draft-ietf-anima-bootstrapping-keyinfra-01.txt   draft-ietf-anima-bootstrapping-keyinfra-02.txt 
ANIMA WG M. Pritikin ANIMA WG M. Pritikin
Internet-Draft Cisco Internet-Draft Cisco
Intended status: Informational M. Richardson Intended status: Informational M. Richardson
Expires: April 20, 2016 SSW Expires: September 18, 2016 SSW
M. Behringer M. Behringer
S. Bjarnason S. Bjarnason
Cisco Cisco
October 18, 2015 March 17, 2016
Bootstrapping Key Infrastructures Bootstrapping Key Infrastructures
draft-ietf-anima-bootstrapping-keyinfra-01 draft-ietf-anima-bootstrapping-keyinfra-02
Abstract Abstract
This document specifies automated bootstrapping of an key This document specifies automated bootstrapping of a key
infrastructure using vendor installed IEEE 802.1AR manufacturing infrastructure (BSKI) using vendor installed IEEE 802.1AR
installed certificates, in combination with a vendor based service on manufacturing installed certificates, in combination with a vendor
the Internet. Before being authenticated, a new device has only based service on the Internet. Before being authenticated, a new
link-local connectivity, and does not require a routable address. device has only link-local connectivity, and does not require a
When a vendor provides an Internet based service, devices can be routable address. When a vendor provides an Internet based service,
forced to join only specific domains but in limited/disconnected devices can be forced to join only specific domains but in limited/
networks or legacy environments we describe a variety of options that disconnected networks or legacy environments we describe a variety of
allow bootstrapping to proceed. options that allow bootstrapping to proceed.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 20, 2016. This Internet-Draft will expire on September 18, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. Architectural Overview . . . . . . . . . . . . . . . . . . . 5 1.2. Scope of solution . . . . . . . . . . . . . . . . . . . . 5
3. Functional Overview . . . . . . . . . . . . . . . . . . . . . 7 1.3. Trust bootstrap . . . . . . . . . . . . . . . . . . . . . 6
3.1. Behavior of a new entity . . . . . . . . . . . . . . . . 9 2. Architectural Overview . . . . . . . . . . . . . . . . . . . 6
3.1.1. Discovery . . . . . . . . . . . . . . . . . . . . . . 11 3. Functional Overview . . . . . . . . . . . . . . . . . . . . . 9
3.1.2. Identity . . . . . . . . . . . . . . . . . . . . . . 12 3.1. Behavior of a New Entity . . . . . . . . . . . . . . . . 10
3.1.3. Request Join . . . . . . . . . . . . . . . . . . . . 12 3.1.1. Discovery . . . . . . . . . . . . . . . . . . . . . . 12
3.1.4. Imprint . . . . . . . . . . . . . . . . . . . . . . . 13 3.1.2. Identity . . . . . . . . . . . . . . . . . . . . . . 13
3.1.5. Enrollment . . . . . . . . . . . . . . . . . . . . . 14 3.1.3. Request Join . . . . . . . . . . . . . . . . . . . . 14
3.1.6. Being Managed . . . . . . . . . . . . . . . . . . . . 14 3.1.4. Imprint . . . . . . . . . . . . . . . . . . . . . . . 14
3.2. Behavior of a proxy . . . . . . . . . . . . . . . . . . . 15 3.1.5. Enrollment . . . . . . . . . . . . . . . . . . . . . 15
3.3. Behavior of the Registrar (Bootstrap Server) . . . . . . 15 3.1.6. Being Managed . . . . . . . . . . . . . . . . . . . . 16
3.3.1. Entity Authentication . . . . . . . . . . . . . . . . 16 3.2. Behavior of a Proxy . . . . . . . . . . . . . . . . . . . 16
3.3.2. Entity Authorization . . . . . . . . . . . . . . . . 16 3.2.1. CoAP connection to Registrar . . . . . . . . . . . . 16
3.3.3. Claiming the New Entity . . . . . . . . . . . . . . . 17 3.2.2. HTTPS proxy connection to Registrar . . . . . . . . . 17
3.3.4. Log Verification . . . . . . . . . . . . . . . . . . 18 3.3. Behavior of the Registrar (Bootstrap Server) . . . . . . 18
3.3.5. Forwarding Audit Token plus Configuration . . . . . . 18 3.3.1. Entity Authentication . . . . . . . . . . . . . . . . 19
3.4. Behavior of the MASA Service . . . . . . . . . . . . . . 19 3.3.2. Entity Authorization . . . . . . . . . . . . . . . . 19
3.4.1. Issue Authorization Token and Log the event . . . . . 19 3.3.3. Claiming the New Entity . . . . . . . . . . . . . . . 20
3.4.2. Retrieve Audit Entries from Log . . . . . . . . . . . 19 3.3.4. Log Verification . . . . . . . . . . . . . . . . . . 20
3.5. Leveraging the new key infrastructure / next steps . . . 20 3.3.5. Forwarding Audit Token plus Configuration . . . . . . 21
3.5.1. Network boundaries . . . . . . . . . . . . . . . . . 20 3.4. Behavior of the MASA Service . . . . . . . . . . . . . . 21
3.6. Interactions with Network Access Control . . . . . . . . 20 3.4.1. Issue Authorization Token and Log the event . . . . . 21
4. Domain Operator Activities . . . . . . . . . . . . . . . . . 20 3.4.2. Retrieve Audit Entries from Log . . . . . . . . . . . 22
4.1. Instantiating the Domain Certification Authority . . . . 21 3.5. Leveraging the new key infrastructure / next steps . . . 22
4.2. Instantiating the Registrar . . . . . . . . . . . . . . . 21 3.5.1. Network boundaries . . . . . . . . . . . . . . . . . 22
4.3. Accepting New Entities . . . . . . . . . . . . . . . . . 21 3.6. Interactions with Network Access Control . . . . . . . . 22
4.4. Automatic Enrollment of Devices . . . . . . . . . . . . . 22 4. Domain Operator Activities . . . . . . . . . . . . . . . . . 23
4.5. Secure Network Operations . . . . . . . . . . . . . . . . 22 4.1. Instantiating the Domain Certification Authority . . . . 23
5. Protocol Details . . . . . . . . . . . . . . . . . . . . . . 23 4.2. Instantiating the Registrar . . . . . . . . . . . . . . . 23
5.1. Request Audit Token . . . . . . . . . . . . . . . . . . . 25 4.3. Accepting New Entities . . . . . . . . . . . . . . . . . 23
5.2. Request Audit Token from MASA . . . . . . . . . . . . . . 26 4.4. Automatic Enrollment of Devices . . . . . . . . . . . . . 24
5.3. Basic Configuration Information Package . . . . . . . . . 28 4.5. Secure Network Operations . . . . . . . . . . . . . . . . 24
5.4. Request MASA authorization log . . . . . . . . . . . . . 28 5. Protocol Details . . . . . . . . . . . . . . . . . . . . . . 25
6. Reduced security operational modes . . . . . . . . . . . . . 29 5.1. IEEE 802.1AR as client identity . . . . . . . . . . . . . 27
6.1. New Entity security reductions . . . . . . . . . . . . . 29 5.2. EST over CoAP . . . . . . . . . . . . . . . . . . . . . . 28
6.2. Registrar security reductions . . . . . . . . . . . . . . 29 5.3. Request Audit Token . . . . . . . . . . . . . . . . . . . 28
6.3. MASA security reductions . . . . . . . . . . . . . . . . 30 5.4. Request Audit Token from MASA . . . . . . . . . . . . . . 29
7. Security Considerations . . . . . . . . . . . . . . . . . . . 30 5.5. Basic Configuration Information Package . . . . . . . . . 30
7.1. Trust Model . . . . . . . . . . . . . . . . . . . . . . . 32 5.6. Request MASA authorization log . . . . . . . . . . . . . 31
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32 6. Reduced security operational modes . . . . . . . . . . . . . 32
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 32 6.1. Trust Model . . . . . . . . . . . . . . . . . . . . . . . 32
9.1. Normative References . . . . . . . . . . . . . . . . . . 32 6.2. New Entity security reductions . . . . . . . . . . . . . 33
9.2. Informative References . . . . . . . . . . . . . . . . . 32 6.3. Registrar security reductions . . . . . . . . . . . . . . 33
Appendix A. Editor notes . . . . . . . . . . . . . . . . . . . . 33 6.4. MASA security reductions . . . . . . . . . . . . . . . . 34
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34 7. Security Considerations . . . . . . . . . . . . . . . . . . . 34
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 36
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 36
9.1. Normative References . . . . . . . . . . . . . . . . . . 36
9.2. Informative References . . . . . . . . . . . . . . . . . 37
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38
1. Introduction 1. Introduction
To literally "pull yourself up by the bootstraps" is an impossible To literally "pull yourself up by the bootstraps" is an impossible
action. Similarly the secure establishment of a key infrastructure action. Similarly the secure establishment of a key infrastructure
without external help is also an impossibility. Today it is accepted without external help is also an impossibility. Today it is accepted
that the initial connections between nodes are insecure, until key that the initial connections between nodes are insecure, until key
distribution is complete, or that domain-specific keying material is distribution is complete, or that domain-specific keying material is
pre-provisioned on each new device in a costly and non-scalable pre-provisioned on each new device in a costly and non-scalable
manner. This document describes a zero-touch approach to manner. This document describes a zero-touch approach to
skipping to change at page 3, line 45 skipping to change at page 3, line 50
o New entity authentication: "Who is this? What is its identity?" o New entity authentication: "Who is this? What is its identity?"
o New entity authorization: "Is it mine? Do I want it? What are o New entity authorization: "Is it mine? Do I want it? What are
the chances it has been compromised?" the chances it has been compromised?"
o Domain authentication: "What is this domain's claimed identity?" o Domain authentication: "What is this domain's claimed identity?"
o Domain authorization: "Should I join it?" o Domain authorization: "Should I join it?"
A precise answer to these questions can not be obtained without A precise answer to these questions can not be obtained without
leveraging an established key infrastructure(s). The domain's leveraging some established key infrastructure(s). A complexity that
decisions are based on the new entity's authenticated identity, as this protocol deals with are dealing with devices from a variety of
established by verification of previously installed credentials such vendors, and a network infrastructure (the domain) that is operated
as a manufacturer installed IEEE 802.1AR certificate, and verified by parties that do not have any priviledged relationship with the
back-end information such as a configured list of purchased devices device vendors. The domain's decisions are based on the new entity's
or communication with a trusted third-party. The new entity's authenticated identity, as established by verification of previously
decisions are made according to verified communication with a trusted installed credentials such as a manufacturer installed IEEE 802.1AR
third-party or in a strictly auditable fasion. certificate, and verified back-end information such as a configured
list of purchased devices or communication with a (unidirectionally)
trusted third-party. The new entity's decisions are made according
to verified communication with a trusted third-party or in a strictly
auditable fashion.
Optimal security is achieved with IEEE 802.1AR certificates on each Optimal security is achieved with IEEE 802.1AR certificates on each
new entity, accompanied by a third-party Internet based service for new entity, accompanied by a third-party Internet based service for
verification. Bootstrapping concepts run to completion with less verification. Bootstrapping concepts run to completion with less
requirements, but are then less secure. A domain can choose to requirements, but are then less secure. A domain can choose to
accept lower levels of security when a trusted third-party is not accept lower levels of security when a trusted third-party is not
available so that bootstrapping proceeds even at the risk of reduced available so that bootstrapping proceeds even at the risk of reduced
security. Only the domain can make these decisions based on security. Only the domain can make these decisions based on
administrative input and known behavior of the new entity. administrative input and known behavior of the new entity.
The result of bootstrapping is that a domain specific key The result of bootstrapping is that a domain specific key
infrastructure is deployed. Since IEEE 802.1AR PKI certificates are infrastructure is deployed. Since IEEE 802.1AR PKI certificates are
used for identifying the new entity, and the public key of the domain used for identifying the new entity, and the public key of the domain
identity is leveraged during communiciations with an Internet based identity is leveraged during communications with an Internet based
service, which is itself authenticated using HTTPS, bootstrapping of service, which is itself authenticated using HTTPS, bootstrapping of
a domain specific Public Key Infrastructure (PKI) is described. a domain specific Public Key Infrastructure (PKI) is described.
Sufficient agility to support bootstrapping alternative key Sufficient agility to support bootstrapping alternative key
infrastructures (such as symmetric key solutions) is considered infrastructures (such as symmetric key solutions) is considered
although no such alternate key infrastructure is described. although no such alternate key infrastructure is described.
1.1. Terminology 1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
skipping to change at page 4, line 49 skipping to change at page 5, line 10
self signed root certificate. (A string value bound to the Domain self signed root certificate. (A string value bound to the Domain
CA's self signed root certificate subject and issuer fields is CA's self signed root certificate subject and issuer fields is
often colloquially used as a humanized identity value but during often colloquially used as a humanized identity value but during
protocol discussions the more exact term as defined here is used). protocol discussions the more exact term as defined here is used).
drop ship: The physical distribution of equipment containing the drop ship: The physical distribution of equipment containing the
"factory default" configuration to a final destination. In zero- "factory default" configuration to a final destination. In zero-
touch scenarios there is no staging or pre-configuration during touch scenarios there is no staging or pre-configuration during
drop-ship. drop-ship.
imprint: the process where a device that wishes to join a network imprint: the process where a device obtains the cryptographic key
acquires it's domain specific identity. This term is taken from material to identity and trust future interactions with a network.
Konrad Lorenz's work in biology with new ducklings: during a This term is taken from Konrad Lorenz's work in biology with new
critical period, the duckling would assume that anything that ducklings: during a critical period, the duckling would assume
looks like a mother duck is in fact their mother. [imprinting] that anything that looks like a mother duck is in fact their
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].
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.
pledge: the prospective device, which has the identity provided to pledge: the prospective device, which has the identity provided to
at the factory. Neither the device nor the network knows if the at the factory. Neither the device nor the network knows if the
device yet knows if this device belongs with this network. This device yet knows if this device belongs with this network. This
is definition 6, according to [pledge] is definition 6, according to [pledge]
Audit Token: A signed token from the manufacturer authorized signing Audit Token: A signed token from the manufacturer authorized signing
authority indicating that the bootstrapping event has been authority indicating that the bootstrapping event has been
successfully logged. This has been referred to as an successfully logged. This has been referred to as an
"authorization token" indicating that it authorizes bootstrapping "authorization token" indicating that it authorizes bootstrapping
to proceed. to proceed.
Ownership Voucher: A signed voucher from the vendor vouching that a Ownership Voucher: A signed voucher from the vendor vouching that a
specific domain "owns" the new entity. specific domain "owns" the new entity as defined in
[I-D.ietf-netconf-zerotouch].
1.2. Scope of solution
Questions have been posed as to whether this solution is suitable in
general for Internet of Things (IoT) networks. In general the answer
is no, but the terminology of [RFC7228] is best used to describe the
boundaries.
The entire solution described in this document is aimed in general at
non-constrained (i.e. class 2+) devices operating on a non-Challenged
network. The entire solution described here is not intended to be
useable as-is by constrained devices operating on challenged networks
(such as 802.15.4 LLNs).
In many target applications, the systems involved are large router
platforms with multi-gigabit inter-connections, mounted in controlled
access data centers. But this solution is not exclusive to the
large, 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 the 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.
Specifically, there are protocol aspects described here which might
result in congestion collapse or energy-exhaustion of intermediate
battery powered routers in an LLN. Those types of networks SHOULD
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).
Some aspects are in scope for constrained devices on challenged
networks: the certificate contents, and the process by which the four
questions above are resolved is in scope. It is simply the actual
on-the-wire imprint protocol which is likely inappropriate.
1.3. Trust bootstrap
The imprint protocol results in a secure relationship between the
domain registrar and the new device. If the new device is
sufficiently constrained that the ACE protocol should be leveraged
for operation, (see [I-D.ietf-ace-actors]), and the domain registrar
is also the Client Authorization Server or the Authorization Server,
then it may be appropriate to use this secure channel to exchange ACE
tokens.
2. Architectural Overview 2. Architectural Overview
The logical elements of the bootstrapping framework are described in The logical elements of the bootstrapping framework are described in
this section. Figure 1 provides a simplified overview of the this section. Figure 1 provides a simplified overview of the
components. Each component is logical and may be combined with other components. Each component is logical and may be combined with other
components as necessary. components as necessary.
. .
.+------------------------+ .+------------------------+
skipping to change at page 6, line 20 skipping to change at page 7, line 22
| .| A uthorized |Ownership| | .| A uthorized |Ownership|
| .| S igning |Tracker | | .| S igning |Tracker |
| .| A uthority | | | .| A uthority | |
| .+--------------+---------+ | .+--------------+---------+
| .............. ^ | .............. ^
V | V |
+-------+ ............................................|... +-------+ ............................................|...
| | . | . | | . | .
| | . +------------+ +-----------+ | . | | . +------------+ +-----------+ | .
| | . | | | | | . | | . | | | | | .
| <---L2---> | | <-------+ . | | . | | | <-------+ .
| | or | Proxy | | Registrar | . | | . | Proxy | | Registrar | .
| <---L3---> <---L3--> | . | <--------> <-------> | .
| New | . | | | | . | New | . | | | | .
| Entity| . +------------+ +-----+-----+ . | Entity| . +------------+ +-----+-----+ .
| | . | . | | . | .
| | . +-----------------+----------+ . | | . +-----------------+----------+ .
| | . | Domain Certification | . | | . | Domain Certification | .
| | . | Authority | . | | . | Authority | .
+-------+ . | Management and etc | . +-------+ . | Management and etc | .
. +----------------------------+ . . +----------------------------+ .
. . . .
................................................ ................................................
skipping to change at page 7, line 48 skipping to change at page 9, line 8
a key infrastructure; if certain devices in a network do not support a key infrastructure; if certain devices in a network do not support
this approach, they can still be bootstrapped manually. Although this approach, they can still be bootstrapped manually. Although
manual deployment is not scalable and is not a focus of this document manual deployment is not scalable and is not a focus of this document
the necessary mechanisms are called out in this document to ensure the necessary mechanisms are called out in this document to ensure
such edge conditions are covered by the architectural and protocol such edge conditions are covered by the architectural and protocol
models. models.
3. Functional Overview 3. Functional Overview
Entities behave in an autonomic fashion. They discover each other Entities behave in an autonomic fashion. They discover each other
and autonomically bootstrap into a key infrastructure deliminating and autonomically bootstrap into a key infrastructure delineating the
the autonomic domain. See autonomic domain. See [I-D.irtf-nmrg-autonomic-network-definitions]
[I-D.irtf-nmrg-autonomic-network-definitions] for more information. for more information.
This section details the state machine and operational flow for each This section details the state machine and operational flow for each
of the main three entities. The New Entity, the Domain (primarily of the main three entities. The New Entity, the Domain (primarily
the Registrar) and the MASA service. the Registrar) and the MASA service.
The overall flow is shown in Figure 2: A representative flow is shown in Figure 2:
+---------+ +----------+ +-----------+ +--------+ +-------+ +------------+ +------------+
| New | Proxy | | | Vendor | | New | | Proxy | | Domain | | Vendor |
| Entity | not | Domain | | Service | | Entity | | | | Registrar | | Service |
| | shown | | | (Internet)| | | | | | | | (Internet |
+---------+ +----------+ +-----------+ +--------+ +-------+ +------------+ +------------+
| | | | | | |
|<-------discovery--------->| | |<-RFC3927 IPv4 adr | | |
|---IEEE 802.1AR identity-->| | or|<-RFC4862 IPv6 adr | | |
| | | | | | |
| [accept device?] | |-------------------->| | |
| | | | optional: mDNS query| | |
| |---IEEE 802.1AR identity--->| | RFC6763/RFC6762 | | |
| |---Domain ID--------------->| | | | |
| | | |<--------------------| | |
| | [optional: does | mDNS broadcast | | |
| | the device belong | response or periodic| | |
| | to the domain?] | | | |
| | | |<------------------->|<----------------->| |
| | [update audit log] | (d)TLS via the Proxy | |
| | | |<--Registrar TLS server authentication---| |
| |<---device audit log--------| [PROVISIONAL accept of server cert] | |
| |<---audit token-------------| P---IEEE 802.1AR client authentication--->| |
| |<-- ownership voucher-------| P | | |
| | (optional) | P---Request Audit Token (include nonce)-->| |
| | | P | | |
| [ still accept device?] | P | /---> | |
| | | P | | [accept device?] |
|<----audit token-----------| | P | | [contact Vendor] |
|<----ownership voucher-----| (optional) | P | | |--New Entity ID---->|
|<----config information----| | P | | |--Domain ID-------->|
| | | P | | |--optional:nonce--->|
[audit token valid?] | | P | | | [extract DomainID]
[or ownership voucher valid?] | | P | | | |
[apply config information] | | P | optional: | [update audit log]
| | | P | |can | |
|----domain enrollment----->| | P | |occur | optional: is |
|<----domain certificate----| | P | |in | an ownership |
| | | P | |advance | voucher available?
P | | | |
P | | |<-device audit log--|
P | | |<-audit token-------|
P | | | |
P | | |<-optional: --------|
P | \----> | ownership voucher |
P | | |
P | [verify audit log or voucher] |
P | | |
P<--Audit token and/or ownership voucher--| |
[verify response ]| | |
[verify provisional cert ]| | |
| | | |
|---------------------------------------->| |
| Continue with RFC7030 enrollment | |
| using now bidirectionally authenticated | |
| TLS session. | | |
| | | |
| | | |
| | | |
Figure 2 Figure 2
3.1. Behavior of a new entity 3.1. Behavior of a New Entity
A New Entity that has not yet been bootstrapped attempts to find a A New Entity that has not yet been bootstrapped attempts to find a
local domain and join it. local domain and join it. A New Entity MUST NOT automatically
initiate bootstrapping if it has already been configured.
States of a New Entity are as follows: States of a New Entity are as follows:
+--------------+ +--------------+
| Start | | Start |
| | | |
+------+-------+ +------+-------+
| |
+------v-------+ +------v-------+
| Discover | | Discover |
skipping to change at page 9, line 50 skipping to change at page 11, line 43
| Enroll +------+-------+ | Enroll +------+-------+
| Failure | | Failure |
| +------v-------+ | +------v-------+
| | Being | | | Being |
^------------+ Managed | ^------------+ Managed |
Factory +--------------+ Factory +--------------+
reset reset
Figure 3 Figure 3
State descriptions are as follows: State descriptions for the New Entity are as follows:
1. Discover a communication channel to the "closest" Registrar by
trying the following steps in this order:
A. Search for a Proxy on the local link using a link local
discovery protocol (no routable addresses are required for
this approach). If multiple local proxies are discovered
attempt communications with each before widening the search
to other options. The proxy relays information to the
registrar. If this fails:
B. Obtain an IP address using existing methods, such as SLAAC or
DHCPv6, and search for a local registrar using DNS service
discovery. [[EDNOTE: ]]If this fails:
C. Obtain an IP address (as above), and search for the domain 1. Discover a communication channel to the "closest" Registrar.
registrar using a pre-defined Factory provided Internet based
re-direct service. Various methods could be used, such as
DNS or RESTful APIs.
2. Identify itself. This is done by presenting an IEEE 802.1AR 2. Identify itself. This is done by presenting an IEEE 802.1AR
credentials to the discovered Registrar (via a Proxy if credentials to the discovered Registrar (via the Proxy) in a
necessary). Included is a generated nonce that is specific to (d)TLS handshake. (Although the Registrar is also authenticated
this attempt. these credentials are only provisionally accepted at this time).
3. Requests to Join the Discovered domain. The device indicates the 3. Requests to Join the discovered Registrar. The acceptable
Imprint methods it will accept and provides a nonce ensuring that imprint methods are indicated along with a nonce ensuring that
any responses can be associated with this particular any responses can be associated with this particular
bootstrapping attempt. bootstrapping attempt.
4. Imprint on the Registrar. This requires verification of the MASA 4. Imprint on the Registrar. This requires verification of the
service generated Audit Token as provided by the contacted vendor service "Audit Token" or the validation of the vendor
Registrar or the validation of the vendor provided ownership service "Ownership Voucher". Either of these responses contains
voucher. The Audit Token contains the DomainID information for sufficient information for the New Entity to complete
this device and is signed by the MASA service. The device uses a authentication of the Registrar. (The New Entity can now finish
pre-installed root certificate of the MASA service to validate authentication of the Registrar (d)TLS server certificate)
the signature of the Audit Token or the Ownership Voucher.
5. Enroll by accepting the domain specific information from the 5. Enroll by accepting the domain specific information from the
Registrar, and by obtaining a domain certificate from the Registrar, and by obtaining a domain certificate from the
Registrar using a standard enrollment protocol, e.g. Enrolment Registrar using a standard enrollment protocol, e.g. Enrollment
over Secure Transport (EST) [RFC7030]. over Secure Transport (EST) [RFC7030].
6. The New Entity is now a member of, and can be managed by, the 6. The New Entity is now a member of, and can be managed by, the
domain and will only repeat the discovery aspects of domain and will only repeat the discovery aspects of
bootstrapping if it is returned to factory default settings. bootstrapping if it is returned to factory default settings.
The following sections describe each of these steps in more detail. The following sections describe each of these steps in more detail.
3.1.1. Discovery 3.1.1. Discovery
Existing protocols provide the functionality for discovery of the The result of discovery is logically communication with a Proxy
Domain Bootstrap Server. The result of discovery might be instead of a Domain Registrar but in such a case the proxy
communication with a proxy instead of a Domain Bootstrap Server. In facilitates communication with the actual Domain Registrar in a
such a case the proxy facilitates communication with the actual manner that is transparent to the New Entity. Therefore or clarity a
Domain Bootstrap Server in a manner that is transparent to the New Proxy is always assumed.
Entity.
To discover the Domain Bootstrap Server the New Entity performs the To discover the Domain Bootstrap Server the New Entity performs the
following actions in this order: following actions in this order:
1. MUST: Obtains a local address using either IPv4 or IPv6 methods a. MUST: Obtains a local address using either IPv4 or IPv6 methods
as described in [[EDNOTE: do we need a reference?]]. as described in [RFC4862] IPv6 Stateless Address
AutoConfiguration or [RFC3927] Dynamic Configuration of IPv4
2. MUST: Attempt to establish a TLS connection to the next hop Link-Local Addresses.
neighbor at a well known AN port building on the [[EDNOTE: AN
node discovery discussion, need a reference??]]. [Toerless to
provide updated text]
3. MUST: unsecured-GRASP as a link local discovery method?
[Toerless to provide updated text]
4. MAY: Performs DNS-based Service Discovery [RFC6763] over b. MAY: Performs DNS-based Service Discovery [RFC6763] over
Multicast DNS [RFC6762] searching for the service Multicast DNS [RFC6762] searching for the service
"_bootstrapks._tcp.local." "_bootstrapks._tcp.local."
5. MAY: Performs DNS-based Service Discovery [RFC6763] over normal c. 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.
d. MAY: Performs DNS-based Service Discovery [RFC6763] over normal
DNS operations. In this case the domain is known so the service DNS operations. In this case the domain is known so the service
searched for is "_bootstrapks._tcp.example.com". searched for is "_bootstrapks._tcp.example.com".
6. MAY: If no local bootstrapks service is located using the DNS- e. MAY: If no local bootstrapks service is located using the DNS-
based Sevice Discovery methods the New Entity contacts a well based Service Discovery methods the New Entity contacts a well
known vendor provided bootstrapping server by perfoming a DNS known vendor provided bootstrapping server by performing a DNS
lookup using a well known URI such as "bootstrapks.vendor- lookup using a well known URI such as "bootstrapks.vendor-
example.com". example.com".
Once a domain bootstrapping server is discovered the New Entity Once a Registrar is discovered (technically a communication channel
communicates with the discovered server using the bootstrapping through a Proxy) the New Entity communicates with the Registrar using
protocol defined in Section 5. The current DNS services returned the bootstrapping protocol defined in Section 5. The current DNS
during each query is maintained until bootstrapping is completed. If services returned during each query is maintained until bootstrapping
bootstrapping fails and the New Entity returns to the Discovery state is completed. If bootstrapping fails and the New Entity returns to
it picks up where it left off and continues attempting bootstrapping. the Discovery state it picks up where it left off and continues
For example if the first Multicast DNS _bootstrapks._tcp.local attempting bootstrapping. For example if the first Multicast DNS
response doens't work then the second and third responses are tried. _bootstrapks._tcp.local response doesn't work then the second and
If these fail the New Entity moves on to normal DNS-based Service third responses are tried. If these fail the New Entity moves on to
Discovery. normal DNS-based Service Discovery.
Once all discovered services are attempted the device SHOULD return Once all discovered services are attempted the device SHOULD return
to Multicast DNS and keep trying. The New Entity may prioritize to Multicast DNS and keep trying. The New Entity may prioritize
selection order as appropriate for the anticipated environment. selection order as appropriate for the anticipated environment.
[[EDNOTE: An appropriate backoff or rate limiting strategy should be [[EDNOTE: An appropriate backoff or rate limiting strategy should be
defined here such that the device doesn't flood the local network defined here such that the device doesn't flood the local network
with queries. If the device were to eventually give up -- or at with queries. If the device were to eventually give up -- or at
least have too long between attempts -- a power cycle would restart least have too long between attempts -- a power cycle would restart
the backoff mechanism.]] the backoff mechanism.]]
[[EDNOTE: it is unclear yet if discovery happens on a per interface
basis or once per device. What is the requirement around joining
multiple domains; is this a bootstrapping requirement or is this a
broader autonomic requirement]] [[EDNOTE: b. carpenter: I seem to
think we settled on joining one domain (which might be a sub-domain)
and then doing some sort of cross-certification to get authenticated
and authorized in another domain. If so, it isn't a bootstrap
requirement.]]
3.1.2. Identity 3.1.2. Identity
The New Entity identifies itself during the communication protocol The New Entity identifies itself during the communication protocol
handshake. If the client identity is rejected the New Entity repeats handshake. If the client identity is rejected the New Entity repeats
the Discovery process using the next proxy or discovery method the Discovery process using the next proxy or discovery method
available. available.
The boostrapping protocol server is as of yet not validated. Thus The bootstrapping protocol server is not authenticated. Thus this
this connection is provisional and all data recieved is untrusted connection is provisional and all data received is untrusted until
until sufficiently validated even though it is over a (D)TLS sufficiently validated even though it is over a (D)TLS connection.
connection. This is aligned with the existing provisional mode of This is aligned with the existing provisional mode of EST [RFC7030]
EST [RFC7030] during s4.1.1 "Bootstrap Distribution of CA during s4.1.1 "Bootstrap Distribution of CA Certificates".
Certificates".
All security associations established are between the new device and All security associations established are between the new device and
the Bootstrapping server regardless of proxy operations. the Bootstrapping server regardless of proxy operations.
3.1.3. Request Join 3.1.3. Request Join
The New Entity POSTs a request to join the domain to the The New Entity POSTs a request to join the domain to the
Bootstrapping server. This request contains a New Entity generated Bootstrapping server. This request contains a New Entity generated
nonce and informs the Bootstrapping server which imprint methods the nonce and informs the Bootstrapping server which imprint methods the
New Entity will accept. New Entity will accept.
skipping to change at page 13, line 18 skipping to change at page 14, line 31
apply appropriate policy concerning which server to redirect to. apply appropriate policy concerning which server to redirect to.
The nonce ensures the New Entity can verify that responses are The nonce ensures the New Entity can verify that responses are
specific to this bootstrapping attempt. This minimizes the use of specific to this bootstrapping attempt. This minimizes the use of
global time and provides a substantial benefit for devices without a global time and provides a substantial benefit for devices without a
valid clock. valid clock.
3.1.4. Imprint 3.1.4. Imprint
The domain trust anchor is received by the New Entity during the The domain trust anchor is received by the New Entity during the
boostrapping protocol methods in the form of either an Audit Token bootstrapping protocol methods in the form of either an Audit Token
containing the domainID or an explicit ownership voucher. The goal containing the domainID or an explicit ownership voucher. The goal
of the imprint state is to securely obtain a copy of this trust of the imprint state is to securely obtain a copy of this trust
anchor without involving human interaction. anchor without involving human interaction.
The enrollment protocol EST [RFC7030] details a set of non-autonomic The enrollment protocol EST [RFC7030] details a set of non-autonomic
bootstrapping methods such as: bootstrapping methods such as:
o using the Implicit Trust Anchor database (not an autonomic o using the Implicit Trust Anchor database (not an autonomic
solution because the URL must be securely distributed), solution because the URL must be securely distributed),
skipping to change at page 14, line 4 skipping to change at page 15, line 15
This document describes additional autonomic methods: This document describes additional autonomic methods:
MASA audit token Audit tokens are obtained by the Registrar from the MASA audit token Audit tokens are obtained by the Registrar from the
MASA service and presented to the New Entity for validation. MASA service and presented to the New Entity for validation.
These indicate to the New Entity that joining the domain has been These indicate to the New Entity that joining the domain has been
logged by a trusted logging server. logged by a trusted logging server.
Ownership Voucher Ownership Vouchers are obtained by the Registrar Ownership Voucher Ownership Vouchers are obtained by the Registrar
from the MASA service and explicitly indicate the fully qualified from the MASA service and explicitly indicate the fully qualified
domain name of the domain the new entity currently belongs to. domain name of the domain the new entity currently belongs to.
The Ownership Voucher is defined in [I-D.ietf-netconf-zerotouch].
Since client authentication occurs during the TLS handshake the Since client authentication occurs during the TLS handshake the
bootstrapping server has sufficient information to apply appropriate bootstrapping server has sufficient information to apply appropriate
policy concerning which method to use. policy concerning which method to use.
An arbitrary basic configuration information package that is signed An arbitrary basic configuration information package that is signed
by the domain can be delivered alongside the Audit Token or ownership by the domain can be delivered alongside the Audit Token or ownership
validation. This information is signed by the domain private keys validation. This information is signed by the domain private keys
and is a one time delivery containing information such as which and is a one time delivery containing information such as which
enrollment server to communicate with and which management system to enrollment server to communicate with and which management system to
skipping to change at page 14, line 40 skipping to change at page 16, line 5
Enrollment proceeds as described in Enrollment over Secure Transport Enrollment proceeds as described in Enrollment over Secure Transport
(EST) [RFC7030]. The New Entity contacts the Registrar using EST as (EST) [RFC7030]. The New Entity contacts the Registrar using EST as
indicated: indicated:
o The New Entity is authenticated using the IEEE 802.1AR o The New Entity is authenticated using the IEEE 802.1AR
credentials. credentials.
o The EST section 4.1.3 CA Certificates Response is verified using o The EST section 4.1.3 CA Certificates Response is verified using
either the Audit Token which provided the domain identity -or- either the Audit Token which provided the domain identity -or-
o The EST server is authenticated by using the Owership Voucher o The EST server is authenticated by using the Ownership Voucher
indicated fully qualified domain name to build the EST URI such indicated fully qualified domain name to build the EST URI such
that EST section 4.1.1 bootstrapping using the New Entity implicit that EST section 4.1.1 bootstrapping using the New Entity implicit
Trust Anchor database can be used. Trust Anchor database can be used.
3.1.6. Being Managed 3.1.6. Being Managed
Functionality to provide generic "configuration" information is Functionality to provide generic "configuration" information is
supported. The parsing of this data and any subsequent use of the supported. The parsing of this data and any subsequent use of the
data, for example communications with a Network Management System is data, for example communications with a Network Management System is
out of scope but is expected to occur after bootstrapping enrollment out of scope but is expected to occur after bootstrapping enrollment
is complete. This ensures that all communications with management is complete. This ensures that all communications with management
systems which can divulge local security information (e.g. network systems which can divulge local security information (e.g. network
topology or raw key material) is secured using the local credentials topology or raw key material) is secured using the local credentials
issued during enrollment. issued during enrollment.
The New Entity uses bootstrapping to join only one domain.
Management by multiple domains is out-of-scope of bootstrapping.
After the device has successfully joined a domain and is being
managed it is plausible that the domain can insert credentials for
other domains depending on the device capabilities.
See Section 3.5. See Section 3.5.
3.2. Behavior of a proxy 3.2. Behavior of a Proxy
The role of the Proxy is to facilitate communications. The Proxy The role of the Proxy is to facilitate communications. The Proxy
forwards EST transport (TLS or DTLS) packets between the New Entity forwards packets between the New Entity and the Registrar that has
and the Registrar that has been configured on the Proxy. been configured on the Proxy. The Proxy does not terminate the
(d)TLS handshake.
[[EDNOTE: To what extent do we need to explain how this occurs? It In order to permit the proxy functionality to be implemented on the
is sufficient to indicate the basic behavior or do we need to maximum variety of devices the chosen mechanism SHOULD use the
indicate here all the details? A rough implementation of an ipv4 minimum amount of state on the proxy device. While many devices in
proxy would be as follows: the ANIMA target space will be rather large routers, the proxy
function is likely to be implemented in the control plane CPU such a
device, with available capabilities for the proxy function similar to
many class 2 IoT devices.
socat -v tcp4-listen:443,reuseaddr,fork tcp4:registrar.example.com:443 The document [I-D.richardson-anima-state-for-joinrouter] provides a
more extensive analysis of the alternative proxy methods.
There have been suggestions that a stateless proxy implementation 3.2.1. CoAP connection to Registrar
using a DTLS extension would be preferred. Is this a future
optimization opportunity or a short term requirement?]] The proxy MUST implement an IPIP (protocol 41) encapsulation function
for CoAP traffic to the configured UDP port on the registrar. The
proxy does not terminate the CoAP DTLS connection. [[EDNOTE: The
choice of CoAP as the mandatory to implement protocol rather than
HTTP maximizes code reuse on the smallest of devices. Unfortunately
this means this document will have to include the EST over CoAP
details as additional sections. The alternative is to make 'HTTPS
proxy' method the mandatory to implement and provide a less friendly
environment for the smallest of devices. This is a decision we'll
have to see addressed by the broader team.]]
As a result of the Proxy Discovery process in section Section 3.1.1,
the port number exposed by the proxy does not need to be well known,
or require an IANA allocation. The address and port of the Registrar
will be discovered by the GRASP protocol inside the ACP. For the
IPIP encapsulation methods, the port announced by the Proxy MUST be
the same as on the registrar.
The IPIP encapsulation allows the proxy to forward traffic which is
otherwise not to be forwarded, as the traffic between New Node and
Proxy use IPv6 Link Local addresses.
If the Proxy device has more than one interface on which it offers
the proxy function, then it must select a unique IP address per
interface in order so that the proxy can stateless return the reply
packets to the correct link.
3.2.2. HTTPS proxy connection to Registrar
The proxy SHOULD also provide one of: an IPIP encapsulation of HTTP
traffic on TCP port TBD to the registrar, an HTTP proxy which accepts
URLs that reach the Registrar, or a TCP circuit proxy that connects
the New Node to the Registrar.
In order to make the HTTP choice above transparent to the New Node,
the New Node will always initiate an HTTP connection, and will always
send an appropriate CONNECT message to initiate an HTTPS connection
to the registrar. [[EDNOTE: The CONNECT syntax is that the New
Entity specifies the Registrar server in the CONNECT line. See
RFC7231 s4.3.6. We wish the Proxy to override any value with the
locally known-to-the-proxy Registrar address.]]
When the Proxy provides a circuit proxy to the Registrar the
Registrar MUST accept HTTP connections, and be willing to perform an
HTTP proxy (CONNECT) operation to itself, and then initiate HTTPS.
When the Proxy provides a stateless IPIP encapsulation to the
Registrar, then the Registrar will have to perform IPIP
decapsulation, remembering the originating outer IPIP source address
in order to qualify the inner link-local address. Being able to
connect a TCP (HTTP) or UDP (CoAP) socket to a link-local address
with an encapsulated IPIP header requires API extensions beyond
[RFC3542] for UDP use, and requires a form of connection latching
(see section 4.1 of [RFC5386] and all of [RFC5660], except that a
simple IPIP tunnel is used rather than an IPsec tunnel).
3.3. Behavior of the Registrar (Bootstrap Server) 3.3. Behavior of the Registrar (Bootstrap Server)
Once a Registrar is established it listens for new entities and Once a Registrar is established it listens for new entities and
determines if they can join the domain. The registrar delivers any determines if they can join the domain. The registrar delivers any
necessary authorization information to the new device and facilitates necessary authorization information to the new device and facilitates
enrollment with the domain PKI. enrollment with the domain PKI.
Registrar behavior is as follows: Registrar behavior is as follows:
skipping to change at page 17, line 32 skipping to change at page 19, line 46
show in the log. show in the log.
In order to validate the IEEE 802.1AR device identity the Registrar In order to validate the IEEE 802.1AR device identity the Registrar
maintains a database of vendor trust anchors (e.g. vendor root maintains a database of vendor trust anchors (e.g. vendor root
certificates or keyIdentifiers for vendor root public keys). For certificates or keyIdentifiers for vendor root public keys). For
user interface purposes this database can be mapped to colloquial user interface purposes this database can be mapped to colloquial
vendor names. Registrars can be shipped with the trust anchors of a vendor names. Registrars can be shipped with the trust anchors of a
significant number of third-party vendors within the target market. significant number of third-party vendors within the target market.
If a device is accepted into the domain, it is expected request a If a device is accepted into the domain, it is expected request a
domain certificate through a certificate enrolment process. The domain certificate through a certificate enrollment process. The
result is a common trust anchor and device certificates for all result is a common trust anchor and device certificates for all
autonomic devices in a domain (these certificates can subsequently be autonomic devices in a domain (these certificates can subsequently be
used to determine the boundaries of the homenet, to authenticate used to determine the boundaries of the homenet, to authenticate
other domain nodes, and to autonomically enable services on the other domain nodes, and to autonomically enable services on the
homenet). The authorization performed during this phase MAY be homenet). The authorization performed during this phase MAY be
cached for the TLS session and applied to subsequent EST enrollment cached for the TLS session and applied to subsequent EST enrollment
requests so long as the session lasts. requests so long as the session lasts.
3.3.3. Claiming the New Entity 3.3.3. Claiming the New Entity
Claiming an entity establishes an audit log at the MASA server and Claiming an entity establishes an audit log at the MASA server and
provides the Registrar with proof, in the form of a MASA provides the Registrar with proof, in the form of a MASA
authorization token, that the log entry has been inserted. As authorization token, that the log entry has been inserted. As
indicated in Section 3.1.4 a New Entity will only proceed with indicated in Section 3.1.4 a New Entity will only proceed with
bootstrapping if a validated MASA authorization token has been bootstrapping if a validated MASA authorization token has been
recieved. The New Entity therefore enforces that bootstrapping only received. The New Entity therefore enforces that bootstrapping only
occurs if the claim has been logged. occurs if the claim has been logged. There is no requirement for the
vendor to definitively know that the device is owned by the
Registrar's obtain the MASA URI via static configuration or by Registrar.
extracting it from the IEEE 802.1AR credentail. [[EDNOTE: An
appropriate extension for indicating the MASA URI could be defined in
this document]].
If ownership validation methods are being used the 'claiming' occured Registrar's obtain the Vendor URI via static configuration or by
during out-of-band integration within the sales process and is out- extracting it from the IEEE 802.1AR credential. The imprint method
of-scope. Instead the Registar simply requests an ownership supported by the New Entity is known from the IEEE 802.1AR
validation token. credential. [[EDNOTE: An appropriate extension for indicating the
Vendor URI and imprint method could be defined using the methods
described in [I-D.lear-mud-framework]]].
During initial bootstrapping the New Entity provides a nonce specific During initial bootstrapping the New Entity provides a nonce specific
to the particular bootstrapping attempt. The Registrar SHOULD to the particular bootstrapping attempt. The Registrar SHOULD
include this nonce when claiming the New Entity from the MASA include this nonce when claiming the New Entity from the MASA
service. Claims from an unauthenticated Registrar are only serviced service. Claims from an unauthenticated Registrar are only serviced
by the MASA resource if a nonce is provided. by the MASA resource if a nonce is provided.
The Registrar can claim a New Entity that is not online by forming The Registrar can claim a New Entity that is not online by forming
the request using the entities unique identifier and not including a the request using the entities unique identifier and not including a
nonce in the claim request. Audit Tokens obtained in this way do not nonce in the claim request. Audit Tokens obtained in this way do not
have a lifetime and they provide a permanent method for the domain to have a lifetime and they provide a permanent method for the domain to
claim the device. Evidence of such a claim is provided in the audit claim the device. Evidence of such a claim is provided in the audit
log entries available to any future Registrar. Such claims reduce log entries available to any future Registrar. Such claims reduce
the ability for future domains to secure bootstrapping and therefore the ability for future domains to secure bootstrapping and therefore
the Registrar MUST be authenticated by the MASA service. [[EDNOTE: the Registrar MUST be authenticated by the MASA service.
some of this paragraph content belongs in the section on MASA
behavior]] An ownership voucher requires the vendor to definitively know that a
device is owned by a specific domain. The method used to "claim"
this are out-of-scope. The Registrar simply requests an ownership
validation token and the New Entity trusts the response.
3.3.4. Log Verification 3.3.4. Log Verification
The Registrar requests the log information for the new entity from The Registrar requests the log information for the new entity from
the MASA service. The log is verified to confirm that the following the MASA service. The log is verified to confirm that the following
is true to the satisfaction of the Registrar's configured policy: is true to the satisfaction of the Registrar's configured policy:
o Any nonceless entries in the log are associated with domainIDs o Any nonceless entries in the log are associated with domainIDs
recognized by the registrar. recognized by the registrar.
o Any nonce'd entries are older than when the domain is known to o Any nonce'd entries are older than when the domain is known to
have physical possession of the new entity or that the domainIDs have physical possession of the new entity or that the domainIDs
are recognized by the registrar. are recognized by the registrar.
If any of these criteria are unacceptable to the registrar the entity If any of these criteria are unacceptable to the registrar the entity
is rejected. The registar MAY be configured to ignore the history of is rejected. The Registrar MAY be configured to ignore the history
the device but it is RECOMMENDED that this only be configured if of the device but it is RECOMMENDED that this only be configured if
hardware assisted NEA [RFC5209] is supported. hardware assisted NEA [RFC5209] is supported.
3.3.5. Forwarding Audit Token plus Configuration 3.3.5. Forwarding Audit Token plus Configuration
The Registrar forwards the received Audit Token to the New Entity. The Registrar forwards the received Audit Token to the New Entity.
To simplify the message flows an initial configuration package can be To simplify the message flows an initial configuration package can be
delivered at this time which is signed by a representative of the delivered at this time which is signed by a representative of the
domain. domain.
[[EDNOTE: format TBD. The configuration package signature data must [[EDNOTE: format TBD. The configuration package signature data must
skipping to change at page 19, line 34 skipping to change at page 21, line 51
A Registrar POSTs a claim message optionally containing the bootstrap A Registrar POSTs a claim message optionally containing the bootstrap
nonce to the MASA server. nonce to the MASA server.
If a nonce is provided the MASA service responds to all requests. If a nonce is provided the MASA service responds to all requests.
The MASA service verifies the Registrar is representative of the The MASA service verifies the Registrar is representative of the
domain and generates a privacy protected log entry before responding domain and generates a privacy protected log entry before responding
with the Audit Token. with the Audit Token.
If a nonce is not provided then the MASA service MUST authenticate If a nonce is not provided then the MASA service MUST authenticate
the Registrar as a valid customer. This prevents denial of service the Registrar as a valid customer. This prevents denial of service
attacks. The specific level of authentication provided by the attacks.
customer is not defined here. An MASA Practice Statement (MPS)
similar to the Certification Authority CPS, as defined in RFC5280, is
provided by the Factory such that Registrar's can determine the level
of trust they have in the Factory.
3.4.2. Retrieve Audit Entries from Log 3.4.2. Retrieve Audit Entries from Log
When determining if a New Entity should be accepted into a domain the When determining if a New Entity should be accepted into a domain the
Registrar retrieves a copy of the audit log from the MASA service. Registrar retrieves a copy of the audit log from the MASA service.
This contains a list of privacy protected domain identities that have This contains a list of privacy protected domain identities that have
previously claimed the device. Included in the list is an indication previously claimed the device. Included in the list is an indication
of the time the entry was made and if the nonce was included. of the time the entry was made and if the nonce was included.
3.5. Leveraging the new key infrastructure / next steps 3.5. Leveraging the new key infrastructure / next steps
skipping to change at page 20, line 32 skipping to change at page 22, line 40
membership of other devices. This makes it possible to create trust membership of other devices. This makes it possible to create trust
boundaries where domain members have higher level of trusted than boundaries where domain members have higher level of trusted than
external devices. Using the autonomic User Interface, specific external devices. Using the autonomic User Interface, specific
devices can be grouped into to sub domains and specific trust levels devices can be grouped into to sub domains and specific trust levels
can be implemented between those. can be implemented between those.
3.6. Interactions with Network Access Control 3.6. Interactions with Network Access Control
The assumption is that Network Access Control (NAC) completes using The assumption is that Network Access Control (NAC) completes using
the New Entity 802.1AR credentials and results in the device having the New Entity 802.1AR credentials and results in the device having
sufficient connetivity to discovery and communicate with the proxy. sufficient connectivity to discovery and communicate with the proxy.
Any additional connectivity or quarantine behavior by the NAC Any additional connectivity or quarantine behavior by the NAC
infrastructure is out-of-scope. After the devices has completed infrastructure is out-of-scope. After the devices has completed
bootstrapping the mechanism to trigger NAC to re-authenticate the bootstrapping the mechanism to trigger NAC to re-authenticate the
device and provide updated network privileges is also out-of-scope. device and provide updated network privileges is also out-of-scope.
This achieves the goal of a bootstrap architecture that can integrate This achieves the goal of a bootstrap architecture that can integrate
with NAC but does not require NAC within the network where it wasn't with NAC but does not require NAC within the network where it wasn't
previously required. Future optimizations can be achieved by previously required. Future optimizations can be achieved by
integrating the bootstrapping protocol directly into an initial EAP integrating the bootstrapping protocol directly into an initial EAP
exchange. exchange.
skipping to change at page 22, line 19 skipping to change at page 24, line 23
domain infrastructure is plausible. Once set up, no human domain infrastructure is plausible. Once set up, no human
intervention is required in this process. Defining the exact intervention is required in this process. Defining the exact
mechanisms for this is out of scope although the registrar mechanisms for this is out of scope although the registrar
authorization checks is identified as the logical integration authorization checks is identified as the logical integration
point of any future work in this area. point of any future work in this area.
None of these approaches require the network to have permanent None of these approaches require the network to have permanent
Internet connectivity. Even when the Internet based MASA service is Internet connectivity. Even when the Internet based MASA service is
used, it is possible to pre-fetch the required information from the used, it is possible to pre-fetch the required information from the
MASA a priori, for example at time of purchase such that devices can MASA a priori, for example at time of purchase such that devices can
enrol later. This supports use cases where the domain network may be enroll later. This supports use cases where the domain network may
entirely isolated during device deployment. be entirely isolated during device deployment.
Additional policy can be stored for future authorization decisions. Additional policy can be stored for future authorization decisions.
For example an expected deployment time window or that a certain For example an expected deployment time window or that a certain
Proxy must be used. Proxy must be used.
4.4. Automatic Enrollment of Devices 4.4. Automatic Enrollment of Devices
The approach outlined in this document provides a secure zero-touch The approach outlined in this document provides a secure zero-touch
method to enrol new devices without any pre-staged configuration. method to enroll new devices without any pre-staged configuration.
New devices communicate with already enrolled devices of the domain, New devices communicate with already enrolled devices of the domain,
which proxy between the new device and a Registrar. As a result of which proxy between the new device and a Registrar. As a result of
this completely automatic operation, all devices obtain a domain this completely automatic operation, all devices obtain a domain
based certificate. based certificate.
4.5. Secure Network Operations 4.5. Secure Network Operations
The certificate installed in the previous step can be used for all The certificate installed in the previous step can be used for all
subsequent operations. For example, to determine the boundaries of subsequent operations. For example, to determine the boundaries of
the domain: If a neighbor has a certificate from the same trust the domain: If a neighbor has a certificate from the same trust
skipping to change at page 24, line 40 skipping to change at page 26, line 40
| +----------------> | +---------------->
| audit token or owner voucher <----------------+ | audit token or owner voucher <----------------+
<-------------------------------+ | <-------------------------------+ |
| (optional config information) | | | (optional config information) | |
| . | | | . | |
| . | | | . | |
Figure 5 Figure 5
In some use cases the Registrar may need to contact the Vendor in In some use cases the Registrar may need to contact the Vendor in
advanced, for example when the target network is airgapped. The advanced, for example when the target network is air-gapped. The
nonceless request format is provided for this and the resulting flow nonceless request format is provided for this and the resulting flow
is slightly different. The security differences associated with not is slightly different. The security differences associated with not
knowning the nonce are discussed below: knowing the nonce are discussed below:
+-----------+ +----------+ +-----------+ +----------+ +-----------+ +----------+ +-----------+ +----------+
| New | | | | | | | | New | | | | | | |
| Entity | | Proxy | | Registrar | | Vendor | | Entity | | Proxy | | Registrar | | Vendor |
| | | | | | | | | | | | | | | |
++----------+ +--+-------+ +-----+-----+ +--------+-+ ++----------+ +--+-------+ +-----+-----+ +--------+-+
| | | | | | | |
| | | | | | | |
| | | /requestaudittoken | | | /requestaudittoken
| | (nonce +----------------> | | (nonce +---------------->
skipping to change at page 25, line 37 skipping to change at page 27, line 37
HTTP REST | POST /requestaudittoken | | HTTP REST | POST /requestaudittoken | |
Data +----------------------nonce----> (discard | Data +----------------------nonce----> (discard |
| audit token or owner Voucher | nonce) | | audit token or owner Voucher | nonce) |
<-------------------------------+ | <-------------------------------+ |
| (optional config information) | | | (optional config information) | |
| . | | | . | |
| . | | | . | |
Figure 6 Figure 6
5.1. Request Audit Token 5.1. IEEE 802.1AR as client identity
The Registrar authenticates the client and performs authorization
checks to ensure this client is expected to join the domain. This
require a common procedure for representing and verifying the
identity of the client. The methods detailed in [RFC6125] such as
matching DNS Domain Name or Application Service Type are not directly
applicable.
Clients presents an IEEE 802.AR certificate complete with subject
field identifying the device uniquely in the Distinguished Name
serialNumber subfield. The subjectAltName MAY contain a
hardwareModuleName as specified in RFC4108. The Registrar extracts
this information and compares against a per vendor access control
list. (This can be implemented with a single database table so long
as the authority key identifier is also maintained and checked to
ensure that no two vendors collide in their use of serialNumber's).
When enrollment is complete and a local certificate is issued to the
new device the local CA has complete control over the namespace. If
this credential is intended for RFC6125 style TLS connections where
servers are identified by a server's DNS-ID identity the CA is likely
to ensure the dNSName field is populated. For Anima purposes the
IEEE 802.1AR serialNumber and hardwareModuleName fields MUST be
propagated to the issued certificate.
[[EDNOTE: the above authority key identifier trick works for database
lookups and here the inclusion of the DNS name would serve the same
purpose. Alternatively an Anima specified domain specific identifier
must be indicated.]]
5.2. EST over CoAP
[[EDNOTE: In order to support smaller devices the above section on
Proxy behavior introduces mandatory to implement support for CoAP
support by the Proxy. This implies similar support by the New Entity
and Registrar and means that the EST protocol operation encapsulation
into CoAP needs to be described. EST is HTTP based and "CoaP is
designed to easily interface with HTTP for integration" [RFC7252] so
this section is anticipated to be relatively straightforward. A
complexity is that the large message sizes necessary for
bootstrapping will require support for [draft-ietf-core-block].]]
5.3. Request Audit Token
When the New Entity reaches the EST section 4.1.1 "Bootstrap When the New Entity reaches the EST section 4.1.1 "Bootstrap
Distribution of CA Certificates" state but wishes to proceed in a Distribution of CA Certificates" state but wishes to proceed in a
fully automated fashion it makes a request for a MASA authorization fully automated fashion it makes a request for a MASA authorization
token from the Registrar. token from the Registrar.
This is done with an HTTPS POST using the operation path value of This is done with an HTTPS POST using the operation path value of
"/requestaudittoken". "/requestaudittoken".
The request format is JSON object containing a nonce. The request format is JSON object containing a nonce.
skipping to change at page 26, line 19 skipping to change at page 29, line 14
Request) since this allows the MASA service to confirm the actual Request) since this allows the MASA service to confirm the actual
device identity. It is not clear that there is a security benefit device identity. It is not clear that there is a security benefit
from this since its the New Entity that verifies the nonce.]] from this since its the New Entity that verifies the nonce.]]
The Registrar validates the client identity as described in EST The Registrar validates the client identity as described in EST
[RFC7030] section 3.3.2. The registrar performs authorization as [RFC7030] section 3.3.2. The registrar performs authorization as
detailed in Section 3.3.2. If authorization is successful the detailed in Section 3.3.2. If authorization is successful the
Registrar obtains an Audit Token from the MASA service (see Registrar obtains an Audit Token from the MASA service (see
Section 5.2). Section 5.2).
The recieved MASA authorization token is returned to the New Entity. The received MASA authorization token is returned to the New Entity.
As indicated in EST [RFC7030] the bootstrapping server can redirect As indicated in EST [RFC7030] the bootstrapping server can redirect
the client to an alternate server. If the New Entity authenticated the client to an alternate server. If the New Entity authenticated
the Registrar using the well known URI method then the New Entity the Registrar using the well known URI method then the New Entity
MUST follow the redirect automatically and authenticate the new MUST follow the redirect automatically and authenticate the new
Registrar against the redirect URI provided. If the New Entity had Registrar against the redirect URI provided. If the New Entity had
not yet authenticated the Registrar because it was discovered and was not yet authenticated the Registrar because it was discovered and was
not a known-to-be-valid URI then the new Registrar must be not a known-to-be-valid URI then the new Registrar must be
authenticated using one of the two autonomic methods described in authenticated using one of the two autonomic methods described in
this document. this document.
5.2. Request Audit Token from MASA 5.4. Request Audit Token from MASA
The Registrar requests the Audit Token from the MASA service using a The Registrar requests the Audit Token from the MASA service using a
REST interface. For simplicity this is defined as an optional EST REST interface. For simplicity this is defined as an optional EST
message between the Registar and an EST server running on the MASA message between the Registrar and an EST server running on the MASA
service although the Registrar is not required to make use of any service although the Registrar is not required to make use of any
other EST functionality when communicating with the MASA service. other EST functionality when communicating with the MASA service.
(The MASA service MUST properly reject any EST functionality requests (The MASA service MUST properly reject any EST functionality requests
it does not wish to service; a requirement that holds for any REST it does not wish to service; a requirement that holds for any REST
interface). interface).
This is done with an HTTP POST using the operation path value of This is done with an HTTP POST using the operation path value of
"/requestaudittoken". "/requestaudittoken".
The request format is a JSON object optionally containing the nonce The request format is a JSON object optionally containing the nonce
value (as obtained from the bootstrap request) and the IEEE 802.1AR value (as obtained from the bootstrap request) and the IEEE 802.1AR
identity of the device as a serial number (the full certificate is identity of the device as a serial number (the full certificate is
not needed and no proof-of-possession information for the device not needed and no proof-of-possession information for the device
identity is included). The New Entity's serial number is extracted identity is included). The New Entity's serial number is extracted
from the subject name : from the IEEE 802.1AR subject name:
{"nonce":"<64bit nonce value>", "serialnumber", "<subjectname/ {"nonce":"<64bit nonce value>", "serialnumber", "<subjectname/
subjectaltname serial number>"} subjectaltname serial number>"}
Inclusion of the nonce is optional because the Registar might request The Registrar MAY exclude the nonce from the request. Doing so
an authorization token when the New Entity is not online, or when the allows the Registrar to request an authorization token when the New
target bootstrapping environment is not on the same network as the Entity is not online, or when the target bootstrapping environment is
MASA server. not on the same network as the MASA server. If a nonce is not
provided the MASA server MUST authenticate the client as described in
EST [RFC7030] section 3.3.2. The registrar performs authorization as
detailed in Section 3.3.2. If authorization is successful the
Registrar obtains an Audit Token from the MASA service (see
Section 5.4).
The JSON message information is encapsulated in a PKCS7 signed data The JSON message information is encapsulated in a PKCS7 signed data
structure that is signed by the Registrar. The entire certificate structure that is signed by the Registrar. The entire certificate
chain, up to and including the Domain CA, MUST be included in the chain, up to and including the Domain CA, MUST be included in the
PKCS7. PKCS7.
The MASA service checks the internal consistency of the PKCS7 but is The MASA service checks the internal consistency of the PKCS7 but MAY
unable to actually authenticate the domain identity information. The not authenticate the domain identity information. The domain is not
domain is not know to the MASA server in advance and a shared trust know to the MASA server in advance and a shared trust anchor is not
anchor is not implied. The MASA server verifies that the PKCS7 is implied. The MASA server MUST verify that the PKCS7 is signed by a
signed by a Registrar (by checking for the cmc-idRA field in the Registrar certificate (by checking for the cmc-idRA field) that was
Registrar certificate) certificate that was issued by a the root issued by a the root certificate included in the PKCS7. This ensures
certificate included in the PKCS7. This is sufficient for the MASA that the Registrar is in fact an authorized Registrar of the unknown
service to ensure that the Registar is in fact an authorized Registar domain.
of the unknown domain.
The domain ID (e.g. hash of the public key of the domain) is The domain ID (e.g. hash of the public key of the domain) is
extracted from the root certificate and is used to generate the MASA extracted from the root certificate and is used to populate the MASA
authorization token and to update the audit log. authorization token and to update the audit log. The authorization
token consists of the nonce, if supplied, the serialnumber and the
[[EDNOTE: The authorization token response format needs to be defined domain identity:
here. It consists of the nonce, if supplied, the serialnumber and
the trust anchor of the domain. For example:
{"nonce":"<64bit nonce value>", "serialnumber", "<subjectname/ {"nonce":"<64bit nonce value>", "serialnumber", "<subjectname/
subjectaltname serial number>","domainID":} subjectaltname serial number>","domainID":}
]]
[[EDNOTE: This assumes the Registrar can extract the serial number
successfullly from the cilent certificate. The RFC4108
hardwareModuleName is the best known location.]]
[[EDNOTE: There is a strong similarity between this and the previous [[EDNOTE: There is a strong similarity between this and the previous
section. Both involve requesting the Audit Token from the upstream section. Both involve requesting the Audit Token from the upstream
element. Because there are differing requirements on the data element. Because there are differing requirements on the data
submitted and the signing of that data they are specified in distinct submitted and the signing of that data they are specified in distinct
sections. The design team should have a meeting to discuss how to sections. The design team should have a meeting to discuss how to
unify these sections or make the distinctions more clear]] unify these sections or make the distinctions more clear]]
5.3. Basic Configuration Information Package 5.5. Basic Configuration Information Package
When the MASA authorization token is returned to the New Entity an When the MASA authorization token is returned to the New Entity an
arbitrary information package can be signed and delivered along side arbitrary information package can be signed and delivered along side
it. This is signed by the Domain Registar. The New Entity first it. This is signed by the Domain Registrar. The New Entity first
verifies the Audit Token and, if it is valid, then uses the domain's verifies the Audit Token and, if it is valid, then uses the domain's
TA to validate the Information Package. TA to validate the Information Package.
[[EDNOTE: The domainID as included in the log and as sent in the
authorization token is only a hash of the domain root certificate.
This is insufficient for the new entity to move out of the
provisional state as it needs a full root certificate to validate the
TLS certificate chain. This information package could be used to
deliver the full certificate or the full certificate could be
included in the authorization token. Lacking either the new entity
needs to stay in the provisional state until it performs an RFC7030
/getcacerts to obtain the full certificate chain.]]
[[EDNOTE: The package format to be specified here. Any signed format [[EDNOTE: The package format to be specified here. Any signed format
is viable and ideally one can simply be specified from netconf. The is viable and ideally one can simply be specified from netconf. The
Registar knows the New Entity device type from the 802.1AR credential Registar knows the New Entity device type from the 802.1AR credential
and so is able to determine the proper format for the configuration]] and so is able to determine the proper format for the
configuration.]]
5.4. Request MASA authorization log 5.6. Request MASA authorization log
A registrar requests the MASA authorization log from the MASA service A registrar requests the MASA authorization log from the MASA service
using this EST extension. using this EST extension.
This is done with an HTTP GET using the operation path value of This is done with an HTTP GET using the operation path value of
"/requestMASAlog". "/requestMASAlog".
The log data returned is a file consisting of all previous log The log data returned is a file consisting of all previous log
entries. For example: entries. For example:
skipping to change at page 28, line 44 skipping to change at page 31, line 45
"nonce":"<any nonce if supplied (or NULL)>"}, "nonce":"<any nonce if supplied (or NULL)>"},
{"date":"<date/time of the entry>"}, {"date":"<date/time of the entry>"},
"domainID":"<domainID as extracted from the root "domainID":"<domainID as extracted from the root
certificate within the PKCS7 of the certificate within the PKCS7 of the
audit token request>", audit token request>",
"nonce":"<any nonce if supplied (or NULL)>"}, "nonce":"<any nonce if supplied (or NULL)>"},
] ]
Distribution of a large log is less than ideal. This structure can Distribution of a large log is less than ideal. This structure can
be optimized as follows: only the most recent nonce'd log entry is be optimized as follows: All nonce-less entries for the same domainID
required in the response. All nonce-less entries for the same can be condensed into the single most recent nonceless entry.
domainID can be condensed into the single most recent nonceless
entry.
The Registrar uses this log information to make an informed decision The Registrar uses this log information to make an informed decision
regarding the continued bootstrapping of the New Entity. regarding the continued bootstrapping of the New Entity. For example
if the log includes unexpected domainIDs this is indicative of
problematic imprints by the new entity. If unexpected nonce-less
entries exist this is indicative of the permanent ability for the
unknown domain to trigger a reset of the device and take over
management of it. Equipment that is purchased pre-owned can be
expected to have an extensive history.
[[EDNOTE: certificate transparency might offer an alternative log Log entries containing the Domain's ID can be compared against local
entry method]] history logs in search of discrepancies.
[[EDNOTE: certificate transparency style use of merkle tree hash's
might offer an alternative log entry method]]
6. Reduced security operational modes 6. Reduced security operational modes
A common requirement of bootstrapping is to support less secure A common requirement of bootstrapping is to support less secure
operational modes for support specific use cases. The following operational modes for support specific use cases. The following
sections detail specific ways that the New Entity, Registrar and MASA sections detail specific ways that the New Entity, Registrar and MASA
can be configured to run in a less secure mode for the indicated can be configured to run in a less secure mode for the indicated
reasons. reasons.
6.1. New Entity security reductions 6.1. Trust Model
+--------+ +-------+ +------------+ +------------+
| New | | Proxy | | Domain | | Vendor |
| Entity | | | | Registrar | | Service |
| | | | | | | (Internet |
+--------+ +-------+ +------------+ +------------+
Figure 7
New Entity: The New Entity 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.
Proxy: Provides proxy functionalities but is not involved in
security considerations.
Registrar: When interacting with a MASA server the Registrar makes
all decisions. When ownership vouchers are involved the Registrar
is only a conduit and all security decisions are made on the
vendor service.
Vendor Service, MASA: This form of vendor 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. [[EDNOTE: these claims could
be strengthened using by using cryptographic log techniques to
provide append only", cryptographic assured, publicly auditable
logs. Current text provides for a fully trusted vendor.]]
Vendor Service, Ownership Validation: This form of vendor service is
trusted to accurately know which device is owned by which domain.
6.2. New Entity security reductions
Although New Entity can choose to run in less secure modes this is Although New Entity can choose to run in less secure modes this is
MUST NOT be the default state because it permanently degrades the MUST NOT be the default state because it permanently degrades the
security for all other uses cases. security for all other uses cases.
The device may have an operational mode where it skips Audit Token The device may have an operational mode where it skips Audit Token or
validation one time. For example if a physical button is depressed Ownership Voucher validation one time. For example if a physical
during the bootstrapping operation. This can be useful if the MASA button is depressed during the bootstrapping operation. This can be
service is unavailable. This behavior SHOULD be available via local useful if the vendor service is unavailable. This behavior SHOULD be
configuration or physical presence methods to ensure new entities can available via local configuration or physical presence methods to
always be deployed even when autonomic methods fail. ensure new entities can always be deployed even when autonomic
methods fail. This allows for unsecure imprint.
It is RECOMMENDED that this only be available if hardware assisted It is RECOMMENDED that this only be available if hardware assisted
NEA [RFC5209] is supported. NEA [RFC5209] is supported.
6.2. Registrar security reductions 6.3. Registrar security reductions
The Registrar can choose to accept devices using less secure methods. The Registrar can choose to accept devices using less secure methods.
These methods are RECOMMENDED when low security models are needed as These methods are RECOMMENDED when low security models are needed as
the security decisions are being made by the local administrator: the security decisions are being made by the local administrator:
1. The registrar MAY choose to accept all devices, or all devices of 1. The registrar MAY choose to accept all devices, or all devices of
a particular type, at the administrator's discretion. This could a particular type, at the administrator's discretion. This could
occur when informing the Registrar of unique identifiers of new occur when informing the Registrar of unique identifiers of new
entities might be operationally difficult. entities might be operationally difficult.
skipping to change at page 30, line 12 skipping to change at page 34, line 7
and stored until they are needed during bootstrapping operations. and stored until they are needed during bootstrapping operations.
This is for use cases where target network is protected by an air This is for use cases where target network is protected by an air
gap and therefore can not contact the MASA service during New gap and therefore can not contact the MASA service during New
Entity deployment. Entity deployment.
4. The registrar MAY ignore unrecognized nonce-less Audit Log 4. The registrar MAY ignore unrecognized nonce-less Audit Log
entries. This could occur when used equipment is purchased with entries. This could occur when used equipment is purchased with
a valid history being deployed in air gap networks that required a valid history being deployed in air gap networks that required
permanent Audit Tokens. permanent Audit Tokens.
6.3. MASA security reductions These modes are not available for devices that require a vendor
Ownership Voucher. The methods vendors use to determine which
devices are owned by which domains is out-of-scope.
6.4. MASA security reductions
Lower security modes chosen by the MASA service effect all device Lower security modes chosen by the MASA service effect all device
deployments unless paired with strict device ownership validation, in deployments unless bound to the specific device identities. In which
which case these modes can be provided as additional features for case these modes can be provided as additional features for specific
specific customers. The MASA service can choose to run in less customers. The MASA service can choose to run in less secure modes
secure modes by: by:
1. Not enforcing that a Nonce is in the Audit Token. This results 1. Not enforcing that a Nonce is in the Audit Token. This results
in distribution of Audit Tokens that never expire and effectly in distribution of Audit Tokens that never expire and in effect
makes the Domain an always trusted entity to the New Entity makes the Domain an always trusted entity to the New Entity
during any subsequent bootstrapping attempts. That this occured during any subsequent bootstrapping attempts. That this occurred
is captured in the log information so that the Domain registrar is captured in the log information so that the Domain registrar
can make appropriate security decisions when a new device joins can make appropriate security decisions when a New Entity joins
the domain. This is useful to support use cases where Registrars the Domain. This is useful to support use cases where Registrars
might not be online during actual device deployment. Because might not be online during actual device deployment. Because
this results in long lived Audit Tokens and do not require the this results in long lived Audit Tokens and do not require the
proof that the device is online this is only accepted when the proof that the device is online this is only accepted when the
Registrar is authenticated by the MASA server and authorized to Registrar is authenticated by the MASA server and authorized to
provide this functionality. The MASA server is RECOMMENDED to provide this functionality. The MASA server is RECOMMENDED to
use this functionality only in concert with Ownership Validation use this functionality only in concert with Ownership Validation
tracking. tracking.
2. Not verifying ownership before responding with an Audit Token. 2. Not verifying ownership before responding with an Audit Token.
This is expected to be a common operational model because doing This is expected to be a common operational model because doing
skipping to change at page 31, line 14 skipping to change at page 35, line 13
but no programmatic method is provided to ensure good behavior by the but no programmatic method is provided to ensure good behavior by the
MASA service. Nonceless entries into the audit log therefore MASA service. Nonceless entries into the audit log therefore
permanently reduce the value of a device because future Registrars, permanently reduce the value of a device because future Registrars,
during future bootstrap attempts, would now have to be configured during future bootstrap attempts, would now have to be configured
with policy to ignore previously (and potentially unknown) domains. with policy to ignore previously (and potentially unknown) domains.
Future registrars are recommended to take the audit history of a Future registrars are recommended to take the audit history of a
device into account when deciding to join such devices into their device into account when deciding to join such devices into their
network. If the MASA server were to have allowed a significantly network. If the MASA server were to have allowed a significantly
large number of claims this might become onerous to the MASA server large number of claims this might become onerous to the MASA server
which must maintain all the extra log entries. Ensuring the registar which must maintain all the extra log entries. Ensuring the
is representative of a valid customer domain even without validating Registrar is representative of a valid customer domain even without
ownership helps to mitigate this. validating ownership helps to mitigate this.
It is possible for an attacker to send an authorization request to It is possible for an attacker to send an authorization request to
the MASA service directly after the real Registrar obtains an the MASA service directly after the real Registrar obtains an
authorization log. If the attacker could also force the authorization log. If the attacker could also force the
bootstrapping protocol to reset there is a theoretical opportunity bootstrapping protocol to reset there is a theoretical opportunity
for the attacker to use the Audit Token to take control of the New for the attacker to use the Audit Token to take control of the New
Entity but then proceed to enroll with the target domain. Possible Entity but then proceed to enroll with the target domain. Possible
prevention mechanisms include: prevention mechanisms include:
o Per device rate limits on the MASA service ensure such timing o Per device rate limits on the MASA service ensure such timing
attacks are difficult. attacks are difficult.
o In the advent of an unexpectadly lost bootstrapping connection the o In the advent of an unexpectedly lost bootstrapping connection the
Registrar repeats the request for audit log information. Registrar repeats the request for audit log information.
As indicated in EST [RFC7030] the connection is provisional and As indicated in EST [RFC7030] the connection is provisional and
untrusted until the server is successfully authorized. If the server untrusted until the server is successfully authorized. If the server
provides a redirect response the client MUST follow the redirect but provides a redirect response the client MUST follow the redirect but
the connection remains provisional. If the client uses a well known the connection remains provisional. If the client uses a well known
URI for contacting a well known Registrar the EST Implicit Trust URI for contacting a well known Registrar the EST Implicit Trust
Anchor database is used as is described in RFC6125 to authenticate Anchor database is used as is described in RFC6125 to authenticate
the well known URI. In this case the connection is not provisional the well known URI. In this case the connection is not provisional
and RFC6125 methods can be used for each subsequent redirection. and RFC6125 methods can be used for each subsequent redirection.
The MASA service could lock a claim and refuse to issue a new token The MASA service could lock a claim and refuse to issue a new token
or the MASA service could go offline (for example if a vendor went or the MASA service could go offline (for example if a vendor went
out of business). This functionality provides benefits such as theft out of business). This functionality provides benefits such as theft
resistance, but it also implies an operational risk to the Domain resistance, but it also implies an operational risk to the Domain
that Vendor behavior could limit future bootstrapping of the device that Vendor behavior could limit future bootstrapping of the device
by the Domain. This can be mitigated by Registrars that request by the Domain. This can be mitigated by Registrars that request
nonce-less authorization tokens. nonce-less authorization tokens.
7.1. Trust Model
[[EDNOTE: (need to describe that we need to trust the device h/w. To
be completed.)]]
8. Acknowledgements 8. Acknowledgements
We would like to thank the various reviewers for their input, in We would like to thank the various reviewers for their input, in
particular Markus Stenberg, Brian Carpenter, Fuyu Eleven. particular Markus Stenberg, Brian Carpenter, Fuyu Eleven.
9. References 9. References
9.1. Normative References 9.1. Normative References
[IDevID] IEEE Standard, , "IEEE 802.1AR Secure Device Identifier", [IDevID] IEEE Standard, , "IEEE 802.1AR Secure Device Identifier",
December 2009, <http://standards.ieee.org/findstds/ December 2009, <http://standards.ieee.org/findstds/
standard/802.1AR-2009.html>. standard/802.1AR-2009.html>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ Requirement Levels", BCP 14, RFC 2119,
RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC3542] Stevens, W., Thomas, M., Nordmark, E., and T. Jinmei,
"Advanced Sockets Application Program Interface (API) for
IPv6", RFC 3542, May 2003.
[RFC3927] Cheshire, S., Aboba, B., and E. Guttman, "Dynamic
Configuration of IPv4 Link-Local Addresses", RFC 3927, May
2005.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, September 2007.
[RFC5386] Williams, N. and M. Richardson, "Better-Than-Nothing
Security: An Unauthenticated Mode of IPsec", RFC 5386,
November 2008.
[RFC5660] Williams, N., "IPsec Channels: Connection Latching",
RFC 5660, October 2009.
[RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762,
DOI 10.17487/RFC6762, February 2013,
<http://www.rfc-editor.org/info/rfc6762>.
[RFC6763] Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", RFC 6763, DOI 10.17487/RFC6763, February 2013,
<http://www.rfc-editor.org/info/rfc6763>.
[RFC7030] Pritikin, M., Ed., Yee, P., Ed., and D. Harkins, Ed., [RFC7030] Pritikin, M., Ed., Yee, P., Ed., and D. Harkins, Ed.,
"Enrollment over Secure Transport", RFC 7030, DOI "Enrollment over Secure Transport", RFC 7030,
10.17487/RFC7030, October 2013, DOI 10.17487/RFC7030, October 2013,
<http://www.rfc-editor.org/info/rfc7030>. <http://www.rfc-editor.org/info/rfc7030>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained-Node Networks", RFC 7228,
DOI 10.17487/RFC7228, May 2014,
<http://www.rfc-editor.org/info/rfc7228>.
9.2. Informative References 9.2. Informative References
[I-D.behringer-homenet-trust-bootstrap] [I-D.behringer-homenet-trust-bootstrap]
Behringer, M., Pritikin, M., and S. Bjarnason, Behringer, M., Pritikin, M., and S. Bjarnason,
"Bootstrapping Trust on a Homenet", draft-behringer- "Bootstrapping Trust on a Homenet", draft-behringer-
homenet-trust-bootstrap-02 (work in progress), February homenet-trust-bootstrap-02 (work in progress), February
2014. 2014.
[I-D.ietf-ace-actors]
Gerdes, S., Seitz, L., Selander, G., and C. Bormann, "An
architecture for authorization in constrained
environments", draft-ietf-ace-actors-03 (work in
progress), March 2016.
[I-D.ietf-netconf-zerotouch]
Watsen, K. and M. Abrahamsson, "Zero Touch Provisioning
for NETCONF or RESTCONF based Management", draft-ietf-
netconf-zerotouch-07 (work in progress), March 2016.
[I-D.irtf-nmrg-autonomic-network-definitions] [I-D.irtf-nmrg-autonomic-network-definitions]
Behringer, M., Pritikin, M., Bjarnason, S., Clemm, A., Behringer, M., Pritikin, M., Bjarnason, S., Clemm, A.,
Carpenter, B., Jiang, S., and L. Ciavaglia, "Autonomic Carpenter, B., Jiang, S., and L. Ciavaglia, "Autonomic
Networking - Definitions and Design Goals", draft-irtf- Networking - Definitions and Design Goals", draft-irtf-
nmrg-autonomic-network-definitions-07 (work in progress), nmrg-autonomic-network-definitions-07 (work in progress),
March 2015. March 2015.
[I-D.lear-mud-framework]
Lear, E., "Manufacturer Usage Description Framework",
draft-lear-mud-framework-00 (work in progress), January
2016.
[I-D.richardson-anima-state-for-joinrouter]
Richardson, M., "Considerations for stateful vs stateless
join router in ANIMA bootstrap", draft-richardson-anima-
state-for-joinrouter-00 (work in progress), January 2016.
[imprinting] [imprinting]
Wikipedia, , "Wikipedia article: Imprinting", July 2015, Wikipedia, , "Wikipedia article: Imprinting", July 2015,
<https://en.wikipedia.org/wiki/Imprinting_(psychology)>. <https://en.wikipedia.org/wiki/Imprinting_(psychology)>.
[pledge] Dictionary.com, , "Dictionary.com Unabridged", July 2015, [pledge] Dictionary.com, , "Dictionary.com Unabridged", July 2015,
<http://dictionary.reference.com/browse/pledge>. <http://dictionary.reference.com/browse/pledge>.
Appendix A. Editor notes
[[EDNOTE: This section is to capturing rough notes between editors
and Anima Bootstrapping design team members. This entire section to
be removed en masse before finalization]]
Change Discussion:
03 updated figures added "ownership voucher" concepts added "request
join" state to the new entity discussions broke discovery and
identity into two sections added request join section expanded
imprint autonomic methods as per design team discussions
simplified proxy discussion as per design team discussions
clarified 'entity authorization' clarified 'claiming the new
entity' removed EAP-EST references expanded on protocol details as
per ownership validation options slight additions to security
considerations
02 Moved sections for readability, Updated introduction, simplified
functional overview to avoid distractions from optional elements,
addressed updated security considerations, fleshed out state
machines.
The following is a non-prioritized list of work items currently
identified:
o Continue to address gaps/opportunities highlighted by community
work on bootstrappping. Refs: IETF92 "Survey of Security
Bootstrapping", Aana Danping He, behcet Sarikaya. "NETCONF Zero
Touch Update for ANIMA" https://www.ietf.org/proceedings/92/
anima.html and "Bootstrapping Key Infrastructures", Pritikin,
Behringer, Bjarnason
o IN PROGRESS: Intergrate "Ownership Voucher" as a valid optional
format for the MASA response. So long as the issuance of this is
logged and captured in the log response then the basic flow and
threat model is substantially the same.
o COMPLETE (moved to simple proxy): Attempt to re-use existing work
as per the charter: Toerless notes: a) are existing [eap] options?
or too complex? or doens't work? b) our own method (e.g. EAP-
ANIMA c) if b then investigate using signaling protocol).
o
Authors' Addresses Authors' Addresses
Max Pritikin Max Pritikin
Cisco Cisco
Email: pritikin@cisco.com Email: pritikin@cisco.com
Michael C. Richardson Michael C. Richardson
Sandelman Software Works Sandelman Software Works
470 Dawson Avenue 470 Dawson Avenue
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