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