IP Security Maintenance and Extensions
charter-ietf-ipsecme-11-01

The IPsec suite of protocols includes IKEv1 (RFC 2409 and associated
RFCs, IKEv1 is now obsoleted), IKEv2 (RFC 7296), and the IPsec
security architecture (RFC 4301). IPsec is widely deployed in VPN
gateways, VPN remote access clients, and as a substrate for
host-to-host, host-to-network, and network-to-network security.

The IPsec Maintenance and Extensions Working Group continues the work
of the earlier IPsec Working Group which was concluded in 2005. Its
purpose is to maintain the IPsec standard and to facilitate discussion
of clarifications, improvements, and extensions to IPsec, mostly to
ESP and IKEv2. The working group also serves as a focus point for
other IETF Working Groups who use IPsec in their own protocols.

The current work items include:

IKEv1 using shared secret authentication was partially resistant to
quantum computers. IKEv2 removed this feature to make the protocol
more usable. The working group will add a mode to IKEv2 or otherwise
modify IKEv2 to have similar quantum resistant properties than IKEv1
had.

Split-DNS is a common configuration for VPN deployments, in which only
one or a few private DNS domains are accessible and resolvable via the
tunnel. Adding new configuration attributes to IKEv2 for configuring
Split-DNS would allow more deployments to adopt IKEv2. This
configuration should also allow verification of the domains using
DNSSEC. Working group will specify needed configuration attributes for
IKEv2.

Currently, widely used counter mode based ciphers send both the ESP
sequence number and IV in form of counter, as they are very commonly
the same. There has been interest to work on a document that will
compress the packet and derive IV from the sequence number instead of
sending it in separate field. The working group will specify how this
compression can be negotiated in the IKEv2, and specify how the
encryption algorithm and ESP format is used in this case.

The Group Domain of Interpretation (GDOI - RFC 6407) is an IKEv1-based
protocol for negotiating group keys for both multicast and unicast
uses. The Working Group will develop an IKEv2-based alternative that
will include cryptographic updates. A possible starting point is
draft-yeung-g-ikev2

Postquantum Cryptography brings new key exchange methods. Most of
these methods that are known to date have much larger public keys then
conventional Diffie-Hellman public keys. Direct using these methods in
IKEv2 might lead to a number of problems due to the increased size of
initial IKEv2 messages. The working group will analyze the possible
problems and develop a solution, that will make adding Postquantum key
exchange methods more easy. The solution will allow post quantum key
exchange to be performed in parallel with (or instead of) the existing
Diffie-Hellman key exchange.

A growing number of use cases for constrained network - but not
limited to - have shown interest in reducing ESP (resp. IKEv2)
overhead by compressing ESP (resp IKEv2) fields. The WG will define
extensions of ESP and IKEv2 to enable ESP header compression.

draft-mglt-ipsecme-diet-esp and
draft-mglt-ipsecme-ikev2-diet-esp-extension are expected to be good
starting points for ESP compression.
draft-smyslov-ipsecme-ikev2-compression and
draft-smyslov-ipsecme-ikev2-compact are good starting point for IKEv2
compression.

RFC7427 allows peers to indicate hash algorithms they support, thus
eliminating ambiguity in selecting a hash function for digital
signature authentication. However, advances in cryptography lead to a
situation when some signature algorithms have several signature
formats. A prominent example is RSASSA-PKCS#1 and RSASSA-PSS, however
it is envisioned that the same situation may repeat in future with
other signature algorithms. Currently IKE peers have no explicit way
to indicate each other which signature format(s) the support, that
leads to ineroperability problems. The WG will investigate the
situation and come up with a solution that allows peers to deal with
the problem in an interoperable way.

RFC7296 defines a generic notification code that is related to a
failure to handle an internal address failure. That code does not
explicitly allow an initiator to determine why a given address family
is not assigned, nor whether it should try using another address
family. The Working Group will specify a set of more specific
notification codes that will provide sufficient information to the
IKEv2 initiator about the encountered failure.
draft-boucadair-ipsecme-ipv6-ipv4-codes could be used as a starting
point for this item.

Some systems support security labels (aka security context) as one of
the selectors of the SPD. This label needs to be part of the IKE
negotiation for the IPsec SA. non-standard implementations exist for
IKEv1 (formerly abusing IPSEC Security Association Attribute 10, now
using private space IPSEC Security Association Attribute 32001). The
work is to standarize this for IKEv2, in a way that will be backwards
compatible with old implementations, meaning it must not require any
changes to implementations not supporting this.

This charter will expire in December 2019. If the charter is not
updated before that time, the WG will be closed and any remaining
documents revert back to individual Internet-Drafts.