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). The main motivation for 
  this work is that RSA keys are not well suited for environments with 
  resource restrictions (CPU, storage, power) such as the ones considered 
  by the 6lowpan working group. ECC is much well suited for such 
  environments and the lack of support of ECC in CGAs and SeND is a 
  deployment blocker in these environments.

- Definition of X.509 Extended Key Usage 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.

- 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 CGAs to be used in a DHCP environment, and making
  recommandations on which are the best suited.  The analysis will be
  provided as an input to the DHC working group where the actual DHCP
  extensions required to implemented the recommended approaches will
  be defined.

- Update base specifications (RFC 3971 and 3972), if needed.


Goals and Milestones:

Jun 08	  	WG last-call on analysis of hash related threats in SeND
Dec 08	  	WG last-call on Proxy SeND 
Dec 08	  	WG last-call on multiple hash function support in SeND, if required
Set 08	  	WG last-call on CGA-DHCP interaction
Set 08	  	WG last-call on multiple public key algorithm support for CGA
Set 08	  	WG last-call on multiple public key algorithm support for SeND
Dec 08	  	WG last-call on EKU definition for SeND
Feb 09	  	WG last-call on updated SeND specification, if required
Feb 09	  	WG last-call on updated CGA specification, if required

Jul 08	  	Submit draft on analysis of hash related threats in SeND to IESG
Jan 09	  	Submit draft on Proxy SeND to IESG
Jan 09	  	Submit draft on multiple hash function support in SeND to IESG, if required
Oct 08	  	Submit draft on CGA-DHCP interaction to IESG
Oct 08	  	Submit draft on multiple public key algorithm support for CGA to IESG
Oct 08	  	Submit draft on multiple public key algorithm support for SeND to IESG
Jan 09	  	Submit draft on EKU definition for SeND to IESG
Mar 09	  	Submit draft on updated SeND specification to IESG, if required
Mar 09	  	Submit draft on updated CGA specification to IESG, if required

Related drafts:

draft-kempf-cgaext-ringsig-ndproxy-00.txt
draft-jiang-sendcgaext-cga-config-00.txt
draft-krishnan-cgaext-send-cert-eku-00.txt