WG Review: Cga & Send maIntenance (csi)

[IESG Secretary <iesg-secretary at ietf.org>]

A new IETF working group has been proposed in the Internet Area.  
The IESG has not made any determination as yet.  The following 
draft charter was submitted, and is provided for informational 
purposes only.  Please send your comments to the IESG mailing 
list (iesg at ietf.org) by February 7, 2008.

Cga & Send maIntenance (csi)
============================
Current Status: Proposed Working Group

Chair(s):
TBD

Internet Area Area Director(s):
Jari Arkko <jari.arkko at piuha.net>
Mark Townsley <townsley at cisco.com>

Description:

Proposed charter for Cga & Send maIntenance (CSI) BOF

The Secure Neighbor Discovery (SEND) protocol defined by 
RFC 3971 provides security mechanisms protecting different 
functions of the Neighbor Discovery (ND) protocol defined 
by RFC 2461. This includes address resolution (discovering 
link layer address of another node attached to the link), 
router discovery (discovering routers attached to the link), 
and neighbor unreachability detection (detecting that a node 
attached to the link is no longer reachable). SEND protection 
of address resolution and neighbor unreachability detection 
functions relies on IPv6 address proof-of-ownership and message 
integrity protection provided respectively via Cryptographically 
Generated Addresses (CGAs) and RSA Digital Signatures.

CGAs are defined in RFC 3972, and are extended with a CGA extension 
format defined in RFC 4581, and a support for multiple hash 
functions defined in RFC 4982. While CGAs were originally defined 
for the SEND protocol, they have proved to be a useful security tool 
in other environments too, and its usage has been proposed to secure 
other protocols such as the Shim6 multihoming protocol and the Mobile 
IPv6 protocol. While there is very little deployment of SEND to date, 
there are a number of implementations, recommendations in the NIST and 
DOD profiles call for use of SEND, and operating system vendors are 
considering adding SEND to their next releases. As a result, it is 
desirable to review the current state of the SEND and CGA specifications,
maintain and complement them where necessary. Up to date cryptographic 
algorithms are needed, and the protocols need to be able to deal with 
certain common situations currently not supported.

Specifically, the WG will look at the following issues:

- Develop an informational document analyzing the implications of 
recent attacks on hash functions used by SeND protocol. Current SeND 
specification uses the SHA-1 hash algorithm and does not provides 
support for hash algorithm agility, hence the critical need for 
understanding the impact of the attacks on the SeND protocol. In 
addition, if as a result of the aforementioned analysis it is deemed 
necessary, standard-track extensions to the SeND protocol to support 
multiple hash algorithms will be defined.

- Specify a standards-track CGA and SeND extensions to support 
multiple public key algorithms. As currently defined CGA and SeND 
can only use RSA keys, and they lack support for other public key 
algorithms (e.g. Elliptic Curve Cryptography -- ECC).

- Develop X.509 certificate management tools for SeND. SeND utilizes
X.509v3 certificates for performing router authorization. It uses the
X.509 extension for IP addresses to verify whether the router is 
authorized to advertise the mentioned IP addresses. Since the IP 
addresses extension does not explicitly mention what functions the 
node can perform for the IP addresses it becomes impossible to know 
the reason for which the certificate was allowed. In order to facilitate 
issuance of certificates for specific functions, we need to encode the 
functions permitted for the certificate into the certificate itself. The 
WG will develop a certificate profile, including a definition of X.509 
Extended Key Usage for SeND . In addition, the WG will recommend best 
practices for (1) enrollment, (2) revocation checking, and (3) publishing
of certificates. This WG will ensure that the profile and recommended 
practices will cover usage by hosts in addition to routers.  The working 
group will coordinate this and other certificate related activities with 
the PKIX WG.  Prior to IESG submission of the certificate profile, the 
working group will seek input from and coordinate with other groups 
enabling cryptographic identification of device-related properties (e.g.,
IEEE 802.1ar, IEEE 802.16, WiMAX Forum, IETF CAPWAP WG).

- Develop a standard track document defining a mechanism to perform SeND
certificate provisioning for routers. SeND protocol as defined in
RFC3971 specifies how IPv6 nodes can trust the prefixes advertised by a 
router. The solution is based on the use of the IP Address Delegation 
extension (RFC3779) in X.509 v3 certificates (RFC3280).
This work will provide the tools require to provision with the
certificates 
to the routers in an automatic manner.

- Produce a problem statement document for Neighbor Discovery Proxies 
and then specify standards-track SEND Extensions to support Neighbor 
Discovery Proxies: SEND protocol as currently defined in RFC 3971 lacks 
of support for ND Proxies defined in RFC 3775 and RFC 4389.
Extensions to the SEND protocol will be defined in order to provide 
equivalent SEND security capabilities to ND Proxies.

- Develop an informational document analysing different approaches to 
allow SeND and CGAs to be used in conjunction with DHCP, and making 
recommendations on which are the best suited. Recharter based on the 
result of the analysis.

- Update base specifications (RFC 3971 and 3972).

Goals and Milestones:

Jun 08    WG last-call on analysis of hash related threats in SeND
Aug 08    WG last-call on Proxy-SeND problem statement
Dec 08    WG last-call on multiple hash function support in SeND, if
required
Dec 08    WG last-call on multiple public key algorithm support for CGA
Dec 08    WG last-call on multiple public key algorithm support for SeND
Dec 08    WG last-call on certificate profile definition for SeND
Jan 09    WG last-call on Proxy SeND
Jun 09    WG last-call on certificate provision mechanism for SeND routers
Jun 09    WG last-call on certificate management best practices for SeND
routers
Jul 09    WG last-call on CGA-DHCP interaction
Nov 09    WG last-call on updated SeND specification
Nov 09    WG last-call on updated CGA specification

Jul 08    Submit draft on analysis of hash related threats in SeND to
IESG
Sept 08    Submit draft on Proxy-SeND problem statement to IESG
Jan 09    Submit draft on multiple hash function support in SeND to IESG,
if required
Jan 09    Submit draft on multiple public key algorithm support for CGA to
IESG
Jan 09    Submit draft on multiple public key algorithm support for SeND
to IESG
Jan 09    Submit draft on certificate profile definition for SeND to IESG
Feb 09    Submit draft on Proxy SeND to IESG
Jul 09    Submit draft on certificate provision mechanism for SeND routers
to IESG
Jul 09    Submit draft on certificate management best practices for SeND
routers to IESG
Aug 09    Submit draft on CGA-DHCP interaction to IESG
Dec 09    Submit draft on updated SeND specification to IESG
Dec 09    Submit draft on updated CGA specification to IESG
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