Simple Provisioning of Public Names for Residential Networks
draft-ietf-homenet-front-end-naming-delegation-19
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 9526.
|
|
|---|---|---|---|
| Authors | Daniel Migault , Ralf Weber , Michael Richardson , Ray Hunter | ||
| Last updated | 2022-10-19 | ||
| Replaces | draft-mglt-homenet-front-end-naming-delegation | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
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| Additional resources | Mailing list discussion | ||
| Stream | WG state | Submitted to IESG for Publication | |
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| IANA | IANA review state | Version Changed - Review Needed |
draft-ietf-homenet-front-end-naming-delegation-19
Homenet D. Migault
Internet-Draft Ericsson
Intended status: Standards Track R. Weber
Expires: 23 April 2023 Nominum
M. Richardson
Sandelman Software Works
R. Hunter
Globis Consulting BV
20 October 2022
Simple Provisioning of Public Names for Residential Networks
draft-ietf-homenet-front-end-naming-delegation-19
Abstract
Home network owners may have devices or services hosted on this home
network that they wish to access from the Internet (i.e., from a
network outside of the home network). To enable this access, the
names and IP addresses of these devices and services needs to be made
available in the public DNS.
The names and IP address of the home network are present in the
Public Homenet Zone by the Homenet Naming Authority (HNA), which in
turn instructs the DNS Outsourcing Infrastructure (DOI) to publish
the zone on the behalf of the HNA. This document describes how an
HNA can instruct a DOI to publish a Public Homenet Zone on its
behalf.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 23 April 2023.
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Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Selecting Names and Addresses to Publish . . . . . . . . . . 5
4. Dynamic DNS Alternative solutions . . . . . . . . . . . . . . 6
5. Envisioned deployment scenarios . . . . . . . . . . . . . . . 8
5.1. CPE Vendor . . . . . . . . . . . . . . . . . . . . . . . 8
5.1.1. Agnostic CPE . . . . . . . . . . . . . . . . . . . . 8
6. Architecture Description . . . . . . . . . . . . . . . . . . 9
6.1. Architecture Overview . . . . . . . . . . . . . . . . . . 10
6.2. Distribution Manager Communication Channels . . . . . . . 13
7. Control Channel . . . . . . . . . . . . . . . . . . . . . . . 14
7.1. Information to Build the Public Homenet Zone . . . . . . 14
7.2. Information to build the DNSSEC chain of trust . . . . . 15
7.3. Information to set the Synchronization Channel . . . . . 15
7.4. Deleting the delegation . . . . . . . . . . . . . . . . . 16
7.5. Messages Exchange Description . . . . . . . . . . . . . . 16
7.5.1. Retrieving information for the Public Homenet
Zone. . . . . . . . . . . . . . . . . . . . . . . . . 16
7.5.2. Providing information for the DNSSEC chain of
trust . . . . . . . . . . . . . . . . . . . . . . . . 17
7.5.3. Providing information for the Synchronization
Channel . . . . . . . . . . . . . . . . . . . . . . . 18
7.5.4. HNA instructing deleting the delegation . . . . . . . 19
7.6. Securing the Control Channel . . . . . . . . . . . . . . 19
7.7. Implementation Concerns . . . . . . . . . . . . . . . . . 19
8. Synchronization Channel . . . . . . . . . . . . . . . . . . . 20
8.1. Securing the Synchronization Channel . . . . . . . . . . 21
9. DM Distribution Channel . . . . . . . . . . . . . . . . . . . 21
10. HNA Security Policies . . . . . . . . . . . . . . . . . . . . 22
11. Public Homenet Reverse Zone . . . . . . . . . . . . . . . . . 22
12. DNSSEC compliant Homenet Architecture . . . . . . . . . . . . 23
13. Renumbering . . . . . . . . . . . . . . . . . . . . . . . . . 24
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14. Privacy Considerations . . . . . . . . . . . . . . . . . . . 25
15. Security Considerations . . . . . . . . . . . . . . . . . . . 27
15.1. HNA DM channels . . . . . . . . . . . . . . . . . . . . 27
15.2. Names are less secure than IP addresses . . . . . . . . 28
15.3. Names are less volatile than IP addresses . . . . . . . 28
15.4. Deployment Considerations . . . . . . . . . . . . . . . 29
15.5. Operational Considerations . . . . . . . . . . . . . . . 29
16. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30
17. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . 30
18. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 30
19. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
19.1. Normative References . . . . . . . . . . . . . . . . . . 30
19.2. Informative References . . . . . . . . . . . . . . . . . 32
Appendix A. HNA Channel Configurations . . . . . . . . . . . . . 35
A.1. Homenet Public Zone . . . . . . . . . . . . . . . . . . . 36
Appendix B. Information Model for Outsourced information . . . . 37
Appendix C. Example: A manufacturer provisioned HNA product
flow . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40
1. Introduction
Home network owners may have devices or services hosted on this home
network that they wish to access from the Internet (i.e., from a
network outside of the home network). To enable this access, the
names and IP addresses of these devices and services needs to be made
available in the public DNS.
The names and IP address of the home network are present in the
Public Homenet Zone by the Homenet Naming Authority (HNA), which in
turn instructs the DNS Outsourcing Infrastructure (DOI) to publish
the zone on the behalf of the HNA. This document describes how an
HNA can instruct a DOI to publish a Public Homenet Zone on its
behalf.
The document introduces the Synchronization Channel and the Control
Channel between the HNA and the Distribution Manager (DM) that
belongs to the DOI.
The Synchronization Channel (see Section 8) is used to synchronize
the Public Homenet Zone. The HNA is configured as a primary, while
the DM is configured as a secondary.
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The Control Channel (see Section 7) is used to set the
Synchronization Channel. For example, to build the Public Homenet
Zone, the HNA needs the authoritative servers (and associated IP
addresses) of the servers of the DOI actually serving the zone.
Similarly, the DOI needs to know the IP address of the primary (HNA)
as well as potentially the hash of the Key SIgning Key (KSK) in the
DS RRset to secure the DNSSEC delegation with the parent zone.
The remainder of the document is as follows. Section 2 defines the
terminology, Section 3 presents the general problem of publishing
names and IP addresses, Section 4 presents an alternative solution to
the current mechanism described in this document and Section 5
presents some deployment scenarios. Section 6 provides an
architectural view of the HNA, DM and DOI as well as their different
communication channels (Control Channel, Synchronization Channel, DM
Distribution Channel) respectively described in Section 7, Section 8
and Section 9. Section 10 and Section 12 respectively detail HNA
security policies as well as DNSSEC compliance within the home
network. Section 13 discusses how renumbering should be handled.
Finally, Section 14 and Section 15 respectively discuss privacy and
security considerations when outsourcing the Public Homenet Zone.
The appendices discuss several management (see Section 11)
provisioning (see Section 11), configurations (see Appendix B) and
deployment (see Section 5 and Appendix C) aspects.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Customer Premises Equipment: (CPE) is a router providing
connectivity to the home network.
Homenet Zone: is the DNS zone for use within the boundaries of the
home network: 'home.arpa' (see [RFC8375]). This zone is not
considered public and is out of scope for this document.
Registered Homenet Domain: is the domain name that is associated
with the home network. A given home network may have multiple
Registered Homenet Domain.
Public Homenet Zone: contains the names in the home network that are
expected to be publicly resolvable on the Internet. A home
network can have multiple Public Homenet Zones.
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Homenet Naming Authority(HNA): is a function responsible for managing
the Public Homenet Zone. This includes populating the Public Homenet
Zone, signing the zone for DNSSEC, as well as managing the
distribution of that Homenet Zone to the DNS Outsourcing
Infrastructure (DOI).
DNS Outsourcing Infrastructure (DOI): is the infrastructure
responsible for receiving the Public Homenet Zone and publishing
it on the Internet. It is mainly composed of a Distribution
Manager and Public Authoritative Servers.
Public Authoritative Servers: are the authoritative name servers for
the Public Homenet Zone. Name resolution requests for the
Registered Homenet Domain are sent to these servers.
Homenet Authoritative Servers: are authoritative name servers for
the Homenet Zone within the Homenet network.
Distribution Manager (DM): is the (set of) server(s) to which the
HNA synchronizes the Public Homenet Zone, and which then
distributes the relevant information to the Public Authoritative
Servers.
Public Homenet Reverse Zone: The reverse zone file associated with
the Public Homenet Zone.
Reverse Public Authoritative Servers: equivalent to Public
Authoritative Servers specifically for reverse resolution.
Reverse Distribution Manager: equivalent to Distribution Manager
specifically for reverse resolution.
Homenet DNSSEC Resolver: a resolver that performs a DNSSEC
resolution on the home network for the Public Homenet Zone. The
resolution is performed requesting the Homenet Authoritative
Servers.
DNSSEC Resolver: a resolver that performs a DNSSEC resolution on the
Internet for the Public Homenet Zone. The resolution is performed
requesting the Public Authoritative Servers.
3. Selecting Names and Addresses to Publish
While this document does not create any normative mechanism to select
the names to publish, this document anticipates that the home network
administrator (a human being), will be presented with a list of
current names and addresses either directly on the HNA or via another
device such as a phone.
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The administrator would mark which devices and services (by name),
are to be published. The HNA would then collect the IP address(es)
associated with that device or service, and put the name into the
Public Homenet Zone. The address of the device or service can be
collected from a number of places: mDNS [RFC6762], DHCP [RFC8415],
UPnP, PCP [RFC6887], or manual configuration.
A device or service may have Global Unicast Addresses (GUA) (IPv6
[RFC3787] or IPv4), Unique Local IPv6 Addresses (ULA) [RFC4193], as
well IPv6-Link-Local addresses[RFC4291][RFC7404], IPv4-Link-Local
Addresses [RFC3927] (LLA), and private IPv4 addresses [RFC1918]. Of
these the link-local are almost never useful for the Public Zone, and
should be omitted. The IPv6 ULA and the private IPv4 addresses may
be useful to publish, if the home network environment features a VPN
that would allow the home owner to reach the network.
The IPv6 ULA addresses are safer to publish with a significantly
lower probability of collision than RFC1918 addresses.
In general, one expects the GUA to be the default address to be
published. However, publishing the ULA and private IPv4 addresses
may enable local communications within the home network. A direct
advantage of enabling local communication is to enable communications
even in case of Internet disruption. Since communications are
established with names which remain a global identifier, the
communication can be protected by TLS the same way it is protected on
the global Internet - using certificates.
4. Dynamic DNS Alternative solutions
An alternative existing solution for residential customers is to have
a single zone, where a host uses a RESTful HTTP service to register a
single name into a common public zone. This is often called "Dynamic
DNS" [DDNS], and there are a number of commercial providers. While
the IETF has defined a DNS based mechanism Dynamic Update [RFC2136],
in many - as far as the co-authors know in all cases - case
commercial "Dynamic Update" solutions are primarily implemented via a
HTTPS RESTful API.
This section discusses the case where every individual devices are
configured with a Dynamic Update client, followed by the case where
Dynamic Update is being used by a centralized entity like the CPE.
These solutions were typically used by a host behind the CPE and
since the CPE implements some NAT, the host can only be reached from
the global Internet via its CPE IPv4 address. This is the most
common scenario considered in this section, while some variant may
also consider the client being hosted in the CPE.
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For a very few numbers of hosts, the use of such a system provides an
alternative to the architecture described in this document. Dynamic
DNS - even adapted to IPv6 and ignoring those associated with an IPv4
development - does suffer from some severe limitations:
* When devices are individually configured with Dynamic DNS, any
centralized network management entity such as the CPE router is
unaware of the process, and cannot respond to queries for these
names and communications to these names require an Internet
connectivity is order to perform the DNS resolution. Such
dependence does not meet the requirement for internal
communications to be resilient to ISP connectivity disruptions
[RFC7368] Section 3.7.5.
* Similarly, the CPE router cannot control the process. Any host
can do this regardless of whether or not the home network
administrator wants the name published or not. There is therefore
no possible audit trail.
* the credentials for the dynamic DNS server need to be securely
transferred to all hosts that wish to use it. This is not a
problem for a technical user to do with one or two hosts, but it
does not scale to multiple hosts and becomes a problem for non-
technical users.
* "all the good names are taken" - current services provide a small
set of zones shared by all hosts across all home networks. More
especially, there is no notion of a domain specific home network.
As there are some commonalities provided by individual home
networks, there are often conflicts. This makes the home user or
application dependent on having to resolve different names in the
event of outages or disruptions. Distinguishing similar names by
delegation of zones was among the primary design goals of the DNS
system.
* The RESTful services do not always support all RR types. The
homenet user is dependent on the service provider supporting new
types. By providing full DNS delegation, this document enables
all RR types and also future extensions.
* Dynamic Update solution are not interoperable and each provider
has its own way to implement it. [RFC3007] is the standard
solution to update a DNS RRset, but most Dynamic Update providers
use HTTPS RESTful API.
There is no technical reason why a RESTful service could not provide
solutions to many of these problems, but this document describes a
DNS-based solution.
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Dynamic Update can also be implemented by a CPE, in which case the
handling of the zone as well the synchronization of the zone with the
DNS provider is handled by the CPE. The DNS zone are then
synchronized using an alternative mechanism as the one designed for
zone synchronisation inherited from the primary used case where the
synchronization is performed at the node level. Our proposal use the
standard mechanism defined by DNS for zone synchronisation.
5. Envisioned deployment scenarios
A number of deployment scenarios have been envisioned, this section
aims at providing a brief description. The use cases are not
limitations and this section is not normative.
5.1. CPE Vendor
A specific vendor with specific relations with a registrar or a
registry may sell a CPE that is provisioned with a domain name. Such
a domain name does not need to be human readable.
One possible scenario is that the vendor also provisions the HNA with
a private and public key as well as a certificate used for the mutual
TLS authentication. Note that these keys are not expected to be used
for DNSSEC signing. Instead these keys are solely used by the HNA
for the authentication to the DM. Normally the keys should be
necessary and sufficient to proceed to the authentication. The
reason to combine the domain name and the key is that the outsourcing
infrastructure (DOI) likely handles names better than keys and that
domain names might be used as a login which enables the key to be
regenerated.
When the home network owner plugs in the CPE at home, the relation
between HNA and DM is expected to work out-of-the-box.
5.1.1. Agnostic CPE
A CPE that is not preconfigured may also use the protocol defined in
this document but some configuration steps will be needed.
1. The owner of the home network buys a domain name from a
registrar, and as such creates an account on that registrar
2. the registrar may also be providing the outsourcing
infrastructure or the home network may need to create a specific
account on the outsourcing infrastructure.
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* If the DOI is the registrar, it has by design a proof of ownership
of the domain name by the homenet owner. In this case, it is
expected the DOI provides the necessary parameters to the home
network owner to configure the HNA. One potential mechanism to
provide the parameters would be to provide the user with a JSON
object which they can copy paste into the CPE - such as described
in Appendix B. But, what matters here for the DOI is that the HNA
is able to authenticate itself to the DOI.
* If the DOI is not the registrar, then the proof of ownership needs
to be established using protocols like ACME [RFC8555] for example
that will end in the generation of a certificate. ACME is used
here to the purpose of automating the generation of the
certificate, the CA may be a specific CA or the DOI. With that
being done, the DOI has a roof of ownership and can proceed as
above.
6. Architecture Description
This section provides an overview of the architecture for outsourcing
the authoritative naming service from the HNA to the DOI. As a
consequence, this prevents HNA to handle the DNS traffic from the
Internet associated with the resolution of the Homenet Zone as
depicted in Figure 1. More specifically, DNS resolution for the
Public Homenet Zone (here myhome.example) from Internet DNSSEC
resolvers is handled by the DOI as opposed to the HNA. The DOI
benefits from a cloud infrastructure while the HNA is dimensioned for
home network and as such likely enable to support any load. In the
case the HNA is a CPE, outsourcing to the DOI protects the home
network against DDoS for example. Of course the DOI needs to be
informed dynamically about the content of myhome.example. The
description of such a synchronization mechanism is the purpose of
this document.
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Home network | Internet
+----------------------+ | +----------------------+
| HNA | | | DOI |
|+--------------------+| | |+--------------------+|
|| Public Homenet Zone||<------------>|| Public Homenet Zone||
|| (myhome.example) || | || (myhome.example) ||
|+--------------------+| DNS Zone | |+--------------------+|
+----------------------+ Synchron- | +----------------------+
(primary) ization | ^ | (secondary)
| | | (DNS resolution)
| | v
| +-----------------------+
| | Internet |
| | DNSSEC Resolver |
| +-----------------------+
Figure 1: Homenet Naming Architecture Overview
Note that Appendix B shows necessary parameters to configure the HNA.
6.1. Architecture Overview
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Home network | Internet
|
| +----------------------------+
| | DOI |
(primary) Control | | (secondary) |
+-----------------------+ Channel | | +-----------------------+ |
| HNA |<-------------->| Distribution Manager | |
|+---------------------+| | | |+---------------------+| |
|| Public Homenet Zone ||Synchronization || Public Homenet Zone || |
|| (myhome.example) || Channel | | || (myhome.example) || |
|+---------------------+|<-------------->|+---------------------+| |
+-----------^-----------+ | | +-----------------------+ |
. | | ^ Distribution |
. | | | Channel |
+-----------v-----------+ | | v |
| Homenet Authoritative | | | +-----------------------+ |
| Server(s) | | | | Public Authoritative | |
|+---------------------+| | | | Server(s) | |
||Public Homenet Zone || | | |+---------------------+| |
|| (myhome.example) || | | || Public Homenet Zone || |
|+---------------------+| | | || (myhome.example) || |
|| Homenet Zone || | | |+---------------------+| |
|| (home.arpa) || | | +-----------------------+ |
|+---------------------+| | +----------^---|-------------+
+----------^---|--------+ | | |
| | name resolution | |
| v | | v
+----------------------+ | +-----------------------+
| Homenet | | | Internet |
| DNSSEC Resolver | | | DNSSEC Resolver |
+----------------------+ | +-----------------------+
Figure 2: Homenet Naming Architecture
Figure 2 illustrates the architecture where the HNA outsources the
publication of the Public Homenet Zone to the DOI. The DOI will
serve every DNS request of the Public Homenet Zone coming from
outside the home network. When the request is coming within the home
network, the resolution is expected to be handled by the Homenet
Resolver as detailed in further details below.
In this example, The Public Homenet Zone is identified by the
Registered Homenet Domain name - myhome.example. The ".local" as
well as ".home.arpa" are explicitly not considered as Public Homenet
zones and represented as Homenet Zone in Figure 2.
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The HNA SHOULD build the Public Homenet Zone in a single view
populated with all resource records that are expected to be published
on the Internet. The HNA also signs the Public Homenet Zone. The
HNA handles all operations and keying material required for DNSSEC,
so there is no provision made in this architecture for transferring
private DNSSEC related keying material between the HNA and the DM.
Once the Public Homenet Zone has been built, the HNA communicates and
synchronizes it with the DOI using a primary/secondary setting as
depicted in Figure 2. The HNA acts as a hidden master (now
designated as hidden primary) [RFC8499] while the DM behaves as a
secondary responsible for distributing the Public Homenet Zone to the
multiple Public Authoritative Servers that DOI is responsible for.
The DM has three communication channels:
* DM Control Channel (Section 7) to configure the HNA and the DOI.
This includes necessary parameters to configure the primary/
secondary relation as well as some information provided by the DOI
that needs to be included by the HNA in the Public Homenet Zone.
* DM Synchronization Channel (Section 8) to synchronize the Public
Homenet Zone on the HNA and on the DM with the appropriately
configured primary/secondary.
* one or more Distribution Channels (Section 9) that distribute the
Public Homenet Zone from the DM to the Public Authoritative
Servers serving the Public Homenet Zone on the Internet.
There might be multiple DM's, and multiple servers per DM. This
document assumes a single DM server for simplicity, but there is no
reason why each channel needs to be implemented on the same server or
use the same code base.
It is important to note that while the HNA is configured as an
authoritative server, it is not expected to answer DNS requests from
the public Internet for the Public Homenet Zone. More specifically,
the addresses associated with the HNA SHOULD NOT be mentioned in the
NS records of the Public Homenet zone, unless additional security
provisions necessary to protect the HNA from external attack have
been taken.
The DOI is also responsible for ensuring the DS record has been
updated in the parent zone.
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Resolution is performed by DNS(SEC) resolvers. When the resolution
is performed outside the home network, the DNSSEC Resolver resolves
the DS record on the Global DNS and the name associated with the
Public Homenet Zone (myhome.example) on the Public Authoritative
Servers.
On the other hand, to provide resilience to the Public Homenet Zone
in case of WAN connectivity disruption, the Homenet DNSSEC Resolver
SHOULD be able to perform the resolution on the Homenet Authoritative
Servers. These servers are not expected to be mentioned in the
Public Homenet Zone, nor to be accessible from the Internet. As such
their information as well as the corresponding signed DS record MAY
be provided by the HNA to the Homenet DNSSEC Resolvers, e.g., using
HNCP [RFC7788] or a by configuring a trust anchor
[I-D.ietf-dnsop-dnssec-validator-requirements]. Such configuration
is outside the scope of this document. Since the scope of the
Homenet Authoritative Servers is limited to the home network, these
servers are expected to serve the Homenet Zone as represented in
Figure 2.
How the Homenet Authoritative Servers are provisioned is also out of
scope of this specification. It could be implemented using primary
and secondary servers, or via rsync. In some cases, the HNA and
Homenet Authoritative Servers may be combined together which would
result in a common instantiation of an authoritative server on the
WAN and inner homenet interface. Note that [RFC6092] REC-8 states
this must not be the default configuration. Other mechanisms may
also be used.
6.2. Distribution Manager Communication Channels
This section details the DM channels, that is the Control Channel,
the Synchronization Channel and the Distribution Channel.
The Control Channel and the Synchronization Channel are the
interfaces used between the HNA and the DOI. The entity within the
DOI responsible to handle these communications is the DM and
communications between the HNA and the DM MUST be protected and
mutually authenticated. While Section 7.6 discusses in more depth
the different security protocols that could be used to secure, it is
RECOMMENDED to use TLS with mutual authentication based on
certificates to secure the channel between the HNA and the DM.
The information exchanged between the HNA and the DM uses DNS
messages protected by DNS over TLS (DoT) [RFC7858]. This is
configured identically to that described in [RFC9103].
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It is worth noticing that both DM and HNA need to agree on a common
configuration to set up the synchronization channel as well as to
build and server a coherent Public Homenet Zone. Typically, the
visible NS records of the Public Homenet Zone (built by the HNA)
SHOULD remain pointing at the DOI's Public Authoritative Servers' IP
address - which in many cases will be an anycast address. Revealing
the address of the HNA in the DNS is not desirable. In addition, and
depending on the configuration of the DOI, the DM also needs to
update the parent zone's (NS, DS and associated A or AAAA records).
Refer to Section 7.2 for more details.
This specification assumes:
* the DM serves both the Control Channel and Synchronization Channel
on a single IP address, single port and using a single transport
protocol.
* By default, the HNA uses a single IP address for both the Control
and Synchronization channel. However, the HNA MAY use distinct IP
addresses for the Control Channel and the Synchronization Channel
- see Section 8 and Section 7.3 for more details.
The Distribution Channel is internal to the DOI and as such is not
the primary concern of this specification.
7. Control Channel
The DM Control Channel is used by the HNA and the DOI to exchange
information related to the configuration of the delegation which
includes information to build the Public Homenet Zone (Section 7.1),
information to build the DNSSEC chain of trust (Section 7.2) and
information to set the Synchronization Channel (Section 7.3). While
information is carried from the DOI to the HNA and from the HNA to
the DOI, the HNA is always initiating the exchange in both
directions.
As such the HNA has a prior knowledge of the DM identity (X509
certificate), the IP address and port number to use and protocol to
establish a secure session. The DM acquires knowledge of the
identity of the HNA (X509 certificate) as well as the Registered
Homenet Domain. For more detail to see how this can be achieved,
please see Appendix A.1.
7.1. Information to Build the Public Homenet Zone
The HNA builds the Public Homenet Zone based on information retrieved
from the DM (see Section 7.5).
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The information includes at least names and IP addresses of the
Public Authoritative Name Servers. In term of RRset information this
includes:
* the MNAME of the SOA,
* the NS and associated A and AAA RRsets of the name servers.
The DM MAY also provide operational parameters such as other fields
of SOA (SERIAL, RNAME, REFRESH, RETRY, EXPIRE and MINIMUM). As the
information is necessary for the HNA to proceed and the information
is associated with the DM, this information exchange is mandatory.
7.2. Information to build the DNSSEC chain of trust
The HNA SHOULD provide the hash of the KSK via the DS RRset, so the
DOI provides this value to the parent zone. A common deployment use
case is that the DOI is the registrar of the Registered Homenet
Domain and as such, its relationship with the registry of the parent
zone enables it to update the parent zone. When such relation
exists, the HNA should be able to request the DOI to update the DS
RRset in the parent zone. A direct update is especially necessary to
initialize the chain of trust.
Though the HNA may also later directly update the values of the DS
via the Control Channel, it is RECOMMENDED to use other mechanisms
such as CDS and CDNSKEY [RFC7344] for transparent updates during key
roll overs.
As some deployments may not provide a DOI that will be able to update
the DS in the parent zone, this information exchange is OPTIONAL.
By accepting the DS RR, the DM commits to advertise the DS to the
parent zone. On the other hand if the DM does not have the capacity
to advertise the DS to the parent zone, it indicates this by refusing
the DS RR.
7.3. Information to set the Synchronization Channel
The HNA works as a primary authoritative DNS server, while the DM
works like a secondary. As a result, the HNA must provide the IP
address the DM should use to reach the HNA. The synchronization
Channel will be set between that IP address and the IP address of the
DM. By default, the IP address used by the HNA in the Control
Channel is considered by the DM and the explicit specification of the
IP by the HNA is only OPTIONAL. The transport channel (including
port number) is the same as the one used between the HNA and the DM
for the Control Channel.
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7.4. Deleting the delegation
The purpose of the previous sections were to exchange information in
order to set a delegation. The HNA MUST also be able to delete a
delegation with a specific DM. Upon an instruction of deleting the
delegation, the DM MUST stop serving the Public Homenet Zone.
The decision to delete an inactive HNA by the DM is part of the
commercial agreement between DOI and HNA.
7.5. Messages Exchange Description
There are multiple ways this information could be exchanged between
the HNA and the DM. This specification defines a mechanism that re-
use the DNS exchanges format, while the exchange in itself is not a
DNS exchange involved in any DNS operations such as DNS resolution.
Note that while information is provided using DNS exchanges, the
exchanged information is not expected to be set in any zone file,
instead this information is used as commands between the HNA and the
DM.
The Control Channel is not expected to be a long-term session. After
a predefined timer - similar to those used for TCP - the Control
Channel is expected to be terminated - by closing the transport
channel. The Control Channel MAY be re-opened at any time later.
The provisioning process SHOULD provide a method of securing the
Control Channel, so that the content of messages can be
authenticated. This authentication MAY be based on certificates for
both the DM and each HNA. The DM may also create the initial
configuration for the delegation zone in the parent zone during the
provisioning process.
7.5.1. Retrieving information for the Public Homenet Zone.
The information provided by the DM to the HNA is retrieved by the HNA
with an AXFR exchange [RFC1034]. AXFR enables the response to
contain any type of RRsets. The response might be extended in the
future if additional information will be needed. Alternatively, the
information provided by the HNA to the DM is pushed by the HNA via a
DNS update exchange [RFC2136].
To retrieve the necessary information to build the Public Homenet
Zone, the HNA MUST send a DNS request of type AXFR associated with
the Registered Homenet Domain. The DM MUST respond with a zone
template. The zone template MUST contain a RRset of type SOA, one or
multiple RRset of type NS and zero or more RRset of type A or AAAA.
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* The SOA RR indicates to the HNA the value of the MNAME of the
Public Homenet Zone.
* The NAME of the SOA RR MUST be the Registered Homenet Domain.
* The MNAME value of the SOA RDATA is the value provided by the DOI
to the HNA.
* Other RDATA values (RNAME, REFRESH, RETRY, EXPIRE and MINIMUM) are
provided by the DOI as suggestions.
The NS RRsets carry the Public Authoritative Servers of the DOI.
Their associated NAME MUST be the Registered Homenet Domain.
The TTL and RDATA are those expected to be published on the Public
Homenet Zone. The RRsets of Type A and AAAA MUST have their NAME
matching the NSDNAME of one of the NS RRsets.
Upon receiving the response, the HNA MUST validate format and
properties of the SOA, NS and A or AAAA RRsets. If an error occurs,
the HNA MUST stop proceeding and MUST log an error. Otherwise, the
HNA builds the Public Homenet Zone by setting the MNAME value of the
SOA as indicated by the SOA provided by the AXFR response. The HNA
SHOULD set the value of NAME, REFRESH, RETRY, EXPIRE and MINIMUM of
the SOA to those provided by the AXFR response. The HNA MUST insert
the NS and corresponding A or AAAA RRset in its Public Homenet Zone.
The HNA MUST ignore other RRsets. If an error message is returned by
the DM, the HNA MUST proceed as a regular DNS resolution. Error
messages SHOULD be logged for further analysis. If the resolution
does not succeed, the outsourcing operation is aborted and the HNA
MUST close the Control Channel.
7.5.2. Providing information for the DNSSEC chain of trust
To provide the DS RRset to initialize the DNSSEC chain of trust the
HNA MAY send a DNS update [RFC2136] message.
The DNS update message is composed of a Header section, a Zone
section, a Pre-requisite section, and Update section and an
additional section. The Zone section MUST set the ZNAME to the
parent zone of the Registered Homenet Domain - that is where the DS
records should be inserted. As described [RFC2136], ZTYPE is set to
SOA and ZCLASS is set to the zone's class. The Pre-requisite section
MUST be empty. The Update section is a DS RRset with its NAME set to
the Registered Homenet Domain and the associated RDATA corresponds to
the value of the DS. The Additional Data section MUST be empty.
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Though the pre-requisite section MAY be ignored by the DM, this value
is fixed to remain coherent with a standard DNS update.
Upon receiving the DNS update request, the DM reads the DS RRset in
the Update section. The DM checks ZNAME corresponds to the parent
zone. The DM SHOULD ignore the Pre-requisite and Additional Data
sections, if present. The DM MAY update the TTL value before
updating the DS RRset in the parent zone. Upon a successful update,
the DM should return a NOERROR response as a commitment to update the
parent zone with the provided DS. An error indicates the MD does not
update the DS, and the HNA needs to act accordingly or other method
should be used by the HNA.
The regular DNS error message SHOULD be returned to the HNA when an
error occurs. In particular a FORMERR is returned when a format
error is found, this includes when unexpected RRSets are added or
when RRsets are missing. A SERVFAIL error is returned when a
internal error is encountered. A NOTZONE error is returned when
update and Zone sections are not coherent, a NOTAUTH error is
returned when the DM is not authoritative for the Zone section. A
REFUSED error is returned when the DM refuses to proceed to the
configuration and the requested action.
7.5.3. Providing information for the Synchronization Channel
The default IP address used by the HNA for the Synchronization
Channel is the IP address of the Control Channel. To provide a
different IP address, the HNA MAY send a DNS UPDATE message.
Similarly to the Section 7.5.2, the HNA MAY specify the IP address
using a DNS update message. The Zone section sets its ZNAME to the
parent zone of the Registered Homenet Domain, ZTYPE is set to SOA and
ZCLASS is set to the zone's type. Pre-requisite is empty. The
Update section is a RRset of type NS. The Additional Data section
contains the RRsets of type A or AAAA that designates the IP
addresses associated with the primary (or the HNA).
The reason to provide these IP addresses is to keep them unpublished
and prevent them to be resolved.
Upon receiving the DNS update request, the DM reads the IP addresses
and checks the ZNAME corresponds to the parent zone. The DM SHOULD
ignore a non-empty Pre-requisite section. The DM configures the
secondary with the IP addresses and returns a NOERROR response to
indicate it is committed to serve as a secondary.
Similarly to Section 7.5.2, DNS errors are used and an error
indicates the DM is not configured as a secondary.
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7.5.4. HNA instructing deleting the delegation
To instruct to delete the delegation the HNA sends a DNS UPDATE
Delete message.
The Zone section sets its ZNAME to the Registered Homenet Domain, the
ZTYPE to SOA and the ZCLASS to zone's type. The Pre-requisite
section is empty. The Update section is a RRset of type NS with the
NAME set to the Registered Domain Name. As indicated by [RFC2136]
Section 2.5.2 the delete instruction is set by setting the TTL to 0,
the Class to ANY, the RDLENGTH to 0 and the RDATA MUST be empty. The
Additional Data section is empty.
Upon receiving the DNS update request, the DM checks the request and
removes the delegation. The DM returns a NOERROR response to
indicate the delegation has been deleted. Similarly to
Section 7.5.2, DNS errors are used and an error indicates the
delegation has not been deleted.
7.6. Securing the Control Channel
TLS [RFC8446]) MUST be used to secure the transactions between the DM
and the HNA and the DM and HNA MUST be mutually authenticated. The
DNS exchanges are performed using DNS over TLS [RFC7858].
The HNA may be provisioned by the manufacturer, or during some user-
initiated onboarding process, for example, with a browser, signing up
to a service provider, with a resulting OAUTH2 token to be provided
to the HNA. (see Appendix A.1). In the future, other specifications
may consider protecting DNS messages with other transport layers,
among others, DNS over DTLS [RFC8094], or DNS over HTTPs (DoH)
[RFC8484] or DNS over QUIC [RFC9250].
7.7. Implementation Concerns
The Hidden Primary Server on the HNA differs from a regular
authoritative server for the home network due to:
Interface Binding: the Hidden Primary Server will almost certainly
listen on the WAN Interface, whereas a regular Homenet
Authoritative Servers would listen on the internal home network
interface.
Limited exchanges: the purpose of the Hidden Primary Server is to
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synchronize with the DM, not to serve any zones to end users, or
the public Internet. This results in a limited number of possible
exchanges (AXFR/IXFR) with a small number of IP addresses and an
implementation SHOULD enable filtering policies as described in
Section 10.
8. Synchronization Channel
The DM Synchronization Channel is used for communication between the
HNA and the DM for synchronizing the Public Homenet Zone. Note that
the Control Channel and the Synchronization Channel are by
construction different channels even though there they may use the
same IP address. Suppose the HNA and the DM are using a single IP
address and let designate by XX, YYYY and ZZZZ the various ports
involved in the communications. The Control Channel is between the
HNA working as a client using port number YYYY (a high range port)
toward a service provided by the DM at port number XX (well-known
port such as 853 for DoT).
On the other hand, the Synchronization Channel is set between the DM
working as a client using port ZZZZ ( another high range port) toward
a service provided by the HNA at port XX.
As a result, even though the same pair of IP addresses may be
involved the Control Channel and the Synchronization Channel are
always distinct channels.
Uploading and dynamically updating the zone file on the DM can be
seen as zone provisioning between the HNA (Hidden Primary) and the DM
(Secondary Server). This can be handled via AXFR + DNS UPDATE.
The use of a primary / secondary mechanism [RFC1996] is RECOMMENDED
instead of the use of DNS UPDATE [RFC2136]. The primary / secondary
mechanism is RECOMMENDED as it scales better and avoids DoS attacks.
Note that even when UPDATE messages are used, these messages are
using a distinct channel as those used to set the configuration.
Note that there is no standard way to distribute a DNS primary
between multiple devices. As a result, if multiple devices are
candidate for hosting the Hidden Primary, some specific mechanisms
should be designed so the home network only selects a single HNA for
the Hidden Primary. Selection mechanisms based on HNCP [RFC7788] are
good candidates.
The HNA acts as a Hidden Primary Server, which is a regular
authoritative DNS Server listening on the WAN interface.
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The DM is configured as a secondary for the Registered Homenet Domain
Name. This secondary configuration has been previously agreed
between the end user and the provider of the DOI as part of either
the provisioning or due to receipt of DNS UPDATE messages on the DM
Control Channel.
The Public Homenet Reverse Zone MAY also be updated either with DNS
UPDATE [RFC2136] or using a primary / secondary synchronization.
8.1. Securing the Synchronization Channel
The Synchronization Channel uses standard DNS requests.
First the HNA (primary) notifies the DM (secondary) that the zone
must be updated and leaves the DM (secondary) to proceed with the
update when possible/convenient.
More specifically, the HNA sends a NOTIFY message, which is a small
packet that is less likely to load the secondary. Then, the DM sends
AXFR [RFC1034] or IXFR [RFC1995] request. This request consists in a
small packet sent over TCP (Section 4.2 [RFC5936]), which also
mitigates reflection attacks using a forged NOTIFY.
The AXFR request from the DM to the HNA MUST be secured with TLS
[RFC8446]) following DNS Zone Transfer over TLS [RFC9103]. While
[RFC9103] MAY not consider the protection by TLS of NOTIFY and SOA
requests, these MAY still be protected by TLS to provide additional
privacy.
When using TLS, the HNA MAY authenticate inbound connections from the
DM using standard mechanisms, such as a public certificate with
baked-in root certificates on the HNA, or via DANE [RFC6698]. In
addition, to guarantee the DM remains the same across multiple TLS
session, the HNA and DM MAY implement [RFC8672].
The HNA SHOULD apply an ACL on inbound AXFR requests to ensure they
only arrive from the DM Synchronization Channel. In this case, the
HNA SHOULD regularly check (via a DNS resolution) that the address of
the DM in the filter is still valid.
9. DM Distribution Channel
The DM Distribution Channel is used for communication between the DM
and the Public Authoritative Servers. The architecture and
communication used for the DM Distribution Channels are outside the
scope of this document, and there are many existing solutions
available, e.g., rsync, DNS AXFR, REST, DB copy.
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10. HNA Security Policies
The HNA as hidden primary processes only a limited message exchanges.
This should be enforced using security policies - to allow only a
subset of DNS requests to be received by HNA.
The HNA, as Hidden Primary SHOULD drop any DNS queries from the home
network - as opposed to return DNS errors. This could be implemented
via port binding and/or firewall rules. The precise mechanism
deployed is out of scope of this document.
The HNA SHOULD drop any packets arriving on the WAN interface that
are not issued from the DM - as opposed to server as an Homenet
Authoritative Server exposed on the Internet.
Only TLS packet or potentially some DNS packets ( see XoT) packets
SHOULD be allowed.
The HNA SHOULD NOT send DNS messages other than DNS NOTIFY query, SOA
response, IXFR response or AXFR responses. The HNA SHOULD reject any
incoming messages other than DNS NOTIFY response, SOA query, IXFR
query or AXFR query.
11. Public Homenet Reverse Zone
Public Homenet Reverse Zone works similarly to the Public Homenet
Zone. The main difference is that ISP that provides the IP
connectivity is likely also the owner of the corresponding reverse
zone and act as a default DOI for it. If so, the configuration and
the setting of the Synchronization Channel and Control Channel can
largely be automated.
The Public Homenet Zone is associated with a Registered Homenet
Domain and the ownership of that domain requires a specific
registration from the end user as well as the HNA being provisioned
with some authentication credentials. Such steps are mandatory
unless the DOI has some other means to authenticate the HNA. Such
situation may occur, for example, when the ISP provides the Homenet
Domain as well as the DOI.
In this case, the HNA may be authenticated by the physical link
layer, in which case the authentication of the HNA may be performed
without additional provisioning of the HNA. While this may not be so
common for the Public Homenet Zone, this situation is expected to be
quite common for the Reverse Homenet Zone as the ISP owns the IP
address or IP prefix.
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More specifically, a common case is that the upstream ISP provides
the IPv6 prefix to the Homenet with a IA_PD [RFC8415] option and
manages the DOI of the associated reverse zone.
This leaves place for setting up automatically the relation between
HNA and the DOI as described in
[I-D.ietf-homenet-naming-architecture-dhc-options].
In the case of the reverse zone, the DOI authenticates the source of
the updates by IPv6 Access Control Lists. In the case of the reverse
zone, the ISP knows exactly what addresses have been delegated. The
HNA SHOULD therefore always originate Synchronization Channel updates
from an IP address within the zone that is being updated.
For example, if the ISP has assigned 2001:db8:f00d::/64 to the WAN
interface (by DHCPv6, or PPP/RA), then the HNA should originate
Synchronization Channel updates from, for example, 2001:db8:f00d::2.
An ISP that has delegated 2001:db8:aeae::/56 to the HNA via
DHCPv6-PD, then HNA should originate Synchronization Channel updates
an IP within that subnet, such as 2001:db8:aeae:1::2.
With this relation automatically configured, the synchronization
between the Home network and the DOI happens similarly as for the
Public Homenet Zone described earlier in this document.
Note that for home networks connected to by multiple ISPs, each ISP
provides only the DOI of the reverse zones associated with the
delegated prefix. It is also likely that the DNS exchanges will need
to be performed on dedicated interfaces as to be accepted by the ISP.
More specifically, the reverse zone associated with prefix 1 will not
be possible to be performs by the HNA using an IP address that
belongs to prefix 2. Such constraints does not raise major concerns
either for hot standby or load sharing configuration.
With IPv6, the reverse domain space for IP addresses associated with
a subnet such as ::/64 is so large that reverse zone may be
confronted with scalability issues. How the reverse zone is
generated is out of scope of this document. [RFC8501] provides
guidance on how to address scalability issues.
12. DNSSEC compliant Homenet Architecture
[RFC7368] in Section 3.7.3 recommends DNSSEC to be deployed on both
the authoritative server and the resolver. The resolver side is out
of scope of this document, and only the authoritative part of the
server is considered.
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It is RECOMMENDED the HNA signs the Public Homenet Zone.
Secure delegation is achieved only if the DS RRset is properly set in
the parent zone. Secure delegation can be performed by the HNA or
the DOIs and the choice highly depends on which entity is authorized
to perform such updates. Typically, the DS RRset can be updated
manually in the parent zone with nsupdate for example. This requires
the HNA or the DOI to be authenticated by the DNS server hosting the
parent of the Public Homenet Zone. Such a trust channel between the
HNA and the parent DNS server may be hard to maintain with HNAs, and
thus may be easier to establish with the DOI. In fact, the Public
Authoritative Server(s) may use Automating DNSSEC Delegation Trust
Maintenance [RFC7344].
13. Renumbering
During a renumbering of the network, the HNA IP address is changed
and the Public Homenet Zone is updated potentially by the HNA. Then,
the HNA advertises to the DM via a NOTIFY, that the Public Homenet
Zone has been updated and that the IP address of the primary has been
updated. This corresponds to the standard DNS procedure performed on
the Synchronization Channel and no specific actions are expected for
the HNA (See Section 7.3).
The remaining of the section provides recommendations regarding the
provisioning of the Public Homenet Zone - especially the IP
addresses. Renumbering has been extensively described in [RFC4192]
and analyzed in [RFC7010] and the reader is expected to be familiar
with them before reading this section. In the make-before-break
renumbering scenario, the new prefix is advertised, the network is
configured to prepare the transition to the new prefix. During a
period of time, the two prefixes old and new coexist, before the old
prefix is completely removed. In the break-before-make renumbering
scenario, the new prefix is advertised making the old prefix
obsolete.
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In a renumbering scenario, the HNA or Hidden Primary is informed it
is being renumbered. In most cases, this occurs because the whole
home network is being renumbered. As a result, the Public Homenet
Zone will also be updated. Although the new and old IP addresses may
be stored in the Public Homenet Zone, it is RECOMMENDED that only the
newly reachable IP addresses be published. Regarding the Public
Homenet Reverse Zone, the new Public Homenet Reverse Zone has to be
populated as soon as possible, and the old Public Homenet Reverse
Zone will be deleted by the owner of the zone (and the owner of the
old prefix which is usually the ISP) once the prefix is no longer
assigned to the HNA. The ISP SHOULD ensure that the DNS cache has
expired before re-assigning the prefix to a new home network. This
may be enforced by controlling the TTL values.
To avoid reachability disruption, IP connectivity information
provided by the DNS SHOULD be coherent with the IP in use. In our
case, this means the old IP address SHOULD NOT be provided via the
DNS when it is not reachable anymore. Let for example TTL be the TTL
associated with a RRset of the Public Homenet Zone, it may be cached
for TTL seconds. Let T_NEW be the time the new IP address replaces
the old IP address in the Homenet Zone, and T_OLD_UNREACHABLE the
time the old IP is not reachable anymore.
In the case of the make-before-break, seamless reachability is
provided as long as T_OLD_UNREACHABLE - T_NEW > 2 * TTL. If this is
not satisfied, then devices associated with the old IP address in the
home network may become unreachable for 2 * TTL - (T_OLD_UNREACHABLE
- T_NEW). In the case of a break-before-make, T_OLD_UNREACHABLE =
T_NEW, and the device may become unreachable up to 2 * TTL. Of
course if T_NEW >= T_OLD_UNREACHABLE, the disruption is increased.
14. Privacy Considerations
Outsourcing the DNS Authoritative service from the HNA to a third
party raises a few privacy related concerns.
The Public Homenet Zone lists the names of services hosted in the
home network. Combined with blocking of AXFR queries, the use of
NSEC3 [RFC5155] (vs NSEC [RFC4034]) prevents an attacker from being
able to walk the zone, to discover all the names. However, recent
work [GPUNSEC3] or [ZONEENUM] have shown that the protection provided
by NSEC3 against dictionary attacks should be considered cautiously
and [RFC9276] provides guidelines to configure NSEC3 properly. In
addition, the attacker may be able to walk the reverse DNS zone, or
use other reconnaissance techniques to learn this information as
described in [RFC7707].
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The zone is also exposed during the synchronization between the
primary and the secondary. [RFC9103] only specifies the use of TLS
for XFR transfers, which leak the existence of the zone and has been
clearly specified as out of scope of the threat model of [RFC9103].
Additional privacy MAY be provided by protecting all exchanges of the
Synchronization Channel as well as the Control Channel.
In general a home network owner is expected to publish only names for
which there is some need to be able to reference externally.
Publication of the name does not imply that the service is
necessarily reachable from any or all parts of the Internet.
[RFC7084] mandates that the outgoing-only policy [RFC6092] be
available, and in many cases it is configured by default. A well
designed User Interface would combine a policy for making a service
public by a name with a policy on who may access it.
In many cases, and for privacy reasons, the home network owner wished
publish names only for services that they will be able to access.
The access control may consist of an IP source address range, or
access may be restricted via some VPN functionality. The main
advantages of publishing the name are that service may be access by
the same name both within the home and outside the home and that the
DNS resolution can be handled similarly within the home and outside
the home. This considerably eases the ability to use VPNs where the
VPN can be chosen according to the IP address of the service.
Typically, a user may configure its device to reach its homenet
devices via a VPN while the remaining of the traffic is accessed
directly. In such cases, the routing policy is likely to be defined
by the destination IP address.
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Enterprise networks have generally adopted another strategy
designated as split-DNS. While such strategy might appear as
providing more privacy at first sight, its implementation remains
challenging and the privacy advantages needs to be considered
carefully. In split-DNS, names are designated with internal names
that can only be resolved within the corporate network. When such
strategy is applied to homenet, VPNs needs to be both configured with
a naming resolution policies and routing policies. Such approach
might be reasonable with a single VPN, but maintaining a coherent DNS
space and IP space among various VPNs comes with serious
complexities. Firstly, if multiple homenets are using the same
domain name -like home.arpa - it becomes difficult to determine on
which network the resolution should be performed. As a result,
homenets should at least be differentiated by a domain name.
Secondly, the use of split-DNS requires each VPN being associated
with a resolver and specific resolutions being performed by the
dedicated resolver. Such policies can easily raises some conflicts
(with significant privacy issues) while remaining hard to be
implemented.
In addition to the Public Homenet Zone, pervasive DNS monitoring can
also monitor the traffic associated with the Public Homenet Zone.
This traffic may provide an indication of the services an end user
accesses, plus how and when they use these services. Although,
caching may obfuscate this information inside the home network, it is
likely that outside your home network this information will not be
cached.
15. Security Considerations
This document exposes a mechanism that prevents the HNA from being
exposed to the Internet and served DNS request from the Internet.
These requests are instead served by the DOI. While this limits the
level of exposure of the HNA, the HNA remains exposed to the Internet
with communications with the DOI. This section analyses the attack
surface associated with these communications, the data published by
the DOI, as well as operational considerations.
15.1. HNA DM channels
The channels between HNA and DM are mutually authenticated and
encrypted with TLS [RFC8446] and its associated security
considerations apply. To ensure the multiple TLS session are
continuously authenticating the same entity, TLS may take advantage
of second factor authentication as described in [RFC8672].
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At the time of writing TLS 1.2 or TLS 1.3 can be used and TLS 1.3 (or
newer) SHOULD be supported. It is RECOMMENDED that all DNS exchanges
between the HNA and the DM be protected by TLS to provide integrity
protection as well as confidentiality. As noted in [RFC9103], some
level of privacy may be relaxed, by not protecting the existence of
the zone. This MAY involved a mix of exchanges protected by TLS and
exchanges not protected by TLS. This MAY be handled by a off-line
agreement between the DM and HNA as well as with the use of RCODES
defined in Section 7.8 of [RFC9103].
The DNS protocol is subject to reflection attacks, however, these
attacks are largely applicable when DNS is carried over UDP. The
interfaces between the HNA and DM are using TLS over TCP, which
prevents such reflection attacks. Note that Public Authoritative
servers hosted by the DOI are subject to such attacks, but that is
out of scope of our document.
Note that in the case of the Reverse Homenet Zone, the data is less
subject to attacks than in the Public Homenet Zone. In addition, the
DM and RDM may be provided by the ISP - as described in
[I-D.ietf-homenet-naming-architecture-dhc-options], in which case DM
and RDM might be less exposed to attacks - as communications within a
network.
15.2. Names are less secure than IP addresses
This document describes how an end user can make their services and
devices from their home network reachable on the Internet by using
names rather than IP addresses. This exposes the home network to
attackers, since names are expected to include less entropy than IP
addresses. IPv4 Addresses are 4 bytes long leading to 2**32
possibilities. With IPv6 addresses, the Interface Identifier is 64
bits long leading to up to 2^64 possibilities for a given subnetwork.
This is not to mention that the subnet prefix is also of 64 bits
long, thus providing up to 2^64 possibilities. On the other hand,
names used either for the home network domain or for the devices
present less entropy (livebox, router, printer, nicolas, jennifer,
...) and thus potentially exposes the devices to dictionary attacks.
15.3. Names are less volatile than IP addresses
IP addresses may be used to locate a device, a host or a service.
However, home networks are not expected to be assigned a time
invariant prefix by ISPs. In addition IPv6 enables temporary
addresses that makes them even more volatile [RFC8981]. As a result,
observing IP addresses only provides some ephemeral information about
who is accessing the service. On the other hand, names are not
expected to be as volatile as IP addresses. As a result, logging
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names over time may be more valuable than logging IP addresses,
especially to profile an end user's characteristics.
PTR provides a way to bind an IP address to a name. In that sense,
responding to PTR DNS queries may affect the end user's privacy. For
that reason PTR DNS queries and MAY instead be configured to return
with NXDOMAIN.
15.4. Deployment Considerations
The HNA is expected to sign the DNSSEC zone and as such hold the
private KSK/ZSK. To provide resilience against CPE breaks, it is
RECOMMENDED to backup these keys to avoid an emergency key roll over
when the CPE breaks.
The HNA enables to handle network disruption as it contains the
Public Homenet Zone, which is provisioned to the Homenet
Authoritative Servers. However, DNSSEC validation requires to
validate the chain of trust with the DS RRset that is stored into the
parent zone of the Registered Homenet Domain. As currently defined,
the handling of the DS RRset is left to the Homenet DNSSEC resolver
which retrieves from the parent zone via a DNS exchange and cache the
RRset according to the DNS rules, that is respecting the TTL and
RRSIG expiration time. Such constraints do put some limitations to
the type of disruption the proposed architecture can handle. In
particular, the disruption is expected to start after the DS RRset
has been resolved and end before the DS RRset is removed from the
cache. One possible way to address such concern is to describe
mechanisms to provision the DS RRset to the Homenet DNSSEC resolver
for example, via HNCP or by configuring a specific trust anchors
[I-D.ietf-dnsop-dnssec-validator-requirements]. Such work is out of
the scope of this document.
15.5. Operational Considerations
HomeNet technologies makes it easier to expose devices and services
to the Internet. This imposes broader operational considerations for
the operator and the Internet:
* The home network operator must carefully assess whether a device
or service previously fielded only on a home network is robust
enough to be exposed to the Internet
* The home network operator will need to increase the diligence to
regularly managing these exposed devices due to their increased
risk posture of being exposed to the Internet
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* Depending on the operational practices of the home network
operators, there is an increased risk to the Internet architecture
through the possible introduction of additional internet-exposed
system that are poorly managed and likely to be compromised.
Carriers may not to deployed additional mitigations to ensure that
attacks do not originate from their networks.
16. IANA Considerations
This document has no actions for IANA.
17. Acknowledgment
The authors wish to thank Philippe Lemordant for his contributions on
the early versions of the draft; Ole Troan for pointing out issues
with the IPv6 routed home concept and placing the scope of this
document in a wider picture; Mark Townsley for encouragement and
injecting a healthy debate on the merits of the idea; Ulrik de Bie
for providing alternative solutions; Paul Mockapetris, Christian
Jacquenet, Francis Dupont and Ludovic Eschard for their remarks on
HNA and low power devices; Olafur Gudmundsson for clarifying DNSSEC
capabilities of small devices; Simon Kelley for its feedback as
dnsmasq implementer; Andrew Sullivan, Mark Andrew, Ted Lemon, Mikael
Abrahamson, and Ray Bellis for their feedback on handling different
views as well as clarifying the impact of outsourcing the zone
signing operation outside the HNA; Mark Andrew and Peter Koch for
clarifying the renumbering.
At last the authors would like to thank Kiran Makhijani for her in-
depth review that contributed in shaping the final version.
18. Contributors
The co-authors would like to thank Chris Griffiths and Wouter
Cloetens that provided a significant contribution in the early
versions of the document.
19. References
19.1. Normative References
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
<https://www.rfc-editor.org/info/rfc1034>.
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[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.
J., and E. Lear, "Address Allocation for Private
Internets", BCP 5, RFC 1918, DOI 10.17487/RFC1918,
February 1996, <https://www.rfc-editor.org/info/rfc1918>.
[RFC1995] Ohta, M., "Incremental Zone Transfer in DNS", RFC 1995,
DOI 10.17487/RFC1995, August 1996,
<https://www.rfc-editor.org/info/rfc1995>.
[RFC1996] Vixie, P., "A Mechanism for Prompt Notification of Zone
Changes (DNS NOTIFY)", RFC 1996, DOI 10.17487/RFC1996,
August 1996, <https://www.rfc-editor.org/info/rfc1996>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, DOI 10.17487/RFC4034, March 2005,
<https://www.rfc-editor.org/info/rfc4034>.
[RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS
Security (DNSSEC) Hashed Authenticated Denial of
Existence", RFC 5155, DOI 10.17487/RFC5155, March 2008,
<https://www.rfc-editor.org/info/rfc5155>.
[RFC5936] Lewis, E. and A. Hoenes, Ed., "DNS Zone Transfer Protocol
(AXFR)", RFC 5936, DOI 10.17487/RFC5936, June 2010,
<https://www.rfc-editor.org/info/rfc5936>.
[RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating
DNSSEC Delegation Trust Maintenance", RFC 7344,
DOI 10.17487/RFC7344, September 2014,
<https://www.rfc-editor.org/info/rfc7344>.
[RFC7858] Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D.,
and P. Hoffman, "Specification for DNS over Transport
Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May
2016, <https://www.rfc-editor.org/info/rfc7858>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
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[RFC8375] Pfister, P. and T. Lemon, "Special-Use Domain
'home.arpa.'", RFC 8375, DOI 10.17487/RFC8375, May 2018,
<https://www.rfc-editor.org/info/rfc8375>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC9103] Toorop, W., Dickinson, S., Sahib, S., Aras, P., and A.
Mankin, "DNS Zone Transfer over TLS", RFC 9103,
DOI 10.17487/RFC9103, August 2021,
<https://www.rfc-editor.org/info/rfc9103>.
19.2. Informative References
[DDNS] "ddclient", n.d., <https://ddclient.net/protocols.html>.
[GPUNSEC3] Wander, M., Schwittmann, L., Boelmann, C., and T. Weis,
"GPU-Based NSEC3 Hash Breaking", n.d.,
<https://doi.org/10.1109/NCA.2014.27>.
[I-D.ietf-dnsop-dnssec-validator-requirements]
Migault, D. and D. York, "Recommendations for DNSSEC
Resolvers Operators", Work in Progress, Internet-Draft,
draft-ietf-dnsop-dnssec-validator-requirements-01, 13 May
2022, <https://www.ietf.org/archive/id/draft-ietf-dnsop-
dnssec-validator-requirements-01.txt>.
[I-D.ietf-homenet-naming-architecture-dhc-options]
Migault, D., Weber, R., and T. Mrugalski, "DHCPv6 Options
for Home Network Naming Authority", Work in Progress,
Internet-Draft, draft-ietf-homenet-naming-architecture-
dhc-options-21, 3 October 2022,
<https://www.ietf.org/archive/id/draft-ietf-homenet-
naming-architecture-dhc-options-21.txt>.
[I-D.richardson-homerouter-provisioning]
Richardson, M., "Provisioning Initial Device Identifiers
into Home Routers", Work in Progress, Internet-Draft,
draft-richardson-homerouter-provisioning-02, 14 November
2021, <https://www.ietf.org/archive/id/draft-richardson-
homerouter-provisioning-02.txt>.
[RFC2136] Vixie, P., Ed., Thomson, S., Rekhter, Y., and J. Bound,
"Dynamic Updates in the Domain Name System (DNS UPDATE)",
RFC 2136, DOI 10.17487/RFC2136, April 1997,
<https://www.rfc-editor.org/info/rfc2136>.
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[RFC3007] Wellington, B., "Secure Domain Name System (DNS) Dynamic
Update", RFC 3007, DOI 10.17487/RFC3007, November 2000,
<https://www.rfc-editor.org/info/rfc3007>.
[RFC3787] Parker, J., Ed., "Recommendations for Interoperable IP
Networks using Intermediate System to Intermediate System
(IS-IS)", RFC 3787, DOI 10.17487/RFC3787, May 2004,
<https://www.rfc-editor.org/info/rfc3787>.
[RFC3927] Cheshire, S., Aboba, B., and E. Guttman, "Dynamic
Configuration of IPv4 Link-Local Addresses", RFC 3927,
DOI 10.17487/RFC3927, May 2005,
<https://www.rfc-editor.org/info/rfc3927>.
[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for
Renumbering an IPv6 Network without a Flag Day", RFC 4192,
DOI 10.17487/RFC4192, September 2005,
<https://www.rfc-editor.org/info/rfc4192>.
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005,
<https://www.rfc-editor.org/info/rfc4193>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC6092] Woodyatt, J., Ed., "Recommended Simple Security
Capabilities in Customer Premises Equipment (CPE) for
Providing Residential IPv6 Internet Service", RFC 6092,
DOI 10.17487/RFC6092, January 2011,
<https://www.rfc-editor.org/info/rfc6092>.
[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, <https://www.rfc-editor.org/info/rfc6698>.
[RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
RFC 6749, DOI 10.17487/RFC6749, October 2012,
<https://www.rfc-editor.org/info/rfc6749>.
[RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762,
DOI 10.17487/RFC6762, February 2013,
<https://www.rfc-editor.org/info/rfc6762>.
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[RFC6887] Wing, D., Ed., Cheshire, S., Boucadair, M., Penno, R., and
P. Selkirk, "Port Control Protocol (PCP)", RFC 6887,
DOI 10.17487/RFC6887, April 2013,
<https://www.rfc-editor.org/info/rfc6887>.
[RFC7010] Liu, B., Jiang, S., Carpenter, B., Venaas, S., and W.
George, "IPv6 Site Renumbering Gap Analysis", RFC 7010,
DOI 10.17487/RFC7010, September 2013,
<https://www.rfc-editor.org/info/rfc7010>.
[RFC7084] Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic
Requirements for IPv6 Customer Edge Routers", RFC 7084,
DOI 10.17487/RFC7084, November 2013,
<https://www.rfc-editor.org/info/rfc7084>.
[RFC7368] Chown, T., Ed., Arkko, J., Brandt, A., Troan, O., and J.
Weil, "IPv6 Home Networking Architecture Principles",
RFC 7368, DOI 10.17487/RFC7368, October 2014,
<https://www.rfc-editor.org/info/rfc7368>.
[RFC7404] Behringer, M. and E. Vyncke, "Using Only Link-Local
Addressing inside an IPv6 Network", RFC 7404,
DOI 10.17487/RFC7404, November 2014,
<https://www.rfc-editor.org/info/rfc7404>.
[RFC7707] Gont, F. and T. Chown, "Network Reconnaissance in IPv6
Networks", RFC 7707, DOI 10.17487/RFC7707, March 2016,
<https://www.rfc-editor.org/info/rfc7707>.
[RFC7788] Stenberg, M., Barth, S., and P. Pfister, "Home Networking
Control Protocol", RFC 7788, DOI 10.17487/RFC7788, April
2016, <https://www.rfc-editor.org/info/rfc7788>.
[RFC8094] Reddy, T., Wing, D., and P. Patil, "DNS over Datagram
Transport Layer Security (DTLS)", RFC 8094,
DOI 10.17487/RFC8094, February 2017,
<https://www.rfc-editor.org/info/rfc8094>.
[RFC8415] Mrugalski, T., Siodelski, M., Volz, B., Yourtchenko, A.,
Richardson, M., Jiang, S., Lemon, T., and T. Winters,
"Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
RFC 8415, DOI 10.17487/RFC8415, November 2018,
<https://www.rfc-editor.org/info/rfc8415>.
[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS
(DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
<https://www.rfc-editor.org/info/rfc8484>.
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[RFC8499] Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
January 2019, <https://www.rfc-editor.org/info/rfc8499>.
[RFC8501] Howard, L., "Reverse DNS in IPv6 for Internet Service
Providers", RFC 8501, DOI 10.17487/RFC8501, November 2018,
<https://www.rfc-editor.org/info/rfc8501>.
[RFC8555] Barnes, R., Hoffman-Andrews, J., McCarney, D., and J.
Kasten, "Automatic Certificate Management Environment
(ACME)", RFC 8555, DOI 10.17487/RFC8555, March 2019,
<https://www.rfc-editor.org/info/rfc8555>.
[RFC8610] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
Definition Language (CDDL): A Notational Convention to
Express Concise Binary Object Representation (CBOR) and
JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
June 2019, <https://www.rfc-editor.org/info/rfc8610>.
[RFC8672] Sheffer, Y. and D. Migault, "TLS Server Identity Pinning
with Tickets", RFC 8672, DOI 10.17487/RFC8672, October
2019, <https://www.rfc-editor.org/info/rfc8672>.
[RFC8981] Gont, F., Krishnan, S., Narten, T., and R. Draves,
"Temporary Address Extensions for Stateless Address
Autoconfiguration in IPv6", RFC 8981,
DOI 10.17487/RFC8981, February 2021,
<https://www.rfc-editor.org/info/rfc8981>.
[RFC9250] Huitema, C., Dickinson, S., and A. Mankin, "DNS over
Dedicated QUIC Connections", RFC 9250,
DOI 10.17487/RFC9250, May 2022,
<https://www.rfc-editor.org/info/rfc9250>.
[RFC9276] Hardaker, W. and V. Dukhovni, "Guidance for NSEC3
Parameter Settings", BCP 236, RFC 9276,
DOI 10.17487/RFC9276, August 2022,
<https://www.rfc-editor.org/info/rfc9276>.
[ZONEENUM] Wang, Z., Xiao, L., and R. Wang, "An efficient DNSSEC zone
enumeration algorithm", n.d..
Appendix A. HNA Channel Configurations
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A.1. Homenet Public Zone
This document does not deal with how the HNA is provisioned with a
trusted relationship to the Distribution Manager for the forward
zone.
This section details what needs to be provisioned into the HNA and
serves as a requirements statement for mechanisms.
The HNA needs to be provisioned with:
* the Registered Domain (e.g., myhome.example )
* the contact info for the Distribution Manager (DM), including the
DNS name (FQDN), possibly including the IP literal, and a
certificate (or anchor) to be used to authenticate the service
* the DM transport protocol and port (the default is DNS over TLS,
on port 853)
* the HNA credentials used by the DM for its authentication.
The HNA will need to select an IP address for communication for the
Synchronization Channel. This is typically the WAN address of the
CPE, but could be an IPv6 LAN address in the case of a home with
multiple ISPs (and multiple border routers). This is detailed in
Section 7.5.3 when the NS and A or AAAA RRsets are communicated.
The above parameters MUST be be provisioned for ISP-specific reverse
zones. One example of how to do this can be found in
[I-D.ietf-homenet-naming-architecture-dhc-options]. ISP-specific
forward zones MAY also be provisioned using
[I-D.ietf-homenet-naming-architecture-dhc-options], but zones which
are not related to a specific ISP zone (such as with a DNS provider)
must be provisioned through other means.
Similarly, if the HNA is provided by a registrar, the HNA may be
handed pre-configured to end user.
In the absence of specific pre-established relation, these pieces of
information may be entered manually by the end user. In order to
ease the configuration from the end user the following scheme may be
implemented.
The HNA may present the end user a web interface where it provides
the end user the ability to indicate the Registered Homenet Domain or
the registrar for example a preselected list. Once the registrar has
been selected, the HNA redirects the end user to that registrar in
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order to receive a access token. The access token will enable the
HNA to retrieve the DM parameters associated with the Registered
Domain. These parameters will include the credentials used by the
HNA to establish the Control and Synchronization Channels.
Such architecture limits the necessary steps to configure the HNA
from the end user.
Appendix B. Information Model for Outsourced information
This section specifies an optional format for the set of parameters
required by the HNA to configure the naming architecture of this
document.
In cases where a home router has not been provisioned by the
manufacturer (when forward zones are provided by the manufacturer),
or by the ISP (when the ISP provides this service), then a home user/
owner will need to configure these settings via an administrative
interface.
By defining a standard format (in JSON) for this configuration
information, the user/owner may be able to just copy and paste a
configuration blob from the service provider into the administrative
interface of the HNA.
This format may also provide the basis for a future OAUTH2 [RFC6749]
flow that could do the setup automatically.
The HNA needs to be configured with the following parameters as
described by this CDDL [RFC8610]. These are the parameters are
necessary to establish a secure channel between the HNA and the DM as
well as to specify the DNS zone that is in the scope of the
communication.
hna-configuration = {
"registered_domain" : tstr,
"dm" : tstr,
? "dm_transport" : "DoT"
? "dm_port" : uint,
? "dm_acl" : hna-acl / [ +hna-acl ]
? "hna_auth_method": hna-auth-method
? "hna_certificate": tstr
}
hna-acl = tstr
hna-auth-method /= "certificate"
For example:
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{
"registered_domain" : "n8d234f.r.example.net",
"dm" : "2001:db8:1234:111:222::2",
"dm_transport" : "DoT",
"dm_port" : 4433,
"dm_acl" : "2001:db8:1f15:62e:21c::/64"
or [ "2001:db8:1f15:62e:21c::/64", ... ]
"hna_auth_method" : "certificate",
"hna_certificate" : "-----BEGIN CERTIFICATE-----\nMIIDTjCCFGy....",
}
Registered Homenet Domain (registered_domain) The Domain Name of the
zone. Multiple Registered Homenet Domains may be provided. This
will generate the creation of multiple Public Homenet Zones. This
parameter is mandatory.
Distribution Manager notification address (dm) The associated FQDNs
or IP addresses of the DM to which DNS notifies should be sent.
This parameter is mandatory. IP addresses are optional and the
FQDN is sufficient and preferred. If there are concerns about the
security of the name to IP translation, then DNSSEC should be
employed.
As the session between the HNA and the DM is authenticated with TLS,
the use of names is easier.
As certificates are more commonly emitted for FQDN than for IP
addresses, it is preferred to use names and authenticate the name of
the DM during the TLS session establishment.
Supported Transport (dm_transport) The transport that carries the
DNS exchanges between the HNA and the DM. Typical value is "DoT"
but it may be extended in the future with "DoH", "DoQ" for
example. This parameter is optional and by default the HNA uses
DoT.
Distribution Manager Port (dm_port) Indicates the port used by the
DM. This parameter is optional and the default value is provided
by the Supported Transport. In the future, additional transport
may not have default port, in which case either a default port
needs to be defined or this parameter become mandatory.
Note that HNA does not defines ports for the Synchronization Channel.
In any case, this is not expected to part of the configuration, but
instead negotiated through the Configuration Channel. Currently the
Configuration Channel does not provide this, and limits its agility
to a dedicated IP address. If such agility is needed in the future,
additional exchanges will need to be defined.
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Authentication Method ("hna_auth_method"): How the HNA authenticates
itself to the DM within the TLS connection(s). The authentication
method can typically be "certificate", "psk" or "none". This
Parameter is optional and by default the Authentication Method is
"certificate".
Authentication data ("hna_certificate", "hna_key"): : The certificate
chain used to authenticate the HNA. This parameter is optional and
when not specified, a self-signed certificate is used.
Distribution Manager AXFR permission netmask (dm_acl): The subnet
from which the CPE should accept SOA queries and AXFR requests. A
subnet is used in the case where the DOI consists of a number of
different systems. An array of addresses is permitted. This
parameter is optional and if unspecified, the CPE uses the IP
addresses provided by the dm parameter either directly when dm
indicates an IP address or the IP addresses returned by the
DNS(SEC) resolution when dm indicates a FQDN.
For forward zones, the relationship between the HNA and the forward
zone provider may be the result of a number of transactions:
1. The forward zone outsourcing may be provided by the maker of the
Homenet router. In this case, the identity and authorization
could be built in the device at manufacturer provisioning time.
The device would need to be provisioned with a device-unique
credential, and it is likely that the Registered Homenet Domain
would be derived from a public attribute of the device, such as a
serial number (see Appendix C or
[I-D.richardson-homerouter-provisioning] for more details ).
2. The forward zone outsourcing may be provided by the Internet
Service Provider. In this case, the use of
[I-D.ietf-homenet-naming-architecture-dhc-options] to provide the
credentials is appropriate.
3. The forward zone may be outsourced to a third party, such as a
domain registrar. In this case, the use of the JSON-serialized
YANG data model described in this section is appropriate, as it
can easily be copy and pasted by the user, or downloaded as part
of a web transaction.
For reverse zones, the relationship is always with the upstream ISP
(although there may be more than one), and so
[I-D.ietf-homenet-naming-architecture-dhc-options] is always the
appropriate interface.
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The following is an abbridged example of a set of data that
represents the needed configuration parameters for outsourcing.
Appendix C. Example: A manufacturer provisioned HNA product flow
This scenario is one where a homenet router device manufacturer
decides to offer DNS hosting as a value add.
[I-D.richardson-homerouter-provisioning] describes a process for a
home router credential provisioning system. The outline of it is
that near the end of the manufacturing process, as part of the
firmware loading, the manufacturer provisions a private key and
certificate into the device.
In addition to having a assymmetric credential known to the
manufacturer, the device also has been provisioned with an agreed
upon name. In the example in the above document, the name
"n8d234f.r.example.net" has already been allocated and confirmed with
the manufacturer.
The HNA can use the above domain for itself. It is not very pretty
or personal, but if the owner wishes a better name, they can arrange
for it.
The configuration would look like:
{
"dm" : "2001:db8:1234:111:222::2",
"dm_acl" : "2001:db8:1234:111:222::/64",
"dm_ctrl" : "manufacturer.example.net",
"dm_port" : "4433",
"ns_list" : [ "ns1.publicdns.example", "ns2.publicdns.example"],
"zone" : "n8d234f.r.example.net",
"auth_method" : "certificate",
"hna_certificate":"-----BEGIN CERTIFICATE-----\nMIIDTjCCFGy....",
}
The dm_ctrl and dm_port values would be built into the firmware.
Authors' Addresses
Daniel Migault
Ericsson
8275 Trans Canada Route
Saint Laurent, QC 4S 0B6
Canada
Email: daniel.migault@ericsson.com
Migault, et al. Expires 23 April 2023 [Page 40]
Internet-Draft public-names October 2022
Ralf Weber
Nominum
2000 Seaport Blvd
Redwood City, 94063
United States of America
Email: ralf.weber@nominum.com
Michael Richardson
Sandelman Software Works
470 Dawson Avenue
Ottawa, ON K1Z 5V7
Canada
Email: mcr+ietf@sandelman.ca
Ray Hunter
Globis Consulting BV
Weegschaalstraat 3
5632CW Eindhoven
Netherlands
Email: v6ops@globis.net
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