Mobile Ad hoc Networking (MANET) U. Herberg Internet-Draft Fujitsu Laboratories of America Obsoletes: 6622 (if approved) T. Clausen Intended status: Standards Track LIX, Ecole Polytechnique Expires: October 17, 2013 C. Dearlove BAE Systems ATC April 15, 2013 Integrity Check Value and Timestamp TLV Definitions for Mobile Ad Hoc Networks (MANETs) draft-ietf-manet-rfc6622-bis-02 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 Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on October 17, 2013. Copyright Notice Copyright (c) 2013 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 Herberg, et al. Expires October 17, 2013 [Page 1]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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 RFC6622 . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Applicability Statement . . . . . . . . . . . . . . . . . . . 4 4. Security Architecture . . . . . . . . . . . . . . . . . . . . 5 5. Overview and Functioning . . . . . . . . . . . . . . . . . . . 6 6. General ICV TLV Structure . . . . . . . . . . . . . . . . . . 7 7. General Timestamp TLV Structure . . . . . . . . . . . . . . . 7 8. Packet TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 8 8.1. ICV Packet TLV . . . . . . . . . . . . . . . . . . . . . . 8 8.2. TIMESTAMP Packet TLV . . . . . . . . . . . . . . . . . . . 9 9. Message TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 9 9.1. ICV Message TLV . . . . . . . . . . . . . . . . . . . . . 9 9.2. TIMESTAMP Message TLV . . . . . . . . . . . . . . . . . . 9 10. Address Block TLVs . . . . . . . . . . . . . . . . . . . . . . 10 10.1. ICV Address Block TLV . . . . . . . . . . . . . . . . . . 10 10.2. TIMESTAMP Address Block TLV . . . . . . . . . . . . . . . 10 11. ICV: Basic . . . . . . . . . . . . . . . . . . . . . . . . . . 10 12. ICV: Hash Function and Cryptographic Function . . . . . . . . 11 12.1. General ICV TLV Structure . . . . . . . . . . . . . . . . 11 12.1.1. Rationale . . . . . . . . . . . . . . . . . . . . . . 12 12.2. Considerations for Calculating the ICV . . . . . . . . . . 13 12.2.1. Packet ICV TLV . . . . . . . . . . . . . . . . . . . 13 12.2.2. Message ICV TLV . . . . . . . . . . . . . . . . . . . 13 12.2.3. Address Block ICV TLV . . . . . . . . . . . . . . . . 14 12.3. Example of a Message Including an ICV . . . . . . . . . . 14 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 13.1. Expert Review: Evaluation Guidelines . . . . . . . . . . . 16 13.2. Packet TLV Type Registrations . . . . . . . . . . . . . . 16 13.3. Message TLV Type Registrations . . . . . . . . . . . . . . 18 13.4. Address Block TLV Type Registrations . . . . . . . . . . . 19 13.5. Hash Functions . . . . . . . . . . . . . . . . . . . . . . 20 13.6. Cryptographic Functions . . . . . . . . . . . . . . . . . 20 14. Security Considerations . . . . . . . . . . . . . . . . . . . 21 15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 21 16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22 16.1. Normative References . . . . . . . . . . . . . . . . . . . 22 16.2. Informative References . . . . . . . . . . . . . . . . . . 23 Herberg, et al. Expires October 17, 2013 [Page 2]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 1. Introduction This document specifies a syntactical representation of security- related information for use with [RFC5444] addresses, messages, and packets, and also reports and updates IANA registrations (from [RFC6622]) of TLV types and type extension registries for these TLV types. This specification does not represent a stand-alone protocol, but 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. This document retains the IANA registries, defined in [RFC6622], for recording code points for ICV calculations, and requests an additional allocation from each these registries. This document retains the IANA registries, defined in [RFC6622], for recording code points for timestamps, hash-functions, and cryptographic functions, but does not request any additional allocations from these registries. 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. 1.1. Differences from RFC6622 This document obsoletes [RFC6622]. In addition to editorial updates, this document adds a new type extension 2 for the ICV TLV that is specified in Section 12 of this document. It also makes it clear that an ICV TLV may be used to carry a truncated ICV, and that a single- or multi- value ICV or TIMESTAMP Address Block TLV may cover more than one address. 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 Herberg, et al. Expires October 17, 2013 [Page 3]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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. 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 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.) 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 Address Blocks 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 Herberg, et al. Expires October 17, 2013 [Page 4]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 for calculating such ICVs is given, using a cryptographic function and a hash function, for which two TLV type extensions are allocated. 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 [OLSRv2] 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 reports the two IANA registries from [RFC6622] for code points for hash functions and cryptographic functions. Herberg, et al. Expires October 17, 2013 [Page 5]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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 reports and updates IANA registrations (from [RFC6622]) 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 reports previously assigned TLV types (from [RFC6622]) 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 reports and updates these type extension registries, in order to specify internal structure (and accompanying processing) of the <value> field of a TLV. For example, and as reported in this document, an ICV TLV with type extension = 0 specifies that the <value> field has no pre-defined internal structure but is simply a sequence of octets. An ICV TLV with type extension = 1 specifies that the <value> field has a pre- defined internal structure and defines its interpretation. An ICV TLV with type extension = 2 specifies a modified version of this definition. Specifically, with type extension = 1 or type extension = 2 (added in this document), 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 multiple sub-fields indicating which hash function and cryptographic function have been used as specified in Section 12. The difference between the two type extensions is that the ICV TLV Herberg, et al. Expires October 17, 2013 [Page 6]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 with type extension = 2 is calculated also over the source address of the IP datagram carrying the packet, message, or address block. 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 pre-defined 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 Herberg, et al. Expires October 17, 2013 [Page 7]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 timestamp and can, for example, correspond to a POSIX timestamp, GPS timestamp, or a simple sequence number. Note that insuring time synchronization in a MANET may be difficult because of the 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 Packet ICV TLVs already present in the Packet TLV Block MUST be removed before calculating the ICV, and the Packet TLV Block size MUST be recalculated accordingly. 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 Packet ICV 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 Herberg, et al. Expires October 17, 2013 [Page 8]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 Block when removing and verifying the ICV Packet TLV if no other Packet TLVs are present. 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 Message ICV TLVs already present in the Message TLV Block MUST be removed before calculating the ICV, and the message size as well as the Message TLV Block size MUST be recalculated accordingly. Also, all relevant TLVs other than ICV TLVs MUST be added prior to TCV 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 Herberg, et al. Expires October 17, 2013 [Page 9]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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. 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 Address Block ICV 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, is a simple bit-field containing the cryptographic ICV. This assumes that the mechanism stipulating how ICVs are calculated and Herberg, et al. Expires October 17, 2013 [Page 10]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 verified is established outside of this specification, e.g., by administrative configuration or external out-of-band signaling. Thus, 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. <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 Herberg, et al. Expires October 17, 2013 [Page 11]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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 which 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 HMAC function, which is specified as defined in Section 13.6, using the hash function twice. 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 SHOULD be as specified for the relevant cryptographic function (and, if appropriate, hash function). The hash function and the cryptographic function correspond to the entries in two IANA registries, which are reported by this specification and 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 providing 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 Herberg, et al. Expires October 17, 2013 [Page 12]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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. The rationale for the addition of type extension 2 is that the source code 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 TC messages in [OLSRv2]. 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. Packet ICV 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 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 source address of the IP datagram carrying the packet is also concatenated, in the first position, with the data used. 12.2.2. Message ICV 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 = Herberg, et al. Expires October 17, 2013 [Page 13]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 2: o The same procedure as for type extension = 1 is used, except that the source address of the IP datagram carrying the message is also concatenated, in the first position, with the data used. 12.2.3. Address Block ICV 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 concatenated attribute of the addresses in the verification process of the ICV. The considerations 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 source address of the IP datagram carrying the Address Block is also concatenated, in the first position, with the data used. 12.3. Example of a Message Including an ICV The sample message depicted in Figure 1 is derived from Appendix D of [RFC5444]. The message contains an ICV Message TLV, with the value representing an ICV that is 16 octets long of the whole message, 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. Expires October 17, 2013 [Page 14]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PV=0 | PF=8 | Packet Sequence Number | Message Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MF=15 | MAL=3 | Message Length = 44 | Msg Orig Addr | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Message Originator Address (cont) | Hop Limit | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Hop Count | Message Sequence Number | Msg TLV Block | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length = 27 | ICV | MTLVF = 144 | MTLVExt = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Value Len = 23 | Hash Func | Crypto Func |Key ID length=4| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Key Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ICV Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ICV Value (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ICV Value (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ICV Value (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: Example Message with ICV 13. IANA Considerations This specification reports the following, originally specified 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, created in [RFC6622]: Herberg, et al. Expires October 17, 2013 [Page 15]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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]. For both Timestamp and ICV TLVs, functionally similar extensions for Packet, Message, and Address Block TLVs SHOULD be numbered identically. 13.2. Packet TLV Type Registrations 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 are requested to modify this allocation (defining type extension = 2) as indicated. Herberg, et al. Expires October 17, 2013 [Page 16]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 +-----------+------+-----------+------------------------------------+ | Name | Type | Type | Description | | | | Extension | | +-----------+------+-----------+------------------------------------+ | ICV | 5 | 0 | ICV of a packet | | | | 1 | ICV, using a cryptographic | | | | | function and a hash function, as | | | | | specified in Section 12 of this | | | | | document | | | | 2 | ICV, using a cryptographic | | | | | function and a hash function, and | | | | | including the IP datagram source | | | | | address, as specified in | | | | | Section 12 of this document | | | | 3-251 | Unassigned; Expert Review | | | | 252-255 | Experimental Use | | TIMESTAMP | 6 | 0 | Unsigned timestamp of arbitrary | | | | | length, given by the TLV Length | | | | | field. The MANET routing protocol | | | | | has to define how to interpret | | | | | this timestamp | | | | 1 | Unsigned 32-bit timestamp, as | | | | | specified in [IEEE 1003.1-2008 | | | | | (POSIX)] | | | | 2 | NTP timestamp format, as specified | | | | | in [RFC5905] | | | | 3 | Signed timestamp of arbitrary | | | | | length with no constraints such as | | | | | monotonicity. In particular, it | | | | | may represent any random value | | | | 4-251 | Unassigned; Expert Review | | | | 252-255 | Experimental Use | +-----------+------+-----------+------------------------------------+ Table 1: Packet TLV Types 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. More than one TIMESTAMP Packet TLV with the same type extension MUST NOT be included in a packet. Herberg, et al. Expires October 17, 2013 [Page 17]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 13.3. Message TLV Type Registrations 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 are requested to modify this allocation (defining type extension = 2) as indicated. +-----------+------+-----------+------------------------------------+ | Name | Type | Type | Description | | | | Extension | | +-----------+------+-----------+------------------------------------+ | ICV | 5 | 0 | ICV of a message | | | | 1 | ICV, using a cryptographic | | | | | function and a hash function, as | | | | | specified in Section 12 of this | | | | | document | | | | 2 | ICV, using a cryptographic | | | | | function and a hash function, and | | | | | including the IP datagram source | | | | | address, as specified in | | | | | Section 12 of this document | | | | 3-251 | Unassigned; Expert Review | | | | 252-255 | Experimental Use | | TIMESTAMP | 6 | 0 | Unsigned timestamp of arbitrary | | | | | length, given by the TLV Length | | | | | field. | | | | 1 | Unsigned 32-bit timestamp, as | | | | | specified in [IEEE 1003.1-2008 | | | | | (POSIX)] | | | | 2 | NTP timestamp format, as specified | | | | | in [RFC5905] | | | | 3 | Signed timestamp of arbitrary | | | | | length with no constraints such as | | | | | monotonicity. In particular, it | | | | | may represent any random value | | | | 4-251 | Unassigned; Expert Review | | | | 252-255 | Experimental Use | +-----------+------+-----------+------------------------------------+ Table 2: Message TLV Types 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. More than one TIMESTAMP Message TLV with the same type extension MUST NOT be Herberg, et al. Expires October 17, 2013 [Page 18]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 included in a message. 13.4. Address Block TLV Type Registrations 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 are requested to modify this allocation (defining type extension = 2) as indicated. +-----------+------+-----------+------------------------------------+ | Name | Type | Type | Description | | | | Extension | | +-----------+------+-----------+------------------------------------+ | ICV | 5 | 0 | ICV of an object (e.g., an | | | | | address) | | | | 1 | ICV, using a cryptographic | | | | | function and a hash function, as | | | | | specified in Section 12 of this | | | | | document | | | | 2 | ICV, using a cryptographic | | | | | function and a hash function, and | | | | | including the IP datagram source | | | | | address, as specified in | | | | | Section 12 of this document | | | | 3-251 | Unassigned; Expert Review | | | | 252-255 | Experimental Use | | TIMESTAMP | 6 | 0 | Unsigned timestamp of arbitrary | | | | | length, given by the TLV Length | | | | | field | | | | 1 | Unsigned 32-bit timestamp, as | | | | | specified in [IEEE 1003.1-2008 | | | | | (POSIX)] | | | | 2 | NTP timestamp format, as specified | | | | | in [RFC5905] | | | | 3 | Signed timestamp of arbitrary | | | | | length with no constraints such as | | | | | monotonicity. In particular, it | | | | | may represent any random value | | | | 4-251 | Unassigned; Expert Review | | | | 252-255 | Experimental Use | +-----------+------+-----------+------------------------------------+ Table 3: Address Block TLV Types More than one ICV Address Block TLV with the same type extension MAY be associate with an address 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 Herberg, et al. Expires October 17, 2013 [Page 19]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 identifier). ICV Address Block TLVs that carry what is declared to be the same information MUST NOT be associated with the same address. More than one TIMESTAMP Address Block TLV with the same type extension MUST NOT be associated with any address. 13.5. 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 4. This registry is unchanged by this specification. +-------------+-----------+-----------------------------------------+ | Hash | Algorithm | Description | | Function | | | | Value | | | +-------------+-----------+-----------------------------------------+ | 0 | none | The "identity function": The hash value | | | | of an object is the object itself | | 1 | SHA1 | [NIST-FIPS-180-4] | | 2 | SHA224 | [NIST-FIPS-180-4] | | 3 | SHA256 | [NIST-FIPS-180-4] | | 4 | SHA384 | [NIST-FIPS-180-4] | | 5 | SHA512 | [NIST-FIPS-180-4] | | 6-251 | | Unassigned; Expert Review | | 252-255 | | Experimental Use | +-------------+-----------+-----------------------------------------+ Table 4: Hash Function Registry 13.6. 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 5. This registry is unchanged by this specification. Herberg, et al. Expires October 17, 2013 [Page 20]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 +----------------+-----------+--------------------------------------+ | Cryptographic | Algorithm | Description | | Function Value | | | +----------------+-----------+--------------------------------------+ | 0 | none | The "identity function": The value | | | | of an encrypted hash is the hash | | | | itself | | 1 | RSA | [RFC3447] | | 2 | DSA | [NIST-FIPS-186-3] | | 3 | HMAC | [RFC2104] | | 4 | 3DES | [NIST-SP-800-67] | | 5 | AES | [NIST-FIPS-197] | | 6 | ECDSA | [ANSI-X9-62-2005] | | 7-251 | | Unassigned; Expert Review | | 252-255 | | Experimental Use | +----------------+-----------+--------------------------------------+ Table 5: Cryptographic Function Registry 14. Security Considerations This document does not specify a protocol. It provides a syntactical component for cryptographic 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]. Herberg, et al. Expires October 17, 2013 [Page 21]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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. 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. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [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., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, June 2010. [RFC3447] Jonsson, J. and B. Kaliski, "Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1", RFC 3447, February 2003. [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-Hashing for Message Authentication", RFC 2104, February 1997. [NIST-FIPS-197] National Institute of Standards and Technology, "Specification for the Advanced Encryption Standard (AES)", FIPS 197, November 2001. [NIST-FIPS-186-3] National Institute of Standards and Technology, "Digital Signature Standard (DSS)", FIPS 186-3, June 2009. Herberg, et al. Expires October 17, 2013 [Page 22]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 [ANSI-X9-62-2005] American National Standards Institute, "Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Algorithm (ECDSA)", ANSI X9.62-2005, November 2005. [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. [NIST-FIPS-180-4] National Institute of Standards and Technology, "Secure Hash Standard (SHS)", FIPS 180-4, March 2012. [IEEE 1003.1-2008 (POSIX)] IEEE Computer Society, "1003.1-2008 Standard for Information Technology - Portable Operating System Interface (POSIX) Base Specifications, Issue 7", December 2008. 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. [OLSRv2] Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg, "The Optimized Link State Routing Protocol version 2", Work in Progress draft-ietf-manet-olsrv2-19, March 2013. Herberg, et al. Expires October 17, 2013 [Page 23]
Internet-Draft ICV and Timestamp TLVs for MANETs April 2013 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. Expires October 17, 2013 [Page 24]