This allows to control the life-cycle of a nonce in the context of the
ike init task. In the TKM use-case the nonce generator cannot be
destroyed before the ike init task is finalized, otherwise the created
nonce is detected as stale.
This allows to control the life-cycle of a nonce in the context of the
child create task. In the TKM use-case, it is required to reset the
nonce context if the created nonce is not consumed. This happens if the
child SA negotiation fails and it is detected before the SA is
established via the TKM kernel plugin (i.e. rekey collision).
Real AEADs directly provide a suitable IV generator, but traditional crypters
do not. For some (stream) ciphers, we should use sequential IVs, for which
we pass an appropriate generator to the AEAD wrapper.
This is needed to handle DELETEs properly, which was previously done via
CHILD_REKEYING, which we don't use anymore since 5c6a62ceb6 as it prevents
reauthentication.
OpenBSD's isakmpd uses the latest ISAKMP SA to delete other expired SAs.
This caused strongSwan to delete e.g. a rekeyed SA even though isakmpd
meant to delete the old one.
What isakmpd does might not be standard compliant. As RFC 2408 puts
it:
Deletion which is concerned with an ISAKMP SA will contain a
Protocol-Id of ISAKMP and the SPIs are the initiator and responder
cookies from the ISAKMP Header.
This could either be interpreted as "copy the SPIs from the ISAKMP
header of the current message to the DELETE payload" (which is what
strongSwan assumed, and the direction IKEv2 took it, by not sending SPIs
for IKE), or as clarification that ISAKMP "cookies" are actually the
SPIs meant to be put in the payload (but that any ISAKMP SA may be
deleted).
The specific traffic selectors from the acquire events, which are derived
from the triggering packet, are usually prepended to those from the
config. Some implementations might not be able to handle these properly.
References #860.
Some clients like iOS/Mac OS X don't do a mode config exchange on the
new SA during re-authentication. If we don't adopt the previous virtual
IP Quick Mode rekeying will later fail.
If a client does do Mode Config we directly reassign the VIPs we migrated
from the old SA, without querying the attributes framework.
Fixes#807, #810.
If additional tasks get queued before/while rekeying an IKE_SA, these get
migrated to the new IKE_SA. We previously did not trigger initiation of these
tasks, though, leaving the task unexecuted until a new task gets queued.
We are actually not in rekeying state, but just trigger a separate, new IKE_SA
as a replacement for the current IKE_SA. Switching to the REKEYING state
disables the invocation of both IKE and CHILD_SA updown hooks as initiator,
preventing the removal of any firewall rules.
Fixes#885.
The current "inbound" flag is used for two purposes: To define the actual
direction of the SA, but also to determine the operation used for SA
installation. If an SPI has been allocated, an update operation is required
instead of an add.
While the inbound flag normally defines the kind of operation required, this
is not necessarily true in all cases. On the HA passive node, we install inbound
SAs without prior SPI allocation.
While the the meaning of the "inbound" flag on the kernel_interface->add_sa()
call is not very clear, we still need that update logic to allow installation of
inbound SAs without SPI allocation. This is used in the HA plugin as a passive
node.
This reverts commit 698ed656.
Previously, we failed without recovery if a private key did not support
a selected signature scheme (based on key strength and the other peer's
supported hash algorithms).
The payload we sent before is not compliant with RFC 2407 and thus some
peers might abort negotiation (e.g. with an INVALID-PROTOCOL-ID error).
Fixes#819.
If this is disabled the schemes configured in `rightauth` are only
checked against signature schemes used in the certificate chain and
signature schemes used during IKEv2 are ignored.
Disabling this could be helpful if existing connections with peers that
don't support RFC 7427 use signature schemes in `rightauth` to verify
certificate chains.
This enables late connection switching based on the signature scheme used
for IKEv2 and allows to enforce stronger signature schemes.
This may break existing connections with peers that don't support RFC 7427
if signature schemes are currently used in `rightauth` for certificate chain
validation and if the configured schemes are stronger than the default used
for IKE (e.g. SHA-1 for RSA).
We use the new signature authentication instead for this. This is not
backward compatible but we only released one version with BLISS support,
and the key format will change anyway with the next release.
The previous code allowed an attacker to slip in an IKE_SA_INIT with
both SPIs and MID 1 set when an IKE_AUTH would be expected instead.
References #816.
It is mandated by the RFCs and it is expected by the task managers.
Initial messages with invalid MID will be treated like regular messages,
so no IKE_SA will be created for them. Instead, if the responder SPI is 0
no SA will be found and the message is rejected with ALERT_INVALID_IKE_SPI.
If an SPI is set and we do find an SA, then we either ignore the message
because the MID is unexpected, or because we don't allow initial messages
on established connections.
There is one exception, though, if an attacker can slip in an IKE_SA_INIT
with both SPIs set before the client's IKE_AUTH is handled by the server,
it does get processed (see next commit).
References #816.
This reverts 8f727d8007 ("Clean up IKE_SA state if IKE_SA_INIT request
does not have message ID 0") because it allowed to close any IKE_SA by
sending an IKE_SA_INIT with an unexpected MID and both SPIs set to those
of that SA.
The next commit will prevent SAs from getting created for IKE_SA_INIT messages
with invalid MID.
Fixes#816.
While the comment is rather clear that we should not adopt live CHILD_SAs
during reauthentication in IKEv2, the code does nonetheless. Add an additional
version check to fix reauthentication if the reauth responder has a replace
uniqueids policy.
Fixes#871.
Under some conditions it can happen that the CREATE_CHILD_SA exchange for
rekeying the IKE_SA initiated by the peer is successful, but the delete message
does not follow. For example if processing takes just too long locally, the
peer might consider us dead, but we won't notice that.
As this leaves the old IKE_SA in IKE_REKEYING state, we currently avoid actively
initiating any tasks, such as rekeying or scheduled DPD. This leaves the IKE_SA
in a dead and unusable state. To avoid that situation, we schedule a timeout
to wait for the DELETE message to follow the CREATE_CHILD_SA, before we
actively start to delete the IKE_SA.
Alternatively we could start a liveness check on the SA after a timeout to see
if the peer still has that state and we can expect the delete to follow. But
it is unclear if all peers can handle such messages in this very special state,
so we currently don't go for that approach.
While we could calculate the timeout based on the local retransmission timeout,
the peer might use a different scheme, so a fixed timeout works as well.
Fixes#742.
Reto Buerki