1. draft-ietf-lisp-sec-12
F. Maino, V. Ermagan, A. Cabellos, D. Saucez
IETF 97, Seoul – November 2016

2. Agenda Most Significant Changes LISP-SEC Overview Q&A Scope
Threat Model
LISP-SEC Operations
Q&A

3. Most Significant Changes
Section 6 (Security Considerations)
Section 6.1 (Mapping System Security) states assumptions on mapping system security
Section 6.4 (Deploying LISP-SEC) warns that according to RFC2119 the security implications associated with the LISP-SEC threat model need to be well understood before ignoring each specific “SHOULD” recommendation. Two examples are brought up:
allowing transport of unencrypted OTK between xTR and MS/MR
allowing ETR/MS to choose HMAC algorithms different than the one specified by the ITR

4. Most Significant Changes (cont)
Section 7 (IANA Considerations) rewritten to be compliant with RFC Registries have been requested, and provisioned with initial values, for:
ECM Authentication Data Type
Map-Reply Authentication Data Type
LISP-SEC Authentication Data HMAC ID
LISP-SEC Authentication Data Key Wrap ID
LISP-SEC Authentication Data Key Derivation Function ID

5. LISP-SEC Overview

6. Scope Protect the Map-Request/Map-Reply exchange
Map-Reply origin authentication, anti-replay and integrity protection
Protect from over claiming attacks
Prevent the ETR from over claiming EID prefixes

7. Threat Model Map Resolver Map Server ITR ETR Site Y Site X ITR ETR
Mapping System
Map Resolver
Map Server
/16 -> {RLOC}
D= , S=
ITR
EID
ETR
Site Y
Site X
/16
ITR
ETR

8. Threat Model
The Mapping System is secure and well functioning, and delivers Map-Requests to their intended destinations as identified by the EID
EID prefix authorization is delegated to mapping Server Configuration
Mapping Server asserts EID prefix authorization
Mapping Server is trusted to do proper RLOC mapping (proxy case)
In the case of ALT Mapping System (as an example), GRE tunnels prevent Man-in-the-Middle (MiM) attacks and provide integrity and confidentiality of the information carried over ALT (i.e. the nonce and the OTK)
GRE tunnels can be secured with IPsec
Since the LISP-MN ETR is authoritative for his own EID prefix, we need to verify how the ETR certificate can be used to assert prefix authorization in RPKI

9. Threat Model (II)
MiM attacks can be mounted outside, and only outside, of the Mapping System infrastructure
ETR can mount prefix overclaiming attacks
maliciously or unintentionally (e.g. because the ETR is hacked/compromised)

10. One-Time Keyed HMAC on Map-Request/Reply
Mapping System
OTK
Map Resolver
OTK-ETR = HKDF(OTK)
Map-Request , n, OTK
Map Server K
/16 -> {RLOC}
Map-Request
, n
AES_wrap_keyK(OTK) K’
Map-Request ,n
AES_wrap_keyK’(OTK-ETR=HKDF(OTK))
EID-AD: HMACOTK-MS[{EID prfx}] K
D= , S=
ITR K’ :
n=nonce,
OTK=One Time Key
EID
OTK-ETR
Map-Reply , n
EID-AD: HMACOTK-MS[{EID prfx}] LOC-AD: HMACOTK-ETR[{Rlocs}]
ETR
Site Y
Site X
/16
ETR
ITR

11. Thanks!