draft-ietf-6lo-ap-nd-01.txt   draft-ietf-6lo-ap-nd-02.txt 
6lo B. Sarikaya, Ed. 6lo B. Sarikaya
Internet-Draft Huawei USA Internet-Draft Huawei USA
Updates: 6775 (if approved) P. Thubert Updates: 6775 (if approved) P. Thubert
Intended status: Standards Track Cisco Intended status: Standards Track Cisco
Expires: November 16, 2017 M. Sethi, Ed. Expires: November 25, 2017 M. Sethi
Ericsson Ericsson
May 15, 2017 May 24, 2017
Address Protected Neighbor Discovery for Low-power and Lossy Networks Address Protected Neighbor Discovery for Low-power and Lossy Networks
draft-ietf-6lo-ap-nd-01 draft-ietf-6lo-ap-nd-02
Abstract Abstract
This document defines an extension to 6LoWPAN Neighbor Discovery. This document defines an extension to 6LoWPAN Neighbor Discovery, RFC
This extension is designed for low-power and lossy network 6775. Nodes supporting this extension compute a cryptographic Owner
environments and it supports multi-hop operation. Nodes supporting Unique Interface ID and associate it with one or more of their
this extension compute a Cryptographically Unique Interface ID and Registered Addresses. Once an address is registered with a
associate it with one or more of their Registered Addresses. The Cryptographic ID, only the owner of that ID can modify the anchor
Cryptographic ID (Crypto-ID) uniquely identifies the owner of the state information of the Registered Address, and Source Address
Registered Address. It is used in place of the EUI-64 address that Validation can be enforced.
is specified in RFC 6775. Once an address is registered with a
Cryptographic ID, only the owner of that ID can modify the state
information of the Registered Address in the 6LR and 6LBR.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on November 16, 2017. This Internet-Draft will expire on November 25, 2017.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 4
4. Protocol Interactions . . . . . . . . . . . . . . . . . . . . 5 4. New Fields and Options . . . . . . . . . . . . . . . . . . . 5
4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 5 4.1. New Crypto-ID . . . . . . . . . . . . . . . . . . . . . . 5
4.2. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . 7 4.2. Updated EARO . . . . . . . . . . . . . . . . . . . . . . 6
4.2.1. Crypto-ID Calculation . . . . . . . . . . . . . . . . 10 4.3. New Crypto-ID Parameters Option . . . . . . . . . . . . . 7
4.3. Multihop Operation . . . . . . . . . . . . . . . . . . . 13 5. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 14 5.1. Protocol Scope . . . . . . . . . . . . . . . . . . . . . 8
6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 14 5.2. Protocol Flows . . . . . . . . . . . . . . . . . . . . . 9
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14 5.3. Multihop Operation . . . . . . . . . . . . . . . . . . . 11
8. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 14 6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 7. IANA considerations . . . . . . . . . . . . . . . . . . . . . 13
9.1. Normative References . . . . . . . . . . . . . . . . . . 15 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
9.2. Informative references . . . . . . . . . . . . . . . . . 16 9. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 13
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
10.1. Normative References . . . . . . . . . . . . . . . . . . 13
10.2. Informative references . . . . . . . . . . . . . . . . . 14
Appendix A. Requirements Addressed in this Document . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
Neighbor discovery for IPv6 [RFC4861] and stateless address Neighbor discovery for IPv6 [RFC4861] and stateless address
autoconfiguration [RFC4862] are together referred to as neighbor autoconfiguration [RFC4862] and their extensions are collectively
discovery protocols (NDP). They are defined for regular hosts that referred to as the IPv6 Neighbor Discovery Protocol (IPv6 NDP). In
have sufficient memory and computation capabilities. These protocols order to enable IPv6 NDP operations over a constrained low-power and
are however not suitable for resource-constrained devices. lossy network (LLN), "Neighbor Discovery optimizations for 6LoWPAN
Therefore, they require adaptation to work on resource-constrained networks" [RFC6775] (6LoWPAN ND), reduces the use of multicast in the
hosts operating over a low-power and lossy network (LLN). Neighbor original protocol and introduces a unicast host address registration
Discovery optimizations for 6LoWPAN networks include simple technique. The registration mechanism leverages a new Address
optimizations such as a host address registration feature. This Registration Option (ARO) that is carried in the unicast Neighbor
feature uses the address registration option (ARO) which is sent in Solicitation (NS) and Neighbor Advertisement (NA) messages between
the unicast Neighbor Solicitation (NS) and Neighbor Advertisement the 6LoWPAN Node (6LN) and the 6LoWPAN Router (6LR), as well as the
(NA) messages [RFC6775]. Duplicate Address Request (DAR) and Duplicate Address Confirmation
(DAC) messages between the 6LR and the 6LoWPAN Border Router (6LBR),
which is the central repository of all the registered addresses in
its domain.
With 6LoWPAN ND [RFC6775], the ARO option includes a EUI-64 interface The registration mechanism in 6LoWPAN ND [RFC6775] was created for
ID to uniquely identify the interface of the Registered Address on the original purpose of Duplicate Address Detection (DAD), whereby
the registering device, so as to correlate further registrations for use of an address would be granted as long as the address is not
the same address and avoid address duplication. The EUI-64 interface already present in the subnet (first come first serve). In order to
ID is not secure and its ownership cannot be verified. Consequently, validate address ownership, the registration mechanism enables the
any device claiming the same EUI-64 interface ID may take over an 6LR and 6LBR to correlate further claims for a registered address
existing registration and attract the traffic for that address. The from the device to which it is granted with a Owner Unique Interface
address registration mechanism in [RFC6775] is limited as it does not IDentifier (OUID). With 6LoWPAN ND, the OUID is derived from the MAC
require a node to prove its ownership of the EUI-64 Interface ID. address of the device (EUI-64), which can be spoofed. Therefore, any
Therefore, any node connected to the subnet and aware of the node connected to the subnet and aware of a registered-address-to-
registered address to EUI-64 interface ID mapping may effectively OUID mapping may effectively fake the OUID, steal the address and
fake the same interface ID and steal an address. attract the traffic for that address towards a different Node. In
order to allow a more secured registration mechanism, the "Update to
6LoWPAN ND" [I-D.ietf-6lo-rfc6775-update] opens the semantics of the
ARO option and allows to transport alternate forms of OUIDs.
In this document, we extend 6LoWPAN ND to protect the address With this specification, a 6LN generates a cryptographic ID (Crypto-
ownership with cryptographic material, but as opposed to Secure ID) and places it in the OUID field in the registration of one (or
Neighbor Discovery (SEND) [RFC3971] and Cryptographically Generated more) of its addresses with the 6LR(s) that it uses as default
Addresses (CGAs) [RFC3972], the cryptographic material generated is router(s). Proof of ownership of the cryptographic ID (Crypto-ID) is
not embedded in the Interface ID (IID) as an IPv6 address. Instead, passed with the first registration to a given 6LR, and enforced at
the generated cryptographic ID is used as a correlator associated the 6LR, in a new Crypto-ID Parameters Option (CIPO). The 6LR
with the registration of the IP address. This approach is made validates ownership of the cryptographic ID upon the creation of a
possible with 6LoWPAN ND [RFC6775], where the 6LR and the 6LBR registration state, or a change in the anchor information, such as
maintain state information for each Registered Address. If a Link-Layer Address and associated Layer-2 cryptographic material.
cryptographic ID is associated with the first 6LoWPAN ND
registration, then it can be used to validate any future updates to
the registration.
In order to achieve this ownership verification, in this extension The protected address registration protocol proposed in this document
specification, the EUI-64 interface ID used in 6LoWPAN ND is replaced enables the enforcement of Source Address Validation (SAVI)
with cryptographic material whose ownership can be verified. The [RFC7039], which ensures that only the correct owner uses a
extension also provides new means for the 6LR to validate ownership registered address in the source address field in IPv6 packets. With
of the registration, and thus, the ownership of registered address. this specification, a 6LN that sources a packet has to use a 6LR to
The resulting protocol is called Protected Address Registration which the source address of the packet is registered to forward the
protocol (ND-PAR). packet. The 6LR maintains state information for the registered
addressed along with the MAC address, and link-layer cryptographic
key associated with that node. In SAVI-enforcement mode, the 6LR
allows only packets from a connected Host if the connected Host owns
the registration of the source address of the packet.
In ND-PAR, a node typically generates one 64-bit cryptographic ID The 6lo adaptation layer framework ([RFC4944], [RFC6282]) expects
(Crypto-ID) and uses it as Unique Interface ID in the registration of that a device forms its IPv6 addresses based on Layer-2 address, so
one (or more) of its addresses with the 6LR, which it attaches to and as to enable a better compression. This is incompatible with "Secure
uses as default router. The 6LR validates ownership of the Neighbor Discovery (SEND)" [RFC3971] and "Cryptographically Generated
cryptographic ID typically upon creation or update of a registration Addresses (CGAs)" [RFC3972], which derive the Interface ID (IID) in
state, for instance following an apparent movement from one point of the IPv6 addresses from cryptographic material. "Privacy
attachment to another. The ARO option is modified to carry the Considerations for IPv6 Address Generation Mechanisms"
Unique Interface ID, and through the DAR/DAC exchange. [I-D.ietf-6man-ipv6-address-generation-privacy] places additional
recommendations on the way addresses should be formed and renewed.
Compared with SeND, this specification saves ~1Kbyte in every NS/NA This specification allows a device to form and register addresses at
message. Also SeND requires one cryptographic address per IPv6 will, without a constraint on the way the address is formed or the
address. This specification separates the cryptographic identifier number of addresses that are registered in parallel. It enables to
from the IPv6 address so that a node can have more than one IPv6 protect multiple addresses with a single cryptographic material and
address protected by the same cryptographic identifier. SeND forces to send the proof only once to a given 6LR for multiple addresses and
the IPv6 address to be cryptographic since it integrates the CGA as refresher registrations.
an IID. 6LoWPAN derives the IPv6 address from other things like a
short address in 802.15.4 to enable a better compression.
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
Readers are expected to be familiar with all the terms and concepts Readers are expected to be familiar with all the terms and concepts
that are discussed in [RFC3971], [RFC3972], [RFC4861], [RFC4919], that are discussed in [RFC3971], [RFC3972], [RFC4861], [RFC4919],
[RFC6775], and [I-D.ietf-6lo-backbone-router] which proposes an [RFC6775], and [I-D.ietf-6lo-backbone-router] which proposes an
skipping to change at page 4, line 27 skipping to change at page 4, line 34
which in most cases is 64 bits long. It is generated using which in most cases is 64 bits long. It is generated using
cryptographic means explained later in this document. cryptographic means explained later in this document.
The document also conforms to the terms and models described in The document also conforms to the terms and models described in
[RFC5889] and uses the vocabulary and the concepts defined in [RFC5889] and uses the vocabulary and the concepts defined in
[RFC4291] for the IPv6 Architecture. [RFC4291] for the IPv6 Architecture.
This document uses [RFC7102] for Terminology in Low power And Lossy This document uses [RFC7102] for Terminology in Low power And Lossy
Networks. Networks.
3. Requirements 3. Updating RFC 6775
In this section we state requirements of a secure neighbor discovery
protocol for low-power and lossy networks.
o The protocol MUST be based on the Neighbor Discovery Optimization
for Low-power and Lossy Networks protocol defined in [RFC6775].
RFC6775 utilizes optimizations such as host-initiated interactions
for sleeping resource-constrained hosts and elimination of
multicast address resolution.
o New options to be added to Neighbor Solicitation messages MUST
lead to small packet sizes, especially compared with existing
protocols such as SEcure Neighbor Discovery (SEND). Smaller
packet sizes facilitate low-power transmission by resource-
constrained nodes on lossy links.
o The support for this registration mechanism SHOULD be extensible
to more LLN links than IEEE 802.15.4 only. Support for at least
the LLN links for which a 6lo "IPv6 over foo" specification
exists, as well as Low-Power Wi-Fi SHOULD be possible.
o As part of this extension, a mechanism to compute a unique
Identifier should be provided with the capability to form a Link
Local Address that SHOULD be unique at least within the LLN
connected to a 6LBR.
o The Address Registration Option used in the ND registration SHOULD
be extended to carry the relevant forms of Unique Interface
IDentifier.
o The Neighbour Discovery should specify the formation of a site-
local address that follows the security recommendations from
[RFC7217].
4. Protocol Interactions
Protected address and registration neighbor discovery protocol (ND-
PAR) modifies Neighbor Discovery Optimization for Low-power and Lossy
Networks [RFC6775] as explained in this section.
4.1. Overview
The scope of the present work is a 6LoWPAN Low Power Lossy Network
(LLN), typically a stub network connected to a larger IP network via
a Border Router called a 6LBR per [RFC6775].
---+-------- ............
| External Network
|
+-----+
| | LLN Border
| | router
+-----+
o o o
o o o o
o o LLN o o o
o o o o
o
Figure 1: Basic Configuration
The 6LBR maintains a registration state for all devices in the
attached LLN, and, in conjunction with the first-hop router (the
6LR), is in a position to validate uniqueness and grant ownership of
an IPv6 address before it can be used in the LLN. This is a
fundamental difference with a classical network that relies on IPv6
address auto-configuration [RFC4862], where there is no guarantee of
ownership from the network, and any IPv6 Neighbor Discovery packet
must be individually secured [RFC3971].
In a mesh network, the 6LR is directly connected to the host device.
This specification expects that the peer-wise layer-2 security is
deployed so that all the packets from a particular host are securely
identifiable by the 6LR. The 6LR may be multiple hops away from the
6LBR. Packets are routed between the 6LR and the 6LBR via other
6LRs. This specification expects that a chain of trust is
established so that a packet that was validated by the first 6LR can
be safely routed by the next 6LRs to the 6LBR.
[I-D.ietf-6tisch-architecture] suggests to use of RPL [RFC6550] as
the routing protocol between the 6LRs and the 6LBR, and leveraging a
backbone router [I-D.ietf-6lo-backbone-router] to extend the LLN in a
larger multilink subnet [RFC4903]. In that model, a registration
flow happens as shown in Figure 2. Note that network beyond the 6LBR
is out of scope for this document.
6LoWPAN Node 6LR 6LBR
(RPL leaf) (router) (root)
| | |
| 6LoWPAN ND |6LoWPAN ND+RPL | Efficient ND
| LLN link |Route-Over mesh| IPv6 link
| | |
| NS(ARO) | |
|-------------->| |
| 6LoWPAN ND | DAR (then DAO)|
| |-------------->|
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | DAC |
| |<--------------|
| NA(ARO) | |
|<--------------| |
Figure 2: (Re-)Registration Flow over Multi-Link Subnet
A new device that joins the network auto-configures an address and
performs an initial registration to an on-link 6LR with an NS message
that carries a new Address Registration Option (ARO) [RFC6775]. The
6LR validates the address with the central 6LBR using a DAR/DAC
exchange, and the 6LR confirms (or denies) the address ownership with
an NA message that also carries an Address Registration Option.
The registration mechanism in [RFC6775] was created for the original
purpose of Duplicate Address Detection (DAD), whereby use of an
address would be granted as long as the address is not already
present in the subnet. But [RFC6775] does not require that the 6LR
use the registration for source address validation (SAVI) [RFC7039].
Protected address registration protocol proposed in this document
enforces SAVI. With this we ensure that only the correct owner uses
the registered address in the source address field. Therefore a
destination node can trust that the source is the real owner without
using SeND. All packets destined for a node go through the 6LR to
which it is attached. The 6LR maintains state information for the
registered addressed along with the MAC address, and link-layer
cryptographic key associated with that node. The 6LR therefore only
delivers packets to the real owner based on its state information.
In order to validate address ownership, the registration mechanism
(that goes all the way to the 6LBR with the DAR/DAC) enables the 6LBR
to correlate further claims for a registered address from the device
to which it is granted, based on a Unique Interface IDentifier (UID).
This UID is derived from the MAC address of the device (EUI-64).
This document uses a randomly generated value as an alternate UID for
the registration. Proof of ownership of the UID is passed with the
first registration to a given 6LR, and enforced at the 6LR, which
validates the proof. With this new operation, the 6LR allows only
packets from a connected host if the connected host owns the
registration of the source address of the packet.
In a multihop 6LoWPAN, the registration with Crypto-ID is propagated
to 6LBR as described in Section 4.3. If a chain of trust is present
between the 6LR and the 6LBR, then there is no need to propagate the
proof of ownership to the 6LBR. All the 6LBR needs to know is that
this particular UID is randomly generated, so as to enforce that any
update via a different 6LR is also random.
4.2. Updating RFC 6775
Protocol interactions are as defined in Figure 2. The Crypto-ID is
calculated as described in Section 4.2.1.
The Target Address field in NS message is set to the prefix
concatenated with the node's address. This address does not need
duplicate address detection as Crypto-ID is globally unique. So a
host cannot steal an address that is already registered unless it has
the key used for generating the Crypto-ID. The same Crypto-ID can
thus be used to protect multiple addresses e.g. when the node
receives a different prefix.
Local or on-link protocol interactions are shown in Figure 3.
Crypto-ID and ARO are passed to and stored by the 6LR/6LBR on the
first NS and not sent again in the next NS. The operation starts
with 6LR sending a Router Advertisement (RA) message to 6LN.
The 6LR/6LBR ensures first-come/first-serve by storing the ARO and
the Crypto-ID correlated to the node being registered. The node is
free to claim any address it likes as long as it is the first to make
such a claim. The node becomes owner of that address and the address
is bound to the Crypto-ID in the 6LR/6LBR registry. This procedure
avoids the constrained device to compute multiple keys for multiple
addresses. The registration process allows the node to tie all the
addresses to the same Crypto-ID and have the 6LR/6LBR enforce first-
come first-serve after that.
A condition where a 6LN uses multiple IPv6 addresses may happen when With this specification, a node SHOULD use a cryptographic identifier
the node moves at a different place and receives a different prefix. (Crypto-ID) as OUID in its registration; the Crypto-ID is calculated
In this scenario, the node uses the same Crypto-ID to protect its new as described in Section 4.1. The fact that a OUID is a Crypto-ID is
IPv6 address. This prevents other nodes from stealing the address indicated in a new 'C' flag in the NS(ARO) message.
and trying to use it as their source address.
Note that if the device that moves always forms new MAC and IP This specification also introduces a new option, the CIPO, that is
address [RFC6775], then this new address can be used for used to prove ownership of the Crypto-ID. A node that registers for
registration. In case of a collision of the new MAC and therefore IP the first time to a 6LR SHOULD place a CIPO option to its
address, the node can easily form a new IPv6 address. This is one registration but is not expected to place the option in the next
case where the use of Crypto-ID would not be needed. Crypto-ID or periodic refresher registrations for that address, or for the
ND-PAR should be activated when the IP address is claimed at another registration of other addresses with the same OUID. When a 6LR
place, or for a different MAC address at the same place, e.g. for MAC receives a NS(ARO) registration with a new Crypto-ID as a OUID, then
address privacy [I-D.ietf-6man-ipv6-address-generation-privacy]. it SHOULD challenge by responding with a NA(ARO) with a status of
"Proof requested". This whole process MAY be skipped in networks
where there is no or ultra low expectations of mobility.
6LN 6LR The challenge will also be triggered in the case of a registration
| | for which the Source Link-Layer Address is not consistent with a
|<------------------- RA --------------------------| state that already exists either at the 6LR or the 6LBR. In the
| | latter case, the 6LBR returns a status of "Proof requested" in the
|----------- NS with ARO and Crypto-ID ----------->| DAR/DAC exchange, which is echoed by the 6LR in the NA (ARO) back to
| | the registering node. This flow should not alter a preexisting state
|<---------- NA with ARO (status=req-proof) -------| in the 6LR or the 6LBR.
| |
|----------- NS with ARO and Crypto-ID ----------->|
| |
|<---------------- NA with ARO --------------------|
| |
... ...
| |
|------------ NS with ARO and Crypto-ID ---------->|
| |
| |
|<---------------- NA with ARO --------------------|
... ...
| |
|----------- NS with ARO and Crypto-ID ----------->|
| |
| |
|<---------------- NA with ARO --------------------|
Figure 3: On-link Protocol Operation Upon a NA(ARO) with a status of "Proof requested", the registering
node SHOULD retry its registration with a CIPO option that proves its
ownership of the Crypto-ID.
Elliptic Curve Cryptography (ECC) is used in the calculation of If the 6LR cannot validate the proof, it responds with a status of
cryptographic identifier (Crypto-ID). The digital signature is "Incorrect Proof". Upon a NA(ARO) with a status of "Incorrect
constructed by using the 6LN's private key over its EUI-64 (MAC) Proof", the registering node SHOULD NOT use this Crypto-ID for
address. The signature value is computed using the ECDSA signature registering with that 6LR anymore.
algorithm and the hash function used is SHA-256 [RFC6234]. Public
Key is the most important parameter in CGA Parameters (sent by 6LN in
an NS message). ECC Public Key could be in uncompressed form or in
compressed form where the first octet of the OCTET STRING is 0x04 and
0x02 or 0x03, respectively. Point compression can further reduce the
key size by about 32 octets.
After calculating its Crypto-ID, a 6LN sends it along with the CGA 4. New Fields and Options
parameters in the first NS message, see Figure 3. In order to send
Crypto-ID, a modified address registration option called Enhanced
Address Registration Option (EARO) is defined in Figure 4. As
defined in the figure this ID is variable length, varying between 64
to 128 bits. This ID is 128 bits long only if it is used as IPv6
address. This may happen when some application uses one IP address
of the device as device ID. It would make sense in that case to
build a real CGA IPv6 address. The prefix of the address would be
obtained from prefix information option (PIO in RA) [RFC4861].
6LN also sends some other parameters to enable 6LR or 6LBR to verify 4.1. New Crypto-ID
the Crypto-ID. The option shown in Figure 5 can be used. In the
figure, CGA Parameters field contains the public key, prefix and some
other values. It is a simplified form of CGA Option defined in
[RFC3971].
4.2.1. Crypto-ID Calculation Elliptic Curve Cryptography (ECC) is used in the calculation of the
Crypto-ID. The digital signature is constructed by using the 6LN's
private key over its EUI-64 (MAC) address. The signature value is
computed using the ECDSA signature algorithm and the hash function
used is SHA-256 [RFC6234]. Public Key is the most important
parameter in CGA Parameters (sent by 6LN in an NS message). ECC
Public Key could be in uncompressed form or in compressed form where
the first octet of the OCTET STRING is 0x04 and 0x02 or 0x03,
respectively. Point compression can further reduce the key size by
about 32 octets.
First, the modifier is set to a random or pseudo-random 128-bit First, the modifier is set to a random or pseudo-random 128-bit
value. Next, concatenate from left to right the modifier, 9 zero value. Next, concatenate from left to right the modifier, 9 zero
octets and the ECC public key. SHA-256 algorithm is applied on the octets and the ECC public key. SHA-256 algorithm is applied on the
concatenation. The 112 leftmost bits of the hash value is taken. concatenation. The 112 leftmost bits of the hash value is taken.
Concatenate from left to right the modifier value, the subnet prefix Concatenate from left to right the modifier value, the subnet prefix
and the encoded public key. NIST P-256 is executed on the and the encoded public key. NIST P-256 is executed on the
concatenation. The leftmost bits of the result is used as the concatenation. The leftmost bits of the result is used as the
Crypto-ID. The length is normally 64 bits, however it could be 128 Crypto-ID. With this specification, the last 64 bits are retained,
bits. but it could be expanded to more bits in the future by increasing the
size of the OUID field.
In respecting the cryptographical algorithm agility [RFC7696], Curve In respecting the cryptographic algorithm agility [RFC7696], Curve
25519 [RFC7748] can also be used instead of NIST P-256. This is 25519 [RFC7748] can also be used instead of NIST P-256. This is
indicated by 6LN by setting the Crypto Type field in CGA Parameters indicated by 6LN by setting the Crypto Type field in the CIPO option
Option to a value of 1. If 6LBR does not support Curve 25519, it to a value of 1. If 6LBR does not support Curve 25519, it will set
will set Crypto Type field to zero. This means that the default Crypto Type field to zero. This means that the default algorithm
algorithm (NIST P-256) will be used. (NIST P-256) will be used.
4.2. Updated EARO
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Status | Reserved | | Type | Length | Status | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |C|T| TID | Registration Lifetime | | Reserved |C|T| TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ Owner Unique ID (EUI-64 or equivalent) + + Owner Unique ID (EUI-64 or equivalent) +
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Enhanced Address Registration Option Figure 1: Enhanced Address Registration Option
Type: Type:
TBA1 33
Length: Length:
8-bit unsigned integer. The length of the option (including the 8-bit unsigned integer. The length of the option (including the
type and length fields) in units of 8 bytes. The value 0 is type and length fields) in units of 8 bytes.
invalid. A value of 3 with the C flag set indicates a Crypto-ID
of 128 bits.
Status: Status:
8-bit unsigned integer. Indicates the status of a registration in 8-bit unsigned integer. Indicates the status of a registration in
the NA response. MUST be set to 0 in NS messages. See below. the NA response. MUST be set to 0 in NS messages. This
specification leverages values introduced in the Update to 6LoWPAN
ND [I-D.ietf-6lo-rfc6775-update], such as 5: Proof Requested, and
does not require additional values to be defined.
Reserved: Reserved:
This field is unused. It MUST be initialized to zero by the This field is unused. It MUST be initialized to zero by the
sender and MUST be ignored by the receiver. sender and MUST be ignored by the receiver.
C: C:
C bit when set is used to indicate that Owner Unique ID fields This specification introduces a C bit, which is set to indicate
contains Crypto-ID. that the Owner Unique ID field contains a Crypto-ID.
T and TID: T and TID:
Defined in [I-D.ietf-6lo-backbone-router]. Defined in [I-D.ietf-6lo-rfc6775-update].
Owner Unique ID: Owner Unique ID:
In this specification, this field contains Crypto-ID, a variable When using this specification, this field contains a Crypto-ID.
length field to carry the Crypto-ID or random UID. This field is
normally 64 bits long. It could be 128 bits long if IPv6 address 4.3. New Crypto-ID Parameters Option
is used as the Crypto-ID.
This specification introduces a new option, the Crypto-ID Parameters
Option (CIPO), that carries the proof of ownership of a crypto-ID.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Pad Length | Crypto Type | | Type | Length | Pad Length | Crypto Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ + + +
| | | |
+ Modifier (16 octets) + + Modifier (16 octets) +
skipping to change at page 12, line 35 skipping to change at page 7, line 48
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
. . . .
. Padding . . Padding .
. . . .
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: CGA Parameters Option Figure 2: Crypto-ID Parameters Option
Type: Type:
TBA2 CIPO, to be assigned by IANA.
Length: Length:
The length of the option in units of 8 octets. The length of the option in units of 8 octets.
Pad Length: Pad Length:
The length of the Padding field. The length of the Padding field.
Crypto Type: Crypto Type:
skipping to change at page 13, line 26 skipping to change at page 8, line 38
Public Key: Public Key:
ECC public key of 6LN. ECC public key of 6LN.
Padding: Padding:
A variable-length field making the option length a multiple of 8, A variable-length field making the option length a multiple of 8,
containing as many octets as specified in the Pad Length field. containing as many octets as specified in the Pad Length field.
4.3. Multihop Operation 5. Protocol Overview
5.1. Protocol Scope
The scope of the present work is a 6LoWPAN Low Power Lossy Network
(LLN), typically a stub network connected to a larger IP network via
a Border Router called a 6LBR per [RFC6775].
The 6LBR maintains a registration state for all devices in the
attached LLN, and, in conjunction with the first-hop router (the
6LR), is in a position to validate uniqueness and grant ownership of
an IPv6 address before it can be used in the LLN. This is a
fundamental difference with a classical network that relies on IPv6
address auto-configuration [RFC4862], where there is no guarantee of
ownership from the network, and any IPv6 Neighbor Discovery packet
must be individually secured [RFC3971].
---+-------- ............
| External Network
|
+-----+
| | 6LBR
+-----+
o o o
o o o o
o o LLN o o o
o o o (6LR)
o (6LN)
Figure 3: Basic Configuration
In a mesh network, the 6LR is directly connected to the host device.
This specification expects that the peer-wise layer-2 security is
deployed so that all the packets from a particular host are securely
identifiable by the 6LR. The 6LR may be multiple hops away from the
6LBR. Packets are routed between the 6LR and the 6LBR via other
6LRs. This specification expects that a chain of trust is
established so that a packet that was validated by the first 6LR can
be safely routed by the next 6LRs to the 6LBR.
5.2. Protocol Flows
The 6TiSCH Architecture [I-D.ietf-6tisch-architecture] suggests to
use of RPL [RFC6550] as the routing protocol between the 6LRs and the
6LBR. In that model, a registration flow happens as shown in
Figure 4.
6LoWPAN Node 6LR 6LBR
(RPL leaf) (router) (RPL root)
| | |
| 6LoWPAN ND | 6LoWPAN ND |
| | |
| | |
| NS(ARO) | |
|-------------->| |
| 6LoWPAN ND | DAR |
| |-------------->|
| |(then RPL DAO) |
| | |
| | DAC |
| |<--------------|
| NA(ARO) | |
|<--------------| |
| | |
| | |
Figure 4: (Re-)Registration Flow
A new device that joins the network auto-configures an address and
performs an initial registration to an on-link 6LR with an NS message
that carries an Address Registration Option (ARO) [RFC6775]. The 6LR
validates the address with the central 6LBR using a DAR/DAC exchange,
and the 6LR confirms (or denies) the address ownership with an NA
message that also carries an Address Registration Option.
In a multihop 6LoWPAN, the registration with Crypto-ID is propagated
to 6LBR as described in Section 5.3. If a chain of trust is present
between the 6LR and the 6LBR, then there is no need to propagate the
proof of ownership to the 6LBR. All the 6LBR needs to know is that
this particular OUID is randomly generated, so as to enforce that any
update via a different 6LR is also random.
Local or on-link protocol interactions are shown in Figure 5.
Crypto-ID and ARO are passed to and stored by the 6LR/6LBR on the
first NS and not sent again in the next NS. The operation starts
with 6LR sending a Router Advertisement (RA) message to 6LN.
The 6LR/6LBR ensures first-come/first-serve by storing the ARO and
the Crypto-ID correlated to the node being registered. The node is
free to claim any address it likes as long as it is the first to make
such a claim. After a successful registration, the node becomes the
owner of the registered address and the address is bound to the
Crypto-ID in the 6LR/6LBR registry. This binding can be verified
later, which prevents other nodes from stealing the address and
trying to attract traffic for that address or use it as their source
address.
A node may uses multiple IPv6 addresses at any time. This condition
may happen for privacy reasons
[I-D.ietf-6man-ipv6-address-generation-privacy], or when the node
moves at a different place and auto-configures an new address from a
different prefix. In those situations, the node may use the same
Crypto-ID to protect multiple IPv6 addresses. The separation of the
address and the Crypto-ID avoids the constrained device to compute
multiple keys for multiple addresses. The registration process
allows the node to tie all of its addresses to the same Crypto-ID and
have the 6LR/6LBR enforce first-come first-serve after that.
6LN 6LR
| |
|<------------------- RA --------------------------|
| |
|----------- NS with ARO and Crypto-ID ----------->|
| |
|<---------- NA with ARO (status=proof requested) -|
| |
|----------- NS with ARO and Crypto-ID ----------->|
| |
|<---------------- NA with ARO --------------------|
| |
... ...
| |
|------------ NS with ARO and Crypto-ID ---------->|
| |
| |
|<---------------- NA with ARO --------------------|
... ...
| |
|----------- NS with ARO and Crypto-ID ----------->|
| |
| |
|<---------------- NA with ARO --------------------|
Figure 5: On-link Protocol Operation
5.3. Multihop Operation
In multihop 6LoWPAN, 6LBR sends RAs with prefixes downstream and it In multihop 6LoWPAN, 6LBR sends RAs with prefixes downstream and it
is the 6LR that receives and relays them to the nodes. 6LR and 6LBR is the 6LR that receives and relays them to the nodes. 6LR and 6LBR
communicate with the ICMPv6 Duplicate Address Request (DAR) and the communicate with the ICMPv6 Duplicate Address Request (DAR) and the
Duplicate Address Confirmation (DAC) messages. The DAR and DAC use Duplicate Address Confirmation (DAC) messages. The DAR and DAC use
the same message format as NS and NA with different ICMPv6 type the same message format as NS and NA with different ICMPv6 type
values. values.
In ND-PAR we extend DAR/DAC messages to carry cryptographically In ND-PAR we extend DAR/DAC messages to carry cryptographically
generated UID. In a multihop 6LoWPAN, the node exchanges the generated OUID. In a multihop 6LoWPAN, the node exchanges the
messages shown in Figure 2. The 6LBR must be aware of who owns an messages shown in Figure 4. The 6LBR must be aware of who owns an
address (EUI-64) to defend the first node if there is an attacker on address (EUI-64) to defend the first node if there is an attacker on
another 6LR. Because of this the content that the source signs and another 6LR. Because of this the content that the source signs and
the signature needs to be propagated to the 6LBR in DAR message. For the signature needs to be propagated to the 6LBR in DAR message. For
this purpose the DAR message sent by 6LR to 6LBR MUST contain CGA this purpose the DAR message sent by 6LR to 6LBR MUST contain the
Parameters and Digital Signature Option carrying the CGA that the CIPO option. DAR message also contains ARO.
node calculates and its public key. DAR message also contains ARO.
It is possible that occasionally, 6LR may miss the node's UID (that It is possible that occasionally, a 6LR may miss the node's OUID
it received in ARO). 6LR should be able to ask for it again. This is (that it received in ARO). 6LR should be able to ask for it again.
done by restarting the exchanges shown in Figure 3. The result This is done by restarting the exchanges shown in Figure 5. The
enables 6LR to refresh the information that was lost. 6LR MUST send result enables 6LR to refresh the information that was lost. 6LR MUST
DAR message with ARO to 6LBR. 6LBR as a reply forms a DAC message send DAR message with ARO to 6LBR. 6LBR as a reply forms a DAC
with the information copied from the DAR and the Status field is set message with the information copied from the DAR and the Status field
to zero. With this exchange, the 6LBR can (re)validate and store the is set to zero. With this exchange, the 6LBR can (re)validate and
information to make sure that the 6LR is not a fake. store the information to make sure that the 6LR is not a fake.
In some cases 6LBR may use DAC message to signal to 6LR that it In some cases 6LBR may use DAC message to signal to 6LR that it
expects Crypto-ID from 6LR also asks 6LR to verify the EUI-64 6LR expects Crypto-ID from 6LR also asks 6LR to verify the EUI-64 6LR
received from 6LN. This may happen when a 6LN node is compromised received from 6LN. This may happen when a 6LN node is compromised
and a fake node is sending the Crypto-ID as if it is the node's EUI- and a fake node is sending the Crypto-ID as if it is the node's EUI-
64. Note that the detection in this case can only be done by 6LBR 64. Note that the detection in this case can only be done by 6LBR
not by 6LR. not by 6LR.
5. Security Considerations 6. Security Considerations
The same considerations regarding the threats to the Local Link The observations regarding the threats to the Local Link Network in
Network covered in [RFC3971] apply. [RFC3971] also apply to this specification.
This document inherits threats discussed in 6LoWPAN ND [RFC6775] and
its update [I-D.ietf-6lo-rfc6775-update] and addresses the potential
attacks related to address stealing and spoofing within a LLN.
Compared with SeND, this specification saves about 1Kbyte in every
NS/NA message. Also, this specification separates the cryptographic
identifier from the registered IPv6 address so that a node can have
more than one IPv6 address protected by the same cryptographic
identifier. SeND forces the IPv6 address to be cryptographic since
it integrates the CGA as the IID in the IPv6 address. This
specification frees the device to form its addresses in any fashion,
so as to enable the classical 6LoWPAN compression which derives IPv6
addresses from Layer-2 addresses, as well as privacy addresses.
The threats discussed in Section 9.2 of [RFC3971] are countered by The threats discussed in Section 9.2 of [RFC3971] are countered by
the protocol described in this document as well. the protocol described in this document as well.
Collisions of Crypto-ID is a possibility that needs to be considered. Collisions of Crypto-ID is a possibility that needs to be considered.
The formula for calculating probability of a collision is 1 - The formula for calculating probability of a collision is 1 -
e^{-k^2/(2n)}. If the Crypto-ID is 64-bit long, then the chance of e^{-k^2/(2n)}. If the Crypto-ID is 64-bit long, then the chance of
finding a collision is 0.01% when the network contains 66 million finding a collision is 0.01% when the network contains 66 million
nodes. It is important to note that the collision is only relevant nodes. It is important to note that the collision is only relevant
when this happens within one stub network (6LBR). A collision of ID when this happens within one stub network (6LBR). A collision of ID
in ND-PAR is a rare event. However, when such a collision does in ND-PAR is a rare event. However, when such a collision does
happen, the protocol operation is not affected, although it opens a happen, the protocol operation is not affected, although it opens a
window for a node to hijack an address from another. The link-layer window for a node to hijack an address from another. The link-layer
security ensures that the nodes would normally not be aware of a security ensures that the nodes would normally not be aware of a
collision on the subnet. If a malicious node is able to gain collision on the subnet. If a malicious node is able to gain
knowledge of a collision through other means, the only thing that it knowledge of a collision through other means, the only thing that it
could do is to steal addresses from the other honest node. This could do is to steal addresses from the other honest node. This
would be no different from what is already possible in a 6lo network would be no different from what is already possible in a 6lo network
today. today.
6. IANA considerations 7. IANA considerations
IANA is requested to assign two new option type values, TBA1 and TBA2 IANA is requested to assign two new option type values for the CIPO
under the subregistry "IPv6 Neighbor Discovery Option Formats". under the subregistry "IPv6 Neighbor Discovery Option Formats".
7. Acknowledgements 8. Acknowledgements
We are grateful to Rene Struik and Robert Moskowitz for their We are grateful to Rene Struik and Robert Moskowitz for their
comments that lead to many improvements to this document. comments that lead to many improvements to this document.
8. Change Log 9. Change Log
o submitted version -00 as a working group draft after adoption, and o submitted version -00 as a working group draft after adoption, and
corrected the order of authors corrected the order of authors
o submitted version -01 with no changes o submitted version -01 with no changes
9. References o submitted version -02 with these changes: Moved Requirements to
Appendix A, Section 4.2 moved to Section 3, New section 4 on New
Fields and Options, Section 4 changed to Protocol Overview as
Section 5 with Protocol Scope and Flows subsections.
9.1. Normative References 10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
"SEcure Neighbor Discovery (SEND)", RFC 3971,
DOI 10.17487/RFC3971, March 2005,
<http://www.rfc-editor.org/info/rfc3971>.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, DOI 10.17487/RFC3972, March 2005,
<http://www.rfc-editor.org/info/rfc3972>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <http://www.rfc-editor.org/info/rfc4291>. 2006, <http://www.rfc-editor.org/info/rfc4291>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007, DOI 10.17487/RFC4861, September 2007,
<http://www.rfc-editor.org/info/rfc4861>. <http://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007, DOI 10.17487/RFC4862, September 2007,
<http://www.rfc-editor.org/info/rfc4862>. <http://www.rfc-editor.org/info/rfc4862>.
[RFC4903] Thaler, D., "Multi-Link Subnet Issues", RFC 4903, [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
DOI 10.17487/RFC4903, June 2007, Bormann, "Neighbor Discovery Optimization for IPv6 over
<http://www.rfc-editor.org/info/rfc4903>. Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012,
<http://www.rfc-editor.org/info/rfc6775>.
[I-D.ietf-6lo-rfc6775-update]
Thubert, P., Nordmark, E., and S. Chakrabarti, "An Update
to 6LoWPAN ND", draft-ietf-6lo-rfc6775-update-05 (work in
progress), May 2017.
10.2. Informative references
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
"SEcure Neighbor Discovery (SEND)", RFC 3971,
DOI 10.17487/RFC3971, March 2005,
<http://www.rfc-editor.org/info/rfc3971>.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, DOI 10.17487/RFC3972, March 2005,
<http://www.rfc-editor.org/info/rfc3972>.
[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
"Transmission of IPv6 Packets over IEEE 802.15.4
Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007,
<http://www.rfc-editor.org/info/rfc4944>.
[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011,
<http://www.rfc-editor.org/info/rfc6282>.
[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6 [RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
over Low-Power Wireless Personal Area Networks (6LoWPANs): over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals", Overview, Assumptions, Problem Statement, and Goals",
RFC 4919, DOI 10.17487/RFC4919, August 2007, RFC 4919, DOI 10.17487/RFC4919, August 2007,
<http://www.rfc-editor.org/info/rfc4919>. <http://www.rfc-editor.org/info/rfc4919>.
[RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing [RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing
Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889, Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889,
September 2010, <http://www.rfc-editor.org/info/rfc5889>. September 2010, <http://www.rfc-editor.org/info/rfc5889>.
skipping to change at page 16, line 17 skipping to change at page 15, line 27
DOI 10.17487/RFC6234, May 2011, DOI 10.17487/RFC6234, May 2011,
<http://www.rfc-editor.org/info/rfc6234>. <http://www.rfc-editor.org/info/rfc6234>.
[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J., [RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
JP., and R. Alexander, "RPL: IPv6 Routing Protocol for JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks", RFC 6550, Low-Power and Lossy Networks", RFC 6550,
DOI 10.17487/RFC6550, March 2012, DOI 10.17487/RFC6550, March 2012,
<http://www.rfc-editor.org/info/rfc6550>. <http://www.rfc-editor.org/info/rfc6550>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
Bormann, "Neighbor Discovery Optimization for IPv6 over
Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012,
<http://www.rfc-editor.org/info/rfc6775>.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and [RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
2014, <http://www.rfc-editor.org/info/rfc7102>. 2014, <http://www.rfc-editor.org/info/rfc7102>.
[RFC7039] Wu, J., Bi, J., Bagnulo, M., Baker, F., and C. Vogt, Ed., [RFC7039] Wu, J., Bi, J., Bagnulo, M., Baker, F., and C. Vogt, Ed.,
"Source Address Validation Improvement (SAVI) Framework", "Source Address Validation Improvement (SAVI) Framework",
RFC 7039, DOI 10.17487/RFC7039, October 2013, RFC 7039, DOI 10.17487/RFC7039, October 2013,
<http://www.rfc-editor.org/info/rfc7039>. <http://www.rfc-editor.org/info/rfc7039>.
[RFC7217] Gont, F., "A Method for Generating Semantically Opaque [RFC7217] Gont, F., "A Method for Generating Semantically Opaque
skipping to change at page 16, line 47 skipping to change at page 16, line 5
[RFC7696] Housley, R., "Guidelines for Cryptographic Algorithm [RFC7696] Housley, R., "Guidelines for Cryptographic Algorithm
Agility and Selecting Mandatory-to-Implement Algorithms", Agility and Selecting Mandatory-to-Implement Algorithms",
BCP 201, RFC 7696, DOI 10.17487/RFC7696, November 2015, BCP 201, RFC 7696, DOI 10.17487/RFC7696, November 2015,
<http://www.rfc-editor.org/info/rfc7696>. <http://www.rfc-editor.org/info/rfc7696>.
[RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves [RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves
for Security", RFC 7748, DOI 10.17487/RFC7748, January for Security", RFC 7748, DOI 10.17487/RFC7748, January
2016, <http://www.rfc-editor.org/info/rfc7748>. 2016, <http://www.rfc-editor.org/info/rfc7748>.
9.2. Informative references
[I-D.ietf-6lo-backbone-router] [I-D.ietf-6lo-backbone-router]
Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo- Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo-
backbone-router-03 (work in progress), January 2017. backbone-router-03 (work in progress), January 2017.
[I-D.ietf-6tisch-architecture] [I-D.ietf-6tisch-architecture]
Thubert, P., "An Architecture for IPv6 over the TSCH mode Thubert, P., "An Architecture for IPv6 over the TSCH mode
of IEEE 802.15.4", draft-ietf-6tisch-architecture-11 (work of IEEE 802.15.4", draft-ietf-6tisch-architecture-11 (work
in progress), January 2017. in progress), January 2017.
[I-D.ietf-6man-ipv6-address-generation-privacy] [I-D.ietf-6man-ipv6-address-generation-privacy]
Cooper, A., Gont, F., and D. Thaler, "Privacy Cooper, A., Gont, F., and D. Thaler, "Privacy
Considerations for IPv6 Address Generation Mechanisms", Considerations for IPv6 Address Generation Mechanisms",
draft-ietf-6man-ipv6-address-generation-privacy-08 (work draft-ietf-6man-ipv6-address-generation-privacy-08 (work
in progress), September 2015. in progress), September 2015.
Appendix A. Requirements Addressed in this Document
In this section we state requirements of a secure neighbor discovery
protocol for low-power and lossy networks.
o The protocol MUST be based on the Neighbor Discovery Optimization
for Low-power and Lossy Networks protocol defined in [RFC6775].
RFC6775 utilizes optimizations such as host-initiated interactions
for sleeping resource-constrained hosts and elimination of
multicast address resolution.
o New options to be added to Neighbor Solicitation messages MUST
lead to small packet sizes, especially compared with existing
protocols such as SEcure Neighbor Discovery (SEND). Smaller
packet sizes facilitate low-power transmission by resource-
constrained nodes on lossy links.
o The support for this registration mechanism SHOULD be extensible
to more LLN links than IEEE 802.15.4 only. Support for at least
the LLN links for which a 6lo "IPv6 over foo" specification
exists, as well as Low-Power Wi-Fi SHOULD be possible.
o As part of this extension, a mechanism to compute a unique
Identifier should be provided with the capability to form a Link
Local Address that SHOULD be unique at least within the LLN
connected to a 6LBR.
o The Address Registration Option used in the ND registration SHOULD
be extended to carry the relevant forms of Unique Interface
IDentifier.
o The Neighbour Discovery should specify the formation of a site-
local address that follows the security recommendations from
[RFC7217].
Authors' Addresses Authors' Addresses
Behcet Sarikaya (editor) Behcet Sarikaya
Huawei USA Huawei USA
5340 Legacy Dr. Building 3 5340 Legacy Dr. Building 3
Plano, TX 75024 Plano, TX 75024
Email: sarikaya@ieee.org Email: sarikaya@ieee.org
Pascal Thubert Pascal Thubert
Cisco Systems, Inc Cisco Systems, Inc
Building D Building D
45 Allee des Ormes - BP1200 45 Allee des Ormes - BP1200
MOUGINS - Sophia Antipolis 06254 MOUGINS - Sophia Antipolis 06254
FRANCE FRANCE
Phone: +33 497 23 26 34 Phone: +33 497 23 26 34
Email: pthubert@cisco.com Email: pthubert@cisco.com
Mohit Sethi (editor) Mohit Sethi
Ericsson Ericsson
Hirsalantie Hirsalantie
Jorvas 02420 Jorvas 02420
Email: mohit@piuha.net Email: mohit@piuha.net
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