--- 1/draft-ietf-manet-packetbb-sec-03.txt 2011-07-11 22:16:04.000000000 +0200 +++ 2/draft-ietf-manet-packetbb-sec-04.txt 2011-07-11 22:16:05.000000000 +0200 @@ -1,18 +1,18 @@ Mobile Ad hoc Networking (MANET) U. Herberg Internet-Draft T. Clausen Intended status: Standards Track LIX, Ecole Polytechnique -Expires: September 30, 2011 March 29, 2011 +Expires: January 12, 2012 July 11, 2011 MANET Cryptographical Signature TLV Definition - draft-ietf-manet-packetbb-sec-03 + draft-ietf-manet-packetbb-sec-04 Abstract This document describes general and flexible TLVs (type-length-value structure) for representing cryptographic signatures as well as timestamps, using the generalized MANET packet/message format [RFC5444]. It defines two Packet TLVs, two Message TLVs, and two Address Block TLVs, for affixing cryptographic signatures and timestamps to a packet, message and address, respectively. @@ -24,21 +24,21 @@ 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 30, 2011. + This Internet-Draft will expire on January 12, 2012. Copyright Notice Copyright (c) 2011 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 @@ -50,61 +50,71 @@ Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Applicability Statement . . . . . . . . . . . . . . . . . . . 3 4. Security Architecture . . . . . . . . . . . . . . . . . . . . 4 5. Protocol Overview and Functioning . . . . . . . . . . . . . . 5 6. Imported TLV Fields . . . . . . . . . . . . . . . . . . . . . 5 7. General Signature TLV Structure . . . . . . . . . . . . . . . 5 - 7.1. Rationale . . . . . . . . . . . . . . . . . . . . . . . . 6 8. General Timestamp TLV Structure . . . . . . . . . . . . . . . 6 - 9. Packet TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 9.1. Packet SIGNATURE TLV . . . . . . . . . . . . . . . . . . . 7 - 9.2. Packet TIMESTAMP TLV . . . . . . . . . . . . . . . . . . . 8 - 10. Message TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 10.1. Message SIGNATURE TLV . . . . . . . . . . . . . . . . . . 8 - 10.2. Message TIMESTAMP TLV . . . . . . . . . . . . . . . . . . 8 - 11. Address Block TLVs . . . . . . . . . . . . . . . . . . . . . . 9 - 11.1. Address Block SIGNATURE TLV . . . . . . . . . . . . . . . 9 - 11.2. Address Block TIMESTAMP TLV . . . . . . . . . . . . . . . 9 - 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 - 12.1. TLV Registrations . . . . . . . . . . . . . . . . . . . . 9 - 12.1.1. Expert Review: Evaluation Guidelines . . . . . . . . 10 - 12.1.2. Packet TLV Type Registrations . . . . . . . . . . . . 10 - 12.1.3. Message TLV Type Registrations . . . . . . . . . . . 10 - 12.1.4. Address Block TLV Type Registrations . . . . . . . . 11 + 9. Packet TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 6 + 9.1. Packet SIGNATURE TLV . . . . . . . . . . . . . . . . . . . 6 + 9.2. Packet TIMESTAMP TLV . . . . . . . . . . . . . . . . . . . 7 + 10. Message TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 7 + 10.1. Message SIGNATURE TLV . . . . . . . . . . . . . . . . . . 7 + 10.2. Message TIMESTAMP TLV . . . . . . . . . . . . . . . . . . 7 + 11. Address Block TLVs . . . . . . . . . . . . . . . . . . . . . . 8 + 11.1. Address Block SIGNATURE TLV . . . . . . . . . . . . . . . 8 + 11.2. Address Block TIMESTAMP TLV . . . . . . . . . . . . . . . 8 + 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 + 12.1. TLV Registrations . . . . . . . . . . . . . . . . . . . . 8 + 12.1.1. Expert Review: Evaluation Guidelines . . . . . . . . 9 + 12.1.2. Packet TLV Type Registrations . . . . . . . . . . . . 9 + 12.1.3. Message TLV Type Registrations . . . . . . . . . . . 9 + 12.1.4. Address Block TLV Type Registrations . . . . . . . . 10 12.2. New IANA Registries . . . . . . . . . . . . . . . . . . . 11 - 12.2.1. Expert Review: Evaluation Guidelines . . . . . . . . 12 - 12.2.2. Hash Function . . . . . . . . . . . . . . . . . . . . 12 - 12.2.3. Cryptographic Algorithm . . . . . . . . . . . . . . . 12 - 13. Security Considerations . . . . . . . . . . . . . . . . . . . 13 - 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13 + 12.2.1. Expert Review: Evaluation Guidelines . . . . . . . . 11 + 12.2.2. Hash Function . . . . . . . . . . . . . . . . . . . . 11 + 12.2.3. Cryptographic Algorithm . . . . . . . . . . . . . . . 11 + 13. Security Considerations . . . . . . . . . . . . . . . . . . . 12 + 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12 15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 15.1. Normative References . . . . . . . . . . . . . . . . . . . 13 - 15.2. Informative References . . . . . . . . . . . . . . . . . . 14 - Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 14 - A.1. Example of a Signed Message . . . . . . . . . . . . . . . 14 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 + 15.2. Informative References . . . . . . . . . . . . . . . . . . 13 + Appendix A. Signature Decomposition into Cryptographic + Function of a Hash Value . . . . . . . . . . . . . . 13 + A.1. General Signature TLV Structure . . . . . . . . . . . . . 13 + A.1.1. Rationale . . . . . . . . . . . . . . . . . . . . . . 14 + A.2. Considerations for Calculating the Signature . . . . . . . 15 + A.2.1. Packet SIGNATURE TLV . . . . . . . . . . . . . . . . 15 + A.2.2. Message SIGNATURE TLV . . . . . . . . . . . . . . . . 15 + A.2.3. Address Block SIGNATURE TLV . . . . . . . . . . . . . 15 + A.3. Example of a Signed Message . . . . . . . . . . . . . . . 15 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Introduction This document specifies: o two TLVs for carrying cryptographic signatures and timestamps in packets, messages and address blocks as defined by [RFC5444], - o how cryptographic signatures are calculated, taking (for Message - TLVs) into account the mutable message header fields ( and ) where these fields are present in - messages. + o a generic framework for calculating cryptographic signatures, + taking (for Message TLVs) into account the mutable message header + fields ( and ) where these fields + are present in messages, + + o a specific calculation of signatures, decomposed as a + cryptographic function over the hash value of the content to be + signed, in the Appendix A of this document. This document requests from IANA: o allocations for these Packet, Message, and Address Block TLVs from the 0-223 Packet TLV range, the 0-127 Message TLV range and the 0-127 Address Block TLV range from [RFC5444], o creation of two IANA registries for recording code points for hash function and signature calculation, respectively. @@ -125,26 +135,38 @@ included MAY be used by a routing protocol, or by an extension of a routing protocol, according to its specification. This document specifies how to include a cryptographic signature for a packet, message or address by way of such TLVs. This document also specifies how to treat "mutable" fields ( and ), if present, in the message header when calculating signatures, such that the resulting signature can be correctly verified by any recipient, and how to include this signature. + This document is split into two parts: (i) a generic framework of + creating signatures in the presence of mutable fields, and how to + include these signatures in TLVs, (ii) a specific description of how + to calculate a signature, using a cryptographic function over the + hash value of the content to be signed, in the Appendix A of this + document. Note that (ii) is a possible and widely-used way of + calculating a signature, but other means may exist. Such other means + of calculating a signature have to be specified in another document. + That new document MUST use the TLV structures specified in this + document, as well as the described considerations when calculating + the signatures. + 4. Security Architecture Basic MANET routing protocol specifications are often "oblivious to security", however have a clause allowing a control message to be rejected as "badly formed" prior to it being processed or forwarded. - Protocols such as [NHDP] and [OLSRv2] recognize external reasons + Protocols such as [RFC6130] and [OLSRv2] recognize external reasons (such as failure to verify a signature) for rejecting a message as "badly formed", and therefore "invalid for processing". This architecture is a result of the observation that with respect to security in MANETs, "one size rarely fits all" and that MANET routing protocol deployment domains have varying security requirements ranging from "unbreakable" to "virtually none". The virtue of this approach is that MANET routing protocol specifications (and implementations) can remain "generic", with extensions providing proper deployment-domain specific security mechanisms. @@ -160,23 +182,26 @@ "badly formed", as appropriate for a given deployment-domain specific security requirement. o Code-points and an exchange format for information, necessary for specification of such MANET routing protocol security extensions. This document addresses the last of these issues, by specifying a common exchange format for cryptographic signatures, making reservations from within the Packet TLV, Message TLV and Address Block TLV registries of [RFC5444], to be used (and shared) among - MANET routing protocol security extensions, establishing two IANA - registries for code-points for hash functions and cryptographic - functions adhering to [RFC5444]. + MANET routing protocol security extensions. + + For the specific decomposition of a signature into a cryptographic + function over a hash value, specified in Appendix A, 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 of [RFC5444] as described in its Appendix B. o is a specific example of the Security Considerations section of [RFC5444] (the authentication part). 5. Protocol Overview and Functioning @@ -196,80 +221,32 @@ 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]. 7. General Signature TLV Structure - The following data structure allows representation of a cryptographic - signature, including specification of the appropriate hash function - and cryptographic function used for calculating the signature. This - data structure is specified, using the regular expression - syntax of [RFC5444], as: - - := - - - - - where: - - 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 key - index of the key which was used to sign the message, which allows - unique identification of different keys with the same originator. - It is the responsibility of each key originator to make sure that - actively used keys that it issues have distinct key indices and - that all key indices have a value unequal to 0x00. Value 0x00 is - reserved for a pre-installed, shared key. - - is an unsigned integer field, whose length is - - 3, and which contains the cryptographic signature. - - The basic version of this TLV assumes that calculating the signature - can be decomposed into: - - signature-value = cryptographic-function(hash-function(content)) - - The hash function and the cryptographic function correspond to the - entries in two IANA registries, set up by this specification in - Section 12. - -7.1. Rationale + The following data structure allows a generic representation of a + cryptographic signature. This data structure is + specified, using the regular expression syntax of [RFC5444], as: - The rationale for separating the hash function and the cryptographic - function into two octets instead of having all combinations in a - single octet - possibly as TLV type extension - is twofold: First, if - further hash functions or cryptographic functions are added in the - future, the number space might not remain continuous. More - importantly, the number space of possible combinations would be - rapidly exhausted. As new or improved cryptographic mechanism are - continuously being developed and introduced, this format should be - able to accommodate such for the foreseeable future. + := - The rationale for not including a field that lists parameters of the - cryptographic signature in the TLV is, that before being able to - validate a cryptographic signature, routers have to exchange or - acquire keys (e.g. public keys). Any additional parameters can be - provided together with the keys in that bootstrap process. It is - therefore not necessary, and would even entail an extra overhead, to - transmit the parameters within every message. One inherently - included parameter is the length of the signature, which is - - 3 and which depends on the choice of the cryptographic function. + This generic specification allows for adding a signature in a TLV, + using TLV type extension 0, and does not stipulate how to calculate + the signature-value. Appendix A specifies a concrete calculation of + the signature-value, using a cryptographic function over a hash + function of the content to be signed. Other methods of how to + calculate the signature-value may be specified in future documents. 8. General Timestamp TLV Structure The following data structure allows the representation of a timestamp. This data structure is specified as: := where: @@ -286,26 +263,21 @@ 9. Packet TLVs Two Packet TLVs are defined, for including the cryptographic signature of a packet, and for including the timestamp indicating the time at which the cryptographic signature was calculated. 9.1. Packet SIGNATURE TLV A Packet SIGNATURE TLV is an example of a Signature TLV as described - in Section 7. When calculating the for a Packet, - the signature is calculated over the three fields , - and (in that order), - concatenated with the entire Packet, including the packet header, all - Packet TLVs (other than Packet SIGNATURE TLVs) and all included - Messages and their message headers. + in Section 7. The following considerations apply: o As packets defined in [RFC5444] are never forwarded by routers, it is unnecessary to consider mutable fields (e.g. and ), if present, when calculating the signature. o any Packet SIGNATURE TLVs already present in the Packet TLV block MUST be removed before calculating the signature, and the Packet TLV block size MUST be recalculated accordingly. The TLVs can be @@ -326,24 +298,21 @@ 10. Message TLVs Two Message TLVs are defined, for including the cryptographic signature of a message, and for including the timestamp indicating the time at which the cryptographic signature was calculated. 10.1. Message SIGNATURE TLV A Message SIGNATURE TLV is an example of a Signature TLV as described in Section 7. When determining the for a message, - the signature is calculated over the three fields , - , and (in that order), - concatenated with the entire message with the following - considerations: + the following considerations must be applied: o the fields and , if present, MUST both be assumed to have the value 0 (zero) when calculating the signature. o any Message SIGNATURE TLVs already present in the Message TLV block MUST be removed before calculating the signature, and the message size as well as the Message TLV block size MUST be recalculated accordingly. The TLVs can be restored after having calculated the signature value. @@ -362,28 +331,26 @@ 11. Address Block TLVs Two Address Block TLVs are defined, for associating a cryptographic signature to an address, and for including the timestamp indicating the time at which the cryptographic signature was calculated. 11.1. Address Block SIGNATURE TLV An Address Block SIGNATURE TLV is an example of a Signature TLV as - described in Section 7. The signature is calculated over the three - fields , , and (in - that order), concatenated with the address, concatenated with any - other values, for example, any other TLV value that is associated - with that address. A routing protocol or routing protocol extension - using Address Block SIGNATURE TLVs MUST specify how to include any - such concatenated attribute of the address in the verification - process of the signature. + described in Section 7. The signature is calculated over the + address, concatenated with any other values, for example, any other + TLV value that is associated with that address. A routing protocol + or routing protocol extension using Address Block SIGNATURE TLVs MUST + specify how to include any such concatenated attribute of the address + in the verification process of the signature. 11.2. Address Block TIMESTAMP TLV An Address Block TIMESTAMP TLV is an example of a Timestamp TLV as described in Section 8. If both a TIMESTAMP TLV and a SIGNATURE TLV are associated with an address, the timestamp value should be considered when calculating the value of the signature. 12. IANA Considerations @@ -423,69 +390,81 @@ 12.1.2. Packet TLV Type Registrations The Packet TLVs as specified in Table 1 must be allocated from the "Packet TLV Types" namespace of [RFC5444]. +-----------+------+-----------+------------------------------------+ | Name | Type | Type | Description | | | | Extension | | +-----------+------+-----------+------------------------------------+ - | SIGNATURE | TBD3 | 0 | Signature of a packet | - | | | 1-223 | Expert Review | + | SIGNATURE | TBD1 | 0 | Signature of a packet | + | | | 1 | Signature, decomposed into | + | | | | cryptographic function over a hash | + | | | | value, as specified in Appendix A | + | | | | in this document. | + | | | 2-223 | Expert Review | | | | 224-255 | Experimental Use | - | TIMESTAMP | TBD4 | 0 | Unsigned timestamp of arbitrary | + | TIMESTAMP | TBD2 | 0 | Unsigned timestamp of arbitrary | | | | | length, given by the TLV length | | | | | field. The MANET routing protocol | | | | | has to define how to interpret | | | | | this timestamp | | | | 1-223 | Expert Review | | | | 224-255 | Experimental Use | +-----------+------+-----------+------------------------------------+ Table 1: Packet TLV types 12.1.3. Message TLV Type Registrations The Message TLVs as specified in Table 2 must be allocated from the "Message TLV Types" namespace of [RFC5444]. +-----------+------+-----------+------------------------------------+ | Name | Type | Type | Description | | | | Extension | | +-----------+------+-----------+------------------------------------+ - | SIGNATURE | TBD1 | 0 | Signature of a message | - | | | 1-223 | Expert Review | + | SIGNATURE | TBD3 | 0 | Signature of a message | + | | | 1 | Signature, decomposed into | + | | | | cryptographic function over a hash | + | | | | value, as specified in Appendix A | + | | | | in this document. | + | | | 2-223 | Expert Review | | | | 224-255 | Experimental Use | - | TIMESTAMP | TBD2 | 0 | Unsigned timestamp of arbitrary | + | TIMESTAMP | TBD4 | 0 | Unsigned timestamp of arbitrary | | | | | length, given by the TLV length | | | | | field. | | | | 1-223 | Expert Review | | | | 224-255 | Experimental Use | +-----------+------+-----------+------------------------------------+ Table 2: Message TLV types 12.1.4. Address Block TLV Type Registrations The Address Block TLVs as specified in Table 3 must be allocated from the "Address Block TLV Types" namespace of [RFC5444]. +-----------+------+-----------+------------------------------------+ | Name | Type | Type | Description | | | | Extension | | +-----------+------+-----------+------------------------------------+ - | SIGNATURE | TBD1 | 0 | Signature of an object (e.g. an | + | SIGNATURE | TBD5 | 0 | Signature of an object (e.g. an | | | | | address) | - | | | 1-223 | Expert Review | + | | | 1 | Signature, decomposed into | + | | | | cryptographic function over a hash | + | | | | value, as specified in Appendix A | + | | | | in this document. | + | | | 2-223 | Expert Review | | | | 224-255 | Experimental Use | - | TIMESTAMP | TBD2 | 0 | Unsigned timestamp of arbitrary | + | TIMESTAMP | TBD6 | 0 | Unsigned timestamp of arbitrary | | | | | length, given by the TLV length | | | | | field. | | | | 1-223 | Expert Review | | | | 224-255 | Experimental Use | +-----------+------+-----------+------------------------------------+ Table 3: Address Block TLV types 12.2. New IANA Registries @@ -504,41 +483,42 @@ 12.2.1. Expert Review: Evaluation Guidelines For the registries for the following tables where an Expert Review is required, the designated expert SHOULD take the same general recommendations into consideration as are specified by [RFC5444]. 12.2.2. Hash Function IANA is requested to create a new registry for the hash functions - that can be used when creating a signature. The initial assignments - and allocation policies are specified in Table 4. + that can be used when creating a signature, as specified in the + Appendix A of this document. The initial assignments and allocation + policies are specified in Table 4. +-------------+-----------+-----------------------------------------+ | Hash | Algorithm | Description | | function | | | | value | | | +-------------+-----------+-----------------------------------------+ | 0 | none | The "identity function": the hash value | | | | of an object is the object itself | | 1-223 | | Expert Review | | 224-255 | | Experimental Use | +-------------+-----------+-----------------------------------------+ Table 4: Hash-Function registry 12.2.3. Cryptographic Algorithm IANA is requested to create a new registry for the cryptographic - function. Initial assignments and allocation policies are specified - in Table 5. + function, as specified in the Appendix A of this document. Initial + assignments and allocation policies are specified in Table 5. +----------------+-----------+--------------------------------------+ | Cryptographic | Algorithm | Description | | function value | | | +----------------+-----------+--------------------------------------+ | 0 | none | The "identity function": the value | | | | of an encrypted hash is the hash | | | | itself | | 1-223 | | Expert Review | | 224-255 | | Experimental Use | @@ -585,52 +564,156 @@ [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, BCP 14, March 1997. [RFC5444] Clausen, T., Dearlove, C., Dean, J., and C. Adjih, "Generalized MANET Packet/Message Format", RFC 5444, February 2009. 15.2. Informative References - [NHDP] Clausen, T., Dean, J., and C. Dearlove, "MANET - Neighborhood Discovery Protocol (NHDP)", RFC 6130, - March 2011. - [OLSRv2] Clausen, T., Dearlove, C., and P. Jacquet, "The Optimized Link State Routing Protocol version 2", work in progress draft-ietf-manet-olsrv2-11.txt, April 2010. -Appendix A. Examples + [RFC6130] Clausen, T., Dean, J., and C. Dearlove, "MANET + Neighborhood Discovery Protocol (NHDP)", RFC 6130, + March 2011. -A.1. Example of a Signed Message +Appendix A. Signature Decomposition into Cryptographic Function of a + Hash Value + + This section specifies how to calculate the signature-value in a + Signature TLV, as described in Section 7. A common way of + calculating a signature is applying a cryptographic function on a + hash value of the content. This decomposition is specified in the + following, using a type extension of 1 in the Signature TLVs. + +A.1. General Signature TLV Structure + + The following data structure allows representation of a cryptographic + signature, including specification of the appropriate hash function + and cryptographic function used for calculating the signature: + + := + + + + + where: + + 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 key + index of the key which was used to sign the message, which allows + unique identification of different keys with the same originator. + It is the responsibility of each key originator to make sure that + actively used keys that it issues have distinct key indices and + that all key indices have a value unequal to 0x00. Value 0x00 is + reserved for a pre-installed, shared key. + + is an unsigned integer field, whose length is + - 3, and which contains the cryptographic signature. + + The version of this TLV, specified in this section, assumes that + calculating the signature can be decomposed into: + + signature-value = cryptographic-function(hash-function(content)) + + The hash function and the cryptographic function correspond to the + entries in two IANA registries, set up by this specification in + Section 12. + +A.1.1. Rationale + + The rationale for separating the hash function and the cryptographic + function into two octets instead of having all combinations in a + single octet - possibly as TLV type extension - is twofold: First, if + further hash functions or cryptographic functions are added in the + future, the number space might not remain continuous. More + importantly, the number space of possible combinations would be + rapidly exhausted. As new or improved cryptographic mechanism are + continuously being developed and introduced, this format should be + able to accommodate such for the foreseeable future. + + The rationale for not including a field that lists parameters of the + cryptographic signature in the TLV is, that before being able to + validate a cryptographic signature, routers have to exchange or + acquire keys (e.g. public keys). Any additional parameters can be + provided together with the keys in that bootstrap process. It is + therefore not necessary, and would even entail an extra overhead, to + transmit the parameters within every message. One inherently + included parameter is the length of the signature, which is + - 3 and which depends on the choice of the cryptographic function. + +A.2. Considerations for Calculating the Signature + + In the following, considerations are listed, which have to be applied + when calculating the signature for Packet, Message and Address + SIGNATURE TLVs, respectively. + +A.2.1. Packet SIGNATURE TLV + + When determining the for a Packet, the signature is + calculated over the three fields , and (in that order), concatenated with the + entire Packet, including the packet header, all Packet TLVs (other + than Packet SIGNATURE TLVs) and all included Messages and their + message headers. + +A.2.2. Message SIGNATURE TLV + + When determining the for a message, the signature + is calculated over the three fields , , and (in that order), concatenated with the + entire message. + +A.2.3. Address Block SIGNATURE TLV + + When determining the for an address, the signature + is calculated over the three fields , , and (in that order), concatenated with the + address, concatenated with any other values, for example, any other + TLV value that is associated with that address. A routing protocol + or routing protocol extension using Address Block SIGNATURE TLVs MUST + specify how to include any such concatenated attribute of the address + in the verification process of the signature. + +A.3. Example of a Signed Message The sample message depicted in Figure 1 is derived from the appendix of [RFC5444]. A SIGNATURE Message TLV has been added, with the value - representing a 15 octet long signature of the whole message. + representing a 14 octet long signature of the whole message. The + type extension of the Message TLV is 1, for the specific + decomposition of a signature into a cryptographic function over a + hash value, as specified in Appendix A. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 0 1 0 0 0| Packet Sequence Number | Message Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1 1 1 1 0 0 1 1|0 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0| Orig Addr | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Originator Address (cont) | Hop Limit | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Hop Count | Message Sequence Number |0 0 0 0 0 0 0 0| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - |0 0 0 1 1 1 1 0| SIGNATURE |0 0 0 1 0 0 0 0|0 0 0 1 0 0 1 0| + |0 0 0 1 1 1 1 0| SIGNATURE |1 0 0 1 0 0 0 0|0 0 0 0 0 0 0 1| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Hash Func | Crypto Func | Key Index | Sign. Value | + |0 0 0 1 0 0 1 0| Hash Func | Crypto Func | Key Index | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Signature Value (cont) | + | Signature Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signature Value (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signature Value (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signature Value (cont) | TLV Type |0 0 0 1 0 0 0 0| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 0 0 1 1 0| Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value (cont) |0 0 0 0 0 0 1 0|