It also changes that payloads are built before installing the CHILD_SA
on the responder, that is, the KE payload is generated before keys are
derived, so that key_exchange_t::get_public_key() is called before
get_shared_secret(), or its internal equivalent, which could be relevant
for KE implementations that want to ensure that the key can't be
accessed again after the key derivation.
Initially, this is handled with a key derivation for each
IKE_INTERMEDIATE exchange. When rekeying, the keys are derived only
once all IKE_FOLLOWUP_KE exchanges are done.
The message ID of the first IKE_AUTH exchange is a safe-guard against
potential truncation attacks if IKE_INTERMEDIATE exchanges are not used
for multiple key exchanges but some other future use where the number of
exchanges might not depend on the selected proposal.
We currently only support these exchanges for additional key exchanges,
so once we have the final keys derived and the ike-init task is removed,
we don't expect any more of them.
The kernel now allows a 0 replay window with ESN for SAs that are
explicitly tagged as outbound SAs. But not just that, it actually
rejects outbound SAs with replay windows > 0. So we add a version check
to control the replay window size. Note that adding the attribute
unconditionally would be fine even for older kernels, but if somebody
backports the direction patches, the installation of outbound SAs might
fail if the replay window is not adjusted accordingly.
The previous code had some issues because it handled each child config
separately. Not only was this quite inefficient because all IKE_SAs had
to be enumerated for every config, it also caused problems with the check
for other CHILD_SAs in order to decide whether to delete the IKE_SA or
not. Because CHILD_SAs are deleted with an INFORMATIONAL exchange, they
are not immediately gone. This caused a race condition and with more
than one child config and SAs the IKE_SA could be kept because it
could appear as if other, unrelated CHILD_SAs were still there.
Another race condition, which is fixed by the previous commit, occurred
when only changing child configs. Then it could happen that the code
deemed the IKE_SA empty and a delete for it was queued. If that happened
while the IKE_SA was deleting one of the CHILD_SAs (or was busy with some
other exchange), the IKE_SA was not switched to IKE_DELETING. So it
looked usable and create-child tasks for the updated configs might have
gotten queued. Unfortunately, once the ike-delete task is eventually
executed, these tasks would be gone and the replacement CHILD_SAs never
created. This commit additionally avoids actually deleting the IKE_SA
even if all child configs change or get removed if any new CHILD_SAs are
to be initiated.
The IKE_SA might be busy with a different task while a request to
terminate it is getting queued, we don't want to use such an IKE_SA to
initiate new CHILD_SAs as these tasks will get lost once the IKE_SA is
terminated.
The empty array of rules for `assert_message_empty()` and the resulting
size 0 triggers warnings like these:
allocation of insufficient size '0' for type 'listener_message_rule_t' with size '12'
Using calloc() with `nmemb` set to 0 triggers the same warning.
The number of elements is the first argument, their size the second.
The previous code triggered the following warning:
'calloc' sizes specified with 'sizeof' in the earlier argument and not in the later argument
Instead of just adding the offset internally, this way the reported
base address is always the first assignable address (e.g. for
192.168.0.0/24 vs. 192.168.0.1/24).
Closesstrongswan/strongswan#2264
If a base address is configured, we don't expect the pool to be empty,
so reject the creation (e.g. with the broadcast address as base).
References strongswan/strongswan#2205
This is a patch from the OpenWrt package sources necessary to adapt to
changes from 2008 that abstracted the option datatype (added a list
type).
Signed-off-by: Noel Kuntze <[email protected]>
Reviewed-by: Philip Prindeville <[email protected]>
Tobias Brunner