draft-ietf-lisp-sec-11.txt   draft-ietf-lisp-sec-12.txt 
Network Working Group F. Maino Network Working Group F. Maino
Internet-Draft V. Ermagan Internet-Draft V. Ermagan
Intended status: Experimental Cisco Systems Intended status: Experimental Cisco Systems
Expires: April 6, 2017 A. Cabellos Expires: May 20, 2017 A. Cabellos
Technical University of Catalonia Technical University of Catalonia
D. Saucez D. Saucez
INRIA INRIA
October 3, 2016 November 16, 2016
LISP-Security (LISP-SEC) LISP-Security (LISP-SEC)
draft-ietf-lisp-sec-11 draft-ietf-lisp-sec-12
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
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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 April 6, 2017. This Internet-Draft will expire on May 20, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 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
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
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 . . . . . . . . . . . . . . . . . . . . . 3
3. LISP-SEC Threat Model . . . . . . . . . . . . . . . . . . . . 4 3. LISP-SEC Threat Model . . . . . . . . . . . . . . . . . . . . 4
4. Protocol Operations . . . . . . . . . . . . . . . . . . . . . 4 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 . . . . . . . . . . . . . . 9
5.3. Map-Register LISP-SEC Extentions . . . . . . . . . . . . 10 5.3. Map-Register LISP-SEC Extentions . . . . . . . . . . . . 11
5.4. ITR Processing . . . . . . . . . . . . . . . . . . . . . 10 5.4. ITR Processing . . . . . . . . . . . . . . . . . . . . . 11
5.4.1. Map-Reply Record Validation . . . . . . . . . . . . . 12 5.4.1. Map-Reply Record Validation . . . . . . . . . . . . . 13
5.4.2. PITR Processing . . . . . . . . . . . . . . . . . . . 13 5.4.2. PITR Processing . . . . . . . . . . . . . . . . . . . 14
5.5. Encrypting and Decrypting an OTK . . . . . . . . . . . . 13 5.5. Encrypting and Decrypting an OTK . . . . . . . . . . . . 14
5.6. Map-Resolver Processing . . . . . . . . . . . . . . . . . 14 5.6. Map-Resolver Processing . . . . . . . . . . . . . . . . . 15
5.7. Map-Server Processing . . . . . . . . . . . . . . . . . . 14 5.7. Map-Server Processing . . . . . . . . . . . . . . . . . . 15
5.7.1. Map-Server Processing in Proxy mode . . . . . . . . . 15 5.7.1. Map-Server Processing in Proxy mode . . . . . . . . . 16
5.8. ETR Processing . . . . . . . . . . . . . . . . . . . . . 15 5.8. ETR Processing . . . . . . . . . . . . . . . . . . . . . 16
6. Security Considerations . . . . . . . . . . . . . . . . . . . 16 6. Security Considerations . . . . . . . . . . . . . . . . . . . 17
6.1. Mapping System Security . . . . . . . . . . . . . . . . . 16 6.1. Mapping System Security . . . . . . . . . . . . . . . . . 17
6.2. Random Number Generation . . . . . . . . . . . . . . . . 16 6.2. Random Number Generation . . . . . . . . . . . . . . . . 17
6.3. Map-Server and ETR Colocation . . . . . . . . . . . . . . 16 6.3. Map-Server and ETR Colocation . . . . . . . . . . . . . . 17
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 6.4. Deploying LISP-SEC . . . . . . . . . . . . . . . . . . . 17
7.1. HMAC functions . . . . . . . . . . . . . . . . . . . . . 16 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
7.2. Key Wrap Functions . . . . . . . . . . . . . . . . . . . 17 7.1. ECM AD Type Registry . . . . . . . . . . . . . . . . . . 18
7.3. Key Derivation Functions . . . . . . . . . . . . . . . . 17 7.2. Map-Reply AD Type Registry . . . . . . . . . . . . . . . 18
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18 7.3. HMAC Functions . . . . . . . . . . . . . . . . . . . . . 19
9. Normative References . . . . . . . . . . . . . . . . . . . . 18 7.4. Key Wrap Functions . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 7.5. Key Derivation Functions . . . . . . . . . . . . . . . . 20
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20
9. Normative References . . . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
The Locator/ID Separation Protocol [RFC6830] defines a set of The Locator/ID Separation Protocol [RFC6830] is a network-layer-based
functions for routers to exchange information used to map from non- protocol that enables separation of IP addresses into two new
routable Endpoint Identifiers (EIDs) to routable Routing Locators numbering spaces: Endpoint Identifiers (EIDs) and Routing Locators
(RLOCs). If these EID-to-RLOC mappings, carried through Map-Reply (RLOCs). EID-to-RLOC mappings are stored in a database, the LISP
messages, are transmitted without integrity protection, an adversary Mapping System, and made available via the Map-Request/Map-Reply
can manipulate them and hijack the communication, impersonate the lookup process. If these EID-to-RLOC mappings, carried through Map-
requested EID, or mount Denial of Service or Distributed Denial of Reply messages, are transmitted without integrity protection, an
Service attacks. Also, if the Map-Reply message is transported adversary can manipulate them and hijack the communication,
unauthenticated, an adversarial LISP entity can overclaim an EID- impersonate the requested EID, or mount Denial of Service or
prefix and maliciously redirect traffic directed to a large number of Distributed Denial of Service attacks. Also, if the Map-Reply
hosts. A detailed description of "overclaiming" attack is provided message is transported unauthenticated, an adversarial LISP entity
in [RFC7835]. can overclaim an EID-prefix and maliciously redirect traffic directed
to a large number of hosts. The LISP-SEC threat model, described in
Section 3, is built on top of the LISP threat model defined in
[RFC7835], that includes a detailed description of "overclaiming"
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 security, including the right
for a LISP entity to register an EID-prefix or to claim presence at for a LISP entity to register an EID-prefix or to claim presence at
an RLOC, is out of the scope of LISP-SEC. Additional security an RLOC, is out of the scope of LISP-SEC. Additional security
considerations are described in Section 6. 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-OTK: The One-Time Key generated at the ITR. ITR One-Time Key (ITR-OTK): The One-Time Key generated at the ITR.
MS-OTK: The One-Time Key generated at the Map-Server.
Encapsulated Control Message (ECM): A LISP control message that is MS One-Time Key (MS-OTK): The One-Time Key generated at the Map-
prepended with an additional LISP header. ECM is used by ITRs to Server.
send LISP control messages to a Map-Resolver, by Map-Resolvers to
forward LISP control messages to a Map-Server, and by Map-
Resolvers to forward LISP control messages to an ETR.
Authentication Data (AD): Metadata that is included either in a Authentication Data (AD): Metadata that is included either in a
LISP ECM header or in a Map-Reply message to support LISP Encapsulated Control Message (ECM) header, as defined in
Section 6.1.8 of [RFC6830], or in a Map-Reply message to support
confidentiality, integrity protection, and verification of EID- confidentiality, integrity protection, and verification of EID-
prefix authorization. prefix authorization.
OTK-AD: The portion of ECM Authentication Data that contains a OTK Authentication Data (OTK-AD): The portion of ECM
One-Time Key. Authentication Data that contains a One-Time Key.
EID-AD: The portion of ECM and Map-Reply Authentication Data EID Authentication Data (EID-AD): The portion of ECM and Map-Reply
used for verification of EID-prefix authorization. Authentication Data used for verification of EID-prefix
authorization.
PKT-AD: The portion of Map-Reply Authentication Data used to Packet Authentication Data (PKT-AD): The portion of Map-Reply
protect the integrity of the Map-Reply message. Authentication Data used to protect the integrity of the Map-Reply
message.
For definitions of other terms, notably Map-Request, Map-Reply, For definitions of other terms, notably Map-Request, Map-Reply,
Ingress Tunnel Router (ITR), Egress Tunnel Router (ETR), Map-Server Ingress Tunnel Router (ITR), Egress Tunnel Router (ETR), Map-Server
(MS), and Map-Resolver (MR) please consult the LISP specification (MS), and Map-Resolver (MR) please consult the LISP specification
[RFC6830]. [RFC6830].
3. LISP-SEC Threat Model 3. LISP-SEC Threat Model
LISP-SEC addresses the control plane threats, described in [RFC7835], LISP-SEC addresses the control plane threats, described in [RFC7835],
that target EID-to-RLOC mappings, including manipulations of Map- that target EID-to-RLOC mappings, including manipulations of Map-
Request and Map-Reply messages, and malicious ETR EID prefix Request and Map-Reply messages, and malicious ETR EID prefix
overclaiming. LISP-SEC makes two main assumptions: (1) the LISP overclaiming. LISP-SEC makes two main assumptions: (1) the LISP
mapping system is expected to deliver a Map-Request message to their mapping system is expected to deliver a Map-Request message to their
intended destination ETR as identified by the EID, and (2) no man-in- intended destination ETR as identified by the EID, and (2) no man-in-
the-middle (MITM) attack can be mounted within the LISP Mapping the-middle (MITM) attack can be mounted within the LISP Mapping
System. Furthermore, while LISP-SEC enables detection of EID prefix System. How the Mapping System is protected from MITM attacks
overclaiming attacks, it assumes that Map-Servers can verify the EID depends from the particular Mapping Systems used, and is out of the
prefix authorization at time of registration. scope of this memo. Furthermore, while LISP-SEC enables detection of
EID prefix overclaiming attacks, it assumes that Map-Servers can
verify the EID prefix authorization at time of 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 in
the access network, outside of the boundaries of the LISP mapping the access network, outside of the boundaries of the LISP mapping
system. An on-path attacker, outside of the LISP mapping system can, system. An on-path attacker, outside of the LISP mapping system can,
for example, hijack Map-Request and Map-Reply messages, spoofing the for example, hijack Map-Request and Map-Reply messages, spoofing the
identity of a LISP node. Another example of on-path attack, called identity of a LISP node. Another example of on-path attack, called
overclaiming attack, can be mounted by a malicious Egress Tunnel overclaiming attack, can be mounted by a malicious Egress Tunnel
Router (ETR), by overclaiming the EID-prefixes for which it is Router (ETR), by overclaiming the EID-prefixes for which it is
authoritative. In this way the ETR can maliciously redirect traffic authoritative. In this way the ETR can maliciously redirect traffic
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Those trust relationships are used to securely distribute a One-Time Those trust relationships are used to securely distribute a One-Time
Key (OTK) that provides origin authentication, integrity and anti- Key (OTK) that provides origin authentication, integrity and anti-
replay protection to mapping data conveyed via the mapping lookup replay protection to mapping data conveyed via the mapping lookup
process, and that effectively prevent overclaiming attacks. The process, and that effectively prevent overclaiming attacks. The
processing of security parameters during the Map-Request/Map-Reply processing of security parameters during the Map-Request/Map-Reply
exchange is as follows: exchange is as follows:
o The ITR-OTK is generated and stored at the ITR, and securely o The ITR-OTK is generated and stored at the ITR, and securely
transported to the Map-Server. transported to the Map-Server.
o The Map-Server uses the ITR-OTK to compute an HMAC that protects o The Map-Server uses the ITR-OTK to compute a Keyed-Hashing for
the integrity of the mapping data known to the Map-Server to Message Authentication (HMAC) [RFC2104] that protects the
prevent overclaiming attacks. The Map-Server also derives a new integrity of the mapping data known to the Map-Server to prevent
OTK, the MS-OTK, that is passed to the ETR, by applying a Key overclaiming attacks. The Map-Server also derives a new OTK, the
Derivation Function (KDF) to the ITR-OTK. MS-OTK, that is passed to the ETR, by applying a Key Derivation
Function (KDF) 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
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match EID-prefix that covers the requested EID in the received match EID-prefix that covers the requested EID in the received
Map-Request. The Map-Server adds this EID-prefix, together with Map-Request. The Map-Server adds this EID-prefix, together with
an HMAC computed using the ITR-OTK, to a new Encapsulated Control an HMAC computed using the ITR-OTK, to a new Encapsulated Control
Message that contains the received Map-Request. Message that contains the received Map-Request.
o The Map-Server derives a new OTK, the MS-OTK, by applying a Key o 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 included
in the Encapsulated Control Message that the Map-Server uses to in the Encapsulated Control Message that the Map-Server uses to
forward the Map-Request to the ETR. To provide MS-OTK forward the Map-Request to the ETR. To provide MS-OTK
confidentiality over the path between the Map-Server and the ETR, confidentiality over the path between the Map-Server and the ETR,
the MS-OTK should be encrypted using the key shared between the the MS-OTK SHOULD be encrypted using the key shared between the
ETR and the Map-Server in order to secure ETR registration ETR and the Map-Server in order to secure ETR registration
[RFC6833]. [RFC6833].
o If the Map-Server is acting in proxy mode, as specified in o If the Map-Server is acting in proxy mode, as specified in
[RFC6830], the ETR is not involved in the generation of the Map- [RFC6830], the ETR is not involved in the generation of the Map-
Reply. In this case the Map-Server generates the Map-Reply on Reply. In this case the Map-Server generates the Map-Reply on
behalf of the ETR as described below. behalf of the ETR as described below.
o The ETR, upon receiving the ECM encapsulated Map-Request from the o 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
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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 (Encapsulated Control Message) defined in
[RFC6830] with Type set to 8, and S bit set to 1 to indicate that the [RFC6830] with Type set to 8, and S bit set to 1 to indicate that the
LISP header includes Authentication Data (AD). The format of the LISP header includes Authentication Data (AD). The format of the
LISP-SEC ECM Authentication Data is defined in the following figure. LISP-SEC ECM Authentication Data is defined in the following figure.
OTK-AD stands for One-Time Key Authentication Data and EID-AD stands OTK-AD stands for One-Time Key Authentication Data and EID-AD stands
for EID Authentication Data. 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AD Type |V| Reserved | Requested HMAC ID | | ECM AD Type |V| Reserved | Requested HMAC ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\
| OTK Length | OTK Encryption ID | | | OTK Length | OTK Encryption 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 | Reserved | EID HMAC ID |EID-AD
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ |
| Reserved | EID mask-len | EID-AFI | | | | Reserved | EID mask-len | EID-AFI | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Rec | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Rec |
~ EID-prefix ... ~ | | ~ EID-prefix ... ~ | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+/ |
~ EID HMAC ~ | ~ EID HMAC ~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+
LISP-SEC ECM Authentication Data LISP-SEC ECM Authentication Data
AD Type: 1 (LISP-SEC Authentication Data) 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. Reserved: 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 requested by the ITR. See
Section 5.4 for details. Section 5.4 for details.
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 OTK Encryption ID: The identifier of the key wrapping algorithm
used to encrypt the One-Time-Key. When a 128-bit OTK is sent used to encrypt the One-Time-Key. When a 128-bit OTK is sent
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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 OTK Encryption ID: The identifier of the key wrapping algorithm
used to encrypt the One-Time-Key. When a 128-bit OTK is sent used to encrypt the One-Time-Key. When a 128-bit OTK is sent
unencrypted by the Map-Resolver, the OTK Encryption ID is set to unencrypted by the Map-Resolver, the OTK Encryption ID is set to
NULL_KEY_WRAP_128. See Section 5.5 for more details. NULL_KEY_WRAP_128. See Section 5.5 for more details.
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 for details.
One-Time-Key: the OTK encrypted (or not) as specified by OTK One-Time-Key: the OTK encrypted (or not) as specified by OTK
Encryption ID. See Section 5.5 for details. Encryption ID. 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 SHOULD 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.
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. Reserved: Set to 0 on transmission and ignored on receipt.
skipping to change at page 9, line 20 skipping to change at page 10, line 5
to 0. The HMAC covers the entire EID-AD. to 0. The HMAC covers 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 [RFC6830], with Type set to 2, LISP-SEC uses the Map-Reply defined in [RFC6830], with Type set to 2,
and S bit set to 1 to indicate that the Map-Reply message includes and S bit set to 1 to indicate that the Map-Reply message includes
Authentication Data (AD). The format of the LISP-SEC Map-Reply Authentication Data (AD). The format of the LISP-SEC Map-Reply
Authentication Data is defined in the following figure. PKT-AD is Authentication Data is defined in the following figure. PKT-AD is
the Packet Authentication Data that covers the Map-Reply payload. 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AD Type | Reserved | | MR AD Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <---+
| EID-AD Length | KDF ID | | | EID-AD Length | KDF ID | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Record Count | Reserved | EID HMAC ID | EID-AD | Record Count | Reserved | EID HMAC ID |EID-AD
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\ |
| Reserved | EID mask-len | EID-AFI | | | | Reserved | 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 LISP-SEC Map-Reply Authentication Data
AD Type: 1 (LISP-SEC Authentication Data) 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.
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
skipping to change at page 10, line 30 skipping to change at page 11, line 13
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 Location Data. integrity of the Map-reply.
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
The second bit after the Type field in a Map-Register message is This memo is allocating one of the bits marked as Reserved in the
allocated as the S bit. The S bit indicates to the Map-Server that Map-Register message defined in Section 6.1.6 of [RFC6830]. More
the registering ETR is LISP-SEC enabled. An ETR that supports LISP- precisely, the second bit after the Type field in a Map-Register
SEC MUST set the S bit in its Map-Register messages. message is allocated as the S bit. The S bit indicates to the Map-
Server that the registering ETR is LISP-SEC enabled. An ETR that
supports LISP-SEC MUST set the S bit in its Map-Register messages.
5.4. ITR Processing 5.4. ITR Processing
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, together with the nonce generated as specified in
[RFC6830]. [RFC6830].
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. If the ITR and
the Map-Resolver are configured with a shared key, the ITR-OTK the Map-Resolver are configured with a shared key, the ITR-OTK
confidentiality SHOULD be protected by wrapping the ITR-OTK with the confidentiality SHOULD be protected by wrapping the ITR-OTK with the
algorithm specified by the OTK Encryption ID field. See Section 5.5 algorithm specified by the OTK Encryption ID field. See Section 5.5
for further details on OTK encryption. for further details on OTK encryption.
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. 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.
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 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 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 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 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 S-bit set to 0, the ITR expects a Map-Reply with S-bit set to 0, and
skipping to change at page 11, line 37 skipping to change at page 12, line 26
Upon receiving a Map-Reply, the ITR must verify the integrity of both 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 EID-AD and the PKT-AD, and MUST discard the Map-Reply if one of
the integrity checks fails. the integrity checks fails.
The integrity of the EID-AD is verified using the locally stored ITR- 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 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 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 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 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 with a different Requested HMAC ID field, according to ITR's local
policy. The ITR MUST set the EID HMAC ID field to 0 before computing policy. The scope of the HMAC operation covers the entire EID-AD,
the HMAC. 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 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 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 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 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- 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- 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. 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 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 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 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, 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 a new Map-Request with a different Requested HMAC ID according to
ITR's local policy. 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) 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 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 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- 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 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 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 the Map-Reply EID-record to its EID-to-RLOC cache, as described in
[RFC6830]. An example of Map-Reply record validation is provided in [RFC6830]. An example of Map-Reply record validation is provided in
Section 5.4.1. Section 5.4.1.
The ITR SHOULD send SMR triggered Map-Requests over the mapping The ITR SHOULD send SMR triggered Map-Requests over the mapping
system in order to receive a secure Map-Reply. If an ITR accepts 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 piggybacked Map-Replies, it SHOULD also send a Map-Request over the
mapping system in order to securely verify the piggybacked Map-Reply. mapping system in order to verify the piggybacked Map-Reply with a
secure Map-Reply.
5.4.1. Map-Reply Record Validation 5.4.1. Map-Reply Record Validation
The payload of a Map-Reply may contain multiple EID-records. The 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 whole Map-Reply is signed by the ETR, with the PKT HMAC, to provide
integrity protection and origin authentication to the EID-prefix integrity protection and origin authentication to the EID-prefix
records claimed by the ETR. The Authentication Data field of a Map- 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 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 signed by the Map-Server, with the EID HMAC, to provide integrity
protection and origin authentication to the EID-prefix records protection and origin authentication to the EID-prefix records
inserted by the Map-Server. inserted by the Map-Server.
Upon receiving a Map-Reply with the S-bit set, the ITR first checks 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 the validity of both the EID HMAC and of the PKT-AD HMAC. If either
one of the HMACs is not valid, a log message is issued and the Map- one of the HMACs is not valid, a log action MUST be taken and the
Reply is not processed any further. If both HMACs are valid, the ITR Map-Reply MUST NOT be processed any further. If both HMACs are
proceeds with validating each individual EID-record claimed by the valid, the ITR proceeds with validating each individual EID-record
ETR by computing the intersection of each one of the EID-prefix claimed by the ETR by computing the intersection of each one of the
contained in the payload of the Map-Reply with each one of the EID- EID-prefix contained in the payload of the Map-Reply with each one of
prefixes contained in the EID-AD. An EID-record is valid only if at the EID-prefixes contained in the EID-AD. An EID-record is valid
least one of the intersections is not the empty set. only if at least one of the intersections is not the empty set.
For instance, the Map-Reply payload contains 3 mapping record EID- For instance, the Map-Reply payload contains 3 mapping record EID-
prefixes: prefixes:
1.1.1.0/24 2001:db8:0102::/48
1.1.2.0/24 2001:db8:0103::/48
1.2.0.0/16 2001:db8:0200::/40
The EID-AD contains two EID-prefixes: The EID-AD contains two EID-prefixes:
1.1.2.0/24 2001:db8:0103::/48
1.2.3.0/24 2001:db8:0203::/48
The EID-record with EID-prefix 1.1.1.0/24 is not processed since it The EID-record with EID-prefix 2001:db8:0102::/48 is not eligible to
is not included in any of the EID-ADs signed by the Map-Server. A be used by the ITR since it is not included in any of the EID-ADs
log message is issued. signed by the Map-Server. A log action MUST be taken.
The EID-record with EID-prefix 1.1.2.0/24 is stored in the map-cache The EID-record with EID-prefix 2001:db8:0103::/48 is eligible to be
because it matches the second EID-prefix contained in the EID-AD. used by the ITR because it matches the second EID-prefix contained in
the EID-AD.
The EID-record with EID-prefix 1.2.0.0/16 is not processed since it The EID-record with EID-prefix 2001:db8:0200::/40 is not eligible to
is not included in any of the EID-ADs signed by the Map-Server. A be used by the ITR since it is not included in any of the EID-ADs
log message is issued. In this last example the ETR is trying to signed by the Map-Server. A log action MUST be taken. In this last
over claim the EID-prefix 1.2.0.0/16, but the Map-Server authorized example the ETR is trying to over claim the EID-prefix
only 1.2.3.0/24, hence the EID-record is discarded. 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 5.4.2. PITR Processing
The processing performed by a PITR is equivalent to the processing of The processing performed by a PITR is equivalent to the processing of
an ITR. However, if the PITR is directly connected to the ALT, the an ITR. However, if the PITR is directly connected to a Mapping
PITR performs the functions of both the ITR and the Map-Resolver System such as LISP+ALT [RFC6836], the PITR performs the functions of
forwarding the Map-Request encapsulated in an ECM header that both the ITR and the Map-Resolver forwarding the Map-Request
includes the Authentication Data fields as described in Section 5.6. encapsulated in an ECM header that includes the Authentication Data
fields as described in Section 5.6.
5.5. Encrypting and Decrypting an OTK 5.5. Encrypting and Decrypting an OTK
MS-OTK confidentiality is required in the path between the Map-Server MS-OTK confidentiality is required in the path between the Map-Server
and the ETR, the MS-OTK SHOULD be encrypted using the preconfigured 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 key shared between the Map-Server and the ETR for the purpose of
securing ETR registration [RFC6833]. Similarly, if ITR-OTK securing ETR registration [RFC6833]. Similarly, if ITR-OTK
confidentiality is required in the path between the ITR and the Map- confidentiality is required in the path between the ITR and the Map-
Resolver, the ITR-OTK SHOULD be encrypted with a key shared between Resolver, the ITR-OTK SHOULD be encrypted with a key shared between
the ITR and the Map-Resolver. the ITR and the Map-Resolver.
The OTK is encrypted using the algorithm specified in the OTK The OTK is encrypted using the algorithm specified in the OTK
Encryption ID field. When the AES Key Wrap algorithm is used to Encryption ID field. When the AES Key Wrap algorithm is used to
encrypt a 128-bit OTK, according to [RFC3339], the AES Key Wrap encrypt a 128-bit OTK, according to [RFC3394], the AES Key Wrap
Initialization Value MUST be set to 0xA6A6A6A6A6A6A6A6 (64 bits). Initialization Value MUST be set to 0xA6A6A6A6A6A6A6A6 (64 bits).
The output of the AES Key Wrap operation is 192-bit long. The most The output of the AES Key Wrap operation is 192-bit long. The most
significant 64-bit are copied in the One-Time Key Preamble field, significant 64-bit are copied in the One-Time Key Preamble field,
while the 128 less significant bits are copied in the One-Time Key while the 128 less significant bits are copied in the One-Time Key
field of 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.
skipping to change at page 14, line 17 skipping to change at page 15, line 15
When a 128-bit OTK is sent unencrypted the OTK Encryption ID is set When a 128-bit OTK is sent unencrypted the OTK Encryption ID is set
to NULL_KEY_WRAP_128, and the OTK Preamble is set to to NULL_KEY_WRAP_128, and the OTK Preamble is set to
0x0000000000000000 (64 bits). 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.
The Map-Resolver, as specified in [RFC6833], originates a new ECM Protecting the confidentiality of the ITR-OTK and, in general, the
header with the S-bit set, that contains the unencrypted ITR-OTK, as security of how the Map-Request is handed by the Map-Resolver to the
specified in Section 5.5, and the other data derived from the ECM Map-Server, is specific to the particular Mapping System used, and
Authentication Data of the received encapsulated Map-Request. outside of the scope of this memo.
The Map-Resolver then forwards the received Map-Request, encapsulated In Mapping Systems where the Map-Server is compliant with [RFC6833],
in the new ECM header that includes the newly computed Authentication the Map-Resolver originates a new ECM header with the S-bit set, that
Data fields. contains the unencrypted ITR-OTK, as specified in Section 5.5, and
the other data derived from the ECM Authentication Data of the
received encapsulated Map-Request.
The Map-Resolver then forwards to the Map-Server the received Map-
Request, encapsulated in the new ECM header that includes the newly
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,
the Map-Server process the Map-Request according to the value of the the Map-Server process the Map-Request according to the value of the
S-bit contained in the Map-Register sent by the ETR during S-bit contained in the Map-Register sent by the ETR during
registration. registration.
If the S-bit contained in the Map-Register was clear the Map-Server If the S-bit contained in the Map-Register was clear the Map-Server
decapsulates the ECM and generates a new ECM encapsulated Map-Request decapsulates the ECM and generates a new ECM encapsulated Map-Request
that does not contain an ECM Authentication Data, as specified in that does not contain an ECM Authentication Data, as specified in
[RFC6830]. The Map-Server does not perform any further LISP-SEC [RFC6830]. The Map-Server does not perform any further LISP-SEC
processing. processing, and the Map-Reply will not be protected.
If the S-bit contained in the Map-Register was set the Map-Server If the S-bit contained in the Map-Register was set the Map-Server
decapsulates the ECM and generates a new ECM Authentication Data. decapsulates the ECM and generates a new ECM Authentication Data.
The Authentication Data includes the OTK-AD and the EID-AD, that The Authentication Data includes the OTK-AD and the EID-AD, that
contains EID-prefix authorization information, that are ultimately contains EID-prefix authorization information, that are ultimately
sent to the requesting ITR. sent to 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.
skipping to change at page 16, line 19 skipping to change at page 17, line 23
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.
Map-Register security, including the right for a LISP entity to It is assumed that the Mapping System ensures the confidentiality of
register an EID-prefix or to claim presence at an RLOC, is out of the the OTK, and the integrity of the Map-Reply data. However, how the
scope of LISP-SEC. LISP Mapping System is secured is out of the scope of this document.
Similarly, Map-Register security, including the right for a LISP
entity to register an EID-prefix or to claim presence at an RLOC, is
out of the scope of LISP-SEC.
6.2. Random Number Generation 6.2. Random Number Generation
The ITR-OTK MUST be generated by a properly seeded pseudo-random (or The ITR-OTK MUST be generated by a properly seeded pseudo-random (or
strong random) source. See [RFC4086] for advice on generating strong random) source. See [RFC4086] for advice on generating
security-sensitive random data security-sensitive random data
6.3. Map-Server and ETR Colocation 6.3. Map-Server and ETR Colocation
If the Map-Server and the ETR are colocated, LISP-SEC does not If the Map-Server and the ETR are colocated, LISP-SEC does not
provide protection from overclaiming attacks mounted by the ETR. provide protection from overclaiming attacks mounted by the ETR.
However, in this particular case, since the ETR is within the trust However, in this particular case, since the ETR is within the trust
boundaries of the Map-Server, ETR's overclaiming attacks are not boundaries of the Map-Server, ETR's overclaiming attacks are not
included in the threat model. included in the threat model.
6.4. Deploying LISP-SEC
This memo is written according to [RFC2119]. Specifically, the use
of the key word SHOULD "or the adjective 'RECOMMENDED', mean that
there may exist valid reasons in particular circumstances to ignore a
particular item, but the full implications must be understood and
carefully weighed before choosing a different course".
Those deploying LISP-SEC according to this memo, should carefully
weight how the LISP-SEC threat model applies to their particular use
case or deployment. If they decide to ignore a particular
recommendation, they should make sure the risk associated with the
corresponding threats is well understood.
As an example, in certain closed and controlled deployments, it is
possible that the threat associated with a MiTM between the xTR and
the Mapping System is very low, and after carfeul consideration it
may be decided to allow a NULL key wrapping algorithm while carrying
the OTKs between the xTR and the Mapping System.
As an example at the other end of the spectrum, in certain other
deployments, attackers may be very sophisticated, and force the
deployers to enforce very strict policies in term of HMAC algorithms
accepted by an ITR.
Similar considerations apply to the entire LISP-SEC threat model, and
should guide the deployers and implementors whenever they encounter
the key word SHOULD across this memo.
7. IANA Considerations 7. IANA Considerations
7.1. HMAC functions 7.1. ECM AD Type Registry
The following HMAC ID values are defined by this memo for use as IANA is requested to create the "ECM Authentication Data Type"
Requested HMAC ID, EID HMAC ID, and PKT HMAC ID in the LISP-SEC registry with values 0-255, for use in the ECM LISP-SEC Extensions
Authentication Data: Section 5.1. The registry MUST be initially populated with the
following values:
Name Value Defined In
-------------------------------------------------
Reserved 0 This memo
LISP-SEC-ECM-EXT 1 This memo
HMAC Functions
Values 2-255 are unassigned. They are to be assigned according to
the "Specification Required" policy defined in [RFC5226].
7.2. Map-Reply AD Type Registry
IANA is requested to create the "Map-Reply Authentication Data Type"
registry with values 0-255, for use in the Map-Reply LISP-SEC
Extensions Section 5.2. The registry MUST be initially populated
with the following values:
Name Value Defined In
-------------------------------------------------
Reserved 0 This memo
LISP-SEC-MR-EXT 1 This memo
HMAC Functions
Values 2-255 are unassigned. They are to be assigned according to
the "Specification Required" policy defined in [RFC5226].
7.3. HMAC Functions
IANA is requested to create the "LISP-SEC Authentication Data HMAC
ID" registry with values 0-65535 for use as Requested HMAC ID, EID
HMAC ID, and PKT HMAC ID in the LISP-SEC Authentication Data:
Name Number Defined In Name Number Defined In
------------------------------------------------- -------------------------------------------------
NONE 0 NONE 0 This memo
AUTH-HMAC-SHA-1-96 1 [RFC2104] AUTH-HMAC-SHA-1-96 1 [RFC2104]
AUTH-HMAC-SHA-256-128 2 [RFC4634] AUTH-HMAC-SHA-256-128 2 [RFC6234]
values 2-65535 are reserved to IANA.
HMAC Functions HMAC Functions
AUTH-HMAC-SHA-1-96 MUST be supported, AUTH-HMAC-SHA-256-128 should be Values 3-65535 are unassigned. They are to be assigned according to
the "Specification Required" policy defined in [RFC5226].
AUTH-HMAC-SHA-1-96 MUST be supported, AUTH-HMAC-SHA-256-128 SHOULD be
supported. supported.
7.2. Key Wrap Functions 7.4. Key Wrap Functions
The following OTK Encryption ID values are defined by this memo for IANA is requested to create the "LISP-SEC Authentication Data Key
use as OTK key wrap algorithms ID in the LISP-SEC Authentication Wrap ID" registry with values 0-65535 for use as OTK key wrap
Data: algorithms ID in the LISP-SEC Authentication Data:
Name Number Defined In Name Number Defined In
------------------------------------------------- -------------------------------------------------
NULL-KEY-WRAP-128 1 Reserved 0 This memo
NULL-KEY-WRAP-128 1 This memo
AES-KEY-WRAP-128 2 [RFC3394] AES-KEY-WRAP-128 2 [RFC3394]
values 0 and 3-65535 are reserved to IANA.
Key Wrap Functions Key Wrap Functions
Values 3-65535 are unassigned. They are to be assigned according to
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 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).
7.3. Key Derivation Functions 7.5. Key Derivation Functions
The following KDF ID values are defined by this memo for use as KDF IANA is requested to create the "LISP-SEC Authentication Data Key
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:
Name Number Defined In Name Number Defined In
------------------------------------------------- -------------------------------------------------
NONE 0 NONE 0 This memo
HKDF-SHA1-128 1 [RFC5869] HKDF-SHA1-128 1 [RFC5869]
values 2-65535 are reserved to IANA.
Key Derivation Functions Key Derivation Functions
Values 2-65535 are unassigned. They are to be assigned according to
the "Specification Required" policy defined in [RFC5226].
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. Normative References
skipping to change at page 18, line 43 skipping to change at page 21, line 24
[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", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008, DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>. <http://www.rfc-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, DOI 10.17487/RFC5869, May 2010,
<http://www.rfc-editor.org/info/rfc5869>. <http://www.rfc-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,
<http://www.rfc-editor.org/info/rfc6234>.
[RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The
Locator/ID Separation Protocol (LISP)", RFC 6830, Locator/ID Separation Protocol (LISP)", RFC 6830,
DOI 10.17487/RFC6830, January 2013, DOI 10.17487/RFC6830, January 2013,
<http://www.rfc-editor.org/info/rfc6830>. <http://www.rfc-editor.org/info/rfc6830>.
[RFC6833] Fuller, V. and D. Farinacci, "Locator/ID Separation [RFC6833] Fuller, V. and D. Farinacci, "Locator/ID Separation
Protocol (LISP) Map-Server Interface", RFC 6833, Protocol (LISP) Map-Server Interface", RFC 6833,
DOI 10.17487/RFC6833, January 2013, DOI 10.17487/RFC6833, January 2013,
<http://www.rfc-editor.org/info/rfc6833>. <http://www.rfc-editor.org/info/rfc6833>.
[RFC6836] Fuller, V., Farinacci, D., Meyer, D., and D. Lewis,
"Locator/ID Separation Protocol Alternative Logical
Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836,
January 2013, <http://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, DOI 10.17487/RFC7835, April 2016,
<http://www.rfc-editor.org/info/rfc7835>. <http://www.rfc-editor.org/info/rfc7835>.
Authors' Addresses Authors' Addresses
Fabio Maino Fabio Maino
Cisco Systems Cisco Systems
170 Tasman Drive 170 Tasman Drive
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