draft-ietf-lisp-sec-17.txt   draft-ietf-lisp-sec-18.txt 
Network Working Group F. Maino Network Working Group F. Maino
Internet-Draft V. Ermagan Internet-Draft Cisco Systems
Intended status: Standards Track Cisco Systems Intended status: Standards Track V. Ermagan
Expires: June 2, 2019 A. Cabellos Expires: December 4, 2019 Google
A. Cabellos
Universitat Politecnica de Catalunya Universitat Politecnica de Catalunya
D. Saucez D. Saucez
INRIA INRIA
November 29, 2018 June 2, 2019
LISP-Security (LISP-SEC) LISP-Security (LISP-SEC)
draft-ietf-lisp-sec-17 draft-ietf-lisp-sec-18
Abstract Abstract
This memo specifies LISP-SEC, a set of security mechanisms that This memo specifies LISP-SEC, a set of security mechanisms that
provides origin authentication, integrity and anti-replay protection provides origin authentication, integrity and anti-replay protection
to LISP's EID-to-RLOC mapping data conveyed via mapping lookup to LISP's EID-to-RLOC mapping data conveyed via mapping lookup
process. LISP-SEC also enables verification of authorization on EID- process. LISP-SEC also enables verification of authorization on EID-
prefix claims in Map-Reply messages. prefix claims in Map-Reply messages.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in BCP14 [RFC2119]
[RFC8174] when, and only when, they appear in all capitals, as shown
here.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 2, 2019. This Internet-Draft will expire on December 4, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 3 2. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 4
3. LISP-SEC Threat Model . . . . . . . . . . . . . . . . . . . . 4 3. LISP-SEC Threat Model . . . . . . . . . . . . . . . . . . . . 4
4. Protocol Operations . . . . . . . . . . . . . . . . . . . . . 5 4. Protocol Operations . . . . . . . . . . . . . . . . . . . . . 5
5. LISP-SEC Control Messages Details . . . . . . . . . . . . . . 7 5. LISP-SEC Control Messages Details . . . . . . . . . . . . . . 7
5.1. Encapsulated Control Message LISP-SEC Extensions . . . . 7 5.1. Encapsulated Control Message LISP-SEC Extensions . . . . 7
5.2. Map-Reply LISP-SEC Extensions . . . . . . . . . . . . . . 9 5.2. Map-Reply LISP-SEC Extensions . . . . . . . . . . . . . . 10
5.3. Map-Register LISP-SEC Extentions . . . . . . . . . . . . 11 5.3. Map-Register LISP-SEC Extentions . . . . . . . . . . . . 11
5.4. ITR Processing . . . . . . . . . . . . . . . . . . . . . 11 5.4. ITR Processing: Generating a Map-Request . . . . . . . . 12
5.4.1. Map-Reply Record Validation . . . . . . . . . . . . . 13 5.4.1. PITR Processing . . . . . . . . . . . . . . . . . . . 12
5.4.2. PITR Processing . . . . . . . . . . . . . . . . . . . 14 5.5. Encrypting and Decrypting an OTK . . . . . . . . . . . . 12
5.5. Encrypting and Decrypting an OTK . . . . . . . . . . . . 14 5.5.1. Unencrypted OTK . . . . . . . . . . . . . . . . . . . 14
5.6. Map-Resolver Processing . . . . . . . . . . . . . . . . . 15 5.6. Map-Resolver Processing . . . . . . . . . . . . . . . . . 14
5.7. Map-Server Processing . . . . . . . . . . . . . . . . . . 15 5.7. Map-Server Processing . . . . . . . . . . . . . . . . . . 15
5.7.1. Map-Server Processing in Proxy mode . . . . . . . . . 16 5.7.1. Generating a LISP-SEC Protected Encapsulated Map-
5.8. ETR Processing . . . . . . . . . . . . . . . . . . . . . 16 Request . . . . . . . . . . . . . . . . . . . . . . . 17
6. Security Considerations . . . . . . . . . . . . . . . . . . . 17 5.7.2. Generating a Proxy Map-Reply . . . . . . . . . . . . 18
6.1. Mapping System Security . . . . . . . . . . . . . . . . . 17 5.8. ETR Processing . . . . . . . . . . . . . . . . . . . . . 18
6.2. Random Number Generation . . . . . . . . . . . . . . . . 17 5.9. ITR Processing: Receiving a Map-Reply . . . . . . . . . . 18
6.3. Map-Server and ETR Colocation . . . . . . . . . . . . . . 17 5.9.1. Map-Reply Record Validation . . . . . . . . . . . . . 20
6.4. Deploying LISP-SEC . . . . . . . . . . . . . . . . . . . 18 6. Security Considerations . . . . . . . . . . . . . . . . . . . 21
6.5. Shared Keys Provisioning . . . . . . . . . . . . . . . . 18 6.1. Mapping System Security . . . . . . . . . . . . . . . . . 21
6.6. Replay Attacks . . . . . . . . . . . . . . . . . . . . . 18 6.2. Random Number Generation . . . . . . . . . . . . . . . . 21
6.7. Message Privacy . . . . . . . . . . . . . . . . . . . . . 19 6.3. Map-Server and ETR Colocation . . . . . . . . . . . . . . 21
6.4. Deploying LISP-SEC . . . . . . . . . . . . . . . . . . . 21
6.5. Shared Keys Provisioning . . . . . . . . . . . . . . . . 22
6.6. Replay Attacks . . . . . . . . . . . . . . . . . . . . . 22
6.7. Message Privacy . . . . . . . . . . . . . . . . . . . . . 22
6.8. Denial of Service and Distributed Denial of Service 6.8. Denial of Service and Distributed Denial of Service
Attacks . . . . . . . . . . . . . . . . . . . . . . . . . 19 Attacks . . . . . . . . . . . . . . . . . . . . . . . . . 23
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
7.1. ECM AD Type Registry . . . . . . . . . . . . . . . . . . 19 7.1. ECM AD Type Registry . . . . . . . . . . . . . . . . . . 23
7.2. Map-Reply AD Type Registry . . . . . . . . . . . . . . . 19 7.2. Map-Reply AD Type Registry . . . . . . . . . . . . . . . 23
7.3. HMAC Functions . . . . . . . . . . . . . . . . . . . . . 20 7.3. HMAC Functions . . . . . . . . . . . . . . . . . . . . . 24
7.4. Key Wrap Functions . . . . . . . . . . . . . . . . . . . 20 7.4. Key Wrap Functions . . . . . . . . . . . . . . . . . . . 24
7.5. Key Derivation Functions . . . . . . . . . . . . . . . . 21 7.5. Key Derivation Functions . . . . . . . . . . . . . . . . 25
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25
9. Normative References . . . . . . . . . . . . . . . . . . . . 21 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23 9.1. Normative References . . . . . . . . . . . . . . . . . . 25
9.2. Informative References . . . . . . . . . . . . . . . . . 27
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27
1. Introduction 1. Introduction
The Locator/ID Separation Protocol The Locator/ID Separation Protocol
[I-D.ietf-lisp-rfc6830bis],[I-D.ietf-lisp-rfc6833bis] is a network- [I-D.ietf-lisp-rfc6830bis],[I-D.ietf-lisp-rfc6833bis] is a network-
layer-based protocol that enables separation of IP addresses into two layer-based protocol that enables separation of IP addresses into two
new numbering spaces: Endpoint Identifiers (EIDs) and Routing new numbering spaces: Endpoint Identifiers (EIDs) and Routing
Locators (RLOCs). EID-to-RLOC mappings are stored in a database, the Locators (RLOCs). EID-to-RLOC mappings are stored in a database, the
LISP Mapping System, and made available via the Map-Request/Map-Reply LISP Mapping System, and made available via the Map-Request/Map-Reply
lookup process. If these EID-to-RLOC mappings, carried through Map- lookup process. If these EID-to-RLOC mappings, carried through Map-
skipping to change at page 3, line 36 skipping to change at page 3, line 42
[RFC7835], that includes a detailed description of "overclaiming" [RFC7835], that includes a detailed description of "overclaiming"
attack. attack.
This memo specifies LISP-SEC, a set of security mechanisms that This memo specifies LISP-SEC, a set of security mechanisms that
provides origin authentication, integrity and anti-replay protection provides origin authentication, integrity and anti-replay protection
to LISP's EID-to-RLOC mapping data conveyed via mapping lookup to LISP's EID-to-RLOC mapping data conveyed via mapping lookup
process. LISP-SEC also enables verification of authorization on EID- process. LISP-SEC also enables verification of authorization on EID-
prefix claims in Map-Reply messages, ensuring that the sender of a prefix claims in Map-Reply messages, ensuring that the sender of a
Map-Reply that provides the location for a given EID-prefix is Map-Reply that provides the location for a given EID-prefix is
entitled to do so according to the EID prefix registered in the entitled to do so according to the EID prefix registered in the
associated Map-Server. Map-Register security, including the right associated Map-Server. Map-Register/Map-Notify security, including
for a LISP entity to register an EID-prefix or to claim presence at the right for a LISP entity to register an EID-prefix or to claim
an RLOC, is out of the scope of LISP-SEC. Additional security presence at an RLOC, is out of the scope of LISP-SEC as those
considerations are described in Section 6. protocols are protected by the security mechanisms specified in
[I-D.ietf-lisp-rfc6833bis]. However, LISP-SEC extends the Map-
Register message to allow an ITR to securely downgrade to non LISP-
SEC Map-Requests. Additional security considerations are described
in Section 6.
2. Definition of Terms 2. Definition of Terms
One-Time Key (OTK): An ephemeral randomly generated key that must One-Time Key (OTK): An ephemeral randomly generated key that must
be used for a single Map-Request/Map-Reply exchange. be used for a single Map-Request/Map-Reply exchange.
ITR One-Time Key (ITR-OTK): The One-Time Key generated at the ITR. ITR One-Time Key (ITR-OTK): The One-Time Key generated at the
Ingress Tunnel Router (ITR).
MS One-Time Key (MS-OTK): The One-Time Key generated at the Map- MS One-Time Key (MS-OTK): The One-Time Key generated at the Map-
Server. Server.
Authentication Data (AD): Metadata that is included either in a Authentication Data (AD): Metadata that is included either in a
LISP Encapsulated Control Message (ECM) header, as defined in LISP Encapsulated Control Message (ECM) header, as defined in
Section 6.1.8 of [I-D.ietf-lisp-rfc6833bis], or in a Map-Reply [I-D.ietf-lisp-rfc6833bis], or in a Map-Reply message to support
message to support confidentiality, integrity protection, and confidentiality, integrity protection, and verification of EID-
verification of EID-prefix authorization. prefix authorization.
OTK Authentication Data (OTK-AD): The portion of ECM OTK Authentication Data (OTK-AD): The portion of ECM
Authentication Data that contains a One-Time Key. Authentication Data that contains a One-Time Key.
EID Authentication Data (EID-AD): The portion of ECM and Map-Reply EID Authentication Data (EID-AD): The portion of ECM and Map-Reply
Authentication Data used for verification of EID-prefix Authentication Data used for verification of EID-prefix
authorization. authorization.
Packet Authentication Data (PKT-AD): The portion of Map-Reply Packet Authentication Data (PKT-AD): The portion of Map-Reply
Authentication Data used to protect the integrity of the Map-Reply Authentication Data used to protect the integrity of the Map-Reply
skipping to change at page 4, line 44 skipping to change at page 5, line 8
message to their intended destination ETR as identified by the EID, message to their intended destination ETR as identified by the EID,
and (2) no man-in-the-middle (MITM) attack can be mounted within the and (2) no man-in-the-middle (MITM) attack can be mounted within the
LISP Mapping System. How the Mapping System is protected from MITM LISP Mapping System. How the Mapping System is protected from MITM
attacks depends from the particular Mapping Systems used, and is out attacks depends from the particular Mapping Systems used, and is out
of the scope of this memo. Furthermore, while LISP-SEC enables of the scope of this memo. Furthermore, while LISP-SEC enables
detection of EID prefix overclaiming attacks, it assumes that Map- detection of EID prefix overclaiming attacks, it assumes that Map-
Servers can verify the EID prefix authorization at time of Servers can verify the EID prefix authorization at time of
registration. registration.
According to the threat model described in [RFC7835] LISP-SEC assumes According to the threat model described in [RFC7835] LISP-SEC assumes
that any kind of attack, including MITM attacks, can be mounted in that any kind of attack, including MITM attacks, can be mounted
the access network, outside of the boundaries of the LISP mapping outside of the boundaries of the LISP mapping system. An on-path
system. An on-path attacker, outside of the LISP mapping system can, attacker, outside of the LISP mapping system can, for example, hijack
for example, hijack Map-Request and Map-Reply messages, spoofing the Map-Request and Map-Reply messages, spoofing the identity of a LISP
identity of a LISP node. Another example of on-path attack, called node. Another example of on-path attack, called overclaiming attack,
overclaiming attack, can be mounted by a malicious Egress Tunnel can be mounted by a malicious Egress Tunnel Router (ETR), by
Router (ETR), by overclaiming the EID-prefixes for which it is overclaiming the EID-prefixes for which it is authoritative. In this
authoritative. In this way the ETR can maliciously redirect traffic way the ETR can maliciously redirect traffic directed to a large
directed to a large number of hosts. number of hosts.
4. Protocol Operations 4. Protocol Operations
The goal of the security mechanisms defined in The goal of the security mechanisms defined in
[I-D.ietf-lisp-rfc6833bis] is to prevent unauthorized insertion of [I-D.ietf-lisp-rfc6833bis] is to prevent unauthorized insertion of
mapping data by providing origin authentication and integrity mapping data by providing origin authentication and integrity
protection for the Map-Registration, and by using the nonce to detect protection for the Map-Register, and by using the nonce to detect
unsolicited Map-Reply sent by off-path attackers. unsolicited Map-Reply sent by off-path attackers.
LISP-SEC builds on top of the security mechanisms defined in LISP-SEC builds on top of the security mechanisms defined in
[I-D.ietf-lisp-rfc6833bis] to address the threats described in [I-D.ietf-lisp-rfc6833bis] to address the threats described in
Section 3 by leveraging the trust relationships existing among the Section 3 by leveraging the trust relationships existing among the
LISP entities participating to the exchange of the Map-Request/Map- LISP entities participating to the exchange of the Map-Request/Map-
Reply messages. Those trust relationships are used to securely Reply messages. Those trust relationships are used to securely
distribute a One-Time Key (OTK) that provides origin authentication, distribute, as described in Section 7.4, a per-message One-Time Key
integrity and anti-replay protection to mapping data conveyed via the (OTK) that provides origin authentication, integrity and anti-replay
mapping lookup process, and that effectively prevent overclaiming protection to mapping data conveyed via the mapping lookup process,
attacks. The processing of security parameters during the Map- and that effectively prevent overclaiming attacks. The processing of
Request/Map-Reply exchange is as follows: security parameters during the Map-Request/Map-Reply exchange is as
follows:
o The ITR-OTK is generated and stored at the ITR, and securely o Per each Map-Request message a new ITR-OTK is generated and stored
transported to the Map-Server. at the ITR, and securely transported to the Map-Server.
o The Map-Server uses the ITR-OTK to compute a Keyed-Hashing for o The Map-Server uses the ITR-OTK to compute a Keyed-Hashing for
Message Authentication (HMAC) [RFC2104] that protects the Message Authentication (HMAC) [RFC2104] that protects the
integrity of the mapping data known to the Map-Server to prevent integrity of the mapping data known to the Map-Server to prevent
overclaiming attacks. The Map-Server also derives a new OTK, the overclaiming attacks. The Map-Server also derives a new OTK, the
MS-OTK, that is passed to the ETR, by applying a Key Derivation MS-OTK, that is passed to the ETR, by applying a Key Derivation
Function (KDF) to the ITR-OTK. Function (KDF) (e.g. [RFC5869]) to the ITR-OTK.
o The ETR uses the MS-OTK to compute an HMAC that protects the o The ETR uses the MS-OTK to compute an HMAC that protects the
integrity of the Map-Reply sent to the ITR. integrity of the Map-Reply sent to the ITR.
o Finally, the ITR uses the stored ITR-OTK to verify the integrity o Finally, the ITR uses the stored ITR-OTK to verify the integrity
of the mapping data provided by both the Map-Server and the ETR, of the mapping data provided by both the Map-Server and the ETR,
and to verify that no overclaiming attacks were mounted along the and to verify that no overclaiming attacks were mounted along the
path between the Map-Server and the ITR. path between the Map-Server and the ITR.
Section 5 provides the detailed description of the LISP-SEC control Section 5 provides the detailed description of the LISP-SEC control
messages and their processing, while the rest of this section messages and their processing, while the rest of this section
describes the flow of protocol operations at each entity involved in describes the flow of LISP protocol operations at each entity
the Map-Request/Map-Reply exchange: involved in the Map-Request/Map-Reply exchange:
o The ITR, upon needing to transmit a Map-Request message, generates 1. The ITR, upon needing to transmit a Map-Request message,
and stores an OTK (ITR-OTK). This ITR-OTK is included into the generates and stores an OTK (ITR-OTK). This ITR-OTK is included
Encapsulated Control Message (ECM) that contains the Map-Request into the Encapsulated Control Message (ECM) that contains the
sent to the Map-Resolver. To provide confidentiality to the ITR- Map-Request sent to the Map-Resolver. ITR-OTK confidentiality
OTK over the path between the ITR and its Map-Resolver, the ITR- and integrity protection MUST be provided in the path between the
OTK SHOULD be encrypted using a preconfigured key shared between ITR and the Map-Resolver. This can be achieved either by
the ITR and the Map-Resolver, similar to the key shared between encrypting the ITR-OTK with the pre-shared secret known to the
the ETR and the Map-Server in order to secure ETR registration ITR and the Map-Resolver (as specified in Section 5.5), or by
[I-D.ietf-lisp-rfc6833bis]. enabling DTLS between the ITR and the Map-Resolver.
o The Map-Resolver decapsulates the ECM message, decrypts the ITR- 2. The Map-Resolver decapsulates the ECM message, decrypts the ITR-
OTK, if needed, and forwards through the Mapping System the OTK, if needed, and forwards through the Mapping System the
received Map-Request and the ITR-OTK, as part of a new ECM received Map-Request and the ITR-OTK, as part of a new ECM
message. As described in Section 5.6, the LISP Mapping System message. The LISP Mapping System delivers the ECM to the
delivers the ECM to the appropriate Map-Server, as identified by appropriate Map-Server, as identified by the EID destination
the EID destination address of the Map-Request. address of the Map-Request. As mentioned in Section 3, how the
Mapping System is protected from MITM attacks depends from the
particular Mapping Systems used, and is out of the scope of this
memo.
o The Map-Server is configured with the location mappings and policy 3. The Map-Server is configured with the location mappings and
information for the ETR responsible for the EID destination policy information for the ETR responsible for the EID
address. Using this preconfigured information, the Map-Server, destination address. Using this preconfigured information, the
after the decapsulation of the ECM message, finds the longest Map-Server, after the decapsulation of the ECM message, finds the
match EID-prefix that covers the requested EID in the received longest match EID-prefix that covers the requested EID in the
Map-Request. The Map-Server adds this EID-prefix, together with received Map-Request. The Map-Server adds this EID-prefix,
an HMAC computed using the ITR-OTK, to a new Encapsulated Control together with an HMAC computed using the ITR-OTK, to a new
Message that contains the received Map-Request. Encapsulated Control Message that contains the received Map-
Request.
o The Map-Server derives a new OTK, the MS-OTK, by applying a Key 4. The Map-Server derives a new OTK, the MS-OTK, by applying a Key
Derivation Function (KDF) to the ITR-OTK. This MS-OTK is included Derivation Function (KDF) to the ITR-OTK. This MS-OTK is
in the Encapsulated Control Message that the Map-Server uses to included in the Encapsulated Control Message that the Map-Server
forward the Map-Request to the ETR. To provide MS-OTK uses to forward the Map-Request to the ETR. MS-OTK
confidentiality over the path between the Map-Server and the ETR, confidentiality and integrity protection MUST be provided in the
the MS-OTK SHOULD be encrypted using the key shared between the path between the Map-Server and the ETR. This can be achieved
ETR and the Map-Server in order to secure ETR registration either by encrypting the MS-OTK with the pre-shared secret known
[I-D.ietf-lisp-rfc6833bis]. to the Map-Server and the ETR (as specified in Section 5.5), or
by enabling DTLS between the Map-Server and the ETR.
o If the Map-Server is acting in proxy mode, as specified in 5. If the Map-Server is acting in proxy mode, as specified in
[I-D.ietf-lisp-rfc6833bis], the ETR is not involved in the [I-D.ietf-lisp-rfc6833bis], the ETR is not involved in the
generation of the Map-Reply. In this case the Map-Server generation of the Map-Reply and steps 6 and 7 are skipped. In
generates the Map-Reply on behalf of the ETR as described below. this case the Map-Server generates the Map-Reply on behalf of the
ETR as described in Section 5.7.2.
o The ETR, upon receiving the ECM encapsulated Map-Request from the 6. The ETR, upon receiving the ECM encapsulated Map-Request from the
Map-Server, decrypts the MS-OTK, if needed, and originates a Map-Server, decrypts the MS-OTK, if needed, and originates a Map-
standard Map-Reply that contains the EID-to-RLOC mapping Reply that contains the EID-to-RLOC mapping information as
information as specified in [I-D.ietf-lisp-rfc6833bis]. specified in [I-D.ietf-lisp-rfc6833bis].
o The ETR computes an HMAC over this standard Map-Reply, keyed with 7. The ETR computes an HMAC over the Map-Reply, keyed with MS-OTK to
MS-OTK to protect the integrity of the whole Map-Reply. The ETR protect the integrity of the whole Map-Reply. The ETR also
also copies the EID-prefix authorization data that the Map-Server copies the EID-prefix authorization data that the Map-Server
included in the ECM encapsulated Map-Request into the Map-Reply included in the ECM encapsulated Map-Request into the Map-Reply
message. The ETR then sends this complete Map-Reply message to message. The ETR then sends the complete Map-Reply message to
the requesting ITR. the requesting ITR.
o The ITR, upon receiving the Map-Reply, uses the locally stored 8. The ITR, upon receiving the Map-Reply, uses the locally stored
ITR-OTK to verify the integrity of the EID-prefix authorization ITR-OTK to verify the integrity of the EID-prefix authorization
data included in the Map-Reply by the Map-Server. The ITR data included in the Map-Reply by the Map-Server. The ITR
computes the MS-OTK by applying the same KDF used by the Map- computes the MS-OTK by applying the same KDF (as specified in the
Server, and verifies the integrity of the Map-Reply. If the ECM encapsulated Map-Reply) used by the Map-Server, and verifies
integrity checks fail, the Map-Reply MUST be discarded. Also, if the integrity of the Map-Reply. If the integrity checks fail,
the EID-prefixes claimed by the ETR in the Map-Reply are not equal the Map-Reply MUST be discarded. Also, if the EID-prefixes
or more specific than the EID-prefix authorization data inserted claimed by the ETR in the Map-Reply are not equal or more
by the Map-Server, the ITR MUST discard the Map-Reply. specific than the EID-prefix authorization data inserted by the
Map-Server, the ITR MUST discard the Map-Reply.
5. LISP-SEC Control Messages Details 5. LISP-SEC Control Messages Details
LISP-SEC metadata associated with a Map-Request is transported within LISP-SEC metadata associated with a Map-Request is transported within
the Encapsulated Control Message that contains the Map-Request. the Encapsulated Control Message that contains the Map-Request.
LISP-SEC metadata associated with the Map-Reply is transported within LISP-SEC metadata associated with the Map-Reply is transported within
the Map-Reply itself. the Map-Reply itself.
5.1. Encapsulated Control Message LISP-SEC Extensions 5.1. Encapsulated Control Message LISP-SEC Extensions
LISP-SEC uses the ECM (Encapsulated Control Message) defined in LISP-SEC uses the ECM defined in [I-D.ietf-lisp-rfc6833bis] with S
[I-D.ietf-lisp-rfc6833bis] with Type set to 8, and S bit set to 1 to bit set to 1 to indicate that the LISP header includes Authentication
indicate that the LISP header includes Authentication Data (AD). The Data (AD). The format of the LISP-SEC ECM Authentication Data is
format of the LISP-SEC ECM Authentication Data is defined in the defined in Figure 1 . OTK-AD stands for One-Time Key Authentication
following figure. OTK-AD stands for One-Time Key Authentication Data Data and EID-AD stands for EID Authentication Data.
and EID-AD stands for EID Authentication Data.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ECM AD Type |V| Reserved | Requested HMAC ID | | ECM AD Type |V| Unassigned | Requested HMAC ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\
| OTK Length | OTK Encryption ID | | | OTK Length | Key ID | OTK Wrap. ID | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| One-Time-Key Preamble ... | | | One-Time-Key Preamble ... | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+OTK-AD +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+OTK-AD
| ... One-Time-Key Preamble | | | ... One-Time-Key Preamble | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
~ One-Time Key (128 bits) ~/ ~ One-Time Key (128 bits) ~/
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+
| EID-AD Length | KDF ID | | | EID-AD Length | KDF ID | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Record Count | Reserved | EID HMAC ID |EID-AD | Record Count |E| Unassigned | EID HMAC ID |EID-AD
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ |
| Reserved | EID mask-len | EID-AFI | | | | Unassigned | EID mask-len | EID-AFI | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Rec | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Rec |
~ EID-prefix ... ~ | | ~ EID-prefix ... ~ | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/ |
~ EID HMAC ~ | ~ EID HMAC ~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+
LISP-SEC ECM Authentication Data Figure 1: LISP-SEC ECM Authentication Data
ECM AD Type: 1 (LISP-SEC Authentication Data). See Section 7. ECM AD Type: 1 (LISP-SEC Authentication Data). See Section 7.
V: Key Version bit. This bit is toggled when the sender switches V: Key Version bit. This bit is toggled when the sender switches
to a new OTK wrapping key to a new OTK wrapping key
Reserved: Set to 0 on transmission and ignored on receipt. Unassigned: Set to 0 on transmission and ignored on receipt.
Requested HMAC ID: The HMAC algorithm requested by the ITR. See Requested HMAC ID: The HMAC algorithm, that will be used to
Section 5.4 for details. protect the mappings, requested by the ITR. See Section 5.4 for
details, and Section 7.3 for HMAC IDs that MUST be supported.
OTK Length: The length (in bytes) of the OTK Authentication Data OTK Length: The length (in bytes) of the OTK Authentication Data
(OTK-AD), that contains the OTK Preamble and the OTK. (OTK-AD), that contains the OTK Preamble and the OTK.
OTK Encryption ID: The identifier of the key wrapping algorithm Key ID: The identifier of the pre-shared secret shared by an ITR
used to encrypt the One-Time-Key. When a 128-bit OTK is sent and the Map-Resolver, and by the Map-Server and an ETR. Per-
unencrypted by the Map-Resolver, the OTK Encryption ID is set to message keys are derived from the pre-shared secret to encrypt,
NULL_KEY_WRAP_128. See Section 5.5 for more details. authenticate the origin and protect the integrity of the OTK. The
Key ID allows to rotate between multiple pre-shared secrets in a
non disruptive way.
OTK Wrapping ID: The identifier of the key derivation function and
of the key wrapping algorithm used to encrypt the One-Time-Key.
See Section 5.5 for more details, and Section 7.4 for Wrapping IDs
that MUST be supported.
One-Time-Key Preamble: set to 0 if the OTK is not encrypted. When One-Time-Key Preamble: set to 0 if the OTK is not encrypted. When
the OTK is encrypted, this field MAY carry additional metadata the OTK is encrypted, this field MAY carry additional metadata
resulting from the key wrapping operation. When a 128-bit OTK is resulting from the key wrapping operation. When a 128-bit OTK is
sent unencrypted by Map-Resolver, the OTK Preamble is set to sent unencrypted by Map-Resolver, the OTK Preamble is set to
0x0000000000000000 (64 bits). See Section 5.5 for details. 0x0000000000000000 (64 bits). See Section 5.5.1 for details.
One-Time-Key: the OTK encrypted (or not) as specified by OTK One-Time-Key: the OTK wrapped as specified by OTK Wrapping ID.
Encryption ID. See Section 5.5 for details. See Section 5.5 for details.
EID-AD Length: length (in bytes) of the EID Authentication Data EID-AD Length: length (in bytes) of the EID Authentication Data
(EID-AD). The ITR MUST set EID-AD Length to 4 bytes, as it only (EID-AD). The ITR MUST set EID-AD Length to 4 bytes, as it only
fills the KDF ID field, and all the remaining fields part of the fills the KDF ID field, and all the remaining fields part of the
EID-AD are not present. An EID-AD MAY contain multiple EID- EID-AD are not present. An EID-AD MAY contain multiple EID-
records. Each EID-record is 4-byte long plus the length of the records. Each EID-record is 4-byte long plus the length of the
AFI-encoded EID-prefix. AFI-encoded EID-prefix.
KDF ID: Identifier of the Key Derivation Function used to derive KDF ID: Identifier of the Key Derivation Function used to derive
the MS-OTK. The ITR MAY use this field to indicate the the MS-OTK. The ITR MAY use this field to indicate the
recommended KDF algorithm, according to local policy. The Map- recommended KDF algorithm, according to local policy. The Map-
Server can overwrite the KDF ID if it does not support the KDF ID Server can overwrite the KDF ID if it does not support the KDF ID
recommended by the ITR. See Section 5.4 for more details. recommended by the ITR. See Section 5.4 for more details, and
Section 7.5 for KDF IDs that MUST be supported.
Record Count: The number of records in this Map-Request message. Record Count: The number of records in this Map-Request message.
A record is comprised of the portion of the packet that is labeled A record is comprised of the portion of the packet that is labeled
'Rec' above and occurs the number of times equal to Record Count. 'Rec' above and occurs the number of times equal to Record Count.
Reserved: Set to 0 on transmission and ignored on receipt. E: ETR-Cant-Sign bit. This bit is set to 1 to signal to the ITR
that at least one of the ETRs authoritative for the EID prefixes
of this Map-Reply has not enabled LISP-SEC. This allows the ITR
to securely downgrade to non LISP-SEC requests, as specified in
Section 5.7, if so desired.
Unassigned: Set to 0 on transmission and ignored on receipt.
EID HMAC ID: Identifier of the HMAC algorithm used to protect the EID HMAC ID: Identifier of the HMAC algorithm used to protect the
integrity of the EID-AD. This field is filled by Map-Server that integrity of the EID-AD. This field is filled by Map-Server that
computed the EID-prefix HMAC. See Section 5.4 for more details. computed the EID-prefix HMAC. See Section 5.4 for more details,
and Section 7.3 for HMAC IDs that MUST be supported.
EID mask-len: Mask length for EID-prefix. EID mask-len: Mask length for EID-prefix.
EID-AFI: Address family of EID-prefix according to [RFC5226] EID-AFI: Address family of EID-prefix according to [RFC5226]
EID-prefix: The Map-Server uses this field to specify the EID- EID-prefix: The Map-Server uses this field to specify the EID-
prefix that the destination ETR is authoritative for, and is the prefix that the destination ETR is authoritative for, and is the
longest match for the requested EID. longest match for the requested EID.
EID HMAC: HMAC of the EID-AD computed and inserted by Map-Server. EID HMAC: HMAC of the EID-AD computed and inserted by Map-Server.
Before computing the HMAC operation the EID HMAC field MUST be set Before computing the HMAC operation the EID HMAC field MUST be set
to 0. The HMAC covers the entire EID-AD. to 0. The HMAC MUST cover the entire EID-AD.
5.2. Map-Reply LISP-SEC Extensions 5.2. Map-Reply LISP-SEC Extensions
LISP-SEC uses the Map-Reply defined in [I-D.ietf-lisp-rfc6833bis], LISP-SEC uses the Map-Reply defined in [I-D.ietf-lisp-rfc6833bis],
with Type set to 2, and S bit set to 1 to indicate that the Map-Reply with Type set to 2, and S-bit set to 1 to indicate that the Map-Reply
message includes Authentication Data (AD). The format of the LISP- message includes Authentication Data (AD). The format of the LISP-
SEC Map-Reply Authentication Data is defined in the following figure. SEC Map-Reply Authentication Data is defined in Figure 2. PKT-AD is
the Packet Authentication Data that covers the Map-Reply payload.
PKT-AD is the Packet Authentication Data that covers the Map-Reply
payload.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MR AD Type | Reserved | | MR AD Type | Unassigned |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+
| EID-AD Length | KDF ID | | | EID-AD Length | KDF ID | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Record Count | Reserved | EID HMAC ID |EID-AD | Record Count | Unassigned | EID HMAC ID |EID-AD
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ |
| Reserved | EID mask-len | EID-AFI | | | | Unassigned | EID mask-len | EID-AFI | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Rec | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Rec |
~ EID-prefix ... ~ | | ~ EID-prefix ... ~ | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/ |
~ EID HMAC ~ | ~ EID HMAC ~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+
| PKT-AD Length | PKT HMAC ID |\ | PKT-AD Length | PKT HMAC ID |\
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
~ PKT HMAC ~PKT-AD ~ PKT HMAC ~PKT-AD
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/
LISP-SEC Map-Reply Authentication Data Figure 2: LISP-SEC Map-Reply Authentication Data
MR AD Type: 1 (LISP-SEC Authentication Data). See Section 7. MR AD Type: 1 (LISP-SEC Authentication Data). See Section 7.
EID-AD Length: length (in bytes) of the EID-AD. An EID-AD MAY EID-AD Length: length (in bytes) of the EID-AD. An EID-AD MAY
contain multiple EID-records. Each EID-record is 4-byte long plus contain multiple EID-records. Each EID-record is 4-byte long plus
the length of the AFI-encoded EID-prefix. the length of the AFI-encoded EID-prefix.
KDF ID: Identifier of the Key Derivation Function used to derive KDF ID: Identifier of the Key Derivation Function used to derive
MS-OTK. See Section 5.7 for more details. MS-OTK. See Section 5.7 for more details, and Section 7.5 for KDF
IDs that MUST be supported.
Record Count: The number of records in this Map-Reply message. A Record Count: The number of records in this Map-Reply message. A
record is comprised of the portion of the packet that is labeled record is comprised of the portion of the packet that is labeled
'Rec' above and occurs the number of times equal to Record Count. 'Rec' above and occurs the number of times equal to Record Count.
Reserved: Set to 0 on transmission and ignored on receipt. Unassigned: Set to 0 on transmission and ignored on receipt.
EID HMAC ID: Identifier of the HMAC algorithm used to protect the EID HMAC ID: Identifier of the HMAC algorithm used to protect the
integrity of the EID-AD. See Section 5.7 for more details. integrity of the EID-AD. See Section 5.7 for more details, and
Section 7.3 for HMAC IDs that MUST be supported.
EID mask-len: Mask length for EID-prefix. EID mask-len: Mask length for EID-prefix.
EID-AFI: Address family of EID-prefix according to [RFC5226]. EID-AFI: Address family of EID-prefix according to [RFC8060].
EID-prefix: This field contains an EID-prefix that the destination EID-prefix: This field contains an EID-prefix that the destination
ETR is authoritative for, and is the longest match for the ETR is authoritative for, and is the longest match for the
requested EID. requested EID.
EID HMAC: HMAC of the EID-AD, as computed by the Map-Server. EID HMAC: HMAC of the EID-AD, as computed by the Map-Server.
Before computing the HMAC operation the EID HMAC field MUST be set Before computing the HMAC operation the EID HMAC field MUST be set
to 0. The HMAC covers the entire EID-AD. to 0. The HMAC covers the entire EID-AD.
PKT-AD Length: length (in bytes) of the Packet Authentication Data PKT-AD Length: length (in bytes) of the Packet Authentication Data
(PKT-AD). (PKT-AD).
PKT HMAC ID: Identifier of the HMAC algorithm used to protect the PKT HMAC ID: Identifier of the HMAC algorithm used to protect the
integrity of the Map-reply. integrity of the Map-Reply. See Section 7.3 for HMAC IDs that
MUST be supported.
PKT HMAC: HMAC of the whole Map-Reply packet, including the LISP- PKT HMAC: HMAC of the whole Map-Reply packet, including the LISP-
SEC Authentication Data. The scope of the authentication goes SEC Authentication Data. The scope of the authentication goes
from the Map-Reply Type field to the PKT HMAC field included. from the Map-Reply Type field to the PKT HMAC field included.
Before computing the HMAC operation the PKT HMAC field MUST be set Before computing the HMAC operation the PKT HMAC field MUST be set
to 0. See Section 5.8 for more details. to 0. See Section 5.8 for more details.
5.3. Map-Register LISP-SEC Extentions 5.3. Map-Register LISP-SEC Extentions
This memo is allocating one of the bits marked as Reserved in the This memo is allocating one of the bits marked as Unassigned in the
Map-Register message defined in Section 6.1.6 of Map-Register message defined in [I-D.ietf-lisp-rfc6833bis]. More
[I-D.ietf-lisp-rfc6833bis]. More precisely, the second bit after the precisely, the second bit after the Type field in a Map-Register
Type field in a Map-Register message is allocated as the S bit. The message is allocated as the S bit. The S bit indicates to the Map-
S bit indicates to the Map-Server that the registering ETR is LISP- Server that the registering ETR is LISP-SEC enabled. An ETR that
SEC enabled. An ETR that supports LISP-SEC MUST set the S bit in its supports LISP-SEC MUST set the S bit in its Map-Register messages.
Map-Register messages.
5.4. ITR Processing 5.4. ITR Processing: Generating a Map-Request
Upon creating a Map-Request, the ITR generates a random ITR-OTK that Upon creating a Map-Request, the ITR generates a random ITR-OTK that
is stored locally, together with the nonce generated as specified in is stored locally (until the corresponding Map-Reply is received),
together with the nonce generated as specified in
[I-D.ietf-lisp-rfc6833bis]. [I-D.ietf-lisp-rfc6833bis].
ITR-OTK confidentiality and integrity protection MUST be provided in
the path between the ITR and the Map-Resolver. This can be achieved
either by encrypting the ITR-OTK with the pre-shared secret known to
the ITR and the Map-Resolver (see Section 5.5), or by enabling DTLS
between the ITR and the Map-Resolver.
The Map-Request MUST be encapsulated in an ECM, with the S-bit set to The Map-Request MUST be encapsulated in an ECM, with the S-bit set to
1, to indicate the presence of Authentication Data. If the ITR and 1, to indicate the presence of Authentication Data.
the Map-Resolver are configured with a shared key, the ITR-OTK
confidentiality SHOULD be protected by wrapping the ITR-OTK with the ITR-OTK is wrapped with the algorithm specified by the OTK Wrapping
algorithm specified by the OTK Encryption ID field. See Section 5.5 ID field. See Section 5.5 for further details on OTK encryption. If
for further details on OTK encryption. the NULL-KEY-WRAP-128 algorithm is selected and DTLS is not enabled
in the path between the ITR and the Map-Resolver, the Map-Request
MUST be dropped and an appropiate log action SHOULD be taken.
The Requested HMAC ID field contains the suggested HMAC algorithm to The Requested HMAC ID field contains the suggested HMAC algorithm to
be used by the Map-Server and the ETR to protect the integrity of the be used by the Map-Server and the ETR to protect the integrity of the
ECM Authentication data and of the Map-Reply. ECM Authentication data and of the Map-Reply.
The KDF ID field specifies the suggested key derivation function to The KDF ID field specifies the suggested key derivation function to
be used by the Map-Server to derive the MS-OTK. A KDF Value of NONE be used by the Map-Server to derive the MS-OTK. A KDF Value of NONE
(0), MAY be used to specify that the ITR has no preferred KDF ID. (0), MAY be used to specify that the ITR has no preferred KDF ID.
The EID-AD length is set to 4 bytes, since the Authentication Data The EID-AD length is set to 4 bytes, since the Authentication Data
does not contain EID-prefix Authentication Data, and the EID-AD does not contain EID-prefix Authentication Data, and the EID-AD
contains only the KDF ID field. contains only the KDF ID field.
In response to an encapsulated Map-Request that has the S-bit set, an 5.4.1. PITR Processing
ITR MUST receive a Map-Reply with the S-bit set, that includes an
EID-AD and a PKT-AD. If the Map-Reply does not include both ADs, the
ITR MUST discard it. In response to an encapsulated Map-Request with
S-bit set to 0, the ITR expects a Map-Reply with S-bit set to 0, and
the ITR SHOULD discard the Map-Reply if the S-bit is set.
Upon receiving a Map-Reply, the ITR must verify the integrity of both
the EID-AD and the PKT-AD, and MUST discard the Map-Reply if one of
the integrity checks fails. After processing the Map-Reply, the ITR
must discard the <nonce,ITK-OTK> pair associated to the Map-Reply
The integrity of the EID-AD is verified using the locally stored ITR-
OTK to re-compute the HMAC of the EID-AD using the algorithm
specified in the EID HMAC ID field. If the EID HMAC ID field does
not match the Requested HMAC ID the ITR SHOULD discard the Map-Reply
and send, at the first opportunity it needs to, a new Map-Request
with a different Requested HMAC ID field, according to ITR's local
policy. The scope of the HMAC operation covers the entire EID-AD,
from the EID-AD Length field to the EID HMAC field, which must be set
to 0 before the computation of the HMAC.
ITR MUST set the EID HMAC ID field to 0 before computing the HMAC.
To verify the integrity of the PKT-AD, first the MS-OTK is derived
from the locally stored ITR-OTK using the algorithm specified in the
KDF ID field. This is because the PKT-AD is generated by the ETR
using the MS-OTK. If the KDF ID in the Map-Reply does not match the
KDF ID requested in the Map-Request, the ITR SHOULD discard the Map-
Reply and send, at the first opportunity it needs to, a new Map-
Request with a different KDF ID, according to ITR's local policy.
The derived MS-OTK is then used to re-compute the HMAC of the PKT-AD
using the Algorithm specified in the PKT HMAC ID field. If the PKT
HMAC ID field does not match the Requested HMAC ID the ITR SHOULD
discard the Map-Reply and send, at the first opportunity it needs to,
a new Map-Request with a different Requested HMAC ID according to
ITR's local policy or until all HMAC IDs supported by the ITR have
been attempted.
Each individual Map-Reply EID-record is considered valid only if: (1) The processing performed by a PITR is equivalent to the processing of
both EID-AD and PKT-AD are valid, and (2) the intersection of the an ITR. However, if the PITR is directly connected to a Mapping
EID-prefix in the Map-Reply EID-record with one of the EID-prefixes System such as LISP+ALT [RFC6836], the PITR performs the functions of
contained in the EID-AD is not empty. After identifying the Map- both the ITR and the Map-Resolver forwarding the Map-Request
Reply record as valid, the ITR sets the EID-prefix in the Map-Reply encapsulated in an ECM header that includes the Authentication Data
record to the value of the intersection set computed before, and adds fields as described in Section 5.6.
the Map-Reply EID-record to its EID-to-RLOC cache, as described in
[I-D.ietf-lisp-rfc6833bis]. An example of Map-Reply record
validation is provided in Section 5.4.1.
The ITR SHOULD send SMR triggered Map-Requests over the mapping 5.5. Encrypting and Decrypting an OTK
system in order to receive a secure Map-Reply. If an ITR accepts
piggybacked Map-Replies, it SHOULD also send a Map-Request over the
mapping system in order to verify the piggybacked Map-Reply with a
secure Map-Reply.
5.4.1. Map-Reply Record Validation MS-OTK confidentiality and integrity protection MUST be provided in
the path between the Map-Server and the ETR. This can be achieved
either by enabling DTLS between the Map-Server and the ITR or by
encrypting the MS-OTK with the pre-shared secret known to the Map-
Server and the ETR [I-D.ietf-lisp-rfc6833bis].
The payload of a Map-Reply may contain multiple EID-records. The Similarly, ITR-OTK confidentiality and integrity protection MUST be
whole Map-Reply is signed by the ETR, with the PKT HMAC, to provide provided in the path between the ITR and the Map-Resolver. This can
integrity protection and origin authentication to the EID-prefix be achieved either by enabling DTLS between the Map-Server and the
records claimed by the ETR. The Authentication Data field of a Map- ITR, or by encrypting the ITR-OTK with the pre-shared secret known to
Reply may contain multiple EID-records in the EID-AD. The EID-AD is the ITR and the Map-Resolver. The ITR/Map-Resolver pre-shared key is
signed by the Map-Server, with the EID HMAC, to provide integrity similar to the Map-Server/ETR pre-shared key. However, to prevent
protection and origin authentication to the EID-prefix records ETR's overclaiming attacks, the ITR/Map-Resolver pre-shared secret
inserted by the Map-Server. MUST have a different value than the Map-Server/ETR pre-shared
secret.
Upon receiving a Map-Reply with the S-bit set, the ITR first checks This section describes OTK processing in the ITR/Map-Resolver path,
the validity of both the EID HMAC and of the PKT-AD HMAC. If either as well as in the Map-Server/ETR path.
one of the HMACs is not valid, a log action MUST be taken and the
Map-Reply MUST NOT be processed any further. If both HMACs are
valid, the ITR proceeds with validating each individual EID-record
claimed by the ETR by computing the intersection of each one of the
EID-prefix contained in the payload of the Map-Reply with each one of
the EID-prefixes contained in the EID-AD. An EID-record is valid
only if at least one of the intersections is not the empty set.
For instance, the Map-Reply payload contains 3 mapping record EID- It's important to note that, to prevent ETR's overclaiming attacks,
prefixes: the ITR/Map-Resolver pre-shared secret MUST be different from the
Map-Server/ETR pre-shared secret.
2001:db8:0102::/48 The OTK is wrapped using the algorithm specified in the OTK Wrapping
ID field. This field identifies both the:
2001:db8:0103::/48 o Key Encryption Algorithm used to encrypt the wrapped OTK, as well
as the
2001:db8:0200::/40 o Key Derivation Function used to derive a per-message encryption
key.
The EID-AD contains two EID-prefixes: Implementations of this specification MUST support OTK Wrapping ID
AES-KEY-WRAP-128+HKDF-SHA256 that specifies the use of the HKDF-
SHA256 Key Derivation Function specified in[RFC4868] to derive a per-
message encryption key (per-msg-key), as well as the AES-KEY-WRAP-128
Key Wrap algorithm used to encrypt a 128-bit OTK, according to
[RFC3394].
2001:db8:0103::/48 The key wrapping process for OTK Wrapping ID AES-KEY-WRAP-128+HKDF-
SHA256 is described below:
2001:db8:0203::/48 1. The KDF algorithm is identified by the field 'OTK Wrapping ID'
according to the table in Section Section 7.4.
The EID-record with EID-prefix 2001:db8:0102::/48 is not eligible to 2. The Key Wrap algorithm is identified by the field 'OTK Wrapping
be used by the ITR since it is not included in any of the EID-ADs ID' according to the table in Section Section 7.4.
signed by the Map-Server. A log action MUST be taken.
The EID-record with EID-prefix 2001:db8:0103::/48 is eligible to be 3. If the NULL-KEY-WRAP-128 algorithm (defined in (Section 7.4)) is
used by the ITR because it matches the second EID-prefix contained in selected and DTLS is not enabled, the Map-Request MUST be dropped
the EID-AD. and an appropiate log action SHOULD be taken.
The EID-record with EID-prefix 2001:db8:0200::/40 is not eligible to 4. The pre-shared secret used to derive the per-msg-key is
be used by the ITR since it is not included in any of the EID-ADs represented by PSK[Key ID], that is the pre-shared secret
signed by the Map-Server. A log action MUST be taken. In this last identified by the 'Key ID'.
example the ETR is trying to over claim the EID-prefix
2001:db8:0200::/40, but the Map-Server authorized only
2001:db8:0203::/48, hence the EID-record is discarded.
5.4.2. PITR Processing 5. The per-message encryption key key is computed as:
The processing performed by a PITR is equivalent to the processing of * per-msg-key = KDF( nonce + s + PSK[Key ID] )
an ITR. However, if the PITR is directly connected to a Mapping
System such as LISP+ALT [RFC6836], the PITR performs the functions of
both the ITR and the Map-Resolver forwarding the Map-Request
encapsulated in an ECM header that includes the Authentication Data
fields as described in Section 5.6.
5.5. Encrypting and Decrypting an OTK * where the nonce is the value in the Nonce field of the Map-
Request, and
MS-OTK confidentiality is required in the path between the Map-Server * 's' is the string "OTK-Key-Wrap"
and the ETR, the MS-OTK SHOULD be encrypted using the preconfigured
key shared between the Map-Server and the ETR for the purpose of
securing ETR registration [I-D.ietf-lisp-rfc6833bis]. Similarly, if
ITR-OTK confidentiality is required in the path between the ITR and
the Map-Resolver, the ITR-OTK SHOULD be encrypted with a key shared
between the ITR and the Map-Resolver.
The OTK is encrypted using the algorithm specified in the OTK 6. According to [RFC3394] the per-msg-key is used to wrap the OTK
Encryption ID field. When the AES Key Wrap algorithm is used to with AES-KEY-WRAP-128. The AES Key Wrap Initialization Value
encrypt a 128-bit OTK, according to [RFC3394], the AES Key Wrap MUST be set to 0xA6A6A6A6A6A6A6A6 (64 bits). The output of the
Initialization Value MUST be set to 0xA6A6A6A6A6A6A6A6 (64 bits). AES Key Wrap operation is 192-bit long. The most significant
The output of the AES Key Wrap operation is 192-bit long. The most 64-bit are copied in the One-Time Key Preamble field, while the
significant 64-bit are copied in the One-Time Key Preamble field, 128 less significant bits are copied in the One-Time Key field of
while the 128 less significant bits are copied in the One-Time Key the LISP-SEC Authentication Data.
field of the LISP-SEC Authentication Data.
When decrypting an encrypted OTK the receiver MUST verify that the When decrypting an encrypted OTK the receiver MUST verify that the
Initialization Value resulting from the AES Key Wrap decryption Initialization Value resulting from the AES Key Wrap decryption
operation is equal to 0xA6A6A6A6A6A6A6A6. If this verification fails operation is equal to 0xA6A6A6A6A6A6A6A6. If this verification fails
the receiver MUST discard the entire message. the receiver MUST discard the entire message.
When a 128-bit OTK is sent unencrypted the OTK Encryption ID is set 5.5.1. Unencrypted OTK
to NULL_KEY_WRAP_128, and the OTK Preamble is set to
0x0000000000000000 (64 bits). MS-OTK confidentiality and integrity protection MUST be provided in
the path between the Map-Server and the ETR. Similarly, ITR-OTK
confidentiality and integrity protection MUST be provided in the path
between the ITR and the Map-Resolver.
However, when DTLS is enabled the OTK MAY be sent unencrypted as
transport layer security is providing confidentiality and integrity
protection.
When a 128-bit OTK is sent unencrypted the OTK Wrapping ID is set to
NULL_KEY_WRAP_128, and the OTK Preamble is set to 0x0000000000000000
(64 bits).
5.6. Map-Resolver Processing 5.6. Map-Resolver Processing
Upon receiving an encapsulated Map-Request with the S-bit set, the Upon receiving an encapsulated Map-Request with the S-bit set, the
Map-Resolver decapsulates the ECM message. The ITR-OTK, if Map-Resolver decapsulates the ECM message. The ITR-OTK, if
encrypted, is decrypted as specified in Section 5.5. encrypted, is decrypted as specified in Section 5.5.
Protecting the confidentiality of the ITR-OTK and, in general, the Protecting the confidentiality of the ITR-OTK and, in general, the
security of how the Map-Request is handed by the Map-Resolver to the security of how the Map-Request is handed by the Map-Resolver to the
Map-Server, is specific to the particular Mapping System used, and Map-Server, is specific to the particular Mapping System used, and
skipping to change at page 15, line 37 skipping to change at page 15, line 22
header with the S-bit set, that contains the unencrypted ITR-OTK, as header with the S-bit set, that contains the unencrypted ITR-OTK, as
specified in Section 5.5, and the other data derived from the ECM specified in Section 5.5, and the other data derived from the ECM
Authentication Data of the received encapsulated Map-Request. Authentication Data of the received encapsulated Map-Request.
The Map-Resolver then forwards to the Map-Server the received Map- The Map-Resolver then forwards to the Map-Server the received Map-
Request, encapsulated in the new ECM header that includes the newly Request, encapsulated in the new ECM header that includes the newly
computed Authentication Data fields. computed Authentication Data fields.
5.7. Map-Server Processing 5.7. Map-Server Processing
Upon receiving an ECM encapsulated Map-Request with the S-bit set, Upon receiving an ECM encapsulated Map-Request with the S-bit set to
the Map-Server process the Map-Request according to the value of the 1, the Map-Server process the Map-Request according to the value of
S-bit contained in the Map-Register sent by the ETR during the security-capable S-bit and of the proxy map-reply P-bit contained
registration. in the Map-Register sent by the ETRs authoritative for that prefix
during registration.
If the S-bit contained in the Map-Register was clear the Map-Server Processing of the Map-Request MUST proceed in the order described in
decapsulates the ECM and generates a new ECM encapsulated Map-Request the table below, applying the processing corresponding to the first
that does not contain an ECM Authentication Data, as specified in rule that matches the conditions indicated in the first column:
[I-D.ietf-lisp-rfc6833bis]. The Map-Server does not perform any
further LISP-SEC processing, and the Map-Reply will not be protected.
If the S-bit contained in the Map-Register was set the Map-Server +----------------+--------------------------------------------------+
decapsulates the ECM and generates a new ECM Authentication Data. | Matching | Processing |
The Authentication Data includes the OTK-AD and the EID-AD, that | Condition | |
contains EID-prefix authorization information, that are ultimately +----------------+--------------------------------------------------+
sent to the requesting ITR. | 1. At least | The Map-Server MUST generate a LISP-SEC |
| one of the | protected Map-Reply as specified in Section |
| ETRs | 5.7.2. The ETR-Cant-Sign E-bit in the EID |
| authoritative | Authentication Data (EID-AD) MUST be set to 0. |
| for the EID | |
| prefix | |
| included in | |
| the Map- | |
| Request | |
| registered | |
| with the P-bit | |
| set to 1 | |
| | |
| 2. At least | The Map-Server MUST generate a LISP-SEC |
| one of the | protected Encapsulated Map-Request (as specified |
| ETRs | in Section 5.7.1), to be sent to one of the |
| authoritative | authoritative ETRs that registered with the |
| for the EID | S-bit set to 1 (and the P-bit set to 0). If |
| prefix | there is at least one ETR that registered with |
| included in | the S-bit set to 0, the ETR-Cant-Sign E-bit of |
| the Map- | the EID-AD MUST be set to 1 to signal the ITR |
| Request | that a non LISP-SEC Map-Request might reach |
| registered | additional ETRs that have LISP-SEC disabled. |
| with the S-bit | |
| set to 1 | |
| | |
| 3. All the | The Map-Server MUST send a Negative Map-Reply |
| ETRs | protected with LISP-SEC, as described in Section |
| authoritative | 5.7.2. The ETR-Cant-Sign E-bit MUST be set to 1 |
| for the EID | to signal the ITR that a non LISP-SEC Map- |
| prefix | Request might reach additional ETRs that have |
| included in | LISP-SEC disabled. |
| the Map- | |
| Request | |
| registered | |
| with the S-bit | |
| set to 0 | |
+----------------+--------------------------------------------------+
In this way the ITR that sent a LISP-SEC protected Map-Request always
receives a LISP-SEC protected Map-Reply. However, the ETR-Cant-Sign
E-bit set to 1 specifies that a non LISP-SEC Map-Request might reach
additional ETRs that have LISP-SEC disabled. This mechanism allows
the ITR to securely downgrade to non LISP-SEC requests, if so
desired.
5.7.1. Generating a LISP-SEC Protected Encapsulated Map-Request
The Map-Server decapsulates the ECM and generates a new ECM
Authentication Data. The Authentication Data includes the OTK-AD and
the EID-AD, that contains EID-prefix authorization information, that
are eventually received by the requesting ITR.
The Map-Server updates the OTK-AD by deriving a new OTK (MS-OTK) from The Map-Server updates the OTK-AD by deriving a new OTK (MS-OTK) from
the ITR-OTK received with the Map-Request. MS-OTK is derived the ITR-OTK received with the Map-Request. MS-OTK is derived
applying the key derivation function specified in the KDF ID field. applying the key derivation function specified in the KDF ID field.
If the algorithm specified in the KDF ID field is not supported, the If the algorithm specified in the KDF ID field is not supported, the
Map-Server uses a different algorithm to derive the key and updates Map-Server uses a different algorithm to derive the key and updates
the KDF ID field accordingly. the KDF ID field accordingly.
The Map-Server and the ETR MUST be configured with a shared key for MS-OTK confidentiality and integrity protection MUST be provided in
mapping registration according to [I-D.ietf-lisp-rfc6833bis]. If MS- the path between the Map-Server and the ETR. This can be achieved
OTK confidentiality is required, then the MS-OTK SHOULD be encrypted, either by enabling DTLS between the Map-Server and the ETR, or by
by wrapping the MS-OTK with the algorithm specified by the OTK encrypting the MS-OTK with the pre-shared secret known to the Map-
Encryption ID field as specified in Section 5.5. Server and the ETR.
The Map-Request MUST be encapsulated in an ECM, with the S-bit set to
1, to indicate the presence of Authentication Data.
MS-OTK is wrapped with the algorithm specified by the OTK Wrapping ID
field. See Section 5.5 for further details on OTK encryption. If
the NULL-KEY-WRAP-128 algorithm is selected and DTLS is not enabled
in the path between the Map-Server and the ETR, the Map-Request MUST
be dropped and an appropiate log action SHOULD be taken.
The Map-Server includes in the EID-AD the longest match registered The Map-Server includes in the EID-AD the longest match registered
EID-prefix for the destination EID, and an HMAC of this EID-prefix. EID-prefix for the destination EID, and an HMAC of this EID-prefix.
The HMAC is keyed with the ITR-OTK contained in the received ECM The HMAC is keyed with the ITR-OTK contained in the received ECM
Authentication Data, and the HMAC algorithm is chosen according to Authentication Data, and the HMAC algorithm is chosen according to
the Requested HMAC ID field. If The Map-Server does not support this the Requested HMAC ID field. If The Map-Server does not support this
algorithm, the Map-Server uses a different algorithm and specifies it algorithm, the Map-Server uses a different algorithm and specifies it
in the EID HMAC ID field. The scope of the HMAC operation covers the in the EID HMAC ID field. The scope of the HMAC operation covers the
entire EID-AD, from the EID-AD Length field to the EID HMAC field, entire EID-AD, from the EID-AD Length field to the EID HMAC field,
which must be set to 0 before the computation. which must be set to 0 before the computation.
The Map-Server then forwards the updated ECM encapsulated Map- The Map-Server then forwards the updated ECM encapsulated Map-
Request, that contains the OTK-AD, the EID-AD, and the received Map- Request, that contains the OTK-AD, the EID-AD, and the received Map-
Request to an authoritative ETR as specified in Request to an authoritative ETR as specified in
[I-D.ietf-lisp-rfc6833bis]. [I-D.ietf-lisp-rfc6833bis].
5.7.1. Map-Server Processing in Proxy mode 5.7.2. Generating a Proxy Map-Reply
If the Map-Server is in proxy mode, it generates a Map-Reply, as LISP-SEC proxy Map-Reply are generated according to
specified in [I-D.ietf-lisp-rfc6833bis], with the S-bit set to 1. [I-D.ietf-lisp-rfc6833bis], with the Map-Replay S-bit set to 1. The
The Map-Reply includes the Authentication Data that contains the EID- Map-Reply includes the Authentication Data that contains the EID-AD,
AD, computed as specified in Section 5.7, as well as the PKT-AD computed as specified in Section 5.7.1, as well as the PKT-AD
computed as specified in Section 5.8. computed as specified in Section 5.8.
5.8. ETR Processing 5.8. ETR Processing
Upon receiving an ECM encapsulated Map-Request with the S-bit set, Upon receiving an ECM encapsulated Map-Request with the S-bit set,
the ETR decapsulates the ECM message. The OTK field, if encrypted, the ETR decapsulates the ECM message. The OTK field, if encrypted,
is decrypted as specified in Section 5.5 to obtain the unencrypted is decrypted as specified in Section 5.5 to obtain the unencrypted
MS-OTK. MS-OTK.
The ETR then generates a Map-Reply as specified in The ETR then generates a Map-Reply as specified in
skipping to change at page 17, line 15 skipping to change at page 18, line 35
The EID-AD is copied from the Authentication Data of the received The EID-AD is copied from the Authentication Data of the received
encapsulated Map-Request. encapsulated Map-Request.
The PKT-AD contains the HMAC of the whole Map-Reply packet, keyed The PKT-AD contains the HMAC of the whole Map-Reply packet, keyed
with the MS-OTK and computed using the HMAC algorithm specified in with the MS-OTK and computed using the HMAC algorithm specified in
the Requested HMAC ID field of the received encapsulated Map-Request. the Requested HMAC ID field of the received encapsulated Map-Request.
If the ETR does not support the Requested HMAC ID, it uses a If the ETR does not support the Requested HMAC ID, it uses a
different algorithm and updates the PKT HMAC ID field accordingly. different algorithm and updates the PKT HMAC ID field accordingly.
The scope of the HMAC operation covers the entire PKT-AD, from the The scope of the HMAC operation covers the entire PKT-AD, from the
Map-Reply Type field to the PKT HMAC field, which must be set to 0 Map-Reply Type field to the PKT HMAC field, which must be set to 0
before the computation. bendlfore the computation.
Finally the ETR sends the Map-Reply to the requesting ITR as Finally the ETR sends the Map-Reply to the requesting ITR as
specified in [I-D.ietf-lisp-rfc6833bis]. specified in [I-D.ietf-lisp-rfc6833bis].
5.9. ITR Processing: Receiving a Map-Reply
In response to an encapsulated Map-Request that has the S-bit set, an
ITR MUST receive a Map-Reply with the S-bit set, that includes an
EID-AD and a PKT-AD. If the Map-Reply does not include both ADs, the
ITR MUST discard it. In response to an encapsulated Map-Request with
S-bit set to 0, the ITR expects a Map-Reply with S-bit set to 0, and
the ITR SHOULD discard the Map-Reply if the S-bit is set.
Upon receiving a Map-Reply, the ITR must verify the integrity of both
the EID-AD and the PKT-AD, and MUST discard the Map-Reply if one of
the integrity checks fails. After processing the Map-Reply, the ITR
must discard the <nonce,ITK-OTK> pair associated to the Map-Reply
The integrity of the EID-AD is verified using the ITR-OTK (stored
locally for the duration of this exchange) to re-compute the HMAC of
the EID-AD using the algorithm specified in the EID HMAC ID field.
If the EID HMAC ID field does not match the Requested HMAC ID the ITR
SHOULD discard the Map-Reply and send, at the first opportunity it
needs to, a new Map-Request with a different Requested HMAC ID field,
according to ITR's local policy. The scope of the HMAC operation
covers the entire EID-AD, from the EID-AD Length field to the EID
HMAC field, which must be set to 0 before the computation of the
HMAC.
ITR MUST set the EID HMAC ID field to 0 before computing the HMAC.
To verify the integrity of the PKT-AD, first the MS-OTK is derived
from the locally stored ITR-OTK using the algorithm specified in the
KDF ID field. This is because the PKT-AD is generated by the ETR
using the MS-OTK. If the KDF ID in the Map-Reply does not match the
KDF ID requested in the Map-Request, the ITR SHOULD discard the Map-
Reply and send, at the first opportunity it needs to, a new Map-
Request with a different KDF ID, according to ITR's local policy.
Without consistent configuration of involved entities, extra delays
may be experienced. However, since HKDF-SHA1-128 is specified as
mandatory to implement in Section 7.5, the process will eventually
converge.
The derived MS-OTK is then used to re-compute the HMAC of the PKT-AD
using the Algorithm specified in the PKT HMAC ID field. If the PKT
HMAC ID field does not match the Requested HMAC ID the ITR SHOULD
discard the Map-Reply and send, at the first opportunity it needs to,
a new Map-Request with a different Requested HMAC ID according to
ITR's local policy or until all HMAC IDs supported by the ITR have
been attempted.
Each individual Map-Reply EID-record is considered valid only if: (1)
both EID-AD and PKT-AD are valid, and (2) the intersection of the
EID-prefix in the Map-Reply EID-record with one of the EID-prefixes
contained in the EID-AD is not empty. After identifying the Map-
Reply record as valid, the ITR sets the EID-prefix in the Map-Reply
record to the value of the intersection set computed before, and adds
the Map-Reply EID-record to its EID-to-RLOC cache, as described in
[I-D.ietf-lisp-rfc6833bis]. An example of Map-Reply record
validation is provided in Section 5.9.1.
The ITR SHOULD send SMR triggered Map-Requests over the mapping
system in order to receive a secure Map-Reply. If an ITR accepts
piggybacked Map-Replies, it SHOULD also send a Map-Request over the
mapping system in order to verify the piggybacked Map-Reply with a
secure Map-Reply.
5.9.1. Map-Reply Record Validation
The payload of a Map-Reply may contain multiple EID-records. The
whole Map-Reply is signed by the ETR, with the PKT HMAC, to provide
integrity protection and origin authentication to the EID-prefix
records claimed by the ETR. The Authentication Data field of a Map-
Reply may contain multiple EID-records in the EID-AD. The EID-AD is
signed by the Map-Server, with the EID HMAC, to provide integrity
protection and origin authentication to the EID-prefix records
inserted by the Map-Server.
Upon receiving a Map-Reply with the S-bit set, the ITR first checks
the validity of both the EID HMAC and of the PKT-AD HMAC. If either
one of the HMACs is not valid, a log action MUST be taken and the
Map-Reply MUST NOT be processed any further. If both HMACs are
valid, the ITR proceeds with validating each individual EID-record
claimed by the ETR by computing the intersection of each one of the
EID-prefix contained in the payload of the Map-Reply with each one of
the EID-prefixes contained in the EID-AD. An EID-record is valid
only if at least one of the intersections is not the empty set.
For instance, the Map-Reply payload contains 3 mapping record EID-
prefixes:
2001:db8:102::/48
2001:db8:103::/48
2001:db8:200::/40
The EID-AD contains two EID-prefixes:
2001:db8:103::/48
2001:db8:203::/48
The EID-record with EID-prefix 2001:db8:102::/48 is not eligible to
be used by the ITR since it is not included in any of the EID-ADs
signed by the Map-Server. A log action MUST be taken.
The EID-record with EID-prefix 2001:db8:103::/48 is eligible to be
used by the ITR because it matches the second EID-prefix contained in
the EID-AD.
The EID-record with EID-prefix 2001:db8:200::/40 is not eligible to
be used by the ITR since it is not included in any of the EID-ADs
signed by the Map-Server. A log action MUST be taken. In this last
example the ETR is trying to over claim the EID-prefix
2001:db8:200::/40, but the Map-Server authorized only
2001:db8:203::/48, hence the EID-record is discarded.
6. Security Considerations 6. Security Considerations
6.1. Mapping System Security 6.1. Mapping System Security
The LISP-SEC threat model described in Section 3, assumes that the The LISP-SEC threat model described in Section 3, assumes that the
LISP Mapping System is working properly and eventually delivers Map- LISP Mapping System is working properly and eventually delivers Map-
Request messages to a Map-Server that is authoritative for the Request messages to a Map-Server that is authoritative for the
requested EID. requested EID.
It is assumed that the Mapping System ensures the confidentiality of It is assumed that the Mapping System ensures the confidentiality of
skipping to change at page 19, line 36 skipping to change at page 23, line 25
7.1. ECM AD Type Registry 7.1. ECM AD Type Registry
IANA is requested to create the "ECM Authentication Data Type" IANA is requested to create the "ECM Authentication Data Type"
registry with values 0-255, for use in the ECM LISP-SEC Extensions registry with values 0-255, for use in the ECM LISP-SEC Extensions
Section 5.1. The registry MUST be initially populated with the Section 5.1. The registry MUST be initially populated with the
following values: following values:
Name Value Defined In Name Value Defined In
------------------------------------------------- -------------------------------------------------
Reserved 0 This memo Unassigned 0 This memo
LISP-SEC-ECM-EXT 1 This memo LISP-SEC-ECM-EXT 1 This memo
HMAC Functions HMAC Functions
Values 2-255 are unassigned. They are to be assigned according to Values 2-255 are unassigned. They are to be assigned according to
the "Specification Required" policy defined in [RFC5226]. the "Specification Required" policy defined in [RFC5226].
7.2. Map-Reply AD Type Registry 7.2. Map-Reply AD Type Registry
IANA is requested to create the "Map-Reply Authentication Data Type" IANA is requested to create the "Map-Reply Authentication Data Type"
registry with values 0-255, for use in the Map-Reply LISP-SEC registry with values 0-255, for use in the Map-Reply LISP-SEC
Extensions Section 5.2. The registry MUST be initially populated Extensions Section 5.2. The registry MUST be initially populated
with the following values: with the following values:
Name Value Defined In Name Value Defined In
------------------------------------------------- -------------------------------------------------
Reserved 0 This memo Unassigned 0 This memo
LISP-SEC-MR-EXT 1 This memo LISP-SEC-MR-EXT 1 This memo
HMAC Functions HMAC Functions
Values 2-255 are unassigned. They are to be assigned according to Values 2-255 are unassigned. They are to be assigned according to
the "Specification Required" policy defined in [RFC5226]. the "Specification Required" policy defined in [RFC5226].
7.3. HMAC Functions 7.3. HMAC Functions
IANA is requested to create the "LISP-SEC Authentication Data HMAC IANA is requested to create the "LISP-SEC Authentication Data HMAC
skipping to change at page 20, line 41 skipping to change at page 24, line 31
AUTH-HMAC-SHA-1-96 MUST be supported, AUTH-HMAC-SHA-256-128 SHOULD be AUTH-HMAC-SHA-1-96 MUST be supported, AUTH-HMAC-SHA-256-128 SHOULD be
supported. supported.
7.4. Key Wrap Functions 7.4. Key Wrap Functions
IANA is requested to create the "LISP-SEC Authentication Data Key IANA is requested to create the "LISP-SEC Authentication Data Key
Wrap ID" registry with values 0-65535 for use as OTK key wrap Wrap ID" registry with values 0-65535 for use as OTK key wrap
algorithms ID in the LISP-SEC Authentication Data: algorithms ID in the LISP-SEC Authentication Data:
Name Number Defined In Name Number KEY WRAP KDF
------------------------------------------------- -----------------------------------------------------------------
Reserved 0 This memo Unassigned 0 None None
NULL-KEY-WRAP-128 1 This memo NULL-KEY-WRAP-128 1 This memo None
AES-KEY-WRAP-128 2 [RFC3394] AES-KEY-WRAP-128+HKDF-SHA256 2 [RFC3394] [RFC4868]
Key Wrap Functions Key Wrap Functions
Values 3-65535 are unassigned. They are to be assigned according to Values 3-65535 are unassigned. They are to be assigned according to
the "Specification Required" policy defined in [RFC5226]. the "Specification Required" policy defined in [RFC5226].
NULL-KEY-WRAP-128, and AES-KEY-WRAP-128 MUST be supported. NULL-KEY-WRAP-128, and AES-KEY-WRAP-128+HKDF-SHA256 MUST be
supported.
NULL-KEY-WRAP-128 is used to carry an unencrypted 128-bit OTK, with a NULL-KEY-WRAP-128 is used to carry an unencrypted 128-bit OTK, with a
64-bit preamble set to 0x0000000000000000 (64 bits). 64-bit preamble set to 0x0000000000000000 (64 bits).
7.5. Key Derivation Functions 7.5. Key Derivation Functions
IANA is requested to create the "LISP-SEC Authentication Data Key IANA is requested to create the "LISP-SEC Authentication Data Key
Derivation Function ID" registry with values 0-65535 for use as KDF Derivation Function ID" registry with values 0-65535 for use as KDF
ID in the LISP-SEC Authentication Data: ID in the LISP-SEC Authentication Data:
skipping to change at page 21, line 38 skipping to change at page 25, line 30
HKDF-SHA1-128 MUST be supported HKDF-SHA1-128 MUST be supported
8. Acknowledgements 8. Acknowledgements
The authors would like to acknowledge Pere Monclus, Dave Meyer, Dino The authors would like to acknowledge Pere Monclus, Dave Meyer, Dino
Farinacci, Brian Weis, David McGrew, Darrel Lewis and Landon Curt Farinacci, Brian Weis, David McGrew, Darrel Lewis and Landon Curt
Noll for their valuable suggestions provided during the preparation Noll for their valuable suggestions provided during the preparation
of this document. of this document.
9. Normative References 9. References
[I-D.ietf-lisp-rfc6830bis] 9.1. Normative References
Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A.
Cabellos-Aparicio, "The Locator/ID Separation Protocol
(LISP)", draft-ietf-lisp-rfc6830bis-26 (work in progress),
November 2018.
[I-D.ietf-lisp-rfc6833bis] [I-D.ietf-lisp-rfc6833bis]
Fuller, V., Farinacci, D., and A. Cabellos-Aparicio, Fuller, V., Farinacci, D., and A. Cabellos-Aparicio,
"Locator/ID Separation Protocol (LISP) Control-Plane", "Locator/ID Separation Protocol (LISP) Control-Plane",
draft-ietf-lisp-rfc6833bis-22 (work in progress), November draft-ietf-lisp-rfc6833bis-24 (work in progress), February
2018. 2019.
[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
Hashing for Message Authentication", RFC 2104, Hashing for Message Authentication", RFC 2104,
DOI 10.17487/RFC2104, February 1997, <https://www.rfc- DOI 10.17487/RFC2104, February 1997, <https://www.rfc-
editor.org/info/rfc2104>. editor.org/info/rfc2104>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc- DOI 10.17487/RFC2119, March 1997, <https://www.rfc-
editor.org/info/rfc2119>. editor.org/info/rfc2119>.
[RFC3394] Schaad, J. and R. Housley, "Advanced Encryption Standard [RFC3394] Schaad, J. and R. Housley, "Advanced Encryption Standard
(AES) Key Wrap Algorithm", RFC 3394, DOI 10.17487/RFC3394, (AES) Key Wrap Algorithm", RFC 3394, DOI 10.17487/RFC3394,
September 2002, <https://www.rfc-editor.org/info/rfc3394>. September 2002, <https://www.rfc-editor.org/info/rfc3394>.
[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", BCP 106, RFC 4086, "Randomness Requirements for Security", BCP 106, RFC 4086,
DOI 10.17487/RFC4086, June 2005, <https://www.rfc- DOI 10.17487/RFC4086, June 2005, <https://www.rfc-
editor.org/info/rfc4086>. editor.org/info/rfc4086>.
[RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA-
384, and HMAC-SHA-512 with IPsec", RFC 4868,
DOI 10.17487/RFC4868, May 2007, <https://www.rfc-
editor.org/info/rfc4868>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226, IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008, <https://www.rfc- DOI 10.17487/RFC5226, May 2008, <https://www.rfc-
editor.org/info/rfc5226>. editor.org/info/rfc5226>.
[RFC5869] Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand [RFC5869] Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand
Key Derivation Function (HKDF)", RFC 5869, Key Derivation Function (HKDF)", RFC 5869,
DOI 10.17487/RFC5869, May 2010, <https://www.rfc- DOI 10.17487/RFC5869, May 2010, <https://www.rfc-
editor.org/info/rfc5869>. editor.org/info/rfc5869>.
[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
(SHA and SHA-based HMAC and HKDF)", RFC 6234,
DOI 10.17487/RFC6234, May 2011, <https://www.rfc-
editor.org/info/rfc6234>.
[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
January 2012, <https://www.rfc-editor.org/info/rfc6347>. January 2012, <https://www.rfc-editor.org/info/rfc6347>.
[RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis, [RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis,
"Locator/ID Separation Protocol Alternative Logical "Locator/ID Separation Protocol Alternative Logical
Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836, Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836,
January 2013, <https://www.rfc-editor.org/info/rfc6836>. January 2013, <https://www.rfc-editor.org/info/rfc6836>.
[RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID
Separation Protocol (LISP) Threat Analysis", RFC 7835, Separation Protocol (LISP) Threat Analysis", RFC 7835,
DOI 10.17487/RFC7835, April 2016, <https://www.rfc- DOI 10.17487/RFC7835, April 2016, <https://www.rfc-
editor.org/info/rfc7835>. editor.org/info/rfc7835>.
[RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical
Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060,
February 2017, <https://www.rfc-editor.org/info/rfc8060>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References
[I-D.ietf-lisp-rfc6830bis]
Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A.
Cabellos-Aparicio, "The Locator/ID Separation Protocol
(LISP)", draft-ietf-lisp-rfc6830bis-26 (work in progress),
November 2018.
Authors' Addresses Authors' Addresses
Fabio Maino Fabio Maino
Cisco Systems Cisco Systems
170 Tasman Drive 170 Tasman Drive
San Jose, California 95134 San Jose, California 95134
USA USA
Email: fmaino@cisco.com Email: fmaino@cisco.com
Vina Ermagan Vina Ermagan
Cisco Systems Google
170 Tasman Drive California
San Jose, California 95134
USA USA
Email: vermagan@cisco.com Email: ermagan@gmail.com
Albert Cabellos Albert Cabellos
Universitat Politecnica de Catalunya Universitat Politecnica de Catalunya
c/ Jordi Girona s/n c/ Jordi Girona s/n
Barcelona 08034 Barcelona 08034
Spain Spain
Email: acabello@ac.upc.edu Email: acabello@ac.upc.edu
Damien Saucez Damien Saucez
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