Mobile Ad hoc Networking (MANET)                              U. Herberg
Internet-Draft                           Fujitsu Laboratories of America
Intended status: Standards Track                              T. Clausen
Expires: March 9, May 18, 2012                           LIX, Ecole Polytechnique
                                                       September 6,
                                                       November 15, 2011

             MANET Cryptographical Signature TLV Definition
                    draft-ietf-manet-packetbb-sec-06
                    draft-ietf-manet-packetbb-sec-07

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
   [RFC5444].  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
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   This Internet-Draft will expire on March 9, May 18, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   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  . . . . . . . . . . . . . . .  8
     10.2. Address Block TIMESTAMP TLV  . . . . . . . . . . . . . . .  9
   11. Signature: Basic . . . . . . . . . . . . . . . . . . . . . . .  9
   12. Signature: Cryptographic Function over a Hash Value  . . . . .  9
     12.1. General Signature TLV Structure  . . . . . . . . . . . . .  9
       12.1.1.  Rationale . . . . . . . . . . . . . . . . . . . . . . 10
     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  . . . . . . . . . . . . . . . 11
   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

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].

   <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:

   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 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].

   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 may 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:

   <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 may, 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.  The TLVs can 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
   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.

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
   TLV value 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.

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 value should be
   considered when calculating the value of the signature.

11.  Signature: Basic

   The basic signature proposed, 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.

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.

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 twofold: First, if
   further hash functions or cryptographic functions are added in the
   future, the number space might not remain continuous.  More
   importantly, the number space of possible combinations would be
   rapidly exhausted.  As new or improved cryptographic mechanism are
   continuously being developed and introduced, this format should be
   able to accommodate such for the foreseeable future.

   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
   TLV value 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.  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,

   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 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.

   +-----------+------+-----------+------------------------------------+
   |    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.         |
   |           |      |   2-223   |            Expert Review           |
   |           |      |  224-255  |          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           |
   |           |      |   1-223   |            Expert Review           |
   |           |      |  224-255  |          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.         |
   |           |      |   2-223   |            Expert Review           |
   |           |      |  224-255  |          Experimental Use          |
   | TIMESTAMP | TBD4 |     0     |   Unsigned timestamp of arbitrary  |
   |           |      |           |   length, given by the TLV length  |
   |           |      |           |               field.               |
   |           |      |   1-223   |            Expert Review           |
   |           |      |  224-255  |          Experimental Use          |
   +-----------+------+-----------+------------------------------------+

                        Table 2: Message TLV types

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.         |
   |           |      |   2-223   |            Expert Review           |
   |           |      |  224-255  |          Experimental Use          |
   | TIMESTAMP | TBD6 |     0     |   Unsigned timestamp of arbitrary  |
   |           |      |           |   length, given by the TLV length  |
   |           |      |           |               field.               |
   |           |      |   1-223   |            Expert Review           |
   |           |      |  224-255  |          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    |
   |    1-223    |           |              Expert Review              |
   |   224-255   |           |             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                |
   |      1-223     |           |             Expert Review            |
   |     224-255    |           |           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.

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-olsrv2-12.txt, July 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. M/S 345
   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/