MANET Cryptographical Signature TLV Definition
draft-ietf-manet-packetbb-sec-08
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (manet WG) | |
|---|---|---|---|
| Authors | Ulrich Herberg , Thomas H. Clausen | ||
| Last updated | 2012-03-01 (Latest revision 2012-01-31) | ||
| Replaces | draft-herberg-manet-packetbb-sec | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text xml htmlized pdfized bibtex | ||
| Reviews | |||
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| Responsible AD | Adrian Farrel | ||
| IESG note | Stan Ratliff (sratliff@cisco.com) is the document shepherd. | ||
| Send notices to | manet-chairs@tools.ietf.org, draft-ietf-manet-packetbb-sec@tools.ietf.org |
draft-ietf-manet-packetbb-sec-08
Mobile Ad hoc Networking (MANET) U. Herberg
Internet-Draft Fujitsu Laboratories of America
Intended status: Standards Track T. Clausen
Expires: August 3, 2012 LIX, Ecole Polytechnique
January 31, 2012
MANET Cryptographical Signature TLV Definition
draft-ietf-manet-packetbb-sec-08
Abstract
This document describes general and flexible TLVs (type-length-value
structure) for representing cryptographic signatures 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 cryptographic signatures 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
working documents as Internet-Drafts. The list of current Internet-
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 August 3, 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 . . . . . . . . . . . . . . . . . . . 4
4. Security Architecture . . . . . . . . . . . . . . . . . . . . 4
5. Overview and Functioning . . . . . . . . . . . . . . . . . . . 5
6. General Signature TLV Structure . . . . . . . . . . . . . . . 6
7. General Timestamp TLV Structure . . . . . . . . . . . . . . . 6
8. Packet TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Packet SIGNATURE TLV . . . . . . . . . . . . . . . . . . . 7
8.2. Packet TIMESTAMP TLV . . . . . . . . . . . . . . . . . . . 7
9. Message TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Message SIGNATURE TLV . . . . . . . . . . . . . . . . . . 8
9.2. Message TIMESTAMP TLV . . . . . . . . . . . . . . . . . . 8
10. Address Block TLVs . . . . . . . . . . . . . . . . . . . . . . 8
10.1. Address Block SIGNATURE TLV . . . . . . . . . . . . . . . 9
10.2. Address Block TIMESTAMP TLV . . . . . . . . . . . . . . . 9
11. Signature: Basic . . . . . . . . . . . . . . . . . . . . . . . 9
12. Signature: Cryptographic Function over a Hash Value . . . . . 10
12.1. General Signature TLV Structure . . . . . . . . . . . . . 10
12.1.1. Rationale . . . . . . . . . . . . . . . . . . . . . . 11
12.2. Considerations for Calculating the Signature . . . . . . . 11
12.2.1. Packet SIGNATURE TLV . . . . . . . . . . . . . . . . 11
12.2.2. Message SIGNATURE TLV . . . . . . . . . . . . . . . . 11
12.2.3. Address Block SIGNATURE TLV . . . . . . . . . . . . . 11
12.3. Example of a Signed Message . . . . . . . . . . . . . . . 12
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
13.1. Expert Review: Evaluation Guidelines . . . . . . . . . . . 13
13.2. Packet TLV Type Registrations . . . . . . . . . . . . . . 13
13.3. Message TLV Type Registrations . . . . . . . . . . . . . . 14
13.4. Address Block TLV Type Registrations . . . . . . . . . . . 15
13.5. Hash Function . . . . . . . . . . . . . . . . . . . . . . 15
13.6. Cryptographic Algorithm . . . . . . . . . . . . . . . . . 16
14. Security Considerations . . . . . . . . . . . . . . . . . . . 16
15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
16.1. Normative References . . . . . . . . . . . . . . . . . . . 17
16.2. Informative References . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
This document specifies:
o Two TLVs for carrying cryptographic signatures and timestamps in
packets, messages, and address blocks as defined by [RFC5444],
o A generic framework for calculating cryptographic signatures,
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 requests from IANA:
o Allocations for these Packet, Message, and Address Block TLVs from
the 0-223 Packet TLV range, the 0-127 Message TLV range and the
0-127 Address Block TLV range from [RFC5444],
o Creation of two IANA registries for recording code points for hash
function and signature calculation, respectively.
Finally, this document defines, in Section 12:
o One common method for generating signatures 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].
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<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.
This document specifies how to include a cryptographic signature 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
signatures, such that the resulting signature can be correctly
verified by any recipient, and how to include this signature.
This document describes a generic framework for creating signatures,
and how to include these signatures in TLVs. In Section 12, an
example method for calculating such signatures 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" prior to it being processed or forwarded.
MANET routing protocols such as [RFC6130] and [OLSRv2] recognize
external reasons (such as failure to verify a signature) for
rejecting a message as "badly formed", 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:
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o Security-oblivious MANET routing protocol specifications, with a
clause allowing an extension to reject a message (prior to
processing/forwarding) as "badly formed".
o MANET routing protocol security extensions, rejecting messages as
"badly formed", 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 signatures, making
reservations from within the Packet TLV, Message TLV, and Address
Block TLV registries of [RFC5444], to be used (and shared) among
MANET routing protocol security extensions.
For the specific decomposition of a signature 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 Signature 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].
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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, a SIGNATURE TLV with
Type Extension = 0 specifies that the <value> field has no pre-
defined internal structure, but is simply a sequence of octets. A
SIGNATURE 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 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 Signature TLV Structure
The value of the Signature TLV is:
<value> := <signature-value>
where:
<signature-value> is a field, of <length> octets, which contains the
information, to be interpreted by the signature verification
process, as specified by the Type Extension.
Note that this does not stipulate how to calculate the <signature-
value>, nor the internal structure hereof, if any; such MUST be
specified by way of the Type Extension for the SIGNATURE TLV type,
see Section 13. This document specifies two such type-extensions,
for signatures without pre-defined structures, and for signatures
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:
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<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.
8. Packet TLVs
Two Packet TLVs are defined, for including the cryptographic
signature of a packet, and for including the timestamp indicating the
time at which the cryptographic signature was calculated.
8.1. Packet SIGNATURE TLV
A Packet SIGNATURE TLV is an example of a Signature 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 signature.
o Any Packet SIGNATURE TLVs already present in the Packet TLV block
MUST be removed before calculating the signature, and the Packet
TLV block size MUST be recalculated accordingly. Removed
SIGNATURE TLVs SHOULD be restored after having calculated the
signature value.
The rationale for removing any Packet SIGNATURE TLV already present
prior to calculating the signature is that several signatures may be
added to the same packet, e.g., using different signature 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 a SIGNATURE
TLV, the TIMESTAMP TLV SHOULD be added to the packet before any
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SIGNATURE TLV, in order that it be included in the calculation of the
signature.
9. Message TLVs
Two Message TLVs are defined, for including the cryptographic
signature of a message, and for including the timestamp indicating
the time at which the cryptographic signature was calculated.
9.1. Message SIGNATURE TLV
A Message SIGNATURE TLV is an example of a Signature TLV as described
in Section 6. When determining the <signature-value> for a message,
the following considerations MUST be applied:
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
signature.
o Any Message SIGNATURE TLVs already present in the Message TLV
block MUST be removed before calculating the signature, and the
message size as well as the Message TLV block size MUST be
recalculated accordingly. Removed SIGNATURE TLVs SHOULD be
restored after having calculated the signature value.
The rationale for removing any Message SIGNATURE TLV already present
prior to calculating the signature is that several signatures may be
added to the same message, e.g., using different signature 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 a SIGNATURE
TLV, the TIMESTAMP TLV SHOULD be added to the message before the
SIGNATURE TLV, in order that it be included in the calculation of the
signature.
10. Address Block TLVs
Two Address Block TLVs are defined, for associating a cryptographic
signature to an address, and for including the timestamp indicating
the time at which the cryptographic signature was calculated.
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10.1. Address Block SIGNATURE TLV
An Address Block SIGNATURE TLV is an example of a Signature TLV as
described in Section 6. The signature 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 SIGNATURE TLVs MUST specify how to
include any such concatenated attribute of the address in the
verification process of the signature. When determining the
<signature-value> for an address, the following consideration MUST be
applied:
o If other TLV values are concatenated with the address for
calculating the signature, these TLVs MUST NOT be Address Block
SIGNATURE TLVs already associated with the address.
The rationale for not concatenating the address with any SIGNATURE
TLV values already associated with the address when calculating the
signature is that several signatures may be added to the same
address, e.g., using different signature functions.
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 a SIGNATURE TLV
are associated with an address, the TIMESTAMP TLV <value> SHOULD be
considered when calculating the value of the signature.
11. Signature: Basic
The basic signature, represented by way of a SIGNATURE TLV with Type
Extension = 0, is a simple bit-field containing the cryptographic
signature. This assumes that the mechanism stipulating how
signatures 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 <signature-value> for when
using Type Extension = 0 is:
<signature-value> := <signature-data>
where:
<signature-data> is an unsigned integer field, of length <length>,
which contains the cryptographic signature.
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12. Signature: Cryptographic Function over a Hash Value
One common way of calculating a signature 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
Signature TLVs.
12.1. General Signature TLV Structure
The following data structure allows representation of a cryptographic
signature, including specification of the appropriate hash function
and cryptographic function used for calculating the signature:
<signature-value> := <hash-function>
<cryptographic-function>
<key-index>
<signature-data>
where:
<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-index> is an 8-bit unsigned integer field specifying the key
index of the key which 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 indices and
that all key indices have a value not equal to 0x00. The value
0x00 is reserved for a pre-installed, shared key.
<signature-data> is an unsigned integer field, whose length is
<length> - 3, and which contains the cryptographic signature.
The version of this TLV, specified in this section, assumes that
calculating the signature can be decomposed into:
signature-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.
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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 signature in the TLV is that, before being able to
validate a cryptographic signature, 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 signature, which is <length>
- 3, and which depends on the choice of the cryptographic function.
12.2. Considerations for Calculating the Signature
In the following, considerations are listed, which MUST be applied
when calculating the signature for Packet, Message and Address
SIGNATURE TLVs, respectively.
12.2.1. Packet SIGNATURE TLV
When determining the <signature-value> for a Packet, the signature is
calculated over the three fields <hash-function>, <cryptographic-
function> and <key-index> (in that order), concatenated with the
entire Packet, including the packet header, all Packet TLVs (other
than Packet SIGNATURE TLVs) and all included Messages and their
message headers, in accordance with Section 8.1.
12.2.2. Message SIGNATURE TLV
When determining the <signature-value> for a message, the signature
is calculated over the three fields <hash-function>, <cryptographic-
function>, and <key-index> (in that order), concatenated with the
entire message. The considerations in Section 9.1 MUST be applied.
12.2.3. Address Block SIGNATURE TLV
When determining the <signature-value> for an address, the signature
is calculated over the three fields <hash-function>, <cryptographic-
function>, and <key-index> (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
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Address Block SIGNATURE TLVs MUST specify how to include any such
concatenated attribute of the address in the verification process of
the signature. The considerations in Section 10.2 MUST be applied.
12.3. Example of a Signed Message
The sample message depicted in Figure 1 is derived from appendix D of
[RFC5444]. The message contains a SIGNATURE Message TLV, with the
value representing a 16 octet long signature of the whole message.
The type extension of the Message TLV is 1, for the specific
decomposition of a signature into a cryptographic function over a
hash value, as specified in Section 12.
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 = 40 | Msg. Orig Addr|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message Originator Address (cont) | Hop Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Hop Count | Message Sequence Number | Msg. TLV Block|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length = 30 | SIGNATURE | MTLVF = 144 | MTLVExt = 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Value Len = 19 | Hash Func | Crypto Func | Key Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signature Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signature Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signature Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signature Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Example message with signature
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,
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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:
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", "Assigned Value", "Registration", "Unassigned",
"Reserved", "Hierarchical Allocation", and "Designated Expert".
The following policies are used with the meanings defined in [BCP26]:
"Private Use", "Expert Review", and "Standards Action".
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.
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.
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+-----------+------+-----------+------------------------------------+
| Name | Type | Type | Description |
| | | Extension | |
+-----------+------+-----------+------------------------------------+
| SIGNATURE | TBD1 | 0 | Signature of a packet |
| | | 1 | Signature, 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 |
| | | 1-251 | Expert Review |
| | | 252-255 | Experimental Use |
+-----------+------+-----------+------------------------------------+
Table 1: Packet TLV types
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 | |
+-----------+------+-----------+------------------------------------+
| SIGNATURE | TBD3 | 0 | Signature of a message |
| | | 1 | Signature, 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. |
| | | 1-251 | 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 | |
+-----------+------+-----------+------------------------------------+
| SIGNATURE | TBD5 | 0 | Signature of an object (e.g. an |
| | | | address) |
| | | 1 | Signature, 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. |
| | | 1-251 | Expert Review |
| | | 252-255 | Experimental Use |
+-----------+------+-----------+------------------------------------+
Table 3: Address Block TLV types
13.5. Hash Function
IANA is requested to create a new registry for hash functions that
can be used when creating a signature, 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 |
| 1-251 | | Expert Review |
| 252-255 | | Experimental Use |
+-------------+-----------+-----------------------------------------+
Table 4: Hash-Function registry
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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 |
| 1-251 | | Expert Review |
| 252-255 | | Experimental Use |
+----------------+-----------+--------------------------------------+
Table 5: Cryptographic function registry
14. Security Considerations
This document does not specify a protocol. It provides a syntactical
component for cryptographic signatures 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 signatures of a
message or a packet.
As an example, a MANET routing protocol that uses this component to
reject "badly formed" messages if a control message does not contain
a valid signature, SHOULD indicate the security assumption that if
the signature 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.
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16. References
16.1. Normative References
[BCP26] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226, BCP 26,
May 2008.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, BCP 14, March 1997.
[RFC5444] Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
"Generalized MANET Packet/Message Format", RFC 5444,
February 2009.
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
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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