a full Man-in-the-
Middle attack is not possible, despite the provisional TLS
authentication by the pledge (see Section 5.) Instead we examine the
case of a fake registrar (Rm) that communicates with the pledge in
parallel or in close time proximity with the intended registrar.
(This scenario is intentionally supported as described in
Section 4.1.)
The fake registrar (Rm) can obtain a voucher signed by the MASA
either directly or through arbitrary intermediaries. Assuming that
the MASA accepts the registrar voucher-request (either because Rm is
collaborating with a legitimate registrar according to supply chain
information, or because the MASA is in audit-log only mode), then a
voucher linking the pledge to the registrar Rm is issued.
Such a voucher, when passed back to the pledge, would link the pledge
to registrar Rm, and would permit the pledge to end the provisional
state. It now trusts Rm and, if it has any security vulnerabilities
leveragable by an Rm with full administrative control, can be assumed
to be a threat against the intended registrar.
Pritikin, et al. Expires 15 May 2021 [Page 87]
Internet-Draft BRSKI November 2020
This flow is mitigated by the intended registrar verifying the audit
logs available from the MASA as described in Section 5.8. Rm might
chose to collect a voucher-request but wait until after the intended
registrar completes the authorization process before submitting it.
This pledge voucher-request would be 'stale' in that it has a nonce
that no longer matches the internal state of the pledge. In order to
successfully use any resulting voucher the Rm would need to remove
the stale nonce or anticipate the pledge's future nonce state.
Reducing the possibility of this is why the pledge is mandated to
generate a strong random or pseudo-random number nonce.
Additionally, in order to successfully use the resulting voucher the
Rm would have to attack the pledge and return it to a bootstrapping
enabled state. This would require wiping the pledge of current
configuration and triggering a re-bootstrapping of the pledge. This
is no more likely than simply taking control of the pledge directly
but if this is a consideration the target network is RECOMMENDED to
take the following steps:
* Ongoing network monitoring for unexpected bootstrapping attempts
by pledges.
* Retrieval and examination of MASA log information upon the
occurrence of any such unexpected events. Rm will be listed in
the logs along with nonce information for analysis.
11.5. Trusting manufacturers
The BRSKI extensions to EST permit a new pledge to be completely
configured with domain specific trust anchors. The link from built-
in manufacturer-provided trust anchors to domain-specific trust
anchors is mediated by the signed voucher artifact.
If the manufacturer's IDevID signing key is not properly validated,
then there is a risk that the network will accept a pledge that
should not be a member of the network. As the address of the
manufacturer's MASA is provided in the IDevID using the extension
from Section 2.3, the malicious pledge will have no problem
collaborating with it's MASA to produce a completely valid voucher.
BRSKI does not, however, fundamentally change the trust model from
domain owner to manufacturer. Assuming that the pledge used its
IDevID with RFC7030 EST and BRSKI, the domain (registrar) still needs
to trust the manufacturer.
Establishing this trust between domain and manufacturer is outside
the scope of BRSKI. There are a number of mechanisms that can
adopted including:
Pritikin, et al. Expires 15 May 2021 [Page 88]
Internet-Draft BRSKI November 2020
* Manually configuring each manufacturer's trust anchor.
* A Trust-On-First-Use (TOFU) mechanism. A human would be queried
upon seeing a manufacturer's trust anchor for the first time, and
then the trust anchor would be installed to the trusted store.
There are risks with this; even if the key to name mapping is
validated using something like the WebPKI, there remains the
possibility that the name is a look alike: e.g, dem0.example. vs
demO.example.
* scanning the trust anchor from a QR code that came with the
packaging (this is really a manual TOFU mechanism)
* some sales integration process where trust anchors are provided as
part of the sales process, probably included in a digital packing
"slip", or a sales invoice.
* consortium membership, where all manufacturers of a particular
device category (e.g, a light bulb, or a cable-modem) are signed
by an certificate authority specifically for this. This is done
by CableLabs today. It is used for authentication and
authorization as part of TR-79: [docsisroot] and [TR069].
The existing WebPKI provides a reasonable anchor between manufacturer
name and public key. It authenticates the key. It does not provide
a reasonable authorization for the manufacturer, so it is not
directly useable on it's own.
11.6. Manufacturer Maintenance of trust anchors
BRSKI depends upon the manufacturer building in trust anchors to the
pledge device. The voucher artifact which is signed by the MASA will
be validated by the pledge using that anchor. This implies that the
manufacturer needs to maintain access to a signing key that the
pledge can validate.
The manufacturer will need to maintain the ability to make signatures
that can be validated for the lifetime that the device could be
onboarded. Whether this onboarding lifetime is less than the device
lifetime depends upon how the device is used. An inventory of
devices kept in a warehouse as spares might not be onboarded for many
decades.
Pritikin, et al. Expires 15 May 2021 [Page 89]
Internet-Draft BRSKI November 2020
There are good cryptographic hygiene reasons why a manufacturer would
not want to maintain access to a private key for many decades. A
manufacturer in that situation can leverage a long-term certificate
authority anchor, built-in to the pledge, and then a certificate
chain may be incorporated using the normal CMS certificate set. This
may increase the size of the voucher artifacts, but that is not a
significant issues in non-constrained environments.
There are a few other operational variations that manufacturers could
consider. For instance, there is no reason that every device need
have the same set of trust anchors pre-installed. Devices built in
different factories, or on different days, or any other consideration
could have different trust anchors built in, and the record of which
batch the device is in would be recorded in the asset database. The
manufacturer would then know which anchor to sign an artifact
against.
Aside from the concern about long-term access to private keys, a
major limiting factor for the shelf-life of many devices will be the
age of the cryptographic algorithms included. A device produced in
2019 will have hardware and software capable of validating algorithms
common in 2019, and will have no defense against attacks (both
quantum and von-neuman brute force attacks) which have not yet been
invented. This concern is orthogonal to the concern about access to
private keys, but this concern likely dominates and limits the
lifespan of a device in a warehouse. If any update to firmware to
support new cryptographic mechanism were possible (while the device
was in a warehouse), updates to trust anchors would also be done at
the same time.
The set of standard operating procedures for maintaining high value
private keys is well documented. For instance, the WebPKI provides a
number of options for audits at [cabforumaudit], and the DNSSEC root
operations are well documented at [dnssecroot].
It is not clear if Manufacturers will take this level of precaution,
or how strong the economic incentives are to maintain an appropriate
level of security.
This next section examines the risk due to a compromised manufacturer
IDevID signing key. This is followed by examination of the risk due
to a compromised MASA key. The third section sections below examines
the situation where MASA web server itself is under attacker control,
but that the MASA signing key itself is safe in a not-directly
connected hardware module.
Pritikin, et al. Expires 15 May 2021 [Page 90]
Internet-Draft BRSKI November 2020
11.6.1. Compromise of Manufacturer IDevID signing keys
An attacker that has access to the key that the manufacturer uses to
sign IDevID certificates can create counterfeit devices. Such
devices can claim to be from a particular manufacturer, but be
entirely different devices: Trojan horses in effect.
As the attacker controls the MASA URL in the certificate, the
registrar can be convinced to talk to the attackers' MASA. The
Registrar does not need to be in any kind of promiscuous mode to be
vulnerable.
In addition to creating fake devices, the attacker may also be able
to issue revocations for existing certificates if the IDevID
certificate process relies upon CRL lists that are distributed.
There does not otherwise seem to be any risk from this compromise to
devices which are already deployed, or which are sitting locally in
boxes waiting for deployment (local spares). The issue is that
operators will be unable to trust devices which have been in an
uncontrolled warehouse as they do not know if those are real devices.
11.6.2. Compromise of MASA signing keys
There are two periods of time in which to consider: when the MASA key
has fallen into the hands of an attacker, and after the MASA
recognizes that the key has been compromised.
11.6.2.1. Attacker opportunties with compromised MASA key
An attacker that has access to the MASA signing key could create
vouchers. These vouchers could be for existing deployed devices, or
for devices which are still in a warehouse. In order to exploit
these vouchers two things need to occur: the device has to go through
a factory default boot cycle, and the registrar has to be convinced
to contact the attacker's MASA.
If the attacker controls a Registrar which is visible to the device,
then there is no difficulty in delivery of the false voucher. A
possible practical example of an attack like this would be in a data
center, at an ISP peering point (whether a public IX, or a private
peering point). In such a situation, there are already cables
attached to the equipment that lead to other devices (the peers at
the IX), and through those links, the false voucher could be
delivered. The difficult part would be get the device put through a
factory reset. This might be accomplished through social engineering
of data center staff. Most locked cages have ventilation holes, and
possibly a long "paperclip" could reach through to depress a factory
Pritikin, et al. Expires 15 May 2021 [Page 91]
Internet-Draft BRSKI November 2020
reset button. Once such a piece of ISP equipment has been
compromised, it could be used to compromise equipment that was
connected to (through long haul links even), assuming that those
pieces of equipment could also be forced through a factory reset.
The above scenario seems rather unlikely as it requires some element
of physical access; but were there a remote exploit that did not
cause a direct breach, but rather a fault that resulted in a factory
reset, this could provide a reasonable path.
The above deals with ANI uses of BRSKI. For cases where 802.11 or
802.15.4 is involved, the need to connect directly to the device is
eliminated, but the need to do a factory reset is not. Physical
possession of the device is not required as above, provided that
there is some way to force a factory reset. With some consumers
devices with low overall implementation quality, the end users might
be familiar with needing to reset the device regularly.
The authors are unable to come up with an attack scenario where a
compromised voucher signature enables an attacker to introduce a
compromised pledge into an existing operator's network. This is the
case because the operator controls the communication between
Registrar and MASA, and there is no opportunity to introduce the fake
voucher through that conduit.
11.6.2.2. Risks after key compromise is known
Once the operator of the MASA realizes that the voucher signing key
has been compromised it has to do a few things.
First, it MUST issue a firmware update to all devices that had that
key as a trust anchor, such that they will no longer trust vouchers
from that key. This will affect devices in the field which are
operating, but those devices, being in operation, are not performing
onboarding operations, so this is not a critical patch.
Devices in boxes (in warehouses) are vulnerable, and remain
vulnerable until patched. An operator would be prudent to unbox the
devices, onboard them in a safe environment, and then perform
firmware updates. This does not have to be done by the end-operator;
it could be done by a distributor that stores the spares. A
recommended practice for high value devices (which typically have a
<4hr service window) may be to validate the device operation on a
regular basis anyway.
Pritikin, et al. Expires 15 May 2021 [Page 92]
Internet-Draft BRSKI November 2020
If the onboarding process includes attestations about firmware
versions, then through that process the operator would be advised to
upgrade the firmware before going into production. Unfortunately,
this does not help against situations where the attacker operates
their own Registrar (as listed above).
[RFC8366] section 6.1 explains the need for short-lived vouchers.
The nonce guarantees freshness, and the short-lived nature of the
voucher means that the window to deliver a fake voucher is very
short. A nonceless, long-lived voucher would be the only option for
the attacker, and devices in the warehouse would be vulnerable to
such a thing.
A key operational recommendation is for manufacturers to sign
nonceless, long-lived vouchers with a different key that they sign
short-lived vouchers. That key needs significantly better
protection. If both keys come from a common trust-anchor (the
manufacturer's CA), then a compromise of the manufacturer's CA would
compromise both keys. Such a compromise of the manufacturer's CA
likely compromises all keys outlined in this section.
11.6.3. Compromise of MASA web service
An attacker that takes over the MASA web service has a number of
attacks. The most obvious one is simply to take the database listing
customers and devices and to sell this data to other attackers who
will now know where to find potentially vulnerable devices.
The second most obvious thing that the attacker can do is to kill the
service, or make it operate unreliably, making customers frustrated.
This could have a serious affect on ability to deploy new services by
customers, and would be a significant issue during disaster recovery.
While the compromise of the MASA web service may lead to the
compromise of the MASA voucher signing key, if the signing occurs
offboard (such as in a hardware signing module, HSM), then the key
may well be safe, but control over it resides with the attacker.
Such an attacker can issue vouchers for any device presently in
service. Said device still needs to be convinced to do through a
factory reset process before an attack.
If the attacker has access to a key that is trusted for long-lived
nonceless vouchers, then they could issue vouchers for devices which
are not yet in service. This attack may be very hard to verify and
as it would involve doing firmware updates on every device in
warehouses (a potentially ruinously expensive process), a
manufacturer might be reluctant to admit this possibility.
Pritikin, et al. Expires 15 May 2021 [Page 93]
Internet-Draft BRSKI November 2020
11.7. YANG Module Security Considerations
As described in the Security Considerations section of [RFC8366]
(section 7.4), the YANG module specified in this document defines the
schema for data that is subsequently encapsulated by a CMS signed-
data content type, as described in Section 5 of [RFC5652]. As such,
all of the YANG modeled data is protected from modification.
The use of YANG to define data structures, via the 'yang-data'
statement, is relatively new and distinct from the traditional use of
YANG to define an API accessed by network management protocols such
as NETCONF [RFC6241] and RESTCONF [RFC8040]. For this reason, these
guidelines do not follow template described by Section 3.7 of
[RFC8407].
12. Acknowledgements
We would like to thank the various reviewers for their input, in
particular William Atwood, Brian Carpenter, Fuyu Eleven, Eliot Lear,
Sergey Kasatkin, Anoop Kumar, Tom Petch, Markus Stenberg, Peter van
der Stok, and Thomas Werner
Significant reviews were done by Jari Arko, Christian Huitema and
Russ Housley.
Henk Birkholz contributed the CDDL for the audit log response.
This document started it's life as a two-page idea from Steinthor
Bjarnason.
In addition, significant review comments were received by many IESG
members, including Adam Roach, Alexey Melnikov, Alissa Cooper,
Benjamin Kaduk, Eric Vyncke, Roman Danyliw, and Magnus Westerlund.
13. References
13.1. Normative References
[I-D.ietf-anima-autonomic-control-plane]
Eckert, T., Behringer, M., and S. Bjarnason, "An Autonomic
Control Plane (ACP)", Work in Progress, Internet-Draft,
draft-ietf-anima-autonomic-control-plane-30, 30 October
2020, <http://www.ietf.org/internet-drafts/draft-ietf-
anima-autonomic-control-plane-30.txt>.
[I-D.ietf-anima-grasp]
Bormann, C., Carpenter, B., and B. Liu, "A Generic
Autonomic Signaling Protocol (GRASP)", Work in Progress,
Pritikin, et al. Expires 15 May 2021 [Page 94]
Internet-Draft BRSKI November 2020
Internet-Draft, draft-ietf-anima-grasp-15, 13 July 2017,
<http://www.ietf.org/internet-drafts/draft-ietf-anima-
grasp-15.txt>.
[IDevID] "IEEE 802.1AR Secure Device Identifier", December 2009,
<http://standards.ieee.org/findstds/standard/802.1AR-
2009.html>.
[ITU.X690.1994]
International Telecommunications Union, "Information
Technology - ASN.1 encoding rules: Specification of Basic
Encoding Rules (BER), Canonical Encoding Rules (CER) and
Distinguished Encoding Rules (DER)", ITU-T Recommendation
X.690, 1994.
[REST] Fielding, R.F., "Architectural Styles and the Design of
Network-based Software Architectures", 2000,
<http://www.ics.uci.edu/~fielding/pubs/dissertation/
top.htm>.
[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>.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<https://www.rfc-editor.org/info/rfc3339>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H.
Levkowetz, Ed., "Extensible Authentication Protocol
(EAP)", RFC 3748, DOI 10.17487/RFC3748, June 2004,
<https://www.rfc-editor.org/info/rfc3748>.
[RFC3927] Cheshire, S., Aboba, B., and E. Guttman, "Dynamic
Configuration of IPv4 Link-Local Addresses", RFC 3927,
DOI 10.17487/RFC3927, May 2005,
<https://www.rfc-editor.org/info/rfc3927>.
[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", BCP 106, RFC 4086,
DOI 10.17487/RFC4086, June 2005,
<https://www.rfc-editor.org/info/rfc4086>.
Pritikin, et al. Expires 15 May 2021 [Page 95]
Internet-Draft BRSKI November 2020
[RFC4519] Sciberras, A., Ed., "Lightweight Directory Access Protocol
(LDAP): Schema for User Applications", RFC 4519,
DOI 10.17487/RFC4519, June 2006,
<https://www.rfc-editor.org/info/rfc4519>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<https://www.rfc-editor.org/info/rfc4648>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007,
<https://www.rfc-editor.org/info/rfc4862>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
<https://www.rfc-editor.org/info/rfc4941>.
[RFC5272] Schaad, J. and M. Myers, "Certificate Management over CMS
(CMC)", RFC 5272, DOI 10.17487/RFC5272, June 2008,
<https://www.rfc-editor.org/info/rfc5272>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<https://www.rfc-editor.org/info/rfc5280>.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, DOI 10.17487/RFC5652, September 2009,
<https://www.rfc-editor.org/info/rfc5652>.
[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>.
[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
Verification of Domain-Based Application Service Identity
within Internet Public Key Infrastructure Using X.509
(PKIX) Certificates in the Context of Transport Layer
Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March
2011, <https://www.rfc-editor.org/info/rfc6125>.
Pritikin, et al. Expires 15 May 2021 [Page 96]
Internet-Draft BRSKI November 2020
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762,
DOI 10.17487/RFC6762, February 2013,
<https://www.rfc-editor.org/info/rfc6762>.
[RFC6763] Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", RFC 6763, DOI 10.17487/RFC6763, February 2013,
<https://www.rfc-editor.org/info/rfc6763>.
[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>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<https://www.rfc-editor.org/info/rfc7230>.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014,
<https://www.rfc-editor.org/info/rfc7231>.
[RFC7469] Evans, C., Palmer, C., and R. Sleevi, "Public Key Pinning
Extension for HTTP", RFC 7469, DOI 10.17487/RFC7469, April
2015, <https://www.rfc-editor.org/info/rfc7469>.
[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>.
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/info/rfc7951>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[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>.
Pritikin, et al. Expires 15 May 2021 [Page 97]
Internet-Draft BRSKI November 2020
[RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>.
[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>.
[RFC8368] Eckert, T., Ed. and M. Behringer, "Using an Autonomic
Control Plane for Stable Connectivity of Network
Operations, Administration, and Maintenance (OAM)",
RFC 8368, DOI 10.17487/RFC8368, May 2018,
<https://www.rfc-editor.org/info/rfc8368>.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
Documents Containing YANG Data Models", BCP 216, RFC 8407,
DOI 10.17487/RFC8407, October 2018,
<https://www.rfc-editor.org/info/rfc8407>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8610] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
Definition Language (CDDL): A Notational Convention to
Express Concise Binary Object Representation (CBOR) and
JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
June 2019, <https://www.rfc-editor.org/info/rfc8610>.
13.2. Informative References
[brewski] "Urban Dictionary: Brewski", October 2019,
<https://www.urbandictionary.com/define.php?term=brewski>.
[cabforumaudit]
"Information for Auditors and Assessors", August 2019,
<https://cabforum.org/information-for-auditors-and-
assessors/>.
[Dingledine2004]
Dingledine, R., Mathewson, N., and P. Syverson, "Tor: the
second-generation onion router", 2004,
<https://spec.torproject.org/tor-spec>.
Pritikin, et al. Expires 15 May 2021 [Page 98]
Internet-Draft BRSKI November 2020
[dnssecroot]
"DNSSEC Practice Statement for the Root Zone ZSK
Operator", December 2017,
<https://www.iana.org/dnssec/dps/zsk-operator/dps-zsk-
operator-v2.0.pdf>.
[docsisroot]
"CableLabs Digital Certificate Issuance Service", February
2018, <https://www.cablelabs.com/resources/digital-
certificate-issuance-service/>.
[I-D.ietf-ace-coap-est]
Stok, P., Kampanakis, P., Richardson, M., and S. Raza,
"EST over secure CoAP (EST-coaps)", Work in Progress,
Internet-Draft, draft-ietf-ace-coap-est-18, 6 January
2020, <http://www.ietf.org/internet-drafts/draft-ietf-ace-
coap-est-18.txt>.
[I-D.ietf-anima-constrained-voucher]
Richardson, M., Stok, P., and P. Kampanakis, "Constrained
Voucher Artifacts for Bootstrapping Protocols", Work in
Progress, Internet-Draft, draft-ietf-anima-constrained-
voucher-09, 2 November 2020, <http://www.ietf.org/
internet-drafts/draft-ietf-anima-constrained-voucher-
09.txt>.
[I-D.ietf-anima-reference-model]
Behringer, M., Carpenter, B., Eckert, T., Ciavaglia, L.,
and J. Nobre, "A Reference Model for Autonomic
Networking", Work in Progress, Internet-Draft, draft-ietf-
anima-reference-model-10, 22 November 2018,
<http://www.ietf.org/internet-drafts/draft-ietf-anima-
reference-model-10.txt>.
[I-D.ietf-netconf-keystore]
Watsen, K., "A YANG Data Model for a Keystore", Work in
Progress, Internet-Draft, draft-ietf-netconf-keystore-20,
20 August 2020, <http://www.ietf.org/internet-drafts/
draft-ietf-netconf-keystore-20.txt>.
[I-D.richardson-anima-state-for-joinrouter]
Richardson, M., "Considerations for stateful vs stateless
join router in ANIMA bootstrap", Work in Progress,
Internet-Draft, draft-richardson-anima-state-for-
joinrouter-03, 22 September 2020, <http://www.ietf.org/
internet-drafts/draft-richardson-anima-state-for-
joinrouter-03.txt>.
Pritikin, et al. Expires 15 May 2021 [Page 99]
Internet-Draft BRSKI November 2020
[imprinting]
"Wikipedia article: Imprinting", July 2015,
<https://en.wikipedia.org/wiki/Imprinting_(psychology)>.
[IoTstrangeThings]
"IoT of toys stranger than fiction: Cybersecurity and data
privacy update (accessed 2018-12-02)", March 2017,
<https://www.welivesecurity.com/2017/03/03/internet-of-
things-security-privacy-iot-update/>.
[livingwithIoT]
"What is it actually like to live in a house filled with
IoT devices? (accessed 2018-12-02)", February 2018,
<https://www.siliconrepublic.com/machines/iot-smart-
devices-reality>.
[minerva] Richardsdon, M., "Minerva reference implementation for
BRSKI", 2020, <https://minerva.sandelman.ca/>.
[minervagithub]
Richardsdon, M., "GITHUB hosting of Minerva reference
code", 2020, <https://github.com/ANIMAgus-minerva>.
[openssl] "OpenSSL X509 utility", September 2019,
<https://www.openssl.org/docs/man1.1.1/man1/openssl-
x509.html/>.
[RFC2663] Srisuresh, P. and M. Holdrege, "IP Network Address
Translator (NAT) Terminology and Considerations",
RFC 2663, DOI 10.17487/RFC2663, August 1999,
<https://www.rfc-editor.org/info/rfc2663>.
[RFC5209] Sangster, P., Khosravi, H., Mani, M., Narayan, K., and J.
Tardo, "Network Endpoint Assessment (NEA): Overview and
Requirements", RFC 5209, DOI 10.17487/RFC5209, June 2008,
<https://www.rfc-editor.org/info/rfc5209>.
[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
Uniform Resource Identifiers (URIs)", RFC 5785,
DOI 10.17487/RFC5785, April 2010,
<https://www.rfc-editor.org/info/rfc5785>.
[RFC6960] Santesson, S., Myers, M., Ankney, R., Malpani, A.,
Galperin, S., and C. Adams, "X.509 Internet Public Key
Infrastructure Online Certificate Status Protocol - OCSP",
RFC 6960, DOI 10.17487/RFC6960, June 2013,
<https://www.rfc-editor.org/info/rfc6960>.
Pritikin, et al. Expires 15 May 2021 [Page 100]
Internet-Draft BRSKI November 2020
[RFC6961] Pettersen, Y., "The Transport Layer Security (TLS)
Multiple Certificate Status Request Extension", RFC 6961,
DOI 10.17487/RFC6961, June 2013,
<https://www.rfc-editor.org/info/rfc6961>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained-Node Networks", RFC 7228,
DOI 10.17487/RFC7228, May 2014,
<https://www.rfc-editor.org/info/rfc7228>.
[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
2014, <https://www.rfc-editor.org/info/rfc7258>.
[RFC7435] Dukhovni, V., "Opportunistic Security: Some Protection
Most of the Time", RFC 7435, DOI 10.17487/RFC7435,
December 2014, <https://www.rfc-editor.org/info/rfc7435>.
[RFC7575] Behringer, M., Pritikin, M., Bjarnason, S., Clemm, A.,
Carpenter, B., Jiang, S., and L. Ciavaglia, "Autonomic
Networking: Definitions and Design Goals", RFC 7575,
DOI 10.17487/RFC7575, June 2015,
<https://www.rfc-editor.org/info/rfc7575>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[slowloris]
"Slowloris (computer security)", February 2019,
<https://en.wikipedia.org/wiki/
Slowloris_(computer_security)/>.
[softwareescrow]
"Wikipedia article: Software Escrow", October 2019,
<https://en.wikipedia.org/wiki/Source_code_escrow>.
[Stajano99theresurrecting]
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>.
[TR069] "TR-69: CPE WAN Management Protocol", February 2018,
<https://www.broadband-forum.org/standards-and-software/
technical-specifications/tr-069-files-tools>.
Pritikin, et al. Expires 15 May 2021 [Page 101]
Internet-Draft BRSKI November 2020
[W3C.WD-capability-urls-20140218]
Tennison, J., "Good Practices for Capability URLs", World
Wide Web Consortium WD WD-capability-urls-20140218, 18
February 2014,
<https://www.w3.org/TR/2014/WD-capability-urls-20140218>.
Appendix A. IPv4 and non-ANI operations
The specification of BRSKI in Section 4 intentionally only covers the
mechanisms for an IPv6 pledge using Link-Local addresses. This
section describes non-normative extensions that can be used in other
environments.
A.1. IPv4 Link Local addresses
Instead of an IPv6 link-local address, an IPv4 address may be
generated using [RFC3927] Dynamic Configuration of IPv4 Link-Local
Addresses.
In the case that an IPv4 Link-Local address is formed, then the
bootstrap process would continue as in the IPv6 case by looking for a
(circuit) proxy.
A.2. Use of DHCPv4
The Pledge MAY obtain an IP address via DHCP [RFC2131]. The DHCP
provided parameters for the Domain Name System can be used to perform
DNS operations if all local discovery attempts fail.
Appendix B. mDNS / DNSSD proxy discovery options
Pledge discovery of the proxy (Section 4.1) MAY be performed with
DNS-based Service Discovery [RFC6763] over Multicast DNS [RFC6762] to
discover the proxy at "_brski-proxy._tcp.local.".
Proxy discovery of the registrar (Section 4.3) MAY be performed with
DNS-based Service Discovery over Multicast DNS to discover registrars
by searching for the service "_brski-registrar._tcp.local.".
To prevent unaccceptable levels of network traffic, when using mDNS,
the congestion avoidance mechanisms specified in [RFC6762] section 7
MUST be followed. The pledge SHOULD listen for an unsolicited
broadcast response as described in [RFC6762]. This allows devices to
avoid announcing their presence via mDNS broadcasts and instead
silently join a network by watching for periodic unsolicited
broadcast responses.
Pritikin, et al. Expires 15 May 2021 [Page 102]
Internet-Draft BRSKI November 2020
Discovery of registrar MAY also be performed with DNS-based service
discovery by searching for the service "_brski-
registrar._tcp.example.com". In this case the domain "example.com"
is discovered as described in [RFC6763] section 11 (Appendix A.2
suggests the use of DHCP parameters).
If no local proxy or registrar service is located using the GRASP
mechanisms or the above mentioned DNS-based Service Discovery
methods, the pledge MAY contact a well known manufacturer provided
bootstrapping server by performing a DNS lookup using a well known
URI such as "brski-registrar.manufacturer.example.com". The details
of the URI are manufacturer specific. Manufacturers that leverage
this method on the pledge are responsible for providing the registrar
service. Also see Section 2.7.
The current DNS services returned during each query are maintained
until bootstrapping is completed. If bootstrapping fails and the
pledge returns to the Discovery state, it picks up where it left off
and continues attempting bootstrapping. For example, if the first
Multicast DNS _bootstrapks._tcp.local response doesn't work then the
second and third responses are tried. If these fail the pledge moves
on to normal DNS-based Service Discovery.
Appendix C. Example Vouchers
Three entities are involved in a voucher: the MASA issues (signs) it,
the registrar's public key is mentioned in the voucher, and the
pledge validates it. In order to provide reproduceable examples the
public and private keys for an example MASA and registrar are first
listed.
The keys come from an open source reference implementation of BRSKI,
called "Minerva" [minerva]. It is available on github
[minervagithub]. The keys presented here are used in the unit and
integration tests. The MASA code is called "highway", the Registrar
code is called "fountain", and the example client is called "reach".
The public key components of each are presented as both base64
certificates, as well as being decoded by openssl's x509 utility so
that the extensions can be seen. This was version 1.1.1c of the
[openssl] library and utility.
C.1. Keys involved
The Manufacturer has a Certificate Authority that signs the pledge's
IDevID. In addition the Manufacturer's signing authority (the MASA)
signs the vouchers, and that certificate must distributed to the
devices at manufacturing time so that vouchers can be validated.
Pritikin, et al. Expires 15 May 2021 [Page 103]
Internet-Draft BRSKI November 2020
C.1.1. Manufacturer Certificate Authority for IDevID signatures
This private key is Certificate Authority that signs IDevID
certificates:
<CODE BEGINS> file "vendor.key"
-----BEGIN EC PRIVATE KEY-----
MIGkAgEBBDCAYkoLW1IEA5SKKhMMdkTK7sJxk5ybKqYq9Yr5aR7tNwqXyLGS7z8G
8S4w/UJ58BqgBwYFK4EEACKhZANiAAQu5/yktJbFLjMC87h7b+yTreFuF8GwewKH
L4mS0r0dVAQubqDUQcTrjvpXrXCpTojiLCzgp8fzkcUDkZ9LD/M90LDipiLNIOkP
juF8QkoAbT8pMrY83MS8y76wZ7AalNQ=
-----END EC PRIVATE KEY-----
<CODE ENDS>
This public key validates IDevID certificates:
file: examples/vendor.key
<CODE BEGINS> file "vendor.cert"
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 519772114 (0x1efb17d2)
Signature Algorithm: ecdsa-with-SHA256
Issuer: C = Canada, ST = Ontario, OU = Sandelman, CN = highway-test.example.com CA
Validity
Not Before: Feb 12 22:22:21 2019 GMT
Not After : Feb 11 22:22:21 2021 GMT
Subject: C = Canada, ST = Ontario, OU = Sandelman, CN = highway-test.example.com CA
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (384 bit)
pub:
04:2e:e7:fc:a4:b4:96:c5:2e:33:02:f3:b8:7b:6f:
ec:93:ad:e1:6e:17:c1:b0:7b:02:87:2f:89:92:d2:
bd:1d:54:04:2e:6e:a0:d4:41:c4:eb:8e:fa:57:ad:
70:a9:4e:88:e2:2c:2c:e0:a7:c7:f3:91:c5:03:91:
9f:4b:0f:f3:3d:d0:b0:e2:a6:22:cd:20:e9:0f:8e:
e1:7c:42:4a:00:6d:3f:29:32:b6:3c:dc:c4:bc:cb:
be:b0:67:b0:1a:94:d4
ASN1 OID: secp384r1
NIST CURVE: P-384
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:TRUE
X509v3 Key Usage: critical
Certificate Sign, CRL Sign
X509v3 Subject Key Identifier:
Pritikin, et al. Expires 15 May 2021 [Page 104]
Internet-Draft BRSKI November 2020
5E:0C:A9:52:5A:8C:DF:A9:0F:03:14:E9:96:F1:80:76:8C:53:8A:08
X509v3 Authority Key Identifier:
keyid:5E:0C:A9:52:5A:8C:DF:A9:0F:03:14:E9:96:F1:80:76:8C:53:8A:08
Signature Algorithm: ecdsa-with-SHA256
30:65:02:30:5f:21:fd:c6:ab:d6:94:a6:cd:ca:37:2c:81:33:
87:fe:7b:e1:b5:1a:e8:6c:05:43:a6:8b:4e:22:b5:55:e9:48:
0c:b5:97:f3:c9:1a:65:d9:97:4b:f0:21:86:0d:cb:26:02:31:
00:e3:2d:0d:08:49:4d:a3:f5:dc:57:1f:a7:13:26:a4:e0:d6:
3a:c2:d5:4a:50:83:62:26:2e:79:2b:d0:a5:ee:66:d5:bf:16:
9a:33:75:b4:d1:8d:ba:d3:50:77:6b:92:df
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
<CODE ENDS>
C.1.2. MASA key pair for voucher signatures
The MASA is the Manufacturer Authorized Signing Authority. This
keypair signs vouchers. An example TLS certificate Section 5.4 HTTP
authentication is not provided as it is a common form.
This private key signs the vouchers which are presented below:
<CODE BEGINS> file "masa.key"
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIFhdd0eDdzip67kXx72K+KHGJQYJHNy8pkiLJ6CcvxMGoAoGCCqGSM49
AwEHoUQDQgAEqgQVo0S54kT4yfkbBxumdHOcHrpsqbOpMKmiMln3oB1HAW25MJV+
gqi4tMFfSJ0iEwt8kszfWXK4rLgJS2mnpQ==
-----END EC PRIVATE KEY-----
<CODE ENDS>
This public key validates vouchers, and it has been signed by the CA
above:
file: examples/masa.key
Pritikin, et al. Expires 15 May 2021 [Page 105]
Internet-Draft BRSKI November 2020
<CODE BEGINS> file "masa.cert"
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 463036244 (0x1b995f54)
Signature Algorithm: ecdsa-with-SHA256
Issuer: C = Canada, ST = Ontario, OU = Sandelman, CN = highway-test.example.com CA
Validity
Not Before: Feb 12 22:22:41 2019 GMT
Not After : Feb 11 22:22:41 2021 GMT
Subject: C = Canada, ST = Ontario, OU = Sandelman, CN = highway-test.example.com MASA
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:aa:04:15:a3:44:b9:e2:44:f8:c9:f9:1b:07:1b:
a6:74:73:9c:1e:ba:6c:a9:b3:a9:30:a9:a2:32:59:
f7:a0:1d:47:01:6d:b9:30:95:7e:82:a8:b8:b4:c1:
5f:48:9d:22:13:0b:7c:92:cc:df:59:72:b8:ac:b8:
09:4b:69:a7:a5
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:FALSE
Signature Algorithm: ecdsa-with-SHA256
30:66:02:31:00:bd:55:e5:9b:0e:fb:fc:5e:95:29:e3:81:b3:
15:35:aa:93:18:a2:04:be:44:72:b2:51:7d:4d:6d:eb:d1:d5:
c1:10:3a:b2:39:7b:57:3f:c5:cc:b0:a3:0e:e7:99:46:ba:02:
31:00:f6:7f:44:7d:b7:14:fa:d1:67:6a:d4:11:c3:4b:ae:e6:
fb:9a:98:56:fa:85:21:2e:5c:48:4c:f0:3f:f2:9b:3f:ae:88:
20:a7:ae:f9:72:ff:5b:f9:78:68:cf:0f:48:c9
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
<CODE ENDS>
Pritikin, et al. Expires 15 May 2021 [Page 106]
Internet-Draft BRSKI November 2020
C.1.3. Registrar Certificate Authority
This Certificate Authority enrolls the pledge once it is authorized,
and it also signs the Registrar's certificate.
<CODE BEGINS> file "ownerca_secp384r1.key"
-----BEGIN EC PRIVATE KEY-----
MIGkAgEBBDCHnLI0MSOLf8XndiZqoZdqblcPR5YSoPGhPOuFxWy1gFi9HbWv8b/R
EGdRgGEVSjKgBwYFK4EEACKhZANiAAQbf1m6F8MavGaNjGzgw/oxcQ9l9iKRvbdW
gAfb37h6pUVNeYpGlxlZljGxj2l9Mr48yD5bY7VG9qjVb5v5wPPTuRQ/ckdRpHbd
0vC/9cqPMAF/+MJf0/UgA0SLi/IHbLQ=
-----END EC PRIVATE KEY-----
<CODE ENDS>
The public key is indicated in a pledge voucher-request to show
proximity.
file: examples/ownerca_secp384r1.key
<CODE BEGINS> file "ownerca_secp384r1.cert"
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 694879833 (0x296b0659)
Signature Algorithm: ecdsa-with-SHA256
Issuer: DC = ca, DC = sandelman, CN = fountain-test.example.com Unstrung Fountain Root CA
Validity
Not Before: Feb 25 21:31:45 2020 GMT
Not After : Feb 24 21:31:45 2022 GMT
Subject: DC = ca, DC = sandelman, CN = fountain-test.example.com Unstrung Fountain Root CA
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (384 bit)
pub:
04:1b:7f:59:ba:17:c3:1a:bc:66:8d:8c:6c:e0:c3:
fa:31:71:0f:65:f6:22:91:bd:b7:56:80:07:db:df:
b8:7a:a5:45:4d:79:8a:46:97:19:59:96:31:b1:8f:
69:7d:32:be:3c:c8:3e:5b:63:b5:46:f6:a8:d5:6f:
9b:f9:c0:f3:d3:b9:14:3f:72:47:51:a4:76:dd:d2:
f0:bf:f5:ca:8f:30:01:7f:f8:c2:5f:d3:f5:20:03:
44:8b:8b:f2:07:6c:b4
ASN1 OID: secp384r1
NIST CURVE: P-384
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:TRUE
X509v3 Key Usage: critical
Certificate Sign, CRL Sign
Pritikin, et al. Expires 15 May 2021 [Page 107]
Internet-Draft BRSKI November 2020
X509v3 Subject Key Identifier:
B9:A5:F6:CB:11:E1:07:A4:49:2C:A7:08:C6:7C:10:BC:87:B3:74:26
X509v3 Authority Key Identifier:
keyid:B9:A5:F6:CB:11:E1:07:A4:49:2C:A7:08:C6:7C:10:BC:87:B3:74:26
Signature Algorithm: ecdsa-with-SHA256
30:64:02:30:20:83:06:ce:8d:98:a4:54:7a:66:4c:4a:3a:70:
c2:52:36:5a:52:8d:59:7d:20:9b:2a:69:14:58:87:38:d8:55:
79:dd:fd:29:38:95:1e:91:93:76:b4:f5:66:29:44:b4:02:30:
6f:38:f9:af:12:ed:30:d5:85:29:7c:b1:16:58:bd:67:91:43:
c4:0d:30:f9:d8:1c:ac:2f:06:dd:bc:d5:06:42:2c:84:a2:04:
ea:02:a4:5f:17:51:26:fb:d9:2f:d2:5c
-----BEGIN CERTIFICATE-----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=
-----END CERTIFICATE-----
<CODE ENDS>
C.1.4. Registrar key pair
The Registrar is the representative of the domain owner. This key
signs registrar voucher-requests, and terminates the TLS connection
from the pledge.
<CODE BEGINS> file "jrc_prime256v1.key"
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIFZodk+PC5Mu24+ra0sbOjKzan+dW5rvDAR7YuJUOC1YoAoGCCqGSM49
AwEHoUQDQgAElmVQcjS6n+Xd5l/28IFv6UiegQwSBztGj5dkK2MAjQIPV8l8lH+E
jLIOYdbJiI0VtEIf1/Jqt+TOBfinTNOLOg==
-----END EC PRIVATE KEY-----
<CODE ENDS>
The public key is indicated in a pledge voucher-request to show
proximity.
Pritikin, et al. Expires 15 May 2021 [Page 108]
Internet-Draft BRSKI November 2020
<CODE BEGINS> file "jrc_prime256v1.cert"
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 1066965842 (0x3f989b52)
Signature Algorithm: ecdsa-with-SHA256
Issuer: DC = ca, DC = sandelman, CN = fountain-test.example.com Unstrung Fountain Root CA
Validity
Not Before: Feb 25 21:31:54 2020 GMT
Not After : Feb 24 21:31:54 2022 GMT
Subject: DC = ca, DC = sandelman, CN = fountain-test.example.com
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:96:65:50:72:34:ba:9f:e5:dd:e6:5f:f6:f0:81:
6f:e9:48:9e:81:0c:12:07:3b:46:8f:97:64:2b:63:
00:8d:02:0f:57:c9:7c:94:7f:84:8c:b2:0e:61:d6:
c9:88:8d:15:b4:42:1f:d7:f2:6a:b7:e4:ce:05:f8:
a7:4c:d3:8b:3a
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Extended Key Usage: critical
CMC Registration Authority
X509v3 Key Usage: critical
Digital Signature
Signature Algorithm: ecdsa-with-SHA256
30:65:02:30:66:4f:60:4c:55:48:1e:96:07:f8:dd:1f:b9:c8:
12:8d:45:36:87:9b:23:c0:bc:bb:f1:cb:3d:26:15:56:6f:5f:
1f:bf:d5:1c:0e:6a:09:af:1b:76:97:99:19:23:fd:7e:02:31:
00:bc:ac:c3:41:b0:ba:0d:af:52:f9:9c:6e:7a:7f:00:1d:23:
c8:62:01:61:bc:4b:c5:c0:47:99:35:0a:0c:77:61:44:01:4a:
07:52:70:57:00:75:ff:be:07:0e:98:cb:e5
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
<CODE ENDS>
Pritikin, et al. Expires 15 May 2021 [Page 109]
Internet-Draft BRSKI November 2020
C.1.5. Pledge key pair
The pledge has an IDevID key pair built in at manufacturing time:
<CODE BEGINS> file "idevid_00-D0-E5-F2-00-02.key"
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIBHNh6r8QRevRuo+tEmBJeFjQKf6bpFA/9NGoltv+9sNoAoGCCqGSM49
AwEHoUQDQgAEA6N1Q4ezfMAKmoecrfb0OBMc1AyEH+BATkF58FsTSyBxs0SbSWLx
FjDOuwB9gLGn2TsTUJumJ6VPw5Z/TP4hJw==
-----END EC PRIVATE KEY-----
<CODE ENDS>
The certificate is used by the registrar to find the MASA.
<CODE BEGINS> file "idevid_00-D0-E5-F2-00-02.cert"
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 226876461 (0xd85dc2d)
Signature Algorithm: ecdsa-with-SHA256
Issuer: C = Canada, ST = Ontario, OU = Sandelman, CN = highway-test.example.com CA
Validity
Not Before: Feb 3 06:47:20 2020 GMT
Not After : Dec 31 00:00:00 2999 GMT
Subject: serialNumber = 00-D0-E5-F2-00-02
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:03:a3:75:43:87:b3:7c:c0:0a:9a:87:9c:ad:f6:
f4:38:13:1c:d4:0c:84:1f:e0:40:4e:41:79:f0:5b:
13:4b:20:71:b3:44:9b:49:62:f1:16:30:ce:bb:00:
7d:80:b1:a7:d9:3b:13:50:9b:a6:27:a5:4f:c3:96:
7f:4c:fe:21:27
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Subject Key Identifier:
45:88:CC:96:96:00:64:37:B0:BA:23:65:64:64:54:08:06:6C:56:AD
X509v3 Basic Constraints:
CA:FALSE
1.3.6.1.5.5.7.1.32:
..highway-test.example.com:9443
Signature Algorithm: ecdsa-with-SHA256
30:65:02:30:23:e1:a9:2e:ef:22:12:34:5a:a5:c2:15:d6:28:
bd:ed:3d:96:d6:ce:04:95:ef:a7:c8:dc:18:a8:31:c7:b8:04:
34:f2:b7:4d:79:8a:67:22:24:03:4f:c5:cd:d6:06:ba:02:31:
00:b3:8d:5c:0a:d0:fe:04:83:90:d3:4f:6d:72:97:b3:3e:02:
Pritikin, et al. Expires 15 May 2021 [Page 110]
Internet-Draft BRSKI November 2020
ea:f1:c8:5a:32:72:58:b7:45:02:50:78:bc:04:1d:23:5e:22:
6f:c3:7f:8c:7c:d7:9b:70:20:91:b4:e1:7f
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
<CODE ENDS>
C.2. Example process
The JSON examples below are wrapped at 60 columns. This results in
strings that have newlines in them, which makes them invalid JSON as
is. The strings would otherwise be too long, so they need to be
unwrapped before processing.
For readability, the output of the asn1parse has been truncated at 72
columns rather than wrapped.
C.2.1. Pledge to Registrar
As described in Section 5.2, the pledge will sign a pledge voucher-
request containing the registrar's public key in the proximity-
registrar-cert field. The base64 has been wrapped at 60 characters
for presentation reasons.
Pritikin, et al. Expires 15 May 2021 [Page 111]
Internet-Draft BRSKI November 2020
<CODE BEGINS> file "vr_00-D0-E5-F2-00-02.b64"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=
<CODE ENDS>
The ASN1 decoding of the artifact:
file: examples/vr_00-D0-E5-F2-00-02.b64
0:d=0 hl=4 l=1759 cons: SEQUENCE
4:d=1 hl=2 l= 9 prim: OBJECT :pkcs7-signedData
15:d=1 hl=4 l=1744 cons: cont [ 0 ]
19:d=2 hl=4 l=1740 cons: SEQUENCE
23:d=3 hl=2 l= 1 prim: INTEGER :01
26:d=3 hl=2 l= 13 cons: SET
28:d=4 hl=2 l= 11 cons: SEQUENCE
30:d=5 hl=2 l= 9 prim: OBJECT :sha256
41:d=3 hl=4 l= 905 cons: SEQUENCE
45:d=4 hl=2 l= 9 prim: OBJECT :pkcs7-data
Pritikin, et al. Expires 15 May 2021 [Page 112]
Internet-Draft BRSKI November 2020
56:d=4 hl=4 l= 890 cons: cont [ 0 ]
60:d=5 hl=4 l= 886 prim: OCTET STRING :{"ietf-voucher-request:v
950:d=3 hl=4 l= 490 cons: cont [ 0 ]
954:d=4 hl=4 l= 486 cons: SEQUENCE
958:d=5 hl=4 l= 364 cons: SEQUENCE
962:d=6 hl=2 l= 3 cons: cont [ 0 ]
964:d=7 hl=2 l= 1 prim: INTEGER :02
967:d=6 hl=2 l= 4 prim: INTEGER :0D85DC2D
973:d=6 hl=2 l= 10 cons: SEQUENCE
975:d=7 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
985:d=6 hl=2 l= 93 cons: SEQUENCE
987:d=7 hl=2 l= 15 cons: SET
989:d=8 hl=2 l= 13 cons: SEQUENCE
991:d=9 hl=2 l= 3 prim: OBJECT :countryName
996:d=9 hl=2 l= 6 prim: PRINTABLESTRING :Canada
1004:d=7 hl=2 l= 16 cons: SET
1006:d=8 hl=2 l= 14 cons: SEQUENCE
1008:d=9 hl=2 l= 3 prim: OBJECT :stateOrProvinceName
1013:d=9 hl=2 l= 7 prim: UTF8STRING :Ontario
1022:d=7 hl=2 l= 18 cons: SET
1024:d=8 hl=2 l= 16 cons: SEQUENCE
1026:d=9 hl=2 l= 3 prim: OBJECT :organizationalUnitName
1031:d=9 hl=2 l= 9 prim: UTF8STRING :Sandelman
1042:d=7 hl=2 l= 36 cons: SET
1044:d=8 hl=2 l= 34 cons: SEQUENCE
1046:d=9 hl=2 l= 3 prim: OBJECT :commonName
1051:d=9 hl=2 l= 27 prim: UTF8STRING :highway-test.example.com
1080:d=6 hl=2 l= 32 cons: SEQUENCE
1082:d=7 hl=2 l= 13 prim: UTCTIME :200203064720Z
1097:d=7 hl=2 l= 15 prim: GENERALIZEDTIME :29991231000000Z
1114:d=6 hl=2 l= 28 cons: SEQUENCE
1116:d=7 hl=2 l= 26 cons: SET
1118:d=8 hl=2 l= 24 cons: SEQUENCE
1120:d=9 hl=2 l= 3 prim: OBJECT :serialNumber
1125:d=9 hl=2 l= 17 prim: UTF8STRING :00-D0-E5-F2-00-02
1144:d=6 hl=2 l= 89 cons: SEQUENCE
1146:d=7 hl=2 l= 19 cons: SEQUENCE
1148:d=8 hl=2 l= 7 prim: OBJECT :id-ecPublicKey
1157:d=8 hl=2 l= 8 prim: OBJECT :prime256v1
1167:d=7 hl=2 l= 66 prim: BIT STRING
1235:d=6 hl=2 l= 89 cons: cont [ 3 ]
1237:d=7 hl=2 l= 87 cons: SEQUENCE
1239:d=8 hl=2 l= 29 cons: SEQUENCE
1241:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Subject Key Ident
1246:d=9 hl=2 l= 22 prim: OCTET STRING [HEX DUMP]:04144588CC9696
1270:d=8 hl=2 l= 9 cons: SEQUENCE
1272:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Basic Constraints
1277:d=9 hl=2 l= 2 prim: OCTET STRING [HEX DUMP]:3000
Pritikin, et al. Expires 15 May 2021 [Page 113]
Internet-Draft BRSKI November 2020
1281:d=8 hl=2 l= 43 cons: SEQUENCE
1283:d=9 hl=2 l= 8 prim: OBJECT :1.3.6.1.5.5.7.1.32
1293:d=9 hl=2 l= 31 prim: OCTET STRING [HEX DUMP]:0C1D6869676877
1326:d=5 hl=2 l= 10 cons: SEQUENCE
1328:d=6 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
1338:d=5 hl=2 l= 104 prim: BIT STRING
1444:d=3 hl=4 l= 315 cons: SET
1448:d=4 hl=4 l= 311 cons: SEQUENCE
1452:d=5 hl=2 l= 1 prim: INTEGER :01
1455:d=5 hl=2 l= 101 cons: SEQUENCE
1457:d=6 hl=2 l= 93 cons: SEQUENCE
1459:d=7 hl=2 l= 15 cons: SET
1461:d=8 hl=2 l= 13 cons: SEQUENCE
1463:d=9 hl=2 l= 3 prim: OBJECT :countryName
1468:d=9 hl=2 l= 6 prim: PRINTABLESTRING :Canada
1476:d=7 hl=2 l= 16 cons: SET
1478:d=8 hl=2 l= 14 cons: SEQUENCE
1480:d=9 hl=2 l= 3 prim: OBJECT :stateOrProvinceName
1485:d=9 hl=2 l= 7 prim: UTF8STRING :Ontario
1494:d=7 hl=2 l= 18 cons: SET
1496:d=8 hl=2 l= 16 cons: SEQUENCE
1498:d=9 hl=2 l= 3 prim: OBJECT :organizationalUnitName
1503:d=9 hl=2 l= 9 prim: UTF8STRING :Sandelman
1514:d=7 hl=2 l= 36 cons: SET
1516:d=8 hl=2 l= 34 cons: SEQUENCE
1518:d=9 hl=2 l= 3 prim: OBJECT :commonName
1523:d=9 hl=2 l= 27 prim: UTF8STRING :highway-test.example.com
1552:d=6 hl=2 l= 4 prim: INTEGER :0D85DC2D
1558:d=5 hl=2 l= 11 cons: SEQUENCE
1560:d=6 hl=2 l= 9 prim: OBJECT :sha256
1571:d=5 hl=2 l= 105 cons: cont [ 0 ]
1573:d=6 hl=2 l= 24 cons: SEQUENCE
1575:d=7 hl=2 l= 9 prim: OBJECT :contentType
1586:d=7 hl=2 l= 11 cons: SET
1588:d=8 hl=2 l= 9 prim: OBJECT :pkcs7-data
1599:d=6 hl=2 l= 28 cons: SEQUENCE
1601:d=7 hl=2 l= 9 prim: OBJECT :signingTime
1612:d=7 hl=2 l= 15 cons: SET
1614:d=8 hl=2 l= 13 prim: UTCTIME :200225230448Z
1629:d=6 hl=2 l= 47 cons: SEQUENCE
1631:d=7 hl=2 l= 9 prim: OBJECT :messageDigest
1642:d=7 hl=2 l= 34 cons: SET
1644:d=8 hl=2 l= 32 prim: OCTET STRING [HEX DUMP]:B1E88AF0B2D1C5
1678:d=5 hl=2 l= 10 cons: SEQUENCE
1680:d=6 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
1690:d=5 hl=2 l= 71 prim: OCTET STRING [HEX DUMP]:304502201C7003
The JSON contained in the voucher request:
Pritikin, et al. Expires 15 May 2021 [Page 114]
Internet-Draft BRSKI November 2020
{"ietf-voucher-request:voucher":{"assertion":"proximity","cr
eated-on":"2020-02-25T18:04:48.652-05:00","serial-number":"0
0-D0-E5-F2-00-02","nonce":"aMjgueKUT-22wVimj6z27Q","proximit
y-registrar-cert":"MIIB/DCCAYKgAwIBAgIEP5ibUjAKBggqhkjOPQQDA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"}}
C.2.2. Registrar to MASA
As described in Section 5.5 the registrar will sign a registrar
voucher-request, and will include pledge's voucher request in the
prior-signed-voucher-request.
<CODE BEGINS> file "parboiled_vr_00-D0-E5-F2-00-02.b64"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, et al. Expires 15 May 2021 [Page 115]
Internet-Draft BRSKI November 2020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<CODE ENDS>
Pritikin, et al. Expires 15 May 2021 [Page 116]
Internet-Draft BRSKI November 2020
The ASN1 decoding of the artifact:
file: examples/parboiled_vr_00_D0-E5-02-00-2D.b64
0:d=0 hl=4 l=4087 cons: SEQUENCE
4:d=1 hl=2 l= 9 prim: OBJECT :pkcs7-signedData
15:d=1 hl=4 l=4072 cons: cont [ 0 ]
19:d=2 hl=4 l=4068 cons: SEQUENCE
23:d=3 hl=2 l= 1 prim: INTEGER :01
26:d=3 hl=2 l= 13 cons: SET
28:d=4 hl=2 l= 11 cons: SEQUENCE
30:d=5 hl=2 l= 9 prim: OBJECT :sha256
41:d=3 hl=4 l=2572 cons: SEQUENCE
45:d=4 hl=2 l= 9 prim: OBJECT :pkcs7-data
56:d=4 hl=4 l=2557 cons: cont [ 0 ]
60:d=5 hl=4 l=2553 prim: OCTET STRING :{"ietf-voucher-request:v
2617:d=3 hl=4 l=1135 cons: cont [ 0 ]
2621:d=4 hl=4 l= 508 cons: SEQUENCE
2625:d=5 hl=4 l= 386 cons: SEQUENCE
2629:d=6 hl=2 l= 3 cons: cont [ 0 ]
2631:d=7 hl=2 l= 1 prim: INTEGER :02
2634:d=6 hl=2 l= 4 prim: INTEGER :3F989B52
2640:d=6 hl=2 l= 10 cons: SEQUENCE
2642:d=7 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
2652:d=6 hl=2 l= 109 cons: SEQUENCE
2654:d=7 hl=2 l= 18 cons: SET
2656:d=8 hl=2 l= 16 cons: SEQUENCE
2658:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
2670:d=9 hl=2 l= 2 prim: IA5STRING :ca
2674:d=7 hl=2 l= 25 cons: SET
2676:d=8 hl=2 l= 23 cons: SEQUENCE
2678:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
2690:d=9 hl=2 l= 9 prim: IA5STRING :sandelman
2701:d=7 hl=2 l= 60 cons: SET
2703:d=8 hl=2 l= 58 cons: SEQUENCE
2705:d=9 hl=2 l= 3 prim: OBJECT :commonName
2710:d=9 hl=2 l= 51 prim: UTF8STRING :fountain-test.example.co
2763:d=6 hl=2 l= 30 cons: SEQUENCE
2765:d=7 hl=2 l= 13 prim: UTCTIME :200225213154Z
2780:d=7 hl=2 l= 13 prim: UTCTIME :220224213154Z
2795:d=6 hl=2 l= 83 cons: SEQUENCE
2797:d=7 hl=2 l= 18 cons: SET
2799:d=8 hl=2 l= 16 cons: SEQUENCE
2801:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
2813:d=9 hl=2 l= 2 prim: IA5STRING :ca
2817:d=7 hl=2 l= 25 cons: SET
2819:d=8 hl=2 l= 23 cons: SEQUENCE
2821:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
Pritikin, et al. Expires 15 May 2021 [Page 117]
Internet-Draft BRSKI November 2020
2833:d=9 hl=2 l= 9 prim: IA5STRING :sandelman
2844:d=7 hl=2 l= 34 cons: SET
2846:d=8 hl=2 l= 32 cons: SEQUENCE
2848:d=9 hl=2 l= 3 prim: OBJECT :commonName
2853:d=9 hl=2 l= 25 prim: UTF8STRING :fountain-test.example.co
2880:d=6 hl=2 l= 89 cons: SEQUENCE
2882:d=7 hl=2 l= 19 cons: SEQUENCE
2884:d=8 hl=2 l= 7 prim: OBJECT :id-ecPublicKey
2893:d=8 hl=2 l= 8 prim: OBJECT :prime256v1
2903:d=7 hl=2 l= 66 prim: BIT STRING
2971:d=6 hl=2 l= 42 cons: cont [ 3 ]
2973:d=7 hl=2 l= 40 cons: SEQUENCE
2975:d=8 hl=2 l= 22 cons: SEQUENCE
2977:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Extended Key Usag
2982:d=9 hl=2 l= 1 prim: BOOLEAN :255
2985:d=9 hl=2 l= 12 prim: OCTET STRING [HEX DUMP]:300A06082B0601
2999:d=8 hl=2 l= 14 cons: SEQUENCE
3001:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Key Usage
3006:d=9 hl=2 l= 1 prim: BOOLEAN :255
3009:d=9 hl=2 l= 4 prim: OCTET STRING [HEX DUMP]:03020780
3015:d=5 hl=2 l= 10 cons: SEQUENCE
3017:d=6 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
3027:d=5 hl=2 l= 104 prim: BIT STRING
3133:d=4 hl=4 l= 619 cons: SEQUENCE
3137:d=5 hl=4 l= 498 cons: SEQUENCE
3141:d=6 hl=2 l= 3 cons: cont [ 0 ]
3143:d=7 hl=2 l= 1 prim: INTEGER :02
3146:d=6 hl=2 l= 4 prim: INTEGER :296B0659
3152:d=6 hl=2 l= 10 cons: SEQUENCE
3154:d=7 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
3164:d=6 hl=2 l= 109 cons: SEQUENCE
3166:d=7 hl=2 l= 18 cons: SET
3168:d=8 hl=2 l= 16 cons: SEQUENCE
3170:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
3182:d=9 hl=2 l= 2 prim: IA5STRING :ca
3186:d=7 hl=2 l= 25 cons: SET
3188:d=8 hl=2 l= 23 cons: SEQUENCE
3190:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
3202:d=9 hl=2 l= 9 prim: IA5STRING :sandelman
3213:d=7 hl=2 l= 60 cons: SET
3215:d=8 hl=2 l= 58 cons: SEQUENCE
3217:d=9 hl=2 l= 3 prim: OBJECT :commonName
3222:d=9 hl=2 l= 51 prim: UTF8STRING :fountain-test.example.co
3275:d=6 hl=2 l= 30 cons: SEQUENCE
3277:d=7 hl=2 l= 13 prim: UTCTIME :200225213145Z
3292:d=7 hl=2 l= 13 prim: UTCTIME :220224213145Z
3307:d=6 hl=2 l= 109 cons: SEQUENCE
3309:d=7 hl=2 l= 18 cons: SET
Pritikin, et al. Expires 15 May 2021 [Page 118]
Internet-Draft BRSKI November 2020
3311:d=8 hl=2 l= 16 cons: SEQUENCE
3313:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
3325:d=9 hl=2 l= 2 prim: IA5STRING :ca
3329:d=7 hl=2 l= 25 cons: SET
3331:d=8 hl=2 l= 23 cons: SEQUENCE
3333:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
3345:d=9 hl=2 l= 9 prim: IA5STRING :sandelman
3356:d=7 hl=2 l= 60 cons: SET
3358:d=8 hl=2 l= 58 cons: SEQUENCE
3360:d=9 hl=2 l= 3 prim: OBJECT :commonName
3365:d=9 hl=2 l= 51 prim: UTF8STRING :fountain-test.example.co
3418:d=6 hl=2 l= 118 cons: SEQUENCE
3420:d=7 hl=2 l= 16 cons: SEQUENCE
3422:d=8 hl=2 l= 7 prim: OBJECT :id-ecPublicKey
3431:d=8 hl=2 l= 5 prim: OBJECT :secp384r1
3438:d=7 hl=2 l= 98 prim: BIT STRING
3538:d=6 hl=2 l= 99 cons: cont [ 3 ]
3540:d=7 hl=2 l= 97 cons: SEQUENCE
3542:d=8 hl=2 l= 15 cons: SEQUENCE
3544:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Basic Constraints
3549:d=9 hl=2 l= 1 prim: BOOLEAN :255
3552:d=9 hl=2 l= 5 prim: OCTET STRING [HEX DUMP]:30030101FF
3559:d=8 hl=2 l= 14 cons: SEQUENCE
3561:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Key Usage
3566:d=9 hl=2 l= 1 prim: BOOLEAN :255
3569:d=9 hl=2 l= 4 prim: OCTET STRING [HEX DUMP]:03020106
3575:d=8 hl=2 l= 29 cons: SEQUENCE
3577:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Subject Key Ident
3582:d=9 hl=2 l= 22 prim: OCTET STRING [HEX DUMP]:0414B9A5F6CB11
3606:d=8 hl=2 l= 31 cons: SEQUENCE
3608:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Authority Key Ide
3613:d=9 hl=2 l= 24 prim: OCTET STRING [HEX DUMP]:30168014B9A5F6
3639:d=5 hl=2 l= 10 cons: SEQUENCE
3641:d=6 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
3651:d=5 hl=2 l= 103 prim: BIT STRING
3756:d=3 hl=4 l= 331 cons: SET
3760:d=4 hl=4 l= 327 cons: SEQUENCE
3764:d=5 hl=2 l= 1 prim: INTEGER :01
3767:d=5 hl=2 l= 117 cons: SEQUENCE
3769:d=6 hl=2 l= 109 cons: SEQUENCE
3771:d=7 hl=2 l= 18 cons: SET
3773:d=8 hl=2 l= 16 cons: SEQUENCE
3775:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
3787:d=9 hl=2 l= 2 prim: IA5STRING :ca
3791:d=7 hl=2 l= 25 cons: SET
3793:d=8 hl=2 l= 23 cons: SEQUENCE
3795:d=9 hl=2 l= 10 prim: OBJECT :domainComponent
3807:d=9 hl=2 l= 9 prim: IA5STRING :sandelman
Pritikin, et al. Expires 15 May 2021 [Page 119]
Internet-Draft BRSKI November 2020
3818:d=7 hl=2 l= 60 cons: SET
3820:d=8 hl=2 l= 58 cons: SEQUENCE
3822:d=9 hl=2 l= 3 prim: OBJECT :commonName
3827:d=9 hl=2 l= 51 prim: UTF8STRING :fountain-test.example.co
3880:d=6 hl=2 l= 4 prim: INTEGER :3F989B52
3886:d=5 hl=2 l= 11 cons: SEQUENCE
3888:d=6 hl=2 l= 9 prim: OBJECT :sha256
3899:d=5 hl=2 l= 105 cons: cont [ 0 ]
3901:d=6 hl=2 l= 24 cons: SEQUENCE
3903:d=7 hl=2 l= 9 prim: OBJECT :contentType
3914:d=7 hl=2 l= 11 cons: SET
3916:d=8 hl=2 l= 9 prim: OBJECT :pkcs7-data
3927:d=6 hl=2 l= 28 cons: SEQUENCE
3929:d=7 hl=2 l= 9 prim: OBJECT :signingTime
3940:d=7 hl=2 l= 15 cons: SET
3942:d=8 hl=2 l= 13 prim: UTCTIME :200225230449Z
3957:d=6 hl=2 l= 47 cons: SEQUENCE
3959:d=7 hl=2 l= 9 prim: OBJECT :messageDigest
3970:d=7 hl=2 l= 34 cons: SET
3972:d=8 hl=2 l= 32 prim: OCTET STRING [HEX DUMP]:3D818C51D6C4B4
4006:d=5 hl=2 l= 10 cons: SEQUENCE
4008:d=6 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
4018:d=5 hl=2 l= 71 prim: OCTET STRING [HEX DUMP]:30450220589E5D
The JSON contained in the voucher request. Note that the previous
voucher request is in the prior-signed-voucher-request attribute.
Pritikin, et al. Expires 15 May 2021 [Page 120]
Internet-Draft BRSKI November 2020
{"ietf-voucher-request:voucher":{"assertion":"proximity","cr
eated-on":"2020-02-25T23:04:49.054Z","serial-number":"00-D0-
E5-F2-00-02","nonce":"aMjgueKUT-22wVimj6z27Q","prior-signed-
voucher-request":"MIIG3wYJKoZIhvcNAQcCoIIG0DCCBswCAQExDTALBg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"}}
C.2.3. MASA to Registrar
The MASA will return a voucher to the registrar, to be relayed to the
pledge.
Pritikin, et al. Expires 15 May 2021 [Page 121]
Internet-Draft BRSKI November 2020
<CODE BEGINS> file "voucher_00-D0-E5-F2-00-02.b64"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<CODE ENDS>
The ASN1 decoding of the artifact:
file: examples/voucher_00-D0-E5-F2-00-02.b64
0:d=0 hl=4 l=1735 cons: SEQUENCE
4:d=1 hl=2 l= 9 prim: OBJECT :pkcs7-signedData
15:d=1 hl=4 l=1720 cons: cont [ 0 ]
19:d=2 hl=4 l=1716 cons: SEQUENCE
23:d=3 hl=2 l= 1 prim: INTEGER :01
26:d=3 hl=2 l= 13 cons: SET
28:d=4 hl=2 l= 11 cons: SEQUENCE
30:d=5 hl=2 l= 9 prim: OBJECT :sha256
41:d=3 hl=4 l= 888 cons: SEQUENCE
45:d=4 hl=2 l= 9 prim: OBJECT :pkcs7-data
Pritikin, et al. Expires 15 May 2021 [Page 122]
Internet-Draft BRSKI November 2020
56:d=4 hl=4 l= 873 cons: cont [ 0 ]
60:d=5 hl=4 l= 869 prim: OCTET STRING :{"ietf-voucher:voucher":
933:d=3 hl=4 l= 483 cons: cont [ 0 ]
937:d=4 hl=4 l= 479 cons: SEQUENCE
941:d=5 hl=4 l= 356 cons: SEQUENCE
945:d=6 hl=2 l= 3 cons: cont [ 0 ]
947:d=7 hl=2 l= 1 prim: INTEGER :02
950:d=6 hl=2 l= 4 prim: INTEGER :1B995F54
956:d=6 hl=2 l= 10 cons: SEQUENCE
958:d=7 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
968:d=6 hl=2 l= 93 cons: SEQUENCE
970:d=7 hl=2 l= 15 cons: SET
972:d=8 hl=2 l= 13 cons: SEQUENCE
974:d=9 hl=2 l= 3 prim: OBJECT :countryName
979:d=9 hl=2 l= 6 prim: PRINTABLESTRING :Canada
987:d=7 hl=2 l= 16 cons: SET
989:d=8 hl=2 l= 14 cons: SEQUENCE
991:d=9 hl=2 l= 3 prim: OBJECT :stateOrProvinceName
996:d=9 hl=2 l= 7 prim: UTF8STRING :Ontario
1005:d=7 hl=2 l= 18 cons: SET
1007:d=8 hl=2 l= 16 cons: SEQUENCE
1009:d=9 hl=2 l= 3 prim: OBJECT :organizationalUnitName
1014:d=9 hl=2 l= 9 prim: UTF8STRING :Sandelman
1025:d=7 hl=2 l= 36 cons: SET
1027:d=8 hl=2 l= 34 cons: SEQUENCE
1029:d=9 hl=2 l= 3 prim: OBJECT :commonName
1034:d=9 hl=2 l= 27 prim: UTF8STRING :highway-test.example.com
1063:d=6 hl=2 l= 30 cons: SEQUENCE
1065:d=7 hl=2 l= 13 prim: UTCTIME :190212222241Z
1080:d=7 hl=2 l= 13 prim: UTCTIME :210211222241Z
1095:d=6 hl=2 l= 95 cons: SEQUENCE
1097:d=7 hl=2 l= 15 cons: SET
1099:d=8 hl=2 l= 13 cons: SEQUENCE
1101:d=9 hl=2 l= 3 prim: OBJECT :countryName
1106:d=9 hl=2 l= 6 prim: PRINTABLESTRING :Canada
1114:d=7 hl=2 l= 16 cons: SET
1116:d=8 hl=2 l= 14 cons: SEQUENCE
1118:d=9 hl=2 l= 3 prim: OBJECT :stateOrProvinceName
1123:d=9 hl=2 l= 7 prim: UTF8STRING :Ontario
1132:d=7 hl=2 l= 18 cons: SET
1134:d=8 hl=2 l= 16 cons: SEQUENCE
1136:d=9 hl=2 l= 3 prim: OBJECT :organizationalUnitName
1141:d=9 hl=2 l= 9 prim: UTF8STRING :Sandelman
1152:d=7 hl=2 l= 38 cons: SET
1154:d=8 hl=2 l= 36 cons: SEQUENCE
1156:d=9 hl=2 l= 3 prim: OBJECT :commonName
1161:d=9 hl=2 l= 29 prim: UTF8STRING :highway-test.example.com
1192:d=6 hl=2 l= 89 cons: SEQUENCE
Pritikin, et al. Expires 15 May 2021 [Page 123]
Internet-Draft BRSKI November 2020
1194:d=7 hl=2 l= 19 cons: SEQUENCE
1196:d=8 hl=2 l= 7 prim: OBJECT :id-ecPublicKey
1205:d=8 hl=2 l= 8 prim: OBJECT :prime256v1
1215:d=7 hl=2 l= 66 prim: BIT STRING
1283:d=6 hl=2 l= 16 cons: cont [ 3 ]
1285:d=7 hl=2 l= 14 cons: SEQUENCE
1287:d=8 hl=2 l= 12 cons: SEQUENCE
1289:d=9 hl=2 l= 3 prim: OBJECT :X509v3 Basic Constraints
1294:d=9 hl=2 l= 1 prim: BOOLEAN :255
1297:d=9 hl=2 l= 2 prim: OCTET STRING [HEX DUMP]:3000
1301:d=5 hl=2 l= 10 cons: SEQUENCE
1303:d=6 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
1313:d=5 hl=2 l= 105 prim: BIT STRING
1420:d=3 hl=4 l= 315 cons: SET
1424:d=4 hl=4 l= 311 cons: SEQUENCE
1428:d=5 hl=2 l= 1 prim: INTEGER :01
1431:d=5 hl=2 l= 101 cons: SEQUENCE
1433:d=6 hl=2 l= 93 cons: SEQUENCE
1435:d=7 hl=2 l= 15 cons: SET
1437:d=8 hl=2 l= 13 cons: SEQUENCE
1439:d=9 hl=2 l= 3 prim: OBJECT :countryName
1444:d=9 hl=2 l= 6 prim: PRINTABLESTRING :Canada
1452:d=7 hl=2 l= 16 cons: SET
1454:d=8 hl=2 l= 14 cons: SEQUENCE
1456:d=9 hl=2 l= 3 prim: OBJECT :stateOrProvinceName
1461:d=9 hl=2 l= 7 prim: UTF8STRING :Ontario
1470:d=7 hl=2 l= 18 cons: SET
1472:d=8 hl=2 l= 16 cons: SEQUENCE
1474:d=9 hl=2 l= 3 prim: OBJECT :organizationalUnitName
1479:d=9 hl=2 l= 9 prim: UTF8STRING :Sandelman
1490:d=7 hl=2 l= 36 cons: SET
1492:d=8 hl=2 l= 34 cons: SEQUENCE
1494:d=9 hl=2 l= 3 prim: OBJECT :commonName
1499:d=9 hl=2 l= 27 prim: UTF8STRING :highway-test.example.com
1528:d=6 hl=2 l= 4 prim: INTEGER :1B995F54
1534:d=5 hl=2 l= 11 cons: SEQUENCE
1536:d=6 hl=2 l= 9 prim: OBJECT :sha256
1547:d=5 hl=2 l= 105 cons: cont [ 0 ]
1549:d=6 hl=2 l= 24 cons: SEQUENCE
1551:d=7 hl=2 l= 9 prim: OBJECT :contentType
1562:d=7 hl=2 l= 11 cons: SET
1564:d=8 hl=2 l= 9 prim: OBJECT :pkcs7-data
1575:d=6 hl=2 l= 28 cons: SEQUENCE
1577:d=7 hl=2 l= 9 prim: OBJECT :signingTime
1588:d=7 hl=2 l= 15 cons: SET
1590:d=8 hl=2 l= 13 prim: UTCTIME :200225230449Z
1605:d=6 hl=2 l= 47 cons: SEQUENCE
1607:d=7 hl=2 l= 9 prim: OBJECT :messageDigest
Pritikin, et al. Expires 15 May 2021 [Page 124]
Internet-Draft BRSKI November 2020
1618:d=7 hl=2 l= 34 cons: SET
1620:d=8 hl=2 l= 32 prim: OCTET STRING [HEX DUMP]:8942CA3867D9AC
1654:d=5 hl=2 l= 10 cons: SEQUENCE
1656:d=6 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256
1666:d=5 hl=2 l= 71 prim: OCTET STRING [HEX DUMP]:30450221008A11
Appendix D. Additional References
RFC EDITOR Please remove this section before publication. It exists
just to include references to the things in the YANG descriptions
which are not otherwise referenced in the text so that xml2rfc will
not complain.
[ITU.X690.1994]
Authors' Addresses
Max Pritikin
Cisco
Email: pritikin@cisco.com
Michael C. Richardson
Sandelman Software Works
Email: mcr+ietf@sandelman.ca
URI: http://www.sandelman.ca/
Toerless Eckert
Futurewei Technologies Inc. USA
2330 Central Expy
Santa Clara, CA 95050
United States of America
Email: tte+ietf@cs.fau.de
Michael H. Behringer
Email: Michael.H.Behringer@gmail.com
Kent Watsen
Watsen Networks
Email: kent+ietf@watsen.net
Pritikin, et al. Expires 15 May 2021 [Page 125]
