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rfc:rfc7182

Internet Engineering Task Force (IETF) U. Herberg Request for Comments: 7182 Fujitsu Laboratories of America Obsoletes: 6622 T. Clausen Category: Standards Track LIX, Ecole Polytechnique ISSN: 2070-1721 C. Dearlove

                                                       BAE Systems ATC
                                                            April 2014
        Integrity Check Value and Timestamp TLV Definitions
                for Mobile Ad Hoc Networks (MANETs)

Abstract

 This document revises, extends, and replaces RFC 6622.  It describes
 general and flexible TLVs for representing cryptographic Integrity
 Check Values (ICVs) and timestamps, using the generalized Mobile Ad
 Hoc Network (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, a message, and one or
 more addresses, respectively.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc7182.

Herberg, et al. Standards Track [Page 1] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

Copyright Notice

 Copyright (c) 2014 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
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Table of Contents

 1. Introduction ....................................................3
    1.1. Differences from RFC 6622 ..................................4
 2. Terminology .....................................................4
 3. Applicability Statement .........................................5
 4. Security Architecture ...........................................6
 5. Overview and Functioning ........................................7
 6. General ICV TLV Structure .......................................8
 7. General Timestamp TLV Structure .................................8
 8. Packet TLVs .....................................................9
    8.1. ICV Packet TLV .............................................9
    8.2. TIMESTAMP Packet TLV ......................................10
 9. Message TLVs ...................................................10
    9.1. ICV Message TLV ...........................................10
    9.2. TIMESTAMP Message TLV .....................................10
 10. Address Block TLVs ............................................11
    10.1. ICV Address Block TLV ....................................11
    10.2. TIMESTAMP Address Block TLV ..............................11
 11. ICV: Basic ....................................................11
 12. ICV: Hash Function and Cryptographic Function .................12
    12.1. General ICV TLV Structure ................................12
         12.1.1. Rationale .........................................14
         12.1.2. Parameters ........................................15
    12.2. Considerations for Calculating the ICV ...................15
         12.2.1. ICV Packet TLV ....................................15
         12.2.2. ICV Message TLV ...................................16
         12.2.3. ICV Address Block TLV .............................16
    12.3. Example of a Message Including an ICV ....................17
 13. IANA Considerations ...........................................19
    13.1. Expert Review: Evaluation Guidelines .....................19
    13.2. Packet TLV Types .........................................20
    13.3. Message TLV Types ........................................20

Herberg, et al. Standards Track [Page 2] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

    13.4. Address Block TLV Types ..................................20
    13.5. ICV Packet TLV Type Extensions ...........................21
    13.6. TIMESTAMP Packet TLV Type Extensions .....................21
    13.7. ICV Message TLV Type Extensions ..........................22
    13.8. TIMESTAMP Message TLV Type Extensions ....................23
    13.9. ICV Address Block TLV Type Extensions ....................24
    13.10. TIMESTAMP Address Block TLV Type Extensions .............25
    13.11. Hash Functions ..........................................26
    13.12. Cryptographic Functions .................................27
 14. Security Considerations .......................................28
 15. Acknowledgements ..............................................28
 16. References ....................................................29
    16.1. Normative References .....................................29
    16.2. Informative References ...................................30

1. Introduction

 This document specifies a syntactical representation of security-
 related information for use with [RFC5444] addresses, messages, and
 packets.  It also specifies IANA registrations of TLV types and type
 extension registries for these TLV types.  This specification does
 not represent a stand-alone protocol, but it is intended for use by
 MANET routing protocols or security extensions thereof.
 Specifically, this document, which revises, extends, and replaces
 [RFC6622], specifies:
 o  Two kinds of TLV: one for carrying Integrity Check Values (ICVs)
    and one for timestamps in packets, messages, and Address Blocks as
    defined by [RFC5444].
 o  A generic framework for use of these TLVs, accounting for specific
    features of Packet, Message, and Address Block TLVs.
 o  IANA registrations for TLVs, and registries for TLV type
    extensions, replacing those from [RFC6622].
 This document specifies IANA registries for recording code points for
 ICV TLVs and TIMESTAMP TLVs, as well as timestamps, hash functions,
 and cryptographic functions.
 Moreover, in Section 12, this document defines the following:
 o  A method for generating ICVs using a combination of a
    cryptographic function and a hash function and for including such
    ICVs in the value field of a TLV.

Herberg, et al. Standards Track [Page 3] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

1.1. Differences from RFC 6622

 This document obsoletes [RFC6622], replacing that document as the
 specification of two TLV types, TIMESTAMP and ICV, for packets,
 messages and Address Blocks.  For the ICV type, this document
 specifies a new type extension, 2 (see Section 12), in addition to
 including the original type extensions (0 and 1) from [RFC6622].
 The TLV value of an ICV TLV with type extension = 2 has the same
 internal structure as an ICV TLV with type extension = 1 but is
 calculated also over the source address of the IP datagram carrying
 the packet, message, or Address Block.  The rationale for adding this
 type extension is that some MANET protocols, such as [RFC6130], use
 the IP source address of the IP datagram carrying the packet,
 message, or Address Block, e.g., to identify links with neighbor
 routers.  If this address is not otherwise contained in the packet,
 message, or Address Block payload (which is permitted, e.g., in
 [RFC6130]), then the address is not protected against tampering.
 This document also incorporates a number of editorial improvements
 over [RFC6622].  In particular, it makes it clear that an ICV TLV may
 be used to carry a truncated ICV and that a single or multivalue
 TIMESTAMP or ICV Address Block TLV may cover more than one address.
 Moreover, to be consistent with the terminology in [RFC5444], the
 name of the TLVs specified in this document have changed from "Packet
 ICV TLV" to "ICV Packet TLV" and from "Packet TIMESTAMP TLV" to
 "TIMESTAMP Packet TLV" (and similar for Message and Address Block
 TLVs).
 A normative requirement in Section 9.2 has changed from SHOULD to
 MUST in the following sentence:
    If a message contains one or more TIMESTAMP TLVs and one or more
    ICV TLVs, then the TIMESTAMP TLVs (as well as any other Message
    TLVs) MUST be added to the message before the ICV TLVs....

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].

Herberg, et al. Standards Track [Page 4] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 This document uses the terminology and notation defined in [RFC5444].
 In particular, the following TLV fields and notation from [RFC5444]
 are used in this specification:
 <msg-hop-limit>  is the hop limit of a message, as specified in
    Section 5.2 of [RFC5444].
 <msg-hop-count>  is the hop count of a message, as specified in
    Section 5.2 of [RFC5444].
 <length>  is the length of the value field in a TLV in octets, as
    specified in Section 5.4.1 of [RFC5444].
 single-length  is the length of a single value in the value field in
    a TLV in octets, as specified in Section 5.4.1 of [RFC5444].  (It
    is equal to <length> except in a multivalue Address Block TLV.)
 In addition to using the regular expressions defined in Section 2.1.1
 of [RFC5444], this document defines the following:
 + - One or more occurrences of the preceding element or group.

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 the 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 an ICV for a packet, a
 message, and addresses in an Address Block within a message, using
 such TLVs.  This document also specifies how to treat an empty Packet
 TLV Block, and "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.
 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
 and a hash function, for which two TLV type extensions are allocated.
 This document does not specify a protocol.  Protocol specifications
 that make use of the framework, specified in this document, will
 reference this document in a normative way, and they may require the
 implementation of some or all of the algorithms described in this
 document.  As this document does not specify a protocol itself, key

Herberg, et al. Standards Track [Page 5] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 management and key exchange mechanisms are out of scope and may be
 specified in the protocol or protocol extension using this
 specification.

4. Security Architecture

 MANET routing protocol specifications may have a clause allowing a
 control message to be rejected as "badly formed" or "insecure" prior
 to the message being processed or forwarded.  In particular, MANET
 routing protocols such as the Neighborhood Discovery Protocol (NHDP)
 [RFC6130] and the Optimized Link State Routing Protocol version 2
 [RFC7181] recognize external reasons (such as failure to verify an
 ICV) for rejecting a message that would be considered "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 security mechanisms specific to a deployment domain.
 The MANET routing protocol "security architecture", in which this
 specification situates itself, can therefore be summarized as
 follows:
 o  MANET routing protocol specifications, each 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, each rejecting
    messages as "badly formed" or "insecure", as appropriate for a
    given security requirement specific to a deployment domain.
 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 the points above, by specifying a
 common exchange format for cryptographic ICVs and timestamps, making
 reservations from within the Packet TLV, Message TLV, and Address
 Block TLV registries of [RFC5444], to be used by (and shared among)
 MANET routing protocol security extensions.
 For the specific decomposition of an ICV using a cryptographic
 function and a hash function (specified in Section 12), this document
 specifies two IANA registries (see Section 13) for code points for
 hash functions and cryptographic functions.

Herberg, et al. Standards Track [Page 6] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 With respect to [RFC5444], this document is:
 o  Intended to be used in the non-normative, but intended, mode of
    use described in Appendix B of [RFC5444].
 o  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, and also specifies IANA registrations (see Section 13) of
 TLV types and type extension registries for these TLV types.
 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 specifies TLV type assignments (see Section 13) 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 specifies these type extension registries, in order to
 specify internal structure (and accompanying processing) of the
 <value> field of a TLV.
 For example, and as specified in this document, an ICV TLV with type
 extension = 0 specifies that the <value> field has no predefined
 internal structure, but is simply a sequence of octets.  An ICV TLV
 with type extension = 1 specifies that the <value> field has a
 predefined internal structure and defines its interpretation.  An ICV
 TLV with type extension = 2 (added in this document) is the same as
 an ICV TLV with type extension = 1, except that the integrity
 protection also covers the source address of the IP datagram carrying
 the packet, message, or Address Block.
 Specifically, with type extension = 1 or type extension = 2, the
 <value> field contains the result of combining a cryptographic
 function and a hash function, calculated over the contents of the
 packet, message, or Address Block.  The <value> field contains sub-
 fields indicating which hash function and cryptographic function have
 been used, as specified in Section 12.

Herberg, et al. Standards Track [Page 7] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 Other documents can request assignments for other type extensions; if
 they do so, they MUST 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 <length> octets (except in a
    multivalue Address Block TLV, where each <ICV-value> is of length
    single-length octets) that contains the information to be
    interpreted by the ICV verification process, as specified by the
    type extension.
 Note that this does not specify how to calculate the <ICV-value> nor
 the internal structure thereof, if any; such information MUST be
 specified by the type extension for the ICV TLV type; see Section 13.
 This document specifies three such type extensions: one for ICVs
 without predefined structures and two for ICVs constructed combining
 a cryptographic function and a hash function.

7. General Timestamp TLV Structure

 The value of the Timestamp TLV is:
    <value> := <time-value>+
 where:
    <time-value> is a field, of length <length> octets (except in a
    multivalue Address Block TLV, where each <time-value> is of length
    single-length octets) that contains the timestamp.
 Note that this does not specify how to calculate the <time-value> nor
 the internal structure thereof, if any; such information MUST be
 specified by the type extension for the TIMESTAMP TLV type; see
 Section 13.
 A timestamp is essentially "freshness information".  As such, its
 setting and interpretation are to be determined by the MANET routing
 protocol, or MANET routing protocol extension, that uses the
 timestamp and can, for example, correspond to a POSIX timestamp, GPS
 timestamp, or a simple sequence number.  Note that ensuring time
 synchronization in a MANET may be difficult because of the

Herberg, et al. Standards Track [Page 8] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 decentralized architecture as well as highly dynamic topology due to
 mobility or other factors.  It is out of scope for this document to
 specify a time synchronization mechanism.

8. Packet TLVs

 Two Packet TLVs are defined: one for including the cryptographic ICV
 of a packet and one for including the timestamp indicating the time
 at which the cryptographic ICV was calculated.

8.1. ICV Packet TLV

 An ICV Packet TLV is an example of an ICV TLV as described in
 Section 6.  When determining the <ICV-value> for a packet, and adding
 an ICV Packet TLV to a packet, the following considerations MUST be
 applied:
 o  Because packets as defined in [RFC5444] are never forwarded by
    routers, no special considerations are required regarding mutable
    fields (i.e., <msg-hop-count> and <msg-hop-limit>), if present
    within any messages in the packet, when calculating the ICV.
 o  Any ICV Packet 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.
 o  If the Packet TLV Block now contains no Packet TLVs, the Packet
    TLV Block MUST be removed, and the phastlv bit in the <pkt-flags>
    field in the Packet Header MUST be cleared ('0').
 o  Any removed ICV Packet TLVs MUST be restored after having
    calculated the ICV, and the Packet TLV Block size MUST be
    recalculated accordingly.
 o  When any removed ICV Packet TLVs, and the newly calculated ICV
    Packet TLV, are added to the packet, if there is no Packet TLV
    Block, then one MUST be added, including setting ('1') the phastlv
    bit in the <pkt-flags> field in the Packet Header.
 The rationale for removing any ICV Packet TLVs already present prior
 to calculating the ICV is that several ICV TLVs may be added to the
 same packet, e.g., using different ICV cryptographic and/or hash
 functions.  The rationale for removing an empty Packet TLV Block is
 because the receiver of the packet cannot tell the difference between
 what was an absent Packet TLV Block, and what was an empty Packet TLV
 Block when removing and verifying the ICV Packet TLV if no other
 Packet TLVs are present.

Herberg, et al. Standards Track [Page 9] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

8.2. TIMESTAMP Packet TLV

 A TIMESTAMP Packet TLV is an example of a Timestamp TLV as described
 in Section 7.  If a packet contains one or more TIMESTAMP TLVs and
 one or more ICV TLVs, then the TIMESTAMP TLVs (as well as any other
 Packet TLVs) MUST be added to the packet before the ICV TLVs, in
 order to include the timestamps and other TLVs in the calculation of
 the ICVs.

9. Message TLVs

 Two Message TLVs are defined: one for including the cryptographic ICV
 of a message and one for including the timestamp indicating the time
 at which the cryptographic ICV was calculated.

9.1. ICV Message TLV

 An ICV Message 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:
 o  The fields <msg-hop-limit> and <msg-hop-count>, if present in the
    Message Header, MUST both be assumed to have the value 0 (zero)
    when calculating the ICV.
 o  Any ICV Message 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.  Also, all relevant TLVs other than ICV TLVs MUST be
    added prior to ICV value calculation.
 o  Any removed ICV Message TLVs MUST be restored after having
    calculated the ICV, and the message size as well as the Message
    TLV Block size MUST be recalculated accordingly.
 The rationale for removing any ICV Message TLVs already present prior
 to calculating the ICV is that several ICV TLVs may be added to the
 same message, e.g., using different ICV cryptographic and/or hash
 functions.

9.2. TIMESTAMP Message TLV

 A TIMESTAMP Message TLV is an example of a Timestamp TLV as described
 in Section 7.  If a message contains one or more TIMESTAMP TLVs and
 one or more ICV TLVs, then the TIMESTAMP TLVs (as well as any other
 Message TLVs) MUST be added to the message before the ICV TLVs, in
 order to include the timestamps and other Message TLVs in the
 calculation of the ICV.

Herberg, et al. Standards Track [Page 10] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

10. Address Block TLVs

 Two Address Block TLVs are defined: one for associating a
 cryptographic ICV to one or more addresses and their associated
 information and one for including the timestamp indicating the time
 at which the cryptographic ICV was calculated.

10.1. ICV Address Block TLV

 An ICV Address Block TLV is an example of an ICV TLV as described in
 Section 6.  The ICV is calculated over one or more addresses,
 concatenated with any other values -- for example, other Address
 Block TLV <value> fields -- associated with those addresses.  A MANET
 routing protocol, or MANET routing protocol extension, using ICV
 Address Block TLVs MUST specify how to include any such concatenated
 attributes of the addresses in the calculation and verification
 processes for the ICV.  When determining an <ICV-value> for one or
 more addresses, the following consideration MUST be applied:
 o  If other TLV values are concatenated with the addresses for
    calculating the ICV, the corresponding TLVs MUST NOT be ICV
    Address Block TLVs already associated with any of the addresses.
 The rationale for not concatenating the addresses with any ICV TLV
 values already associated with the addresses when calculating the ICV
 is that several ICVs may be added to the same address or addresses,
 e.g., using different ICV cryptographic and/or hash functions, and
 the order of addition is not known to the recipient.

10.2. TIMESTAMP Address Block TLV

 A TIMESTAMP Address Block TLV is an example of a Timestamp TLV as
 described in Section 7.  If one or more TIMESTAMP TLVs and one or
 more ICV TLVs are associated with an address, the relevant TIMESTAMP
 TLV <time-value>(s) MUST be included before calculating the value of
 the ICV to be contained in the ICV TLV value (i.e., concatenated with
 the associated addresses 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, has as TLV value a simple bit-field without specified
 structure (i.e, without explicitly included hash function, crypto
 function, key ID or other parameters).  Moreover, it is not specified
 how to calculate the <ICV-value>.  It is assumed that the mechanism
 specifying how ICVs are calculated and verified, as well as which
 parameters (if any) need to be exchanged prior to using the TLV with

Herberg, et al. Standards Track [Page 11] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 type extension = 0, is established outside of this specification,
 e.g., by administrative configuration or external out-of-band
 signaling.
 The <ICV-value>, when using type extension = 0, is:
    <ICV-value> := <ICV-data>
 where:
    <ICV-data> is a field, of length <length> octets (or single-length
    octets in a multivalue Address Block TLV) that contains the
    cryptographic ICV.

12. ICV: Hash Function and Cryptographic Function

 One common way of calculating an ICV is combining a cryptographic
 function and a hash function applied to the content.  This
 decomposition is specified in this section, using either type
 extension = 1 or type extension = 2, 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-id-length>
                   <key-id>?
                   <ICV-data>
 where:
    <hash-function> is a one-octet unsigned integer field specifying
    the hash function.
    <cryptographic-function> is a one-octet unsigned integer field
    specifying the cryptographic function.
    <key-id-length> is a one-octet unsigned integer field specifying
    the length of the <key-id> field as a number of octets.  The value
    zero (0x00) is reserved for using a single pre-installed, shared
    key.

Herberg, et al. Standards Track [Page 12] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

    <key-id> is a field specifying the key identifier of the key that
    was used to calculate the ICV of 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 zero (0x00), the <key-id> field is not
    contained in the TLV, and a single pre-installed, shared key is
    used.
    <ICV-data> is a field with length <length> - 3 - <key-id-length>
    octets (except in a multivalue Address Block TLV, in which it is
    single-length - 3 - <key-id-length> octets) and that contains the
    cryptographic ICV.
 The version of this TLV, specified in this section, assumes that,
 unless otherwise specified, calculating the ICV can be decomposed
 into:
    ICV-value = cryptographic-function(hash-function(content))
 In some cases, a different combination of cryptographic function and
 hash function may be specified.  This is the case for the Hashed
 Message Authentication Code (HMAC) function, which is specified as
 defined in Section 13.12, using the hash function twice.  Using
 cryptographic-function "none" is provided for symmetry and possible
 future use, but it SHOULD NOT be used with any currently specified
 hash function.
 The difference between the two type extensions is that in addition to
 the information covered by the ICV using type extension = 1 (which is
 detailed in the following sections), the ICV using type extension = 2
 also MUST cover the source address of the IP datagram carrying the
 corresponding packet, message, or Address Block.
 The <ICV-data> field MAY be truncated after being calculated, this is
 indicated by its length, calculated as described above.  The
 truncation MUST be as specified for the relevant cryptographic
 function (and, if appropriate, hash function).
 o  When using truncation, the guidelines for minimal ICV length set
    out in [NIST-SP-800-107] MUST be followed.  In particular the
    <ICV-data> field when using HMAC MUST NOT be truncated below 4
    octets.
 o  The truncated ICV length MUST be so large that the probability of
    success of a dictionary attack is acceptably small.  Such a
    success will arise if the ICV of a spoofed packet or message is
    verified.  The probability of success is a function of (a) how

Herberg, et al. Standards Track [Page 13] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

    many routers can be attacked, (b) how fast a router can receive
    packets or messages and attempt to verify their ICV, (c) the
    truncated ICV length, and (d) the lifetime of the network.  If the
    truncated ICV length in bits is L, then 2^L packets or messages
    are required to attack with certainty of success.  With a
    verification rate of R packets/messages per second, applied to N
    routers over an available time of T, the probability of success is
    given by NRT/2^L.  If this is not to exceed a probability of P,
    then L > log2(NRT/P).  For example, if N is 32, R is 1000, T is
    86400 (I day) and P is 10^-6, then L must be at least 52 bits.
 Some of the cryptographic and hash functions listed in Section 13
 require the length of the content to be digitally signed to be a
 multiple of a certain number of octets.  As a consequence, they
 specify padding mechanisms, e.g., AES-CMAC [RFC4493] specifies a
 padding mechanism for message lengths that are not equal to a
 multiple of 16 octets.  Implementations of the framework in this
 document MUST support appropriate padding mechanisms, as specified in
 the cryptographic or hash function specifications.
 The hash function and the cryptographic function correspond to the
 entries in two IANA registries, which are described 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 a TLV type extension -- is that adding
 further hash functions or cryptographic functions in the future may
 lead to a non-contiguous number space as well as a smaller overall
 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.  Any
 additional parameters can be provided together with the keys in that
 bootstrap process.  Therefore, it is not necessary, and would even
 entail an extra overhead, to transmit the parameters within every
 message.
 The rationale for the addition of type extension = 2 is that the
 source address is used in some cases, such as when processing HELLO
 messages in [RFC6130].  This is applicable only to packets (which
 only ever travel one hop) and messages (and their Address Blocks)
 that only travel one hop.  It is not applicable to messages that may
 be forwarded more than one hop, such as Topology Control (TC)
 messages in [RFC7181].

Herberg, et al. Standards Track [Page 14] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

12.1.2. Parameters

 As described in Section 12.1.1, parameters are selected
 administratively on each router before using this framework in a
 MANET, in addition to exchanging the keys between MANET routers.
 This was a design decision in [RFC6622] and is kept in this
 specification for reasons of backwards compatibility.
 The following parameters are RECOMMENDED and SHOULD be those chosen
 administratively, unless there are good reasons otherwise:
 o  For crypto function RSA:
  • Signature scheme: RSASSA-PSS with the default parameters:

rSASSA-PSS-Default-Identifier (as defined in [RFC3447])

  • Common exponent: 65537
 o  For crypto function ECDSA:
  • Curve name: exchanged as part of key distribution
  • Hash function: The hash function MUST be pinned to the curve,

i.e., use SHA-256 for the p-256 curve, SHA-384 for p-384, etc.

 o  For crypto function AES:
  • Authentication algorithm: Cipher-Based Message Authentication

Code (CMAC) (as defined in [RFC4493])

  • Hash function: None

12.2. Considerations for Calculating the ICV

 The considerations listed in the following subsections MUST be
 applied when calculating the ICV for Packet, Message, and Address
 Block TLVs, respectively.

12.2.1. ICV Packet TLV

 When determining the <ICV-data> for a packet, with type
 extension = 1:
 o  The ICV is calculated over the fields <hash-function>,
    <cryptographic-function>, <key-id-length>, and -- if present --
    <key-id> (in that order), followed by the entire packet, including

Herberg, et al. Standards Track [Page 15] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

    the Packet Header, including all Packet TLVs (other than ICV
    Packet TLVs), and all included messages.  The considerations of
    Section 8.1 MUST be applied.
 When determining the <ICV-data> for a packet, with type
 extension = 2:
 o  The same procedure as for type extension = 1 is used, except that
    the data used consists of a representation of the source address
    of the IP datagram carrying the packet, followed by the remaining
    data (as for type extension = 1).  The representation of the
    source address consists of a single octet containing the address
    length, in octets, followed by that many octets containing the
    address in network byte order.

12.2.2. ICV Message TLV

 When determining the <ICV-data> for a message, with type
 extension = 1:
 o  The ICV is calculated over the fields <hash-function>,
    <cryptographic-function>, <key-id-length>, and -- if present --
    <key-id> (in that order), followed by the entire message.  The
    considerations in Section 9.1 MUST be applied.
 When determining the <ICV-data> for a message, with type
 extension = 2:
 o  The same procedure as for type extension = 1 is used, except that
    the data used consists of a representation of the source address
    of the IP datagram carrying the message, followed by the remaining
    data (as for type extension = 1).  The representation of the
    source address consists of a single octet containing the address
    length, in octets, followed by that many octets containing the
    address in network byte order.

12.2.3. ICV Address Block TLV

 When determining the <ICV-data> for one or more addresses, with type
 extension = 1:
 o  The ICV is calculated over the fields <hash-function>,
    <cryptographic-function>, <key-id-length>, and -- if present --
    <key-id> (in that order), followed by the addresses, and followed
    by any other values -- for example, other Address Block TLV
    <value>s that are associated with those addresses.  A MANET
    routing protocol, or MANET routing protocol extension, using ICV
    Address Block TLVs MUST specify how to include any such

Herberg, et al. Standards Track [Page 16] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

    concatenated attribute of the addresses in the verification
    process of the ICV.  The consideration in Section 10.1 MUST be
    applied.
 When determining the <ICV-data> for one or more addresses, with type
 extension = 2:
 o  The same procedure as for type extension = 1 is used, except that
    the data used consists of a representation of the source address
    of the IP datagram carrying the Address Block, followed by the
    remaining data (as for type extension = 1).  The representation of
    the source address consists of a single octet containing the
    address length, in octets, followed by that many octets containing
    the address in network byte order.

12.3. Example of a Message Including an ICV

 The sample message depicted in Figure 1 is derived from Appendix E of
 [RFC5444].  The message contains an ICV Message TLV, with the value
 representing an ICV that is 16 octets long and a key identifier that
 is 4 octets long.  The type extension of the Message TLV is 1, for
 the specific decomposition of an ICV using a cryptographic function
 and a hash function, as specified in Section 12.

Herberg, et al. Standards Track [Page 17] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Message Type  | MF=15 | MAL=3 |      Message Length = 82      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Message Originator Address                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Hop Limit   |   Hop Count   |    Message Sequence Number    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Message TLV Block Length = 36 |   TLV Type    |  MTLVF = 16   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Value Len = 6 |                     Value                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                 Value (cont)                  |TLV Type = ICV |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  MTLVF = 144  |  MTLVExt = 1  |Value Len = 23 |   Hash Func   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Crypto Func  | KeyID Len = 4 |        Key Identifier         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Key Identifier (cont)     |           ICV Value           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       ICV Value (cont)                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       ICV Value (cont)                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       ICV Value (cont)                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       ICV Value (cont)        | Num Addr = 2  |   ABF = 48    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Tail Len = 2  |             Mid 0             |     Mid 1     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Mid 1 (cont)  | Prefix Length |    ABTLV Block Length = 0     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Num Addr = 3  |   ABF = 128   | Head Len = 2  |     Head      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Head (cont)  |             Mid 0             |     Mid 1     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Mid 1 (cont)  |             Mid 2             |ABTLV Block ...|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |... Length = 9 |   TLV Type    |  ABTLVF = 16  | Value Len = 2 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             Value             |   TLV Type    |  ABTLVF = 32  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Index Start  |  Index Stop   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                  Figure 1: Example Message with ICV

Herberg, et al. Standards Track [Page 18] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 MF:      Message Flags, see Section 5.2 of [RFC5444].
 MAL:     Message Address Length, see Section 5.2 of [RFC5444].
 MTLVF:   Message TLV Flags, see Section 5.4.1 of [RFC5444].
 MTLVExt: Message TLV Type Extension, see Section 5.4.1 of [RFC5444].
 AF:      Address Block Flags, see Section 5.3 of [RFC5444].
 ABTLV:   Address Block TLV, see Section 5.4 of [RFC5444].
 ABTLVF:  Address Block TLV Flags, see Section 5.4.1 of [RFC5444].
                   Example Message with ICV - Legend

13. IANA Considerations

 The IANA registrations for TLV Types and the TLV type extension
 registries given in this specification replace the identical
 registrations and registries from [RFC6622].
 This specification defines the following TLV Types, replacing the
 original specifications in [RFC6622]:
 o  Two Packet TLV Types, which have been allocated from the 0-223
    range of the "Packet TLV Types" repository of [RFC5444], as
    specified in Table 1.
 o  Two Message TLV Types, which have been allocated from the 0-127
    range of the "Message TLV Types" repository of [RFC5444], as
    specified in Table 2.
 o  Two Address Block TLV Types, which have been allocated from the
    0-127 range of the "Address Block TLV Types" repository of
    [RFC5444], as specified in Table 3.
 This specification updates the following registries that were created
 in [RFC6622]:
 o  A type extension registry for each of these TLV types with values
    as listed in Tables 1, 2, and 3.
 The following terms are used as defined in [BCP26]: "Namespace",
 "Registration", and "Designated Expert".
 The following policy is used as defined in [BCP26]: "Expert Review".

13.1. Expert Review: Evaluation Guidelines

 For TLV type extensions registries where an Expert Review is
 required, the Designated Expert SHOULD take the same general
 recommendations into consideration as those specified by [RFC5444].

Herberg, et al. Standards Track [Page 19] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 For both TIMESTAMP and ICV TLVs, functionally similar extensions for
 Packet, Message, and Address Block TLVs SHOULD be numbered
 identically.

13.2. Packet TLV Types

 IANA has, in accordance with [RFC6622], made allocations from the
 "Packet TLV Types" namespace of [RFC5444] for the Packet TLVs
 specified in Table 1.  IANA has modified this allocation as
 indicated.
                  +------+-------------+-----------+
                  | Type | Description | Reference |
                  +------+-------------+-----------+
                  |  5   |     ICV     |  RFC 7182 |
                  |  6   |  TIMESTAMP  |  RFC 7182 |
                  +------+-------------+-----------+
                       Table 1: Packet TLV Types

13.3. Message TLV Types

 IANA has, in accordance with [RFC6622], made allocations from the
 "Message TLV Types" namespace of [RFC5444] for the Message TLVs
 specified in Table 2.  IANA has modified this allocation as
 indicated.
                  +------+-------------+-----------+
                  | Type | Description | Reference |
                  +------+-------------+-----------+
                  |  5   |     ICV     |  RFC 7182 |
                  |  6   |  TIMESTAMP  |  RFC 7182 |
                  +------+-------------+-----------+
                      Table 2: Message TLV Types

13.4. Address Block TLV Types

 IANA has, in accordance with [RFC6622], made allocations from the
 "Address Block TLV Types" namespace of [RFC5444] for the Packet TLVs
 specified in Table 3.  IANA has modified this allocation as
 indicated.

Herberg, et al. Standards Track [Page 20] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

                  +------+-------------+-----------+
                  | Type | Description | Reference |
                  +------+-------------+-----------+
                  |  5   |     ICV     |  RFC 7182 |
                  |  6   |  TIMESTAMP  |  RFC 7182 |
                  +------+-------------+-----------+
                   Table 3: Address Block TLV Types

13.5. ICV Packet TLV Type Extensions

 IANA has, in accordance with [RFC6622], made allocations from the
 "ICV Packet TLV Type Extensions" namespace of [RFC6622] for the
 Packet TLVs specified in Table 4.  IANA has modified this allocation
 (including defining type extension = 2) as indicated.
 +-----------+-------------------------------------------+-----------+
 |    Type   |                Description                | Reference |
 | Extension |                                           |           |
 +-----------+-------------------------------------------+-----------+
 |     0     |              ICV of a packet              |  RFC 7182 |
 |     1     | ICV, using a cryptographic function and a |  RFC 7182 |
 |           | hash function, as specified in Section 12 |           |
 |           |              of this document             |           |
 |     2     | ICV, using a cryptographic function and a |  RFC 7182 |
 |           |    hash function, and including the IP    |           |
 |           |  datagram source address, as specified in |           |
 |           |        Section 12 of this document        |           |
 |   3-251   |         Unassigned; Expert Review         |           |
 |  252-255  |       Reserved for Experimental Use       |  RFC 7182 |
 +-----------+-------------------------------------------+-----------+
                Table 4: ICV Packet TLV Type Extensions
 More than one ICV Packet TLV with the same type extension MAY be
 included in a packet if these represent different ICV calculations
 (e.g., with type extension 1 or 2 and different cryptographic
 function and/or hash function or with a different key identifier).
 ICV Packet TLVs that carry what is declared to be the same
 information MUST NOT be included in the same packet.

13.6. TIMESTAMP Packet TLV Type Extensions

 IANA has, in accordance with [RFC6622], made allocations from the
 "TIMESTAMP Packet TLV Type Extensions" namespace of [RFC6622] for the
 Packet TLVs specified in Table 5.  IANA has modified this allocation
 as indicated.

Herberg, et al. Standards Track [Page 21] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 +-----------+-------------------------------------------+-----------+
 |    Type   |                Description                | Reference |
 | Extension |                                           |           |
 +-----------+-------------------------------------------+-----------+
 |     0     |  Unsigned timestamp of arbitrary length,  |  RFC 7182 |
 |           | 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  |  RFC 7182 |
 |           |            in [IEEE1003.1-2008]           |           |
 |     2     |   NTP timestamp format, as specified in   |  RFC 7182 |
 |           |                 [RFC5905]                 |           |
 |     3     | Signed timestamp of arbitrary length with |  RFC 7182 |
 |           |  no constraints such as monotonicity.  In |           |
 |           |  particular, it may represent any random  |           |
 |           |                   value                   |           |
 |   4-251   |         Unassigned; Expert Review         |           |
 |  252-255  |       Reserved for Experimental Use       |  RFC 7182 |
 +-----------+-------------------------------------------+-----------+
             Table 5: TIMESTAMP Packet TLV Type Extensions
 More than one TIMESTAMP Packet TLV with the same type extension MUST
 NOT be included in a packet.

13.7. ICV Message TLV Type Extensions

 IANA has, in accordance with [RFC6622], made allocations from the
 "ICV Message TLV Type Extensions" namespace of [RFC6622] for the
 Message TLVs specified in Table 6.  IANA has modified this allocation
 (including defining type extension = 2) as indicated.

Herberg, et al. Standards Track [Page 22] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 +-----------+-------------------------------------------+-----------+
 |    Type   |                Description                | Reference |
 | Extension |                                           |           |
 +-----------+-------------------------------------------+-----------+
 |     0     |              ICV of a message             |  RFC 7182 |
 |     1     | ICV, using a cryptographic function and a |  RFC 7182 |
 |           | hash function, as specified in Section 12 |           |
 |           |              of this document             |           |
 |     2     | ICV, using a cryptographic function and a |  RFC 7182 |
 |           |    hash function, and including the IP    |           |
 |           |  datagram source address, as specified in |           |
 |           |        Section 12 of this document        |           |
 |   3-251   |         Unassigned; Expert Review         |           |
 |  252-255  |       Reserved for Experimental Use       |  RFC 7182 |
 +-----------+-------------------------------------------+-----------+
               Table 6: ICV Message TLV Type Extensions
 More than one ICV Message TLV with the same type extension MAY be
 included in a message if these represent different ICV calculations
 (e.g., with type extension 1 or 2 and different cryptographic
 function and/or hash function or with a different key identifier).
 ICV Message TLVs that carry what is declared to be the same
 information MUST NOT be included in the same message.

13.8. TIMESTAMP Message TLV Type Extensions

 IANA has, in accordance with [RFC6622], made allocations from the
 "TIMESTAMP Message TLV Type Extensions" namespace of [RFC6622] for
 the Message TLVs specified in Table 7.  IANA has modified this
 allocation as indicated.

Herberg, et al. Standards Track [Page 23] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 +-----------+-------------------------------------------+-----------+
 |    Type   |                Description                | Reference |
 | Extension |                                           |           |
 +-----------+-------------------------------------------+-----------+
 |     0     |  Unsigned timestamp of arbitrary length,  |  RFC 7182 |
 |           | 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  |  RFC 7182 |
 |           |         in POSIX [IEEE1003.1-2008]        |           |
 |     2     |   NTP timestamp format, as specified in   |  RFC 7182 |
 |           |                 [RFC5905]                 |           |
 |     3     | Signed timestamp of arbitrary length with |  RFC 7182 |
 |           |  no constraints such as monotonicity.  In |           |
 |           |  particular, it may represent any random  |           |
 |           |                   value                   |           |
 |   4-251   |         Unassigned; Expert Review         |           |
 |  252-255  |       Reserved for Experimental Use       |  RFC 7182 |
 +-----------+-------------------------------------------+-----------+
            Table 7: TIMESTAMP Message TLV Type Extensions
 More than one TIMESTAMP Message TLV with the same type extension MUST
 NOT be included in a message.

13.9. ICV Address Block TLV Type Extensions

 IANA has, in accordance with [RFC6622], made allocations from the
 "ICV Address Block TLV Type Extensions" namespace of [RFC6622] for
 the Address Block TLVs specified in Table 8.  IANA has modified this
 allocation (including defining type extension = 2) as indicated.

Herberg, et al. Standards Track [Page 24] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 +-----------+-------------------------------------------+-----------+
 |    Type   |                Description                | Reference |
 | Extension |                                           |           |
 +-----------+-------------------------------------------+-----------+
 |     0     |    ICV of an object (e.g., an address)    |  RFC 7182 |
 |     1     | ICV, using a cryptographic function and a |  RFC 7182 |
 |           | hash function, as specified in Section 12 |           |
 |           |              of this document             |           |
 |     2     | ICV, using a cryptographic function and a |  RFC 7182 |
 |           |    hash function, and including the IP    |           |
 |           |  datagram source address, as specified in |           |
 |           |        Section 12 of this document        |           |
 |   3-251   |         Unassigned; Expert Review         |           |
 |  252-255  |       Reserved for Experimental Use       |  RFC 7182 |
 +-----------+-------------------------------------------+-----------+
            Table 8: ICV Address Block TLV Type Extensions
 More than one ICV Address Block TLV with the same type extension MAY
 be associated with an address if these represent different ICV
 calculations (e.g., with type extension = 1 or type extension = 2 and
 different cryptographic function and/or hash function or with a
 different key identifier).  ICV Address Block TLVs that carry what is
 declared to be the same information MUST NOT be associated with the
 same address.

13.10. TIMESTAMP Address Block TLV Type Extensions

 IANA has, in accordance with [RFC6622], made allocations from the
 "TIMESTAMP Address Block TLV Type Extensions" namespace of [RFC6622]
 for the Address Block TLVs specified in Table 9.  IANA has modified
 this allocation as indicated.

Herberg, et al. Standards Track [Page 25] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 +-----------+-------------------------------------------+-----------+
 |    Type   |                Description                | Reference |
 | Extension |                                           |           |
 +-----------+-------------------------------------------+-----------+
 |     0     |  Unsigned timestamp of arbitrary length,  |  RFC 7182 |
 |           | 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  |  RFC 7182 |
 |           |         in POSIX [IEEE1003.1-2008]        |           |
 |     2     |   NTP timestamp format, as specified in   |  RFC 7182 |
 |           |                 [RFC5905]                 |           |
 |     3     | Signed timestamp of arbitrary length with |  RFC 7182 |
 |           |  no constraints such as monotonicity.  In |           |
 |           |  particular, it may represent any random  |           |
 |           |                   value                   |           |
 |   4-251   |         Unassigned; Expert Review         |           |
 |  252-255  |       Reserved for Experimental Use       |  RFC 7182 |
 +-----------+-------------------------------------------+-----------+
         Table 9: TIMESTAMP Address Block TLV Type Extensions
 More than one TIMESTAMP Address Block TLV with the same type
 extension MUST NOT be associated with any address.

13.11. Hash Functions

 IANA has, in accordance with [RFC6622], created a 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 10.  IANA has modified this
 allocation as indicated.

Herberg, et al. Standards Track [Page 26] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 +---------+-----------+---------------------------------+-----------+
 |  Value  | Algorithm |           Description           | Reference |
 +---------+-----------+---------------------------------+-----------+
 |    0    |    none   |   The "identity function": The  |  RFC 7182 |
 |         |           |  hash value of an object is the |           |
 |         |           |          object itself          |           |
 |    1    |   SHA-1   |        [NIST-FIPS-180-4]        |  RFC 7182 |
 |    2    |  SHA-224  |        [NIST-FIPS-180-4]        |  RFC 7182 |
 |    3    |  SHA-256  |        [NIST-FIPS-180-4]        |  RFC 7182 |
 |    4    |  SHA-384  |        [NIST-FIPS-180-4]        |  RFC 7182 |
 |    5    |  SHA-512  |        [NIST-FIPS-180-4]        |  RFC 7182 |
 |  6-251  |           |    Unassigned; Expert Review    |           |
 | 252-255 |           |  Reserved for Experimental Use  |  RFC 7182 |
 +---------+-----------+---------------------------------+-----------+
                   Table 10: Hash Function Registry

13.12. Cryptographic Functions

 IANA has, in accordance with [RFC6622], created a registry for the
 cryptographic functions, as specified in Section 12 of this document.
 Initial assignments and allocation policies are specified in
 Table 11.  IANA has modified this allocation as indicated.
 +---------+-----------+---------------------------------+-----------+
 |  Value  | Algorithm |           Description           | Reference |
 +---------+-----------+---------------------------------+-----------+
 |    0    |    none   |   The "identity function": The  |  RFC 7182 |
 |         |           |  value of an encrypted hash is  |           |
 |         |           |         the hash itself         |           |
 |    1    |    RSA    |            [RFC3447]            |  RFC 7182 |
 |    2    |    DSA    |        [NIST-FIPS-186-4]        |  RFC 7182 |
 |    3    |    HMAC   |            [RFC2104]            |  RFC 7182 |
 |    4    |    3DES   |         [NIST-SP-800-67]        |  RFC 7182 |
 |    5    |    AES    |         [NIST-FIPS-197]         |  RFC 7182 |
 |    6    |   ECDSA   |            [RFC6090]            |  RFC 7182 |
 |  7-251  |           |    Unassigned; Expert Review    |           |
 | 252-255 |           |  Reserved for Experimental Use  |  RFC 7182 |
 +---------+-----------+---------------------------------+-----------+
               Table 11: Cryptographic Function Registry

Herberg, et al. Standards Track [Page 27] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

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 how to use the
 framework and the TLVs presented in this document.  In addition, the
 protection that the MANET routing protocol or MANET routing protocol
 extensions attain by using this framework MUST be described.
 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
 Systems), Justin Dean (NRL), Paul Lambert (Marvell), Jerome Milan
 (Ecole Polytechnique), and Henning Rogge (FGAN) for their
 constructive comments on [RFC6622].
 The authors also appreciate the detailed reviews of [RFC6622] from
 the Area Directors, in particular Stewart Bryant (Cisco), Stephen
 Farrell (Trinity College Dublin), and Robert Sparks (Tekelec), as
 well as Donald Eastlake (Huawei) from the Security Directorate.
 The authors would like to thank Justin Dean (NRL) and Henning Rogge
 (FGAN) for their constructive comments on this specification.

Herberg, et al. Standards Track [Page 28] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

16. References

16.1. Normative References

 [BCP26]    Narten, T. and H. Alvestrand, "Guidelines for Writing an
            IANA Considerations Section in RFCs", BCP 26, RFC 5226,
            May 2008.
 [IEEE1003.1-2008]
            IEEE, "Portable Operating System Interface (POSIX)", IEEE
            1003.1-2008, Base Specifications, Issue 7, December 2008.
 [NIST-FIPS-180-4]
            National Institute of Standards and Technology, "Secure
            Hash Standard (SHS)", FIPS 180-4, March 2012.
 [NIST-FIPS-186-4]
            National Institute of Standards and Technology, "Digital
            Signature Standard (DSS)", FIPS 186-4, July 2013.
 [NIST-FIPS-197]
            National Institute of Standards and Technology,
            "Specification for the Advanced Encryption Standard
            (AES)", FIPS 197, November 2001.
 [NIST-SP-800-107]
            National Institute of Standards and Technology,
            "Recommendation for Applications Using Approved Hash
            Algorithms", SP 800-107, Revision 1, August 2012.
 [NIST-SP-800-67]
            National Institute of Standards and Technology,
            "Recommendation for the Triple Data Encryption Algorithm
            (TDEA) Block Cipher", Special Publication 800-67, Revision
            1, January 2012.
 [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", BCP 14, RFC 2119, March 1997.
 [RFC3447]  Jonsson, J. and B. Kaliski, "Public-Key Cryptography
            Standards (PKCS) #1: RSA Cryptography Specifications
            Version 2.1", RFC 3447, February 2003.

Herberg, et al. Standards Track [Page 29] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

 [RFC4493]  Song, JH., Poovendran, R., Lee, J., and T. Iwata, "The
            AES-CMAC Algorithm", RFC 4493, June 2006.
 [RFC5444]  Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
            "Generalized Mobile Ad Hoc Network (MANET) Packet/Message
            Format", RFC 5444, February 2009.
 [RFC5905]  Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
            Time Protocol Version 4: Protocol and Algorithms
            Specification", RFC 5905, June 2010.
 [RFC6090]  McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic
            Curve Cryptography Algorithms", RFC 6090, February 2011.

16.2. Informative References

 [RFC6130]  Clausen, T., Dearlove, C., and J. Dean, "Mobile Ad Hoc
            Network (MANET) Neighborhood Discovery Protocol (NHDP)",
            RFC 6130, April 2011.
 [RFC6622]  Herberg, U. and T. Clausen, "Integrity Check Value and
            Timestamp TLV Definitions for Mobile Ad Hoc Networks
            (MANETs)", RFC 6622, May 2012.
 [RFC7181]  Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg,
            "The Optimized Link State Routing Protocol Version 2", RFC
            7181, April 2014.

Herberg, et al. Standards Track [Page 30] RFC 7182 ICV and Timestamp TLVs for MANETs April 2014

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/
 Christopher Dearlove
 BAE Systems Advanced Technology Centre
 West Hanningfield Road
 Great Baddow, Chelmsford
 United Kingdom
 Phone: +44 1245 242194
 EMail: chris.dearlove@baesystems.com
 URI:   http://www.baesystems.com/

Herberg, et al. Standards Track [Page 31]

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