Internet DRAFT - draft-ietf-manet-packetbb-sec
draft-ietf-manet-packetbb-sec
Mobile Ad hoc Networking (MANET) U. Herberg
Internet-Draft Fujitsu Laboratories of America
Intended status: Standards Track T. Clausen
Expires: September 7, 2012 LIX, Ecole Polytechnique
March 6, 2012
Integrity Check Value and Timestamp TLV Definitions for MANETs
draft-ietf-manet-packetbb-sec-09
Abstract
This document describes general and flexible TLVs for representing
cryptographic integrity check values (ICV) (i.e. digital signatures
or MACs) as well as timestamps, using the generalized MANET packet/
message format defined in RFC 5444. It defines two Packet TLVs, two
Message TLVs, and two Address Block TLVs, for affixing ICVs and
timestamps to a packet, message and address, respectively.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 7, 2012.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Applicability Statement . . . . . . . . . . . . . . . . . . . 3
4. Security Architecture . . . . . . . . . . . . . . . . . . . . 4
5. Overview and Functioning . . . . . . . . . . . . . . . . . . . 5
6. General ICV TLV Structure . . . . . . . . . . . . . . . . . . 6
7. General Timestamp TLV Structure . . . . . . . . . . . . . . . 6
8. Packet TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Packet ICV TLV . . . . . . . . . . . . . . . . . . . . . . 7
8.2. Packet TIMESTAMP TLV . . . . . . . . . . . . . . . . . . . 7
9. Message TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 7
9.1. Message ICV TLV . . . . . . . . . . . . . . . . . . . . . 7
9.2. Message TIMESTAMP TLV . . . . . . . . . . . . . . . . . . 8
10. Address Block TLVs . . . . . . . . . . . . . . . . . . . . . . 8
10.1. Address Block ICV TLV . . . . . . . . . . . . . . . . . . 8
10.2. Address Block TIMESTAMP TLV . . . . . . . . . . . . . . . 9
11. ICV: Basic . . . . . . . . . . . . . . . . . . . . . . . . . . 9
12. ICV: Cryptographic Function over a Hash Value . . . . . . . . 9
12.1. General ICV TLV Structure . . . . . . . . . . . . . . . . 9
12.1.1. Rationale . . . . . . . . . . . . . . . . . . . . . . 10
12.2. Considerations for Calculating the ICV . . . . . . . . . . 11
12.2.1. Packet ICV TLV . . . . . . . . . . . . . . . . . . . 11
12.2.2. Message ICV TLV . . . . . . . . . . . . . . . . . . . 11
12.2.3. Address Block ICV TLV . . . . . . . . . . . . . . . . 11
12.3. Example of a Message including an ICV . . . . . . . . . . 11
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
13.1. Expert Review: Evaluation Guidelines . . . . . . . . . . . 13
13.2. Packet TLV Type Registrations . . . . . . . . . . . . . . 14
13.3. Message TLV Type Registrations . . . . . . . . . . . . . . 15
13.4. Address Block TLV Type Registrations . . . . . . . . . . . 16
13.5. Hash Function . . . . . . . . . . . . . . . . . . . . . . 17
13.6. Cryptographic Algorithm . . . . . . . . . . . . . . . . . 17
14. Security Considerations . . . . . . . . . . . . . . . . . . . 18
15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
16.1. Normative References . . . . . . . . . . . . . . . . . . . 18
16.2. Informative References . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20
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1. Introduction
This document specifies:
o Two TLVs for carrying integrity check values (ICV) and timestamps
in packets, messages, and address blocks as defined by [RFC5444],
o A generic framework for ICVs, accounting (for Message TLVs) for
mutable message header fields (<msg-hop-limit> and <msg-hop-
count>), where these fields are present in messages.
This document sets up IANA registries for recording code points for
hash function and ICV calculation, respectively.
Moreover, this document defines, in Section 12:
o One common method for generating ICVs as a cryptographic function,
calculated over the hash value of the content to be signed.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC2119].
This document uses the terminology and notation defined in [RFC5444].
In particular, the following TLV fields from [RFC5444] are used in
this specification:
<msg-hop-limit> - hop limit of a message, as specified in Section
5.2 of [RFC5444].
<msg-hop-count> - hop count of a message, as specified in Section
5.2 of [RFC5444].
<length> - length of a TLV in octets, as specified in Section 5.4.1
of [RFC5444].
3. Applicability Statement
MANET routing protocols using the format defined in [RFC5444] are
accorded the ability to carry additional information in control
messages and packets, through inclusion of TLVs. Information so
included MAY be used by a MANET routing protocol, or by an extension
of a MANET routing protocol, according to its specification.
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This document specifies how to include an ICV for a packet, a
message, and addresses in address blocks within a message, by way of
such TLVs. This document also specifies how to treat "mutable"
fields, specifically the <msg-hop-count> and <msg-hop-limit> fields,
if present in the message header when calculating ICVs, such that the
resulting ICV can be correctly verified by any recipient, and how to
include this ICV.
This document describes a generic framework for creating ICVs, and
how to include these ICVs in TLVs. In Section 12, an example method
for calculating such ICVs is given, using a cryptographic function
over the hash value of the content to be signed.
4. Security Architecture
Basic MANET routing protocol specifications are often "oblivious to
security", however have a clause allowing a control message to be
rejected as "badly formed" or "insecure" prior to it being processed
or forwarded. MANET routing protocols such as [RFC6130] and [OLSRv2]
recognize external reasons (such as failure to verify an ICV) for
rejecting a message, and therefore "invalid for processing". This
architecture is a result of the observation that with respect to
security in MANETs, "one size rarely fits all" and that MANET routing
protocol deployment domains have varying security requirements
ranging from "unbreakable" to "virtually none". The virtue of this
approach is that MANET routing protocol specifications (and
implementations) can remain "generic", with extensions providing
proper deployment-domain specific security mechanisms.
The MANET routing protocol "security architecture", in which this
specification situates itself, can therefore be summarized as
follows:
o Security-oblivious MANET routing protocol specifications, with a
clause allowing an extension to reject a message (prior to
processing/forwarding) as "badly formed" or "insecure".
o MANET routing protocol security extensions, rejecting messages as
"badly formed" or "insecure", as appropriate for a given
deployment-domain specific security requirement.
o Code-points and an exchange format for information, necessary for
specification of such MANET routing protocol security extensions.
This document addresses the last of these issues, by specifying a
common exchange format for cryptographic ICVs, making reservations
from within the Packet TLV, Message TLV, and Address Block TLV
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registries of [RFC5444], to be used (and shared) among MANET routing
protocol security extensions.
For the specific decomposition of an ICV into a cryptographic
function over a hash value, specified in Section 12, this document
establishes two IANA registries for code-points for hash functions
and cryptographic functions adhering to [RFC5444].
With respect to [RFC5444], this document:
o Is intended to be used in the non-normative, but intended, mode of
use described in Appendix B of [RFC5444].
o Is a specific example of the Security Considerations section of
[RFC5444] (the authentication part).
5. Overview and Functioning
This document specifies a syntactical representation of security
related information for use with [RFC5444] addresses, messages, and
packets, as well as establishes IANA registrations and registries.
Moreover, this document provides guidelines for how MANET routing
protocols, and MANET routing protocol extensions, using this
specification, should treat ICV and Timestamp TLVs, and mutable
fields in messages. This specification does not represent a stand-
alone protocol; MANET routing protocols and MANET routing protocol
extensions, using this specification, MUST provide instructions as to
how to handle packets, messages and addresses with security
information, associated as specified in this document.
This document requests assignment of TLV types from the registries
defined for Packet, Message and Address Block TLVs in [RFC5444].
When a TLV type is assigned from one of these registries, a registry
for "Type Extensions" for that TLV type is created by IANA. This
document utilizes these "Type Extension" registries so created, in
order to specify internal structure (and accompanying processing) of
the <value> field of a TLV.
For example, and as defined in this document, an ICV TLV with Type
Extension = 0 specifies that the <value> field has no pre-defined
internal structure, but is simply a sequence of octets. An ICV TLV
with Type Extension = 1 specifies that the <value> field has a pre-
defined internal structure, and defines its interpretation
(specifically, the <value> field consists of a cryptographic
operation over a hash value, with fields indicating which hash
function and cryptographic operation has been used, specified in
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Section 12).
Other documents can request assignments for other Type Extensions,
and MUST, if so, specify their internal structure (if any) and
interpretation.
6. General ICV TLV Structure
The value of the ICV TLV is:
<value> := <ICV-value>
where:
<ICV-value> is a field, of <length> octets, which contains the
information, to be interpreted by the ICV verification process, as
specified by the Type Extension.
Note that this does not stipulate how to calculate the <ICV-value>,
nor the internal structure hereof, if any; such MUST be specified by
way of the Type Extension for the ICV TLV type, see Section 13. This
document specifies two such type-extensions, for ICVs without pre-
defined structures, and for ICVs constructed by way of a
cryptographic operation over a hash-value.
7. General Timestamp TLV Structure
The value of the Timestamp TLV is:
<value> := <time-value>
where:
<time-value> is an unsigned integer field, of length <length>, which
contains the timestamp.
Note that this does not stipulate how to calculate the <time-
value>, nor the internal structure hereof, if any; such MUST be
specified by way of the Type Extension for the TIMESTAMP TLV type,
see Section 13.
A timestamp is essentially "freshness information". As such, its
setting and interpretation is to be determined by the MANET routing
protocol, or MANET routing protocol extension, that uses the
timestamp, and can, e.g., correspond to a UNIX-timestamp, GPS
timestamp or a simple sequence number.
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8. Packet TLVs
Two Packet TLVs are defined, for including the cryptographic ICV of a
packet, and for including the timestamp indicating the time at which
the cryptographic ICV was calculated.
8.1. Packet ICV TLV
A Packet ICV TLV is an example of an ICV TLV as described in
Section 6.
The following considerations apply:
o As packets defined in [RFC5444] are never forwarded by routers, no
special considerations are required regarding mutable fields (e.g.
<msg-hop-count> and <msg-hop-limit>), if present, when calculating
the ICV.
o Any Packet ICV TLVs already present in the Packet TLV block MUST
be removed before calculating the ICV, and the Packet TLV block
size MUST be recalculated accordingly. Removed ICV TLVs MUST be
restored after having calculated the ICV value.
The rationale for removing any Packet ICV TLV already present prior
to calculating the ICV is that several ICVs may be added to the same
packet, e.g., using different ICV functions.
8.2. Packet TIMESTAMP TLV
A Packet TIMESTAMP TLV is an example of a Timestamp TLV as described
in Section 7. If a packet contains a TIMESTAMP TLV and an ICV TLV,
the TIMESTAMP TLV SHOULD be added to the packet before any ICV TLV,
in order that it be included in the calculation of the ICV.
9. Message TLVs
Two Message TLVs are defined, for including the cryptographic ICV of
a message, and for including the timestamp indicating the time at
which the cryptographic ICV was calculated.
9.1. Message ICV TLV
A Message ICV TLV is an example of an ICV TLV as described in
Section 6. When determining the <ICV-value> for a message, the
following considerations MUST be applied:
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o The fields <msg-hop-limit> and <msg-hop-count>, if present, MUST
both be assumed to have the value 0 (zero) when calculating the
ICV.
o Any Message ICV TLVs already present in the Message TLV block MUST
be removed before calculating the ICV, and the message size as
well as the Message TLV block size MUST be recalculated
accordingly. Removed ICV TLVs MUST be restored after having
calculated the ICV value.
The rationale for removing any Message ICV TLV already present prior
to calculating the ICV is that several ICVs may be added to the same
message, e.g., using different ICV functions.
9.2. Message TIMESTAMP TLV
A Message TIMESTAMP TLV is an example of a Timestamp TLV as described
in Section 7. If a message contains a TIMESTAMP TLV and an ICV TLV,
the TIMESTAMP TLV SHOULD be added to the message before the ICV TLV,
in order that it be included in the calculation of the ICV.
10. Address Block TLVs
Two Address Block TLVs are defined, for associating a cryptographic
ICV to an address, and for including the timestamp indicating the
time at which the cryptographic ICV was calculated.
10.1. Address Block ICV TLV
An Address Block ICV TLV is an example of an ICV TLV as described in
Section 6. The ICV is calculated over the address, concatenated with
any other values, for example, any other Address Block TLV <value>
fields, that is associated with that address. A MANET routing
protocol or MANET routing protocol extension using Address Block ICV
TLVs MUST specify how to include any such concatenated attribute of
the address in the verification process of the ICV. When determining
the <ICV-value> for an address, the following consideration MUST be
applied:
o If other TLV values are concatenated with the address for
calculating the ICV, these TLVs MUST NOT be Address Block ICV TLVs
already associated with the address.
The rationale for not concatenating the address with any ICV TLV
values already associated with the address when calculating the ICV
is that several ICVs may be added to the same address, e.g., using
different ICV functions.
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10.2. Address Block TIMESTAMP TLV
An Address Block TIMESTAMP TLV is an example of a Timestamp TLV as
described in Section 7. If both a TIMESTAMP TLV and an ICV TLV are
associated with an address, the TIMESTAMP TLV <value> MUST be covered
when calculating the value of the ICV to be contained in the ICV TLV
value (i.e. concatenated with the associated address and any other
values as described in Section 10.1).
11. ICV: Basic
The basic ICV, represented by way of an ICV TLV with Type Extension =
0, is a simple bit-field containing the cryptographic ICV. This
assumes that the mechanism stipulating how ICVs are calculated and
verified is established outside of this specification, e.g., by way
of administrative configuration or external out-of-band signaling.
Thus, the <ICV-value> for when using Type Extension = 0 is:
<ICV-value> := <ICV-data>
where:
<ICV-data> is an unsigned integer field, of length <length>, which
contains the cryptographic ICV.
12. ICV: Cryptographic Function over a Hash Value
One common way of calculating an ICV is applying a cryptographic
function on a hash value of the content. This decomposition is
specified in the following, using a Type Extension = 1 in the ICV
TLVs.
12.1. General ICV TLV Structure
The following data structure allows representation of a cryptographic
ICV, including specification of the appropriate hash function and
cryptographic function used for calculating the ICV:
<ICV-value> := <hash-function>
<cryptographic-function>
<key-index>
<ICV-data>
where:
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<hash-function> is an 8-bit unsigned integer field specifying the
hash function.
<cryptographic-function> is an 8-bit unsigned integer field
specifying the cryptographic function.
<key-id-length> is an 8-bit unsigned integer field specifying the
length of the <key-id> field in number of octets. The value 0x00
is reserved for using a pre-installed, shared key.
<key-id> is a field specifying the key identifier of the key that
was used to sign the message, which allows unique identification
of different keys with the same originator. It is the
responsibility of each key originator to make sure that actively
used keys that it issues have distinct key identifiers. If <key-
id-length> equals to 0x00, the <key-id> field is not contained in
the TLV, and a pre-installed, shared key is used.
<ICV-data> is an unsigned integer field, whose length is <length> -
3 - <key-id-length>, and which contains the cryptographic ICV.
The version of this TLV, specified in this section, assumes that
calculating the ICV can be decomposed into:
ICV-value = cryptographic-function(hash-function(content))
The hash function and the cryptographic function correspond to the
entries in two IANA registries, set up by this specification in
Section 13.
12.1.1. Rationale
The rationale for separating the hash function and the cryptographic
function into two octets instead of having all combinations in a
single octet - possibly as TLV type extension - is that adding
further hash functions or cryptographic functions in the future may
lead to a non-contiguous number space.
The rationale for not including a field that lists parameters of the
cryptographic ICV in the TLV is that, before being able to validate a
cryptographic ICV, routers have to exchange or acquire keys (e.g.
public keys). Any additional parameters can be provided together
with the keys in that bootstrap process. It is therefore not
necessary, and would even entail an extra overhead, to transmit the
parameters within every message. One implicitly available parameter
is the length of the ICV, which is <length> - 3 - <key-id-length>,
and which depends on the choice of the cryptographic function.
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12.2. Considerations for Calculating the ICV
In the following, considerations are listed, which MUST be applied
when calculating the ICV for Packet, Message and Address ICV TLVs,
respectively.
12.2.1. Packet ICV TLV
When determining the <ICV-value> for a Packet, the ICV is calculated
over the fields <hash-function>, <cryptographic-function> <key-id-
length>, and - if present - <key-id> (in that order), concatenated
with the entire Packet, including the packet header, all Packet TLVs
(other than Packet ICV TLVs) and all included Messages and their
message headers, in accordance with Section 8.1.
12.2.2. Message ICV TLV
When determining the <ICV-value> for a message, the ICV is calculated
over the fields <hash-function>, <cryptographic-function> <key-id-
length>, and - if present - <key-id> (in that order), concatenated
with the entire message. The considerations in Section 9.1 MUST be
applied.
12.2.3. Address Block ICV TLV
When determining the <ICV-value> for an address, the ICV is
calculated over the fields <hash-function>, <cryptographic-function>
<key-id-length>, and - if present - <key-id> (in that order),
concatenated with the address, concatenated with any other values,
for example, any other address block TLV <value> that is associated
with that address. A MANET routing protocol or MANET routing
protocol extension using Address Block ICV TLVs MUST specify how to
include any such concatenated attribute of the address in the
verification process of the ICV. The considerations in Section 10.2
MUST be applied.
12.3. Example of a Message including an ICV
The sample message depicted in Figure 1 is derived from appendix D of
[RFC5444]. The message contains an ICV Message TLV, with the value
representing a 16 octet long ICV of the whole message, and a 4 octet
long key identifier. The type extension of the Message TLV is 1, for
the specific decomposition of an ICV into a cryptographic function
over a hash value, as specified in Section 12.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PV=0 | PF=8 | Packet Sequence Number | Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MF=15 | MAL=3 | Message Length = 44 | Msg. Orig Addr|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message Originator Address (cont) | Hop Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Hop Count | Message Sequence Number | Msg. TLV Block|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length = 27 | ICV | MTLVF = 144 | MTLVExt = 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Value Len = 23 | Hash Func | Crypto Func |Key ID length=4|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Key Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICV Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICV Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICV Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICV Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Example message with ICV
13. IANA Considerations
This specification defines:
o Two Packet TLV types, which must be allocated from the 0-223 range
of the "Assigned Packet TLV Types" repository of [RFC5444] as
specified in Table 1,
o Two Message TLV types, which must be allocated from the 0-127
range of the "Assigned Message TLV Types" repository of [RFC5444]
as specified in Table 2,
o Two Address Block TLV types, which must be allocated from the
0-127 range of the "Assigned Address Block TLV Types" repository
of [RFC5444] as specified in Table 3.
This specification requests:
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o Creation of type extension registries for these TLV types with
initial values as in Table 1 to Table 3.
IANA is requested to assign the same numerical value to the Packet
TLV, Message TLV and Address Block TLV types with the same name.
The following terms are used with the meanings defined in [BCP26]:
"Namespace", "Registration", and "Designated Expert".
The following policy is used with the meanings defined in [BCP26]:
"Expert Review".
13.1. Expert Review: Evaluation Guidelines
For the registries for TLV type extensions where an Expert Review is
required, the designated expert SHOULD take the same general
recommendations into consideration as are specified by [RFC5444].
For the Timestamp TLV, the same type extensions for all Packet,
Message and Address Block TLVs SHOULD be numbered identically.
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13.2. Packet TLV Type Registrations
IANA is requested to make allocations from the "Packet TLV Types"
namespace of [RFC5444] for the Packet TLVs specified in Table 1.
+-----------+------+-----------+------------------------------------+
| Name | Type | Type | Description |
| | | Extension | |
+-----------+------+-----------+------------------------------------+
| ICV | TBD1 | 0 | ICV of a packet |
| | | 1 | ICV, decomposed into cryptographic |
| | | | function over a hash value, as |
| | | | specified in Section 12 in this |
| | | | document. |
| | | 2-251 | Expert Review |
| | | 252-255 | Experimental Use |
| TIMESTAMP | TBD2 | 0 | Unsigned timestamp of arbitrary |
| | | | length, given by the TLV length |
| | | | field. The MANET routing protocol |
| | | | has to define how to interpret |
| | | | this timestamp |
| | | 1 | Unsigned 32-bit timestamp as |
| | | | specified in [POSIX] |
| | | 2 | NTP timestamp format as defined in |
| | | | [RFC4330] |
| | | 3 | Signed timestamp of arbitrary |
| | | | length with no constraints such as |
| | | | monotonicity. In particular, it |
| | | | may represent any random value |
| | | 4-251 | Expert Review |
| | | 252-255 | Experimental Use |
+-----------+------+-----------+------------------------------------+
Table 1: Packet TLV types
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13.3. Message TLV Type Registrations
IANA is requested to make allocations from the "Message TLV Types"
namespace of [RFC5444] for the Message TLVs specified in Table 2.
+-----------+------+-----------+------------------------------------+
| Name | Type | Type | Description |
| | | Extension | |
+-----------+------+-----------+------------------------------------+
| ICV | TBD3 | 0 | ICV of a message |
| | | 1 | ICV, decomposed into cryptographic |
| | | | function over a hash value, as |
| | | | specified in Section 12 in this |
| | | | document. |
| | | 2-251 | Expert Review |
| | | 252-255 | Experimental Use |
| TIMESTAMP | TBD4 | 0 | Unsigned timestamp of arbitrary |
| | | | length, given by the TLV length |
| | | | field. |
| | | 1 | Unsigned 32-bit timestamp as |
| | | | specified in [POSIX] |
| | | 2 | NTP timestamp format as defined in |
| | | | [RFC4330] |
| | | 3 | Signed timestamp of arbitrary |
| | | | length with no constraints such as |
| | | | monotonicity. In particular, it |
| | | | may represent any random value |
| | | 4-251 | Expert Review |
| | | 252-255 | Experimental Use |
+-----------+------+-----------+------------------------------------+
Table 2: Message TLV types
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13.4. Address Block TLV Type Registrations
IANA is requested to make allocations from the "Address Block TLV
Types" namespace of [RFC5444] for the Packet TLVs specified in
Table 3.
+-----------+------+-----------+------------------------------------+
| Name | Type | Type | Description |
| | | Extension | |
+-----------+------+-----------+------------------------------------+
| ICV | TBD5 | 0 | ICV of an object (e.g. an address) |
| | | 1 | ICV, decomposed into cryptographic |
| | | | function over a hash value, as |
| | | | specified in Section 12 in this |
| | | | document. |
| | | 2-251 | Expert Review |
| | | 252-255 | Experimental Use |
| TIMESTAMP | TBD6 | 0 | Unsigned timestamp of arbitrary |
| | | | length, given by the TLV length |
| | | | field. |
| | | 1 | Unsigned 32-bit timestamp as |
| | | | specified in [POSIX] |
| | | 2 | NTP timestamp format as defined in |
| | | | [RFC4330] |
| | | 3 | Signed timestamp of arbitrary |
| | | | length with no constraints such as |
| | | | monotonicity. In particular, it |
| | | | may represent any random value |
| | | 4-251 | Expert Review |
| | | 252-255 | Experimental Use |
+-----------+------+-----------+------------------------------------+
Table 3: Address Block TLV types
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13.5. Hash Function
IANA is requested to create a new registry for hash functions that
can be used when creating an ICV, as specified in Section 12 of this
document. The initial assignments and allocation policies are
specified in Table 4.
+-------------+-----------+-----------------------------------------+
| Hash | Algorithm | Description |
| function | | |
| value | | |
+-------------+-----------+-----------------------------------------+
| 0 | none | The "identity function": the hash value |
| | | of an object is the object itself |
| 1 | SHA1 | [SHS] |
| 2 | SHA224 | [SHS] |
| 3 | SHA256 | [SHS] |
| 4 | SHA384 | [SHS] |
| 5 | SHA512 | [SHS] |
| 6-251 | | Expert Review |
| 252-255 | | Experimental Use |
+-------------+-----------+-----------------------------------------+
Table 4: Hash-Function registry
13.6. Cryptographic Algorithm
IANA is requested to create a new registry for the cryptographic
function, as specified in Section 12 of this document. Initial
assignments and allocation policies are specified in Table 5.
+----------------+-----------+--------------------------------------+
| Cryptographic | Algorithm | Description |
| function value | | |
+----------------+-----------+--------------------------------------+
| 0 | none | The "identity function": the value |
| | | of an encrypted hash is the hash |
| | | itself |
| 1 | RSA | [RFC3447] |
| 2 | DSA | [DSA] |
| 3 | HMAC | [RFC2104] |
| 4 | 3DES | [3DES] |
| 5 | AES | [AES] |
| 6 | ECDSA | [ECDSA] |
| 7-251 | | Expert Review |
| 252-255 | | Experimental Use |
+----------------+-----------+--------------------------------------+
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Table 5: Cryptographic function registry
14. Security Considerations
This document does not specify a protocol. It provides a syntactical
component for cryptographic ICVs of messages and packets as defined
in [RFC5444]. It can be used to address security issues of a MANET
routing protocol or MANET routing protocol extension. As such, it
has the same security considerations as [RFC5444].
In addition, a MANET routing protocol or MANET routing protocol
extension that uses this specification MUST specify the usage as well
as the security that is attained by the cryptographic ICVs of a
message or a packet.
As an example, a MANET routing protocol that uses this component to
reject "badly formed" or "insecure" messages if a control message
does not contain a valid ICV, SHOULD indicate the security assumption
that if the ICV is valid, the message is considered valid. It also
SHOULD indicate the security issues that are counteracted by this
measure (e.g. link or identity spoofing) as well as the issues that
are not counteracted (e.g. compromised keys).
15. Acknowledgements
The authors would like to thank Bo Berry (Cisco), Alan Cullen (BAE),
Justin Dean (NRL), Christopher Dearlove (BAE), Paul Lambert
(Marvell), Jerome Milan (Ecole Polytechnique) and Henning Rogge
(FGAN) for their constructive comments on the document.
The authors also appreciate the detailed reviews from the Area
Directors, in particular Stewart Bryant (Cisco), Stephen Farrel
(Trinity College Dublin), and Robert Sparks (Tekelec), as well as
Donald Eastlake (Huawei) from the Security Directorate.
16. References
16.1. Normative References
[3DES] National Institute of Standards and Technology,
"Recommendation for the Triple Data Encryption Algorithm
(TDEA) Block Cipher", NIST Special Publication 800-67,
May 2004.
[AES] National Institute of Standards & Technology,
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"Specification for the Advanced Encryption Standard
(AES)", FIPS 197, November 2001.
[BCP26] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226, BCP 26,
May 2008.
[DSA] National Institute of Standards & Technology, "Digital ICV
Standard", NIST, FIPS PUB 186, May 1994.
[ECDSA] American National Standards Institute, "Public Key
Cryptography for the Financial Services Industry: The
Elliptic Curve Digital ICV Algorithm (ECDSA)", ANS X9.62-
2005, November 2005.
[POSIX] IEEE Computer Society, "1003.1-2008 Standard for
Information Technology - Portable Operating System
Interface (POSIX)", Base Specifications Issue 7,
December 2008.
[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
Hashing for Message Authentication", RFC 2104,
February 1997.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, BCP 14, March 1997.
[RFC3447] Staddon, J. and B. Kaliski, "Public-Key Cryptography
Standards (PKCS) #1: RSA Cryptography Specifications
Version 2.1", RFC 3447, February 2003.
[RFC4330] Mills, D., "Simple Network Time Protocol (SNTP) Version 4
for IPv4, IPv6 and OSI", RFC 4330, January 2006.
[RFC5444] Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
"Generalized MANET Packet/Message Format", RFC 5444,
February 2009.
[SHS] National Institute of Standards and Technology, "Secure
Hash Standard", NIST FIPS 180-2, August 2002.
16.2. Informative References
[OLSRv2] Clausen, T., Dearlove, C., and P. Jacquet, "The Optimized
Link State Routing Protocol version 2", work in
progress draft-ietf-manet-olsrv2-13.txt, October 2011.
[RFC6130] Clausen, T., Dean, J., and C. Dearlove, "MANET
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Neighborhood Discovery Protocol (NHDP)", RFC 6130,
March 2011.
Authors' Addresses
Ulrich Herberg
Fujitsu Laboratories of America
1240 E. Arques Ave.
Sunnyvale, CA, 94085
USA
Email: ulrich@herberg.name
URI: http://www.herberg.name/
Thomas Heide Clausen
LIX, Ecole Polytechnique
91128 Palaiseau Cedex,
France
Phone: +33 6 6058 9349
Email: T.Clausen@computer.org
URI: http://www.thomasclausen.org/
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