[strongSwan] disregarded diffie hellmann group

[Tobias Brunner]

Hi Marco,

> It looks like the other peer (which should be a checkpoint) when acting
> as a responder claim the dhgroup. Instead when acting as initiator is
> going to drop the dh group request.

You didn't clarify if that happens during a CHILD_SA initiation with
IKE_AUTH or with CREATE_CHILD_SA.  During IKE_AUTH, the DH group is
always omitted, so it really shouldn't matter who is initiator (and
removing the DH group from the proposal doesn't make a difference).
However, during CREATE_CHILD_SA DH is optional.  But enforcing a DH
group as responder and not proposing one as initiator of the same
CHILD_SA doesn't really make sense.  So if that's the case, it sounds
like a bug.

Regards,
Tobias