NETCONF Working Group K. Watsen
Internet-Draft Juniper Networks
Intended status: Standards Track M. Abrahamsson
Expires: September 17, 2016 T-Systems
March 16, 2016
Zero Touch Provisioning for NETCONF or RESTCONF based Management
draft-ietf-netconf-zerotouch-07
Abstract
This draft presents a secure technique for establishing a NETCONF or
RESTCONF connection between a newly deployed device, configured with
just its factory default settings, and its deployment specific
network management system (NMS).
Editorial Note (To be removed by RFC Editor)
This draft contains many placeholder values that need to be replaced
with finalized values at the time of publication. This note
summarizes all of the substitutions that are needed. Please note
that no other RFC Editor instructions are specified anywhere else in
this document.
This document contains references to other drafts in progress, both
in the Normative References section, as well as in body text
throughout. Please update the following references to reflect their
final RFC assignments:
o draft-ietf-netconf-call-home
o draft-ietf-netconf-restconf
o draft-ieft-netconf-server-model
o draft-pritikin-anima-bootstrapping-keyinfra
Artwork in this document contains shorthand references to drafts in
progress. Please apply the following replacements:
o "XXXX" --> the assigned RFC value for this draft
Artwork in this document contains placeholder values for the date of
publication of this draft. Please apply the following replacement:
o "2016-03-16" --> the publication date of this draft
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The following one Appendix section is to be removed prior to
publication:
o Appendix A. Change Log
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
1.3. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 7
2. Guiding Principles . . . . . . . . . . . . . . . . . . . . . 7
2.1. Trust Anchors . . . . . . . . . . . . . . . . . . . . . . 8
2.2. Conveying Trust . . . . . . . . . . . . . . . . . . . . . 8
2.3. Ownership . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Information Types . . . . . . . . . . . . . . . . . . . . . . 9
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3.1. Redirect Information . . . . . . . . . . . . . . . . . . 9
3.2. Bootstrap Information . . . . . . . . . . . . . . . . . . 10
4. Sources for Bootstrapping Data . . . . . . . . . . . . . . . 11
4.1. Removable Storage . . . . . . . . . . . . . . . . . . . . 12
4.2. DNS Server . . . . . . . . . . . . . . . . . . . . . . . 12
4.3. DHCP Server . . . . . . . . . . . . . . . . . . . . . . . 14
4.4. Bootstrap Server . . . . . . . . . . . . . . . . . . . . 15
5. Workflow Overview . . . . . . . . . . . . . . . . . . . . . . 15
5.1. Onboarding and Ordering Devices . . . . . . . . . . . . . 15
5.2. Owner Stages the Network for Bootstrap . . . . . . . . . 18
5.3. Device Powers On . . . . . . . . . . . . . . . . . . . . 20
6. Device Details . . . . . . . . . . . . . . . . . . . . . . . 23
6.1. Factory Default State . . . . . . . . . . . . . . . . . . 23
6.2. Boot Sequence . . . . . . . . . . . . . . . . . . . . . . 25
6.3. Processing a Source of Boostrapping Data . . . . . . . . 26
6.4. Validating Signed Data . . . . . . . . . . . . . . . . . 27
6.5. Processing Redirect Information . . . . . . . . . . . . . 28
6.6. Processing Bootstrap Information . . . . . . . . . . . . 28
7. YANG-defined API and Artifacts . . . . . . . . . . . . . . . 29
7.1. Module Overview . . . . . . . . . . . . . . . . . . . . . 29
7.2. API Examples . . . . . . . . . . . . . . . . . . . . . . 31
7.2.1. Unsigned Redirect Information . . . . . . . . . . . . 31
7.2.2. Signed Redirect Information . . . . . . . . . . . . . 32
7.2.3. Unsigned Bootstrap Information . . . . . . . . . . . 35
7.2.4. Signed Bootstrap Information . . . . . . . . . . . . 37
7.2.5. Progress Notifications . . . . . . . . . . . . . . . 41
7.3. Artifact Examples . . . . . . . . . . . . . . . . . . . . 43
7.3.1. Signed Redirect Information . . . . . . . . . . . . . 43
7.3.2. Signed Bootstrap Information . . . . . . . . . . . . 45
7.3.3. Owner Certificate . . . . . . . . . . . . . . . . . . 46
7.3.4. Ownership Voucher . . . . . . . . . . . . . . . . . . 48
7.4. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 48
8. Security Considerations . . . . . . . . . . . . . . . . . . . 61
8.1. Immutable storage for trust anchors . . . . . . . . . . . 61
8.2. Clock Sensitivity . . . . . . . . . . . . . . . . . . . . 61
8.3. Blindly authenticating a bootstrap server . . . . . . . . 61
8.4. Entropy loss over time . . . . . . . . . . . . . . . . . 62
8.5. Serial Numbers . . . . . . . . . . . . . . . . . . . . . 62
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 62
9.1. The BOOTP Manufacturer Extensions and DHCP Options
Registry . . . . . . . . . . . . . . . . . . . . . . . . 62
9.1.1. DHCP v4 Option . . . . . . . . . . . . . . . . . . . 62
9.1.2. DHCP v6 Option . . . . . . . . . . . . . . . . . . . 63
9.2. The IETF XML Registry . . . . . . . . . . . . . . . . . . 63
9.3. The YANG Module Names Registry . . . . . . . . . . . . . 63
10. Other Considerations . . . . . . . . . . . . . . . . . . . . 63
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 64
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 64
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12.1. Normative References . . . . . . . . . . . . . . . . . . 64
12.2. Informative References . . . . . . . . . . . . . . . . . 65
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 67
A.1. Ownership Voucher . . . . . . . . . . . . . . . . . . . . 67
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 69
B.1. ID to 00 . . . . . . . . . . . . . . . . . . . . . . . . 69
B.2. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 70
B.3. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 70
B.4. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 70
B.5. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 70
B.6. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 71
B.7. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 71
B.8. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 71
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 71
1. Introduction
A fundamental business requirement for any network operator is to
reduce costs where possible. For network operators, deploying
devices to many locations can be a significant cost, as sending
trained specialists to each site to do installations is both cost
prohibitive and does not scale.
This document defines bootstrapping strategies enabling devices to
securely obtain bootstrapping data with no installer input, beyond
physical placement and connecting network and power cables. The
ultimate goal of this document is to enable a secure NETCONF
[RFC6241] or RESTCONF [draft-ietf-netconf-restconf] connection to the
deployment specific network management system (NMS).
1.1. Use Cases
o Connecting to a remotely administered network
This use-case involves scenarios, such as a remote branch
office or convenience store, whereby a device connects as an
access gateway to an ISP's network. Assuming it is not
possible to customize the ISP's network to provide any
bootstrapping support, and with no other nearby device to
leverage, the device has no recourse but to reach out to an
Internet-based bootstrap server to bootstrap off of.
o Connecting to a locally administered network
This use-case covers all other scenarios and differs only in
that the device may additionally leverage nearby devices, which
may direct it to use a local service to bootstrap off of. If
no such information is available, or the device is unable to
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use the information provided, it can then reach out to network
just as it would for the remotely administered network use-
case.
1.2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in the
sections below are to be interpreted as described in RFC 2119
[RFC2119].
This document uses the following terms:
Artifact: The term "artifact" is used throughout to represent the
encoded form of any of Bootstrap Information, Redirect
Information, Owner Certificate, and Ownership Voucher. The
Bootstrap Server defined in this document is purposed to provide
these artifacts, but they can also be provided by any other
mechanism (removable storage, DHCP server, etc.), secure or not,
so long as the principles for when the bootstrapping data needs
to be signed is enforced.
Bootstrapping Data: The term "bootstrapping data" is used throughout
this document to refer to the collection of data that a device
may obtain from any source of bootstrapping data, including a
removable storage device, a DHCP server, a DNS server, a Redirect
Server, and/or a Bootstrap Server. This data includes both
Redirect Information as well as Bootstrap Information.
Bootstrap Information: The term "bootstrap information" is used
herein to refer to bootstrapping data that is used to guide a
device to install a specific boot-image and commit a specific
configuration. This data is formally defined by the "bootstrap-
information" container in the YANG module defined in Section 7.4.
Bootstrap Server: The term "bootstrap server" is used within this
document to mean any RESTCONF server implementing the YANG module
defined in Section 7.4.
Device: The term "device" is used throughout this document to refer
to the network element that needs to be bootstrapped. The device
is the RESTCONF client to a Bootstrap Server (see above) and, at
the end of bootstrapping process, the device is the NETCONF or
RESTCONF server to a deployment-specific NMS. See Section 6 for
more information about devices.
Initial Secure Device Identifier (IDevID): The term "IDevID" is
defined in [Std-802.1AR-2009] as "the Secure Device Identifier
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(DevID) installed on the device by the manufacturer". By
example, an IDevID certificate, signed by the manufacturer may
encode a manufacturer assigned unique identifier (e.g., serial
number) and a public key matching a private key held within a TPM
chip embedded within the device.
Network Management System (NMS): The acronym "NMS" is used
throughout this document to refer to the deployment specific
management system that the bootstrapping process is responsible
for introducing devices to. From a device's perspective, when
the bootstrapping process has completed, the NMS is a NETCONF or
RESTCONF client.
Owner: See Rightful Owner.
Owner Certificate: The term "owner certificate" is used in this
document to represent an X.509 certificate, signed by the
device's manufacturer or delegate, that binds an owner identity
to the owner's private key, which the owner can subsequently use
to sign artifacts. The owner certificate is used by devices only
when validating owner signatures on signed data. This data is
formally defined by the "owner-certificate" container in the YANG
module defined in Section 7.4.
Ownership Voucher: The term "ownership voucher" is used in this
document to represent manufacturer-specific artifact, signed by
the device's manufacturer or delegate, binding an owner identity
(same as in the Owner Certificate) to one or more device
identities (e.g., serial numbers). The ownership voucher is used
by devices only when validating owner signatures on signed data.
This data is formally defined by the "ownership-voucher"
container in the YANG module defined in Section 7.4.
Redirect Information: The term "redirect information" is used herein
to refer to bootstrapping data that redirects a device to connect
to another Bootstrap Server. This data is formally defined by
the "redirect-information" container in the YANG module defined
in Section 7.4.
Redirect Server: The term "redirect server" is used to refer to a
Bootstrap Server that only returns Redirect Information. A
Redirect Server is particularly useful when hosted by a
manufacturer, to redirect devices to a deployment-specific
bootstrap server.
Rightful Owner: The term "rightful owner" is used herein to refer to
the person or organization that purchased a device. Ownership is
conveyed by a chain of trust established by a sequence of
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authenticated secure connections and/or Signed Data, as described
in Section 2.3.
Signed Data: The term "signed data" is used throughout to mean
either Redirect Information or Bootstrap Information that has
been signed by a device's Rightful Owner's private key. These
artifacts MUST be signed whenever communicated using an unsecured
mechanism. Any time data is signed, it MUST be presented along
with an Owner Certificate and Ownership Voucher, which themselves
do not need to be signed by the Rightful Owner's private key, as
they already are signed by the manufacturer.
Unsigned Data: The term "unsigned data" is used throughout to mean
either Redirect Information or Bootstrap Information that has not
been signed by a device's Rightful Owner's private key. The
option to use unsigned data MUST only be available only when the
data is obtained over an authenticated secure connection, such as
to a Bootstrap Server.
1.3. Tree Diagrams
A simplified graphical representation of the data models is used in
this document. The meaning of the symbols in these diagrams is as
follows:
o Brackets "[" and "]" enclose list keys.
o Braces "{" and "}" enclose feature names, and indicate that the
named feature must be present for the subtree to be present.
o Abbreviations before data node names: "rw" (read-write) represents
configuration data and "ro" (read-only) represents state data.
o Symbols after data node names: "?" means an optional node, "!"
means a presence container, and "*" denotes a list and leaf-list.
o Parentheses enclose choice and case nodes, and case nodes are also
marked with a colon (":").
o Ellipsis ("...") stands for contents of subtrees that are not
shown.
2. Guiding Principles
This section provides overarching principles guiding the solution
presented in this document.
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2.1. Trust Anchors
A trust anchor is used in cryptography to represent an entity in
which trust is implicit and not derived. In public key
infrastructure using X.509 certificates, a root certificate is the
trust anchor from which the chain of trust is derived. The solution
presented in this document requires that all the entities involved
possess specific trust anchors in order to ensure mutual
authentication throughout the zero touch bootstrapping process.
2.2. Conveying Trust
A device in its factory default state possesses a limited set of
manufacturer specified trust anchors. In this document, there are
two types of trust anchors of interest. The first type of trust
anchor is used to authenticate a secure connection to, for instance,
a manufacturer-hosted Internet-based bootstrap server. The second
type of trust anchor is used to authenticate manufacturer-signed
data, such as the owner certificate and ownership voucher described
in this document.
In the first case, trust is conveyed by the device first
authenticating the secure connection to the server and then by the
device trusting that the server would only provide data that its
rightful owner staged for it to find. For instance, the staged data
may be redirect information that includes the IP address and another
trust anchor certificate for the deployment-specific bootstrap
server. The device can then use the discovered trust anchor to
authenticate a secure connection to the deployment-specific bootstrap
server.
In the second case, trust is conveyed by the device first
authenticating the owner certificate and ownership voucher and then,
using the public key in the owner certificate, authenticate a signed
artifact, such as redirect information. And again the device can use
the discovered trust anchor to authenticate a secure connection to
the deployment-specific bootstrap server.
2.3. Ownership
The goal of this document is to enable a device to connect with its
rightful owner's NMS. This entails the manufacturer being able to
track who owns which devices (out of the scope of this document), as
well as an ability to convey that information to devices (in scope).
Matching the two ways to convey trust, this document provides both a
protocol oriented solution as well as an artifact based solution for
conveying ownership.
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The protocol based solution conveys ownership by the device first
authenticating a secure connection to a bootstrap server and then
trusting that the server would only provide data that its rightful
owner staged for it to find. In the case of a manufacturer-hosted
bootstrap server, the manufacturer takes the onus of ensuring that
only data configured by the device's rightful owner is made available
to the device. With this approach, the assignment of a device to an
owner is ephemeral, with the manufacturer being able is reassign the
device at any time.
The artifact based solution, which is ideal for when a secure
connection cannot be established (e.g., loading data off a removable
storage device), involves the manufacturer signing an owner
certificate and then later, when the ownership for devices is
established, the manufacturer signing a voucher that assigns those
devices to the owner, and then the owner using their private key to
sign the artifacts. Thus, from the device's perspective, it can use
the presented ownership voucher to validate the presented owner
certificate, which it can then use to validate the signature over the
presented artifact. With this approach, the assignment of a device
to an owner is somewhat permanent, as the ability for the
manufacturer to reliably distribute CRLs to revoke assignments not
possible when the devices do not contain a real time clock (see
Section 8 for information about this).
3. Information Types
This document presumes there exists two types of zero touch
information: redirect information and bootstrap information.
Both information types MAY be signed or unsigned, though in some
contexts, as described below, the bootstrap information type MUST be
signed, as there is not otherwise possible for a device to process
it, even in a degraded manner.
Both information types MAY be encoded using various technologies.
This document only tries to support the encodings supported by
RESTCONF, namely XML and JSON, while leaving extensibility mechanisms
in place to support future extensions.
3.1. Redirect Information
Redirect information provides a list of bootstrap servers, where each
list entry includes the bootstrap server's hostname or IP address, an
optional port, and an optional trust anchor certificate. The
redirect information type is formally defined by the "redirect-
information" grouping defined in Section 7.4.
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As its name suggests, redirect information guides the device to
attempt to connect to the specified bootstrap servers, until finding
one that it can bootstrap itself off of. Redirect information is
primarily distinguished from standard HTTP redirect by its optional
inclusion of trust anchors, in which case it may be referred to as a
"secure redirect".
Redirect information may be signed or unsigned. If the redirect
information is not signed, then the device MUST NOT trust any
included trust anchor certificates, equivalent to had they not been
specified at all.
When redirect information is signed, then the device MUST establish a
secure connection to the specified bootstrap server using X.509
certificate path validation ([RFC6125], Section 6) to the specified
trust anchor, and MUST send its IDevID certificate in the form of a
client certificate, and MUST POST notifications to the bootstrap
server. Furthermore, in this case, any data obtained from the
bootstrap server MAY NOT be signed, as it is already trusted by
virtue of the secure connection.
When redirect information is unsigned, or doesn't specify a trust
anchor certificate, and the device connects to the bootstrap server
by blindly accepting the bootstrap server's TLS certificate, the
device MUST NOT send its IDevID certificate in the form of a client
certificate, and MUST NOT POST notifications to the bootstrap server.
Furthermore, the device MUST assert that any data obtained from the
bootstrap server is signed, much as it would assert bootstrap
information loaded from a removable storage device is signed.
3.2. Bootstrap Information
Bootstrap information provides all the data neccessary for the device
to bootstrap itself, in order to be considered ready to be managed.
This data includes criteria about the boot image the device MUST be
running, an initial configuration the device MUST commit, and an
optional script that, if specified, the device MUST successfully
execute. Descriptions for these follow:
o The boot image creteria is used to ensure the device is running a
version of software that will be able to understand the
configuration and script, if any. The criteria is flexible in
that it allows for both an absolute specification of the boot
image a device MUST be running, or just a list of YANG modules
that the device MUST be able to understand.
o The configuration can configure any aspect of the device but, in
order to fulfill the goal of the zero touch bootstrapping process,
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to establish a NETCONF or RESTCONF connection to the device's
deployment specific NMS, the configuration MUST minimally
configure an administrator account (e.g., username, SSH public
key) that the NMS can use to log into the device with, and
configure the device to either listen for inbound NETCONF/RESTCONF
connections, or for the device to initiate an outbound NETCONF/
RESTCONF call home connection [draft-ietf-netconf-call-home]. The
bootstrap information examples provided in Section 7.2.3,
Section 7.2.4, and Section 7.3.2 all illustrate a minimal initial
configuration.
o The script, if any, is used to perform non-configuration related
activities deemed necessary. The script format is manufacturer
specific. Requirements for scripts, such as exit status codes,
are defined in the "script" node's description statement provided
in the YANG module defined in Section 7.4.
Bootstrap information may be signed or unsigned. If the device is
accessing the bootstrap server in an unsecured manner (e.g., from a
removable storage device or from an untrusted server), then the
bootstrap information MUST be signed, otherwise it MAY be signed.
Devices MUST process bootstrap information as is specified in
Section 6.6.
The bootstrap information type is formally defined by the "bootstrap-
information" grouping defined in Section 7.4.
4. Sources for Bootstrapping Data
Following are the sources of bootstrapping data that are referenced
by the workflows presented in Section 5.3. Other sources of
bootstrapping data may be defined in future documents, so long as the
principles for when the bootstrapping data needs to be signed are
enforced.
Each of the descriptions below show how the bootstrapping data needs
to be handled in a manner consistent with the guiding principles in
Section 2.
For devices supporting more than one source for bootstrapping data,
no particular sequencing order has to be observed, as each source is
equally secure, in that the chain of trust always goes back to the
same root of trust, the manufacturer. That said, from a privacy
perspective, it is RECOMMENDED that a device try to leverage local
sources before remote source. For this reason, all the examples used
in this document assume a removable storage device is accessed before
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a DHCP server, which itself is accessed before an Internet-based
bootstrap server.
4.1. Removable Storage
A device MAY attempt to acquire bootstrapping data from a directly
attached removable storage device. The bootstrapping data MAY be
either redirect information or bootstrap information.
If redirect information is provided, it SHOULD be signed, as
removable storage devices are not trustworthy. However, if the
redirect information is not signed, then the device MUST NOT trust
any included trust anchor certificates, which means that the device
would have to establish an unsecured connection to the specified
bootstrap servers. See Section 3.1 for more about this case.
If bootstrap information is provided, it MUST be signed, as removable
storage devices are not trustworthy and there is no option to process
the data in a degraded manner, unlike as with redirect information.
For the case when the signed bootstrap information is provided, it is
notable that even the raw boot image file itself can be on the
removable storage device, by letting the URL reference a local file
(e.g., file:///path/to/file), making use of the removable storage
device a fully self-standing bootstrapping solution.
However, regardless if the boot image file resides on the local
storage device or if the device must follow the URL to download it
from a remote (and unsecured) server, the device MUST authenticate
the validity of the boot image file, either by using the MD5 and SHA
fingerprints supplied by the bootstrapping information, or by virtual
of the boot image containing an embedded signature, if any.
4.2. DNS Server
A device MAY attempt to acquire bootstrapping data from a DNS server
using DNS-based service discovery (DNS-SD) [RFC6763]. Due to DNS
packet size limitations the bootstrapping data provided using DNS-SD
can only be redirect information, no support for bootstrap
information using DNS-SD is provided by this document.
The redirect information provided SHOULD be signed, as this document
does not define a solution to secure the DNS records using DNSSEC
[RFC6698]. However, if the redirect information is not signed, then
the device MUST NOT trust any included trust anchor certificates,
which means that the device would have to establish an unsecured
connection to the specified bootstrap servers. See Section 3.1 for
more about this case.
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To use this approach, the device MAY perform DNS-SD via multicast DNS
[RFC6762] searching for the service "_zerotouch._tcp.local.".
Alternatively the device MAY perform DNS-SD via normal DNS operation,
using the domain returned to it from the DHCP server, searching for
the service "_zerotouch._tcp.example.com".
The mapping of redirect information onto DNS SRV [RFC2782] and DNS
TXT [RFC1035] records as follows: is as follows:
o The bootstrap server's hostname or IP address is returned by the
"Target" component of the DNS SRV record.
o The bootstrap server's port is returned by the "Port" component of
the DNS SRV record.
o The bootstrap server's trust anchor is returned using the key
"anchor" in the DNS TXT record with the binary value being the
`gzip` compression over the redirect-information's "trust-anchor"
value. To save additional space, it is RECOMMENDED that the trust
anchor certificate uses an elliptical curve algorithm, rather than
the seemingly ubiquitous RSA algorithm.
o The signature over the preceding three values is returned using
the key "sig" in the DNS TXT record with the binary value being
the `gzip` compression over the redirect-information's "signature"
value.
o The owner certificate is returned using the key "cert" in the DNS
TXT record with the binary value being the `gzip` compression over
the redirect-information's "owner-certificate/certificate" value.
There isn't enough space to support returning CRLs. To save
additional space, it is RECOMMENDED that the owner certificate
uses an elliptical curve algorithm, rather than the seemingly
ubiquitous RSA algorithm.
o The ownership voucher is returned using the key "voucher" in the
DNS TXT record binary value being the `gzip` compression over the
redirect-information's "ownership-voucher/voucher" value. There
isn't enough space to support returning CRLs.
The applicability of this approach across vendors is limited due to
the ownership voucher being a manufacturer-specific format. This
limitation only impacts signed data, when the ownership voucher is
used; there is no such limitation when unsigned data is communicated.
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4.3. DHCP Server
A device MAY attempt to acquire bootstrapping data from a DHCP server
(e.g., using one of the DHCP options defined in Section 9.1). The
bootstrapping data MAY be either redirect information or bootstrap
information.
If redirect information is provided, it SHOULD be signed, as the DHCP
protocol is not a secure protocol. However, if the redirect
information is not signed, then the device MUST NOT trust any
included trust anchor certificates, which means that the device would
have to establish an unsecured connection to the specified bootstrap
servers. See Section 3.1 for more about this case.
If bootstrap information is provided, it MUST be signed, as the DHCP
protocol is not a secure protocol and there is no option to process
the data in a degraded manner, unlike as with redirect information.
For the case when the signed bootstrap information is provided, it is
notable that the URL would have to point to another file server
(e.g., http://, ftp://, etc.), as DHCP servers do not themselves
distribute files. In this case, the device MUST authenticate the
validity of the boot image file, either by using the MD5 and SHA
fingerprints supplied by the bootstrapping information, or by virtual
of the boot image containing an embedded signature, if any.
It is expected that DHCP servers will provide redirect information
more often than bootstrap information, since redirect information is
more generic, potentially applicable to a large number of devices,
with the number limited only by the number of devices listed by the
associated ownership voucher. Still, because the ownership voucher
is a manufacturer specific format, it is advisable for devices to
send the Vendor Class Identifier (option 60) field in its DHCP lease
request, so that the DHCP server doesn't accidentally hand it another
manufacturer's voucher format.
If it is desired for the DHCP server to return bootstrap information,
care should be taken to ensure that bootstrap information is
applicable to all the devices that might connect to the DHCP server.
The device SHOULD again pass the Vendor Class Identifier (option 60)
field in its DHCP lease request. However, if it is desired to return
device-specific bootstrap information, then the device SHOULD also
send the Client Identifier (option 61) field in its DHCP lease
request so that the DHCP server can select the specific bootstrap
information that has been staged for that one device.
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4.4. Bootstrap Server
A device MAY attempt to acquire bootstrapping data from a trusted
Internet-based bootstrap server, a server implementing the RESTCONF
API defined by the YANG module provided in Section 7.4. The
bootstrapping data provided by the server MAY be either redirect
information or bootstrap information.
Actually, a bootstrap server is not only a source for bootstrapping
data, but it is also the consumer of notification messages from
devices. These notification messages both enable visability into the
bootstrapping process (e.g., reporting warnings and errors) and well
as provide potentially useful completion status information (e.g.,
the device's SSH host-keys).
If the device is able to authenticate the bootstrap server, using
X.509 certificate path validation ([RFC6125], Section 6) to a trust
anchor the device was manufactured with, or it securely learned from
another source of bootstrapping data, then the data the device
obtains from the bootstrap server MAY NOT be signed. Notably, this
is the only mechanism defined in this document whereby unsigned
bootstrap information (not redirect information) can be used. When
the device is able to authenticate the bootstrap server's TLS
certificate, the device MUST send its IDevID certificate in the form
of client-certificate and it MUST POST notifications to the bootstrap
server.
If the device is unable to authenticate the bootstrap server's TLS
certificate, for any reason, then any data it receives from the
bootstrap server MUST be signed in order for the device to be able to
make use of it. When the device is not able to authenticate the
bootstrap server, the device MUST NOT send its IDevID in the form of
a client-certificate and it MUST NOT POST any notifications to the
bootstrap server.
5. Workflow Overview
The zero touch solution presented in this document is conceptualized
to be composed of the workflows described in this section.
Implementations MAY vary in details. Each diagram is followed by a
detailed description of the steps presented in the diagram, with
further explanation on how implementations may vary.
5.1. Onboarding and Ordering Devices
The following diagram illustrates key interactions that occur from
when a prospective owner enrolls in a manufacturer's zero touch
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program to when the manufacturer ships devices for an order placed by
the prospective owner.
+-----------+
+------------+ |Prospective| +---+
|Manufacturer| | Owner | |NMS|
+------------+ +-----------+ +---+
| | |
| | |
| 1. initiate enrollment | |
#<-----------------------------| |
# | |
# | |
# IDevID trust anchor | |
#-----------------------------># set IDevID trust anchor |
# #--------------------------->|
# | |
# (optional) bootstrap server | |
# account credentials | |
#-----------------------------># (optional) set credentials |
# #--------------------------->|
# | |
# | |
# (optional) owner certificate | |
#-----------------------------># (optional) set certificate |
| #--------------------------->|
| | |
| | |
| 2. place device order | |
|<-----------------------------# model devices |
| #--------------------------->|
| | |
| 3. ship devices and send | |
| device identifiers and | |
| ownership vouchers | |
|-----------------------------># set device identifiers |
| # and ownership vouchers |
| #--------------------------->|
| | |
| | |
The interactions in the above diagram are described below.
1. A prospective owner of a manufacturer's devices, or an existing
owner that wishes to start using zero touch for future device
orders, would initiate an enrollment process with the
manufacturer, or the manufacturer's delegate.
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2.
Regardless how the prospective owner intends to bootstrap
their devices, they will always obtain from the manufacturer
or delegate the trust anchor certificate needed to
authenticate device IDevID certificates. This certificate
will need to be installed on the prospective owner's NMS so
that the NMS can subsequently authenticate the device's IDevID
certificates.
If the manufacturer hosts an Internet based bootstrap server,
such as described in Section 4.4, then credentials necessary
to configure the bootstrap server would be provided to the
prospective owner. If the bootstrap server is configurable
through an API (outside the scope of this document), then the
credentials might be installed on the prospective owner's NMS
so that the NMS can subsequently configure the manufacturer-
hosted bootstrap server directly.
If the manufacturer's devices are able to acquire
bootstrapping data from sources other than a manufacturer-
hosted Internet-based bootstrap server (e.g., removable
storage, DHCP server, etc.), then the manufacturer would
additionally provide an owner certificate to the prospective
owner. How the owner certificate is used to enable devices to
validate signed bootstrapping data is described in
Section 6.4. Not depicted, the owner certificate is generated
by the prospective owner previously sending a certificate
signing request to the manufacturer for signing, thus
resulting in the owner certificate. Assuming the prospective
owner's NMS is able to prepare and sign the bootstrapping
data, the owner certificate would be installed on the NMS at
this time.
3. Some time later, the prospective owner places an order with the
manufacturer, perhaps with a special flag checked for zero touch
handling. At this time, or perhaps before placing the order, the
owner may model the devices in their NMS. That is, create
virtual objects for the devices with no real-world device
associations. For instance the model can be used to simulate the
device's location in the network and the configuration it should
have when fully operational.
4. When the manufacturer ships the devices for the order, the
manufacturer notifies the owner of the devices' unique
identifiers and shipping destinations, which the owner can use to
stage the network for when the devices powers on. Additionally,
the manufacturer may send an ownership voucher, assigning
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ownership of those devices to the rightful owner. The owner sets
this information on their NMS, perhaps binding specific device
identifiers and ownership vouchers (if supported) to specific
modeled devices.
5.2. Owner Stages the Network for Bootstrap
The following diagram illustrates how an owner stages the network for
bootstrapping devices.
+----------+ +------------+
|Deployment| |Manufacturer| +------+ +------+
| Specific | | Hosted | |Local?| | Local| +---------+
+---+ |Bootstrap | | Bootstrap | | DNS | | DHCP | |Removable|
|NMS| | Server | | Server | |Server| |Server| | Storage |
+---+ +----------+ +------------+ +------+ +------+ +---------+
| | | | | |
activate | | | | | |
modeled | | | | | |
1. device | | | | | |
----------->| | | | | |
| | | | | |
| 2. (optional) configure | | |
| bootstrap server | | | |
|------->| | | | |
| | | | | |
| 3. (optional) configure | | |
| redirect server | | | |
|--------------------->| | | |
| | | | | |
| | | | | |
| 4. (optional) configure DNS server| | |
|---------------------------------->| | |
| | | | | |
| | | | | |
| 4. (optional) configure DHCP server | |
|------------------------------------------->| |
| | | | | |
| | | | | |
| 5. (optional) store bootstrapping artifacts on media |
|----------------------------------------------------->|
| | | | | |
| | | | | |
The interactions in the above diagram are described below.
1. Having previously modeled the devices, including setting their
fully operational configurations, associating device identifiers
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and ownership vouchers (if supported), the owner "activates" one
or more modeled devices. That is, tell the NMS to perform the
steps necessary to prepare for when the real-world devices are
powered up and initiate the bootstrapping process. Note that, in
some deployments, this step might be combined with the last step
from the previous workflow. Here it is depicted that an NMS
performs the steps, but they may be performed manually or through
some other mechanism.
2. If it is desired to use a deployment specific bootstrap server,
it MUST be configured to provide the bootstrapping information
for the specific devices. Whenever a deployment specific
bootstrap server is used, the NMS MUST also configure some other
source of bootstrapping data (i.e. an Internet based redirect
server, a local DHCP server, a removable storage device, etc.)
with redirect information, so that the device can discover where
the deployment specific server is located and how to establish a
connection to it. Configuring the bootstrap server MAY occur via
a programmatic API not defined by this document. Illustrated
here as an external component, the bootstrap server MAY be
implemented as an internal component of the NMS itself.
3. If it is desired to use a manufacturer or delegate hosted
bootstrap server, it MUST be configured to provide the
bootstrapping information for the specific devices. The
configuration MUST be either redirect or bootstrap information.
That is, either the manufacturer hosted bootstrap server will
redirect the device to another bootstrap server, or provide the
device with its bootstrapping information itself. The types of
bootstrapping information the manufacturer hosted bootstrap
server supports MAY vary by implementation; some implementations
may only support redirect information, or only support bootstrap
information, or support both redirect and bootstrap information.
Configuring the bootstrap server MAY occur via a programmatic API
not defined by this document.
4. If it is desired to use a DNS server to supply bootstrapping
information, a DNS server needs to be configured. If multicast
DNS-SD is desired, then the server MUST reside on the local
network, otherwise the MAY reside on a remote network. Please
see Section 4.2 for more information about how to configure DNS
servers. Configuring the DHCP server MAY occur via a
programmatic API not defined by this document.
5. If it is desired to use a DHCP server to supply bootstrapping
data, the DHCP server MUST be accessible via the network the
device is located, either direct or via a DHCP relay. Please see
Section 4.3 for more information about how to configure DHCP
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servers. Configuring the DHCP server MAY occur via a
programmatic API not defined by this document.
6. If it is desired to use a removable storage device (e.g., USB
flash drive) to supply bootstrapping information, the information
would need to be placed onto it. Please see Section 4.1 for more
information about how to configure a removable storage device.
5.3. Device Powers On
The following diagram illustrates how a device might behave when
powered on. Note that this is merely exemplary, subject to which
bootstrapping strategies the device supports, which may be more or
less than depicted below.
This diagram sequences the sources of bootstrapping information (see
Section 4) based on locality, or how "close" the data is to the
device, which is RECOMMENDED. Whether this sequence makes sense for
a specific type of device needs to be determined by the manufacturer.
+------------+ +----------+
+------+ |Manufacturer| |Deployment|
+---------+ | Local| | Hosted | | Specific |
+------+ |Removable| | DHCP | | Bootstrap | |Bootstrap | +---+
|Device| | Storage | |Server| | Server | | Server | |NMS|
+------+ +---------+ +------+ +------------+ +----------+ +---+
| | | | | |
| | | | | |
| 1. if not factory default, then exit. | | |
| | | | | |
| | | | | |
| 2. (optional) check | | | |
#----------->| | | | |
# if signed redirect information found | | |
#------------------------------------------------------># webhook |
# either NMS-initiated NC or RC connection #--------->#
#<-----------------------------------------------------------------#
# or device-initiated NC or RC call home connection | |
#----------------------------------------------------------------->|
# else if signed bootstrap information found (call home)| |
#----------------------------------------------------------------->|
# if bootstrapped then exit, else move to next step. | |
| | | | | |
| | | | | |
| 3. (optional) check | | | |
#------------------------>| | | |
# if signed redirect information found | | |
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#------------------------------------------------------># webhook |
# either NMS-initiated NC or RC connection #--------->#
#<-----------------------------------------------------------------#
# or device-initiated NC or RC call home connection | |
#----------------------------------------------------------------->|
# else if signed bootstrap information found (call home)| |
#----------------------------------------------------------------->|
# if bootstrapped then exit, else move to next step. | |
| | | | | |
| | | | | |
| 4. (optional) check | | | |
#-------------------------------------->| | |
# if signed or unsigned redirect information found | |
#------------------------------------------------------># webhook |
# either NMS-initiated NC or RC connection #--------->#
#<-----------------------------------------------------------------#
# or device-initiated NC or RC call home connection | |
#----------------------------------------------------------------->|
# else if signed or unsigned bootstrap info found (call home) |
#----------------------------------------------------------------->|
# if bootstrapped then exit, else move to next step. | |
| | | | | |
|
| 5. loop and/or wait for manual provisioning.
|
[Key: NC==NETCONF, RC==RESTCONF]
The interactions in the above diagram are described below.
1. Upon power being applied, the device's bootstrapping logic first
checks to see if it is running in its factory default state. If
it has a modified state, then the bootstrapping logic would exit
and none to the following interactions would occur.
2. If the device is able to load bootstrapping data from a removable
storage device (e.g., USB flash drive), it is RECOMMENDED that it
try to do so first. Details such as the format of filesystem and
the naming of the files are left to the device's manufacturer to
define. Assuming a removable storage device is attached to the
device, the device would check for bootstrapping data and, if
found, validate that it has been signed using the procedure
described in Section 6.4. The bootstrapping data MAY either be
redirect information or bootstrap information. How the device
processes each is follows:
* In the case that redirect information is found (e.g., the
example depicted in Section 7.3.1), the device would use the
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redirect information to establish a secure connection to a
deployment-specific bootstrap server. In theory this
bootstrap server could return a response that redirected the
device to yet another bootstrap server (e.g., the example
depicted in Section 7.2.1), but in this example it is depicted
that it returns bootstrap information (e.g., the example
depicted in Section 7.2.3). Using this bootstrap information,
the device would set its boot image and its initial
configuration. If the bootstrap server supports notifying
external systems (e.g., via a webhook) when a device has
notified the bootstrap server that it is ready to be managed
(e.g., the example depicted in Section 7.2.5), it might do so
at this time, which could prompt the NMS to initiate a NETCONF
or RESTCONF connection to the device at this time.
Alternatively, the initial configuration the device installs
could configure the device to initiate a NETCONF or RESTCONF
call home [draft-ietf-netconf-call-home] connection to the
deployment-specific NMS. All of these sub-steps are depicted
in the diagram above.
* In the case that bootstrap information is found (e.g., the
example depicted in Section 7.2.2), the device would use the
bootstrap information to install a boot image, which itself
could be located on the same removable storage device, and set
its initial configuration. In this case, since there is no
easy way to notify the NMS that the device is ready to be
managed (e.g., via a webhook), it is RECOMMENDED that the
initial configuration directs the device to proactively
initiate a NETCONF or RESTCONF call home
[draft-ietf-netconf-call-home] connection to the deployment-
specific NMS.
If the device is unable to bootstrap using any of the information
on the removable storage device, it would proceed to the next
source of bootstrapping information, if any.
3. If the device is able to load bootstrapping data from a DHCP
server, when obtaining a DHCP assignment, it may receive a
response that includes a Zero Touch Information DHCP option
(Section 9.1).
* If the redirect information contained in the DHCP option is
signed, then it is RECOMMENDED that the device establish a
secure TLS connection to the bootstrap server, by
authenticating its TLS server certificate using the provided
trust anchor, and download any data that has been staged for
it there, which MAY not be signed, since the server's
certificate could be trusted.
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* On the other hand, if the redirect information contained in
the DHCP option is unsigned, then it is RECOMMENDED that the
device establish a unsecured TLS connection to the bootstrap
server, by blindly accepting its TLS server certificate, and
download any data that has been staged for it there, which
then MUST be signed, since the server's certificate could not
be trusted.
In either case, the remainder of the device's logic is the same
as described above for when using a removable storage device. If
the device is unable to bootstrap using information provided by a
DHCP server, it would proceed to the next source of bootstrapping
information, if any.
4. If the device is able to load bootstrapping data from a trusted
Internet-based bootstrap server, as preconfigured in its factory
default settings (Section 6.1), it is RECOMMENDED that the device
attempts to establish a secure TLS connection to the bootstrap
server, authenticating its TLS server certificate using the trust
anchors set by its factory default state (Section 6.1), and
download any data that has been staged for it there, which MAY
not be signed, since the server's certificate could be trusted.
In either case, the remainder of the device's logic is the same
as described above for when using a removable storage device. If
the device is unable to bootstrap using information provided by a
DHCP server, it would proceed to the next source of bootstrapping
information, if any.
5. If no more sources of bootstrapping information are available,
the device MAY retry again all sources of bootstrapping data and/
or MAY provide manageability interfaces for manual configuration
(e.g., CLI, HTTP, NETCONF, etc.). If manual configuration is
allowed, and such configuration is provided, the device MUST
immediately cease trying to obtain bootstrapping data, as it
would then no longer be in its factory default state.
6. Device Details
Devices supporting Zero Touch MUST have the preconfigured factory
default state and bootstrapping logic described in the following
sections.
6.1. Factory Default State
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+------------------------------------------------------------------+
| <device> |
| |
| +----------------------------------------------------------+ |
| | <read-only storage> | |
| | | |
| | 1. list of trusted Internet based bootstrap servers | |
| | 2. list of trust anchor certs for bootstrap servers | |
| | 3. trust anchor cert for owner certificates | |
| | 4. trust anchor cert for device ownership vouchers | |
| | 5. IDevID cert & associated intermediate certificate(s) | |
| +----------------------------------------------------------+ |
| |
| +----------------------+ |
| | <secure storage> | |
| | | |
| | 6. private key | |
| +----------------------+ |
| |
+------------------------------------------------------------------+
Each numbered item below corresponds to a numbered item in the
diagram above.
1. Devices that support loading bootstrapping data from an Internet-
based bootstrap server (see Section 4) MUST be manufactured with
a list of trusted bootstrap servers. Each bootstrap server MAY
be identified by just its hostname or IP address, and an optional
port. Note that it is not necessary to configure URLs, as the
RESTCONF protocol defines how the bootstrap server API specified
in Section 7.4 maps into URLs.
2. Devices that support loading bootstrapping data from an Internet-
based bootstrap server (see Section 4) SHOULD be manufactured
with a list of trust anchor certificates that can be for X.509
certificate path validation [RFC6125], Section 6) on the
bootstrap server's TLS server certificate.
3. Devices that support loading owner signed data (see Section 1.2)
MUST be manufactured with the trust anchor certificate for the
owner certificates that the manufacturer provides to prospective
owners when they enroll in the manufacturer's Zero Touch program
(see Section 5.1).
4. Devices that support loading owner signed data (see Section 1.2)
MUST also be manufactured with the trust anchor certificate for
the device ownership vouchers that the manufacturer provides to
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prospective owners when it ships out an order of Zero Touch
devices (see Section 5.1).
5. Devices MUST be manufactured with an initial device identifier
(IDevID), as defined in [Std-802.1AR-2009]. The IDevID is an
X.509 certificate, encoding a unique device identifier (e.g.,
serial number). The device MUST also possess any intermediate
certificates between the IDevID certificate and the
manufacturer's IDevID trust anchor certificate.
6. Device MUST be manufactured with a private key that corresponds
to the public key encoded in the device's IDevID certificate.
This private key SHOULD be securely stored, ideally by a
cryptographic processor (e.g., a TPM).
6.2. Boot Sequence
A device claiming to support Zero Touch MUST support the boot
sequence described in this section.
Power On
|
v No
1. Running default config? --------> Boot normally
|
| Yes
v
2. For each supported source for bootstrapping data,
try to load bootstrapping data from the source
|
|
v Yes
3. Able to bootstrap off any source? -----> Run with new configuration
|
| No
v
4. Loop or wait for manual provisioning.
These interactions are described next.
1. When the device powers on, it first checks to see if it is
running the factory default configuration. If it is running a
modified configuration, then it boots normally.
2. The device iterates over its list of sources for bootstrapping
data Section 4. Details for how to processes a source of
bootstrapping data are provided in Section 6.3.
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3. If the device is able to bootstrap itself off any of the sources
for bootstrapping data, it runs with the new bootstrapped
configuration.
4. Otherwise the device MAY loop back through the list of
bootstrapping sources again and/or wait for manual provisioning.
6.3. Processing a Source of Boostrapping Data
This section describes a recursive algorithm that a device claiming
to support Zero Touch MUST use to authenticate bootstrapping data. A
device enters this algorithm for each new source of bootstrapping
data. The first time the device enters this algorithm, it MUST
initialize a conceptual trust state variable, herein referred to as
"trust-state", to FALSE. The ultimate goal of this algorithm is for
the device to process bootstrap information (not redirect
information) while its trust-state is TRUE.
If the data source is a bootstrap server, and the device is able to
authenticate the server using X.509 certificate path validation
([RFC6125], Section 6) to one of the the device's preconfigured trust
anchors, or to a trust anchor that it learned from a previous step,
then the device MUST set trust-state to TRUE. If trust-state is
TRUE, when connecting to the bootstrap server, the device MUST use
its IDevID certificate for a client-certificate based authentication
and MUST POST progress notifications using the bootstrap server's
"notification" action. Otherwise, if trust-state is FALSE, when
connecting to the bootstrap server, the device MUST NOT use its
IDevID certificate for a client-certificate based authentication and
MUST NOT POST progress notifications using the bootstrap server's
"notification" action. When accessing a bootstrap server, the device
MUST only access its top-level resource, to obtain all the data
staged for it in one GET request, so that it can determine if the
data is signed or not, and thus act accordingly.
For any data source, if the data is signed (i.e. the data includes a
'signature' field) and the device is able to validate the signed data
using the algorithm described in Section 6.4, then the device MUST
set trust-state to TRUE, else the device MUST set trust-state to
FALSE. Note, this is worded to cover the special case when signed
data is returned even from a trusted bootstrap server.
If the data is bootstrap information (not redirect information), and
trust-state is FALSE, the device MUST exit the recursive algorithm,
returning to the state machine described in Section 6.2. Otherwise,
the device MUST attempt to process the bootstrap information as
described in Section 6.6. In either case, success of failure, the
device MUST exit the recursive algorithm, returning to the state
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machine described in Section 6.2, the only difference being in how it
responds to the "Able to bootstrap off any source?" conditional
described in that state machine.
If the data is redirect information, the device MUST process the
redirect information as described in Section 6.5. This is the
recursion step, it will cause to device to reenter this algorithm,
but this time the data source will most definitely be a bootstrap
server, as that is all redirect information is able to do, though
it's interesting to note that the bootstrap server's response MAY be
more redirect information.
6.4. Validating Signed Data
Whenever a device is presented signed data, it MUST validate the
signed data as described in this section.
Whenever there is signed data, the device MUST also be provided an
ownership voucher and an owner certificate. How all the needed
records are provided for each source of bootstrapping data is defined
in Section 4
The device MUST first authenticate the ownership voucher by
validating the signature on it to one of its preconfigured trust
anchors (see Section 6.1) and verify that the voucher contains the
device's unique identifier (e.g., serial number). If the
authentication of the voucher is successful, the device extracts the
Rightful owner's identity from the voucher for use in the next step.
Next the device MUST authenticate the owner certificate by performing
X.509 certificate path validation on it to one of its preconfigured
trust anchors (see Section 6.1) and by verifying that the Subject
contained in the certificate matches the Rightful owner identity
extracted from the voucher in the previous step. If the
authentication of the certificate is successful, the device extracts
the owner's public key from the certificate for use in the next step.
Finally the device MUST authenticate the signed data by verifying the
signature on it was generated by the private key matching the public
key extracted from the owner certificate in the previous step.
If any of these steps fail, then the device MUST mark the data as
invalid and not perform any of the subsequent steps.
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6.5. Processing Redirect Information
In order to process redirect information (Section 3.1), the device
MUST follow the steps presented in this section.
Processing redirect information is straightforward. Essentially the
device MUST immediately attempt to establish a RESTCONF connection to
the provided bootstrap server IP address or hostname.
If a hostname is provided, and its DNS resolution is to more than one
IP address, the device MUST attempt to try to connect to all of them,
sequentially, until it is able to successfully bootstrap off one of
them.
If the redirect information includes a trust anchor, and the redirect
information can be trusted (e.g., trust-state is TRUE), then the
device MUST authenticate the bootstrap server using X.509 certificate
path validation ( [RFC6125], Section 6) using the specified trust
anchor.
6.6. Processing Bootstrap Information
In order to process bootstrap information (Section 3.2), the device
MUST follow the steps presented in this section.
When processing bootstrap information, the device MUST first process
the boot image information, then commit the initial configuration,
and then execute the script, if any, in that order. If the device
encounters an error at any step, it MUST NOT proceed to the next
step.
First the device MUST determine if the image it is running satisfies
the specified "boot-image" criteria. If it does not, the device MUST
download and install the specified boot image, and reboot. Upon
rebooting, the device MUST still be in its factory default state,
causing the bootstrapping process to run again, which will eventually
come to this very point, but this time the device's running image
will satisfy the specified criteria, and thus the device moves to
processing the next step.
Next the device commits the provided initial configuration. Assuming
no errors, the device moves to processing the next step.
Next, for devices that support executing scripts, if a script has
been specified, the device executes the script, checking its exit
status code to determine if it succeeded, had warning, or had errors.
In the case of errors, the device MUST reset itself in such a way
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that force the reinstallation of its boot image, thereby wiping out
any bad state the script might have left behind.
At this point, the device has completely processed the bootstrapping
data and is ready to be managed. If the configuration configured the
device it initiate a call home connection, it should proceed to do so
now. Otherwise, the device should wait for a NETCONF or RESTCONF
client to connect to it.
7. YANG-defined API and Artifacts
Central to the solution presented in this document is the use of a
YANG module [RFC6020] to simultaneously define a RESTCONF based API
for a bootstrap/redirect server as well as the encoding for signed
artifacts that can be conveyed outside of the RESTCONF protocol
(DHCP, FTP, TFTP, etc.).
The module defined in this section makes extensive use of data types
defined in [RFC2315], [RFC5280], [RFC6991], and [RFC5280].
7.1. Module Overview
The following tree diagram Section 1.3 provides an overview for both
the API and artifacts that can be used outside of RESTCONF.
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module: ietf-zerotouch-bootstrap-server
+--ro devices
+--ro device* [unique-id]
+--ro unique-id string
+--ro (type)?
| +--:(redirect-information)
| | +--ro redirect-information
| | +--ro bootstrap-server* [address]
| | +--ro address inet:host
| | +--ro port? inet:port-number
| | +--ro trust-anchor binary
| +--:(bootstrap-information)
| +--ro bootstrap-information
| +--ro boot-image
| | +--ro modules
| | | +--ro module*
| | | +--ro name? yang:yang-identifier
| | | +--ro revision? string
| | +--ro name string
| | +--ro md5 string
| | +--ro sha1 string
| | +--ro uri* inet:uri
| +--ro configuration
| +--ro script? string
+--ro owner-certificate
| +--ro certificate binary
| +--ro issuer-crl? binary
+--ro ownership-voucher
| +--ro voucher binary
| +--ro issuer-vrl? binary
+--ro signature? binary
+---x notification
+---w input
+---w notification-type enumeration
+---w message? string
+---w ssh-host-keys
| +---w ssh-host-key*
| +---w format enumeration
| +---w key-data string
+---w trust-anchors
+---w trust-anchor*
+---w protocol* enumeration
+---w certificate binary
In the above diagram, notice that all of the protocol accessible node
are read-only, to assert that devices can only pull data from the
bootstrap server.
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Also notice that the module defines an action statement, which
devices may use to provide progress notifications to the bootstrap
server.
7.2. API Examples
This section presents some examples illustrating device interactions
with a bootstrap server to access Redirect and Bootstrap information,
both unsigned and signed, as well as to send a progress notification.
These examples show the bootstrap information containing
configuration defined by [RFC7317] and
[draft-ietf-netconf-server-model].
7.2.1. Unsigned Redirect Information
The following example illustrates a device using the API to fetch its
bootstrapping data. In this example, the device receives unsigned
redirect information. This example is representative of a response a
trusted redirect server might return.
REQUEST
-------
['\' line wrapping added for formatting only]
GET https://example.com/restconf/data/ietf-zerotouch-bootstrap-server:\
devices/device=123456 HTTP/1.1
HOST: example.com
Accept: application/yang.data+xml
RESPONSE
--------
HTTP/1.1 200 OK
Date: Sat, 31 Oct 2015 17:02:40 GMT
Server: example-server
Content-Type: application/yang.data+xml
<!-- '\' line wrapping added for formatting purposes only -->
<device
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<unique-id>123456789</unique-id>
<redirect-information>
<bootstrap-server>
<address>phs1.example.com</address>
<port>8443</port>
<trust-anchor>
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WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW\
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
RJSUJQFRStS0Cg==
</trust-anchor>
</bootstrap-server>
<bootstrap-server>
<address>phs2.example.com</address>
<port>8443</port>
<trust-anchor>
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW\
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
RJSUJQFRStS0Cg==
</trust-anchor>
</bootstrap-server>
</redirect-information>
</device>
7.2.2. Signed Redirect Information
The following example illustrates a device using the API to fetch its
bootstrapping data. In this example, the device receives signed
redirect information. This example is representative of a response
that redirect server might return if concerned the device might not
be able to authenticate its TLS certificate.
REQUEST
-------
['\' line wrapping added for formatting only]
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GET https://example.com/restconf/data/ietf-zerotouch-bootstrap-server:\
devices/device=123456 HTTP/1.1
HOST: example.com
Accept: application/yang.data+xml
RESPONSE
--------
HTTP/1.1 200 OK
Date: Sat, 31 Oct 2015 17:02:40 GMT
Server: example-server
Content-Type: application/yang.data+xml
<!-- '\' line wrapping added for formatting purposes only -->
<device
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<unique-id>123456789</unique-id>
<redirect-information>
<bootstrap-server>
<address>phs1.example.com</address>
<port>8443</port>
<trust-anchor>
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW\
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
RJSUJQFRStS0Cg==
</trust-anchor>
</bootstrap-server>
<bootstrap-server>
<address>phs2.example.com</address>
<port>8443</port>
<trust-anchor>
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
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V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW\
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
RJSUJQFRStS0Cg==
</trust-anchor>
</bootstrap-server>
</redirect-information>
<owner-certificate>
<certificate>
MIIExTCCA62gAwIBAgIBATANBgkqhkiG9w0BAQsFADCBqjELMAkGA1UEBhMCVVMx\
EzARBgNVBAgTCkNhbGlmb3JuaWExEjAQBgNVBAcTCVN1bm55dmFsZTEZMBcGA1UE\
ChQQSnVuaXBlcl9OZXR3b3JrczEdMBsGA1UECxQUQ2VydGlmaWNhdGVfSXNzdWFu\
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
ap1DgmS3IaYl/s4OOF8yzcYJprm8O7NyZp+Y9H1U/7Qfp97/KbqwCgkHSzOlnt0X\
KQTpIM/rNrbrkuTmalezFoFS7mrxLXJAsfP1guVcD7sLCyjvegL8pRCCrU9xyKLF\
8u/Qz4s0x0uzcGYh0sd3iWj21+AtigSLdMD76/j/VzftQL8B1yp3vc1EZiowOwq4\
KmORbiKU2GTGZkaCgCjmrWpvrYWLoXv/sf2nPLyK6YjiWsslOJtRO+KzRbs2B18C\
AwEAAaOCAW0wggFpMBIGA1UdEwEB/wQIMAYBAf8CAQAwHQYDVR0OBBYEFHppoyXF\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAOBgNVHQ8BAf8EBAMCAgQwQgYDVR0fBDswOTA3oDWgM4YxaHR0cDovL2NybC5q\
dW5pcGVyLm5ldD9jYT1KdW5pcGVyX1RydXN0X0FuY2hvcl9DQTANBgkqhkiG9w0B\
AQsFAAOCAQEAOuD7EBilqQcT3t2C4AXta1gGNNwdldLLw0jtk4BMiA9l//DZfskB\
2AaJtiseLTXsMF6MQwDs1YKkiXKLu7gBZDlJ6NiDwy1UnXhi2BDG+MYXQrc6p76K\
z3bsVwZlaJQCdF5sbggc1MyrsOu9QirnRZkIv3R8ndJH5K792ztLquulAcMfnK1Y\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX7WJzEbT/G7MUfo\
Sb+U2PVsQTDWEzUjVnG7vNWYxirnAOZ0OXEWWYxHUJntx6DsbXYuX7D1PkkNr7ir\
96DpOPtX7h8pxxGSDPBXIyvg02aFMphstQ==
</certificate>
<issuer-crl>
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
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X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAO==
</issuer-crl>
</owner-certificate>
<ownership-voucher>
<voucher>
ChQQSnVuaXBlcl9OZXR3b3JrczEdMBsGA1UECxQUQ2VydGlmaWNhdGVfSXNzdWFu\
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAO
</voucher>
<issuer-crl>
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
KQTpIM/rNrbrkuTmalezFoFS7mrxLXJAsfP1guVcD7sLCyjvegL8pRCCrU9xyKLF\
8u/Qz4s0x0uzcGYh0sd3iWj21+AtigSLdMD76/j/VzftQL8B1yp3vc1EZiowOwq4\
AwEAAaOCAW0wggFpMBIGA1UdEwEB/wQIMAYBAf8CAQAwHQYDVR0OBBYEFHppoyXF\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX=
</issuer-crl>
</ownership-voucher>
<signature>
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX=
</signature>
</device>
7.2.3. Unsigned Bootstrap Information
The following example illustrates a device using the API to fetch its
bootstrapping data. In this example, the device receives unsigned
bootstrapping information. This example is representative of a
response a locally deployed bootstrap server might return.
REQUEST
-------
['\' line wrapping added for formatting only]
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GET https://example.com/restconf/data/ietf-zerotouch-bootstrap-server:\
devices/device=123456 HTTP/1.1
HOST: example.com
Accept: application/yang.data+xml
RESPONSE
--------
HTTP/1.1 200 OK
Date: Sat, 31 Oct 2015 17:02:40 GMT
Server: example-server
Content-Type: application/yang.data+xml
<!-- '\' line wrapping added for formatting purposes only -->
<device
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<unique-id>123456789</unique-id>
<bootstrap-information>
<boot-image>
<name>
boot-image-v3.2R1.6.img
</name>
<md5>
SomeMD5String
</md5>
<sha1>
SomeSha1String
</sha1>
<uri>
ftp://ftp.example.com/path/to/file
</uri>
</boot-image>
<configuration>
<!-- from ietf-system.yang -->
<system xmlns="urn:ietf:params:xml:ns:yang:ietf-system">
<authentication>
<user>
<name>admin</name>
<ssh-key>
<name>admin's rsa ssh host-key</name>
<algorithm>ssh-rsa</algorithm>
<key-data>AAAAB3NzaC1yc2EAAAADAQABAAABAQDeJMV8zrtsi8CgEsR\
jCzfve2m6zD3awSBPrh7ICggLQvHVbPL89eHLuecStKL3HrEgXaI/O2Mw\
E1lG9YxLzeS5p2ngzK61vikUSqfMukeBohFTrDZ8bUtrF+HMLlTRnoCVc\
WAw1lOr9IDGDAuww6G45gLcHalHMmBtQxKnZdzU9kx/fL3ZS5G76Fy6sA\
vg7SLqQFPjXXft2CAhin8xwYRZy6r/2N9PMJ2Dnepvq4H2DKqBIe340jW\
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EIuA7LvEJYql4unq4Iog+/+CiumTkmQIWRgIoj4FCzYkO9NvRE6fOSLLf\
gakWVOZZgQ8929uWjCWlGlqn2mPibp2Go1</key-data>
</ssh-key>
</user>
</authentication>
</system>
<!-- from ietf-netconf-server.yang -->
<netconf-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
<call-home>
<application>
<name>config-mgr</name>
<ssh>
<endpoints>
<endpoint>
<name>east-data-center</name>
<address>11.22.33.44</address>
</endpoint>
<endpoint>
<name>west-data-center</name>
<address>55.66.77.88</address>
</endpoint>
</endpoints>
<host-keys>
<host-key>my-call-home-x509-key</host-key>
</host-keys>
</ssh>
</application>
</call-home>
</netconf-server>
</configuration>
</bootstrap-information>
</device>
7.2.4. Signed Bootstrap Information
The following example illustrates a device using the API to fetch its
bootstrapping data. In this example, the device receives signed
bootstrap information. This example is representative of a response
that bootstrap server might return if concerned the device might not
be able to authenticate its TLS certificate.
REQUEST
-------
['\' line wrapping added for formatting only]
GET https://example.com/restconf/data/ietf-zerotouch-bootstrap-server:\
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devices/device=123456 HTTP/1.1
HOST: example.com
Accept: application/yang.data+xml
RESPONSE
--------
HTTP/1.1 200 OK
Date: Sat, 31 Oct 2015 17:02:40 GMT
Server: example-server
Content-Type: application/yang.data+xml
<!-- '\' line wrapping added for formatting purposes only -->
<device
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<unique-id>123456789</unique-id>
<bootstrap-information>
<boot-image>
<name>
boot-image-v3.2R1.6.img
</name>
<md5>
SomeMD5String
</md5>
<sha1>
SomeSha1String
</sha1>
<uri>
/path/to/on/same/bootserver
</uri>
</boot-image>
<configuration>
<!-- from ietf-system.yang -->
<system xmlns="urn:ietf:params:xml:ns:yang:ietf-system">
<authentication>
<user>
<name>admin</name>
<ssh-key>
<name>admin's rsa ssh host-key</name>
<algorithm>ssh-rsa</algorithm>
<key-data>AAAAB3NzaC1yc2EAAAADAQABAAABAQDeJMV8zrtsi8CgEsR\
jCzfve2m6zD3awSBPrh7ICggLQvHVbPL89eHLuecStKL3HrEgXaI/O2Mw\
E1lG9YxLzeS5p2ngzK61vikUSqfMukeBohFTrDZ8bUtrF+HMLlTRnoCVc\
WAw1lOr9IDGDAuww6G45gLcHalHMmBtQxKnZdzU9kx/fL3ZS5G76Fy6sA\
vg7SLqQFPjXXft2CAhin8xwYRZy6r/2N9PMJ2Dnepvq4H2DKqBIe340jW\
EIuA7LvEJYql4unq4Iog+/+CiumTkmQIWRgIoj4FCzYkO9NvRE6fOSLLf\
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gakWVOZZgQ8929uWjCWlGlqn2mPibp2Go1</key-data>
</ssh-key>
</user>
</authentication>
</system>
<!-- from ietf-netconf-server.yang -->
<netconf-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
<call-home>
<application>
<name>config-mgr</name>
<ssh>
<endpoints>
<endpoint>
<name>east-data-center</name>
<address>11.22.33.44</address>
</endpoint>
<endpoint>
<name>west-data-center</name>
<address>55.66.77.88</address>
</endpoint>
</endpoints>
<host-keys>
<host-key>my-call-home-x509-key</host-key>
</host-keys>
</ssh>
</application>
</call-home>
</netconf-server>
</configuration>
</bootstrap-information>
<owner-certificate>
<certificate>
MIIExTCCA62gAwIBAgIBATANBgkqhkiG9w0BAQsFADCBqjELMAkGA1UEBhMCVVMx\
EzARBgNVBAgTCkNhbGlmb3JuaWExEjAQBgNVBAcTCVN1bm55dmFsZTEZMBcGA1UE\
ChQQSnVuaXBlcl9OZXR3b3JrczEdMBsGA1UECxQUQ2VydGlmaWNhdGVfSXNzdWFu\
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
ap1DgmS3IaYl/s4OOF8yzcYJprm8O7NyZp+Y9H1U/7Qfp97/KbqwCgkHSzOlnt0X\
KQTpIM/rNrbrkuTmalezFoFS7mrxLXJAsfP1guVcD7sLCyjvegL8pRCCrU9xyKLF\
8u/Qz4s0x0uzcGYh0sd3iWj21+AtigSLdMD76/j/VzftQL8B1yp3vc1EZiowOwq4\
KmORbiKU2GTGZkaCgCjmrWpvrYWLoXv/sf2nPLyK6YjiWsslOJtRO+KzRbs2B18C\
AwEAAaOCAW0wggFpMBIGA1UdEwEB/wQIMAYBAf8CAQAwHQYDVR0OBBYEFHppoyXF\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
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MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAOBgNVHQ8BAf8EBAMCAgQwQgYDVR0fBDswOTA3oDWgM4YxaHR0cDovL2NybC5q\
dW5pcGVyLm5ldD9jYT1KdW5pcGVyX1RydXN0X0FuY2hvcl9DQTANBgkqhkiG9w0B\
AQsFAAOCAQEAOuD7EBilqQcT3t2C4AXta1gGNNwdldLLw0jtk4BMiA9l//DZfskB\
2AaJtiseLTXsMF6MQwDs1YKkiXKLu7gBZDlJ6NiDwy1UnXhi2BDG+MYXQrc6p76K\
z3bsVwZlaJQCdF5sbggc1MyrsOu9QirnRZkIv3R8ndJH5K792ztLquulAcMfnK1Y\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX7WJzEbT/G7MUfo\
Sb+U2PVsQTDWEzUjVnG7vNWYxirnAOZ0OXEWWYxHUJntx6DsbXYuX7D1PkkNr7ir\
96DpOPtX7h8pxxGSDPBXIyvg02aFMphstQ==
</certificate>
<issuer-crl>
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAO==
</issuer-crl>
</owner-certificate>
<ownership-voucher>
<voucher>
ChQQSnVuaXBlcl9OZXR3b3JrczEdMBsGA1UECxQUQ2VydGlmaWNhdGVfSXNzdWFu\
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAO
</voucher>
<issuer-vrl>
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
KQTpIM/rNrbrkuTmalezFoFS7mrxLXJAsfP1guVcD7sLCyjvegL8pRCCrU9xyKLF\
8u/Qz4s0x0uzcGYh0sd3iWj21+AtigSLdMD76/j/VzftQL8B1yp3vc1EZiowOwq4\
AwEAAaOCAW0wggFpMBIGA1UdEwEB/wQIMAYBAf8CAQAwHQYDVR0OBBYEFHppoyXF\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX=
</issuer-vrl>
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</ownership-voucher>
<signature>
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX=
</signature>
</device>
7.2.5. Progress Notifications
The following example illustrates a device using the API to post a
notification to the server. The device may send more than one
notification to the server (e.g., to provide status updates). The
YANG module defines only one notification type, bootstrap-complete.
Other notification types may be defined through YANG augmentation.
The bootstrap server MUST NOT process a notification from a device
without first authenticating the device. This is in contrast to when
a device is fetching data from the server, a read-only operation, in
which case device authentication is not strictly required.
In this example, the device sends a notification indicating that it
has completed bootstrapping off the data provided by the server.
This example also illustrates the device sending its SSH host keys to
the bootstrap server, which it might, for example, forward onto a
downstream NMS component, so that the NMS can subsequently
authenticate the device when establishing a NETCONF over SSH
connection to it.
Note that the need for a device to provide its SSH host key (or TLS
server certificate) in the "bootstrap-complete" message is
unnecessary when the device is able to present its IDevID certificate
[Std-802.1AR-2009] as its SSH host key or TLS server certificate,
when subsequently establishing a NETCONF or RESTCONF connection with
the deployment-specific NMS.
REQUEST
-------
['\' line wrapping added for formatting only]
POST https://example.com/restconf/data/ietf-zerotouch-bootstrap-server:\
devices/device=123456/notification HTTP/1.1
HOST: example.com
Content-Type: application/yang.data+xml
<!-- '\' line wrapping added for formatting purposes only -->
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<input
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<notification-type>bootstrap-complete</notification-type>
<message>example message</message>
<ssh-host-keys>
<ssh-host-key>
<format>ssh-rsa</format>
<key-data>
AAAAB3NzaC1yc2EAAAADAQABAAABAQDeJMV8zrtsi8CgEsRCjCzfve2m6\
zD3awSBPrh7ICggLQvHVbPL89eHLuecStKL3HrEgXaI/O2MwjE1lG9YxL\
zeS5p2ngzK61vikUSqfMukeBohFTrDZ8bUtrF+HMLlTRnoCVcCWAw1lOr\
9IDGDAuww6G45gLcHalHMmBtQxKnZdzU9kx/fL3ZS5G76Fy6sA5vg7SLq\
QFPjXXft2CAhin8xwYRZy6r/2N9PMJ2Dnepvq4H2DKqBIe340jWqEIuA7\
LvEJYql4unq4Iog+/+CiumTkmQIWRgIoj4FCzYkO9NvRE6fOSLLf6gakW\
VOZZgQ8929uWjCWlGlqn2mPibp2Go1
</key-data>
</ssh-host-key>
<ssh-host-key>
<format>ssh-dsa</format>
<key-data>
zD3awSBPrh7ICggLQvHVbPL89eHLuecStKL3HrEgXaI/O2MwjE1lG9YxL\
zeS5p2ngzK61vikUSqfMukeBohFTrDZ8bUtrF+HMLlTRnoCVcCWAw1lOr\
9IDGDAuww6G45gLcHalHMmBtQxKnZdzU9kx/fL3ZS5G76Fy6sA5vg7SLq\
AAAAB3NzaC1yc2EAAAADAQABAAABAQDeJMV8zrtsi8CgEsRCjCzfve2m6\
QFPjXXft2CAhin8xwYRZy6r/2N9PMJ2Dnepvq4H2DKqBIe340jWqEIuA7\
LvEJYql4unq4Iog+/+CiumTkmQIWRgIoj4FCzYkO9NvRE6fOSLLf6gakW\
VOZZgQ8929uWjCWlGlqn2mPibp2Go1
</key-data>
</ssh-host-key>
</ssh-host-keys>
<trust-anchors>
<trust-anchor>
<protocol>netconf-ssh</protocol>
<protocol>netconf-tls</protocol>
<protocol>restconf-tls</protocol>
<protocol>netconf-ch-ssh</protocol>
<protocol>netconf-ch-tls</protocol>
<protocol>restconf-ch-tls</protocol>
<certificate>
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW\
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QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
RJSUJQFRStS0Cg==
</certificate>
</trust-anchor>
</trust-anchors>
</input>
RESPONSE
--------
HTTP/1.1 204 No Content
Date: Sat, 31 Oct 2015 17:02:40 GMT
Server: example-server
7.3. Artifact Examples
This section presents some examples for how the same information
provided by the API can be packaged into stand alone artifacts. The
encoding for these artifacts is the same as if an HTTP GET request
had been sent to the RESTCONF URL for the specific resource. These
examples show the bootstrap information containing configuration
defined by [RFC7317] and [draft-ietf-netconf-server-model].
Encoding these artifacts for use outside of the RESTCONF protocol
extends their utility for other deployment scenarios, such as when a
local DHCP server or a removable storage device is used. By way of
example, this may be done to address an inability for the device to
access an Internet facing bootstrap/redirect server, or just for a
preference to use locally deployed infrastructure.
7.3.1. Signed Redirect Information
The following example illustrates how a redirect can be encoded into
an artifact for use outside of the RESTCONF protocol. The redirect
information is signed so that it is secure even when no transport-
level security is provided.
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<!-- '\' line wrapping added for formatting purposes only -->
<redirect-information
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<bootstrap-server>
<address>phs1.example.com</address>
<port>8443</port>
<trust-anchor>
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW\
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
RJSUJQFRStS0Cg==
</trust-anchor>
</bootstrap-server>
<bootstrap-server>
<address>phs1.example.com</address>
<port>8443</port>
<trust-anchor>
WmdsK2gyTTg3QmtGMjhWbW1CdFFVaWc3OEgrRkYyRTFwdSt4ZVRJbVFFM\
lLQllsdWpOcjFTMnRLR05EMUc2OVJpK2FWNGw2NTdZNCtadVJMZgpRYjk\
zSFNwSDdwVXBCYnA4dmtNanFtZjJma3RqZHBxeFppUUtTbndWZTF2Zwot\
NGcEk3UE90cnNFVjRwTUNBd0VBQWFPQ0FSSXdnZ0VPCk1CMEdBMVVkRGd\
VEJiZ0JTWEdlbUEKMnhpRHVOTVkvVHFLNWd4cFJBZ1ZOYUU0cERZd05ER\
V6QVJCZ05WQkFNVENrTlNUQ0JKYzNOMVpYS0NDUUNVRHBNSll6UG8zREF\
NQmdOVkhSTUJBZjhFCkFqQUFNQTRHQTFVZER3RUIvd1FFQXdJSGdEQnBC\
Z05WSFI4RVlqQmdNRjZnSXFBZ2hoNW9kSFJ3T2k4dlpYaGgKYlhCc1pTN\
WpiMjB2WlhoaGJYQnNaUzVqY215aU9LUTJNRFF4Q3pBSkJnTlZCQVlUQW\
QmdOVkJBWVRBbFZUTVJBd0RnWURWUVFLRXdkbAplR0Z0Y0d4bE1RNHdEQ\
MkF6a3hqUDlVQWtHR0dvS1U1eUc1SVR0Wm0vK3B0R2FieXVDMjBRd2kvZ\
25PZnpZNEhONApXY0pTaUpZK2xtYWs3RTRORUZXZS9RdGp4NUlXZmdvN2\
</bootstrap-server>
<signature>
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX=
</signature>
</redirect-information>
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7.3.2. Signed Bootstrap Information
The following example illustrates how bootstrapping data can be
encoded into an artifact for use outside of the RESTCONF protocol.
The bootstrap information is signed so that it is secure when no
transport-level security is provided.
<!-- '\' line wrapping added for formatting purposes only -->
<bootstrap-information
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<boot-image>
<name>
boot-image-v3.2R1.6.img
</name>
<md5>
SomeMD5String
</md5>
<sha1>
SomeSha1String
</sha1>
<uri>
file:///some/path/to/raw/file
</uri>
</boot-image>
<configuration>
<!-- from ietf-system.yang -->
<system xmlns="urn:ietf:params:xml:ns:yang:ietf-system">
<authentication>
<user>
<name>admin</name>
<ssh-key>
<name>admin's rsa ssh host-key</name>
<algorithm>ssh-rsa</algorithm>
<key-data>AAAAB3NzaC1yc2EAAAADAQABAAABAQDeJMV8zrtsi8CgEsRC\
jCzfve2m6zD3awSBPrh7ICggLQvHVbPL89eHLuecStKL3HrEgXaI/O2Mwj\
E1lG9YxLzeS5p2ngzK61vikUSqfMukeBohFTrDZ8bUtrF+HMLlTRnoCVcC\
WAw1lOr9IDGDAuww6G45gLcHalHMmBtQxKnZdzU9kx/fL3ZS5G76Fy6sA5\
vg7SLqQFPjXXft2CAhin8xwYRZy6r/2N9PMJ2Dnepvq4H2DKqBIe340jWq\
EIuA7LvEJYql4unq4Iog+/+CiumTkmQIWRgIoj4FCzYkO9NvRE6fOSLLf6\
gakWVOZZgQ8929uWjCWlGlqn2mPibp2Go1</key-data>
</ssh-key>
</user>
</authentication>
</system>
<!-- from ietf-netconf-server.yang -->
<netconf-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
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<call-home>
<application>
<name>config-mgr</name>
<ssh>
<endpoints>
<endpoint>
<name>east-data-center</name>
<address>11.22.33.44</address>
</endpoint>
<endpoint>
<name>west-data-center</name>
<address>55.66.77.88</address>
</endpoint>
</endpoints>
<host-keys>
<host-key>my-call-home-x509-key</host-key>
</host-keys>
</ssh>
</application>
</call-home>
</netconf-server>
</configuration>
</bootstrap-information>
7.3.3. Owner Certificate
The following example illustrates how the owner certificate, along
with its CRL, can be encoded into an artifact for use outside of the
RESTCONF protocol. Note that the inclusion of the CLR is optional,
and only present to support cases where the device is deployed on a
private network, such that it would be unable to validate the
revocation status of the certificate using an online lookup of the
CRL or using OCSP. As the owner certificate and CRL are already
signed by the manufacturer, an additional owner signature is
unnecessary.
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<!-- '\' line wrapping added for formatting purposes only -->
<owner-certificate
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<certificate>
MIIExTCCA62gAwIBAgIBATANBgkqhkiG9w0BAQsFADCBqjELMAkGA1UEBhMCVVMx\
EzARBgNVBAgTCkNhbGlmb3JuaWExEjAQBgNVBAcTCVN1bm55dmFsZTEZMBcGA1UE\
ChQQSnVuaXBlcl9OZXR3b3JrczEdMBsGA1UECxQUQ2VydGlmaWNhdGVfSXNzdWFu\
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
ap1DgmS3IaYl/s4OOF8yzcYJprm8O7NyZp+Y9H1U/7Qfp97/KbqwCgkHSzOlnt0X\
KQTpIM/rNrbrkuTmalezFoFS7mrxLXJAsfP1guVcD7sLCyjvegL8pRCCrU9xyKLF\
8u/Qz4s0x0uzcGYh0sd3iWj21+AtigSLdMD76/j/VzftQL8B1yp3vc1EZiowOwq4\
KmORbiKU2GTGZkaCgCjmrWpvrYWLoXv/sf2nPLyK6YjiWsslOJtRO+KzRbs2B18C\
AwEAAaOCAW0wggFpMBIGA1UdEwEB/wQIMAYBAf8CAQAwHQYDVR0OBBYEFHppoyXF\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAOBgNVHQ8BAf8EBAMCAgQwQgYDVR0fBDswOTA3oDWgM4YxaHR0cDovL2NybC5q\
dW5pcGVyLm5ldD9jYT1KdW5pcGVyX1RydXN0X0FuY2hvcl9DQTANBgkqhkiG9w0B\
AQsFAAOCAQEAOuD7EBilqQcT3t2C4AXta1gGNNwdldLLw0jtk4BMiA9l//DZfskB\
2AaJtiseLTXsMF6MQwDs1YKkiXKLu7gBZDlJ6NiDwy1UnXhi2BDG+MYXQrc6p76K\
z3bsVwZlaJQCdF5sbggc1MyrsOu9QirnRZkIv3R8ndJH5K792ztLquulAcMfnK1Y\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX7WJzEbT/G7MUfo\
Sb+U2PVsQTDWEzUjVnG7vNWYxirnAOZ0OXEWWYxHUJntx6DsbXYuX7D1PkkNr7ir\
96DpOPtX7h8pxxGSDPBXIyvg02aFMphstQ==
</certificate>
<issuer-crl>
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAO==
</issuer-crl>
</owner-certificate>
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7.3.4. Ownership Voucher
The following example illustrates how the ownership voucher, along
with its CRL, can be encoded into an artifact for use outside of the
RESTCONF protocol. Note that the inclusion of the CLR is optional,
and only present to support cases where the device is deployed on a
private network, such that it would be unable to validate the
revocation status of the certificate using an online lookup of the
CRL or using OCSP. As the ownership voucher and CRL are already
signed by the manufacturer, an additional owner signature is
unnecessary.
<!-- '\' line wrapping added for formatting purposes only -->
<ownership-voucher
xmlns="urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server">
<voucher>
ChQQSnVuaXBlcl9OZXR3b3JrczEdMBsGA1UECxQUQ2VydGlmaWNhdGVfSXNzdWFu\
Y2UxGTAXBgNVBAMUEFRQTV9UcnVzdF9BbmNob3IxHTAbBgkqhkiG9w0BCQEWDmNh\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
yh/JaftWYf7m3KBzOdg2MIHfBgNVHSMEgdcwgdSAFDSljCNmTN5b+CDujJLlyDal\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
MBAGA1UEBxMJU3Vubnl2YWxlMRkwFwYDVQQKFBBKdW5pcGVyX05ldHdvcmtzMR0w\
GwYDVQQLFBRDZXJ0aWZpY2F0ZV9Jc3N1YW5jZTEZMBcGA1UEAxQQVFBNX1RydXN0\
X0FuY2hvcjEdMBsGCSqGSIb3DQEJARYOY2FAanVuaXBlci5jb22CCQDUbsEdTn5v\
MjAO
</voucher>
<issuer-crl>
QGp1bmlwZXIuY29tMB4XDTE0MDIyNzE0MTM1MloXDTE1MDIyNzE0MTM1MlowMDET\
MBEGA1UEChQKVFBNX1ZlbmRvcjEZMBcGA1UEAxQQSnVuaXBlcl9YWFhYWF9DQTCC\
ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBANL5Mk5qFsVuqo+JmXWLmFxI\
RDEuRiZNRNLeJpgN9YWkXLAZX2rASwy041EMmZ6KAkWUd3ZmXucfoLpdRemfuPii\
KQTpIM/rNrbrkuTmalezFoFS7mrxLXJAsfP1guVcD7sLCyjvegL8pRCCrU9xyKLF\
8u/Qz4s0x0uzcGYh0sd3iWj21+AtigSLdMD76/j/VzftQL8B1yp3vc1EZiowOwq4\
AwEAAaOCAW0wggFpMBIGA1UdEwEB/wQIMAYBAf8CAQAwHQYDVR0OBBYEFHppoyXF\
WFPaoYGwpIGtMIGqMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTES\
NTOufhQsD2t4TYpEkzLEiZqSswdBOaPxPcJLQNW8Bw2xN+A9GX=
</issuer-crl>
</ownership-voucher>
7.4. YANG Module
The bootstrap server's device-facing interface is normatively defined
by the following YANG module:
<CODE BEGINS> file "ietf-zerotouch-bootstrap-server@2016-03-16.yang"
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module ietf-zerotouch-bootstrap-server {
yang-version "1.1";
namespace
"urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server";
prefix "ztbs";
import ietf-yang-types { // RFC 6991
prefix yang;
}
import ietf-inet-types { // RFC 6991
prefix inet;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
description
"This module defines the southbound interface for Zero Touch
bootstrap servers.
Copyright (c) 2014 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD
License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision "2016-03-16" {
description
"Initial version";
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reference
"RFC XXXX: Zero Touch Provisioning for NETCONF Call Home";
}
container devices {
config false;
description
"This is the top-level container for a device-facing protocol.
As such it is read-only, how this data is configured is outside
the scope of this data-model. Further, it is expected that
devices would only be able to access their data and not the
data for any other device.";
list device {
key unique-id;
description
"A device's record entry. This is the only RESTCONF resource
that a device is expected to GET. Getting this just this
top-level provides the device with all the data it needs in
a single request, which is ideal from both a performance and
a resiliency perspectives..";
leaf unique-id {
type string;
description
"A unique identifier for the device (e.g., serial number).
Each device accesses its bootstrapping record by its unique
identifier.";
}
choice type {
description
"This choice statement ensures the response only contains
redirect-information or bootstrap-information.";
container redirect-information {
description
"This is redirect information data. Its purpose is to
redirect the device to another bootstrap server. It
contains a list of bootstrap servers.";
list bootstrap-server {
key address;
description
"A bootstrap server entry.";
leaf address {
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type inet:host;
description
"The IP address or hostname of the bootstrap server
the device should redirect to.";
}
leaf port {
type inet:port-number;
default 443;
description
"The port number the bootstrap server listens on.";
}
leaf trust-anchor {
type binary;
mandatory true;
description
"An X.509 v3 certificate structure as specified by RFC
5280, Section 4 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690. A
certificate that a device can use as a trust anchor to
authenticate the bootstrap server it is being redirected
to.";
reference
"RFC 5280:
Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile.
ITU-T X.690:
Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
}
container bootstrap-information {
description
"This is bootstrap information data. Its purpose is to
provide the device everything it needs to bootstrap
itself.";
container boot-image {
description
"Specifies criteria for the boot image the device MUST be
running.";
container modules {
description
"Specifies a list of YANG modules that the device MUST
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support. This node is optional. When this node is
specified, the remaining nodes MUST be processed only
in case the currently running image does not support
any of the YANG modules, as a means to obtain a valid
image. When this node is not specified, then the
device MUST ensure it is running the exact image, as
specified by the remaining 'boot-image' nodes.";
list module {
description
"Specifies a specific YANG modules, by its name and
revision date. The revision date is provided as a
minimal revision date, and supported revision
thereafter is considered sufficient";
leaf name {
type yang:yang-identifier;
description
"The YANG module's name.";
}
leaf revision {
type string {
pattern '\d{4}-\d{2}-\d{2}';
}
description
"Represents a specific date in 2016-03-16 format.";
}
}
}
leaf name {
type string;
mandatory true;
description
"The name of a software image that either the device
MUST be running, or MUST install only if its currently
running image cannot support any of the required YANG
modules.";
}
leaf md5 {
type string;
mandatory true;
description
"The hex-encoded MD5 hash over the boot-image file.";
}
leaf sha1 {
type string;
mandatory true;
description
"The hex-encoded SHA-1 hash over the boot-image file.";
}
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leaf-list uri {
type inet:uri;
min-elements 1;
description
"An ordered list of URIs to where the boot-image file
may be obtained. When the bootstrap information is
obtained from a bootstrap server, it is RECOMMENDED
that the list begins with absolute paths (e.g.,
beginning with '/') to the bootstrap server, so as
to leverage the existing secure connection. If remote
URLs are also present in the list, deployments MUST
know in advance which URI schemes (https, http, ftp,
file, etc.) a device supports. If a secure scheme
(e.g., https) is provided, devices MAY blindly accept
the server's credentials (e.g., TLS certificate).
Regardless how obtained, the device MUST ensure that
the boot-image is valid, either by leveraging a
signature embedded in the boot-image itself, if it
exists, or by first comparing the downloaded image to
both the MD5 and SHA1 fingerprints provided above.";
}
}
anyxml configuration { // pyang doesn't support anydata yet!
description
"Any configuration data model known to the device. It may
contain manufacturer-specific and/or standards-based data
models.";
}
leaf script {
type string;
description
"A device specific script that enables the execution of
commands to perform actions not possible thru configuration
alone. The script SHOULD be executed with 'root' level
permissions.
If a script is erroneously provided to a device that
does not support the execution of scripts, the device
SHOULD send a 'script-warning' notification message,
but otherwise continue processing the bootstrapping
data as if the script had not been present.
The script would return exit status code '0' on success
and non-zero on error, with accompanying stderr/stdout
for logging purposes. In the case of an error, the exit
status code will specify what the device should do.
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If the exit status code is greater than zero, then the
device should assume that the script had soft failure
that the script believes does not affect manageability.
If the device obtained the bootstrap information from
a bootstrap server, it SHOULD send a 'script-warning'
notification message.
If the exit status code is less than zero, the device
should assume the script had a hard error that the
script believes will affect manageability. In this
case, the device should try to send a 'script-error'
notification message followed by a reset that will
force a new boot-image install (wiping out anything
the script may have done) and restart the entire
bootstrapping process again.";
}
}
}
container owner-certificate {
when "../ownership-voucher" {
description
"The owner certificate is only configurable when there
also exists an ownership voucher.";
}
description
"It is intended that the device will fetch this container
as a whole, as it contains values that need to be
processed together.";
leaf certificate {
type binary;
mandatory true;
description
"An X.509 v3 certificate structure as specified by RFC
5280, Section 4 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690.
This certificate, signed by a manufacturer or delegate,
for an owner, must encode a manufacturer-assigned value
identifying the organization. This identifier must match
the owner identifier encoded in the ownership voucher.";
reference
"RFC 5280:
Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile.
ITU-T X.690:
Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
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Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
leaf issuer-crl {
type binary;
description
"An CRL structure as specified by RFC 5280, Section 5
encoded using the ASN.1 distinguished encoding rules
(DER), as specified in ITU-T X.690. The CRL for the
CA that signed the owner certificate. The CRL should
be as up to date as possible. This leaf is optional
as it is only needed to support deployments where the
device is unable to download the CRL from and of the
distribution points listed in the owner certificate.";
reference
"RFC 5280:
Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile.
ITU-T X.690:
Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
container ownership-voucher {
when "../signature" {
description
"An ownership voucher is only configurable when there
also exists a signature.";
}
must "../owner-certificate" {
description
"An owner certificate must be present whenever an
ownership voucher is present.";
}
description
"This container contains the ownership voucher that the
device uses to ascertain the identity of its rightful
owner, as certified by its manufacturer.";
leaf voucher {
type binary;
mandatory true;
description
"A manufacturer-specific encoding binding unique device
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identifiers to an owner identifier value matching the
value encoded in the owner-certificate below.";
}
leaf issuer-vrl {
type binary;
description
"An manufacturer-specific encoding of a voucher revocation
list (VRL) for the issuer used by the manufacturer or
delegate to sign ownership vouchers. The VRL should be
as up to date as possible. This leaf is optional as it
is only needed to support deployments where the device
is unable to download the VRL from the manufacturer or
delegate using some manufacturer-specific mechanism.";
}
}
leaf signature {
type binary;
must "../ownership-voucher" {
description
"An ownership voucher must be present whenever an
signature is present.";
}
description
"A PKCS #7 SignedData structure as specified by RFC
2315, Section 9.1 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690.
This signature is generated using the owner's private
private key and an owner-selected digest algorithm over
the redirect-information or the bootstrap-information
nodes, which ever is present, and in whatever encoding
they are presented in (e.g., XML, JSON, etc.).";
// is there a canonical format?
reference
"RFC 2315:
PKCS #7: Cryptographic Message Syntax Version 1.5
ITU-T X.690:
Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
action notification {
input {
leaf notification-type {
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type enumeration {
enum bootstrap-initiated {
description
"Indicates that the device has just accessed
the bootstrap server. The 'message' field
below SHOULD contain any additional information
that the manufacturer thinks might be useful,
or omitted entirely.";
}
enum validation-error {
description
"Indicates that the device had an issue validating
the response from the bootstrap server. The
'message' field below SHOULD indicate the specific
error. This message also indicates that the device
has abandoned trying to bootstrap off this bootstrap
server.";
}
enum signature-validation-error {
description
"Indicates that the device had an issue validating
the bootstrapping data. For instance, this could
be due to the device expecting signed data, but
only found unsigned data, or because the ownership
voucher didn't include its unique identifier, or
because the signature didn't match, or and other
relevant error. This 'message' field below SHOULD
indicate the specific error. This message also
indicates that the device has abandoned trying to
bootstrap off this bootstrap server.";
}
enum image-mismatch {
description
"Indicates that the device has determined that
its running image does not meet the specified
criteria. The 'message' field below SHOULD
indicate both what image the device is currently
running as well as the criteria that failed.";
}
enum image-download-error {
description
"Indicates that the device had an issue downloading
the image, which could be anything from the file
server being unreachable to the downloaded file
being the incorrect file (signature mismatch). The
'message' field about SHOULD indicate the specific
error. This message also indicates that the device
has abandoned trying to bootstrap off this bootstrap
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server.";
}
enum config-warning {
description
"Indicates that the device obtained warning messages
when it committed the initial configuration. The
'message' field below SHOULD indicate the warning
messages that were generated.";
}
enum config-error {
description
"Indicates that the device obtained error messages
when it committed the initial configuration. The
'message' field below SHOULD indicate the error
messages that were generated. This message also
indicates that the device has abandoned trying to
bootstrap off this bootstrap server.";
}
enum script-warning {
description
"Indicates that the device obtained a greater than
zero exit status code from the script when it was
executed. The 'message' field below SHOULD indicate
both the resulting exit status code and well as
capture any stdout/stderr messages the script may
have produced.";
}
enum script-error {
description
"Indicates that the device obtained a less than zero
exit status code from the script when it was executed.
The 'message' field below SHOULD indicate both the
resulting exit status code and well as capture any
stdout/stderr messages the script may have produced.
This message also indicates that the device has
abandoned trying to bootstrap off this bootstrap
server.";
}
enum bootstrap-complete {
description
"Indicates that the device successfully processed the
all the bootstrapping data and that it is ready to
be managed. The 'message' field below SHOULD contain
any additional information that the manufacturer
thinks might be useful, or omitted entirely. At
this point, the device is not expected to access
the bootstrap server again.";
}
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enum informational {
description
"Provided any additional information not captured by
any of the other notification-type. The 'message'
field below SHOULD contain any additional information
that the manufacturer thinks might be useful, or
omitted entirely.";
}
}
mandatory true;
description
"The type of notification provided.";
}
leaf message {
type string;
description
"An optional human-readable value.";
}
container ssh-host-keys {
description
"A list of SSH host keys an NMS may use to authenticate
a NETCONF connection to the device with.";
list ssh-host-key {
when "../type = bootstrap-complete" {
description
"SSH host keys are only sent when the notification
type is 'bootstrap-complete'.";
}
description
"An SSH host-key";
leaf format {
type enumeration {
enum ssh-dss { description "ssh-dss"; }
enum ssh-rsa { description "ssh-rsa"; }
}
mandatory true;
description
"The format of the SSH host key.";
}
leaf key-data {
type string;
mandatory true;
description
"The key data for the SSH host key";
}
}
}
container trust-anchors {
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description
"A list of trust anchor certificates an NMS may use to
authenticate a NETCONF or RESTCONF connection to the
device with.";
list trust-anchor {
when "../type = bootstrap-complete" {
description
"Trust anchors are only sent when the notification
type is 'bootstrap-complete'.";
}
description
"A list of trust anchor certificates an NMS may use to
authenticate a NETCONF or RESTCONF connection to the
device with.";
leaf-list protocol {
type enumeration {
enum netconf-ssh { description "netconf-ssh"; }
enum netconf-tls { description "netconf-tls"; }
enum restconf-tls { description "restconf-tls"; }
enum netconf-ch-ssh { description "netconf-ch-ssh"; }
enum netconf-ch-tls { description "netconf-ch-tls"; }
enum restconf-ch-tls { description "restconf-ch-tls"; }
}
min-elements 1;
description
"The protocols that this trust anchor secures.";
}
leaf certificate {
type binary;
mandatory true;
description
"An X.509 v3 certificate structure as specified by RFC
5280, Section 4 encoded using the ASN.1 distinguished
encoding rules (DER), as specified in ITU-T X.690.";
reference
"RFC 5280:
Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile.
ITU-T X.690:
Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER),
Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).";
}
}
}
}
} // end action
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}
}
}
<CODE ENDS>
8. Security Considerations
8.1. Immutable storage for trust anchors
Devices MUST ensure that all their trust anchor certificates,
including those for the owner certificate and ownership voucher, are
protected from external modification.
It may be necessary to update these certificates over time (e.g., the
manufacturer wants to delegate trust to a new CA). It is therefore
expected that devices MAY update these trust anchors when needed
through a verifiable process, such as a software upgrade using signed
software images.
8.2. Clock Sensitivity
The solution in this document relies on TLS certificates, owner
certificates, ownership vouchers, and CRLs, all of which require an
accurate clock in order to be processed correctly. Devices
implementations should take care to ensure the devices have a
reliable clock when processing signed data, ideally be using a built-
in real time clock (RTC). If a device does not have an RTC, then it
SHOULD try to use NTP to initialize its clock before processing any
time-sensitive bootstrapping data. It is understood that NTP is
itself unsecured, not enabling the client to authenticate the server,
and therefore easily spoofed. In the case that NTP is spoofed, it is
possible for a replay attack to occur where an ownership voucher
assignment from a previous owner is replayed on a device that has
since been claimed by a new owner. For this reason, for devices that
do not contain an RTC, it is RECOMMENDED that manufacturers only
issue a single ownership voucher for the lifetime of a device.
8.3. Blindly authenticating a bootstrap server
This document allows a device to blindly authenticate a bootstrap
server's TLS certificate. It does so to allow for cases where the
redirect information may be obtained in an unsecured manner (e.g.,
via a DNS service discovery lookup, where only a hostname or IP
address is returned).
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To compensate for this, this document requires that devices do not
send their IDevID certificate for client authentication, and that
they do not POST any progress notifications, and that they assert
that data downloaded from the server is signed, just as bootstrapping
data would need to be signed if read from a removable storage device.
8.4. Entropy loss over time
Section 7.2.7.2 of the IEEE Std 802.1AR-2009 standard says that
IDevID certificate should never expire (i.e. having a notAfter
99991231235959Z). Given the long-lived nature of these certificates,
it is paramount to use a strong key length (e.g., 512-bit ECC).
8.5. Serial Numbers
This draft suggests using the device's serial number as the unique
identifier in its IDevID certificate. This is because serial numbers
are ubiquitous and prominently contained in invoices and on labels
affixed to devices and their packaging. That said, serial numbers
many times encode revealing information, such as the device's model
number, manufacture date, and/or sequence number. Knowledge of this
information may provide an adversary with details needed to launch an
attack.
9. IANA Considerations
9.1. The BOOTP Manufacturer Extensions and DHCP Options Registry
The following registrations are in accordance to RFC 2939 [RFC2939]
for "BOOTP Manufacturer Extensions and DHCP Options" registry
maintained at http://www.iana.org/assignments/bootp-dhcp-parameters.
9.1.1. DHCP v4 Option
Tag: XXX
Name: Zero Touch Redirect Information
Returns a YANG-defined redirect-information object, encoded in
the encoding specified by 'encoding'. Currently only "xml"
and "json" are supported.
Code Len
+-----+-----+----------+---------------------+
| XXX | n | encoding |redirect-information |
+-----+-----+----------+---------------------+
Reference: RFC XXXX
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9.1.2. DHCP v6 Option
Tag: YYY
Name: Zero Touch Redirect Information
Returns a YANG-defined redirect-information object, encoded in
the encoding specified by 'encoding'. Currently only "xml"
and "json" are supported.
Code Len
+-----+-----+----------+---------------------+
| XXX | n | encoding |redirect-information |
+-----+-----+----------+---------------------+
Reference: RFC XXXX
9.2. The IETF XML Registry
This document registers one URI in the IETF XML registry [RFC3688].
Following the format in [RFC3688], the following registration is
requested:
URI: urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server
Registrant Contact: The NETCONF WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
9.3. The YANG Module Names Registry
This document registers one YANG module in the YANG Module Names
registry [RFC6020]. Following the format defined in [RFC6020], the
the following registration is requested:
name: ietf-zerotouch-bootstrap-server
namespace: urn:ietf:params:xml:ns:yang:ietf-zerotouch-bootstrap-server
prefix: ztbs
reference: RFC XXXX
10. Other Considerations
Both this document and [draft-pritikin-anima-bootstrapping-keyinfra]
define bootstrapping mechanisms. The authors have collaborated on
both solutions and believe that each solution has merit and, in fact,
can work together. That is, it is possible for a device to support
both solutions simultaneously.
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11. Acknowledgements
The authors would like to thank for following for lively discussions
on list and in the halls (ordered by last name): David Harrington,
Michael Behringer, Dean Bogdanovic, Martin Bjorklund, Joe Clarke,
Toerless Eckert, Stephen Farrell, Stephen Hanna, Wes Hardaker, Russ
Mundy, Reinaldo Penno, Randy Presuhn, Max Pritikin, Michael
Richardson, Juergen Schoenwaelder.
Special thanks goes to Steve Hanna, Russ Mundy, and Wes Hardaker for
brainstorming the original I-D's solution during the IETF 87 meeting
in Berlin.
12. References
12.1. Normative References
[draft-ietf-netconf-call-home]
Watsen, K., "NETCONF Call Home (work in progress)", draft-
ieft-netconf-restconf-10 (work in progress), December
2015, <https://tools.ietf.org/html/draft-ietf-netconf-
call-home-17>.
[draft-ietf-netconf-restconf]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", draft-ieft-netconf-restconf-10 (work in
progress), 2016, <https://tools.ietf.org/html/draft-ietf-
netconf-restconf-10>.
[draft-ietf-netconf-server-model]
Watsen, K., "NETCONF Server Model (work in progress)",
draft-ieft-netconf-server-model-09 (work in progress),
March 2016, <http://tools.ietf.org/html/
draft-ietf-netconf-call-home-17>.
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
November 1987, <http://www.rfc-editor.org/info/rfc1035>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2315] Kaliski, B., "PKCS #7: Cryptographic Message Syntax
Version 1.5", RFC 2315, DOI 10.17487/RFC2315, March 1998,
<http://www.rfc-editor.org/info/rfc2315>.
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[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
DOI 10.17487/RFC2782, February 2000,
<http://www.rfc-editor.org/info/rfc2782>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<http://www.rfc-editor.org/info/rfc5280>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<http://www.rfc-editor.org/info/rfc6020>.
[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
Verification of Domain-Based Application Service Identity
within Internet Public Key Infrastructure Using X.509
(PKIX) Certificates in the Context of Transport Layer
Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March
2011, <http://www.rfc-editor.org/info/rfc6125>.
[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>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<http://www.rfc-editor.org/info/rfc6991>.
[Std-802.1AR-2009]
IEEE SA-Standards Board, "IEEE Standard for Local and
metropolitan area networks - Secure Device Identity",
December 2009, <http://standards.ieee.org/findstds/
standard/802.1AR-2009.html>.
12.2. Informative References
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[draft-pritikin-anima-bootstrapping-keyinfra]
Pritikin, M., Behringer, M., and S. Bjarnason,
"Bootstrapping Key Infrastructures", draft-pritikin-anima-
bootstrapping-keyinfra-03 (work in progress), 2016,
<https://tools.ietf.org/html/draft-pritikin-anima-
bootstrapping-keyinfra>.
[RFC2939] Droms, R., "Procedures and IANA Guidelines for Definition
of New DHCP Options and Message Types", BCP 43, RFC 2939,
DOI 10.17487/RFC2939, September 2000,
<http://www.rfc-editor.org/info/rfc2939>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<http://www.rfc-editor.org/info/rfc6241>.
[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
of Named Entities (DANE) Transport Layer Security (TLS)
Protocol: TLSA", RFC 6698, DOI 10.17487/RFC6698, August
2012, <http://www.rfc-editor.org/info/rfc6698>.
[RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for
System Management", RFC 7317, DOI 10.17487/RFC7317, August
2014, <http://www.rfc-editor.org/info/rfc7317>.
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Appendix A. Examples
A.1. Ownership Voucher
Following describes an example data-model for an ownership voucher.
Real vouchers are expected to be encoded in a manufacturer-specific
format outside the of scope for this draft.
A tree diagram describing an ownership voucher:
module: ietf-zerotouch-ownership-voucher
+--rw voucher
+--rw owner-id string
+--rw unique-id* string
+--rw created-on yang:date-and-time
+--rw expires-on? yang:date-and-time
+--rw signature string
The YANG module for this example voucher:
<CODE BEGINS> file "ietf-zerotouch-ownership-voucher@2016-03-16.yang"
module ietf-zerotouch-ownership-voucher {
namespace
"urn:ietf:params:xml:ns:yang:ietf-zerotouch-ownership-voucher";
prefix "ztov";
import ietf-yang-types { prefix yang; }
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
description
"This module defines the format for a ZeroTouch ownership voucher,
which is produced by Vendors, relayed by Bootstrap Servers, and
consumed by devices. The purpose of the voucher is to enable a
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device to ascertain the identity of its rightful owner, as
certified by its Vendor.
Copyright (c) 2014 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD
License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision "2016-03-16" {
description
"Initial version";
reference
"RFC XXXX: Zero Touch Provisioning for NETCONF Call Home";
}
// top-level container
container voucher {
description
"A voucher, containing the owner's identifier, a list of
device's unique identifiers, information on when the
voucher was created, when it might expire, and the
vendor's signature over the above values.";
leaf owner-id {
type string;
mandatory true;
description
"A Vendor-assigned value for the rightful owner of the
devices enumerated by this voucher. The owner-id value
must match the value in the owner-certificate below";
}
leaf-list unique-id {
type string;
min-elements 1;
description
"The unique identifier (e.g., serial-number) for a device.
The value must match the value in the device's IDevID
certificate. A device uses this value to determine if
the voucher applies to it.";
}
leaf created-on {
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type yang:date-and-time;
mandatory true;
description
"The date this voucher was created";
}
leaf expires-on {
type yang:date-and-time;
description
"The date this voucher expires, if at all. Use of this
value requires that the device has access to a trusted
real time clock";
}
leaf signature {
type string;
mandatory true;
description
"The signature over the concatenation of all the previous
values";
}
}
}
<CODE ENDS>
Appendix B. Change Log
B.1. ID to 00
o Major structural update; the essence is the same. Most every
section was rewritten to some degree.
o Added a Use Cases section
o Added diagrams for "Actors and Roles" and "NMS Precondition"
sections, and greatly improved the "Device Boot Sequence" diagram
o Removed support for physical presence or any ability for
configlets to not be signed.
o Defined the Zero Touch Information DHCP option
o Added an ability for devices to also download images from
configuration servers
o Added an ability for configlets to be encrypted
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o Now configuration servers only have to support HTTP/S - no other
schemes possible
B.2. 00 to 01
o Added boot-image and validate-owner annotations to the "Actors and
Roles" diagram.
o Fixed 2nd paragraph in section 7.1 to reflect current use of
anyxml.
o Added encrypted and signed-encrypted examples
o Replaced YANG module with XSD schema
o Added IANA request for the Zero Touch Information DHCP Option
o Added IANA request for media types for boot-image and
configuration
B.3. 01 to 02
o Replaced the need for a configuration signer with the ability for
each NMS to be able to sign its own configurations, using
manufacturer signed ownership vouchers and owner certificates.
o Renamed configuration server to bootstrap server, a more
representative name given the information devices download from
it.
o Replaced the concept of a configlet by defining a southbound
interface for the bootstrap server using YANG.
o Removed the IANA request for the boot-image and configuration
media types
B.4. 02 to 03
o Minor update, mostly just to add an Editor's Note to show how this
draft might integrate with the draft-pritikin-anima-bootstrapping-
keyinfra.
B.5. 03 to 04
o Major update formally introducing unsigned data and support for
Internet-based redirect servers.
o Added many terms to Terminology section.
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o Added all new "Guiding Principles" section.
o Added all new "Sources for Bootstrapping Data" section.
o Rewrote the "Interactions" section and renamed it "Workflow
Overview".
B.6. 04 to 05
o Semi-major update, refactoring the document into more logical
parts
o Created new section for information types
o Added support for DNS servers
o Now allows provisional TLS connections
o Bootstrapping data now supports scripts
o Device Details section overhauled
o Security Considerations expanded
o Filled in enumerations for notification types
B.7. 05 to 06
o Minor update
o Added many Normative and Informative references.
o Added new section Other Considerations.
B.8. 06 to 07
o Minor update
o Added an Editorial Note section for RFC Editor.
o Updated the IANA Considerations section.
Authors' Addresses
Kent Watsen
Juniper Networks
EMail: kwatsen@juniper.net
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Mikael Abrahamsson
T-Systems
EMail: "mikael.abrahamsson@t-systems.se
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