If we haven't received the third QM message for multiple exchanges the
return value of NEED_MORE for passive tasks that are not responsible for
a specific exchange would trigger a fourth empty QM message.
Fixes: 4de361d92c ("ikev1: Fix handling of overlapping Quick Mode exchanges")
References #1076.
In some cases the third message of a Quick Mode exchange might arrive
after the first message of a subsequent Quick Mode exchange. Previously
these messages were handled incorrectly and the second Quick Mode
exchange failed.
Some implementations might even try to establish multiple Quick Modes
simultaneously, which is explicitly allowed in RFC 2409. We don't fully
support that, though, in particular in case of retransmits.
Fixes#1076.
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).
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.
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.
As we now use the same reqid for multiple CHILD_SAs with the same selectors,
having marks based on the reqid makes not that much sense anymore. Instead we
use unique marks that use a custom identifier. This identifier is reused during
rekeying, keeping the marks constant for any rule relying on it (for example
installed by updown).
This also simplifies handling of reqid allocation, as we do not have to query
the marks that is not yet assigned for an unknown reqid.
We currently send the notify in Main Mode only, as it is explicitly not allowed
by RFC 2407 to send (unprotected) notifications in Aggressive Mode. To make
that work, we'd need to handle that notify in Aggressive Mode, which could
allow a MitM to inject such notifies and do some harm.
Signed-off-by: Thomas Egerer <[email protected]>
I still think ipsec/l2tp with fragmentation support is a useful
fallback option in case the Windows IKEv2 connection fails because
of fragmentation problems.
Tested with Windows XP, 7 and 8.1.
When an initiator starts reauthentication on a connection that uses push
mode to assign a virtual IP, we can't execute the Mode Config before releasing
the virtual IP. Otherwise we would request a new and different lease, which
the client probably can't handle. Defer Mode Config execution, so the same IP
gets first released then reassigned during reauthentication.
If a peer immediately sends DELETE messages when completing Quick Mode rekeying,
the third Quick Mode message and the DELETE are sent simultaneously. This
implies that DELETE messages may arrive before the completing third Quick Mode
message.
Handle this case by ignoring the DELETE INFORMATIONAL in Quick Mode and let
the delete task handle it.
Similar to assign_vips() used by a peer assigning virtual IPs to the other peer,
the handle_vips() hook gets invoked on a peers after receiving attributes. On
release of the same attributes the hook gets invoked again.
This is useful to inspect handled attributes, as the ike_updown() hook is
invoked after authentication, when attributes have not been handled yet.
If PFS is configured for a CHILD_SA first try to create a list of
proposals with using DH group negotiated during phase 1. If the
resulting list is empty (i.e. the DH group(s) configured for PFS differ
from the one(s) configured for the IKE_SA), fall back to the first
configured DH group from the CHILD_SA.
This modificiation is due to the fact that it is likely that the peer
supports the same DH group for PFS it did already for the IKE_SA.
The configuration string is appended to the XAuth backend name, separated by
a colon. The configuration string is passed untouched to the backend, where
it can change the behavior of the XAuth module.
When a CHILD_SA is closed in IKEv1, if it is not being rekeyed and
closeaction has been set, we can now perform a restart or hold as is
currently done for IKEv2.
This new flag gives the kernel-interface a hint how it should priorize the
use of newly installed SAs during rekeying.
Consider the following rekey procedure in IKEv2:
Initiator --- Responder
I1 -------CREATE-------> R1
I2 <------CREATE--------
-------DELETE-------> R2
I3 <------DELETE--------
SAs are always handled as pairs, the following happens at the SA level:
* Initiator starts the exchange at I1
* Responder installs new SA pair at R1
* Initiator installs new SA pair at I2
* Responder removes old SA pair at R2
* Initiator removes old SA pair at I3
This makes sure SAs get installed/removed overlapping during rekeying. However,
to avoid any packet loss, it is crucial that the new outbound SA gets
activated at the correct position:
* as exchange initiator, in I2
* as exchange responder, in R2
This should guarantee that we don't use the new outbound SA before the peer
could install its corresponding inbound SA.
The new parameter allows the kernel backend to install the new SA with
appropriate priorities, i.e. it should:
* as exchange inititator, have the new outbound SA installed with higher
priority than the old SA
* as exchange responder, have the new outbound SA installed with lower
priority than the old SA
While we could split up the SA installation at the responder, this approach
has another advantage: it allows the kernel backend to switch SAs based on
other criteria, for example when receiving traffic on the new inbound SA.
While this was problematic in earlier releases, it seems that it works just
fine the way we handle compression now. So there is no need to disable it over
NATed connections or when using forceencaps.
If two peers rekey Quick Modes at the same time, the original Quick Mode is
in REKEYING state and hence the requid is not reused. This is required though,
as two identical policies won't work if they have different requids.
This XAuth backend does not do any authentication of client credentials
but simply sends a successful XAuth status to the client, thereby
concluding the XAuth exchange. This can be useful to fallback to basic
RSA authentication with clients that can not be configured without XAuth
authentication.
Cisco 5505 firewalls don't return the port if we send a specific one, letting
the is_contained_in() checks fail. Using get_subset() selection builds the
Quick Mode correctly with the common subset of selectors.
Based on an initial patch from Paul Stewart.
Tobias Brunner