wdiff rfc7985.original rfc7985.txt

Mobile Ad hoc Networking (MANET)
Internet Engineering Task Force (IETF) J. Yi
Internet-Draft
Request for Comments: 7985 T. Clausen
Updates: 7186 (if approved) Ecole Polytechnique
Intended status:
Category: Informational U. Herberg
Expires: February 28, 2017 August 27,
ISSN: 2070-1721 October 2016

Security Threats for to Simplified Multicast Forwarding (SMF)
draft-ietf-manet-smf-sec-threats-06

Abstract

This document analyzes security threats of the to Simplified Multicast
Forwarding (SMF) mechanism, (SMF), including the vulnerabilities of duplicate packet
detection and relay set selection mechanisms. This document is not
intended to propose solutions to the threats described.

This

In addition, this document also updates RFC7186 RFC 7186 regarding the threats to the
relay set selection mechanisms using RFC6130. the Mobile Ad Hoc Network
(MANET) Neighborhood Discovery Protocol (NHDP) (RFC 6130).

Status of this This Memo

This Internet-Draft document is submitted in full conformance with the
provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents not an Internet Standards Track specification; it is
published for informational purposes.

This document is a product of the Internet Engineering Task Force
(IETF). Note that other groups may also distribute
working It has been approved for publication by the Internet
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Drafts is at http://datatracker.ietf.org/drafts/current/.

Internet-Drafts approved by the
IESG are draft documents valid for a maximum candidate for any level of Internet Standard; see
Section 2 of six months RFC 7841.

Information about the current status of this document, any errata,
and how to provide feedback on it may be updated, replaced, or obsoleted by other documents obtained 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 February 28, 2017.
http://www.rfc-editor.org/info/rfc7985.

This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3
3. SMF Threats Threat Overview . . . . . . . . . . . . . . . . . . . . . 4
4. Threats to Duplicate Packet Detection . . . . . . . . . . . . 5
4.1. Attack to The on the Hop Limit Field . . . . . . . . . . . . . . 6 5
4.2. Threats to Identification-based Identification-Based Duplicate Packet
Detection . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2.1. Pre-activation Pre-Activation Attacks (Pre-Play) . . . . . . . . . . 7
4.2.2. De-activation Attacks (Sequence Number wrangling) Wrangling) . . 8
4.3. Threats to Hash-based Hash-Based Duplicate Packet Detection . . . . . 9 8
4.3.1. Attack on the Hash-Assistant Value . . . . . . . . . . . . 9
5. Threats to Relay Set Selection . . . . . . . . . . . . . . . . 10 9
5.1. Common Threats to Relay Set Selection Common Threats . . . . . . . . . . . . 10
5.2. Threats to the E-CDS Algorithm . . . . . . . . . . . . . . . . 10
5.2.1. Link Spoofing . . . . . . . . . . . . . . . . . . . . 11 10
5.2.2. Identity Spoofing . . . . . . . . . . . . . . . . . . 11 10
5.3. Threats to S-MPR Algorithm . . . . . . . . . . . . . . . . 11
5.4. Threats to the MPR-CDS Algorithm . . . . . . . . . . . . . . . 12 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . References . . 13
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
9.
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . 13
Acknowledgments . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 14

1. Introduction

This document analyzes security threats to the Simplified Multicast
Forwarding (SMF) mechanism [RFC6621]. SMF aims at providing basic Internet
Protocol (IP) multicast forwarding, forwarding in a way that is suitable for limited
wireless mesh and Mobile Ad hoc NETworks Hoc Networks (MANET). SMF is constituted consists of
two major functional components:
Duplicate Packet Detection duplicate packet detection (DPD) and Relay Set Selection.
relay set selection (RSS).

SMF is typically used in decentralized wireless environments, environments and is
potentially exposed to various attacks and misconfigurations. Some In a
wireless environment, some of these attacks and misconfigurtions, in a wireless enviroment, misconfigurations
represent threats of particular significance as compared to what they
would do in wired networks. [RFC6621] briefly discusses several of
these, but does not define any explicit security measures for
protecting the integrity of the protocol.

This document is based on the assumption that no additional security
mechanism
mechanism, such as IPsec IPsec, is used in the IP layer, as not all MANET
deployments may be suitable able to deploy support deployment of such common IP
protection mechanisms (e.g., because of limited resources of MANET routers to support may have limited
resources for supporting the IPsec stack). It also assumes that
there is no lower-layer protection
either. protection. The document analyzes possible
attacks on on, and mis-
configurations of misconfigurations of, SMF and outlines the
consequences of such attacks/
mis-configurations attacks/misconfigurations to the state
maintained by SMF in each router.

In the Security Considerations section of [RFC6621], denial-of-
service attack
service-attack scenarios are briefly discussed. This document
further analyzes and describes the potential vulnerabilities of of, and
attack vectors for for, SMF. While completeness in such analysis is
always a goal, no claims of being complete are made. The goal of
this document is to be helpful for when deploying SMF in a network and needing to understand
for understanding the risks thereby incurred - incurred, as well as for providing a
reference to and documented experience with SMF as input for
possibly possible
future developments of SMF.

This document is not intended to propose solutions to the threats
described. [RFC7182] provides a framework that can be used with SMF,
and depending on how it is used - used, may offer some degree of protection
against the threats described in this document related to identity
spoofing. spoofing described in this
document.

This document also updates [RFC7186], specifically with respect to
threats to relay set selection (RSS) mechanisms which that are using MANET
NHDP [RFC6130].

2. Terminology

This document uses the terminology and notation defined in [RFC5444],
[RFC6130], [RFC6621] [RFC6621], and [RFC4949].

Additionally, this document introduces the following terminology:

SMF router: A MANET router, running SMF as specified in [RFC6621].

Attacker: A device that is present in the network and intentionally
seeks to compromise the information bases in SMF routers. It may
generate syntactically correct SMF control messages.

Legitimate SMF router: An SMF router that is correctly configured
and not compromised by an attacker.

3. SMF Threats Threat Overview

An SMF router requires an external dynamic neighborhood discovery
mechanism in order to maintain suitable topological information
describing its immediate neighborhood, and thereby allowing it to
select reduced relay sets for forwarding multicast data traffic.
Such an external dynamic neighborhood discovery mechanism may be
provided by lower-
layer lower-layer interface information, by a concurrently
operating MANET routing protocol that already maintains such
information such as
[RFC7181], (e.g., [RFC7181]) or by explicitly using the MANET
Neighborhood Discovery Protocol (NHDP) [RFC6130]. If NHDP is used
for both 1-hop and 2-hop neighborhood discovery by SMF, SMF
implicitly inherits the vulnerabilities of NHDP discussed in
[RFC7186]. As SMF relies on NHDP to assist in network layer network-layer 2-hop
neighborhood discovery (no matter if other lower-layer mechanisms are
used for 1-hop neighborhood discovery), this document assumes that
NHDP is used in SMF. The threats that are NHDP-specific NHDP specific are
indicated explicitly.

Based on neighborhood discovery mechanisms, [RFC6621] specifies two
principal functional components: Duplicate Packet Detection duplicate packet detection (DPD) and
Relay Set Selection
relay set selection (RSS).

DPD is required by SMF in order to be able to detect duplicate
packets and eliminate their redundant forwarding. An Attacker attacker has
two ways in which to harm the DPD mechanisms, specifically mechanisms. Specifically, it can:

o "deactivate" DPD, so as to make making it such that duplicate packets are not
correctly detected, and that as detected. As a consequence consequence, they are (redundantly)
transmitted, increasing which increases the load on the network,
draining drains the
batteries of the routers involved, etc.

o "pre-activate" DPD, so as to make making DPD detect a later arriving (valid)
packet as being a duplicate, which therefore won't duplicate and will, therefore, not be forwarded.

Attacks on DPD can be achieved by replaying existing packets, by
wrangling sequence numbers, by manipulating hash values, etc., and etc.; these are
detailed in Section 4.

RSS produces a reduced relay set for forwarding multicast data
packets across the a MANET. For use in SMF, [RFC6621] specifies several
relay set
algorithms, algorithms including E-CDS (Essential Connected Dominating
Set) [RFC5614], S-MPR (Source-based Multi-point (Source-Based Multipoint Relay, as known from
[RFC3626] and [RFC7181]), or and MPR-CDS [MPR-CDS], for use in SMF. (Multipoint Relay Connected
Dominating Set) [MPR-CDS]. An
Attacker attacker can disrupt the RSS
algorithm, and thereby the SMF operation, by degrading it to
classical flooding, flooding or by "masking" certain parts of the network from
the multicasting domain. Attacks on RSS algorithms are detailed in
Section 5.

Other than the attacks on DPD and RSS, a common vulnerability of
MANETs is "jamming", i.e., a device generates massive amounts of
interfering radio transmissions, which will prevent legitimate
traffic (e.g., control traffic as well as data traffic) on part of a
network. The attacks on DPD and RSS can be further enhanced by
jamming.

4. Threats to Duplicate Packet Detection

Duplicate Packet Detection packet detection (DPD) is required for packet dissemination
in MANETs because: (1) packets may be transmitted retransmitted via the same
physical interface as the one over which they were received, and (2)
a router may receive multiple copies of the same packet (on the same, same
or on different interfaces) from different neighbors. DPD is thus
used to check if whether or not an incoming packet has been previously received or
not.
received.

DPD is achieved by maintaining a record of recently processed
multicast packets, and comparing later received multicast packets
herewith. A duplicate packet detected is silently dropped and is not
inserted into the forwarding path of that router, nor is it delivered
to an application. DPD, as proposed by SMF, supports both IPv4 and
IPv6 and for each suggests two duplicate packet detection mechanisms: mechanisms for each:
1) IP packet header content identification-based DPD (I-DPD), using packet
headers, in
combination with flow state, to estimate temporal uniqueness of a
packet, and 2) hash-based DPD (H-DPD), employing hashing of selected
IP packet header fields and payload for the same effect.

In the Security Considerations section of [RFC6621], a selection of
threats to DPD are briefly introduced. This section expands on that
discussion,
discussion and describes how to effectively launch the attacks on DPD -
-- for example, by way of manipulating jitter and/or the Hash-
Assistant Value. In the remainder of this section, common threats to
packet detection mechanisms are first discussed. Then discussed first; then, the threats to
I-DPD and H-DPD are introduced separately. The threats described in
this section are applicable to general SMF implementations, no matter
if
regardless of whether NHDP is used or not. used.

4.1. Attack to The on the Hop Limit Field

One immediate DoS Denial-of-Service (DoS) attack is based on manipulating
the Time-to-Live (TTL, for IPv4) or hop limit Hop Limit (for IPv6) field. As
routers only forward packets with TTL > 1, an attacker can forward an
otherwise valid packet, packet while drastically reducing the TTL hereof.
This will inhibit recipient routers from later forwarding the same
multicast packet, even if received with a different TTL - essentially --
essentially, an attacker thus can thus instruct its neighbors to block the
forwarding of valid multicast packets.

For example, in Figure 1, router A forwards a multicast packet with a
TTL of 64 to the network. A, B, and C are legitimate SMF routers,
and X is an attacker. In a wireless environment, jitter is commonly
used to avoid systematic collisions in MAC Media Access Control (MAC)
protocols [RFC5148]. An attacker can thus increase the probability
that its invalid packets arrive first by retransmitting them without
applying jitter. In this example, router X forwards the packet
without applying jitter and reduces the TTL to 1. Router C thus
records the duplicate detection value (hash value for H-DPD, H-DPD or the
header content of the packets for I-DPD) but does not forward the
packet (due to TTL == 1) not forward. 1). When a second copy of the same packet,
with a non-maliciously manipulated TTL value (63 in this case),
arrives from router B, it will be discarded as a duplicate packet.

.---.
| X |
--'---' __
packet with TTL=64 / \ packet with TTL=1
/ \
.---. .---.
| A | | C |
'---' '---'
packet with TTL=64 \ .---. /
\-- | B |__/ packet with TTL=63
'---'

Figure 1

As the TTL of a packet is intended to be manipulated by
intermediaries forwarding it, classic methods such as integrity check
values (e.g., digital signatures) are typically calculated with by setting
TTL fields to some pre-determined predetermined value (e.g., 0) - such is -- for example example, the
case for IPsec Authentication Headers - -- rendering such an attack
more difficult to both detect and counter.

If the attacker has access to a "wormhole" through the network (a
directional antenna, a tunnel to a collaborator collaborator, or a wired
connection, allowing it to bridge parts of a network otherwise
distant), it can make sure that the packets with such an artificially
reduced TTL arrive before their unmodified counterparts.

4.2. Threats to Identification-based Identification-Based Duplicate Packet Detection

I-DPD uses a specific DPD identifier in the packet header to identify
a packet. By default, such packet identification is not provided by
the IP packet header (for both IPv4 and IPv6). Therefore, additional
identification headers, such as the fragment header, a hop-by-hop
header option, or IPSec IPsec sequencing, must be employed in order to
support I-DPD. The uniqueness of a packet can then be identified by
the source IP address of the packet originator and the sequence
number (from the fragment header, hop-by-hop header option, or
IPsec). By doing so, each intermediate router can keep a record of
recently received packets and determine whether or not the incoming
packet has been received or not. received.

4.2.1. Pre-activation Pre-Activation Attacks (Pre-Play)

In a wireless environment, or across any other shared channel, an
attacker can perceive the identification tuple (source IP address,
sequence number) of a packet. It is possible to generate a packet
with the same (source IP address, sequence number) pair with invalid
content. If the sequence number progression is predictable, then it
is trivial to generate and inject invalid packets with "future"
identification information into the network. If these invalid
packets arrive before the legitimate packets that they are spoofing,
the latter will be treated as a duplicate and will be discarded.
This can prevent multicast packets from reaching parts of the
network.

Figure 2 gives an example of a pre-activation attack. A, B B, and C
are legitimate SMF routers, and X is the attacker. The line between
the routers presents the packet forwarding. Router A is the source
and originates a multicast packet with sequence number n. When
router X receives the packet, it generates an invalid packet with the
source address of A and sequence number n. If the invalid packet
arrives at router C before the forwarding of router B, the valid
packet will be dropped by C as a duplicate packet. An attacker can
manipulate jitter to make sure that the invalid packets arrive first.
Router X can even generate packets with future sequence numbers (if
they are predictable), so that the future legitimate packets with the
same sequence numbers will be dropped as duplicate ones.

.---.
| X |
--'---' __
packet with seq=n / \ invalid packet with seq=n
/ \
.---. .---.
| A | | C |
'---' '---'
packet with seq=n \ .---. /
\-- | B |__/ valid packet with seq=n
'---'

Figure 2

As SMF currently does not currently have any timestamp mechanisms to protect
data packets, there is no viable way to detect such pre-play attacks
by way of timestamps. Especially, if the attack is based on
manipulation of jitter, the validation of the timestamp would not be
helpful because the timing is still valid (but with (but, much less value). valuable).

4.2.2. De-activation Attacks (Sequence Number wrangling) Wrangling)

An attacker can also seek to de-activate DPD, DPD by modifying the
sequence number in packets that it forwards. Thus, routers will not
be able to detect an actual duplicate packet as a duplicate - --
rather, they will treat them as new packets, i.e., process and
forward them. This is similar to DoS attacks, as each packet that is
considered unique will be multicasted: for a network with n routers,
there will be n-1 retransmissions. This can easily cause the
"broadcast storm" problem discussed in [MOBICOM99]. The consequence
of this attack is an increased channel load, the origin of which
appears to be a router other than the attacker.

Given the topology shown in Figure 2, on receiving a packet with
seq=n, the attacker X can forward the packet with a modified sequence
number n+i. This has two consequences: firstly, router C will not be
able to detect that the packet forwarded by X is a duplicate packet;
secondly, the consequent packet with seq=n+i generated by router A
probably
will probably be treated as a duplicate packet, packet and will be dropped by
router C.

4.3. Threats to Hash-based Hash-Based Duplicate Packet Detection

When explicit sequence numbers in packet headers is undesired, hash-
based DPD can be used. A hash of the non-mutable fields in the
header of and the data payload can be generated, generated and recorded at the
intermediate routers. A packet can thus be uniquely identified by
the source IP address of the packet and its hash-value.

The hash algorithm used by SMF is being applied only to provide a
reduced probability of collision and is not being used for
cryptographic or authentication purposes. Consequently, a digest
collision is still possible. In case the source router or gateway
identifies that it recently has recently generated or injected a packet with
the same hash-value, it inserts a "Hash-Assist Value (HAV)" IPv6
header option into the packet, such that also calculating the hash also
over this HAV will render the resulting value unique.

4.3.1. Attack on the Hash-Assistant Value

The HAV header is helpful when a digest collision happens. However,
it also introduces a potential vulnerability. As the HAV option is
only added when the source or the ingress SMF router detects that the
coming
incoming packet has digest collision with previously generated
packets, it actually can actually be regarded as a "flag" of potential digest
collision. An attacker can discover the HAV header, header and be able to
conclude that a hash collision is possible if the HAV header is
removed. By doing so, the modified packet received by other SMF
routers will be treated as duplicate packets, packets and will be dropped
because they have the same hash value with the precedent packet. as previously received packets.

In the example of shown in Figure 3, Router routers A and B are legitimate SMF
routers; X is an attacker. Router A generates two packets packets, P1 and
P2, with the same hash value h(P1)=h(P2)=x. Based on the SMF
specification, a
hash-assistant value (HAV) HAV is added to the latter packet P2, so that
h(P2+HAV)=x', to avoid
h(P2+HAV)=x' avoids digest collision. When the attacker X detects
the HAV of P2, it is able to conclude that a collision is possible by
removing the HAV header. By doing so, packet P2 will be treated as a
duplicate packet by router B, B and will be dropped.

P2 P1 P2 P1
.---. h(P2+HAV)=x' h(P1)=x .---. h(P2)=x h(P1)=x .---.
| A |---------------------------> | X | ----------------------> | B |
`---' `---' `---'

Figure 3

5. Threats to Relay Set Selection

A framework for an RSS mechanism, rather than a specific RSS algorithm
algorithm, is provided by SMF. It Relay Set Selection is normally
achieved by distributed algorithms that can dynamically generate a
topological Connected Dominating Set based on 1-hop and 2-hop
neighborhood information. In this section, the common threats to the RSS
framework are first discussed. Then specific threats to the three commonly used algorithms: Essential
algorithms (Essential Connection Dominating Set (E-CDS) algorithm, Source-based (E-CDS), Source-Based
Multipoint Relay (S-MPR) (S-MPR), and Multipoint Relay Connected Dominating
Set (MPR-CDS) (MPR-CDS)) explicitly enumerated by [RFC6621] are analyzed. As
the relay set selection is based on 1-hop and 2-hop neighborhood
information, which rely on NHDP, the threats described in this
section are NHDP-specific. NHDP specific.

5.1. Common Threats to Relay Set Selection Common Threats

Common (i.e., non algorithm specific)

Non-algorithm-specific threats to RSS algorithms, including Denial of Service attack, DoS
attacks, eavesdropping, message timing
attack attacks, and broadcast storm have been storm,
are discussed in [RFC7186].

5.2. Threats to the E-CDS Algorithm

The "Essential Connected Dominating Set" (E-CDS) algorithm [RFC5614]
forms a single CDS mesh for the an SMF operating region. It This algorithm
requires 2-hop neighborhood information (the identify identity of the
neighbors, the link to the neighbors neighbors, and the neighbors' priority information)
information), as collected through NHDP or another process.

An SMF Router router will select itself as a relay, if:

o The SMF Router router has a higher priority than all of its symmetric
neighbors, or

o There does not exist a A path from the neighbor with the largest priority to any other neighbor,
neighbor via neighbors with greater
priority. priority than the current
router does not exist.

An attacker can disrupt the E-CDS algorithm by link spoofing or
identity spoofing.

5.2.1. Link Spoofing

Link spoofing implies that an attacker advertises non-existing links
to another router (present (which may or may not be present in the network or not). network).

An attacker can declare itself with to have high route priority, priority and spoofs spoof
the links to as many legitimate SMF Routers routers as possible to declare
high connectivity. By doing so, it can prevent legitimate SMF
Routers
routers from self-selecting selecting themselves as relays. As the "super" relay in
the network, the attacker can manipulate the traffic relayed by it. it relays.

5.2.2. Identity Spoofing

Identity spoofing implies that an attacker determines and makes use
of the identity of other legitimate routers, without being authorized
to do so. The identity of other routers can be obtained by
overhearing
eavesdropping the control messages or the source/destination address
from datagrams. The attacker can then generate control or datagram
traffic,
traffic by pretending to be a legitimate router.

Because E-CDS self-selection is based on the router priority value,
an attacker can spoof the identity of other legitimate routers, routers and
declares
declare a different router priority value. If it declares a higher
priority of that a
spoofed router, router has a higher priority, it can prevent other routers
from selecting themselves as relays. On the other hand, if the
attacker declares lower priority of that a spoofed router, router has a lower priority, it can
force other routers to selecting select themselves as relays, relays to degrade the
multicast forwarding to classical flooding.

5.3. Threats to S-MPR Algorithm

The source-based multipoint relay (S-MPR) S-MPR set selection algorithm enables individual routers, using
2-hop topology information, to select relays from among their set of
neighboring routers. MPRs are selected so by each router such that forwarding to the router's complete a
message generated by it, and relayed only by its MPRs, will reach all
of its 2-hop neighbor
set is covered. neighbors.

An SMF router forwards a multicast packet if and only if:

o the packet has not been received before, and

o the neighbor from which the packet was received has selected the
router as MPR.

Because MPR calculation is based on the willingness declared by the
SMF routers, routers and the connectivity of the routers, it can be disrupted
by both link spoofing and identity spoofing. The These threats and its their
impacts have been illustrated in section Section 5.1 of [RFC7186].

5.4. Threats to the MPR-CDS Algorithm

MPR-CDS is a derivative from S-MPR. The main difference between
S-MPR and MPR-CDS is that while S-MPR forms a different broadcast
tree for each source in the network, MPR-CDS forms a unique broadcast
tree for all sources in the network.

As MPR-CDS combines E-CDS and S-MPR and the simple combination of the
two algorithms does not address the weakness, weaknesses; the vulnerabilities
of E-CDS and S-MPR that are discussed in Section Sections 5.2 and Section 5.3 apply
to MPR-CDS also.

6. Security Considerations

This document does not specify a protocol or a procedure. The whole
document, however, reflects on security considerations for SMF for
regarding packet dissemination in MANETs. Possible attacks to the
two main functional components of SMF, duplicate packet detection detection,
and relay set selection, selection are analyzed and documented.

Although neither [RFC6621] nor this document propose mechanisms to
secure the SMF protocol, there are several possibilities to secure
the protocol in the future and driving drive new work by suggesting which
threats discussed in the previous sections could be addressed.

For the I-DPD mechanism, employing randomized packet sequence numbers
can avoid some pre-activation attacks based on sequence number
prediction. If predicable sequence numbers have to be used, applying
timestamps can mitigate pre-activation attacks.

For the H-DPD mechanism, applying cryptographically strong hashes can
make the digest collisions effectively impossible, and it can avoid
the use of hash-assistant value. a HAV.

[RFC7182] specifies a framework for representing cryptographic
Integrity Check Values (ICVs) and timestamps in MANETs. Based on
[RFC7182], [RFC7183] specifies integrity and replay protection for
NHDP using shared keys, keys as a mandatory-to-implement security
mechanism. If SMF is using NHDP as the neighborhood discovery
protocol, implementing [RFC7183] remains advisable so as to enable
integrity protection for NHDP control messages. This can help mitigating
mitigate threats related to identity spoofing through the exchange of
HELLO
messages, messages and provides provide some general protection against identity
spoofing by admitting only trusted routers to the network using ICVs
in HELLO messages.

Using ICVs does, does not, of course, not address the problem of attackers, attackers able
to also generate valid ICVs. Detection and exclusion of such
attackers is, in general, a challenge, which challenge that is not unrelated to how
[RFC7182] is used. If, for example, it is used with a shared key (as
per [RFC7183]), excluding single attackers generally is not aided by
the use of ICVs. However However, if routers have sufficient capabilities to
support the use of asymmetric keys (as per [RFC7859]), part of
addressing this challenge becomes one of providing key revocation, revocation in
a way that does not in itself introduce additional vulnerabilities.

As [RFC7183] does not protect the integrity of the multicast user
datagram, and as no mechanism is specified by SMF for doing so,
duplicate packet detection remains vulnerable to the threats
introduced in Section 4.

If pre-activation/de-activation attacks and attack attacks on hash-assistant
value the HAV of the
multicast datagrams are to be mitigated, a datagram-
level datagram-level integrity
protection mechanism is desired, by taking consideration of the
identity field or hash-assistant value. HAV. However, this would not be helpful for the
attacks on the TTL (or hop
limit Hop Limit for IPv6) field, because the mutable
fields are generally not considered when ICV is calculated.

7. IANA Considerations

This document contains no actions for IANA.

[RFC Editor: please remove this section prior to publication.]

8. Acknowledgments

The authors would like to thank Christopher Dearlove (BAE Systems
ATC) who provided detailed review and valuable comments.

9. References

9.1.

7.1. Normative References

[RFC6130] Clausen, T., Dean, J., and C. Dearlove, C., and J. Dean, "Mobile Ad Hoc
Network (MANET) Neighborhood Discovery Protocol (NHDP)",
RFC 6130, DOI 10.17487/RFC6130, April 2011. 2011,
<http://www.rfc-editor.org/info/rfc6130>.

[RFC6621] Macker, J., Ed., "Simplified Multicast Forwarding",
RFC 6621, DOI 10.17487/RFC6621, May 2012. 2012,
<http://www.rfc-editor.org/info/rfc6621>.

[RFC7186] Yi, J., Herberg, U., and T. Clausen, "Security Threats for
the Neighborhood Discovery Protocol (NHDP)", RFC 7186,
DOI 10.17487/RFC7186, April 2014.

9.2. 2014,
<http://www.rfc-editor.org/info/rfc7186>.

7.2. Informative References

[MOBICOM99]
Ni, S., Tseng, Y., Chen, Y., and J. Sheu, "The Broadcast
Storm Problem broadcast
storm problem in a Mobile Ad Hoc Network", mobile ad hoc network", MobiCom
'99 Proceedings of the 5th annual ACM/IEEE international
conference on Mobile computing and networking,
DOI 10.1145/313451.313525, 1999.

[MPR-CDS] Adjih, C., Jacquet, P., and L. Viennot, "Computing
Connected Dominating Sets with Multipoint Relays", Journal
of Ad Hoc and Sensor Wireless Networks 2002, January 2002.

[RFC3626] Clausen, T. T., Ed. and P. Jacquet, "The Optimized Ed., "Optimized Link
State Routing Protocol", Protocol (OLSR)", RFC 3626,
DOI 10.17487/RFC3626, October 2003. 2003,
<http://www.rfc-editor.org/info/rfc3626>.

[RFC4949] Shirey, R., "Internet Security Glossary, Version 2",
FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007. 2007,
<http://www.rfc-editor.org/info/rfc4949>.

[RFC5148] Clausen, T., Dearlove, C., and B. Adamson, "Jitter
Considerations in Mobile Ad Hoc Networks (MANETs)",
RFC 5148, DOI 10.17487/RFC5148, February 2008. 2008,
<http://www.rfc-editor.org/info/rfc5148>.

[RFC5444] Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
"Generalized MANET Mobile Ad Hoc Network (MANET) Packet/Message
Format", RFC 5444, DOI 10.17487/RFC5444, February 2009. 2009,
<http://www.rfc-editor.org/info/rfc5444>.

[RFC5614] Ogier, R. and P. Spagnolo, "Mobile Ad Hoc Network (MANET)
Extension of OSPF Using Connected Dominating Set (CDS)
Flooding", RFC 5614, DOI 10.17487/RFC5614, August 2009. 2009,
<http://www.rfc-editor.org/info/rfc5614>.

[RFC7181] Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg,
"The Optimized Link State Routing Protocol version Version 2",
RFC 7181, DOI 10.17487/RFC7181, April 2014. 2014,
<http://www.rfc-editor.org/info/rfc7181>.

[RFC7182] Herberg, U., Clausen, T., and C. Dearlove, "Integrity
Check Value and Timestamp TLV Definitions for Mobile Ad
Hoc Networks (MANETs)", RFC 7182, DOI 10.17487/RFC7182,
April 2014. 2014, <http://www.rfc-editor.org/info/rfc7182>.

[RFC7183] Herberg, U., Dearlove, C., and T. Clausen, "Integrity
Protection for the Neighborhood Discovery Protocol (NHDP)
and Optimized Link State Routing Protocol Version 2
(OLSRv2)", RFC 7183, DOI 10.17487/RFC7183, April 2014. 2014,
<http://www.rfc-editor.org/info/rfc7183>.

[RFC7859] Dearlove, C., "Identity-Based Signatures for Mobile Ad Hoc
Network (MANET) Routing Protocols", RFC 7859,
DOI 10.17487/RFC7859, May 2016,
<http://www.rfc-editor.org/info/rfc7859>.

Acknowledgments

The authors would like to thank Christopher Dearlove (BAE Systems
ATC) who provided detailed review and valuable comments.

Authors' Addresses
Jiazi Yi
Ecole Polytechnique
91128 Palaiseau Cedex, Cedex
France

Phone: +33 1 77 57 80 85
Email: jiazi@jiaziyi.com
URI: http://www.jiaziyi.com/

Thomas Heide Clausen
Ecole Polytechnique
91128 Palaiseau Cedex, Cedex
France

Phone: +33 6 6058 9349
Email: T.Clausen@computer.org
URI: http://www.thomasclausen.org/

Ulrich Herberg

Email: ulrich@herberg.name
URI: http://www.herberg.name/