6lo B. Sarikaya
Internet-Draft
Updates: 6775 (if approved) P. Thubert
Intended status: Standards Track Cisco
Expires: March 25, 2018 M. Sethi
Ericsson
September 21, 2017
Address Protected Neighbor Discovery for Low-power and Lossy Networks
draft-ietf-6lo-ap-nd-03
Abstract
This document defines an extension to 6LoWPAN Neighbor Discovery RFC
6775. Nodes supporting this extension compute a cryptographic Owner
Unique Interface ID and associate it with one or more of their
Registered Addresses. Once an address is registered with a
Cryptographic ID, only the owner of that ID can modify the anchor
state information of the Registered Address, and Source Address
Validation can be enforced.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on March 25, 2018.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
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publication of this document. Please review these documents
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carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 4
4. New Fields and Options . . . . . . . . . . . . . . . . . . . 5
4.1. New Crypto-ID . . . . . . . . . . . . . . . . . . . . . . 5
4.2. Updated EARO . . . . . . . . . . . . . . . . . . . . . . 6
4.3. New Crypto-ID Parameters Option . . . . . . . . . . . . . 7
5. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 8
5.1. Protocol Scope . . . . . . . . . . . . . . . . . . . . . 8
5.2. Protocol Flows . . . . . . . . . . . . . . . . . . . . . 9
5.3. Multihop Operation . . . . . . . . . . . . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
7. IANA considerations . . . . . . . . . . . . . . . . . . . . . 13
7.1. Crypto Type Registry . . . . . . . . . . . . . . . . . . 13
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
9. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 13
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
10.1. Normative References . . . . . . . . . . . . . . . . . . 14
10.2. Informative references . . . . . . . . . . . . . . . . . 14
Appendix A. Requirements Addressed in this Document . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
"Neighbor Discovery Optimizations for 6LoWPAN networks" [RFC6775]
(6LoWPAN ND) adapts the classical IPv6 ND protocol [RFC4861][RFC4862]
(IPv6 ND) for operations over a constrained low-power and lossy
network (LLN). In particular, 6LoWPAN ND introduces a unicast host
address registration mechanism that contributes to reduce the use of
multicast messages that are present in the classical IPv6 ND
protocol. 6LoWPAN ND defines a new Address Registration Option (ARO)
that is carried in the unicast Neighbor Solicitation (NS) and
Neighbor Advertisement (NA) messages between the 6LoWPAN Node (6LN)
and the 6LoWPAN Router (6LR). Additionally, it also defines the
Duplicate Address Request (DAR) and Duplicate Address Confirmation
(DAC) messages between the 6LR and the 6LoWPAN Border Router (6LBR).
In LLN networks, the 6LBR is the central repository of all the
registered addresses in its domain.
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The registration mechanism in 6LoWPAN ND [RFC6775] prevents the use
of an address if that address is already present in the subnet (first
come first serve). In order to validate address ownership, the
registration mechanism enables the 6LR and 6LBR to validate claims
for a registered address with an associated Owner Unique Interface
IDentifier (OUID). 6LoWPAN ND specifies that the OUID is derived from
the MAC address of the device (EUI-64), which can be spoofed.
Therefore, any node connected to the subnet and aware of a
registered-address-to-OUID mapping could effectively fake the OUID,
steal the address and redirect traffic for that address towards a
different 6LN. The "Update to 6LoWPAN ND"
[I-D.ietf-6lo-rfc6775-update] defines an Extended ARO (EARO) option
that allows to transport alternate forms of OUIDs, and is a
prerequisite for this specification.
According to this specification, a 6LN generates a cryptographic ID
(Crypto-ID) and places it in the OUID field in the registration of
one (or more) of its addresses with the 6LR(s) that the 6LN uses as
default router(s). Proof of ownership of the cryptographic ID
(Crypto-ID) is passed with the first registration to a given 6LR, and
enforced at the 6LR, in a new Crypto-ID Parameters Option (CIPO).
The 6LR validates ownership of the cryptographic ID upon the creation
of a registration state, or a change in the anchor information, such
as Link-Layer Address and associated Layer-2 cryptographic material.
The protected address registration protocol proposed in this document
enables the enforcement of Source Address Validation (SAVI)
[RFC7039], which ensures that only the correct owner uses a
registered address in the source address field in IPv6 packets.
Consequently, a 6LN that sources a packet has to use a 6LR to which
the source address of the packet is registered to forward the packet.
The 6LR maintains state information for the registered addressed,
including the MAC address, and a link-layer cryptographic key
associated with the 6LN. 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.
The 6lo adaptation layer framework ([RFC4944], [RFC6282]) expects
that a device forms its IPv6 addresses based on Layer-2 address, so
as to enable a better compression. This is incompatible with "Secure
Neighbor Discovery (SEND)" [RFC3971] and "Cryptographically Generated
Addresses (CGAs)" [RFC3972], which derive the Interface ID (IID) in
the IPv6 addresses from cryptographic material. "Privacy
Considerations for IPv6 Address Generation Mechanisms" [RFC7721]
places additional recommendations on the way addresses should be
formed and renewed.
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This document specifies that a device may form and register addresses
at will, without a constraint on the way the address is formed or the
number of addresses that are registered in parallel. It enables to
protect multiple addresses with a single cryptographic material and
to send the proof only once to a given 6LR for multiple addresses and
refresher registrations.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Readers are expected to be familiar with all the terms and concepts
that are discussed in [RFC3971], [RFC3972], [RFC4861], [RFC4919],
[RFC6775], and [I-D.ietf-6lo-backbone-router] which proposes an
evolution of [RFC6775] for wider applicability.
This document defines Crypto-ID as an identifier of variable size
which in most cases is 64 bits long. It is generated using
cryptographic means explained later in this document Section 4.1.
The document also conforms to the terms and models described in
[RFC5889] and uses the vocabulary and the concepts defined in
[RFC4291] for the IPv6 Architecture. Finally, common terminology
related to Low power And Lossy Networks (LLN) defined in [RFC7102] is
also used.
3. Updating RFC 6775
This specification defines a cryptographic identifier (Crypto-ID)
that can be used as a replacement to the MAC address in the OUID
field of the EARO option; the computation of the Crypto-ID is
detailed in Section 4.1. A node in possession of the necessary
cryptographic material SHOULD use Crypto-ID by default as OUID in its
registration. Whether a OUID is a Crypto-ID is indicated by a new
"C" flag in the NS(EARO) message.
This specification introduces a new option, the CIPO, that is used to
prove ownership of the Crypto-ID. A node that registers for the
first time to a 6LR SHOULD place a CIPO option in its registration.
However, it is not expected to place the option in the periodic
refresher registrations for that address, or to register other
addresses with the same OUID. When a 6LR receives a NS(EARO)
registration with a new Crypto-ID as a OUID, it SHOULD challenge by
responding with a NA(EARO) with a status of "Validation Requested".
This process of validation MAY be skipped in networks where there is
no mobility.
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The challenge MUST also be triggered in the case of a registration
for which the Source Link-Layer Address is not consistent with a
state that already exists either at the 6LR or the 6LBR. In the
latter case, the 6LBR returns a status of "Validation Requested" in
the DAR/DAC exchange, which is echoed by the 6LR in the NA (EARO)
back to the registering node. This flow should not alter a
preexisting state in the 6LR or the 6LBR.
Upon receiving a NA(EARO) with a status of "Validation Requested",
the registering node SHOULD retry its registration with a CIPO option
that proves its ownership of the Crypto-ID.
If the 6LR cannot validate the CIPO, it responds with a status of
"Validation Failed". After receiving a NA(EARO) with a status of
"Validation Failed", the registering node MUST NOT use this Crypto-ID
for registering with that 6LR.
4. New Fields and Options
4.1. New Crypto-ID
Elliptic Curve Cryptography (ECC) is used to calculate the Crypto-ID.
Each 6LN using a Crypto-ID for registration MUST have a public/
private key pair. 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.
The Crypto-ID is computed as follows:
1. the modifier is set to a random or pseudo-random 128-bit value
2. the modifier, 9 zero octets and the ECC public key are
concatenated from left to right.
3. the SHA-256 algorithm is applied on the concatenation
4. the 112 leftmost bits of the hash value are retained
5. the modifier value, the subnet prefix and the encoded public key
are concatenated from left to right
6. NIST P-256 is executed on the concatenation
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7. the leftmost bits of the result are used as the Crypto-ID.
With this specification, the last 64 bits are retained, but it could
be expanded to more bits in the future by increasing the size of the
OUID field.
To support cryptographic algorithm agility [RFC7696], Curve25519
[RFC7748] can also be used instead of NIST P-256. This is indicated
by 6LN using the Crypto Type field in the CIPO option. The document
currently only defines two possible values for the Crypto Type field.
A value of 0 indicates that NIST P-256 is used for the signature
operation and SHA-256 as the hash algorithm. A value of 1 indicates
that Curve25519 is used for the signature operation and SHA-256 as
the hash algorithm. New values for the Crypto Type maybe defined in
the future for new curves.
4.2. Updated EARO
This specification updates the EARO option as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Status | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |C|T| TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Owner Unique ID (EUI-64 or equivalent) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Enhanced Address Registration Option
Type: 33
Length: 8-bit unsigned integer. The length of the option
(including the type and length fields) in units of 8
bytes.
Status: 8-bit unsigned integer. Indicates the status of a
registration in the NA response. MUST be set to 0 in
NS messages. This specification uses values
introduced in the update to 6LoWPAN ND
[I-D.ietf-6lo-rfc6775-update], such as "Validation
Requested" and "Validation Failed". No additional
value is defined.
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Reserved: This field is unused. It MUST be initialized to zero
by the sender and MUST be ignored by the receiver.
C: This "C" flag is set to indicate that the Owner
Unique ID field contains a Crypto-ID.
T and TID: Defined in [I-D.ietf-6lo-rfc6775-update].
Owner Unique ID: When the "C" flag is set, this field contains a
Crypto-ID.
4.3. New Crypto-ID Parameters Option
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 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Modifier (16 octets) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Subnet Prefix (8 octets) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| |
+ Public Key (variable length) +
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Padding .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Crypto-ID Parameters Option
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Type: CIPO, to be assigned by IANA.
Length: The length of the option in units of 8 octets.
Pad Length: The length of the Padding field.
Crypto Type: The type of cryptographic algorithm used in
calculation Crypto-ID. Default value of all zeros
indicate NIST P-256. A value of 1 is assigned for
Curve25519. New values may be defined later.
Modifier: 128 bit random value.
Subnet Prefix: 64 bit subnet prefix.
Public Key: ECC public key of 6LN.
Padding: A variable-length field making the option length a
multiple of 8, containing as many octets as specified
in the Pad Length field.
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].
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---+-------- ............
| 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
Figure 4 illustrates a registration flow all the way to a 6LowPAN
Backbone Router (6BBR).
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 (EARO) [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.
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6LN 6LR 6LBR 6BBR
| | | |
| NS(EARO) | | |
|--------------->| | |
| | Extended DAR | |
| |-------------->| |
| | | |
| | | proxy NS(EARO) |
| | |--------------->|
| | | | NS(DAD)
| | | | ------>
| | | |
| | | | <wait>
| | | |
| | | proxy NA(EARO) |
| | |<---------------|
| | Extended DAC | |
| |<--------------| |
| NA(EARO) | | |
|<---------------| | |
| | | |
Figure 4: (Re-)Registration Flow
On-link (local) protocol interactions are shown in Figure 5. Crypto-
ID and ARO are passed to and stored by the 6LR 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 use multiple IPv6 addresses at the same time. 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 bind all of its addresses to
the same Crypto-ID.
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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 a multihop 6LoWPAN, a 6LBR sends RAs with prefixes downstream and
the 6LR receives and relays them to the nodes. 6LR and 6LBR
communicate using ICMPv6 Duplicate Address Request (DAR) and
Duplicate Address Confirmation (DAC) messages. The DAR and DAC use
the same message format as NS and NA, but have different ICMPv6 type
values.
In ND-PAR we extend DAR/DAC messages to carry cryptographically
generated OUID. In a multihop 6LoWPAN, the node exchanges the
messages shown in Figure 4. The 6LBR must identify who owns an
address (EUI-64) to defend it, if there is an attacker on another
6LR. Because of this the content that the source signs and the
signature needs to be propagated to the 6LBR in the DAR message. For
this purpose the DAR message sent by 6LR to 6LBR MUST contain the
CIPO option. The DAR message also contains ARO.
Occasionally, a 6LR might miss the node's OUID (that it received in
ARO). 6LR should be able to ask for it again. This is done by
restarting the exchanges shown in Figure 5. The result enables 6LR
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to refresh the information that was lost. The 6LR MUST send DAR
message with ARO to 6LBR. The 6LBR replies with a DAC message with
the information copied from the DAR, and the Status field is set to
zero. With this exchange, the 6LBR can (re)validate and store the
information to make sure that the 6LR is not a fake.
In some cases, the 6LBR may use a DAC message to solicit a Crypto-ID
from a 6LR and also requests 6LR to verify the EUI-64 6LR 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-64. Note
that the detection in this case can only be done by 6LBR not by 6LR.
6. Security Considerations
The observations regarding the threats to the local network in
[RFC3971] also apply to this specification.
The threats discussed in 6LoWPAN ND [RFC6775] and its update
[I-D.ietf-6lo-rfc6775-update] also apply here. 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 protocol described in
this document as well.
Collisions of Owner Unique Interface IDentifier (OUID) (which is the
Crypto-ID in this specification) is a possibility that needs to be
considered. The formula for calculating the probability of a
collision is 1 - e^{-k^2/(2n)} where n is the maximum population size
(2^64 here, 1.84E19) and K is the actual population (number of
nodes). If the Crypto-ID is 64-bit long, then the chance of finding
a collision is 0.01% when the network contains 66 million nodes. It
is important to note that the collision is only relevant when this
happens within one stub network (6LBR). A collision of Crypto-ID is
a rare event. In the case of a collision, an attacker may be able to
claim the registered address of an another legitimate node. However
for this to happen, the attacker would also need to know the address
which was registered by the legitimate node. This registered address
is however never broadcasted on the network and therefore it provides
an additional entropy of 64-bits that an attacker must correctly
guess. To prevent such a scenario, it is RECOMMENDED that nodes
derive the address being registered independently of the OUID.
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7. IANA considerations
IANA is requested to assign two new option type values for the CIPO
under the subregistry "IPv6 Neighbor Discovery Option Formats".
7.1. Crypto Type Registry
The following Crypto Type values are defined in this document:
+-------------------+-----------------------------------------+
| Crypto Type value | Algorithms |
+-------------------+-----------------------------------------+
| 0 | NIST P-256, SHA-256 [RFC6234] |
| 1 | Curve25519 [RFC7748], SHA-256 [RFC6234] |
+-------------------+-----------------------------------------+
Table 1: Crypto Types
Assignment of new values for new Crypto Type MUST be done through
IANA with "Specification Required" and "IESG Approval" as defined in
[RFC8126].
8. Acknowledgements
Special thanks to Charlie Perkins for his in-depth review and
constructive suggestions. We are also grateful to Rene Struik and
Robert Moskowitz for their comments that lead to many improvements to
this document.
9. Change Log
o submitted version -00 as a working group draft after adoption, and
corrected the order of authors
o submitted version -01 with no changes
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.
o submitted version -03 addressing Charlie Perkins' comments
10. References
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10.1. Normative References
[I-D.ietf-6lo-rfc6775-update]
Thubert, P., Nordmark, E., and S. Chakrabarti, "An Update
to 6LoWPAN ND", draft-ietf-6lo-rfc6775-update-09 (work in
progress), September 2017.
[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>.
[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>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007,
<https://www.rfc-editor.org/info/rfc4862>.
[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,
<https://www.rfc-editor.org/info/rfc6775>.
10.2. Informative references
[I-D.ietf-6lo-backbone-router]
Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo-
backbone-router-04 (work in progress), July 2017.
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
"SEcure Neighbor Discovery (SEND)", RFC 3971,
DOI 10.17487/RFC3971, March 2005,
<https://www.rfc-editor.org/info/rfc3971>.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, DOI 10.17487/RFC3972, March 2005,
<https://www.rfc-editor.org/info/rfc3972>.
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[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals",
RFC 4919, DOI 10.17487/RFC4919, August 2007,
<https://www.rfc-editor.org/info/rfc4919>.
[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,
<https://www.rfc-editor.org/info/rfc4944>.
[RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing
Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889,
September 2010, <https://www.rfc-editor.org/info/rfc5889>.
[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
(SHA and SHA-based HMAC and HKDF)", RFC 6234,
DOI 10.17487/RFC6234, May 2011,
<https://www.rfc-editor.org/info/rfc6234>.
[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,
<https://www.rfc-editor.org/info/rfc6282>.
[RFC7039] Wu, J., Bi, J., Bagnulo, M., Baker, F., and C. Vogt, Ed.,
"Source Address Validation Improvement (SAVI) Framework",
RFC 7039, DOI 10.17487/RFC7039, October 2013,
<https://www.rfc-editor.org/info/rfc7039>.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
2014, <https://www.rfc-editor.org/info/rfc7102>.
[RFC7217] Gont, F., "A Method for Generating Semantically Opaque
Interface Identifiers with IPv6 Stateless Address
Autoconfiguration (SLAAC)", RFC 7217,
DOI 10.17487/RFC7217, April 2014,
<https://www.rfc-editor.org/info/rfc7217>.
[RFC7696] Housley, R., "Guidelines for Cryptographic Algorithm
Agility and Selecting Mandatory-to-Implement Algorithms",
BCP 201, RFC 7696, DOI 10.17487/RFC7696, November 2015,
<https://www.rfc-editor.org/info/rfc7696>.
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[RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy
Considerations for IPv6 Address Generation Mechanisms",
RFC 7721, DOI 10.17487/RFC7721, March 2016,
<https://www.rfc-editor.org/info/rfc7721>.
[RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves
for Security", RFC 7748, DOI 10.17487/RFC7748, January
2016, <https://www.rfc-editor.org/info/rfc7748>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
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].
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Authors' Addresses
Behcet Sarikaya
Plano, TX
USA
Email: sarikaya@ieee.org
Pascal Thubert
Cisco Systems, Inc
Building D
45 Allee des Ormes - BP1200
MOUGINS - Sophia Antipolis 06254
FRANCE
Phone: +33 497 23 26 34
Email: pthubert@cisco.com
Mohit Sethi
Ericsson
Hirsalantie
Jorvas 02420
Email: mohit@piuha.net
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