One document matched: draft-ietf-anima-bootstrapping-keyinfra-01.xml
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docName="draft-ietf-anima-bootstrapping-keyinfra-01"
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<front>
<title>Bootstrapping Key Infrastructures</title>
<author fullname="Max Pritikin" initials="M." surname="Pritikin">
<organization>Cisco</organization>
<address>
<email>pritikin@cisco.com</email>
</address>
</author>
<author fullname="Michael C. Richardson" initials="M."
surname="Richardson">
<organization abbrev="SSW">Sandelman Software Works</organization>
<address>
<postal>
<street>470 Dawson Avenue</street>
<city>Ottawa</city>
<region>ON</region>
<code>K1Z 5V7</code>
<country>CA</country>
</postal>
<email>mcr+ietf@sandelman.ca</email>
<uri>http://www.sandelman.ca/</uri>
</address>
</author>
<author fullname="Michael H. Behringer" initials="M.H."
surname="Behringer">
<organization>Cisco</organization>
<address>
<email>mbehring@cisco.com</email>
</address>
</author>
<author fullname="Steinthor Bjarnason" initials="S." surname="Bjarnason">
<organization>Cisco</organization>
<address>
<email>sbjarnas@cisco.com</email>
</address>
</author>
<date year="2015" />
<area>Operations and Management</area>
<workgroup>ANIMA WG</workgroup>
<abstract>
<t>This document specifies automated bootstrapping of an key
infrastructure using vendor installed IEEE 802.1AR manufacturing
installed certificates, in combination with a vendor based service on
the Internet. Before being authenticated, a new device has only
link-local connectivity, and does not require a routable address. When a
vendor provides an Internet based service, devices can be forced to join
only specific domains but in limited/disconnected networks or legacy
environments we describe a variety of options that allow bootstrapping
to proceed.</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>To literally "pull yourself up by the bootstraps" is an impossible
action. Similarly the secure establishment of a key infrastructure
without external help is also an impossibility. Today it is accepted
that the initial connections between nodes are insecure, until key
distribution is complete, or that domain-specific keying material is
pre-provisioned on each new device in a costly and non-scalable manner.
This document describes a zero-touch approach to bootstrapping an entity
by securing the initial distribution of key material using third-party
generic keying material, such as a manufacturer installed IEEE 802.1AR
certificate <xref target="IDevID"></xref>, and a corresponding
third-party service on the Internet.</t>
<t>The two sides of an association being bootstrapped authenticate each
other and then determine appropriate authorization. This process is
described as four distinct steps between the existing domain and the new
entity being added:</t>
<t><list style="symbols">
<t>New entity authentication: "Who is this? What is its
identity?"</t>
<t>New entity authorization: "Is it mine? Do I want it? What are the
chances it has been compromised?"</t>
<t>Domain authentication: "What is this domain's claimed
identity?"</t>
<t>Domain authorization: "Should I join it?"</t>
</list></t>
<t>A precise answer to these questions can not be obtained without
leveraging an established key infrastructure(s). The domain's decisions
are based on the new entity's authenticated identity, as established by
verification of previously installed credentials such as a manufacturer
installed IEEE 802.1AR certificate, and verified back-end information
such as a configured list of purchased devices or communication with a
trusted third-party. The new entity's decisions are made according to
verified communication with a trusted third-party or in a strictly
auditable fasion.</t>
<t>Optimal security is achieved with IEEE 802.1AR certificates on each
new entity, accompanied by a third-party Internet based service for
verification. Bootstrapping concepts run to completion with less
requirements, but are then less secure. A domain can choose to accept
lower levels of security when a trusted third-party is not available so
that bootstrapping proceeds even at the risk of reduced security. Only
the domain can make these decisions based on administrative input and
known behavior of the new entity.</t>
<t>The result of bootstrapping is that a domain specific key
infrastructure is deployed. Since IEEE 802.1AR PKI certificates are used
for identifying the new entity, and the public key of the domain
identity is leveraged during communiciations with an Internet based
service, which is itself authenticated using HTTPS, bootstrapping of a
domain specific Public Key Infrastructure (PKI) is described. Sufficient
agility to support bootstrapping alternative key infrastructures (such
as symmetric key solutions) is considered although no such alternate key
infrastructure is described.</t>
<section title="Terminology">
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
<xref target="RFC2119"></xref>.</t>
<t>The following terms are defined for clarity:</t>
<t><list style="hanging">
<t hangText="DomainID:">The domain identity is the 160-bit SHA-1
hash of the BIT STRING of the subjectPublicKey of the domain trust
anchor that is stored by the Domain CA. This is consistent with
the RFC5280 Certification Authority subject key identifier of the
Domain CA's self signed root certificate. (A string value bound to
the Domain CA's self signed root certificate subject and issuer
fields is often colloquially used as a humanized identity value
but during protocol discussions the more exact term as defined
here is used).</t>
<t hangText="drop ship:">The physical distribution of equipment
containing the "factory default" configuration to a final
destination. In zero-touch scenarios there is no staging or
pre-configuration during drop-ship.</t>
<t hangText="imprint:">the process where a device that wishes to
join a network acquires it's domain specific identity. This term
is taken from Konrad Lorenz's work in biology with new ducklings:
during a critical period, the duckling would assume that anything
that looks like a mother duck is in fact their mother. <xref
target="imprinting"></xref></t>
<t hangText="pledge:">the prospective device, which has the
identity provided to at the factory. Neither the device nor the
network knows if the device yet knows if this device belongs with
this network. This is definition 6, according to <xref
target="pledge"></xref></t>
<t hangText="Audit Token:">A signed token from the manufacturer
authorized signing authority indicating that the bootstrapping
event has been successfully logged. This has been referred to as
an "authorization token" indicating that it authorizes
bootstrapping to proceed. </t>
<t hangText="Ownership Voucher:">A signed voucher from the vendor
vouching that a specific domain "owns" the new entity. </t>
</list></t>
</section>
</section>
<section title="Architectural Overview">
<t>The logical elements of the bootstrapping framework are described in
this section. Figure 1 provides a simplified overview of the components.
Each component is logical and may be combined with other components as
necessary.</t>
<t></t>
<figure>
<artwork><![CDATA[ .
.+------------------------+
+--------------Drop Ship-------------->.| Vendor Service |
| .+------------------------+
| .| M anufacturer| |
| .| A uthorized |Ownership|
| .| S igning |Tracker |
| .| A uthority | |
| .+--------------+---------+
| .............. ^
V |
+-------+ ............................................|...
| | . | .
| | . +------------+ +-----------+ | .
| | . | | | | | .
| <---L2---> | | <-------+ .
| | or | Proxy | | Registrar | .
| <---L3---> <---L3--> | .
| New | . | | | | .
| Entity| . +------------+ +-----+-----+ .
| | . | .
| | . +-----------------+----------+ .
| | . | Domain Certification | .
| | . | Authority | .
+-------+ . | Management and etc | .
. +----------------------------+ .
. .
................................................
"Domain" components
]]></artwork>
<postamble>Figure 1</postamble>
</figure>
<t><list style="hanging">
<t hangText="Domain:">The set of entities that trust a common key
infrastructure trust anchor. This includes the Proxy, Registrar,
Domain Certificate Authority, Management components and any existing
entity that is already a member of the domain.</t>
<t hangText="Domain CA:">The domain Certification Authority (CA)
provides certification functionalities to the domain. At a minimum
it provides certification functionalities to the Registrar and
stores the trust anchor that defines the domain. Optionally, it
certifies all elements.</t>
<t hangText="Registrar:">A representative of the domain that is
configured, perhaps autonomically, to decide whether a new device is
allowed to join the domain. The administrator of the domain
interfaces with a Registrar to control this process. Typically a
Registrar is "inside" its domain.</t>
<t hangText="New Entity:">A new device or virtual machine or
software component that is not yet part of the domain.</t>
<t hangText="Proxy:">A domain entity that helps the New Entity join
the domain. A Proxy facilitates communication for devices that find
themselves in an environment where they are not provided
connectivity until after they are validated as members of the
domain. The New Entity is unaware that they are communicating with a
proxy rather than directly with the Registrar. </t>
<t hangText="MASA Service:">A Manufacturer Authorized Signing
Authority (MASA) service on the global Internet. The MASA provides a
trusted repository for audit log information concerning privacy
protected bootstrapping events. </t>
<t hangText="Ownership Tracker">An Ownership Tracker service on the
global internet. The Ownership Tracker uses business processes to
accurately track ownership of all devices shipped against domains
that have purchased them. Although optional this component allows
vendors to provide additional value in cases where their sales and
distribution channels allow for accurately tracking of such
ownership.</t>
</list></t>
<t>We assume a multi-vendor network. In such an environment there could
be a MASA or Ownership Tracker for each vendor that supports devices
following this document's specification, or an integrator could provide
a MASA service for all devices. It is unlikely that an integrator could
provide Ownership Tracking services for multiple vendors.</t>
<t>This document describes a secure zero-touch approach to bootstrapping
a key infrastructure; if certain devices in a network do not support
this approach, they can still be bootstrapped manually. Although manual
deployment is not scalable and is not a focus of this document the
necessary mechanisms are called out in this document to ensure such edge
conditions are covered by the architectural and protocol models.</t>
</section>
<section title="Functional Overview">
<t>Entities behave in an autonomic fashion. They discover each other and
autonomically bootstrap into a key infrastructure deliminating the
autonomic domain. See <xref
target="I-D.irtf-nmrg-autonomic-network-definitions"></xref> for more
information.</t>
<t>This section details the state machine and operational flow for each
of the main three entities. The New Entity, the Domain (primarily the
Registrar) and the MASA service.</t>
<t>The overall flow is shown in Figure 2:</t>
<figure>
<artwork><![CDATA[
+---------+ +----------+ +-----------+
| New | Proxy | | | Vendor |
| Entity | not | Domain | | Service |
| | shown | | | (Internet)|
+---------+ +----------+ +-----------+
| | |
|<-------discovery--------->| |
|---IEEE 802.1AR identity-->| |
| | |
| [accept device?] |
| | |
| |---IEEE 802.1AR identity--->|
| |---Domain ID--------------->|
| | |
| | [optional: does
| | the device belong
| | to the domain?]
| | |
| | [update audit log]
| | |
| |<---device audit log--------|
| |<---audit token-------------|
| |<-- ownership voucher-------|
| | (optional) |
| | |
| [ still accept device?] |
| | |
|<----audit token-----------| |
|<----ownership voucher-----| (optional) |
|<----config information----| |
| | |
[audit token valid?] | |
[or ownership voucher valid?] | |
[apply config information] | |
| | |
|----domain enrollment----->| |
|<----domain certificate----| |
| | |]]></artwork>
<postamble>Figure 2</postamble>
</figure>
<t></t>
<section title="Behavior of a new entity">
<t>A New Entity that has not yet been bootstrapped attempts to find a
local domain and join it.</t>
<t>States of a New Entity are as follows:</t>
<t></t>
<figure>
<artwork><![CDATA[ +--------------+
| Start |
| |
+------+-------+
|
+------v-------+
| Discover |
+------------> |
| +------+-------+
| |
| +------v-------+
| | Identity |
^------------+ |
| rejected +------+-------+
| |
| +------v-------+
| | Request |
| | Join |
| +------+-------+
| |
| +------v-------+
| | Imprint | Optional
^------------+ <--+Manual input
| Bad Vendor +------+-------+
| response |
| +------v-------+
| | Enroll |
^------------+ |
| Enroll +------+-------+
| Failure |
| +------v-------+
| | Being |
^------------+ Managed |
Factory +--------------+
reset
]]></artwork>
<postamble>Figure 3</postamble>
</figure>
<t></t>
<t>State descriptions are as follows:</t>
<t><list style="numbers">
<t>Discover a communication channel to the "closest" Registrar by
trying the following steps in this order:<list style="letters">
<t>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:</t>
<t>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:</t>
<t>Obtain an IP address (as above), and search for the domain
registrar using a pre-defined Factory provided Internet based
re-direct service. Various methods could be used, such as DNS
or RESTful APIs.</t>
</list></t>
<t>Identify itself. This is done by presenting an IEEE 802.1AR
credentials to the discovered Registrar (via a Proxy if
necessary). Included is a generated nonce that is specific to this
attempt.</t>
<t>Requests to Join the Discovered domain. The device indicates
the Imprint methods it will accept and provides a nonce ensuring
that any responses can be associated with this particular
bootstrapping attempt. </t>
<t>Imprint on the Registrar. This requires verification of the
MASA service generated Audit Token as provided by the contacted
Registrar or the validation of the vendor provided ownership
voucher. The Audit Token contains the DomainID information for
this device and is signed by the MASA service. The device uses a
pre-installed root certificate of the MASA service to validate the
signature of the Audit Token or the Ownership Voucher. </t>
<t>Enroll by accepting the domain specific information from the
Registrar, and by obtaining a domain certificate from the
Registrar using a standard enrollment protocol, e.g. Enrolment
over Secure Transport (EST) <xref target="RFC7030"></xref>.</t>
<t>The New Entity is now a member of, and can be managed by, the
domain and will only repeat the discovery aspects of bootstrapping
if it is returned to factory default settings.</t>
</list>The following sections describe each of these steps in more
detail.</t>
<section anchor="ProxyDiscovery" title="Discovery">
<t>Existing protocols provide the functionality for discovery of the
Domain Bootstrap Server. The result of discovery might be
communication with a proxy instead of a Domain Bootstrap Server. In
such a case the proxy facilitates communication with the actual
Domain Bootstrap Server in a manner that is transparent to the New
Entity.</t>
<t>To discover the Domain Bootstrap Server the New Entity performs
the following actions in this order:</t>
<t><list style="numbers">
<t>MUST: Obtains a local address using either IPv4 or IPv6
methods as described in [[EDNOTE: do we need a reference?]].</t>
<t>MUST: Attempt to establish a TLS connection to the next hop
neighbor at a well known AN port building on the [[EDNOTE: AN
node discovery discussion, need a reference??]]. [Toerless to
provide updated text]</t>
<t>MUST: unsecured-GRASP as a link local discovery method?
[Toerless to provide updated text]</t>
<t>MAY: Performs DNS-based Service Discovery [RFC6763] over
Multicast DNS [RFC6762] searching for the service
"_bootstrapks._tcp.local."</t>
<t>MAY: Performs DNS-based Service Discovery [RFC6763] over
normal DNS operations. In this case the domain is known so the
service searched for is "_bootstrapks._tcp.example.com". </t>
<t>MAY: If no local bootstrapks service is located using the
DNS-based Sevice Discovery methods the New Entity contacts a
well known vendor provided bootstrapping server by perfoming a
DNS lookup using a well known URI such as
"bootstrapks.vendor-example.com".</t>
</list>Once a domain bootstrapping server is discovered the New
Entity communicates with the discovered server using the
bootstrapping protocol defined in <xref
target="ProtocolDetails"></xref>. The current DNS services returned
during each query is maintained until bootstrapping is completed. If
bootstrapping fails and the New Entity returns to the Discovery
state it picks up where it left off and continues attempting
bootstrapping. For example if the first Multicast DNS
_bootstrapks._tcp.local response doens't work then the second and
third responses are tried. If these fail the New Entity moves on to
normal DNS-based Service Discovery.</t>
<t>Once all discovered services are attempted the device SHOULD
return to Multicast DNS and keep trying. The New Entity may
prioritize selection order as appropriate for the anticipated
environment.</t>
<t>[[EDNOTE: An appropriate backoff or rate limiting strategy should
be defined here such that the device doesn't flood the local network
with queries. If the device were to eventually give up -- or at
least have too long between attempts -- a power cycle would restart
the backoff mechanism.]]</t>
<t>[[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.]]</t>
</section>
<section title="Identity">
<t>The New Entity identifies itself during the communication
protocol handshake. If the client identity is rejected the New
Entity repeats the Discovery process using the next proxy or
discovery method available. </t>
<t>The boostrapping protocol server is as of yet not validated. Thus
this connection is provisional and all data recieved is untrusted
until sufficiently validated even though it is over a (D)TLS
connection. This is aligned with the existing provisional mode of
EST [RFC7030] during s4.1.1 "Bootstrap Distribution of CA
Certificates".</t>
<t>All security associations established are between the new device
and the Bootstrapping server regardless of proxy operations. </t>
</section>
<section title="Request Join">
<t>The New Entity POSTs a request to join the domain to the
Bootstrapping server. This request contains a New Entity generated
nonce and informs the Bootstrapping server which imprint methods the
New Entity will accept. </t>
<t>As indicated in EST [RFC7030] the bootstrapping server MAY
redirect the client to an alternate server. This is most useful in
the case where the New Entity has resorted to a well known vendor
URI and is communicating with the vendor's Registrar directly. In
this case the New Entity has authenticated the Registrar using the
local Implicit Trust Anchor database and can therefore treat the
redirect URI as a trusted URI which can also be validated using the
Implicit Trust Anchor database. Since client authentication occurs
during the TLS handshake the bootstrapping server has sufficient
information to apply appropriate policy concerning which server to
redirect to. </t>
<t>The nonce ensures the New Entity can verify that responses are
specific to this bootstrapping attempt. This minimizes the use of
global time and provides a substantial benefit for devices without a
valid clock. </t>
</section>
<section anchor="AcceptDomain" title="Imprint">
<t>The domain trust anchor is received by the New Entity during the
boostrapping protocol methods in the form of either an Audit Token
containing the domainID or an explicit ownership voucher. The goal
of the imprint state is to securely obtain a copy of this trust
anchor without involving human interaction.</t>
<t>The enrollment protocol EST <xref target="RFC7030"></xref>
details a set of non-autonomic bootstrapping methods such as:</t>
<t><list style="symbols">
<t>using the Implicit Trust Anchor database (not an autonomic
solution because the URL must be securely distributed),</t>
<t>engaging a human user to authorize the CA certificate using
out-of-band data (not an autonomic solution because the human
user is involved),</t>
<t>using a configured Explicit TA database (not an autonomic
solution because the distribution of an explicit TA database is
not autonomic),</t>
<t>and using a Certificate-Less TLS mutual authentication method
(not an autonomic solution because the distribution of symmetric
key material is not autonomic).</t>
</list>This document describes additional autonomic methods:</t>
<t><list style="hanging">
<t hangText="MASA audit token">Audit tokens are obtained by the
Registrar from the MASA service and presented to the New Entity
for validation. These indicate to the New Entity that joining
the domain has been logged by a trusted logging server.</t>
<t hangText="Ownership Voucher">Ownership Vouchers are obtained
by the Registrar from the MASA service and explicitly indicate
the fully qualified domain name of the domain the new entity
currently belongs to. </t>
</list></t>
<t>Since client authentication occurs during the TLS handshake the
bootstrapping server has sufficient information to apply appropriate
policy concerning which method to use. </t>
<t>An arbitrary basic configuration information package that is
signed by the domain can be delivered alongside the Audit Token or
ownership validation. This information is signed by the domain
private keys and is a one time delivery containing information such
as which enrollment server to communicate with and which management
system to communicate with. It is intended as a limited basic
configuration for these purposes and is not intended to deliver
entire final configuration to the device.</t>
<t>If the autonomic methods fail the New Entity returns to discovery
state and attempts bootstrapping with the next available discovered
Registrar. </t>
</section>
<section title="Enrollment">
<t>As the final step of bootstrapping a Registrar helps to issue a
domain specific credential to the New Entity. For simplicity in this
document, a Registrar primarily facilitates issuing a credential by
acting as an RFC5280 Registration Authority for the Domain
Certification Authority.</t>
<t>Enrollment proceeds as described in Enrollment over Secure
Transport (EST) [RFC7030]. The New Entity contacts the Registrar
using EST as indicated:</t>
<t><list style="symbols">
<t>The New Entity is authenticated using the IEEE 802.1AR
credentials.</t>
<t>The EST section 4.1.3 CA Certificates Response is verified
using either the Audit Token which provided the domain identity
-or-</t>
<t>The EST server is authenticated by using the Owership Voucher
indicated fully qualified domain name to build the EST URI such
that EST section 4.1.1 bootstrapping using the New Entity
implicit Trust Anchor database can be used. </t>
</list></t>
</section>
<section title="Being Managed">
<t>Functionality to provide generic "configuration" information is
supported. The parsing of this data and any subsequent use of the
data, for example communications with a Network Management System is
out of scope but is expected to occur after bootstrapping enrollment
is complete. This ensures that all communications with management
systems which can divulge local security information (e.g. network
topology or raw key material) is secured using the local credentials
issued during enrollment.</t>
<t>See <xref target="PostEnrollment"></xref>.</t>
</section>
</section>
<section title="Behavior of a proxy">
<t>The role of the Proxy is to facilitate communications. The Proxy
forwards EST transport (TLS or DTLS) packets between the New Entity
and the Registrar that has been configured on the Proxy.</t>
<t>[[EDNOTE: To what extent do we need to explain how this occurs? It
is sufficient to indicate the basic behavior or do we need to indicate
here all the details? A rough implementation of an ipv4 proxy would be
as follows:</t>
<figure>
<artwork><![CDATA[socat -v tcp4-listen:443,reuseaddr,fork tcp4:registrar.example.com:443]]></artwork>
</figure>
<t></t>
<t>There have been suggestions that a stateless proxy implementation
using a DTLS extension would be preferred. Is this a future
optimization opportunity or a short term requirement?]]</t>
</section>
<section title="Behavior of the Registrar (Bootstrap Server)">
<t>Once a Registrar is established it listens for new entities and
determines if they can join the domain. The registrar delivers any
necessary authorization information to the new device and facilitates
enrollment with the domain PKI.</t>
<t>Registrar behavior is as follows:</t>
<t></t>
<figure>
<artwork><![CDATA[Contacted by New Entity
+
|
+-------v----------+
| Entity | fail?
| Authentication +---------+
+-------+----------+ |
| |
+-------v----------+ |
| Entity | fail? |
| Authorization +--------->
+-------+----------+ |
| |
+-------v----------+ |
| Claiming the | fail? |
| Entity +--------->
+-------+----------+ |
| |
+-------v----------+ |
| Log Verification | fail? |
| +--------->
+-------+----------+ |
| |
+-------v----------+ +----v-------+
| Forward | | |
| Audit | | Reject |
| token + config | | Device |
| to the Entity | | |
+------------------+ +------------+]]></artwork>
<postamble>Figure 4</postamble>
</figure>
<section title="Entity Authentication">
<t>The applicable authentication methods detailed in EST [RFC7030]
are:</t>
<t><list style="symbols">
<t>the use of an IEEE 802.1AR IDevID credential,</t>
<t>or the use of a secret that is transmitted out of band
between the New Entity and the Registrar (this use case is not
autonomic).</t>
</list></t>
</section>
<section anchor="AcceptingTheEntity" title="Entity Authorization">
<t>In a fully automated network all devices must be securely
identified and authorized to join the domain.</t>
<t>A Registrar accepts or declines a request to join the domain,
based on the authenticated identity presented. Automated acceptance
criteria include:</t>
<t><list style="symbols">
<t>allow any device of a specific type (as determined by the
IEEE 802.1AR device identity),</t>
<t>allow any device from a specific vendor (as determined by the
IEEE 802.1AR identity),</t>
<t>allow a specific device from a vendor (as determined by the
IEEE 802.1AR identity)</t>
</list>Since all New Entities accept Audit Tokens the Registrar
MUST use the vendor provided MASA service to verify that the
device's history log does not include unexpected Registrars. If a
device had previously registered with another domain, the Registrar
of that domain would show in the log.</t>
<t>In order to validate the IEEE 802.1AR device identity the
Registrar maintains a database of vendor trust anchors (e.g. vendor
root certificates or keyIdentifiers for vendor root public keys).
For user interface purposes this database can be mapped to
colloquial vendor names. Registrars can be shipped with the trust
anchors of a significant number of third-party vendors within the
target market. </t>
<t>If a device is accepted into the domain, it is expected request a
domain certificate through a certificate enrolment process. The
result is a common trust anchor and device certificates for all
autonomic devices in a domain (these certificates can subsequently
be used to determine the boundaries of the homenet, to authenticate
other domain nodes, and to autonomically enable services on the
homenet). The authorization performed during this phase MAY be
cached for the TLS session and applied to subsequent EST enrollment
requests so long as the session lasts.</t>
</section>
<section title="Claiming the New Entity">
<t>Claiming an entity establishes an audit log at the MASA server
and provides the Registrar with proof, in the form of a MASA
authorization token, that the log entry has been inserted. As
indicated in <xref target="AcceptDomain"></xref> a New Entity will
only proceed with bootstrapping if a validated MASA authorization
token has been recieved. The New Entity therefore enforces that
bootstrapping only occurs if the claim has been logged. </t>
<t>Registrar's obtain the MASA URI via static configuration or by
extracting it from the IEEE 802.1AR credentail. [[EDNOTE: An
appropriate extension for indicating the MASA URI could be defined
in this document]]. </t>
<t>If ownership validation methods are being used the 'claiming'
occured during out-of-band integration within the sales process and
is out-of-scope. Instead the Registar simply requests an ownership
validation token.</t>
<t>During initial bootstrapping the New Entity provides a nonce
specific to the particular bootstrapping attempt. The Registrar
SHOULD include this nonce when claiming the New Entity from the MASA
service. Claims from an unauthenticated Registrar are only serviced
by the MASA resource if a nonce is provided.</t>
<t>The Registrar can claim a New Entity that is not online by
forming the request using the entities unique identifier and not
including a 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 claim the device. Evidence of such a claim is
provided in the audit log entries available to any future Registrar.
Such claims reduce the ability for future domains to secure
bootstrapping and therefore the Registrar MUST be authenticated by
the MASA service. [[EDNOTE: some of this paragraph content belongs
in the section on MASA behavior]] </t>
</section>
<section title="Log Verification">
<t>The Registrar requests the log information for the new entity
from the MASA service. The log is verified to confirm that the
following is true to the satisfaction of the Registrar's configured
policy:</t>
<t><list style="symbols">
<t>Any nonceless entries in the log are associated with
domainIDs recognized by the registrar. </t>
<t>Any nonce'd entries are older than when the domain is known
to have physical possession of the new entity or that the
domainIDs are recognized by the registrar.</t>
</list>If any of these criteria are unacceptable to the registrar
the entity is rejected. The registar MAY be configured to ignore the
history of the device but it is RECOMMENDED that this only be
configured if hardware assisted NEA [RFC5209] is supported.</t>
</section>
<section title="Forwarding Audit Token plus Configuration">
<t>The Registrar forwards the received Audit Token to the New
Entity. To simplify the message flows an initial configuration
package can be delivered at this time which is signed by a
representative of the domain.</t>
<t>[[EDNOTE: format TBD. The configuration package signature data
must contain the full certificate path sufficient for the new entity
to use the domainID information (as a trust anchor) to accept and
validate the configuration)]]</t>
</section>
</section>
<section title="Behavior of the MASA Service">
<t>The MASA service is provided by the Factory provider on the global
Internet. The URI of this service is well known. The URI SHOULD also
be provided as an IEEE 802.1AR IDevID X.509 extension (a "MASA Audit
Token Distribution Point" extension).</t>
<t>The MASA service provides the following functionalities to
Registrars:</t>
<section title="Issue Authorization Token and Log the event">
<t>A Registrar POSTs a claim message optionally containing the
bootstrap nonce to the MASA server.</t>
<t>If a nonce is provided the MASA service responds to all requests.
The MASA service verifies the Registrar is representative of the
domain and generates a privacy protected log entry before responding
with the Audit Token.</t>
<t>If a nonce is not provided then the MASA service MUST
authenticate the Registrar as a valid customer. This prevents denial
of service attacks. The specific level of authentication provided by
the 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.</t>
</section>
<section title="Retrieve Audit Entries from Log">
<t>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. This contains a list of privacy protected domain identities
that have previously claimed the device. Included in the list is an
indication of the time the entry was made and if the nonce was
included.</t>
</section>
</section>
<section anchor="PostEnrollment"
title="Leveraging the new key infrastructure / next steps">
<t>As the devices have a common trust anchor, device identity can be
securely established, making it possible to automatically deploy
services across the domain in a secure manner.</t>
<t>Examples of services:<list style="symbols">
<t>Device management.</t>
<t>Routing authentication.</t>
<t>Service discovery.</t>
</list></t>
<section anchor="boundary" title="Network boundaries">
<t>When a device has joined the domain, it can validate the domain
membership of other devices. This makes it possible to create trust
boundaries where domain members have higher level of trusted than
external devices. Using the autonomic User Interface, specific
devices can be grouped into to sub domains and specific trust levels
can be implemented between those.</t>
</section>
</section>
<section title="Interactions with Network Access Control">
<t>The assumption is that Network Access Control (NAC) completes using
the New Entity 802.1AR credentials and results in the device having
sufficient connetivity to discovery and communicate with the proxy.
Any additional connectivity or quarantine behavior by the NAC
infrastructure is out-of-scope. After the devices has completed
bootstrapping the mechanism to trigger NAC to re-authenticate the
device and provide updated network privileges is also out-of-scope.
</t>
<t>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 previously required. Future optimizations can be achieved by
integrating the bootstrapping protocol directly into an initial EAP
exchange. </t>
</section>
</section>
<section title="Domain Operator Activities">
<t>This section describes how an operator interacts with a domain that
supports the bootstrapping as described in this document.</t>
<section title="Instantiating the Domain Certification Authority">
<t>This is a one time step by the domain administrator. This is an
"off the shelf" CA with the exception that it is designed to work as
an integrated part of the security solution. This precludes the use of
3rd party certification authority services that do not provide support
for delegation of certificate issuance decisions to a domain managed
Registration Authority.</t>
</section>
<section title="Instantiating the Registrar">
<t>This is a one time step by the domain administrator. One or more
devices in the domain are configured take on a Registrar function.</t>
<t>A device can be configured to act as a Registrar or a device can
auto-select itself to take on this function, using a detection
mechanism to resolve potential conflicts and setup communication with
the Domain Certification Authority. Automated Registrar selection is
outside scope for this document.</t>
</section>
<section anchor="accepting" title="Accepting New Entities">
<t>For each New Entity the Registrar is informed of the unique
identifier (e.g. serial number) along with the manufacturer's
identifying information (e.g. manufacturer root certificate). This can
happen in different ways:</t>
<t><list style="numbers">
<t>Default acceptance: In the simplest case, the new device
asserts its unique identity to the registrar. The registrar
accepts all devices without authorization checks. This mode does
not provide security against intruders and is not recommended.</t>
<t>Per device acceptance: The new device asserts its unique
identity to the registrar. A non-technical human validates the
identity, for example by comparing the identity displayed by the
registrar (for example using a smartphone app) with the identity
shown on the packaging of the device. Acceptance may be triggered
by a click on a smartphone app "accept this device", or by other
forms of pairing. See also <xref
target="I-D.behringer-homenet-trust-bootstrap"></xref> for how the
approach could work in a homenet.</t>
<t>Whitelist acceptance: In larger networks, neither of the
previous approaches is acceptable. Default acceptance is not
secure, and a manual per device methods do not scale. Here, the
registrar is provided a priori with a list of identifiers of
devices that belong to the network. This list can be extracted
from an inventory database, or sales records. If a device is
detected that is not on the list of known devices, it can still be
manually accepted using the per device acceptance methods.</t>
<t>Automated Whitelist: an automated process that builds the
necessary whitelists and inserts them into the larger network
domain infrastructure is plausible. Once set up, no human
intervention is required in this process. Defining the exact
mechanisms for this is out of scope although the registrar
authorization checks is identified as the logical integration
point of any future work in this area.</t>
</list></t>
<t>None of these approaches require the network to have permanent
Internet connectivity. Even when the Internet based MASA service is
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
enrol later. This supports use cases where the domain network may be
entirely isolated during device deployment.</t>
<t>Additional policy can be stored for future authorization decisions.
For example an expected deployment time window or that a certain Proxy
must be used.</t>
</section>
<section title="Automatic Enrollment of Devices">
<t>The approach outlined in this document provides a secure zero-touch
method to enrol new devices without any pre-staged configuration. New
devices communicate with already enrolled devices of the domain, which
proxy between the new device and a Registrar. As a result of this
completely automatic operation, all devices obtain a domain based
certificate.</t>
</section>
<section title="Secure Network Operations">
<t>The certificate installed in the previous step can be used for all
subsequent operations. For example, to determine the boundaries of the
domain: If a neighbor has a certificate from the same trust anchor it
can be assumed "inside" the same organization; if not, as outside. See
also <xref target="boundary"></xref>. The certificate can also be used
to securely establish a connection between devices and central control
functions. Also autonomic transactions can use the domain certificates
to authenticate and/or encrypt direct interactions between devices.
The usage of the domain certificates is outside scope for this
document.</t>
</section>
</section>
<section anchor="ProtocolDetails" title="Protocol Details">
<t>For simplicity the bootstrapping protocol is described as extensions
to EST [RFC7030].</t>
<t>EST provides a bootstrapping mechanism for new entities that are
configured with the URI of the EST server such that the Implicit TA
database can be used to authenticate the EST server. Alternatively EST
clients can "engage a human user to authorize the CA certificate using
out-of-band data such as a CA certificate". EST does not provide a
completely automated method of bootstrapping the PKI as both of these
methods require some user input (either of the URI or authorizing the CA
certificate).</t>
<t>This section details additional EST functionality that support
automated bootstrapping of the public key infrastructure. These
additions provide for fully automated bootstrapping. These additions are
to be optionally supported by the EST server within the same .well-known
URI tree as the existing EST URIs.</t>
<t>The "New Entity" is the EST client and the "Registrar" is the EST
server.</t>
<t>The extensions for the client are as follows:</t>
<t><list style="symbols">
<t>The New Entity provisionally accept the EST server certificate
during the TLS handshake as detailed in EST section 4.1.1
("Bootstrap Distribution of CA Certificates").</t>
<t>The Registrar requests and validates the Audit Token from the
vendor authorized MASA service. </t>
<t>The New Entity requests and validates the Audit Token as
described below. At this point the New Entity has sufficient
information to validate domain credentials.</t>
<t>The New Entity calls the EST defined /cacerts method to obtain
the current CA certificate. These are validated using the Audit
Token.</t>
<t>The New Entity completes bootstrapping as detailed in EST section
4.1.1.</t>
</list></t>
<t>These extensions could be implemented as an independent protocol from
EST but since the overlap with basic enrollment is extensive,
particularly with respect to client authorization, they are presented
here as additions to EST.</t>
<t>In order to obtain a validated Audit Token and Audit Log the
Registrar contacts the MASA service Service using REST calls:</t>
<figure>
<artwork><![CDATA[ +-----------+ +----------+ +-----------+ +----------+
| New | | | | | | |
| Entity | | Proxy | | Registrar | | Vendor |
| | | | | | | |
++----------+ +--+-------+ +-----+-----+ +--------+-+
| | | |
| | | |
| (D)TLS hello | | |
Establish +---------------> (D)TLS hello | |
(D)TLS | |---------------> |
connection | (forwarding) | |
| Server Cert <---------------+ |
<---------------+ | |
| Client Cert | | |
+-------------------------------> |
| | | |
HTTP REST | POST /requestaudittoken | |
Data +--------------------nonce------> |
| . | /requestaudittoken
| . +---------------->
| <----------------+
| | /requestauditlog
| +---------------->
| audit token or owner voucher <----------------+
<-------------------------------+ |
| (optional config information) | |
| . | |
| . | |]]></artwork>
<postamble>Figure 5</postamble>
</figure>
<t>In some use cases the Registrar may need to contact the Vendor in
advanced, for example when the target network is airgapped. The
nonceless request format is provided for this and the resulting flow is
slightly different. The security differences associated with not
knowning the nonce are discussed below:</t>
<figure>
<artwork><![CDATA[ +-----------+ +----------+ +-----------+ +----------+
| New | | | | | | |
| Entity | | Proxy | | Registrar | | Vendor |
| | | | | | | |
++----------+ +--+-------+ +-----+-----+ +--------+-+
| | | |
| | | |
| | | /requestaudittoken
| | (nonce +---------------->
| | unknown) <----------------+
| | | /requestauditlog
| | +---------------->
| | <----------------+
| (D)TLS hello | | |
Establish +---------------> (D)TLS hello | |
(D)TLS | |---------------> |
connection | (forwarding) | |
| SerVer Cert <---------------+ |
<---------------+ | |
| Client Cert | | |
+-------------------------------> |
| | | |
HTTP REST | POST /requestaudittoken | |
Data +----------------------nonce----> (discard |
| audit token or owner Voucher | nonce) |
<-------------------------------+ |
| (optional config information) | |
| . | |
| . | |]]></artwork>
<postamble>Figure 6</postamble>
</figure>
<t></t>
<section title="Request Audit Token">
<t>When the New Entity reaches the EST section 4.1.1 "Bootstrap
Distribution of CA Certificates" state but wishes to proceed in a
fully automated fashion it makes a request for a MASA authorization
token from the Registrar.</t>
<t>This is done with an HTTPS POST using the operation path value of
"/requestaudittoken".</t>
<t>The request format is JSON object containing a nonce.</t>
<t>Request media type: application/auditnonce</t>
<t>Request format: a JSON file with the following:</t>
<t>{"nonce":"<64bit nonce value>",
"OwnershipValidation":boolean}</t>
<t>[[EDNOTE: exact format TBD. There is an advantage to having the
client sign the nonce (similar to a PKI Certification Signing Request)
since this allows the MASA service to confirm the actual device
identity. It is not clear that there is a security benefit from this
since its the New Entity that verifies the nonce.]]</t>
<t>The Registrar validates the client identity as described in EST
[RFC7030] section 3.3.2. The registrar performs authorization as
detailed in <xref target="AcceptingTheEntity"></xref>. If
authorization is successful the Registrar obtains an Audit Token from
the MASA service (see <xref target="RequestAuditToken"></xref>).</t>
<t>The recieved MASA authorization token is returned to the New
Entity.</t>
<t>As indicated in EST [RFC7030] the bootstrapping server can redirect
the client to an alternate server. If the New Entity authenticated the
Registrar using the well known URI method then the New Entity MUST
follow the redirect automatically and authenticate the new Registrar
against the redirect URI provided. If the New Entity had not yet
authenticated the Registrar because it was discovered and was not a
known-to-be-valid URI then the new Registrar must be authenticated
using one of the two autonomic methods described in this document.
</t>
</section>
<section anchor="RequestAuditToken"
title="Request Audit Token from MASA">
<t>The Registrar requests the Audit Token from the MASA service using
a REST interface. For simplicity this is defined as an optional EST
message between the Registar and an EST server running on the MASA
service although the Registrar is not required to make use of any
other EST functionality when communicating with the MASA service. (The
MASA service MUST properly reject any EST functionality requests it
does not wish to service; a requirement that holds for any REST
interface).</t>
<t>This is done with an HTTP POST using the operation path value of
"/requestaudittoken".</t>
<t>The request format is a JSON object optionally containing the nonce
value (as obtained from the bootstrap request) and the IEEE 802.1AR
identity of the device as a serial number (the full certificate is not
needed and no proof-of-possession information for the device identity
is included). The New Entity's serial number is extracted from the
subject name :</t>
<t>{"nonce":"<64bit nonce value>", "serialnumber",
"<subjectname/subjectaltname serial number>"}</t>
<t>Inclusion of the nonce is optional because the Registar might
request an authorization token when the New Entity is not online, or
when the target bootstrapping environment is not on the same network
as the MASA server.</t>
<t>The JSON message information is encapsulated in a PKCS7 signed data
structure that is signed by the Registrar. The entire certificate
chain, up to and including the Domain CA, MUST be included in the
PKCS7.</t>
<t>The MASA service checks the internal consistency of the PKCS7 but
is unable to actually authenticate the domain identity information.
The domain is not know to the MASA server in advance and a shared
trust anchor is not implied. The MASA server verifies that the PKCS7
is signed by a Registrar (by checking for the cmc-idRA field in the
Registrar certificate) certificate that was issued by a the root
certificate included in the PKCS7. This is sufficient for the MASA
service to ensure that the Registar is in fact an authorized Registar
of the unknown domain. </t>
<t>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
authorization token and to update the audit log.</t>
<t>[[EDNOTE: The authorization token response format needs to be
defined here. It consists of the nonce, if supplied, the serialnumber
and the trust anchor of the domain. For example:</t>
<t>{"nonce":"<64bit nonce value>", "serialnumber",
"<subjectname/subjectaltname serial number>","domainID":}</t>
<t>]]</t>
<t>[[EDNOTE: This assumes the Registrar can extract the serial number
successfullly from the cilent certificate. The RFC4108
hardwareModuleName is the best known location.]]</t>
<t>[[EDNOTE: There is a strong similarity between this and the
previous section. Both involve requesting the Audit Token from the
upstream element. Because there are differing requirements on the data
submitted and the signing of that data they are specified in distinct
sections. The design team should have a meeting to discuss how to
unify these sections or make the distinctions more clear]]</t>
</section>
<section title="Basic Configuration Information Package">
<t>When the MASA authorization token is returned to the New Entity an
arbitrary information package can be signed and delivered along side
it. This is signed by the Domain Registar. The New Entity first
verifies the Audit Token and, if it is valid, then uses the domain's
TA to validate the Information Package.</t>
<t>[[EDNOTE: The package format to be specified here. Any signed
format is viable and ideally one can simply be specified from netconf.
The Registar knows the New Entity device type from the 802.1AR
credential and so is able to determine the proper format for the
configuration]]</t>
</section>
<section title="Request MASA authorization log">
<t>A registrar requests the MASA authorization log from the MASA
service using this EST extension.</t>
<t>This is done with an HTTP GET using the operation path value of
"/requestMASAlog".</t>
<t>The log data returned is a file consisting of all previous log
entries. For example:</t>
<t><figure>
<artwork><![CDATA["log":[
{"date":"<date/time of the entry>"},
"domainID":"<domainID as extracted from the root
certificate within the PKCS7 of the
audit token request>",
"nonce":"<any nonce if supplied (or NULL)>"},
{"date":"<date/time of the entry>"},
"domainID":"<domainID as extracted from the root
certificate within the PKCS7 of the
audit token request>",
"nonce":"<any nonce if supplied (or NULL)>"},
] ]]></artwork>
</figure></t>
<t>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
required in the response. All nonce-less entries for the same domainID
can be condensed into the single most recent nonceless entry.</t>
<t>The Registrar uses this log information to make an informed
decision regarding the continued bootstrapping of the New Entity.</t>
<t>[[EDNOTE: certificate transparency might offer an alternative log
entry method]]</t>
</section>
</section>
<section title="Reduced security operational modes">
<t>A common requirement of bootstrapping is to support less secure
operational modes for support specific use cases. The following sections
detail specific ways that the New Entity, Registrar and MASA can be
configured to run in a less secure mode for the indicated reasons.</t>
<section title="New Entity security reductions">
<t>Although New Entity can choose to run in less secure modes this is
MUST NOT be the default state because it permanently degrades the
security for all other uses cases. </t>
<t>The device may have an operational mode where it skips Audit Token
validation one time. For example if a physical button is depressed
during the bootstrapping operation. This can be useful if the MASA
service is unavailable. This behavior SHOULD be available via local
configuration or physical presence methods to ensure new entities can
always be deployed even when autonomic methods fail.</t>
<t>It is RECOMMENDED that this only be available if hardware assisted
NEA [RFC5209] is supported.</t>
</section>
<section title="Registrar security reductions">
<t>The Registrar can choose to accept devices using less secure
methods. These methods are RECOMMENDED when low security models are
needed as the security decisions are being made by the local
administrator:<list style="numbers">
<t>The registrar MAY choose to accept all devices, or all devices
of a particular type, at the administrator's discretion. This
could occur when informing the Registrar of unique identifiers of
new entities might be operationally difficult.</t>
<t>The registrar MAY choose to accept devices that claim a unique
identity without the benefit of authenticating that claimed
identity. This could occur when the New Entity does not include an
IEEE 802.1AR factory installed credential.</t>
<t>The registrar MAY request nonce-less Audit Tokens from the MASA
service. These tokens can then be transmitted to the Registrar and
stored until they are needed during bootstrapping operations. This
is for use cases where target network is protected by an air gap
and therefore can not contact the MASA service during New Entity
deployment.</t>
<t>The registrar MAY ignore unrecognized nonce-less Audit Log
entries. This could occur when used equipment is purchased with a
valid history being deployed in air gap networks that required
permanent Audit Tokens. </t>
</list></t>
</section>
<section title="MASA security reductions">
<t>Lower security modes chosen by the MASA service effect all device
deployments unless paired with strict device ownership validation, in
which case these modes can be provided as additional features for
specific customers. The MASA service can choose to run in less secure
modes by:</t>
<t><list style="numbers">
<t>Not enforcing that a Nonce is in the Audit Token. This results
in distribution of Audit Tokens that never expire and effectly
makes the Domain an always trusted entity to the New Entity during
any subsequent bootstrapping attempts. That this occured is
captured in the log information so that the Domain registrar can
make appropriate security decisions when a new device joins the
domain. This is useful to support use cases where Registrars might
not be online during actual device deployment. Because this
results in long lived Audit Tokens and do not require the proof
that the device is online this is only accepted when the Registrar
is authenticated by the MASA server and authorized to provide this
functionality. The MASA server is RECOMMENDED to use this
functionality only in concert with Ownership Validation tracking.
</t>
<t>Not verifying ownership before responding with an Audit Token.
This is expected to be a common operational model because doing so
relieves the vendor providing MASA services from having to
tracking ownership during shipping and supply chain and allows for
a very low overhead MASA service. The Registrar uses the audit log
information as a defense in depth strategy to ensure that this
does not occur unexpectedly (for example when purchasing new
equipment the Registrar would throw an error if any audit log
information is reported). </t>
</list></t>
</section>
</section>
<section title="Security Considerations">
<t>In order to support a wide variety of use cases, devices can be
claimed by a registrar without proving possession of the device in
question. This would result in a nonceless, and thus always valid,
claim. Or would result in an invalid nonce being associated with a
claim. The MASA service is required to authenticate such Registrars but
no programmatic method is provided to ensure good behavior by the MASA
service. Nonceless entries into the audit log therefore permanently
reduce the value of a device because future Registrars, during future
bootstrap attempts, would now have to be configured with policy to
ignore previously (and potentially unknown) domains.</t>
<t>Future registrars are recommended to take the audit history of a
device into account when deciding to join such devices into their
network. If the MASA server were to have allowed a significantly large
number of claims this might become onerous to the MASA server which must
maintain all the extra log entries. Ensuring the registar is
representative of a valid customer domain even without validating
ownership helps to mitigate this.</t>
<t>It is possible for an attacker to send an authorization request to
the MASA service directly after the real Registrar obtains an
authorization log. If the attacker could also force the bootstrapping
protocol to reset there is a theoretical opportunity 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 prevention mechanisms
include:</t>
<t><list style="symbols">
<t>Per device rate limits on the MASA service ensure such timing
attacks are difficult.</t>
<t>In the advent of an unexpectadly lost bootstrapping connection
the Registrar repeats the request for audit log information. </t>
</list></t>
<t>As indicated in EST [RFC7030] the connection is provisional and
untrusted until the server is successfully authorized. If the server
provides a redirect response the client MUST follow the redirect but the
connection remains provisional. If the client uses a well known URI for
contacting a well known Registrar the EST Implicit Trust Anchor database
is used as is described in RFC6125 to authenticate the well known URI.
In this case the connection is not provisional and RFC6125 methods can
be used for each subsequent redirection. </t>
<t>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 out
of business). This functionality provides benefits such as theft
resistance, but it also implies an operational risk to the Domain that
Vendor behavior could limit future bootstrapping of the device by the
Domain. This can be mitigated by Registrars that request nonce-less
authorization tokens.</t>
<section title="Trust Model">
<t>[[EDNOTE: (need to describe that we need to trust the device h/w.
To be completed.)]]</t>
</section>
</section>
<section title="Acknowledgements">
<t>We would like to thank the various reviewers for their input, in
particular Markus Stenberg, Brian Carpenter, Fuyu Eleven.</t>
</section>
</middle>
<back>
<references title="Normative References">
&RFC2119;
&RFC7030;
<reference anchor="IDevID"
target="http://standards.ieee.org/findstds/standard/802.1AR-2009.html">
<front>
<title>IEEE 802.1AR Secure Device Identifier</title>
<author surname="IEEE Standard"></author>
<date month="December" year="2009" />
</front>
</reference>
</references>
<references title="Informative References">
&I-D.behringer-autonomic-network-framework;
&I-D.irtf-nmrg-autonomic-network-definitions;
<reference anchor="imprinting"
target="https://en.wikipedia.org/wiki/Imprinting_(psychology)">
<front>
<title>Wikipedia article: Imprinting</title>
<author surname="Wikipedia"></author>
<date month="July" year="2015" />
</front>
</reference>
<!-- http://dictionary.reference.com/cite.html?qh=pledge&ia=luna
@article {Dictionary.com2015,
title = {Dictionary.com Unabridged},
month = {Jul},
day = {03},
year = {2015},
url = {http://dictionary.reference.com/browse/pledge},
} -->
<reference anchor="pledge"
target="http://dictionary.reference.com/browse/pledge">
<front>
<title>Dictionary.com Unabridged</title>
<author surname="Dictionary.com"></author>
<date month="July" year="2015" />
</front>
</reference>
</references>
<section title="Editor notes">
<t>[[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]]</t>
<t>Change Discussion:</t>
<t><list style="hanging">
<t hangText="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 </t>
<t hangText="02">Moved sections for readability, Updated
introduction, simplified functional overview to avoid distractions
from optional elements, addressed updated security considerations,
fleshed out state machines.</t>
</list></t>
<t>The following is a non-prioritized list of work items currently
identified:<list style="symbols">
<t>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</t>
<t>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.</t>
<t>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).</t>
<t></t>
</list></t>
</section>
</back>
</rfc>
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